2,590 research outputs found
Characteristics of multiple‐year nitrous oxide emissions from conventional vegetable fields in southeastern China
The annual and interannual characteristics of nitrous oxide (N2O) emissions from conventional vegetable fields are poorly understood. We carried out 4 year measurements of N2O fluxes from a conventional vegetable cultivation area in the Yangtze River delta. Under fertilized conditions subject to farming practices, approximately 86% of the annual total N2O release occurred following fertilization events. The direct emission factors (EFd) of the 12 individual vegetable seasons investigated ranged from 0.06 to 14.20%, with a mean of 3.09% and a coefficient of variation (CV) of 142%. The annual EFd varied from 0.59 to 4.98%, with a mean of 2.88% and an interannual CV of 74%. The mean value is much larger than the latest default value (1.00%) of the Intergovernmental Panel on Climate Change. Occasional application of lagoon‐stored manure slurry coupled with other nitrogen fertilizers, or basal nitrogen addition immediately followed by heavy rainfall, accounted for a substantial portion of the large EFds observed in warm seasons. The large CVs suggest that the emission factors obtained from short‐term observations that poorly represent seasonality and/or interannual variability will inevitably yield large uncertainties in inventory estimation. The results of this study indicate that conventional vegetable fields associated with intensive nitrogen addition, as well as occasional applications of manure slurry, may substantially account for regional N2O emissions. However, this conclusion needs to be further confirmed through studies at multiple field sites. Moreover, further experimental studies are needed to test the mitigation options suggested by this study for N2O emissions from open vegetable fields
Radiative viscosity of neutron stars
We study non-linear effects of radiative viscosity of matter in neutron
stars for both direct Urca process and modified Urca process, and find that
non-linear effects will decrease the ratio of radiative viscosity to bulk
viscosity from 1.5 to 0.5 (for direct Urca process) and 0.375 (for modified
Urca process). Which means that for small oscillations of neutron star, the
large fraction of oscillation energy is emitted as neutrinos; but for large
enough ones, bulk viscous dissipation dominates.Comment: 11pages, 4 figure
Trace amounts of copper induce neurotoxicity in the cholesterol-fed mice through apoptosis
AbstractEvidence has been gathered to suggest that trace amounts of copper induce neurotoxicity by interaction with elevated cholesterol in diet. Copper treatment alone showed no significant learning and memory impairments in behavioral tasks. However, copper-induced neurotoxicity was significantly increased in mice given elevated-cholesterol diet. Trace amounts of copper decreased the activity of SOD and increased the level of malondialdehyde (MDA) in the brain of cholesterol-fed mouse. Copper also caused an increase in amyloid precursor protein (APP) mRNA level and the activation of caspase-3 in the brain of cholesterol-fed mice. The apoptosis-induced nuclear DNA fragmentation was detected in the brain of those mice by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end-labeling staining. These findings suggest that trace amounts of copper induce neurotoxicity in cholesterol-fed mice through apoptosis caused by oxidative stress
(4-Bromo-3,5-dimethyl-1H-pyrazol-1-yl)(2,6-difluorophenyl)methanone
There are two molecules in the asymmetric unit of the title compound, C12H9BrF2N2O. They have very similar conformations: the dihedral angles between their pyrazole and benzene ring systems are 78.4 (3) and 78.6 (4)°. In the crystal, weak aromatic π–π stacking [centroid–centroid separation = 3.696 (5) Å] helps to establish the packing
Drug-Induced Modulation of T Lymphocytes as a Potential Mechanism of Susceptibility to Infections in Patients with Multiple Myeloma During Bortezomib Therapy
Mercury, Cadmium and Lead Biogeochemistry in the Soil–Plant–Insect System in Huludao City
Mercury, cadmium, and lead concentrations of ashed plants and insects samples were investigated and compared with those of soil to reveal their biogeochemical processes along food chains in Huludao City, Liaoning Province, China. Concentration factors of each fragments of the soil–plant–the herbivorous insect–the carnivorous insect food chain were 0.18, 6.57, and 7.88 for mercury; 6.82, 2.01, and 0.48 for cadmium; 1.47, 2.24, and 0.57 for lead, respectively. On the whole, mercury was the most largely biomagnified, but cadmium and lead were not greatly accumulated in the carnivorous insects as expected when the food chain extended to the secondary consumers. Results indicated that concentration factors depended on metals and insects species of food chains
塑造核心价值观,推动医院大发展
Objective: to investigate the significance of core values in the development of the hospital. Method: to retrospectively analyze core values shaping experience and method in Taihe hospital. Results and conclusion: Core values play an important role in the development of the hospital. The hospital could improve its core competitiveness and achieve a higher goal once people-centered core values are established.目的 探讨核心价值观在医院发展中的重要作用。方法 回顾分析太和医院核心价值观的塑造经验与方法。结果与结论 核心价值观在医院建设发展中具有重要地位,只有确立以人为本的核心价值观,才能提高医院的核心竞争力,使其不断向更高目标前进
Risk of Salmonella shedding in different pig production systems
The objective of this paper is to describe the Salmonella transfer risk in different conventional and organic pig production systems. Twelve organic, 12 conventional outdoor and 12 conventional indoor herds participated in the investigation. Faecal sam-ples from approximately 50 pigs per herd collected before and after transport to the abattoir were ana-lysed for density of Salmonella, and meat juice sam-ples from the pigs were analysed for antibodies against S. enterica. The results showed that 9,5 % of the organic and 8,1 % of the conventional outdoor pigs were seropositive, but they were unlikely to shed Salmonella on-farm, and less than 1,9 % of the pigs were shedding Salmonella at the abattoir. The indoor pigs had a seroprevalence of 6,8 %, and 2,6 % and 4,0 % of the pigs were shedding Salmonella on-farm and at the abattoir, respectively. This suggests that pigs from low input systems may be more resistant to the pathogen. Further analyses of the data are needed to evaluate the effect of different management strategies in the herds
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