In this paper, we present a P2P-based database sharing system that provides information sharing capabilities through keyword-based search techniques. Our system requires neither a global schema nor schema mappings between different databases, and our keyword-based search algorithms are robust in the presence of frequent changes in the content and membership of peers. To facilitate data integration, we introduce keyword join operator to combine partial answers containing different keywords into complete answers. We also present an efficient algorithm that optimize the keyword join operations for partial answer integration. Our experimental study on both real and synthetic datasets demonstrates the effectiveness of our algorithms, and the efficiency of the proposed query processing strategies. / Singapore-MIT Alliance (SMA)

This inquiry explores the possibility of applying principles from Plato?s education system in the Republic to modern military leadership development programs. Both are concerned with producing a ?guard-dog? that will serve the interests of the state rather than exploit vulnerable civilians. Plato proposes educating guardians with a natural disposition to believe the ?noble lie,? that it is better to serve others than to pursue selfinterest for personal gain; but, would the proper tension in moral sensibilities prescribed by the Platonic Grid help or hinder a military leader to successfully act on the battlefield? First, I examine Plato?s theory to familiarize military leaders with the education system from the Republic; including his views on unity, reality, the theory of the forms, and recollection of knowledge that underlie Plato?s enquiry into the nature of justice, and lead to the need for inner harmony of the soul through the proper tension of wisdom, courage, and temperance to rule the three elements of the soul. Then I analyze the key leaders from the Battle of Balaclava, the Battle of Gettysburg, and the siege of the Alamo for possible correlations of the application of the Platonic Grid aligned with the ?noble lie? to success on the battlefield. This includes inquiry into the likelihood that belief in the ?noble lie? can motivate soldiers to make the ultimate sacrifice. I conclude by examining how Plato?s theories could be assimilated into a military pedagogy to produce modern day ?dogs of war? that leads to the startling conclusion that adherence to the ?noble lie? could also be in the self-interest of the guardian who seeks to serve the best interest of her nation.

Lipid bi-layers are ubiquitous components of biological cells and are found in a variety of cell components. In biological membranes, lipid bi-layer membranes carry membrane proteins, which control transport of material and communication of signals in and out the cell. There are several disadvantages involved with patch clamping method as a way of studying biological membranes and protein interactions. Hence, artificial synthesis of bi-layer has been of great interest in basic biophysical studies, drug discoveries in pharmaceutical studies and study of protein nanopores for precise engineering applications. However, conventional lipid bi-layer synthesis techniques require skilled operators, have low repeatability (reliability), have portability restrictions and result in unstable bi-layers having a short lifetime. In this investigation a novel microfluidic device and a method for artificial synthesis of lipid bi-layer in-situ are explored. In the proposed method, lipid trapped at an aperture on a Teflon sheet, is thinned to form a lipid bi-layer by a continuous flow of buffer solution on both sides of the aperture in the microfluidic device. The microfluidic device is expected to have advantages from its compact design. Further, the new approach is expected to be repetitive and good for automation removing the requirement of a skilled operator. The microfluidic device was fabricated using two glass substrates. Two channels of ? ? shape were etched and through holes were fabricated at all four terminal ends of the microchannels on each glass substrate. A thin Teflon sheet carrying a 100?m diameter hole was sandwiched between the two glass wafers forming two sets of microchannels on both sides of the aperture. An analytical microfluid model of the microchannels was developed to investigate the nature of the flow and to select microchannel parameters. Experiments using the proposed device were performed to verify the feasibility of the novel approach for lipid bi-layer synthesis. Experimental results suggest formation of a lipid bi-layer at an aperture on the Teflon sheet but further investigation might be necessary for verification. Life time of the bi-layer is short mainly due to low quality of the used aperture.

This study constructs a two-step model to test the most prominent market timing factors. We decompose equity issuances into 1) firm-specific components, which are predicted by firms’ characteristics, and 2) market-wide components, which are predicted by aggregate time series measures. Our evidence shows that, at the firm level, firms with higher market-to-book ratio, smaller size, more growth opportunities, and fewer tangible assets are more likely to issue equity. At the aggregate level, a greater proportion of firms issue equity in years with higher aggregate market-to-book ratio and lower asymmetric information. After controlling for the aggregate market-to-book ratio and information asymmetry, sentiment has no direct effect on equity issuance. This paper provides direct evidence that firms time their favorable market conditions to reduce adverse selection costs, and to exploit higher individual security valuations or capture growth opportunities.

