VictorJuiz/thesis huggingface dataset:
Triple Fortification of Salt with Vitamin A, Self-emulsifying Drug Delivery System, Iron, and Iodine
Keywords: Vitamin A
Microemulsion
Self-emulsifying drug delivery system
Spray drying
Microencapsulation
Bioavailability

Triple fortification of salt with vitamin A, iron, and iodine has been investigated in the past to reduce micronutrient deficiencies in the developing world. The objective is to develop integrated nutrient delivery technology by microencapsulating a self-emulsifying drug delivery system (SEDDS) made of surfactants and a bioactive compound, retinyl palmitate. The SEDDS is used to enhance absorption of the vitamin A through food systems and to achieve targeted release of the active ingredient. Encapsulating vitamin A was difficult when using the spray dryer and the enteric coating, Aquacoat®. Losses of the micronutrient after a three month storage period ranged from 50-99% at both 25°C/20% RH and 45°C/60% RH. The result of a matrix encapsulation and poor coating formation contributed to the high losses. Further investigation of coating systems with the aim of stabilizing all three samples for a six month storage period such as using other encapsulating methods is recommended.
Perceptions of Emergency Department Team Members on the Implementation of Clinical Decision Units
Keywords: Clinical Decision Units
Emergency Department
Perceptions of Emergency Department Team Members
CDU Implementation

Objectives: CDUs have been implemented to address ED wait times. The objectives of this study were to investigate ED team members’ perceptions on the implementation of CDUs as well as the impact of CDUs on the delivery of emergency care. Methods: A case study design and change theories found in the literature were used to investigate the implementation of CDUs in four hospitals. Semi-structured interviews with ED team members led to the creation of themes for analysis. Results: Analysis demonstrated that patient flow, work processes and communication contribute to the type of CDU set-up, whether it is a co-located or virtual CDU. The sustainability of CDUs relies on communication and a common vision in the fulfillment of purposes and goals. Conclusions: This study contributes to the understanding of the implementation of CDUs. The application of change frameworks assists with the identification of key success factors for implementing and sustaining change.
Disrupting the Non-specific Interactions between DNA and the Escherichia coli Transcriptional Repressor NikR
Keywords: NikR
nickel
transcription factor
transcriptional repressor

The Escherichia coli transcription factor NikR is responsible for nickel-mediated repression of the nik operon. The crystal structure of NikR in complex with its operator sequence provided insight into the mechanistic details of nickel-activated NikR-DNA complex formation. The crystal structure revealed that the α3 helix and its preceding loop (residues 63-79) in two of the metal-binding domains—which become structurally ordered after high-affinity nickel binding—make non-specific contacts with the DNA phosphodiester backbone. The proposed mechanism of NikR binding to DNA suggests that the non-specific interactions between the DNA phosphodiester backbone and the positively-charged residues Lys64 and Arg65 anchor NikR to the DNA, thereby allowing the protein to initiate a one-dimensional search for its recognition sequence. The DNA-binding studies presented here strongly support an important role for Lys64 and Arg65 in NikR-DNA complex formation which is in agreement with the proposed model of NikR binding to DNA.
Thermally Conductive Polymer Composites for Electronic Packaging Applications
Keywords: Composites
Electronic Packaging
Thermal Conductivity
Electrical Conductivity
Nano
heat sinks

Advancements in the semiconductor industry have lead to the miniaturization of components and increased power densities, resulting in thermal management issues. In response to this shift, finding multifunctional materials with excellent thermal conductivity and tailored electrical properties are becoming increasingly important. For this research thesis, three different studies were conducted to develop and characterize thermally conductive polymer composites. In the first study, a PPS matrix was combined with different types of carbon-based fillers to determine the effects of filler’s size, shape, and orientation on thermal conductivity. In the second study, effects of adding ceramic- and carbon- based fillers on the tailored thermal and electrical properties of composites were investigated. Lastly, the possibility of improving the thermal conductivity by introducing and aligning polymer fibers in the composites was investigated. The composites were characterized with respect to their physical, thermal, and electrical properties to propose possibilities of application in the electronic packaging industries.
Ecological Interface Design for a Water Monitoring Decision Aid
Keywords: human factors
interface design

