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41.
 Most studies characterizing successful biological invaders emphasize those traits that help a species establish a new population. Invasions are, however, multi-phase processes with at least two phases, dispersal and introduction, that occur before establishment. Characteristics that enhance survival at any of these three phases will contribute to invasion success. Here, we synthesize information on the dispersal, introduction, and establishment of fishes mediated by ship ballast-water transport. We synthesize 54 reports of at least 31 fish species collected from ballast tanks (Phase 1), including 28 new reports from our recent studies (1986 to 1996). Our literature survey revealed 40 reports of 32 fish species whose introductions have been attributed to ballast transport (Phase 2), of which at least 24 survived to establish persistent populations (Phase 3). We detected little overlap at the species level between these two data sets (Phase 1 vs Phases 2 and 3), but patterns emerged at the family level. The Gobiidae (6 species), Clupeidae (4 species), and Gasterosteidae (1 species) were the most commonly found fish families in ballast tanks (Phase 1). The Gobiidae (13 species), Blenniidae (6 species) and Pleuronectidae (2 species) dominated the list of ballast-mediated introductions (Phase 2); gobies and blennies were the families most frequently established (Phase 3). The invasive success of gobies and blennies may be explained in part by their crevicolous nature: both groups seek refuge and lay eggs in small holes, and may take advantage of the ballast-intake holes on ship hulls. This behavior, not typically associated with invasive ability, may contribute to successful introduction and establishment by facilitating the dispersal phase of invasion. The failure of the pleuronectids to invade may reflect poor salinity match between donor and recipient regions. To develop a predictive framework of invasion success, organisms must be sampled at all three phases of the invasion process. Our comparison of two ballast sampling methods suggests that fishes have been undersampled in ballast-water studies, including our own, and that the role of ballast transport in promoting fish invasions has been underestimated. Received: 13 January 1999 / Accepted: 24 February 2000  相似文献   
42.
Since the damage suffered by buildings as a consequence of explosions usually affect the people inside them, it is important to take it into account when performing consequence analysis. The aim of this paper is to provide a methodology to estimate consequences to buildings from pressure waves produced by spherical vessel burst. This is done by combining characteristic overpressure–impulse–distance curves [González Ferradás, E., Diaz Alonso, F., Sanchez Perez, J.F., Miñana Aznar, A., Ruiz Gimeno, J. and Martinez Alonso, J., 2006, Characteristic overpressure–impulse–distance curves for vessel burst, Process Safety Progress, 25(3): 250–254] with PROBIT equations. The main advantage of this methodology is that it allows an overview of all the magnitudes involved, as damage is shown in the same graph as the overpressure, impulse and distance. In this paper diagrams and equations are presented to determine minor damage to buildings (broken windows, displacement of doors and window frames, tile displacement, etc.), major structural damage (cracks in walls, collapse of some walls) and collapse (the damage is so extensive that the building is partially or totally demolished).  相似文献   
43.
A survey to estimate the polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) emissions of Spanish hot dip galvanising sector was carried out during 2002. This investigation is the first presenting Spanish experimental data related to this industrial sector. Three different matrices: flue gas, ash and filter dust were tested to quantify the PCDD/Fs generated during the galvanising process. The organic source of PCDD/F formation could be from the insufficient degreasing o from inhibitors or additives used in the pickling steps such as quinoline, isoquinoline, 8-methylquinoline or polyether phosphoric acid. Low levels PCDD/Fs were achieved in air emissions when air control devices are used. On the contrary, filter dusts are highly contaminated; indicating that the absence of air control devices would increase the risk of fugitive emissions. Homologue profiles and Principal Component Analysis demonstrate there are differences in the formation mechanisms in the bath zone (ashes) compared to the stack location (filter dusts and air emissions), related to the de novo synthesis and reaction time. The annual PCDD/F emission to the atmosphere for this sector during 2002 has been estimated in 0.023g I-TEQ. The emission factor of plants with air control devices has been calculated at 0.030microg I-TEQ/ton of galvanised steel.  相似文献   
44.
