943 resultados para 010506 Statistical Mechanics, Physical Combinatorics and Mathematical Aspects of Condensed Matter
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The aim of this study was to analyze photosynthate partitioning in tomato photomorphogenic mutants at the ends of the vegetative (40 days after emergence [DAE]) and reproductive (69 DAE) stages and to determine its interaction with morphoanatomical aspects. The mutants aurea (au), phytochrome-deficient, high pigment-1 (hp1), light-exaggerated response, were studied along with the non-mutant Micro-Tom (MT) cultivar. The plants were analyzed at 40 and 68 DAE to identify photosynthate source organs and tissues as well as the target organs of remobilized photosynthate during the reproductive stage. The plants were evaluated for their internal and external morphology as well as the percentage of dry mass of their organs. Photosynthate allocation in the hp1 mutant occurred primarily in the roots and leaves, and allocation in the au mutant occurred primarily in fruits. The au mutant showed a high capacity for photosynthate remobilization to fruit during the reproductive stage, and the predominant sources of these remobilized photosynthates were the leaf spongy parenchyma, the root vascular cylinder and the marrow stem.
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This paper presents results describing the physical, mechanical, and thermal properties (melt flow index - MFI and oxidative induction time - OIT) of high density polyethylene and poly (vinyl chloride) after weathering exposure (6, 12, 18, and 30 months). The materials exposed were geomembranes of two thicknesses: 1.0 and 2.0 mm (PVC) and 0.8 and 2.5 mm (HDPE). The climate parameters (average) obtained were 25 degrees C (temperature), 93 mm (precipitation), 66% (relative humidity), and 19 MJ/m(2). day (intensity of global radiation). Some results showed, for instance, that the behavior of the geomembranes changed after the exposures. A few minor variations in physical properties occurred. The density and thickness, for instance, varied 0.5-1.0% (average) for both the PVC and HDPE geomembranes. The mechanical properties changed as a function of the period of exposure. In general, some decreases were verified by the deformation of PVC. The samples became more rigid. In contrast, HDPE geomembranes became more ductile. Despite the variations in elasticity, some increases in deformability were verified. An MFI test showed some degradation in HDPE geomembranes. OIT tests revealed small values for both intact and exposed samples.
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Yellow fever is a re-emerging infectious disease that currently is at risk of urbanization due to the advance of the Aedes aegypti vector. The disease affects about 200,000 individuals annually, mainly in tropical Africa and South America. It causes severe disease involving especially the liver, with lesions characterized by midzonal steatosis, apoptosis and lytic necrosis of the hepatocytes. Quantitative histological and immunohistochemical analysis of 53 human hepatic samples demonstrated apoptosis, steatosis and lytic necrosis of hepatocytes with midzonal pattern. No substantial alterations and reticular network were observed. The inflammatory infiltrate consisted of mononuclear cells and intensity was minimal or moderate, disproportionate to the intense death of the hepatocytes. Hepatic damage in yellow fever resulted mainly from a massive death of hepatocytes due to apoptosis and to a lesser extent due to lytic necrosis. It is recommended that therapeutic regimens for serious cases should include measures to protect against apoptosis. (c) 2005 Elsevier B.V. All rights reserved.
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Brain activity contains three fundamental aspects: (a) The physiological aspect, covering all kinds of processes that involve matter and/or energy; (b) the mental unconscious aspect, consisting of dynamical patterns (i.e., frequency, amplitude and phase-modulated waves) embodied in neural activity. These patterns are variously operated (transmitted, stored, combined, matched, amplified, erased, etc), forming cognitive and emotional unconscious processes and (c) the mental conscious aspect, consisting of feelings experienced in the first-person perspective and cognitive functions grounded in feelings, as memory formation, selection of the focus of attention, voluntary behavior, aesthetical appraisal and ethical judgment. Triple-aspect monism (TAM) is a philosophical theory that provides a model of the relation of the three aspects. Spatially distributed neuronal dendritic potentials generate amplitude-modulated waveforms transmitted to the extracellular medium and adjacent astrocytes, prompting the formation of large waves in the astrocyte network, which are claimed to both integrate distributed information and instantiate feelings. According to the valence of the feeling, the large wave feeds back on neuronal synapses, modulating (reinforcing or depressing) cognitive and behavioral functions.
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Tetralogy of Fallot is a complex cardiac malformation characterized by four anatomical defects: pulmonary valve stenosis, right ventricular hypertrophy, interventricular septal defect and aortic dextroposition. Imaging techniques are useful in the diagnosis of this disease, such as radiography for screening and Doppler echocardiography for a definitive diagnosis. Our objective is to report the radiographic and Doppler echocardiographic aspects of a tetralogy of Fallot case in a 10 month-old Border Collie dog.
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Lymphomas are malignant neoplasms resulting from clonal proliferations of lymphocytes, originated from lymphoid organs, but can develop in any organ by the migration of lymphocytes to the organ's tissue. Lymphoma constitutes one of the most common neoplasms in cats. Imaging techniques like radiology, ultrasound and tomography may help in diagnosing and classifying lymphomas. Our objective is to report the radiographic and tomographic characteristics of a mediastinal lymphoma in a cat, which occupied a large thoracic and abdominal area and infiltrated into the medullary canal causing acute paraparesis. The tomographic exam was essential for identifying the mass, its extension and its location, besides identifying how compromised the adjacent structures were, but the histopathological examination was crucial to diagnose the nature of the lesion.
