Comprendre l’enrichissement des liquides sulfurés en éléments chalcophiles et sidérophiles pouvantmener à la formation de gisements de sulfures magmatiques.Le premier objectif de cette thèse a été de quantifier les variations des coefficients de partage (Dsul/sil)de Co, Ni, Cu, Pd, Ag, Pt et Au dans des conditions crustales typiques des intrusions de la région deNoril’sk-Talnakh (Russie), par le biais d’une étude expérimentale en autoclave à chauffage interne,effectuée à 1200 °C, 70 MPa, sous différentes fugacités d’oxygène.Les résultats montrent que les Dsul/sil de Pd, Ag, Pt et Au augmentent avec la teneur de ces élémentsdans le liquide sulfuré, indiquant qu’ils ne suivent pas la loi de Henry, au contraire de ceux de Co, Ni, etCu. Ces Dsul/sil permettent de reproduire les teneurs en métaux des sulfures naturels de la région deNoril’sk, à partir d’un magma parent plus enrichi en Pd et Pt que les laves de la région, et en invoquantl’interaction entre des masses de liquide silicaté et de liquide sulfuré pour pouvoir enrichir ce dernier(facteur R entre 300 et 1000 pour les sulfures massifs et entre 300 et 6000 pour les disséminés).Le second objectif de cette thèse a été de modéliser, par une approche thermodynamique, les variationsdes Dsul/sil en fonction des conditions magmatiques. Ce modèle décrit les variations des Dsul/sil avec latempérature, la pression, la fugacité d’oxygène et la chimie des liquides, et suggère que les magmasmafiques à l’équilibre avec les liquides sulfurés les plus enrichis sont ceux qui ont les plus faiblestempératures et pressions, et les fugacités d’oxygène les plus élevées. / A comprehensive knowledge of metal partitioning between sulfide liquid and silicate melt is essential tounderstand sulfide liquid enrichment in chalcophile and siderophile elements that can lead to theformation of magmatic sulfide ore deposits.The first aim of this thesis was to quantify the partition coefficients (Dsul/sil) for Co, Ni, Cu, Pd, Ag, Pt andAu at crustal conditions relevant to the Noril’sk-Talnakh region (Russia), through an experimental studyconducted in internal heated pressure vessels at 1200 °C, 70 MPa, and under variable oxygenfugacities.Our results show that Dsul/sil for Pd, Ag, Pt and Au increase with the content of the element in the sulfideliquid, showing that they do not follow Henry’s law, in contrast to those for Co, Ni, and Cu. These Dsul/silcan reproduce the metal contents of natural sulfides of the Noril’sk region, starting from a parent magmaPd- and Pt-richer than the lavas of the region, and invoking an interaction between the masses of silicateliquid and sulfide liquid in order to enrich the latter.The second objective of this thesis was to model Dsul/sil variations as a function of magmatic conditions,using a thermodynamic approach. This modeling allows investigating the variations of Dsul/sil withtemperature, pressure, oxygen fugacity and the compositions of both liquids and suggests that the maficmagmas with the lowest temperatures and pressures and the highest oxygen fugacities are those inequilibrium with the most enriched sulfide liquid.

O presente trabalho analisou o comportamento tribológico do revestimento superficial cromo duro, aplicado em cilindros de laminação e sua influência durante o processo de laminação a frio, para ligas de aço, cobre e alumínio. Iniciou-se o processo com a análise dos mecanismos de desgaste que ocorrem em cilindros de laminação. Em função das dimensões dos cilindros de laminação, foram produzidas réplicas obtidas em vários cilindros de laminação em diferentes empresas, antes e após a campanha dos cilindros de laminação. Consideramos no processo de amostragem, 3 tipos de acabamento do cilindro: texturizado, jateado e retificado. E ainda, cilindro sem e com revestimento de cromo. A estrutura da Texturização Shot Blaster (SBT) não atende todos os requisitos relacionados ao produto acabado. A camada de cromo duro, aplicado sobre estes cilindros de laminação SBT, melhora a qualidade da superfície da chapa, sendo de interesse para aquelas siderúrgicas que não têm outra alternativa às novas estruturas de superfície, podendo ser obtidas pelos métodos: Electro Discharge Texturing (EDT), Laser Texturing (LT), Electro Beam Texturing (EBT). A função das superfícies geradas, obtidas por estes métodos diferentes vai influenciar as propriedades tribológicas durante os processos de laminação e deformação de chapa. Por outro lado, pode aumentar o custo final do produto ou exigem grandes investimentos para obtenção de tais métodos. / The present work analyzed the tribological behavior of the hard chrome surface coating applied in rolling cylinders and their influence during the cold rolling process for steel, copper and aluminum alloys. The process started by analyzing the wear mechanisms that occur in work rolls. In function on the dimensions of the work rolls, replicas were obtained from several rolls and in different companies, before and after the roll chance. We consider in the sampling process, three types of work rolls finish: texturing, shot blasted and rectified. And still, work rolls without and with chrome coating. The Texture Shot Blaster (SBT) structure is not available in all respects related to the finished product. The hard chromium layer applied to these SBT rollers improves the surface quality of the sheet and is of interest to steel parts that are not of good capacity: EDT Textures, Laser texturing (LT), electrical beam texturization (EBT). The function of the generated surfaces obtained by these different methods is going to influence the tribological properties during the subsequent forming processes. On the other hand, they can increase the product final cost or require large investments to obtain such methods.

