254 research outputs found
The Political Economy of Biotechnology
The introduction of GE to agriculture has encoun-tered strong resistance, reflecting conflicting groups within and between countries. This has resulted in a regulatory environment that has limited the application of GE mostly to feed and fiber and practically restricted its application in food. While agricultural biotechnology has already provided significant benefits, much of its potential has not been reached. Regulation of agricultural biotechnology reflects conflicting interests and varying political power of different groups. The relatively supportive regulation of biotechnology in the U.S. reflects that it is an American technology, and supporting groups like the farm lobby, technology manufacturers, and U.S. consumers outweigh the objections of environmentalists and other opposition to the technology. In Europe, growing concern about environmental side-effects of agriculture, the fact that GE technology was imported, and the power of environmental groups has resulted in restrictive regulation. To a large extent, the fate of GE depends on the level of goodwill it generates among voters, and as long as a large segment of the population is apprehensive about its benefits, heavy restrictions about the technology that prevent it from reaching its potential will persist
Global anthropogenic emissions (CAMS-GLOB-ANT) for the Copernicus Atmosphere Monitoring Service simulations of air quality forecasts and reanalyses
Anthropogenic emissions are the result of many different economic sectors, including transportation, power generation, industrial, residential and commercial activities, waste treatment and agricultural practices. Air quality models are used to forecast the atmospheric composition, analyze observations and reconstruct the chemical composition of the atmosphere during the previous decades. In order to drive these models, gridded emissions of all compounds need to be provided. This paper describes a new global inventory of emissions called CAMS-GLOB-ANT, developed as part of the Copernicus Atmosphere Monitoring Service (CAMS; https://doi.org/10.24380/eets-qd81, Soulie et al., 2023). The inventory provides monthly averages of the global emissions of 36 compounds, including the main air pollutants and greenhouse gases, at a spatial resolution of 0.1° × 0.1° in latitude and longitude, for 17 emission sectors. The methodology to generate the emissions for the 2000–2023 period is explained, and the datasets are analyzed and compared with publicly available global and regional inventories for selected world regions. Depending on the species and regions, good agreements as well as significant differences are highlighted, which can be further explained through an analysis of different sectors as shown in the figures in the Supplement.</p
Valganciclovir for Symptomatic Congenital Cytomegalovirus Disease
BACKGROUND: The treatment of symptomatic congenital cytomegalovirus (CMV) disease with intravenous
ganciclovir for 6 weeks has been shown to improve audiologic outcomes at 6 months, but the benefits wane over time.
METHODS: We conducted a randomized, placebo-controlled trial of valganciclovir therapy in neonates with symptomatic congenital CMV disease, comparing 6 months of therapy with 6 weeks of therapy. The primary end point was the change in hearing in the better ear
(“best-ear” hearing) from baseline to 6 months. Secondary end points included the change in hearing from baseline to follow-up at 12 and 24 months and neurodevelopmental
outcomes, with each end point adjusted for central nervous system involvement at baseline.
RESULTS: A total of 96 neonates underwent randomization, of whom 86 had follow-up data at 6 months that could be evaluated. Best-ear hearing at 6 months was similar in the 6-month group and the 6-week group (2 and 3 participants, respectively, had improvement; 36 and 37 had no change; and 5 and 3 had worsening; P=0.41). Totalear hearing (hearing in one or both ears that could be evaluated) was more likely to be improved or to remain normal at 12 months in the 6-month group than in the
6-week group (73% vs. 57%, P=0.01). The benefit in total-ear hearing was maintained at 24 months (77% vs. 64%, P=0.04). At 24 months, the 6-month group, as compared
with the 6-week group, had better neurodevelopmental scores on the Bayley Scales of Infant and Toddler Development, third edition, on the language-composite component (P=0.004) and on the receptive-communication scale (P=0.003). Grade 3 or 4 neutropenia occurred in 19% of the participants during the first 6 weeks. During the
next 4.5 months of the study, grade 3 or 4 neutropenia occurred in 21% of the participants in the 6-month group and in 27% of those in the 6-week group (P=0.64).
CONCLUSIONS: Treating symptomatic congenital CMV disease with valganciclovir for 6 months, as compared with 6 weeks, did not improve hearing in the short term but appeared to improve hearing and developmental outcomes modestly in the longer term. (Funded by the National Institute of Allergy and Infectious Diseases; ClinicalTrials.gov number,
NCT00466817.
Influence of physical properties on polymer flammability in the cone calorimeter
The relationship between physical properties and fire performance as measured in the cone calorimeter is not well understood. A number of studies have identified relationships between the physical and chemical properties of polymeric materials and their gasification behaviour which can be determined through numerical pyrolysis models. ThermaKin, a one-dimensional pyrolysis model, has recently been employed to predict the burning behaviour in fire calorimetry experiments. The range of thermal, chemical and optical properties of various polymers have been utilised to simulate
the processes occurring within a polymer exposed to a uniform heat flux, such as in a cone calorimeter. ThermaKin uses these material properties to predict the mass flux history in a cone calorimeter. Multiplying the mass flux history by the heat of combustion of the fuel gases gives the HRR history and these have been calculated for cone calorimeter experiments at 50 kW m-2 incident heat flux for the lowest, average and highest values of physical parameters exhibited by common
polymers. In contrast with actual experiments in fire retardancy, where several parameters change on incorporation of an additive, this study allows for the effect of each parameter to be seen in isolation. The parameters used in this study are grouped into physical properties (density, heat capacity and thermal conductivity), optical properties (absorption and reflectivity), and chemical properties (heat of decomposition, kinetic parameter and heat of combustion). The study shows
how the thermal decomposition kinetic parameters effect the surface burning (pyrolysis) temperature and resulting heat release rate history, as well as the relative importance of other properties directly related to the chemical composition. It also illustrates the effect of thermal inertia (the product of density, heat capacity and thermal conductivity) and of the samples’ ability to absorb radiant heat
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