33 resultados para min-max shadow maps
em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (BDPI/USP)
Resumo:
We have analyzed XMM-Newton archive data for five clusters of galaxies (redshifts 0.223-0.313) covering a wide range of dynamical states, from relaxed objects to clusters undergoing several mergers. We present here temperature maps of the X-ray gas together with a preliminary interpretation of the formation history of these clusters. (c) 2007 COSPAR. Published by Elsevier Ltd. All rights reserved.
Resumo:
We report the analysis of a uniform sample of 31 light curves of the nova-like variable UU Aqr with eclipse-mapping techniques. The data were combined to derive eclipse maps of the average steady-light component, the long-term brightness changes, and the low- and high-frequency flickering components. The long-term variability responsible for the ""low-brightness`` and ""high-brightness`` states is explained in terms of the response of a viscous disk to changes of 20%-50% in the mass transfer rate from the donor star. Low- and high-frequency flickering maps are dominated by emission from two asymmetric arcs reminiscent of those seen in the outbursting dwarf nova IP Peg, and they are similarly interpreted as manifestations of a tidally induced spiral shock wave in the outer regions of a large accretion disk. The asymmetric arcs are also seen in the map of the steady light aside from the broad brightness distribution of a roughly steady-state disk. The arcs account for 25% of the steady-light flux and are a long-lasting feature in the accretion disk of UU Aqr. We infer an opening angle of 10 degrees +/- 3 degrees for the spiral arcs. The results suggest that the flickering in UU Aqr is caused by turbulence generated after the collision of disk gas with the density-enhanced spiral wave in the accretion disk.
Resumo:
We detail an innovative new technique for measuring the two-dimensional (2D) velocity moments (rotation velocity, velocity dispersion and Gauss-Hermite coefficients h(3) and h(4)) of the stellar populations of galaxy haloes using spectra from Keck DEIMOS (Deep Imaging Multi-Object Spectrograph) multi-object spectroscopic observations. The data are used to reconstruct 2D rotation velocity maps. Here we present data for five nearby early-type galaxies to similar to three effective radii. We provide significant insights into the global kinematic structure of these galaxies, and challenge the accepted morphological classification in several cases. We show that between one and three effective radii the velocity dispersion declines very slowly, if at all, in all five galaxies. For the two galaxies with velocity dispersion profiles available from planetary nebulae data we find very good agreement with our stellar profiles. We find a variety of rotation profiles beyond one effective radius, i.e. rotation speed remaining constant, decreasing and increasing with radius. These results are of particular importance to studies which attempt to classify galaxies by their kinematic structure within one effective radius, such as the recent definition of fast- and slow-rotator classes by the Spectrographic Areal Unit for Research on Optical Nebulae project. Our data suggest that the rotator class may change when larger galactocentric radii are probed. This has important implications for dynamical modelling of early-type galaxies. The data from this study are available on-line.
Resumo:
Leishmania spp. are the causative agents of leishmaniasis, a complex of diseases with a broad spectrum of clinical manifestations. Leishmania (Leishmania) amazonensis is a main etiological agent of diffuse cutaneous leishmaniasis. Leishmania spp., as other trypanosomatids, possess a metabolism based significantly on the consumption of amino acids. However, the transport of amino acids in these organisms remains poorly understood with few exceptions. Glutamate transport is an important biological process in many organisms. In the present work, the transport of glutamate is characterized. This process is performed by a single kinetic system (K-m=0.59 +/- 0.04 mM, V-max=0.123 +/- 0.003 nmol/min per 20 x 10(6) cells) showing an energy of activation of 52.38 +/- 4.7 kJ/mol and was shown to be partially inhibited by analogues, such as glutamine, aspartate, alpha-ketoglutarate and oxaloacetate, methionine, and alanine. The transport activity was sensitive to the extracellular concentration of H+ but not to Na+ or K+. However, unlike other amino acid transporters presently characterized, the treatment with specific ionophores confirmed the participation of a K+, and not H+ membrane gradient in the transport process.
