This report is mainly based on the paper "Optimal multiple stopping and valuation of swing options" by R. Carmona and N. Touzi (1). Here the authors model and solve optimal stopping problems with more than one exercise time. The existence of optimal stopping times is firstly proved and they then construct the value function of American put options with multiple exercises in the case of the Black-Scholes model, characterizing the exercise boundaries of the perpetual case. Finally, they extend the analysis to the swing contracts with infinitely many exercise rights. In this report, we concentrate on explaining their rigorous mathematical analysis in detail, especially for the valuation of the perpetual American put options with single exercise and two exercise rights, and the characteristics of the exercise boundaries of the multiple stopping case. These results are presented as theorems in Chapter 2 and Chapter 3. / text

The United Republic of Tanzania was formed on 26 April 1964 by the union of Tanganyika and the insular state of Zanzibar, comprising the islands of Zanzibar and Pemba. Today’s Tanzania is a key East Africa country, with a multiparty political system, and a well-developed civil society. It is the region’s largest country in terms of both land size and population, and major regional economic power. On 31st of October 2010, Tanzania held its fourth general elections since the re-introduction of the multi-party system in 1992. The famous ruling party is Chama Cha Mapinduzi (CCM), won both the Union and the Zanzibar presidents, and maintained its comfortable control of the National Assembly and of the Zanzibar House of Representatives. Though the development of news reporting has historically been central to conceptions of journalism in the many developing countries, studies on professionalism in developing countries are rare. In this con­nec­tion, academic research has largely overlooked the truth relating to the subject of professionalism in journalism in Africa, including in Tanzania. For instance, there are hardly any studies of the phenomena of chequebook journalism and envelope journalism, which are conspicuously wide­spread in African countries. In the cases of both chequebook journalism and envelope journalism, we refer to phenomena, where journalists accept payments from different news sources, in order to give them (preference in) coverage. Invariably, there is a commodification of the journalist services vis á vis the coverage of news from different sources. A few existing studies have used directories from the East African countries. However, they face the face the caveat of little effort being made to adjust them the realities of the African setting. To address this challenge, this study – which focuses on journalistic professionalism in Tanzania - addresses the phenomena by using different approach of literature reviews: incorporating structural functionalism, journalism ethics, and normative models of development or advancing media. Specifically, it indicates cognitive differences in terms of how journalists in Tanzania perceive and experience chequebook journalism and envelope journalism. The data, which were used in the study, were collected using documents review, interviews, and focus group discussions (FGD). Accordingly, the instruments used to collect data included both structured and unstructured questionnaires. The findings indicate that Tanzanian journalists revere chequebook journalism and envelope journalism, and the practice has reached unprecedented levels in the country. The main reason for this is socio-economic: journalists getting low salary make them more vulnerable and therefore motivated to accept payments from news sources. The problem of supplementing their incomes through this disputed practice has, however, unfavorably affected journalist’s objectivity and professionalism. Additionally, development news reporting which seldom offers envelope journalism is being avoided. One alarming result is a shift from a traditional model of journalism, where journalists strive to report any legitimate news, to a public relations model, where news is heavily influenced by source and amount of payments. These results suggest that the public may be short-changed on its informational needs by being fed tactfully structured elitist news. Given the media's role in the development process, this may adversely affect development in the developing countries like Tanzania.   Keywords: Envelope Journalism, Ethics, Professionalism, Journalism, Journalist, and Chequebook Journalism. / Kinondoni District, Dar es Salaam, Tanzania.

No description available.

The common envelope (CE) interaction is a still poorly understood, yet critical phase of evolution in binary systems that is responsible for various astrophysical classes and phenomena. In this thesis, we use various approaches and techniques to investigate different aspects of this interaction, and compare our models to observations. We start with a semi-empirical analysis of post-CE systems to predict the outcome of a CE interaction. Using detailed stellar evolutionary models, we revise the α equation and calculate the ejection efficiency, α, both from observations and simulations consistently. We find a possible anti-correlation between α and the secondary-to- primary mass ratio, suggesting that the response of the donor star might be important for the envelope ejection. Secondly, we present a survey of three-dimensional hydrodynamical simulations of the CE evolution using two different numerical techniques, and find very good agreement overall. However, most of the envelope of the donor is still bound at the end of the simulations and the final orbital separations are larger than the ones of young observed post-CE systems. Despite these two investigations, questions remain about the nature of the extra mechanism required to eject the envelope. In order to study the dynamical response of the donor, we perform one-dimensional stellar evolution simulations of stars evolving with mass loss rates from 0.001 up to a few M⊙/yr. For mass-losing giant stars, the evolution is dynamical and not adiabatic, and we find no significant radius increase in any case. Finally, we investigate whether the substellar companions recently observed in close orbits around evolved stars could have survived the CE interaction, and whether they might have been more massive prior to their engulfment. Using an analytical prescription for the disruption of gravitationally bound objects by ram pressure stripping, we find that the Earth-mass planets around KIC 05807616 could be the remnants of a Jovian-mass planet, and that the other substellar objects are unlikely to have lost significant mass during the CE interaction. / Graduate

