Excellence in Research Australia (ERA) - Collection - UQ eSpace

Zinc neurotoxicity is promoted by nerve growth factor but is prevented by leukaemia inhibitor factor

2007-08-23T00:00:00Z

Zirconium alloying and grain refinement of magnesium alloys

Qian, Ma og StJohn, D. H. og Frost, M. T. — 2007-08-24T00:00:00Z

Factors that influence alloying zirconium to magnesium with a Mg-33.3Zr master alloy and the subsequent grain refinement are discussed based on a large number of experiments conducted at the laboratory scale (up to 30 kg of melt). It is shown that the zirconium particles released from the Zirmax(R) master alloy must be brought into thorough contact with the melt by an appropriate stirring process in order to attain a good dissolution of zirconium. The influence of alloying temperature on the recovery of zirconium was found to be negligible in the range from 680 to 780 degreesC. An ideal zirconium alloying process should end up with both high soluble and high total zirconium in the melt in order to achieve the best grain refinement in the final alloy. The distribution of zirconium in the final alloy microstructure is inhomogeneous and almost all of the zirconium in solution is concentrated in zirconium-rich cores in the microstructure.

Zirconium alloying and grain refinement of magnesium alloys with zirmax

Qian, Ma og StJohn, D. H. og Frost, M.T. — 2009-11-30T00:00:00Z

Zivile konfliktbearbeitung in der Suedsee [Conflict Transformation in the South Seas]

Böge, Volker — 2010-10-04T00:00:00Z

Z(n) elliptic Gaudin model with open boundaries

2007-08-13T00:00:00Z

ZnO Films Grown on Si Substrates with Au Nanocrystallites as Nuclei

2010-01-15T00:00:00Z

ZnO films were grown on Si substrates with Au nanocrystallites at different temperatures. The morphologies of Au at different annealing temperatures suggest that Au nanocrystallites can perform in the role of crystal nucleus. Surface morphologies of as-grown ZnO films were characterized as a number of hexagonal heaps in the size range of 3−5 μm by scanning electron microscopy. X-ray diffraction data support the theory that the ZnO grains are well-aligned in the c-axis. Cathodoluminescence mappings show that the ultraviolet emission at the band edge is suppressed on top of the hexagonal heap in which the green band is intense. The red shift of the E2 mode demonstrates that the ZnO films in our work are under a weak tensile stress. This should be attributed to the effect of Au nanocrystallites. The convergent beam electron diffraction (CBED) patterns further reveal that the ZnO films grow in Zn-polar. An ab initio simulation agrees well with the results obtained from the CBED images and provides an intrinsic geometry of the growth of ZnO films.

ZnS nanowires and their coaxial lateral nanowire heterostructures with BN

2008-02-18T00:00:00Z

ZnS nanowires and their coaxial lateral BN nanowire heterostructures with a length of hundreds of micrometers and an average diameter of similar to 300 nm were fabricated via one-step chemical vapor deposition method. Wurtzite ZnS nanowires were coated by a shell of fluffylike hexagonal BN sheets distributed randomly. Thermogravimetric analysis indicates that the heterostructures have a much better oxidation resistance compared with ZnS nanowires. Their similar optical property suggests that the ZnS/BN heterostructures would have potential applications in thermally and chemically rigorous environments. (c) 2007 American Institute of Physics.

Zoledronic acid prevents osteopenia and increases bone strength in a rabbit model of distraction osteogenesis

2008-01-25T00:00:00Z

Prolonged healing times and stress-shielding osteopenia remain problematic in distraction osteogenesis. In this study of 30 rabbits, zoledronic acid increased regenerate volume, mineralization, and tibial strength and prevented osteopenia over a 6-week period. Translation to the clinical setting, if safe, could improve outcomes in distraction osteogenesis in children. Introduction: Because the external fixators for limb lengthening and reconstruction are designed to control the positions of bone fragments accurately, they also produce stress-shielding effects on the forming regenerate and surrounding bone. Osteopenia, leading to refracture and limitations on rehabilitation, are common consequences, potentially increasing morbidity and detracting from final clinical outcome. Materials and Methods: We examined the effect of zoledronic acid on distraction osteogenesis in 42 immature male NZW rabbits. The model chosen results in reliable regenerate formation and stress-shielding osteopenia. Fourteen animals received either Saline, zoledronic acid 0.1 mg/kg at surgery (ZOL), or another dose 2 weeks postoperatively (Redosed ZOL). Rabbits underwent DXA for bone mineral content and bone mineral density in regenerate and surrounding segments of operated and contralateral tibias. After death at 6 weeks, 30 pairs of tibias underwent quantitative computerized tomography (QCT) and four-point bend testing, and 12 were examined by histomorphometry. The study was powered at 0.8 to show differences of 1.3 SDs for mineral and mechanical parameters. Results: Osteopenia observed in tibias of the Saline group was absent in ZOL and Redosed ZOL tibias, the latter exhibiting higher bone mineral density and bone mineral content over contralateral regions (p < 0.01). Regenerate bone mineral content was higher in ZOL and Redosed ZOL versus Saline groups at 4 and 6 weeks (p < 0.01). Cross-sectional area was 49% and 59% greater at 6 weeks in ZOL and Redosed ZOL regenerates compared with the Saline group (p < 0.01). ZOL and Redosed ZOL tibias were 29% and 89% stronger by four-point bending than the Saline group (p < 0.01). Histomorphometry in the regenerate of ZOL and Redosed ZOL groups revealed higher trabecular bone volume and trabecular number compared with the Saline group (P < 0.001). Conclusions: Zoledronic acid administration led to significantly greater bone area, mineral content, strength, and trabecular number with reduced stress-shielding osteopenia in this model of distraction osteogenesis. These data suggest that intraoperative and postoperative zoledronic acid administration could improve outcomes in children undergoing limb lengthening.

