Cytogenetic characterization reveals differences in nuclear organization of cystic cells among Brazilian species of Triatoma (Heteroptera, Reduviidae)

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

Localization of collisionally inhomogeneous condensates in a bichromatic optical lattice

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

Diagnóstico ambiental de metais e organoclorados em córregos adjacentes a áreas de cultivo de cana-de-açúcar (Estado de São Paulo, Brasil)

Sugar cane cultivation in the State of São Paulo has expanded in the last years, with an annual production of 200 10(6) t in an area of 2.5 10(6) hectares. The use of herbicides, pesticides and fertilizers in sugar cane plantations, together with deforestation of riparian vegetation, have caused impacts on the hydric resources of the adjacent areas. The aim of this work is to evaluate the influence of sugar cane plantations on streams in the central region of the State of São Paulo, studying 16 organochlorinated compounds and 7 metals (Cu, Fe, Cd, Zn, Mn, Cr and Ni) found in the sediments of 11 streams. The results show that there is a higher concentration of metals and organochlorinated compounds in streams without riparian vegetation when compared to forested areas.

Oxisol subsurface chemical attributes related to sugarcane productivity

Embora haja homogeneidade nas características morfológicas na classe dos Latossolos, existe grande diversidade química na subsuperfície. Trabalhos indicam que a produção agrícola apresenta correlação significativa com atributos químicos de subsuperfície, que são mais estáveis que na camada arável, sujeita a alterações decorrentes da exploração agrícola. Pelo exposto, o presente estudo avaliou os efeitos dos atributos químicos de subsuperfície de Latossolos da região Centro-Sul do Brasil na produtividade agrícola dos três primeiros cortes de clones de cana-de-açúcar e da variedade RB72454. Utilizaram-se os dados de produtividade agrícola correspondentes ao período de 1993 a 1998. Os solos foram caracterizados sob o ponto de vista granulométrico e químico na profundidade entre 0,8 e 1,0 m e foram feitos estudos de correlação entre tais atributos e as médias de produtividade agrícola diária durante o ciclo dos clones de cada ensaio e da variedade RB72454 e análise de regressão múltipla, com as variáveis selecionadas pelo procedimento stepwise em função do R². As características químicas de subsuperfície dos Latossolos influenciaram na produtividade agrícola da cana-de-açúcar, principalmente no 3º corte. Para as médias dos clones, o modelo de produtividade do 3º corte em função de saturação por bases e fósforo, mostra R² = 0,31, ou seja, que 31% da variação de TCH dia-1 pode ser explicada por esses dois atributos. No caso da variedade RB72454, essa mesma variação no 3º corte é explicada em 47% pelos atributos soma de bases e teores de cálcio e matéria orgânica. As variações de produtividade de 1º e 2º cortes foram melhor explicadas pelo pHágua.

Effect of Mouriri pusa extracts on experimentally induced gastric lesions in rodents: Role of endogenous sulfhydryls compounds and nitric oxide in gastroprotection

Several plants are used in folk medicine to treat gastrointestinal disorders. Mouriri pusa Gardn. (Melastomataceae) is a medicinal plant commonly used in the central region of Brazil against gastric ulcer. Two organic extracts methanolic (MeOH) and dichloromethane (DCM) obtained by sequential extraction from the leaves of Mouriri pusa were evaluated for their ability to protect the gastric mucosa against injuries caused by necrotizing agents (0.3 M HCl/60% EtOH, absolute ethanol, non-steroidal anti-inflammatory drug, stress and pylorus ligature) in mice and rats. The best results were obtained after pretreatment with MeOH extract whereas the DCM extract did not show the same significant antiulcerogenic activity. No acute toxicity was observed in animals treated with 5 g/kg, p.o. of MeOH extract. The mechanism involving the antiulcerogenic action of MeOH extract seemed to be related to NO generation and also suggested the effective participation of endogenous sulfhydryl group in the gastroprotective action. Phytochemical investigation of the MeOH extract of Mouriri pusa yielded tannins, flavonoids and (-)-epicatechin. The presence of these phenolic compounds probably would explain the antiulcerogenic effect of the polar extract of Mouriri pusa leaves. (c) 2006 Elsevier B.V.. All rights reserved.

