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A pilot study on remediation of muddy tidal flat using porous pile 全文
2017
Ryu, Sung-Hoon | Nakashita, Shinya | Lee, In-Cheol | Kim, Dong-Sun | Kim, Jong Ryol | Hibino, Tadashi | Yamamoto, Tamiji | Asaoka, Satoshi | Kim, Kyunghoi
In order to prove that porous piles are effective in remediating muddy tidal flat sediments and increasing the biomass, field experiments were carried out at the tidal flat of a brackish river located in Hiroshima City, Japan. Porous piles with a diameter of 16cm and height of 50cm were installed in the muddy sediment that covers the sand layer of the tidal flat. After installation, concentrations of dissolved oxygen in interstitial water in and around the porous piles increased to a maximum concentration of 6mg/l due to enhancement of the groundwater flow. The increase of dissolved oxygen in the interstitial water produced a decrease in the concentration of ammonia and an increase in the individual number of benthos at the porous pile site. From these results, we concluded that the porous pile is an effective technology for remediation of muddy tidal flats.
显示更多 [+] 显示较少 [-]Distribution and antimicrobial susceptibility of Vibrio species associated with zooplankton in coastal area of Korea 全文
2017
Yang, Ji Hye | Mok, Jong Soo | Jung, Yeoun Joong | Lee, Ka Jeong | Kwon, Ji Young | Park, Kunbawui | Moon, Seong Yong | Kwon, Soon Jae | Ryu, A Ra | Lee, Tea Seek
Vibrio parahaemolyticus and V. vulnificus are the most common pathogens causing seafood-borne illnesses in Korea. This study determines the abundance and antimicrobial resistance of pathogenic Vibrio species in seawater and zooplankton samples from the Geoje Island coast in Korea, which is an important area for coastal fisheries, the fishing industry, and tourism. The two Vibrio species were detected more in mesozooplankton samples than in seawater samples. V. parahaemolyticus isolates showed greater resistance than those of V. vulnificus for antimicrobials. Of V. parahaemolyticus isolates, 93.3% exhibited resistance to three or more antimicrobial agents. Conversely, more than 80% of V. vulnificus isolates showed susceptibility to all antimicrobials examined, with the exception of rifampicin. Our findings show that strong antimicrobial resistance of V. parahaemolyticus in the surveyed area was exposed to conventionally used antibiotics, therefore necessitating proper surveillance programs for the monitoring of antimicrobial resistance patterns in seawater bodies and aquatic animals.
显示更多 [+] 显示较少 [-]Ports and pests: Assessing the threat of aquatic invasive species introduced by maritime shipping activity in Cuba 全文
2017
O'Brien, Charleen E. | Johnston, Matthew W. | Kerstetter, David W.
Aquatic invasive species (AIS) are biological pollutants that cause detrimental ecological, economic, and human-health effects in their introduced communities. With increasing globalization through maritime trade, ports are vulnerable to AIS exposure via commercial vessels. The Cuban Port of Mariel is poised to become a competitive transshipment hub in the Caribbean and the intent of this study was to evaluate present and potential impacts AIS pose with the likely future increase in shipping activity. We utilized previous assessment frameworks and publicly accessible information to rank AIS by level of threat. Fifteen AIS were identified in Cuba and one, the Asian green mussel Perna viridis (Linnaeus, 1758), had repeated harmful economic impacts. Five species associated with trade partners of Port Mariel were considered potentially detrimental to Cuba if introduced through shipping routes. The results presented herein identify species of concern and emphasize the importance of prioritizing AIS prevention and management within Cuba.
显示更多 [+] 显示较少 [-]Response of the pearl oyster Pinctada margaritifera to cadmium and chromium: Identification of molecular biomarkers 全文
2017
Gueguen, Yannick | Denis, Saulnier | Adrien, Santini | Kevin, Magre | Pierre, Garen | Solène, Bernagout | Marine, Nohl | Patrick, Bouisset | Herehia, Helme | Serge, Planes | Gilles, Le Moullac
Response of the pearl oyster Pinctada margaritifera to cadmium and chromium: Identification of molecular biomarkers 全文
2017
Gueguen, Yannick | Denis, Saulnier | Adrien, Santini | Kevin, Magre | Pierre, Garen | Solène, Bernagout | Marine, Nohl | Patrick, Bouisset | Herehia, Helme | Serge, Planes | Gilles, Le Moullac
This study was designed to identify in the pearl oyster Pinctada margaritifera, used as a bio-accumulator, molecular biomarkers for the presence of heavy metals in the lagoon environment. Pearl oysters were exposed to 2 concentrations (1 and 10μgL−1) of cadmium (Cd) and chromium (Cr) compared to a control. Twelve target genes encoding proteins potentially involved in the response to heavy metal contamination with antioxidant, detoxification or apoptosis activities were selected. P. margaritifera accumulated Cd but not Cr, and mortality was related to the amount of Cd accumulated in tissues. In response to Cd-Cr contamination, metallothionein (MT) was significantly up-regulated by Cd-Cr at both concentrations, while 7 others (SOD, CAT, GPX, GSTO, GSTM, CASP, MDR) were down-regulated. Based on the development of these molecular tools, we propose that the pearl oyster, P. margaritifera, could be used as a sentinel species for heavy metal contamination in the lagoons of tropical ecosystems.
