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Burden of Childhood Oral Diseases in Protracted Refugee Situations
No full textM.S.Background: Dental health is an important factor that can affect the overall health of people. Dental caries and its consequences have a negative impact on children’s quality of life. In the literature, data on the prevalence of oral diseases of children who live in informal camps located in low and middle-income countries (LMICs) is very limited. The aims of the study were to assess the prevalence of oral diseases and conditions in Syrian refugee children, living in camps in Bekaa, Lebanon, in terms of dental caries, pain presence, intensity and duration, the presence of dental abscess, and to assess the oral hygiene among them. Also, to evaluate the relationship between level of caries and the duration of displacement. Methods: The data of this study were analyzed after reviewing 910 questionnaires and dental records done by Global Miles for Smiles on Syrian refugee children aged between 4 to16 years who attending schools in camps located in Bekaa, Lebanon. Each chart included two parts. The first part was a questionnaire about the intensity and duration of pain, diet habit, oral hygiene and the duration of living in camps. The second section provided data related to the patient’s oral health status. Descriptive statistics and Mann- Whitney U Test were used to evaluate the data. The level of significance was set at 5%. Results: A total of 823 children charts were included in this study. The children's age ranged from 4 to 16 with the mean age 9.1 years (SD = 2.3). The percentage of males and females in this study were 52% and 48%, respectively. The prevalence of dental caries among the refugee children was 90.2%. Also, the number of decayed teeth in children who were displaced for more than 5 years was statistically significantly higher than the number of decayed teeth in children who have been displaced for less than five years. (P = 0.015). More than half of the children complained of oral pain with different levels ranging from mild to severe. The prevalence of dental abscess was 8.9%. Also, approximately one third of the children had never brushed their teeth and approximately 62% had never been to a dentist. Conclusions: The prevalence of oral diseases among refugee children living in camps in LMICs is high. This finding emphasizes the necessity of providing comprehensive interventions in order to improve the dental health status of this population.**To request an accessible version of the file(s) associated with this item, contact [email protected]. Please include the item's persistent URL [http://hdl.handle.net/. . .] in your request.*
Enhancement of Human Gingival Fibroblast Migration by Strontium
No full textM.S.Background: Human gingival fibroblast (HGF) migration is critically important in tissue regeneration and healing. After a dental implant is placed, fibroblasts are primary cells to repopulate the wound, attach to implant abutment, and form a healthy and collagen-rich connective tissue seal. Over the past decades, strontium, which is an alkaline earth metal, has attracted attention owing to its beneficial effects in osteoblast proliferation and osteoporosis treatment. Recently published work has highlighted the potential positive effect on gingival fibroblasts. Aim: The goal of the present study was to evaluate the ability of strontium to enhance fibroblast cells migration and attachment in vitro. Methods: HGF scratch cell migration assays were performed on collagen coated or uncoated cell culture plates. HGFs were exposed to strontium directly in solution or indirectly through conditioned media released from alginate-strontium scaffolds (0%,5%,10%). In addition, cell attachment on strontium alginate coated titanium surfaces was evaluated. Results: A trend for increased cell migration with 1mM(10%) strontium at 48 hours was observed. Cells grown in alginate media or on alginate coated titanium surfaces exhibit changes in their morphology, impaired growth and migration although a small positive effect was observed from strontium. Conclusion: These findings suggest that strontium citrate displays a positive effect on cells migration at 10% concentration with no cytotoxic effect observed. Further research is warranted in this area.**To request an accessible version of the file(s) associated with this item, contact [email protected]. Please include the item's persistent URL [http://hdl.handle.net/. . .] in your request.*
Identifying and Analyzing Human Genetic Variation through a Key Example in the Growth Hormone Receptor Gene