As corridas bancárias são motivo de preocupação das autoridades monetárias desde pelo menos o início da década de 20. Isso se justifica pelos impactos que uma crise financeira sistêmica pode causar na economia, a partir da falência de bancos. A quebra de uma instituição financeira, ou ainda uma situação temporária de dificuldade para honrar compromissos imediatos, pode gerar desconfiança nos depositantes, pelo receio de perder suas economias, fazendo com que corram aos bancos para retirar seus recursos ali depositados. Essa situação pode se espalhar por todo o sistema bancário por meio de efeitodominó, em virtude do sentimento de pânico que os assola, levando a economia a um colapso. Para minimizar o temor e a desconfiança, preservando a estabilidade do sistema financeiro, é prudente se ter no sistema financeiro um mecanismo de proteção aos depositantes, cujo objetivo seja o de inibir o início de uma crise bancária. Esse mecanismo, aqui chamado sistema de seguro de depósito, é formado por um grupo de bancos que pagam um prêmio de seguro, com o objetivo de formar um grande fundo, cuja função é reembolsar os depositantes quando da quebra de um desses bancos participantes. Para que funcione apropriadamente, o sistema de seguro de depósito deve ter suas características bem delineadas, no intuito de minimizar a possibilidade de que atitudes, mais arriscadas por parte dos bancos e menos precavidas por parte dos depositantes, elevem o risco de quebra de um banco. Este estudo tem o objetivo de analisar, por meio de pesquisa exploratória, tais características, trazendo para a discussão contribuições teóricas e práticas recentes em matéria de mecanismos de seguro depósito no Brasil e no exterior, de modo a elencar os aspectos mais eficientes das características, que poderiam ser aproveitados com vistas a aprimorar o sistema de seguro depósito brasileiro, o FGC, Fundo Garantidor de Créditos, já que há previsão de regulamentá-lo via Lei Complementar ao artigo 192 da Constituição Federal de 1988. A análise das características trouxe como diferenciais em relação ao que já existe no FGC, a atribuição de maiores poderes e responsabilidades ao FGC, deixando de ser um simples intermediário para reembolso de depositantes, e o prêmio do seguro, cuja metodologia de cálculo poderia evoluir do método linear, igual para todos os bancos, para o ajustado ao risco incorrido por cada instituição participante. A ampliação dos poderes e responsabilidades poderia atribuir maior competência ao FGC para atuar em situações de insolvência bancária, imputando-lhe o papel de encontrar a melhor e mais eficiente solução, mas isso exigiria mudanças estruturais enormes na agência, especialmente quanto ao tamanho da equipe técnica. A tarefa de definir a forma de cálculo do prêmio de seguro é demasiadamente complexa, uma vez que a metodologia pode não ser simples, pois deveria atender a particularidades de diferentes tipos de bancos. Além disso, a tendência da regulação bancária brasileira caminha cada vez mais ao encontro das normas baseadas em princípios, não em regras, isto é, a regulação cada vez mais vai trabalhar o que deve ser feito pelas instituições financeiras, ao invés de como elas devem fazer. Essa dinâmica não permite a definição uma metodologia de cálculo único, que permita comparar o risco tomado de uma instituição com seus pares. / Bank runs concern monetary authorities at least since the beginning of the 1920\'s, due to the harming impacts a systemic financial crisis may cause on the whole economy, beginning after a bank failure. A bank disruption or just a temporary liquidity problem can generate mistrust on depositors, that fearing the loss of their savings would run to the bank to withdraw all their money. This situation may be spread all over the financial system in an accumulated effect caused by panic, leading to a collapse in the local economy. In the attempt to minimize the fear and mistrust, as well as to preserve the financial system stability, there must be a mechanism of depositor protection aiming to stop the starting up of a bank crisis. This mechanism, hereinafter called deposit insurance system, DIS, consists in the collection of an insurance premium by a group of banks in order to establish a fund that will refund depositors if one of the member banks fails. DIS must have its features well designed to work properly, and to avoid riskier attitudes from the banks and less caution from the depositors that could increase the chance of bankrupting. The purpose of this work is to research literature and international recent practices regarding DIS, in order to list the most efficient points which could be considered to improve the Brazilian DIS, named Fundo Garantidor de Créditos, FGC. Besides, the Brazilian Federal Constitution prescribes regulation of this matter by particular law, but this is still not accomplished. The analysis brought out some important issues which are not in course in the FGC such as the assignment of major powers and responsibilities to FGC, and the increment of its