The middle Cambrian (Drumian) Rockslide Formation is a deeper-water succession of mixed carbonates and siliciclastics. At the Ravens Throat River location it hosts a Burgess Shale-type (BST) deposit. The BST units are found in two separate 1m thick horizons of green-coloured calcareous mudstone and contain a biota similar to that of the Wheeler and Marjum formations of Utah, and to some extent the Burgess Shale itself. The biota is low in diversity and preserves mainly robust soft-tissue parts. The lithologically heterogeneous composition of the formation (shale, dolomite, lime mudstone, sandstone, mudstone) and absence of metamorphism offer an opportunity to analyze the depositional environment and taphonomy of this deeper water unit. Geochemical analysis including, trace elements, organic carbon, biomarker, and synchrotron were attempted and yielded varying results. Trace element ratios, particularly V/Sc, indicate low oxygenation of the bottom waters during the deposition of the fossil-bearing interval. These results differ from most other BST deposits, which suggest that oxygenated bottom waters were maintained throughout sedimentation. In addition, organic matter in the sediments and δ13Corg values suggest the presence of benthic microbial mats. Silver is concentrated mostly in nm to μm-sized particles in the fossilifereous calcareous mudstone, suggesting elevated levels in the depositional environment. Organic films and the evidence for hyoliths feeding on them suggest an in situ preservation of the biota, perhaps from sudden and short anoxic events and quick burial under either microbial mats or the muddy sediment. This is also supported by the presence of only very rare trace fossils.

The present work reports the study of noncoherent photon upconversion (NCPU) via triplet-triplet annihilation (TTA) in polymer systems. This upconversion mechanism has application in photovoltaic devices through the utilization of sub-band gap photons for potentially enhanced power conversion efficiencies. First, homomolecular TTA was studied in zinc tetraphenylporphyrin (ZnTPP) in polymer matrices. Here, ZnTPP acts as both the sensitizer and upconverting emitter as TTA yields an S2 excited porphyrin. Use of poly(methyl methacrylate) (PMMA) as the host polymer demonstrates aggregation-driven upconverted fluorescence (UC) by TTA (TTA-UC). The dye-loading ratio of the precursor solution was varied, controlling the degree of pre-aggregation. Power-dependence studies of the champion film demonstrated that TTA-UC is occurring toward the strong annihilation kinetic limit. A sub-linear dependence of upconverted fluorescence on film thickness was observed in this system. The ZnTPP study was extended to polymers possessing low glass transition temperatures, representing molecular diffusion-driven TTA-UC. Upconverted fluorescence was not observed in ZnTPP in a polyurethane (PU) matrix, likely due to coordination of the PU to the axial position of the Zn2+ ion. Low intensity NCPU via homomolecular TTA was observed in ZnTPP in a poly(ethylene glycol) (PEG) matrix, but the kinetic limit was not determined due to film photodegradation. Dye-loading studies revealed that porphyrin self-quenching was evident at low dye concentrations. Likely reasons for the low upconverted fluorescence intensities realized are this self-quenching and the possibility of PEG coordination to the Zn2+ ion, though it is believed self-quenching is the dominant parasitic effect. Strategies to determine the effect and extent of polymer coordination to the Zn2+ ion are discussed. The study of polymer-based NCPU is extended to a pair of macromolecules, each containing a single ruthenium tris(bipyridine) (Ru(bpy)3) core and multiple pendant arms, which in turn, each contain eight 9,10-diphenylanthracene (DPA) moieties. A power-dependence study of NCPU in this system is reported, and TTA-UC in the weak annihilation kinetic limit was observed. Upconverted fluorescence quantum yields vary linearly with excitation power in both polymers, consistent with the observed kinetic limit. Stern-Volmer experiments have compared the quenching of Ru(bpy)3 phosphorescence (Ph) by monomeric and polymeric DPA. These data show an enhancement in quenching rate constant for the DPA polymer (pDPA). Kinetic analysis of the Ru-DPA polymers has revealed that the energy scheme realized in this system is intrachain TTET from Ru(bpy)3 core to DPA emitter followed by interchain TTA between excited DPA moieties. Low intensity upconverted fluorescence is observed in Ru-DPA containing thin films. Based on the results presented, the requirements of future photophysically-active polymers are discussed with regards to meaningful application in photovoltaics.

