Can seasonal differences influence food web structure on preserved habitats? Responses from two Brazilian streams

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

Rotifer abundance, biomass, and secondary production after the recovery of hydrologic connectivity between a river and two marginal lakes (São Paulo, Brazil)

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

Mass spectrometric characterization of two novel inflammatory peptides from the venom of the social wasp Polybia paulista

The social wasp P. paulista is relatively common in southeast Brazil causing many medically important stinging incidents. The seriousness of these incidents is dependent on the amount of venom inoculated by the wasps into the victims, and the characteristic envenomation symptoms are strongly dependent on the types of peptides present in the venom. In order to identify some of these naturally occurring peptides available in very low amounts, an analytical protocol was developed that uses a combination of reversed-phase and normal-phase high-performance liquid chromatography (HPLC) of wasp venom for peptide purification, with matrix-assisted laser desorption/ionization time-of-flight post-source decay mass spectrometry (MALDI-Tof-PSD-MS) and low-energy collision-induced dissociation (CID) in a quadrupole time-of-flight tandem mass spectrometry (QTof-MS/MS) instrument for peptide sequencing at the sub-picomole level. The distinction between Leu and Ile was achieved both by observing d-type fragment ions obtained under CID conditions and by comparison of retention times of the natural peptides and their synthetic counterparts (with different combinations of I and/or L at N- and C-terminal positions). To distinguish the isobaric residues K and Q, acetylation of peptides was followed by Q-Tof-MS analysis. The primary sequences obtained were INWLKLGKMVIDAL-NH2 (MW 1611.98Da) and IDWLKLGKMVMDVL-NH2 (MW 1658.98Da). Micro-scale bioassay protocols characterized both peptides as presenting potent hemolytic action, mast cell degranulation, and chemotaxis of poly-morphonucleated leukocyte (PMNL) cells. The primary sequences and the bioassay results suggest that these toxins constitute members of a new sub-class of mastoparan toxins, directly involved in the occurrence of inflammatory processes after wasp stinging. Copyright (C) 2004 John Wiley Sons, Ltd.

Spatial expression of two anti-inflammatory mediators, annexin 1 and galectin-1, in nasal polyposis

Background There is renewed interest in the role played by specific counter-regulatory mechanisms to control the inflammatory host response, poorly investigated in human pathology. Here, we monitored the expression of two anti-inflammatory mediators, annexin 1 and galectin-1, and assessed their potential link to glucocorticoids' (GCs) effective control of nasal polyposis (NP).Methods Total patterns of mRNA and protein expression were analysed by quantitative real-time PCR (qPCR) and Western blotting analyses, whereas ultrastructural immunocytochemistry was used for spatial localization and quantification of each mediator, focusing on mast cells, eosinophils and epithelial cells.Results Up-regulation of the annexin 1 gene, and down-regulation of galectin-1 gene, was detected in polypoid tissue compared with nasal mucosa. Patient treatment with betamethasone augmented galectin-1 protein expression in polyps. At the cellular level, control mast cells and eosinophils displayed higher annexin 1 expression, whereas marked galectin-1 immunolabelling was detected in the granule matrix of mast cells. Cells of glandular duct epithelium also displayed expression of both annexin 1 and galectin-1, augmented after treatment.Conclusion Mast cells and epithelial cells appeared to be pivotal cell types involved in the expression of both annexin 1 and galectin-1. It is possible that annexin 1 and galectin-1 could be functionally associated with a specific mechanism in NP and that GC exert at least part of their beneficial effects on the airway mucosa by up-regulating, in a specific cell target fashion, these anti-inflammatory agonists.

Light-cone gauge integrals: prescriptionlessness at two loops

The only calculations performed beyond one-loop level in the light-cone gauge make use of the Mandelstam-Leibbrandt (ML) prescription in order to circumvent the notorious gauge dependent poles. Recently we have shown that in the context of negative dimensional integration method (NDIM) such prescription can be altogether abandoned, at least in one-loop order calculations. We extend our approach, now studying two-loop integrals pertaining to two-point functions. While previous works on the subject present only divergent parts for the integrals, we show that our prescriptionless method gives the same results for them, besides finite parts for arbitrary exponents of propagators. (C) 2000 Elsevier B.V. B.V. All rights reserved.

Consistency of superspace low energy equations of motion of 4D Type II superstring with Type II sigma model at tree-level

We derive the torsion constraints and show the consistency of equations of motion of four-dimensional Type II supergravity in superspace. with Type II sigma model. This is achieved by coupling the four-dimensional compactified Type II Berkovits' superstring to an N = 2 curved background and requiring that the sigma-model has superconformal invariance at tree-level. We compute this in a manifestly 4D N = 2 supersymmetric way. The constraints break the target conformal and SU(2) invariances and the dilaton will be a conformal, SU(2) x U(1) compensator. For Type II superstring in four dimensions, worldsheet supersymmetry requires two different compensators. One type is described by chiral and anti-chiral superfields. This compensator can be identified with a vector multiplet. The other Type II compensator is described by twist-chiral and twist-anti-chiral superfields and can be identified with a tensor hypermultiplet. Also, the superconformal invariance at tree-level selects a particular gauge, where the matter is fixed, but not the compensators. After imposing the reality conditions, we show that the Type II sigma model at tree-level is consistent with the equations of motion for Type II supergravity in the string gauge. (C) 2003 Elsevier B.V All rights reserved.

