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Dreissenid mussels arrived at the Waverly Shoal located above the inflow of the Niagara River in 1989, initiating marked changes in the water and sediment chemistry, and benthic invertebrate community composition at an Ontario Ministry of the Environment, Conservation and Parks monitoring station. Here we examine change in the nearshore of eastern Lake Erie until 2019, inferred from monitoring at this station. Dreissenid numbers peaked in 1991, exceeding 200,000 individual m-2, and remained above 20,000 individual m-2 until 2004 after which numbers progressively declined. In 1993, the population transitioned from mixed Dreissena polymorpha and D. bugensis, to D. bugensis in subsequent years. The decrease in particle size and increase in organic content of surficial sediment which began the year after mussel arrival has persisted until present time. The low concentrations of trace metals and PAHs at the station increased slightly after the physical alteration in bed sediments and has either not changed or declined. After an initial increase in Secchi depth, water clarity changed little over post invasion years, with prevailing moderate water clarity interspersed with periods of bed resuspension and high turbidity. Calcium concentration in the water column, which fell dramatically after the arrival of dreissenids, has gradually increased in recent years. Chlorophyll a and total phosphorus levels indicating oligo-mesotrophic conditions have not varied systematically over the years, other than a modest decline in chlorophyll a after dreissenid arrival. Benthic invertebrate assemblages have gone through multiple alterations, with shifting abundance of amphipods, oligochaetes, chironomids, gastropods and sphaeriids attributed to invasive species rather than the physical environment. Collectively, the data suggests the nearshore ecosystem has shifted in benthic productivity and trophic transfers mediated by the benthos and invasive species, with water and sediment quality appearing to not vary beyond the range driven by inherently fluctuating physical conditions. [ABSTRACT FROM AUTHOR]

Understanding the geological uncertainty of hydrostratigraphic models is important for risk assessment in hydrogeology. An important feature of sedimentary deposits is the directional ordering of hydrostratigraphic units (HSU). Geostatistical simulation methods propose efficient algorithm for assessing HSU uncertainty. Among different geostatistical methods to simulate categorical data, Bayesian maximum entropy method (BME) and its simplified version Markov-type categorical prediction (MCP) present interesting features. In particular, the zero-forcing property of BME and MCP can provide a valuable constrain on directional properties. We illustrate the ability of MCP to simulate vertically ordered units. A regional hydrostratigraphic system with 11 HSU and different abundances is used. The transitional deterministic model of this system presents lateral variations and vertical ordering. The set of 66 (11 × 12/2) bivariate probability functions is directly calculated on the deterministic model with fast Fourier transform. Despite the trends present in the deterministic model, MCP is unbiased for the HSU proportions in the non-conditional case. In the conditional cases, MCP proved robust to datasets over-representing some HSU. The inter-realizations variability is shown to closely follow the amount and quality of data provided. Our results with different conditioning datasets show that MCP replicates adequately the directional units arrangement. Thus, MCP appears to be a practical method for generating stochastic models in a 3D hydrostratigraphic context. [ABSTRACT FROM AUTHOR]

ZnO nanotubes were prepared by selectivedissolution of electrodepositednanorods. The effect of solution pH, rod morphology, and chlorideion concentration on the dissolution mechanism was studied. The selectiveetching was rationalized in terms of the surface energy of the differentZnO crystal faces and reactant diffusion. The nanorod diameter andchloride concentration are the most influential parameters on thedissolution mechanism because they control homogeneous dissolutionor selective etching of the (110) and (002) surfaces. Bulk solutionpH only has an effect on the rate of dissolution. By accurate controlof the dissolution process, the nanomorphology can be tailored, andthe formation of rods with a thin diameter (10–20 nm), cavity,or ultra-thin-walled tubes (2–5 nm) can beachieved. [ABSTRACT FROM AUTHOR]

