Microbial growth and the oxidation of inorganic sulphur compounds

The work reported in this thesis is aimed at providing a broader basis for the understanding of the growth, physiology and ecology of bacteria that oxidise inorganic sulphur compounds either as a source of energy for growth or during heterotrophic metabolism. Using chemostat culture techniques, observed yields (Y) , true molar growth yields (Y max) and maintenance coefficients were obtained for Thiobacillus versutus T.neopolitanus, T. acidophilus and Thermothrix thiopara under various conditions. This was the first report of the ability of T. acidophilus to grow on soluble inorganic sulphur compounds, and of T. neapolitanus and Thermothrlx thiopnra to grow in continuous culture on tetrathionate or trithionate. The Y max values in this study were analysed in terms of 'biochemical efficiency' of the organisms. Previously only two distinct classes of inorganic sulphur oxidisers were identified on the basis of Y values. This study reassesses these findings as it is shown that a range of Y max values on thiosulphate exist. This may mean a greater" 'biochemical diversity' in terms of carbon metabolism, inorganic sulphur compound oxidation and/or energy conservation. The kinetics of growth of Thermothrix thlonara. Thiobacillus versutus and T. neopolitanus were studied at various temperatures in thiosulphate- limited culture . In T. versutus no significant difference was seen in Y max and m at growth temperatures of 17°-35⁰C. In T. neagolitanus . yield varied little with temperature, falling slightly at 10⁰ C above the optimum. Thermothrix thionara had similar Y max values at 65 and 72⁰ C. The biochemical implications of the high Y max values obtained for Thermothrix thiopara are discussed in detail. Using steady state pH values between pH 5.5-8.A, no significant difference in Y max was found for T. versutus and T . neapolitanus. The importance of heterotrophic and facultative inorganic sulphur oxidisers is discussed. Various enrichment and isolation techniques are described for obtaining novel facultative organisms. The isolation and study of a heterotrophic inorganic sulphur oxidiser led to a subsequent study to assess the ability of known heterotrophs to oxidise thiosulphate. Batch culture experiments revealed a rarity of organisms able to oxidise thiosulphate to sulphate but a common ability to oxidise this substrate quantitatively to tetrathionate. The organisms did not appear to obtain any useful energy from the oxidation. The ability of T. acldorhllus to growmixotrophicallv was investigated. In batch culture , tetrathionate and glucose were used simul taneously without diauxie, but yields and growth rates were lower mixotrophically than heterotrophically. In chemostat culture, dual limitation by glucose and tetrathionate resulted in biomass production greater than the. sum on the two substrates separately. Ribulose 1,5-bisphosphatecarboxylase activity was monitored during transitions from heterotrophic to mixotrophic to autotrophic growth. The behaviour of T. acidophilus was compared and contrasted with other facultative inorganic sulphur oxidisers

Expert judgment in climate science: How it is used and how it can be justified.

Like any science marked by high uncertainty, climate science is characterized by a widespread use of expert judgment. In this paper, we first show that, in climate science, expert judgment is used to overcome uncertainty, thus playing a crucial role in the domain and even at times supplanting models. One is left to wonder to what extent it is legitimate to assign expert judgment such a status as an epistemic superiority in the climate context, especially as the production of expert judgment is particularly opaque. To begin answering this question, we highlight the key components of expert judgment. We then argue that the justification for the status and use of expert judgment depends on the competence and the individual subjective features of the expert producing the judgment since expert judgment involves not only the expert's theoretical knowledge and tacit knowledge, but also their intuition and values. This goes against the objective ideal in science and the criteria from social epistemology which largely attempt to remove subjectivity from expertise

Interview with Thelma Mitch

An interview with Thelma Mitch regarding her experiences in a one-room school house.https://scholars.fhsu.edu/ors/1164/thumbnail.jp