Economic design of two-stage (X)over-bar charts: the Markov chain approach

When the (X) over bar chart is in use, samples are regularly taken from the process, and their means are plotted on the chart. In some cases, it is too expensive to obtain the X values, but not the values of a correlated variable Y. This paper presents a model for the economic design of a two-stage control chart, that is. a control chart based on both performance (X) and surrogate (Y) variables. The process is monitored by the surrogate variable until it signals an out-of-control behavior, and then a switch is made to the (X) over bar chart. The (X) over bar chart is built with central, warning. and action regions. If an X sample mean falls in the central region, the process surveillance returns to the (Y) over bar chart. Otherwise. The process remains under the (X) over bar chart's surveillance until an (X) over bar sample mean falls outside the control limits. The search for an assignable cause is undertaken when the performance variable signals an out-of-control behavior. In this way, the two variables, are used in an alternating fashion. The assumption of an exponential distribution to describe the length of time the process remains in control allows the application of the Markov chain approach for developing the cost function. A study is performed to examine the economic advantages of using performance and surrogate variables. (C) 2003 Elsevier B.V. All rights reserved.

IDENTIFICATION OF A PUTATIVE MEMBRANE-INSERTED SEGMENT IN THE ALPHA-TOXIN OF STAPHYLOCOCCUS-AUREUS

To gain a fuller understanding of the regions of the Staphylococcus aureus alpha-toxin important in pore formation, we have used Forster dipole-dipole energy transfer to demonstrate that a central glycine-rich region of alpha-toxin (the so-called ''hinge'' region) inserts deeply into the bilayer on association of toxin with liposomes. Mutant alpha-toxins with unique cysteine (C) residues at positions 69 and 130 [Palmer, M., et al. (1993) J. Biol. Chem. 268, 11959) were reacted with the C-specific fluorophore acrylodan, which acted as an energy donor. The chosen acceptor was N-(7-nitrobenz-2-oxa-13-diazol-4-yl)-1,2-bis(hexadecanoyl) -sn-glycero-3-phosphoethanolamine (NBD-PE). Measurement of the degree of donor quenching with increasing NBD-PE in the inner bilayer leaflet enables the distance of closest approach between donor and acceptor to be estimated. For toxin labeled with acrylodan at position 130 (in the hinge region), this distance is approximately 5 +/- 2 Angstrom, showing that the probe is close to the inner surface of the liposomes. A second probe labeled at position 69 (in the N-terminal domain) shows negligible energy transfer, indicating a distance of closest approach >40 Angstrom. This implies that this N-terminal region remains ''outside'' the liposome. We propose a model in which the central region of the alpha-toxin inserts into the membrane and possibly participates in forming the wall of the pore.

NUCLEAR DENSITIES AND THE STATISTICS OF NUCLEONIC CONSTITUENTS

In the quark model of the nucleon, the Fermi statistics of the elementary constituents can influence significantly the properties of multinucleon bound systems. In the Skyrme model, on the other hand, the basic quanta are bosons, so that qualitatively different statistics effects can be expected a priori. In order to illustrate this point, we construct schematic one-dimensional quark and soliton models which yield fermionic nucleons with identical baryon densities. We then compare the baryon densities of a two-nucleon bound state in both models. Whereas in the quark model the Pauli principle for quarks leads to a depletion of the density in the central region of the nucleus, the soliton model predicts a slight increase of the density in that region, due to the bosonic statistics of the meson-field quanta.

