3,315 research outputs found
Age frequency distribution and revised stable isotope curves for New Zealand speleothems: Palaeoclimatic implications
The occurrence of speleothems in New Zealand with reversed magnetism indicates that secondary calcite deposition in caves has occurred for more than 780 thousand years (ka). 394 uranium-series dates on 148 speleothems show that such deposition has taken place somewhere in the country with little interruption for more than 500 ka. A relative probability distribution of speleothem ages indicates that most growth occurred in mild, moist interglacial and interstadial intervals, a conclusion reinforced by comparing peaks and troughs in the distribution with time series curves of speleothem δO and δC values. The stable isotope time series were constructed using data from 15 speleothems from two different regions of the country. The greater the number of overlapping speleothem series (i.e. the greater the sample depth) for any one region, the more confidence is justified in considering the stacked record to be representative of the region. Revising and extending earlier work, composite records are produced for central-west North Island (CWNI) and north-west South Island (NWSI). Both demonstrate that over the last 15 ka the regions responded similarly to global climatic events, but that the North Island site was also influenced by the waxing and waning of regional subtropical marine influences that penetrated from the north but did not reach the higher latitudes of the South Island. Cooling marking the commencement of the last glacial maximum (LGM) was evident from about 28 ka. There was a mid-LGM interstadial at 23-21.7 ka and Termination 1 occurred around 18.1 ka. The glacial-interglacial transition was marked by a series of negative excursions in δO that coincide with dated recessional moraines in South Island glaciers. A late glacial cooling event, the NZ Late Glacial Reversal, occurred from 13.4-11.2 ka and this was followed by an early Holocene optimum at 10.8 ka. Comparison of δO records from NWSI and EPICA DML ice-core shows climatic events in New Zealand to lag those in Antarctica by several centuries to a thousand years. Waxing and waning of subantarctic and subtropical oceanic influences in the Tasman Sea are considered the immediate drivers of palaeoclimatic change
Promoting writing amongst peers: establishing a community of writing practice for early career academics
In the current research-focused climate, academics are facing increasing pressure to produce research outputs. This pressure can prove particularly daunting for early career (EC) academics, who are simultaneously attempting to master new teaching and administrative demands while establishing their own independent research trajectories. Previous reports suggest that academic writing retreats can be an effective way of increasing research outputs. Such retreats generally involve academics from a range of career stages and require expert facilitators. Through organising a series of structured writing events, this project aims to cultivate an enduring community of practice for academic writers. Reflecting on our EC retreat and subsequent writing days with academics from different career stages, we suggest that success hinged on three key factors: (1) A formal structure comprising bounded periods of intense writing, flanked by group reviewing and goal-setting; (2) Co-located writing with participants based in a shared space, away from their usual workstation and distractions; (3) Peer discussions involving participants at a similar career stage. Specifically we found that writing amongst ‘equals’ increased productivity and confidence amongst EC academics
Integrated stratigraphy of the Kimmeridge Clay Formation (Upper Jurassic) based on exposures and boreholes in south Dorset, UK
For the purposes of a high-resolution multi-disciplinary study of the Upper Jurassic Kimmeridge Clay Formation, two boreholes were drilled at Swanworth Quarry and one at Metherhills, south Dorset, UK. Together, the cores represent the first complete section through the entire formation close to the type section. We present graphic logs that record the stratigraphy of the cores, and outline the complementary geophysical and analytical data sets (gamma ray, magnetic susceptibility, total organic carbon, carbonate, [delta]13Corg). Of particular note are the new borehole data from the lowermost part of the formation which does not crop out in the type area. Detailed logs are available for download from the Kimmeridge