976 resultados para Special Euclidean group


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The purpose of the present study was to evaluate the effects of 8 weeks of strength and power training on the expression of genes related to the canonical WNT pathway and beta-catenin protein levels in physically active men. Twenty-five subjects (27.4 +/- A 4.6 years) were balanced based on their relative maximum strength in the squat exercise (squat 1RM/body mass) and randomly assigned to strength training (ST) (n = 10), power training (PT) (n = 10), and control (C) (n = 5) groups. The ST and the PT groups performed high and low intensity squats, respectively, thrice a week, for 8 weeks. Muscle biopsies from the vastus lateralis muscle were collected before and after the training period. Relative strength and power increased similarly in both ST and PT groups (P < 0.001). Fiber cross-sectional area also increased similarly in both ST and PT groups. Gene expression and beta-catenin protein expression levels were assessed by real-time PCR and Western blot. Certain genes were up-regulated in the ST group (WNT1: 6.4-fold, P < 0.0001; SFRP1: 3.3-fold, P < 0.0001 and LEF1: 7.3-fold, P < 0.0001) and also in the PT group (WNT1: 24.9-fold, P < 0.0001; SFRP1: 2.7-fold, P < 0.0001; LEF1: 34.1-fold, P < 0.0001 and Cyclin D1: 7.7-fold, P < 0.001). In addition, the expression of key WNT pathway genes was substantially more responsive to PT than to ST (WNT1: P < 0.0001; LEF1: P < 0.0001 and Cyclin D1: P < 0.001). Finally, the total beta-catenin protein content increased only in the PT group (P < 0.05). Our data indicate that a PT regimen triggers greater responses in key elements of the WNT pathway.

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Angiotensin I-converting enzyme (ACE) is recognized as one of the main effector molecules involved in blood pressure regulation. In the last few years some polymorphisms of ACE such as the insertion/deletion (I/D) polymorphism have been described, but their physiologic relevance is poorly understood. In addition, few studies investigated if the specific activity of ACE domain is related to the I/D polymorphism and if it can affect other systems. The aim of this study was to establish a biochemical and functional characterization of the I/D polymorphism and correlate this with the corresponding ACE activity. For this purpose, 119 male brazilian army recruits were genotyped and their ACE plasma activities evaluated from the C- and N-terminal catalytic domains using fluorescence resonance energy transfer (FRET) peptides, specific for the C-domain (Abz-LFK(Dnp)OH), N-domain (Abz-SDK(Dnp)P-OH) and both C- and N-domains (Abz-FRK(Dnp)P-OH). Plasma kallikrein activity was measured using Z-Phe-Arg-AMC as substrate and inhibited by selective plasma kallikrein inhibitor (PKSI). Some physiological parameters previously described related to the I/D polymorphism such as handgrip strength, blood pressure, heart rate and BMI were also evaluated. The genotype distribution was II n = 27, ID n = 64 and DD n = 28. Total plasma ACE activity of both domains in II individuals was significantly lower in comparison to ID and DD. This pattern was also observed for C- and N-domain activities. Difference between ID and DD subjects was observed only with the N-domain specific substrate. Blood pressure, heart rate, handgrip strength and BMI were similar among the genotypes. This polymorphism also affected the plasma kallikrein activity and DD group presents high activity level. Thus, our data demonstrate that the I/D ACE polymorphism affects differently both ACE domains without effects on handgrip strength. Moreover, this polymorphism influences the kallikrein-kinin system of normotensive individuals. (C) 2009 Elsevier Ltd. All rights reserved.

