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81.
The behavior of the herbicide terbuthylazine (TA) was studied in a clay loam soil after the addition of different organic amendments (OAs). Addition of poultry compost (PC) and urban sewage sludge (USS) retarded degradation of TA with half-life values of 60.3 and 73.7 d, respectively. In contrast, addition of corn straw (CS) did not significantly alter the degradation of TA (half-life 55.5 d) compared with its degradation in nonamended soils (half-life 57.3 d). Sterilization of amended and nonamended soils resulted in a partial inhibition of TA degradation, indicating that biotic and abiotic processes are involved in TA degradation in soil. Degradation of TA led to the formation of desethyl-terbuthylazine, which was detected in low amounts (<8% of the initially applied TA) in all soils. Adsorption of TA was relatively low, with Kd values ranging from 2.31 L kg(-1) in the nonamended soil to 3.93 L kg(-1) in the soil amended with USS. In general, Kd values increased with increasing soil organic carbon content. The dissolved organic matter extracted from the OAs did not appear to interact with the pesticide or the soil surfaces, suggesting that it would not probably facilitate herbicide transport. Desorption studies indicated a slight hysteresis of TA desorption in the amended soils compared with TA desorption in the nonamended soil, which was entirely reversible. These findings might have practical implications for the environmental fate of TA in agricultural soils, where the studied OAs are commonly used.  相似文献   
82.
This paper addresses environmental monitoring through a robust dynamic integration between biomonitor and biosensor systems, a strategy that has not been attempted before. The two systems are conceptually interrelated and methodologically correlated to a cooperative/synergistic scheme (CSS) with a view to minimise uncertainty and monitoring costs and increase reliability of pollution control and abatement. The structures and operations of the biosensor component (in terms of sensitivity, device and method versatility, nature-mimicking physicochemical mechanisms, prospects and technological input) are such that they reinforce or promote the structures and operations of the natural component (in terms of bio-surveillance, impact assessment, environmental quality indexing, stress responses, metabolic pathways, etc.) and vice versa. The bioindicator ontology presented herein, including concepts, relations and controlled vocabulary aiming at establishing an integrated methodology for mapping/assessing negative environmental externalities, provides a useful tool for the design/development/implementation of an environmental network for the monitoring of a variety of pollutants over time and space and the assessment of environmental quality; the collection of the available information and its classification into taxonomic and partonomic relations allows the construction of a database that links pollutants with organisms' response, at a phenomenological and in-depth level, considering ecological parameters, relations and geomorphologic characteristics. As a result, a computer program has been designed/developed as a decision support system and has been successfully tested on a representative population of species indigenous to southern Greece. Significantly, a novel system in the form of a rational framework at the conceptual design level has been developed, that actually contributes towards achieving a cost-effective long-term monitoring program, with the flexibility to counter on-course any (anticipated or not) variations/modifications of the surveillance environment. This novel and pioneering approach will further offer a dynamic system utilised in (a) environmental impact studies and risk assessment (positive/analytic approach), (b) decision-making in the short-run (normative/tactic approach), and (c) policy-making in the long-run (normative/strategic approach). The proposed CSS, based on the integration of multiple data sources, can establish a local area network, incorporated into/expanding to a wide area network, thus offering the potential of better predictive ability and greater lead-time warning at alarm conditions than that provided by separate, stand-alone surveillance modalities.  相似文献   
83.
Tourism is a vital sector of Cyprus economy, attracting millions of tourists every year and providing economic growth and employment for the country. The aim of this study was to investigate the impacts of projected climate change in the tourism industry in Cyprus (Republic of Cyprus) using both “Tourism Climate Index” (TCI) and “Beach Climate Index” (BCI). TCI refers to tourism activities mainly related to sightseeing, nature-based tourism, and religious tourism etc., while BCI represents beach tourism that constitutes 85 % of tourism activities in Cyprus. The projections of climate change impacts in tourism are performed for 2071–2100 period, using regional climate model output employing the A1B greenhouse gas emissions scenario. The 1961–1990 period is used as the control run to compare the respective results of the future projections. The significant warming anticipated in the distant future (increases in annual and summer temperatures close to 4 °C) will have adverse impacts on Cyprus tourism industry regarding sightseeing tourism. TCI results for the distant future period show only acceptable conditions for general tourism activities during summer in contrast with the good/very good conditions in the present climate. Conversely, this type of tourism seems to be benefited in shoulder seasons, i.e., during spring and autumn; TCI and hence tourist activities improve in the distant future in relation to the present climate. On the other hand, concerning beach tourism, future projections indicate that it will not be negatively affected by future climate change and any changes will be positive.  相似文献   
84.
