65 research outputs found
Quantifying nitrogen fluxes and their influence on the greenhouse gas balance: recent findings of the NitroEurope Integrated Project
The generation of reactive nitrogen (Nr) by human activities to stimulate agricultural productivity and the unintended formation of Nr in combustion processes both have major impacts on the global environment. Effects of excess Nr include the deterioration of air quality, water quality, soil quality and a decline in biodiversity. One of the most controversial impacts of nitrogen, however, is on the greenhouse gas balance. While recent papers have highlighted a possible benefit of nitrogen in enhancing rates of carbon sequestration, there remain many trade-offs between nitrogen and greenhouse gas exchange. The result is that the net effect of Nr on the global radiative balance has yet to be fully quantified. To better understand these relationships requires intense measurement and modelling of Nr fluxes at various temporal and spatial scales in order to make the link between different nitrogen forms and their fate in the environment. It is essential to measure fluxes for a wide range of ecosystems considering the biosphere-atmosphere exchange of the Nr components and greenhouse gases, as well as the fixation of di-nitrogen and its creation by denitrification. Long-term observations are needed for representative ecosystems, together with results from experiments addressing the responses of the key nitrogen and greenhouse gas fluxes to different global change drivers. The NitroEurope Integrated Project (in short NEU IP), funded under the 6th Framework Programme of the European Commission, has developed and applied a strategy for quantifying these different terms on multiple scales. With the project nearing completion, this presentation reports selected preliminary findings. It highlights the first estimates of Nr inputs and net green-house gas exchange for a series of 13 flux âsupersitesâ, complemented by the emerging results of Nr concentrations and related N inputs at a network of 58 âinferential sitesâ, which extend the European representativity of the results. In addition, new low cost methods to measure nitrogen fluxes will be reported, which have been extensively tested at those sites. Results from this 3-tier flux network are underpinned by emerging findings from an extensive network of manipulation sites. A combination of modelling at plot, landscape and European scales is used to upscale the results. Finally the talk will illustrate how nitrogen mitigation techniques are being considered at the European scale, including an estimation of the scale of costs involved in simultaneously mitigating nitrous oxide, ammonia and nitrate losse
Persistence of engineered nanoparticles in a municipal solid-waste incineration plant
More than 100 million tonnes of municipal solid waste are incinerated worldwide every year1. However, little is known about the fate of nanomaterials during incineration, even though the presence of engineered nanoparticles in waste is expected to grow2. Here, we show that cerium oxide nanoparticles introduced into a full-scale waste incineration plant bind loosely to solid residues from the combustion process and can be efficiently removed from flue gas using current filter technology. The nanoparticles were introduced either directly onto the waste before incineration or into the gas stream exiting the furnace of an incinerator that processes 200,000 tonnes of waste per year. Nanoparticles that attached to the surface of the solid residues did not become a fixed part of the residues and did not demonstrate any physical or chemical changes. Our observations show that although it is possible to incinerate waste without releasing nanoparticles into the atmosphere, the residues to which they bind eventually end up in landfills or recovered raw materials, confirming that there is a clear environmental need to develop degradable nanoparticles
HIT family genes: FHIT but not PKCI-1/HINT produces altered transcripts in colorectal cancer
Forty-five colorectal adenocarcinomas were examined for alterations in the HIT family genes FHIT and PKCI-1/HINT by a combination of reverse transcriptase polymerase chain reaction and DNA sequencing. In all cases a single transcript corresponding to the reported sequence was detected using primers specific for the PKCI-1/HINT gene. In contrast multiple transcripts were detected using primers specific for the FHIT gene transcript. 6% (3/45) of tumours evinced no detectable expression of any FHIT transcript and a further 12% (6/45) produced only the normal full length transcripts. Ninety-six aberrant transcripts were characterized from the remaining tumours. Deviations from the normal full length sequence characterized included deletions, insertions of novel sequences, a point mutation as well as the usage of a putative alternate splice site in exon 10. Message variants were detected with approximately equal frequency in all tumour stages with the exception that templates with insertions were found solely in Dukesâ stage B tumours (P < 0.001). With the exception of the putative alternate splice site, aberrant transcripts were not detected in matched normal mucosa. These results suggest that members of the HIT family of genes are only selectively involved in tumorigenesis and that perturbation of FHIT gene expression is an early event in colorectal tumorigenesis. © 1999 Cancer Research Campaig
The value of manure - Manure as co-product in life cycle assessment
Research ArticleLivestock production is important for food security, nutrition, and landscape maintenance, but it is associated
with several environmental impacts. To assess the risk and benefits arising from livestock production, transparent
and robust indicators are required, such as those offered by life cycle assessment. A central question in
such approaches is how environmental burden is allocated to livestock products and to manure that is re-used for
agricultural production. To incentivize sustainable use of manure, it should be considered as a co-product as long
as it is not disposed of, or wasted, or applied in excess of crop nutrient needs, in which case it should be treated
as a waste. This paper proposes a theoretical approach to define nutrient requirements based on nutrient response
curves to economic and physical optima and a pragmatic approach based on crop nutrient yield adjusted for nutrient losses to atmosphere and water. Allocation of environmental burden to manure and other livestock
products is then based on the nutrient value from manure for crop production using the price of fertilizer
nutrients. We illustrate and discuss the proposed method with two case studiesinfo:eu-repo/semantics/publishedVersio
Beyond âBRICSâ: ten theses on SouthâSouth cooperation in the twenty-first century
Grounded in a review of past and present academic SouthâSouth cooperation literatures, this article advances ten theses that problematise empirical, theoretical, conceptual and methodological issues essential to discussions of SouthâSouth cooperation in the 21st century. This endeavour is motivated by the perceived undermining, especially in the contemporary Anglophone academic SouthâSouth cooperation literature, of the emancipatory potential historically associated with SouthâSouth cooperation. By drawing on the interventionist SouthâSouth cooperation agendas of âleftâ-leaning Latin America-Caribbean governments, the article seeks to establish a dialogue between social science theories and less âvisibleâ analyses from academic (semi)peripheries. The ten theses culminate in an exploration of the potential of SouthâSouth cooperation to promote âalternativeâ development
Global Boundary Stratotype Section and Point (GSSP) for the Anthropocene Series: Where and how to look for potential candidates
International audienc
Evolving Cuban-CARICOM relations : a comparative cost/benefit analysis
Survey of the basic developmental dynamics involved in the evolving Cuban-CARICOM relationship. On the basis of a cost-risk/benefit analysis, the author provides some projections regarding the future of this relationship. He concludes that there appear sufficient potential benefits for both sides to deepen the relationship. Cuban-CARICOM integration, however, has no top priority for either partner
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