Dynamic neural networks for real-time water level predictions of sewerage systems-covering gauged and ungauged sites

[[abstract]]In this research, we propose recurrent neural networks (RNNs) to build a relationship between rainfalls and water level patterns of an urban sewerage system based on historical torrential rain/storm events. The RNN allows signals to propagate in both forward and backward directions, which offers the network dynamic memories. Besides, the information at the current time-step with a feedback operation can yield a time-delay unit that provides internal input information at the next time-step to effectively deal with time-varying systems. The RNN is implemented at both gauged and ungauged sites for 5-, 10-, 15-, and 20-min-ahead water level predictions. The results show that the RNN is capable of learning the nonlinear sewerage system and producing satisfactory predictions at the gauged sites. Concerning the ungauged sites, there are no historical data of water level to support prediction. In order to overcome such problem, a set of synthetic data, generated from a storm water management model (SWMM) under cautious verification process of applicability based on the data from nearby gauging stations, are introduced as the learning target to the training procedure of the RNN and moreover evaluating the performance of the RNN at the ungauged sites. The results demonstrate that the potential role of the SWMM coupled with nearby rainfall and water level information can be of great use in enhancing the capability of the RNN at the ungauged sites. Hence we can conclude that the RNN is an effective and suitable model for successfully predicting the water levels at both gauged and ungauged sites in urban sewerage systems.[[incitationindex]]SCI[[booktype]]紙

Flood Vulnerability and Risk Maps in Taipei City, Taiwan

This paper presents the process of constructing a flood risk map in Taipei City. The study calculates the social vulnerability index (SVI) for flooding at a district level, based on five factors including (1) female population (2) alone living elderly (3) low-income households (4) household income and (5) house-hold possessions. The index is determined according to the factor ratios in a district comparing to the statistical average across Taipei City. By combining the SVI with spatial varied flood potential information simulated by a hydraulic model, the flood risk index is obtained for district level that has an area of about 0.2 km2. Results show that the flood risk in Taipei City changed from 2002 to 2010 due to changes in the demographic structure. During the period from 2002 to 2004, the most obvious change of flood risk occurred in the Wanhua district due to the increase in the ratio of household possessions, which escalated the vulnerability to flooding. Between 2005 and 2007, the ratio of household possessions dropped in the Nankang district such that the flood risk reduced mostly in the region

Effects of epinephrine on heart rate variability and cytokines in a rat sepsis model

Catecholamines have both anti-inflammatory and vasoactive properties. A decreased cardiac response to catecholamines has been associated with a high risk of death in sepsis and septic shock. The aim of this study was to investigate the effects of epinephrine (EPI) on heart rate variability and autonomic balance, as well as cytokine levels, in a rat sepsis model. Thirty-six male Sprague-Dawley rats were assigned to 4 experimental groups and 2 control groups of 6 rats each. The rats in the experimental groups were inoculated with a lipopolysaccharide (LPS, endotoxin) to establish a sepsis model. Group A received only LPS; group B received LPS, antecedent EPI and the nonselective beta-blocker propranolol; group C received LPS and antecedent EPI; and group D received LPS, antecedent EPI and the selective beta1-blocker esmolol. One control group received EPI and the other received saline placebo. Heart rate variability was analyzed and tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β) levels were measured. Measurements were carried out at baseline and 0, 0.5, 2, and 4 hours after LPS inoculation. There were significant differences in heart rate variability and cytokine levels between the groups, indicating that LPS infusion caused autonomic imbalance. Antecedent EPI significantly decreased the level of TNF-α in group C compared with group A in which TNF-α level peaked at 2 hours and then declined. Propranolol (group B) but not esmolol (group D) administration resulted in elevated TNF-α levels, comparable to those observed in group A. In conclusion, antecedent administration of EPI in a rat sepsis model inhibits the production of TNF-α possibly via the β2-adrenoreceptor

The Role of the p38 MAPK Signaling Pathway in High Glucose-Induced Epithelial-Mesenchymal Transition of Cultured Human Renal Tubular Epithelial Cells

Epithelial-mesenchymal transition of tubular epithelial cells, which is characterized by a loss of epithelial cell characteristics and a gain of ECM-producing myofibroblast characteristics, is an essential mechanism that is involved in tubulointerstitial fibrosis, an important component of the renal injury that is associated with diabetic nephropathy. Under diabetic conditions, p38 MAPK activation has been reported in glomeruli and mesangial cells; however, studies on p38 MAPK in TECs are lacking. In this study, the role of p38 MAPK in AP-1 activation and in the EMT in the human proximal tubular epithelial cell line (HK-2) under high glucose concentration conditions is investigated.A vector for small interfering RNA that targets p38 MAPK was constructed; the cells were then either transfected with p38 siRNA or pretreated with a chemical inhibitor of AP-1 and incubated with low glucose plus TGF-β1 or high glucose for 48 h. Cells that were not transfected or pretreated and were exposed to low glucose with or without TGF-β1 or high glucose for 48 h were considered to be the controls. We found that high glucose induced an increase in TGF-β1. And high glucose-induced p38 MAPK activation was inhibited by p38 siRNA (P<0.05). A significant decline in E-cadherin and CK expression and a notable increase in vimentin and α-SMA were detected when exposed to low glucose with TGF-β1 or high glucose, and a significant raise of secreted fibronectin were detected when exposed to high glucose; whereas these changes were reversed when the cells were treated with p38 siRNA or AP-1 inhibitor (P<0.05). AP-1 activity levels and Snail expression were up-regulated under high glucose conditions but were markedly down-regulated through knockdown of p38 MAPK with p38 siRNA or pretreatment with AP-1 inhibitor (P<0.05).This study suggests that p38 MAPK may play an important role in the high glucose-induced EMT by activating AP-1 in tubular epithelial cells

