Background: The Internet has created new efficient channels of doing business. For this nontraditional market, a business strategy that is both effective and efficient needs to be employed. The Long Tail business strategy was developed by Chris Anderson in 2006. It is possible that the Long Tail strategy not only can increase revenue by offering more “niche” products, but also can enhance customers’ loyalty toward the company. However, in order to achieve the latter, companies need to communicate with customers in more effective and more efficient ways. Therefore, communication is inevitably the fundamental element for companies’ efforts to build customer relationships. The Long-Tail, suggested by Anderson and Sugaya, to be an effective strategy for enhancing customer loyalty. But can it fit in the case of Swedish Apple Premium Resellers?   Purpose: The purpose of this thesis is to test if the Long-Tail strategy can enhance e-loyalty by adding value to online marketing communications in the case of Apple Premium Resellers’ customers in Sweden. Method: The data collection was mainly through questionnaires -- a quantitative approach. The target group was Apple Premium Resellers’ customers in Sweden. The questionnaire was distributed in Stockholm and Jönköping. Various statistical techniques as well as theories and models were used for data analysis. Conclusion:It can be concluded that the Long Tail strategy can add value to the online marketing communications, and improved online marketing communications can enhance customer loyalty in e-commerce. Therefore, the Long-Tail strategy can enhance e-loyalty by adding value to online marketing communications in the case of Swedish Apple Premium Resellers.

This paper studies the dependence structure between the real estate and financial markets in the United States from roughly 1975 to 2010, including the stock, bond and foreign exchange markets. This analysis uses dynamic copulas, including the Gaussian, Gumbel and Clayton copula. The Gumbel and Clayton copulas are used to separately capture the tail dependence of data. The dependence between the property indices (HPI and NCREIF) and the three financial markets is analyzed using the parameters of the copula. The property indices are divided in two different ways: by different regions and by different types of real estate. Although we study the dependence between the real estate and the financial markets in the U.S., the main objective of this paper is to analyze the change in the dependence structure when financial disasters occur. This study indicates that the real estate and the stock markets were positively related during this time period, and this dependence drove extreme movement when financial crises occurred. This dependence differed depending on the type of financial crisis, such as the Internet bubble crisis or the financial crisis in 2008. The dependence between the real estate and bond markets was also positively related, and extreme movement also occurred during financial crises. As for the dependence between the real estate and foreign exchange markets, although the results shows that dependence decreased when financial crises occurred, this is because the value of U.S. dollars are opposite to those of the index, and the left tail dependence exists as previous result. When looking at different regions or types of property, the differences in dependence structure were not obvious, although they were positively related. Both right and left tail dependences existed for most regions and property types, although some regions or types showed either right or left tail dependences alone. Therefore, investors should focus on the relationship between different markets, not on the region or type of real estate.

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The Red Tail site (FbNp-10) is a multicomponent habitation site located 2.5 km north of Saskatoon within the boundaries of Wanuskewin Heritage Park. The site was initially tested in the early 1980s and then excavated during the summers of 1988 and 1989 by University of Saskatchewan archaeology field school students, paid crews and many volunteers. Evidence from the site indicates that it was inhabited numerous times, beginning around 4,300 years before present with a McKean occupation, which also included the only Mckean house pit feature found on the Canadian Plains. Other associations with archaeological cultures include Sandy Creek, Besant and Avonlea, revealing that the most recent identifiable occupation to have occurred was between 1,300 – 1,000 years before present. The Sandy Creek component is only the second to be recovered from a site within Wanuskewin Heritage Park. As the longest running archaeological project in Canada, the sites that have been excavated at Wanuskewin have involved a number of volunteers and the success of such a cultural facility would not be possible without the interest of members of the public. The dissemination of information about archaeology to the public has a colourful past in Saskatchewan that began in 1935 with the formation of the Saskatoon Archaeological Society; a group of avocationals who were interested in learning and sharing information about this province’s rich cultural history. Since then, the Saskatchewan Archaeological Society and its associated chapters were formed and awareness for the importance of preserving the past has been communicated through many avenues, including programs that invite members of the public to participate in archaeological opportunities within the province. An examination of these avenues of information sharing demonstrates how important public interest and support is to archaeology and heritage works in Saskatchewan.

