This dissertation addresses the modeling and solution of mixed-integer linear multistage stochastic programming problems involving both endogenous and exogenous uncertain parameters. We propose a composite scenario tree that captures both types of uncertainty, and we exploit its unique structure to derive new theoretical properties that can drastically reduce the number of non-anticipativity constraints (NACs). Since the reduced model is often still intractable, we discuss two special solution approaches. The first is a sequential scenario decomposition heuristic in which we sequentially solve endogenous MILP subproblems to determine the binary investment decisions, fix these decisions to satisfy the first-period and exogenous NACs, and then solve the resulting model to obtain a feasible solution. The second approach is Lagrangean decomposition. We present numerical results for a process network planning problem and an oilfield development planning problem. The results clearly demonstrate the efficiency of the special solution methods over solving the reduced model directly. To further generalize this work, we also propose a graph-theory algorithm for non-anticipativity constraint reduction in problems with arbitrary scenario sets. Finally, in a break from the rest of the thesis, we present the basics of stochastic programming for non-expert users.

Recent evaluations of the regulatory in vitro genotoxicity tests have revealed that the mammalian cell tests are sensitive for the prediction of rodent carcinogenicity, but not very specific; they produce positive results for many non-carcinogens. Studies to investigate the potential causes of this poor specificity have focused on the high test concentrations of chemicals and the often associated high cytotoxicity. Others have sought to develop alternative in vitro assays that retain high sensitivity but also have higher specificity. One such test is the GADD45a-GFP “GreenScreen HC” genotoxicity assay, which uses elements of the cellular DNA damage response in a green fluorescent protein (GFP) reporter system to detect genotoxic hazard. Published validation studies for this assay have shown both high sensitivity and high specificity. Suggestions that the high specificity of the assay is attributable to the method of cytotoxicity estimation, relative cell density (RCD), and further that this method leads to overestimation of cytotoxicity and hence lower maximum test concentrations, are investigated in this study.In order to investigate whether high specificity of the GADD45a-GFP assay is a result of inaccurate estimation of cytotoxicity, RCD was compared with other cytotoxicity methods used in screening assays, as well as the cytotoxicity methods used in the regulatory in vitro mammalian genotoxicity tests. Results showed that RCD actually underestimates cytotoxicity in the GADD45-GFP assay and as a consequence, test data are collected up to and beyond the cytotoxicity-limited test concentrations reached in the regulatory tests. The use of RCD was found not to contribute to the high specificity of the GADD45a-GFP assay and indeed, its high specificity was retained regardless of the method used to estimate cytotoxicity.A largely overlooked element in the consideration of the poor specificity of in vitro mammalian genotoxicity assays is the supplementation of assays with exogenous metabolism systems, the most common of which is ‘S9’, a liver-derived preparation. S9 is used to enable the detection of compounds (pro-genotoxins) that undergo metabolic transformation in vivo resulting in the formation of genotoxic carcinogens. However, both the preparation and usage of S9 create a bias towards phase I metabolism, specifically the cytochrome P450 monooxygenases that can catalyse the formation of DNA-reactive species. The neglect of phase II metabolism (detoxification/conjugation) could potentially contribute to the poor specificity of the in vitro mammalian tests and this was explored in the study presented.A review of published data revealed that the prevalence of positive results amongst in vitro mammalian genotoxicity data generated in the presence of S9 was similar in collections of both rodent carcinogens and non-carcinogens. Thus, any increased sensitivity from using S9 is offset by decreased specificity for these tests. However, as inclusion of S9 affected sensitivity and specificity in equal measure it was concluded that S9 is not a confounding factor on the accuracy of the in vitro mammalian genotoxicity tests.

This thesis investigates the ability of rainbow trout to modulate hepatic glucose production (Ra) and disposal (Rd). My goals were to determine: (1) if resting trout can modulate fluxes to cope with exogenous glucose; (2) how fluxes change during graded swimming; (3) how exogenous glucose affects swimming kinetics; and (4) if exogenous glucose affects cost of transport or performance. Results show that resting trout suppress Ra completely and stimulate Rd from 10.6 to 27.6 μmol kg-1 min-1. During swimming, fluxes increase from 15.6 to 21.9 μmol kg-1 min-1, but only at speeds >2.4 BL s-1. When given glucose, trout suppress Ra from 16.4 to 4.1 μmol kg-1 min-1 and stimulate Rd from 16.4 to 40.1 μmol kg-1 min-1. Glucose lowers metabolic rate but does not affect critical swimming speed. Therefore, this research shows that rainbow trout have a much better capacity for glucoregulation than generally suggested by current literature.

