Stress resistance and ageing in Saccharomyces cerevisiae

The budding yeast, Saccharomyces cerevisiae, can be used as a model in which the processes behind ageing can be investigated. Yeast life span can be determined in two ways, i) the number of buds produced by an actively dividing mother cell can be counted as a measure of a yeast's budding life span, ii) the viability over time of cells arrested in GO can be recorded as a measure of yeast's chronological life span. As is the case for Drosophila and C. elegans increasing the cellular stress resistance and antioxidant scavenging capabilities of yeast extends the chronological life span. By increasing the stress resistance of cerevisiae through the overactivation of the heat shock response resulting from defects in the Hsp90 chaperone the chronological ageing of GO arrested cells was extended. The budding potential of these cells however was not increased. Extensions to the chronological lifespan of yeast adapted torespiratory growth was achieved with the overexpression of the superoxide dismutase enzymes, Cu,Zn-Sod and Mn-Sod, as well as catalase. A two-fold extension to chronological lifespan extension was observed in cells with increased Cu,Zn-Sod activity. In this strain levels of free radicals are low and the onset of total cellular protein oxidation, which coincides with a dramatic reduction in cellular viability, is delayed. The generation of free radicals during respiration is therefore a limiting factor for longevity. Over expressions of the free radical scavenging enzymes did not increase the budding potential of yeast cells. Despite the benefits for chronological survival gained from the overexpression of Mn-Sod, a disruption in mitochondrial morphology and inheritance in this strain leads to a reduced number of buds a mother cell could produce. A future goal for yeast ageing research is the identification of novel pathways involved in the determination of lifespan. The final part of this study included the development of a system by which the Euroscarf collection of deleted yeast strains can be screened for long lived mutants

Development of a voltage‐tuneable RF coil to enable double resonance experiments with Fast Field‐Cycling MRI

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A varactor-tuned RF coil for nuclear quadrupole double resonance with Fast Field-Cycling MRI

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THE PREVALENCE OF UNWANTED SEXUAL EXPERIENCES AMONG BELGIAN AND SOUTH AFRICAN STUDENTS

Child sexual abuse (CSA) is a global problem and South Africa has been identified as a high-CSA incidence country (Jewkes, 2002; Meier, 2002; New York Times, 2002 cited in Women’sInternational Network, 2002). Belgium is a low-CSA incidence country (Finkelhor, 1994) andthe comparison of two similar populations from these countries would elucidate differences inunwanted sexual experiences of these two settings, reflecting social and cultural variables thatmay affect the problem. Back, Jackson, Fitzgerald, Shaffer, Salstrom and Osman (2003),contend that very few studies have compared individuals of different nationalities and alsothose residing in their own countries, which limits the understanding of potential culturaldifferences regarding CSA. In their study of 65 North American and 88 Singaporean womencollege students they found 15,4% of North American respondents had been exposed to CSAcompared to 4,5% of Singaporean respondents, the majority of whom did not considerthemselves as being abused. Miller, Johnson and Johnson (1991) contend that self-reportbiases and definitional problems permeate CSA research and they developed an Early SexualExperience Checklist (ESEC) which seeks to avoid such problems. They argued that, becausethe ESEC assesses an explicit variety of non-coital responses and provides a non-restrictiveresponse format, a high incidence of unwanted sexual experiences may be reported as is thecase in their study

Development of an RF coil tuning system to enable Nuclear Quadrupole Double Resonance in Fast Field-Cycling MRI

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Enabling Nuclear Quadrupole Double Resonance capabilities for Fast Field-Cycling MRI

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Techniques and Bio-Medical Applications of Field-Cycling Magnetic Resonance

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The role of micronutrients in the infection and subsequent response to hepatitis C virus

Micronutrient deficiencies develop for a variety of reasons, whether geographic, socioeconomic, nutritional, or as a result of disease pathologies such as chronic viral infection. As micronutrients are essential for a strong immune response, deficiencies can significantly dampen both the innate and the adaptive arms of antiviral immunity. The innate immune response in particular is crucial to protect against hepatitis C virus (HCV), a hepatotropic virus that maintains chronic infection in up to 80% of individuals if left untreated. While many micronutrients are required for HCV replication, an overlapping group of micronutrients are also necessary to enact a potent immune response. As the liver is responsible for the storage and metabolism of many micronutrients, HCV persistence can influence the micronutrients’ steady state to benefit viral persistence both directly and by weakening the antiviral response. This review will focus on common micronutrients such as zinc, iron, copper, selenium, vitamin A, vitamin B12, vitamin D and vitamin E. We will explore their role in the pathogenesis of HCV infection and in the response to antiviral therapy. While chronic hepatitis C virus infection drives deficiencies in micronutrients such as zinc, selenium, vitamin A and B12, it also stimulates copper and iron excess; these micronutrients influence antioxidant, inflammatory and immune responses to HCV

Field-Cycling Magnetic Resonance Imaging - a Curiosity or the Next Big Thing?

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Fast Field-Cycling MRI : A New Imaging Modality

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