Effects of Capping on Biodegradation of Organic Contaminants in Sediments

Sediment capping remains an effective remediation technique for contaminated sediments due to its capability to contain contaminants and provide a sound habitat for indigenous biota. This research investigated the effect of capping on biodegradation of organic contaminants in Anacostia River sediments using both experimental and modeling techniques. 14C–Phenanthrene mineralization was monitored under various redox conditions in Anacostia River sediments. Mineralization of 14C–phenanthrene was strongly linked to sulfate reduction, which was the more energetic process than any other anaerobic condition in Anacostia sediments. Sulfate is a more promising terminal electron acceptor for intrinsic degradation in Anacostia River and other PAH contaminated sites. A sediment flux model was developed as a framework for simulations pertinent to this work and for future use in the field of environmental remediation. The model can be used to predict the response of the primary nutrients and overall sediment redox state after step changes in boundary conditions in sediment. Further, this study investigated the effects of reactive capping on long-term attenuation of organic contaminants, polycyclic aromatic hydrocarbons (PAHs) and hexachlorobenzene (HCB). Microcosm studies were conducted to investigate the attenuation potential of PAHs and HCB in Anacostia River sediment mixed with BionSoil as a capping material. BionSoil was used because it is rich in organic and carbon sources for driving anaerobic biodegradation and reductive dechlorination reactions. Faster removal kinetics and high sorption potential of HCB were observed in higher ratios of BionSoil than lower ones while for PAHs there were no differences among the treatments. Generally, degradation kinetics of PAHs and HCB were observed to be the fastest under sulfate-reducing conditions followed by ferric iron-reducing, methanogenesis, and manganic manganese-reducing conditions. Hydrogen concentration trends also suggested that hydrogen was used as an electron donor during both sulfate reduction and methanogenesis. BionSoil was found to be a promising material for ex-situ bioremediation in chlorinated solvents contaminated sites. Detection of the 16S rDNA of Pelobacter sp. and Desulfuromonas sp. by DNA extraction, PCR amplification, cloning and sequencing observed in Anacostia sediment under sulfate reducing conditions. Microbial community analysis results suggested that Pelobacter sp. and Desulfuromonas sp., which are members of Geobacteraceae family, possibly played important roles in the anaerobic degradation of PAHs

Consumer adoption and diffusion of technological innovations : a case of electronic banking technologies