Resumo:
Arginase (L-arginine amidinohydrolase, E.C. 3.5.3.1) is a metalloenzyme that catalyses the hydrolysis Of L-arginine to L-ornithine and urea. In Leishmania spp., the biological role of the enzyme may be involved in modulating NO production upon macrophage infection. Previously, we cloned and characterized the arginase gene from Leishmania (Leishmania) amazonensis. In the present work, we successfully expressed the recombinant enzyme in E. coli and performed biochemical and biophysical characterization of both the native and recombinant enzymes. We obtained K-M and V-max. values of 23.9(+/- 0.96) mM and 192.3 mu mol/min mg protein (+/- 14.3), respectively, for the native enzyme. For the recombinant counterpart, K-M was 21.5(+/- 0.90) mM and V-max was 144.9(+/- 8.9) mu mol/min mg. Antibody against the recombinant protein confirmed a glycosomal cellular localization of the enzyme in promastigotes. Data from light scattering and small angle X-ray scattering showed that a trimeric state is the active form of the protein. We determined empirically that a manganese wash at room temperature is the best condition to purify active enzyme. The interaction of the recombinant protein with the immobilized nickel also allowed us to confirm the structural disposition of histidine at positions 3 and 324. The determined structural parameters provide substantial data to facilitate the search for selective inhibitors of parasitic sources of arginase, which could subsequently point to a candidate for leishmaniasis therapy. (c) 2008 Elsevier B.V. All rights reserved.
Resumo:
Split-hand/foot malformation (SHFM) associated with aplasia of long bones, SHFLD syndrome or Tibial hemimelia-ectrodactyly syndrome is a rare condition with autosomal dominant inheritance, reduced penetrance and an incidence estimated to be about 1 in 1,000,000 liveborns. To date, three chromosomal regions have been reported as strong candidates for harboring SHFLD syndrome genes: 1q42.2-q43, 6q14.1 and 2q14.2. We characterized the phenotype of nine affected individuals from a large family with the aim of mapping the causative gene. Among the nine affected patients, four had only SHFM of the hands and no tibial defects, three had both defects and two had only unilateral tibial hemimelia. In keeping with previous publications of this and other families, there was clear evidence of both variable expression and incomplete penetrance, the latter bearing hallmarks of anticipation. Segregation analysis and multipoint Lod scores calculations (maximum Lod score of 5.03 using the LINKMAP software) using all potentially informative family members, both affected and unaffected, identified the chromosomal region 17p13.1-17p13.3 as the best and only candidate for harboring a novel mutated gene responsible for the syndrome in this family. The candidate gene CRK located within this region was sequenced but no pathogenic mutation was detected.
Resumo:
With the aim of determining the genetic basis of metabolic regulation in tomato fruit, we constructed a detailed physical map of genomic regions spanning previously described metabolic quantitative trait loci of a Solanum pennellii introgression line population. Two genomic libraries from S. pennellii were screened with 104 colocated markers from five selected genomic regions, and a total of 614 bacterial artificial chromosome (BAC)/cosmids were identified as seed clones. Integration of sequence data with the genetic and physical maps of Solanum lycopersicum facilitated the anchoring of 374 of these BAC/cosmid clones. The analysis of this information resulted in a genome-wide map of a nondomesticated plant species and covers 10% of the physical distance of the selected regions corresponding to approximately 1% of the wild tomato genome. Comparative analyses revealed that S. pennellii and domesticated tomato genomes can be considered as largely colinear. A total of 1,238,705 bp from both BAC/cosmid ends and nine large insert clones were sequenced, annotated, and functionally categorized. The sequence data allowed the evaluation of the level of polymorphism between the wild and cultivated tomato species. An exhaustive microsynteny analysis allowed us to estimate the divergence date of S. pennellii and S. lycopersicum at 2.7 million years ago. The combined results serve as a reference for comparative studies both at the macrosyntenic and microsyntenic levels. They also provide a valuable tool for fine-mapping of quantitative trait loci in tomato. Furthermore, they will contribute to a deeper understanding of the regulatory factors underpinning metabolism and hence defining crop chemical composition.
