University of the Sunshine Coast
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Current Status and Potential of Tropical Rock Oyster Aquaculture
No full textThis review summarizes existing literature of tropical rock oyster aquaculture, investigates constraints to industry expansion and provides recommendations for the further development of a contemporary industry. Barriers to development of this industry are varied and complex, and include: a research and development deficit, under-reporting of research projects, lack of species-specific biological and taxonomic knowledge, and poor shellfish food safety reputation. These issues can be linked to the tropics being comprised of many developing economies and the associated challenges of a lack of resources and investment opportunities. Current global interest remains high despite this and tropical oyster aquaculture is considered as a valuable prospective industry. With appropriate support and a collaborative approach, there is an opportunity for developing oyster culture industries to support economic development in some of the poorest regions on Earth. This review provides five key recommendations towards further developing the tropical oyster aquaculture sector: (1) to invest in foundational knowledge to understand the biology of target species and adapt existing culture methods accordingly; (2) to utilize molecular tools to clarify taxonomic ambiguity and apply novel technologies; (3) to establish a stable spat supply by progressing hatchery production; (4) to promote collaboration and widespread dissemination of information; and (5) to improve industry reputation through research, education, and quality control
Improved biodegradable magnesium alloys through advanced solidification processing
No full textThe potential of using external fields to reduce the cost of emerging magnesium alloys used for the manufacture of medical implant devices while maintaining biocompatibility and mechanical performance is explored. Zirconium (Zr) is often added to high performance magnesium alloys as a grain refiner which is expensive, and there is uncertainty about whether or not Zr is harmful to the biocompatibility of the alloy. This is a significant barrier to the adoption of alloys that contain Zr because of the need to undertake cytotoxicity and haemocompatibility testing, as well as evaluation of long-term clinical effects. An alternative approach is to investigate methods to minimise or eliminate the need for Zr addition. External fields applied during solidification of the alloy provide an opportunity to produce a refined microstructure without the addition of Mg–Zr master alloy presenting a distinct advantage both from biodegradation and biocompatibility perspectives. Preliminary work evaluates the effect of ultrasonic treatment on microstructure and mechanical properties of Mg–Zn–Ca alloys with and without Zr and then compares their in-vivo corrosion performance to that of WE43. A framework for future research is proposed along with opportunities for the development of lower cost alloys with at least equal biocompatibility, mechanical and corrosion performance
Empathy and experience: understanding tourists’ swim with whale encounters
No full textWhale-related tourism is an increasingly popular activity which may be used to drive conservation efforts. This study explored the relationships between empathy, conservation behaviors, anthropomorphism, connectedness to nature, and experiences of whale watchers and swim-with whale tourists. Participants (n = 45) from Australia and the Kingdom of Tonga completed trait questionnaires pre-swim and then questionnaires relating to their experience at post-swim. The predictions of the dispositional empathy with nature theory were supported as empathy was associated with higher anthropomorphism, connectedness to nature, and greater intention to engage in conservation behavior. Females were also higher than males on empathy. Being close to the whales, making eye contact, and seeing calves resulted in greater enjoyment. Understanding the potential connection visitors may have during a whale encounter will enhance experience design and identify avenues to increase conservation efforts
Changing Contexts of Practice: Challenges for Social Work and Community Development
No full textIn a rapidly changing global environment, there have been renewed calls to position community development more centrally in social work, particularly in the face of contemporary practice challenges. This paper analyses the broad policy contexts of neoliberalism, globalisation, and governance change and discusses how these forces interact with social work and community development, drawing on examples from Australia and Ireland. The paper argues that sociopolitical forces both restrict and present opportunities for social work and community development practice and we seek to reactivate debate about the position of community development within changing and challenging contexts
The multi-element stoichiometry of wet eucalypt forest is transformed by recent, frequent fire
No full textBackground and aims:
Fires can alter the elemental stoichiometry of ecosystems, reflecting altered patterns of biogeochemical cycling in the post-fire environment. However, elements other than carbon (C), nitrogen (N), and phosphorus (P) have rarely been studied in this context. Thus, we aimed to expand the understanding of fire’s stoichiometric and biogeochemical effects to encompass a broader suite of biogenic elements.
Methods:
We compared the stoichiometric ratios of C, N, P, potassium (K), sodium (Na), magnesium (Mg), and sulfur (S) in soil, plant litter, and beetles (Thalycrodes pulchrum) between forest plots that have been burned biennially at low intensity since 1972 and plots that have remained unburned.