Abstract: ZnO nanostructured films fabricated by electrochemical deposition exhibit a variety of morphologies. Understanding their respective nucleation and growth mechanisms requires in situ techniques. A time-resolved X-ray absorption and fluorescence method is described, which adequately captures both processes and illustrates differences in the growth rates for films deposited at different potentials. In so doing, the new method has significant advantages over a previous method of continually scanning across the near-edge region of the absorption spectrum while the film was being deposited. [Copyright &y& Elsevier]

Diode laser spectra of SF5Cl have been recorded in the ν8 band region at a temperature of ca. 240 K, a pressure of 0.25 mbar and an instrumental bandwidth of ca. 0.001 cm-1. Four regions have been studied: a first one in the P-branch (906.849–907.687 cm-1), a second one in the Q-branch (910.407–910.944 cm-1), and two other ones in the R-branch (913.957–914.556 and 917.853–918.705 cm-1).The whole ν1/ν8 dyad of SF535Cl has been previously recorded in the group of Professor H. Bürger in Wuppertal, thanks to a Fourier transform infrared spectrometer [J. Mol. Spectrosc. 208 (2001) 169]. These data have thus been combined with our diode laser ones in the aim of refining the analysis. We used an effective Hamiltonian developed up to the fourth order and a set of programs called C4vTDS. One thousand three hundred and forty-six transitions for ν1, 495 (FTIR: 351; diode laser: 144) transitions for ν8, and 406 ground state combination differences have been assigned and fitted. A global fit has been obtained with a rms of 0.00081 cm-1 for the ν1 band, 0.0012 cm-1 for the FTIR data of the ν8 band, 0.00055 cm-1 for the diode laser data of this same band, and 0.00064 cm-1 for the ground state. It appears that more data (for instance, using a supersonic jet) are still necessary to obtain a completely satisfactory analysis of the ν8 region. [Copyright &y& Elsevier]

• Stochastic point conductivities are upscaled to define block K-tensor components. • A new bivariate Gaussian transformation preserves tensor components' correlations. • Linear coregionalisation model is used for simulation of equiprobable tensor fields. • Gradual deformation method (GDM) is used to calibrate fields to head observations. • Capture zones obtained with PEST and calibrated tensor fields are compared. Quasi-point hydraulic properties (K) measured locally under laboratory or field conditions need to be upscaled to block-scale K -tensors for use in flow simulators. The upscaled model also needs to be calibrated to hydraulic head observations. The calibration must preserve spatial covariance, cross-covariance and non-linear relations between tensor components. We apply a new upscaling method that allows to compute and model the covariance between block K -tensor components. We use a gradual deformation method for calibration of simulated K -tensor fields to measured head data. Our method incorporates a new bivariate transform that preserves the non-linear relations between K -tensor components. The ensemble of calibrated realizations allows quantification of uncertainty of groundwater flow models. A comparison with PEST on a test case defining capture zones for water supply wells shows that our method calibrates better to measured heads than PEST, provides more realistic K -tensors and results in larger capture zones. [ABSTRACT FROM AUTHOR]

Electrodeposition of highly crystalline ZnO nanostructures directlyonto copper phthalocyanine and pentacene thin films, from aqueous solutions containing zinc nitrate and dissolved oxygen, has been successfully demonstrated for the first time using a two-step electrochemical deposition process. Importantly, surface activation of the molecular thin film substrates by depositing a thin layer of ZnO nanoparticles at high cathodic overpotentials prior to film growth was found to be crucialfor achieving a dense coverage of ZnO nanostructures with uniform morphology. The mechanism for ZnO deposition via electroreduction of hydroxide precursor species (oxygen and NO3–ions) at the organic-electrolyte interface was shown to be analogous to that reported for conventional inorganic and metal electrodes. Comparison of cathodic current density-time curves, measured during deposition, with film orientation and morphology revealed that the cathodic current density and number of nucleation sites are key factors in determining the characteristics of ZnO film growth on organic substrates. Significantly, the CuPc and pentacene films are not damaged or degraded during this process. [ABSTRACT FROM AUTHOR]

