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361.
During 1993-1996 and 2001-2003, we evaluated the percentage of plants (incidence) exhibiting ozone-induced foliar symptoms on vegetation within a National Wildlife Refuge located along the Atlantic Ocean coast of New Jersey, USA. Incidence varied among plant species and years. Bioindicator plants most sensitive to ozone, across all years, included native common milkweed (Asclepias syriaca) and wild grape (Vitis spp.), as well as introduced tree-of-heaven (Ailanthus altissima). Less sensitive bioindicators included Virginia creeper (Parthenocissus quinquefolia) and winged sumac (Rhus coppolina). Black cherry (Prunus serotina) and sassafras (Sassafras albidum) were least sensitive. The greatest incidence of ozone symptoms, across all plant species, occurred in 1996, followed by 2001>1995>1994>1993>2003>2002. A model was developed that showed a statistically significant relationship between incidence of ozone symptoms and the following parameters: plant species, Palmer Drought Severity Index, and the interaction of W126 x N100 measures of ambient ozone.  相似文献   
362.
Electrolytic reactive barriers (e(-) barriers) consist of closely spaced permeable electrodes installed across a groundwater contaminant plume in a permeable reactive barrier format. Application of sufficient potential to the electrodes results in sequential oxidation and reduction of the target contaminant. The objective of this study was to quantify the mass distribution of compounds produced during sequential electrolytic oxidation and reduction of ordinance related compounds (ORCs) in a laboratory analog to an e(-) barrier. In this study, a series of column tests were conducted using RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) and TNT (2,4,6-trinitrotoluene) as representative ORCs. The experimental setup consisted of a plexiglass column packed with quartz-feldspar sand to simulate aquifer conditions. A single set of porous electrodes consisting of expanded titanium-mixed metal oxide mesh was placed at the midpoint of the sand column as a one-dimensional analog to an e(-) barrier. Constant current of 20mA (variable voltage) was applied to the electrode set. Initial studies involved quantification of reaction products using unlabeled RDX and TNT. Approximately 70% of the influent concentration was transformed, in one pass, through sequential oxidation-reduction for both contaminants. Following the unlabeled studies, (14)C labeled RDX and TNT were introduced to determine the mass balance. An activity balance of up to 96% was achieved for both (14)C-RDX and (14)C-TNT. For both contaminants, approximately 21% of the influent activity was mineralized to (14)CO(2). The proportion of the initial activity in the dissolved fraction was different for the two test contaminants. Approximately 30% of the initial (14)C-RDX was recovered as unreacted in the dissolved phase. The balance of the (14)C-RDX was recovered as non-volatile, non-nitroso transformation products. None of the (14)C-RDX was sorbed to the column sand packing. For (14)C-TNT approximately 51% of the initial activity was recovered in the dissolved phase, the majority was unreacted TNT. The balance of the (14)C-TNT was either sorbed to the sand packing (approximately 24%) or dissolved/mineralized as unidentified ring cleavage products ( approximately 4%).  相似文献   
363.
Brick manufacturing industries are challenged to comply with clean air mandates. Dry air scrubbers have been used to remove acid gases from the exhaust air from brick manufacturing plants. The use of dry air scrubbers results in the production of large quantities of an alkaline powder by-product. A greenhouse experiment was conducted to evaluate the potential of using dairy lagoon sludge stabilized with the scrubber by-product as a soil amendment. Lagoon sludge was stabilized with scrubber by-product at an application rate of 20 gl(-1). The sludge-scrubber by-product mixture was applied to a sandy loam soil to provide amendments ranging between 28 and 168 kg of plant available nitrogen (PAN)/ha for the growth of Helianthus annuus (sunflower). Use of the sludge-scrubber by-product mixture as a nitrogen fertilizer did not adversely affect sunflower seedling emergence; however, significantly higher (p<0.05) plant volume indices, leaf area, dry shoot and root masses, and seed yields were obtained for mature plants grown in sludge-treated soil relative to the control or fertilizer treatment. The sludge amendment did not severely impact gas exchange or chlorophyll a fluorescence of the plants and nutrient content of the sunflower tissues was generally within a sufficient range. The increased growth and yield of sunflower plants indicated the potential of the sludge-scrubber by-product mixture as a soil amendment in agricultural crop production.  相似文献   
364.
