CloudTree: A Library to Extend Cloud Services for Trees

In this work, we propose a library that enables on a cloud the creation and management of tree data structures from a cloud client. As a proof of concept, we implement a new cloud service CloudTree. With CloudTree, users are able to organize big data into tree data structures of their choice that are physically stored in a cloud. We use caching, prefetching, and aggregation techniques in the design and implementation of CloudTree to enhance performance. We have implemented the services of Binary Search Trees (BST) and Prefix Trees as current members in CloudTree and have benchmarked their performance using the Amazon Cloud. The idea and techniques in the design and implementation of a BST and prefix tree is generic and thus can also be used for other types of trees such as B-tree, and other link-based data structures such as linked lists and graphs. Preliminary experimental results show that CloudTree is useful and efficient for various big data applications

Kinetics and Mechanism of Oxygen Delignification

Considerable research has been conducted into the kinetics and selectivity of the oxygen delignification process to overcome limitation in its use. However most studies were performed in a batch reactor whereby the hydroxide and dissolved oxygen concentrations are changing during the reaction time in an effort to simulate tower performance in pulp mills. This makes it difficult to determine the reaction order of the different reactants in the rate expressions. Also the lignin content and cellulose degradation of the pulp are only established at the end of the experiment when the sample is removed from the batch reactor. To overcome these deficiencies, we have adopted a differential reactor system used frequently for fluid-solid rate studies (so-called Berty reactor) for measurement of oxygen delignification kinetics. In this reactor, the dissolved oxygen concentration and the alkali concentration in the feed are kept constant, and the rate of lignin removal is determined from the dissolved lignin content in the outflow stream measured by UV absorption. The mass of lignin removed is verified by analyzing the pulp at several time intervals. Experiments were performed at different temperatures, oxygen pressures and caustic concentrations. The delignification rate was found to be first order in HexA-free residual lignin content. The delignification rate reaction order in caustic concentration and oxygen pressure were determined to be 0.42 and 0.44 respectively. The activation energy was found to be 53kJ/mol. The carbohydrate degradation during oxygen delignification can be described by two contributions: one due to radicals produced by phenolic delignification, and a much smaller contribution due to alkaline hydrolysis. From the first order of the reaction and the pKa of the active lignin site, a new oxygen delignification mechanism is proposed. The number 3 carbon atom in the aromatic ring with the attached methoxyl group forms the lignin active site for oxygen adsorption and subsequent electrophic reaction to form a hydroperoxide with a pKa value similar to that of the present delignification kinetics. The uniform presence of the aromatic methoxyl groups in residual lignin further support the first order in lignin kinetics

Molecular and functional analysis of Drosophila Hillarin and its leech homolog

This thesis describes the molecular and functional analysis of the leech Hillarin and its Drosophila homolog D-hil. Leech Hillarin was identified by screening a leech expression library with the mAb Lan3-15, which specifically labels the axon hillock region of leech neurons. Database searches revealed that leech Hillarin has a number of potential homologs in a variety of organisms such as yeast, cyanobacterium, fly, nematode, mouse and human and that these proteins share two novel protein domains, the W180 domain and the H domain. The W180 domain is enriched with tryptophans whereas the H domain shares high number of invariant residues among family members and was named since it was first described in Hillarin. Drosophila member of this protein family, D-hil, is localized to the neuropil of central nervous system neurons, the cortex of metaphase S2 cells, and the cleavage furrow of dividing S2 cells. The protein level of D-hil starts to increase 12 hours after egg laying and the expression persists into adult stage, indicating the expression of D-hil is developmentally regulated. Pnut, a Drosophila septin member, was identified as an interactor of D-hil. The interaction is supported by the co-immunoprecipitation and co-localization results. Furthermore, GFP-D-hil in transfected S2 cells co-localizes with Pnut and F-actin. Genetic interaction studies between a mutant Pnut allele and a mutant D-hil allele suggest that they function in the same genetic pathway since D-hilPnut double mutants show double amount of polyploid cells in the third instar larval brains compared to that of the Pnut single mutants. This genetic interaction between D-hil and Pnut further supports their interaction in vivo

The Role of Chaos in One-Dimensional Heat Conductivity

We investigate the heat conduction in a quasi 1-D gas model with various degree of chaos. Our calculations indicate that the heat conductivity $\kappa$ is independent of system size when the chaos of the channel is strong enough. The different diffusion behaviors for the cases of chaotic and non-chaotic channels are also studied. The numerical results of divergent exponent $\alpha$ of heat conduction and diffusion exponent $\beta$ are in consistent with the formula $\alpha=2-2/\beta$. We explore the temperature profiles numerically and analytically, which show that the temperature jump is primarily attributed to superdiffusion for both non-chaotic and chaotic cases, and for the latter case of superdiffusion the finite-size affects the value of $\beta$ remarkably.Comment: 6 pages, 7 figure

Help-seeking intention among college students: Cross-cultural study between East Asian international students and domestic students in the Unites States

The purpose of this study is to understand East Asian international student’s underutilization of counseling services (versus U.S. domestic students) by applying Theory of Reasoned Action/Planned Behavior (TRA/PB) and Ludwikowski, Vogel, and Armstrong (2009)’s stigma model to help-seeking. Participants were 146 East Asian international students and 210 domestic college students at Purdue University. AMOS 23.0 for Structural Equation Modeling was used to conduct a Latent Mean Analysis (LMA) and a multigroup analysis. The multigroup analysis results found that help-seeking intention was explained by the same hypothesized model in both groups, which was based on the TRA/PB (Ajzen, 2012) and the stigma model (Ludwikowski et al., 2009). However, no significant group differences were found for most of the hypothesized paths, except a path from personal stigma to self-stigma. The LMA results revealed that East Asian international students reported significantly higher help-seeking intention and lower self-stigma and perceived behavior control. Historically, Asian students are known to have more stigma and negative attitudes (Sue & Sue, 2008), so this finding draws our attention to the further cross-cultural studies about the reason for this discrepancy. Implications for theory, research, and practice are addressed