Although satellite radar altimetry was developed and optimized for open oceans, it has been used to monitor variations in the level of inland water-bodies such as lakes and rivers. Here, for the first time, we have further used the altimetry-derived variation of water level for estimating the fluctuation of water storage as an addition to the present in situ water storage estimation systems to be used in remote areas and in emergency situation such as in the events flooding monitoring and for studying the effect of climate change. Lake Dongting, the second largest lake in China, influenced frequently by flooding, was, therefore, chosen to demonstrate the potential of the technique. By using the concept of an "assumed reference point", we converted Topex/Poseidon satellite altimetry data on water level variations in Lake Dongting to "water level" data. The "water level" time-series data and in situ water storage were used to establish a rating curve. From the rating curve, we converted data on "water level" derived from seven years (1993-1999) of Topex/Poseidon data to actual water storage in Lake Dongting. The result reveals that the seasonal and annual fluctuations of water storage occurred during the 1990s with a more frequent flooding at the late 1990s' especially the flooding in whole catchment level in 1998 and 1999. The study supports the usefulness of satellite altimetry for dense and continuous monitoring of the temporal variations in water dynamic in moderate to large lakes.

Circular RNAs (circRNAs) have emerged as vital regulators in the chemoresistance of diverse human tumors, including ovarian cancer. In the present study, we attempted to explore the function of circ_CELSR1 in paclitaxel resistance of ovarian cancer. Quantitative real-time PCR (qRT-PCR) was conducted for the expression of circ_CELSR1, miR-149-5p and salt inducible kinase 2 (SIK2). Cell Counting Kit-8 (CCK-8) assay was performed to evaluate the half-maximal inhibitory concentration (IC 50 ) of paclitaxel and cell viability. Colony formation assay was adopted for cell colony formation. Flow cytometry analysis was conducted to analyze cell cycle process and apoptosis. Western blot assay was utilized to determine the protein levels. RNA immunoprecipitation (RIP) and dual-luciferase reporter assays were conducted to verify the association between miR-149-5p and circ_CELSR1 or SIK2. Murine xenograft model assay was carried out to determine the effect of circ_CELSR1 in paclitaxel resistance in vivo. Circ_CELSR1 was upregulated in paclitaxel-resistant ovarian cancer tissues and cells. Circ_CELSR1 knockdown enhanced paclitaxel sensitivity and cell apoptosis and repressed cell viability, colony formation and cell cycle process in paclitaxel-resistant ovarian cancer cells. For mechanism analysis, circ_CELSR1 could positively modulate SIK2 expression via sponging miR-149-5p. MiR-149-5p inhibition effectively restored the impacts of circ_CELSR1 knockdown on paclitaxel resistance and cell progression in paclitaxel-resistant ovarian cancer cells. MiR-149-5p overexpression suppressed paclitaxel resistance and cell progression in paclitaxel-resistant ovarian cancer cells by interacting with SIK2. In addition, circ_CELSR1 silencing impeded paclitaxel resistance of ovarian cancer in vivo. Circ_CELSR1 improved the resistance of ovarian cancer to paclitaxel by regulating miR-149-5p/SIK2 axis.

Abstract:In order to determine material fluxes in rivers by non-contact methods, it is essential to estimate river discharge first. Although developed and optimized for open oceans, satellite radar altimetry has the potential to monitor variations in the levels of inland waters such as lakes and rivers. Making use of the concept of an 'assumed reference point', we converted TOPEX/Poseidon satellite altimetry data on water level variations in the Yangtze River (Changjiang) to 'water level' data. We also used 'water level' time-series data and in situ river discharge to establish a rating curve. By use of the rating curve, we converted data on 'water level' derived from 7 years (1993-99) of TOPEX/Poseidon data to actual river discharge. On the basis of statistical correlation between discharge and nutrient concentration data collected in 1987-88 and in 1998-99, we estimated the total amounts of freshwater and material fluxes transferred by the Yangtze River during the 1990s. The result reveals that an overall, but very slight, increase in freshwater and material fluxes occurred during the 1990s.