In joint human-automation systems, operators must often supervise the automation and adapt their reliance on it based on judgments of its context-specific reliability. For this to occur, operators should trust the automation appropriately. In the design of a water monitoring decision aid’s display, Ecological Interface Design was used to satisfy design guidelines for supporting appropriate trust. Design focused upon a visualization that made the aid’s use of the Dempster-Shafer theory directly perceptible. The display was evaluated using a signal detection theory-based approach that measured reliance on automation. Results indicated that the ecological display yielded less appropriate reliance and poorer performance than a conventional display for a highly reliable decision aid. However, the experimental task prevented participants from adapting to the aid’s context-specific reliabilities, reducing the validity of the findings. A subsequent study is proposed to further study the effects of ecological displays on automation reliance.
Differences in Performance and Herbivory Along a Latitudinal Gradient for Common Burdock (Arctium minus)
Keywords: Range margin, herbivory, arctium minus, burdock, latitudinal gradient, soil feedback, physical defense

Plant populations near the northern limits of their geographic distribution may experience different biotic pressures than southern populations. For instance, if herbivores are scarce in northern populations, performance of their host plants may benefit. In this study, I looked at populations of burdock (Arctium minus) along an 815 km latitudinal gradient from the northern range limit to more southern populations. I found that plant height, stem diameter, and number of seeds all increased on approaching the northern limit. In addition, I also found significant decreases in herbivory by generalist and specialist leaf and seed predators, even though northern plants invested less in physical and possibly chemical defenses. In an experiment in which seeds were planted in different soils, marginal soil initially produced smaller plants, but subsequently larger plants than soil from southern populations. These results indicate northern populations experience relaxed pressure from natural enemies and may benefit as a result.
Validation of de novo Bioinformatic Predictions of Arabidopsis thaliana Cis-regulatory Elements using in planta GUS Expression Assays
Keywords: cis-regulatory elements
bioinformatics
GUS
cold stress
enhancer
silencer
insulator
local control regions (LCRs)
MARs/SARs
in planta
evening element
circadian rhythm
arabidopsis
genotoxic
bleomycin
mitomycin c
heat stress
stem epidermis
root
abscisic acid (ABA)
osmotic stress
salt stress
synthetic constructs
expression assays
transcription factor binding sites
CaMV35S
columbia-0

The study of cis-regulatory elements (CREs) will allow for increased understanding of regulation and lead to insight regarding the mechanisms governing growth, development, health, and disease. The aim of this study was to characterize the de novo in silico predictions of Arabidopsis CREs. Eight synthetic and 30 native promoter-constructs containing an eGFP/GUS reporter protein were generated for cold, genotoxic, heat, osmotic, and salt stress; the circadian clock; ABA signaling; root and epidermis tissue. Constructs were stably transformed into A. thaliana Col-0 and the effects of the CREs were evaluated by in planta stress or tissue assays using GUS expression levels. Results reveal a novel genotoxic element that specifically directs GUS expression in rosette leaves during genotoxic stress. Results also look promising for novel epidermis and root-specific elements. Results of these assays validate the de novo prediction pipeline's ability to identify novel and known CREs related to abiotic stress.
Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FTICR-MS) for the Study of Noncovalent Complexes
Keywords: Mass Spectrometry
noncovalent
Electron capture dissociation

Mass spectrometry has become an important tool for analysis of protein complexes. This study utilizes electrospray ionization (ESI) coupled to a Fourier transform ion cyclotron resonance mass spectrometer (FTICR-MS) to analyze noncovalent complexes in the gas phase. Binding of cucurbit[7]uril (CB7) to intact bovine insulin and the B-chain of insulin was investigated. Competition experiments involving the B-chain and a mutant B-chain were performed to probe the solution-phase binding site. Electron capture dissociation (ECD) of CB7 complexed to intact insulin and to the B-chain, produced a series of peptidic fragments of insulin in complex with CB7. Analysis of these fragments allowed the determination of the apparent gas-phase binding site, which appears different than the proposed solution-phase binding-site. These studies thus suggest that CB7 migrates when the complex is transferred from solution to gas phase. The results of this study caution against using ECD-MS as a stand-alone structural probe of solutionphase binding.
Association Between Early Follow-up with a Nephrologist and Death in Survivors of Acute Kidney Injury
Keywords: acute kidney injury