Today, technological advancements occur rather constantly as companies introduce innovative products and services to consumers. Consequently, technological innovations have brought fundamental changes in many areas of consumers\u27 lives. One such area is exchange, transactions, and contacts mediated by electronic technology. Among many technological innovations, electronic banking is currently one of the most available technological options to consumers. Electronic banking technologies refer to all the financial activities involving electronic media such as Automated Teller Machines (ATMs), debit cards, direct deposit/payment, smart cards, and computer banking. Using these electronic banking technologies, consumers can conduct fast and convenient financial transaction activities and obtain their account information without paying a visit to bank branches. This study presents a model of consumer adoption and diffusion of technological innovations. This model conceptualizes that an individual consumer\u27s adoption of a technological innovation is influenced by consumer, innovation, and communication factors. First, consumer factors refer to characteristics of consumers such as demographic and socioeconomic characteristics. Consumers\u27 particular characteristics may affect their decision to adopt technological innovations. Second, innovation factors include consumers\u27 perceived innovation characteristics. How consumers perceive a technology, e.g., as useful, reliable, secure is believed to influence their decision to adopt and use the technology. Finally, communication factors refer to how the information about technological innovation is passed on to consumers. Channel and mode of communication are considered to have impacts on consumer adoption of technological innovations. Three research objectives are generated from the conceptual model. The first objective is to examine the extent to which consumers adopt a variety of electronic banking technologies and to describe the characteristics of adopters and non-adopters of electronic banking technologies. The second objective is to identify the underlying factors that affect consumer adoption of electronic banking technologies accurately. The third objective is to investigate the role of communication in consumer adoption of electronic banking technologies. In order to address each objective, three independent yet related studies were conducted employing two nationally representative databases: The 1995 Survey of Consumer Finances (SCF) commissioned by Federal Reserve Board and the 1999 University of Michigan Survey of Consumers. The first study examined the diffusion of various electronic banking technologies, such as ATMs, debit cards, smart cards, direct deposit, and direct payment, along with the characteristics of adopters and non-adopters of those technologies. Using the 1995 Survey of Consumer Finances, it was found that, in general, more educated, more affluent, and younger consumers who are likely to communicate with professional information providers tend to adopt electronic banking technologies more readily than their counterparts. However, the specific factors that affect the adopters\u27 decision varied across different types of banking technologies. The second study investigated the impacts of innovation and consumer factors on adoption of both mature and newer innovations, i.e., ATMs and computer banking. Accessibility is an important factor that needs to be accounted for in modeling consumer adoption of computer banking because a consumer\u27s decision to adopt the electronic banking technologies can be restricted by whether the consumer has access to the technologies. Therefore, accessibility was explicitly incorporated in modeling consumer adoption of computer banking. An adjustment to avoid biased estimation was made by employing a censored probit model. Using a national sample of 890 consumers, the empirical model estimated the effects of perceived innovation characteristics and consumer characteristics on the adoption computer banking and the ATM. Results suggested that there was significant sample selection bias with regard to access when estimating the consumer adoption of computer banking. It was found that individual socioeconomic characteristics were significant predictors of accessibility to computer banking. Perceived innovation characteristics were highly significant in influencing consumers\u27 adoption of both computer banking and ATMs. The results suggest the importance of communication strategies to change consumers\u27 perceptions of electronic banking technologies as secure, reliable, convenient, and easy-to-use. The third study explored communication strategies to facilitate diffusion of innovations. More specifically, the effects of channel and communication mode on consumers\u27 adoption of electronic banking innovations were examined with the proposed taxonomy of channel and communication mode. Using data from the 1999 University of Michigan Survey of Consumers, consumers were classified into five electronic-banking-user dusters, individual consumers\u27 adoption was influenced by communication patterns, and innovators and laggards were found to have different preferences for channel and communication mode. Therefore, innovators and laggards can be reached effectively by adopting the right channel and communication mode. Laggards need tailored communication efforts that consider their preference for interpersonal, conversational communication, innovators can be reached relatively easily via written communication from professional information sources. In sum, the three research studies reveal that consumer adoption and diffusion of electronic banking technologies are influenced by joint influences of consumer, innovation, and communication factors. Among these factors, consumers\u27 perceptions of innovations are a more important determining factor of their adoption decisions than consumers\u27 demographic characteristics. In addition, when predicting adoption of newer innovations such as computer banking, accessibility also needs to be considered In order to adjust for sample selection bias. Communication is the process that diffusion agents, such as financial institutions and the government, can use to influence consumer adoption of electronic banking technologies. In order to facilitate consumer adoption. It is necessary to promote convenient, secure, reliable, and easy-to-use features to potential adopters by employing appropriate channels and communication modes. Finally, implications for practitioners, policy makers, and future research are discussed

Factors That Enhance Consumer Trust in Human-Computer Interaction: An Examination of Interface Factors and Moderating Influences

The Internet coupled with agent technology presents a unique setting to examine consumer trust. Since the Internet is a relatively new, technically complex environment where human-computer interaction (HCI) is the basic communication modality, there is greater perception of risk facing consumers and hence a greater need for trust. In this dissertation, the notion of consumer trust was revisited and conceptually redefined adopting an integrative perspective. A critical test of trust theory revealed its cognitive (i.e., competence, information credibility), affective (i.e., benevolence), and intentional (i.e., trusting intention) constructs. The theoretical relationships among these trust constructs were confirmed through confirmatory factor analysis and structural equation modeling. The primary purpose of this dissertation was to investigate antecedent and moderating factors affecting consumer trust in HCI. This dissertation focused on interface-based antecedents of trust in the agent-assisted shopping context aiming at discovering potential interface strategies as a means to enhance consumer trust in the computer agent. The effects of certain interface design factors including face human-likeliness, script social presence, information richness, and price increase associated with upgrade recommendation by the computer agent were examined for their usefulness in enhancing the affective and cognitive bases for consumer trust. In addition, the role of individual difference factors and situational factors in moderating the relationship between specific types of computer interfaces and consumer trust perceptions was examined. Two experiments were conducted employing a computer agent, Agent John, which was created using MacroMedia Authorware. The results of the two experiments showed that certain interface factors including face and script could affect the affective trust perception. Information richness did not enhance consumers’ cognitive trust perceptions; instead, the percentage of price increase associated with Agent John’s upgrade recommendation affected individuals’ cognitive trust perceptions. Interestingly, the moderating influence of consumer personality (especially feminine orientation) on trust perceptions was significant. The consequences of enhanced consumer trust included increased conversion behavior, satisfaction and retention, and to a lesser extent, self-disclosure behavior. Finally, theoretical and managerial implications as well as future research directions were discussed

