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Clam predator protection is effective and necessary for food production Полный текст
2015
Shellfish aquaculture is a widely practiced way of producing food for human consumption in coastal areas. When farming intertidal clams, farmers commonly protect young seedling clams from predatory losses by covering farmed plots with netting or screening. Recent discussion of the effectiveness of protective nets or screens and their environmental effects has raised questions concerning the utility of the practice. We provide data based on a review of more than 35 peer-reviewed articles, as well as our own research that demonstrates the efficacy of predator protection for clam farms in various habitats around the world. In addition, we evaluate the effects of screening on temperature, and comment on ancient practices of clam gardening as conducted in the Pacific Northwest.
Показать больше [+] Меньше [-]A review of standards and guidelines set by international bodies for the parameters of indoor air quality Полный текст
2015
Abdul–Wahab, Sabah Ahmed | Chin Fah En, Stephen | Elkamel, Ali | Ahmadi, Lena | Yetilmezsoy, Kaan
Standards and guidelines as defined by various international agencies are employed by the researchers to evaluate an acceptable quality of air in indoor as well as outdoor environments. The main objective of this paper is to establish a comprehensive review of Indoor Air Quality (IAQ) guidelines and other standard values that are implemented currently. For this purpose, the present study summarizes the main standards and guidelines related to key indoor air pollutants and levels of thermal comfort developed by different agencies around the world. These agencies and organizations include the American Society of Heating, Refrigerating and Air– Conditioning Engineers (ASHRAE), the Hong Kong Environmental Protection Department (HKEPD), the World Health Organization (WHO), and the National Health and Medical Research Council (NHMRC) of Australia. Common indoor air pollutants that are found to frequently affect indoor populations are, carbon dioxide (CO2), nitrogen dioxide (NO2), formaldehyde (HCHO), carbon monoxide (CO), sulfur dioxide (SO2), and particulate matter in sizes <2.5 and 10 μm (PM2.5 and PM10, respectively). Other factors that affect IAQ are the moisture content of the air (i.e., relative humidity), the temperature of the indoor air, and the air speed or movement. Sick building syndrome (SBS) describes the various interactions between these major pollutants and factors of IAQ that cause adverse health effects on humans. In addition, this paper reviews various stipulated guidelines that are implemented by the relevant regulatory institutions and agencies to prevent SBS.
Показать больше [+] Меньше [-]Sampling frequency of ciliated protozoan microfauna for seasonal distribution research in marine ecosystems Полный текст
2015
Xu, Henglong | Yong, Jiang | Xu, Guangjian
Sampling frequency is important to obtain sufficient information for temporal research of microfauna. To determine an optimal strategy for exploring the seasonal variation in ciliated protozoa, a dataset from the Yellow Sea, northern China was studied. Samples were collected with 24 (biweekly), 12 (monthly), 8 (bimonthly per season) and 4 (seasonally) sampling events. Compared to the 24 samplings (100%), the 12-, 8- and 4-samplings recovered 94%, 94%, and 78% of the total species, respectively. To reveal the seasonal distribution, the 8-sampling regime may result in >75% information of the seasonal variance, while the traditional 4-sampling may only explain <65% of the total variance. With the increase of the sampling frequency, the biotic data showed stronger correlations with seasonal variables (e.g., temperature, salinity) in combination with nutrients. It is suggested that the 8-sampling events per year may be an optimal sampling strategy for ciliated protozoan seasonal research in marine ecosystems.
Показать больше [+] Меньше [-]Scallop larvae hatcheries as source of bacteria carrying genes encoding for non-enzymatic phenicol resistance Полный текст
2015
Miranda, Claudio D. | Rojas, Rodrigo | Geisse, Julieta | Romero S., Jaime | González-Rocha, Gerardo
Scallop larvae hatcheries as source of bacteria carrying genes encoding for non-enzymatic phenicol resistance Полный текст
2015
Miranda, Claudio D. | Rojas, Rodrigo | Geisse, Julieta | Romero S., Jaime | González-Rocha, Gerardo
The main aim of the study was to evaluate the role of scallop hatcheries as source of the floR and cmlA genes. A number of 133 and 121 florfenicol-resistant strains were isolated from scallop larval cultures prior to their transfer to seawater and from effluent samples from 2 commercial hatcheries and identified by 16S rRNA gene sequence analysis, observing a predominance of the Pseudomonas, Pseudoalteromonas and Halomonas genera and exhibiting an important incidence of co-resistance to streptomycin, oxytetracycline and co-trimoxazole. A high percentage of strains from both hatcheries carried the floR gene (68.4% and 89.3% of strains), whereas a lower carriage of the cmlA gene was detected (27.1% and 54.5% of strains). The high prevalence of floR-carrying bacteria in reared scallop larvae and hatchery effluents contributes to enrich the marine resistome in marine environments, prompting the need of a continuous surveillance of these genes in the mariculture environments.