functions so that it turns out to be more than just a pay-box. Other important issue is the change in the methodology in which the deposit insurance premium is calculated, from a flat method to a risk adjusted one. The enlarging of powers and responsibilities could give FGC new attributions in the case of insolvent banks resolution, but it would certainly demand large modifications in FGC present structure, especially regarding technical staff. The task of establishing the insurance premium calculation is highly complex, since the methodology is supposed to achieve different kind of banks. Moreover, national banking regulation Moreover, national banking regulation tends to be more principles-based than rules-based, which means, it tends to specify what banks should do, not how they should do it. This dynamic does not allow the use of a unique methodology to calculate DIS, and imposing, as consequence, obstacles to the comparison of the risk taken by different institutions.

O presente trabalho visa a analisar aspectos específicos da microeconomia bancária no que se refere à relação entre banco e consumidor. Três diferentes abordagens são adotadas. No primeiro capítulo a abordagem é teórica. Um modelo de equilíbrio geral com incerteza é desenvolvido, com o objetivo de analisar a relação depositante banco e as características do equilíbrio dos contratos de depósito bancários. Questões como eficiência e concentração são analisadas, tanto em um contexto estático quanto na relação de longo prazo entre bancos e depositante. Os resultados sugerem contratos de equilíbrio com características contingentes ao espaço de contratos factíveis e uma relação entre esforço eficiente do banco e não comprometimento pleno do depositante na relação de longo prazo. A segunda parte do trabalho se concentra em analisar empiricamente a relação entre banco e tomador de recursos e tem como objetivo contribuir com avanços metodológicos para a decomposição do spread bancário no Brasil. Para tanto, estima-se uma função custo multiproduto para o setor bancário brasileiro e calcula-se, a partir dela, os preços de Aumann-Shapley dos diversos produtos oferecidos pelos bancos. Essa aplicação da teoria de alocação de custos conjuntos à firma bancária permite que se faça a alocação dos custos administrativos de forma mais precisa, melhorando a decomposição do spread no Brasil. Além disso, novos avanços são conseguidos em termos de precisão por meio da ampliação da amostra e portanto pela correção de um grave viés de seleção presente na abordagem original do Banco Central. A terceira - e última - parte do trabalho faz uma discussão institucional dos sistemas de resolução de insolvências coorporativas e da relação destes com a decisão do banco de emprestar e portanto com o funcionamento do mercado de crédito. A motivação foi a de analisar um aspecto específico da relação banco tomador com impactos diretos sobre preço e volume de empréstimos concedidos. Neste ponto, questões relacionadas a incentivos e eficiência emergem e são analisados tendo como pano de fundo a reforma do sistema legal de insolvência brasileiro, atualmente em curso. / The present work analyzes specific aspects of microeconomics of banking, concerning the relationship between financial intermediaries and non-financial agents. Three different approaches are adopted. In the first chapter the approach is theoretical. A model of general equilibrium with uncertainty is developed, analyzing the relationship between banks and depositors and the characteristics of the equilibrium deposit contracts. Efficiency and concentration issues are analyzed, in a static context and in a long-term relationship among banks and depositors. Results suggest that deposit contracts observed in equilibrium are contingent to the space of contract possibilities and that it exists a relationship between efficient effort exerted by the bank and no full commitment by depositors in a long term relationship. Chapter 2 makes an empirical analysis of the bank-borrower relationship, contributing with methodological improvements for the decomposition of banking spreads in Brazil. A multi-product cost function for the Brazilian banking industry is estimated and used to calculate the Aumann-Shapley prices for each of the defined banking products. That application of cost allocation to the banking firm allows a better allocation of administrative costs, improving on the original decomposition made by Brazilian Central Bank. Additionally, a more accurate decomposition results from the use of a larger sample and therefore the correction of a serious selection bias present in the original approach. The third chapter concentrates on an institutional discussion about insolvency resolution. The main motivation was the analysis of a specific aspect of the bank-borrower relationship and its impacts on price and volumes of loan concessions. At this point, incentives and efficiency issues emerge and are analyzed having the Brazilian legal system of insolvency reform, now in course, as a background.