No description available.

This study used binary logistic regression analysis to examine the role of empathy,anger management, and normative beliefs about aggression on overt bullying, relational bullying, and prosocial behavior in urban African-American middle school children. Participants included 177 African-American sixth, seventh and eighth grade students from two public, urban middle schools in a large city in the Southeast United States. The results of this study indicated that binary logistic regression models including empathy, anger management, and normative beliefs about aggression predicted prosocial behavior, and marginally predicted relational bullying. Nonnative beliefs about aggression had a significant moderating effect, such that for participants who endorsed higher normative beliefs about aggression, low levels of empathy significantly increased the likelihood of being classified as a relational bully. Participants in this study reported highly aggressive behavior, with 24% of the sample being identified as overt bullies. Significant gender differences were also identified in this study. Boys reported more relational aggression than girls, and girls reported higher levels of empathy, and prosocial behavior. Implications for future research and intervention programs for bullying among middle school children are discussed.

Potato chips are very popular in the United States. Recently, an enormous interest in developing snacks from fruits and vegetables with high quality has been assessed. Mango, due to its characteristic flavor and nutritional value, is excellent for snack production. Osmotic dehydration (OD) as a pre-treatment and vacuum frying (1.33 kPa) processes were proposed to obtain high quality mango chips. Mango ?Tommy Atkins? slices were pre-treated with different OD concentrations (40, 50, and 65w/v), times (45, 60, and 70 min), and temperatures (22, 40, and 57oC). Physical and chemical properties (aw, pH, oBrix, sugar gain, water loss, and shrinkage) after OD were studied. The pre-treated slices were vacuum fried (1.33 kPa) at 120, 130, and 138oC and product quality attributes (PQA) (oil content, texture, porosity, color, microstructure, and carotenoid content) were determined. Microstructure of the chips was analyzed using an environmental scanning electron microscope. Effect of frying temperatures at optimum OD (65 w/v at 40oC) times was tested. The consumer tests showed that samples were all acceptable. The best mango chips process was the one with 65 w/v concentration for 60 min (pre-treatment) and vacuum frying at 120oC. Kinetic studies on oil content, texture, porosity, color, and carotenoid retention were performed. Oil absorption was modeled by a fractional conversion kinetic model. Absorption rate constant increased with frying temperature. Diameter changes in the chips, although not significant (P>0.05), followed an initial expansion to later decrease. Thickness of the slices increased (puffed) (around 60%) with time for all frying temperatures. Texture changes were for two frying periods: (1) water removal and crust formation and (2) slices became tougher and crispier and the end of frying. Porosity in the samples increased with frying, and a fractional conversion best described this phenomenon. Color *a (redness) increased with frying time and temperature and was modeled using a logistic model. Color *b (yellowness) increased up to 30 s of frying and then decreased. Carotenoids degradation followed a first order model, with a significant (P<0.05) decrease with frying temperature. Mango chips fried under atmospheric fryer had less carotenoid retention (25%) than with a vacuum fryer.

This thesis examines the portrayal of Aboriginal Peoples in two Saskatchewan daily newspapers. This research is based on the question: "How is the notion of Aboriginal Peoples socially constructed in the print media?" Previous research indicates that media portrayals of minority groups are often partial and stereotypical. Such portrayals are partly responsible for linking the unacceptable behavior of minority groups to phenotypic traits, and thereby contributing to the social significance of "race." Discourse analysis is used to analyze 437 newspaper articles that were collected using a full-text keyword search of the EBSCO Host database, which indexes articles from the Leader Post and the Star Phoenix. In general, the results reveal that Aboriginal peoples are regularly portrayed as problematic; either as having problems themselves, or as causing problems for non-Aboriginal peoples. The results support the view that race is socially constructed and demonstrate that "race," through media discourse, can become a socially acceptable explanation for social problems.