Remote and in situ photogrammetric history of the Kidd Copper tailings site,Sudbury, Ontario

There is much concern regarding the genesis of acidic leachate by mine tailings and its potential impact on local water systems. Genesis of the leachate and its subsequent escape into the surrounding watershed is controlled by the primary distribution of facies within the tailings pond. Leachate generation and percolation is enhanced in high-sulphide coarse-grained sands, while percolation is restricted in fine-grained clays formed from bentonitic slimes. The Kidd Copper deposit, located on the South Range of the Sudbury Basin, was a typical offset dike nickel deposit, where mining took place between 1970 and 1990. Using a sequence of temporally separate aerial photographs dating from 1945 to 2002, it is possible to document the initial development of the mine, its closure and the subsequent degradation of the mine tailings waste that was produced during mining activity. Since the mine's closure, the resulting tailings deposit has progressively oxidized, generating acid-rich leachate. Leachate can escape from the tailings via surface run-off and subsurface flow. The spatial distribution of possible flow pathways was mapped using a combination of sub-centimetre-resolution real-time kinematic (RTK) GPS and individual, high-resolution, oriented photographs of subsurface pits. Lithologic mapping information of the Kidd Copper tailings deposit can provide an insight into the distribution of local aquifers and aquitards. Subsurface lithologic mapping was achieved using a combination of sub-centimetre-resolution RTK GPS and individual, high-resolution, oriented photographs of subsurface pits. The photograph of each pit provides lithologic information of a specific point in the tailings deposit, while the high-resolution GPS locates the individual photographs in three-dimensional (3D) geographic space. Combining these data allows us to identify continuous lithologic surfaces between pits, leading to the construction of a 3D model of the deposition of the tailings pond. Grain size and textural details extracted from the images of each lithology permit discrimination between aquifers and aquitards. The final geometric model could be used as input for estimating the hydrologic and chemical evolution of the tailings.     

Recovering Reasoning Processes from User Interactions

Understanding how analysts use visual-analytics (VA) tools can help reveal their reasoning processes when using these tools. By examining analysts' interaction logs, the authors identified the analysts' strategies, methods, and findings when using a financial VA tool.     

Composite chitosan and calcium sulfate scaffold for dual delivery of vancomycin and recombinant human bone morphogenetic protein-2

A biodegradable, composite bone graft, composed of chitosan microspheres embedded in calcium sulfate, was evaluated in vitro for point-of-care loading and delivery of antibiotics and growth factors to prevent infection and stimulate healing in large bone injuries. Microspheres were loaded with rhBMP-2 or vancomycin prior to mixing into calcium sulfate loaded with vancomycin. Composites were evaluated for set time, drug release kinetics, and bacteriostatic/bactericidal activity of released vancomycin, induction of ALP expression by released rhBMP-2, and interaction of drugs on cells. Results showed the composite set in under 36 min and released vancomycin levels that were bactericidal to S. aureus (>MIC 8–16 μg/mL) for 18 days. Composites exhibited a 1 day-delayed release, followed by a continuous release of rhBMP-2 over 6 weeks; ranging from 0.06 to 1.49 ng/mL, and showed a dose dependent release based on initial loading. Released rhBMP-2 levels were, however, too low to induce detectable levels of ALP in W20-17 cells, due to the affinity of rhBMP-2 for calcium-based materials. With stimulating amounts of rhBMP-2 (>50 ng/mL), the ALP response from W-20-17 cells was inhibited when exposed to high vancomycin levels (1,800–3,600 μg/mL). This dual-delivery system is an attractive alternative to single delivery or preloaded systems for bone regeneration since it can simultaneously fight infection and deliver a potent growth factor. Additionally, this composite can accommodate a wide range of therapeutics and thus be customizable for specific patient needs, however, the potential interactive effects of multiple agents must be investigated to ensure that functional activity is not altered.     

Firm Partial Modularity and Performance in the Electronic Manufacturing Services Industry

Firms continue to develop new ways to decentralize non-core activities to outside parties. Scholars have approached this issue with modularity theory, suggesting a continuum of arrangements ranging from hierarchy to market. Hierarchy relies on fiat, while partially modular forms, those forms between hierarchy and market, require greater coordination, communication and relationships between firms than do fully modular (or market) forms. While modularity theory identifies this continuum, the associated empirical literature tends to dichotomize modularity: firms are either modular or they are not. Nor does the empirical literature examine the performance outcomes of modular arrangements within this continuum. By examining firms that vary between full integration and partial modularity with a continuous modularity measure, this paper empirically examines the performance outcomes associated with a range of modularity levels. We derive this measure from a peculiar inventory option available within the electronic manufacturing services (EMS) industry. Our data include observations on 260 firms over five years. We find that more firms rely on partially modular arrangements, the lower their performance. We suggest explanations for this result, and areas of future research meant to pursue it.     

Family involvement in school and low-income children's literacy: Longitudinal associations between and within families.