A tecnologia da aplicação tem papel fundamental na agricultura, pois proporciona uma correta aplicação do produto biologicamente ativo no alvo, ocasionando um melhor aproveitamento dos agrotóxicos. O objetivo do trabalho foi avaliar a influência de diferentes pontas e pressões na qualidade da pulverização na cultura do tomate por meio da quantificação do depósito e da cobertura foliar. Foram estudadas as pontas GA 11002 (jato plano com indução de ar), TTJ 60-11002 (jato plano duplo) e TT 11002 (jato plano padrão), todas nas pressões de 200, 350 e 500 kPa. Para todos os tratamentos a taxa de aplicação foi de 180 L ha-1. O percentual de cobertura foliar foi quantificado por meio da análise de imagens que detectaram o traçador fluorescente LRM 100 com o auxílio de luz ultravioleta. As imagens foram capturadas por uma câmera digital e processadas pelo software QUANT. O depósito foi quantificado pela extração e quantificação do traçador azul brilhante FD&C N°1 por meio de espectrofotometria. Para ambos os parâmetros foram analisadas amostras do estrato superior e inferior da planta. Houve diferença estatística somente para a cobertura foliar, sendo que na parte superior da planta a ponta de jato plano duplo apresentou menor cobertura na menor pressão. Nas maiores pressões houve um aumento da cobertura foliar favorecido pela formação de gotas médias e finas pelas pontas avaliadas. No estrato inferior a eficiência na cobertura foliar da ponta de jato plano diminui com o aumento da pressão. O depósito de pulverização foi favorecido pelo aumento da cobertura foliar. / The application technology plays a key role in agriculture as it provides a correct application of the product biologically active in the target, causing a better use of pesticides. The aim of this study was to evaluate the influence of different nozzles and spray pressures acting on tomato by quantifying the deposit and leaf coverage. Were studied the nozzles GA 11002 (flat fan air induction), TTJ 60-11002 (twin flat fan) and TT 11002 (standard flat fan), all pressures of 200, 350 and 500 kPa. For all treatments, the application rate was 180 L h-1. The percentage of leaf coverage was quantified by image analysis to detect the fluorescent tracer LRM 100 with the aid of ultraviolet light. The images were captured by a digital camera and processed by software QUANT. The deposit was quantified by extraction and quantification of tracer bright blue FD&C N° 1 by spectrophotometry. For both parameters were analyzed samples of top and bottom of the parts plant. Statistical difference only for leaf coverage, and at the top of the plant to twin flat fan nozzles showed lower coverage in less pressure. In the higher pressures there was an increase of leaf coverage favored by the formation of fine droplets medium and evaluated nozzles. In the bottom part plant coverage efficiency of foliar flat fan nozzles decreases with increasing pressure. The spray deposit was favored by increased leaf coverage.

Grain size, 14C age, and X-ray diffraction (XRD) analyses of sediments indicate possible tsunami deposits on the southern coast of Java near Pangandaran and Adipala. Previous studies that have described known recent and paleotsunami deposits were used for comparison. Fining-upward grain size trends, interbedded sand and mud, sediment composition, and trends in heavy mineral abundances are among the characteristics used for tsunami deposit identification. At Batu Kalde, an archaeological site south of Pangandaran, a layer of aragonitic sand with marine fossils was found atop a layer of archaeological fragments at an elevation of ~2-5 m. It is likely this layer was deposited by a tsunami, potentially generated by a mega-thrust earthquake. Archaeological material remains suggest that the tsunami occurred ~1300 years ago. A bivalve with an age of 5584-5456 cal YBP was buried within the deposit, perhaps long after its death. At Goa Panggung, a cave east of Batu Kalde, fining-upward grain size trends, composition of sediments, and radiocarbon ages suggest the presence of at least one tsunami deposit. A 5040-4864 cal YBP piece of charcoal overlying modern organic matter suggest that the tsunami first scoured the cave floor, reworking existing material and making interpretation difficult. At Adipala, in western Central Java, fining-upward grain size, upward decrease in heavy mineral abundances, and lateral continuity of sand layers revealed the existence of two possible tsunami deposits buried within the sediments in a swale ~1.6 km from the ocean. Age of the deposits is undetermined.

