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Pigment and Thiamine Dynamics in Marine Phytoplankton and CopepodsWänstrand, Ingrid January 2004 (has links)
Based on a field study and several mesocosm experiments, I evaluated the use of pigments as chemotaxonomical biomarkers for phytoplankton community composition in the Baltic Sea and I examined effects of inorganic nutrients on the dynamics of carotenoids and thiamine (vitamin B1) at the phytoplankton–copepod level in marine pelagic food webs. My results show that HPLC pigment analysis combined with CHEMTAX data processing was an accurate alternative to microscopic analysis of Baltic Sea phytoplankton. Experimental supply of N, P and Si affected copepod growth and biochemical status via changes in biomass and composition of their phytoplankton diet. Net population growth rates were generally higher when phytoflagellates dominated (low Si:N ratio) and lower when diatoms dominated (high Si:N ratio). Copepod body concentrations of astaxanthin decreased with fertilization. Correlations with reduced under-water irradiance were consistent with the photo-protective function of this antioxidant. Thiamine concentrations in phytoplankton also decreased with fertilization. In copepods, low Si:N ratios resulted in higher thiamine concentrations than high Si:N ratios. Thiamine concentration and degree of phosphorylation were useful as indicators of thiamine shortage both in phytoplankton and copepods. The concentrations of thiamine and astaxanthin in the copepod communities were positively correlated. As copepods constitute a major link between pelagic primary producers and higher trophic levels, fertilization effects may be responsible for astaxanthin and thiamine deficiencies in salmon suffering from the M74 syndrome, which appeared concurrently with large-scale eutrophication in the Baltic Sea. As both thiamine and astaxanthin are deficient in M74-affected salmon, there is a need for physiological and molecular investigations of possible interactions between the two compounds in living cells.
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Radionuclides in the Baltic Sea : Ecosystem models and experiments on transport and fateKumblad, Linda January 2004 (has links)
Manmade radionuclides have been introduced to the environment for almost a century. The main source has been the nuclear weapons testing programmes, but accidental releases from the nuclear power production industries have also contributed. The risk to humans from potential releases from nuclear facilities is evaluated in safety assessments. Essential components of these assessments are exposure models, which estimate the transport of radionuclides in the environment, the uptake in biota, and transfer to humans. Recently, there has been a growing concern for radiological protection of the whole environment, not only humans, and a first attempt has been to employ model approaches based on stylised environments and transfer functions to biota based exclusively on bioconcentration factors. They are generally of a non-mechanistic nature and involve no knowledge of the actual processes involved, which is a severe limitation when assessing real ecosystems. The research presented in this thesis attempts to introduce a methodology for modelling exposure of biota that is based on systems ecological theories and concepts. All presented papers concern bioaccumulation and circulation of radionuclides in coastal areas of the Baltic Sea, which is a sea surrounded by several nuclear power plants, waste repositories and reprocessing facilities. Paper I illustrates how an ecosystem model can be used to predict the fate of C-14 in a bay, and to explore the influence of uptake route and water exchange on the concentrations in biota. Due to the longevity of many radionuclides, time spans of thousands of years need to be considered in assessments of nuclear waste facilities. In Paper II, the methodological problems associated with these long timescales are discussed and a new modelling approach is proposed. An extension and generalisation of the C-14 flow model into a generic model for other radionuclides is described and tested in Paper III. This paper also explores the importance of three radionuclide specific mechanisms (plant uptake, excretion and adsorption to organic surfaces) for the concentrations in biota. In Paper IV, the bioaccumulation kinetics of three radionuclides in three key benthic species of the Baltic Sea is studied experimentally. Paper V considers remobilisation and redistribution of sediment-associated radionuclides due to biological mixing, in a microcosm study. The findings in this thesis show both that it was possible to use an ecosystem approach to assess the exposure to biota, and that this approach can handle many of the problems identified in the use of traditional exposure models for radionuclides. To conclude, frameworks for the protection of the environment from ionising radiation would benefit from implementing methodologies based on ecologically sound principles and modelling techniques.
