Cu isotopes in groundwater for hydrogeochemical mineral exploration: A case study using the world-class Mount Isa Cu–Pb–Zn deposit (Australia)

Copper is the crux resource in the transition to renewable energy sources, with green technologies such as solar panels, wind turbines and batteries all relying on this critical metal for their componentry, and more importantly for connection to electrical grids. While demand intensifies, copper discovery rates continue to fall due to increased scarcity of deposits that are outcropping and/or detectable by conventional means. This has engendered novel methods of detecting Cu-bearing ore under cover, such as hydrogeochemical analyses to trace ore mineral interaction with natural waters. This notably includes the development of Cu isotope systematics in natural waters, wherein proximal to Cu-bearing ore bodies enrichment of water in the heavier Cu isotope occurs (e.g. from oxidative weathering), thus providing a fingerprint of water interaction with Cu-bearing sulfides. Here, Cu isotope compositions for eighteen groundwater samples overlying and distal to the world-class, sediment-hosted stratiform Mount Isa Cu–Zn–Pb deposit were analyzed to assess the utility of groundwater Cu isotope compositions as an exploration tool for Cu-bearing ore under cover. A further 12 chalcopyrite Cu isotope compositions were determined from two drill cores directly overlying the main Cu-bearing ore body, to establish a baseline Cu isotope composition for the Mt Isa deposit. Cu isotope data were synthesized together with field water parameters and placed within a geological context to construct a framework for interpretation. When accounting for industrially impacted sites and underlying geology, results show a clear trend towards heavy Cu isotope enrichment in groundwater proximal to known mineralization, with enrichments of ∼1 per mil (‰) or more relative to distal groundwater and primary deposit chalcopyrite. These results corroborate and expand upon similar work from surface and groundwater samples around porphyry, exotic and IOCG Cu-bearing deposits. Moreover, these results strongly indicate that groundwater Cu isotope systematics for exploration under cover has great potential as a vectoring tool, illustrating that thus far the technique is applicable across deposit types

Research and Consultancy Services in the Mining Industry in Zimbabwe: A Coordinated Approach Through the Mineral Resources Centre

IMR Report.Education in the engineering fields can be considerably enhanced if it is designed to address the immediate and long-term needs of society. In this context education not only comprises the provision of basic training, but also includes the careful planning and execution of applied and fundamental research. This paper focuses on education and research institutions that provide services to the mining sector in Zimbabwe and describes a new approach to meeting high-quality teaching, research and consultancy requirements against a background of diminishing government funding. Key units within the University of Zimbabwe providing services to the mining industry include the Institute of Mining Research, The Departments of Geology and Physics in the Faculty of Science and Mining Engineering and Metallurgy in the Faculty of Engineering. Within government, services are provided principally by the Departments of Geological Survey, Metallurgy and Mining Engineering, and the Scientific and Industrial Research and Development Centre. The major source of funding for all of these institutions is Government. There is a degree of overlap between these institutions, some of which were established more than 30 years ago with terms of reference appropriate for the time. With decreasing funding exacerbated by a harsh economic climate in Zimbabwe there is need to revisit the charters of these organizations and to review the provision of services to the mining sector. Recognition of this situation has led the Department of Geology to spearhead a new initiative to establish an alternative structure through which consultancy and research in mining related topics can be coordinated at the University of Zimbabwe. The Mineral Resources Centre (MRC) was established to facilitate fund-raising activities through consultancy services, research, postgraduate training and capital investment. By representing a group of like-minded stakeholders, the MRC can address larger projects, and thus secure more funding than individual entities will be able to obtain. The MRC is designed to be a lightweight structure that will not replace any of the existing teaching and research departments. The MRC is not be bound to any particular faculty within the university, and may even include stakeholders from outside the university. Interested parties are invited to participate on a voluntary basis in accordance with the management and quality- control guidelines laid out by the MRC. Participation is on a contract basis and will be determined for each project. Service providers that participate in the MRC agree to use their resources in the best possible way, so that services can be presented in unison. In combining forces between various departments with expertise in Earth Sciences, it is envisaged that a wider audience can be reached, a better service can be provided and a larger resource base can be tapped both within the private and the public sectors. The MRC may help coordinate capital investment, and human resource development in the various participating entities. Considering the limited availability of financial and human resources in Zimbabwe, coordination and prevention of unnecessary overlap is in itself a valuable exercise

Comparative Therapeutic Effects of Natural Compounds Against Saprolegnia spp. (Oomycota) and Amyloodinium ocellatum (Dinophyceae)