A key feature of best practice prudential supervision of financial institutions is the use of a risk rating system to formalise the outcome of supervisory reviews and ongoing monitoring processes. The Australian Prudential Regulation Authority (APRA) implemented the Probability and Impact Rating System (PAIRS) in 2002. Given the favourable economic conditions in which PAIRS was developed and has so far operated, any form of validation using backtesting methods is prevented. Consequently, this thesis seeks to develop a framework with which to evaluate and better understand the PAIRS risk rating system for authorised deposit-taking institutions. Specifically, we specify and estimate models in which the risk ratings are related to the statistical data that supervisors have access to when forming their expert judgement assessments of the PAIRS risk components. Whereas prior studies have generally focused on the overall supervisory rating, we model the primary components of the PAIRS rating (inherent risk, management and control risk, and capital support risk) as well as the aggregate risk of failure rating. Using a sample of ratings from 2002 to 2006, we find that the statistical data is able to explain much of the variability in ratings for credit unions and building societies (CUBS) and Australian and foreign subsidiary banks but not foreign bank branches. As expected, the regressions are stronger for inherent risk and capital support risk ratings than management and control risk ratings. However, supervisors?? consideration of adverse qualitative factors adds considerable explanatory power to a model based solely on statistical data, particularly for management and control risk ratings. We also model the determinants of supervisory exceptions and capital adequacy breaches over 1992 to 2006 and find that the risk indicators associated with a higher likelihood of an exception and/or breach are generally consistent with the risk indicators associated with supervisory risk ratings. The outcomes of the thesis have a number of policy implications and practical applications. For example, the estimated models have the potential to be used as a quality and consistency tool to detect rating outliers within PAIRS. We also propose some improvements to APRA??s exception reporting system for CUBS.

The purpose of this thesis is to examine the problem of gazumping, to consider the various factors which give rise to it, to examine the adequacy of existing legal doctrine in redressing it, to explore statutory provisions designed to reduce gazumping and to propose reform of the law to address the problem. The term gazumping refers to a practice by which a vendor accepts a purchaser's offer to purchase land or property, and before exchanging contracts, withdraws from the existing agreement in order to accept a higher price from another purchaser. This thesis proceeds on the assumption that gazumping is an undesirable practice, particularly from the prospective purchaser' perspective. The practice of gazumping initially boomed in a volatile property market with constantly rising house prices and where demand exceeded supply. A purchaser who believes he or she has secured the purchase of his or her desired property may suffer emotional stress and significant costs which cannot be recovered when the vendor reneges on his or her agreement. The thesis notes that gazumping occurs at the pre-contractual stage in the sale of property because there is no legally binding relationship before the formal exchange of contracts. The thesis posits that the existing law in various Australian jurisdictions offers inadequate protection to prospective purchasers of property. The thesis examines the inadequacy of existing legal doctrines and remedies in addressing the problem of gazumping at the pre-contractual stage and arrives at the conclusion that existing legal doctrine is inadequate. The thesis notes legislative and other measures in response to gazumping in Australia and other common law jurisdictions and concludes that these too were inadequate in not going far enough to eliminate or reduce gazumping. The competing merits of these approaches are considered. The thesis establishes that the solution to gazumping lies in an early protection of the purchaser�s interest in land. This is because as soon as an agreement is enforceable the purchaser acquires an equitable interest and in the event of any breach of the agreement by the vendor, the purchaser, as a general rule, can obtain either damages or specific performance. The thesis raises seven key recommendations for law reform aimed to minimise the occurrence of gazumping and to provide the purchaser with tools against the practice of gazumping. It considers that the recommendations can minimise the undesirable practice of gazumping where the current law is inadequate and also achieve several other objectives.