Resumo:
Cells recruited by the innate immune response rely on surface-expressed molecules in order to receive signals from the local environment and to perform phagocytosis, cell adhesion, and others processes linked to host defense. Hundreds of surface antigens designated through a cluster of differentiation (CD) number have been used to identify particular populations of leukocytes. Surprisingly, we verified that the genes that encode Cd36 and Cd83 are constitutively expressed in specific neuronal cells. For instance, Cd36 mRNA is expressed in some regions related to circuitry involved in pheromone responses and reproductive behavior. Cd44 expression, reanalyzed and detailed here, is associated with the laminar formation and midline thalamic nuclei in addition to striatum, extended amygdala, and a few hypothalamic, cortical, and hippocampal regions. A systemic immune challenge was able to increase Cd44 expression quickly in the area postrema and motor nucleus of the vagus but not in regions presenting expressive constitutive expression. In contrast to Cd36 and Cd44, Cd83 message was widely distributed from the olfactory bulb to the brain stem reticular formation, sparing the striatopallidum, olivary region, and cerebellum. Its pattern of expression nevertheless remained strongly associated with hypothalamic, thalamic, and hindbrain nuclei. Unlike the other transcripts, Cd83 mRNA was rapidly modulated by restraint stress. Our results indicate that these molecules might play a role in specific neural circuits and present functions other than those attributed to leukocyte biology. The data also suggest that these surface proteins, or their associated mRNA, could be used to label neurons in specific circuits/regions. J. Comp. Neurol. 517:906-924, 2009. (C) 2009 Wiley-Liss, Inc.
Resumo:
The present study describes the enzymatic properties and molecular identification of 5`-nucleotidase in soluble and microsomal fractions from rat cardiac ventricles. Using AMP as a substrate, the results showed that the cation and the concentration required for maximal activity in the two fractions was magnesium at a final concentration of 1 mM. The pH optimum for both fractions was 9.5. The apparent K-m (Michaelis constant) values calculated from the Eadie-Hofstee plot were 59.7 +/- 10.4 mu M and 134.8 +/- 32.1 mu M, with V-max values of 6.7 +/- 0.4 and 143.8 +/- 23.8 nmol P-i/min/mg of protein (means +/- S.D., n = 4) from soluble and microsomal fractions respectively. Western blotting analysis of ecto-5`-nucleotidase revealed a 70 kDa protein in both fractions, with the major proportion present in the microsomal fraction. The presence of these enzymes in the heart probably has a physiological function in adenosine signalling. Furthermore, the presence of ecto-5`-nucleotidase in the microsomal fraction could have a role in the modulation of the excitation-contraction-coupling process through involvement of the Ca2+ influx into the sarcoplasmic reticulum. The measurement of maximal enzyme activities in the two fractions highlights the potential capacity of the different pathways of purine metabolism in the heart.
