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To exam ine the residues and distributions of hexachlorocyclohexanes (HCHs), dichlorodiphenyltrichloroethane (DDT), and other organochlorine pesticides (OCPs ) in the Weihe River basin of northwest China, a gas chromatography-mass spectrometer (GC-MS) was employed to analyze the samples collected from surface water, suspended solids, and sediments. Results showed that total concentrations of HCHs, DDT, and othe r OCPs in surface water were in the range of 2.41-178.18, 0.94-116.83, and 3.64-37.17 ng/L, respectiv ely; in suspended solids they were 5 1.76-241.23, 2.82-12.23, and 11.35-37.67 ng/L, respectively; and in sediments they were 74.13-517.49, 1.20-370.98, and 7.94-110.13 ng/g dry weight, respectively. The α-HCH/γ-HCH ratio indicated that historical usage of technical mixtures of HCHs was the main source of HCHs. The DDT ratio indicated that DDT at most sites came from older uses of technical DDT. Compared with some guideline values of OCPs in surface water, the concentrations of HCHs and DDT were at safe levels. Meanwhile, the Weihe Riv er sediments have high ecological risk pesticides.
Cryptotaenia japonica Hassk of the Apiaceae family serves as an important vegetable and a medicinal herb in Asia and North America. High temperature leads to serious damage during summer. Here, deep transcriptome sequencing was performed to obtain information on gene expression and heat shock protein genes in C. Japonica Hassk. A total of 40,734 unigenes were assembled and annotated. Gene Ontology and Clusters of Orthologous Groups were used to classify the functions of the unigenes. The pathway was also predicted based on Kyoto Encyclopedia of Genes and Genomes. The amounts of 2,791 simple sequence repeats were identified in 11,217 unigenes. To further investigate the expression under high temperature, 14 unigenes that encode CjHsp genes were selected based on the annotation of the Nr and Nt databases from C. japonica Hassk. The expression profiles of CjHsp genes under high-temperature treatments of 30 and 38 C were analyzed using qRT-PCR in C. japonica Hassk. Results showed that these CjHsp genes were regulated under high-temperature treatment. These findings provide the first information on C. japonica Hassk transcriptome and enhance understanding on the mechanisms of gene regulation under high-temperature stress in C. Japonica Hassk.
Lakes are one of the most important wetland types on the earth with many ecosystem functions. With continuing economic growth and climate change, lake abundance and surface areas throughout the world have been threatened by many factors, including by human and environmental disruptions. However, we still have limited knowledge on how human activities and climate change affect lake reductions and associated ecosystem services. Elucidating the underlying mechanisms of lake shrinkage will help maintain an ecological balance in urban planning, especially in rapidly developing countries. We explore the determinants of lake shrinkage and abundance reduction from the 1980s to the 2010s using remote sensing data of lakes in two large cities in eastern China: Nanchang and Shanghai. In order to account for the non-independence of time-series data, time series auto-regressive generalized least squares (GLS) models were used to examine the relationship between lake area/abundance and human activities and climate change. Our results show that human activities rather than climate change, are the most important determinants for the areas and numbers of lake shrinkage, and gross domestic product (GDP) and population size could explain more than half of the variation in the number and area of lakes with areas larger than 20 ha in the two cities. GDP and lake area shrinkage do not exhibit a linear relationship. This highlights the importance of wetland protection in the early development stage. Because the main determinants are human activities, cities have the ability to protect wetlands via suitable planning.
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