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691.
692.
Three decades ago, the observation that first trimester fetuses with excess fluid accumulation at the back of the neck were more likely to be aneuploid, gave rise to a new era of prenatal screening. The nuchal translucency (NT) measurement in combination with serum biomarkers and maternal age, resulted in the first trimester combined screening (FTCS) program. The introduction of noninvasive prenatal testing (NIPT) over the past decade has introduced the option for parents to receive highly sensitive and specific screening information for common trisomy from as early as 10 weeks gestation, altering the traditional pathway FTCS pathway. The retention of the 11–13-week NT ultrasound remains important in the detection of structural anomalies; however, the optimal management of pregnancies with a low-risk NIPT result and an isolated increased NT measurement in an era of advanced genomic testing options is a new dilemma for clinicians. For parents, the prolonged period between the initial diagnosis in first trimester, and prognostic information at each successive stage of investigations up to 22–24 weeks, can be emotionally challenging. This article addresses the common questions from parents and clinicians as they navigate the uncertainty of having a fetus diagnosed with an increased NT after a low-risk NIPT result and presents suggested approaches to management. 相似文献
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694.
Jesper Luxh?i Sander Bruun Lars Stoumann Jensen Jakob Magid Anne Jensen Thomas Larsen 《Waste management & research》2007,25(2):170-176
Application of municipal solid waste (MSW) to arable land can be used to close the nutrient cycle between urban and rural areas. The aim of the current study was to quantify net N mineralization and respiration from composted MSW (CMSW) and anaerobically digested MSW (ADMSW) applied to soil, and to test whether a simple relationship between net N mineralization and respiration that was developed for plant materials, was applicable for these types of MSW. In a laboratory experiment, CMSW and ADMSW were incorporated into soil and incubated at 15 degrees C. During the 149-day experiment, netN mineralization and respiration were determined. Cumulative respiration derived from both MSW types was very steep during the first 30 days, after which it levelled off. However, calculated on the basis of applied C, the ADMSW was 10 times more degradable than the CMSW. Both MSW types caused initial net N immobilization followed by re-mineralization. A simple model based on the relationship between net N mineralization and respiration was only applicable for the MSW after significant modifications. If farmers are to recognize CMSW and ADMSW as valuable fertilizers, it is important that they can be produced with higher maturity, in order to avoid initial N immobilization. 相似文献
695.
The Victorian Country Fire Authority in Australia runs the Community Fireguard (CFG) programme to assist individuals and communities in preparing for fire. The objective of this qualitative research was to understand the impact of CFG groups on their members' fire preparedness and response during the 2009 Australian bushfires. Social connectedness emerged as a strong theme, leading to an analysis of data using social capital theory. The main strength of the CFG programme was that it was driven by innovative community members; however, concerns arose regarding the extent to which the programme covered all vulnerable areas, which led the research team to explore the theory of diffusion of innovation. The article concludes by stepping back from the evaluation and using both applied theories to reflect on broad options for community fire preparedness programmes in general. The exercise produced two contrasting options for principles underlying community fire preparedness programmes. 相似文献
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697.
Using bomb radiocarbon to estimate age and growth of the white shark,Carcharodon carcharias,from the southwestern Indian Ocean 总被引:1,自引:0,他引:1
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699.
Christian Butzeck Uwe Schröder J. Oldeland S. Nolte K. Jensen 《Journal of Coastal Conservation》2016,20(3):221-236
Climate change and engineering activities have modified the hydrology and morphology of estuaries. However, the potential effects of these modifications on vegetation succession in estuarine marshes are still poorly understood. Therefore, we studied temporal changes in tidal habitats of the Elbe estuary over a period of 30 years. We compared vegetation maps from 1980 to 2010 and calculated the change in area of habitats with respect to three salinity and three elevational zones. To analyze the direction of the temporal change, we differentiated between progressive and regressive succession. By using regression tree models (conditional inference trees), we identified the most influential factors determining progressive or regressive succession of low marshes. The total area of the estuarine tidal marshes at the Elbe increased by 2 % from 1980 to 2010, but changes were unequal among the salinity zones. In the salt and brackish zones, the area covered by high marshes increased substantially but decreased in the tidal freshwater zone, while that covered by low marshes decreased in all the salinity zones. Additionally, we determined high persistence of tidal flats and high marshes, whereas only 19 to 28 % of the low marshes found in 1980 remained in 2010. In salt and brackish marshes, more than two-thirds of the area that had been identified as low marshes in 1980 had progressively developed into high marshes. In contrast, 44 % of the area of low marshes in tidal freshwater marshes showed regressive succession back into tidal flats. The distance to the navigation channel was the main factor determining successional direction in salt and brackish marshes. Here, greater proximity to the channel was correlated with higher risk of regressive succession. In tidal freshwater marshes, we identified both the distance to the navigation channel and the situation on the river shore (i.e. inner bank, outer bank or straight bank) as the main factors for marsh succession. Here, considerable engineering activities in the channel had simultaneously decreased the mean low water level and increased the mean high water level between 1980 and 2010, which led to an increase in tidal amplitude. It is quite likely that these changes negatively modified marsh distribution, increased regressive succession and, thus, lowered the quality of tidal freshwater marshes. 相似文献
700.
A method that can be used for the monitoring of exposure to alkylating agents in the environment is presented. It is based on the quantification of alkylated N‐terminal valines in hemoglobin, using a modified Edman degradation procedure. The detection limit (GC/electron capture detector or GC/MS) is increased by two magnitudes of ten when using pentafluorophenyl isothiocyanate instead of phenyl isothiocyanate in the derivatization step. As little as one nmole N‐(—2 hydroxyethyl)valine per gram hemoglobin can be detected under practical conditions. 相似文献