In computations over many-sorted algebras, one typically encounters error cases, caused by attempting to evaluate an operation outside its domain (e.g. division by the integer 0; taking the square root of a negative integer; popping an empty stack). We present a method for systematically dealing with such error cases, namely the construction of an "error algebra" based on the original algebra. As an application of this method, we show that it provides a good semantics for (possibly improper) function tables. / Thesis / Master of Science (MSc)

The Arctic region appears as a pristine remote environment, yet there is increasing evidence that it is greatly impacted by pollution such as lead (Pb) and mercury (Hg). In this environment deposition of Hg has increased threefold since the last industrial revolution. In this study five cryosolic soil profiles within non-sorted circles (NSC) in the Abisko region, northwest of Sweden, has been analyzed to improve our understanding regarding how pollutants are distributed within such type of soil. The soil samples have been analyzed with the use of X-ray fluorescence analysis (XRF), for the measurements of the total concentrations of e.g. lead (Pb) and zirconium (Zr). The soil samples were also analyzed for Hg and LOI. In each sample Zr was used to determine whether metal concentrations were naturally derived from soil silicate minerals or from non-silicate (anthropogenic) sources. From the inner domains of the circles towards the outer domains where the latter contained the highest amounts of organic matter that bind these metals the Pb and Hg concentrations increased. The highest concentrations of Pb (47 mg/kg) and Hg (359 µg/kg) are found in the surface layer (about7 cmdeep) at the edges of the circles. In a buried layer (O-horizon) found in the inner domain, the concentration of Hg was 60µg/kg. Within the studied NSC the concentrations anthropogenic derived Pb and Hg in the surface layer of the circles outer domain was estimated to constitute 95 - 100 % of the total metal burden. In the buried organic layer 95 % of Hg was estimated to be anthropogenic. Clearly, the soil was strongly affected by anthropogenic Pb and Hg concentration.

Subarctic and alpine areas are sensitive to climatic change when they lie at the margin of permafrost occurrence. Patterned ground in such areas is generated from an interplay among different mechanisms such as temperature, hydrology, soil texture, snow cower and vegetation. The aim of this study is to describe the connection between patterned ground characteristics and altitude and to evaluate the impact different variables have on the appearance of patterned ground. To understand these interactions is a discussion of self-organization processes, threshold effects and feedback mechanisms essential.  In this investigation, characteristics of patterned ground are examined along an elevation gradient in the Abisko area in Northern Sweden. The study is limited to formations that are categorized into non-sorted circles on flat ground. To detect significant correlations between the characteristics of patterned ground and altitude nine places between 400 and 1400 m above sea level with at least 100 m difference in altitudes were investigated. These sites were categorized into six ridges and three sinks to evaluate the importance of topography. Non-sorted circles have less dwarf shrub, more moss-lichen cover and more cryptogam crust than surrounding ground. Outside the formations the amount of dwarf shrub decreases and the moss-lichen cover increases above 1000 m above sea level. At the highest altitude also a cryptogam crust is occurring around non sorted circles. Significant correlations exist between declining ground temperature and altitude, declining distance between non-sorted circles and altitude, and less dwarf shrub vegetation on non-sorted circles and altitude. These relationships are expected and can be connected to cryoturbation and abiotic stress. Shorter distance between formations can be linked to increased abiotic stress and less coverage soil stabilizing dwarf shrub vegetation. Formations are larger in sinks than ridges and surrounded by less dwarf shrub and more moss-lichen vegetation. This difference can be explained by longer snow duration, humid soil conditions and prolonged freezing processes in ground. Non-sorted circles on an east aspect slope ridge at about 900 meters altitude is characterized by low soil temperatures, high soil moisture, low height and low coverage plants. Around these formations is a well-developed ground cover consisting primarily of dwarf shrub vegetation. These observations are a sign of positive interaction resulting in strong self-generating soil movements that have exceeded a threshold when breaking through vegetation cover. Low soil temperature and high moisture at the time of measurement might be explained by existing ice-front and free water convection. These patterned ground characteristics can be linked to permafrost, the inflow of water from higher leeward slopes and thin snow cower.

