Polychlorinated biphenyls (PCBs) and hexachlorobenzene (HCB) in the equatorial Indian Ocean: Temporal trend, continental outflow and air-water exchange

Nineteen pairs of air and seawater samples collected from the equatorial Indian Ocean onboard the Shiyan I from 4/2011 to 5/2011 were analyzed for PCBs and HCB. Gaseous concentrations of Sigma(ICES)PCBs (ICES: International Council for the Exploration of the Seas) and HCB were lower than previous data over the study area. Air samples collected near the coast had higher levels of PCBs relative to those collected in the open ocean, which may be influenced by proximity to source regions and air mass origins. Dissolved concentrations of Sigma(ICES)PCBs and HCB were 1.4-14 pg L-1 and 0.94-13 pg L-1, with the highest concentrations in the sample collected from Strait of Malacca. Fugacity fractions suggest volatilization of PCBs and HCB from the seawater to air during the cruise, with fluxes of 0.45-34 ng m(-2) d(-1) and 0.36-18 ng m(-2) d(-1), respectively. (c) 2014 Elsevier Ltd. All rights reserved.Nineteen pairs of air and seawater samples collected from the equatorial Indian Ocean onboard the Shiyan I from 4/2011 to 5/2011 were analyzed for PCBs and HCB. Gaseous concentrations of Sigma(ICES)PCBs (ICES: International Council for the Exploration of the Seas) and HCB were lower than previous data over the study area. Air samples collected near the coast had higher levels of PCBs relative to those collected in the open ocean, which may be influenced by proximity to source regions and air mass origins. Dissolved concentrations of Sigma(ICES)PCBs and HCB were 1.4-14 pg L-1 and 0.94-13 pg L-1, with the highest concentrations in the sample collected from Strait of Malacca. Fugacity fractions suggest volatilization of PCBs and HCB from the seawater to air during the cruise, with fluxes of 0.45-34 ng m(-2) d(-1) and 0.36-18 ng m(-2) d(-1), respectively. (c) 2014 Elsevier Ltd. All rights reserved

Frontier ocean thermal/power and solar PV systems for transformation towards net-zero communities

Ocean thermal and power energy systems are promising driving forces for seashore coastal communities to achieve net-zero energy/emission target, whereas energy planning and management on ocean thermal/power and distributed building integrated photovoltaic (BIPV) systems are critical, in terms of serving scale sizing and planning on geographical locations of district building community, and cycling aging of battery storages. However, the current literature provides insufficient studies on this topic. This study aims to address this research gap by transforming towards zero-energy coastal communities from the district level in subtropical regions, including centralised seawater-based chiller systems, distributed BIPVs and coastal oscillating water column technologies, as well as multi-directional Vehicle-to-Building energy interaction paradigms. Advanced energy management strategies were explored to enhance renewable penetration, import cost-saving, and deceleration of battery cycling aging, in response to relative renewable-to-demand difference, off-peak grid information with low price, and real-time battery cycling aging. Furthermore, in accordance with the power generation characteristic of two wave stations (i.e., Kau Yi Chau (KYC) and West Lamma Channel (WLC)) in Hong Kong, energy system planning and structural configurations of the coastal community were proposed and comparatively studied for the multi-criteria performance improvement. Research results showed that, compared to an air-cooled chiller, the water-cooled chiller with a much higher Coefficient of Performance (COP) will reduce the energy consumption of cooling systems, leading to a decrease in total electric demand from 134 to 126.5 kWh/m2·a. The scale for the net-zero energy district community with distributed BIPVs and oscillating water column was identified as 5 high-rise office buildings, 5 high-rise hotel buildings, 150 private cars and 120 public shuttle buses. Furthermore, the geographical location planning scheme on the Case 1 (office buildings close to KYC, and hotel buildings close to WLC) was identified as the most economically and environmentally feasible scheme, whereas the Case 3 (only office buildings are planned close to all power supply with oscillating water column) showed the highest flexibility in grid electricity shifting, together with the highest value of equivalent battery relative capacity. This study demonstrates techno-economic performances and energy flexibility of frontier ocean energy technologies in a coastal community under advanced energy management strategies, together with technical guidance for serving scale sizing and planning on geographical locations. The research results highlight the prospects and promote frontier ocean energy techniques in subtropical coastal regions.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care. Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Design & Construction Managemen

