899 resultados para Economies of density
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The adverse effects on Latin America and the Caribbean of the global economic and financial crisis, the worst since the 1930s, have been considerably less than was once feared. Although a run of growth was cut short in 2009 and regional output shrank by 1.9%, the impact of the crisis was limited by the application of countercyclical fiscal and monetary policies by many of the region’s governments. The recovery in the economies, particularly in South America, has gone hand-in-hand with the rapid resurgence of the emerging economies of Asia, with all the favourable consequences this has had for global trade. A similar pattern may be observed regarding the impact of the crisis on labour markets in Latin America and the Caribbean. Although millions of people lost their jobs or had to trade down to lower-quality work, levels of employment (including formal employment) fell by less than originally foreseen. At the same time, real wages rose slightly in a context of falling inflation. The labour market thus stabilized domestic demand, and this contributed to the recovery that began in many countries in late 2009. Improved international trade and financing conditions, and the pick-up in domestic demand driven by macroeconomic policies, have led different commentators to estimate growth in the region’s economy at some 6% in 2010. As detailed in the first part of this edition of the Bulletin, the upturn has been manifested at the regional level by the creation of formal employment, a rise in the employment rate, a decline in joblessness and a moderate increase in real wages. Specifically, it is estimatedthat the regional unemployment rate will have dropped by 0.6 percentage points, from 8.1% in 2009 to 7.5% in 2010. The performance of different countries and subregions has been very uneven, however. On the one hand, there is Brazil, where high economic growth has been accompanied by vigorous creation of formal jobs and the unemployment rate has dropped to levels not seen in a long time. Other countries in South America have benefited from strong demand for natural resources from the Asian countries. Combined with higher domestic demand, this has raised their economic growth rates and had a positive impact on employment indicators. On the other hand, the recovery is still very weak in certain countries and subregions, particularly in the Caribbean, with employment indicators continuing to worsen.Thus, the recovery in the region’s economy in 2010 may be characterized as dynamic but uneven. Growth estimates for 2011 are less favourable. The risks associated with the imbalances in the world economy and the withdrawal of countercyclical fiscal packages are likely to cause the region to grow more slowly in 2011. Accordingly, a small further reduction of between 0.2 and 0.4 percentage points in the unemployment rate is projected for 2011. However, these indicators of recovery do not guarantee growth with decent work in the long term. To bolster the improvement in labour market indicators and generate more productive employment and decent work, the region’s countries need to strengthen their macroeconomic policies, improve regional and global policy coordination, identify and remove bottlenecks in the labour market itself and enhance instruments designed to promote greater equality. Like the rest of the world, the Latin American and Caribbean region is also confronted with the challenge of transforming the way it produces so that its economies can develop along tracks that are sustainable in the long term. Climate change and the consequent challenge of developing and strengthening low-carbon production and consumption patterns will also affect the way people work. A great challenge ahead is to create green jobs that combine decent work with environmentally sustainable production patterns. From this perspective, the second part of this Bulletin discusses the green jobs approach, offering some information on the challenges and opportunities involved in moving towards a sustainable economy in the region and presenting a set of options for addressing environmental issues and the repercussions of climate change in the world of work. Although the debate about the green jobs concept is fairly new in the region, examples already exist and a number of countries have moved ahead with the application of policies and programmes in this area. Costa Rica has formulated a National Climate Change Strategy, for example, whose foremost achievements include professional training in natural-resource management. In Brazil, fuel production from biomass has increased and social housing with solar panelling is being built. A number of other countries in the region are making progress in areas such as ecotourism, sustainable agriculture and infrastructure for climate change adaptation, and in formalizing the work of people who recycle household waste. The shift towards a more environmentally sustainable economy may cause jobs to be destroyed in some economic sectors and created in others. The working world will inevitably undergo major changes. If the issue is approached by way of social dialogue and appropriate public policies, there is a chance to use this shift to create more decent jobs, thereby contributing to growth in the economy, the construction of higher levels of equality and protection for the environment.
