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151.
152.
Larval dispersal is a critical component of marine species’ life histories because it controls their population dynamics. Dispersal distance can be inferred by the presence and scale of spatial genetic structure (SGS). The larvae of Antillogorgia elisabethae, a surface brooding Caribbean octocoral, have been observed to settle within meters of maternal colonies, although many disperse over greater distances. Using a spatially hierarchical sampling design, A. elisabethae recruits were collected from a site off the coast of Great Abaco, The Bahamas, in June of 2009–2011. Seven microsatellite loci were used to determine whether genetic structure was present among recruits on scales of <1 m to 10s of meters. Multilocus genotypes were autocorrelated within spatial distance classes using Moran’s I coefficient as an estimate of genetic similarity, and Rousset’s genetic distance (â). Genetic structure was present on a scale of <10 m in 2010, but not in the other 2 years, suggesting that larval dispersal was more localized in 2010. Moran’s I coefficients were positive and significant for 0–1, 1–2 and 2–5 m classes in 2010, and the average genetic distance (â) among recruits in the 0–1 m class was significantly lower than the other classes. Autocorrelograms suggested that genetic patch sizes were 7.5 m in 2010, and 20 m in 2009 and 2011. Differences in the SGS of recruits between years might reflect temporal variation in temperature, wind and/or current speeds affecting larval dispersal, or variation in reproduction at the site. 相似文献
153.
Filip Johnsson David Reiner Kenshi Itaoka Howard Herzog 《International Journal of Greenhouse Gas Control》2010,4(2):410-418
This paper presents results from a survey of stakeholder attitudes towards Carbon Capture and Storage (CCS). The survey is the first to make a global comparison across three major regions: North America, Japan, and Europe. It is based on a 30-question survey which targeted individuals working at stakeholder organizations that seek to shape, and will need to respond to, policy on CCS, including electric utilities, oil and gas companies, CO2-intensive industries and non-governmental organizations (NGOs). The paper reports results from the original survey carried out in 2006 and from a recent follow up on key CCS questions (April 2009).The results show generally small differences across the regions and between the different groups of stakeholders. All believed that the challenge of significant reductions in emissions using only current technologies was severe. There was a widespread belief that CCS as well as renewable technologies such as solar power will achieve major market entry into the electricity sector within the next 10–20 years, whereas there is more scepticism about the role of hydrogen and especially nuclear fusion in the next 50 years. All groups were generally positive towards renewable energy. Yet, there were some notable areas of disagreement in the responses, for example, as expected, NGOs considered the threat of climate change to be more serious than the other groups. North American respondents were more likely to downplay the threat compared to those of the other regions. The Japanese were more concerned about the burden that would be placed on industry in the coming decade as a result of emissions constraints and NGOs were more likely to believe that the burden imposed would be light or very light. NGO respondents also believed CCS to be far more attractive than nuclear power (fission) but much less than renewables. As expected, the risk for leakage from reservoirs was ranked number one of the risk options given. The follow-up study generally confirmed the results of the original study with a few notable differences. As expected, the results of the follow-up shows that respondents consider CCS to play an increased role in the national climate debate. In Japan, there was an increased fraction of respondents who claimed that their organization has a clear position on CCS. 相似文献
154.
Neufeld HS Peoples SJ Davison AW Chappelka AH Somers GL Thomley JE Booker FL 《Environmental pollution (Barking, Essex : 1987)》2012,160(1):74-81
Ozone-sensitive and -tolerant individuals of cutleaf coneflower (Rudbeckia laciniata L.) were compared for their gas exchange characteristics and total non-structural carbohydrates at Purchase Knob, a high elevation site in Great Smoky Mountains National Park, USA. Photosynthesis and stomatal conductance decreased with increased foliar stipple. Sensitive plants had lower photosynthetic rates for all leaves, except the very youngest and oldest when compared to tolerant plants. Stomatal conductance decreased with increasing leaf age, but no ozone-sensitivity differences were found. Lower leaves had less starch than upper ones, while leaves on sensitive plants had less than those on tolerant plants. These results show that ambient levels of ozone in Great Smoky Mountains National Park can adversely affect gas exchange, water use efficiency and leaf starch content in sensitive coneflower plants. Persistence of sensitive genotypes in the Park may be due to physiological recovery in low ozone years. 相似文献
155.
Kinsey JS Timko MT Herndon SC Wood EC Yu Z Miake-Lye RC Lobo P Whitefield P Hagen D Wey C Anderson BE Beyersdorf AJ Hudgins CH Thornhill KL Winstead E Howard R Bulzan DI Tacina KB Knighton WB 《Journal of the Air & Waste Management Association (1995)》2012,62(4):420-430
The emissions from a Garrett-AiResearch (now Honeywell) Model GTCP85-98CK auxiliary power unit (APU) were determined as part of the National Aeronautics and Space Administration's (NASA's) Alternative Aviation Fuel Experiment (AAFEX) using both JP-8 and a coal-derived Fischer Tropsch fuel (FT-2). Measurements were conducted by multiple research organizations for sulfur dioxide (SO2, total hydrocarbons (THC), carbon monoxide (CO), carbon dioxide (CO2), nitrogen oxides (NOx), speciated gas-phase emissions, particulate matter (PM) mass and number, black carbon, and speciated PM. In addition, particle size distribution (PSD), number-based geometric mean particle diameter (GMD), and smoke number were also determined from the data collected. The results of the research showed PM mass emission indices (EIs) in the range of 20 to 700 mg/kg fuel and PM number EIs ranging from 0.5 x 10(15) to 5 x 10(15) particles/kg fuel depending on engine load and fuel type. In addition, significant reductions in both the SO2 and PM EIs were observed for the use of the FT fuel. These reductions were on the order of approximately 90% for SO2 and particle mass EIs and approximately 60% for the particle number EI, with similar decreases observed for black carbon. Also, the size of the particles generated by JP-8 combustion are noticeably larger than those emitted by the APU burning the FT fuel with the geometric mean diameters ranging from 20 to 50 nm depending on engine load and fuel type. Finally, both particle-bound sulfate and organics were reduced during FT-2 combustion. The PM sulfate was reduced by nearly 100% due to lack of sulfur in the fuel, with the PM organics reduced by a factor of approximately 5 as compared with JP-8. 相似文献
156.