Investigating Effects of Heterogeneity and Fracture Distribution on Two-Phase Flow in Fractured Reservoir with adaptive time strategy

Modeling of fluid flow in porous media is a pillar in geoscience applications. Previous studies have revealed that heterogeneity and fracture distribution have considerable influence on fluid flow. In this work, a numerical investigation of two-phase flow in heterogeneous fractured reservoir is presented. First, the discrete fracture model is implemented based on a hybrid-dimensional modeling approach, and an equivalent continuum approach is integrated in the model to reduce computational cost. A multilevel adaptive strategy is devised to improve the numerical robustness and efficiency. It allows up to 4-levels adaption, where the adaptive factors can be modified flexibly. Then, numerical tests are conducted to verify the the proposed method and to evaluate its performance. Different adaptive strategies with 3-levels, 4-levels and fixed time schemes are analyzed to evaluate the computational cost and convergence history. These evaluations demonstrate the merits of this method compared to the classical method. Later, the heterogeneity in permeability field, as well as initial saturation, is modeled in a layer model, where the effect of layer angle and permeability on fluid flow is investigated. A porous medium containing multiple length fractures with different distributions is simulated. The fine-scale fractures are upscaled based on the equivalent approach, while the large-scale fractures are retained. The conductivity of the rock matrix is enhanced by the upscaled fine-scale fractures. The difference of hydraulic property between homogeneous and heterogeneous situations is analyzed. It reveals that the heterogeneity may influence fluid flow and production, while these impacts are also related to fracture distribution and permeability.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Delft Institute of Applied Mathematic

Nanosecond pulsed laser irradiation induced hierarchical micro/nanostructures on Zr-based metallic glass substrate

A large effective surface area is beneficial to enhance the applications of metallic glasses (MGs) in heterogeneous catalysis and biomedical engineering. For the purpose of increasing effective surface area, in this study, hierarchical micro/nanostructures were fabricated on a Zr-based MG substrate by nanosecond pulsed laser irradiation. Experimental results indicated that a layer of micron-scale laser pulse tracks covered by a cotton-like MG thin film with nanometer-scale microstructure was formed in the laser irradiated region. This hierarchical micro/nanostructures retained amorphous characteristic and exhibited uniform element distribution. Its formation mechanism was investigated by analyzing the laser irradiation process and morphologies. Nanoindentation results indicated that the cotton-like MG thin film was very loose and soft compared to the as-cast MG substrate, showing different plastic deformation behavior. Results from this study indicate that nanosecond pulsed laser irradiation is an effective method to generate hierarchical micro/nanostructures on MG substrates, which can increase their effective surface areas and improve their potential applications as biomaterials and catalysts. (C) 2016 Elsevier Ltd. All rights reserved

Global effects of subchronic treatment of microcystin-LR on rat splenetic protein levels

