26 resultados para Arthur, W. Brian
em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (BDPI/USP)
Resumo:
Genetic mutations responsible for oblique facial clefts (ObFC), a unique class of facial malformations, are largely unknown. We show that loss-of-function mutations in SPECC1L. are pathogenic for this human developmental disorder and that SPECC1L is a critical organizer of vertebrate facial morphogenesis. During murine embryogenesis, Speed 1 1 is expressed in cell populations of the developing facial primordial, which proliferate and fuse to form the face. In zebrafish, knockdown of a SPECC1L homolog produces a faceless phenotype with loss of jaw and facial structures, and knockdown in Drosophila phenocopies mutants in the integrin signaling pathway that exhibit cell-migration and -adhesion defects. Furthermore, in mammalian cells, SPECC1L colocalizes with both tubulin and actin, and its deficiency results in defective actin-cytoskeleton reorganization, as well as abnormal cell adhesion and migration. Collectively, these data demonstrate that SPECC1L functions in actin-cytoskeleton reorganization and is required for proper facial morphogenesis.
Resumo:
Neste ensaio, ressalta-se a importância da disciplina Psicologia Social na obra de T. W. Adorno e a concepção que formula acerca dessa disciplina. Esse autor defende que há uma nova forma de configuração dos indivíduos, expressada por atitudes e comportamentos individuais padronizados e por um ego frágil, facilmente cooptado por movimentos sociais totalitários. Tais indivíduos surgem em uma sociedade caracterizada por uma forma de dominação calcada na racionalidade administrativa e tecnológica. Para esse autor, a Psicologia Social deveria estudar esse objeto para que, com o esclarecimento produzido e difundido, os indivíduos possam resistir à adesão cega a movimentos sociais irracionais, tal como o fascismo, insistindo que a determinação desses movimentos não é individual, mas social.
Resumo:
Enfatiza-se a importância da realidade e da experiência atual na constituição do sujeito, por meio da apresentação das ideias de Hans W. Loewald e do exame de sua concepção original de realidade. A natureza relacional das pulsões, a ideia do novo objeto na relação analítica, a noção de invenção da realidade, o conceito de sublimação e a forma de compreender o simbolismo estão entre as formulações mais importantes de Loewald acerca do papel do ambiente na constituição do sujeito. Suas formulações também permitem a compreensão da inserção do sujeito na realidade social contemporânea.
Resumo:
Ethanol oxidation has been studied on Pt-Sn and Pt-Sn-W electrodes prepared in an arc-melting furnace. Different electrochemical techniques like cyclic voltammetry and chronoamperometry were used to evaluate the catalytic activity of these materials. The electro-oxidation process was also investigated by in situ infrared reflectance spectroscopy in order to determine adsorbed intermediates and reaction products. Experimental results indicated that Pt-Sn and Pt-Sn-W alloys are able to oxidize ethanol mainly to acetaldehyde and acetic acid. Adsorbed CO was also detected, demonstrating the viability of splitting the C-C bond in the ethanol molecule during the oxidation process. The adsorbed CO was further oxidized to CO2.This reaction product was clearly detected by SNIFTIRS. Pt-Sn-W catalyst showed a better electrochemical performance than Pt-Sn that, in it turn, is better than Pt-alone.
Resumo:
A considerable portion of Brazil's commercial eucalypt plantations is located in areas Subjected to periods of water deficit and grown in soils with low natural fertility, particularly poor In potassium. Potassium is influential in controlling water relations of plants. The objective of this study was to verify the influence of potassium fertilization and soil water potential (psi(w)) oil the dry matter production and oil water relations Of eucalypt seedlings grown under greenhouse conditions. the experimental units were arranged in 4x4x2 randomized blocks factorial design, as follow: four species of Eucalyptus (Eucalyptus grandis, Eucalyptus urophylla, Eucalyptus camaldulensis and hybrid Eucalyptus grandis x Eucalyptus urophylla), four dosages of K (0, 50, 100 and 200 mg dm(-3)) and two soil water potentials (-0.01 M Pa and -0.1 M Pa). Plastic containers with 15 cm diameter and 18 cm height, with Styrofoam base, containing 3.0 dm(3) of soil and two plants per container were used. Soil water potential was kept at -0.01 MPa for 40 days after seeding. Afterward, the experimental units were divided into two groups: in one group the potential was kept at 0.01 MPa, and in the other one, at -0.10 MPa. Sol I water potential was control led gravimetrically twice a day with water replacement until the desired potential was reestablished. A week before harvesting, the leaf water potential (psi), the photosynthetic rate (A), the stomatal conductance (gs) and the transpiration rate were evaluated. The last week before harvesting, the mass of the containers was recorded daily before watering to determine the consumption of water by the plants. After harvesting, total dry matter and leaf area were evaluated. the data were Submitted to analysis of variance, to Tukey's tests and regression analyses. The application of K influenced A, gs and the transpiration rate. Plants deficient in K showed lower A and higher Us and transpiration rates. There were no statistical differences in A, gs and transpiration rates ill plants with and Without water deficit. The addition of K reduced the consumption of water per unit of leaf area and, in general, plants submitted to water deficit presented a lower consumption of water.