Zolpidem: Helping Parkinson’s disease?

Nissen, Lisa Monique — 2010-02-22T00:00:00Z

[0 0 1] zone-axis bright-field diffraction contrast from coherent Ge(Si) islands on Si(0 0 1): Dedicated to Professor Fang-hua Li on the occasion of her 70th birthday

2007-08-15T00:00:00Z

Coherent Ge(Si)/Si(001) quantum dot islands grown by solid source molecular beam epitaxy at a growth temperature of 700degreesC were investigated using transmission electron microscopy working at 300 kV. The [001] zone-axis bright-field diffraction contrast images of the islands show strong periodicity with the change of the TEM sample substrate thickness and the period is equal to the effective extinction distance of the transmitted beam. Simulated images based on finite element models of the displacement field and using multi-beam dynamical diffraction theory show a high degree of agreement. Studies for a range of electron energies show the power of the technique for investigating composition segregation in quantum dot islands. (C) 2003 Elsevier B.V. All rights reserved.

Zoo people: Their attitudes to the role of zoos

Tribe, A. — 2010-04-27T00:00:00Z

Zoos and animal welfare

Tribe, Andrew — 2010-04-27T00:00:00Z

Despite their popularity and place in our tourism history, in recent years zoos have undergone considerable change in both their structure and function. Whilst remaining attractive places to visit, zoos now seek a new image – one that emphasizes their role in conservation and public education. However, changes in public expectations and the zoo’s own objectives mean that today there is far more scrutiny of the way in which their animals are managed and utilised.

Zoos and Conservation - what the visitors think

Tribe, A. og Booth, R. J. — 2007-08-24T00:00:00Z

Zoos and the animal welfare debate

Tribe, Andrew — 2010-04-27T00:00:00Z

Zoos, tourism and conservation

Tribe, A. — 2007-08-27T00:00:00Z

Zoo Tourism

Tribe, A. — 2007-08-14T00:00:00Z

This paper reviews and evaluates zoo tourism worldwide, including the scope of the industry, its key issues and its impacts on wildlife, host communities and economies, and provides guidelines for its further development and sustainability. It is a paper that has been widely used by the zoo industry particularly as a basis for evaluating its scope, impact and development. Tribe, A. was the sole author.

Zoysia japonica (Zoysia Grass) ‘Palisades’

Loch, D. S. og Roche, M. B. — 2010-01-11T00:00:00Z

Zwei Aufsätze über Leben und Tod: Sigmund Freuds Jenseits des Lustprinzips und Arthur Schopenhauers Transscendente Spekulation über die anscheinende Absichtlichkeit im Schicksal des Einzelnen

Atzert, Stephan — 2007-08-15T00:00:00Z

Zygosity Diagnosis in the Absence of Genotypic Data: An Approach Using Latent Class Analysis

2007-08-14T00:00:00Z

For zygosity diagnosis in the absence of genotypic data, or in the recruitment phase of a twin study where only single twins from same-sex pairs are being screened, or to provide a test for sample duplication leading to the false identification of a dizygotic pair as monozygotic, the appropriate analysis of respondents' answers to questions about zygosity is critical. Using data from a young adult Australian twin cohort (N = 2094 complete pairs and 519 singleton twins from same-sex pairs with complete responses to all zygosity items), we show that application of latent class analysis (LCA), fitting a 2-class model, yields results that show good concordance with traditional methods of zygosity diagnosis, but with certain important advantages. These include the ability, in many cases, to assign zygosity with specified probability on the basis of responses of a single informant (advantageous when one zygosity type is being oversampled); and the ability to quantify the probability of misassignment of zygosity, allowing prioritization of cases for genotyping as well as identification of cases of probable laboratory error. Out of 242 twins (from 121 like-sex pairs) where genotypic data were available for zygosity confirmation, only a single case was identified of incorrect zygosity assignment by the latent class algorithm. Zygosity assignment for that single case was identified by the LCA as uncertain (probability of being a monozygotic twin only 76%), and the co-twin's responses clearly identified the pair as dizygotic (probability of being dizygotic 100%). In the absence of genotypic data, or as a safeguard against sample duplication, application of LCA for zygosity assignment or confirmation is strongly recommended.

Zymogen granule exocytosis is characterized by long fusion pore openings and preservation of vesicle lipid identity

Thorn, P. og Fogarty, K. E. og Parker, I. — 2007-09-19T00:00:00Z

The dynamics of the fusion pore that forms between a secretory vesicle and the plasma membrane are important in the regulation of both exocytosis and endocytosis. Here, we describe characteristics of fusion during zymogen granule exocytosis in exocrine pancreatic acinar cells. By using fluorescence recovery after photobleaching techniques, we show that the fusion pore remains open to allow free aqueous exchange with the vesicle lumen. There is no lipid interchange between the plasma and granule membranes during this time, and at the end of its life, the intact granule shrinks in situ, probably by a gradual pinching off of membrane patches. We propose that the protracted fusion pore lifetime is adapted to permit compound exocytosis, whereby the lingering primary granule acts as a conduit through which the contents of a secondary granule can be released. The lack of lipid intermixing may then facilitate selective recycling of granule membrane and preservation of apical membrane integrity.