显示更多 [+] 显示较少 [-]Response of the pearl oyster Pinctada margaritifera to cadmium and chromium: Identification of molecular biomarkers 全文
2017
Gueguen, Yannick | Saulnier, Denis | Santini, Adrien | Magre, Kevin | Garen, Pierre | Bernagout, Solene | Nohl, Marine | Bouisset, Patrick | Helme, Herehia | Planes, Serge | Le Moullac, Gilles
This study was designed to identify in the pearl oyster Pinctada margaritifera, used as a bio-accumulator, molecular biomarkers for the presence of heavy metals in the lagoon environment. Pearl oysters were exposed to 2 concentrations (1 and 10 μg L− 1) of cadmium (Cd) and chromium (Cr) compared to a control. Twelve target genes encoding proteins potentially involved in the response to heavy metal contamination with antioxidant, detoxification or apoptosis activities were selected. P. margaritifera accumulated Cd but not Cr, and mortality was related to the amount of Cd accumulated in tissues. In response to Cd-Cr contamination, metallothionein (MT) was significantly up-regulated by Cd-Cr at both concentrations, while 7 others (SOD, CAT, GPX, GSTO, GSTM, CASP, MDR) were down-regulated. Based on the development of these molecular tools, we propose that the pearl oyster, P. margaritifera, could be used as a sentinel species for heavy metal contamination in the lagoons of tropical ecosystems.
显示更多 [+] 显示较少 [-]A facile and cost-effective method for removal of indoor airborne psychrotrophic bacterial and fungal flora based on silver and zinc oxide nanoparticles decorated on fibrous air filter 全文
2017
Pokhum, Chonlada | Intasanta, Varol | Yaipimai, Wittaya | Subjalearndee, Nakarin | Srisitthiratkul, Chutima | Pongsorrarith, Voraluck | Phanomkate, Nipon | Chawengkijwanich, Chamorn
In tropical countries, food and agricultural crops need to be kept cool to reduce spoilage and quality losses. Airborne psychrotrophic bacteria and fungi can cause adverse effects on food quality and consumers' health safety. The present study aimed to present a facile and cost-effective approach to remove airborne microbes from indoor air by employing silver (Ag) and zinc oxide (ZnO) to decorate fibrous air filters. A water-based anti-germ solution containing Ag/ZnO nanoparticles was first prepared using high-speed homogenization. Second, a commercially available washable non-woven air filter (thickness 50 mm) was coated by aerosol generated from the mixture using spray coating process. This facile method successfully led to homogeneous coating of active nanomaterials on the filter's surface as unveiled by scanning electron microscope (SEM) with energy dispersive X-ray spectroscopy (EDX). On laboratory scale, the Ag/ZnO air filter was shown to exhibit antibacterial effectiveness against Staphylococcus aureus and Escherichia coli under contact mode following an antibacterial standard method (AATCC 147-2011). Finally, the Ag/ZnO filter was assembled into a commercial air filtration system (670 × 820 × 1420 mm) containing two UVA light lamps (365 nm). The Ag/ZnO air-filtration unit was placed in a 45-m3 cold storage room (4–5 °C) for evaluation of airborne psychrotrophic microbial reduction efficiency. The developed Ag/ZnO air filter reduced the airborne psychrotrophic germs concentrations by ∼50% and its efficiency increased to ∼70% when combined with UVA illumination. Based on these results, a simple and low-cost ZnO/Ag air filter was successfully introduced as an effective strategy for removal of psychrotrophic microbes from indoor air.
显示更多 [+] 显示较少 [-]Impacts of Regional Transport on Particulate Matter Pollution in China: a Review of Methods and Results 全文
2017
Sun, Jinjin | Huang, Lin | Liao, Hong | Li, Jingyi | Hu, Jianlin
China has been suffering serious particulate matter (PM) pollution in recent decades. Local emission and regional transport both contribute to PM pollution. Determining the contributions of local emissions vs. regional transport to PM concentrations is crucial in making effective PM control policies. This paper reviews the recent research on the contributions of regional transport to PM pollution in four regions in China, i.e., the northern China, eastern China, southern China, and the western China, respectively. The major findings include (1) HYSPLIT is the most popular methods in studies in all regions and often is used in combination with the CA, PSCF, and CWT techniques to investigate the transport pathways and source origins; (2) during the relatively polluted period, transport contributes over 50% of the PM concentrations in Beijing, Shanghai, Hangzhou, Guangzhou, Hong Kong, and Chengdu. Regional transport is important for PM pollution in major cities of China; and (3) regional transport exhibits clear seasonal variations and long term trends. The findings have important implication for emission control programs in these regions.
