1,009 research outputs found
High resolution record of the Last Glacial Maximum in eastern Australia
A continuous, high resolution (average ca. 22 year) record encompassing the Last Glacial Maximum (LGM) has been developed using multiple proxies (aeolian sediment flux, grain size, pollen and charcoal) in lake sediment from Tortoise Lagoon (TOR), North Stradbroke Island, Queensland, Australia. The presence of Asteraceae tubilifloreae and spineless Asteraceae (common indicators of glacial conditions in Australia) at TOR indicates significantly cooler temperatures (mean annual temperature up to 6oC lower than today). In addition to the palaeoclimatic reconstruction, a record of palaeodust transport pathways for eastern Australia was developed using ICP-MS trace element analysis and geochemical âfingerprintingâ of TOR aeolian sediment to continental dust source areas. Vectors between dominant dust source areas and North Stradbroke Island allowed the reconstruction of the position and intensity of LGM dust transport pathways. Furthermore, changes in likely synpotic scale conditions can be postulated based on the position of the dust transport corridors. Similarities between the vegetation at TOR during the LGM and that at temperate sites e.g. Caledonia Fen, Victoria (Kershaw et al. 2007), Redhead Lagoon, New South Wales (Williams et al. 2006) and Barrington Tops, New South Wales (Sweller and Martin 2001) suggests that this record reflects regional conditions across southeastern Australia. The TOR record also correlates well with that from nearby Native Companion Lagoon which suggests that the LGM was actually an extended period of ca. 8 â 10 kyr, characterised by 2 periods of increased aridity (ca. 30 â 26.5 kyr and 21 â 19.5 kyr) (Petherick et al. 2008). A growing number of records from across the Southern Hemisphere e.g. New Zealand (Suggate and Almond 2003; Alloway et al. 2007; Newnham et al. 2007), Chile (Denton et al. 1999), Antarctica (Röthlisberger et al. 2002; EPICA 2006) and Australia (Smith 2009) also show evidence that the LGM encompassed a longer period of time than traditionally accepted, and was not uniformly cool and dry
Model fitting for small skin permeability data sets: hyperparameter optimisation in Gaussian Process Regression
This is the pre-peer reviewed version of the following article: Parivash Ashrafi, Yi Sun, Neil Davey, Roderick G. Adams, Simon C. Wilkinson, and Gary Patrick Moss, âModel fitting for small skin permeability data sets: hyperparameter optimisation in Gaussian Process Regressionâ, Journal of Pharmacy and Pharmacology, Vol. 70 (3): 361-373, March 2018, which has been published in final form at https://doi.org/10.1111/jphp.12863. Under embargo until 17 January 2019. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.Objectives The aim of this study was to investigate how to improve predictions from Gaussian Process models by optimising the model hyperparameters. Methods Optimisation methods, including Grid Search, Conjugate Gradient, Random Search, Evolutionary Algorithm and Hyper-prior, were evaluated and applied to previously published data. Data sets were also altered in a structured manner to reduce their size, which retained the range, or âchemical spaceâ of the key descriptors to assess the effect of the data range on model quality. Key findings The Hyper-prior Smoothbox kernel results in the best models for the majority of data sets, and they exhibited significantly better performance than benchmark quantitative structureâpermeability relationship (QSPR) models. When the data sets were systematically reduced in size, the different optimisation methods generally retained their statistical quality, whereas benchmark QSPR models performed poorly. Conclusions The design of the data set, and possibly also the approach to validation of the model, is critical in the development of improved models. The size of the data set, if carefully controlled, was not generally a significant factor for these models and that models of excellent statistical quality could be produced from substantially smaller data sets.Peer reviewedFinal Accepted Versio
A late-Holocene record of coastal wetland development and fire regimes in tropical northern Australia
This study presents three records of environmental change during the late-Holocene from wetlands across Bentinck Island in the South Wellesley Islands, northern Australia. Radiometric dating provided ages for sediment cores with the longest chronology spanning the last 1250 cal. yr BP. Palynological results show the diverse mangrove community transitioned to woodland- and wetland-dominated vegetation over the last 850âyears on the southeast coast. The key driver of this landscape change was likely late-Holocene sea level regression and coastal progradation in the Gulf of Carpentaria. This study found freshwater wetlands expanded across Bentick Island over the last 500âyears, with sedges and rushes peaking in the last 350âyears. Macroscopic and microscopic charcoal records, coupled with archaeological evidence, highlights the spatial and temporal variation in fire regimes across the island, reflecting the traditional fire management practices of the Kaiadilt people during the late-Holocene. This study finds a significant increase in charcoal accumulation in the 1900s when Kaiadilt fire practices were disrupted and the South Wellesley Islands were abandoned. The pollen record reflects little change in the vegetation despite the shifting fire regime, highlighting the importance of multi-proxy approaches to reconstructing past environments in tropical northern Australia where vegetation is adapted to fire
Do Mental Health First Aidâą courses enhance knowledge?