Who Uses Stereotypes Against Saleswomen? Femininity As Self-Schema and Biases in Trust Judgment

While the idea that schemas can explain individual cognitive processes is well accepted in academia, to date, few studies in marketing have demonstrated that consumers' femininity as self-schema can affect perceptions of others in exchange relationship. This paper examined how consumers' femininity as self-schema could moderate their trust judgments in the context of computer-simulated online shopping. The first experiment demonstrated how consumer femininity could possibly be related to the use of sex-role stereotypes against female sales agents. High feminine individuals appeared to distrust a female sales agent whose sales approach was incongruent with feminine sex role. In contrast, low feminine individuals' trust judgment of a female agent was independent of her compliance to sex role. The second experiment measuring response latency demonstrated that the distrustful reactions to a gender-norm dissonant female agent by high feminine individuals required short response time, which suggests such negative trust judgments could be a result of schema-based, quick processing instead of detailed, elaborate processing. Discussions of the experimental findings and future research directions are offered. [to cite]

Exposure to loneliness cues reduces prosocial behavior: Evidence from N400 and P300

Loneliness is a major risk factor for morbidity and mortality. However, the effect of loneliness on subsequent prosocial behavior is not well known. Understanding the neurobiological mechanisms underlying loneliness is necessary to address this research gap. We investigate the mechanism using a modified public goods game (PGG) wherein participants can choose to act for a collective or selfish interest after being exposed to loneliness cues. Both behavioral (Study 1) and event-related potential (ERP) (Study 2) measures were used to explore this relationship. In Study 1 (N = 131), we found that participants exhibited decreased prosocial actions under the loneliness priming condition as opposed to the control condition. In Study 2 (N = 17), frontal N400 and posterior P300 components were identified under the loneliness priming condition as opposed to the control condition. Increased (decreased) frontal N400 and posterior P300 lead to selfish (prosocial) choices. These results indicate that humans instinctively perceive loneliness as inconsistency with their desired social-relational life, which in turn stimulates coping strategies for self-preservation. This study contributes to our understanding of the neurobiological basis of loneliness associated with prosocial behavior

On Ditransitive Idioms: With Respect to Korean, Hebrew, and English

This paper investigates ditransitive idioms of Korean in comparison with Hebrew and English. It describes the distribution of ditransitive idioms on the basis of fixed- and open-slot dimension, following Mishani-Uval and Siloni (2016), and discusses it in relation to argument structure types, verb types, and the word order. This paper shows that the distribution of idioms is sensitive to verb classification of Rappaport Hovav and Levin (2008) (i.e. give- vs. send-type verbs) in all three languages: Fixed-Goal (Open-Theme) idioms and Full idioms (with Fixed-Goal and Fixed-Theme) occur with send-type verbs only in all three languages. Give-type verbs only occur in Fixed-Theme (Open-Goal) idioms. I propose that an analysis that incorporates the idea of verb-sensitivity in structural terms such as Hallman (2015) can account for the similarities and differences in the distribution of ditransitive idioms across the three languages. In doing so, this paper defends (i) Constituency-based approaches to idiom formation and (ii) the base-generation hypothesis for the word order permutation in Korean ditransitives

Development of Dynamic Substrates for Studies of Cell Adhesion and Migration

A class of model substrates that modulate the dynamic environment for a variety of cell adhesion and migration experiments was developed. The substrate is based on an electrochemically switchable self-assembled monolayer that presents redox active hydroquinone groups. In the presence of the cells, the surface can be activated to undergo chemoselective reaction between quinone monolayers and oxyamine-tethered ligands resulting in ligand immobilization on the surface. The dynamic substrates were used to probe in real-time how the interplay between the population of cells, the initial pattern geometry, ligand density, ligand affinity and integrin composition affects cell migration and growth. The study also showed cell migration was affected by initial events which dictated subsequent motility that superseded the composition of the underlying surface chemistry. Whole genome microarray analysis indicates that several classes of genes ranging from signal transduction to cytoskeletal reorganization are differentially regulated depending on the nature of the surface conditions. A combined photochemical and electrochemical approach generated model substrates presenting molecularly defined gradients of ligands for studying cell migration and polarization. Deprotection of a photo-labile group by ultraviolet light revealed redox active molecules in patterns and gradients; consequently so were the coupled ligand molecules. We show quantitatively the subtle interplay between ligand slope, density and affinity that causes a cell to modulate its adhesion and migration position and behavior during directed movement. The methodology for immobilizing ligand and patterning gradient was also used in producing co-culture model substrate and nanoarrays for adhesion study