Santiago, Chile, is one of the most polluted cities in South America. As a response, over the past 15 yr, numerous pollution reduction programs have been implemented by the environmental authority, Comisión Nacional del Medio Ambiente. This paper assesses the effectiveness of these interventions by examining the trends of fine particulate matter (PM(2.5)) and its associated elements. Daily fine particle filter samples were collected in Santiago at a downtown location from April 1998 through March 2003. Additionally, meteorological variables were measured continuously. Annual average concentrations of PM(2.5) decreased only marginally, from 41.8 microg/m3 for the 1998-1999 period to 35.4 microg/m3 for the 2002-2003 period. PM(2.5) concentrations exceeded the annual U.S. Environmental Protection Agency standard of 15 microg/m3. Also, approximately 20% of the daily samples exceeded the old standard of 65 microg/m3, whereas approximately half of the samples exceeded the new standard of 35 microg/m3 (effective in 2006). Mean PM(2.5) levels measured during the cold season (April through September) were three times higher than those measured in the warm season (October through March). Particulate mass and elemental concentration trends were investigated using regression models, controlling for year, month, weekday, wind speed, temperature, and relative humidity. The results showed significant decreases for Pb, Br, and S concentrations and minor but still significant decreases for Ni, Al, Si, Ca, and Fe. The larger decreases were associated with specific remediation policies implemented, including the removal of lead from gasoline, the reduction of sulfur levels in diesel fuel, and the introduction of natural gas. These results suggest that the pollution reduction programs, especially the ones related to transport, have been effective in reducing various important components of PM(2.5). However, particle mass and other associated element levels remain high, and it is thus imperative to continue the efforts to improve air quality, particularly focusing on industrial sources.  相似文献   
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The Chinese mitten crab (Eriocheir sinensis) is native to east Asia, is established throughout Europe, and is introduced but geographically restricted in North America. We developed and compared two separate environmental niche models using genetic algorithm for rule set prediction (GARP) and mitten crab occurrences in Asia and Europe to predict the species' potential distribution in North America. Since mitten crabs must reproduce in water with >15% per hundred salinity, we limited the potential North American range to freshwater habitats within the highest documented dispersal distance (1260 km) and a more restricted dispersal limit (354 km) from the sea. Applying the higher dispersal distance, both models predicted the lower Great Lakes, most of the eastern seaboard, the Gulf of Mexico and southern extent of the Mississippi River watershed, and the Pacific northwest as suitable environment for mitten crabs, but environmental match for southern states (below 35 degrees N) was much lower for the European model. Use of the lower range with both models reduced the expected range, especially in the Great Lakes, Mississippi drainage, and inland areas of the Pacific Northwest. To estimate the risk of introduction of mitten crabs, the amount of reported ballast water discharge into major United States ports from regions in Asia and Europe with established mitten crab populations was used as an index of introduction effort. Relative risk of invasion was estimated based on a combination of environmental match and volume of unexchanged ballast water received (July 1999-December 2003) for major ports. The ports of Norfolk and Baltimore were most vulnerable to invasion and establishment, making Chesapeake Bay the most likely location to be invaded by mitten crabs in the United States. The next highest risk was predicted for Portland, Oregon. Interestingly, the port of Los Angeles/Long Beach, which has a large shipping volume, had a low risk of invasion. Ports such as Jacksonville, Florida, had a medium risk owing to small shipping volume but high environmental match. This study illustrates that the combination of environmental niche- and vector-based models can provide managers with more precise estimates of invasion risk than can either of these approaches alone.  相似文献   
48.
During the last 10 years, high atmospheric concentrations of airborne particles recorded in the Mexico City metropolitan area have caused concern because of their potential harmful effects on human health. Four monitoring campaigns have been carried out in the Mexico City metropolitan area during 2000-2002 at three sites: (1) Xalostoc, located in an industrial region; (2) La Merced, located in a commercial area; and (3) Pedregal, located in a residential area. Results of gravimetric and chemical analyses of 330 samples of particulate matter (PM) with an aerodynamic diameter less than 2.5 microm (PM2.5) and PM with an aerodynamic diameter less than 10 microm (PM10) indicate that (1) PM2.5/PM10 average ratios were 0.42, 0.46, and 0.52 for Xalostoc, La Merced, and Pedregal, respectively; (2) the highest PM2.5 and PM10 concentrations were found at the industrial site; (3) PM2.5 and PM10 concentrations were lower at nighttime; (4) PM2.5 and PM10 spatial averages concentrations were 35 and 76 microg/m3, respectively; and (5) when the PM2.5 standard was exceeded, nitrate, sulfate, ammonium, organic carbon, and elemental carbon concentrations were high. Twenty-four hour averaged PM2.5 concentrations in Mexico City and Sao Paulo were similar to those recorded in the 1980s in Los Angeles. PM10 concentrations were comparable in Sao Paulo and Mexico City but 3-fold lower than those found in Santiago.  相似文献   
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Low-density polyethylene (LDPE), biaxially oriented polypropylene (BOPP), and expanded polystyrene (EXPS) are the most common plastics found in every home of the world, but only ~ 10% enter the recycling chains. Consequently, the study of plastic biodegradation by microorganisms and insects, such as the wax moths, has gained special interest. Galleria mellonella (L.) has been shown to consume single-layered polyethylene and polystyrene, though biological impacts of this consumption have been rarely reported. We evaluated the consumption of different plastics by G. mellonella larvae (L7, mean size: 25–30 mm) and its effect on larval duration, survival, and development. For this, we offered the larvae five diets: single-layered LDPE, EXPS, BOPP, triple-layered polyethylene (SB, for silo-bags), and a control with beeswax. We recorded the state and weight of the materials and the state of larvae until they reached the adult stage. Larvae consumed more PE (both LDPE and SB) and EXPS than BOPP; still, they were able to emerge as adults in all treatments. Larvae that consumed plastics turned into pupal stage faster than those that consumed beeswax, regardless of the type and amount of plastic consumed. This is the first report of wild G. mellonella larvae in Argentina consuming biaxially polypropylene and silo-bags.

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