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21.
Environmental Science and Pollution Research - Elemental status of 214 mares aged 3–7 years from 11 breeds was studied: Arabian purebred (n = 20), Bashkir (n = 20), Kabarda (n = 20), Vyatka...  相似文献   
22.
While collating contributions and comments from 36 researchers, the coordinating authors accidentally omitted Dr. Suzanne Carrière from the list of contributing co-authors. Dr. Carrière’s data are described in Tables 1 and 3, Figure 2 and several places in the narrative. The new author list is thus updated in this article.  相似文献   
23.
Doroth&#;e Ehrich  Niels M. Schmidt  Gilles Gauthier  Ray Alisauskas  Anders Angerbj&#;rn  Karin Clark  Frauke Ecke  Nina E. Eide  Erik Framstad  Jay Frandsen  Alastair Franke  Olivier Gilg  Marie-Andr&#;e Giroux  Heikki Henttonen  Birger H&#;rnfeldt  Rolf A. Ims  Gennadiy D. Kataev  Sergey P. Kharitonov  Siw T. Killengreen  Charles J. Krebs  Richard B. Lanctot  Nicolas Lecomte  Irina E. Menyushina  Douglas W. Morris  Guy Morrisson  Lauri Oksanen  Tarja Oksanen  Johan Olofsson  Ivan G. Pokrovsky  Igor Yu. Popov  Donald Reid  James D. Roth  Sarah T. Saalfeld  Gustaf Samelius  Benoit Sittler  Sergey M. Sleptsov  Paul A. Smith  Aleksandr A. Sokolov  Natalya A. Sokolova  Mikhail Y. Soloviev  Diana V. Solovyeva 《Ambio》2020,49(3):786-800
Lemmings are a key component of tundra food webs and changes in their dynamics can affect the whole ecosystem. We present a comprehensive overview of lemming monitoring and research activities, and assess recent trends in lemming abundance across the circumpolar Arctic. Since 2000, lemmings have been monitored at 49 sites of which 38 are still active. The sites were not evenly distributed with notably Russia and high Arctic Canada underrepresented. Abundance was monitored at all sites, but methods and levels of precision varied greatly. Other important attributes such as health, genetic diversity and potential drivers of population change, were often not monitored. There was no evidence that lemming populations were decreasing in general, although a negative trend was detected for low arctic populations sympatric with voles. To keep the pace of arctic change, we recommend maintaining long-term programmes while harmonizing methods, improving spatial coverage and integrating an ecosystem perspective.  相似文献   
24.
As the result of our research, the specific procedures to use emission factor methodology were developed and applied for trace metal emission evaluation into the atmosphere over the territory of the former Soviet Union. The existing data on heavy metal emissions were revised as background information from official sources and expert estimations. Source categories and different initial information as well as the concept of spatial emission distribution were defined and observed. The calculated atmospheric emissions of lead, cadmium and mercury were produced among the main source categories of 12 NIS countries for 1990, 1995 and 1997, using modified emission coefficients.Total cadmium emissions into the atmosphere from determined source categories were estimated as 388.4 tonnes in 1990 for the whole domain with reduction by up to 207.0 tonnes per year for 1997. Mercury emissions were estimated as equal to 303.2 tonnes in 1990 and 159.8 tonnes in 1997. Lead emission amounted to 24903.0 tonnes in 1990, and 9652.5 tonnes in 1997.The results of the evaluation demonstrated the general trends of atmospheric heavy metal emissions with a greater decrease during the first half of the 1990s followed later by the rather stable level to be explained by recession in industrial activity and fuel consumption in NIS in that period. The significant spatial variations of atmospheric emissions over vast territories are described based on the results of their distribution according to 1×1 degree grid with remarkably higher values in the location of industrial cities.  相似文献   
25.
The PM(2.5) concentration and its elemental composition were measured in the Cincinnati metropolitan area, which is characterized by intense highway traffic. The spatial and temporal variations were investigated for various chemical elements that contributed to the PM(2.5) fraction during a 1-year-long measurement campaign (December 2001-November 2002). The ambient aerosol monitoring was performed in 11 locations around the city during nine measurement cycles. During each cycle, four Harvard-type impactors were operating in parallel in specific locations to explore various factors affecting the PM(2.5) elemental concentrations. The sampling was performed during business days, thus assuring traffic uniformity. The 24-h PM(2.5) samples were collected on Teflon and quartz filters. Teflon filters were analyzed by X-ray fluorescence (XRF) analysis while quartz filters were analyzed by thermal-optical transmittance (TOT) analysis. In addition to PM(2.5) measurements, particle size-selective sampling was performed in two cycles using micro-orifice uniform deposit impactor; the collected fractionated deposits were analyzed by XRF. It was found that PM(2.5) concentration ranged from 6.70 to 48.3 mug m(-3) and had low spatial variation (median coefficient of variation, CV=11.3%). The elemental concentrations demonstrated high spatial variation, with the median CV ranged from 38.2% for Fe to 68.7% for Ni. For traffic-related trace metals, the highest concentration was detected in the city center site, which was close to a major highway. The particle size selective measurement revealed that mass concentration of the trace metals, such as Zn, Pb, Ni, as well as that of sulfur reach their peak values in the particle size range of 0.32-1.0 mum. Meteorological parameters and traffic intensity were not found to have a significant influence on the PM(2.5) elemental concentrations.  相似文献   
26.