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Managing water according to river basins : Information management, institutional arrangements and strategic policy support - with focus on the EU Water Framework DirectiveNilsson, Susanna January 2006 (has links)
Today, there is a general notion that water resources are best managed according to their river basins. River basin management may be approached from a wide variety of angles. This thesis focuses on information management, institutional arrangements and strategic policy support, with special reference to the EU Water Framework Directive (WFD). The overall objective is to examine strategies, possibilities and hindrances for river basin management, with the ultimate goal of identifying key aspects to be considered - and prioritised - for “successful” European water management and WFD implementation. An assessment of the information management of three transboundary water regimes in Europe showed that a technical/scientific paradigm ap-pears to dominate in river basin accords. This is visible, for example, in the data collection, which is dominated by state and environmental impact information, and the use of passive channels for communicating with stakeholders and other interest groups. The studies addressing institutional arrangements for river basin management according to the WFD showed that the implementa-tion level of the directive is relatively low – both at national and international levels. For instance, competent authorities have not been established (strictly) according to the borders of the estab-lished River Basin District (RBDs). Further, in international RBDs, the ambitions and plans for cooperation vary considerably. Despite the general low implementation level, steps have still been taken in the “direction” of river basin management. At the national level, all examined countries have established RBDs according to river basins, and at the international level, joint river basin management plans will probably be coordinated for a majority of river basins shared by EU Member States. However, the same pattern could not be discerned for river basins extending outside the borders of the EU. In order to support strategic policy making on issues related to the implementation of the WFD, two assessments were made, one addressing international co-operation and water quality in the Baltic Sea Region, and one encompassing rankings of all the newly established RBDs based on a number of identical indicators. Although there is a need to refine these assessments, they may be regarded as simple – but yet robust – models for bench-marking. / QC 20100914
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How to ensure that the nightmare won’t happen again : Bankernas nyckeltal, kapitalstruktur och riskreglering i ett konjunkturperspektivJohansson, Gustav, Söderlund, Fredrik January 2009 (has links)
Syftet är att evaluera Baselramverkets riskreglering i en konjunkturcykel med hänsyn till Östersjöregionens storbankers systemviktiga funktion. Studien antar främst en kvantitativ ansats i de två första delarna, nyckeltalsanalysen och buffertsimuleringen men även en kvalitativ ansats antas i den tredje delen, intervjuer. Studien utgår från teorierna om Basel I och Basel II, nyckeltalsteori samt från tidigare forskning. Resultatet i studien består av nyckeltalanalys och simulering av åtta, i Östersjöregionen verksamma, bankers nyckeltal och buffert under 21 år samt sex djupintervjuer med representanter för såväl banker som regulatorer. Slutsatser Att det inte finns något samband mellan Baselregleringens kapitaltäckning och bankernas risk eller konjunktur, att riskvägningen tenderar till att vara godtycklig och har större påverkan på buffert än Baselregleringens kapitaltäckning samt att mer transparens behövs i bankerna tyder på att Baselregleringens kapitaltäckningskrav i mycket liten utsträckning visar Östersjöregionens storbankers faktiska risk. / The purpose is to evaluate the Basel framework risk regulation in an economic cycle, in account to the systemic function of the large banks in the Baltic Sea region. The study mainly adopts a quantitative approach in the two first parts, the key ratio analysis and the buffer simulation. A qualitative element is also implemented in the third part, interviews. In a theoretical perspective the study is based on the Basel I and Basel II framework, key ratio theories and previously conducted research. The result consists of key ratios analysis and buffer simulation for eight banks in the Baltic Sea region for a period of 21 years and interviews with six representatives of banks and regulatory institutions. Conclusion The absence of correlation between the Basel regulation capital adequacy and the bank risk nor economic cycle, that risk weighting tends to be arbitrary and have greater impact on bank buffer than capital adequacy regulation has, and that more transparency is needed in banking; suggests that the Basel capital adequacy to a small extent reflect actual risk.
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Den Gropkeramiska kulturens framträdande : en kritisk analys gällande tre av de främsta teorierna kring den Gropkeramiska kulturens framträdande i Nordeuropa / The emergence of the Pitted Ware Culture : a critical analysis of three primary theories explaining the emergence of the Pitted Ware culture in Northern EuropePalmgren, Erik January 2013 (has links)
In this essay the author has chosen to analyze the similarities and differences between some of the northern Europe’s late Mesolithic and Neolithic cultures. The research is of a processual standpoint and the information is mainly gathered from secondary sources as well as ethnological studies. The material collected has been analyzed in both a processual and a post-processual manner to most accurately study the foundations of the three primary theories describing the Pitted Ware Culture’s origin. During the course of the study the author also found a possible fourth alternative, and the possibility of exogamy as a factor in the emerge of the Pitted Ware Culture has also been questioned. This work has prompted for a rigorous collection of information to be able to properly present all theories strong and weak points, without bias for any theory. The conclusion of these studies is that it is very hard to pinpoint exactly what it is that has given the Pitted Ware Culture its typical cultural traits, although a possible sequence of events has been presented in this text.