Background: Survivors of severe acute kidney injury remain at high risk of death well-after apparent recovery from the initial event. Methods: We conducted a cohort study of hospitalized adults in Ontario from 1996 to 2008 with acute kidney injury who received temporary dialysis and survived for 90 days following discharge independent from dialysis. The exposure was nephrology follow-up. We used propensity scores to match individuals with early nephrology follow-up to those without. The primary outcome was time to mortality. Results : We identified 3877 patients with acute kidney injury who met the eligibility criteria. A total of 1583 patients had nephrology follow. The incidence of all-cause mortality was lower in those with early nephrology follow-up as compared to those without early follow-up (8.4 vs. 10.6 per 100 person-years, HR 0.76 (95% CI 0.62-0.93)). Conclusions: Nephrology follow-up after hospitalization with acute kidney injury and temporary dialysis was associated with improved survival.
Pursuing Enterprise Risk Management: A Local Roadmap for Canadian Health Care Leaders
Keywords: ERM
Risk Management
Organizational Risk
Health Care
Corporate Risk
Clinical Risk
Planning
Mitigation
Decision Support
Enterprise Risk
Health Care Management
Risk Assessment
Risk Program
Liability
Risk Model
Knowledge Transfer
Canadian Health Care
Public Health Care
Enterprise Risk Management

An in-depth analysis of organizational risk management in health care, and in particular the concepts of Enterprise Risk Management (ERM), has identified a five part model that can be used by Canadian health care leaders as an evidence supported approach to successful organizational risk management. The Model for Organizational Risk Management has been developed as a basis for linking the components of an ERM framework into a Canadian health organization in order to overcome the barriers that commonly disrupt strategic risk management. The Model addresses how an ERM framework can fit within an existing health organization by building off of and enhancing existing processes and resources in order to ensure familiarity, acceptance, and sustainability of the risk management program. By approaching the Model in a stepwise fashion (based on individual organizational context) health care leaders are provided with a roadmap from which to advance their own organizational risk management program.
Clinical and Spatiotemporal Aspects of Gait: A Secondary Analysis of the Walking Characteristics of Subjects with Sub-acute Incomplete Spinal Cord Injury
Keywords: spinal cord injury
walking
sub-acute
spatiotemporal

Objective: To describe the walking characteristics of a sample of ambulatory subjects with sub-acute incomplete spinal cord injury (iSCI). Methods: 52 subjects were included in a secondary analysis of clinical and spatiotemporal measures of walking. The study sample was described as a whole and subsequently divided into subgroups on the basis of 3 clinical factors (etiology, severity, and neurological level of injury) and 4 gait factors (gait aid, velocity, symmetry, and variability). Results: Clinical and spatiotemporal parameters were highly variable across the study population. Sub–groups with unique gait features were best identified by velocity and variability. Conclusions: Spatiotemporal measures of walking provide augmented description of walking in the sub-acute iSCI population. Sub-grouping by gait factors warrants further investigation with respect to their ability to act as predictors and modifiers of treatment effect.
A Systematic Review and Appraisal of International Early Breast Cancer Guidelines for Systemic Therapy, and a Global Physician Survey Examining Practice Patterns by Resource Setting: Potential Implications for International Health Policy
Keywords: breast cancer
guidelines
adjuvant
therapy
international
global
practice
policy
low and middle income
resources