Culturomics is emerging as an important field within science, as a way to measure attitudes and beliefs and their dynamics across time and space via quantitative analysis of digitized data from literature, news, film, social media, and more. Sentiment analysis is a culturomics tool that, within the last decade, has provided a means to quantify the polarity of attitudes expressed within various media. Conservation science is a crisis discipline; therefore, accurate and effective communication are paramount. We investigated how conservation scientists communicate their findings through scientific journal articles. We analyzed 15,001 abstracts from articles published from 1998 to 2017 in 6 conservation-focused journals selected based on indexing in scientific databases. Articles were categorized by year, focal taxa, and the conservation status of the focal species. We calculated mean sentiment score for each abstract (mean adjusted z score) based on 4 lexicons (Jockers-Rinker, National Research Council, Bing, and AFINN). We found a significant positive annual trend in the sentiment scores of articles. We also observed a significant trend toward increasing negativity along the spectrum of conservation status categories (i.e., from least concern to extinct). There were some clear differences in the sentiments with which research on different taxa was reported, however. For example, abstracts mentioning lobe finned fishes tended to have high sentiment scores, which could be related to the rediscovery of the coelacanth driving a positive narrative. Contrastingly, abstracts mentioning elasmobranchs had low scores, possibly reflecting the negative sentiment score associated with the word shark. Sentiment analysis has applications in science, especially as it pertains to conservation psychology, and we suggest a new science-based lexicon be developed specifically for the field of conservation.  相似文献   
365.
The embryonic development and the level of dependency of the embryos from the maternal organism were investigated for Centroscymnus coelolepis. During the development, there is a 22–32% loss of organic matter and gains of 95–122% and 29–46% on moisture and inorganic matter, respectively. Only 28–48% of the initial yolk energy is conserved in embryos, being the remaining used in catabolism. In late pregnancy, the epithelium thickness of uterine villi decreases and vascularity increases. Results suggest that only water and minerals are transferred from the mother to the embryos. Monounsaturated fatty acids are the main type of fatty acids representing 48% of the total yolk fatty acid content, followed by polyunsaturated (30%) and saturated fatty acids (18–21%).  相似文献   
366.
367.
The increasing problem of antibiotic resistance in common pathogenic bacteria and the concern about the spreading of antibiotics in the environment bring the need to find new methods to control fish pathogens. Phage therapy represents a potential alternative to antibiotics, but its use in aquaculture requires a detailed understanding of bacterial communities, namely of fish pathogenic bacteria. Therefore, in this study the seasonal dynamics of the overall bacterial communities, microbiological water quality and disease-causing bacteria were followed in a marine aquaculture system of Ria de Aveiro (Portugal). Analysis of the bacterial diversity of the water samples by denaturing gradient gel electrophoresis (DGGE) of 16S rRNA gene fragments indicates that the bacterial community structure varied seasonally, showing a higher complexity during the warm season. The diversity of the main fish pathogenic bacteria, assessed by DGGE targeting the Vibrio genus, showed lower seasonal variation, with new dominating populations appearing mainly in the spring. Bacterial indicators, faecal coliforms and enterococci, enumerated by the filter-membrane method, also varied seasonally. The fluorescent in situ hybridization (FISH) results showed that the specific groups of bacteria varied during the study period and that the non-indigenous Enterobactereaceae family was the most abundant group followed by Vibrio and Aeromonas. The seasonal variation detected in terms of density and structure of total and pathogenic bacterial communities demonstrates the need for a careful monitoring of water through the year in order to select the suitable phages to inactivate fish pathogenic bacteria. The spring season seems to be the critical time period when phage therapy should be applied.  相似文献   
368.
