Using seasonal climate forecasting in agriculture: a participatory decision-making approach

Farm Management,

Latin hypercube sampling with dependence and applications in finance

In Monte Carlo simulation, Latin hypercube sampling (LHS) [McKay et al. (1979)] is a well-known variance reduction technique for vectors of independent random variables. The method presented here, Latin hypercube sampling with dependence (LHSD), extends LHS to vectors of dependent random variables. The resulting estimator is shown to be consistent and asymptotically unbiased. For the bivariate case and under some conditions on the joint distribution, a central limit theorem together with a closed formula for the limit variance are derived. It is shown that for a class of estimators satisfying some monotonicity condition, the LHSD limit variance is never greater than the corresponding Monte Carlo limit variance. In some valuation examples of financial payoffs, when compared to standard Monte Carlo simulation, a variance reduction of factors up to 200 is achieved. LHSD is suited for problems with rare events and for high-dimensional problems, and it may be combined with Quasi-Monte Carlo methods. --Monte Carlo simulation,variance reduction,Latin hypercube sampling,stratified sampling

From membrane to nucleus: New roles and functions of SUMOylated IGF-1R and EGFR

Cell surface receptor tyrosine kinases (RTKs) role in cell signaling have been studied for decades and their role in cancer progression are undisputable. The insulin-like growth factor 1 receptor, IGF-1R, has been demonstrated to play a critical part in tumorigenesis; downregulation of the IGF-1R in tumor xenografts results in complete tumor regression. Previously, RTK research has focused on the canonical signaling pathways activated by ligand binding at the plasma membrane. However, strong evidence keeps emerging that several RTKs have a second functionally mechanism, inside the cell nucleus, where the receptors reside after ligand stimulation. The aim of this thesis was to elucidate the function of recently discovered nuclear IGF-1R as well as to investigate its nuclear translocation pathway. Since it was previously shown that SUMOylation of the IGF-1R is essential for its nuclear translocation we also set out to investigate SUMO modification of the epidermal growth factor receptor (EGFR). In paper I, we present a functional role for nuclear IGF-1R in gene transcription. Inside the nucleus, IGF-1R functions as a co-activator to LEF-1/TCF transcription factor. Nuclear IGF-1R enhances transcription of cyclin D1 and axin2, and we show that it is enriched in the cyclin D1 promoter region. In the following study, paper II, we propose a pathway by which IGF-1R is transported into the nucleus. IGF-1R is transported along microtubules via the dynactin transportation complex, to the nuclear pore where it is transferred to importin-β which guides the receptor to the nuclear pore complex protein RanBP2, which further assists the receptor into the cell nucleus in a RanGTPase dependent manner. Inhibition or obstruction of any of these components results in a reduction in nuclear IGF-1R. Further, we suggest that RanBP2 is the SUMO E3 ligase in IGF-1R SUMOylation and we show that SUMO-1 modification of the receptor is also important for its stability. In paper III, we demonstrate that the EGFR is SUMOylated and propose five lysine residues as SUMO-1 targets which were identified by two different mass spectrometry strategies. One of these residues, lysine 37, came up as a suggested target in both mass spectrometry methods. EGFR mutated in this site – EGFR-K37R – causes a decrease in protein levels as well as transcriptional activity of cyclin D1 and c-myc, two target genes of nuclear EGFR. To summarize, our data shows (I) a pathway by which nuclear IGF-1R is being transported and the functional importance of nuclear IGF-1R as a co-activator in transcription and (II) that the EGFR is also SUMOylated and might play a role in its transcriptional activity. Together these results may unravel new mechanisms for IGF-1R and EGFR that have implications in carcinogenesis

Mary Wollstonecraft’s cottage economics: property, political economy, and the European future

This paper discusses the figure of the cottage throughout Wollstonecraft’s writings in the context of her ongoing critique of political economy. It explores links between Wollstonecraft and agrarian economic alternatives proposed by her radical contemporaries. Whilst the cottage is a well-recognised trope in the late eighteenth-century picturesque, this paper argues that Wollstonecraft’s cottages need to be seen in a distinct light: as embodying a critique of a particular form of economic modernity and as measuring the possibility of an alternative economic future for Europe

Credit gap risk in a first passage time model with jumps

The payoff of many credit derivatives depends on the level of credit spreads. In particular, credit derivatives with a leverage component are subject to gap risk, a risk associated with the occurrence of jumps in the underlying credit default swaps. In the framework of first passage time models, we consider a model that addresses these issues. The principal idea is to model a credit quality process as an Itô integral with respect to a Brownian motion with a stochastic volatility. Using a representation of the credit quality process as a time-changed Brownian motion, one can derive formulas for conditional default probabilities and credit spreads. An example for a volatility process is the square root of a Lévy-driven Ornstein-Uhlenbeck process. The model can be implemented efficiently using a technique called Panjer recursion. Calibration to a wide range of dynamics is supported. We illustrate the effectiveness of the model by valuing a leveraged credit-linked note. --gap risk,credit spreads,credit dynamics,first passage time models,stochastic volatility,general Ornstein-Uhlenbeck processes

Genre and the mediation of political economy in Edmund Burke's 'Reflections on the revolution in France' and Mary Wollstonecraft's 'A vindication of the rights of men'

This paper explores the generic fluidity of Burke's Reflections on the Revolution in France within the context of the rise of political economy at the end of the eighteenth century and the crisis of the concept of value at that time. It argues that the generic mix of Burke's text can be read as a rhetorical strategy which at once conveys but also mystifies the perceived truths of a labour economy in thrall to the circulation of goods. At the same time, Burke's text seeks to maintain a fiction of the beauty of the social order through a sensationalist and aesthetic terminology and style, thus establishing political economy as a science to be mediated by the aesthetic. Some attention is also paid to Wollstonecraft's response to Burke in her Vindication of the Rights of Men, especially her attack on his gentlemanly authorial persona, and her resistance to Burke's desire to separate the aesthetic and the affective from the realms of political and economic life

Credit dynamics in a first passage time model with jumps

The payoff of many credit derivatives depends on the level of credit spreads. In particular, the payoff of credit derivatives with a leverage component is sensitive to jumps in the underlying credit spreads. In the framework of first passage time models we extend the model introduced in [Overbeck and Schmidt, 2005] to address these issues. In the extended a model, a credit quality process is driven by an Itô integral with respect to a Brownian motion with stochastic volatility. Using a representation of the credit quality process as a time-changed Brownian motion, we derive formulas for conditional default probabilities and credit spreads. An example for a volatility process is the square root of a Lévy-driven Ornstein-Uhlenbeck process. We show that jumps in the volatility translate into jumps in credit spreads. We examine the dynamics of the OS-model and the extended model and provide examples. --gap risk,credit spreads,credit dynamics,first passage time models,Lévy processes,general Ornstein-Uhlenbeck processes

Fostering Metacognition in CPS Training – Tools and Techniques

Metacognition is described as the awareness of one’s own cognitive processes, as well as the ability to regulate them. This Master’s project provides an insight into how metacognition can be integrated into a Creative Problem Solving training with the aim of enhancing the participants’ understanding of relevant strategies employed in the context of creative thinking, enabling them to accelerate the application of their learning outside the training environment. A toolkit for metacognitive instruction within a CPS training is provided, consisting of specific tools as well as guidelines and suggestions for the trainer