Resumo:
A rapid, sensitive and specific method for quantifying ciprofibrate in human plasma using bezafibrate as the internal standard (IS) is described. The sample was acidified prior extraction with formic acid (88%). The analyte and the IS were extracted from plasma by liquid-liquid extraction using an organic solvent (diethyl ether/dichloromethane 70/30 (v/v)). The extracts were analyzed by high performance liquid chromatography coupled with electrospray tandem mass spectrometry (HPLC-MS/MS). Chromatography was performed using Genesis C18 4 mu m analytical column (4.6 x 150 mm i.d.) and a mobile phase consisting of acetonitrile/water (70/30, v/v) and 1 mM acetic acid. The method had a chromatographic run time of 3.4 min and a linear calibration curve over the range 0.1-60 mu g/mL (r > 0.99). The limit of quantification was 0.1 mu g/mL. The intra- and interday accuracy and precision values of the assay were less than 13.5%. The stability tests indicated no significant degradation. The recovery of ciprofibrate was 81.2%, 73.3% and 76.2% for the 0.3, 5.0 and 48.0 ng/mL standard concentrations, respectively. For ciprofibrate, the optimized parameters of the declustering potential, collision energy and collision exit potential were -51 V, -16 eV and -5 V, respectively. The method was also validated without the use of the internal standard. This HPLC-MS/MS procedure was used to assess the bioequivalence of two ciprofibrate 100 mg tablet formulations in healthy volunteers of both sexes. The following pharmacokinetic parameters were obtained from the ciprofibrate plasma concentration vs. time curves: AUC(last), AUC(0-168 h), C(max) and T(max). The geometric mean with corresponding 90% confidence interval (CI) for test/reference percent ratios were 93.80% (90% CI = 88.16-99.79%) for C(max), 98.31% (90% CI = 94.91-101.83%) for AUC(last) and 97.67% (90% CI = 94.45-101.01%) for AUC(0-168 h). Since the 90% Cl for AUC(last), AUC(0-168 h) and C(max) ratios were within the 80-125% interval proposed by the US FDA, it was concluded that ciprofibrate (Lipless (R) 100 mg tablet) formulation manufactured by Biolab Sanus Farmaceutica Ltda. is bioequivalent to the Oroxadin (R) (100 mg tablet) formulation for both the rate and the extent of absorption. (C) 2011 Published by Elsevier B.V.
Resumo:
Crithidia deanei, a monoxenic trypanosomatid, presents an endosymbiotic bacterium in its cytoplasm. Both the protozoan and the bacterium maintain intensive metabolic exchange, resulting in an interesting model to study the coevolution of metabolisms. The relevance of L-proline for the growth of C. deanei and its transport into these cells was studied. Both the endosymbiont-containing (wild) and the endosymbiont-free protozoa (aposymbiont or cured) strains, when grown in medium supplemented with L-proline, reached higher cell densities than those grown in unsupplemented media. We biochemically characterized the uptake of L-proline in both the wild (K(m)=0.153 +/- 0.022 mM, V(max)=0.239 +/- 0.011 nmol min(-1) per 4 x 10(7) cells) and the aposymbiont strains (K(m)=0.177 +/- 0.049 mM, V(max)=0.132 +/- 0.012 nmol min(-1) per 4 x 10(7) cells). These data suggest a single type of proline transporter whose activity is upregulated by the presence of the symbiotic bacterium. Proline transport was further characterized and was found to be insensitive to the extracellular concentration of Na(+), but sensitive to K(+) and pH. The abolition of proline uptake by respiratory chain inhibitors and valinomycin indicates that the proline transport in C. deanei is dependent on the plasma membrane K(+) gradient.
Resumo:
Objective: We investigated the influence of acute inflammation in skin isograft acceptance. Methods: Two mouse lines selected for maximal (AIR(MAX)) or minimal inflammatory response (AIR(MIN)) were transplanted with syngeneic skin. Cellular infiltrates and cytokine production were measured 1, 3, 7 or 14 days post-transplantation. The percentage of CD4(+) CD25(+) Foxp3(+) cells in the lymph nodes was also evaluated. Results: Grafts were totally accepted in 100% of AIR(MAX) and in 26% of AIR(MIN) mice. In the latter, partial acceptance was observed in 74% of the animals. Emigrated cells were basically PMN and were enhanced in AIR(MAX) transplants. IL-10 production by graft infiltrating cells showed no interline differences. IFN-gamma was increased in AIR(MIN) grafts at day 14 and lower percentages of CD4(+)CD25(+)Foxp3(+) cells in the lymph nodes were observed in these mice. Conclusions: Our data suggest that differences in graft acceptance might be due to a lack of appropriate regulation of the inflammatory response in AIR(MIN) mice compromising the self/non-self recognition.