Drilling Project web-site at http://kimmeridge.earth.ox.ac.uk/. Of further interest is a mid-eudoxus Zone positive shift in the [delta]13Corg record, a feature that is also registered in Tethyan carbonate successions, suggesting that it is a regional event and may therefore be useful for correlation. The lithostratigraphy of the cores has been precisely correlated with the nearby cliff section, which has also been examined and re-described. Magnetic-susceptibility and spectral gamma-ray measurements were made at a regular spacing through the succession, and facilitate core-to-exposure correlation. The strata of the exposure and core have been subdivided into four main mudrock lithological types: (a) medium-dark–dark-grey marl; (b) medium-dark–dark grey–greenish black shale; (c) dark-grey–olive-black laminated shale; (d) greyish-black–brownish-black mudstone. The sections also contain subordinate amounts of siltstone, limestone and dolostone. Comparison of the type section with the cores reveals slight lithological variation and notable thickness differences between the coeval strata. The proximity of the boreholes and different parts of the type section to the Purbeck–Isle of Wight Disturbance is proposed as a likely control on the thickness changes
Quantifying the contribution of riparian soils to the provision of ecosystem services
Riparian areas, the interface between land and freshwater ecosystems, are considered to play a pivotal role in the supply of regulating, provisioning, cultural and supporting services. Most previous studies, however, have tended to focus on intensive agricultural systems and only on a single ecosystem function. Here, we present the first study which attempts to assess a wide range of ecological processes involved in the provision of the ecosystem service of water quality regulation across a diverse range of riparian typologies. Specifically, we focus on 1) evaluating the spatial variation in riparian soils properties with respect to distance with the river and soil depth in contrasting habitat types; 2) gaining further insights into the underlying mechanisms of pollutant removal (i.e. pesticide sorption/degradation, denitrification, etc.) by riparian soils; and 3) quantify and evaluate how riparian vegetation across different habitat types contribute to the provision of watercourse shading. All the habitats were present within a single large catchment and included: (i) improved grassland, (ii) unimproved (semi-natural) grassland, (iii) broadleaf woodland, (iv) coniferous woodland, and (iv) mountain, heath and bog. Taking all the data together, the riparian soils could be statistically separated by habitat type, providing evidence that they deliver ecosystem services to differing extents. Overall, however, our findings seem to contradict the general assumption that soils in riparian area are different from neighbouring (non-riparian) areas and that they possess extra functionality in terms of ecosystem service provision. Watercourse shading was highly habitat specific and was maximal in forests (ca. 52% shade cover) in comparison to the other habitat types (7–17%). Our data suggest that the functioning of riparian areas in less intensive agricultural areas, such as those studied here, may be broadly predicted from the surrounding land use, however, further research is required to critically test this across a wider range of ecosystems
The influence of cervical and thoracic lymphadenectomy on corneal allograft rejection in inbred rats
Aim To investigate the site of alloantigen presentation in
the rat following orthotopic corneal transplantation.
Methods Adult inbred Fischer 344 rats received
penetrating corneal allografts from inbred Wistar Furth
donors (n¼17), without lymphadenectomy. A second
group (n¼8) underwent bilateral removal of superficial
cervical and facial lymph nodes 7 days before
transplantation. A third group (n¼9) underwent bilateral
removal of superficial cervical, facial, internal jugular and
posterior cervical nodes. Graft survival was assessed by
corneal clarity and rejection was confirmed histologically.
Results All allografts underwent rejection. The median
time to rejection for unmodified allografts was day 15,
compared with day 14.5 for minimally
lymphadenectomised recipients and day 18 for more
extensively lymphadenectomised recipients (p>0.05, all
comparisons). The median day to rejection for the
combined group of lymphadenectomised rats was day
17 (p>0.05 compared with unmodified grafts). The
rejection process was similar in all recipients.
