Fiskodling har visat sig påverka den biologiska mångfalden negativt, bl. a genom ökad näringsbelastning och ändrad genetisk uppsättning genom att man avlat den odlade fisken på andra egenskaper än vad som är fördelaktigt i det vilda. Syftet med denna studie var att undersöka vilken påverkan inplanterad fisk har på invertebratfaunan och därigenom den biologiska mångfalden. Studien är utförd på Hökensåsområdet i Västra Götalands län där det finns ett 20-tal sjöar som ingår i en sportfiskeverksamhet. I studien ingår sju stycken sjöar; fyra som årligen inplanteras med fisk och tre icke-inplanterade. Genom bottenfaunaprov har invertebratfauna samlats in, artbestämts, räknats och mätts. Ingen signifikant skillnad har kunnat påvisas mellan sjögrupperna med hänsyn till diversitetsindex, antal taxa eller storlek på taxa. Inte heller har jag kunnat påvisa signifikant korrelation mellan mängd inplanterad fisk/år- och (a) diversitetsindex, (b) antal taxa. En eventuell faktor som kan ha påverkat resultatet är det statistiskt sett låga antalet sjöar, sjöarnas varienarande egenskaper och miljö samt att den optimala tidpunkten för insamling av bottenfauna är senare på året än när studien genomfördes. Stark korrelation mellan antal taxa och graden av försurning kunde påvisas. / Pisciculture has been shown to affect biodiversity negatively, e.g. owing to increased nutrient loading and modified genetic set by breeding at other qualities then what is advantageous in in the wild. The purpose of this study was to investigate which impact stocked fish has on the invertebrate fauna and thereby biodiversity. The study is performed at Hökensås area in Västra Götalands län, where there are about 20 lakes included in a sport fishing business. There are seven lakes included in the study; four which yearly became stocked with fish and three non-stocked. By bottom fauna samples invertebrate fauna has been collected, identified, counted and measured. No significant differences have been detected between the lake groups considering diversity index, number of taxa or size of taxa. Nor has significant correlation between amount stocked fish/year- and (a) diversity index, (b) number of taxa been shown. A possible factor that may have affected the result is, from a statistical point of view, the low number of lakes, the varying qualities of the lakes and that the collecting of invertebrate fauna was performed too early in the year than optimal. Strong correlation between number of taxa and grade of acidification was detected.

In an education it is necessary to re-evaluate those principles which are the foundation of how one learns. Only by challenging these basic principles is it possible to prevent stagnation and to cultivate discoveries. The discoveries of this work focus on the architectural object/thing and fundamentally how it is conceived, constructed, and thought about. This work challenges the previous education by not relying on a program, building type, human needs or context. The work attempts to apprehend and understand a basic notion about architecture. The premise is that exploration of an architectural element will lead to thoughtfully about concerns which were previously believed to be ‘generators.’ / Master of Architecture

Using a game theoretical setting, this paper studies how a multinational company's (MNC) choice of using one set (OSB) or two sets of books (TSB) is affected by a strategically acting tax auditor (TA). First, a divisionalized MNC with a producing division in a low tax country and a selling division in a high tax country chooses either OSB or TSB. With OSB, the unique transfer price coordinates the quantity decision and determines the tax payments. With TSB, two transfer prices are used for both tasks. Second, a TA may audit the MNC's transfer prices. It turns out that the TA's bargaining power and his personal audit costs critically influence the MNC's transfer pricing decision. For a low bargaining power and low audit costs, the MNC keeps OSB with positive probability. When the TA's bargaining power is high, the negotiation benefits from using a single transfer price are outweighed by the costs of a reduced flexibility. Then, the MNC keeps TSB with either tax aggressive or compliant reported transfer prices. In addition, a raise in the tax difference induces less tax aggressive behavior. Intuitively, tax aggressiveness should be even more attractive in this case. This intuition is not true in our setting since the TA's audit probability increases and, thus, makes profit shifting less attractive. / Series: WU International Taxation Research Paper Series

A computer controlled dry kiln system, designed and assembled at Virginia Tech, was used in a comparison study of end check damage and acoustic emission count rate for red oak wood samples using two variations of a drying schedule based upon a standard 4/4 red oak drying schedule (T4D2). Time was the controlling variable for the system. In run A, the lumber samples were dried using eight large step changes in temperature and relative humidity. In run B, a similar charge was dried over the same time period using 48 smaller step changes in temperature and relative humidity. The lumber samples that were dried with the schedule featuring large changes in temperature and relative humidity suffered much more extensive end check damage than the wood samples dried with a schedule employing smaller changes in temperature and humidity. The acoustic emission count rate data were not recorded in the final tests due to equipment malfunction. Acoustic emission count rate data recorded from preliminary drying runs indicated that the acoustic emission count rate from a sample board increases with large changes in the ambient air temperature and relative humidity. It then decreases to zero as the wood surfaces achieve an equilibrium state. The automated kiln control system performed successfully. / M.S.

