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The article provides information on the opal industry of Australia. Topics discussed include opal formation on the Great Artesian Basin, the black opal and opalized fossils found in Lightning Ridge area in New South Wales, and the boulder opal found in Queensland fields. Also noted are the challenges facing the Australian opal industry such as drought.

An at-sea experiment in deep water was conducted to explore the impact of small-scale sound-speed variability on mid-frequency (1 – 10 kHz) acoustic propagation. Short-range (1 – 5 km) acoustic transmissions were sent through the upper ocean (0 – 200 m) while oceanographic instruments simultaneously measured the ocean environment within 2 km of the single upper turning points of the acoustic transmissions. During these transmissions, acoustic receptions over a 7.875 m vertical line array show closely spaced, sometimes interfering arrivals. Ray and full-wave simulations of the transmissions using nearby sound-speed profiles are compared deterministically to the received acoustic signals. The sensitivity of the acoustic arrivals to the vertical scales of ocean sound speed is tested by comparing the observed and simulated arrival intensity where the sound-speed profile used by the simulation is smoothed to varying scales. Observations and modeling both suggest that vertical fine-scale structures (1 – 10 m) embedded in the sound-speed profile have strong second derivatives which allow for the formation of acoustic caustics as well as potentially interfering acoustic propagation multipaths. [ABSTRACT FROM AUTHOR]

The article offers information on a museum exhibition titled "Nature Art Science" in which artist Paula Crevoshay displayed her gems and precious stones.

We describe a simple model of heterogeneous, interacting agents making decisions between n ≥ 2 discrete choices. For a special class of interactions, our model is the mean field description of random field Potts-like models and is effectively solved by finding the extrema of the average energy E per agent. In these cases, by studying the propagation of decision changes via avalanches, we argue that macroscopic dynamics is well captured by a gradient flow along E. We focus on the permutation symmetric case, where all n choices are (on average) the same, and spontaneous symmetry breaking (SSB) arises purely from cooperative social interactions. As examples, we show that bimodal heterogeneity naturally provides a mechanism for the spontaneous formation of hierarchies between decisions and that SSB is a preferred instability to discontinuous phase transitions between two symmetric points. Beyond the mean field limit, exponentially many stable equilibria emerge when we place this model on a graph of finite mean degree. We conclude with speculation on decision making with persistent collective oscillations. Throughout the paper, we emphasize analogies between methods of solution to our model and common intuition from diverse areas of physics, including statistical physics and electromagnetism. [ABSTRACT FROM AUTHOR]

The article presents views of Ian Harebottle, chief executive officer (CEO) at colored gemstones producer Gemfields, on the success of his firm. It mentions Gemfields clients appreciate the standards set by the company on emerald and ruby mining and distribution. It also mentions the Kagem emerald mine in Zambia has paid federal taxes.

Development of an effective HIV/AIDS vaccine remains a big challenge, largely due to the enormous HIV diversity which propels immune escape. Thus novel vaccine strategies are targeting multiple variants of conserved antibody and T cell epitopic regions which would incur a huge fitness cost to the virus in the event of mutational escape. Besides immunogen design, the delivery modality is critical for vaccine potency and efficacy, and should be carefully selected in order to not only maximize transgene expression, but to also enhance the immuno-stimulatory potential to activate innate and adaptive immune systems. To date, five HIV vaccine candidates have been evaluated for efficacy and protection from acquisition was only achieved in a small proportion of vaccinees in the RV144 study which used a canarypox vector for delivery. Conversely, in the STEP study (HVTN 502) where human adenovirus serotype 5 (Ad5) was used, strong immune responses were induced but vaccination was more associated with increased risk of HIV acquisition than protection in vaccinees with pre-existing Ad5 immunity. The possibility that pre-existing immunity to a highly promising delivery vector may alter the natural course of HIV to increase acquisition risk is quite worrisome and a huge setback for HIV vaccine development. Thus, HIV vaccine development efforts are now geared toward delivery platforms which attain superior immunogenicity while concurrently limiting potential catastrophic effects likely to arise from pre-existing immunity or vector-related immuno-modulation. However, it still remains unclear whether it is poor immunogenicity of HIV antigens or substandard immunological potency of the safer delivery vectors that has limited the success of HIV vaccines. This article discusses some of the promising delivery vectors to be harnessed for improved HIV vaccine efficacy. [ABSTRACT FROM AUTHOR]

In the wake of its phenomenal economic growth since 1978, China has captured the attention of the global gem and jewelry industry. Already a global hub for jewelry manufacturing, it is now a rapidly growing consumer market. While rising costs of labor in China have created challenges for the manufacturing sector, this has led to greater domestic consumption of luxury products, including jewelry. The highest growth potential lies in the inland urban centers, as Chinese citizens continue a massive migration from rural areas to the cities. Chinese consumers are becoming more knowledgeable about gemstones and jewelry and more astute in their purchases. They have a keen sense of both value and brand trust, and they have become more open to contemporary and Western designs and materials. At the same time, technological advances in manufacturing are leading to higher quality standards and lower labor costs, allowing China to meet the increasing demands of the global and domestic markets. Although the recent global economic crisis has affected domestic sales, the Chinese gem and jewelry industry shows great potential for growth. [ABSTRACT FROM AUTHOR]