Показать больше [+] Меньше [-]Scallop larvae hatcheries as source of bacteria carrying genes encoding for non-enzymatic phenicol resistance Полный текст
2015
Miranda, Claudio D. | Rojas, Rodrigo | Geisse, Julieta | Romero Ormazábal, Jaime | González Rocha, Gerardo
Artículo de publicación ISI | The main aim of the study was to evaluate the role of scallop hatcheries as source of the floR and cmIA genes. A number of 133 and 121 florfenicol-resistant strains were isolated from scallop larval cultures prior to their transfer to seawater and from effluent samples from 2 commercial hatcheries and identified by 16S rRNA gene sequence analysis, observing a predominance of the Pseudomonas, Pseudoalteromonas and Halomonas genera and exhibiting an important incidence of co-resistance to streptomycin, oxytetracycline and co-trimoxazole. A high percentage of strains from both hatcheries carried the floR gene (68.4% and 89.3% of strains), whereas a lower carriage of the cmIA gene was detected (27.1% and 54.5% of strains). The high prevalence of floR-carrying bacteria in reared scallop larvae and hatchery effluents contributes to enrich the marine resistome in marine environments, prompting the need of a continuous surveillance of these genes in the mariculture environments. | Science and Technology National Council (CONICYT) of Chile 1090793
Показать больше [+] Меньше [-]Modeling the dispersion of viable and total Escherichia coli cells in the artificial semi-enclosed bathing area of Santa Marinella (Latium, Italy) Полный текст
2015
Bonamano, S. | Madonia, A. | Borsellino, C. | Stefanì, C. | Caruso, G. | De Pasquale, F. | Piermattei, V. | Zappalà, G. | Marcelli, M.
Coastal areas are strongly affected by episodes of fecal contamination due to polluted water inflows from inadequately treated sewages. The present study aims to investigate the dispersion of Escherichia coli in the artificial semi-enclosed bathing area of Santa Marinella (Latium, Italy) through in situ samplings carried out in summer 2012 and the application of a dynamic model. Collected samples were analyzed by the Culture-Based technique and the Fluorescent Antibody method in order to estimate both the viable culturable cells and the total E. coli population, respectively. The in situ datasets were used to test the proposed modeling approach and simulate the behavior of bacteria as particles subjected, or not, to decay. Next, the flushing time and the computation of the Microbiological Potential Risk Area allowed the evaluation of the contribution of physical and biological processes to coliform dispersion and the related potential risk for bathers.
Показать больше [+] Меньше [-]Soil Pollution Due to Irrigation with Arsenic-Contaminated Groundwater: Current State of Science Полный текст
2015
Gillispie, Elizabeth C. | Sowers, Tyler D. | Duckworth, Owen W. | Polizzotto, Matthew L.
Food with elevated arsenic concentrations is becoming widely recognized as a global threat to human health. This review describes the current state of knowledge of soil pollution derived from irrigation with arsenic-contaminated groundwater, highlighting processes controlling arsenic cycling in soils and resulting arsenic impacts on crop and human health. Irrigation practices utilized for both flooded and upland crops have the potential to load arsenic to soils, with a host of environmental and anthropogenic factors ultimately determining the fate of arsenic. Continual use of contaminated groundwater for irrigation may result in soils with concentrations sufficient to create dangerous arsenic concentrations in the edible portions of crops. Recent advances in low-cost water and soil management options show promise for mitigating arsenic impacts of polluted soils. Better understanding of arsenic transfer from soil to crops and the controls on long-term soil arsenic accumulation is needed to establish effective arsenic mitigation strategies within vulnerable agronomic systems.
