Historically, the Defense Meteorological Satellite Program’s Operational Linescan System (DMSP-OLS) was the unique satellite sensor used to collect the nighttime light, which is an efficient means to ...map the global economic activities. Since it was launched in October 2011, the Visible Infrared Imaging Radiometer Suite (VIIRS) sensor on the Suomi National Polar-orbiting Partnership (NPP) Satellite has become a new satellite used to monitor nighttime light. This study performed the first evaluation on the NPP-VIIRS nighttime light imagery in modeling economy, analyzing 31 provincial regions and 393 county regions in China. For each region, the total nighttime light (TNL) and gross regional product (GRP) around the year of 2010 were derived, and a linear regression model was applied on the data. Through the regression, the TNL from NPP-VIIRS were found to exhibit R2 values of 0.8699 and 0.8544 with the provincial GRP and county GRP, respectively, which are significantly stronger than the relationship between the TNL from DMSP-OLS (F16 and F18 satellites) and GRP. Using the regression models, the GRP was predicted from the TNL for each region, and we found that the NPP-VIIRS data is more predictable for the GRP than those of the DMSP-OLS data. This study demonstrates that the recently released NPP-VIIRS nighttime light imagery has a stronger capacity in modeling regional economy than those of the DMSP-OLS data. These findings provide a foundation to model the global and regional economy with the recently availability of the NPP-VIIRS data, especially in the regions where economic census data is difficult to access.
A long-standing question in the theory of measures of noncompactness is that for the Kuratowski measure of noncompactness α defined on a metric space M, and for every bounded subset B⊂M, is there a ...countable subset B0⊂B such that α(B0)=α(B)? In this paper, we give an affirmative answer to the question above. It is done by showing that for each nonempty set B of a Banach space, there is a countable subset B0⊂B so that B is strongly finitely representable in B0, and that there is a free ultrafilter U so that B is affinely isometric to a subset of the ultrapower co(B0)U of co(B0).
Several studies showed the linkage of the Three Gorges Dam to the downstream coastal ecosystem in the East China Sea, yet its potential influence on the total suspended matters (TSM) in the Yangtze ...Estuary and its adjacent coastal waters has not been reported, possibly due to technical difficulties in obtaining statistically meaningful results. Here, a new remote sensing algorithm was established to estimate TSM from MODIS observations over the Yangtze Estuary and its adjacent coastal waters. The algorithm was based on a piecewise regression between TSM and surface reflectance at 645 and 869nm, leading to RMS uncertainties of only 20–30% for TSM between 2mgL−1 and 1762mgL−1. The algorithm was applied to MODIS data to derive TSM distribution maps from 2000 to 2010 at 250m resolution, which revealed significant spatial and temporal (seasonal and inter-annual) variability. Mean TSM in the Yangtze Estuary increased from 44.4±34.1mgL−1 in May to 96.0±58.0mgL−1 in October, while much higher TSM was found in the nearby Hangzhou Bay (between 100.3±51.6mgL−1 in August and 290.2±120.0mgL−1 in February). Two regions showed significantly out-of-phase seasonality: region A1 in the Yangtze Estuary driven by sediment discharge from the Yangtze River and region A2 in offshore waters and part of Hangzhou Bay driven by winds. The annual mean TSM in region A1 showed significantly decreasing trend in the 11-year period (−2.8mgL−1/yr), which appeared to be caused by the construction of the TGD. The study also has established a TSM environmental data record (EDR) to assess future TSM in the ecologically and economically important Yangtze Estuary and Hangzhou Bay.