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Politicians and tax practitioners often claim that tax uncertainty negatively affects investment. In many countries, firms can request fee-based Advance Tax Rulings (ATRs) to mitigate tax uncertainty. We analyze theoretically the circumstances under which investors request ATRs, how tax authorities should price them and how they can affect investment. We assume that tax authorities integrate investors' reasoning into their decisions. We find that it is often optimal for tax authorities to charge prohibitively high fees to discourage firms from requesting an ATR. However, we find that revenue-maximizing tax authorities offer ATRs if the ruling enables them either to significantly reduce their tax audit costs or to increase the probability of detecting ambiguous tax issues. Under certain circumstances, ATRs may effectively foster investment and potentially benefit both the tax authorities and taxpayers. Our results provide new explanations for why taxpayers that face high levels of tax uncertainty often do not request ATRs, even when the fee is rather low. Our results also hold when the tax authority maximizes social wealth instead of its revenues. Regulatory changes in ATR requirements might serve as a natural quasi-experiment for an empirical study of our predictions regarding investment decisions. (authors' abstract) / Series: WU International Taxation Research Paper Series

Title: Modelling the Orion Nebula Cluster Author: Václav Pavlík Department: Astronomical Institute of the Charles University Supervisor: doc. RNDr. Ladislav Šubr, Ph.D. (Astronomical Institute of the Charles University) Abstract: Young star clusters are widely discussed from the point of view of their evolution and structure. In this work we focused our attention on studying a typical representative of these objects - the Orion Nebula Cluster (ONC, M 42) - based on the observational data, including their confrontation with N- body models from Šubr et al. (2012). These numerical models were inspired by the recently proposed evolutionary scenario, according to which the star clusters begin their evolution from very dense initial conditions. From the analysis of the X-ray sources we revealed that the ONC is likely to be rotationally symmetric in the inner area (� 0.7 pc). Further analysis including also optical and IR observational data led us to the conclusion that the ONC is elongated from the North-East to the South-West on large scales (up to 2 pc). We also compared radial profiles of different mass groups of stars and we discovered a possibly inverse mass segregation between stars with masses in the interval (1 ; 5) M⊙ and the stars less massive than 0.5 M⊙ in the range from 0.5 pc to 1.5 pc. This...

