Persistence of culturable Escherichia coli fecal contaminants in dairy alpine grassland soils

Our knowledge of Escherichia coli (E. coli) ecology in the field is very limited in the case of dairy alpine grassland soils. Here, our objective was to monitor field survival of E. coli in cow pats and underlying soils in four different alpine pasture units, and to determine whether the soil could constitute an environmental reservoir. E. coli was enumerated by MPN using a selective medium. E. coli survived well in cow pats (10(7) to 10(8) cells g(-1) dry pat), but cow pats disappeared within about 2 mo. In each pasture unit, constant levels of E. coli (10(3) to 10(4) cells g(-1) dry soil) were recovered from all topsoil (0-5 cm) samples regardless of the sampling date, that is, under the snow cover, immediately after snow melting, or during the pasture season (during and after the decomposition of pats). In deeper soil layers below the root zone (5-25 cm), E. coli persistence varied according to soil type, with higher numbers recovered in poorly-drained soils (10(3) to 10(4) cells g(-1) dry soil) than in well-drained soils (< 10(2) cells g(-1) dry soil). A preliminary analysis of 38 partial uidA sequences of E. coli from pat and soils highlighted a cluster containing sequences only found in this work. Overall, this study raises the possibility that fecal E. coli could have formed a naturalized (sub)population, which is now part of the indigenous soil community of alpine pasture grasslands, the soil thus representing an environmental reservoir of E. coli.     

Theory of planned behaviour, identity and intentions to engage in environmental activism

This study incorporated identity constructs into the theory of planned behaviour (TPB) to investigate intentions to engage in environmental activism. First year students and participants of a students of sustainability conference (n=169) were administered a questionnaire survey that measured standard TPB constructs as well as environmental group membership and self-identity as an environmental activist. Consistent with predictions, environmental group membership and self-identity were positive predictors of intentions. Thus, greater involvement in environmental groups and a stronger sense of the self as an environmental activist were associated with stronger intentions to engage in environmental activism. There was also evidence that self-identity was a stronger predictor of intentions for participants with low rather than high environmental group membership. In accordance with the standard TPB model, participants with more positive attitudes toward and a greater sense of normative support for environmental activism also had greater intentions to engage in the behaviour. The implications for groups seeking to harness support for activities to protect the environment are discussed.     

Climatic design of vernacular housing in different provinces of China

For 2000 years, the inter-connexion between the specific structure of the Chinese eastern climates and the cultural background have produced remarkable vernacular housing types, both well adapted to the local conditions, and reflecting consistent values and knowledge. Stemming from a similar archetypal form, each house plan is translated through the specificity of the climate and resources of its site. One can think that the value and the diversity of this housing stock is due to the combination of the specific structure of the Chinese eastern climates, which creates the contrast of cold-dry winters and hot-humid summers, with the structure of the Ming t'ang, which contains the opposition of the yin and the yang. These two strong factors imprint a substantial cultural and conceptual unity upon all these housing types. Moreover, on the one hand, the geographical variations and, on the other hand, the local building materials generate a large diversity of housing types, of building techniques and of climatic devices which can be observed all around the country. These lessons could be valuable design guidelines from the past for the future.     

Temporal Trends of Young-of-Year Fishes in Lake Erie and Comparison of Diel Sampling Periods

We explored temporal trends of young-of-year (YOY) fishes caught in bottom trawl hauls at an established offshore monitoring site in Lake Erie in fall during 1961–2001. Sampling was conducted during morning, afternoon, and night in each year. Catches per hour (CPH) of alewife (Alosa pseudoharengus) YOY were relatively low and exhibited no temporal trend. This result was consistent with the species’ intolerance to Lake Erie’s adverse winter water temperatures. Gizzard shad (Dorosoma cepedianum) YOY decreased sharply after 1991, which was consistent with recent oligotrophication of the lake. Following the establishment in 1979 and rapid increase of white perch (Morone americana) YOY, white bass (Morone chrysops) and freshwater drum (Aplodinotus grunniens) YOY decreased. Trout-perch (Percopsis omiscomaycus) YOY decreased during 1986–1991, but recovered to previous levels during 1991–2001. The recovery coincided with the resurgence of mayflies (Ephemoptera) in the lake. CPH of spottail shiner (Notropis hudsonius) and emerald shiner (N. atherinoides) YOY exhibited no temporal trend between 1961 and the late 1970s to early 1980s. CPH of yellow perch (Perca flavescens) YOY decreased during 1961–1988, and walleye (Sander vitreum) YOY increased overall during the time series. These observations were consistent with published studies of adults in the region. CPH of 4 of the 10 species of YOY considered were greatest during night. CPH for walleye YOY was higher in the morning than in the afternoon, but there was no significant difference between night and morning abundances. The results suggest that (1) CPH of YOY fishes may be a useful monitoring tool for Lake Erie, and (2) offshore monitoring programs that do not include night sampling periods may underestimate recruitment for several common species.     

