Historic brownfields and industrial activity in Kingston, Ontario: Assessing potential contributions to mercury contamination in sediment of the Cataraqui River

The waterfront of historic Kingston, Ontario (pop: 113,000) has been used for industrial activities for over a century. More than 40 industries have existed within the inner harbour, and while many of these industries are no longer present, the properties that they operated on remain as potential sources of persistent contamination to the present day, including mercury. To assess the extent and distribution of total mercury (THg) contamination, 21 sediment cores as well as pore water samples were collected within the inner harbour of Kingston. The spatial distribution of THg in the surface sediment is not homogenous; with concentrations in the surface sediment along the southwestern shoreline, adjacent to the former industrial properties, are significantly greater (p < 0.01) than the rest of the inner harbour, and were above the Federal severe effect limit (> 2000 ug/kg;) guideline for sediment. MeHg was detected in some sediment cores, and was found to have a significant, positive correlation with [THg] in the surface sediment (0-5 cm). THg was not found in storm sewer discharges, but was detected in terrestrial soil near the Kingston Rowing Club at a concentration of more than 4000 ug/kg. Significant [THg] was detected in runoff draining from contaminated shoreline soils, indicating that erosion from terrestrial sources may be an ongoing source of Hg to the sediment. It can be concluded that there is an increased risk over time to surrounding ecosystems where properties with historical contamination are not remediated until they are developed.     

Hydrocarbon binary diffusion coefficient measurements for use in combustion modeling

Recent studies have identified uncertainties in fuel diffusion coefficients as a source of significant uncertainty in combustion modeling. This paper presents accurate binary diffusion coefficients of linear hydrocarbons in helium and nitrogen at temperatures from 300 K to 723 K. Diffusion coefficients are determined using a reversed-flow gas chromatography (RF-GC) system. Earlier work in our laboratory has established the validity of this methodology for noble gases and methane under these elevated-temperature conditions, and we utilize the methodology to measure diffusion coefficients for longer chain systems of interest in combustion modeling: ethane, propane, and n-butane. For propane and n-butane in nitrogen, the present results show dramatically different (up to 16.9% deviation at the highest common temperature) diffusion coefficients than previous work in addition to extending the available temperature range. The effects of decomposition of the analyte at higher temperatures and adhesion of the analyte on the diffusion column at lower temperatures during the measurements are briefly considered but have only a small impact on the present systems.     

The preparation of hydroxystearic acids from red oil (Commercial oleic acid)

The hydroacetoxylation of red oil (commercial oleic acid) in acetic acid solution has been studied. The optimum hydroacetoxylation conditions were obtained under anhydrous conditions using sulphuric acid as a catalyst at:

1. 1.
   a concentration of 1% (based on the wt of red oil).     

Interactions between Whey Protein Isolate and Soy Protein Fractions at Oil–Water Interfaces: Effects of Heat and Concentration of Protein in the Aqueous Phase

ABSTRACT:  The 2 main storage proteins of soy—glycinin (11S) and β-conglycinin (7S)—exhibit unique behaviors during processing, such as gelling, emulsifying, or foaming. The objective of this work was to observe the interactions between soy protein isolates enriched in 7S or 11S and whey protein isolate (WPI) in oil–water emulsion systems. Soy oil emulsion droplets were stabilized by either soy proteins (7S or 11S rich fractions) or whey proteins, and then whey proteins or soy proteins were added to the aqueous phase. Although the emulsifying behavior of these proteins has been studied separately, the effect of the presence of mixed protein systems at interfaces on the bulk properties of the emulsions has yet to be characterized. The particle size distribution and viscosity of the emulsions were measured before and after heating at 80 and 90 °C for 10 min. In addition, SDS-PAGE electrophoresis was carried out to determine if protein adsorption or exchanges at the interface occurred after heating. When WPI was added to soy protein emulsions, gelling occurred with heat treatment at WPI concentrations >2.5%. In addition, whey proteins were found adsorbed at the oil–water interface together with 7S or 11S proteins. When 7S or 11S fractions were added to WPI-stabilized emulsions, no gelation occurred at concentrations up to 2.5% soy protein. In this case also, 7S or 11S formed complexes at the interface with whey proteins during heating.     

