Using iron and sulphur oxidising bacteria to catalyse the breakdown of sulphides that host the gold is an important biological method for the pretreatment of refractory gold ores. Following this biological treatment, a combination of chemical and physical methods is used for leaching (such as the cyanide process) and concentration (such as carbon in pulp or electrowinning) of the gold. Although these methods are well accepted by industry, they harbour limitations in the processing of low grade refractory ores and regulatory agency/public acceptance of cyanide use. Thus, it is beneficial for industry to develop environmentally friendly, as well as cost efficient, leaching and concentration techniques that are based on micro-organisms. This may soon be possible by adapting the results of recent multidisciplinary research, which has shown that micro-organisms are capable of driving a biogeochemical cycle of gold dispersion, transport and re-concentration in the supergene environment. The indigenous microbiota in biologically active soil microcosms from a number of Australian sites are capable of solubilising up to 80 wt-% of the gold contained in soils and deeper regolith materials. Studies using molecular microbial techniques have shown that a metallophilic bacterium, Cupriavidus metallidurans, is present in biofilms on gold grains from a number of Australian sites. Cupriavidus metallidurans is capable of actively accumulating gold from solution and therefore contributes to the formation of secondary gold grains and nuggets. Identifying the biochemical and physiological pathways that lead to the dispersion and accumulation of gold in regolith and quantifying the reaction kinetics of these processes may thus lead to the development of industrial bio-processing capacities for gold containing ores.

The aim of this study was to investigate the longitudinal positron emission tomography (PET) metabolic changes in the elderly.

Objective: To provide a narrative review of studies regarding the outcomes of Virtual Reality (VR)-based treatment and rehabilitation programmes within the paediatric population.Methods: Studies related to the use of VR across a number of paediatric areas (e.g. cerebral palsy, autism, foetal alcohol syndrome and attention deficits) were identified and summarized.Results: Outcomes from the studies reviewed provide preliminary support for the use of VR.Conclusion: VR may be an effective treatment method for specific disorders, although the generalizability of this literature is hindered by several methodological limitations, such as small samples and the absence of appropriate control participants.

Landscape salinisation is a widespread phenomenon resulting from irrigation agriculture and river regulation in arid and semi-arid climates (Jolly et al 2008). In the Lower River Murray floodplains of Southern Australia, it is currently estimated that 25% of the floodplains area is impacted by salinity, with this proportion potentially increasing to 50% by 2050 (River Murray Water Catchment Management Board 2003). Salinity is threatening the health of many ecosystems in these floodplains, including several wetlands of high conservation value and large tracts of River Red Gum (Eucalyptus camaldulensis) forests. There are several causes for the salinisation of the floodplains, including a decreased flooding frequency and an increased input of saline groundwater induced by vegetation clearing and irrigation returns (Jolly 1996). Salinisation is also caused by increased soil waterlogging in the floodplains, including from raised pool levels behind weirs and barrages and the conversion of wetlands into disposal basins for excess irrigation water (Walker 1992, Jolly 1996).

We investigated the associations between Boston naming and the animal fluency tests and cortical atrophy in 19 probable AD and 5 multiple domain amnestic mild cognitive impairment patients who later converted to AD. We applied a surface-based computational anatomy technique to MRI scans of the brain and then used linear regression models to detect associations between animal fluency and Boston Naming Test (BNT) performance and cortical atrophy. The global permutation-corrected significance for the maps associating BNT performance with cortical atrophy was p = .0124 for the left and p = .0196 for the right hemisphere and for the animal fluency maps p = .055 for the left and p = .073 for the right hemisphere. The degree of language impairment correlated with cortical atrophy in the left temporal and parietal lobes (BA 20, 21, 37, 39, 40, and 7), bilateral frontal lobes (BA 8, 9, and 44) and the right temporal pole (BA 38). Using a novel 3D mapping technique, we demonstrated that in AD language abilities are strongly influenced by the integrity of the perisylvian cortical regions.

Understanding the microbial processes affecting the mobility of Au is important in the development of biogeochemical models describing the formation of secondary anomalies and Au grains in soils and deeper regolith materials. This study characterizes bacterial activity in auriferous soils that is linked to the microbially mediated solubilization of Au, as a result of production and consumption of free amino acids, which can form stable complexes with Au. Through the application of 16S rDNA fingerprinting and community level physiological profiling (CLPP), concurrently with Au mobility data, microcosm experiments have demonstrated the role that mobile Au plays in determining the structure and function of bacterial communities in auriferous soils. The bacterial community of auriferous soils displayed genetic differences compared to non-auriferous (background) soils associated with the appearance of Methylocella sp., Arthrobacter sp. and Bacillus sp., as well as functional differences in the utilization of D-Cellobiose, L-Serine, L-Phenylalanine, L-Arginine and N-Acetyl-D-Glucosamine. These results suggest that soil bacterial communities are linked to biogeochemical Au cycling, and that microbial fingerprinting analyses may be used as a screening tool in Au exploration to differentiate auriferous from background terrains.