Because the mechanisms that lie behind the formation and preservation of asymmetric non-sorted stripes have not yet been established, and their particular shape has been given little attention by authors before, this study aims at giving a better understanding of the landforms and the environmental conditions under which they exist, with emphasis on under what circumstances the asymmetry develops. For this purpose, the roles of vegetation and snow were key concerns as well as the wind regime in relation to the vegetation, snow and morphology. The study consists of a thorough description of non-sorted stripes in the valley Gohpasvaggi, near Abisko field station in Northern Sweden. It comprises investigations of the ground thermal regime, soil moisture and other environmental parameters considered likely to have implications for the occurrence and appearance of the landforms. Results showed that the non-sorted stripe continues to the depth of ca 40-50 cm in the form of distortions of the deeper horizons, whereas the asymmetry is limited to the shallower A-horizon. In the stripe ridges there seems to be an upward movement in the soil that is likely physically driven (e.g. frost action). The furrow between the stripe ridges appears to be a quiescent area with normal soil development. The net downward movement here is likely biologically driven. The asymmetry can be related to the wind based on their corresponding direction and on the understanding of how feedback mechanisms involving wind, snow and vegetation works to maintain the micro topography. Differential frost heave and free convection of water in soil are plausible explanations for the origin of the non-sorted stripes in Gohpasvaggi. The current maintenance of the stripes is likely a combination of biological, physical and hydrological mechanisms that interact and depend on each other.

Ce travail présente une analyse de l'évolution morphologique et des processus sédimentaires actuels du plateau continental interne sud-aquitain, (sud-est du Golfe de Gascogne, France),secteur riche en données, mais sur lequel de nombreuses questions restent néanmoins en suspens. Il s'articule autour de deux zones ateliers complémentaires : la zone de « La Salie-Biscarrosse » sur le plateau continental interne sud-aquitain au sud des passes du Bassin d'Arcachon (entre 5 et 50 m de profondeur d’eau), et la tête du canyon de Capbreton et ses abords (entre 5 et 120 m de profondeur d’eau). Deux approches sont utilisées : (1) une approche descriptive et comparative (dans le temps), utilisant des données géo-acoustiques(sondeur multi faisceaux, sonar latéral et sondeur de sédiments), des prélèvements et (2) une approche mettant en oeuvre des modélisations numériques des interactions houles / courants /sédiments. Les résultats obtenus sur le plateau interne aquitain ont permis d'améliorer la connaissance de la morphologie, de la nature et de la géométrie interne des corps sédimentaires, d'étudier leur évolution au cours des 29 dernières années (entre 1984 et 2013)et de proposer des facteurs à l’origine de cette évolution. Le résultat majeur est la mise en évidence de « sorted bebforms » entretenus par la houle; dont la surprenante migration vers le nord-est est à associer à la récente découverte d'intenses épisodes de « poleward current » sur le plateau. Le suivi entre 1998 et 2013 de l’évolution morphologique de la tête du Canyon de Capbreton, située à seulement 250 m du littoral montre une évolution rapide qui fluctue cependant autour d'une position d'équilibre. Par ailleurs l’influence de la dérive littorale sur les transferts de sédiments du plateau vers le canyon a pu être démontrée. En-effet, les arguments morphologiques et sédimentaires, associés à la modélisation numérique, prouvent que la dérive littorale aquitaine alimente épisodiquement (conditions de houle forte) la tête de canyon en sables littoraux. / This study proposes an analysis of the morphological evolution and recent sedimentary processes of the south Aquitaine inner shelf (south east Bay of Biscay, France). This area is greatly documented but improvement of our knowledge is needed for a better understanding.Two complementary study areas are analyzed: « La Salie-Biscarrosse » area of the south-Aquitaine inner shelf (in a water depth extending from 5 to 50 m), and the head of the Capbreton Canyon (in a water depth extending from 5 to 120 m). Two approaches are used:(1) a descriptive and comparative analysis of the geophysical and sedimentological data setsand (2) a numerical modeling taking into account swell, current and sediments. The results obtained allow the description and the interpretation of the morphology, the nature, the internal geometry of the sedimentary structures, and their evolution along the last 29 years(between 1984 and 2013). The major result highlights the presence of sorted bedforms maintained by the swell, migrating northeastward and associated with the recent discovery of punctual poleward current on the shelf. The seafloor morphology of the Capbreton Canyonhead located only 250 m off the coastline, has experienced significant changes between 1998 and 2013, nonetheless it oscillates around a position of equilibrium. Furthermore, the influence of the littoral drift on sediment transfer from the shelf to the canyon was demonstrated. Sedimentary and morphological evidences combined with numerical modelingattest to the feeding of the Capbreton canyon head with coastal sand supplied by the southward long shore drift under high-energy wave conditions.

