289 research outputs found

    On The Evolution of TFP in Latin America (revised)

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    Due to several policy distortions, including import-substitution industrialization, widespread government intervention and both domestic and international competitive barriers, there has been a general presumption that Latin America has been much less productive than the leading economies in the last decades. In this paper we show, however, that until the late seventies Latin American countries had high productivity levels relative to the United States. It is only after the late seventies that we observe a fast decrease of relative TFP in Latin America. We also show that the inclusion of human capital in the production function makes a crucial di¤erence in the TFP calculations for Latin America.

    The Evolution of International Output Differences (1960-2000): From Factors to Productivity

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    This article presents a group of exercises of level and growth decomposition of output per worker using cross-country data from 1960 to 2000. It is shown that at least until 1975 factors of production (capital and education) were the main source of output dispersion across economies and that productivity variance was considerably smaller than in later years. Only after this date did the prominence of productivity start to show up in the data, as the majority of the literature has found. The growth decomposition exercises showed that the reversal of relative importance of productivity vis-a-vis factors is explained by the very good (bad) performance of productivity of fast- (slow-) growing economies. Although growth in the period, is on average, is mostly due to factor accumulation, its variance is explained by productivity.Cross-Country Income Inequality, Development, Total Factor Productivity, Aggregate Production Function, Growth Decomposition

    An assessment on the use of the debye-hückel equation for the thermodynamic modeling of aqueous systems containing polymers and salts

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    In this work, a study on the role of the long-range term of excess Gibbs energy models in the modeling of aqueous systems containing polymers and salts is presented. Four different approaches on how to account for the presence of polymer in the long-range term were considered, and simulations were conducted considering aqueous solutions of three different salts. The analysis of water activity curves showed that, in all cases, a liquid-phase separation may be introduced by the sole presence of the polymer in the long-range term, regardless of how it is taken into account. The results lead to the conclusion that there is no single exact solution for this problem, and that any kind of approach may introduce inconsistencies.CAPES, CNPq and FAPES

    Short Weak Links with Distinct Chemical Potentials at the Boundary

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    The difference between the chemical potentials for pairs (μ) and quasiparticles (μρ) at the boundaries of a short superconducting weak link, which is usually disregarded, is shown to be important when solving for the behavior of the link using the time-dependent Ginzburg-Landau equation, Selected computational results are presented to illustrate the effects of the improved boundary conditions on the space (time) dependence of μ, μρ, and normal current Jη

    Bromeliaceae species from coastal restinga habitats, Brazilian states of Rio de Janeiro, Espírito Santo, and Bahia.

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    Bromeliaceae is one of the most representative plant families in restinga habitats. We analyzed the speciesrichness and composition of Bromeliaceae in 13 restinga habitats along the Brazilian coast. We found a total of 41species distributed along the restinga habitats studied. The restinga of Praia do Sul, in the state of Rio de Janeiro, hadthe highest number of species (15), whereas the restinga of Abaeté, in the state of Bahia, had the lowest (4). Our dataare suggestive that the Doce River may represent the limit of distribution for some bromeliad species, with some speciesoccurring only south of that river and others occurring only to the north of it. The differences in Bromeliaceae speciescomposition among restinga habitats probably are not only due to differences in local environmental conditions, butalso due to the geographic distribution pattern of each species and to the present degree of disturbance at each restinga

    Accuracy of Hidden Markov Models in Identifying Alterations in Movement Patterns during Biceps-Curl Weight-Lifting Exercise

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    This paper presents a comparison of mathematical and cinematic motion analysis regarding the accuracy of the detection of alterations in the patterns of positional sequence during biceps-curl lifting exercise. Two different methods, one with and one without metric data from the environment, were used to identify the changes. Ten volunteers performed a standing biceps-curl exercise with additional loads. A smartphone recorded their movements in the sagittal plane, providing information on joints and barbell sequential position changes during each lift attempt. An analysis of variance revealed significant differences in joint position (p < 0.05) among executions with three different loads. Hidden Markov models were trained with data from the bi-dimensional coordinates of the joint positional sequence to identify meaningful alteration with load increment. Tests of agreement tests between the results provided by the models with the environmental measurements, as well as those from image coordinates, were performed. The results demonstrated that it is possible to efficiently detect changes in the patterns of positional sequence with and without the necessity of measurement and/or environmental control, reaching an agreement of 86% between each other, and 100% and 86% for each respective method to the results of ANOVA. The method developed in this study illustrates the viability of smartphone camera use for identifying positional adjustments due to the inability to control limbs in an adequate range of motion with increasing load during a lifting task.info:eu-repo/semantics/publishedVersio

    A Rapidly Incremented Tethered-Swimming Maximal Protocol for Cardiorespiratory Assessment of Swimmers

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    Incremental exercise testing is the standard means of assessing cardiorespiratory capacity of endurance athletes. While the maximal rate of oxygen consumption is typically used as the criterion measurement in this regard, two metabolic breakpoints that reflect changes in the dynamics of lactate production/consumption as the work rate is increased are perhaps more relevant for endurance athletes from a functional standpoint. Exercise economy, which represents the rate of oxygen consumption relative to performance of submaximal work, is also an important parameter to measure for endurance-athlete assessment. Ramp incremental tests comprising a gradual but rapid increase in work rate until the limit of exercise tolerance is reached are useful for determining these parameters. This type of test is typically performed on a cycle ergometer or treadmill because there is a need for precision with respect to work-rate incrementation. However, athletes should be tested while performing the mode of exercise required for their sport. Consequently, swimmers are typically assessed during free-swimming incremental tests where such precision is difficult to achieve. We have recently suggested that stationary swimming against a load that is progressively increased (incremental tethered swimming) can serve as a "swim ergometer" by allowing sufficient precision to accommodate a gradual but rapid loading pattern that reveals the aforementioned metabolic breakpoints and exercise economy. However, the degree to which the peak rate of oxygen consumption achieved during such a protocol approximates the maximal rate that is measured during free swimming remains to be determined. In the present article, we explain how this rapidly incremented tethered-swimming protocol can be employed to assess the cardiorespiratory capacity of a swimmer. Specifically, we explain how assessment of a short-distance competitive swimmer using this protocol revealed that his rate of oxygen uptake was 30.3 and 34.8 mL∙min 1∙kg-1BM at his gas-exchange threshold and respiratory compensation point, respectively.info:eu-repo/semantics/publishedVersio
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