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Membrane lipid remodeling in response to salinity
No full textSalinity is one of the most decisive environmental factors threatening the productivity of crop plants. Understanding the mechanisms of plant salt tolerance is critical to be able to maintain or improve crop yield under these adverse environmental conditions. Plant membranes act as biological barriers, protecting the contents of cells and organelles from biotic and abiotic stress, including salt stress. Alterations in membrane lipids in response to salinity have been observed in a number of plant species including both halophytes and glycophytes. Changes in membrane lipids can directly affect the properties of membrane proteins and activity of signaling molecules, adjusting the fluidity and permeability of membranes, and activating signal transduction pathways. In this review, we compile evidence on the salt stress responses of the major membrane lipids from different plant tissues, varieties, and species. The role of membrane lipids as signaling molecules in response to salinity is also discussed. Advances in mass spectrometry (MS)-based techniques have largely expanded our knowledge of salt-induced changes in lipids, however only a handful studies have investigated the underlying mechanisms of membrane lipidome regulation. This review provides a comprehensive overview of the recent works that have been carried out on lipid remodeling of plant membranes under salt treatment. Challenges and future perspectives in understanding the mechanisms of salt-induced changes to lipid metabolisms are proposed
Nursing knowledge of Alcohol and Other Drugs (AOD) in a regional health district: an exploratory study
No full textNurses remain at the forefront of direct patient care due to the nature of their role; they are in a position to provide assessment, response and referral of individuals in healthcare settings with problematic alcohol and other drug (AOD) use. We aim to determine the AOD knowledge of nurses in a regional health district in Australia and the awareness of an AOD service operating in the clinical environment. We employed a cross-sectional online survey, with descriptive and correlational analysis performed to explore relations between knowledge and both assessment and referral practices for individuals with problematic AOD use. Results indicate good knowledge of the AOD service, with confidence to refer to the service associated with recent contact. Lower satisfaction levels with the AOD service were found in nurses who had no recent contact with the service. Awareness of the service was also positively associated with completion of the electronic AOD assessment. These results indicate that the presence of experienced AOD clinicians may increase familiarity with AOD services and increase screening. Given the link between familiarity and comfort with the AOD service and referral, establishing specialised AOD nursing positions remains an important strategy. We argue that the presence of specialised AOD nurses has a flow on effect in maintaining continuing screening and encouraging nurses to refer individuals with problematic AOD use for ongoing care and treatment
Elemental signatures of Australopithecus africanus teeth reveal seasonal dietary stress
No full textReconstructing the detailed dietary behaviour of extinct hominins is challenging1—particularly for a species such as Australopithecus africanus, which has a highly variable dental morphology that suggests a broad diet2,3. The dietary responses of extinct hominins to seasonal fluctuations in food availability are poorly understood, and nursing behaviours even less so; most of the direct information currently available has been obtained from high-resolution trace-element geochemical analysis of Homo sapiens (both modern and fossil), Homo neanderthalensis4 and living apes5. Here we apply high-resolution trace-element analysis to two A. africanus specimens from Sterkfontein Member 4 (South Africa), dated to 2.6–2.1 million years ago. Elemental signals indicate that A. africanus infants predominantly consumed breast milk for the first year after birth. A cyclical elemental pattern observed following the nursing sequence—comparable to the seasonal dietary signal that is seen in contemporary wild primates and other mammals—indicates irregular food availability. These results are supported by isotopic evidence for a geographical range that was dominated by nutritionally depauperate areas. Cyclical accumulation of lithium in A. africanus teeth also corroborates the idea that their range was characterized by fluctuating resources, and that they possessed physiological adaptations to this instability. This study provides insights into the dietary cycles and ecological behaviours of A. africanus in response to food availability, including the potential cyclical resurgence of milk intake during times of nutritional challenge (as observed in modern wild orangutans5). The geochemical findings for these teeth reinforce the unique place of A. africanus in the fossil record, and indicate dietary stress in specimens that date to shortly before the extinction of Australopithecus in South Africa about two million years ago
The acute physiological status of white sharks (Carcharodon carcharias) exhibits minimal variation after capture on SMART drumlines
