95 resultados para Physiological medium
Resumo:
We use multiwavelength data (H I, FUV, NUV, R) to search for evidence of star formation in the intragroup medium of the Hickson Compact Group 100. We find that young star-forming regions are located in the intergalactic H I clouds of the compact group which extend to over 130 kpc away from the main galaxies. A tidal dwarf galaxy (TDG) candidate is located in the densest region of the H I tail, 61 kpc from the brightest group member and its age is estimated to be only 3.3 Myr. Fifteen other intragroup H II regions and TDG candidates are detected in the Galaxy Evolution Explorer (GALEX) FUV image and within a field 10' x 10' encompassing the H I tail. They have ages <200 Myr, H I masses of 10(9.2-10.4) M(circle dot), 0.001
Resumo:
Context. Compact groups of galaxies are entities that have high densities of galaxies and serve as laboratories to study galaxy interactions, intergalactic star formation and galaxy evolution. Aims. The main goal of this study is to search for young objects in the intragroup medium of seven compact groups of galaxies: HCG 2, 7, 22, 23, 92, 100 and NGC 92 as well as to evaluate the stage of interaction of each group. Methods. We used Fabry-Perot velocity fields and rotation curves together with GALEX NUV and FUV images and optical R-band and HI maps. Results. (i) HCG 7 and HCG 23 are in early stages of interaction; (ii) HCG 2 and HCG 22 are mildly interacting; and (iii) HCG 92, HCG 100 and NGC 92 are in late stages of evolution. We find that all three evolved groups contain populations of young blue objects in the intragroup medium, consistent with ages < 100 Myr, of which several are younger than < 10 Myr. We also report the discovery of a tidal dwarf galaxy candidate in the tail of NGC 92. These three groups, besides containing galaxies that have peculiar velocity fields, also show extended HI tails. Conclusions. Our results indicate that the advanced stage of evolution of a group, together with the presence of intragroup HI clouds, may lead to star formation in the intragroup medium. A table containing all intergalactic HII regions and tidal dwarf galaxies confirmed to date is appended.
Resumo:
This work aimed to evaluate cardiac morphology/function and histological changes induced by bone marrow cells (BMCs) and cultured mesenchymal stem cells (MSCs) injected at the myocardium of spontaneously hypertensive rats (SHR) submitted to surgical coronary occlusion. Female syngeneic adult SHR, submitted (MI) or not (C) to coronary occlusion, were treated 24 h later with in situ injections of normal medium (NM), or with MSCs (MSC) or BMCs (BM) from male rats. The animals were evaluated after 1 and 30 days by echocardiography, histology of heart sections and PCR for the Y chromosome. Improved ejection fraction and reduced left ventricle infarcted area were observed in MSC rats as compared to the other experimental groups. Treated groups had significantly reduced lesion tissue score, increased capillary density and normal (not-atrophied) myocytes, as compared to NM and C groups. The survival rate was higher in C, NM and MSC groups as compared to MI and BM groups. In situ injection of both MSCs and BMCs resulted in improved cardiac morphology, in a more physiological model of myocardial infarction represented by surgical coronary occlusion of spontaneously hypertensive rats. Only treatment with MSCs, however, ameliorated left ventricle dysfunction, suggesting a positive role of these cells in heart remodeling in infarcted hypertensive subjects.
Resumo:
We have numerically solved the Heisenberg-Langevin equations describing the propagation of quantized fields through an optically thick sample of atoms. Two orthogonal polarization components are considered for the field, and the complete Zeeman sublevel structure of the atomic transition is taken into account. Quantum fluctuations of atomic operators are included through appropriate Langevin forces. We have considered an incident field in a linearly polarized coherent state (driving field) and vacuum in the perpendicular polarization and calculated the noise spectra of the amplitude and phase quadratures of the output field for two orthogonal polarizations. We analyze different configurations depending on the total angular momentum of the ground and excited atomic states. We examine the generation of squeezing for the driving-field polarization component and vacuum squeezing of the orthogonal polarization. Entanglement of orthogonally polarized modes is predicted. Noise spectral features specific to (Zeeman) multilevel configurations are identified.
Resumo:
For Au + Au collisions at 200 GeV, we measure neutral pion production with good statistics for transverse momentum, p(T), up to 20 GeV/c. A fivefold suppression is found, which is essentially constant for 5 < p(T) < 20 GeV/c. Experimental uncertainties are small enough to constrain any model-dependent parametrization for the transport coefficient of the medium, e. g., <(q) over cap > in the parton quenching model. The spectral shape is similar for all collision classes, and the suppression does not saturate in Au + Au collisions.