Microcystin-LR (MCLR), released by toxic cyanobacterial blooms, has received worldwide concerns in the past decades for its hepatotoxicity. Recent studies show that microcystins (MCs) can be accumulated in immune organs and exert notable immunotoxicity. In order to better understand cellular responses in immune tissues disrupted by MCLR treatment, this work mainly focuses on the spleen impairments of rats. After a subchronic 50 d exposure (1 or 10 mu g/kg body weight per day), spleen index, MCLR accumulation, histological change and plasma lysozyme activity were detected in MCLR-treated rat. Results indicated that prolonged exposure of MCLR led to toxin accumulation and caused severe damage in spleen of rats, and eventually impaired the immune functions. To further our understanding of the toxic effects of MCLR on the spleen and the mechanisms behind it, a proteomic analysis was performed to determine the global effects of MCLR on splenetic protein levels. In total, 48 proteins were identified and showed a significant increase or decrease in abundance compared to the control after MCLR exposure. These proteins are mainly involved in immune response, oxidative stress, energetic metabolism and the cytoskeleton assembly, indicating that MCLR exerts complex toxic effects in rat spleen and jointly results in immunotoxicity. (C) 2012 Elsevier B.V. All rights reserved.Microcystin-LR (MCLR), released by toxic cyanobacterial blooms, has received worldwide concerns in the past decades for its hepatotoxicity. Recent studies show that microcystins (MCs) can be accumulated in immune organs and exert notable immunotoxicity. In order to better understand cellular responses in immune tissues disrupted by MCLR treatment, this work mainly focuses on the spleen impairments of rats. After a subchronic 50 d exposure (1 or 10 mu g/kg body weight per day), spleen index, MCLR accumulation, histological change and plasma lysozyme activity were detected in MCLR-treated rat. Results indicated that prolonged exposure of MCLR led to toxin accumulation and caused severe damage in spleen of rats, and eventually impaired the immune functions. To further our understanding of the toxic effects of MCLR on the spleen and the mechanisms behind it, a proteomic analysis was performed to determine the global effects of MCLR on splenetic protein levels. In total, 48 proteins were identified and showed a significant increase or decrease in abundance compared to the control after MCLR exposure. These proteins are mainly involved in immune response, oxidative stress, energetic metabolism and the cytoskeleton assembly, indicating that MCLR exerts complex toxic effects in rat spleen and jointly results in immunotoxicity. (C) 2012 Elsevier B.V. All rights reserved

Abundance and Diversity of Soybean-Nodulating Rhizobia in Black Soil Are Impacted by Land Use and Crop Management

To investigate the effects of land use and crop management on soybean rhizobial communities, 280 nodule isolates were trapped from 7 fields with different land use and culture histories. Besides the known Bradyrhizobium japonicum, three novel genospecies were isolated from these fields. Grassland (GL) maintained a higher diversity of soybean bradyrhizobia than the other cultivation systems. Two genospecies (Bradyrhizobium spp. I and III) were distributed widely in all treatments, while Bradyrhizobium sp. II was found only in GL treatment. Cultivation with soybeans increased the rhizobial abundance and diversity, except for the soybean monoculture (S-S) treatment. In monoculture systems, soybeans favored Bradyrhizobium sp. I, while maize and wheat favored Bradyrhizobium sp. III. Fertilization decreased the rhizobial diversity indexes but did not change the species composition. The organic carbon (OC) and available phosphorus (AP) contents and pH were the main soil parameters positively correlated with the distribution of Bradyrhizobium spp. I and II and Bradyrhizobium japonicum and negatively correlated with Bradyrhizobium sp. III. These results revealed that different land uses and crop management could not only alter the diversity and abundance of soybean rhizobia, but also change interactions between rhizobia and legume or nonlegume plants, which offered novel information about the biogeography of rhizobia.To investigate the effects of land use and crop management on soybean rhizobial communities, 280 nodule isolates were trapped from 7 fields with different land use and culture histories. Besides the known Bradyrhizobium japonicum, three novel genospecies were isolated from these fields. Grassland (GL) maintained a higher diversity of soybean bradyrhizobia than the other cultivation systems. Two genospecies (Bradyrhizobium spp. I and III) were distributed widely in all treatments, while Bradyrhizobium sp. II was found only in GL treatment. Cultivation with soybeans increased the rhizobial abundance and diversity, except for the soybean monoculture (S-S) treatment. In monoculture systems, soybeans favored Bradyrhizobium sp. I, while maize and wheat favored Bradyrhizobium sp. III. Fertilization decreased the rhizobial diversity indexes but did not change the species composition. The organic carbon (OC) and available phosphorus (AP) contents and pH were the main soil parameters positively correlated with the distribution of Bradyrhizobium spp. I and II and Bradyrhizobium japonicum and negatively correlated with Bradyrhizobium sp. III. These results revealed that different land uses and crop management could not only alter the diversity and abundance of soybean rhizobia, but also change interactions between rhizobia and legume or nonlegume plants, which offered novel information about the biogeography of rhizobia

Treatment performance of integrated vertical-flow constructed wetland plots for domestic wastewater