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This issue of the Economic and Social Panorama of the Community of Latin American and Caribbean States is a contribution by the Economic Commission for Latin America and the Caribbean (ECLAC) to the third Summit of Heads of State and Government of the Community of Latin American and Caribbean States (CELAC), to be held in San José in January 2015. This document is based on excerpts from some of the annual flagships published by the Commission in 2014: Statistical Yearbook for Latin America and the Caribbean 2013 (LC/G.2582-P); Demographic Observatory 2013 (LC/G.2615-P); Economic Survey of Latin America and the Caribbean 2014 (LC/G.2619-P); Preliminary Overview of the Economies of Latin America and the Caribbean 2014 (LC/G.2632-P); Foreign Direct Investment in Latin America and the Caribbean 2013 (LC/G.2615-P); Latin America and the Caribbean in the World Economy 2014 (LG/G.2625-P) “Social Panorama Social of Latin America 2014. Briefing Paper”; as well as the Gender Equality Observatory of Latin America and the Caribbean. Annual Report 2013-2014 (LC/G.2626).
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This paper outlines the results of a study into the biological aspects of Aphis gossypii Glöver on colored cotton cultivars through the construction of life tables. In addition, we evaluate the influence of density of gossypol glands and trichomes of leaves on the biology of the aphid. Tests were conducted in a climate chamber at 25 ± 2°C, with relative humidity (RH) at 70 ± 10%, and a photophase of 12 hours, using the cultivars BRS Rubi, BRS Safira, and BRS Verde. Newly hatched nymphs were individually isolated in petri dishes containing leaf discs of cotton cultivars on a layer of water-agar (1%) of approximately 5 mm thick. An evaluation of the trichomes and gossypol gland densities of the cotton leaf plants was performed under a stereomicroscope, delimited to an area of 1 cm², and a count and identification of those on the surface was made. The feed substrates that were evaluated influenced the nymphal stage of A. gossypii. BRS Verde provided the shortest duration and BRS Safira was the longest during this phase. The cultivar BRS Verde, with the lowest density of trichomes, provided a large number of nymphs and led to a higher net reproductive rate (R0). Given these results, conclusions can be drawn that the colored cotton cultivars influence the duration of nymphal and adult stages of A. gossypii. The cultivar with a high density of trichomes on leaves (BRS Safira) adversely affects the fertility parameters of A. gossypii.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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For every possible spectrum of 2(N)-dimensional density operators, we construct an N-qubit X-state of the same spectrum and maximal genuine multipartite (GM-) concurrence, hence characterizing a global unitary transformation that -constrained to output X-states-maximizes the GM-concurrence of an arbitrary input mixed state of N qubits. We also apply semidefinite programming methods to obtain N-qubit X-states with maximal GM-concurrence for a given purity and to provide an alternative proof of optimality of a recently proposed set of density matrices for the purpose, the so-called X-MEMS. Furthermore, we introduce a numerical strategy to tailor a quantum operation that converts between any two given density matrices using a relatively small number of Kraus operators. We apply our strategy to design short operator-sum representations for the transformation between any given N-qubit mixed state and a corresponding X-MEMS of the same purity.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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1. Distance sampling is a widely used technique for estimating the size or density of biological populations. Many distance sampling designs and most analyses use the software Distance. 2. We briefly review distance sampling and its assumptions, outline the history, structure and capabilities of Distance, and provide hints on its use. 3. Good survey design is a crucial prerequisite for obtaining reliable results. Distance has a survey design engine, with a built-in geographic information system, that allows properties of different proposed designs to be examined via simulation, and survey plans to be generated. 4. A first step in analysis of distance sampling data is modeling the probability of detection. Distance contains three increasingly sophisticated analysis engines for this: conventional distance sampling, which models detection probability as a function of distance from the transect and assumes all objects at zero distance are detected; multiple-covariate distance sampling, which allows covariates in addition to distance; and mark–recapture distance sampling, which relaxes the assumption of certain detection at zero distance. 5. All three engines allow estimation of density or abundance, stratified if required, with associated measures of precision calculated either analytically or via the bootstrap. 6. Advanced analysis topics covered include the use of multipliers to allow analysis of indirect surveys (such as dung or nest surveys), the density surface modeling analysis engine for spatial and habitat-modeling, and information about accessing the analysis engines directly from other software. 7. Synthesis and applications. Distance sampling is a key method for producing abundance and density estimates in challenging field conditions. The theory underlying the methods continues to expand to cope with realistic estimation situations. In step with theoretical developments, state-of- the-art software that implements these methods is described that makes the methods accessible to practicing ecologists.
