887 resultados para Gondwana sources
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The Enriquillo and Azuei are saltwater lakes located in a closed water basin in the southwestern region of the island of La Hispaniola, these have been experiencing dramatic changes in total lake-surface area coverage during the period 1980-2012. The size of Lake Enriquillo presented a surface area of approximately 276 km2 in 1984, gradually decreasing to 172 km2 in 1996. The surface area of the lake reached its lowest point in the satellite observation record in 2004, at 165 km2. Then the recent growth of the lake began reaching its 1984 size by 2006. Based on surface area measurement for June and July 2013, Lake Enriquillo has a surface area of ~358 km2. Sumatra sizes at both ends of the record are 116 km2 in 1984 and 134 km2in 2013, an overall 15.8% increase in 30 years. Determining the causes of lake surface area changes is of extreme importance due to its environmental, social, and economic impacts. The overall goal of this study is to quantify the changing water balance in these lakes and their catchment area using satellite and ground observations and a regional atmospheric-hydrologic modeling approach. Data analyses of environmental variables in the region reflect a hydrological unbalance of the lakes due to changing regional hydro-climatic conditions. Historical data show precipitation, land surface temperature and humidity, and sea surface temperature (SST), increasing over region during the past decades. Salinity levels have also been decreasing by more than 30% from previously reported baseline levels. Here we present a summary of the historical data obtained, new sensors deployed in the sourrounding sierras and the lakes, and the integrated modeling exercises. As well as the challenges of gathering, storing, sharing, and analyzing this large volumen of data in a remote location from such a diverse number of sources.
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Based on the Heckscher-Ohlin-Vanek model, this paper investigates relative factor abundance in Brazil, as revealed by its international trade. We study two different time periods: one characterized by high trade barriers (1980 to 1985) and the trade liberalization period (1990 to 1995). Two alternative methodologies are used: the estimation of factor intensity regressions on net exports and the direct computation of factor content in net exports. In the factor intensity regression, we incorporate technological changes that might have occurred over time, and those turned out to be significant. Both methods yield the same results: the Brazilian international trade reveals relative abundance in capital, land and unskilled labor, and scarcity in skilled labor, with qualitatively equivalent results for the two time periods studied.
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This paper presents a poverty profile for Brazil, based on three different sources of household data for 1996. We use PPV consumption data to estimate poverty and indigence lines. “Contagem” data is used to allow for an unprecedented refinement of the country’s poverty map. Poverty measures and shares are also presented for a wide range of population subgroups, based on the PNAD 1996, with new adjustments for imputed rents and spatial differences in cost of living. Robustness of the profile is verified with respect to different poverty lines, spatial price deflators, and equivalence scales. Overall poverty incidence ranges from 23% with respect to an indigence line to 45% with respect to a more generous poverty line. More importantly, however, poverty is found to vary significantly across regions and city sizes, with rural areas, small and medium towns and the metropolitan peripheries of the North and Northeast regions being poorest.
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This paper studies the joint determination of the wage payments period between firms and employees. The aggregate timeseries analysis reaches two conclusions: a) the average payments period keep an equilibrium relationship with the previous inflation peak, this indicates some degree of irreversibility of payments practices. b) the low previous inflation peak .;:;_asticity of ave r age payments periods reveal.s a high degree of rigidity of payments practices.The framework developed in the paper incorporates the fol.l.owing sources of payments practices rigidity: a)interactions between optimal. payments period decisions and optimal. number of trips to the bank. b)the occurrence of Pare to inneficiencies in the bargaining process between firms and empl.oyees due to wage regulation. c) integer restrictions on payments frequencies produced by upper bounds on the payments period. The empirical. part of the paper assesses the rel.evance of these different sources of payments practices rigidity using Brazil.ian micro data.
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Although the existence of spinoff equity gains is well documented, their source remains controversial. Arnong many potential causes, the literature suggests that spinoff equity gains could arise from expected tax benefits, expected takeover premia, operating performance improvement or from refocusing benefits. This paper investigates the link between spinoff announcement and post completion equity gains and post spinoff operating performance changes, takeover activity and refocusing benefits. The results indicate that spinoff announcement retums reflect anticipated takeover premiums as well as expected operating performance gains and refocusing benefits unrelated to operating performance. However, only the parent's operating performance gains are anticipated at the spinoff announcement. We find that post spinoff equity gains are driven mostly by operating performance changes for both parents and spun off subsidiaries. Takeover activity and unrelatedness of business lines between parent and subsidiary expIain littIe of post spinoff equity gains. OveralI, the data suggests that spinoffs equity gains mostly reflect anticipated real economic gains in terms of improved operating performance, and to a lesser extent takeover premium and refocusing benefit.
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Abstract. Interplanetary scintillation observations of 48 of the 55 Augusto et al. (1998) flat spectrum radio sources were carried out at 111 MHz using the interplanetary scintillation method on the Large Phased Array (LPA) in Russia. Due to the large size of the LPA beam (1◦ × 0.5◦) a careful inspection of all possible confusion sources was made using extant large radio surveys: 37 of the 48 sources are not confused. We were able to estimate the scintillating flux densities of 13 sources, getting upper limits for the remaining 35. Gathering more or improving extant VLBI data on these sources might significantly improve our results. This proof-of-concept project tells us that compact (<1 ) flat spectrum radio sources show strong enough scintillations at 111 MHz to establish/constrain their spectra (low-frequency end). Key words. galaxies: general – galaxies: active – galaxies: quasars: general
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The present study examines the effect of four semi-purified diets (casein-gelatin based) where the source of fatty acids was free (esterified) oleic acid and linoleic acid (LA) (LOA diet), linseed and olive oil (predominantly LA and linolenic acid) (LO diet), cod liver oil (rich in highly unsaturated fatty acids) (CLO diet), and soybean lecithin (phospholipids; mostly LA) (LE diet) on the growth of juvenile South American catfish (surubim, Pseudoplatystoma fasciatum, Pimelodidae) (0.98 +/- 0.04 g individual weight). Fish were fed at a restricted-readjusted feeding rate for 8 wk. At the end of the experiment, LE-diet-fed fish grew significantly larger than those of the other three groups (P < 0.05). Considerable cannibalism was observed in all the treatments. It is suggested that the quantitative growth performance may possibly change under other conditions, with less or no cannibalism. Survival did not differ significantly among the fish fed four different diets. Muscle and liver lipid contents did not vary among dietary treatments (P > 0.05), but whole-body lipid concentrations were affected by dietary treatments. Fish fed LE diet contained significantly lower lipid level than those fed three other diets (P < 0.05). Muscle and liver fatty acid profiles reflected dietary fatty acid composition. Arachidonic acid level was significantly higher in muscle and liver of fish fed LOA and LE diets than in those fed LO and CLO diets. The results suggest that the efficiency of elongation and desaturation of 18C fatty acids depends on the dietary lipid source, and South American catfish has considerable capacity to transform linoleate to arachidonate.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)