No full textDrumlines incorporating SMART (Shark-Management-Alert-in-Real-Time) technology are a new tool used in several bather protection programmes globally. In New South Wales (NSW), Australia, the white shark (Carcharodon carcharias) is a target species for SMART drumlines because they are often involved in attacks on humans. To understand white shark sensitivity to capture and to establish protocols around acceptable timeframes for responding to alerts, 47 juvenile and subadult white sharks were caught on SMART drumlines at five locations off the east coast of Australia. There was no at-vessel mortality during the sampling period. After capture, blood was sampled from each shark to assess its acute physiological status. Of the 18 metabolites investigated, only lactate and aspartate aminotransferase exhibited significant positive relationships with the capture duration on SMART drumlines. These results indicate that the capture process is relatively benign and that the current response times used here are appropriate to minimize long-term negative impacts on released white sharks. Where white sharks are likely to interact negatively with beachgoers, SMART drumlines can therefore be a useful addition to bather protection programmes that also aim to minimize harm to captured animals. Other shark species captured on SMART drumlines should also be investigated to gain broader understanding of potential physiological consequences of using this new technology
Minoritised academics talking about marginalised subjects: Islamophobia, racism and the academy in Australia
No full textBlack salve composition: an evaluation of the potential for normal tissue toxicity and treatment failure from black salve products
No full textBlack salve, used as an alternative skin cancer therapy, contains both herbal and chemical constituents, including extracts of the rhizomes of Sanguinaria canadensis and zinc chloride. Black salves may be ordered online and have been associated with cases of extensive tissue necrosis and treatment failures that have resulted in patient fatalities. Despite these adverse outcomes and continued use by patients, black salve products have not been quantitatively assessed to determine their constituent concentrations. Thirteen different black salve products from eight manufacturers were analysed using validated HPLC-MS and ICP-MS methods to assess S. canadensis alkaloid and zinc chloride concentrations. This analysis revealed a dramatic variation in constituent concentrations between manufacturers of black salve products. The alkaloid sanguinarinewas found at concentrations significantly exceeding the cytotoxic IC50 of normal humanepidermal keratinocytes in the majority of black salve products, with one black salve examined having a concentration 900 times the IC50 level. The majority of products contained zinc chloride at concentrations known to kill normal human tissue, while one black salve product was found to contain an elevated lead level of 258 ppm, which exceeds the 10 ppm FDA determined lead limit for cosmetic products. Whilst some of the black salve products were found to contain high concentrations of constituents cytotoxic to normal tissue, others were found to contain insufficient cytotoxic constituents to be reasonably expected to exert any anti-cancer activity. In their current formulations, the majority of black salves analysed pose a significant risk of harm to patients and should not be available for unregulated clinical use. Further black salve toxicity testing is urgently required
Bioaccumulation of organochlorine compounds in large, threatened elasmobranchs off northern New South Wales, Australia
No full textPersistent organic pollutants (POPs) include polychlorinated biphenyls (PCBs) dichlorodiphenyltrichloroethane (DDT) and hexachlorobenzene (HCB), which are resistant to biodegradation and therefore accumulate in the marine environment. In Australia, POPs occur in high concentrations primarily in costal water near farming regions and urban centres. From contaminated sediments and biota, POPs are transferred and biomagnified in larger marine organisms. We quantified POPs concentrations in 57 individuals from ten species of sharks and rays caught in bather-protection gillnets deployed off northern New South Wales, Australia. Polychlorinated biphenyls, DDTs and HCB were detected in all species. For some individuals, concentrations were at levels known to have deleterious sub-lethal effects. Overall, the POP concentrations analysed in this study were comparable to those in similar species from more polluted regions, and may have negative impacts on longer-term health. Future research is warranted to investigate spatio-temporal patterns of species-specific contaminant loads and their implications
Phosphate loading alters schwertmannite transformation rates and pathways during microbial reduction
No full textAcid sulfate systems commonly contain the metastable ferric oxyhydroxysulfate mineral schwertmannite, as well as phosphate (PO43−) - a nutrient that causes eutrophication when present in excess. However, acid sulfate systems often experience reducing conditions that destabilize schwertmannite. Under such conditions, the longterm fate of both schwertmannite and PO43− may be influenced by interactions during microbially-mediated Fe (III) and SO42− reduction. This study investigates the influence of PO43− on Fe(III) and SO42− reduction and the subsequentmineralogical transformation(s) in schwertmannite-rich systems exposed to reducing conditions. To accomplish this, varied PO43− loadings were established in microbially-inoculated schwertmannite suspensions that were incubated under anoxic conditions for 82 days. Increased PO43− attenuated the onset of microbial Fe (III) reduction. This delayed consequent pH increases, which in turn had cascading effects on the initiation of SO42− reduction and subsequent mineral species formed. Under zero PO43− loading, goethite (αFeOOH) formed first, followed by mackinawite (FeS) and siderite (FeCO3). In contrast, in higher PO43− treatments, vivianite (Fe3(PO4)2) and/or sulfate green rust (FeII4FeIII2(OH)12SO4) became increasingly important over time at the expense of goethite and mackinawite compared to PO43−-free conditions. The findings imply that PO43− loading alters the rates and onset of microbial Fe(III)- and SO42−- reduction and the subsequent formation of secondary Febearing phases. In addition, schwertmannite reduction and the associated mineralogical evolution under anoxic conditions appears to sequester large quantities of PO43− in the form of green rusts and vivianite