A considerable part of the global pool of terrestrial carbon is stored in high latitude soils. In these soils, repeated cycles of freezing and thawing creates soil motion (cryoturbation) that in combination with other cryogenic disturbance processes may play a profound role in controlling the carbon balance of the arctic soil. Conditions for cryogenic soil processes are predicted to dramatically change in response to the ongoing climate warming, but little is known how these changes may affect the ability of arctic soils to accumulate carbon. In this thesis, I utilize a patterned ground system, referred to as non-sorted circles, as experimental units and quantify how cryogenic soil processes affect plant communities and carbon fluxes in arctic soils. I show that the cryoturbation has been an important mechanism for transporting carbon downwards in the studied soil over the last millennia. Interestingly, burial of organic material by cryoturbation appears to have mainly occurred during bioclimatic events occurring around A.D. 900-1250 and A.D. 1650-1950 as indicated by inferred 14C ages. Using a novel photogrammetric approach, I estimate that about 0.2-0.8 % of the carbon pool is annually subjected to a net downward transport induced by the physical motion of soil. Even though this flux seems small, it suggests that cryoturbation is an important transporter of carbon over centennial and millennial timescales and contributes to translocate organic matter to deeper soil layers where respiration proceeds at slow rates. Cryogenic processes not only affect the trajectories of the soil carbon, but also generate plant community changes in both species composition and abundance, as indicated by a conducted plant survey on non-sorted circles subjected to variable differential frost heave during the winter. Here, disturbance-tolerant plant species, such as Carex capillaris and Tofieldia pusilla, seem to be favoured by disturbance generated by the differential heave. Comparison with findings from a previous plant survey on the site conducted in the 1980s suggest that the warmer temperatures during the last decades have resulted in decreased differential heave in the studied non-sorted circles. I argue that this change in cryogenic activity has increased abundance of plants present in the 1980s. The fact that the activity and function of the non-sorted circles in Abisko are undergoing changes is further supported by their contemporary carbon dioxide (CO2) fluxes. Here, my measurements of CO2 fluxes suggest that all studied non-sorted circles act as net CO2 sources and thus that the carbon balance of the soils are in a transition state. My results highlight the complex but important relationship between cryogenic soil processes and the carbon balance of arctic soils.