Orientador: Alexandre Ninhaus Silveira / Resumo: Pseudoplatystoma reticulatum, Leiarius marmoratus e o híbrido resultante do cruzamento entre essas espécies apresentam características zootécnicas interessantes e promissoras para o cultivo em piscicultura. Porém, a larvicultura dessas espécies apresentam altos índices de mortalidade, pois nesse período as larvas não estão totalmente desenvolvidas e não possuem o sistema digestório completamente formado. Pesquisas relacionadas ao desenvolvimento do sistema digestório de larvas tem sido uma ferramenta importante para o conhecimento sobre os períodos de alimentação endógena, exógena e mista. Neste sentido, este trabalho teve como objetivo analisar e comparar as características anatômicas, histológicas e histoquímicas do sistema digestório de Pseudoplatystoma reticulatum, Leiarius marmoratus e do híbrido, nas fases inicias de desenvolvimento após eclosão. As amostras foram fixadas em solução de karnovsky (paraformoldeído 4% + glutaraldeído 2% + tampão fosfato Sorensen 0,1 M, pH 7,2), e processadas para análise anatômica, histológica e histoquímica. As larvas de P. reticulatum, L. marmoratus e híbrido eclodiram 24 horas após a fertilização. As larvas recém-eclodidas apresentaram-se pouco desenvolvidas e com escassez de cromatóforos. A cavidade bucofaríngea pôde ser observada, mas não foi possível diferenciar os componentes do tubo digestivo. As reservas de vitelo foram observadas até o 3º DPE em P. reticulatum e em L. marmoratus e no Híbrido até o 4º DPE. Para os três modelos bio... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Pseudoplatystoma reticulatum, Leiarius marmoratus and the hybrid resulting from the cross between these species show interesting and promising zootechnical characteristics for fish farming. The main bottleneck of larviculture today is the high mortality rate in the early stages of life, because in this period the larvae are not fully developed and do not have a fully formed digestive system. Research related to the development of the digestive system of larvae, has been an important tool for understanding the periods of endogenous, exogenous and mixed feeding. In this sense, this work aimed to analyze and compare the anatomical, histological and histochemical characteristics of the digestive system of Pseudoplatystoma reticulatum, Leiarius marmoratus and the hybrid, in the early stages of development after hatching. The samples were fixed in a karnovsky solution (paraformoldehyde 4% + glutaraldehyde 2% + phosphate buffer Sorensen 0.1 M, pH 7.2), and processed for anatomical, histological and histochemical analysis. The larvae of P. reticulatum, L. marmoratus and hybrid hatched 24 hours after fertilization. The newly hatched larvae were poorly developed, with a shortage of chromatophores. The buccopharyngeal cavity could be observed, but it was not possible to differentiate the components of the digestive tract. Calf reserves were observed until the 3º DPE in P. reticulatum and in L. marmoratus and in the hybrid until the 4º DPE. For the three biological models, the first gobl... (Complete abstract click electronic access below) / Mestre

The aim of this diploma thesis realized as a comparative study was the study of regulation of carotenoid and ergosterol production in several carotenogenic yeast strains. Yeasts were exposed to exogenous stress factors. Salt stress and oxidative stress (hydrogen peroxide) were reached by addition of NaCl and hydrogen peroxide into production media. Complex changes on metabolome (e.g. pigment and ergosterol production, RP-HPLC), proteome and genome were followed. Proteome changes were analyzed by PAGE-SDS and 2D electrophoresis. To isolation and analysis of chromosome DNA pulsed field gel electrophoresis (PFGE) was used. Six yeast strains were enrolled into the comparative study; three strains of the genus Rhodotorula and three strains of the genus Sporobolomyces. While yeasts Rhodotorula sp. were characterized by enhanced biomass as well as carotenoid production in normal and stress conditions, production of biomass by Sporobolomyces sp. was substantially lower. Carotenoid production in Sporobolomyces sp. was higher than in Rhodotorula sp.; the highest increase of was beta-carotene production was observed in Sporobolomyces salmonicolor cells stressed by salt (4x higher than in control) or peroxide (5x higher). Proteins were isolated from yeast cells by combination of mechanical and chemical disruption by glass beads and NaOh or SDS. Better yields were obtained by NaOH. Two staining methods were tested in PAGE-SDS protein analysis. Coomassie Brilliant Blue staining exhibited lower sensitivity, silver staining led to better visualisation of minor protein fractions too. 1D protein profiles was difficult to evaluate, therefore, 2D electrophoresis of selected strains (R.glutinis, R.rubra) was done. In yeast genome analysis by PFGE at minimum 7 DNA fractions were observed. These results probably are not final, further study will be needed for detailed characterization of red yeast genome.