As a self-organizing entity, an ant colony must divide a limited number of workers among numerous competing functions. Adaptive patterns of labor allocation should vary with colony need across each annual cycle, but remain almost entirely undescribed in ants. Allocation to foraging in 55 field colonies of the Florida harvester ant (Pogonomyrmex badius) followed a consistent annual pattern over 4 years. Foragers preceded larvae in spring and peaked during maximal larval production in summer (0.37). In spring, proportion foraging increased due to an increase in forager number and reduction in colony size, and in late summer, it decreased as colony size increased through new worker birth and a loss of ~3 % of foragers per day. The removal of 50 % of the forager population revealed that, at the expense of larval survival, colonies did not draw workers from other castes to fill labor gaps. To determine if labor allocation was age specific, whole colonies were marked with cuticle color-specific wire belts and released, and each cohort's time to first foraging was noted. Workers that eclosed in summer alongside sexual alates darkened quickly and became foragers at ~43 days of age, whereas autumn-born workers required 200 or more days to do so. Following colony reproduction, these long-lived individuals foraged alongside short-lived, summer-born sisters during the next calendar year. Therefore, the large-scale, predictable patterns of labor allocation in P. badius appear to be driven by bimodal worker development rate and age structure, rather than worker responsiveness to changes in colony demand.  相似文献   
85.
The amount of food and when it is available affect both the timing of reproduction and the number of gametes produced by purple sea urchins, Strongylocentrotus purpuratus. To investigate this further, the effects of food availability on feeding rates, gonad growth, and gamete development were examined in S. purpuratus collected from the Point Loma kelp forest near San Diego, California, USA (32.69° N, 117.26° W) in September (Fall) 2007, and February (Spring) and July (Summer) 2008, using laboratory mesocosms. Each seasonal laboratory feeding experiment lasted 3 months, and different levels of food availability were established with different feeding frequencies (from 1 to 7 days week−1). Gonad tissues of male and female urchins were staged at the end of each experiment using histological analyses. Reduced food availability resulted in increased daily consumption rates, especially in the Fall when gamete development began. Food limitation at this time resulted in failure to produce viable gametes, suggesting there is a critical period early in gonad development when food limitation affects reproductive competency. Food limitation later in gonad development did not stop viable gamete production, although it did reduce gamete output.  相似文献   
86.
A large-scale database concerning benthic copepods from the Arctic, Baltic Sea, North Sea, British Isles, Adriatic Sea and Crete was compiled to assess species richness, biodiversity, communities, ecological range size and biogeographical patterns. The Adriatic showed the highest evenness and the most species-rich communities. Assemblages from the North Sea, British Isles, Baltic and Crete had a lower evenness. The British Isles were characterised by impoverished communities. The ecological specificity of copepod species showed two diverging trends: higher specificity of species in more diverse assemblages was observed in the Adriatic, North Sea and Baltic. A uniformly high species specificity disregarding sample diversity was found on Crete and in the British Isles. Benthic copepod communities showed distinct patterns that clearly fit the predefined geographical regions. Communities were distinguishable and β-diversity was found to be high around Europe, indicating a high species turnover on the scale of this investigation. The British Isles and the North Sea were found to be faunistic links to the Baltic and the Arctic.  相似文献   
87.