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The Scandinavian settlement at Grobiņa : the connections between the settlement, the local population and GotlandGunnarsson, Daniel January 2012 (has links)
In the town of Grobiņa in Latvia several cemeteries with grave goods and burial traditions that could be linked to Gotland have been excavated, as well as cemeteries of local type. The town itself has been interpreted as the site of a Vendel age settlement, possibly beginning around 650 AD. The aim of this thesis is to study the characteristics of the settlement and in particular its relation to Gotland. A study of the age of circular disc brooches discovered in and around Grobiņa has also been carried out as a part of the analysis. This type of brooches is very typical for Gotland during Vendel and Viking age. / I Grobiņa i västra Lettland har ett flertal vendeltida gravfält med gravgåvor och begravningstraditioner som kan kopplas till Gotland påträffats. Även gravfält av lokal typ har påträffats. Grobiņa har tolkats som platsen för en vendeltida bosättning, möjligen grundad cirka 650 e. Kr. Syftet med uppsatsen är att studera bosättningens karaktär, och i synnerhet dess förhållande till Gotland. En studie av de dosformade spännen som påträffats i och omkring Grobiņa har också genomförts som en del av analysen. Denna typ av spännen är typisk för Gotland under vendel- och vikingatid.
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Untersuchung von Meeresspiegelvariationen in der Ostsee: Kombination von Satellitenaltimetrie, Pegelmessungen und einem ozeanographischen Modell / Analysis of Sea Level Variations in the Baltic Sea: Combination of Satellite Altimetry, Tide Gauge Observations and an Oceanographic ModelNovotny, Kristin 28 November 2007 (has links) (PDF)
Die Bestimmung von Variationen des Meeresspiegels ist heute wichtiger Gegenstand geodätischer Forschungen. So stellt der mittlere Meeresspiegel eine geometrische Grenzfläche der Erdfigur dar. Seine säkulare Änderung ist darüber hinaus eine wichtige Größe u.a. bei der Planung künftiger Küstenschutzmaßnahmen. Die zuverlässige Schätzung dieser Größen aus den relativ kurzen Zeitreihen aktueller Satellitenaltimeterbeobachtungen wird jedoch durch lang- und kurzzeitig wirkende Meeresspiegelvariationen erschwert. Am Beispiel der Ostsee wurde ein Verfahren entwickelt, diese Variationen in den Beobachtungsdaten mit Hilfe modellierter Oberflächenauslenkungen, die einem hochauflösenden ozeanographischen Modell der Ostsee entnommen wurden, zu reduzieren. Die Streuung der beobachteten Höhen wurde so von ursprünglich etwa 15 bis 25cm auf unter 10cm reduziert. Vor der Nutzung des Modells ergab der Vergleich der modellierten mit beobachteten Variationen des Meeresspiegels eine Genauigkeit der modellierten Meeresspiegelauslenkungen von 5 bis 15cm. Darüber hinaus konnte unter Verwendung von Pegelbeobachtungen eine Modellverbesserung erzielt werden. Die Kombination der Beobachtungen unterschiedlicher Altimetermissionen erforderte des Weiteren eine Homogenisierung der Reihen und die Überprüfung ihrer Langzeitstabilität. Hierzu erfolgte eine absolute Altimetervalidierung durch Vergleich mit Pegelmessungen in der südlichen Ostsee. Relative Biaswerte wurden durch Vergleich der Beobachtungen unterschiedlicher Altimeter im Bereich der gesamten Ostsee ermittelt. Die korrigierten und um die modellierten Meeresspiegelvariationen reduzierten Altimetermeeresspiegelhöhen bildeten im Weiteren die Grundlage zur Bestimmung des mittleren Meeresspiegels der Ostsee und seiner säkularen Änderung. Der lineare Trend des Meeresspiegelanstieges in der Ostsee, bezogen auf das Geoid, ergab sich zu (+1,2+-0,8)mm/Jahr. Die Kombination dieses Wertes mit der an Küstenpegeln beobachteten relativen Meeresspiegeländerung erlaubte weiterhin die Schätzung postglazialer Landhebungsraten im Küstenbereich an den Pegelstationen. Die mittlere Meerestopographie innerhalb der offenen Ostsee wurde, bezogen auf ein regionales Geoidmodell, mit einer Genauigkeit von etwa 3 bis 10cm bestimmt. Das erarbeitete Verfahren zeigt das Potential der Kombination geodätischer Beobachtungsverfahren mit den Ergebnissen einer präzisen Modellierung der beobachteten Größe. Die Arbeit stellt eine regionale Studie dar, die - bei Vorhandensein entsprechender Daten - auch auf andere Regionen übertragbar ist. / The determination of sea level variations is a major topic of present geodetic research. The mean sea surface is a geometric boundary surface to describe the figure of the Earth. Its secular change has, for instance, to be considered in future coastal protection projects. However, the