This paper investigates the relationship between vacant job positions and unemployed workers, illustrated by the Beveridge curve, a tool for observing the matching process and the condition of a labour market. The Swedish case is studied together with its three largest labour market regions, i.e., Stockholm-, Västra Götaland- and Skåne county. A comparison opens up a discussion of whether local labour markets with similar characteristics located in different parts of the country behave similarly or in what way they distinguish. Furthermore, these three regions are expected to influence the Swedish Beveridge curve to a larger extent, which is also examined in the paper. In addition, the effect of an exogenous shock, such as the building of the Öresund Bridge, expanding the labour market of Skåne county by connection to another metropolitan area, Copenhagen, is studied. This is done by comparing the matching efficiency before and after the bridge is opened. Moreover, the effect in Skåne is then analysed in accordance with the same period for the other regions included, to get an indication of whether the bridge alone provides a change in matching efficiency or if changes are connected to national events that influence all regions similarly.  The analysis is based on monthly data from year 1996-2020, collected from the Swedish Public Employment service and Statistics Sweden, primarily. Graphical illustrations of the Beveridge curve in combination with OLS regressions provide concluding results that the Beveridge curves for the three regional labour markets observed are shaped rather similarly and experience shifts and movements during the same time points, generally. Skåne county is the exception and experience more horizontal and vertical movements compared to Stockholm- and Västra Götaland county and the Swedish average. Furthermore, there are statistically significant estimates ensuring the negative relationship between unemployment- and vacancy rate, i.e., a downward sloping Beveridge curve for all regions. Not enough evidence on the effect of the Öresund Bridge on the matching efficiency of Skåne county is provided to present a valid conclusion regarding this topic.

No description available.

Past literature has supported the supplementation of 25-OHD3 into poultry diets to reduce leg issues and improve muscle accretion. In addition, exogenous feed enzymes are included into poultry diets to increase nutrient utilization. The first objective of this thesis was to determine the effects of different sources and levels 25-OHD3 supplementation on D0-53 Ross x Ross 708 male broiler performance, processing yield, tibia ash, serum Ca and 25-OHD3 status. Data demonstrated that 25-OHD3 supplementation into diets with Low VitD3 (165 IU/kg) can improve broiler performance compared to High VitD3 (2756 IU/kg). The second objective was to investigate the effects of varying phytase inclusion with different xylanase levels on D0-56 Ross x Ross 708 male broiler performance, processing yield and tibia ash. Data exhibited some performance benefit (D46 and D56) when utilizing phytase (1000 and 1500 FTU/kg) with 1500 EPU/kg xylanase and phytase (250 and 1500 FTU/kg) with 3000 EPU/kg xylanase.

The total removal of antibiotic growth promoters (AGP) from poultry feed is underway in the United States. Feed additive strategies will be utilized to maintain the efficient growth, health, and economic value found with current commercial broiler production. Experiment 1 investigated the effects of feeding an encapsulated butyric acid and zinc product (EBAZ) at 3 inclusions on d 0- 49 Ross x Ross 708 male and female broiler performance, blood chemistry, and cecal short-chain fatty acid content. These data suggest that EBAZ can be safely included at 0.5 g/kg and at 2.5 g/kg into diets for Ross x Ross 708 male and female broilers. The objective of the second experiment was to examine the efficacy of 2 commercially available carbohydrases in commercial diets on d 0-57 male broiler performance and processing. The resulting data demonstrates that the inclusion of xylanase (CE2) improved broiler performance thus, increased potential gross profits.

No description available.