Animated feather coats using field lines

The tedious task of manually placing feathers on computer animated objects involves aligning feathers, ensuring that they do not insect each other or penetrate the surface, deforming every feather to match the local surface features, and ensuring that the feather coat is consistent when the underlying object is animated.

We present a technique for generating a feather coat over an object. Feather orientation is specified quickly and easily, feathers are deformed while ensuring collision prevention, and the coat can be animated. We create a vector field in the space surrounding the body object and deform feathers to align with the field lines. The non-intersection property of the field lines ensures that feather intersections are avoided. We provide a formulation of a suitable vector field and demonstrate that it is capable of producing realistic feather coats. The process can easily be integrated into the work-flow of standard modelling and animation processes.

We show examples of feather coat creation on a range of objects, proving that field line based placement of feather coats provides the desired functionality for feather modelling and animation.

Phylogenetic analysis of beak and feather disease virus across a host ring-species complex

Pathogens have been hypothesized to play a major role in host diversity and speciation. Susceptibility of hybrid hosts to pathogens is thought to be a common phenomenon that could promote host population divergence and subsequently speciation. However, few studies have tested for pathogen infection across animal hybrid zones while testing for codivergence of the pathogens in the hybridizing host complex. Over 8 y, we studied natural infection by a rapidly evolving single-strand DNA virus, beak and feather diseases virus (BFDV), which infects parrots, exploiting a host-ring species complex (Platycercus elegans) in Australia. We found that host subspecies and their hybrids varied strikingly in both BFDV prevalence and load: both hybrid and phenotypically intermediate subspecies had lower prevalence and load compared with parental subspecies, while controlling for host age, sex, longitude and latitude, as well as temporal effects. We sequenced viral isolates throughout the range, which revealed patterns of genomic variation analogous to Mayr's ring-species hypothesis, to our knowledge for the first time in any host-pathogen system. Viral phylogeny, geographic location, intraspecific host density, and parrot community diversity and composition did not explain the differences in BFDV prevalence or load between subpopulations. Overall, our analyses suggest that functional host responses to infection, or force of infection, differ between subspecies and hybrids. Our findings highlight the role of host hybridization and clines in altering host-pathogen interactions, dynamics that can have important implications for models of speciation with gene flow, and offer insights into how pathogens may adapt to diverging host populations.

Prevalence of beak and feather disease virus in wild Platycercus elegans: comparison of three tissue types using a probe-based real-time qPCR test

The detection of avian viruses in wild populations has considerable conservation implications. For DNA-based studies, feathers may be a convenient sample type for virus screening and are, therefore, an increasingly common technique. This is despite recent concerns about DNA quality, ethics, and a paucity of data comparing the reliability and sensitivity of feather sampling to other common sample types such as blood. Alternatively, skeletal muscle tissue may offer a convenient sample to collect from dead birds, which may reveal viraemia. Here, we describe a probe-based quantitative real-time PCR for the relative quantification of beak and feather disease virus (BFDV), a pathogen of serious conservation concern for parrots globally. We used this method to test for BFDV in wild crimson rosellas (Platycercus elegans), and compared three different sample types. We detected BFDV in samples from 29 out of 84 individuals (34.5%). However, feather samples provided discordant results concerning virus presence when compared with muscle tissue and blood, and estimates of viral load varied somewhat between different sample types. This study provides evidence for widespread infection of BFDV in wild crimson rosellas, but highlights the importance of sample type when generating and interpreting qualitative and quantitative avian virus data.

The ecology and evolution of beak and feather disease virus in Platycercus elegans

 This thesis explores the complex ecological and evolutionary interactions between beak and feather disease virus and one of its hosts the crimson rosella. The work identifies several factors that predict viral infection in wild birds and determines how host population structure influences viral evolution.

An experimental examination of interindividual variation in feather corticosterone content in the House Sparrow, Passer domesticus in southeast Australia

Non-invasive techniques for measuring glucocorticoids (GCs) have become more prevalent, due to the advantage of eliminating the effects of animal disturbance on GC levels and their potential to provide an integrated, historic estimate of circulating GC levels. In the case of birds, corticosterone (CORT) is deposited in feathers, and may reflect a bird's GC status over the period of feather synthesis. This technique thus permits a retrospective view of the average circulating GC levels during the moult period. While it is generally assumed that differences in feather CORT content (CORTf) between individuals reflects their different stress histories during either natural or induced moult, it is not clear how much of this variation is due to extrinsic versus intrinsic factors. We examined this question by determining CORTf in free-living house sparrows (Passer domesticus) from two populations, one urban and the other rural, that were plucked before and after exposure to different plasma CORT levels while held captive. We experimentally manipulated plasma CORT by implanting birds with either a corticosterone-filled, metyrapone-filled, or empty ('sham') silastic capsule as replacement feathers first emerged. The pattern of post-treatment CORTf was consistent with our expectations, based on plasma CORT levels of an experimentally implanted reference group. However, there was no statistically significant difference in CORTf between these treatment groups unless sex, population origin, and CORTf of original feathers for each individual were included in a model. Thus, birds with higher CORTf in feathers removed for this experiment tended to have higher CORTf in post-treatment replacement feathers, irrespective of treatment. In addition, we found that feather fault bar scores were significantly higher in CORT-treated birds than in the other two treatment groups, but did not vary directly with CORTf level. Our study therefore broadly confirms the use of feathers as a non-invasive tool to estimate plasma CORT during moult in birds, but importantly demonstrates the potential for intrinsic differences in stress characteristics between populations and individuals to obscure the effects extrinsic stressors might have on CORTf .