This thesis analyses the issue of solar access in environmentally sensitive attitudes to architecture. The primary intention of the study is to scrutinize the relationship between solar access and building form (volume) and investigate the efficiency of solar control on / by this form by means of &lsquo / solar envelope&rsquo / technique which is, first, defined by Knowles and developed in different ways in the last 30 years. Solar envelope in Knowles&rsquo / terms can be defined as the building volume resulting from shadow casting restrictions and must be recognized as a both theoretical and technical method in the form generation of any building. Similar to the concept of maximum developable volume allowed under height restrictions or floor area ratios, solar envelope is, rather, defined by solar access concerns. This method is applicable on single buildings as well as dense urban areas (residential and mix use areas) and is a supportive tool in the form generation in any stage of design. Buildings constructed without exceeding the abstract solar envelope that is constructed on the basis of solar access will be successful in the means of passive solar and low-energy design. Such a success will supply a sustainable development, which is globally discussed as a result of environmental and energy crisis. The aim of this thesis is to represent the method of constructing solar envelope, in case study, with its fundamental aspects and tools. Odt&uuml / kent residences will be the objects of this study. Results of this application will be tested with shadow maps and evaluations both for the existing situation and the proposed envelopes will be developed.

The aim of this study was to investigate the effects of windows and building envelope materials on the thermal performance of residential buildings, for the climatic conditions of Ankara. The effects of the thermal mass of the building envelope, together with the effects of glazing type and shading conditions of south-facing windows on thermal performance were investigated using two computer-based thermal analysis programs called: ECOTECT 5.0 and ENERGY-10. The hypothetical building model used for computer simulations was based on the sample residential building defined in the Turkish Standards on the Regulations for Building Insulation, TSE 825, as prepared by the T&uuml / rk Standartlari Enstit&uuml / s&uuml / (TSE, Turkish Standards Institute). Simulation studies were first conducted with ECOTECT 5.0, but since the results did not conform to earlier researches and, since this discrepancy could not be explained even by the support forum prepared by the authors of this software, it was decided to continue the simulations with ENERGY-10, which proved to be more consistent. The results of 240 program runs of ENERGY- 10 were explained through graphical and statistical analysis on the basis of annual heating, cooling, and total energy needs of the building model. The study showed that building envelope materials having high thermal storage capacities together with high-performance glazing, in terms of increased thermal resistance, provided significant energy savings, which could be augmented by increasing the size of south-facing windows. The study also revealed that shading devices in the form of fixed overhangs applied to a south-facing window of any size did not provide substantial reductions in the energy demands of residential buildings, when annual total energy demands were considered for the climatic conditions of Ankara.

Hepatitis B virus (HBV) is a global public health problem with an estimated number of 350 million carriers world wide who are at risk of development of severe liver disease and hepatocellular carcinoma. Despite currently available nucleoside analogue therapies no general therapeutic breakthrough, which completely clears infection has been achieved after more then two decades of research. Therefore there is a continuing need to identify new antiviral targets that may be translated into useful therapies. / Hepatitis B fusion represents a possible novel antiviral target. However, its mechanism and the envelope proteins involved remain unknown, due to the lack of an efficient infection system to study the early stages of virus infection. On the other hand, the study of the related duck hepatitis B virus (DHBV) and the ability to carry out an in vitro infection of primary duck hepatocytes has provided some insight into the hepadnaviral mechanism of entry and the role of envelope proteins domains in this process. ( For complete abstract open document)

Diss. (sammanfattning) Stockholm : Karol. inst., 2005. / Härtill 4 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 5 uppsatser.

abstract: Protein folding is essential in all cells, and misfolded proteins cause many diseases. In the Gram-negative bacterium Escherichia coli, protein folding must be carefully controlled during envelope biogenesis to maintain an effective permeability barrier between the cell and its environment. This study explores the relationship between envelope biogenesis and cell stress, and the return to homeostasis during envelope stress. A major player in envelope biogenesis and stress response is the periplasmic protease DegP. Work presented here explores the growth phenotypes of cells lacking degP, including temperature sensitivity and lowered cell viability. Intriguingly, these cells also accumulate novel cytosolic proteins in their envelope not present in wild-type. Association of novel proteins was found to be growth time- and temperature-dependent, and was reversible, suggesting a dynamic nature of the envelope stress response. Two-dimensional gel electrophoresis of envelopes followed by mass spectrometry identified numerous cytoplasmic proteins, including the elongation factor/chaperone TufA, illuminating a novel cytoplasmic response to envelope stress. A suppressor of temperature sensitivity was characterized which corrects the defect caused by the lack of degP. Through random Tn10 insertion analysis, aribitrarily-primed polymerase chain reaction and three-factor cross, the suppressor was identified as a novel duplication-truncation of rpoE, here called rpoE'. rpoE' serves to subtly increase RpoE levels in the cell, resulting in a slight elevation of the SigmaE stress response. It does so without significantly affecting steady-state levels of outer membrane proteins, but rather by increasing proteolysis in the envelope independently of DegP. A multicopy suppressor of temperature sensitivity in strains lacking degP and expressing mutant OmpC proteins, yfgC, was characterized. Bioinformatics suggests that YfgC is a metalloprotease, and mutation of conserved domains resulted in mislocalization of the protein. yfgC-null mutants displayed additive antibiotic sensitivity and growth defects when combined with null mutation in another periplasmic chaperone, surA, suggesting that the two act in separate pathways during envelope biogenesis. Overexpression of YfgC6his altered steady-state levels of mutant OmpC in the envelope, showing a direct relationship between it and a major constituent of the envelope. Curiously, purified YfgC6his showed an increased propensity for crosslinking in mutant, but not in a wild-type, OmpC background. / Dissertation/Thesis / Ph.D. Microbiology 2010