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The reproductive biology and population dynamics of the cirolanid isopod Excirolana armata (Dana, 1853) were analysed through monthly samples from December 2003 to November 2005 on Una beach, Sao Paulo state (24 degrees S), in Southeastern Brazil. Sampling was performed along three transects established from the base of foredunes to the waterline. On Una beach, E. armata showed continuous reproduction with higher abundances of ovigerous females in winter and spring (July-November) with a higher peak of juveniles in spring (November 2004). The fecundity ranged from 2 to 18 eggs/embryos per female, depending on the female length. The incubation period was estimated as 2 months. The life span of males and females was nearly 1 year. The short life span and the high energetic expenditure inherent to reproduction with maternal care, probably kept females from producing more than one brood in their lifetime. When comparing the population of E. armata on Una beach (24 degrees S) with populations in Southern Brazil (32 degrees S), Uruguay (34 degrees S) and Argentina (36 degrees S), it was verified that several biological population traits (length of the smallest juvenile, length of the largest individual, length of the smallest and largest ovigerous females, range of fecundity and life span) tended to increase at higher latitudes, whereas other traits (instantaneous rate of mortality and the curvature parameter of von Bertalanffy growth function) tended to decrease. However, comparing E. armata on Una beach (24 degrees S) with a population situated at a close latitude (25 degrees S), unexpected differences in relation to population structure and to growth demonstrated and reinforced the importance of density-dependent factors over life history traits of E. armata on dissipative beaches.
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The aim of the present study was to evaluate the influence of seasonality on the behavior of phytoplankton associations in eutrophic reservoirs with different depths in northeastern Brazil. Five collections were carried out at each of the reservoirs at two depths (0.1 m and near the sediment) at three-month intervals in each season (dry and rainy). The phytoplankton samples were preserved in Lugol's solution and quantified under an inverted microscope for the determination of density values, which were subsequently converted to biomass values based on cellular biovolume and classified in phytoplankton associations. The following abiotic variables were analyzed: water temperature, dissolved oxygen, pH, turbidity, water transparency, total phosphorus, total dissolved phosphorus, orthophosphate and total nitrogen. The data were investigated using canonical correspondence analysis. The influence of seasonality on the dynamics of the phytoplankton community was lesser in the deeper reservoirs. Depth affected the behavior of the algal associations. Variation in light availability was a determinant of changes in the phytoplankton structure. Urosolenia and Anabaena associations were more abundant in shallow ecosystems with a larger eutrophic zone, whereas the Microcystis association was more related to deep ecosystems with adequate availability of nutrients. The distribution of Cyclotella, Geitlerinema, Planktothrix, Pseudanabaena and Cylindrospermopsis associations was different from that seen in subtropical regions and the substitution of these associations was related to a reduction in the eutrophic zone rather than the mixture zone. Published by Elsevier GmbH.