Extracellular matrix of porcine pericardium: Biochemistry and collagen architecture

Pericardial tissue has been used to construct bioprostheses employed in the repair of different kinds of injuries, mostly cardiac. However, calcification and mechanical failure have been the main causes of the limited durability of cardiac bioprostheses constructed with bovine pericardium. In the course of this work, a study was conducted on porcine fibrous pericardium, its microscopic structure and biochemical nature. The general morphology and architecture of collagen were studied under conventional light and polarized light microscopy. The biochemical study of the pericardial matrix was conducted according to the following procedures: swelling test, hydroxyproline and collagen dosage, quantification of amino acids in soluble collagen, component extraction of the extracellular matrix of the right and left ventral regions of pericardium with different molarities of guanidine chloride, protein and glycosaminoglycan (GAG) dosage, sodium dodecyl sulfate-polyacrylamide gel electrophoresis and total GAG analysis. Microscopic analysis showed collagen fibers arranged in multidirectionally oriented layers forming a closely knit web, with a larger number of fibers obliquely oriented, initiating at the lower central region toward the upper left lateral relative to the heart. No qualitative differences were found between proteins extracted from the right and left regions. Likewise, no differences were found between fresh and frozen material. Protein dosages from left frontal and right frontal pericardium regions showed no significant differences. The quantities of extracted GAGs were too small for detection by the method used. Enzymatic digestion and electrophoretic analysis showed that the GAG found is possibly dermatan sulfate. The proteoglycan showed a running standard very similar to the small proteoglycan decorin.

A new specimen of Stratiotosuchus maxhechti (Baurusuchidae, Crocodyliformes) from the Adamantina Formation (Upper Cretaceous), southeastern Brazil.

This is a report about the second occurrence and description of the third specimen of Stratiotosuchus maxhechti (Baurusuchidae, Crocodyliformes) from the Bauru Basin, Upper Cretaceous of southeastern Brazil. The material was found in the typical reddish, fine-grained sandstone from the Adamantina Formation, Bauru Group, Monte Alto County, São Paulo State. These strata are considered to be Campanian-Maastrichtian in age. It is the second skull of Stratiotosuchus maxhechti recovered where the choanal region and the skull-mandible articulation is preserved. The holotype of this species comes from the Adamantina Formation from southwestern São Paulo State, while this new specimen comes from its northern-central region, making possible biocbronological and paleoccological correlations among different geographically distant stratigraphic horizons within the Bauru Basin. The main osteologic contributions from this new specimen are the surangular taking part in the skull/mandible articulation and the presence of a relatively well-preserved choanal region, which are not seen in the holotype, furthering the knowledge of Stratiotosuchus maxhechti. Based on the features of this new specimen, an emended diagnosis is provided.

Laser 904 nm action on bone repair in rats with osteoporosis

The aim of the present study was to determine the action of AsGA laser irradiation on bone repair in the tibia of osteopenic rats. The animals were randomly divided into eight experimental groups according to the presence of ovarian hormone (sham group) or the absence of the hormone (OVX group), as well as being irradiated or non-irradiated. Low-level 904-nm laser (50 mJ/cm(2)) accelerated the repair process of osteopenic fractures, especially in the initial phase of bone regeneration.Introduction The development of new techniques to speed the process of bone repair has provided significant advances in the treatment of fractures. Some attention recently focused on the effects of biostimulation on bone.Methods Forty-eight adult rats were randomly divided into eight experimental groups (six animals in each group) according to the presence of ovarian hormone (sham group) or absence of the hormone (ovariectomized (OVX) group) as well as being irradiated or non-irradiated. For the application of low-level laser therapy, the animals were anesthetized with one third of the dose sufficient to immobilize the animal and irradiated with AsGa laser (904 nm, 50 mJ/cm(2) for 2s, point form and in contact). The control animals received the same type of manipulation as the irradiated animals, but with the laser turned off. Half of the animals were killed 7 days following the confection of the bone defect, and the other half were killed 21 days after the surgery. After complete demineralization, the tibias were cut cross-sectionally in the central region of the bone defect and embedded in paraffin blocks. The blocks were then cut in semi-seriated slices and stained with hematoxylin and eosin.Results There was new bone formation in the animals in the OVX group with laser treatment killed after 7 days (p<0.001). The lowest percentage of bone formation was observed in the OVX without laser killed after 7 days (p>0.05). All animals killed after 21 days exhibited linear closure of the lesion.Conclusion Low-level 904-nm laser (50 mJ/cm(2)) accelerated the repair process of osteopenic fractures, especially in the initial phase of bone regeneration.

