The age of the Emeishan lavas in SW China remains poorly constrained because the extrusive rocks are (1) thermally overprinted and so represent an open system unsuitable for 40Ar/39Ar geochronology ...and (2) in most cases devoid of zircon so that it is impossible for the application of U–Pb geochronology. Existing radiometric age constraints of Emeishan large igneous province are mainly from the application of SIMS and LA-ICP-MS U–Pb techniques to zircons from mafic and felsic intrusions, which represent indirect constraints for the lavas. In an attempt to directly determine the age of the Emeishan lava succession, high-resolution chemical abrasion-thermal ionization mass spectrometry (CA-TIMS) zircon U–Pb techniques have been used on the felsic ignimbrite at the uppermost part of the Emeishan lava succession. These techniques have yielded a weighted mean 206Pb/238U age of 259.1±0.5Ma (n=6; MSWD=0.7). We interpret this age as the termination age of the Emeishan flood basalts. The age of the Guadalupian–Lopingian boundary is still unconstrained by high-resolution geochronology but is likely to be close to our new age for this felsic ignimbrite.
•High-resolution U–Pb age of the Emeishan ignimbrite is reported at 259.1±0.5Ma.•Termination age of the Emeishan LIP is 259.1±0.5Ma.•The age of the Guadalupian–Lopingian boundary is close to the new age acquired.
The main goal of this paper is to develop a fast and effective meshless method by using radial basis function (RBF) for the time domain model equations of electromagnetic wave concentration device. ...This is mainly because the complex model equations involve different partial differential equations in different subdomains, which makes the meshless method very attractive and also very challenging. In order to simulate the propagation of electromagnetic waves in the electromagnetic concentrator, perfect matching layer technology was used to reduce an unbounded domain problem into a bounded domain problem. Borrowing the idea of the leap-frog finite-difference time-domain scheme, I develop the leap-frog RBF meshless method to solve the coupled complex modeling equations. The numerical results obtained by using a multiquadric RBF and Gaussian RBF demonstrate that our RBF method is very effective.
The systemic inflammatory response plays an important role in cancer development and progression. An original inflammation-based staging system for predicting survival in patients undergoing ...transarterial chemoembolization (TACE) combined with recombinant human type-5 adenovirus H101 is not available. This study aimed to validate the prognostic value of inflammation scores for patients with hepatocellular carcinoma (HCC) who were treated with TACE combined with H101.
The data from 216 patients with HCC who underwent TACE combined with H101 from January 2007 to July 2015 were retrospectively collected, and the association of the inflammation scores with overall survival (OS) was analyzed. Univariate and multivariate analyses were performed to identify variables associated with OS. The prognostic value of the inflammation scores, including the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), neutrophil/ platelet-to-lymphocyte ratio (NLR-PLR), modified Glasgow Prognostic Score (mGPS), prognostic nutritional index (PNI), prognostic index (PI), tumor-node-metastasis (TNM), Barcelona Clinic Liver Cancer (BCLC) and Cancer of the Liver Italian Program (CLIP) staging systems were analyzed and compared using the areas under the receiver operating characteristic curves (AUROCs).
The estimated 1-, 2-, and 3-year OS rates were 61.3%, 44.2%, and 40.5% for the entire study cohort, respectively; the median OS was 17 months. According to the multivariate Cox proportional hazards model, the pretreatment NLR, tumor diameter and pretreatment alpha-fetoprotein (AFP) levels were independent predictors of OS. The CLIP score had superior discriminative abilities compared with other staging systems, and the NLR-PLR score consistently displayed a higher AUROC value than the other inflammation-based prognostic scores. The combination of the NLR-PLR and CLIP scores exhibited a superior prognostic ability for OS compared to the NLR-PLR or CLIP scores alone.
The NLR-PLR score is a more powerful predictive system than the other inflammation-based scores for patients with HCC who were treated with TACE and H101. The predictive ability may be improved by utilizing a combination of the NLR-PLR and CLIP scores.
