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841.
We tested the effects of osmotic stress on survival, developmental rate, and level of HSPs on American horseshoe crab (Limulus polyphemus) embryos. Animals were maintained in the laboratory at an ambient salinity of 20 ppt and then exposed to 4-h osmotic shocks
at salinities of 10, 30, 40, 50, and 60 ppt, with a control group at 20 ppt. Horseshoe crab embryos had 100% developmental
success (defined as individuals reaching the first instar or trilobite larval stage) at all salinities. However, osmotic stresses,
especially hyperosmotic conditions, slowed the rate of development. Embryos subjected to osmotic stress showed higher levels
of HSP70 and HSP90 than control animals kept at a salinity of 20 ppt. HSPs are of value to horseshoe crab embryos in surviving
the fluctuating salinities that are typical of estuarine beach habitats. 相似文献
842.
Jodi D. Hoffman Diana W. Bianchi Lisa M. Sullivan Brenda L. Mackinnon Jamie Collins Fergal D. Malone T. Flint Porter David A. Nyberg Christine H. Comstock Radek Bukowski Richard L. Berkowitz Susan J. Gross Lorraine Dugoff Sabrina D. Craigo Ilan E. Timor-Tritsch Stephen R. Carr Honor M. Wolfe Mary E. D'Alton 《黑龙江环境通报》2008,28(13):1204-1208
843.
844.
845.
Ann T.W. Yu C.S. Poon Agnes Wong Robin Yip Lara Jaillon 《Waste management (New York, N.Y.)》2013,33(1):138-146
Waste management in the building industry in Hong Kong has become an important environmental issue. Particularly, an increasing amount of construction and demolition (C&D) waste is being disposed at landfill sites. In order to reduce waste generation and encourage reuse and recycling, the Hong Kong Government has implemented the Construction Waste Disposal Charging Scheme (CWDCS) to levy charges on C&D waste disposal to landfills. In order to provide information on the changes in reducing waste generation practice among construction participants in various work trades, a study was conducted after 3 years of implementation of the CWDCS via a structured questionnaire survey in the building industry in Hong Kong. The study result has revealed changes with work flows of the major trades as well as differentiating the levels of waste reduced. Three building projects in the public and private sectors were selected as case studies to demonstrate the changes in work flows and the reduction of waste achieved. The research findings reveal that a significant reduction of construction waste was achieved at the first 3 years (2006–2008) of CWDCS implementation. However, the reduction cannot be sustained. The major trades have been influenced to a certain extent by the implementation of the CWDCS. Slight improvement in waste management practices was observed, but reduction of construction waste in the wet-finishing and dry-finishing trades has undergone little improvement. Implementation of the CWDCS has not yet motivated subcontractors to change their methods of construction so as to reduce C&D waste. 相似文献
846.
An Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopic method was used to measure organic functional groups and inorganic ions at Tonto National Monument (TNM), an Interagency Monitoring of Protected Visual Environments (IMPROVE) sampling site in a rural area near Phoenix, Arizona. Functional groups and ions from common aerosol compound classes such as aliphatic and aromatic CH, methylene, methyl, aldehydes/ketones, carboxylic acids, ammonium sulfate and nitrate as well as functional groups from difficult to measure compound classes such as esters/lactones, acid anhydrides, carbohydrate hydroxyl and ethers, amino acids, and amines were quantified. On average, ~33% of the PM1.0 mass was composed of organic aerosol. The average (standard deviation) composition of the organic aerosol at TNM was 34% (6%) biogenic functional groups, 21% (5%) oxygenated functional groups, 28% (7%) aliphatic hydrocarbon functional groups (aliphatic CH, methylene and methyl) and 17% (1%) aromatic hydrocarbon functional groups. Compositional analysis, functional group correlations, and back trajectories were used to identify three types of events with source signatures: primary biogenic-influenced, urban-influenced, and regional background. The biogenic-influenced event had high concentrations of amino acids and carbohydrate hydroxyl and ether, as well as aliphatic CH and aromatic CH functional groups and qualitatively high levels of silicate. The urban-influenced events had back trajectories traveling directly from the Phoenix area and high concentrations of hydrocarbons, oxygenated functional groups, and inorganic ions. This aerosol characterization suggests that both primary emissions in Phoenix and secondary formation of aerosols from Phoenix emissions had a major impact on the aerosol composition and concentration at TNM. The regional background source had low concentrations of all functional groups, but had higher concentrations of biogenic functional groups than the urban source. 相似文献
847.
