Exposure to Mycobacterium avium Decreases the Protective Effect of the DNA Vaccine pVAXhsp65 Against Mycobacterium tuberculosis-Induced Inflammation of the Pulmonary Parenchyma

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

Influence of light intensity and salt-treatment on mode of photosynthesis and enzymes of the antioxidative response system of Mesembryanthemum crystallinum

The metabolic switch From C-3-photosynthesis to crassulacean acid metabolism (CAM),and the antioxidative response of Mesembryanthemum crystallinum L. plants cultured under severe salt stress and high light intensities, and a combination of booth stress conditions, were studied. High light conditions led to a more rapid CAM induction than salinity. The induction time was still shortened when both stress factors were combined. A main pattern observed in CAM plants was a decrease in mitochondrial Mn-superoxide dismutase (SOD) activity during the day. The activities of the chloroplastic Fe-SOD and cytosolic CuZn-SOD were increased due to salt treatment after a lag phase, while catalase activity was decreased. Combination of salt and light stress did not lead to a higher SOD activity as found after application of one stress factor alone, indicating that there is a threshold level of the oxidative stress response. The fact that salt-stressed plants grown under high light conditions showed permanent photoinhibition and lost the ability for nocturnal malate storage after 9 d of treatment indicate serious malfunction of metabolism, leading to accelerated senescence. Comparison of CuZn-SOD activity with CuZn-SOD protein amount, which was determined immunologically, indicates that the activity of the enzyme is at least partially post-translationally regulated.

How C-terminal carboxyamidation alters the biological activity of peptides from the venom of the eumenine solitary wasp

Inflammatory peptides display different types of post-transcriptional modifications, such as C-terminal amidation, that alter their biological activity. Here we describe the structural and molecular dynamics features of the mast cell degranulating peptide, eumenine mastoparan-AF (EMP-AF-NH2), found in the venom of the solitary wasp, and of its carboxyl-free C-terminal form (EMP-AF-COO-) characterized by a reduced activity. Circular dichroism indicates that both peptides switch from a random coil conformation in water to a helical structure in TFE and SDS micelles. NMR data, in 30% TFE, reveal that the two peptides fold into an alpha-helix spanning most of their length, while they differ in terms of molecular rigidity. To understand the origins of the conformational flexibility observed in the case of EMP-AF-COO-, a 5 ns MD simulation was carried out for each peptide, in an explicit water/TFE environment. The results show that the two peptides differ in an H-bond between Leu14 NH2 and the backbone carbonyl of Ile11. The loss of that H-bond in EMP-AF-COO- leads to a significant modification of its structural dynamics. In fact, as evidenced by essential dynamics analysis, while EMP-AF-NH2 exists mainly as a rigid structure, EMP-AF-COO- presents two helical stretches that fluctuate in some sort of independent fashion. We conclude that the diverse biological activity of the two peptides is not simply due to the reduction of the net positive charge, as generally suggested, but also to a structural perturbation of the amphipathic alpha-helix that affects their ability to perturb the cell membrane.

The cetacean offal connection: Feces and vomits of spinner dolphins as a food source for reef fishes

At Fernando de Noronha Archipelago, southwest Atlantic, reef fishes associated with spinner dolphins (Stenella longirostris) were recorded when the cetaceans congregated in a shallow inlet. In the reef waters the dolphins engaged in several behaviors such as resting, aerial displays and other social interactions, as well as eliminative behaviors such as defecating and vomiting. Twelve fish species in seven families were recorded feeding on dolphin offal. The black durgon (Melichthys niger) was the most ubiquitous waste-eater, and its group size was positively and significantly correlated with dolphin group size. The durgons recognized the postures a dolphin adopts prior to defecating or vomiting, and began to converge to an individual shortly before it actually voided. Offal was quickly fed upon, and the fishes concentrated in the area occupied by the dolphins until the latter left the shallows. Since all the recorded offal-feeding species feed on plankton or drifting algae, feeding on cetacean droppings may be regarded as a switch from foraging on drifting organisms to foraging on drifting offal, a predictable food source in the inlet. Further instances of this cetacean-fish association are predicted to occur at sites where these mammals congregate over reefs with clear water and plankton-eating fishes.

MORPHOLOGICAL CASTE DIFFERENCES IN POLYBIA AEQUATORIALIS (HYMENOPTERA: VESPIDAE: POLISTINAE: EPIPONINI), A SOCIAL WASP of THE HIGHLANDS of COSTA RICA

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

Usando um voltímetro para medir tempo

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

Métodos de geração de colunas para problemas de atribuição

Este trabalho apresenta métodos de geração de colunas para dois importantes problemas de atribuição: o Problema Generalizado de Atribuição (PGA) e o Problema de Atribuição de Antenas a Comutadores (PAAC). O PGA é um dos mais representativos problemas de Otimização Combinatória e consiste em otimizar a atribuição de n tarefas a m agentes, de forma que cada tarefa seja atribuída a exatamente um agente e a capacidade de cada agente seja respeitada. O PAAC consiste em atribuir n antenas a m comutadores em uma rede de telefonia celular, de forma a minimizar os custos de cabeamento entre antenas e comutadores e os custos de transferência de chamadas entre comutadores. A abordagem tradicional de geração de colunas é comparada com as propostas neste trabalho, que utilizam a relaxação lagrangeana/surrogate. São apresentados testes computacionais que demonstram a efetividade dos algoritmos propostos.

