A study of chemolithoautotrophic bacterial rhodanese, and its potential contribution to cyanide wastage during cyanidation of biooxidized concentrates

Bibliography: leaves 119-129.Refractory gold-bearing metal-sulfide ores and concentrates can be successfully and economically treated by biooxidation prior to cyanidation. However, one of the major drawbacks of the biooxidation process is the excessive consumption of cyanide during the gold dissolution process. The largest proportion of cyanide wastage is attributed to thiocyanate formation. Thiocyanate can be formed by spontaneous chemical reactions between reactive sulfur species and cyanide. The enzyme rhodanese (thiosulfate: cyanide sulfurtransferase EC 2.8.1.1) is also able to catalyze the formation of thiocyanate using thiosulfate and cyanide as substrates. Therefore, the most relevant members of the microbial consortium responsible for biooxidation of gold-bearing ores or concentrates were investigated to determine whether they were able to contribute to thiocyanate formation by means of a enzyme reaction mechanism indicative of rhodanese. Together with a Thiobacillus caldus strain (T. caldus MNG), isolated from a biooxidation pilot plant, the sulfur-oxidizers Thiobacillus ferrooxidans ATCC 33020 (also able to oxidize iron) and Thiobacillus thiooxidans ATCC 19377 demonstrated rhodanese activity. However, the obligate iron-oxidizer Leptospirillum ferrooxidans DSM 2705 had no detectable rhodanese activity. High levels of rhodanese activity were detected from the mixed microbial population of a biooxidation pilot plant, which appeared to be dominated by T. caldus MNG. This T. caldus strain was initially identified in the biooxidation pilot plant using the PCR based 16S rDNA profiling technique of Rawlings (1995), and the identification confirmed by 16S rDNA sequencing. Therefore, T. caldus MNG is considered the major contributor to the rhodanese activity of the biooxidation pilot plant mixed culture. Within the range of sulfur substrates tested, the rhodanese enzyme of T. caldus MNG behaved exclusively as a thiosulfate: cyanide sulfurtransferase, and the rhodanese activity of T. caldus MNG appeared to be dependent on the physiological state of the cell during batch growth. An attempt to isolate a rhodanese gene from T. caldus MNG by Southern hybridization, using the Azotobacter vinelandii rhdA gene as a probe, was unsuccessful. On balance of the information available from this study, and reported elsewhere, rhodanese activity probably does not contribute as much to thiocyanate formation in the cyanidation plant as does the spontaneous chemical formation of thiocyanate

Geology and drilling history of the Ashida #1 geothermal test, Opihikao prospect, Hawaii

Discussion of the drilling program and interpretation of downhole geology based on cuttings samples from the Barnwell Ashida #1 well.For Barnwell Industries, Inc., Honolulu, Hawaii

Geology and drilling history of Lanipuna #1/sidetrack, Tokyo lands prospect, Hawaii

Discussion of the drilling program and interpretation of downhole geology based on cuttings samples from the Barnwell Lanipuna #1 sidetrack well.For Barnwell Industries, Inc., New York, New York

A study of the reading interests and reading habits of English (first language) secondary-school pupils in South Africa: with particular reference to the Province of Natal

The study derives from a belief, based on many researchers' writings, that wide and frequent book-reading aids the development of knowledge, emotional maturity and human sympathy, which are all essential attributes in a fragmented culture such as South Africa's. It is not accepted that conventional secondary-school literature-teaching in this country promotes a lifelong reading habit among the majority of pupils and a plea is made for the recognition of Reading as a curricular entity in its own right. The study suggests that, owing to a paucity of local research in this field, South African teachers and educational authorities are severely disadvantaged. If they are unable to offer advice based on a proper study of their pupils as readers, they run the risk of guiding many pupils' reading along paths that cannot promise satisfaction and fulfilment. Such stultifying of reading habits would contradict the aims of the present National Core Syllabuses for English (First Language). The thesis sets little store by the investigation of specific bookchoices, pointing out that the validity of such incidental findings, if gleaned from a latitudinal survey, is questionable. Instead, using the findings of questionnaires administered to nearly 2 800 pupils and their teachers, the thesis investigates the relationships between voluntary leisure-time reading and such factors as age, gender, intelligence, academic achievement and standard of living. It also looks at the influences of parents, teachers, peers, contemporary literature-teaching practices, school and public libraries, and leisure- time pursuits other than reading. Many suggestions are offered for further research into finer aspects of those considerations. Many of the findings serve merely to corroborate research from abroad, particularly in respect of age, gender and intelligence. That is none the less alarming when a striking decline in reading is found to occur in the early years of the secondary school. A number of other interesting findings emerge. Standard of living is shown to be inversely correlated with amount of reading, and television-viewing is not found to displace reading. Nor are other leisure-time pursuits found to affect amount of reading: avid readers are by and large extremely active and committed pupils. Reading emerges from the study as providing its own peculiar satisfaction, as does each of the other leisure activities investigated. The challenge is to ensure that infrequent readers become aware of what reading has to offer, and strategies for attempting to achieve that are posited, particularly with regard to the roles of public and school libraries. The roles of teachers and parents are found to be crucial to the development of an appetite for books, and it is suggested that schools and parents liaise formally and closely in this matter. The study groups pupils by a number of personal variables, and investigates their reactions to common forms and genres as well as to certain specifics of style, thereby discussing the relationship between reading, social maturity and academic achievement It argues strongly for recognition of the fact that educating secondary-school pupils in the development of keen and sensitive lifelong reading habits is a process which cannot be systematically taught as a set of skills

