خيارات البحث
النتائج 791 - 800 من 2,459
Contingency plan improvement for managing oil spills in the coastal waters of Thailand
2014
Singkran, Nuanchan
The estimated risks of being impacted by oil spills in the coastal waters were used to improve the oil spill contingency plan of Thailand. Functional roles of local agencies are integrated into the plan. Intensive measures are suggested for the coastal provinces located in high-very high risk zones, whereas light and moderate measures are suggested for the coastal provinces located in low and moderate risk zones, respectively. The estimated percentage risks due to simulated oil slicks hitting the coast and/or important resources (PRoilspill) were used to guide the year-round water activities that should be carefully handled at a certain radius with a low-moderate PRoilspill, whereas they should be avoided at a certain radius with a high-very high PRoilspill. Important measures before, during, and post periods of an oil spill incident are suggested to prevent and monitor oil spill incidents and mitigate their impacts on the environment.
اظهر المزيد [+] اقل [-]Late Holocene evolution and increasing pollution in Guanabara Bay, Rio de Janeiro, SE Brazil
2014
Vilela, Claudia Gutterres | Figueira, Brígida Orioli | Macedo, Mariana Cardoso | Baptista Neto, José Antonio
To detect changes during the Late Holocene and historical periods in Guanabara Bay, the paleoecological and ecological parameters from nine cores were analysed using foraminiferal assemblages and bioindicators. Using radiocarbon dates and sedimentation rates in the cores, it was possible to detect the first Europeans’ arrival in the 16th century. Foraminiferal bioindicators of organic matter and human pollution were correlated with radiocarbon dates from the bottom and middle of the cores in each region and revealed an increase in pollution along the cores. The foraminiferal results were compared with total organic carbon (TOC) values before, during and after European settlement and showed a historical increase in organic matter.Pristine mangrove ecosystems are characterised by agglutinated species such as Ammotium salsum, and the presence of this organism also confirmed the extent of historical mangrove forests. Ammonia tepida, Buliminella elegantissima and Elphidium excavatum were the dominant species, but they presented distinct patterns over time. B. elegantissima was dominant before the European influence in older sediments with high organic matter content that were found at deeper intervals. A. tepida is dominant in younger sediments at upper intervals, as a bioindicator of human pollution.
اظهر المزيد [+] اقل [-]The interaction between organic phosphate ester and p53: An integrated experimental and in silico approach
2014
Li, Fei | Li, Renmin | Yang, Xianhai | You, Liping | Zhao, Jianmin | Wu, Huifeng
Concerns have been raised in regards to the environmental impact of the more used organophosphate flame retardants (OPFRs). In this study, to better understand the relationship between molecular structural features of OPFRs and binding affinity for the tumor suppressor p53, an integrated experimental and in silico approach was used. From docking analysis, hydrogen bonding and hydrophobic interactions were found to be the dominant interactions, which implied the binding affinities of the compounds. The binding constants of 5 OPFRs were determined by surface plasmon resonance technology (SPR). Based on the observed interactions, appropriate molecular structural parameters were adopted to develop a quantitative structure-activity relationship (QSAR) model. The developed QSAR model had good robustness, predictive ability and mechanism interpretability. The interactions between the OPFRs and p53 (Ebinding) and the partition ability of the OPFRs into the bio-phase are main factors governing the binding affinities.
اظهر المزيد [+] اقل [-]Meteorologically-driven circulation and flushing times of the Bay of Algeciras, Strait of Gibraltar
2014
Sánchez-Garrido, José C. | Lafuente, Jesús García | Sammartino, Simone | Naranjo, Cristina | de los Santos, Francisco J. | Álvarez Fanjul, Enrique
A primitive-equation model has been used to investigate the meteorologically-driven circulation of the Bay of Algeciras. It is shown that the mean circulation of Atlantic Water (AW) is characterized by an anticyclonic cell, while Mediterranean Water (MW) follows a preferred cyclonic pathway. Meteorological forcing distorts substantially the AW mean circulation pattern, and only modulates that of the MW. Winds drive a vertical circulation cell in the Atlantic layer consistent with Ekman dynamics, whereas the horizontal circulation pattern is markedly dependent on the swift Atlantic jet entering the Mediterranean and changes from clearly anticyclonic to cyclonic as the jet separates or approaches the strait’s northern shoreline. This occurs through atmospheric pressure-driven acceleration/deceleration of the jet, in agreement with internal hydraulics theory predictions. It is also found that the renewal of AW is largely modulated by tides, with meteorological forcing playing a secondary role. The opposite applies to the renewal of MW.
اظهر المزيد [+] اقل [-]Health–risk assessment of workers exposed to flour dust: A cross–sectional study of random samples of bakeries workers
2014
Moghaddasi, Yousef | Mirmohammadi, Seyedtaghi | Ahmad, Anees | Etemadi Nejad, Syavash | Yazdani, Jamshid
The objectives of this study were to measure exposure to dust in the small bakery shops, to define the determinants of occupational asthma, and to propose control measures for this. The study included bakery workers of one hundred bakeries (the cases; n=200, the controls; n=20). Their individual information was obtained by a simple questionnaire based on “Ear–Nose–Throat” (ENT) work–related symptoms such as coughing, wheezing, chest tightness and irritations. Subjects were considered as “possible occupational asthma cases”. Medical visit was carried out to complete clinical and lung function investigations for these subjects. The mean flour dust concentration in the current study was 28mg/m3. Fifty six of bakery workers had work related symptoms significantly higher than those in controls. The spirometric results illustrated that the workers with experience of less than five years are not affected as there was no significant difference between exposed cases and controls in mean forced expiratory volume in one second (FEV1) or forced vital capacity (FVC) percent determined. But workers with experience of five years or more showed significantly lower mean FEV1 and FVC percent predicted when compared with controls. The results of lung function test for subjects demonstrated that the flour dust pollution adversely affects on main lung function parameters, such as FVC and FEV1. This study confirms that the risk of pulmonary disease among flour dust exposed workers is higher than the unexposed control subjects.