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Under physiological conditions, elderly people present memory deficit associated with neuronal loss. This pattern is also associated with Alzheimer`s disease but, in this case, in a dramatically intensified level. Kinin receptors have been involved in neurodegeneration and increase of amyloid-beta concentration, associated with Alzheimer`s disease (AD). Considering these findings, this work evaluated the role of kinin receptors in memory consolidation during the aging process. Male C57BI/6 (wt), knock-out B1 (koB1) or B2 (koB2) mice (3, 6, 12 and 18-month-old - mo; n = 10 per group) were submitted to an acquisition session, reinforcement to learning (24 h later: test 1) and final test (7 days later: test 2), in an active avoidance apparatus, to evaluate memory. Conditioned avoidance responses (CAR, % of 50 trials) were registered. In acquisition sessions, similar CAR were obtained among age matched animals from all strains. However, a significant decrease in CAR was observed throughout the aging process (3mo: 8.8 +/- 2.3%; 6mo: 4.1 +/- 0.6%; 12mo: 2.2 +/- 0.6%, 18mo: 3.6 +/- 0.6%, P < 0.01), indicating a reduction in the learning process. In test 1, as expected, memory retention increased significantly (P < 0.05) in all 3- and 6-month-old animals as well as in 12-month-old-wt and 12-month-old-koB1 (P < 0.01), compared to the training session. However, 12-month-old-koB2 and all 18-month-old animals did not show an increase in memory retention. In test 2, 3- and 6-month-old wt and koB1 mice of all ages showed a significant improvement in memory (P < 0.05) compared to test 1. However, 12-month-old wt and koB2 mice of all ages showed no difference in memory retention. We suggest that, during the aging process, the B1 receptor could be involved in neurodegeneration and memory loss. Nevertheless, the B2 receptor is apparently acting as a neuroprotective factor. (C) 2009 Elsevier Ltd. All rights reserved.

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We show that commutative group spherical codes in R(n), as introduced by D. Slepian, are directly related to flat tori and quotients of lattices. As consequence of this view, we derive new results on the geometry of these codes and an upper bound for their cardinality in terms of minimum distance and the maximum center density of lattices and general spherical packings in the half dimension of the code. This bound is tight in the sense it can be arbitrarily approached in any dimension. Examples of this approach and a comparison of this bound with Union and Rankin bounds for general spherical codes is also presented.

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Heart failure (HF) is associated with changes in the skeletal muscle (SM) which might be a consequence of the unbalanced local expression of pro- (TNF-alpha) and anti- (IL-10) inflammatory cytokines, leading to inflammation-induced myopathy, and SM wasting. This local effect of HF on SM may, on the other hand, contribute to systemic inflammation, as this tissue actively secretes cytokines. Since increasing evidence points out to an anti-inflammatory effect of exercise training, the goal of the present study was to investigate its effect in rats with HF after post-myocardial infarction (MI), with special regard to the expression of TNF-alpha and IL-10 in the soleus and extensor digitorum longus (EDL), muscles with different fiber composition. Wistar rats underwent left thoracotomy with ligation of the left coronary artery, and were randomly assigned to either a sedentary (Sham-operated and MI sedentary) or trained (Sham-operated and MI trained) group. Animals in the trained groups ran on a treadmill (0% grade at 13-20 m/min) for 60 min/day, 5 days/week, for 8-10 weeks. The training protocol was able to reverse the changes induced by MI, decreasing TNF-alpha protein (26%, P < 0.05) and mRNA (58%, P < 0.05) levels in the soleus, when compared with the sedentary MI group. Training also increased soleus IL-10 expression (2.6-fold, P < 0.001) in post-MI HF rats. As a consequence, the IL-10/TNF-alpha ratio was increased. This ""anti-inflammatory effect"" was more pronounced in the soleus than in the EDL, suggesting a fiber composition dependent response. (C) 2009 Elsevier Ltd. All rights reserved.

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Miarka, B, Del Vecchio, FB, and Franchini, E. Acute effects and postactivation potentiation in the special judo fitness test. J Strength Cond Res 25(2): 427-431, 2011-The purpose of this study was to compare the acute short-term effects of (1) plyometric exercise, (2) combined strength and plyometric exercise (contrast), and (3) maximum strength performance in the Special Judo Fitness Test (SJFT). Eight male judo athletes (mean +/- SD, age, 19 +/- 1 years; body mass, 60.4 +/- 5 kg; height, 168.3 +/- 5.4 cm) took part in this study. Four different sessions were completed; each session had 1 type of intervention: (a) SJFT control, (b) plyometric exercises + SJFT, (c) maximum strength + SJFT, and (d) contrast + SJFT. The following variables were quantified: throws performed during series A, B, and C; total number of throws; heart rate immediately and 1 minute after the test; and test index. Significant differences were found in the number of throws during series A: the plyometric exercise (6.4 +/- 0.5 throws) was superior (p < 0.05) to the control condition (5.6 +/- 0.5 throws). Heart rate 1 minute after the SJFT was higher (p < 0.01) during the plyometric exercise (192 +/- 8 bpm) than during the contrast exercise (184 +/- 9 bpm). The contrast exercise (13.58 +/- 0.72) resulted in better index values than the control (14.67 +/- 1.30) and plyometric exercises (14.51 +/- 0.54). Thus, this study suggests that contrast and plyometric exercises performed before the SJFT can result in improvements in the test index and anaerobic power of judo athletes, respectively.