Emerging challenges of risk management, environmental protection, and land-use planning requires integration of stakeholder values and expert judgment. The process of decision making in situation of high uncertainty can be assisted through the use of decision support systems (DSSs). Such DSSs are often based on tools for spatial data representation (GIS) and environmental models that are integrated using multi-criteria decision analysis (MCDA). This paper presents DecernsMCDA implementing all major types of multi-criteria methods and tools (AHP, MAUT, Outranking) under the same user interface. In addition to providing ability for testing model uncertainty associated with selection of specific MCDA algorithms, DecernsMCDA implements new algorithms for parameter uncertainty analysis based on probabilistic approaches and fuzzy sets. The paper illustrates application of DecernsMCDA for selecting remedial alternative at radiologically contaminated sites.  相似文献   
27.
The chemical composition of secondary organic aerosol (SOA) generated from the ozonolysis of isoprene (C5H8) in the presence of an OH scavenger was examined using high-resolution electrospray ionization mass spectrometry (ESI-MS) in the mass range m/z = 50–1000. The chemical composition of SOA is complex, with more than 1000 assigned peaks observed in the positive and negative ion mode spectra. Only a small fraction of peaks correspond to known products of isoprene oxidation, such as pyruvic acid, glycolic acid, methylglyoxal, etc. The absolute majority of the detected peaks correspond to highly oxidized oligomeric constituents of SOA, with an average O:C molar ratio of 0.6. The corresponding organic mass (OM) to organic oxygen (OO) ratio is 2.4. Approximately 8% of oxygen atoms in SOA are in the form of peroxides, as quantified with an iodide test. Double bond equivalency (DBE) factors, representing the sum of all double bonds and rings, increase by 1 for every 1–2 additional carbon atoms in the molecule. The number of unoxidized CC double bonds is estimated to be less than 10%; the remaining DBE is due to CO carbonyl groups. Kendrick analysis suggests that the prevalent oligomer building blocks are small carbonyls with a C1–C2 skeleton. Formaldehyde (CH2O) is identified as the most common repetitive building block in the observed oligomeric compounds.  相似文献   
28.
The crayfish play an essential role in the biomonitoring and may reflect ambient water quality through the biochemical, behavioural and physiological reactions. To assess whether narrow-clawed crayfish Astacus leptodactylus can respond by heart rate changes to presence in water of such biocide as chloramine-T, adult males were exposed to its low (2 and 5 mg L?1), moderate (10 mg L?1, commonly used in industry and aquaculture) and exceeded (20 and 50 mg L?1) concentrations. In addition, a physical stress test evaluated energy expenditure following the chemical trials. Three key reactions (cardiac initial, first-hour and daily prolonged exposure) were discussed with particular focus on crayfish initial reaction as the most meaningful in on-line water quality biomonitoring. After short-term exposure to both chloramine-T concentrations, crayfish were found to respond rapidly, within 2–5 min. According to heart rate changes, the 1-h exposure did not adversely affect crayfish at either concentration, as well as during daily exposure to 10 mg L?1. As assessed by the heart rate, the 24-h exposure to 50 mg L?1 of chloramine-T was toxic for crayfish and led to substantial loss of energy that became apparent during subsequently conducted physical stress. The results supported a hypothesis that crayfish vital functions are connected with environment they inhabit closely enough to serve as biological monitors. Crayfish were tolerant to short-term chloramine-T exposure, while rapid crayfish reaction to an increased chemical level indicated their high sensitivity, an essential attribute of real-time environmental assessment.  相似文献   
29.
We present the results of theoretical studies of the pressure fluid flow fundamental characteristics in tube coalescers used in the treatment processes for oily wastewater. It is shown that three different regions of flow (wall sublayer, transition sublayer, and flow kernel), having their own hydrodynamic characteristics, are formed in a cross section of the tube coalescer. In the viscous wall sublayer (of thickness δ*), viscous frictional forces exceed inertial forces (Reδ* < 1), and “creeping flow” is observed. This region borders on the transition sublayer (of thickness δ** = δ*), in which inertial forces exceed viscous frictional forces (Reδ** > 1). For both laminar and turbulent flow, distribution laws of local velocities and velocity gradients along the pipe radius are obtained in each of the three regions. In the flow kernel, the linear distribution law of velocity gradients gives a square distribution law of velocities for both types of flow, but for the turbulent flow, the correction coefficients = β and = 2β ? 1 must be introduced.  相似文献   
30.
Persecution and overexploitation by humans are major causes of species extinctions. Rare species, often confined to small geographic ranges, are usually at highest risk, whereas extinctions of superabundant species with very large ranges are rare. The Yellow‐breasted Bunting (Emberiza aureola) used to be one of the most abundant songbirds of the Palearctic, with a very large breeding range stretching from Scandinavia to the Russian Far East. Anecdotal information about rapid population declines across the range caused concern about unsustainable trapping along the species’ migration routes. We conducted a literature review and used long‐term monitoring data from across the species’ range to model population trend and geographical patterns of extinction. The population declined by 84.3–94.7% between 1980 and 2013, and the species’ range contracted by 5000 km. Quantitative evidence from police raids suggested rampant illegal trapping of the species along its East Asian flyway in China. A population model simulating an initial harvest level of 2% of the population, and an annual increase of 0.2% during the monitoring period produced a population trajectory that matched the observed decline. We suggest that trapping strongly contributed to the decline because the consumption of Yellow‐breasted Bunting and other songbirds has increased as a result of economic growth and prosperity in East Asia. The magnitude and speed of the decline is unprecedented among birds with a comparable range size, with the exception of the Passenger Pigeon (Ectopistes migratorius), which went extinct in 1914 due to industrial‐scale hunting. Our results demonstrate the urgent need for an improved monitoring of common and widespread species’ populations, and consumption levels throughout East Asia.  相似文献   
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