Breast cancer is a growing international health epidemic, and patients in low and middle income countries (LMCs) have worse outcomes than those in high income countries. High quality, well-implemented guidelines help improve patient outcomes, but are often not resource-sensitive, and support therapies that may not be feasible in LMCs. A systematic review to address the content, quality, and resource-sensitivity of international breast cancer guidelines was completed. Also, a survey of global physicians evaluated the impact of resource setting on practice patterns and guideline use. Guideline use did not appear to be directed by quality (which was variable across guidelines) or resource-sensitivity (found in few guidelines). However, practice patterns were found to vary by resource setting and by continent, often due to the cost of certain therapies. In order for guidelines to better impact global breast cancer outcomes, they need to be of higher quality, more resource-sensitive, and better implemented.
The Impact of Coagulation on Endocrine Disrupting Compounds, Pharmaceutically Active Compounds and Natural Organic Matter
Keywords: Water treatment
Natural organic matter
Endocrine disrupting compounds
Pharmaceuticals
Coagulation
LC-OCD

Previous research indicates that pharmaceutically active compounds (PhACs) and endocrine-disrupting compounds (EDCs) are poorly removed during conventional drinking water treatment processes including coagulation; however, removal efficiency increases in the presence of natural organic matter (NOM). Therefore, this project investigates the link between various NOM types with EDC/PhAC removal. Bench-scale coagulation tests were conducted on three different source waters spiked with environmentally relevant levels (nominally 1000 ng/L) of EDCs/PhACs. Two different coagulants were used: polyaluminum chloride (PACl) and aluminum sulphate (alum). NOM was characterized using size exclusion liquid chromatography-organic carbon detection (LC-OCD). Results for Lake Ontario, Otonabee and Grand River water indicate that certain EDCs/PhACs are significantly removed during coagulation while others increase in concentration. Concurrently, particular NOM fractions (biopolymers and humic substances) are also being removed. Solvents used for EDC/PhAC spiking (acetone and acetonitrile) did not affect coagulation, but contributed to low molecular weight neutral and hydrophobic NOM fractions.
Spatially Heterogeneous Prey Patterns may be Necessary for Predator Survival: a Model and a Review of the Aquatic Literature
Keywords: Allen Paradox
prey patches
energetic efficiency

The Allen Paradox is the observation that, in aquatic communities, there is insufficient prey production to support predator growth. An assessment of the literature reveals that this paradox remains apparent in one of every four studies. Here, a novel explanation for this paradox is proposed: predators that feed in a spatially-heterogeneous-prey environment (SHPE) may experience a greater net energy gain than in a corresponding uniform-prey environment (UPE), meaning that predators may require less food than has been traditionally perceived. A model was developed to simulate a predator’s energy gain while feeding in a SHPE rather than a UPE. According to the simulation, a greater net energy gain in a SHPE than a UPE is possible, but only under certain conditions. Since prey can be utilized more efficiently in a SHPE, a given amount of prey production can supply more predator growth, which can have positive implications in fish stocking.
A Spatially-filtered Finite-difference Time-domain Method with Controllable Stability Beyond the Courant Limit
Keywords: computational electromagnetics
finite-difference time-domain
spatial filtering
stability limit
CFL limit
CFL extension factor
subgridding scheme
FDTD
spatially-filtered FDTD method
spatially-filtered subgridding scheme
discrete cosine transform
discrete sine transform
discrete fourier transform

This thesis introduces spatial filtering, which is a technique to extend the time step size beyond the conventional stability limit for the Finite-Difference Time-Domain (FDTD) method, at the expense of transforming field nodes between the spatial domain and the discrete spatial-frequency domain and removing undesired spatial-frequency components at every FDTD update cycle. The spatially-filtered FDTD method is demonstrated to be almost as accurate as and more efficient than the conventional FDTD method via theories and numerical examples. Then, this thesis combines spatial filtering and an existing subgridding scheme to form the spatially-filtered subgridding scheme. The spatially-filtered subgridding scheme is more efficient than existing subgridding schemes because the former allows the time step size used in the dense mesh to be larger than the dense mesh CFL limit. However, trade-offs between accuracy and efficiency are required in complicated structures.
Osteopetrosis Mutation R444L causes Endoplasmic Reticulum Retention and Misprocessing of Vacuolar H+-ATPase a3 Subunit
Keywords: osteopetrosis
v-atpase