Howard P. Gates Jr. Lawrence A. Goldmuntz 《Journal of the Air & Waste Management Association (1995)》2013,63(9):891-892
Carboxyhemoglobin (COHb) levels in blood are principally due to inhalation of carbon monoxide, although a low level (approximately 0.3%) of COHb is endogenous. A carboxyhemoglobin level above 1.5 % in non-smokers indicates exposure to CO in excess of the 10 mg/m3 air quality standard established under the Clean Air Act Amendments of 1970. In most major U.S. cities, automobile emissions constitute the principal source of CO; in Chicago, according to EPA estimates,1 light duty vehicles are responsible for 69.3% of all CO emissions. Thus as new automobiles incorporating emission controls enter the automotive fleet and older, emission-uncontrolled automobiles are phased out, ambient CO concentrations should decline and corresponding reductions in blood carboxyhemoglobin levels of nonsmokers can be expected. 相似文献
157.
Earl W. Edelen Howard L. Clark 《Journal of the Air & Waste Management Association (1995)》2013,63(3):1-4
Abstract Concentrations of 38 gas-phase organic air toxics were measured over a 2-yr period at four different sites in and around Pittsburgh, PA, to investigate spatial variations in health risks from chronic exposure. The sites were chosen to represent different exposure regimes: a downtown site with substantial mobile source emissions; two residential sites adjacent to one of the most heavily industrialized zones in Pittsburgh; and a regional background site. Lifetime cancer risks and non-cancer hazard quotients were estimated using a traditional and interactive risk models. Although study average concentrations of specific air toxics varied by as a much as a factor of 26 between the sites, the additive cancer risks of the gas-phase organic air toxics varied by less than a factor of 2, ranging from 6.1 × 10-5 to 9.5 × 10-5. The modest variation in risks reflects the fact that two regionally distributed toxics, formalde-hyde and carbon tetrachloride (CCl4), contributed more than half of the cancer risk at all four sites. Benzene contributed substantial cancer risks at all sites, whereas trichloroethene and 1,4-dichlorobenzene only contributed substantial cancer risks at the downtown site. Only acrolein posed a non-cancer risk. Diesel particulate matter is estimated to pose a much greater cancer risk in Pittsburgh than other classes of air toxics including gas-phase organic, metals, polycyclic aromatic hydrocarbons, and coke oven emissions. Health risks of air toxics in Pittsburgh are comparable with those in other urban areas in the United States. 相似文献
158.
159.
The role of political conservatism and religion in shaping attitudes toward environmental consumption in the US is examined. Previous research suggests that while there is a mixed relationship between religiosity (measured in various ways) and environmentalism, political conservatives are unlikely to support pro-environment measures. Using nationally representative survey data, mixed results are found regarding the relationship of religiosity and environmental consumption: religious attendance and religious identity are positively related to environmental consumption, while belief in an involved God and biblical literalism are negatively related. Increased levels of religiosity, however, mute the otherwise strong negative effect of political conservatism. This suggests, surprisingly, that Green marketers and activists are likely to face less conservative resistance to environmental consumption among religious Americans. 相似文献
160.
Anthropogenic pollution and variability of manganese in alluvial sediments of the Yellow River,Ningxia, northwest China 总被引:9,自引:0,他引:9
Peiyue Li Hui Qian Ken W. F. Howard Jianhua Wu Xinsheng Lyu 《Environmental monitoring and assessment》2014,186(3):1385-1398
Heavy metal pollution of sediments is a global concern and can be a serious problem in heavily industrialized parts of the world. Pollution by manganese is particularly common due to its ubiquitous natural occurrence, ease of mobilization, and extensive association with industry. In Ningxia, China, manganese pollution of Yellow River alluvial sediments was assessed by comparing manganese concentrations in 35 sediment samples with background values derived from similar sediments obtained at sites considered remote from potential sources of contamination. Natural background values of manganese were found to range from 192 to 323 mg/kg for surface sediments, and from 220 to 325 and 283 to 394 mg/kg for subsurface sediments at depths of 45–50 and 95–100 cm, respectively. In the study area, manganese content ranged from 565 to 1,363 mg/kg, indicating anthropogenic pollution extending to a depth of at least 1 m in the study area. All 35 samples were found to exceed the threshold effect concentration (TEC) of 460 mg/kg, below which adverse effects on sediment-dwelling organisms are not expected to occur, and one sample (T12) was found to exceed the probable effect concentration (PEC) of 1,100 mg/kg. PEC defines the threshold above which adverse effects are likely to be observed. Variogram analysis of the surface sediment manganese data revealed adherence to a Gaussian model, and ordinary kriging was used to generate a manganese distribution map. Analysis of the high nugget effect ratio indicates high, small-scale variations that are consistent with potential emissions from an adjacent electrolytic manganese plant. 相似文献