No full textPh.D.To define what it means to be human, we must first appreciate the full scope of human variation. This means we must consider both single nucleotide variants and structural variants to map human variation. The majority of human research tends to focus on the previous, despite the fact that structural variants conservatively constitute two to seven times more base pairs that are variable among primate species when compared to single-nucleotide variants. There are several methods of identifying structural variations in genomes. For short-reads sequences, these include read depth, split-read, and paired-end methodologies. Utilizing massive genomic databases that are available today, one can then discover important demographic information about a variant of interest and look to the genetic data collected in different populations and in ancient samples to begin to understand the evolutionary history of that variant. The methodologies outlined in this dissertation were followed to perform an evolutionary and phenotypic analysis of a common exonic deletion in the growth hormone receptor gene (GHRd3) that has only been observed in humans and extinct hominins. This deletion has been linked to response to growth hormone, placenta size, birth weight, growth after birth, time of menarche, adult height, and longevity. To further evaluate its phenotypic effects, a mouse line engineered to contain the deletion was used. Pleiotropic and sex-specific effects on organismal growth, the expression levels of hundreds of genes, and serum lipid composition were documented, potentially involving the nutrient-dependent mTORC1 pathway. Together with statistical analyses performed on this locus, these growth and metabolic effects are consistent with a model in which the allele frequency of GHRd3 varies throughout human evolution as a response to fluctuations in resource availability. Further analyses are currently being performed, including additional RNA-sequencing experiments to analyze the effect of the variant under nutrient restricted environmental conditions. This study is a case example that shows how genetic variants can have sex-specific effects and how these variants can interact with developmental and metabolic pathways. We hope that this work will serve as a model for similar studies in the future.**To request an accessible version of the file(s) associated with this item, contact [email protected]. Please include the item's persistent URL [http://hdl.handle.net/. . .] in your request.*
Indoleamine 2,3-dioxygenase Regulates PD-1 Expression on CD8+ T Cells via Kynurenine Activation of the Aryl Hydrocarbon Receptor
No full textPh.D.Epithelial ovarian cancer (EOC) is the deadliest gynecologic malignancy in the United States. Despite initial response to surgery and platinum- and taxane-based chemotherapy, the majority of patients relapse and ultimately die from their disease within five years. Work by our group has shown that the presence of intra-epithelial CD8+ tumor-infiltrating lymphocytes is associated with favorable outcomes in EOC patients. However, suppressive mechanisms in the tumor microenvironment inhibit antigen-specific immunity, impacting tumor growth and metastasis. Our group has also shown that tumor-derived antigen-specific CD8+ T cells from ovarian cancer demonstrate impaired effector function and enriched expression of the inhibitory molecule programmed cell death protein 1 (PD-1). Moreover, we demonstrated that expression of the enzyme indoleamine 2,3-dioxygenase (IDO) in ovarian tumor correlates with poor prognosis and poor tumor infiltration by CD8+ T cells. However, a complete understanding of the cellular and molecular mechanisms of IDO-mediated suppression of T cells remains unclear, and is therefore the focus of my thesis work.**To request an accessible version of the file(s) associated with this item, contact [email protected]. Please include the item's persistent URL [http://hdl.handle.net/. . .] in your request.*
The Experiential Meaning of High-Fidelity Simulation in Novice Registered Nurses' Current Practice: A Hermeneutic Phenomenological Study