Resumo:
We present the genome sequences of a new clinical isolate of the important human pathogen, Aspergillus fumigatus, A1163, and two closely related but rarely pathogenic species, Neosartorya fischeri NRRL181 and Aspergillus clavatus NRRL1. Comparative genomic analysis of A1163 with the recently sequenced A. fumigatus isolate Af293 has identified core, variable and up to 2% unique genes in each genome. While the core genes are 99.8% identical at the nucleotide level, identity for variable genes can be as low 40%. The most divergent loci appear to contain heterokaryon incompatibility ( het) genes associated with fungal programmed cell death such as developmental regulator rosA. Cross-species comparison has revealed that 8.5%, 13.5% and 12.6%, respectively, of A. fumigatus, N. fischeri and A. clavatus genes are species-specific. These genes are significantly smaller in size than core genes, contain fewer exons and exhibit a subtelomeric bias. Most of them cluster together in 13 chromosomal islands, which are enriched for pseudogenes, transposons and other repetitive elements. At least 20% of A. fumigatus-specific genes appear to be functional and involved in carbohydrate and chitin catabolism, transport, detoxification, secondary metabolism and other functions that may facilitate the adaptation to heterogeneous environments such as soil or a mammalian host. Contrary to what was suggested previously, their origin cannot be attributed to horizontal gene transfer ( HGT), but instead is likely to involve duplication, diversification and differential gene loss (DDL). The role of duplication in the origin of lineage-specific genes is further underlined by the discovery of genomic islands that seem to function as designated ""gene dumps'' and, perhaps, simultaneously, as "" gene factories''.
Resumo:
Large parity-violating longitudinal single-spin asymmetries A(L)(e+) = 0.86(-0.14)(+0.30) and Ae(L)(e-) = 0.88(-0.71)(+0.12) are observed for inclusive high transverse momentum electrons and positrons in polarized p + p collisions at a center-of-mass energy of root s = 500 GeV with the PHENIX detector at RHIC. These e(+/-) come mainly from the decay of W(+/-) and Z(0) bosons, and their asymmetries directly demonstrate parity violation in the couplings of the W(+/-) to the light quarks. The observed electron and positron yields were used to estimate W(+/-) boson production cross sections for the e(+/-) channels of sigma(pp -> W(+)X) X BR(W(+) -> e(+) nu(e)) = 144.1 +/- 21.2(stat)(-10.3)(+3.4)(syst) +/- 21.6(norm) pb, and sigma(pp -> W(-)X) X BR(W(-) -> e(-) (nu) over bar (e)) = 3.17 +/- 12.1(stat)(-8.2)(+10.1)(syst) +/- 4.8(norm) pb.
Resumo:
We report the first measurement of the parity-violating single-spin asymmetries for midrapidity decay positrons and electrons from W(+) and W(-) boson production in longitudinally polarized proton-proton collisions at root s = 500 GeV by the STAR experiment at RHIC. The measured asymmetries, A(L)(W+) = -0.27 +/- 0.10(stat.) +/- 0.02(syst.) +/- 0.03(norm.) and A(L)(W-) = 0.14 +/- 0.19(stat.) +/- 0.02(syst.) +/- 0.01(norm.), are consistent with theory predictions, which are large and of opposite sign. These predictions are based on polarized quark and antiquark distribution functions constrained by polarized deep-inelastic scattering measurements.
Resumo:
Background: Citrus canker is a disease that has severe economic impact on the citrus industry worldwide. There are three types of canker, called A, B, and C. The three types have different phenotypes and affect different citrus species. The causative agent for type A is Xanthomonas citri subsp. citri, whose genome sequence was made available in 2002. Xanthomonas fuscans subsp. aurantifolii strain B causes canker B and Xanthomonas fuscans subsp. aurantifolii strain C causes canker C. Results: We have sequenced the genomes of strains B and C to draft status. We have compared their genomic content to X. citri subsp. citri and to other Xanthomonas genomes, with special emphasis on type III secreted effector repertoires. In addition to pthA, already known to be present in all three citrus canker strains, two additional effector genes, xopE3 and xopAI, are also present in all three strains and are both located on the same putative genomic island. These two effector genes, along with one other effector-like gene in the same region, are thus good candidates for being pathogenicity factors on citrus. Numerous gene content differences also exist between the three cankers strains, which can be correlated with their different virulence and host range. Particular attention was placed on the analysis of genes involved in biofilm formation and quorum sensing, type IV secretion, flagellum synthesis and motility, lipopolysacharide synthesis, and on the gene xacPNP, which codes for a natriuretic protein. Conclusion: We have uncovered numerous commonalities and differences in gene content between the genomes of the pathogenic agents causing citrus canker A, B, and C and other Xanthomonas genomes. Molecular genetics can now be employed to determine the role of these genes in plant-microbe interactions. The gained knowledge will be instrumental for improving citrus canker control.