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Background and Study Aim: Judo is very physiological demanding sport, but there are no many physical fitness specific tests. One of the most used specific judo tests is the Special Judo Fitness Test (SJFT) proposed by Sterkowicz ( 1995). Although this test has been used by many coaches in different countries no classificatory table was found to classify the judo athletes according to their results. Thus, the aim of this work was to present a classificatory table for this test. Material/Methods: For this purpose 141 judo athletes ( mean +/-standard deviation: 21.3+/-4.5years-old; 74.2+/-15.9 kg of body mass and 176.7+/-8.2 cm of height; judo ranking between 3(rd) kyu and 3(rd) dan) familiarized with the SJFT performed it once in order to provide data to establish a classificatory table. Results: After the analysis of data distribution a five scale table (20% for each classificatory category) was developed considering the variables used in the SJFT ( number of throws, heart rate after and 1 min after the test and index). Conclusions: The classificatory table can help coaches using the SJFT to classify their athletes` level and to monitor their physical fitness progress.

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A niobium single crystal was subjected to equal channel angular pressing (ECAP) at room temperature after orienting the crystal such that [1 -1 -1] ayen ND, [0 1 -1] ayen ED, and [-2 -1 -1] ayen TD. Electron backscatter diffraction (EBSD) was used to characterize the microstructures both on the transverse and the longitudinal sections of the deformed sample. After one pass of ECAP the single crystal exhibits a group of homogeneously distributed large misorientation sheets and a well formed cell structure in the matrix. The traces of the large misorientation sheets match very well with the most favorably oriented slip plane and one of the slip directions is macroscopically aligned with the simple shear plane. The lattice rotation during deformation was quantitatively estimated through comparison of the orientations parallel to three macroscopic axes before and after deformation. An effort has been made to link the microstructure with the initial crystal orientation. Collinear slip systems are believed to be activated during deformation. The full constraints Taylor model was used to simulate the orientation evolution during ECAP. The result matched only partially with the experimental observation.

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The present paper proposes a flexible consensus scheme for group decision making, which allows one to obtain a consistent collective opinion, from information provided by each expert in terms of multigranular fuzzy estimates. It is based on a linguistic hierarchical model with multigranular sets of linguistic terms, and the choice of the most suitable set is a prerogative of each expert. From the human viewpoint, using such model is advantageous, since it permits each expert to utilize linguistic terms that reflect more adequately the level of uncertainty intrinsic to his evaluation. From the operational viewpoint, the advantage of using such model lies in the fact that it allows one to express the linguistic information in a unique domain, without losses of information, during the discussion process. The proposed consensus scheme supposes that the moderator can interfere in the discussion process in different ways. The intervention can be a request to any expert to update his opinion or can be the adjustment of the weight of each expert`s opinion. An optimal adjustment can be achieved through the execution of an optimization procedure that searches for the weights that maximize a corresponding soft consensus index. In order to demonstrate the usefulness of the presented consensus scheme, a technique for multicriteria analysis, based on fuzzy preference relation modeling, is utilized for solving a hypothetical enterprise strategy planning problem, generated with the use of the Balanced Scorecard methodology. (C) 2009 Elsevier Inc. All rights reserved.

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The approach presented in this paper consists of an energy-based field-circuit coupling in combination with multi-physics simulation of the acoustic radiation of electrical machines. The proposed method is applied to a special switched reluctance motor with asymmetric pole geometry to improve the start-up torque. The pole shape has been optimized, subject to low torque ripple, in a previous study. The proposed approach here is used to analyze the impact of the optimization on the overall acoustic behavior. The field-circuit coupling is based on a temporary lumped-parameter model of the magnetic part incorporated into a circuit simulation based on the modified nodal analysis. The harmonic force excitation is calculated by means of stress tensor computation, and it is transformed to a mechanical mesh by mapping techniques. The structural dynamic problem is solved in the frequency domain using a finite-element modal analysis and superposition. The radiation characteristic is obtained from boundary element acoustic simulation. Simulation results of both rotor types are compared, and measurements of the drive are presented.

