Olympic Dam: BHP thinking big about the future.

Olympic Dam is one of the world's most significant polymetallic orebodies producing copper, uranium, gold, and silver in remote South Australia. The polymetallic deposit is located 520 km north-northwest of Adelaide, South Australia and has an inferred resource of 2660 Mt at 1.2% Cu, 1.4 kg t-1 U3Os, and 0.5 g t-1 Au. Ore is mined from the underground operation at a rate of approximately 10 mt year-1, and is processed on site through a concentrator and hydrometallurgical facility, smelter, and electrolytic refinery. Olympic Dam is one of the only sites in the world to claim the 'mine to market' title. Protection of the workforce and the environment has been a primary focus for the operations through its 30+ year life and will continue to be into the future. Broken Hill Propriety Company (BHP) believes that its most important asset is its people. With such a large orebody and a very long potential mine life, it is important to think strategically about the future to ensure the viability of the operation. This requires development of mine and surface processing facilities in a staged manner. Importantly, it also involves the development of people. This presentation provides an overview of BHP's work at Olympic Dam and outlines development plans for Olympic Dam into the future.© 2020 ICRP. Published by SAGE.

Skin prick testing and peanut-specific IgE can predict peanut challenge outcomes in preschoolchildren with peanut sensitization.

BACKGROUND: The rise in peanut allergy is a source of considerable burden in the community. A growing number of preschoolchildren have been identified as peanut sensitized in the course of investigation of other allergic conditions. Although many have never knowingly ingested peanuts and their clinical reactivity is not known, it has been common practice to place these children on avoidance diets for many years. OBJECTIVE: To determine the utility of skin prick tests (SPT) and fluorescent-enzyme immunoassays (FEIA) for identifying either peanut allergy or tolerance in preschoolchildren with peanut sensitization. METHODS: Forty-nine preschoolchildren (<5 years of age) with peanut sensitization (SPT ≥ 2 mm or peanut-specific IgE ≥ 0.35 kU/L) but unknown clinical reactivity had graded open peanut challenges reaching a total of 11 g. A positive challenge was defined as an objective IgE-mediated reaction during challenge or the 2-h observation. RESULTS: Forty-nine percent (24/49) of children had positive challenges. An SPT of >7 mm on the day of challenge predicted a positive challenge with a sensitivity of 83% and a negative predictive value (NPV) of 84%. An FEIA of >2.0 kU/L showed a sensitivity of 79% and an NPV of 80%. Predicting challenge outcome from a combination of SPT and FEIA (SPT >7 and/or FEIA >2 is positive) increased sensitivity to 96% and NPV to 95%. CONCLUSION AND CLINICAL RELEVANCE: At least half of preschoolchildren with peanut sensitization and no antecedent history of peanut ingestion can tolerate peanuts. A SPT<7 mm and FEIA<2 kU/L identify children most likely to tolerate peanut, with only a 5% likelihood of failing an oral challenge. This study assists clinicians considering challenges in very young peanut-sensitized children.

Strong "quantum" chaos in the global ballooning mode spectrum of three-dimensional plasmas.

The spectrum of ideal magnetohydrodynamic (MHD) pressure-driven (ballooning) modes in strongly nonaxisymmetric toroidal systems is difficult to analyze numerically owing to the singular nature of ideal MHD caused by lack of an inherent scale length. In this paper, ideal MHD is regularized by using a k-space cutoff, making the ray tracing for the WKB ballooning formalism a chaotic Hamiltonian billiard problem. The minimum width of the toroidal Fourier spectrum needed for resolving toroidally localized ballooning modes with a global eigenvalue code is estimated from the Weyl formula. This phase-space-volume estimation method is applied to two stellarator cases.

Electrophysiological evidence for vestibular activation of the guinea pig hippocampus.

Vestibular information modulates hippocampal activity for spatial processing and place cell firing. However, evidence of a purely vestibular stimulus modulating hippocampal activity is confounded as most studies use stimuli containing somatosensory and visual components. In the present study, high-frequency electrical stimulation of specific vestibular sensory regions of the right labyrinth in anaesthetized guinea pigs induced an evoked field potential in the hippocampal formation bilaterally with a latency of about 40 ms following stimulation onset. Field potentials localized in the hippocampal formation occurred with stimulus current parameters that were too small to produce eye movements. This provides direct electrophysiological evidence of vestibular input to the hippocampus.

Cellular localization of CD4 in the human placenta. Implications for maternal-to-fetal transmission of HIV.

CD4 is a 55-kDa glycoprotein that serves as an important cellular differentiation Ag and cell signaling protein on T lymphocytes, as well as a principal receptor for HIV-1 on a variety of cell types including lymphocytes. CD4 receptor expression in syncytiotrophoblasts, the principal cellular barrier in the human placenta, has not been clearly defined. Knowledge concerning the expression of the CD4 receptor on placental trophoblasts is important to define potential mechanisms of transmission of the virus between maternal blood and fetal tissues. Both mature and immature placenta (n = 10) were examined using an avidin D-based immunohistochemical procedure that permits clear morphologic distinction of cell types in placental sections. Syncytiotrophoblasts were defined using anti-cytokeratin mAb (AE1/3), whereas endothelial cells in placental villi were distinctly identified using a mAb directed to CD31. Placental Hofbauer cells (macrophages) and other leukocytes were identified by mAb staining of leukocyte common Ag (CD45). CD4 expression (identified by staining with three separate anti-CD4 mAb) was exclusively localized using this immunohistochemical method to leukocytes in placental villi (e.g., Hofbauer cells); however, no CD4 staining was evident in syncytiotrophoblasts, cytotrophoblasts, or villus endothelial cells. Furthermore, immunoaffinity-purified trophoblasts were negative for CD4 receptor expression. CD4 RNA was not identified in purified trophoblasts using both Northern blot assay and a sensitive polymerase chain reaction method to identify CD4 RNA. In addition, time course studies of purified trophoblasts immediately after purification and at 24, 48, and 72 h in culture indicated that CD4 RNA was not present as a transient, but labile transcript in trophoblasts. These data indicate that the transmission of HIV-1 across syncytiotrophoblasts may occur by mechanisms other than by binding the CD4 receptor and that tissue leukocytes (in particular Hofbauer cells) are likely the principal CD4+ cellular target of HIV-1 in the placenta.

A supervised independent-living orientation program for adolescents.

A program is described that provides for transition into a relatively unstructured supervised independent-living program for adolescents with a history of behavioral and emotional disturbance, often including delinquency and/or psychiatric hospitalization. Contracts used to define expectations, logistics, and conflicts experienced by the youths are discussed. Developmental issues are highlighted, focusing on the rapprochement subphase.