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Minas frescal cheese is a semi-skimmed product with high moisture and simple preparation and one of the most consumed in Brazil. Thus, the aim of this study was to combine the characteristics of inulin and gum acacia (by having fibers and being prebiotic) to produce a minas frescal cheese. Were evaluate the characteristics physical and chemical, microbial and sensory acceptance (hedonic scale) of each cheese. Three cheeses were prepared; one as a standard (QP) without inulin, and others with 0.49% (QI25) and 0.98% (QI50) inulin, the amount of gum acacia was maintained. The yield of the formulations with gum acacia and inulin were 9.76% for (QI25) and to 20.03% (QI50) higher than the standard sample. In relation to moisture content, samples containing inulin and gum acacia showed values greater than the standard sample. The sensory analysis indicated no differences between scores for color, aroma and texture, but significant differences were detected for flavor, in which (QI25) received the highest acceptance. Regarding the energy value, it was obtained 276 kcal (QP), 215 kcal (QI25) and 190 kcal (QI50). Therefore, the developed product presents satisfactory results for sensory, microbiological and physical- chemical analyses.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Some aspects of the biology, reproduction and morphology of Gundlachia ticaga (MARCUS & MARCUS 1962) were studied and compared with literature data. A sample of similar to 100 specimens, collected in a darn in Ribeirao Preto, were maintained in Petri dishes at the laboratory during a period no longer than a month. The oviposition, number of capsules, and incubation time of eggs were registered for each individual. A morphologic study was carried out in both, alive and fixed specimens. Although some morphological discrepancies were identified, the majority of data confirms what was previously described for the species. Regarding the biology, however, the results were somewhat different from those previously reported. The incubation time of the eggs varied from 10 to 13 days, and the number of embryos in the interior of the ovigerous capsules varied from 1 to 4. In addition, each individual laid 9 eggs during the first month of the reproductive period. The formation of septa occurred in some animals and intermediary phases are figured.
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Objective: Patients with high cervical spinal cord injury are usually dependent on mechanical ventilation support, which, albeit life saving, is associated with complications and decreased life expectancy because of respiratory infections. Diaphragm pacing stimulation (DPS), sometimes referred to as electric ventilation, induces inhalation by stimulating the inspiratory muscles. Our objective was to highlight the indications for and some aspects of the surgical technique employed in the laparoscopic insertion of the DPS electrodes, as well as to describe five cases of tetraplegic patients submitted to the technique. Methods: Patient selection involved transcutaneous phrenic nerve studies in order to determine whether the phrenic nerves were preserved. The surgical approach was traditional laparoscopy, with four ports. The initial step was electrical mapping in order to locate the "motor points" (the points at which stimulation would cause maximal contraction of the diaphragm). If the diaphragm mapping was successful, four electrodes were implanted into the abdominal surface of the diaphragm, two on each side, to stimulate the branches of the phrenic nerve. Results: Of the five patients, three could breathe using DPS alone for more than 24 h, one could do so for more than 6 h, and one could not do so at all. Conclusions: Although a longer follow-up period is needed in order to reach definitive conclusions, the initial results have been promising. At this writing, most of our patients have been able to remain ventilator-free for long periods of time.
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The histomorphometric and proliferative characteristics of the collared peccary (Tayassu tajacu) placenta and uterus were analyzed. The material was examined by standard histological techniques and histochemistry (PAS, Perls and Alcian Blue pH 0.5 and 2.5%) and the cellular proliferation by AgNORs and flow cytometry. All the analyzed morphometric variables differed between pregnant and non-pregnant uteri in the luteal phase using the Dunnet test. Height and gland diameter of uterine glands increased linearly during pregnancy, with an intense positive PAS and Perls reaction in all stages. The cells with more than seven AgNORs per nuclei and the cells in the G2M cell cycle phase in the maternal tissue also increased after 70 days of pregnancy. The uteroplacental ridges had a linear increase in size with two distinct areas, base and top, with uterine epithelium and trophoblastic cells changing their morphology following the placental ridge development. Flow cytometry analysis showed the percentage of cells in each cell cycle phase with a quadratic behavior for stages G2/M in the maternal tissue, suggesting an increase in proliferative capacity of maternal tissue after 65 days of pregnancy. The same quadratic effect was observed in the G0/G1 phase in both maternal and fetal tissues. Cells in apoptosis showed cubic behavior in both tissues. The morphometric and cellular dynamic aspects observed in this study have not been previously described and they extend our knowledge of functions relating to maternal-fetal dynamics in this species.
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Bordetella avium is an opportunistic pathogen that presents tropism for ciliated epithelia, leading to upper respiratory tract disease in turkeys. This agent has also been associated with Lockjaw Syndrome in psittacine birds, but literatures describing the importance of this agent in such species are rare. The purpose of the present study was to report the first outbreak of B. avium infection in juvenile cockatiels demonstrating the Lockjaw Syndrome in Brazil and to investigate the antimicrobial resistance profile and phenotypic and genotypic characteristics of these strains. Surprising, the strains obtained from five infected cockatiel chicks from three different breeders from different Brazilian states showed a clonal relationship using the Pulsed Field Gel Electrophoresis and Single Enzyme Amplified Fragment Length Polymorphism techniques. The virulence potentials of the B. avium strains were assessed using tracheal adherence and cytotoxic effects on a VERO cell monolayer. (C) 2012 Elsevier B.V. All rights reserved.