Study of trace metal leaching from coals into seawater

The behaviour of three South African coals in water and, particularly in seawater, was examined. A sequential speciation procedure used to evaluate trace metal partitioning in coal has shown that trace metals will not be easily released from these coals into environmental ecosystems. Only a few trace elements are slightly leached from these coals into water or seawater at pH around 8. On the other hand, Mn is highly leached from these coals into water or seawater. It has been clearly shown that Mn concentrations are highly correlated to sulfate and calcium concentrations indicating that Mn is mainly solubilized into water simultaneously to gypsum; the leaching efficiency being severely reduced for coal having a high calcite content. The leaching percentage of Mn into seawater is enhanced by the presence of seawater salts that increases gypsum solubility. The leaching process of Mn from coal into water or seawater is governed by gypsum solubilization and is relatively rapid during the first thirty minutes, then very slow. In this study, it has been also shown that, depending on their physico-chemical properties, trace metals may be removed from seawater solutions in the presence of coal having a high calcite content. In this work, it has been also shown that some elements, particularly Fe, are greatly solubilized into seawater in the presence of a strong chelating agent like EDTA. Like for Mn, the leaching rate of metals from coal in the presence of EDTA is relatively rapid during the first 30 min then much slower, suggesting a solubilization process simultaneously to gypsum or/and calcite solubilization.     

Cadmium concentrations in tissues of willow ptarmigan (Lagopus lagopus) and rock ptarmigan (Lagopus muta) in Nunavik, Northern Québec

Willow and rock ptarmigan were obtained from Northern Québec. Willow ptarmigan were found to have mean cadmium concentrations of 179.7 microg/g (dw) in the kidneys and 25.8 microg/g (dw) in the liver; these levels were three times higher than those found in the rock ptarmigan. The cadmium levels in the ptarmigan were below the threshold above which adverse effects can be observed in birds. The difference between the two ptarmigan species in cadmium content is explained by the diet. A comparison of their diet showed that willow, which stores cadmium, is an important food resource for willow ptarmigan but not for rock ptarmigan. Because there is limited information available on the consumption of ptarmigan kidneys and liver by the Inuit, and the fact that this is a traditional way of life and provides nutritional benefits to the Inuit population, no consumption guidelines are proposed.     

Varying Stable Nitrogen Isotope Ratios of Different Coastal Marsh Plants and Their Relationships with Wastewater Nitrogen and Land Use in New England, USA

The stable nitrogen isotope ratios of some biota have been used as indicators of sources of anthropogenic nitrogen. In this study the relationships of the stable nitrogen isotope ratios of marsh plants, Iva frutescens (L.), Phragmites australis (Cav.) Trin ex Steud, Spartina patens (Ait.) Muhl, Spartina alterniflora Loisel, Ulva lactuca (L.), and Enteromorpha intestinalis (L.) with wastewater nitrogen and land development in New England are described. Five of the six plant species (all but U. lactuca) showed significant relationships of increasing δ ¹⁵N values with increasing wastewater nitrogen. There was a significant (P < 0.0001) downward shift in the δ ¹⁵N of S. patens (6.0 ± 0.48‰) which is mycorrhizal compared with S. alterniflora (8.5 ± 0.41‰). The downward shift in δ ¹⁵N may be caused by the assimilation of fixed nitrogen in the roots of S. patens. P. australis within sites had wide ranges of δ ¹⁵N values, evidently influenced by the type of shoreline development or buffer at the upland border. In residential areas, the presence of a vegetated buffer (n = 24 locations) significantly (P < 0.001) reduced the δ ¹⁵N (mean = 7.4 ± 0.43‰) of the P. australis compared to stands where there was no buffer (mean = 10.9 ± 1.0‰; n = 15). Among the plant species, I. frutescens located near the upland border showed the most significant (R ² = 0.64; P = 0.006) inverse relationship with the percent agricultural land in the watershed. The δ ¹⁵N of P. australis and I. frustescens is apparently an indicator of local inputs near the upland border, while the δ ¹⁵N of Spartina relates with the integrated, watershed-sea nitrogen inputs.