气相色谱法测定水和废水中丙烯腈

本文通过采用气相色谱法，以ＧＤＸ－５０２为固定相，ＦＩＤ为检测器测定水和废水中的丙烯腈，精密度和回收率高．方法简便易行，能满足行业废水和地面水的监队是水和废水中丙烯腈分析的较理想方法。     

The social contexts of some very low frequency calls of African elephants

Summary Several types of low frequency calls made by African elephants, Loxodonta africana, and the contexts in which they occurred are described. These calls had fundamental frequencies ranging from 14–35 Hz and sound pressure levels as high as 103±3dB (re 20 Pa) at 5 m from the source. Very low frequency sounds are subject to very little environmental attenuation, suggesting that sounds at the frequencies and sound pressure levels measured from elephants may be audible to conspecifics several km away. Long-term records on the behavior of elephants and on the contexts of specific call types suggest that elephants make use of infrasound in the spatial coordination of groups and as they search for mates.     

A comparison of Cu, Pb, As, Cd, Zn, Fe, Ni and Mn determined by acid extraction/ICP-OES and ex situ field portable X-ray fluorescence analyses

Total concentrations of Cu, Pb, As, Cd, Zn, Fe, Ni and Mn were determined for 81 soil samples using two types of field portable X-ray fluorescence (FPXRF) system; dual isotope and X-ray tube. FPXRF metal concentrations were statistically compared with analytical results from aqua regia extractions followed by Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) analysis. The ability of each FPXRF instrument to produce analytical results comparable to the reference method was assessed by linear regression. A high degree of linearity was found for Fe and Pb with the X-ray tube instrument and for Fe, Cu, Pb, Zn, Cd and Mn with the dual source instrument. FPXRF analyser performance improved with increased analysis time for Cu, Mn and Pb, whilst Fe, Zn, Cd, Ni and As showed no significant improvement. Particle size did not influence FPXRF analyser performance. Both the dual isotope and the X-ray tube FPXRF instruments are effective tools for rapid, quantitative assessment of soil metal contamination and for monitoring the efficacy of remediation strategies.     

Comparison of spontaneous antibiotic resistance frequency of Salmonella Typhimurium growth in glucose amended continuous culture at slow and fast dilution rates

The objective of the study was to determine the frequency of spontaneous acquisition of resistance to select antibiotics by Salmonella Typhimurium (ST) when grown in glucose amended continuous flow culture at slow (D = 0.025 h(-1)) or fast (D = 0.27 h(-1)) dilution rates. The bacterium was grown in LB minimal medium (pH 6.25) containing no antibiotics. Upon achieving steady state, samples were plated to tryptic soy agar (TSA) alone or supplemented (per ml) with 2 and 16 microg oxytetracycline, 4 and 16 microg tetracycline, 2 and 64 microg kanamycin, and 0.25 and 2 microg enrofloxacin. Regardless of growth rate, CFU of resistant ST from the TSA containing antibiotics was less than 2 x 10(1) except for 2 microg kanamycin and 0.25 microg enrofloxacin treatments (higher than 1 x 10(9) and 4 x 10(7) CFU of resistant ST for trials 1 and 2, respectively). Frequency of recovering resistant ST from the TSA containing the higher antibiotic concentrations was less than 1 in 10(9) for all antibiotics, but was higher on the media containing 2 microg kanamycin and 0.25 microg enrofloxacin at both slow and fast growth rates. In general, minimal susceptibility differences were detected for isolates from slow and fast dilution rates.     

Landscape assessment of side channel plugs and associated cumulative side channel attrition across a large river floodplain

Determining the influences of anthropogenic perturbations on side channel dynamics in large rivers is important from both assessment and monitoring perspectives because side channels provide critical habitat to numerous aquatic species. Side channel extents are decreasing in large rivers worldwide. Although riprap and other linear structures have been shown to reduce side channel extents in large rivers, we hypothesized that small “anthropogenic plugs” (flow obstructions such as dikes or berms) across side channels modify whole-river geomorphology via accelerating side channel senescence. To test this hypothesis, we conducted a geospatial assessment, comparing digitized side channel areas from aerial photographs taken during the 1950s and 2001 along 512 km of the Yellowstone River floodplain. We identified longitudinal patterns of side channel recruitment (created/enlarged side channels) and side channel attrition (destroyed/senesced side channels) across n?=?17 river sections within which channels were actively migrating. We related areal measures of recruitment and attrition to the density of anthropogenic side channel plugs across river sections. Consistent with our hypothesis, a positive spatial relationship existed between the density of anthropogenic plugs and side channel attrition, but no relationship existed between plug density and side channel recruitment. Our work highlights important linkages among side channel plugs and the persistence and restoration of side channels across floodplain landscapes. Specifically, management of small plugs represents a low-cost, high-benefit restoration opportunity to facilitate scouring flows in side channels to enable the persistence of these habitats over time.     

Correction to: Status and trends of circumpolar peregrine falcon and gyrfalcon populations

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.     

Ecolinguistics,GIS, and Corpus Linguistics for the Analysis of the Rosemont Copper Mine Debate

This article details an integration of geographical information system (GIS) and corpus linguistics (CL) techniques for an ecolinguistic analysis of a contentious, environmental debate in Arizona, USA. The application of GIS and CL procedures enabled the mapping of place name mentions present within two interest group corpora as well as the mapping of particular meanings and representations of specific places prominent in the debate, that is, maps representing both places and the discursive representations of those places were produced. The corpus-aided analysis and the GIS visualizations exhibit how different interest groups refer to and represent geographical places within their texts and how these references to and representations of places index ideological positions towards the mine and the environment. This integrated CL–GIS approach to the study of environmental discourse provides insights into the discursive representation of place and the importance that references to places serve within environmental discourse. The article briefly discusses the ecolinguistics framework underpinning the work, explains the GIS–CL approach, displays and interprets corpus findings and GIS visualizations, and details implications for additional GIS–CL research for environmental discourse.     

The influence of mix parameters and binder choice on the carbonation of cement solidified wastes

This paper explores the kinetics of carbonation of cement-based solidified hazardous waste. This study is part of a wide investigation into the effects of carbonation on solidified waste forms. Two commercially produced heavy metal wastes were solidified with three different types of Portland cement and two mineral admixtures and carbonated under controlled conditions. Measurements of the uptake of carbon dioxide were made for the different mixes and areas showing the degree of carbonation for each cement system were defined. The effects of water/binder ratio, waste and binder type on both total uptake of carbon dioxide and rate of carbonation were investigated and are discussed.