Padrões de distribuição de líquidos obtidos com bicos TF-VS4, TJ60-11006 e TQ15006 em mesa de prova

The performance of a spray boom can be evaluated from its individual nozzle distribution patterns determined in a patternator (test table), as discussed by Perecin et al. (1994). The distribution pattern of three nozzle types obtained in a patternator at six heights were compared in order to propose a formula for determining the variation coefficient. The simulation of a spray boom was conducted from individual nozzle distribution patterns, and obtained the random variation coefficients (RVC) and the systematic variation coefficients (SVC). The results showed good performance of the TF-SV4 nozzles, with CV smaller than 10%, for nozzle spacing as large as 50 cm. The TQ15006 nozzles showed high variability in the central region of the distribution pattern, resulting in high CV from nozzle spacings as narrow as 25 cm. The TJ60-11006 behaved as intermediate between TF-VS4 and TQ15006. The formula proposed for determining the variation coefficient is [(RVC) 2+(SVC) 2] 1/2.

Synapsis in supernumerary chromosomes of Prochilodus lineatus (Teleostei: Prochilodontidae)

Meiotic analysis performed on a sample of 10 specimens of Prochilodus lineatus revealed continuous filaments of different sizes stained by AgNO3, corresponding to the bivalent of the normal complement. Small supernumerary chromosomes were observed as isolated and well stained bodies, scattered among the other elements. Synaptonemal complex studies have shown that the beginning of chromosome pairing process in P. lineatus usually occurs from the telomeres to the pericentromeric region. At the end of the pachytene 27 bivalents are perfectly paired and the small supernumerary chromosomes of this species are seen as bivalents, trivalents, or tetravalents. The central region of these small chromosomes show a trick staining when they formed bivalents or tetravalents. This portion seems to correspond to the pericentromeric region of the regular chromosomes with the heterochromatic characteristic of B chromosomes.

Leading particle effect, inelasticity, and the connection between average multiplicities in e+e- and pp processes

The Regge-Mueller formalism is used to describe the inclusive spectrum of the proton in pp collisions. From such a description the energy dependences of both average inelasticity and leading proton multiplicity are calculated. These quantities are then used to establish the connection between the average charged particle multiplicities measured in e+e- and pp/p̄p processes. The description obtained for the leading proton cross section implies that Feynman scaling is strongly violated only at the extreme values of xF, that is at the central region (xF≈0) and at the diffraction region (XF≈1), while it is approximately observed in the intermediate region of the spectrum. ©1999 The American Physical Society.

Snake assemblage in a disturbed grassland environment in Rio Grande do Sul State, southern Brazil: Population fluctuations of Liophis poecilogyrus and Pseudablabes agassizii

A mark-recapture study of a snake assemblage using pitfall traps with drift fences was carried out in a disturbed grassland environment (e.g. cattle breeding and cultivations), located in the Pampa Biome, in the central region of the Rio Grande do Sul State, southern Brazil. From February 2001 to January 2004 we caught 272 snakes belonging to 20 species from the following families: Elapidae (5%), Viperidae (10%), and Colubridae (85%). The assemblage had a unimodal seasonal pattern of activity, and the highest number of captures occurred between September and May. There was a positive and significant correlation between the number of captures and monthly minimum and maximum average temperatures. Recruitment was observed from January to April. During the study, the area was affected by human activities, which altered the community structure: Pseudablabes agassizii was negatively affected by habitat devastation while Liophis poecilogyrus took advantage of this. Our results reinforced the impression that Pseudablabes agassizii is a habitat specialist species. We extend the understanding of the susceptibility of this species to environmental destruction in open natural environments of South America, and propose its use as a potential bio-indicator of the Pampa biome. We also discuss the importance of conservation strategies for snakes in grasslands of southern Brazil. © Finnish Zoological and Botanical Publishing Board 2007.