939 resultados para Directional imbalance of freight rates
Resumo:
Basic parameters of sedimentation environment are considered: the Western Boundary Deep Current that transports sedimentary material and distributes it on the survey area; the nepheloid layer, its features, and the distribution of concentrations and particulate standing crop in it; distribution of horizontal and vertical fluxes of sedimentary material; and bottom sediments and their absolute masses (accumulation rates). Comparison of vertical fluxes of particulate matter and accumulation rates of sediments showed that contemporary fluxes of sedimentary material to the bottom provided distribution of accumulation rates of sediments within the survey area during Holocene.
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We have conducted an integrated paleomagnetic and biostratigraphic study on the Cenozoic sedimentary sequences of the southern Iberia Abyssal Plain margin, focusing on Ocean Drilling Program (ODP) Sites 897, 898, 900, 1067, 1068, and 1069. Reliable magnetostratigraphy from these six sites is presented in this paper. Sedimentary sections from Holes 897C, 898A, 900A, 1067A, 1068A, and 1069A have recorded a pattern of magnetic polarity reversals that correlates well with the known magnetic polarity timescale for the past 56 m.y. The polarity patterns from the Pliocene-Pleistocene turbidite sequence at the Leg 149 sites show that a reliable magnetostratigraphy can be established from the early Pliocene to Holocene, including the Gilbert/Gauss boundary (3.58 m.y.) through the Matuyama/Brunhes boundary (0.78 m.y.). On the basis of distinct intervals of magnetic reversal zones and biostratigraphic datums, five magnetozones (C21n-C25n) can be recognized at the three Leg 173 sites that range from middle Eocene to late Paleocene in age. The magnetostratigraphy of the Iberia sections allows the determination of sedimentation rates and better constraints on the timing of deformation. Combining the age and average inclination information available from the magnetostratigraphy, we also present paleolatitudes vs. time for the Iberia drill sites.
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Seaweeds are key species of the Baltic Sea benthic ecosystems. They are the substratum of numerous fouling epibionts like bryozoans and tubeworms. Several of these epibionts bear calcified structures and could be impacted by the high pCO2 events of the late summer upwellings in the Baltic nearshores. Those events are expected to increase in strength and duration with global change and ocean acidification. If calcifying epibionts are impacted by transient acidification as driven by upwelling events, their increasing prevalence could cause a shift of the fouling communities toward fleshy species. The aim of the present study was to test the sensitivity of selected seaweed macrofoulers to transient elevation of pCO2 in their natural microenvironment, i.e. the boundary layer covering the thallus surface of brown seaweeds. Fragments of the macroalga Fucus serratus bearing an epibiotic community composed of the calcifiers Spirorbis spirorbis (Annelida) and Electra pilosa (Bryozoa) and the non-calcifier Alcyonidium hirsutum (Bryozoa) were maintained for 30 days under three pCO2 conditions: natural 460±59 µatm, present-day upwelling1193±166 µatm and future upwelling 3150±446 µatm. Only the highest pCO2 caused a significant reduction of growth rates and settlement of S. spirorbis individuals. Additionally, S. spirorbis settled juveniles exhibited enhanced calcification of 40% during daylight hours compared to dark hours, possibly reflecting a day-night alternation of an acidification-modulating effect by algal photosynthesis as opposed to an acidification-enhancing effect of algal respiration. E. pilosa colonies showed significantly increased growth rates at intermediate pCO2 (1193 µatm) but no response to higher pCO2. No effect of acidification on A. hirsutum colonies growth rates was observed. The results suggest a remarkable resistance of the algal macro-epibionts to levels of acidification occurring at present day upwellings in the Baltic. Only extreme future upwelling conditions impacted the tubeworm S. spirorbis, but not the bryozoans.
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Turbulence profile measurements made on the upper continental slope and shelf of the southeastern Weddell Sea reveal striking contrasts in dissipation and mixing rates between the two sites. The mean profiles of dissipation rates from the upper slope are 1-2 orders of magnitude greater than the profiles collected over the shelf in the entire water column. The difference increases toward the bottom where the dissipation rate of turbulent kinetic energy and the vertical eddy diffusivity on the slope exceed 10?7 W kg?1 and 10?2 m2 s?1, respectively. Elevated levels of turbulence on the slope are concentrated within a 100 m thick bottom layer, which is absent on the shelf. The upper slope is characterized by near-critical slopes and is in close proximity to the critical latitude for semidiurnal internal tides. Our observations suggest that the upper continental slope of the southern Weddell Sea is a generation site of semidiurnal internal tide, which is trapped along the slope along the critical latitude, and dissipates its energy in a inline image m thick layer near the bottom and within inline image km across the slope.
Resumo:
As the success of East Asian countries has shown, labor-intensive industry is recognized to lead economic growth in the early stages of development, utilizing relatively low labor costs. This same growth process has already started in South and South East Asian LDCs since the mid-1990s. However, the manufacturing sector in sub-Saharan Africa has been underdeveloped and manufacturing exports, in particular labour-intensive goods, have stagnated. This paper investigates the international competitiveness of the African manufacturing sector and its determinants through an analytical survey of empirical studies and a comparison with Asian low income countries. Empirical evidences indicate that primary factors of competitiveness, namely productivity, labour cost and exchange rate are unfavorable in sub-Saharan Africa. Representative arguments attribute the weak competitiveness to problems in the business environment, factor endowment, and the exchange rate. However, careful review shows that labour cost is beyond the range explained by endowment and misalignment of exchange rates have been reduced in Africa. Moreover, comparison with Asian low income countries which have competitiveness in labour-intensive goods shows no difference in the quality of business environment, while the labour cost is significantly lower than sub-Saharan African countries. Although results should be considered tentative, high labour cost beyond endowment and conservative investment behavior emerge as important factors for the weak competitiveness in sub-Saharan Africa when controlling income level.