The two-loop massless (lambda/4!)phi(4) model in nontranslational invariant domain

We study the (lambda/4!)phi(4) massless scalar field theory in a four-dimensional Euclidean space, where all but one of the coordinates are unbounded. We are considering Dirichlet boundary conditions in two hyperplanes, breaking the translation invariance of the system. We show how to implement the perturbative renormalization up to two-loop level of the theory. First, analyzing the full two and four-point functions at the one-loop level, we show that the bulk counterterms are sufficient to render the theory finite. Meanwhile, at the two-loop level, we must also introduce surface counterterms in the bare Lagrangian in order to make finite the full two and also four-point Schwinger functions. (c) 2006 American Institute of Physics.

Search for the standard model Higgs boson decaying into two photons in pp collisions at root s=7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for Supersymmetry in pp Collisions at root s=7 TeV in Events with Two Photons and Missing Transverse Energy

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Is the LHC observing the pseudoscalar state of a two-Higgs-doublet model?

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A two band model for superconductivity: probing interband pair formation

We propose a two band model for superconductivity. It turns out that the simplest nontrivial case considers solely interband scattering, and both bands can be modeled as symmetric (around the Fermi level) and flat, thus each band is completely characterized by its half-band width Wn (n=1,2). A useful dimensionless parameter is d, proportional to W2 - W1. The case delta = 0 retrieves the conventional BCS model. We probe the specific heat, the ratio gap over critical temperature, the thermodynamic critical field and tunneling conductance as functions of d and temperature (from zero to Tc). We compare our results with experimental results for MgB2 and good quantitative agreement is obtained, indicating the relevance of interband coupling. Work in progress also considers the inclusion of band hybridization and general interband as well as intra-band scattering mechanisms.

Shade level effects on yield and chemical composition of the leaf essential oil of Pothomorphe umbellata (L.) Miquel

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Characterization of two full-sized P elements from Drosophila sturtevanti and Drosophila prosaltans

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

Optimum zinc supplementation level in Nile tilapia Oreochromis niloticus juveniles diets

The present study was designed to determine the optimum dietary zinc supplementation to Nile tilapia juveniles (13.3 +/- 1.13 g), by using vegetable-based diets supplemented with increasing levels of zinc from commercial-grade zinc sulfate monohydrate, a previously determined zinc source of higher bioavailability. The basal diet was supplemented with 25, 50, 100, 150, 200, 300, or 400 mg/kg Zn. The experiment was conducted in forty 250-l tanks arranged in a recirculating water system. The experimental period was divided in two phases. For the first 10-week experimental phase, fish were fed satiation diets supplemented with increasing levels of zinc. For the second 5-week experimental phase, fish that were fed diets supplemented with 0-300 mg/kg Zn during the first phase were fed the 400 mg/kg Zn-supplemented diet; fish fed the diet supplemented with 400 mg/kg Zn (first phase) were fed the nonzinc-supplemented diet (second phase). Broken-line analysis showed that the optimum dietary zinc supplementation ((ZnSO4H2O)-H-.) to Nile tilapia juveniles, using weight gain and bone zinc saturation as response criteria, was 44.50 and 79.51 mg/kg Zn, respectively. When challenged by a zinc-deficient diet, tilapia mobilized stored bone zinc to preserve its zinc status. By considering that bone zinc saturation is a more accurate response criterion than weight gain, it was concluded that the optimum dietary zinc supplementation ((ZnSO4H2O)-H-.) in vegetable-based diets to Nile tilapia juveniles is 79.51 mg/kg Zn. (C) 2004 Elsevier B.V. All rights reserved.

Taxonomic status of the genus Sotalia: Species level ranking for tucuxi (Sotalia fluviatilis) and costero (Sotalia guianensis) dolphins

Dolphins of the genus Sotalia are found along the Caribbean and Atlantic coasts of Central and South America and in the Amazon River and most of its tributaries. At present, the taxonomy of these dolphins remains unresolved. Although five species were described in the late 1800s, only one species is recognized currently (Sotalia fluviatilis) with two ecotypes or subspecies, the coastal subspecies (Sotalia fluviatilis guianensis) and the riverine subspecies (Sotalia fluviatilis fluviatilis). Recent morphometric analyses, as well as mitochondrial DNA analysis, suggested recognition of each subspecies as separate species. Here we review the history of the classification of this genus and present new genetic evidence from ten nuclear and three mitochondrial genes supporting the elevation of each subspecies to the species level under the Genealogical/Lineage Concordance Species Concept and the criterion of irreversible divergence. We also review additional evidence for this taxonomic revision from previously published and unpublished genetic, morphological, and ecological studies. We propose the common name costero for the coastal species, Sotalia guianensis (Van Beneden 1864), and accept the previously proposed tucuxi dolphin, Sotalia fluviatilis (Gervais, 1853), for the riverine species.