No full textPh.D.This dissertation, composed of 3 manuscripts, provides a foundation for the evaluation of high-fidelity simulation in nursing education. The first manuscript provides a review of the literature on the evidence of learning outcomes in high-fidelity simulation in undergraduate nursing education. The second manuscript is an evolutionary concept analysis of the concept simulation. It provides a historical perspective on the use of simulation in nursing education, and provides clear definitions of levels of fidelity. The third manuscript provides the dissertation study, which examines the common meanings and shared practices of new registered nurses applying high-fidelity simulation learning in their clinical practice. The hermeneutic phenomenological method was used, interviewing 15 nurses who had approximately 1 year of clinical practice. Hermeneutic methodology was selected to fill gaps in understanding that remain in nursing science following quantitative study. Further research is warranted.**To request an accessible version of the file(s) associated with this item, contact [email protected]. Please include the item's persistent URL [http://hdl.handle.net/. . .] in your request.*
Examination of Group Gender Composition on Group Member Satisfaction, Cohesion, and Outcome
No full textPh.D.Studies have yielded conflicting results regarding benefits for both homogeneous or heterogeneous group composition on the development of positive group climate, cohesion, and performance outcomes. Research is limited regarding the impact of gender composition in counseling groups. This study examined the impact of diverse gender group composition, and the experience of being a minority or majority group member in terms of gender (e.g., men as minority; women as majority group member) on group climate, cohesion, group member satisfaction, and performance outcomes. The participants (n = 234; 31 groups) in this study were graduate students in either a masters degree program in Counseling or a Ph.D. program in Counseling Psychology at a northeastern university. The measures used in this study were The Group Questionnaire, the Inventory of Interpersonal Problems-Circumplex-Item Response Theory, and Satisfaction with Group. Multiple ANOVAs, and MANOVAs were conducted with follow-up tests conducted when main effects or interaction effects were significant. Study results indicated a main effect for gender, with males as group minority in this study reporting lower ratings of group climate and outcome than women consistently over time. The effect of time was significant so that members of all groups, homogeneous and heterogeneous, reported less interpersonal distress over time. Discussion of findings, study limitations, implications for counseling practice, and recommendations for future research are included in this study.**To request an accessible version of the file(s) associated with this item, contact [email protected]. Please include the item's persistent URL [http://hdl.handle.net/. . .] in your request.*
Probable Ice-Rich Deposits on North-Facing Slopes in Alba Patera, Mars
No full textM.S.Water ice is believed to have played an important role in the recent (1000 km basal diameter. Unconformable deposits lie on north-facing portions of the caldera walls. These deposits exhibit two textures: a smooth texture and a hummocky texture consisting of decameter-scale hills.**To request an accessible version of the file(s) associated with this item, contact [email protected]. Please include the item's persistent URL [http://hdl.handle.net/. . .] in your request.*
Seismic Resilience Quantification for a Set of Buildings
No full textIn recent years, the topic of resilience has caught the attention of the structural engineering community. Several approaches have been proposed through the years to quantify resilience for various infrastructure systems, but quantifying the resilience of buildings, and groups of buildings, remains challenging. Here, research was conducted to investigate the effectiveness of three different approaches proposed to quantify resilience, based on results from performance-based assessments. The proposed approaches use repair costs, occupancy levels, and asset values as the functionality measures to quantify resilience. Resilience indexes are quantified for four different example buildings using the three approaches. Performance-based assessments of the buildings are performed following the procedures of the Federal Emergency Management Agency (FEMA) P-58 document using an intensity-based method and the simplified analysis procedures. The proposed methodology by the Resilience-based Earthquake Design Initiative Rating System (REDi), to account for downtimes due to delays calculated from the FEMA P-58 assessments, are incorporated in the resilience quantification for the four example buildings. The delays due to downtimes are included in the computation of resilience index considering two scenarios based on different impeding factors.