The fish parasites Saprolegnia spp. (Oomycota) and Amyloodinium ocellatum (Dinophyceae) cause important losses in freshwater and marine aquaculture industry, respectively. The possible adverse effects of compounds used to control these parasites in aquaculture resulted in increased interest on the search for natural products with antiparasitic activity. In this work, eighteen plant-derived compounds (2′,4′-Dihydroxychalcone; 7-Hydroxyflavone; Artemisinin; Camphor (1R); Diallyl sulfide; Esculetin; Eucalyptol; Garlicin 80%; Harmalol hydrochloride dihydrate; Palmatine chloride; Piperine; Plumbagin; Resveratrol; Rosmarinic acid; Sclareolide; Tomatine, Umbelliferone, and Usnic Acid) have been tested in vitro. Sixteen of these were used to determine their effects on the gill cell line G1B (ATCC®CRL-2536™) and on the motility of viable dinospores of Amyloodinium ocellatum, and thirteen were screened for inhibitory activity against Saprolegnia spp. The cytotoxicity results on G1B cells determined that only two compounds (2′,4′-Dihydroxychalcone and Tomatine) exhibited dose-dependent toxic effects. The highest surveyed concentrations (0.1 and 0.01 mM) reduced cell viability by 80%. Upon lowering the compound concentration the percentage of dead cells was lower than 20%. The same two compounds revealed to be potential antiparasitics by reducing in a dose-dependent manner the motility of A. ocellatum dinospores up to 100%. With respect to Saprolegnia, a Minimum Inhibitory Concentration was found for Tomatine (0.1 mM), Piperine and Plumbagin (0.25 mM), while 2′,4′-Dihydroxychalcone considerably slowed down mycelial growth for 24 h at a concentration of 0.1 mM. Therefore, this research allowed to identify two compounds, Tomatine and 2′,4′-Dihydroxychalcone, effective against both parasites. These compounds could represent promising candidates for the treatment of amyloodiniosis and saprolegniosis in aquaculture. Nevertheless, further in vitro and in vivo tests are required in order to determine concentrations that are effective against the considered pathogens but at the same time safe for hosts, environment and consumers

A magmatic copper and fluid source for the sediment-hosted Mount Isa deposit

The world class Mount Isa deposit is a unique, sediment-hosted, copper deposit with no known equivalent around the world and a controversial origin. We report δ65Cu values (n = 90) from chalcopyrite grains collected systematically across the entire deposit. The δ65Cu shows a unimodal distribution with limited variability (min = −0.87 ‰; max = 0.88 ‰) and an average value (+0.13 ‰) comparable to average igneous rocks. In general, the δ65Cu values in chalcopyrite are lower near major structures and heavier further away, consistent with equilibrium fractionation with distance from the fluid source. The range in δ65Cu of chalcopyrite from the Mount Isa deposit is less variable compared to sedimentary copper, VMS and porphyry/epithermal deposits, but similar to Michigan deposits; meanwhile, average δ65Cu at Mt. Isa is distinctly higher than sedimentary copper deposits, but similar to VMS, porphyry/epithermal and Michigan deposits. These data suggest that, from a copper isotope perspective, the Mount Isa deposit is clearly different from sedimentary copper deposits and more like VMS, porphyry copper/epithermal and Michigan style deposits. The average δ65Cu (+0.13 ‰) is almost identical to the average δ65Cu (+0.14 ‰) from Proterozoic basalts and suggests that copper was sourced from the underlying mafic rocks; the limited fractionation and the normal distribution of the δ65Cu indicate a very effective leaching mechanism and transport by a hot fluid from which chalcopyrite precipitated without significant fractionation of copper isotopes

Transcriptome analysis of amyloodinium ocellatum tomonts revealed basic information on the major potential virulence factors

The ectoparasite protozoan Amyloodinium ocellatum (AO) is the etiological agent of amyloodiniosis in European seabass (Dicentrarchus labrax) (ESB). There is a lack of information about basic molecular data on AO biology and its interaction with the host. Therefore, de novo transcriptome sequencing of AO tomonts was performed. AO trophonts were detached from infested ESB gills, and quickly becoming early tomonts were purified by Percoll\uae density gradient. Tomont total RNA was processed and quality was assessed immediately. cDNA libraries were constructed using TruSeq\uae Stranded mRNA kit and sequenced using Illumina sequencer. CLC assembly was used to generate the Transcriptome assembly of AO tomonts. Out of 48,188 contigs, 56.12% belong to dinophyceae wherein Symbiodinium microadriaticum had 94.61% similarity among dinophyceae. Functional annotations of contigs indicated that 12,677 had associated GO term, 9005 with KEGG term. The contigs belonging to dinophyceae resulted in the detection of several peptidases. A BLAST search for known virulent factors from the virulence database resulted in hits to Rab proteins, AP120, Ribosomal phosphoprotein, Heat-shock protein70, Casein kinases, Plasmepsin IV, and Brucipain. Hsp70 and casein kinase II alpha were characterized in-silico. Altogether, these results provide a reference database in understanding AO molecular biology, aiding to the development of novel diagnostics and future vaccines

Cryptochromes and neuronal-activity markers colocalize in the retina of migratory birds during magnetic orientation