•Regional TSM remote sensing model for the Yangtze Estuary•Short-term variability and long-term trend of TSM distributions•Influence of Three Gorges Dam on the TSM in the Yangtze Estuary
The Middle and Lower Yangtze River (MLY) basin holds the most freshwater in East Asia; however, the conditions of basin-scale water turbidity remain unknown. In this work, a remote sensing algorithm ...was developed to estimate the concentrations of the total suspended sediments (TSS) in large lakes and reservoirs over the MLY basin and was based on a band ratio between 555nm and 645nm of the atmospherically corrected surface reflectance of the Moderate Resolution Imaging Spectroradiometer (MODIS). In situ samples used to calibrate the algorithm were collected from 58 lakes and reservoirs with a TSS range of 1 to 300mgL−1, and the uncertainty of this algorithm was 30–40%. The algorithm was subsequently applied to a total of 102 lakes and reservoirs located in the MLY basin to derive TSS maps from 2000 to 2014 at a 250m spatial resolution, and the first comprehensive document of the TSS distributions and dynamics of large inland waters of the MLY basin was created. The seasonal patterns among the selected water bodies were similar, with the largest TSS concentrations occurring in the first and fourth quarters in a year and the lowest values occurring in the third quarter. In contrast, spatial heterogeneities were revealed by the 15-year long-term mean TSS climatology information. Although most lakes downstream of Poyang Lake were turbid with 15-year TSS climatology values of 45–100mgL−1, waters between Poyang and Doting Lake were relatively clearer with TSS climatology values of 15–45mgL−1, and the clearest waters (<15mgL−1) were found in reservoirs. The turbidity of 64.5% (e.g., 49/76) for lakes in Class II exhibited a decreasing trend over the 15-year period, and the Three Gorges Reservoir (TGR) and Dongting Lake in Class I also showed significant TSS declines. Analysis with meteorological data shows that the intra-annual variations appear to be significantly correlated with local precipitation, with a time lag of two months for TSS. The prominent TSS decreasing trend of the lakes in Class II was probably linked to the significant NDVI increase in the MLY basin, whereas the TSS decrease in the TGR and Dongting Lake is likely to be attributed to the impoundment of the Three Gorges Dam. The TSS environmental data record (EDR) of large inland waters presented in this study serves as an important reference for future water quality monitoring and evaluation in the MLY and in China.
•Propose a TSS model for inland waters of the Middle and Lower Yangtze River basin•Establish a 15-year TSS environmental data record of 102 large water bodies•Reveal significant spatial and temporal turbidity dynamics for these inland waters•Many natural lakes showed TSS decreasing trends over the recent 15-year period.•Examine the driving forces for the seasonal and inter-annual turbidity changes
China's largest freshwater lake, Poyang Lake, is well known for its ecological and economic importance as well as its rapid changes in lake inundation areas. However, due to technical difficulties, ...to date long-term records of its dynamic inundation areas are lacking, not to mention how they are affected by climate change and/or human activities. Using Moderate Resolution Imaging Spectroradiometer (MODIS) medium-resolution (250-m) data collected between 2000 and 2010 and an objective water/land delineation method, we documented and studied the short- and long-term characteristics of lake inundation. Significant seasonality and inter-annual variability were found in the monthly and annual mean inundation areas. The inundation area ranged between 714.1km2 in October 2009 and 3162.9km2 in August 2010, and the inundation area during any particular year could change by a factor of 2.3–3.2. During the 11-year period, the maximum possible inundation area was 14 times the minimum possible inundation area, indicating extreme variability. Both the annual mean and minimum inundation areas showed statistically significant declining trends from 2000 to 2010 (−30.2km2yr−1 and−23.9km2yr−1, p<0.05). The changes of the inundation area were primarily driven by local precipitation during non-summer months, while during summer months of July to September when the outflow into the Yangtze River was impeded the effect of precipitation became less significant. These results provide long-term baseline data to monitor future changes in Poyang Lake's inundation area in a timely fashion, for example quantifying the extreme drought conditions during spring 2011.
► Short- and long-term patterns of Poyang Lake's inundation were studied using MODIS. ► Significant seasonality and inter-annual inundation variability were found. ► Variation patterns were driven by precipitation and modulated by the Yangtze River.
Ever since its planning in the 1990s, the Three Gorges Dam (TGD) caused endless debate in China on its potential impacts on the environment and humans. However, to date, synoptic assessment of ...environmental changes and their potential linkage with the TGD is still lacking. Here, we combine remote sensing, meteorological, and hydrological observations to investigate the potential influence of the TGD on the downstream freshwater lakes. A 10 year Moderate Resolution Imaging Spectroradiometer (MODIS) time series from 2000 to 2009 revealed significantly decreasing trends (3.3 and 3.6%/year) in the inundation areas of the two largest freshwater lakes of China (Poyang Lake and Dongting Lake) downstream of the TGD since its impoundment in 2003, after which both relative humidity and surface runoff coefficient of the lakes’ drainages also dropped dramatically. These environmental changes appear to be linked to the TGD.
Basin-scale water volumes of lakes and reservoirs are difficult to obtain due to a number of challenges. In this study, area-based water storage estimation models are proposed for large lakes and ...reservoirs in the Yangtze River Basin (YRB). The models are subsequently applied to Moderate Resolution Imaging Spectroradiometer (MODIS) observations of 128 large lakes and 108 reservoirs between 2000 and 2014, and the first comprehensive map of the temporal and spatial dynamics of water storage in large water bodies in the YRB is provided. The results show that 53.91% of the lakes experienced significant decreasing trends in water storage during this period, and the total water storage in lakes showed a decreasing trend of 14 million m
month
. By contrast, a monthly mean increase of 177 million m
was observed for water storage in reservoirs. Our analysis revealed that the pronounced increase in reservoirs was primarily due to the rapid water level increase in the Three Gorges Reservoir in recent years, while understanding the water loss in lakes requires additional studies. The long-term data presented in this study provide critical baseline information for future water resource monitoring and regulation in the YRB and China.
patients with acute basal ganglia ischemic stroke (BGIS) show changes in local brain activity represented by the amplitude of low-frequency fluctuation (ALFF), but the time-varying characteristics of ...this local nerve activity are still unclear. This study aimed to investigate the abnormal time-varying local brain activity of patients with acute BGIS by using the ALFF method combined with the sliding-window approach.