Vitamin D in Australia : issues and recommendations

BACKGROUND A significant number of Australians and people from specific groups within the community are suffering from vitamin D deficiency. It is no longer acceptable to assume that all people in Australia receive adequate vitamin D from casual exposure to sunlight.OBJECTIVE This article provides information on causes, consequences, treatment and prevention of vitamin D deficiency in Australia. DISCUSSION People at high risk of vitamin D deficiency include the elderly, those with skin conditions where avoidance of sunlight is required, dark skinned people (particularly women during pregnancy or if veiled) and patients with malabsorption, eg. coeliac disease. For most people, deficiency can be prevented by 5&ndash;15 minutes exposure of face and upper limbs to sunlight 4&ndash;6 times per week. If this is not possible then a vitamin D supplement of at least 400 IU* per day is recommended. In cases of established vitamin D deficiency, supplementation with 3000-5000 IU per day for at least 1 month is required to replete body stores. Increased availability of larger dose preparations of cholecalciferol would be a useful therapy in the case of severe deficiencies. * 40 IU (international units) = 1 &micro;g<br /

Biological lubricant composition and method of applying lubricant composition

Fluid compositions and methods for lubrication of mammalian joints are disclosed, including both natural and artificial fluids. Synovial fluid acts to lubricate the bearing surfaces of bones and bone-like structures which are held in frictional contact within biological joints. Such fluids may be used to treat arthritic, injured, and diseased joints. Synovial fluid containing a dextran-based hydrogel with lipids provides enhanced rheological and tribological properties of such a fluid. Phospholipids are particularly useful in dextran-based compositions for synovial fluid. One phospholipid that can be used advantageously in synovial fluid is dipalmitoyl phosphatidylcholine (DPPC)

Developing a GamePlan: Libraries and Campus Athletic Departments

At a number of academic libraries, librarians have begun partnering with Athletic Departments to deliver information literacy to freshman athletes. This breakout session will present three different endeavors designed to meet the needs of the incoming student athlete. UCLA’s College Library has recently expanded collaboration with their athletic department from an annual one-shot for incoming football players to an ongoing partnership integrating library instruction and awareness into the freshman football and basketball teams’ total academic experience. Arizona State University faced two challenges: help student-athletes learn to use the Library\u27s resources, and train their tutors and mentors. Every ASU freshman athlete takes a one-credit Life Skills course, and working in collaboration with the Office of Student Athlete Development, the Instruction team had the unprecedented opportunity to help design the curriculum for a library-focused unit that would not only teach the athletes and their academic coaches about the available resources, but also require the students to write a reflective essay on the experience of searching for relevant information in a library resource. At Willamette University, the librarians have worked with the Athletic Department to create a program called “GamePlan”. The program, which now includes football, crew, basketball, soccer and volleyball teams, is in its third year. Each Fall semester is treated as an “information challenge”, broken up into seven different 20-minute sessions. The sessions, held in the evenings, are focused on individual topics with explicit objectives

Biological lubricant composition and method of applying lubricant composition

Fluid compositions and methods for lubrication of mammalian joints are disclosed, including both natural and artificial fluids. Synovial fluid acts to lubricate the bearing surfaces of bones and bone-like structures which are held in frictional contact within biological joints. Such fluids may be used to treat arthritic, injured, and diseased joints. Synovial fluid containing a dextran-based hydrogel with lipids provides enhanced rheological and tribological properties of such a fluid. Phospholipids are particularly useful in dextran-based compositions for synovial fluid. One phospholipid that can be used advantageously in synovial fluid is dipalmitoyl phosphatidylcholine (DPPC)

Prioritizing the protection and creation of natural and naturebased features for coastal resilience using a GIS-based ranking framework – an exportable approach

Increasing the preservation and creation of natural and nature-based features (NNBF), like wetlands, living shorelines, beaches, dunes and other natural features to improve community resilience in the face of increasing coastal flooding may be achieved by highlighting the locally relevant benefits that these features can provide. Here we present a novel application of the least-cost geospatial modeling approach to generate inundation pathways that highlight landscape connections between NNBF and vulnerable infrastructure. Inundation pathways are then used to inform a ranking framework that assesses NNBF based on their provision of benefits and services to vulnerable infrastructure and for the broader community including 1) the flooding mitigation potential of NNBF, 2) the relative impact of those NNBF on local infrastructure, and 3) co-benefits for the broader community linked to incentive programs like nutrient reduction crediting and the Federal Emergency Management Agency’s Community Rating System. Inundation pathways are also used to identify locations lacking in benefits from NNBF as target areas for NNBF restoration or creation. This approach, applied here for coastal Virginia, with project outputs available via an interactive map viewer1, can be customized for application in any community to identify high-priority NNBF that are particularly beneficial for preservation and to identify target areas for new or restored features