Conclusions Removal of multiple lymph nodes in the
neck and thorax did not significantly influence the
incidence, tempo or nature of the corneal allograft
response. Sensitisation and clonal expansion of corneal
alloantigen-reactive cells cannot occur only in superficial
cervical, facial, internal jugular and posterior cervical
lymph nodes in the rat.We acknowledge financial support from the Australian National Health and
Medical Research Council and the Ophthalmic Research Institute of Australia
An examination of students’ perceptions of their interprofessional placements in residential aged care
It is essential that health professionals are trained to provide optimal care for our ageing population. Key to this is a positive attitude to older adults along with the ability to work in teams and provide interprofessional care. There is limited evidence on the impact an interprofessional education (IPE) placement in a residential aged care facility (RACF) has on students. In 2015 in Western Australia, 51 students (30 % male, median age 23 years), from seven professions, undertook a placement between 2 and 13 weeks in length at 1 RACF. Pre- and post-placement measurements of attitudes to the elderly were collected using the Ageing Semantic Differential (ASD) questionnaire and level of readiness for interprofessional learning with the Readiness for Interprofessional Learning Scale (RIPLS). A total of 47 students completed matched ASD and RIPLS surveys. The mean total score on the ASD survey decreased significantly from pre- to post-placement from 116.0 to 108.9 (p = 0.033), indicating attitudes became increasingly positive towards older adults. Significant differences post-placement were seen indicating better readiness for interprofessional learning, for two out of four subscales on the RIPLS, namely “teamwork & collaboration” (42.1 – 44.0; (p = 0.000)) and “positive professional identity” (18.2 – 19.3 (p = 0.001)). The degree of change is similar to findings from other settings. The results support IPE-focussed student placements within RACF positively influence student’s attitudes towards the older adult as well as increase student’s readiness for interprofessional learning, confirming RACF are valuable places for training health professional
Delineating and mapping riparian areas for ecosystem service assessment
Riparian buffers, the interface between terrestrial and freshwater ecosystems, have the potential to protect water bodies from land-based pollution, and also for enhancing the delivery of a range of ecosystem services. The UK currently has no defined optimal width or maximum extent of riparian buffers for specific ecosystem services. Here, we present the first study, which attempts to (a) compare and critique different riparian buffer delineation methods and (b) investigate how ecological processes, for example, pollutant removal, nutrient cycling, and water temperature regulation, are affected spatially by proximity to the river and also within a riparian buffer zone. Our results have led to the development of new concepts for riparian delineation based on ecosystem service-specific scenarios. Results from our study suggest that choice of delineation method will influence not only the total area of potential riparian buffers but also the proportion of land cover types included, which in turn will determine their main ecosystem provision. Thus, for some ecological processes (e.g., pollutant removal), a fixed-distance approach will preserve and protect its ecosystem function, whereas for processes such as denitrification, a variable-width buffer will reflect better riparian spatial variability maximizing its ecological value. In summary, riparian delineation within UK habitats should be specific to the particular ecosystem service(s) of interest (e.g., uptake of nutrients and shading), and the effectiveness of the buffer should be ground-truthed to ensure the greatest level of protection
The power of social networks: A model for weaving the Scholarship of Teaching and Learning into institutional culture
This paper offers a guide for those seeking to integrate the Scholarship of Teaching and Learning (SoTL) into higher education institutions to improve the quality of student learning. The authors posit that weaving SoTL into institutional cultures requires the coordinated actions of individuals working in linked social networks rather than individuals acting in isolation. Analyzing both the barriers and potential pathways to integrating SoTL into institutional cultures, the authors provide a conceptual model along with examples of practical strategies for overcoming resistance to change within institutions. The paper provides examples from a variety of different international contexts to show how incentives and other non-coercive measures can motivate faculty and administrators to weave SoTL into institutional fabrics.
Drawing on social network theory and the concept of communities of practice, the paper presents a model with attendant strategies for disseminating SoTL values and practices across all three levels of postsecondary institutions: the micro, the meso, and the macro. The authors argue that for SoTL to take root in organizational cultures, there must be 1) effective communication and dissemination of SoTL activity across all levels, 2) well established social networks and links between these levels (nodes), and 3) sustained support by senior administration. The authors conclude by suggesting ways their model could be tested
Cyclotrimerisation of isocyanates catalysed by low-coordinate Mn(II) and Fe(II) m-terphenyl complexes
Two- and three-coordinate m-terphenyl complexes of manganese and iron are efficient catalysts for the selective cyclotrimerisation of primary aliphatic isocyanates affording isocyanurates in short reaction times and under mild conditions
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