اظهر المزيد [+] اقل [-]Trace metal concentrations in Spartina densiflora and associated soil from a Patagonian salt marsh
2014
Idaszkin, Yanina L. | Bouza, Pablo J. | Marinho, Carmen H. | Gil, Mónica N.
The objectives of this study were to (i) assess in situ trace metal concentrations in soil and in Spartina densiflora in a Patagonian salt marsh (Rawson, Chubut, Argentina) and (ii) investigate the relationship between trace metal concentrations in soils and in plants to improve our knowledge regarding the ability of S. densiflora to take up and accumulate trace metals from the soil within its native region. Our results indicate that the soil and S. densiflora exhibit low metal concentrations in the Rawson salt marsh. S. densiflora accumulates Zn in below- and above-ground plant structures and Cr in below-ground parts. These results suggest at the time of this study there is scarce human impact associated with metals in the Rawson salt marsh.
اظهر المزيد [+] اقل [-]Macrobenthic succession and characteristics of a man-made intertidal sandflat constructed in the diversion channel of the Ohta River Estuary
2014
Nishijima, Wataru | Nakano, Yoichi | Nakai, Satoshi | Okuda, Tetsuji | Imai, Tsuyoshi | Okada, Mitsumasa
We compared succession and characteristics of the macrobenthic community in a small-scale experimental intertidal sandflat constructed in the artificial diversion channel of the Ohta River Estuary with those of three natural intertidal sandflats at lower elevation in the same channel. The macrobenthic population density in the man-made intertidal sandflat increased significantly between 3 and 9months after construction. Simplisetia erythraeensis was dominant (98% of individuals) after 9months, but its proportion gradually declined with the increase in biodiversity until 26months, indicating that succession of the macrobenthic community was nearly complete by 26months. The macrobenthic community in the man-made intertidal sandflat differed from those of the three natural intertidal sandflats, and its population density was about double that at the natural sites, with smaller temporal fluctuation. The different structures of the macrobenthic communities in the man-made and natural intertidal sandflats were likely caused by differences in elevation.
اظهر المزيد [+] اقل [-]De novo transcriptomic profile in the gonadal tissues of the intertidal whelk Reishia clavigera
2014
Ho, Kevin K.Y. | Leung, Priscilla T.Y. | Ip, Jack C.H. | Qiu, J.W. | Leung, Kenneth M.Y.
The intertidal whelk Reishia clavigera (formerly named as Thais clavigera) is one of the most sensitive species to organotin-associated imposex. However, the limited information on mRNA transcriptome of the species has restricted the molecular investigation on such endocrine disruption. By means of Illumina sequencing, we obtained a global de novo transcriptome from the gonadal tissues of both male and female R. clavigera, with 197,324 assembled transcripts and 151,684 condensed non-redundant transcripts. Blast hit results from the NCBI’s non-redundant molluscan database showed that 28,948 transcripts were successfully annotated with significant matches at an e-value of ⩽1e−6. Among them, 1108 transcripts were assigned a well-defined gene ontology term. As the first transcriptomic study on the gonadal tissues of R. clavigera, this study has enhanced the information of mRNA transcriptome on this species and will thus facilitate mechanistic studies of chemical contaminants (e.g., organotins) on this common biomonitor species.
اظهر المزيد [+] اقل [-]Kelp Gulls (Larus dominicanus) killed and injured by discarded monofilament lines at a marine recreational fishery in northern Patagonia
2014
Yorio, Pablo | Marinao, Cristian | Suárez, Nicolás
Among marine debris, monofilament fishing lines often result in negative impacts on marine organisms. We characterized marine debris and incidence of lost and discarded monofilament lines along beaches used by recreational fishers, and report the impact of lines on Kelp Gulls (Larus dominicanus) at the Bahía San Blas protected area, site of one of the main shore-based recreational fisheries of the southwestern Atlantic. Over 55% of the marine debris recorded originated from recreational fishing activities. Balls of tangled monofilament lines were found at a rate of 40.5 items per km. A total of 27 adult Kelp Gulls were found entangled with monofilament. All individuals were tangled to vegetation within colony boundaries. Four of the gulls had a monofilament line protruding from the bill, showing that they may be also killed when trying to obtain bait. Our results indicate that lost or discarded monofilament lines in the Bahía San Blas recreational fishing area result in undesired impacts on coastal wildlife.
اظهر المزيد [+] اقل [-]Courage under fire: Seagrass persistence adjacent to a highly urbanised city–state
2014
Yaakub, Siti Maryam | McKenzie, Len J. | Erftemeijer, Paul L.A. | Bouma, Tjeerd | Todd, Peter A.
Due to increasing development Southeast Asia’s coastlines are undergoing massive changes, but the associated impacts on marine habitats are poorly known. Singapore, a densely populated island city–state, is a quintessential example of coastal modification that has resulted in the (hitherto undocumented) loss of seagrass. We reconstructed the historic extent and diversity of local seagrass meadows through herbarium records and backwards extrapolation from contemporary seagrass locations. We also determined the current status of seagrass meadows using long-term monitoring data and identified the main threats to their presence in Singapore. Results show that, even though ∼45% of seagrass has been lost during the last five decades, species diversity remains stable. The main cause of seagrass loss was, and continues to be, land reclamation. We conclude that strict controls on terrestrial runoff and pollution have made it possible for seagrass to persist adjacent to this highly urbanised city–state.
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