17872 research outputs found
Sort by
Influence of Multivalent Metal Cations on Carbohydrate Separations and Fragmentation Patterns via Ion Mobility-Mass Spectrometry
No full textCarbohydrates, oligosaccharides, and glycans occupy a corner of biopolymers that can be overlooked in the shadow of proteins and nucleic acids but are nonetheless essential for the survival of biological organisms. However, unlike other biological macromolecules, known carbohydrate units have largely homogeneous elemental compositions, where species are instead distinguished by variations in stereochemistry and branching patterns. Because this creates a scenario where complex biological samples may contain isomeric mixtures which cannot be differentiated by mass isolation, incorporating ion mobility separations in front of mass spectrometry can provide another dimension of information to distinguish among isomers. Yet another angle for enhancing glycan analysis with ion mobility-mass spectrometry is by leveraging interactions between carbohydrate species and metal cations, which can form adducts that have altered gas-phase structures relative to protonated or deprotonated ions. In some situations, metal adduction exaggerates the differences in effective size among isomers and thereby facilitates isomeric glycan separation in the drift time space.
This dissertation is focused on conveying the utility of metal-glycan interactions for improving the ion mobility-mass spectrometric analysis of carbohydrate species while also describing some complementary experiments that were pursued in support of glycan analysis. Of note, ultraviolet photodissociation (UVPD) with metal-enhanced fragmentation and Fourier multiplexing of ion mobility-ion trap mass spectrometry contributed well to isomeric mixture analysis. Divalent metal cations including select transition metals and alkaline earth metals were evaluated for their potential to enhance drift time separations, with transition metals proving particularly useful in this regard for mixture analysis. Preliminary oligosaccharide analysis with divalent metal species found that carbohydrates will form both singly-charged monomeric metal-glycan adducts as well as doubly-charged dimeric metal-glycan adducts where both appear at the same m/z value. These dimers were subsequently scrutinized for the potential to form heterodimeric metal-glycan dimers wherein two different isomeric glycans could form a single dimer during a mixture analysis without mobility separation and form chimeric mass spectra. Through a combination of isotopic labeling and ion mobility-mass spectrometry, it was shown that heterodimeric metal-glycan species will form, and that mobility separation is vital for analyzing glycan mixtures.Washington State University, Chemistr
The moderating effects of ethnic and sexual identity on emotion openness and depression among lesbian, gay, and bisexual Asians
No full textThesis (Ph.D.), Psychology - Clinical, Washington State UniversityLesbian, gay, and bisexual (LGB) Asians often encounter racism and homophobia in their lives because of their ethnic and sexual identities, and consequently, they could suffer from depression. Previous research demonstrated that emotional openness, the ability to accept and process one’s emotion, could enhance the resilience of sexual minorities against depression. Therefore, LGB Asians, being sexual minorities, could benefit from emotional openness for their mental health. On the other hand, LGB Asians, given their ethnic identity, could follow the cultural norm of emotional suppression, and thus, they might not benefit from emotional openness as other sexual minorities could. The present study examined how ethnic and sexual identities would moderate the relationship between emotional openness and depressive symptoms among LGB Asians. It was hypothesized that LGB Asians with a strong sexual identity could experience fewer depressive symptoms at higher levels of emotional openness. In contrast, it was predicted that LGB Asians with a strong ethnic identity could experience more depressive symptoms at higher levels of emotional openness. One hundred and fifty-six LGB Asians were recruited to complete an online survey on ethnic and sexual identities, emotional openness, and depressive symptoms. Emotional openness, but not ethnic and sexual identities, emerged as a resilience factor against depressive symptoms for LGB Asians. Both the ethnic and sexual identities of LGB Asians failed to moderate the relationship between emotional openness and depression. Post-hoc meditational analyses revealed the impact of the unique combination of ethnic and sexual identities on the identity development and promotion of emotional openness among LGB Asians. Limitations of the study and future research directions were discussed.Washington State University, Psychology - Clinica
DATA-DRIVEN ALGORITHMS FOR DISTRIBUTION SYSTEM OPERATION AND CONTROL
No full textThesis (Ph.D.), Electrical Engineering, Washington State UniversityTransactive energy systems are emerging as a transformative solution for the problems that distribution system operators face due to an increase in the use of distributed energy resources and rapid growth in the scalability of managing active distribution system. To meet the reliability, sustainability and security requirements, efficient management and control of distributed generators, energy storage systems, and demand response is necessary to provide services such as reactive power compensation, voltage control, energy balancing, peak load reduction. These edge resources can also be used for system restoration after the extreme events and enabling resiliency of the electric grid. While there are numbers of related resources focused on solving these problems, availability of additional data resources has not been utilized to its potential to enable the reliable, sustainable and resilient electric grid. In order to address these challenges, data-driven algorithms have been proposed in this dissertation to utilize those new data to effectively monitor and control the energy storage system, distributed energy systems, and demand response.Washington State University, Electrical Engineerin
