Immunity to K1 killer toxin: internal TOK1 blockade.

K1 killer strains of Saccharomyces cerevisiae harbor RNA viruses that mediate secretion of K1, a protein toxin that kills virus-free cells. Recently, external K1 toxin was shown to directly activate TOK1 channels in the plasma membranes of sensitive yeast cells, leading to excess potassium flux and cell death. Here, a mechanism by which killer cells resist their own toxin is shown: internal toxin inhibits TOK1 channels and suppresses activation by external toxin

Exploring visitor experiences along the Going-to-the-Sun corridor of Glacier National Park

Visitor use on the Going-to-the-Sun Road (GTSR) corridor is one of the most critical issues that Glacier National Park faces. According to the park’s General Management Plan, it should be addressed to safeguard the quality of park resources and the visitor experiences. 80% of park visitors travel along at least some part of the road, which is the primary park experience and one of the most spectacular highlights of the park. The road was built in early 1930, and now brings almost 2 million visitors annually into the heart of Glacier NP. Increased number of cars on this narrow historic road caused traffic problems such as crowding at pullouts and traffic jams, as well as safety issues. The situation with traffic worsened also because of the road reconstruction which was aimed to rehabilitate the road and solve traffic problems in the long run. A new 10-year reconstruction project started in 2007; as a part of it a free shuttle service was introduced. It poses important questions about impacts on visitor behavior, visitor use, and visitor experiences in the park. Understanding existing patterns and trends in the current context is important. This exploratory research attempts to identify and describe the nature of actual and desired experiences from the perspective of visitors. It reveals the primary dimensions of the experiences, discusses the factors that influence them, and talks about connections, common patterns and trends. Data collection and analysis for this study were guided by the method of Grounded Theory. Fifty in-depth interviews with diverse Glacier NP visitors in various parts of the GTSR corridor were conducted. Interviews were tape-recorded, transcribed, and analyzed using a system of coding that identifies themes through which interviews can be organized, interpreted and presented. Through this process, three main categories of visitor experiences were identified: “Glacier as a Unique Setting”, “Motivations and Benefits”, and “Human Interactions”. They represent mainly social dimensions of visitor experiences and include some biophysical elements. Aspects that are associated with managerial dimensions are discussed separately with less depth within the forth category – “Managerial Issues”. The results of this study imply that there is a broad range of experiences occurring within this key corridor of Glacier NP. There is no single story and combination of the revealed dimensions; every visitor is different and his/her experience is unique. However, some common patterns exist, and several experience typologies are identified. Using tools such as the Recreation Opportunity Spectrum is recommended to embrace the diversity of experiences, while protecting the setting from changes in the conditions, and better preserving and improving different types of visitor experiences in Glacier NP

Poly(ionic liquids) for CO2 capture

In an attempt to halt the drastic accumulation of carbon dioxide (CO2) in the atmosphere, many countries have agreed to implement industrial solutions for CO2 capture, storage and utilisation. The primary objective is to separate CO2 from water vapour and nitrogen exhaust streams of combustion industries by using established techniques, such as chemical absorption (amine scrubbing), physical adsorption, and cryogenic distillation. While these techniques are already very well established on the market for other applications, their disadvantages in terms of energy and reagent consumption has promoted the use of alternative technical solutions, like membrane based CO2 capture. Poly(ionic liquids) (PILs) represent a group of innovative polymers with high affinity for CO2 molecules that may exhibit facilitated transport properties. They have been successfully employed in membrane contactors as substitutes for CO2 sorbents like amine solutions and ionic liquids (IL). PILs are mostly synthesised from IL monomers to overcome the restrictions of ILs liquid state of matter by polymerisation. This method allows the production of tailor made PILs with desirable properties. However, their mechanical properties are often impaired by low molecular chain length of the polymeric backbone. Alternatives suggest to incorporate the ILs in the form of IL pendants in the polymeric chain of already available polymers with well established polymeric structure and known mechanical properties. Although the synthetic changes in the polymer chains might affect their mechanical parameters, it seems to be more realistic to find a compromise between improved separation performance of PILs and process-ability of commercial polymeric precursors. This work extends the family of polymer derived PILs by exploring various synthetic possibilities for IL pendant incorporation. PIL synthesis were conducted on a variety of commercially available polymers, e.g. cellulose acetate, poly(vinylbenzyl) chloride, poly(diallyldimethyl chloride), used as parent materials. This polymer choice allowed the investigation of the polymeric backbone influence on the properties of the derived PILs. Also, the synthetic composition of ILs was diversified to produce pure and mixed PILs that might intensify the interactions between the pendants on intra- and intermolecular level within the polymeric matrix. The IL pendants contained functional groups that could exhibit hydrogen bonding interactions and affect the CO2 transport mechanism. These aspects are thought to affect positively the solubility of CO2 molecules in the PIL matrix and contribute to their preferential transport across the selective layer. As the gas transport also depends on the diffusion of CO2 molecules, the polymer matrix structure plays a crucial role in the membrane separation performance. Since PILs are polymers in solid-like state, the gas diffusion is restricted by their molecular dynamics. This restriction may be circumvented by decreasing the glass transition temperature of PILs, and therefore affecting the viscoelastic properties of the material. To do so, PILs were diluted with ILs having a lower viscosity by physical blending. Additionally, the effect of metal salt additives was studied to further facilitate interactions between the PIL matrix and permeating CO2 molecules. The synthesised PILs and PIL/additive blends underwent a thorough characterisation defining their properties from bulk polymer phase to thin-film composite (TFC) membranes. This multifaceted investigation established the link between the intrinsic properties of PILs with their separation performance by combining the results obtained in gas sorption, time-lag, and mixed-gas permeation tests. The latter, conducted in sweep mode with humidified feed, allowed the assessment of industrially relevant conditions for flue gas CO2 capture. Upon incorporation of IL pendants into the polymer backbone, the PIL separation performance improved in the majority of cases studied. The PIL CO2/N2 selectivity improved most when the IL pendant exhibited ability for hydrogen bonding, as the solubility of CO2 was affected. In addition, all PIL-based membranes showed enhanced CO2 permeances in mixed-gas tests with humidified feed, confirming their viability for industrially relevant applications. In general, the PIL-based TFC membranes fully exposed their potential as CO2 selective materials. Their versatility and ease of processing ensure the possibility for commercialisation once the optimisation of the large-scale employment is investigated. Initial assessment of their commercial value provides essential prospects for PILs to become established as a new generation of commercial polymer-based materials for CO2 capture.status: publishe