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Mach number and thermal effects on the mechanisms of sound generation and propagation are investigated in spatially evolving two-dimensional isothermal and non-isothermal mixing layers at Mach number ranging from 0.2 to 0.4 and Reynolds number of 400. A characteristic-based formulation is used to solve by direct numerical simulation the compressible Navier-Stokes equations using high-order schemes. The radiated sound is directly computed in a domain that includes both the near-field aerodynamic source region and the far-field sound propagation. In the isothermal mixing layer, Mach number effects may be identified in the acoustic field through an increase of the directivity associated with the non-compactness of the acoustic sources. Baroclinic instability effects may be recognized in the non-isothermal mixing layer, as the presence of counter-rotating vorticity layers, the resulting acoustic sources being found less efficient. An analysis based on the acoustic analogy shows that the directivity increase with the Mach number can be associated with the emergence of density fluctuations of weak amplitude but very efficient in terms of noise generation at shallow angle. This influence, combined with convection and refraction effects, is found to shape the acoustic wavefront pattern depending on the Mach number.
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The umbilical cord blood (UCB) is an important source of hematopoietic stem cells with great deal of interest in regenerative medicine. The UCB cells have been extensively studied as an alternative to the bone marrow transplants. The challenge is to define specific methods to purify and characterize these cells in different animal species. This study is aimed at morphological characterization of progenitor cells derived from UCB highlighting relevant differences with peripheral blood of adult in dog and cats. Therefore, blood was collected from 18 dogs and 5 cats' umbilical cords from fetus in various developmental stages. The mononuclear cells were separated using the gradient of density Histopaque-1077. Characterization of CD34+ cells was performed by flow cytometric analysis and transmission electron microscopy. Granulocytes (ancestry of the basophiles, eosinophiles, and neutrophiles) and agranulocytes (represented by immature lymphocytes) were identified. We showed for the first time the ultrastructural features of cat UCB cells. Microsc. Res. Tech. 75:766770, 2012. (C) 2011 Wiley Periodicals, Inc.
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The fast and strong social and economic transformations in the economies of many countries has raised the competition for consumers. One of the elements required to adapt to such scenario is knowing customers and their perceptions about products or services, mainly regarding word of mouth recommendations. This study adapts, to the fast food business, a model originally designed to analyze the antecedents of the intent to recommend by clients of formal restaurants. Three constructs were considered: service quality, satisfaction, and social well-being, the latter comprised of positive and negative affections. Six hypotheses were considered, three of which relating to social well-being (that it influences satisfaction, service quality, and the intent to recommend), two relating to service quality (that in influences the intent to recommend and satisfaction), and one relating to the influence of satisfaction on the intent to recommend. None was rejected, indicating adherence and adjustment of the simplication and adaptation of the consolidated model. Through a successful empirical application, the main contribution made by this research is the simplification of a model through its application in a similar context, but with a different scope.
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Graphene has received great attention due to its exceptional properties, which include corners with zero effective mass, extremely large mobilities, this could render it the new template for the next generation of electronic devices. Furthermore it has weak spin orbit interaction because of the low atomic number of carbon atom in turn results in long spin coherence lengths. Therefore, graphene is also a promising material for future applications in spintronic devices - the use of electronic spin degrees of freedom instead of the electron charge. Graphene can be engineered to form a number of different structures. In particular, by appropriately cutting it one can obtain 1-D system -with only a few nanometers in width - known as graphene nanoribbon, which strongly owe their properties to the width of the ribbons and to the atomic structure along the edges. Those GNR-based systems have been shown to have great potential applications specially as connectors for integrated circuits. Impurities and defects might play an important role to the coherence of these systems. In particular, the presence of transition metal atoms can lead to significant spin-flip processes of conduction electrons. Understanding this effect is of utmost importance for spintronics applied design. In this work, we focus on electronic transport properties of armchair graphene nanoribbons with adsorbed transition metal atoms as impurities and taking into account the spin-orbit effect. Our calculations were performed using a combination of density functional theory and non-equilibrium Greens functions. Also, employing a recursive method we consider a large number of impurities randomly distributed along the nanoribbon in order to infer, for different concentrations of defects, the spin-coherence length.
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Máster en Oceanografía