Produção de leite, consumo e digestibilidade aparente dos nutrientes, pH e concentração de amônia ruminal em vacas lactantes recebendo rações contendo silagem de milho e fenos de alfafa e de capim-coastcross

Utilizaram-se 10 vacas lactantes HPC e mestiças H*Z, com 55 dias de parição, peso médio de 540 kg, distribuídas em um delineamento em switch-back com o objetivo de avaliar a produção e a composição do leite, o consumo e a digestibilidade aparente de matéria seca (MS), matéria orgânica (MO), fibra em detergente neutro (FDN), proteína bruta (PB), carboidratos totais (CT) e extrato etéreo (EE), e o pH e a concentração de amônia ruminal. Os animais foram alimentados ad libitum com cinco dietas contendo silagem de milho (SM), feno de alfafa (FA), feno de capim-coastcross (FCC), ½ FA+½ SM, ½ FCC+1/2 SM, na proporção de 60%, da ração total (base de matéria seca). Os consumos dos nutrientes não foram influenciados pelas dietas. As digestibilidades aparentes de MS, PB e FDN foram maiores para as dietas contendo silagem de milho. O pH e a concentração de amônia do líquido ruminal não foram influenciados pelas dietas, porém observou-se resposta quadrática para o tempo de coletas. Registrou-se maior produção de leite para os animais que receberam silagem de milho. Os teores de proteína bruta e gordura do leite não foram influenciados pelas dietas.

Thermally activated dynamics in La2CuO4+delta: tilts of the CuO6 octahedra and interstitial O

An intense peak of the elastic energy loss versus temperature is found in La2CuO4 at 150 K (in the LTO phase), at a vibration frequency of similar to 280 Hz. From the dependence of the dissipation curve on frequency it is deduced that the relaxation rate has an activation enthalpy of 0.23 eV. The peak is ascribed to a thermally activated dynamics of the tilts of the CuO6 octahedra which form the La2CuO4 lattice, a fraction of which are supposed to be able to switch between energetically equivalent configurations. The peak is suppressed by interstitial O; this is explained by supposing that each interstitial atom can block several octahedra into a configuration that can accommodate the distortion due to its presence. Increasing the content of excess O, two new thermally activated processes develop, attributed to the hopping of interstitial O atoms which are isolated and which are paired or otherwise aggregated. The activation enthalpy for the diffusion of O at low values of 6 is 0.48 eV.

AATS for the (X)over-bar chart with variable parameters

A Fortran computer program is given for the computation of the adjusted average time to signal, or AATS, for adaptive (X) over bar charts with one, two, or all three design parameters variable: the sample size, n, the sampling interval, h, and the factor k used in determining the width of the action limits. The program calculates the threshold limit to switch the adaptive design parameters and also provides the in-control average time to signal, or ATS.

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.

Weed seed-germination .3. bidens-pilosa L

The germination of seeds of Bidens pilosa L. colected at different places was analyzed by dose-response curves for induction and reversion of germination in seeds pre-incubated at 25 degrees C or 36 degrees C during 24 hours. Our results indicate that phytochrome is responsible for the control of seed germination id Bidens pilosa and the level of pre-existing active form of phytochrome (Pfr) above the threshold switch the seed to germinate in darkness.

Changeover during in situ compositional modulation of hexacyanoferrate (Prussian Blue) material

This paper describes the importance of (H2O)(6) clusters in controlling the properties of hexacyanoferrate (Prussian Blue) materials. A careful in situ study of compositional changes by using electrogravimetric techniques (in ac and dc modes) in hexacyanoferrates containing K+ alkali metals reveals the existence of a changeover in the properties of these films in a narrow potential range. Control of the compositional variation of the changeover is dependent on the K+ stoichiometric number in the compound structure. However, a specific K+ occupation in the compound structure activates the occupation of the (H2O)(6) cluster by H3O+ and/or H+, causing the changeover in the properties of hexacyanoferrate film. Thus, the information thus obtained is very useful for understanding the mechanisms involved in the electrochemical reversible switch between ferrimagnetism/paramagnetism, semiconductor/metal and electroluminescence/nonelectroluminescence properties of molecular cyanide materials.

AATS for the X̄ Chart with Variable Parameters

A Fortran computer program is given for the computation of the adjusted average time to signal, or AATS, for adaptive X̄ charts with one, two, or all three design parameters variable: the sample size, n, the sampling interval, h, and the factor k used in determining the width of the action limits. The program calculates the threshold limit to switch the adaptive design parameters and also provides the in-control average time to signal, or ATS.

Affinities of the Saw-billed Hermit (Ramphodon naevius) determined by cytochrome-b sequence data

We sequenced 912 bp of the cytochrome-b gene to examine phylogenetic relationships of the enigmatic Saw-billed Hermit (Ramphodon naevius), a large and distinctive hummingbird endemic to tropical forests of southeastern Brazil. Bootstrapped maximum parsimony and maximum likelihood analyses of sequence data from 11 hummingbirds and several outgroups (two swifts, one goatsucker) support: (a) monophyly of the traditional hermit (Phaethornithinae) and nonhermit (Trochilinae) subfamilies, (b) placement of Ramphodon among hermits, and (c) a sister relationship between Ramphodon and an exemplar of the widespread polytypic hermit genus Glaucis. The association of Ramphodon with derived hermit lineages is concordant with subfamilial patterns of wing anatomy and nest architecture. However, the unusual plumages (striped underparts) and male bills (long, serrated, hooked) shared by Ramphodon and the Tooth-billed Hummingbird (Androdon aequatorialis) appear to have evolved within separate hermit and nonhermit tooth-billed clades. Distal placement of the Ramphodon-Glaucis clade within hermits implies that even distinctive Brazilian endemics such as Ramphodon are derived forms that evolved relatively recently.