Resumo:
As insects increase in radiotolerance as they develop and usually several developmental stages of the pest may be present in the fresh shipped commodity, it is important to know the radiation susceptibility of the stages of the target insect before the establishment of ionizing radiation quarantine treatments. This study was performed to determine the radiotolerance of eggs of the oriental fruit moth, Grapholita molesta (Busck) (Lepidoptera: Tortricidae), to gamma radiation. This species is considered as one of the most serious worldwide pests for temperate fruits, especially peaches. Eggs (12 h old) were exposed to 0 (control), 25, 35, 50, 75, 100, 125 and 150 Gy of gamma radiation. Surviving larvae were allowed to feed on an artificial diet. Three days after irradiation, it was verified that larvae`s cephalic capsules were significantly affected by gamma radiation, and the estimated mean LD(90) and LD(99) were 66.3 Gy and 125.8 Gy, respectively. Oriental fruit moth eggs revealed to be quite radiosensitive and very low doses as 50 Gy were sufficient to disrupt G. molesta embryogenesis. At 25 Gy, only male adults originated from the surviving larvae and, after mating with untreated fertile females, shown to be sterile. (C) 2010 Elsevier Ltd. All rights reserved.
Resumo:
Molybdenum and tungsten bimetallic oxides were synthetized according to the following methods: Pechini, coprecipitation and solid state reaction (SSR). After the characterization, those solids were carbureted at programmed temperature. The carburation process was monitored by checking the consumption of carburant hydrocarbon and CO produced. The monitoring process permits to avoid or to diminish the formation of pirolytic carbon.
Resumo:
Diamond-like carbon (DLC), also known as amorphous hydrogenated carbon (a-C:H), are a class of materials with excellent mechanical, tribological and biological properties. When the DLC films are enhanced with other elements, all of these properties can be changed within a certain range. In this work, reactive magnetron sputtering was used to deposit W-DLC (hydrogenated tungsten carbide) films on Ti6A14V (implant material). Many films were made using pure tungsten (99.99%) target and different plasmas processes, with different ratio among argon and methane. It was possible to change the films composition (from pure amorphous carbon to carbon enhanced with tungsten) according to ratio of argon and methane plasma. Between all films processed, the carbon films enhanced with tungsten showed good results in the ""in vitro"" cytotoxicity testing. Raman spectroscopy was used to analyze the chemical bonds kinds and the chemical bonds quantities. The Rutherford Back Scattering (RBS) was used to analyze the films compositions. The chemical inertness was analyzed by scanning voltametry. W-DLC thin films obtained in these processes have low roughness, high chemical resistance, good adhesion and show a high biocompatibility, when compared with common DLC thin films. Hence we have concluded that the tungsten concentrations in the DLC films make an important role to improve the properties of the DLC layers. (C) 2007 Elsevier B.V. All rights reserved.
Resumo:
The present study evaluated the potential of a w/o microemulsion as a topical carrier system for delivery of the antioxidant quercetin. Topical and transdermal delivery of quercetin were evaluated in vitro Using porcine car skin mounted on a Franz diffusion cell and in vivo on hairless-skin mice. Skin irritation by topical application of the microemulsion containing quercetin, and the protective effect of the formulation on UVB-induced decrease of endogenous reduced glutathione levels and increase of cutaneous proteinase secretion/activity were also investigated. The w/o microemulsion increased the penetration of quercetin into the stratum corneum and epidermis plus dermis at 3, 6. 9 and 12 h post-application in vitro and in vivo at 6 h post-application. No transdermal delivery of quercetin Occurred. By evaluating established endpoints of skin irritation (erythema formation, epidermis thickening and infiltration of inflammatory cells), the Study demonstrated that the daily application of the w/o microemulsion for up to 2 days did not cause skin irritation. W/o microemulsion containing quercetin significantly prevented the UVB irradiation-induced GSH depletion and secretion/activity of metalloproteinases. (C) 2008 Elsevier B.V. All rights reserved.
Resumo:
Stable multiple emulsions containing andiroba oil and sunscreen have been formulated. These were prepared using the two-step procedure. The formulations were characterized and their stability over the time was evaluated by centrifugation, macroscopic, and microscopic analyses, and rheological measurements. The photoprotective efficacy of the O/W and O1/W/O2 containing or not andiroba oil was evaluated by in vivo sun protection factor determination according to the FDA method. The formulations exhibited good stability during 30 days after preparation at different temperatures. These presented pseudoplastic flow behaviour and thixotropy. The increase of in vivo SPF value was not observed when andiroba oil was incorporated into emulsions containing ethylhexyl methoxycinnamate. These multiple emulsions can be utilized as an interesting topical vehicle.
Resumo:
Emulsions containing liquid crystals present interesting properties and advantages such as the skin moisturize increase, active release modulation, and emulsion stabilization. In this work, emulsions containing annatto, coffee and tea tree oils, and nonionic surfactants were developed. The HLB method was used for selection of surfactants. The required HLB value was established (9.0). Liquid crystals were attained when used the surfactant mixture Ceteareth-5 and Steareth-2 and identified as lamellar. The emulsions showed pseudoplastic behavior and tixotropy. The ternary diagram was useful in the selection of the proportion of surfactant and oily phase considering skin compatibility and liquid crystal presence.