Birds of a feather: the geographic interconnection of Australian universities on Twitter

Purpose
Regardless of their virtual nature, research suggests that social media networks are still influenced by geography. This research investigates the connections between Australian universities on the Twitter social media system.

Design/methodology/approach
This research employs network analysis and visualisation to characterise the connections between Australian universities on Twitter.

Findings
A strong relationship to geography, both at the intra-state level and the inter-state level, was observed in the connections between Australian universities on Twitter. A relationship between number of followers and time since joining Twitter was also observed.

Research limitations/implications
The research presented is limited to Australian universities only and represents a snapshot in time only.

Practical implications
Australian universities have the opportunity to reach beyond the geographically restricted connections observed here, to actively seek new audiences, and to realise the cited benefits of online social media relating to increased connection across physical and digital frontiers. By capitalising on the strong ‘locality’ observed in social media connections, a university could become a desirable source of information that is likely to be of interest to, and valued by, local constituents.

Originality/value
This paper contributes to the research literature on university use of social media by addressing the so far largely silent area of inter-institutional connections via social media, and the influence of physical geography on the connections between universities on Twitter. It also offers a practical methodology for those interested in further research in this area.

Development of a novel cellulose/duck feather composite fibre regenerated in ionic liquid

By blending cellulose and duck feather in the common solvent 1-allyl-3-methylimidazoloium chloride, a regenerated composite fibre has been developed with improved fibres over regenerated cellulose fibres (RCF). The mechanical properties of composite fibre was shown to be better than RCF with a 63.7% improvement in tensile strain. Here, we thoroughly characterise the composite fibre and show that the composite fibre has many advantages over RCFs both from a spinning perspective and as a regenerated fibre.

Generating heat from conducting polypyrrole-coated PET fabrics

Heating effects in polypyrrole-coated polyethyleneterephthalate (PET)-Lycra® fabrics were studied. Chemical synthesis was employed to coat the PET fabrics by polypyrrole using ferric chloride as oxidant and antraquinone- 2-sulfonic acid (AQSA) and naphthalene sulfonic acid (NSA) as dopants. The coated fabrics exhibited reasonable electrical stability, possessed high electrical conductivity, and were effective in heat generation. Surface resistance of polypyrrole-coated fabrics ranged from approximately 150 to 500 /square. Different connections between conductive fabrics and the power source were examined. When subjected to a constant voltage of 24 V, the current transmitted through the fabric decreased about 10% in 72 h. An increase in resistance of conductive fabrics subjected to constant voltage was observed

Effect of storage on the biochemical and processing quality of Adzuki Bean (Vigna angularis)

Storage of adzuki beans and other pulse grains causes biochemical and physical changes that affect the hydration properties of the beans. This affects the quality of products made from the beans such as the Japanese bean paste “ann.” Storage, particularly under unfavourable conditions, leads to the “hard shell” phenomenon, where beans fail to imbibe water when soaked and remain hard, and the “hard-to-cook” phenomenon where the seeds hydrate normally, but the cotyledon fails to hydrate and soften during cooking. The hard shell phenomenon is attributable to impermeability of the seed coat to water, which is due to biochemical changes in the seed coat, such as the formation of protein-tannin complexes, and biophysical changes such as reduction in size or closure of the straphiole aperture in the hilum area—the main area for water entry into the adzuki bean. The hard-to-cook phenomenon is due to changes in the cotyledon tissue, which include formation of insoluble pectinates, lignification of the cell wall and middle lamella, interaction of condensed tannins with proteins and starch, and changes to the structure and functionality of the cellular proteins and starch.

Non-invasive sampling techniques : applications for mapping the generic variation of powerful owls

The Powerful Owl (Ninox strenua) is endemic to Australia, being resident in the three eastern mainland states and the Australian Capital Territory. It is classified nationally as of conservation significance and vulnerable in the state of Victoria. The elusive nature of this owl, along with its dispersed distribution, low population density and difficulty in identifying individual birds, limit the collection of ecological data. Molecular methods can be used to obtain crucial ecological information, essential for Powerful Owl conservation.

