760 research outputs found

    Projected changes in ENSO-driven regional tropical cyclone tracks

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    Simulations and projections of the El Nino Southern Oscillation's (ENSO's) influence on TC track variability was analysed globally using Coupled Model Intercomparison project Phase 5 (CMIP5) models. The ability of these models to simulate the historical (1970-2000) ENSO-TC track relationship and inform us of the likely projected changes resulting from high carbon emissions (RCP8.5) in a climate projection (2070-2100) was determined through cluster analysis. The number of seasonal TC occurrences during traditional ENSO events ("El Nino" and "La Nina") in each cluster were used to determine whether each cluster was "El Nino dominant", "La Nina dominant" or "neither". Only seven out of a combined total of 28 clusters across all basins were found to disagree in terms of "ENSO dominance" between the observed records and historical model simulations. This suggests that models can simulate the ENSO and TC track relationship reasonably well. Under sustained high carbon emissions, La Nina TCs were projected to become dominant over El Nino TCs in the central South Indian Ocean ( 60-100 degrees E), the southern Bay of Bengal and over straight-moving TCs in the South China Sea. El Nino TCs were projected to increase and become dominant over La Nina TCs in a larger area of the western South Pacific ( 160 degrees E-165 degrees W) and central North Pacific ( 160 degrees E-145 degrees W) Oceans. Projections of track directions and lifetimes, while less robust, indicated that El Nino TCs would track westward more often in the Coral Sea (150-165 degrees E), while El Nino TCs that took an eastward track here would have longer lifetimes ( 3 days)

    An integrated approach for the restoration of Australian temperate grasslands invaded by Nassella trichotoma

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    Invasive plants are considered to be one of the biggest threats to environmental assets, and once established, they can be immensely difficult to control. Nassella trichotoma is an aggressive, perennial grass species, and is considered to be one of the most economically damaging weeds to grazing systems due to its unpalatability, as well as being one of the leading causes of biodiversity loss in grassland communities. This species produces high density seedbanks that rapidly respond to disturbance events. Despite control programs being developing in Australia since the 1930s, this species is still widespread throughout south-east Australia, indicating that a new management approach is critical to control this Weed of National Significance at the landscape scale. The present study explored the effect of 12 different combinations of herbicide, fire, a second application of herbicide, grazing exclusion, tillage and broadcasting seeds in order to reduce the above and below-ground density of N. trichotoma. A control treatment was also included. The results were assessed using a Hierarchy analysis, whereby treatments of increasing complexity were compared for their efficacy in reducing N. trichotoma cover and seedbank density, while simultaneously increasing the establishment of the broadcast species. Whilst all integrated treatments effectively reduced N. trichotoma’s seedbank, the treatments that included fire performed significantly better at simultaneously reducing N. trichotoma and increasing the establishment of broadcasted seeds. Overall, the integration of herbicide, fire and broadcasting native seeds was observed to provide the most economically feasible management strategy for the landscape scale restoration of a degraded temperate grassland dominated by N. trichotoma. © 2022, The Author(s)

    Does climate play any role in covid-19 spreading? : an Australian perspective

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    Compared to other countries, the COVID-19 pandemic did not severely affect Australia as measured by total deaths until mid-2021. Though a substantial number of daily confirmed cases (up to 698) were reported during the second wave, most of them were from the southern state of Victoria. This study examined the possible correlations between climate variables and the number of daily confirmed COVID-19 cases in Victoria, Australia, from 25 January to 31 October 2020. Appropriate regression models and cross-correlation diagnostics were used to examine the effect of temperature, rainfall, solar exposure, and ultraviolet index (UVI) with the number of daily confirmed cases. Significant positive associations were identified for solar exposure and maximum and average UVI for confirmed cases one and 19 days later. Negative associations for these variables were found for confirmed cases five days later. Minimum temperature had a significant negative correlation one day later and a positive effect 21 days later. No significant correlation was found for maximum temperature and rainfall. The most significant relationships were found for confirmed cases 19 days after changes in the meteorological variables. A 1% increase in solar exposure, maximum UVI, and average UVI was associated with a 0.31% (95% CI: 0.13 to 0.51), 0.71% (95% CI: 0.43 to 0.98), and 0.63% (95%CI: 0.20 to 1.61) increase 19 days later in the number of confirmed cases, respectively. The implications of these results can be used in the public health management of any possible future events in Australia. It also highlights the significance of considering the climatic variables and seasonality in all kinds of epidemics and pandemics. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

    Tropical cyclone activity in the Solomon Islands region : climatology, variability, and trends

