Urbanisation and the ecology of powerful owls ninox strenua in outer Melbourne, Victoria

Historically, the Powerful Owl (Ninox strenua) has been seen as a southeastern Australian species restricted to, or most numerous in, dense gullies of tall open forests in hilly or mountainous areas of the coast and Great Divide. However, recent research has revealed that Powerful Owls may breed numerously and successfully in a wider range of habitats than previously believed, including the forests and woodlands within the metropolitan areas of some major cities.Here we report on the breeding of a number of pairs of Powerful Owls in the Yarra Valley, Victoria. Study sites ranged from relatively undisturbed, wet sclerophyll forest 80 km from central Melbourne, through dry sclerophyll, eucalypt-dominated open forest with some disturbance, to a highly disturbed urban parkland only 18 km from central Melbourne. We found that Powerful Owls breed successfully in some urban areas, but are limited in the amount of human disturbance they can tolerate near their nesting hollow. In the most heavily utilized section of the urban parkland, all breeding attempts were unsuccessful and in one year the young were apparently eaten by one of the parents. This followed construction of a timber boardwalk under the nest tree during the breeding season. The Powerful Owls subsequently moved to a more secluded nesting hollow and raised two young. Recommendations for management of Powerful Owls in urban areas are discussed in the context
of these results.

The Omp85 family of proteins is essential for outer membrane biogenesis in mitochondria and bacteria

Integral proteins in the outer membrane of mitochondria control all aspects of organelle biogenesis, being required for protein import, mitochondrial fission, and, in metazoans, mitochondrial aspects of programmed cell death. How these integral proteins are assembled in the outer membrane had been unclear. In bacteria, Omp85 is an essential component of the protein insertion machinery, and we show that members of the Omp85 protein family are also found in eukaryotes ranging from plants to humans. In eukaryotes, Omp85 is present in the mitochondrial outer membrane. The gene encoding Omp85 is essential for cell viability in yeast, and conditional omp85 mutants have defects that arise from compromised insertion of integral proteins like voltage-dependent anion channel (VDAC) and components of the translocase in the outer membrane of mitochondria (TOM) complex into the mitochondrial outer membrane.

Conservation management and diets of Powerful Owls (Ninox strenua) in outer urban Melbourne, Australia

The Powerful Owl Ninox strenua is Australia’s largest owl, and is mainly found east of the Great Dividing Range on the mainland in tall-open forests. The species is considered rare, both nationally and in the State of Victoria; and threatened in the Greater Melbourne area. Recovery plans for the future conservation management of N. strenua are being prepared in 2 states.

Historically, Powerful Owls have been thought to require large homes ranges (about 1000 ha per pair) in suitable old-growth forest, which provides nest hollows for the owls and their arboreal marsupial prey. Recent research, however, has found N. strenua may be more numerous and breed more successfully in a wider range of habitats than previously believed. In particular, the birds have been found living in forests and woodlands within the greater metropolitan areas of cities. The most extreme case is where a nest tree has been found within 800m of urban settlement and 6km from the centre of Brisbane.

In this paper we report on the diet, habitat use, and conservation management by a number of breeding pairs of owls in outer urban Melbourne. Study sites range from a relatively undisturbed rainforest habitat 80km from central Melbourne, through dry sclerophyll, eucalyptus-dominated open forest with some disturbance to a site 8km from central Melbourne in highly disturbed urban parkland.

Diets of the families of owls were determined by analyzing remains in regurgitated pellets. The data confirm that arboreal marsupials constitute the major prey items, especially the Common Ringtail Possum Pseudocheirus peregrinus. There were differences in diets depending on the availability of prey species, which suggest a level of opportunism not previously suspected. Our study is also the first to confirm the owls capture adult Common Brushtail Possums Trichosurus vulpecula (15% of pellets containing the remains of this large opossum have bones of mature adults at 1 site) and thus take prey up to two and a half times their own weight. As well our data suggest Powerful Owls are not restricted to hollow-dwelling prey, as in some sites the marsupials rested during the day either in leafy nests called dreys (P. peregrinus) or in house roofs (T. vulpecula).

In the most heavily disturbed sites, breeding success has been reduced, and we have evidence that in one particular year the young were eaten by one of the parents. This followed construction of a bicycle track under the nest during the breeding season. Recommendations are made for the future conservation and habitat management of Powerful Owls in the Yarra Valley corridor.

