In vitro osteoblast-like cell proliferation on nano-hydroxyapatite coatings with different morphologies on a titanium-niobium shape memory alloy

The morphology of nanomaterials significantly affects their physical, chemical, and biological properties. In the present study, nano-hydroxyapatite coatings with different morphologies were produced on the surface of a titanium-niobium shape memory alloy via a hydrothermal process. The effect of the nano-hydroxyapatite coatings on the in vitro proliferation of SaOS-2 osteoblast-like cells was investigated. Factors including crystallinity, surface micro-roughness, and surface energy of the nano-hydroxyapatite coatings were discussed. Results show that in vitro proliferation of the osteoblast-like cells was significantly enhanced on the nano-hydroxyapatite-coated titanium-niobium alloy compared to the titanium-niobium alloy without coating. The cell numbers on the nano-hydroxyapatite-coated titanium-niobium alloy changed consistently with the surface energy of the hydroxyapatite coatings. This study suggests that surface energy as a characteristic parameter influencing the in vitro proliferation of osteoblast-like cells was predominant over the crystallinity and surface micro-roughness of the nano-hydroxyapatite coatings.

Structure and properties of biomedical films prepared from aqueous and acidic silk fibroin solutions

Silk fibroin films are promising materials for a range of biomedical applications. To understand the effects of casting solvents on film properties, we used water (W), formic acid (FA), and trifluoroacetic acid (TFA) as solvents. We characterized molecular weight, secondary structure, mechanical properties, and degradation behavior of cast films. Significant degradation of fibroin was observed for TFA-based film compared to W and TA-based films when analyzed by SDS-PAGE. Fibroin degradation resulted in a significant reduction in tensile strength and modulus of TFA-based films. Compared to water, TFA-based films demonstrated lower water solubility (19.6% vs. 62.5% in 12 h) despite having only a marginal increase in their ß-sheet content (26.9% vs. 23.7%). On the other hand, FA-based films with 34.3% ß-sheet were virtually water insoluble. Following solubility treatment, ß-sheet content in FA-based films increased to 50.9%. On exposure to protease XIV, water-annealed FA-based films lost 74% mass in 22 days compared to only 30% mass loss by ethanol annealed FA films. This study demonstrated that a small variation in the ß-sheet percentage and random coil conformations resulted in a significant change in the rates of enzymatic degradation without alteration to their tensile properties. The film surface roughness changed with the extent of enzymatic hydrolysis.

Use of the program explication method to explore the benefits of a service for homeless and marginalized young people

Maintaining the alignment between the dynamic development of health and social services and the rapidly advancing scientific evaluation literature is a central challenge facing service administrators. We describe “program explication,” a consulting method designed to assist services to identify and review implicit program logic assumptions against the evaluation literature. Program explication initially facilitates agency staff to identify and document service components and activities considered critical for improving client outcomes. Program assumptions regarding the relationship between service activities and client outcomes are then examined against available scientific evidence. We demonstrate the application of this method using an example of its use in reviewing a service for homeless young people operating in Melbourne, Australia, known as the Young People's Health Service (YPHS). The YPHS involved 21 activities organized within 4 components. The intended benefits of each of the activities were coherently articulated and logically consistent. Our literature search revealed moderate to strong evidence for around 1 quarter of the activities. The program explication method proved feasible for describing and appraising the YPHS service assumptions, thereby enhancing service evaluability.

Mislabeling marine protected areas and why it matters : a case study of Australia

As part of international obligations and national policies, most nations are working toward establishing comprehensive, adequate, and representative systems of terrestrial and marine protected areas (MPAs). Assigning internationally recognized International Union for Conservation of Nature (IUCN) protected area categories to these MPAs is an important part of this process. The most recent guidance from the IUCN clearly states that commercial or recreational fishing is inappropriate in MPAs designated as category II (National Park). However, in at least two developed countries with long histories of protected area development (e.g., Canada and Australia), category II is being assigned to a number of MPAs that allow some form of commercial or recreational fishing. Using Australia as a case study, this article explores the legal and policy implications of applying protected area categories to MPAs and the consequences for misapplying them. As the Australian Government is about to embark on potentially one of the largest expansions of MPA networks in the world, ensuring the application of IUCN categories is both transparent and consistent with international practice will be important, both for the sake of international conventions and to accurately track conservation progress.

The disappearing mammal fauna of northern Australia : context, cause, and response

This article provides a context to, attempts an explanation for, and proposes a response to the recent demonstration of rapid and severe decline of the native mammal fauna of Kakadu National Park. This decline is consistent with, but might be more accentuated than, declines reported elsewhere in northern Australia; however, such a comparison is constrained by the sparse information base across this region. Disconcertingly, the decline has similarities with the earlier phase of mammal extinctions that occurred elsewhere in Australia. We considered four proximate factors (individually or interactively) that might be driving the observed decline: habitat change, predation (by feral cats), poisoning (by invading cane toads), and novel disease. No single factor readily explains the current decline. The current rapid decline of mammals in Kakadu National Park and northern Australia suggests that the fate of biodiversity globally might be even bleaker than evident in recent reviews, and that the establishment of conservation reserves alone is insufficient to maintain biodiversity. This latter conclusion is not new; but the results reported here further stress the need to manage reserves far more intensively, purposefully, and effectively, and to audit regularly their biodiversity conservation performance.

Towards a framework for implementing individual funding based on an Australian case study

Although individual funding is increasingly being used around the globe as a mechanism to fund social care, its implementation is proving to be problematic and implementation strategies are not well developed. This paper proposes a framework for the successful introduction and implementation of individual funding programs based on the analysis of data collected in a qualitative case study conducted in an Australian not-for-profit disability agency over a 4-year period from 2003 to 2007. Data were gathered through participant observation and interviews with program participants and managers, and the findings were validated with those involved. Bronfenbrenner’s ecological systems theory is used to analyze the findings from a micro, meso, exo, and macro perspective. The following factors were found to be important for successful implementation: the meaningful involvement of the person with disability in decision-making; adequate resources; access to information and appropriate supports; suitable activities being available; knowledge of policies and procedures; policies ensuring oversight and responsible accountability; employment conditions for workers being safeguarded; and support for staff and managers to adjust to their new roles. Knowledge of effective implementation strategies is important for disability agencies and for governments promoting individual funding because this radically different funding arrangement requires new implementation strategies.