Les aminopeptidases représentent un groupe d’enzymes qui possèdent une fonction cellulaire clef dans les mécanismes physiologiques et pathologiques. Elles interviennent dans la cascade enzymatique après l’action des endoprotéases, dans l’homéostasie au travers le renouvellement du pool d’acides aminés, dans le métabolisme énergétique, la régulation de l’activité des peptides bioactifs, la présentation antigénique ainsi dans une diversité de mécanismes pathologiques tels que les maladies neurologiques et les infections virales et parasitaires. Les aminopeptidases TETs sont capables de former des macro-assemblages tétraédriques comprenant douze sous-unités. En vue de mieux comprendre leur fonction biologique et leur mode d'action, nous avons étudié les propriétés fonctionnelles et structurales de deux nouveaux complexes TETs issus d'archées hyperthermophiles. L'archée hyperthermophile Methanocaldococcus jannaschii ne possède qu'une version de TET (MjTET) qui a été produite dans Escherichia coli et purifiée sous forme de dodécamère. La recherche de son activité enzymatique et de ses substrats peptidiques par des tests chromogéniques et fluorogéniques, ainsi que des études par HPLC en phase inverse, montre que cette enzyme est une leucine aminopeptidase activée par le cobalt se distinguant des autres aminopeptidases M42 par son très large spectre d'action qui s'étend aux résidus aromatiques. Une structure complète de cette aminopeptidase a été résolue en combinant la cristallographie (2.4 Å) et la cryo-EM (4,1 Å). L'analyse de la poche de spécificité de MjTET permet de mieux comprendre les bases structurales de la discrimination de substrat chez les TETs. De plus, l'analyse de la structure interne de la particule permet de proposer un nouveau mécanisme de navigation des peptides à l’intérieur des particules tétraédriques de la famille TET.L'archée hyperthermophile Pyrococcus horikoshii comporte trois types de complexes TETs. L'étude d'une protéine présentant ~20 % d'identité avec ces systèmes, nous a permis d'identifier une quatrième version du système TET dans cet organisme : PhTET4. La protéine recombinante a été purifiée. Elle forme un complexe dodécamérique tétraédrique. Les études biochimiques révèlent que l'enzyme possède une spécificité très étroite dirigée exclusivement vers l'hydrolyse des résidus glycines de l'extrémité N-terminale des peptides. De plus, elle estactivée par le nickel. Ces caractéristiques permettent de proposer que, chez les archées, la multiplication et la spécialisation des enzymes TETs seraient associées au caractère hétérotrophes alors que le système des archées autotrophes se réduirait à une TET unique apte à assurer une fonction de « ménage ». / Aminopeptidases represent a group of enzymes displaying key cellular function inphysiological and pathological mechanisms. They are involved in the enzymatic cascade beyond the action of endoproteases, in homeostasis through the renewal of the amino acid pool, in the energy metabolism, in the regulation of bioactive peptide activities, in the antigen presentation and in a diversity of pathological mechanisms such as neurological diseases as well as viral and parasitic infections. Aminopeptidases TET are able of forming tetrahedral macro-assemblies built by twelve subunits. In order to better understand their biological function and their mode of action, we studied the functional and structural properties of two novel TET complexes derived from hyperthermophilic archaea. The hyperthermophilic archaeon Methanocaldococcus jannaschii has only one version of TET (MjTET) that was produced in Escherichia coli and purified as dodecameric macromolecule. The search for its enzymatic activity and peptide substrates by using chromogenic/fluorogenic assays and reverse phase HPLC studies, demonstrated that this enzyme is a cobalt-activated leucine aminopeptidase, discriminated from other M42 aminopeptidases by its very broad activity spectrum, that extends to aromatic residues. Complete structure of this aminopeptidase was determined by combining X-ray crystallography (2.4 Å) and cryo-electron microscopy (4.1 Å). Analysis of MjTET specificity pocket indicated possible molecular bases for substrate discrimination in TET peptidases. In depth investigation of the particle internal structure allowed to propose a novel peptide trafficking mechanism for the TET family tetrahedral particles. Three types of TET complexes are present in the hyperthermophilic archaea, Pyrococcus horikoshii. The study of an unassigned protein displaying ~20% identity with the PhTETs systems allowed us to identify a fourth version of TET complex in this organism: PhTET4. The recombinant protein was purified. It formed tetrahedral dodecameric complex. Biochemical studies indicated that the enzyme has a very narrow hydrolytic specificity directed exclusively toward the peptide N-terminal glycine residues. In addition, this enzyme is activated by nickel ions. These features allowed proposing that, in archaea, the multiplicity of specialized TET systems could be associated with heterotrophy while unique TET system displaying “housekeeping” function is present in autotrophic organisms.

Målet med den här studien var att undersöka kiselalger och dess eventuella missbildningar i tre vattendrag i södra Sverige - Höje å, Skivarpsån och M42. Kiselalger används som bioindikator för vattenkvalitet i hela Europa, men de befintliga kiselalgsindexen visar inte eventuell förekomst av miljöfarliga ämnen. Det har dock visats att en förekomst > 1 % av missbildade kiselalger indikerar påverkan av miljöfarliga ämnen, såsom pesticider och tungmetaller. Denna studie är en av få som har undersökt kiselalgers missbildningar i vattendrag som är mer eller mindre påverkade av herbicider. Sex prov från varje vattendrag analyserades - kiselalger räknades och identifierades till artnivå och missbildningar dokumenterades och kategoriserades. Vattendragen delades in efter PTI (Pesticide Toxicity Index), där Höje å hade lägst PTI och ansågs minst påverkad av herbicider. Skivarpsån och M42 hade högre PTI, och ansågs därför ha en högre herbicidpåverkan. Det fanns en signifikant skillnad i missbildningsfrekvens vattendragen emellan, den kunde dock inte kopplas till PTI. Både Höje å och M42 hade > 1 % missbildningar. Skivarpsåns missbildningsfrekvens var < 1 % trots vattendragets relativt höga PTI. Det är möjligt att missbildningsfrekvensen bättre hade reflekterat PTI om herbicidprovtagningen skett någon månad tidigare, då herbicidhalter kan variera och kiselalger har visat sig kunna spegla ett vattendrags mående upp till tre månader bakåt i tiden. En annan förklaring till en varierande missbildningsfrekvens kan vara en lika varierande artsammansättning. Vissa arter är mindre “benägna” att missbildas än andra - ett prov som domineras av sådana skulle därför kunna innehålla få missbildningar trots eventuell miljögiftspåverkan. Det krävs dock ytterligare studier för att bättre förstå kiselalgers missbildningar i förhållande till herbicider.