“NOT TAINTED BY THE PAST”: RE-CONSTRUCTIONS AND NEGOTIATIONS OF COLOURED IDENTITIES AMONG UNIVERSITY COLOURED STUDENTS IN POST- APARTHEID SOUTH AFRICA

The South African coloured identity is a profoundly complex construction that, on the one hand, is interpreted as an ambiguous and ‘in-between’ identity and, on the other hand, its own ambiguity and complexity provides multiple means and strategies of production and articulation within various contexts. This dissertation seeks to examine a production of multiple discourses by post-apartheid coloured youth in order to re-construct and negotiate their identities moving through various social contexts of everyday experiences within diverse university settings. Similarly to other minority and marginalized youth, coloured students produce various discourses and practices as the medium of counter-hegemonic formation and negotiation of their minoritized and marginalized identities. In this sense, coloured students implement produced discourses and practices as instrumental agency to create resistance and challenge the dominant discourses on their marginalized and minoritized identities, simultaneously determining alternate characteristics for the same identities. Turning to the current conceptualizations of coloured identities as heterogeneous, non-static and highly contextual, I analyze two dominant discourses produced by the coloured students: coloured as an ethnic/hybrid cultural identity and an adoption of an inclusive South African national identity, simultaneously rejecting coloured identity as a product of the apartheid social engineering. Additionally, integrating an ecological approach and ecology model of identity development, created and utilized by Renn (1998, 2004) in her work that explores how multiracial students construct their identities in the context of higher education, I develop an ecology model of coloured students’ identity development and present the data to determine what factors and opportunities, provided by microsystems, mesosystem, exosystems and macrosystem of identity development, are significant and how they influence coloured students’ identities production, development and negotiation in and out of the university environments. The dissertation analysis on coloured identities builds on nine months of ethnographic fieldwork in the Western Cape, South Africa, including limited participant observation and semi-structured interviews with the undergraduate and graduate coloured students of the University of the Western Cape and University of Stellenbosch, the Western Cape, South Africa

Lean Production Supply Chain and QFD-Analysis in the Process of Healthcare

The research examines the process of providing medical care to patients, including patients with self-referrals (patients without referral), in the planning and diagnostic department and the trauma department of the city clinical hospital. The aim of the research is to determine the percentage of refusals of "self-converters", patients of the hospital who refused to be hospitalized after the initial examination and laboratory tests, reduce the cost of medical care, increase efficiency, consider options for reducing the percentage of refusals from hospitalization, patients in need of medical care. The result of the research expands the boundaries of the application of the Lean Production Supply Chain philosophy to the service sector. Improvement of the production and pre-production domain of medical services provision through the introduction of lean manufacturing and QFD-analysis, reduction of losses and analysis of the decrease in the number of refusals from hospitalization of "self-converters". The results of the research can be applied in internal and external processes of medical establishments and in organizations engaged in providing services to industrial enterprises. The use of lean manufacturing tools allows reducing all types of losses and servicing cycle time. The application of QFD improves the service process in a full life cycle, not only in the manufacturing field, but also in the service sector