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This paper reviews the relationship between public sector investment and private sector investment through government expenditures financed by government bonds in the Japanese economy. This study hypothesizes that deficit financing by bond issues does not crowd out private sector investment, and this finance method may crowd in. Thus the government increases bond issues and sells them in the domestic and international financial markets. This method does not affect interest rates because they are insensitive to government expenditures and they depend on interest rates levels in the international financial market more than in the domestic financial market because of globalization and integration among financial markets.
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This paper explores the interaction between upstream firms and downstream firms in a two-region general equilibrium model. In many countries, lower tariff rates are set for intermediate manufactured goods and higher tariff rates are set for final manufactured goods. The derived results imply that such settings of tariff rates tend to preserve a symmetric spread of upstream and downstream firms, and continuing tariff reduction may cause core-periphery structures. In the case in which the circular causality between upstream and downstream firms is focused as agglomeration forces, the present model is fully solved. Thus, we find that (1) the present model displays, at most, three interior steady states, (2) when the asymmetric steady-states exist, they are unstable and (3) location displays hysteresis when the transport costs of intermediate manufactured goods are sufficiently high.
Resumo:
This work explores the automatic recognition of physical activity intensity patterns from multi-axial accelerometry and heart rate signals. Data collection was carried out in free-living conditions and in three controlled gymnasium circuits, for a total amount of 179.80 h of data divided into: sedentary situations (65.5%), light-to-moderate activity (17.6%) and vigorous exercise (16.9%). The proposed machine learning algorithms comprise the following steps: time-domain feature definition, standardization and PCA projection, unsupervised clustering (by k-means and GMM) and a HMM to account for long-term temporal trends. Performance was evaluated by 30 runs of a 10-fold cross-validation. Both k-means and GMM-based approaches yielded high overall accuracy (86.97% and 85.03%, respectively) and, given the imbalance of the dataset, meritorious F-measures (up to 77.88%) for non-sedentary cases. Classification errors tended to be concentrated around transients, what constrains their practical impact. Hence, we consider our proposal to be suitable for 24 h-based monitoring of physical activity in ambulatory scenarios and a first step towards intensity-specific energy expenditure estimators
Resumo:
Connexin-43 (Cx43), a gap junction protein involved in control of cell proliferation, differentiation and migration, has been suggested to have a role in hematopoiesis. Cx43 is highly expressed in osteoblasts and osteogenic progenitors (OB/P). To elucidate the biologic function of Cx43 in the hematopoietic microenvironment (HM) and its influence in hematopoietic stem cell (HSC) activity, we studied the hematopoietic function in an in vivo model of constitutive deficiency of Cx43 in OB/P. The deficiency of Cx43 in OB/P cells does not impair the steady state hematopoiesis, but disrupts the directional trafficking of HSC/progenitors (Ps) between the bone marrow (BM) and peripheral blood (PB). OB/P Cx43 is a crucial positive regulator of transstromal migration and homing of both HSCs and progenitors in an irradiated microenvironment. However, OB/P Cx43 deficiency in nonmyeloablated animals does not result in a homing defect but induces increased endosteal lodging and decreased mobilization of HSC/Ps associated with proliferation and expansion of Cxcl12-secreting mesenchymal/osteolineage cells in the BM HM in vivo. Cx43 controls the cellular content of the BM osteogenic microenvironment and is required for homing of HSC/Ps in myeloablated animals
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The implementation of a charging policy for heavy goods vehicles in European Union (EU) member countries has been imposed to reflect costs of construction and maintenance of infrastructure as well as externalities such as congestion, accidents and environmental impact. In this context, EU countries approved the Eurovignette directive (1999/62/EC) and its amending directive (2006 /38/EC) which established a legal framework to regulate the system of tolls. Even if that regulation seek s to increase the efficien cy of freight, it will trigger direct and indirect effects on Spain’s regional economies by increasing transport costs. This paper presents the development of a multiregional Input-Output methodology (MRIO) with elastic trade coefficients to predict in terregional trade, using transport attributes integrated in multinomial logit models. This method is highly useful to carry out an ex-ante evaluation of transport policies because it involves road freight transport cost sensitivity, and determine regional distributive and substitution economic effect s of countries like Spain, characterized by socio-demographic and economic attributes, differentiated region by region. It will thus be possible to determine cost-effective strategies, given different policy scenarios. MRIO mode l would then be used to determine the impact on the employment rate of imposing a charge in the Madrid-Sevilla corridor in Spain. This methodology is important for measuring the impact on the employment rate since it is one of the main macroeconomic indicators of Spain’s regional and national economic situation. A previous research developed (DESTINO) using a MRIO method estimated employment impacts of road pricing policy across Spanish regions considering a fuel tax charge (€/liter) in the entire shortest cost path network for freight transport. Actually, it found that the variation in employment is expected to be substantial for some regions, and negligible for others. For example, in this Spanish case study of regional employment has showed reductions between 16.1% (Rioja) and 1.4% (Madrid region). This variation range seems to be related to either the intensity of freight transport in each region or dependency of regions to transport intensive economic sect ors. In fact, regions with freight transport intensive sectors will lose more jobs while regions with a predominantly service economy undergo a fairly insignificant loss of employment. This paper is focused on evaluating a freight transport vehicle-kilometer charge (€/km) in a non-tolled motorway corridor (A-4) between Madrid-Sevilla (517 Km.). The consequences of the road pricing policy implementation show s that the employment reductions are not as high as the diminution stated in the previous research because this corridor does not affect the whole freight transport system of Spain.