Traditional high resolution mass spectrometry (HRMS) analysis for polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) can be time consuming and expensive. Consequently, alternative methods are of great interest to regulatory agencies and others characterizing contaminated sites. One factor that hinders acceptance of alternative methods is a lack of performance information that assesses the alternative method's impacts on analytical results. The U.S. Environmental Protection Agency's Superfund Innovative Technology Evaluation Monitoring and Measurement Technologies Program (EPA SITE MMT) encourages the development and implementation of innovative and alternative monitoring methods by providing performance information on site characterization technologies. This paper presents a comparison of the results obtained from laboratory-based alternative approaches for screening sediment and soil samples for dioxin toxicity equivalents (TEQ(D/F)) to results obtained using traditional HRMS. The laboratory-based approaches included modifying the traditional HRMS analysis to make it more cost-effective (alternate 1613B), analyzing extracts that had been prepared for HRMS using low resolution mass spectrometry, and determining total organic carbon (TOC) content as an indicator of PCDD/F content. These comparisons demonstrated that TEQ(D/F) values generated using toxicity equivalency factors proposed by the World Health Organization in 1998 applied to alternate 1613B and LRMS analyses have a strong linear correlation to the TEQ(D/F) values derived in the same fashion from traditional HRMS analysis. These results would have placed >90% of the samples within the same concentration intervals using ranges of <0.05, 0.05-0.50, 0.50-5, and >5ng TEQ/g. Natural log transformed data for TOC had significantly weaker correlation to TEQ(D/F), indicating that TOC is not a reliable indicator of TEQ(D/F) concentrations. 相似文献
848.
Ann Sloan Devlin Sarah Donovan Arianne NicolovOlivia Nold Andrea PackardGabrielle Zandan 《Journal of environmental psychology》2009
The impact of the number of displayed credentials (0, 2, 4, or 9) and the presence or absence of family photographs on participants' judgments of a therapist's qualities was assessed. In a between-participants design, 227 participants made these judgments after viewing a projected digital image of a therapist's office. The judgments of the characteristics yielded three factors, Qualifications, Friendliness, and Energy. Analyses indicated that in general, the greater the number of credentials, the more positive the judgment of the therapist's Qualifications and Energy. The presence of family pictures had no significant impact on judgments. Results are discussed in terms of recommendations for the counseling environment. 相似文献
849.
Although humans are a major mechanism for short and long distance seed dispersal, there is limited research testing clothing as a vector. The effect of different types of material (sports vs hiking socks), or different items of clothing (boots, socks, laces vs legs) or the same item (socks) worn in different places on seed composition were assessed in Kosciuszko National Park, Australia. Data was analyzed using Repeated Measures ANOVA, independent and paired t-tests, Multi-dimensional Scaling Ordinations and Analysis of Similarity. A total of 24,776 seeds from 70 taxa were collected from the 207 pieces of clothing sampled, with seed identified from 31 native and 19 non-native species. Socks worn off-track collected more native seeds while those worn on roadsides collected more non-native seeds. Sports socks collected a greater diversity of seeds and more native seeds than hiking socks. Boots, uncovered socks and laces collect more seeds than covered socks and laces, resulting in 17% fewer seeds collected when wearing trousers. With seeds from over 179 species (134 recognized weeds) collected on clothing in this, and nine other studies, it is clear that clothing contributes to unintended human mediated seed dispersal, including for many invasive species. 相似文献
850.
Stephen S. Warrner Robert U. Fischer Ann M. Holtrop Leon C. Hinz Jr. James M. Novak 《Environmental management》2010,46(5):761-770
Stream habitat assessments are conducted to evaluate biological potential, determine anthropogenic impacts, and guide restoration
projects. Utilizing these procedures, managers must first select a representative stream reach, which is typically selected
based on several criteria. To develop a consistent and unbiased procedure for choosing sampling locations, the Illinois Department
of Natural Resources and the Illinois Natural History Survey have proposed a technique by which watersheds are divided into
homogeneous stream segments called valley segments. Valley segments are determined by GIS parameters including surficial geology,
predicted flow, slope, and drainage area. To date, no research has been conducted to determine if the stream habitat within
a valley segment is homogeneous and if different valley segments have varying habitat variables. Two abutting valley segments
were randomly selected within 13 streams in the Embarras River watershed, located in east-central Illinois. One hundred meter
reaches were randomly selected within each valley segment, and a transect method was used to quantify habitat characteristics
of the stream channel. Habitat variables for each stream were combined through a principal components analysis (PCA) to measure
environmental variation between abutting valley segments. A multivariate analysis of variance (MANOVA) was performed on PCA
axes 1–3. The majority of abutting valley segments were significantly different from each other indicating that habitat variability
within each valley segment was less than variability between valley segments (5.37 ≤ F ≤ 245.13; P ≤ 0.002). This comparison supports the use of the valley segment model as an effective management tool for identifying representative
sampling locations and extrapolating reach-specific information. 相似文献