Osteopetrosis is characterized by increased bone density and fragility. The R444L missense mutation in the human V-ATPase a3 subunit causes this disease. Modeling the R444L mutation in mouse a3 caused endoplasmic reticulum (ER) retention of a3 with attendant abrogation of maturation and trafficking of the glycoprotein and its degradation. The mutant protein also displayed altered conformation and increased degradation. Together, these data suggest that R444 is involved in protein folding or stability significant to mammalian a3, and that infantile osteopetrosis caused by the R444L mutation in the V-ATPase a3 subunit is another member of the growing class of protein folding diseases. We also ascertained that the N-Glycosylation sites of the a3 glycoprotein lie at position N484 and N504, data that help to refine the topology of the a subunit. Overall, this study sheds new light onto the role that R444 plays in a subunit structure, and refines a subunit topology.
An Investigation of Outcomes in Relation to Thiamin Status of Ambulatory Patients with Heart Failure
Keywords: thiamin
heart failure

Thiamin is a required coenzyme in energy producing reactions that subsequently fuel myocardial contraction. Therefore, thiamin deficiency (TD) might contribute to the reduction in myocardial function observed in patients with heart failure (HF) by limiting the available energy and subsequently aggravating cardiac performance. While the prevalence of TD as well as the impact of supplementation has been examined in patients with HF, none of these studies to date has examined the impact of TD on clinical outcomes. Therefore, this study investigated the associations between erythrocyte [TPP] levels and outcomes in ambulatory patients with HF. Time-to-event probabilities were found to be not significant for acute decompensated heart failure, mortality, all-cause hospitalizations, arrhythmias, myocardial infarctions and other adverse events. Further investigations into the longer term impact of TD on outcomes and the effects of thiamin supplementation as an adjunct therapy in delaying the disease progression are needed.
Adapting S. cerevisiae Chemical Genomics for Identifying the Modes of Action of Natural Compounds
Keywords: chemical biology
Saccharomyces cerevisiae
natural products
chemical genomics

Natural compounds have been largely excluded from characterization via high-throughput profiling strategies due to their limited abundance. Herein, I describe the modification of high-throughput yeast chemical genomic (CG) interaction profiling to permit identifying the modes of action of natural compounds. The previous assay proceeded by evaluating the genome-wide yeast deletion collection for drug-hypersensitivity in a volume of 0.7mL. Compound consumption was minimized with the adapted approach by reducing the assay volume 70% through simplifying the complexity of the yeast deletion pool screened. By recreating each yeast mutant in a drug-hypersensitive background, I created a novel resource that increases compound efficiency and further diminishes compound use. Evaluating a series of characterized compounds analyzed previously by the traditional CG approach validated the adaptations incorporated did not negatively affect the quality of data yielded. Ultimately, this modified strategy will be used to screen thousands of natural compounds contained within the RIKEN NPDepo library.
Gingival Microleakage of Class V Resin Composite Restorations with Fiber Inserts
Keywords: Class V
Composite restorations
Fiber inserts
Microleakage

This study investigated the effect on microleakage of different bonding agents and glass and polyethylene fibers inserted at gingival margins of class V composite restorations. Sixty premolars were sterilized. Class V cavities were prepared, 1 mm below the cementoenamel junction. Prepared tooth were randomly divided into 12 groups (n=10). In experimental groups fiber inserts were inserted at the gingival seat. The control groups had no inserts. Restorations were incrementally placed and polymerized. Specimens were then stored in water and thermocycled for 500 cycles, then immersed in 2% procion dye and sectioned buccolingually, then dye penetration was assessed. Data were analyzed with the Kruskal-Wallis test and analysis of variance of ranks. No significant differences were found among the types of fiber or the two types of composites. Significant differences were found between the bonding agents. SE and LS show significantly lower microleakage than NT in class V composite restorations in dentin.