金融在一國的經濟發展過程中，扮演相當重要的角色，隨著經濟的發展程度愈高，對金融的依賴則愈深。因此，一旦金融體系發生危機，可能造成支付系統的中斷，對一國的經濟與社會都會造成重大不利的影響。因此，存款保險制度的建立，其宗旨便是在防止此種危機的發生，以維護金融體系的安定與保障存款人的權益。 　　由於金融產業環境特殊，存款保險在制度的設計上，亦面臨諸多不易克服的問題。在本論文中，提出幾個重要相關的問題，並配合美國存款保險制度的發展經驗，提出分析探討。 　　本論文認為：在組織經營上，政府應介入存款保險制度的運作，才足以維護金融安定。在投保方式方面，基於政策性質，亦應以強制參加為宜。在訂價方面，應加強隱藏價格（監理措施）的發展，不宜過分強調風險費率的功能。在處理問題金融機構時，應及早建立一套因應措施，對問題機構予以迅速解決，避免造成損失擴大。 　　我國存款保險制度的成立較慢，在組織架構的設計上仍未臻完備，本文透過多項相關問題的探討，提供有關方面作為決策之參考。

<p>A low content of organic matter, which is largely refractory in nature, is characteristic of most sediments, meaning that aquatic deposit-feeders live on a very poor food source. The food is derived mainly from sedimenting phytodetritus, and in temperate waters like the Baltic Sea, from seasonal phytoplankton blooms. Deposit-feeders are either bulk-feeders, or selective feeders, which preferentially ingest the more organic-rich particles in the sediment, including phytodetritus, microbes and meiofauna.</p><p>The soft-bottom benthos of the Baltic Sea has low species biodiversity and is dominated by a few macrobenthic species, among which the most numerous are the two deposit-feeding amphipods <i>Monoporeia affinis</i> and<i> Pontoporeia femorata</i>, and the bivalve <i>Macoma balthica</i>. This thesis is based on laboratory experiments on the feeding of these three species, and on the priapulid <i>Halicryptus spinulosus.</i> </p><p>Feeding by benthic animals is often difficult to observe, but can be effectively studied by the use of tracers. Here we used the radioactive isotope ¹⁴C to label food items and to trace the organic matter uptake in the animals, while the stable isotopes ¹³C and¹⁵N were used to follow feeding on aged organic matter in the sediment. </p><p>The abundance of<i> M. balthica</i> and the amphipods tends to be negatively correlated, i.e., fewer bivalves are found at sites with dense populations of amphipods, with the known explanation that newly settled <i>M. balthica</i> spat are killed by the amphipods. Whether the postlarvae are just accidentally killed, or also ingested after being killed was tested by labelling the postlarvae with ¹⁴C and Rhodamine B. Both tracer techniques gave similar evidence for predation on and ingestion of postlarval bivalves. We calculated that this predation was likely to supply less than one percent of the daily carbon requirement for <i>M. affinis</i>, but might nevertheless be an important factor limiting recruitment of <i>M. balthica. </i></p><p>The two amphipods <i>M. affinis</i> and <i>P. femorata </i>are partly vertically segregated in the sediment, but whether they also feed at different depths was unknown. By adding fresh 14C-labelled algae either on the sediment surface or mixed into the sediment, we were able to distinguish surface from subsurface feeding. We found <i>M. affinis</i> and <i>P. femorata</i> to be surface and subsurface deposit-feeders, respectively. </p><p>Whether the amphipods also feed on old organic matter, was studied by adding fresh ¹⁴C-labelled algae on the sediment surface, and using aged, one-year-old ¹³C- and ¹⁵N-labelled sediment as deep sediment. Ingestion of old organic matter, traced by the stable isotopes, differed between the two species, with a higher uptake for <i>P. femorata</i>, suggesting that <i>P. femorata</i> utilises the older, deeper-buried organic matter to a greater extent.</p><p>Feeding studies with juveniles of both <i>M. affinis</i> and <i>P. femorata</i> had not been done previously. In an experiment with the same procedure and treatments as for the adults, juveniles of both amphipod species were found to have similar feeding strategies. They fed on both fresh and old sediment, with no partitioning of food resources, making them likely to be competitors for the same food resource. </p><p>Oxygen deficiency has become more wide-spread in the Baltic Sea proper in the last half-century, and upwards of 70 000km² are now devoid of macrofauna, even though part of that area does not have oxygen concentrations low enough to directly kill the macrofauna. We made week-long experiments on the rate of feeding on ¹⁴C-labelled diatoms spread on the sediment surface in different oxygen concentrations for both the amphipod species, <i>M. balthica</i> and <i>H. spinulosus. </i>The amphipods were the most sensitive to oxygen deficiency and showed reduced feeding and lower survival at low oxygen concentrations.<i> M. balthica</i> showed reduced feeding at the lowest oxygen concentration, but no mortality increase. The survival of <i>H. spinulosus</i> was unaffected, but it did not feed, showing that it is not a surface deposit-feeder. We conclude that low oxygen concentrations that are not directly lethal, but reduce food intake, may lead to starvation and death in the longer term.</p>