Tuberculosis and malaria are among the most deadly infectious diseases in the world. The prevalence in regions without well-established public health causes economical and financial burdens for both society and patients. There is an urgent need to find effective treatments due to the emergence of drug-resistant strains. The aim of the studies reported here was to gain knowledge from the protein structures that can lead to the elimination of these pathogens. In these studies, protein crystallography is the main method used to solve protein structure. Based on the protein structure, we used different methods to characterize the protein function of three lipid-binding proteins (LprG, LprA, and gp232), and to identify potent inhibitors against Plasmodium falciparum enoyl-ACP reductase (PfENR), a drug target protein involved in central lipid metabolism. To characterize the function of two lipid-binding proteins (LprG and LprA), liquid chromatography-mass spectrometry (LC-MS) was used to analyze the ligand extract. In the study of tail fiber protein from mycobacteriophage, we used protein sequence alignment to identify gp232 as a major tail fiber protein, which potentially binds to lipids on the cellular surface of mycobacteria. A pull-down assay and imaging methods (fluorescence microscopy and electron microscopy) were conducted to confirm the function of gp232. In the structural study of PfENR, the structure-activity relationships method was used to find potent inhibitors against PfENR, which would show stronger inhibition than the known inhibitor triclosan. The triclosan-like analogs with modification at the 5-position revealed a new binding site in PfENR that has great potential for improving the potency of inhibition. We found that two inhibitors containing the core structure of piperidine and tetrahydroquinoline reached this new binding site and were 10-fold more potent than triclosan. The structural study of PfENR provides structural insights into the inhibitor-binding site that can lead to the discovery of new drugs. The comprehensive knowledge that we gained from the structural studies of these lipid-binding proteins provide new information that could lead to a greater understanding of pathogen physiology or guide the discovery of effective treatments to eliminate the pathogens.

As robots continue to enter people's spaces and environments, it will be increasingly important to have effective interfaces for interaction and communication. One such aspect of this communication is people's awareness of the robot's actions and state. We believe that using high-level state representations, as a peripheral awareness channel, will help people to be aware of the robotic states in an easy to understand way. For example, when a robot is boxed in a small area, it can suggest a negative robot state (e.g., not willing to work in a small area as it cannot clean the entire room) by appearing unhappy to people. To investigate this, we built a robotic dog tail prototype and conducted a study to investigate how different tail motions (based on several motion parameters, e.g., speed) influence people’s perceptions of the robot. The results from this study formed design guidelines that Human-Robot Interaction (HRI) designers can leverage to convey robotic states. Further, we evaluated our overall approach and tested these guidelines by conducting a design workshop with interaction designers where we asked them to use the guidelines to design tail behaviors for various robotic states (e.g., looking for dirt) for robots working in different environments (e.g., domestic service). Results from this workshop helped in improving the confusing parts in our guidelines and making them easy to use by the designers. In conclusion, this thesis presents a set of solidified design guidelines that can be leveraged by HRI designers to convey the states of robots in a way that people can readily understand when and how to interact with them.

The bacteriophage lambda tail protein gpK is required for tail assembly. The activity of the protein can be found at the assembling tail tip and is believed to be localized to this structure. GpK is a 27 kDa protein that has sequence identity to two families of proteins: the Mov34 family of peptidases and the NlpC/P60 family of peptidoglycan endopeptidases. Point substitutions and complementation data confirm that gpK possesses each of these domains and that they can function in trans. When the Mov34 domain is inactivated tail assembly is disrupted whereas when the NlpC/P60 domain is inactivated tails assemble but are inactive. Evidence is presented here that the C-terminal domain possesses lytic activity in isolation but not when part of the full-length protein.

The bacteriophage lambda tail protein gpK is required for tail assembly. The activity of the protein can be found at the assembling tail tip and is believed to be localized to this structure. GpK is a 27 kDa protein that has sequence identity to two families of proteins: the Mov34 family of peptidases and the NlpC/P60 family of peptidoglycan endopeptidases. Point substitutions and complementation data confirm that gpK possesses each of these domains and that they can function in trans. When the Mov34 domain is inactivated tail assembly is disrupted whereas when the NlpC/P60 domain is inactivated tails assemble but are inactive. Evidence is presented here that the C-terminal domain possesses lytic activity in isolation but not when part of the full-length protein.

Peroxisomes are dynamic and multifunctional organelles, which are essential for human health and development. They are remarkably diverse, with functions that vary significantly between cells and organisms, and can dramatically change their size, shape and dynamics in response to cellular cues. In the past few years, several studies have significantly increased our understanding of the basic principles that enable peroxisome biogenesis and degradation, as well as their pivotal role in cellular signalling and homeostasis. However, several of these processes are still poorly understood. In this thesis we initially studied the peroxisome targeting mechanism of a group of C-terminally anchored membrane proteins, known as tail-anchored (TA) proteins. In order to investigate the molecular signals that enable TA protein targeting to cellular organelles, we analysed the physicochemical properties of a cohort of TA proteins both in silico and in vivo, and show that a combination of transmembrane domain (TMD) hydrophobicity and C-terminal tail charge determines organelle-specific targeting. Focusing on peroxisomes, we demonstrate that a balance between TMD hydrophobicity and high positive tail charge directs TA proteins to this organelle, and enables binding to the peroxisomal chaperone PEX19. These results allowed us to create a bioinformatical tool to predict the targeting of uncharacterised TA proteins and further develop our understanding of the molecular mechanisms involved in the targeting of this protein group. From our initial TA protein screen, we identified the TA protein MIRO1 at peroxisomes and looked at its role in the regulation of peroxisome motility. We show that endogenous MIRO1 localises to mitochondria and peroxisomes, and that dual targeting depends on the C-terminal tail. MIRO1 expression significantly increased peroxisome motility in several cell lines, and revealed a role for motility in peroxisome dynamics, by inducing organelle proliferation and elongation. These results reveal a new molecular complex at peroxisomes and provide us with a tool to further dissect the role of motility on peroxisome function.