We examined the connection between individuals’ relationships with the natural environment and their environmental behaviors with a focus on commitment to the environment, defined as psychological attachment and long-term orientation to the natural world. Commitment is theorized to emerge from structural interdependence with the environment and to lead to pro-environmental behaviors. Close relationships research has identified three key antecedents to commitment (satisfaction, alternatives, and investments). We developed environment-specific measures of these constructs, and factor analysis verified three distinct factors. A path analysis revealed that satisfaction with the environment and investments in the environment, but not alternatives to the environment, predicted commitment to the environment. Moreover, commitment mediated the effects of satisfaction and investments on general ecological behavior and willingness to sacrifice for the environment. In regression analyses, commitment predicted general ecological behavior and willingness to sacrifice for the environment, even when controlling for ecological worldview, inclusion of nature in the self, connectedness to nature, and environmental identity. Individuals who are satisfied with and invested in the natural world are likely to be committed to the environment and act with the well-being of the environment in mind.  相似文献   
369.
Western North America is experiencing a dramatic expansion of piñon (Pinus spp.) and juniper (Juniperus spp.) (P-J) trees into shrub-steppe communities. Feature extracted data acquired from remotely sensed imagery can help managers rapidly and accurately assess this land cover change in order to manage rangeland ecosystems at a landscape-scale. The objectives of this study were to: (1) develop an effective and efficient method for accurately quantifying P-J tree canopy cover and density directly from high resolution photographs and (2) compare feature-extracted data to typical in-situ datasets used by land managers. Tree cover was extracted from aerial-photography using Feature Analyst®. Tree density was calculated as the sum of the total number of individual polygons (trees) within the tree cover output file after isolation using a negative buffer post-processing technique. Feature-extracted data were compared to ground reference measurements from Utah’s Division of Wildlife Resources Range Trend Project (DWR-RTP). We found that the proposed feature-extraction techniques used for measuring cover and density were highly correlated to ground reference and DWR-RTP datasets. Feature-extracted measurements of cover generally showed a near 1:1 relationship to these data, while tree density was underestimated; however, after calibration for juvenile trees, a near 1:1 relationship was realized. Feature-extraction techniques used in this study provide an efficient method for assessing important rangeland indicators, including: density, cover, and extent of P-J tree encroachment. Correlations found between field and feature-extracted data provide evidence to support extrapolation between the two approaches when assessing woodland encroachment.  相似文献   
370.
The effectiveness of riparian zones in mitigating nutrient in ground and surface water depends on the climate, management, and hydrogeomorphology of a site. The purpose of this study was to determine the efficacy of a well drained, mixed-deciduous riparian forest to buffer a river from N originating from a poorly drained grass seed cropping system. The study site was adjacent to the Calapooia River in the Willamette Valley, Oregon. Water was found to move from the rapid drainage of swale surface water. During winter hydrological events, the riparian forest also received river water. Low nitrate (NO3-) concentrations (0.2-0.4 mg NO3- -NL(-1)) in the shallow groundwater of the cropping system were associated with low rates of mineralization and nitrification (33 kg N ha(-1) yr(-1)) and high grass seed crop uptake of N (155 kg N ha(-1) yr(-1)). The riparian forest soil had higher rates of mineralization (117 kg N ha(-1) yr(-1)) that produced quantities of soil N that were within the range of literature values for plant uptake, leading to relatively low concentrations of shallow groundwater NO3 (0.6-1.8 mg NO3- -NL(-1)). The swale that dissected the cropping system and riparian area was found to have the highest rates of denitrification and to contribute dissolved organic C to the river. Given the dynamic nature of the hydrology of the Calapooia River study site, data suggest that the riparian forest plays a role not only in reducing export of NO3- from the cropping system to the river but also in processing nutrients from river water.  相似文献   
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