12 We investigated the associations between Boston naming and the animal fluency tests and cortical atrophy in 19 probable AD and 5 13 multiple domain amnestic mild cognitive impairment patients who later converted to AD. We applied a surface-based computational 14 anatomy technique to MRI scans of the brain and then used linear regression models to detect associations between animal fluency 15 and Boston Naming Test (BNT) performance and cortical atrophy. The global permutation-corrected significance for the maps associ16 ating BNT performance with cortical atrophy was p = .0124 for the left and p = .0196 for the right hemisphere and for the animal fluency 17 maps p = .055 for the left and p = .073 for the right hemisphere. The degree of language impairment correlated with cortical atrophy in 18 the left temporal and parietal lobes (BA 20, 21, 37, 39, 40, and 7), bilateral frontal lobes (BA 8, 9, and 44) and the right temporal pole 19 (BA 38). Using a novel 3D mapping technique, we demonstrated that in AD language abilities are strongly influenced by the integrity of 20 the perisylvian cortical regions. 21 ! 2007 Published by Elsevier Inc.

Using iron- and sulfur-oxidising bacteria to catalyse the breakdown of sulfides that host the gold is an important biological method for the pretreatment of refractory gold ores. Following this biological treatment a combination of chemical and physical methods are used for leaching (such as the cyanide process) and concentration (such as carbon-in-pulp or electrowinning) of gold. Although these methods are well accepted by industry, they harbour limitations in the processing of low-grade refractory ores, and regulatory agency/public acceptance of cyanide use. Thus, it is beneficial to industry to develop environmentally friendly, cost-efficient leaching and concentration techniques that are based on micro-organisms. This may soon be possible by adapting the results of recent regolith geoscience research, which has shown that microorganisms are capable of driving a biogeochemical cycle of gold dispersion, transport and reconcentration in the supergene environment. The indigenous microbiota in biologically active soil microcosms from a number of Australian sites are capable of solubilising up to 80 wt per cent of the gold contained in these materials during 50 days of incubation. Studies using molecular microbial techniques have shown that a metallophilic bacterium, Ralstonia metallidurans, is present in biofilms on gold grains from a number of Australian sites. R metallidurans is capable of actively accumulating gold from solution, suggesting that the bacterium may contribute to the formation of secondary gold grains and nuggets. Identifying the biochemical and physiological pathways that lead to the dispersion and accumulation of gold in regolith, and quantifying the reaction kinetics of these processes may thus lead to the development of industrial bio-processing capacities for gold-containing ores.

Due to a combination of river regulation, dryland salinity and irrigation return, lower River Murray floodplains (Australia) and associated wetlands are undergoing salinisation. It was hypothesised that salinisation would provide suitable conditions for the accumulation of sulfidic materials (soils and sediments enriched in sulfides, such as pyrite) in these wetlands. A survey of nine floodplain wetlands representing a salinity gradient from fresh to hypersaline determined that surface sediment sulfide concentrations varied from <0.05% to ~1%. Saline and permanently flooded wetlands tended to have greater sulfide concentrations than freshwater ones or those with more regular wetting–drying regimes. The acidification risk associated with the sulfidic materials was evaluated using field peroxide oxidations tests and laboratory measurements of net acid generation potential. Although sulfide concentration was elevated in many wetlands, the acidification risk was low because of elevated carbonate concentration (up to 30% as CaCO3) in the sediments. One exception was Bottle Bend Lagoon (New South Wales), which had acidified during a draw-down event in 2002 and was found to have both actual and potential acid sulfate soils at the time of the survey (2003). Potential acid sulfate soils also occurred locally in the hypersaline Loveday Disposal Basin. The other environmental risks associated with sulfidic materials could not be reliably evaluated because no guideline exists to assess them. These include the deoxygenation risk following sediment resuspension and the generation of foul odours during drying events. The remediation of wetland salinity in the Murray–Darling Basin will require that the risks associated with disturbing sulfidic materials during management actions be evaluated.