Toronto Harbour, adjacent to a large urban centre on Lake Ontario, receives inputs from storm sewers, combined sewer overflows, and urban runoff that lead to contrasting water quality over the waterfront. Toronto’s Inner and Outer Harbours, mesotrophic and meso-oligotrophic, respectively, were investigated in 2008 to assess how water quality conditions were affected by loading gradients, weather and lake circulation. Spatially-intensive measurements of UV fluorescence, turbidity, conductivity, and chlorophyll a, together with lab-based analysis of chemistry at discrete sites, were used to depict patterns and contrasts in water quality in the harbour. Spatially-integrated field sensor data were also employed to examine the efficacy of using discrete water quality sampling to represent average conditions. Nitrogen, total phosphorus, dissolved organic carbon, major ions and E. coli gradients were a recurrent feature among surveys with concentrations decreasing away from the Don River mouth. The limited point-sample data reasonably depicted average conditions among areas of the harbour on the days of survey as did the results interpolated for a long-term monitoring station in the Inner Harbour. The strong variability seen within the Inner Harbour indicates that the most affected water quality conditions are likely under represented by area-wide conditions. Temporal variability in water quality, correlated with the discharge from the Don River, was strong yet under represented by the field-based sampling. Empirical prediction of total phosphorus concentrations in the Inner Harbour, and correlated with Don River discharge, were used to demonstrate both the critical need to address temporal variability in monitoring design and the possibility of using empirical predictive approaches drawing upon field sensor data to fill this gap. [ABSTRACT FROM AUTHOR]

We discuss the manifestation of dynamic heterogeneities in binary glass formers made of components with strongly different glass transition temperatures as revealed by 2 H and 31 P nuclear magnetic resonance spectroscopy (NMR) techniques such as line-shape, spin-lattice relaxation, and 2D exchange NMR. Polymer–plasticizer and non-polymeric mixtures are considered. Together with results from dielectric spectroscopy as well as from dynamic light scattering the component dynamics is probed separately. While the high- T g component shows relaxation features similar to that of neat glass formers, the majority of the low- T g component displays significantly faster dynamics and shows pronounced dynamic heterogeneities, i.e., an extremely broad distribution of correlation times G (ln τ ), which may lead to quasi-logarithmic correlation functions and which are reflected in a characteristic NMR phenomenology. Consequently, two glass transition temperatures with non-trivial concentration dependences are identified. The dynamic heterogeneities are transient in nature as proven by 2D exchange NMR. Thus, below the upper T g liquid-like (isotropic) reorientation as well as exchange within the distribution G (ln τ ) is observed in an essentially rigid matrix formed by the high- T g component. Yet, we find indications that a small fraction of the low- T g component follows the dynamics of the high- T g component. The results are compared with those collected for glass formers subjected to confining geometries. In both cases, the NMR features are very similar suggesting that also in binary glass formers (intrinsic) confinement effects may control the dynamics. [ABSTRACT FROM AUTHOR]

Abstract: The risk of groundwater contamination from shale gas exploration and development is a major societal concern, especially in populated areas where groundwater is an essential source of drinking water and for agricultural or industrial use. Since groundwater decontamination is difficult, or nearly impossible, it is essential to evaluate exploration and production conditions that would prevent or at least minimize risks of groundwater contamination. The current consensus in recent literature is that these risks are primarily related to engineering issues, including casing integrity and surface activities, such as truck traffic (equipment and fluid haulage), waste management (mainly drill cuttings), and water storage and treatment when hydraulic fracturing is utilized. Concerns have also been raised with respect to groundwater contamination that could result from potential fracture or fault interconnections between the shale unit and surficial aquifers, which would allow fracturing fluids and methane to reach the surface away from the wellbore. Despite the fact that groundwater resources are relatively well characterized in some regions, there is currently no recognized method to evaluate the vulnerability or risks to aquifers resulting from hydrocarbon industry operations carried out at great depths. This paper focuses on the Utica Shale of the St. Lawrence Platform (Quebec), where an environmental study aiming to evaluate potential risks for aquifers related to shale gas development has been initiated. To provide the context of these research efforts, this paper describes the regional tectono-stratigraphic evolution and current stress regime of the Cambrian–Ordovician St. Lawrence Platform, as well as the Utica Shale internal stratigraphy, mineralogy and thermal maturation. Then, the hydrogeological context of the St. Lawrence Platform is discussed. Finally, the methodology for this environmental study, based on geological, geophysical, geomechanical, hydrogeological and geochemical data, is presented. [Copyright &y& Elsevier]