Migratory birds can use a magnetic compass for orientation during their migratory journeys covering thousands of kilometers. But how do they sense the reference direction provided by the Earth’s magnetic field? Behavioral evidence and theoretical considerations have suggested that radical-pair processes in differently oriented, light-sensitive molecules of the retina could enable migratory birds to perceive the magnetic field as visual patterns. The cryptochromes (CRYs) have been suggested as the most likely candidate class of molecules, but do CRYs exist in the retina of migratory birds? Here, we show that at least one CRY1 and one CRY2 exist in the retina of migratory garden warblers and that garden-warbler CRY1 (gwCRY1) is cytosolic. We also show that gwCRY1 is concentrated in specific cells, particularly in ganglion cells and in large displaced ganglion cells, which also showed high levels of neuronal activity at night, when our garden warblers performed magnetic orientation. In addition, there seem to be striking differences in CRY1 expression between migratory and nonmigratory songbirds at night. The difference in CRY1 expression between migrants and nonmigrants is particularly pronounced in the large displaced ganglion cells known to project exclusively to a brain area where magnetically sensitive neurons have been reported. Consequently, cytosolic gwCRY1 is well placed to possibly be the primary magnetic-sensory molecule required for light-mediated magnetoreception

Ultrasensitive TES Bolometers for Space Based FIR Astronomy

We present results from the development of a background limited transition edge sensor (TES) bolometer for the wavelength band 30–60 μm. The bolometer consists of a Ti/Au superconducting thermometer and a Ta radiation absorber deposited on a 200μm×300μm200μm×300μm membrane of SixNySixNy suspended on long, narrow legs. This device is voltage biased and the current through the device is measured by a SQUID amplifier. The thermometer has transition temperature Tc = 108 mKTc = 108 mK and the device is operated from a 70 mK base plate. FIR radiation is coupled into a multimodc horn with entrance aperture of 450 μm, length 4.5 mm and exit aperture of 45 μm, which feeds a metal integrating cavity containing the detector. The radiation band is defined by a pair of lowpass and highpass mesh filters in front of the horn. Here we present measurements of optical noise equivalent power (NEP), optical efficiency, dynamic range and time constant. The results show that measured TES detectors are close to meeting the requirement of the “Band 3” of SAFARI FTS imaging instrument [1] on the SPICA mission [2]

Breath-Hold Blood Oxygen Level-Dependent MRI: A Tool for the Assessment of Cerebrovascular Reserve in Children with Moyamoya Disease

BACKGROUND AND PURPOSE: There is a critical need for a reliable and clinically feasible imaging technique that can enable prognostication and selection for revascularization surgery in children with Moyamoya disease. Blood oxygen level-dependent MR imaging assessment of cerebrovascular reactivity, using voluntary breath-hold hypercapnic challenge, is one such simple technique. However, its repeatability and reliability in children with Moyamoya disease are unknown. The current study sought to address this limitation. MATERIALS AND METHODS: Children with Moyamoya disease underwent dual breath-hold hypercapnic challenge blood oxygen level-dependent MR imaging of cerebrovascular reactivity in the same MR imaging session. Within-day, within-subject repeatability of cerebrovascular reactivity estimates, derived from the blood oxygen level-dependent signal, was computed. Estimates were associated with demographics and intellectual function. Interrater reliability of a qualitative and clinically applicable scoring scheme was assessed. RESULTS: Twenty children (11 males; 12.1 ± 3.3 years) with 30 MR imaging sessions (60 MR imaging scans) were included. Repeatability was "good" on the basis of the intraclass correlation coefficient (0.70 ± 0.19). Agreement of qualitative scores was "substantial" (κ = 0.711), and intrarater reliability of scores was "almost perfect" (κ = 0.83 and 1). Younger participants exhibited lower repeatability (P = .027). Repeatability was not associated with cognitive function (P > .05). However, abnormal cerebrovascular reactivity was associated with slower processing speed (P = .015). CONCLUSIONS: Breath-hold hypercapnic challenge blood oxygen level-dependent MR imaging is a repeatable technique for the assessment of cerebrovascular reactivity in children with Moyamoya disease and is reliably interpretable for use in clinical practice. Standardization of such protocols will allow further research into its application for the assessment of ischemic risk in childhood cerebrovascular disease

Thermal Dileptons from pi - rho Interactions in a Hot Pion Gas

A systematic study of low mass dilepton production from $\pi-\rho$ interactions in a hot medium is presented. Applying finite temperature perturbation theory the dilepton rate, respectively the virtual photon rate, is computed up to order $g_\rho^2$. For dilepton masses below the $\rho$ the two-body reactions $\pi\pi\to \rho \gamma^*$, $\pi\rho\to \pi \gamma^*$, and the decay process $\rho \to \pi \pi \gamma^*$ give significant contributions. Non-equilibrium contributions to the thermal rate are estimated, including the modification of the particle distribution function with non-zero pion chemical potential. The comparison of the dilepton rate with the recent data measured in nucleus-nucleus collisions at SPS energy by the CERES Collaboration is also performed. It is shown that the additional thermal dileptons from $\pi-\rho$ interactions can partially account for the access of the soft dilepton yield seen experimentally.Comment: 21 pages LaTeX, 8 figs with epsfig.sty macro include