published: Epilepsia 47(S4);274[3.205]2006 Minnesota Epilepsy Group, P.A. 225 Smith Avenue N., Suite 201 St. Paul, MN 55102 Phone: (651) 241-5290 Fax: (651) 241-5248 Background: The ability to predict postoperative memory impairment, and particularly the ability to rule out a severe amnestic outcome following resection of the dominant mesial temporal structures has been an important objective of the Intracarotid Amobarbital Procedure (Wada Test) prior to epilepsy surgery. In most cases, patients undergoing a left hemisphere injection of amobarbital are able to demonstrate adequate recognition memory (using the right hemisphere) to justify left mesial temporal resection. Occasionally however, patients with a clear left temporal seizure focus and an apparently normal right hippocampus, fail the Wada Test. We hypothesized that in left temporal lobe epilepsy (TLE), a later age of seizure onset may account for these unpredicted Wada failures. Specifically, we reasoned that during the critical period of language development in the left hemisphere, preferential connections between the language cortex and the left hippocampus are formed resulting in efficient verbal memory processing. In patients with early onset of left TLE (prior to age 8 years), compensatory connections between the language cortex and the right hippocampus may be strengthened, even when language itself does not reorganize to the right hemisphere. However, when the onset of temporal lobe seizures occurs after this critical period, these connections with the right hippocampus may not develop, resulting in less effective memory processing in the right temporal lobe, particularly when the items to be remembered can be encoded both verbally and visually. Therefore, we predicted that patients with seizure onset > 8 years would have a higher incidence of left injection Wada failures. Methods: Data were reviewed for 69 TLE patients who were admitted to UCLA epilepsy Video EEG monitoring unit for pre-surgical evaluation. Forty-two patients were diagnosed with left mesial TLE and 27 patients had right mesial TLE. Each patient was classified as having early or late onset of seizures based on the cut-off age of 7 years. Comparison of the left and right TLE groups on demographic variables is presented in Table 1. All patients underwent the Wada test with injection of both hemispheres. The memory protocol during the Wada test consisted of presentation of 6 items during the period of maximum drug effect. Recognition memory was tested following complete recovery from the effects of the drug. Sixty percent correct recognition was considered a passing score. The data were subjected to Chi-square analysis. Results Of the 42 patients with left mesial TLE, 18 had early seizure onset (< 7 years of age) while 24 had a late seizure onset (> 8 years of age). All 18 early onset patients passed the Wada test with left sided injection. Among the late onset patients, 19 passed, while 5 obtained a failing score of less than 60% correct. This difference was statistically significant (p<0.05). (Table 2) In the right TLE group, there was no significant difference between the early and late onset groups with 1 of 10 early onset and 1 of 17 late onset patients failing to exceed the 60% correct criterion (Table 3).

The Mini-mental State Examination (MMSE) is a brief cognitive screening instrument frequently used to track Alzheimer disease (AD) progression. We investigated the structural neuroimaging correlates of MMSE performance in patients with clinical and preclinical AD. We analyzed structural magnetic resonance imaging data from 29 probable AD and 5 MCI patients who later converted to probable AD using an advanced 3D cortical mapping technique. MMSE scores were entered as covariates in a general linear model that predicted the gray matter density at each cortical surface point. The results were corrected for multiple comparisons by permutation testing. The global permutation-corrected significance for the maps linking gray matter loss and cognitive decline was P=0.005 for the left and P=0.012 for the right hemisphere. Strongest correlations between MMSE score and gray matter integrity were seen in the entorhinal, parahippocampal, precuneus, superior parietal, and subgenual cingulate/orbitofrontal cortices. Significant correlations were also seen bilaterally in the temporal, the middle frontal and the left angular and supramarginal gyri. As a global cognitive measure, MMSE depends on the integrity of widely distributed cortical areas in both brain hemispheres with left-sided predominance.