Two pilot-scale integrated vertical-flow constructed wetlands (IVCWs) in parallel were employed to evaluate domestic wastewater treatment performance at a loading rate of 250 mm/d, and each was planted with two different plant species: Typha orientalis and Arundo donax var. versicolor (Plot 1), and Canna indica and Pontederia cordata (Plot 2). The results showed that different plant combinations offered no significant improvement in pollutant removal efficiencies (p > 0.05). The mean removal efficiencies associated with Plot 1 and Plot 2 were 59.9% vs. 62.8% for COD, 15.0% vs. 12.8% for TN, and 52.0% vs. 51.1% for TP, respectively. The mean mass removal rates (g m(-2) d(-1)) were 44.3 vs. 46.4 for COD, 1.27 vs. 1.08 for TN, and 0.393 vs. 0.386 for TP, respectively. It was noted that nitrification was the limited step for TN removal. Dissolved oxygen (DO) in the wetland beds was a dependence factor for the removals of organic matter and nitrogen, and it could be used to predict removal rates of chemical oxygen demand (COD) and total nitrogen (TN). Low temperatures had a negative impact on nutrient removals, especially for TN. (C) 2012 Elsevier B.V. All rights reserved.Two pilot-scale integrated vertical-flow constructed wetlands (IVCWs) in parallel were employed to evaluate domestic wastewater treatment performance at a loading rate of 250 mm/d, and each was planted with two different plant species: Typha orientalis and Arundo donax var. versicolor (Plot 1), and Canna indica and Pontederia cordata (Plot 2). The results showed that different plant combinations offered no significant improvement in pollutant removal efficiencies (p > 0.05). The mean removal efficiencies associated with Plot 1 and Plot 2 were 59.9% vs. 62.8% for COD, 15.0% vs. 12.8% for TN, and 52.0% vs. 51.1% for TP, respectively. The mean mass removal rates (g m(-2) d(-1)) were 44.3 vs. 46.4 for COD, 1.27 vs. 1.08 for TN, and 0.393 vs. 0.386 for TP, respectively. It was noted that nitrification was the limited step for TN removal. Dissolved oxygen (DO) in the wetland beds was a dependence factor for the removals of organic matter and nitrogen, and it could be used to predict removal rates of chemical oxygen demand (COD) and total nitrogen (TN). Low temperatures had a negative impact on nutrient removals, especially for TN. (C) 2012 Elsevier B.V. All rights reserved

Ensifer alkalisoli sp nov isolated from root nodules of Sesbania cannabina grown in saline-alkaline soils

A group of Sesbania cannabina rhizobia belonging to four recA genotypes of a novel group was further characterized in comparison with the related Ensifer species. They showed 98.2 to 99.9% similarities among themselves and 92.9 to 93.3% similarities with the most related strain Ensifer sojae CCBAU 05684(T) in multilocus sequence analysis of recA, atpD and gin/I. The genome average nucleotide identity values between representative strain YIC4027(T) and the type strains of its closely related species were 81.6 to 88.9%. Identical symbiotic gene (nodA, nodC and nifH) sequences highly similar with those in other Sesbania-nodulating strains (Rhizobium sp. SIN-1, Neorhizobium huautlense SO2(T), Ensifer saheli ORS609(T) and Rhizobium sp. IRBG74) were detected. The representative strain YIC4027(T) could form effective nodules on its original host Sesbania cannabina, but not on Sophora flavescens, Trifolium repens, Glycine max, Glycyrrhiza uralensis, Phaseolus vulgaris or Medicago sativa. The use of lactulose as sole carbon source, possession of C-13:0 2-OH, C-13:1 at 12-13, C-15:1 iso omega 9c, C-17:0 anteiso and C-18:0 iso and absence of C-14:0 anteiso, C-15:0 anteiso and C-18:0 3-OH in fatty acids distinguished the strain YIC4027(T) from the type strains of its closely related species. Based on all the analyses mentioned above, we propose a novel species Ensifer alkalisoli sp. nov. and designate YIC4027(T) (=HAMBI 3655(T)=LMG 29286(T)) as the type strain. The genome size of YIC4027(T) is 5.97 Mbp, comprising 5588 predicted genes, and the DNA G+C content is 62.2 mol%

Microcystin-LR stabilizes c-myc protein by inhibiting protein phosphatase 2A in HEK293 cells