Treatment of osteoarthritis with aspartame

OBJECTIVE: The binding of sweet-tasting compounds in a human (Mcg) Bence-Jones dimer has been characterized by x-ray crystallography. Aspartame binding in this immunoglobulin fragment is remarkable. Unexpected pain relief noted by A.B.E., a crystallographer with diagnosed osteoarthritis, suggested that the accommodation of aspartame in the active site of the dimer may represent surrogate binding by other proteins, with analgesia as the outcome. METHODS: X-ray analysis of the complex of aspartame and the Bence-Jones dimer was conducted with crystalline Mcg protein and pure aspartame. A single-blind (n = 1) study to confirm analgesia was completed by administration of aspartame to A.B.E. A controlled double-blind trial was performed in patients with x-ray-documented osteoarthritis. Pain and performance changes were evaluated with use of two doses of placebo and two doses of aspartame. Effects on bleeding time were then evaluated by determination of template bleeding times in 34 normal volunteers. Finally, antipyretic effects were studied in Sprague-Dawley rats given intramuscular turpentine injections. RESULTS: Aspartame binding in the Bence-Jones dimer was verified by x-ray crystallography. Improvements in performance and pain relief were observed in A.B.E. at p < 0.001. Decreased pain and improved performance were also observed in patients with osteoarthritis (p < 0.001). Mild antihemostatic responses were observed in bleeding times after aspartame treatment. Modified template bleeding times increased at p < 0.01. Aspartame blocked the turpentine-mediated febrile responses in the treated rats (p < 0.01). CONCLUSIONS: L-Aspartyl-L-phenylalanine methyl ester is biologically active and appears to relieve pain, induce mild antithrombotic effects in humans, and decrease fever in animals.     

Hydrogen Atom Attack on Fluorotoluenes: Rates of Fluorine Displacement

Rates of hydrogen atom attack on o-fluorotoluene (o-FTOL) and m-fluorotoluene (m-FTOL) at temperatures of 988–1144 K and pressures of 2–2.5 bar have been determined in a single-pulse shock tube study. Hydrogen atoms, generated from the decomposition of hexamethylethane, were allowed to react with the substrates and the characteristic products observed. Rate constants for two reaction channels, displacement of fluorine or methyl, were determined relative to displacement of methyl from 1, 3,5-trimethylbenzene (135TMB). Evidence is presented that abstraction of F is unimportant over the studied temperature range. With k(H + 135TMB → m-xylene + CH₃) = 6.7 × 10¹³ exp(–3255/T) cm³ mol⁻¹s⁻¹, the following rate expressions have been derived: k(H + o-FTOL → C₆H₅CH₃ + F) = 8.38 × 10¹³ exp(–6041/T) cm³ mol⁻¹s⁻¹; (1012–1142 K) k(H + o-FTOL → C₆H₅F + CH₃) = 2.37 × 10¹³ exp(–2938/T) cm³ mol⁻¹s⁻¹; (988–1142 K) k(H + m-FTOL → C₆H₅CH₃ + F) = 1.33 × 10¹⁴ exp(–6810/T) cm³ mol⁻¹s⁻¹; (1046–1144 K) k(H + m-FTOL → C₆H₅F + CH3) = 2.04 × 10¹³ exp(–3104/T) cm³ mol⁻¹s⁻¹; (1008–1144 K) Uncertainties in the relative rate constants are estimated to be factors of about 1.1, while the above absolute values have estimated expanded uncertainties of about a factor of 1.4 in rate, 10 kJ mol⁻¹ in the activation energy, and a factor of 3 in the A-factor. The present data are compared with relevant literature data. From our data and the thermochemistry, a model of the elementary steps comprising displacement of F is developed. On the basis of the model fit to our data, rate constants for the addition of atomic fluorine to toluene at 1100 K are derived. Rate expressions for fluorination reactions of toluene are also determined. The significance of the present results is discussed in the context of the formation of fluorinated byproducts in high-temperature systems.     

