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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
Importance of human papillomavirus infection in squamous cell carcinomas of the tongue in Guangdong Province, China
No full textObjective: Tongue squamous cell carcinoma is one of the most common oral tumors. Human papillomavirus (HPV) infection has been proposed as a risk factor for head and neck squamous cell carcinoma, particularly oropharyngeal squamous carcinoma. Methods: In this study, we retrospectively analyzed HPV infection in 121 Chinese patients with tongue squamous cell carcinoma in Guangdong Province. Polymerase chain reaction of HPV DNA and immunohistochemistry staining of p16 protein were used to identify the presence of HPV in formalin-fixed paraffin-embedded samples. Results: HPV DNA was detected in 15.7% (n = 19) of tongue squamous cell carcinoma patients, with HPV16 being the most common type (n = 8, 42.1%). p16 staining did not correlate with detection of HPV DNA. Male sex was associated with HPV-positive tongue squamous cell carcinoma, whereas there were no significant differences in alcohol consumption, smoking, or age when tumors were stratified by HPV. Conclusion: Our study showed that HPV infection contributed to tongue squamous cell carcinoma in a small cohort of patients in Guangdong Province, China. Further investigation is needed to confirm whether HPV is a causal factor for tongue squamous cell carcinoma
Learning and Development in the Franchising Sector and Business Performance
No full textThis research creates new knowledge in the domain of franchising research within the context of Learning and Development (L&D), whilst concomitantly providing actionable insights that will be of value to the franchising sector as well as Human Resource Management (HRM) and L&D professionals. It is envisaged that the results will serve members of the franchising and HRM communities by developing an integrative framework for knowledge exchange and transfer. It is proposed that investment in L&D can and does lead to enhanced channel outcomes for the various players involved in the franchising relationship (franchisees, franchisors, customers, franchise employees, suppliers and industry and the franchise sector as a whole). However, poor participation and engagement in franchisor-initiated L&D activities is widespread in the business format franchising sector in Australia and this phenomenon has impacted franchise system performance. Qualitative empirical examination provides confirmation of this proposition and factors that influence successful L&D execution in terms of achieving enhanced channel outcomes are identified. Therefore, the aim of this thesis is to address the following research question; ‘What factors influence participation and engagement with training interventions and their subsequent ability to achieve enhanced channel outcomes?’ Initially, 20 industry experts were interviewed, with participants comprising a mix of franchisors, franchisees, training and education specialists and suppliers to the franchising sector. Franchisors were selected from a range of industries including business services, retail and home services. The interviews explored the diversity of approaches to L&D strategy and the impact it has on achieving enhanced channel outcomes. Next, a qualitative case study approach was adopted, targeting 60 participants across four franchise groups in order to explore factors that influence franchisee participation and engagement with training interventions. It was determined that for enhanced channel outcomes to occur, certain channel conditions need to be present. These conditions are presented as an integrative framework for knowledge transfer.Submitted in the fulfilment of the requirements of the degree of Doctor of Philosophy, University of the Sunshine Coast, 2020
Clinician‐led design for optimising flow: Seizing the opportunity for a new‐build Australian Emergency Department
No full textA new ED build creates a unique opportunity to improve the way we provide clinical care. Often, the focus is primarily on increasing clinical cubicle numbers but this may have a negligible, or even negative impact on care delivery. Instead, Australian EDs should examine the entire patient journey to inform design, reviewing outdated triage and registration models and maximising physical capacity by introducing advanced split‐flow models that optimise clinical space and provide high‐risk patients faster access to clinical care. Efficient ED patient flow is critical for success and is closely linked with departmental design, but too often this design process is delegated to architects with limited knowledge of ED function and with limited input from emergency clinicians. This relationship between clinicians and architects should remain collaborative but requires re‐alignment. Independent, expert ED‐specific designers can empower and provide valuable support for clinician‐led design teams in their interactions with architects
Infant care practices and parent uptake of safe sleep messages: a cross-sectional survey in Queensland, Australia
No full textBackground:
Globally, the incidence of sleep-related infant mortality declined dramatically following the first public health campaigns seen internationally in the 1990s to reduce the risks of sudden infant death. However, Australian Sudden Unexpected Death in Infancy (SUDI) rates have plateaued with little change in incidence since 2004 despite two further public health safe sleep campaigns. This study aims to describe contemporary infant care practices employed by families related to the current public health SUDI prevention program.
Methods:
A cross-sectional survey of 3341 Queensland primary caregivers with infants approximately 3-months of age was conducted using the Queensland Registry of Births, Deaths and Marriages as a sampling frame. Surveys were returned either via reply-paid mail or online. Questionnaires explored prevalence of infant care practices and awareness of safe sleep recommendations. Univariable analysis was used to generate descriptive statistics for key variables.
Results:
Overall, only 13% of families routinely practised all six ‘Safe Sleeping’ program messages. More than one third (1118, 34%) of infants had slept in a non-supine sleep position at some time. Potentially hazardous sleep environments were common, with 38% of infants sleeping with soft items or bulky bedding, or on soft surfaces. Nearly half, for either day- or night-time sleeps, were routinely placed in a sleep environment that was not designed or recommended for safe infant sleep (i.e. a bouncer, pram, beanbag). Most babies (84%) were reportedly smoke free before and after birth. Sleeping in the same room as their caregiver for night-time sleeps was usual practice for 75% of babies. Half (1600, 50%) of all babies shared a sleep surface in the last two-weeks. At 8-weeks, 17% of infants were no longer receiving any breastmilk.
Conclusions:
The prevalence rates of infant care practices among this Australian population demonstrate many families continue to employ suboptimal practices despite Australia’s current safe sleep campaign. Strategic approaches together with informed decisions about pertinent messages to feature within future public health campaigns and government policies are required so targeted support can be provided to families with young infants to aid the translation of safe sleep evidence into safe sleeping practices