Показать больше [+] Меньше [-]Spatial outlier detection in the PM10 monitoring network of Normandy (France) Полный текст
2015
Michel, Bobbia | Michel, Misiti | Yves, Misiti | Jean-Michel, Poggi | Bruno, Portier
We consider hourly PM10 measurements from 22 monitoring stations located in Basse–Normandie and Haute–Normandie regions (France) and also in the neighboring regions. All considered monitoring stations are either urban background stations or rural ones. The paper focuses on the statistical detection of outliers of the hourly PM10 concentrations from a spatial point of view. The general strategy uses a jackknife type approach and is based on the comparison of the actual measurement with some robust spatial prediction. Two spatial predictions are considered: the first one is based on the median of the concentrations of the closest neighboring stations which directly consider weighted concentrations while the second one is based on kriging increments, instead of more traditional pseudo–innovations. The two methods are applied to the PM10 monitoring network in Normandy and are fully implemented by Air Normand (the official association for air quality monitoring in Haute–Normandie) in the Measurements Quality Control process. Some numerical results are provided on recent data from January 1, 2013 to May 31, 2013 to illustrate and compare the two methods.
Показать больше [+] Меньше [-]Integrating dispersion modelling and lichen sampling to assess harmful heavy metal pollution around the Karabash copper smelter, Russian Federation Полный текст
2015
Pollard, Adam S. | Williamson, Ben J. | Taylor, Mark | Purvis, William O. | Goossens, Marc | Reis, Stefan | Aminov, Pavel | Udachin, Valery | Osborne, Nicholas J.
Cu smelting has had a severe impact on the environment around the town of Karabash, Russia. Dispersion modelling has been carried out to estimate atmospheric fallout of metals and metalloids (henceforth termed metals for brevity) from the copper smelter, calibrated and ground-truthed using metal concentrations in transplanted and naturally growing lichens.Lichens (Hypogymnia physodes) were transplanted in June 2011 from a relatively little impacted ‘reference site’ to stations in NE–SW and W–E transects centred on the smelter at Karabash. The transplants were removed during September 2011 and then analysed for As, Cu and Pb. The results were compared with deposition loads estimated using TAPM modelling which was carried out for particles of various sizes, and with simple chemistries, and with the smelter conceptualised as a continuously emitting point source.Variation in the ratio of lichen divided by modelled concentrations was lowest for Pb, ranging from 30.3 to 939.9 and 4.9–107.8 for PM2.5 and PM10, respectively, across eight sample points.The TAPM modelling is in agreement with previous studies that smelter emissions are the major source of environmental Pb deposition around Karabash. Further modelling will be required to determine whether the Pb in the lichens is largely sourced from current smelter airborne emissions or windblown soil particles containing historic additions of Pb.
Показать больше [+] Меньше [-]The NET effect of dispersants — a critical review of testing and modelling of surface oil dispersion Полный текст
2015
Zeinstra-Helfrich, Marieke | Koops, Wierd | Murk, Albertinka J.
Application of chemical dispersants or mechanical dispersion on surface oil is a trade-off between surface effects (impact of floating oil) and sub-surface effects (impact of suspended oil). Making an informed decision regarding such response, requires insight in the induced change in fate and transport of the oil.We aim to identify how natural, chemical and mechanical dispersion could be quantified in oil spill models. For each step in the dispersion process, we review available experimental data in order to identify overall trends and propose an algorithm or calculation method. Additionally, the conditions for successful mechanical and chemical dispersion are defined.Two commonly identified key parameters in surface oil dispersion are: oil properties (viscosity and presence of dispersants) and mixing energy (often wind speed). Strikingly, these parameters play a different role in several of the dispersion sub-processes. This may explain difficulties in simply relating overall dispersion effectiveness to the individual parameters.
Показать больше [+] Меньше [-]Detection of water quality parameters in Hangzhou Bay using a portable laser fluorometer Полный текст
2015
Chen, Peng | Pan, Delu | Mao, Zhihua | Tao, Bangyi
A field, light-weight laser fluorometer based on the method of laser induced fluorescence was developed for water quality monitoring. The basic instrument configuration uses a high pulse repetition frequency microchip laser, a confocal reflective fluorescent probe and a broadband hyperspectral micro spectrometer; it weights only about 1.7kg. Simultaneous estimates of three important water quality parameters, namely, chlorophyll a (chl-a), colored dissolved organic matter (CDOM), and total suspended matter (TSM) measured by the laser fluorometer were observed to agree well with those measured by traditional methods (0.27–0.84μgL−3 chl-a, R2=0.88; 0.104–0.295m−1 CDOM absorption, R2=0.90; and 59.8–994.9mgL−3 TSM, R2=0.86) in Hangzhou Bay water. Subsequently, distribution and characteristics of CDOM and chl-a laser fluorescence in Hangzhou Bay were analyzed, which will enhance our understanding of biogeochemical processes in this complex estuarine system at high-resolution, high-frequency and long-term scale.
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