Fine-scale adaptation in a clonal sea anemone

Local adaptation in response to fine-scale spatial heterogeneity is well documented in terrestrial ecosystems. In contrast, in marine environments local adaptation has rarely been documented or rigorously explored. This may reflect real or anticipated effects of genetic homogenization, resulting from widespread dispersal in the sea. However, evolutionary theory predicts that for the many benthic species with complex life histories that include both sexual and asexual phases, each parental habitat patch should become dominated by the fittest and most competitive clones. In this study we used genotypic mapping to show that within headlands, clones of the sea anemone Actinia tenebrosa show restricted distributions to specific habitats despite the potential for more widespread dispersal. On these same shores we used reciprocal transplant experiments that revealed strikingly better performance of clones within their natal rather than foreign habitats as judged by survivorship, asexual fecundity, and growth. These findings highlight the importance of selection for fine-scale environmental adaptation in marine taxa and imply that the genotypic structure of populations reflects extensive periods of interclonal competition and site-specific selection.

Asexual reproduction does not produce clonal populations of the brooding coral Pocillopora damicornis on the Great Barrier Reef, Australia

We have investigated the relationship between genotypic diversity, the mode of production of brooded larvae and disturbance in a range of reef habitats, in order to resolve the disparity between the reproductive mode and population structure reported for the brooding coral Pocillopora damicornis. Within 14 sites across six habitats, the ratio of the observed (G o) to the expected (G e) genotypic diversity ranged from 69 to 100% of that expected for random mating. At three other sites in two habitats the G o /G e ranged from 35 to 53%. Two of these sites were recently bleached, suggesting that asexual recruitment may be favoured after disturbance. Nevertheless, our data suggest that brooded larvae, from each of five habitats surveyed, were asexually produced. While clonal recruitment may be important in disturbed habitats, the lack of clonality detected, both in this and earlier surveys of 40 other sites, implies that a disturbance is normally insufficient to explain this species’ continued investment in clonal reproduction.

Electrospinning of nanofibres for construction of vital organ replacements

This paper described the production of a novel biosynthetic material using the manufacturing technique of electro spinning for the construction of scaffold for organ replacement. This electrostatic technique uses an electric field to control the deposition of polymer fibres onto a specific substrate to fabricate fibrous polymer constructs composed of fibre diameters ranging from several microns down to 100 nm or less. Two areas of research, in particular, heart valve leaflets and blood vessel will be discussed. Here, a sandwich structure nanofibre mesh was used to construct materials for leaflets of heart valve and blood vessel. In the case of heart valve leaflet, the randomly oriented polyurethane nanofibres were prepared as the first layer, followed by gelatin-chitosan complex layer. Complex nanofibres were initially used to spin on the PU layer with cross orientation to mimic the fibrosa layer. A gelatin and chitosan complex was then spun onto the other side of PU nanofibre mesh to mimic the ventricularis layer. This particular sandwich structure using the PU layer was designed to simulate the mechanical properties of natural tissue. In addition, this design was aimed to provide good biocompatibility and improved cellular environment to assist in adhesion and proliferation. Smooth muscle cells adhered and flattened out onto the surface of the gelatin-chitosan complex as early as 1 day post seeding. There is great potential for this biosynthetic biocompatible nanofibrous material to be developed for various clinical applications.

Protection behaviour : a phenomenon affecting organ and tissue donation in the 21st century?

UK statistics show that whilst waiting lists for transplantation surgery continue to increase, donor numbers are static. This paper describes the hermeneutic phase of a mixed method study and puts forward the concept of protection behaviour as one explanation for nurses’ reticence to discuss post-mortem donation wishes with patients’ relatives. The desire to protect appears to influence attitudes, confidence levels and perceived ability to become involved in donor identification and donation discussion, consequently affecting the availability of transplantable organs and tissue. By understanding more fully why protective behaviours are employed, it increases the likelihood of a solution being found.

Trapped in white space : the allegations and denials of organ trafficking

Allegations of body parts trafficking implicating the West have been surfacing persistently in the media of many non Western countries for almost 20 years. Western media has responded to the allegations with denials and denunciations. This thesis considers the competing accounts and places them in a framework for analysis.

Converting potential organ donors : a situational analysis of Australian physicians

This theory-building research suggests that the key to unlocking Australia's potential organ donor pool is to reduce the ethical ambiguity and legal uncertainty plaguing physicians' interepretation of the patients's best interests standard. This may generate a greater acceptance of organ donation as part of end-of-life patient care amongst our physicians.

Spectral element model updating for damage identification using clonal selection algorithm

A spectral element model updating procedure is presented to identify damage in a structure using Guided wave propagation results. Two damage spectral elements (DSE1 and DSE2) are developed to model the local (cracks in reinforcement bar) and global (debonding between reinforcement bar and concrete) damage in one-dimensional homogeneous and composite waveguide, respectively. Transfer matrix method is adopted to assemble the stiffness matrix of multiple spectral elements. In order to solve the inverse problem, clonal selection algorithm is used for the optimization calculations. Two displacement-based functions and two frequency-based functions are used as objective functions in this study. Numerical simulations of wave propagation in a bare steel bar and in a reinforcement bar without and with various assumed damage scenarios are carried out. Numerically simulated data are then used to identify local and global damage of the steel rebar and the concrete-steel interface using the proposed method. Results show that local damage is easy to be identified by using any considered objective function with the proposed method while only using the wavelet energy-based objective function gives reliable identification of global damage. The method is then extended to identify multiple damages in a structure. To further verify the proposed method, experiments of wave propagation in a rectangular steel bar before and after damage are conducted. The proposed method is used to update the structural model for damage identification. The results demonstrate the capability of the proposed method in identifying cracks in steel bars based on measured wave propagation data.

A profile of Australian adults who have discussed their posthumous organ donation wishes with family members

Next of kin who are aware of the deceased's organ donation wishes usually will honor those wishes, while next of kin who are unaware of these wishes typically withhold consent for posthumous donation. Encouraging individuals to communicate or register their organ donation wishes is therefore important. Using a sample of 409 participants, the current study sought to develop a profile of Australian adults who had communicated their organ donation wishes to family members. Christian participants and those who had a higher income were more likely to have communicated their donation wishes. Conversely, participants were less likely to have communicated their donation wishes if they were unregistered and undecided/opposed to organ donation, unregistered but willing to donate, or fearful of death. Finally, whether participants had communicated, registered, or communicated and registered their donation wishes was associated with their age, religion, attitude toward organ donation, and recall of media content about organ donation. Messages encouraging the communication of organ donation wishes to family members should therefore be targeted toward those individuals who are most likely to be receptive toward enacting this behavior.

The organ of repetition

This paper considers the practice of learning-by-heart and argues for its relevance to learning, to thought (as defined by Gilles Deleuze) and as a way of turning towards the ‘new’ or ‘the future’, via the operation of repetition. It considers two modes in which rote learning can be productive and provocative—firstly, when the content itself is something worth retaining, and secondly, when the actual process of the learning itself and then the repeating align themselves with the criteria of ‘practice’, as framed by the author here. In the face of rote learning’s reputation as an out-moded pedagogical tool, the paper argues that it inhabits a paradoxical and productive site, whereby what begins as a repetition of the same, can open towards pure repetition (as Deleuze frames this notion), and facilitate inventiveness and a courting of the new. In this way, poetry, and the learning of it by rote, constitute a unique constellation, disputing the platitude that learning is ‘only discovering what one already knew’ and instead proposing that learning is closer to an awesome ordeal, one that leads to concepts and collisions that did not exist before and cannot be predicted in advance.