Results:
Multi-element stoichiometry differed strongly between the fire regimes. Low intensity biennial burning was associated with depletion of C, N, and S relative to P, K, and to a small extent Mg and Na, in soil and litter. The stoichiometry of T. pulchrum biomass was not significantly affected by fire regime, but fire regime-associated variation in the stoichiometry of T. pulchrum biomass was positively correlated with the fire-induced stoichiometric shifts in soil.
Conclusions:
The effects of low intensity prescribed fire on ecological stoichiometry extend to Na, K, Mg, and S in ways consistent with the respective potentials of these elements to volatilize during fire or accumulate in the absence of fire. These effects vary among ecosystem components in a manner that reveals the importance of biological processes and constraints as factors that determine the nature, magnitude, and potential consequences of the stoichiometric signatures of fire regimes. We conclude that long-term changes in fire regime can disrupt or even decouple the biogeochemical cycles of numerous biogenic elements in the soil–plant system
An Experimental Series Investigating the Effects of Hyperinsulinemic Euglycemia on Myocardial Blood Flow Reserve in Healthy Individuals and on Myocardial Perfusion Defect Size following ST-Segment Elevation Myocardial Infarction
No full textBackground:
Incomplete restoration of myocardial blood flow (MBF) is reported in up to 30% of ST-segment elevation myocardial infarction (STEMI) despite prompt mechanical revascularization. Experimental hyperinsulinemic euglycemia (HE) increases MBF reserve (MBFR). If fully exploited, this effect may also improve MBF to ischemic myocardium. Using insulin-dextrose infusions to induce HE, we conducted four experiments to determine (1) how insulin infusion duration, dose, and presence of insulin resistance affect MBFR response; and (2) the effect of an insulin-dextrose infusion given immediately following revascularization of STEMI on myocardial perfusion.
Methods:
The MBFR was determined using myocardial contrast echocardiography. Experiment 1 (insulin duration): 12 participants received an insulin-dextrose or saline infusion for 120 minutes. MBFR was measured at four time intervals during infusion. Experiment 2 (insulin dose): 22 participants received one of three insulin doses (0.5, 1.5, 3.0 mU/kg/minute) for 60 minutes. Baseline and 60-minute MBFRs were determined. Experiment 3 (insulin resistance): five metabolic syndrome and six type 2 diabetes (T2DM) participants received 1.5 mU/kg/minute of insulin-dextrose for 60 minutes. Baseline and 60-minute MBFRs were determined. Experiment 4 (STEMI): following revascularization for STEMI, 20 patients were randomized to receive either 1.5 mU/kg/minute insulin-dextrose infusion for 120 minutes or standard care. Myocardial contrast echocardiography was performed at four time intervals to quantify percentage contrast defect length.
Results:
Experiment 1: MBFR increased with time through to 120 minutes in the insulin-dextrose group and did not change in controls. Experiment 2: compared with baseline, MBFR increased in the 1.5 (2.42 ± 0.39 to 3.25 ± 0.77, P = .002), did not change in the 0.5, and decreased in the 3.0 (2.64 ± 0.25 to 2.16 ± 0.33, P = .02) mU/kg/minute groups. Experiment 3: compared with baseline, MBFR increase was only borderline significant in metabolic syndrome and T2DM participants (1.98 ± 0.33 to 2.59 ± 0.45, P = .04, and 1.67 ± 0.35 to 2.14 ± 0.21, P = .05). Experiment 4: baseline percentage contrast defect length was similar in both groups but with insulin decreased with time and was significantly lower than in controls at 60 minutes (2.8 ± 5.7 vs 13.7 ± 10.6, P = .02).