Longitudinal data from kindergarten to 5th grade on both family involvement in school and children's literacy performance were examined for an ethnically diverse, low-income sample (N = 281). Within families, increased school involvement predicted improved child literacy. In addition, although there was an achievement gap in average literacy performance between children of more and less educated mothers if family involvement levels were low, this gap was nonexistent if family involvement levels were high. These results add to existing evidence on the value of family involvement in school by demonstrating that increased involvement between kindergarten and 5th grade is associated with increased literacy performance and that high levels of school involvement may have added reward for low-income children with the added risk of low parent education. As such, these results support arguments that family involvement in school should be a central aim of practice and policy solutions to the achievement gap between lower and higher income children. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Strategies used in coping with a cancer diagnosis predict meaning in life for survivors.

The search for meaning in life is part of the human experience. A negative life event may threaten perceptions about meaning in life, such as the benevolence of the world and one's sense of harmony and peace. The authors examined the longitudinal relationship between women's coping with a diagnosis of breast cancer and their self-reported meaning in life 2 years later. Multiple regression analyses revealed that positive strategies for coping predicted significant variance in the sense of meaning in life--feelings of inner peace, satisfaction with one's current life and the future, and spirituality and faith--and the absence of such strategies predicted reports of loss of meaning and confusion (ps     

Gender, employment and retirement quality: A life course approach to the differential experiences of men and women.

Using a life course perspective in integrating 2 theories of retirement satisfaction—role theory and continuity theory—this study draws on a sample of retired men (n?=?244) and women (n?=?214), ages 50–72, to investigate factors contributing to the quality of their retirement experience. Overall, we find that men report greater retirement satisfaction than women, although the difference is small. For women, increased retirement quality is associated with good health, a continuous career (fewer years spent in part-time employment), an early retirement (though not earlier than anticipated), and a good postretirement income. For men, the key correlates with retirement quality are good health, an enjoyable preretirement job, low work-role salience, substantial preretirement planning, and retiring for internally motivated reasons (e.g., to do other things). These results underscore the importance of a life course focus on gendered pathways to and through life transitions such as retirement. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A prospective study of adolescents' self-reported depressive symptoms: Are risk behaviours a stronger predictor than anxiety symptoms?

This longitudinal study of adolescents from a Nova Scotia coastal town examined whether change in self-reported depressive symptoms could be predicted from adolescents' concurrent and prior reports of anxiety symptoms and risk behaviors. Questionnaires were completed by 131 youths (80 females, 51 males; aged 12–17 yrs) in their classrooms 2 years apart. Results show that adolescents' concurrent reports of involvement in risk behaviors were linked to an increase in depressive symptoms only when they also were high on anxiety symptoms. Prior involvement in risk behaviors, but not prior anxiety symptoms, also predicted an increase in depressive symptoms. The importance of evaluating covariation among multiple types of symptoms and targeting the positive and negative consequences of risk behaviors adolescents is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interaction of bile salts with gastrointestinal mucins

The properties of three mucins were examined to identify the structural features responsible for their functional differences. Bovine submaxillary mucin (BSM), porcine gastric mucin (PGM), and rat intestinal mucin (RIM) were each characterized, and high carbohydrate contents were found for RIM and PGM. The amino acid compositions were typical of mucin glycoproteins, with over half comprising small, neutral amino acids. Thereafter, each mucin was equilibrated with three different series of concentrations of the bile salts sodium taurocholate, sodium taurodeoxycholate, and sodium taurochenodeoxycholate. Following multiple centrifugations, the supernatant and mucin pellet concentrations of the bile salts were measured. The bile salt pellet concentration was plotted as a function of supernatant concentration, and from the slopes, the excluded volumes were calculated as 25, 29–44, and 28–55 mL/g for BSM, RIM, and PGM, respectively. The intercepts were 8–10, 2–3, and 1–3 mM for BSM, RIM, and PGM, respectively, which represents an estimate of the bound concentration of bile salt. Differences among the bile salts were observed in the excluded volume and amount bound, but no trends were evident. The bile salts may interact as aggregates with the hydrophobic areas and carbohydrate side chains of the mucins, providing favorable sites for association. The binding at low concentrations with exclusion at high concentrations is significant for modulating the absorption of lipid aggregates from the intestine. Finally, the differences among the mucins reflect the unique structure-function relationship of these gastrointestinal mucins.     

Quantitative X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry characterization of the components in DNA

The great diversity of techniques to synthesize and use DNA microarrays has made them extremely flexible for a variety of applications. This flexibility also has made standardization difficult, leading to problems comparing data from these different systems. In this work, we use the surface science techniques of X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (TOF-SIMS) to analyze the components of DNA. The atomic ratios of the components of nucleobases, nucleosides, and nucleotides were characterized by XPS. The chemical shifts in the high-resolution XPS spectra allow for their relatively easy resolution. The unique positive and negative ions from the nucleobases, nucleosides, and nucleotides in their TOF-SIMS spectra were identified. This information was used to build a comprehensive table of all of the molecular ions. These standard spectra of DNA components can be used to predict the relative amounts of the bases within more complex molecules either by univariate analysis (i.e., by relating the base molecular ions to the sugar fragment ions within the nucleotides) or by multivariate analysis (e.g., principal component analysis). Our preliminary examination of four oligonucleotides shows promising results in that we can distinguish between two oligomers of similar composition using univariate and multivariate analysis, although additional studies are needed to expand this method to more complex oligomers.