Non-invasive sampling is a relatively new method used for obtaining genetic material from free-ranging animals. This type of sampling however, is generally overlooked as a potential DNA source. Shed hair and feathers, faeces, urine, skins and eggshells are all potential sources of DNA. Non-invasive sampling regimes may be the only alternative for the genetic analysis of endangered and/or elusive species that are difficult to sample otherwise.

Powerful Owls moult annually. Shed feathers therefore, can be collected from under roost trees and used for genetic analysis. Feathers collected provide DNA that is unique to the individual and can provide additional ecological knowledge of the species.

In this study we collected shed Powerful Owl feathers during 2003 and 2004. In order to obtain samples from across the owl's large distribution, public awareness about the project via the way of flyers, mail-outs, media sources (radio, newspapers and magazines), email lists and public seminars was initiated. Overall, the collection strategy was very successful with over 500 Powerful Owl feather samples being collected.

Genetic information obtained from the analysis of DNA from feathers can enable a more rigorous assessment of population viability of the Powerful Owl. Specifically designed molecular markers will facilitate unequivocal identification of individual birds ("DNA fingerprinting"). Through the application of molecular techniques we can collect ecological information about the Powerful Owl such as, genetic divergence, population structure, dispersal patterns, migration and inbreeding. These questions can not be addressed via traditional data collection and will contribute significantly to the successful conservation of the Powerful Owl and potentially other raptor species.

Optimizing the use of shed feathers for genetic analysis

Shed feathers obtained by noninvasive genetic sampling (NGS) are a valuable source of DNA for genetic studies of birds. They can be collected across a large geographical range and facilitate research on species that would otherwise be extremely difficult to study. A limitation of this approach is uncertainty concerning the quality of the extracted DNA. Here we investigate the relationship between feather type, feather condition and DNA quality (amplification success) in order to provide a simple, cost-effective method for screening samples prior to genetic analysis. We obtained 637 shed feathers of the powerful owl ( Ninox strenua) from across its range in southeastern Australia. The extracted DNA was amplified using polymerase chain reaction for a range of markers including mitochondrial DNA, ND3 and nuclear DNA, a simple sequence repeat (Nst02) and a portion of the CHD-1 gene (P2/P8). We found that feather condition significantly influenced the amplification success of all three loci, with feathers characterized as ‘good’ having greater success. Feather type was found to be of lower importance, with good quality feathers of all types consistently producing high success for all three loci. We also found that the successful amplification of multilocus genotypes was dependant on the condition of the starting material and was highly correlated with successful amplification of the sex-linked CHD-1 locus. Samples with low DNA quality have a higher probability of amplification failure and are more likely to produce incorrect genotypes; therefore, identifying samples with high DNA quality can save substantial time and cost associated with the genetic analysis of NGS. As a result, we propose a method for screening shed feathers in order to provide a subset of samples which will have a greater probability of containing high quality DNA suitable for the amplification of multilocus genotypes.

Polymer coatings containing nano particles of zinc oxide for the UV protection of dyed polyester fabrics

The useful life of many outdoor textile products is limited by degradation caused by exposure to sunlight, in particular by the ultra violet component (below 400 nm). The degradation results in fading of colours and also loss of physical properties, such as tear strength and abrasion resistance. Degradation can be decreased with UV absorbers, often used in conjunction with antioxidants or free radical quenchers. The protection afforded by these organic compounds is, however, limited as they are ultimately destroyed by the UV radiation they absorb.
An alternative approach is to coat fabrics with a polymer containing an inorganic UV absorber, such as zinc oxide. The inherent stability of zinc oxide would be expected to provide a protective effect over a much longer period than can be achieved with an organic UV absorber. A possible disadvantage of zinc oxide when applied in a polymer film is that absorption and scattering of visible light can produce hazy films and, hence, an unacceptable change in fabric appearance.
This poster paper examines the possibility of using nano particles of zinc oxide dispersed in acrylic polymers for protecting dyed polyester fabrics against sunlight fading. Factors affecting both UV absorbance and film clarity will be discussed. The possibility will also be examined that the protective effect may be reduced in some circumstances by reactive oxygen species, generated by the interaction of UV with zinc oxide in the presence of air and water.

Structural function and evolution of the subarctometatarsus

Compares the metatarsal structural design (subarctometatarsus) of recently discovered Chinese feathered dinosaurs with the metatarsus (arctometatarsus) possessed by more advanced theropod dinosaurs and the metatarsus of more primitive forms. The subarctometatarsus was proved to be an intermediate structure. Additionally the metatarsus appears to co-incide with the evolution of the avian feather suggesting a possible relationship between the subarctometatarsus's evolution and the evolution of avian flight.