显示更多 [+] 显示较少 [-]Intraspecific variations in responses to ocean acidification in two branching coral species 全文
2017
Sekizawa, Ayami | Uechi, Hikaru | Iguchi, Akira | Nakamura, Takashi | Kumagai, Naoki H. | Suzuki, Atsushi | Sakai, Keinan | Nojiri, Yukihiro
Ocean acidification is widely recognised to have a negative impact on marine calcifying organisms by reducing calcifications, but controversy remains over whether such organisms could cope with ocean acidification within a range of phenotypic plasticity and/or adapt to future acidifying ocean. We performed a laboratory rearing experiment using clonal fragments of the common branching corals Montipora digitata and Porites cylindrica under control and acidified seawater (lower pH) conditions (approximately 400 and 900μatm pCO2, respectively) and evaluated the intraspecific variations in their responses to ocean acidification. Intra- and interspecific variations in calcification and photosynthetic efficiency were evident according to both pCO2 conditions and colony, indicating that responses to acidification may be individually variable at the colony level. Our results suggest that some corals may cope with ocean acidification within their present genotypic composition by adaptation through phenotypic plasticity, while others may be placed under selective pressures resulting in population alteration.
显示更多 [+] 显示较少 [-]Chemical composition and source apportionment of PM2.5 – A case study from one year continuous sampling in the Chang-Zhu-Tan urban agglomeration 全文
2017
Tang, Xiangbo | Chen, Xiaohong | Tian, Yun
To understand the characteristics and source of atmospheric PM2.5 in Chang-Zhu-Tan urban agglomeration, PM2.5 samples were simultaneously collected at 11 monitoring sites within three cities of Changsha, Zhuzhou and Xiangtan from September 2013 to August 2014. Spatial and temporal variations of PM2.5 mass concentration and chemical compositions were analyzed based on the average values over the measurement sites in a specific urban area, including a comparison of PM2.5 at urban and urban background sites. Source apportionment was performed by PMF 5.0 (positive matrix factorization) model and potential source area affecting PM2.5 mass concentration was simulated using CWT (concentration-weighted trajectory analysis) analysis. The result showed the seasonal variation of PM2.5 mass concentration followed the order of winter > autumn > spring > summer. The OC/EC ratio in each season and each city were greater than 4.0, secondary inorganic ions accounted for at least 91% of the total water soluble inorganic ion concentration, presenting obvious secondary pollution characteristics. Coal combustion and vehicle emissions were two major sources of PM2.5 in all three cities, which accounted for about 35 percent and nearly 26 percent of contributions respectively. In addition, industrial emission and biomass burning were also significant sources in Changsha, while urban dust and biomass burning were significant sources in Zhuzhou and Xiangtan. Chang-zhu-tan urban agglomeration was the main source area of its PM2.5 and easy to form overlapping pollution areas. Meanwhile, northern neighboring city Yueyang and western bordering region Pingxiang also had a certain transmission influence on the formation of PM2.5.
显示更多 [+] 显示较少 [-]Distribution of organic contamination of sediments from Ichkeul Lake and Bizerte Lagoon, Tunisia 全文
2017
Ben Salem, Fida | Ben Said, Olfa | Mahmoudi, Ezzeddine | Duran, Robert | Monperrus, Mathilde
Analyses of organochlorine pesticides (OCPs), polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and butyl tins (BuSn) were conducted on sediments from Ichkeul Lake-Bizerte Lagoon watershed (Tunisia). A total of 59 compounds (16 PAHs, 12 PCBs, 22 OCPs and 9 BuSn) were measured in 40 surface sediment samples collected during two campaigns. High concentrations of total PAHs were identified in the lagoon ranging from 122 to 19600ng·g−1. Several OCPs, including endrin, dieldrin, and lindane (Hexachlorocyclohexane or HCH or BHC) were found in high concentrations in Ichkeul Lake, ranging from 28 to 2012ngg−1. PAHs and OCPs varied seasonally, in response to the complex hydrology of the watershed. The concentrations of total PCBs ranged between 0.04 and 10.653ngg−1 and suggests low total PCBs sediment contamination, when compared to most international criteria. Total BuSn concentrations range between 67 and 526ng·g−1, which are relatively low when compared to most international criteria and ecological risk assessments. This is the first study of organic contamination in Ichkeul Lake (RAMSAR and UNESCO World Heritage site).
显示更多 [+] 显示较少 [-]Potential impacts of shipping noise on marine mammals in the western Canadian Arctic 全文
2017
Halliday, William D. | Insley, Stephen J. | Hilliard, R Casey | de Jong, Tyler | Pine, Matthew K.
As the Arctic warms and sea ice decreases, increased shipping will lead to higher ambient noise levels in the Arctic Ocean. Arctic marine mammals are vulnerable to increased noise because they use sound to survive and likely evolved in a relatively quiet soundscape. We model vessel noise propagation in the proposed western Canadian Arctic shipping corridor in order to examine impacts on marine mammals and marine protected areas (MPAs). Our model predicts that loud vessels are audible underwater when >100km away, could affect marine mammal behaviour when within 2km for icebreakers vessels, and as far as 52km for tankers. This vessel noise could have substantial impacts on marine mammals during migration and in MPAs. We suggest that locating the corridor farther north, use of marine mammal observers on vessels, and the reduction of vessel speed would help to reduce this impact.
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