The outer limits of read-ability

This is a 20-minute presentation that involves 3 simultaneous 16mm film projections and live performance of sound poetry, which addresses issues of traumatic effect and affect. The Outer Limits of Read-ability extends the concerns of my earlier film, entitled Traum A Dream (Australia, 2003), into the immediacy of the performance situation. Traum A Dream has been described as “a representation of traumatised space, depicting a person who is consumed by a body of pain in which slowly something is remembered.” The Outer Limits of Read-ability enlists the strategies of experimental film, direct cinema, and punk, while invoking Artaud's notions of “cruel performance”

Disk-electrospinning of PVA nanofibres

In this study, we demonstrated that a thin aluminium disk can be used as nozzle to electrospin PVA nanofibres on a large-scale. A schematic of this electrospinning system and a SEM image of as-spun PVA nanofibers are shown in Figure 1. The lower part of the disk is inside a bath containing the polymer solution, which is connected to a high voltage powder supply. During electrospinning, the disk rotates and picks up a thin layer of electrically charged PVA solution. A large number of fibres are then electrospun simultaneously from two sides of tile disk and deposited on the electrode collector.
With the small prototype unit we used, the fibre production rate can be as high as 6.0 which is about 270 times higher than that of a corresponding normal needle electrospinning system (0.022g/hr). The effects of appliedb voltage, the distance between the disk nozzle and collector, and PVA concentration on the fibre morphology were examined. The dependency of fibre diameter on the PVA concentration showed a similar trend to that for a conventional electrospinning system using a syringe needle nozzle, but the diameter distribution was wider for the disk electrospun fibres in this study.
The profiles of electric field strength in disk electrospinning showed considerable dependence on the disk thickness, with a thin disk exhibiting similar electric field profile to
that of a needle electrospinning system, but a thick disk (cylinder) exhibiting levelled electric field between the disk and the collector. PVA nanofibres electrospun from disk electrospinning were compared to that electrospun from syringe needle and metal cylinder nozzles.

Needleless electrospinning. I. A comparison of cylinder and disk nozzles

In this study, we demonstrated the needleless electrospinning of poly(vinyl alcohol) (PVA) nanofibers with two nozzles, a rotating disk and a cylinder, and examined the effect of the nozzle shape on the electrospinning process and resultant fiber morphology. The disk nozzle needed a relatively low applied voltage to initiate fiber formation, and the fibers were mainly formed on the top disk edge. Also, the PVA concentration had little influence on the disk electrospinning process (up to 11 wt %). In comparison, the cylinder electrospinning showed a higher dependence on the applied voltage and polymer concentration. The fibers were initiated from the cylinder ends first and then from the entire cylinder surface only if the applied voltage were increased to a certain level. With the same polymer solution, the critical voltage needed to generate nanofibers from the disk nozzle was lower than that needed to generate nanofibers from the cylinder. Both electrospinning systems could produce uniform nanofibers, but the fibers produced from the disk nozzle were finer than those from the cylinder when the operating conditions were the same. A thin disk (8 cm in diameter and 2 mm thick) could produce nanofibers at a rate similar to that of a cylinder of the same diameter but 100 times wider (i.e., 20 cm long). Finite element analysis of electric field profiles of the nozzles revealed a concentrated electric field on the disk edge. For the cylinder nozzle, an uneven distribution of the electric field intensity profile along the nozzle surface was observed. The field lines were mainly concentrated on the cylinder ends, with a much lower electric field intensity formed in the middle surface area. At the same applied voltage, the electric field intensity on the disk edge was much higher than that on the cylinder end. These differences in the electric field intensity profiles could explain the differences in the fiber fineness and rate of the nanofibers produced from these two nozzles. These findings will benefit the design and further development of large-scale electrospinning systems for the mass production of nanofibers for advanced applications.

Current findings on Australian children in postseparation disputes : outer conflict, inner discord

This paper sets out descriptive baseline data on the first 111 Australian families participating in a current study of the efficacy of child-focused and child-inclusive Family Law Mediation. The families come from the first of two treatment groups in that comparative study. While outcome data are not yet available on this group, the baseline data, gathered prior to intervention, are of interest and value. The paper describes the nature of parents' conflict with each other, the strength of their parental alliance, and the psychological functioning of their children at the time of presentation to the mediation service. High mental health risk for the children in these families is evident, both from parents' and children's perspectives. Uniquely, the paper includes the perceptions of 73 children about their parents' conflict and its impact on them. Implications are discussed, underscoring the imperative of early intervention with separating families that includes screening of the children's experience of conflict and their own needs for recovery.