estimation of reliable values for these parameters from the relatively short altimeter observation time series is hampered by long- and short-term sea level variations. For the Baltic Sea, a processing scheme was developed that uses sea surface elevations taken from a high-resolution oceanographic model of the Baltic Sea to reduce these sea level variations in the observations. Thus, the standard deviation of the observed sea level heights was reduced from original values of about 15 to 25cm to final values of less than 10cm. A comparison of the modelled and the observed sea level variations was performed before the model was employed. From this, the accuracy of the modelled sea surface elevations was found to be in the order of 5 to 15cm. Moreover, the oceanographic model could be improved by the assimilation of tide gauge observations. The combination of the observations of different satellite altimeters requires also the homogenisation of the time series and the examination of their temporal stability. The comparison with tide gauge observations at the southern coast of the Baltic Sea allowed the determination of the absolute bias of each altimeter mission. Relative bias values were estimated by comparison of altimetric heights of different missions within the entire Baltic Sea. Finally, the time series of the corrected and reduced altimetric sea level heights formed the basis on which the mean sea surface of the Baltic Sea and its secular change were determined. The linear rate of the sea level rise in the Baltic Sea with respect to the geoid was estimated to (+1,2+-0,8)mm/year. This absolute rate was then combined with the relative sea level change observed at coastal tide gauges, allowing the estimation of the rates of the postglacial rebound in the vicinity of the gauges. The mean sea surface topography in the open Baltic was determined with an accuracy of about 3 to 10cm. A regional geoid model served as the reference surface. The presented procedure shows the potential of combining geodetic observations with the results of a precise model of the observed parameter. It can be regarded as a regional study that can be applied also to other regions where observational and modelled data are available.
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Föroreningen av Östersjöns vatten : Enskilda avlopp och åtgärder för en långsiktig uthållig vattenanvändning / The pollution of the Baltic sea : Private drains and actions for a long-term water useHolmer, Erik January 2008 (has links)
<p>I denna uppsats undersöks det hur det fungerar med enskilda avlopp utanför kommunens VA-nät. Hur enskilda avlopp är uppbyggda och hur de fungerar. Varför man bör ha avloppsrening, och vilka lagar och regler som styr enskilda avlopp. Jag utreder vidare varför man ska jobba för en ökad rening av avlopp och varför man ska jobba mot att uppnå ett uthålligt samhälle.</p><p>Uppsatsen har en teoridel som handlar om hur och varför vi ska sträva efter en uthållig samhällsutveckling. En strävan som kommuner som Söderköping har när dom försöker få människor att byta till hållbara VA-system.</p><p>Med dom här funderingarna som bakgrund och ett antal frågeställningar har jag skrivit en fyllig bakgrund som går igenom Östersjöns problematik och även relevant information om enskilda avlopp. Jag går igenom varför vi behöver en bra rening och hur man kan jobba för att uppnå en bättre rening. Bakgrunden ger en grund för att jag ska kunna genomföra min undersökning på ett bra sätt.</p><p>I resultat delen undersöker jag hur Söderköpings kommun och Allren arbetar med enskilda avlopp. Jag valde Söderköpings kommun för att det är en kustnära kommun som av den anledningen alltid brottas med att inte få ut läckage av näring i Östersjön. Och det märks att dom har tagit detta ämne på allvar då dom jobbar för att skapa recirkulation av näringen genom exempelvis urinsorterande system.</p><p>I slutet av uppsatsen har jag diskussions delar där jag flätar samman uppsatsen och för en diskussion om vad jag har kommit fram till och vad jag har för åsikter om arbetet med enskilda avlopp.</p><p>Uppsatsen avslutas med att jag har med en didaktik del. En didaktisk del som gör det möjligt att lära ut de kunskaper man besitter efter en uppsats.</p>
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Experimental Studies on the Regulation of Pigment Dynamics in Phytoplankton and Copepods by Dissolved Inorganic NutrientsVan Nieuwerburgh, Lies January 2004 (has links)