As biotecnologias reprodutivas têm uma importante relação com os resultados econômicos dos rebanhos leiteiros. Sua adoção implica o investimento de quantidades conhecidas de recursos, porém, há uma clara dificuldade por parte de produtores em avaliarem o retorno desses investimentos. O objetivo deste estudo foi desenvolver um modelo de simulação que permita analisar os impactos do uso de biotecnologias reprodutivas sobre o desempenho econômico de rebanhos leiteiros. Com o auxílio de uma planilha eletrônica do Microsoft® Office Excel®, foi desenvolvido um modelo determinístico, em função de parâmetros produtivos, reprodutivos e econômicos, com o fim de representar a conformação do rebanho em períodos de 21 dias ao longo de 25 anos. Foram realizadas simulações de quatro cenários de aplicação de biotecnologias: inseminação artificial com sêmen convencional (IAC) e com sêmen sexado (IAS), inseminação artificial em tempo fixo com sêmen convencional (IATFC) e com sêmen sexado (IATFS). Finalmente, foram calculados para cada cenário o Payback, o valor presente líquido (VPL) e a taxa interna de retorno (TIR) como indicadores da viabilidade econômica. Sob as condições simuladas, observou-se que o cenário com melhor desempenho econômico foi IATFS (Payback 3 anos; VPL R$ 2.558.490,80; e TIR 42,5% aa), seguido de IATFC (Payback 3 anos; VPL R$ 2.357.639,40; e TIR 42,9% aa). O cenário IAC apresentou valores superiores (Payback 3 anos; VPL de R$ 759.353,90; e TIR 29,3% aa), quando comparado com IAS (Payback 4 anos; VPL R$ 676.870,90; e TIR 23,3% aa). O modelo desenvolvido neste estudo permite auxiliar o processo de tomada de decisão na seleção da estratégia reprodutiva mais adequada com base em parâmetros específicos. / Reproductive biotechnologies have an economic impact on dairy herds. Its implementation requires the investment of known amounts of resources; however, the producers still have a clear difficulty in assessing the profitability of these investments. The aim of this study was to develop a simulation model to analyze how the use of reproductive biotechnologies impact on the economic performance of dairy herds. Using a Microsoft® Office Excel® spreadsheet, a deterministic model was created considering productive, reproductive and economic parameters, in order to represent the herd conformation in 21-day periods over 25 years. Then, four reproductive programs were simulated: artificial insemination using conventional semen (AIC) or sex-sorted semen (AIS) and fixed-time artificial insemination using conventional semen (FTAIC) or sex-sorted semen (FTAIS). Finally, indicators of economic viability: Payback, net present value (NPV) and internal rate of return (IRR) were calculated for each reproductive program. Under the simulated conditions, it was observed that the program with the best economic performance was FTAIS (Payback 3 years; NPV R$ 2,558,490.80; and IRR 42.5% per annum), followed by FTAIC (Payback 3 years; NPV R$ 2,357,639.40; and IRR 42.9% per annum). The AIC program presented higher economic returns (Payback 3 years, NPV R$ 759,353.90, and IRR 29.3% per annum) when compared with AIS (Payback 4 years; NPV R$ 676,870.90, and IRR 23.3% per annum). The mathematical model developed in this study can assists the decision-making process to select the most appropriate reproductive strategy based on specific parameters.

Estrous synchronization and artificial insemination (ESAI) are reproductive technologies that cattlemen can use to improve the reproductive performance of their herds. Controlling the gender ratio of the calf-crop can also improve the opportunity for increased revenue and profit. Producers are able to shift and/or control the gender ratio of their calf crop by incorporating sex-sorted semen into their AI programs. However, decreased conception rates to AI have been previously observed when sex-sorted semen was used in comparison to conventional semen of the same sires. The objective of the first study was to determine if conception rates will differ in females inseminated with conventional semen or SexedULTRA™ sex-sorted semen when estrus is synchronized using an industry-standard, 7-d CO-Synch + Controlled Internal Drug Release (CIDR) protocol for fixed-time artificial insemination (FTAI). The objective of the second study was to determine if conception rate to FTAI differs between SexedULTRA™ sex-sorted and conventional semen when yearling beef heifers are synchronized using a 14-d controlled internal drug release (CIDR) - PGF2α (PGF) protocol modified to optimize the control of ovulation and timing of insemination.

<p>Sorted bedforms are spatial extensive (100 m-km) features present on many inner continental shelves with subtle bathymetric relief (cm-m) and localized, abrupt variations in grain size (fine sand to coarse sand/gravel). Sorted bedforms provide nursery habitat for fish, are a control on benthic biodiversity, function as sediment reservoirs, and influence nearshore waves and currents. Research suggests these bedforms are a consequence of a sediment sorting feedback as opposed to the more common flow-bathymetry interaction. This dissertation addresses three topics related to sorted bedforms: 1) Modeling the long-term evolution of bedform patterns, 2) Refinement of morphological and sediment transport relations used in the sorted bedform model with `machine learning'; 3) Development of a new sorted bedform model using these new `data-driven' components.</p><p> Chapter 1 focuses on modeling the long term evolution of sorted bedforms. A range of sorted bedform model behaviors is possible in the long term, from pattern persistence to spatial-temporal intermittency. Vertical sorting (a result of pattern maturation processes) causes the burial of coarse material until a critical state of seabed coarseness is reached. This critical state causes a local cessation of the sorting feedback, leading to a self-organized spatially intermittent pattern, a hallmark of observed sorted bedforms. Various patterns emerge when numerical experiments include erosion, deposition, and storm events. </p><p> Modeling of sorted bedforms relies on the parameterization of processes that lack deterministic descriptions. When large datasets exist, machine learning (optimization tools from computer science) can be used to develop parameterizations directly from data. Using genetic programming (a machine learning technique) and large multisetting datasets I develop smooth, physically meaningful predictors for ripple morphology (wavelength, height, and steepness; Chapter 2) and near bed suspended sediment reference concentration under unbroken waves (Chapter 3). The new predictors perform better than existing empirical formulations. </p><p> In Chapter 3, the new components derived from machine learning are integrated into the sorted bedform model to create a `hybrid' model: a novel way to incorporate observational data into a numerical model. Results suggest that the new hybrid model is able to capture dynamics absent from previous models, specifically, the two observed end-member pattern modes of sorted bedforms (i.e., coarse material on updrift bedform flanks or coarse material in bedform troughs). However, caveats exist when data driven components do not have parity with traditional theoretical components of morphodynamic models, and I address the challenges of integrating these disparate pieces and the future of this type of `hybrid' modeling.</p> / Dissertation

