956 resultados para Coherent combination
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Searching for an understanding of how the brain supports conscious processes, cognitive scientists have proposed two main classes of theory: Global Workspace and Information Integration theories. These theories seem to be complementary, but both still lack grounding in terms of brain mechanisms responsible for the production of coherent and unitary conscious states. Here we propose following James Robertson's "Astrocentric Hypothesis" - that conscious processing is based on analog computing in astrocytes. The "hardware" for these computations is calcium waves mediated by adenosine triphosphate signaling. Besides presenting our version of this hypothesis, we also review recent findings on astrocyte morphology that lend support to their functioning as Local Hubs (composed of protoplasmic astrocytes) that integrate synaptic activity, and as a Master Hub (composed, in the human brain, by a combination of interlaminar, fibrous, polarized and varicose projection astrocytes) that integrates whole-brain activity.
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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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A randomized double blind and placebo controlled design was used to investigate the hemostatic, biochemical, gastrointestinal and behavioral effects of pre- and postoperative administration of vedaprofen 0.5 mg/kg PO (V), tramadol 2 mg/kg SC (T), their association (VT) or placebo (P) in 40 adult female cats (3.0 +/- 0.32 kg; 1.8 +/- 0.7 years) distributed in groups of 10. Platelet aggregation and bleeding time were measured before and 52 11 after ovariohysterectomy. Serum urea, creatinine, alanine aminotransferase, alkaline phosphatase and gamma-glutamyl transferase concentrations were measured before and 7 days postoperatively. The occurrence of vomiting, frequency and consistency of feces, and behavior were observed for 7 days postoperatively. Morphine (0.5 mg/kg, IM) was used as rescue analgesic. Laboratory variables did not change. Vomiting was observed only after morphine administration. Mild euphoria was observed in T and VT. The perioperative use of vedaprofen and/or tramadol did not modify the hemostatic, biochemical and gastrointestinal function in cats. (C) 2009 ESFM and AAFP. published by Elsevier Ltd. All rights reserved.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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We show that the ground-state energy of the q-deformed Lipkin-Meshkov-Glick Hamiltonian can be estimated by q-deformed coherent states. We also use these coherent states to analyse qualitatively the suppression of the second order ground-state energy phase transition of this model. © 1993.
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We derive simple and physically transparent expressions for the contribution of the strong interaction to one-nucleon-removal processes in peripheral relativistic heavy-ion collisions. The coherent contribution, i.e., the excitation of a giant dipole resonance via meson exchange, is shown to be negligible as well as the interference between Coulomb and nuclear excitation. The incoherent nucleon-knockout contribution is also derived suggesting the nature of the nuclear interaction in this class of processes. We also justify the simple formulae used to fit the data of the E814 Collaboration. © 1995 Elseier Science B.V. All rights reserved.
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Two new species of the genus Eidmanacris are described (E. bidentata and E. corumbatai) and a new combination name ( E. alboannulata) is assigned for the species Arachnomimus alboannulatus Piza, 1960 (= E. bicornis Mesa & Mello, 1985). Morphological and karyologycal information are provided, and the structure of the genital sclerites is discussed. [KEY WORDS: Orthoptera, Grylloidea, Phalangopsidae, Eidmanacris, cricket, phallic sclerites, chromosomes].
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The atomic tunneling between two tunnel-coupled Bose-Einstein condensates (BECs) in a double-well time-dependent trap was studied. For the slowly varying trap, synchronization of oscillations of the trap with oscillations of the relative population was predicted. Using the Melnikov approach, the appearance of the chaotic oscillations in the tunneling phenomena between the condensates was confirmed.
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The aim of this study was to test the hypothesis that protein-calorie undernutrition decreases myocardial contractility jeopardizing ventricular function, and that ventricular dysfunction can be detected noninvasively. Five-month-old male Wistar-Kyoto rats were fed with regular rat chow ad libitum for 90 days (Control group, n = 14). A second group of rats received 50% of the amount of diet consumed by de control group (Food restricted group, n = 14). Global LV systolic function was evaluated in vivo, noninvasively, by transthoracic echocardiogram. After echocardiographic study, myocardial contractility was assessed in vitro in the isovolumetrically beating isolated heart in eight animals from each group (Langendorff preparation). The in vivo LV fractional shortening showed that food restriction depressed LV systolic function (p < 0.05). Myocardial contractility was impaired as assessed by the maximal rate of rise of LV pressure (+dP/dt), and developed pressure at diastolic pressure of 25 mmHg (p < 0.05). Furthermore, food restriction induced eccentric ventricular remodeling, and reduced myocardial elasticity and LV compliance (p < 0.05). In conclusion, food restriction causes systolic dysfunction probably due to myocardial contractility impairment and reduction of myocardial elasticity. © 2002 Elsevier B.V. All rights reserved.