Resumo:
We study trapping and propagation of a matter-wave soliton through the interface between uniform medium and a nonlinear optical lattice. Different regimes for transmission of a broad and a narrow solitons are investigated. Reflections and transmissions of solitons are predicted as a function of the lattice phase. The existence of a threshold in the amplitude of the nonlinear optical lattice, separating the transmission and reflection regimes, is verified. The localized nonlinear surface state, corresponding to the soliton trapped by the interface, is found. Variational approach predictions are confirmed by numerical simulations for the original Gross-Pitaevskii equation with nonlinear periodic potentials.
Resumo:
A simple method was developed for spectrophotometric determination of some nonsteroidal anti-inflammatory drugs (meloxicam, piroxicam and tenoxicam) based on the reduction of copper(II) in buffered solution (pH 7.0) and micellar medium containing 4,4'-dicarboxy-2,2'-buffered solution (pH 7.0) and micellar medium containing 4,4'-dicarboxy-2,2'-biquinoline acid. The-biquinoline acid. The absorbance values at 558 nm, characteristic of the formed Cu(I)/4,4'-dicarboxy-2,2'-biquinoline complexes, are linear with the concentrations (5.7-40 mmol L(-1), n = 5) of these oxicams (meloxicam r = 0.998; piroxicam and tenoxicam r = 0.999). The limit of detection values, in mmol L(-1), calculated for meloxicam (2.7), piroxicam (1.2) and tenoxicam (1.3) was obtained with 99% confidence level and the relative standard deviations for meloxicam (3.1%), piroxicam (5.1%) and tenoxicam (1.2%) were calculated using a 25 mmol L(-1) solution (n = 7). Mean recovery values for meloxicam, piroxicam and tenoxicam forms were 100 +/- 6.9, 98.6 +/- 3.6 and 99.4 +/- 2.5%, respectively. The conditional potential of Cu(II)/Cu(I) in complex medium of 7.5 mmol L(-1) BCA was determined to be 629 +/- 11 mV vs. NHE.
Resumo:
Many different species of Bromeliaceae are endangered and their conservation requires specific knowledge of their growth habits and propagation. In vitro culture of bromeliads is an important method for efficient clonal propagation and ill vitro seed g,germination can be used to maintain genetic variability. The present work aims to evaluate the in vitro growth and nutrient concentration in leaves of the epiphyte bromeliads Vriesea friburguensis Mez, Vriesea hieroglyphica (Carriere) E. Morren, and Vriesea unilateralis Mez, which exhibit slow rates of growth in vivo and in vitro. Initially, we compared the endogenous mineral composition of bromeliad plantlets grown in half-strength Murashige and Skoog (MS) medium and the mineral composition considered adequate in the literature. This approach suggested that calcium (Ca) is a critical nutrient and this was considered for new media formulation. Three new culture media were defined in which the main changes to half-strength MS medium were an increase in Ca, magnesium, sulfur, copper, and chloride and a decrease in iron, maintaining the nitrate: ammonium rate at approximate to 2:1. The main difference among the three new media formulated was Ca concentration, which varied from 1.5 mm in half-strength MS to 3.0, 6.0, and 12 mm in M2, M3, and M4 media, respectively. Consistently, all three species exhibited significantly higher fresh and dry weight on M4, the newly defined medium with the highest level of Ca (12 mm). Leaf nitrogen, potassium, zinc, magnesium and boron concentrations increased as Ca concentration in the medium increased from 1.5 to 12 mm.
Resumo:
We study the evolution of dense clumps and provide an argument that the existence of the clumps is not limited by their crossing times. We claim that the lifetimes of the clumps are determined by turbulent motions on a larger scale, and we predict the correlation of clump lifetime with column density. We use numerical simulations to successfully test this relation. In addition, we study the morphological asymmetry and the magnetization of the clumps as functions of their masses.