Scalable Methods For Genome Assembly
No full textThesis (Ph.D.), Computer Science, Washington State UniversityDe novo genome assembly is a fundamental problem in the field of computational biology. The goal is to reconstruct an unknown genome from short DNA fragments (called “reads”) obtained from it. Over the last decade, with the advent of numerous next-generation sequencing (NGS) platforms (e.g., Illumina, 454 Roche), billions of reads can be generated in a matter of hours, leading to vast amounts of data accumulation per day. This has necessitated efficient parallelization of the assembly process to meet the growing data demands. While multiple parallel solutions to the problem have been proposed in the past, there still exists a gap in terms of the processing power between massively parallel NGS technologies and the ability of current state-of-the-art assemblers to analyze and assemble large and complex genomes. Conducting genome assembly at scale remains a challenge owing to the intense computational and memory requirements of the problem, coupled with inherent complexities in existing parallel tools associated with data movement, use of complex data structures, unstructured memory accesses and repeated I/O operations. In this dissertation, we address the challenges of conducting genome assembly at scale and develop new methods for conducting extreme-scale genome assembly for microbial and complex eukaryotic genomes. Our approach to the problem is two-fold, wherein we make the following contributions: i) FastEtch- a new method targeting fast and space-efficient assemblies, using probabilistic data structures (Count-Min sketch) that executes efficiently on shared-memory platforms with a minimal computational footprint (both memory and time). ii) PaKman- a fully distributed method that tackles assembly of large genomes through the combination of a novel data-structure (PaK-Graph) and algorithmic strategies to simplify the communication and I/O footprint during the assembly process. We present an extensive performance and qualitative evaluation of both our algorithms including comparisons to other state-of-the-art methods. Our results demonstrate that FastEtch can yield one of the best time-memory-quality trade-offs, when compared against many state-of-the-art genome assemblers. PaKman has shown the ability to achieve near-linear speedups on up to 8K cores; outperform state-of-the-art distributed and shared memory tools in performance while delivering comparable (if not better) quality; and reduce time to solution significantly.Washington State University, Computer Scienc
Varietal differences in water relations of wine grapes
No full textThesis (Ph.D.), Horticulture, Washington State UniversityWine grape varieties are classified by their water stress response in two groups: Isohydric varieties showing high and constant water status under drought due to highly sensitive stomata and anisohydric varieties showing low and variable water status under drought due to insensitive stomata. We investigated the soundness of this classification for 18 different varieties in eastern Washington. From 2015 to 2018, dry-down cycles were applied to the vineyard until severe signs of stress were apparent. Physiological parameters as well as soil moisture (ϴv) were monitored. Our results show that there was a continuum of midday leaf water potential pattern (Ψl), progressing from a linear drop to one that shows a plateau down to a level of ϴv. There was also a continuum in the minimal midday Ψl recorded (from -1.3 to -1.9 MPa). Stomatal sensitivity was not correlated with the minimal midday Ψl. When an internal regulation model of Ψl was applied, most varieties showed an efficiency of the stomata in controlling against water potential drop. Chardonnay, however, showed a potential riskier strategy in terms of hydraulic failure. The model’s parameter σ was not correlated with the minimal midday Ψl, nor was it correlated with stomatal sensitivity. In a second experiment, we used a design of scion/rootstock combinations to isolate the effect of the root material, canopy material and grafting union on the water status and stomatal responses seen at the leaf level. Two model genotypes Grenache and Syrah were monitored in 2017 and 2018 in self-grafted, reciprocally grafted and own-rooted combinations while the soil is drying after standardizing the leaf area. No rootstock, scion or grafting union effect was found in any of the combinations. We conclude that leaf area might be an important confounding factor in determining water stress responses among genotypes and that leaf water stress response is not an inherent genetic characteristic. In a third experiment, we tested the effect of vapor pressure deficit (VPD) on stomatal response in a growth chamber setup under high ϴv. When VPD increased from 1.5 to 2.8 KPa, gs decreased by a 1.5 and midday Ψl decreased by a 1.14-foldWashington State University, Horticultur
Free-Choice and Forced-Choice Actions: Shared Representations and Conservation of Cognitive Effort (Dataset)
No full textFresh cheese made safely
No full textQueso fresco is a fresh, crumbly white cheese that has been made for generations by Latin-American families. Traditionally, queso fresco is prepared with fresh dairy milk that has not been pasteurized (heat treated). Unfortunately, this method of making queso fresco can cause serious illness. The instructions in this publication use pasteurized milk to ensure a queso fresco that will not make you sick. To prepare a safe cheese, you can either begin with pasteurized milk or pasteurize your milk before making it into cheese. Procedures on how to sanitize cheese-making equipment are included for the same purpose