A sequential extraction approach was utilized to estimate the distribution of arsenite [As(iii)] and arsenate [As(v)] on iron oxide/hydroxide solids obtained from drinking water distribution systems. The arsenic (As) associated with these solids can be segregated into three operationally defined categories (exchangeable, amorphous and crystalline) according to the sequential extraction literature. The exchangeable As, for the six drinking water solids evaluated, was estimated using 10 mM MgCl(2) and 10 mM NaH(2)PO(4) and represented between 5-34% of the total As available from the solid. The amorphously bound As was estimated using 10 mM (NH(4))(2)C(2)O(4) and represented between 57-124% of the As available from the respective solid. Finally, the crystalline bound As was estimated using titanium citrate and this represented less than 1.5% of the As associated with the solids. A synthetic stomach/intestine extraction approach was also applied to the distribution solids. The stomach fluid was found to extract between 0.5-33.3 microg g(-1) As and 120-2,360 microg g(-1) iron (Fe). The As concentrations in the intestine fluid were between 0.02-0.04 microg g(-1) while the Fe concentration ranged from 0.06-0.7 microg g(-1) for the first six drinking water distribution solids. The elevated Fe levels associated with the stomach fluid were found to produce Fe based precipitates when the intestinal treatment was applied. Preliminary observations indicate that most of the aqueous Fe in the stomach fluid is ferric ion and the observed precipitate produced in the intestine fluid is consistent with the decreased solubility of ferric ion at the pH associated with the intestine.  相似文献   
88.
The priority substances of List I, 76/464/EEC Directive, some of which belong to the new Water Framework Directive 2000/60/EC, have been monitored in the surface waters of Greece through the developed network of 53 sampling stations. The analytical methods used for the determination of these substances included Purge and Trap-Gas chromatography-Mass spectrometry for volatile and semivolatile organic compounds, Gas Chromatography-Electron Capture Detection for organochlorine insecticides, High Performance Liquid Chromatography for pentachlorophenol and Atomic Absorption Spectrometry for metals. The results have shown the presence of several priority substances in Greek surface waters, in most cases at concentrations well below the regulatory limits. However, non-compliance was observed for a limited number of compounds. The monitoring network and the analytical determinations have to be expanded to more water bodies and more priority substances, in order to safeguard the quality of Greek surface waters.  相似文献   
89.
Some of the most spectacular visual signals found in the animal kingdom are based on dietarily derived carotenoid pigments (which cannot be produced de novo), with a general assumption that carotenoids are limited resources for wild organisms, causing trade-offs in allocation of carotenoids to different physiological functions and ornamentation. This resource trade-off view has been recently questioned, since the efficiency of carotenoid processing may relax the trade-off between allocation toward condition or ornamentation. This hypothesis has so far received little exploratory support, since studies of digestive efficiency of wild animals are limited due to methodological difficulties. Recently, a method for quantifying the percentage of fat in fecal samples to measure digestive efficiency has been developed in birds. Here, we use this method to test if the intensity of the carotenoid-based coloration predicts digestive efficiency in a wild bird, the house finch (Haemorhous mexicanus). The redness of carotenoid feather coloration (hue) positively predicted digestion efficiency, with redder birds being more efficient at absorbing fats from seeds. We show for the first time in a wild species that digestive efficiency predicts ornamental coloration. Though not conclusive due to the correlative nature of our study, these results strongly suggest that fat extraction might be a crucial but overlooked process behind many ornamental traits.  相似文献   
90.
Concentrations of total suspended particulate matter, particulate matter with aerodynamic diameter <2.5 μm (PM2.5), particulate matter <10 μm (PM10), and fallout dust were measured at the Iranian Gol-E-Gohar Mining and Industrial Facility. Samples were characterized in terms of mineralogy, morphology, and oxidative potential. Results show that indoor samples exceeded the 24-h PM2.5 and PM10 mass concentration limits (35 and 150 µg m?3, respectively) set by the US National Ambient Air Quality Standards. Calcite, magnetite, tremolite, pyrite, talc, and clay minerals such as kaolinite, vermiculite, and illite are the major phases of the iron ore PM. Accessory minerals are quartz, dolomite, hematite, actinolite, biotite, albite, nimite, laumontite, diopside, and muscovite. The scanning electron microscope structure of fibrous-elongated minerals revealed individual fibers in the range of 1.5 nm to 71.65 µm in length and 0.2 nm to 3.7 µm in diameter. The presence of minerals related to respiratory diseases, such as talc, crystalline silica, and needle-shaped minerals like amphibole asbestos (tremolite and actinolite), strongly suggests the need for detailed health-based studies in the region. The particulate samples show low to medium oxidative potential per unit of mass, in relation to an urban road side control, being more reactive with ascorbate than with glutathione or urate. However, the PM oxidative potential per volume of air is exceptionally high, confirming that the workers are exposed to a considerable oxidative environment. PM released by iron ore mining and processing activities should be considered a potential health risk to the mine workers and nearby employees, and strategies to combat the issue are suggested.  相似文献   
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