954 resultados para OCEANIC BANKS
Resumo:
Calcium carbonate production by marine organisms is an essential process in the global budget of CO32-, and coralline reefs are the most important benthic carbonate producers. Crustose coralline algae (CCA) are well recognized as the most important carbonate builders in the tropical Brazilian continental shelf, forming structural reefs and extensive rhodolith beds. However, the distribution of CCA beds, as well as their role in CO32- mineralization in mesophotic communities and isolated carbonate banks, is still poorly known. To characterize the bottom features of several seamount summits in the Southwestern Atlantic (SWA), side-scan sonar records, remotely operated vehicle imagery, and benthic samples with mixed-gas scuba diving were acquired during two recent research cruises (March 2009 and February 2011). The tops of several seamounts within this region are relatively shallow (similar to 60 m), flat, and dominated by rhodolith beds (Vitoria, Almirante Saldanha, Davis, and Jaseur seamounts, as well as the Trindade Island shelf). On the basis of abundance, dimensions, vitality, and growth rates of CCA nodules, a mean CaCO3 production was estimated, ranging from 0.4 to 1.8 kg m(-2) y(-1) with a total production reaching 1.5 x 10(-3) Gt y(-1). Our results indicate that these SWA seamount summits provide extensive areas of shallow reef area and represent 0.3% of the world's carbonate banks. The importance of this habitat has been highly neglected, and immediate management needs must be fulfilled in the short term to ensure long-term persistence of the ecosystem services provided by these offshore carbonate realms.
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Two defensive tactics of neonates of nurse sharks, Ginglymostoma cirratum, are reported based on underwater observations. Described as "hiding behaviour" and "substrate resemblance", the defensive strategies were categorized according to the predominant habitat in which the individuals were found and to the behaviour displayed by the sharks in the presence of the observer. In structurally more complex habitats with a wide availability of shelters, the preferential behaviour displayed by neonates is to hide inside holes or crevices. When in open areas deprived of refuges, neonates tend to resemble arborescent coverings as seaweed banks or colonies of octocorals, which allows the use of more exposed habitats without increasing the susceptibility of capture by predators. Both aspects are relevant for a better understanding of the behaviour of neonates of G. cirratum and have important implications for identifying important habitat in nursery areas, and also for the management of this vulnerable species off South America.
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This paper examines the role of parent rock, pedogenetic processes and airborne pollution in heavy metal accumulation in soils from a remote oceanic island, Fernando de Noronha, Brazil. We studied five soil profiles developed from different volcanic rocks. Mineralogical composition and total concentrations of major and trace elements were determined in 43 samples. The obtained concentrations range for heavy metals were: Co: 26-261 ppm; Cu: 35-97 ppm; Cr: 350-1446 ppm; Ni: 114-691 ppm; Zn: 101-374 ppm; Hg: 2-150 ppb. The composition of soils is strongly affected by the geochemical character of the parent rock. Pedogenesis appears to be responsible for the accumulation of Zn, Co, and, to a lesser extent, of Ni and Cu, in the upper, Mn- and organic carbon-enriched horizons of the soil profiles. Pedogenic influence may also explain the relationship observed between Cr and the Fe. Hg is likely to have been added to the soil profile by long-range atmospheric transport. Its accumulation in the topsoil was further favoured by the formation of stable complexes with organic matter. Clay minerals do not appear to play an important role in the fixation of heavy metals.
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Financial institutions are directly exposed to the credit risk, that is, the risk of the borrower not fulfill with their obligations, paying their debts in its stated periods established previously. The bank predict this type of risk, including them in their balance-sheets. In 2006/2007 there was the impact of a new financial crisis that spread around the world, known as the crisis of subprime. The objective of this study is to analyze if the provisions for credit risk or liquidation increased the sprouting of the crisis of subprime in ten major national banks, chosen accordant to their total assets. To answer this question, the balance-sheets of each one of these banks in the period of 2005 to 2007 were analyzed. This research is characterized, as for its objectives, as descriptive and as for the procedures as documentary research. It is also characterized as having a qualitative approach. The results show that the crisis of subprime has caused little impact in the credit risk provision of the analyzed institutions. It was noticed a slight increase in the provision indicators at the peak of the crisis in 2006. These percentages were reduced in, 2007, probably reflecting the economic stability of Brazil and the stagnation of the crisis Of subprime in that year, at least in relation to in our country.