As biotecnologias reprodutivas têm uma importante relação com os resultados econômicos dos rebanhos leiteiros. Sua adoção implica o investimento de quantidades conhecidas de recursos, porém, há uma clara dificuldade por parte de produtores em avaliarem o retorno desses investimentos. O objetivo deste estudo foi desenvolver um modelo de simulação que permita analisar os impactos do uso de biotecnologias reprodutivas sobre o desempenho econômico de rebanhos leiteiros. Com o auxílio de uma planilha eletrônica do Microsoft® Office Excel®, foi desenvolvido um modelo determinístico, em função de parâmetros produtivos, reprodutivos e econômicos, com o fim de representar a conformação do rebanho em períodos de 21 dias ao longo de 25 anos. Foram realizadas simulações de quatro cenários de aplicação de biotecnologias: inseminação artificial com sêmen convencional (IAC) e com sêmen sexado (IAS), inseminação artificial em tempo fixo com sêmen convencional (IATFC) e com sêmen sexado (IATFS). Finalmente, foram calculados para cada cenário o Payback, o valor presente líquido (VPL) e a taxa interna de retorno (TIR) como indicadores da viabilidade econômica. Sob as condições simuladas, observou-se que o cenário com melhor desempenho econômico foi IATFS (Payback 3 anos; VPL R$ 2.558.490,80; e TIR 42,5% aa), seguido de IATFC (Payback 3 anos; VPL R$ 2.357.639,40; e TIR 42,9% aa). O cenário IAC apresentou valores superiores (Payback 3 anos; VPL de R$ 759.353,90; e TIR 29,3% aa), quando comparado com IAS (Payback 4 anos; VPL R$ 676.870,90; e TIR 23,3% aa). O modelo desenvolvido neste estudo permite auxiliar o processo de tomada de decisão na seleção da estratégia reprodutiva mais adequada com base em parâmetros específicos. / Reproductive biotechnologies have an economic impact on dairy herds. Its implementation requires the investment of known amounts of resources; however, the producers still have a clear difficulty in assessing the profitability of these investments. The aim of this study was to develop a simulation model to analyze how the use of reproductive biotechnologies impact on the economic performance of dairy herds. Using a Microsoft® Office Excel® spreadsheet, a deterministic model was created considering productive, reproductive and economic parameters, in order to represent the herd conformation in 21-day periods over 25 years. Then, four reproductive programs were simulated: artificial insemination using conventional semen (AIC) or sex-sorted semen (AIS) and fixed-time artificial insemination using conventional semen (FTAIC) or sex-sorted semen (FTAIS). Finally, indicators of economic viability: Payback, net present value (NPV) and internal rate of return (IRR) were calculated for each reproductive program. Under the simulated conditions, it was observed that the program with the best economic performance was FTAIS (Payback 3 years; NPV R$ 2,558,490.80; and IRR 42.5% per annum), followed by FTAIC (Payback 3 years; NPV R$ 2,357,639.40; and IRR 42.9% per annum). The AIC program presented higher economic returns (Payback 3 years, NPV R$ 759,353.90, and IRR 29.3% per annum) when compared with AIS (Payback 4 years; NPV R$ 676,870.90, and IRR 23.3% per annum). The mathematical model developed in this study can assists the decision-making process to select the most appropriate reproductive strategy based on specific parameters.