Nutrient supply in the Southern East China Sea after Typhoon Morakot

Author Posting. © Sears Foundation for Marine Research, 2013. This article is posted here by permission of Sears Foundation for Marine Research for personal use, not for redistribution. The definitive version was published in Journal of Marine Research 71 (2013): 133-149, doi:10.1357/002224013807343425.Recent studies show that typhoons have profound effects on phytoplankton assemblages along their tracks, but it is difficult to quantitatively estimate nutrient supply after a typhoon's passage due to a lack of nutrient information before and after the arrival of a typhoon. During the passage of Typhoon Morakot (July 22 to Aug. 26, 2009), we conducted pre- and post-typhoon field cruises to study nutrient supply in the Southern East China Sea (SECS). The results showed nitrate and phosphate supplies to the water column in the SECS after the typhoon's passage were 5.6 × 1011 g-N/day and 7.8 × 1010 g-P/day which were significantly higher than those before the typhoon occurred (nitrate supply = 1 × 109 g-N/day, phosphate supply = 1.6 × 108 g-P/day). We conclude from this data, and after consulting the available physical data, that the highest nitrate concentration was caused by strong upwelling and/or vertical mixing, and input of nutrient-replete terrestrial waters. The nitrate and phosphate input related to the passage of Typhoon Morakot can account for approximately 86% and 87% of summer nitrate and phosphate supplies to the southern East China Sea.This research was supported by the Top University Program and the National Science Council (NSC101-2116M-110- 001, NSC101-2611-M-110-015-MY3, NSC100-2119-M-110-003, NSC98-2611-M-019-014-MY3, NSC NSC98-2611-M-002-019-MY3) of Taiwan to C.-C. Hung, G.-C.Gong and S. Jan

Corrigendum to “Nutrient supply in the Southern East China Sea after Typhoon Morakot”

Author Posting. © Sears Foundation for Marine Research, 2013. This article is posted here by permission of Sears Foundation for Marine Research for personal use, not for redistribution. The definitive version was published in Journal of Marine Research 71 (2013): 451-452, doi:10.1357/002224013812587609

Biosafety of Non-Surface Modified Carbon Nanocapsules as a Potential Alternative to Carbon Nanotubes for Drug Delivery Purposes

BACKGROUND: Carbon nanotubes (CNTs) have found wide success in circuitry, photovoltaics, and other applications. In contrast, several hurdles exist in using CNTs towards applications in drug delivery. Raw, non-modified CNTs are widely known for their toxicity. As such, many have attempted to reduce CNT toxicity for intravenous drug delivery purposes by post-process surface modification. Alternatively, a novel sphere-like carbon nanocapsule (CNC) developed by the arc-discharge method holds similar electric and thermal conductivities, as well as high strength. This study investigated the systemic toxicity and biocompatibility of different non-surface modified carbon nanomaterials in mice, including multi-walled carbon nanotubes (MWCNTs), single-walled carbon nanotubes (SWCNTs), carbon nanocapsules (CNCs), and C ₆₀ fullerene (C ₆₀). The retention of the nanomaterials and systemic effects after intravenous injections were studied. METHODOLOGY AND PRINCIPAL FINDINGS: MWCNTs, SWCNTs, CNCs, and C ₆₀ were injected intravenously into FVB mice and then sacrificed for tissue section examination. Inflammatory cytokine levels were evaluated with ELISA. Mice receiving injection of MWCNTs or SWCNTs at 50 µg/g b.w. died while C ₆₀ injected group survived at a 50% rate. Surprisingly, mortality rate of mice injected with CNCs was only at 10%. Tissue sections revealed that most carbon nanomaterials retained in the lung. Furthermore, serum and lung-tissue cytokine levels did not reveal any inflammatory response compared to those in mice receiving normal saline injection. CONCLUSION: Carbon nanocapsules are more biocompatible than other carbon nanomaterials and are more suitable for intravenous drug delivery. These results indicate potential biomedical use of non-surface modified carbon allotrope. Additionally, functionalization of the carbon nanocapsules could further enhance dispersion and biocompatibility for intravenous injection