Electroencephalography based brain-computer interfaces (BCIs) show promise of providing an alternative communication channel between the brain and an external device. It is well acknowledged that BCI ...control is a skill and could be improved through practice and training. In this study, we explore the change of BCI behavioral performance as well as the electrophysiological properties across three training sessions in a pool of 42 human subjects. Our results show that the group average of BCI accuracy and the information transfer rate improved significantly in the third session compared to the first session; especially the significance reached in a smaller subset of a low BCI performance group (average accuracy <70%) as well. There was a significant difference of event-related desynchronization (ERD) lateralization for BCI control between the left- and right-hand imagination task in the last two sessions, but this significant difference was not revealed in the first training sessions. No significant change of
value or event-related desynchronization and synchronization (ERD/ERS) for either channel C3 or channel C4, which were used for online control, was found across the training sessions. The change of ERD lateralization was also not significant across the training sessions. The present results indicate that BCI training could induce a change of behavioral performance and electrophysiological properties quickly, within just a few hours of training, distributed into three sessions. Multiple training sessions might especially be beneficial for the low BCI performers.
The standardized EEG electrode array of the IFCN Seeck, Margitta; Koessler, Laurent; Bast, Thomas ...
Clinical neurophysiology,
October 2017, 2017-10-00, 20171001, 2017-10, Volume:
128, Issue:
10
Journal Article
Peer reviewed
Open access
•An array of 25 electrodes is recommended for standard EEGs with inferior temporal electrodes.•Due to thinner skulls (spatial aliasing), pediatric EEG requires as many scalp electrodes as in ...adults.•Arrays with higher electrode numbers (64–256 electrodes) allow source imaging at sublobar level.
Standardized EEG electrode positions are essential for both clinical applications and research. The aim of this guideline is to update and expand the unifying nomenclature and standardized positioning for EEG scalp electrodes. Electrode positions were based on 20% and 10% of standardized measurements from anatomical landmarks on the skull. However, standard recordings do not cover the anterior and basal temporal lobes, which is the most frequent source of epileptogenic activity. Here, we propose a basic array of 25 electrodes including the inferior temporal chain, which should be used for all standard clinical recordings. The nomenclature in the basic array is consistent with the 10–10-system. High-density scalp EEG arrays (64–256 electrodes) allow source imaging with even sub-lobar precision. This supplementary exam should be requested whenever necessary, e.g. search for epileptogenic activity in negative standard EEG or for presurgical evaluation. In the near future, nomenclature for high density electrodes arrays beyond the 10–10 system needs to be defined, to allow comparison and standardized recordings across centers. Contrary to the established belief that smaller heads needs less electrodes, in young children at least as many electrodes as in adults should be applied due to smaller skull thickness and the risk of spatial aliasing.
Changes in water availability strongly affect vegetation growth, and vegetation can also modify land water storage by changing the land surface water balance. Here, based on the terrestrial water ...storage (TWS) data retrieved from the Gravity Recovery and Climate Experiment (GRACE)satellites mission and the normalized difference vegetation index (NDVI) from Jan. 2003 to Dec. 2015, we investigate the interplay between land water and vegetation greenness at a global scale. The results reveal a coherent trend with statistical significance between the terrestrial water storage anomaly (TWSA) and the NDVI in 20.90% of global vegetated lands in contrast to a non-coherent trend of 20.87% in global vegetated lands. Vegetation greenness exhibits a common 0- to 1-month delayed response to the TWSA, and significant positive TWSA-NDVI relationships appear in approximately 43.17% of global vegetated areas. A comparison study suggests that the response of vegetation greenness to the TWSA is more rapid than that to precipitation. Interactions between the TWSA and NDVI are further investigated by using the Granger causality test technique. Globally, a strong interaction between the TWSA and NDVI occurs in over 16.75% of vegetated areas. Simultaneously, vegetation greenness is found to be the Granger cause of the TWSA in over 40.34% of global vegetated areas, indicating widespread impacts of vegetation change on variations in land water storage. A case study in China suggests that vegetation greenness increase is an important reason for the decrease in the TWSA in North and Northwest China, which are traditionally water-limited-growth regions. In two humid regions, Southwest and South China, the influence of the TWSA on vegetation greenness seems to be stronger than that of vegetation greenness on the TWSA. Our study suggests that the GRACE TWS is a useful tool for investigations of interactions between vegetation greenness and land water conditions.
•Temporal relationships between the NDVI and TWSA derived from GRACE were examined.•A significant response of the NDVI to TWSA was found over 43.17% of global vegetated areas.•The response of the NDVI to TWSA is more rapid than that to precipitation.•Interactions between the NDVI and TWSA were detected over 16.75% of global vegetated areas.