Anthropocene streams and base-level controls from historic dams in the unglaciated mid-Atlantic region, USA

Recently, widespread valley-bottom damming for water power was identified as a primary control on valley sedimentation in the mid-Atlantic US during the late seventeenth to early twentieth century. The timing of damming coincided with that of accelerated upland erosion during post-European settlement land-use change. In this paper, we examine the impact of local drops in base level on incision into historic reservoir sediment as thousands of ageing dams breach. Analysis of lidar and field data indicates that historic milldam building led to local base-level rises of 2-5 m (typical milldam height) and reduced valley slopes by half. Subsequent base-level fall with dam breaching led to an approximate doubling in slope, a significant base-level forcing. Case studies in forested, rural as well as agricultural and urban areas demonstrate that a breached dam can lead to stream incision, bank erosion and increased loads of suspended sediment, even with no change in land use. After dam breaching, key predictors of stream bank erosion include number of years since dam breach, proximity to a dam and dam height. One implication of this work is that conceptual models linking channel condition and sediment yield exclusively with modern upland land use are incomplete for valleys impacted by milldams. With no equivalent in the Holocene or late Pleistocene sedimentary record, modern incised stream-channel forms in the mid-Atlantic region represent a transient response to both base-level forcing and major changes in land use beginning centuries ago. Similar channel forms might also exist in other locales where historic milling was prevalent.     

Designing a carbon market that protects forests in developing countries

Firmly incorporated into the Kyoto Protocol, market mechanisms offer an innovative and cost-effective means of controlling atmospheric concentrations of greenhouse gases. However, as with markets for many other goods and services, a carbon market may generate negative environmental externalities. Possible interpretations and application of Kyoto provisions under COP-6bis and COP-7 raise concerns that rules governing forestry with respect to the Kyoto carbon market may increase pressure on native forests and their biodiversity in developing countries. In this paper, we assess the following two specific concerns with Kyoto provisions for forestry measures. First, whether, under the Clean Development Mechanism (CDM), by restricting allowable forestry measures to afforestation and reforestation, and explicitly excluding protection of threatened native forests, the Kyoto Protocol will enhance incentives for degradation and clearing of forests in developing countries; second, whether carbon crediting for forest management in Annex I (industrialized) regions under Article 3.4 creates a dynamic that can encourage displacement of timber harvests from Annex I countries to developing nations. Given current timber extraction patterns in developing regions, additional harvest pressure would certainly entail a considerable cost in terms of biodiversity loss. In both cases, we find that the concerns about deleterious impacts to forests and biodiversity are justified, although the scale of such impacts is difficult to predict. Both to ensure reliable progress in managing carbon concentrations and to avoid unintended consequences with respect to forest biodiversity, the further development of the Kyoto carbon market must explicitly correct these perverse incentives. We recommend several steps that climate policymakers can take to ensure that conservation and restoration of biodiversity-rich natural forests in developing countries are rewarded rather than penalized. To correct incentives to clear natural forests through CDM crediting for afforestation and reforestation, we recommend for the first commitment period that policymakers establish an early base year, such as 1990, such that lands cleared after that year would be ineligible for crediting. We further recommend an exception to this rule for CDM projects that are explicitly designed to promote natural forest restoration and that pass rigorous environmental impact review. Restoration efforts are typically most effective on lands that are adjacent to standing forests and hence likely to have been recently cleared. Thus, we recommend for these projects establishing a more recent base year, such as 2000. For the second and subsequent commitment periods, we recommend that climate policymakers act to restrain inter-annex leakage and its impacts by ensuring that crediting for forest management in industrialized countries is informed by modelling efforts to anticipate the scale of leakage associated with different Annex I 'Land use, land-use change and forestry' policy options, and coupled with effective measures to protect natural forests in developing countries. The latter should include expanding the options permitted under the CDM to carbon crediting for projects that protect threatened forests from deforestation and forest degradation. Ultimately, carbon market incentives for forest clearing can be reduced and incentives for forest conservation most effectively strengthened by fully capturing carbon emissions associated with deforestation and forest degradation in developing countries under a future emissions cap. Finally, we note that these recommendations have broader relevance to any forest-based measures to reduce greenhouse-gas emissions developed outside of the specific context of the Kyoto Protocol.     

The benefits of peer collaboration on strategy use, metacognitive casual attribution, and recall

This study examined the benefits of a peer collaborative activity on cognitive strategy use and effectiveness, and on metacognitive understanding of strategy use. Children's knowledge about the effectiveness of the sorting strategy grouped them into lower and higher metacognitive understanding. Treatment group triads, consisting of children with lower and higher levels of metacognitive understanding, were given a collaborative recall task. Results indicated that interaction with children working at a higher level of metacognitive knowledge, in conjunction with directions to explicitly discuss strategies, increased strategy use and induced higher levels of metacognitive thinking in children who had been operating at lower levels of metacognitive thinking. overall, children's use of the sorting strategy and recall performance improved as a function of treatment group membership. Implications for future research are discussed.