Stage-specific, Nonlinear Surface Ozone Damage to Rice Production in China

China is one of the most heavily polluted nations and is also the largest agricultural producer. There are relatively few studies measuring the effects of pollution on crop yields in China, and most are based on experiments or simulation methods. We use observational data to study the impact of increased air pollution (surface ozone) on rice yields in Southeast China. We examine nonlinearities in the relationship between rice yields and ozone concentrations and find that an additional day with a maximum ozone concentration greater than 120 ppb is associated with a yield loss of 1.12% ± 0.83% relative to a day with maximum ozone concentration less than 60 ppb. We find that increases in mean ozone concentrations, SUM60, and AOT40 during panicle formation are associated with statistically significant yield losses, whereas such increases before and after panicle formation are not. We conclude that heightened surface ozone levels will potentially lead to reductions in rice yields that are large enough to have implications for the global rice market

D-dimer levels and risk of recurrence following provoked venous thromboembolism: findings from the RIETE registry.

Patients with venous thromboembolism (VTE) secondary to transient risk factors may develop VTE recurrences after discontinuing anticoagulation. Identifying at-risk patients could help to guide the duration of therapy. We used the RIETE database to assess the prognostic value of d-dimer testing after discontinuing anticoagulation to identify patients at increased risk for recurrences. Transient risk factors were classified as major (postoperative) or minor (pregnancy, oestrogen use, immobilization or recent travel). In December 2018, 1655 VTE patients with transient risk factors (major 460, minor 1195) underwent d-dimer measurements after discontinuing anticoagulation. Amongst patients with major risk factors, the recurrence rate was 5.74 (95% CI: 3.19-9.57) events per 100 patient-years in those with raised d-dimer levels and 2.68 (95% CI: 1.45-4.56) in those with normal levels. Amongst patients with minor risk factors, the rates were 7.79 (95% CI: 5.71-10.4) and 3.34 (95% CI: 2.39-4.53), respectively. Patients with major risk factors and raised d-dimer levels (n = 171) had a nonsignificantly higher rate of recurrences (hazard ratio [HR]: 2.14; 95% CI: 0.96-4.79) than those with normal levels. Patients with minor risk factors and raised d-dimer levels (n = 382) had a higher rate of recurrences (HR: 2.34; 95% CI: 1.51-3.63) than those with normal levels. On multivariate analysis, raised d-dimers (HR: 1.74; 95% CI: 1.09-2.77) were associated with an increased risk for recurrences in patients with minor risk factors, not in those with major risk factors. Patients with raised d-dimer levels after discontinuing anticoagulant therapy for VTE provoked by a minor transient risk factor were at an increased risk for recurrences

Impacts of biofuel cultivation on mortality and crop yields

Ground-level ozone is a priority air pollutant, causing ~ 22,000 excess deaths per year in Europe1, significant reductions in crop yields2 and loss of biodiversity3. It is produced in the troposphere through photochemical reactions involving oxides of nitrogen (NOx) and volatile organic compounds (VOCs). The biosphere is the main source of VOCs, with an estimated 1,150 TgC yr−1 (~ 90% of total VOC emissions) released from vegetation globally4. Isoprene (2-methyl-1,3-butadiene) is the most significant biogenic VOC in terms of mass (around 500 TgC yr−1) and chemical reactivity4 and plays an important role in the mediation of ground-level ozone concentrations5. Concerns about climate change and energy security are driving an aggressive expansion of bioenergy crop production and many of these plant species emit more isoprene than the traditional crops they are replacing. Here we quantify the increases in isoprene emission rates caused by cultivation of 72 Mha of biofuel crops in Europe. We then estimate the resultant changes in ground-level ozone concentrations and the impacts on human mortality and crop yields that these could cause. Our study highlights the need to consider more than simple carbon budgets when considering the cultivation of biofuel feedstock crops for greenhouse-gas mitigation

Managing nitrogen for sustainable development

International audienceImprovements in nitrogen use efficiency in crop production are critical for addressing the triple challenges of food security, environmental degradation and climate change. Such improvements are conditional not only on technological innovation, but also on socio-economic factors that are at present poorly understood. Here we examine historical patterns of agricultural nitrogen-use efficiency and find a broad range of national approaches to agricultural development and related pollution. We analyse examples of nitrogen use and propose targets, by geographic region and crop type, to meet the 2050 global food demand projected by the Food and Agriculture Organization while also meeting the Sustainable Development Goals pertaining to agriculture recently adopted by the United Nations General Assembly. Furthermore, we discuss socio-economic policies and technological innovations that may help achieve them

Land use change impacts on air quality and climate.

Historical land use and land cover change (referred to herein as “land use change”) has dramatically altered the Earth’s landscape, perturbing energy, moisture, and chemical fluxes and impacting the Earth’s climate. Land use change (LUC) in the next century has been projected to have profound impacts on regional climate. These changes connect to critical issues of food security, energy supply, and biodiversity. Large-scale perturbation of the biosphere will also play a major role in determining atmospheric composition, with implications for both air quality and climate. Our goal here is to review current understanding of the interplay between land use change and atmospheric chemistry, with a focus on short-lived atmospheric pollutants.National Science Foundation (U.S.) (Grant AGS-1238109)Natural Environment Research Council (Great Britain) (Grant NE/G015015/1