Vibrational Properties of Nanoscale Materials: From Nanoparticles to Nanocrystalline Materials

The vibrational density of states (VDOS) of nanoclusters and nanocrystalline materials are derived from molecular-dynamics simulations using empirical tight-binding potentials. The results show that the VDOS inside nanoclusters can be understood as that of the corresponding bulk system compressed by the capillary pressure. At the surface of the nanoparticles the VDOS exhibits a strong enhancement at low energies and shows structures similar to that found near flat crystalline surfaces. For the nanocrystalline materials an increased VDOS is found at high and low phonon energies, in agreement with experimental findings. The individual VDOS contributions from the grain centers, grain boundaries, and internal surfaces show that, in the nanocrystalline materials, the VDOS enhancements are mainly caused by the grain-boundary contributions and that surface atoms play only a minor role. Although capillary pressures are also present inside the grains of nanocrystalline materials, their effect on the VDOS is different than in the cluster case which is probably due to the inter-grain coupling of the modes via the grain-boundaries.Comment: 10 pages, 7 figures, accepted for publication in Phys. Rev.

Radiation Dose-Response for Risk of Myocardial Infarction in Breast Cancer Survivors

Previous reports suggest that radiation therapy for breast cancer can cause ischemic heart disease, with radiationrelated risk increasing linearly with mean whole heart dose. This study aimed to validate these findings and assesses additional risk factors for radiation-related myocardial infarction in a case-control study nested within a cohort of BC survivors treated 70 years of age during 1970-2009. The study confirms a linear relationship between mean whole heart dose and myocardial infarction risk after radiation for breast cancer

Integrated assessment of social and environmental sustainability dynamics in the Ganges-Brahmaputra-Meghna delta, Bangladesh

Deltas provide diverse ecosystem services and benefits for their populations. At the same time, deltas are also recognised as one of the most vulnerable coastal environments, with a range of drivers operating at multiple scales, from global climate change and sea-level rise to deltaic-scale subsidence and land cover change. These drivers threaten these ecosystem services, which often provide livelihoods for the poorest communities in these regions. The imperative to maintain ecosystem services presents a development challenge: how to develop deltaic areas in ways that are sustainable and benefit all residents including the most vulnerable. Here we present an integrated framework to analyse changing ecosystem services in deltas and the implications for human well-being, focussing in particular on the provisioning ecosystem services of agriculture, inland and offshore capture fisheries, aquaculture and mangroves that directly support livelihoods. The framework is applied to the world’s most populated delta, the Ganges-Brahmaputra-Meghna Delta within Bangladesh. The framework adopts a systemic perspective to represent the principal biophysical and socio-ecological components and their interaction. A range of methods are integrated within a quantitative framework, including biophysical and socio-economic modelling and analyses of governance through scenario development. The approach is iterative, with learning both within the project team and with national policy-making stakeholders. The analysis is used to explore physical and social outcomes for the delta under different scenarios and policy choices. We consider how the approach is transferable to other deltas and potentially other coastal areas

Cardiovascular disease incidence after internal mammary chain irradiation and anthracycline-based chemotherapy for breast cancer

Background: Improved breast cancer (BC) survival and evidence showing beneficial effects of internal mammary chain (IMC) irradiation underscore the importance of studying late cardiovascular effects of BC treatment. Methods: We assessed cardiovascular disease (CVD) incidence in 14,645 Dutch BC patients aged <62 years, treated during 1970–2009. Analyses included proportional hazards models and general population comparisons. Results: CVD rate-ratio for left-versus-right breast irradiation without IMC was 1.11 (95% CI 0.93–1.32). Compared to right-sided breast irradiation only, IMC irradiation (interquartile range mean heart doses 9–17 Gy) was associated with increases in CVD rate overall, ischaemic heart disease (IHD), heart failure (HF) and valvular heart disease (hazard ratios (HRs): 1.6–2.4). IHD risk remained increased until at least 20 years after treatment. Anthracycline-based chemotherapy was associated with an increased HF rate (HR = 4.18, 95% CI 3.07–5.69), emerging <5 years and remaining increased at least 10–15 years after treatment. IMC irradiation combined with anthracycline-based chemotherapy was associated with substantially increased HF rate (HR = 9.23 95% CI 6.01–14.18), compared to neither IMC irradiation nor anthracycline-based chemotherapy. Conclusions: Women treated with anthracycline-based chemotherapy and IMC irradiation (in an older era) with considerable mean heart dose exposure have substantially increased incidence of several CVDs. Screening may be appropriate for some BC patient groups

System dynamics of sustainable rice agriculture on the Mekong river delta

Abstract of the posterInternational audienceLarge river deltas across the globe are under increasing economic and environmental pressure due to overpopulation, climate change, and rising sea levels. River catchment sediments and associated discharge feed delta systems providing nutrients that not only enable higher yields in rice production but also the potential for flooding. Indeed, rice production on the Mekong River Delta (MRD) plays a main role in achieving food security for Vietnam, and provides significant export income for the Vietnamese economy (1.16% of GDP in 2018). To sustain high levels of rice production, the Vietnamese government has invested in a system of canals, flood dykes and sluice gates to control flooding of rice paddies and thereby extend the number of growing seasons from two to three rice harvests per year. However, these flood control measures have an unintended consequence in that, rather than allowing paddies to fallow, the exclusion of water and sediments from rice compartments means that soil nutrients become depleted and thus require artificial fertilizers to maintain yields. Furthermore, maintaining high levels of rice production is increasingly difficult as a result of climate change altering flood cycles, upstream hydro dam emplacement reducing sediment supply, and salinity intrusion shrinking available crop areas. In the face of these pressures MRD policy makers are facing pressing decisions in the delta and need to navigate the complexities of deltaic systems and identify optimal and sustainable land use management practices. In this work we present the outcome of the application of an integrated Systems Dynamic Model (SDM) which emulates the distribution of biophysical components for water, suspended sediment, and nutrients over the delta, delivering a calibrated amount to each flood compartment. Biophysical components were calibrated using water quality routing model INCA (Integrated Catchment model), and the engineering hydraulics model MIKE 11 (with the ECO lab module). Spatial elements of the delta, such as soil type and land systems, are coupled to the SDM through a geographic information system (GIS). Model outputs of recent events provide a baseline to develop and test the SDM. Here we show the results of the use of the (SDM) to integrate floods, nutrient supply, environmental/climate change and crop yields to facilitate stakeholders in the production of plausible normative spatially explicit scenarios of the agricultural intensification of the delta, centring on how intensification will occur and who will benefit. We use the SDM to explore scenarios covering the intensification range from local cooperatives that already exist to internationally funded agro-business. The question of livelihoods and community benefits is addressed in the normative outcomes as well as in the potential alignment and deviation form stated policy aims of the Government of Vietnam on the Mekong Delta