Resumo:
Aim. The purpose of present study was to compare the acute physiological responses to a circuit weight training with the responses to a combined circuit training (weight training and treadmill run). Methods. The sample consisted of 25 individuals at an average state of training, 10 men and 15 female, between 18 and 35 year old. There were selected 60 second sets of resistance exercises to the circuit weight training (CWT). Whereas in the combined circuit training (CCT), the subjects spent 30 seconds on the same resistance exercises and 30 seconds running on the treadmill. The rest intervals between the sets lasted 15 seconds. The analysis of variance (ANOVA) with 5% significance level was utilized to the statistical analysis of the results. Results. Comparing circuit training protocols, it was noted that CCT elicits a higher relative and absolute <(V)over dot>O(2) and energy expenditure values than CWT for both genders (P<0.05). Regarding inter-gender comparison, males showed higher absolute and relative <(V)over dot>O(2) and absolute energy expenditure values for both CWT and CCT than females (P<0.05). Females showed a significant greater % <(V)over dot>O(2max) value for both CWT and CCT. Due to the experimental conditions used to state both circuit training bouts (CWT and CCT), the <(V)over dot>O(2) rate found was higher than the values reported by previous studies which used heavier weight lift. Conclusion. CCT seems adequate to produce cardiovascular improvements and greater energy expenditure for both men and women, while CWT group classes are sufficient only for unfit women.
Resumo:
The physiological and perceptual demands together with match notation of a four-set tennis match were studied in two elite professional players during the preparation for the 2008 Davis Cup. The design of this case report is unique in that it is the first to describe the demands of prolonged match-play (197 min) over four sets in ecologically valid conditions. The variables measured before and after each set included blood lactate and glucose concentrations, body mass, and perception of effort. Stroke count for each rally and heart rate were recorded during each set while salivary cortisol concentration was determined before and after the match. The rally length decreased as the match progressed. The results showed significant physiological stress, with each player losing greater than 2.5% of body mass (as fluid) and having elevated salivary cortisol concentrations after the match. Heart rate and perception of effort were also increased following each set indicating increasing stress. However, blood lactate decreased following the fourth set while blood glucose was maintained. The results also suggest that elite players may adjust work rates or tactics to cope with the increased perception of effort. This report shows that four sets of tennis are associated with increasing stress and fatigue.
Resumo:
Background: The involvement of nephrotoxic agents in acute renal failure (ARF) has increased over the last few decades. Among the drugs associated with nephrotoxic ARF are the radiologic contrast media whose nephrotoxic effects have grown, following the increasing diagnostic use of these agents. Methods: We evaluated the effect of iodinated contrast (IC) medium, administered in combination, or not, with hyperhydration or N-acetylcysteine (NAC), on creatinine clearance, production of urinary peroxides and renal histology of rats. Adult Wistar rats treated for 5 days were divided into the following groups: control (saline, 3 ml/kg/day, intraperitoneally [i.p.]), IC (sodium iothalamate meglumine, 3 ml/kg/day i.p.), IC + water (12 mL water, orally + IC, 3 ml/kg/day i.p. after 1 hour), IC + NAC (NAC, 150 mg/kg/day, orally + IC, 3 ml/kg/day i.p. after 1 hour) and IC + water + NAC. Results: IC medium reduced renal function, with maintenance of urinary flow. Hyperhydration did not reduce the nephrotoxic effect of the IC agent, which was observed in the group IC + NAC. The combination of hyperhydration and NAC had no superior protective effect compared with NAC alone. An increase in urinary peroxides was observed in the IC group, with NAC or water or the combination of both reducing this parameter. Histopathologic analysis revealed no significant alterations. Conclusions: In summary, given 5 days previously, NAC was found to be more effective than hyperhydration alone in the prevention of contrast-induced acute renal failure.
Resumo:
Matsushigue, KA, Hartmann, K, and Franchini, E. Taekwondo: Physiological responses and match analysis. J Strength Cond Res 23(4): 1112-1117, 2009-The aim of the present study was to determine the time structure and physiological responses during Songahm Taekwondo (TKD) competition and to compare these variables between winner and non-winner athletes. Fourteen men subjects were analyzed. Blood lactate concentration (LA) and heart rate (HR) were determined before and after the match. The match was filmed for the determination of the number of techniques used, the duration of effort and rest periods (RPs), and the interval between high-intensity movements (HM). Post-match LA was 7.5 +/- 3.8 mmol.L(-1), HR was 183 +/- 9 b.min(-1), and HM was 31 +/- 16 seconds. The mean effort time (862 seconds) did not differ from mean interval time (8 +/- 3 seconds). Winners used a smaller total number of techniques, but post-match LA or HR did not differ from that of non-winners. In conclusion, the glycolytic metabolism was not the predominant energy source and the physiological responses did not differ between winners and non-winners. Coaches and sports scientists should prepare a technical or physical training session considering the low glycolytic contribution in this sport, hence the training protocol should involve high-intensity movements interspersed with longer RPs to provide the creatine phosphate recovery, with special attention given to the technical quality of TKD skills and not to higher technique volume during a simulation of matches.
