Biologically inspired vector fields to generate hair directions

This paper describes how biologically inspired vector fields can be used to partially automate the manual and time-consuming process of specifying hair directions. This approach replicates the consequence of stretching of skin from natural hair development process, in contrast to replicating the appearance of hair. The direction of each hair on the surface of an arbitrary 3D model is determined by interpolating the solution vector field that satisfies a set of user-defined constraints describing the stretching of skin. Results found that the generated hair directional pattern closely resembles that found naturally. Further investigation revealed that the presence of naturally occurring hair types and the varying distribution of hair directions induced by the calculated vector field enhanced the realism of hair coats generated using this approach. Aside from hair or fur, this approach can also be applied to hair-like masses such as grass, feathers, or scales.

Transmissible cancers in an evolutionary context.

Cancer is an evolutionary and ecological process in which complex interactions between tumour cells and their environment share many similarities with organismal evolution. Tumour cells with highest adaptive potential have a selective advantage over less fit cells. Naturally occurring transmissible cancers provide an ideal model system for investigating the evolutionary arms race between cancer cells and their surrounding micro-environment and macro-environment. However, the evolutionary landscapes in which contagious cancers reside have not been subjected to comprehensive investigation. Here, we provide a multifocal analysis of transmissible tumour progression and discuss the selection forces that shape it. We demonstrate that transmissible cancers adapt to both their micro-environment and macro-environment, and evolutionary theories applied to organisms are also relevant to these unique diseases. The three naturally occurring transmissible cancers, canine transmissible venereal tumour (CTVT) and Tasmanian devil facial tumour disease (DFTD) and the recently discovered clam leukaemia, exhibit different evolutionary phases: (i) CTVT, the oldest naturally occurring cell line is remarkably stable; (ii) DFTD exhibits the signs of stepwise cancer evolution; and (iii) clam leukaemia shows genetic instability. While all three contagious cancers carry the signature of ongoing and fairly recent adaptations to selective forces, CTVT appears to have reached an evolutionary stalemate with its host, while DFTD and the clam leukaemia appear to be still at a more dynamic phase of their evolution. Parallel investigation of contagious cancer genomes and transcriptomes and of their micro-environment and macro-environment could shed light on the selective forces shaping tumour development at different time points: during the progressive phase and at the endpoint. A greater understanding of transmissible cancers from an evolutionary ecology perspective will provide novel avenues for the prevention and treatment of both contagious and non-communicable cancers.

The evolutionary ecology of transmissible cancers.

Transmissible tumours, while rare, present a fascinating opportunity to examine the evolutionary dynamics of cancer as both an infectious agent and an exotic, invasive species. Only three naturally-occurring transmissible cancers have been observed so far in the wild: Tasmanian devil facial tumour diseases, canine transmissible venereal tumour, and clam leukaemia. Here, we define four conditions that are necessary and sufficient for direct passage of cancer cells between either vertebrate or invertebrate hosts. Successful transmission requires environment and behaviours that facilitate transfer of tumour cells between hosts including: tumour tissue properties that promote shedding of large numbers of malignant cells, tumour cell plasticity that permits their survival during transmission and growth in a new host, and a 'permissible' host or host tissue. This rare confluence of multiple host- and tumour cell-traits both explains the rarity of tumour cell transmission and provides novel insights into the dynamics that both promote and constrain their growth.

Transmissible cancers in an evolutionary context

Cancer is an evolutionary and ecological process in which complex interactions between tumour cells and their environment share many similarities with organismal evolution. Tumour cells with highest adaptive potential have a selective advantage over less fit cells. Naturally occurring transmissible cancers provide an ideal model system for investigating the evolutionary arms race between cancer cells and their surrounding micro-environment and macro-environment. However, the evolutionary landscapes in which contagious cancers reside have not been subjected to comprehensive investigation. Here, we provide a multifocal analysis of transmissible tumour progression and discuss the selection forces that shape it. We demonstrate that transmissiblecancers adapt to both their micro-environment and macroenvironment,and evolutionary theories applied to organisms are also relevant to these unique diseases.

Health and well-being naturally: 'contact with nature' in health promotion for targeted individuals, communities and populations

Issue addressed: The increase in mental health disorders worldwide makes it important to recognise health promotion interventions that are effective, accessible and affordable. Although natural spaces are coming to be recognised as health-promoting settings for general populations, little is understood about the use of nature contact in treatment and care for individuals experiencing ill-health.

Methods: This paper provides a summary of key research findings and presents a case study examining the self reported health and well-being benefits of nature contact for a small clinical sample. The 'Spectrum of Interventions for Mental Health Problems and Mental Disorders' provides a conceptual framework for ordering current and future information relating to nature-based interventions.

Results: Evidence demonstrates that separately, physical activity, social connection, and contact with nature enhance human health and well-being. The case example illustrates how 'active', 'social' and 'adventurous' contact with nature may be combined within a treatment intervention to protect and enhance the health of individuals experiencing chronic mental, emotional and physical health difficulties.

Conclusions: 'Contact with nature' constitutes a health promotion strategy with potential application in prevention, early intervention, treatment and care. Recommendations include further research to investigate the benefits of nature contact within existing interventions, and the impacts of 'active' and 'social' nature contact within tailored interventions for targeted individuals and communities.