This thesis examines the role of dissolved inorganic nutrients in generating changes in phytoplankton community and pigment composition and if such changes can affect the production of the antioxidant astaxanthin in the ecosystem via pelagic copepods. The background of my studies is the possible relationship between eutrophication and a reproductive disturbance in Baltic populations of Atlantic salmon (M74), which is associated with astaxanthin and thiamine deficiencies and oxidative stress. In the southern Baltic Sea, changes in nutrient loads correlate with observed trends of flagellates replacing diatoms in the phytoplankton. Copepods are the main producers of astaxanthin and a major link between phytoplankton and higher trophic levels. In laboratory and field experiments in the Baltic Sea proper and the Norwegian Sea, I show that astaxanthin synthesis in copepods is fast and depends on pigment composition of the phytoplankton diet. Among single-species diets, a diatom and a green algal cyst yielded the highest astaxanthin levels in copepods, and another diatom species, a green alga and a cyanobacterium the lowest. In nutrient-generated phytoplankton blooms in mesocosms, copepods grazing on diverse communities dominated by weakly silicified diatoms produced more astaxanthin compared with copepods grazing on communities dominated by strongly silicified diatoms. This suggests that diatoms invested in defence mechanisms and escaped grazing at surplus Si. A nutrient-starved diatom culture subjected to intraspecific competition exhibited decreased pigment levels, increased thiamine levels and increased oxidative stress. My results suggest that diatoms are beneficial for astaxanthin and thiamine production compared to other phytoplankton groups, but not under all circumstances. Copepod growth and development also responded to inorganic nutrient availability and affected total astaxanthin production per volume seawater, with highest production when the copepods grazed on diatoms. From an ecosystem perspective, increased N and P loads seem to promote high astaxanthin production, but not when diatoms disappear completely.
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Pelagic microorganisms in the northern Baltic Sea : Ecology, diversity and food web dynamicsBerglund, Johnny January 2005 (has links)
Heterotrophic microorganisms are important for the flow of carbon and nutrients in the sea. Bacteria, nanoflagellates and ciliates are relevant components of the pelagic food web. In order to be able to predict the outcome of e.g. eutrophication or climate change we need to know how the different components of the pelagic food web are regulated. With the focus on the northern Baltic Sea food web, this thesis deals with limitation and control of heterotrophic protists, the effect of resource heterogeneity on food web efficiency and diversity of nanoflagellates. In-situ microcosm experiments showed that the net growth of heterotrophic flagellates were resource limited throughout the year. Field data confirmed that the abundance of flagellates was bottom-up controlled. Furthermore, field data also showed that the annual average biomass of protists, flagellates and ciliates increased with primary productivity. On a smaller seasonal scale temperature and bacterial biomass were able to explain most of the variation in flagellate biovolume. The temporal variation in ciliate biovolume could not be explained by any bottom-up factors like bacterial biomass, flagellate biomass or chlorophyll a. This and an in-situ microcosm experiment implied that the seasonal dynamics of ciliates were more regulated by predators like mesozooplankton. The food web efficiency i.e. how much of production at the resource level is converted to production at the top trophic level, may be affected by specific size or type of resource. Indoor mesocosms revealed that the food web efficiency was 11 times lower when heterotrophic bacteria dominated basal production instead of nano- and micro-sized phytoplankton. This was due to a lengthening of the food web when pico-sized bacteria constituted the main resource. The PCR-DGGE molecular biological method was used to study the diversity of heterotrophic or mixotrophic chrysomonads. The focus was set on chrysomonads due to their relatively large contribution to the nanoflagellate community. Group-specific PCR primers were optimized for the target group. A field survey in the northern Baltic Sea showed that a handful of chrysomonad sequences were present throughout the year. Significantly more chrysomonads were recorded in the basin with higher primary productive and salinity. In total 15-16 different chrysomonad sequences were recorded. Most of them matched uncultured chrysomonad clones.
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