Resumo:
Artioli, GG, Gualano, B, Franchini, E, Batista, RN, Polacow, VO, and Lancha, AH Jr. Physiological, performance, and nutritional profile of the Brazilian Olympic Wushu (kung-fu) team. J Strength Cond Res 23(1): 20-25, 2009-The purpose of the present study was to determine physiological, nutritional, and performance profiles of elite Olympic Wushu (kung-fu) athletes. Ten men and four women elite athletes took part in the study. They completed the following tests: body composition, nutritional assessment, upper-body Wingate Test, vertical jump, lumbar isometric strength, and flexibility. Blood lactate was determined at rest and after the Wingate Test. Blood lactate was also determined during a training session (combat and Taolu training). We found low body fat (men: 9.5 +/- 6.3%; women: 18.0 +/- 4.8%), high flexibility (sit-and-reach-men: 45.5 +/- 6.1 cm; women: 44.0 +/- 6.3 cm), high leg power (vertical jump-men: 37.7 +/- 8.4 cm; women: 32.3 +/- 1.1 cm), high lumbar isometric strength (men: 159 6 13 cm; women: 94 6 6 cm), moderate arm mean and peak power (Wingate Test-men: 4.1 +/- 0.4 and 5.8 +/- 0.5 W.kg(-1), respectively; women: 2.5 +/- 0.3 and 3.4 +/- 0.3 W.kg(-1), respectively), and elevated blood lactate after the Wingate Test (men: 10.8 +/- 2.0 mmol.L(-1); women: 10.2 +/- 2.0 mmol.L(-1)) and during training (combat: 12.0 +/- 1.8 mmol.L(-1); Taolu: 7.7 +/- 3.3 mmol.L(-1)). Men athletes consume a high-fat, low-carbohydrate diet, whereas women consume a moderate, high-carbohydrate diet. Energy consumption was markedly variable. In conclusion, Olympic Wushu seems to be a highly anaerobic-dependent combat sport. Low body fat, high flexibility, leg anaerobic power, isometric strength, and moderately high arm anaerobic power seem to be important for successful competitive performance.
Resumo:
Okuno, NM, Perandini, LAB, Bishop, D, Simoes, HG, Pereira, G, Berthoin, S, Kokubun, E, and Nakamura, FY. Physiological and perceived exertion responses at intermittent critical power and intermittent maximal lactate steady state. J Strength Cond Res 25(7): 2053-2058, 2011-The aim of this study was to compare the power outputs of the intermittent critical power (CPi) with the intermittent maximal lactate steady state (MLSSi) and to compare the physiological and perceptual responses exercising at CPi and MLSSi. Ten subjects performed intermittent trials on a cycle ergometer to determine CPi and MLSSi using 30: 30 seconds of effort and pause. The oxygen uptake ((V) over dotO(2)), heart rate (HR), blood lactate concentration ([Lac]), and rating of perceived exertion (RPE) responses were compared during 30-minute cycling at CPi and MLSSi. The CPi (267 6 45 W) was similar to MLSSi (254 6 39 W), and they were correlated (r = 0.88; p<0.05). The (V) over dotO(2) and HR responses stabilized throughout exercising at CPi (2.52 +/- 0.52 L.min(-1); 156 +/- 8 b.min(-1)) and MLSSi (2.41 +/- 0.32 L.min(-1); 152 +/- 10 b.min(-1)). These physiological variables were similar between conditions. However, the [Lac] and RPE were higher from the middle to the end of exercise duration at CPi ([Lac] = 6.9 +/- 2.6 mM; RPE = 17.1 +/- 2.1 a.u.) compared to MLSSi ([Lac] = 5.1 +/- 0.9 mM; RPE = 15.7 +/- 1.8 a.u.). Therefore, CPi intensity determined from 30: 30 seconds of effort and rest periods on a cycle ergometer is equivalent to the MLSSi, and there is a physiological steady state throughout both exercise intensities, although the [Lac] and RPE responses at CPi are higher than at MLSSi. Thus, the CPi and MLSSi may be used as tools for intermittent training evaluation and prescription.