609 research outputs found
Walter Campbell:A distinguished life
An efficient and simple synthesis approach to form stable (68) Ga-labeled nanogels is reported and their fundamental properties investigated. Nanogels are obtained by self-assembly of amphiphilic statistical prepolymers derivatised with chelating groups for radiometals. The resulting nanogels exhibit a well-defined spherical shape with a diameter of 290 +/- 50 nm. The radionuclide (68) Ga is chelated in high radiochemical yields in an aqueous medium at room temperature. The phagocytosis assay demonstrates a highly increased internalization of nanogels by activated macrophages. Access to these (68) Ga-nanogels will allow the investigation of general behavior and clearance pathways of nanogels in vivo by nuclear molecular imaging
The Economic Impact of Substantial Sea-Level Rise
Using the FUND model, an impact assessment is conducted over the 21st century for rises in sea level of up to 2-m/century and a range of socio-economic scenarios downscaled to the national level, including the four SRES storylines. This model balances the costs of retreat with the costs of protection, including the effects of coastal squeeze. While the costs of sea-level rise increase with greater rise due to greater damage and protection costs, the model suggests that an optimum response in a benefit-cost sense remains widespread protection of developed coastal areas, as identified in earlier analyses. The socio-economic scenarios are also important in terms of influencing these costs. In terms of the four components of costs considered in FUND, protection dominates, with substantial costs from wetland loss under some scenarios. The regional distribution of costs shows that a few regions experience most of the costs, especially East Asia, North America, Europe and South Asia. Importantly, this analysis suggests that protection is much more likely and rational than is widely assumed, even with a large rise in sea level. This is underpinned by the strong economic growth in all the SRES scenarios: without this growth, the benefits of protection are significantly reduced. It should also be noted that some important limitations to the analysis are discussed, which collectively suggest that protection may not be as widespread as suggested in the FUND results. Equity weighting allows the damages to be modified to reflect the wealth of those impacted by sea-level rise. Taking these distributional issues into account increases damage estimates by a factor of three, reflecting that the costs of sea-level rise fall disproportionately on poorer developing countries.Sea-level rise;Socio-economic scenarios;costs;protection;equity weighting
The biodiversity of urban and peri-urban forests and the diverse ecosystem services they provide as socio-ecological systems
Urban and peri-urban forests provide a variety of ecosystem service benefits for urban society. Recognising and understanding the many human-tree interactions that urban forests provide may be more complex but probably just as important to our urbanised society. This paper introduces four themes that link the studies from across the globe presented in this Special Issue: (1) human-tree interactions; (2) urban tree inequity; (3) carbon sequestration in our own neighbourhoods; and (4) biodiversity of urban forests themselves and the fauna they support. Urban forests can help tackle many of the "wicked problems" that confront our towns and cities and the people that live in them. For urban forests to be accepted as an effective element of any urban adaptation strategy, we need to improve the communication of these ecosystem services and disservices and provide evidence of the benefits provided to urban society and individuals, as well as the biodiversity with which we share our town and cities. © 2016 by the authors
Strategic expansion of existing forest monitoring plots: a case study using a stratified GIS-based modelling approach
Background: Understanding the relationship between sites and the plant species they support is essential for effective vegetation management. Site-species matching requires knowledge of the growth response of a given species to the full range of environmental conditions in potential planting sites. This can be achieved by repeatedly measuring species growth at a comprehensive network of sample plots that cover a range of environmental conditions, including topography, climate, and soil factors. The New Zealand Dryland Forests Initiative has established permanent sample plots (PSPs) of a plantation species, Eucalyptus bosistoana F.Muell., across New Zealand. However, these PSPs do not cover the entire range of environmental conditions available for the species and hence there is a need to expand the network of sites. The aim of this study was to determine optimal locations for new PSPs to provide more unique information to support site-species matching studies for Eucalyptus bosistoana in New Zealand.
Methods: A geographic information system (GIS) and stratified random sampling method were used to generate a model to identify optimal locations for E. bosistoana PSP establishment. The variables used in this study included topography, climate, and soil data. Redundancy between the initial set of potential explanatory variables was reduced by a multi-collinearity analysis. The potential habitat for the species was restricted to land with environmental conditions that could support E. bosistoana. All environmental variables were stratified and an initial priority index for each stratum in each variable was calculated. Then a weighted-overlay analysis was conducted to create the final priority index, which was mapped to identify high-priority areas for targeted PSP expansion.
Results: The existing PSP network for E. bosistoana generally covers the environmental conditions in low-elevation New Zealand dry lands, which are located alongside the east coast of the South Island, and the southern part of the North Island. The model identified high priority areas for PSP expansion, including several large regions in the North Island, especially in Rangitikei and Taupo Districts.
Conclusions: The model successfully allowed identification of areas for a strategic expansion of permanent sample plots for E. bosistoana. Newly identified areas expand upon the topographic, climatic, and soil conditions represented by the existing PSP network. The new area for PSP expansion has potential to provide valuable information for further site-species matching studies. The methodology in this paper has potential to be used for other plot networks of a different species, or even natural forests
Influence of cleaning frequency and membrane history onfouling in an anaerobic membrane bioreactor
Correlation of dynamic contrast-enhanced bone perfusion with morphologic ultra-short echo time MR imaging in medication-related osteonecrosis of the jaw
OBJECTIVES: To investigate whether dynamic contrast-enhanced (DCE)-MR bone perfusion could serve as surrogate for morphologic ultra-short echo time (UTE) bone images and to correlate perfusion with morphologic hallmarks in histologically proven foci of medication-related osteonecrosis of the jaw (MRONJ).
METHODS: Retrospective study including 20 patients with established diagnosis of MRONJ. Qualitative consensus assessment of predefined jaw regions by two radiologists was used as reference standard using Likert scale (0-3) for standard imaging hallmarks in MRONJ (osteolysis, sclerosis, periosteal thickening). DCE-MRI measurements performed in corresponding regions of the mandible were then correlated with qualitative scores. Regions were grouped into "non-affected" and "pathologic" based on binarized Likert scores of different imaging hallmarks (0-1 vs 2-3). DCE-MRI measurements among hallmarks were compared using Mann-Whitney-U-testing. ROC (receiver-operating-characteristic) analysis was performed for each of the perfusion parameters to assess diagnostic performance for identification of MRONJ using morphologic ratings as reference standard.
RESULTS: Median perfusion measurements of "pathologic" regions in wash-in, peak enhancement intensity and integrated area under the curve are significantly higher than those of "non-affected" regions, irrespective of reference imaging hallmark (p < 0.05). No significant perfusion differences were found between "pathologic" regions with and without osteolysis (p = 0.180). ROC analysis showed fair diagnostic performance of DCE-MRI parameters for identification of MRONJ (AUC 0.626-0.727).
CONCLUSIONS: DCE bone perfusion parameters are significantly increased in MRONJ compared to non-affected regions, irrespective of osteolysis. Due to certain overlap DCE-MRI bone perfusion cannot serve as full surrogate for UTE bone imaging but may enhance reader confidence
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