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State-owned banks remain dominant in China's financial sector despite over two decades of gradual financial liberalization. Their performance is typically evaluated using commercial banking criteria. The standard view is that because state banks have experienced declining profitability and capital adequacy, they have been a drain on past economic development and endanger future growth prospects. However, we argue that state banks have strong development bank characteristics and hence warrant different performance criteria. The analysis in this paper suggests that while thier commercial performance may have been poor, the overall impact of state banks on China's economic development appears to have been both positive and sustainable. Copyright © 2001 John Wiley & Sons, Ltd.
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Dugong abundances in Moreton Bay (south-east Queensland) were estimated during six bi- monthly aerial surveys throughout 1995. Sampling intensity ranged between 20 and 80% for different sampling zones within the Bay, with a mean intensity of 40.5%. Population estimates for dugongs were corrected for perception bias ( the proportion of animals visible in the transect that were missed by observers), and standardised for availability bias ( the proportion of animals that were invisible due to water turbidity) with survey and species-specific correction factors. Population estimates for dugongs in Moreton Bay ranged from 503 +/- 64 (s.e.) in July to 1019 +/- 166 in January. The highest uncorrected count was 857 dugongs in December. This is greater than previous population estimates, suggesting that either previous surveys have underestimated abundance and/or that this population may have increased through recruitment, immigration, or a combination of both. The high degree of variation in population estimates between surveys may be due to temporal differences in distribution and herding behaviour. In winter, dugongs were found in smaller herds and were dispersed over a wider area than in summer. The Eastern Banks region of the bay supported 80 - 98% of the dugong population at any one time. Within this region, there were several dugong 'hot spots' that were visited repeatedly by large herds. These 'hot spots' contained seagrass communities that were dominated by species that dugongs prefer to eat. The waters of Rous Channel, South Passage and nearby oceanic waters are also frequently inhabited by dugongs in the winter months. Dugongs in other parts of Moreton Bay were at much lower densities than on the Eastern Banks.
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We assayed mtDNA haplotype [300 base pairs (bp) control region] geography and genealogy in the Indo-Pacific tasselfish, Polynemus sheridani from its contiguous estuarine distribution across northern Australia (n = 169). Eight estuaries were sampled from three oceanographic regions (Timor Sea, Gulf of Carpentaria and the Coral Sea) to assess the impact of Pleistocene sea level changes on the historical connectivity among P. sheridani populations. Specifically, we investigated the genetic consequences of disruption to Indian-Pacific Ocean connectivity brought about by the closure of the Torres Strait. Overall there was significant population subdivision among estuaries (F-ST = 0.161, (Phi(ST) = 0.187). Despite a linear distribution, P. sheridani did not show isolation by distance over the entire sampled range because of genetic similarity of estuaries greater than 3000 km apart. However, significant isolation by distance was detected between estuaries separated by less than 3000 km of coastline. Unlike many genetic studies of Indo-Pacific marine species, there was no evidence for an historical division between eastern and western populations. Instead, phylogeographical patterns were dominated by a starlike intraspecific phylogeny coupled with evidence for population expansion in both the Gulf of Carpentaria and the Coral Sea but not the Timor Sea. This was interpreted as evidence for recent west to east recolonization across of northern Australia following the last postglacial marine advance. We argue that although sufficient time has elapsed postcolonization for populations to approach gene flow-drift equilibrium over smaller spatial scales (< 3000 km), the signal of historical colonization persists to obscure the expected equilibrium pattern of isolation by distance over large spatial scales (> 3000 km).