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Flow pumps are important tools in several engineering areas, such as in the fields of bioengineering and thermal management solutions for electronic devices. Nowadays, many of the new flow pump principles are based on the use of piezoelectric actuators, which present some advantages such as miniaturization potential and lower noise generation. In previous work, authors presented a study of a novel pump configuration based on placing an oscillating bimorph piezoelectric actuator in water to generate flow. It was concluded that this oscillatory behavior (such as fish swimming) yields vortex interaction, generating flow rate due to the action and reaction principle. Thus, following this idea the objective of this work is to explore this oscillatory principle by studying the interaction among generated vortex from two bimorph piezoelectric actuators oscillating inside the same pump channel, which is similar to the interaction of vortex generated by frontal fish and posterior ones when they swim together in a group formation. It is shown that parallel-series configurations of bimorph piezoelectric actuators inside the same pump channel provide higher flow rates and pressure for liquid pumping than simple parallel-series arrangements of corresponding single piezoelectric pumps, respectively. The scope of this work includes structural simulations of bimorph piezoelectric actuators, fluid flow simulations, and prototype construction for result validation.

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In this study, the concept of cellular automata is applied in an innovative way to simulate the separation of phases in a water/oil emulsion. The velocity of the water droplets is calculated by the balance of forces acting on a pair of droplets in a group, and cellular automata is used to simulate the whole group of droplets. Thus, it is possible to solve the problem stochastically and to show the sequence of collisions of droplets and coalescence phenomena. This methodology enables the calculation of the amount of water that can be separated from the emulsion under different operating conditions, thus enabling the process to be optimized. Comparisons between the results obtained from the developed model and the operational performance of an actual desalting unit are carried out. The accuracy observed shows that the developed model is a good representation of the actual process. (C) 2010 Published by Elsevier Ltd.

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Bovine bone ash is the main raw material for fabrication of bone china, a special kind of porcelain that has visual and mechanical advantages when compared to usual porcelains. The properties of bone china are highly dependent on the characteristics of the bone ash. However, despite a relatively common product, the science behind formulations and accepted fabrication procedures for bone china is not completely understood and deserves attention for future processing optimizations. In this paper, the influence of the preparation steps (firing, milling, and washing of the bones) on the physicochemical properties of bone ash particles was investigated. Bone powders heat-treated at temperatures varying from 700 to 1000 degrees C were washed and milled. The obtained materials were analyzed in terms of particle size distribution, chemical composition, density, specific surface area, FTIR spectroscopy, dynamic electrophoretic mobility, crystalline phases and scanning electron microscopy. The results indicated that bone ash does not significantly change in terms of chemistry and physical features at calcination temperatures above 700 degrees C. After washing in special conditions, one could only observe hydroxyapatite in the diffraction pattern. By FTIR it was observed that carbonate seems to be mainly concentrated on the surface of the powders. Since this compound can influence in the dispersion stability, and consequently in the quality of the final bone china product, and considering optimal washing parameters based on the dynamic electrophoretic mobility results, we describe a procedure for surface cleaning. (c) 2009 Elsevier Ltd and Techna Group S.r.l. All rights reserved.

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Yellow leaf syndrome was a serious problem in the beginning of the 1990s in Brazil, when yield losses were estimated to be around 50%. The disease is currently endemic, but it is considered potentially important. Previous studies have revealed only the presence of a luteovirus associated with the disease in Brazil. We report that a phytoplasma of 16SrI-B is also associated with this disease. This is the first demonstration of the presence of a group 16SrI-B phytoplasma in association with sugarcane yellow leaf in Brazil.

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Summer squash: a new host of phytoplasm belonging to the 16SrIII group In a commercial field located in the Vale do Ribeira, in the State of Sao Paulo, Brazil, plants of summer squash (Cucurbita pepo L.) exhibiting witches` broom and leaf deformation were observed. PCR assays demonstrated the presence of phytoplasma associated with diseased tissues. A phytoplasma belonging to the 16SrIII group was identified by PCR and RFLP analysis performed with five restriction enzymes. The present note is the first report of the presence of phytoplasma representative of the 16SrIII group in summer squash in Brazil.