In this study, 34 patients with acute BGIS with motor dysfunction and 44 healthy controls (HCs) were recruited. The dynamic amplitude of low-frequency fluctuation (dALFF) was employed to detect the alterations in brain activity induced by acute BGIS patients. A two-sample
-test comparison was performed to compare the dALFF value between the two groups and a Spearman correlation analysis was conducted to assess the relationship between the local brain activity abnormalities and clinical characteristics.
Compared with HCs, the activity of neurons in the left temporal pole (TP), parahippocampal gyrus (paraHIP), middle occipital gyrus (MOG), dorsolateral superior frontal gyrus (SFGdl), medial cingulate cortex (MCC), right rectus, precuneus (PCu) and right cerebellum crus1 were significantly increased in patients with BGIS. In addition, we found that there was a negative correlation (
= -0.458,
= 0.007) between the dALFF value of the right rectus and the scores of the National Institutes of Health Stroke Scale (NIHSS), and a positive correlation (
= 0.488, 0.499,
< 0.05) with the scores of the Barthel Index scale (BI) and the Fugl Meyer motor function assessment (FMA). ROC analysis results demonstrated that the area under the curves (AUC) of the right rectus was 0.880,
<0.001.
The pattern of intrinsic brain activity variability was altered in patients with acute BGIS compared with HCs. The abnormal dALFF variability might be a potential tool to assess motor function in patients with acute BGIS and potentially inform the diagnosis of this disease.
Salvianolate is the main water-soluble bioactive compound of Salvia Miltiorrhiza Bunge and is now clinically used in the treatment of cardiovascular diseases in China. However, its applications in ...the prevention of atrial interstitial fibrosis (AIF) and atrial fibrillation (AF) are not fully revealed.
To investigate the preventive effect of salvianolate on the pathogenesis of AF in post-myocardial infarction (MI) rats and to elucidate the potential mechanisms.
Rats underwent left anterior descending coronary artery ligation were randomized into four groups and administered intraperitoneally with vehicle (MI group, n = 13), or 10, 20 and 40 mg/kg salvianolate (Sal-L, Sal-M and Sal-H group, n = 13, 14 and 13 respectively) for totally five weeks. Rats underwent sham operation was used as control group (Sham, n = 10). Then, echocardiography and AF inducibility test were detected. Tissues and serum were collected for Sirius red and fast green counter stain or hematoxylin-eosin to assess atrial interstitial fibrosis and hypertrophy, or for western blot and ELISA analysis.
Salvianolate injection significantly improved cardiac function, reduced left atrial enlargement and P-wave duration, and decreased not only the vulnerability to AF but also AF duration. Histologic analysis showed that salvianolate mitigated AIF and atrial hypertrophy. Western blot analysis found that salvianolate inhibited the TGFβ1/Smad2/3 mediated-collagen deposition and inhibited the TXNIP/NLRP3 inflammasome /IL-1β and IL-18 signal pathway. ELISA analysis showed that salvianolate significantly reduced the serum concentrations of BNP, IL-6, CRP and TGFβ1.
Salvianolate may constitute a novel upstream therapy for AF by suppressing AIF. The underlying mechanism may be attributable to its inhibitory effects on TGF-β1/Smad2/3 and TXNIP/NLRP3 inflammasome signaling pathway.
Stroke is a brain damage caused by a loss of blood supply to a portion of the brain, which requires prompt and effective treatment. The current pharmacotherapy for ischemic stroke primarily relies on ...thrombolysis using recombinant tissue plasminogen activators(rt-PAs) to breakdown blood clots. Neuroprotective agents that inhibit excitatory neurotransmitters are also used to treat ischemic stroke but have failed to translate into clinical benefits. This poses a major challenge in biomedical research to understand what causes the progressive brain cell death after stroke and how to develop an effective pharmacotherapy for stroke. This brief review analyzes the fate of about 430 potentially useful stroke medications over the period 1995–2015and describes in detail those that successfully reached the market. Hopefully, the information from this analysis will shed light on how future stroke research can improve stroke drug discovery.
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