Conclusions:
Presence of T2DM, insulin infusion duration, and dose are important determinants of the MBFR response to HE. When given immediately following revascularization for STEMI, insulin-dextrose reduces perfusion defect size at one hour. Hyperinsulinemic euglycemia may improve MBF following ischemia, but further studies are needed to clarify this
Hydrogen release from carbon steel in chloride solution under anodic polarization
No full textThe hydrogen permeation current increase was noticed for carbon steel in 0.5 mol/L NaCl solution under strong anodic potentials, which is contrary to the common understanding. Hydrogen permeation under cathodic potentials has been widely studied because of possible hydrogen embrittlement failures of high strength steels in seawater, but investigations of anodic polarization on hydrogen permeation are fairly rare, as the hydrogen evolution reaction shall be retarded. To corroborate the observed phenomenon, experiments were conducted using both as-received and vacuum-annealed sheet specimens. It was verified that the observed phenomena originated from the released hydrogen in traps by metal dissolution under anodic polarization
Chlamydiaceae in wild, feral and domestic pigeons in Switzerland and insight into population dynamics by Chlamydia psittaci multilocus sequence typing
No full textFeral pigeons, common wood pigeons and Eurasian collared doves are the most common representatives of the Columbidae family in Switzerland and are mostly present in highly populated, urban areas. Pigeons may carry various members of the obligate intracellular Chlamydiaceae family, particularly Chlamydia (C.) psittaci, a known zoonotic agent, and C. avium. The objective of the study was to identify the infection rates of common free-roaming pigeons for different Chlamydia species with the overall aim to assess the risk pigeons pose to public health. In this study, 431 pigeons (323 feral pigeons, 34 domestic pigeons, 39 Eurasian collared doves, 35 common wood pigeons) from several geographic locations in Switzerland were investigated for the presence of Chlamydiaceae. Samples consisted of pooled choanal-cloacal swabs (n = 174), liver samples (n = 52), and paired swab and liver samples from 205 pigeons (n = 410). All 636 samples were screened using a Chlamydiaceae family-specific 23S rRNA real-time PCR (qPCR). Subsequent species identification was performed by DNA-microarray assay, sequencing of a 16S rRNA gene fragment and a C. psittaci specific qPCR. In total, 73 of the 431 pigeons tested positive for Chlamydiaceae, of which 68 were positive for C. psittaci, four were C. avium-positive and one pigeon was co-infected with C. avium and C. psittaci. The highest infection rates were detected in feral (64/323) and domestic pigeons (5/34). Common wood pigeons (2/35) and Eurasian collared doves (2/39) revealed lower infection rates. Additionally, multilocus sequence typing of twelve selected C. psittaci-positive samples revealed closely related sequence types (ST) between and within different Swiss cities. Furthermore, liver and corresponding swab samples from the same bird were colonized by the same ST. Considering the high infection rates of C. psittaci in domestic and feral pigeons, close or frequent contact to these birds poses a human health risk
Deactivation and selectivity for electrochemical ozone production at Ni- and Sb-doped SnO2 / Ti electrodes
No full textThis work reports on a time resolved study of the deactivation of electrochemical ozone production (EOP) active anodes using a novel approach to measure total ozone production. The reproducibility and change of the electrodes over time is investigated using a number of electrochemical and physical techniques. The dissolution of antimony from the surface of the nickel- and antimony-doped tin oxide (NATO) electrode is the main process behind the deactivation of the EOP. When surface antimony is depleted, the continued deactivation seems to be connected to the dissolution of nickel. Despite tin (from the coating) and titanium (from the substrate) continuously dissolving during galvanostatic polarization of the NATO electrode, our experiments point out no connection between these processes and the EOP activity. In addition, the selectivity of the electrode is affected by electrolyte penetration, accessing fresh reaction sites that are active on the EOP. The results indicate that both antimony (III) and nickel present at the surface of the NATO are responsible for the EOP activity
Eco-activism and social work: in the public interest
No full textSocial workers are called upon to shift from a human-centric bias to an ecological ethical sensibility by embracing love as integral to their justice mission and by extending the idea of social justice to include environmental and species justice. This book presents the love ethic model as a way to do eco-justice work using public campaigns, research, community arts practice and other nonviolent, direct action strategies. The model is premised on an active and ongoing commitment to the eco-values of love, eco-justice and nonviolence for the purpose of upholding the public interest. The love ethic model is informed by the stories of eco-activists who used nonviolent actions to address ecological issues such as: pollution; degradation of the environment; exploitation of farm animals; mining industry overriding First Nation Peoples’ land rights; and human health and social costs related to the natural resource industries, private land developments and government infrastructure projects. Informed by practice insights by activists from a range of eco-justice concerns, this innovative book provides new directions in social work and environmental studies involving transformational change leadership and dialogical group work between interest groups. It should be considered essential reading for social work students, researchers and practitioners as well as eco-activists more generally. [Book Synopsis