557 research outputs found
Social-ecological innovation : adaptive responses to urban environmental conditions
Novel approaches to natural resource management, particularly those which promote stakeholder participation, have been put forward as fundamental ingredients for establishing resilient, polycentric forms of environmental governance. This is nowhere more pertinent than in the case of the complex adaptive systems associated with urban areas. Decentralisation of urban green space management has been posited as an element thereof which, according to resilience thinking, should contribute to the adaptive capacity of cities and the ecosystem services upon which they rely. Implicit in this move towards increased adaptive capacity is the ability to manage through innovation. Although the importance of innovation towards system adaptability has been acknowledged, little work has thus far been carried out which demonstrates that innovative use of urban green space represents a form of adaptive response to environmental conditions. The current paper reports on research which maps examples of organised social-ecological innovation (OSEI) in an urban study area and evaluates them as adaptive responses to local environmental conditions which may contribute to system resilience. The results present OSEI as a coherent body of responses to local social and environmental deprivation, exhibiting diversity and adaptability according to individual contexts. The study therefore provides evidence for the importance of local stakeholder-led innovation as in the building of adaptive capacity in urban social-ecological systems
A New Way to Conserve Total Energy for Eulerian Hydrodynamic Simulations with Self-Gravity
We propose a new method to conserve the total energy to round-off error in
grid-based codes for hydrodynamic simulations with self-gravity. A formula for
the energy flux due to the work done by the the self-gravitational force is
given, so the change in total energy can be written in conservative form.
Numerical experiments with the code Athena show that the total energy is indeed
conserved with our new algorithm and the new algorithm is second order
accurate. We have performed a set of tests that show the numerical errors in
the traditional, non-conservative algorithm can affect the dynamics of the
system. The new algorithm only requires one extra solution of the Poisson
equation, as compared to the traditional algorithm which includes self-gravity
as a source term. If the Poisson solver takes a negligible fraction of the
total simulation time, such as when FFTs are used, the new algorithm is almost
as efficient as the original method. This new algorithm is useful in Eulerian
hydrodynamic simulations with self-gravity, especially when results are
sensitive to small energy errors, as for radiation pressure dominated flow.Comment: 19 pages, 8 figures, 2 tables, add journal information in New
Astronom
Tracking the global distribution of persistent organic pollutants accounting for e-waste exports to developing regions
Elevated concentrations of various industrial-use Persistent Organic Pollutants (POPs), such as polychlorinated biphenyls (PCBs), have been reported in some developing areas in subtropical and tropical regions known to be destinations of e-waste. We used a recent inventory of the global generation and exports of e-waste to develop various global scale emission scenarios for industrial-use organic contaminants (IUOCs). For representative IUOCs (RIUOCs), only hypothetical emissions via passive volatilization from e-waste were considered whereas for PCBs, historical emissions throughout the chemical life-cycle (i.e., manufacturing, use, disposal) were included. The environmental transport and fate of RIUOCs and PCBs were then simulated using the BETR Global 2.0 model. Export of e-waste is expected to increase and sustain global emissions beyond the baseline scenario, which assumes no export. A comparison between model predictions and observations for PCBs in selected recipient regions generally suggests a better agreement when exports are accounted for. This study may be the first to integrate the global transport of IUOCs in waste with their long-range transport in air and water. The results call for integrated chemical management strategies on a global scale
Appraisal of social-ecological innovation as an adaptive response by stakeholders to local conditions : mapping stakeholder involvement in horticulture orientated green space management
Urban areas are hubs of creativity and innovation providing fertile ground for novel responses to
modern environmental challenges. Previous studies have attempted to conceptualise the ecological,
social and political potential of social-ecological innovation in urban green space management.
However, little work has been conducted on the social-ecological conditions influencing their
occurrence and distribution. Further research is therefore necessary to demonstrate whether
stakeholder stewardship of green resources contributes towards adaptive capacity in socialecological
systems. The research reported here explored the extent of organised social-ecological
innovations in a continuous urban landscape comprising three adjoining metropolitan areas:
Manchester, Salford and Trafford (UK). Examples of horticulture orientated organised socialecological
innovation were identified using a snowball-sampling method. Their distribution, explored
with GIS and remote sensing technology, was found to be significantly associated with levels of both,
social and ecological, deprivation. The study presented social-ecological innovation as an adaptive
response to environmental stressors, conditioned by specific social and ecological parameters in the
landscape. It therefore provides empirical support for social-ecological innovation as a valid
ingredient contributing to resilience in adaptive social-ecological systems. Not only do such collective
community-led elements of natural resource management warrant acknowledgement in urban green
space planning, but their distribution and productivity may provide a valuable social-ecological
laboratory for the study of polycentric governance and adaptive capacity in the urban environment
Long-Term Outcomes of Autologous Stem Cell Transplantation for Follicular Non-Hodgkin Lymphoma: Effect of Histological Grade and Follicular International Prognostic Index
AbstractAlthough results of autologous stem cell transplantation (SCT) for recurrent follicular non-Hodgkin lymphoma (NHL) have been previously reported, the long-term results and evaluation of prognostic factors in a large patient population receiving this therapy are difficult to find in the literature. To address these issues, we evaluated 248 patients with recurrent follicular NHL treated with high-dose chemotherapy and autologous SCT between 7/87 and 6/03. According to the World Health Organization (WHO) classification system, 64 patients (26%) had follicular NHL grade 1 (FL 1), 98 (40%) had FL 2, and 86 (35%) had FL 3. At the time of transplantation, 88 of the patients (35%) had a Follicular Lymphoma International Prognostic Index (FLIPI) score of low risk, 87 (35%) had an intermediate-risk FLIPI score, 37 (15%) had a high-risk FLIPI score, and 36 (15%) had at least 1 missing value, preventing calculation of the FLIPI score. The 5-year overall survival (OS) for all patients was 63%, and the 5-year progression-free survival (PFS) was 44%. In a multivariate analysis, a histological grade of FL 3, a high-risk FLIPI score at the time of transplantation, and having received 3 or more previous chemotherapy regimens were significant factors for predicting a worse OS. In addition, the use of a transplantation regimen including a monoclonal antibody decreased the relative risk of progressive lymphoma. These data suggest that transplantation earlier in the course of the disease for patients with follicular lymphoma with use of a monoclonal antibody–based regimen may lead to improved outcomes
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