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481.
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Advancements in fetal diagnostic imaging have increased prenatal diagnosis of many fetal anomalies. The purpose of this chapter is to review the etiology and natural history of prenatally diagnosed cystic lung lesions, including congenital cystic adenomatoid malformations (CCAM), pulmonary sequestrations (PSs), hybrid lesions, and bronchogenic cysts, and then discuss current concepts in the management and outcome of these lesions. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
484.
Shaocai Yu Rohit Mathur Daiwen Kang Kenneth Schere Daniel Tong 《Atmospheric environment (Oxford, England : 1994)》2009,43(2):355-363
The integrated process rates (IPRs) estimated by the Eta–CMAQ model at grid cells along the trajectory of the air mass transport path were analyzed to quantitatively investigate the relative importance of physical and chemical processes for O3 formation and evolution over the northeastern U.S. during the 2004 International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) period. The Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model is used to determine the back trajectory of air masses reaching the northeast by linking a downwind receptor to upwind source areas. The process analysis is applied to a high O3 episode occurring on July 22, 2004 at three selected sites in the northeastern U.S. The process analysis at the location of the site shows that during the daytime, the O3 concentrations in the surface layer are mainly enhanced by the vertical diffusion of O3-rich air from aloft, followed by horizontal advection (HADV) and chemical production (CHEM), whereas dry deposition (DDEP) and vertical advection (ZADV) mainly deplete O3 concentrations at the sites of Valley Central (VC), NY and Castle Spring (CS), NH. By integrating the effects of each process over the depth of the daytime planetary boundary layer (PBL), it was found that at the VC site, CHEM and HADV contributed about 53% and 41%, respectively, to O3 levels within the PBL. This confirms the significance of regional transport of O3 from the industrialized areas into the Northeast. On the other hand, the process analysis results for O3 formation in moving air masses indicate that on July 22, large chemical production of O3 along the transport path over the polluted urban regions leads to significant increase in O3 in the air mass reaching the VC site, whereas the low chemical production of O3 along the transport path over the low emission regions leads to the low O3 concentration at the site of Belleayre Mountain (BM), NY. The dramatic buildup of O3 concentration from 50 ppb to 102 ppb in the air masses before reaching the VC site after 12:00 EST on 7/22 indicates the significant impact of pollution from the northeastern urban corridor at this site. On the basis of the results at the CS site, it was found that high NOx emissions along the transport path led to large chemical production of O3 in the air mass reaching the CS site on July 22. In contrast, the low chemical production of O3 associated with low emission (relatively clean conditions) along the transport path over the northern portions of the domain is responsible for the low O3 concentration at the CS site on July 26. 相似文献
485.
Non-parametric MLE for Poisson species abundance models allowing for heterogeneity between species 总被引:6,自引:0,他引:6
The proper management of an ecological population is greatly aided by solid information about its species' abundances. For the general heterogeneous Poisson species abundance setting, we develop the non-parametric mle for the entire probability model, namely for the total number N of species and the generating distribution F for the expected values of the species' abundances. Solid estimation of the entire probability model allows us to develop generator-based measures of ecological diversity and evenness which have inferences over similar regions. Also, our methods produce a solid goodness-of-fit test for our model as well as a likelihood ratio test to examine if there is heterogeneity in the expected values of the species' abundances. These estimates and tests are examined, in detail, in the paper. In particular, we apply our methods to important data from the National Breeding Bird Survey and discuss how our methods can also be easily applied to sweep net sampling data. To further examine our methods, we provide simulations for several illustrative situations. 相似文献
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487.
A certification program for consulting meteorologists was established by the American Meteorological Society in 1956.Associated with the many recent advances in meteorology has been the development of the private practice of consulting meteorology. This has arisen out of the need on the part of business, industry, and agriculture for specialized services which extend beyond the public service functions and statutory responsibilities of the National Weather Service. 相似文献
488.
Laura Biganzoli Aamir Ilyas Martijn van Praagh Kenneth M. Persson Mario Grosso 《Waste management (New York, N.Y.)》2013,33(5):1174-1181
Waste incineration bottom ash fine fraction contains a significant amount of aluminium, but previous works have shown that current recovery options based on standard on-step Eddy Current Separation (ECS) have limited efficiency. In this paper, we evaluated the improvement in the efficiency of ECS by using an additional step of crushing and sieving. The efficiency of metallic Al recovery was quantified by measuring hydrogen gas production. The ash samples were also tested for total aluminium content with X-ray fluorescence spectroscopy (XRF). As an alternative to material recovery, we also investigated the possibility to convert residual metallic Al into useful energy, promoting H2 gas production by reacting metallic Al with water at high pH. The results show that the total aluminium concentration in the <4 mm bottom ash fraction is on average 8% of the weight of the dry ash, with less than 15% of it being present in the metallic form. Of this latter, only 21% can be potentially recovered with ECS combined with crushing and sieving stages and subsequently recycled. For hydrogen production, using 10 M NaOH at 1 L/S ratio results in the release of 6–11 l of H2 gas for each kilogram of fine dry ash, equivalent to an energy potential of 118 kJ. 相似文献
489.
Gokmen Tayfur Kenneth K. Tanji Alper Baba 《Environmental monitoring and assessment》2010,169(1-4):509-518
A two-dimensional finite element model was developed to simulate species of selenium transport in two dimensions in both saturated and unsaturated soil zones. The model considers water, selenate, selenite, and selenomethionine uptake by plants. It also considers adsorption and desorption, oxidation and reduction, volatilization, and chemical and biological transformations of selenate, selenite, and selenomethionine. In addition to simulating water flow, selenate, selenite, and selenomethionine transport, the model also simulates organic and gaseous selenium transport. The developed model was applied to simulate two different observed field data. The simulation of the observed data was satisfactory, with mean absolute error of 48.5 μg/l and mean relative error of 8.9%. 相似文献
490.
The objective of this study was to assess the potential of the earthworm Eiseniella tetraedra (Savigny, 1826) as a bioindicator for cadmium (Cd) and lead (Pb) exposure. The importance of earthworms in metal pollution monitoring is widely recognized in terrestrial ecosystems. In this study, the levels of Cd and Pb in soils and earthworm tissues were studied at two locations, Polur Falls and a riverside area located in Abali, in the Elburz Mountains in Iran. At both locations the concentration of Cd and Pb in earthworms was higher than in the surrounding soils and a significant difference was found between the two stations, the latter probably attributable to the (1) amount of pesticides that are used for crop treatment in Abali and (2) presence there of clay, which is known to be rich in Cd. Data indicate that E. tetraedra is an efficient bioaccumulator of Cd and Pb and might act thus serve as a bioindicator of exposure. 相似文献