Purpose Biased assumptions and unhelpful tendencies in human nature can lead people who are experiencing mental illness to shun help and support. Mental illness is often perceived as immutable and/or a sign of weakness. Even those seeking support may not receive the assistance they need. Advice may be unsuitable or people feel too nervous and challenged to help. The Mental Health First Aidâą courses, like general first aid, are designed to enhance community knowledge and thereby support appropriate assistance. The purpose of this paper is to evaluate the extent to which this is achieved. Design/methodology/approach An educational audit based upon a short quiz administered anonymously to 162 tertiary students from a range of disciplines, before and after delivery of the standard 12 hour Mental Health First Aidâą course. This was used to examine assumptions and proposed actions before and after training. Findings Analysis of the 162 responses found that the Mental Health First Aidâą courses significantly improve knowledge. This has the potential to increase understanding and support for those suffering mental illness. Research limitations/implications This educational audit looked only at knowledge improvement. Whether this really does translate into improved outcomes requires further investigation. Practical implications Tertiary students who are enrolled in health courses and others which involve human interaction as provision of services will be empowered with skills that enable them to interact with those who they will be serving at well-informed level and equity. Social implications Social inclusion and de-stigmatising mental health issues Originality/value Mental health first aid courses potentially enable individuals who are not otherwise involved in mental health to assist people in need
Impact of the abolition of EU Milk quotas on Agriculture in the UK
In recent years the CAP has undergone significant reforms, but the dairy sector has largely avoided wholesale changes. The sector, however, is now faced with a significant effort by the Commission to instigate reform. In this study the FAPRI-UK modelling system is simulated to identify the impact of abolishing or phasing out EU milk quotas on the dairy sector in the UK and the results are compared against a 2007 Baseline projection (2007--2016). The results demonstrate that although the impact of the abolition of dairy quotas is fairly modest at the EU-25 level, significant impacts are apparent at the individual country level.Milk Quotas, CAP Reform, Commodity Modelling, Agricultural and Food Policy, International Relations/Trade, Livestock Production/Industries,
Colony-specific differences in decadal longitudinal body composition of a capital-breeding marine top predator
he longâterm studies included in this paper were funded by the Natural Environment Research Council through the grant âSMRU Longâterm measurement of marine mammal population structure, dynamics and trophic interactionsâ, grant reference SMRU1001. PP was in receipt of NERC grant no. NE/G008930/1 and EsmĂ©e Fairbairn Foundation funding during the work. SCS was supported as a postdoctoral fellow in an EPSRC award to RK and PP.1. Capital breeding animals such as true seals (Phocidae) rely on accumulated body reserves to rear offspring. A mother's body composition at the start of a breeding episode may depend on recent environmental conditions and sets the resources available for the reproductive episode. 2. At two grey seal (Halichoerus grypus) breeding colonies with contrasting demographic characteristics, factors influencing individual variation and temporal trends in the body composition (expressed as the lipidâtoâprotein mass ratio) of females were examined. 3. Maternal reproductive expenditure, and the consequences for mothers and their pups, were investigated. 4. Individual variation in postpartum maternal body composition was considerable. Mean values of 27% (±5%) lipid and 18% (±1%) protein were estimated by hydrogen isotope dilution. No evidence of age effects was detected. 5. Mothers with a high lipidâtoâprotein mass ratio expended a higher proportion of lipid resources, conserved protein and returned with more protein the following year. 6. Average maternal postpartum body composition was similar between the two colonies, but temporal patterns differed at one colony where pup production was decreasing from another where pup production was increasing. Mothers at the declining colony consistently weaned larger pups than mothers at the increasing colony across the range of mother sizes, but measures of maternal body composition did not predict pup weaning masses.PostprintPeer reviewe
Ecohydrology of coastal aquifers in humid environments and implications of a drying climate
Coastal groundwater-dependent ecosystems (GDEs), such as wetlands, estuaries and mangrove forests, are globally important habitats that promote biodiversity, provide climate regulation and serve as refugia for plant and animal communities. However, global warming, coastal development and over-abstraction threaten the availability and quality of groundwater in coastal aquifers and, by extension, the ecohydrological function of dependent ecosystems. Because ecohydrological knowledge of coastal groundwater is disparate across disciplines and habitat types, we begin by summarising the physiochemical, biological and hydrological processes supported by groundwater across coastal watersheds. Groundwater makes a significant but poorly recognised contribution to the function and resilience of coastal ecosystems and will play an essential role in climate change mitigation and adaptation. This review then explores how critical ecosystem processes supported by groundwater will be affected in areas of the humid subtropics that are expected to be impacted by climatic drying. Where rainfall is predicted to decrease, reduced groundwater recharge will interrupt the hydrology of coastal GDEs, while anthropogenic pressures, such as land-use intensification and pollution, will diminish the quality of remaining groundwater. The challenges of managing groundwater for multiple purposes under climate change predictions are highlighted. To improve the management of coastal GDEs, research should be aimed at developing robust conceptual models of coastal groundwater systems that quantify biophysical linkages with ecological communities across relevant spatiotemporal scales
Development case study: Baffle basin. Review of coastal ecosystem management to improve the health and resilience of the Great Barrier Reef World Heritage Area
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