Cette thèse s'intéresse à l'utilisation de techniques numériques par approximation sous forme de séries et de techniques de simulation pour l'approximation de la queue de distribution de sommes de variables aléatoires à variations régulières. Le calcul de la probabilité que la somme soit plus grande qu'un seuil donné est important en gestion des risques. En particulier, ce calcul est utilisé pour définir le besoin en capital des sociétés d'assurances ou d'autres institutions financières. Le premier chapitre constitue l'introduction de la thèse. Il explique les principaux résultats et présente les outils mathématiques qui sont développés dans la thèse. Le second chapitre est basé sur le travail : ”Series expansions for the sum of the independent Pareto random variables”, article rédigé avec le Professeur Christian ROBERT, directeur de la thèse. Cet article est soumis à publication. Il propose un algorithme de calcul pour déterminer la queue de distribution d'une somme de variables aléatoires de type Pareto non nécessairement équidistribuées. Il propose une approximation sous forme de série de la fonction de survie de la somme. L'algorithme utilisé pour calculer l'approximation est simple, facile à implémenter, et offre de très bons résultats numériques. Le troisième chapitre de cette thèse est basée sur l'article : ”New efficient estimators in rare event simulation with heavy tails”, publié dans Journal of Computational and Applied Mathematics, et co-écrit avec le Professeur Christian ROBERT. Il s'intéresse à l'approximation par simulation de la probabilité que la somme de variables aléatoires indépendantes à variations régulières soit plus grande qu'un seuil élevé. Des estimateurs efficaces ont déjà été introduits dans la littérature associée à la simulation d'évènements rares. Nous proposons de nouvelles techniques de simulation qui sont plus efficaces que les méthodes précédemment proposées. Le quatrième chapitre poursuit l'analyse de la simulation d'évènements rares du type ”la somme est plus grande qu'un seuil”, mais cette fois-ci il s'intéresse à des situations où les variables aléatoires sont dépendantes. Il se focalise sur le cas où la dépendance est donnée par une copule archimédienne. Ce chapitre est basé sur l'article en relecture : ”Efficient simulation of tail probabilities of sums with heavy tailed random variables and Archimedean copulas”. Les équivalents asymptotiques de la probabilité de dépassement de seuil ne sont connus que dans des cas particuliers et ils fournissent en général des approximations très médiocres de la vraie valeur. Les techniques de simulation sont donc très appréciables pour obtenir rapidement des approximations précises. Nous proposons quatre estimateurs et quatre techniques de simulation associées. Nous montrons que les erreurs relatives sont asymptotiquement bornées pour presque tous les estimateurs. Les simulations montrent que certains estimateurs sont plus précis / This thesis aims to study computation and simulation methods to approximate tail distribution of the sums of regularly varying random variables. The paper proceeds as follows: The first chapter provides the general introduction of the thesis. The second chapter is essentially constituted by the article ”Series expansions for the sum of the independent Pareto random variables” which was co-written with Professor Christian ROBERT, actually submitted for publication. It deals with the problem of estimating tail distribution of the sum of independent Pareto variables. This problem has been studied for a long time but a complete solution has not yet been found. In this section, we acquire an exact formula, a series expansions, for the distribution of the sum of independent Pareto of non-integer tail indices. Not only is this formula simple and easy to apply but it also gives better numerical results than most of existing methods.The third chapter rests on the article ”New efficient estimators in rare event simulation with heavy tails”, co-written with Professor Christian ROBERT, currently published on ”Journal of Computational and Applied Mathematics 261, 39-47” in 2013. Practically, efficient estimation for tail distribution of the sum of i.i.d. regularly varying random variables is one of widely researched problems in rare event simulation. In this context, Asmussen and Kroese’s estimator has performed better than other works. This part will introduce a new way to approach the sum. Our obtained estimator is more efficient than Asmussen and Kroese’s estimator in the case of regularly varying tail. In other cases, combined with techniques of conditional Monte Carlo and importance sampling, our estimator is still better. In the fourth chapter, we continue to study the tail behavior of the sum of regularly varying variables, with additional assumption that the dependence follows an Archimedean copula or an Archimedean survival copula. This section hinges on the article ”Efficient simulation of tail probabilities of sums with heavy tailed random variables and Archimedean copulas” which is under consideration for being published. Almost all previous studies on this problem used asymptotic approaches which are hard to control the errors. Therefore, techniques of simulation to calculate the tail probability of the sum are presented. Though some of our estimators have bounded relative errors while the others do not, all of them give favorable numerical performances for such a challenging problem