Resumo:
Recent evidence suggests that angiotensin II (Ang II) upregulates phosphodiesterase (PDE) 1A expression. We hypothesized that Ang II augmented PDE1 activation, decreasing the bioavailability of cyclic guanosine 3` 5`-monophosphate (cGMP), and contributing to increased vascular contractility. Male Sprague-Dawley rats received mini-osmotic pumps with Ang II (60 ng.min(-1)) or saline for 14 days. Phenylephrine (PE)-induced contractions were increased in aorta (E(max)168%+/- 8% vs 136%+/- 4%) and small mesenteric arteries (SMA; E(max)170%+/- 6% vs 143%+/- 3%) from Ang II-infused rats compared to control. PDE1 inhibition with vinpocetine (10 mu mol/L) reduced PE-induced contraction in aortas from Ang II rats (E(max)94%+/- 12%) but not in controls (154%+/- 7%). Vinpocetine decreased the sensitivity to PE in SMA from Ang II rats compared to vehicle (-log of half maximal effective concentration 5.1 +/- 0.1 vs 5.9 +/- 0.06), but not in controls (6.0 +/- 0.03 vs 6.1 +/- 0.04). Sildenafil (10 mu mol/L), a PDE5 inhibitor, reduced PE-induced maximal contraction similarly in Ang II and control rats. Arteries were contracted with PE (1 mu mol/L), and concentration-dependent relaxation to vinpocetine and sildenafil was evaluated. Aortas from Ang II rats displayed increased relaxation to vinpocetine compared to control (E(max)82%+/- 12% vs 445 +/- 5%). SMA from Ang II rats showed greater sensitivity during vinpocetine-induced relaxation compared to control (-log of half maximal effective concentration 6.1 +/- 0.3 vs 5.3 +/- 0.1). No differences in sildenafil-induced relaxation were observed. PDE1A and PDE1C expressions in aorta and PDE1A expression in SMA were increased in Ang II rats. cGMP production, which is decreased in arteries from Ang II rats, was restored after PDE1 blockade. We conclude that PDE1 activation reduces cGMP bioavailability in arteries from Ang II, contributing to increased contractile responsiveness. (Hypertension. 2011;57[part 2]:655-663.)
Resumo:
The effects of endurance training on PGE(2) levels and upon the maximal activity of hepatic carnitine palmitoyltransferase (CPT) system were studied in rats bearing the Walker 256 carciosarcoma. Animals were randomly assigned to a sedentary control (SC), sedentary tumor-bearing (ST), exercised control (EC), and as an exercised tumor-bearing (ET) group. Trained rats ran on a treadmill (60% VO(2) max) for 60 min/day, 5 days/week, for 8 weeks. We examined the mRNA expression (RT-PCR) and maximal activity (radio-assay) of the carnitine palmitoyltransferase system enzymes (CPT I and CPT II), as well as the gene expression of fatty-acid-binding protein (L-FABP) in the liver. PGE(2) content was measured in the serum, in tumor cells, and in the liver (ELISA). CPT I and CPT II maximal activity were decreased (p < 0.01) in ST when compared with SC. In contrast, serum PGE(2) was increased (p < 0.05) in cachectic animals as compared with SC. In the liver, PGE(2) content was also increased (p < 0.05) when compared with SC. Endurance training restored maximal CPT I and CPT II activity in the tumor-bearing animals (p < 0.0001). Exercise training induced PGE(2) levels to return to control values in the liver of tumor-bearing training rats (p < 0.05) and decreased the eicosanoid content in the tumor (p < 0.01). In conclusion, endurance training was capable of reestablishing liver carnitine palmitoyltransferase (CPT) system activity associated with decreased PGE(2) levels in cachectic tumor-bearing animals, preventing steatosis.
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In this paper we study when the minimal number of roots of the so-called convenient maps horn two-dimensional CW complexes into closed surfaces is zero We present several necessary and sufficient conditions for such a map to be root free Among these conditions we have the existence of specific fittings for the homomorphism induced by the map on the fundamental groups, existence of the so-called mutation of a specific homomorphism also induced by the map, and existence of particular solutions of specific systems of equations on free groups over specific subgroups