Ginsenoside Rg1 (Rg1), a saponin extracted from Panax ginseng, has been well documented to be effective against ischemic/reperfusion (I/R) neuronal injury. However, the underlying mechanisms remain ...obscure. In the present study, we investigated the roles of Nrf2 and miR-144 in the protective effects of Rg1 against I/R-induced neuronal injury. In OGD/R-treated PC12 cells, Rg1 (0.01-1 μmol/L) dose-dependently attenuated the cell injury accompanied by prolonging nuclear accumulation of Nrf2, enhancing the transcriptional activity of Nrf2, as well as promoting the expression of ARE-target genes. The activation of the Nrf2/ARE pathway by Rg1 was independent of disassociation with Keap1, but resulted from post-translational regulations. Knockdown of Nrf2 abolished all the protective changes of Rg1 in OGD/R-treated PC12 cells. Furthermore, Rg1 treatment significantly decreased the expression of miR-144, which downregulated Nrf2 production by targeting its 3'-untranlated region after OGD/R. Knockdown of Nrf2 had no effect on the expression of miR-144, suggesting that miR-144 was an upstream regulator of Nrf2. We revealed that there was a direct binding between Nrf2 and miR-144 in PC12 cells. Application of anti-miR-144 occluded the activation of the Nrf2/ARE pathway by Rg1 in OGD/R-treated PC12 cells. In tMCAO rats, administration of Rg1 (20 mg/kg) significantly alleviated ischemic injury, and activated Nrf2/ARE pathway. The protective effects of Rg1 were abolished by injecting of AAV-HIF-miR-144-shRNA into the predicted ischemic penumbra. In conclusion, our results demonstrate that Rg1 alleviates oxidative stress after I/R through inhibiting miR-144 activity and subsequently promoting the Nrf2/ARE pathway at the post-translational level.
Farm ponds, which are sometimes numerous and widely distributed in agricultural regions, have faced widespread degradation in recent decades. Although conservation strategies for these biodiversity ...hotspots have gradually increased, appropriate approaches for developing country contexts are lacking. Farm ponds provided hydrologic, biogeochemical, and socioeconomic benefits to southern China for thousands of years, but they are facing contemporary threats and management challenges, including (1) inadequate planning in terms of construction and conservation regulations; (2) rural nonpoint source and mini-point source pollution; (3) climate change induced abnormalities in the hydroperiod and disturbance to wildlife; (4) invasive species; and (5) inadequate social and political capacity to consider ecological conservation. Because farm ponds function as wetland complexes that are embedded within or integral to larger ecosystems, their conservation requires collaborative efforts over scales ranging from within-pond to regional. We highlight approaches that build public awareness and involve inventory maps as a basis. Policies that integrate top-down regulation and bottom-up engagement and emphasize sustainable management and utilization are recommended to ensure the effectiveness and continuous improvement of conservation programs. Techniques that involve interconnected smart sensors, volunteering and citizen science, and integrated process-based modeling are preferred when conducting comprehensive descriptions of the pond landscape, numerical assessments on their ecosystem services, and associated conservation cost analyses. Nature-based solutions are increasingly recognized as an important opportunity for coping with water-related crises. This paper presents the first synthetic perspective on the ecological roles of farm ponds in agriculturally dominated developing countries. The analytical framework and conservation suggestions are referential to sustainable rural development and the management of other small, scattered wetlands.
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•Farm ponds are small, scattered wetlands with a long history in southern China.•They provided hydrologic, biogeochemical, biodiversity and socioeconomic functions.•Their ever-increasing degradation threats and management challenges are evaluated.•Policies and approaches are presented to form a collaborative conservation framework.•It is a first synthetic analysis of ponds' ecological roles in developing countries.
Urban flooding has become an increasingly frequent and fatal natural hazard and numerical modeling techniques play a vital role in its prediction and management. We review urban flood numerical ...simulations by systematically summarizing the calculation methods of surface runoff, drainage systems, and coupled models. Following the review, accuracy and computational efficiency are found to be the two key areas hindering the quality improvement of urban flood models, so an investigation of the key trends in the improvement of model accuracy and computational efficiency is conducted. It is found that the 1D-2D coupling model, finite volume method, unstructured meshing method, and hybrid parallel computing applications are the most effective strategies. Furthermore, the complex coupling of models and the lack of validation data are still crucial challenges in the development of urban flood modeling. This result can be used as a guideline for hydrologists in choosing the proper method of urban flood numerical simulation according to the task.
•The methods and applicability of urban flood numerical simulation are summarized to provide support for related research.•We propose that the urban flood model can be improved in two aspects: accuracy and calculation speed model.•The future development of urban flood numerical simulation tends to be modular with a complex coupling model.
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