Microorganisms are likely to have played a significant role in the formation of the Australian regolith and in the transport and transformation of minerals within regolith materials. Single celled bacteria were the only forms of life on the planet for approximately 50% of earths history, first appearing about 4000 x 106 years before present (BP). More complex eukaryotic organisms such as fungi first appeared around 2000 x 106 years BP. Fossil records suggest that these early single celled organisms had similar cell structure to modern bacteria. In contemporary regolith environments about 5000 microbial species have been isolated and identified, with one gram of surface regolith material containing between 106 - 109 cells. However, estimates of the total number of microorganisms in the regolith range from 100,000 to 1 x106 species, suggesting up to 95% of regolith microorganisms are unknown to science. There is much evidence to suggest a role for microbial processes in shaping contemporary regolith environments. For instance, the weathering of rocks as a result of microbial activity is thought to be the dominant form of chemical rock weathering in both geological and contemporary environments. Production of organic acids by bacteria (formic, acetic, lactic, pyruvic, succinic, 2-ketogluconic) and fungi (nitric, sulfuric, citric, oxalic, gluconic), is a biological mechanism these organisms have evolved in order to solubilise and obtain trace elements such as P and S from minerals. Geochemical transformations resulting from microbial activity in the regolith are also well established. One of the most well known is the biological oxidation of pyritic and sulfide minerals, carried out by a group of bacteria known as chemolithoautotrophes. These organisms are highly adapted to low pH environments, and utilise Fe or S as electron donors in their respiratory chain, catalysing Fe and S oxidation through the production of iron or sulfur oxidase enzymes, bacteria are therefore the key biochemical catalysts of geochemical transformations in these environments. Bacteria responsible for the oxidation of sulfide minerals including As, Cu, Co, Fe, Ni, Mo, Pb, Zn have been isolated from sulfidic environments and historically classified as members of the Thiobacillus genus notably (Thiobacillus sp., Acidothibacillus sp. Sulfobacillus thermosulfidooxidans and Acidanus brierleyi). (Mukhopadhyaya et al., 2000). Whilst biological processes responsible for mineral weathering and geochemical transformations have been identified we still lack a sound mechanistic understanding of the principle biological processes underpinning biogeochemical dispersion, mobilization, transport, and mineralisation of minerals & trace elements in the Australian regolith. A more important question is what is the relative role of biological and non-biological (abiotic) processes driving mineral transport, transformation and accumulation in the regolith. BIOLOGICAL ACTIVITY AND BIOGEOCHEMICAL TRANSFORMATIONS Much of the current approach to the study of microbial transformations of minerals has focussed on the identification of organisms, species diversity and population dynamics, (Baker and Banfield, 2003) and their relationship to rates of mineral transformation. In fact environmental microbiology research concerning defining the role of biota in driving biogeochemical transformations in general has focussed on establishing the relationship between bacterial diversity and rates of biogeochemical processes (Rogers and Colloff, 1999). In general there is a paucity of evidence from available studies linking changes in species diversity or shifts in microbial populations to changes in biogeochemical functionality. Traditional microbiological techniques applied to the study of regolith microbial populations fail to identify more than 5% of the species present. They also fail to determine the 'functional attributes' of microbial populations responsible for geochemical transformations.

Until recently, the occurrence of sulfidic materials in saline areas of the River Murray floodplain was not known. When present, they represent a significant hazard for the remediation of wetlands and other habitats through water regime management, such as wetting and drying cycles. This presentation will provide background for research on sulfidic materials in the floodplain environment. The known distribution of these materials and the known or speculated hazards they pose the floodplain environment will be discussed. The key areas for future research will be highlighted. FLOODPLAIN SALINITY - A CHALLENGING ENVIRONMENTAL ISSUE It is currently estimated that 25% of the lower River Murray floodplain is impacted by salinity, with this proportion potentially increasing to 50% by 2050 (RMCWMB 2003). Salinity is threatening the health of many ecosystems in this floodplain, including several Ramsar-listed wetlands and large tracts of red gum forests. Floodplain salinity is a complex problem that will be more difficult to manage than the better known issue of river salinity. The causes for the salinisation of the floodplain include: (i) decreased flooding frequency; (ii) disposal of irrigation water in wetlands; (iii) increased saline groundwater discharge caused by irrigation mounds along the margins of the floodplain; and, (iv) high water tables caused by raised weir pools (Jolly 1996, Figure 1). A number of "environmental flows" initiatives are currently considered to help improve floodplain salinity. These include managed water level manipulations in wetlands, weir draw downs, and increased frequency and duration of overbank flow events through carefully timed releases from reservoirs (MDBC 2000, RMCWMB 2003). In areas impacted by irrigation mounds, salt interception schemes are now designed to improve both river and floodplain salinity. Despite ongoing efforts, halting the ecological decline of the floodplain will be a difficult task.

SUMMARY The formation of potential acid sulphate soils is the result of the reduction of SO4 and Fe3 + under anaerobic reducing conditions. Anaerobic chemoautotrophic bacteria notably the genus Desulfovibrio are known to be responsible for the enzymic reduction of Fe and S under these conditions. Biogeochemical transformations of sulfide minerals responsible for the formation of actual Acid Sulfate Soils are carried out by a group of chemolithotrophic bacteria collectively known as sulfur oxidisers. Whilst this group of organisms has been studied in detail, recent advances in molecular genetic analysis have led to the re-classification of many species previously classified as Thiobacillus. The ecology of these organisms in sulfidic environments and the relationship between chemolitotrophic bacterial activity and rates of sulfide mineral oxidation are poorly understood. Application of new functional molecular biology techniques is discussed, based on the extraction of nucleic acids from sulfidic sediments and the determination of the presence and expression of the sulfur oxidase gene soxB, as a means of determining the mechanistic relationship between biological activity and biogeochemical transformation of sulfide minerals in these environments. Additional molecular techniques that allow the determination of microbial community population dynamics and identification of species based on 16S rRNA analysis are also described.