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    This study examines the climatology, variability, and trends of tropical cyclones (TCs) affecting the Solomon Islands (SI) territory, in the wider southwest Pacific (SWP), using the South Pacific Enhanced Archive for Tropical Cyclones (SPEArTC) database. During the period 1969/1970–2018/2019, 168 TCs were recorded in the SI territory. A cluster analysis is used to objectively partition these tracks into three clusters of similar TC trajectories to obtain better insights into the effects of natural climate variability, particularly due to the El Niño–Southern Oscillation (ENSO) phenomenon, which otherwise is not very apparent for TCs when considered collectively in the SI region. We find that TCs in clusters 1 and 3 show enhanced activity during El Niño phase, whereas TCs in cluster 2 are enhanced during La Niña and neutral phases. In addition to being modulated by ENSO, TCs in clusters 2 and 3 show statistically significant modulation at an intraseasonal timescale due to the Madden–Julian Oscillation (MJO) phenomenon. There are also some indications through sophisticated Bayesian modelling that TCs in clusters 2 and 3 are slightly influenced by the Interdecadal Pacific Oscillation (IPO). These results can have substantial implications for cluster-specific development of TC prediction schemes for the SI region. © 2022 The Authors. International Journal of Climatology published by John Wiley & Sons Ltd on behalf of Royal Meteorological Society

    Assessing Seed Longevity of the Invasive Weed Navua Sedge (Cyperus aromaticus), by Artificial Ageing

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    Navua sedge (Cyperus aromaticus (Ridley) Mattf. & Kukenth) is a significant agricultural and environmental weed found in tropical island countries including north Queensland, Australia. It is a prolific seed producer and consequently forms a high-density seedbank, and therefore understanding the longevity and persistence of the seeds can provide critical information required for the management of this species. A laboratory-controlled artificial ageing experiment was conducted where the seeds were exposed to a temperature of 45 °C and 60% relative humidity for 125 days. Seeds were removed at various times (1, 2, 5, 9, 20, 30, 50, 75, 100 and 125 days) and their viability determined through standard germination tests. It took 20 days in the artificial ageing environment for the seeds to decline to 50% viability which indicates that Navua sedge has relatively short-lived persistent seeds. These findings will assist in developing a better understanding of the seedbank dynamics of this invasive species, allowing managers to tactically implement control strategies and prepare budgets for ongoing treatments, and have implications for the duration and success of management programs

    Stratigraphy and geologic structure of Northern Illinois, with special reference to underground water supplies,

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    At head of title: State of Illinois. Department of Registration and Education. Division of the State Geological Survey.Plates folded in pocket.Includes bibliographical references

    Use of Scenari-aid to aid Maintenance of Stuttering Therapy Outcomes

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    AbstractScenari-Aid is a free online tool providing real-world simulation activities. This study investigated if using Scenari-Aid improves maintenance of stuttering therapy outcomes. An ABAB single subject design (A: pre-access and withdrawal; B: Scenari-Aid access) was used. Post-treatment gains in communication attitude and social participation were maintained 6-months post-treatment. Some improvements in weekly measures were present from A1 to B1 but there were no changesfrom B1 to A2 or A2 to B2. The participant reported using Scenari-Aid to aid initial desensitisation and then only occasionally. Further research is necessary to clarify the role of Scenari-Aid in the maintenance of treatment gains

    Evaluation of Florpyrauxifenbenzyl for the control of Cyperus aromaticus (Navua sedge).

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    Background: Cyperus aromaticus (Navua sedge) is a creeping perennial sedge common to tropical environments, currently threatening many agroecosystems and ecosystems in Pacific Island countries and northern Queensland in Australia. Objective: A glasshouse study was conducted to evaluate the efficacy of florpyrauxifen-benzyl on C. aromaticus plants with and without established rhizomes. Methods: The plants with established rhizomes were treated at three application times being mowed, pre-flowering and flowering growth stages and plants without established rhizomes were treated at seedling, pre-flowering and flowering growth stages. At each application time, plants were treated with four rates of florpyrauxifen-benzyl: 0, 15, 30 and 60 g a.i. ha−1 and control. Results: There was no mortality in the plants with established rhizomes. Reduction in the number of tillers was observed at four weeks after treatment (WAT) in plants treated with 30 and 60 g a.i. ha−1 of herbicide, however, there was new growth from the rhizomes and the number of tillers increased at 8 WAT. Conversely, florpyrauxifen-benzyl provided above 95% control in plants without established rhizomes. Conclusions: These results indicate florpyrauxifen-benzyl can help manage a new C. aromaticus infestation prior to the establishment of rhizomes. However, it has little to no impact on C. aromaticus plants with established rhizomes, and other management options should be employed to control them

    Supporting multiple birth families:Perceptions and experiences of health visitors

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    Objective: To explore the current practice and perceptions of health visitors in supporting multiple birth families. Design and sample: Practicing health visitors across the United Kingdom were invited to complete a cross-sectional, descriptive, online survey. The questionnaire covered multiple birth caseload, education received about multiples and the experience of working with families. Two-hundred and ninety health visitors completed the questionnaire. Descriptive and inferential statistics were used for analysis of the quantitative components and thematic analysis for the qualitative data. Results: Most health visitors had twins on their current workload. Most health visitors had not received any specific training or continuing professional development regarding the needs of multiple birth families. Supporting the families within the confines of reduced time and increased workload was challenging. Daily tasks of caring for multiples were the main areas that health visitors and parents wanted more information about. Conclusions: In the United Kingdom, health visitors are uniquely positioned to support multiple birth families, in particular during the more challenging early years. However, the findings of this study suggest that many health visitors are aware that the care and support that they are able to provide multiple birth families falls short of meeting their needs
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