Resumo:
This article contains the proceedings of a symposium at the 2002 RSA/ISBRA Meeting in San Francisco, organized and chaired by Clive Harper and co-chaired by Izuru Matsumoto. The presentations were (1) Introduction, by Clive Harper; (2) The quality of tissue-a critical issue, by Therese Garrick; (3) The first systematic brain tissue donor program in Japan, by Izuru Matsumoto; (4) Brain scans after death-really! by Adolf Pfefferbaum, Elfar Adalsteinsson, and Edith Sullivan; (5) Capture that (genial) expression, by Joanne Lewohl and Peter Dodd; and (6) Neurochemical/pharmacological studies: experimental design and limitations, by Roger Butterworth.
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Frequent references are made to the use of portfolio spread rates in managing financial risks in banks, but indications as to the procedures for determining such rates are very scant.The purpose of this article is to present some initial ideas on the subject: a Standard Funding system indicates what each portfolio should have earned, while an Actual Funding system points out what each portfolio did, in fact, earn; additionally, by comparing the outcomes of the two funding systems for each portfolio, it is possible to determine what each portfolio earned (or lost) in the way of arbitrage.
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Interest rate risk is one of the major financial risks faced by banks due to the very nature of the banking business. The most common approach in the literature has been to estimate the impact of interest rate risk on banks using a simple linear regression model. However, the relationship between interest rate changes and bank stock returns does not need to be exclusively linear. This article provides a comprehensive analysis of the interest rate exposure of the Spanish banking industry employing both parametric and non parametric estimation methods. Its main contribution is to use, for the first time in the context of banks’ interest rate risk, a nonparametric regression technique that avoids the assumption of a specific functional form. One the one hand, it is found that the Spanish banking sector exhibits a remarkable degree of interest rate exposure, although the impact of interest rate changes on bank stock returns has significantly declined following the introduction of the euro. Further, a pattern of positive exposure emerges during the post-euro period. On the other hand, the results corresponding to the nonparametric model support the expansion of the conventional linear model in an attempt to gain a greater insight into the actual degree of exposure.
Residential property loans and performance during property price booms: evidence from European banks
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Understanding the performance of banks is of the utmost relevance, because of the impact of this sector on economic growth and financial stability. Of all the different assets that make up a bank portfolio, the residential mortgage loans constitute one of its main. Using the dynamic panel data method, we analyse the influence of residential mortgage loans on bank profitability and risk, using a sample of 555 banks in the European Union (EU-15), over the period from 1995 to 2008. We find that banks with larger weights of residential mortgage loans show lower credit risk in good times. This result explains why banks rush to lend on property during booms due to the positive effects it has on credit risk. The results show further that credit risk and profitability are lower during the upturn in the residential property price cycle. The results also reveal the existence of a non-linear relationship (U-shaped marginal effect), as a function of bank’s risk, between profitability and the residential mortgage loans exposure. For those banks that have high credit risk, a large exposure of residential mortgage loans is associated with higher risk-adjusted profitability, through lower risk. For banks with a moderate/low credit risk, the effects of higher residential mortgage loan exposure on its risk-adjusted profitability are also positive or marginally positive.
Resumo:
Analyses of species-diversity patterns of remote islands have been crucial to the development of biogeographic theory, yet little is known about corresponding patterns in functional traits on islands and how, for example, they may be affected by the introduction of exotic species. We collated trait data for spiders and beetles and used a functional diversity index (FRic) to test for nonrandomness in the contribution of endemic, other native (also combined as indigenous), and exotic species to functional-trait space across the nine islands of the Azores. In general, for both taxa and for each distributional category, functional diversity increases with species richness, which, in turn scales with island area. Null simulations support the hypothesis that each distributional group contributes to functional diversity in proportion to their species richness. Exotic spiders have added novel trait space to a greater degree than have exotic beetles, likely indicating greater impact of the reduction of immigration filters and/or differential historical losses of indigenous species. Analyses of species occurring in native-forest remnants provide limited indications of the operation of habitat filtering of exotics for three islands, but only for beetles. Although the general linear (not saturating) pattern of trait-space increase with richness of exotics suggests an ongoing process of functional enrichment and accommodation, further work is urgently needed to determine how estimates of extinction debt of indigenous species should be adjusted in the light of these findings.