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Most hypertensive patients need more than one drug to reach recommended blood-pressure targets. We investigated the effects on 24-h ambulatory blood pressure (ABP) of the angiotensin-receptor blocker, valsartan, in combination with hydrochlorothiazide (HCTZ), compared with the calcium-channel blocker amlodipine in a Brazilian population in a multicentre, double-blind, double-dummy, parallel group, controlled study in 373 patients with essential hypertension. After a 2-week washout period, patients with a mean sitting systolic blood pressure (SBP) of 160-190 mmHg were randomized to receive either valsartan 160 mg o.d., or amlodipine 5 mg o.d. for 2 weeks and subsequently force-titrated to valsartan 160 mg/HCTZ 25 mg o.d. or amlodipine 10 mg o.d. This regimen was continued until the end of the study at week 8. The primary efficacy parameter was the change from baseline to week 8 in mean 24-h SBP. Secondary endpoints were change in mean 24-h diastolic blood pressure (DBP), tolerability and safety of treatments. Valsartan/HCTZ achieved a mean reduction in systolic ABP of -19.1 ± 11.3 mmHg compared with -20.7 ± 12.0 mmHg with amlodipine (p = 0.324 for the comparison) and in diastolic ABP by -11.1 ± 7.4 mmHg vs -11.6 ± 7.2 mmHg by amlodipine (p = 0.853 for the comparison). The valsartan/HCTZ group exhibited markedly lower rates of adverse events and discontinuations than the amlodipine group. Peripheral oedemas were far more frequent with amlodipine than with valsartan/HCTZ (1.6% with valsartan/HCTZ; 16.8% with amlodipine). Thus, the valsartan 160 mg/HCTZ 25 mg combination appears to be as efficacious as amlodipine 10 mg in this patient population but better tolerated.
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Objective: The purpose of this study was to histologically analyze the influence of bioactive glass and/or a calcium sulfate barrier on bone healing in surgically created defects in rat tibias. Material and methods: Sixty-four rats were divided into 4 groups: C (control), CS (calcium sulfate), BG (bioactive glass), and BG/CS (bioactive glass/calcium sulfate). A surgical defect was created in the tibia of each animal. In Group CS, a calcium sulfate barrier was placed to cover the defect. In Group BG the defect was filled with bioactive glass. In Group BG/CS, it was filled with bioactive glass and protected by a barrier of calcium sulfate. Animals were sacrificed at 10 or 30 days post-operative. The formation of new bone in the cortical area of the defect was evaluated histomorphometrically. Results: At 10 days post-operative, Group C presented significantly more bone formation than Groups CS, BG, or BG/CS. No statistically significant differences were found between the experimental groups. At 30 days post-operative, Group C demonstrated significantly more bone formation than the experimental groups. Groups CS and BG/CS showed significantly more bone formation than Group BG. No statistically significant differences were found between Group CS and BG/CS. Conclusions: (a) the control groups had significantly more bone formation than the experimental groups; (b) at 10 days post-operative, no significant differences were found between any of the experimental groups; and (c) at 30 days post-operative, the groups with a calcium sulfate barrier had significantly more bone formation than the group that used bioactive glass only. Copyright © Blackwell Munksgaard 2005.
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The aim of this study was to evaluate the influence of diltiazem in combination with a sucrose-rich diet on gingival alterations in rats. One hundred and twenty male Holtzman rats were randomly assigned to 10 groups (n = 12), being 2 control groups treated with saline and 8 test groups treated with diltiazem in daily doses of 5, 25, 50 and 100 mg/kg during 40 or 60 days. Afterwards, the mandibles were removed for macroscopic, histologic and histometric analyses of the buccal gingiva of the mandibular right first molar. No macroscopic characteristic of gingival overgrowth was observed in any of the groups. The microscopic analysis showed characteristics of normality with inflammatory cells only adjacent to the crevicular epithelium in all groups for both periods. The histometric analysis showed significant differences only for the epithelial tissue area in the 40-day period (Kruskal-Wallis; P = 0.032). Comparing the periods, significant differences regarding the connective and epithelial tissue areas were observed only in the group treated with a 25 mg/kg dose (Mann-Whitney; P = 0.004 and P = 0.007, respectively). Oral administration of diltiazem in combination with a sucrose-rich diet did not induce gingival alterations in rats. © 2009 Sociedade Brasileira de Pesquisa Odontológica.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)