The Australian Farm Business Management Network: Industry, Education, Consultancy and Research Coming Together

Under the sponsorship of the University of Sydney, on 5-6th December 2002 the future of farm management in Australia was discussed. The fundamental conclusion achieved by key primary industry representatives, corporate executives, academics, consultants and researchers is that farm management will have a more significant role to play in the future than previously in servicing the primary sector. The idea of farm management as a profession was proposed. Its basis would be business management supported by farming systems and technology, and using an holistic approach to action (i.e. finance, people and environment). The new profession of Farm Business Management would seek to influence education, research, consultancy and extension in Australia. Interested parties participating of the 2002 National Farm Management Workshop came away with the idea of championing a consultative network, constituted by interested institutions and interested individuals, as a first step in the process of nurturing the future development of farm business management. By integrating farmers and academics with corporate executives, consultants and researchers the objective is to behave as a consultative group. This group will influence educational models, implement consultancy and research strategies, and network in social and professional terms. Moreover, this network will provide a systematic opportunity for the channelling of farm business management and farming systems related information at different levels for education, extension and scientific purposes. This network is called the Australian Farm Business Management Network (AFBMnetwork).Institutional and Behavioral Economics,

The Benefits of Early Book Sharing (BEBS) for child cognitive and socio-emotional development in South Africa: study protocol for a randomised controlled trial

Background:Children in Low and Middle-Income Countries (LMICs) are at risk for problems in their cognitive, social and behavioural development. Factors such as a lack of cognitive stimulation, harsh parenting practices, and severe and persistent aggression in early childhood are central to the genesis of these problems. Interventions that target the intersection between early childhood development, parenting, and early violence prevention are required in order to meaningfully address these problems. Methods:We are conducting a randomized controlled trial to evaluate a parenting intervention for caregivers of children between 23-27 months, designed to promote child cognitive and socio-emotional development in Khayelitsha, a low income peri-urban township in South Africa. Families are randomly allocated to book sharing or to a wait-list control group. In the intervention, we train caregivers in supportive book-sharing with young children. Training is carried out in small groups over a period of eight weeks. Data are collected at baseline, post-intervention and at six months post-intervention. In addition to targeting child cognitive development, the intervention aims to improve child socio-emotional functioning. Discussion:The Benefits of Early Book Sharing (BEBS) trial aims to evaluate the impact of an early parenting intervention on several key risk factors for the development of violence, including aspects of parenting and child cognition, prosocial behaviour, aggression, and socio-emotional functioning. The study is being carried out in a LMIC where violence constitutes a major social and health burden. Since the intervention is brief and, with modest levels of training, readily deliverable in LMIC contexts, a demonstration that it is of benefit to both child cognitive and socio-emotional development would be of significance

Drilling history and geology of the Lanipuna no. 6 geothermal test, Lanipuna prospect, Hawaii

Discussion of the drilling program and interpretation of downhole geology based on cuttings samples from the Lanipuna 6 well.For Barnwell Industries, Inc., Honolulu, Hawaii

Temperature-gradient and heat flow data, Grass Valley, Nevada

A series of 16 shallow and intermediate-depth temperature-gradient holes were drilled for Sunoco Energy Development Co. in Grass Valley, Pershing County, Nevada, on leases held by Aminoil USA, Inc., under the cost-sharing industry-linked program of the Department of Energy. Thirteen shallow (85-152 m) and 3 intermediate-depth (360-457 m) holes were completed and logged during the period June through September, 1979. The locations of these holes and of pre-existing temperature-gradient holes are shown on plate 1. This report constitutes a final data transmittal and disclosure of results. The drilling subcontractor was Southwest Drilling and Exploration, Inc. of Central, Utah. They provided a Gardner-Denver 15W rig, a 3-man crew, and supporting equipment. A l l holes were drilled with mud as the circulating medium. Drilling histories for each hole are summarized in table 1. GeothermEx, Inc. performed on-site geological descriptions of the cuttings; obtained several temperature profiles for each hole, including an equilibrium profile taken 23 days or more after cessation of drilling; selected samples for thermal conductivity measurements; integrated temperature, temperature-gradient, and heat-flow data obtained in this project with published values; and prepared this report

Photogeologic Interpretation of the Baltazor-McGee Geothermal Prospects, Humboldt County, Nevada

GeothermEx, Inc. was asked by Earth Power Corporation in October 1977 to perform a photogeologic study of the Baltazor and McGee geothermal prospects, northern Humboldt County, Nevada and southern Harney County, Oregon (figure 1), as a means of evaluating the geothermal reservoir and heat source at these prospects. Work began in October and was completed in December 1977. It included a brief field reconnaissance, to clarify particular points. This report summarizes findings and offers interpretations of structural features, stratigraphy, recent tectonic events, and subsurface conditions