Background: The abrogation of function of the tumor-suppressor protein p53 as a result of mutation of its gene, TP53, is one of the most common genetic alterations in cancer cells. We evaluated TP53 mutations and survival in patients with squamous-cell carcinoma of the head and neck.Methods: A total of 560 patients with squamous-cell carcinoma of the head and neck who were treated surgically with curative intent were enrolled in our prospective multicenter, 7-year study. TP53 mutations were analyzed in DNA from the tumor specimens with the use of the Affymetrix p53 chip and the Surveyor DNA endonuclease and denaturing high-performance liquid chromatography. Mutations were classified into two groups, disruptive and nondisruptive, according to the degree of disturbance of protein structure predicted from the crystal structure of the p53-DNA complexes. TP53 mutational status was compared with clinical outcome.Results: TP53 mutations were found in tumors from 224 of 420 patients (53.3%). As compared with wild-type TP53, the presence of any TP53 mutation was associated with decreased overall survival (hazard ratio for death, 1.4; 95% confidence interval [CI], 1.1 to 1.8; P=0.009), with an even stronger association with disruptive mutations (hazard ratio, 1.7; 95% CI, 1.3 to 2.4; P<0.001) and no significant association with nondisruptive mutations (hazard ratio, 1.2; 95% CI, 0.9 to 1.7; P=0.16). In multivariate analyses a disruptive TP53 alteration, as compared with the absence of a TP53 mutation, had an independent, significant association with decreased survival (hazard ratio, 1.7; 95% CI, 1.2 to 2.4; P=0.003).Conclusions: Disruptive TP53 mutations in tumor DNA are associated with reduced survival after surgical treatment of squamous-cell carcinoma of the head and neck. [ABSTRACT FROM AUTHOR]

Reports on a case of a 51-year-old man serving a prison sentence for automobile robbery. Medical history of subarachnoid haemorrhage due to a ruptured aneurysm of the anterior communicating artery; The compulsive behavior that lead to a prison sentence; Periods of reactive depression; Neuropsychological assessment after release from prison; CT-scan showing a lesion in the right orbitofrontal paramesial region with reduced blood flow; Orbitalfrontal lesions inducing acquired psychopathy.

OBJECTIVE: Cognitive functions of adolescents treated with ECT for mood disorder were evaluated at long-term follow-up. METHOD: At an average of 3.5 years (SD=1.7) after the last ECT, 10 subjects treated during adolescence with bilateral ECT for severe mood disorder completed a clinical and cognitive evaluation, including the California Verbal Learning Test and Squire's Subjective Memory Questionnaire. The same assessments were given to 10 psychiatric comparison subjects matched for sex, age, and diagnosis. RESULTS: All cognitive test scores of the patients treated with ECT were similar to those of the comparison subjects and did not differ from norms from the community. Six of the 10 ECT-treated patients reported having had memory losses immediately after the ECT course, but only one complained of subjective memory impairment at follow-up. CONCLUSIONS: The results suggest that adolescents given ECT for severe mood disorder do not suffer measurable cognitive impairment at long-term follow-up. [ABSTRACT FROM AUTHOR]