Microcystin-LR is the most toxic and the most frequently encountered toxin produced by the cyanobacteria in the contaminated aquatic environment. Previous studies have demonstrated that Microcystin-LR is a potential carcinogen for animals and humans, and the International Agency for Research on Cancer has classified Microcystin-LR as a possible human carcinogen. However, the precise molecular mechanisms of Microcystin-LR-induced carcinogenesis remain a mystery. C-myc is a proto-oncogene, abnormal expression of which contributes to the tumor development. Although several studies have demonstrated that Microcystin-LR could induce c-myc expression at the transcriptional level, the exact connection between Microcystin-LR toxicity and c-myc response remains unclear. In this study, we showed that the c-myc protein increased in HEK293 cells after exposure to Microcystin-LR. Coexpression of protein phosphatase 2A and two stable c-myc protein point mutants (either c-myc(T58A) or c-myc(562A)) showed that Microcystin-LR increased c-myc protein level mainly through inhibiting protein phosphatase 2A activity which altered the phosphorylation status of serine 62 on c-myc. In addition, we also showed that Microcystin-LR could increase c-myc promoter activity as revealed by luciferase reporter assay. And the TATA box for P1 promoter of c-myc might be involved. Our results suggested that Microcystin-LR can stimulate c-myc transcription and stabilize c-myc protein, which might contribute to hepatic tumorigenesis in animals and humans. (C) 2014 Elsevier Ireland Ltd. All rights reserved.Microcystin-LR is the most toxic and the most frequently encountered toxin produced by the cyanobacteria in the contaminated aquatic environment. Previous studies have demonstrated that Microcystin-LR is a potential carcinogen for animals and humans, and the International Agency for Research on Cancer has classified Microcystin-LR as a possible human carcinogen. However, the precise molecular mechanisms of Microcystin-LR-induced carcinogenesis remain a mystery. C-myc is a proto-oncogene, abnormal expression of which contributes to the tumor development. Although several studies have demonstrated that Microcystin-LR could induce c-myc expression at the transcriptional level, the exact connection between Microcystin-LR toxicity and c-myc response remains unclear. In this study, we showed that the c-myc protein increased in HEK293 cells after exposure to Microcystin-LR. Coexpression of protein phosphatase 2A and two stable c-myc protein point mutants (either c-myc(T58A) or c-myc(562A)) showed that Microcystin-LR increased c-myc protein level mainly through inhibiting protein phosphatase 2A activity which altered the phosphorylation status of serine 62 on c-myc. In addition, we also showed that Microcystin-LR could increase c-myc promoter activity as revealed by luciferase reporter assay. And the TATA box for P1 promoter of c-myc might be involved. Our results suggested that Microcystin-LR can stimulate c-myc transcription and stabilize c-myc protein, which might contribute to hepatic tumorigenesis in animals and humans. (C) 2014 Elsevier Ireland Ltd. All rights reserved

Differential effect of NMDA receptor antagonist in the nucleus accumbens on reconsolidation of morphine -related positive and aversive memory in rats

Dysfunctional reconsolidation processes may help drug memories resist extinction and contribute to high rate of relapse. Reconsolidation of drug memory is mainly affected by the appetitive and aversive emotional experiences associated with an addictive drug. The nucleus accumbens has been shown to mediate the reconsolidation of positive emotional addictive memory, but its role in negative emotional addictive memory remains elusive. In the present study, we used morphine-induced CPP (m-CPP) and morphine-naloxone induced conditioned place aversion (m-CPA) to investigate the role of N-methyl-D-aspartate (NMDA) receptors within the nucleus accumbens on reconsolidation of emotional drug memory. Here we demonstrate that infusion of the NMDA receptor antagonist, D-(-)-2 amino-5-phosphonopentanoic acid ((D)-APV). into the nucleus accumbens before memory reactivation disrupts the reconsolidation of m-CPP, but does not affect m-CPA. The effect on m-CPP reconsolidation depended on memory reactivation: (D)-APV infusion had no effect in the absence of reactivation. The findings show that the glutamatergic NMDA receptor in nucleus accumbens mechanisms involved in reconsolidating aversive and positive morphine-associated memories can be dissociated. (C) 2011 Elsevier B.V. All rights reserved