Long-distance delivery of bacterial virulence factors by Pseudomonas aeruginosa outer membrane vesicles

Bacteria use a variety of secreted virulence factors to manipulate host cells, thereby causing significant morbidity and mortality. We report a mechanism for the long-distance delivery of multiple bacterial virulence factors, simultaneously and directly into the host cell cytoplasm, thus obviating the need for direct interaction of the pathogen with the host cell to cause cytotoxicity. We show that outer membrane–derived vesicles (OMV) secreted by the opportunistic human pathogen Pseudomonas aeruginosa deliver multiple virulence factors, including b-lactamase, alkaline phosphatase, hemolytic phospholipase C, and Cif, directly into the host cytoplasm via fusion of OMV with lipid rafts in the host plasma membrane. These virulence factors enter the cytoplasm of the host cell via N-WASP–mediated actin trafficking, where they rapidly distribute to specific subcellular locations to affect host cell biology. We propose that secreted virulence factors are not released individually as naked proteins into the surrounding milieu where they may randomly contact the surface of the host cell, but instead bacterial derived OMV deliver multiple virulence factors simultaneously and directly into the host cell cytoplasm in a coordinated manner.

Blind alleys, blinding and blinded aliens : mapping the outer limits of the technical image

Marcia Jane's installation work is situated along a historic line of critical enquiry traceable back to Goethe. her energy field series re-tools for digital use the formal erasures of sturcturalist film, where the relationship between the signifier and the signified are inverted.

Oxygen reduction reaction activity of La-based perovskite oxides in alkaline medium : a thin-film rotating ring-disk electrode study

In this work, LaMO₃ and LaNi_0.5M_0.5O₃ (M = Ni, Co, Fe, Mn and Cr) perovskite oxide electrocatalysts were synthesized by a combined ethylenediaminetetraacetic acid-citrate complexation technique and subsequent calcinations at 1000 °C in air. Their powder X-ray diffraction patterns demonstrate the formation of a specific crystalline structure for each composition. The catalytic property of these materials toward the oxygen reduction reaction (ORR) was studied in alkaline potassium hydroxide solution using the rotating disk and rotating ring-disk electrode techniques. Carbon is considered to be a crucial additive component because its addition into perovskite oxide leads to optimized ORR current density. For LaMO₃ (M = Ni, Co, Fe, Mn and Cr)), in terms of the ORR current densities, the performance is enhanced in the order of LaCrO₃, LaFeO₃, LaNiO₃, LaMnO₃, and LaCoO3. For LaNi_0.5M_0.5O₃, the ORR current performance is enhanced in the order of LaNi_0.5Fe_0.5O₃, LaNi_0.5Co_0.5O₃, LaNi_0.5Cr_0.5O₃, and LaNi_0.5Mn_0.5O₃. Overall, LaCoO₃ demonstrates the best performance. Most notably, substituting half of the nickel with cobalt, iron, manganese, or chromium translates the ORR to a more positive onset potential, suggesting the beneficial catalytic effect of two transition metal cations with Mn as the most promising candidate. Koutecky–Levich analysis on the ORR current densities of all compositions indicates that the four-electron pathway is favored on these oxides, which are consistent with hydroperoxide ion formation of <2%.

Optimizing oxygen transport through La0.6Sr0.4Co0.2Fe0.8O3-δ hollow fiber by microstructure modification and Ag/Pt catalyst deposition

This work compares the oxygen permeation fluxes of five different La0.6Sr0.4Co0.2Fe0.8O3−δ membranes (e.g. disk, conventional hollow fiber, modified hollow fiber, Ag- or Pt-deposited hollow fiber membranes) to elucidate the dominance of a particular oxygen transport limiting step (e.g., bulk-diffusion or surface reaction) within each of these membranes. At 900 °C and 100 mL min–1 helium gas sweep rate, the oxygen fluxes for disk, conventional hollow fiber, modified hollow fiber, Ag-deposited modified hollow fiber, and Pt-deposited modified hollow fiber membranes are 0.10, 0.33, 0.84, 1.42, and 2.62 mL min–1 cm–2, respectively, denoting enhanced performance in this sequential order. More than 300% enhancement of fluxes is evidenced by modifying the geometry from disk to conventional hollow fiber. This is attributed to the thickness reduction from 1 mm to 0.3 mm, thus implying bulk-diffusion and surface reaction as the jointly limiting transport step for this disk membrane. In contrast to a conventional hollow fiber that has a sandwich cross-sectional structure (e.g. dense center layer sandwiched by two finger-like layers) as well as dense outer and inner circumference surfaces, the modified hollow fiber has only one dense layer in its outer circumference surface with finger-like porous layer extending all the way from outer cross-sectional part to the inner cross-sectional part. This microstructural difference, in turn, provides substantial reduction of membrane thickness and enlarges surface reaction area for modified hollow fiber (relative to conventional hollow fiber), both of which contributes to the reduced bulk-diffusion and surface reaction resistance; evidenced by almost 250% oxygen flux enhancement. To enhance the performance even further, catalyst (e.g., Ag or Pt) deposition on the outer circumference surface of modified hollow fiber can be utilized to reduce its dominating surface reaction resistance. While both catalysts increase the oxygen fluxes, Pt reveals itself as the better candidate relative to Ag due to melting-induced aggregation and growth of Ag at 950 °C.