Resilience is quantified for a range of different spectral accelerations. Casualties for the range of spectral accelerations considering different collapse modes for the four example buildings are presented. The individual results for each building are also combined using a weight-based approach to quantify the resilience index for an archetype city block. The influence of contractor availability and collapse probability in the resilience indexes for a set of buildings is investigated. The findings presented here are useful both from the perspective of quantifying the resilience of a community on the basis of its building assets, as well as for possible inclusion into broader integrated framework that aims to quantify community resilience.Fulbright Laspau Progra
The Impact of Binge-Like Feeding Behavior on Endogenous GLP-1
No full textM.A.Binge eating disorder (BED) is a growing problem in the United States and affecting millions of people worldwide. Binge eating involves consuming large quantities of food within a discrete period of time. Although the biological mechanisms for food intake are well-studied, the underlying neurohormonal mechanisms in binge-like feeding are not well understood. Glucagon-like peptide-1 (GLP-1) is a hormone produced peripherally from the L-cells of the intestine, and centrally from preproglucagon (PPG) neurons of the nucleus tractus solitarius (NTS). The NTS plays a critical role in integrating information from the periphery and the brain to modulate feeding behavior and appetite, therefore, we examined changes in central and peripheral GLP-1 after binge-like feeding behavior. First, the expression of PPG and GLP-1R mRNA in the NTS was evaluated in male rats maintained on an intermittent access schedule of palatable food intake, known to promote binge-like feeding. Compared to controls, NTS PPG mRNA expression was downregulated in male rats with a history of binge-like intake of palatable food. Furthermore, plasma GLP-1 in these rats was increased, showing an interesting divergence between central and peripheral GLP-1 in rats after binge-like feeding over several weeks. Given that binge eating is more common in females, we built upon these findings by investigating GLP-1 signaling in female rats after binge-like feeding. Intact female rats were given access to palatable food on the same schedule as male rats (either daily or intermittently), but surprisingly, this paradigm failed to produce binge-like behavior in female rats with intermittent palatable food access. This provided evidence for underlying sex differences in binge-like feeding behavior. To further explore this, a separate group of female rats were maintained on a different intermittent palatable food access schedule, and were given access to palatable food either every four days (4D) or ad libitum (AL). This paradigm produced a robust binge-like feeding behavior in 4D rats, showing that female rats are sensitive to the interval schedule of palatable food access. Furthermore, in contrast with our findings in male rats with a history of binge-like intake, 4D female rats did not show downregulation in NTS PPG expression. This suggests the importance of investigating possible confounding variables, such as estrogen, that may interact with the central GLP-1 system to influence binge-like feeding. Collectively, this project provides evidence that changes in endogenous GLP-1 signaling are associated with binge-like feeding. Furthering our knowledge of this mechanism will enhance our understanding of the neurobiology of BED and may provide novel therapeutic options for patients suffering from BED.**To request an accessible version of the file(s) associated with this item, contact [email protected]. Please include the item's persistent URL [http://hdl.handle.net/. . .] in your request.*
Candida albicans Glycosidases, Dfg5 and Dcw1, Regulate Cell Wall Chitin Synthesis
No full textM.S.Objectives: Candida albicans Dfg5 and Dcw1 are cell wall mannosidases with important functions and are ideal drug targets. Our past studies have shown that Dfg5 and Dcw1 not only function in cell wall biogenesis but they also regulate cell signaling via HOG MAPK signaling pathway. Hog1 plays a role in cell wall integrity via regulation of chitin synthases CHS1, CHS2, CHS3 and CHS8 in C. albicans. Our objective was to determine if Dfg5 and Dcw1 regulate chitin synthesis via HOG pathway. Methods: dfg5/dcw1 heterozygous (ES1, ES195) and conditional mutant (ES195+Methionine/Cysteine) strains were used. WT (SC5314) strain and DAY185 (parental) strains were used as negative controls and hog1 knock-out mutant as positive control. Fluorescence microscopy of calcofluor white (CFW) stained mutant and control strains was performed to determine characteristics of cell wall chitin. Quantification of chitin levels was performed by measuring CFW fluorescence of 100 cells per strain. Quantitative PCR analysis was performed to measure the relative expression of chitin synthase genes CHS1, CHS2, CHS3 and CHS8 in mutant and control strains. Strains were also treated with commercially available chitinase to determine cell separation using light microscopy and scanning electron microscopy (SEM) analysis. Results: Fluorescence microscopy showed significantly increased chitin accumulation in the mutants as compared to wild type. Chitin accumulation was observed mainly at the mother-bud neck. Additionally, incubation with chitinase led to cell separation in the mutants further confirming that the phenotype was a result of abnormal chitin accumulation. Chitin synthases CHS2, CHS3 and CHS8 were observed to be significantly upregulated in the ES195-conditional mutant at 6 h and 12 h as compared to the wild type. This upregulation was similar to hog1 knock-out mutant at 12 h for CHS2 and CHS8. A much higher increase in expression of CHS1 was observed in the hog1 knock-out mutant indicating that Hog1 may be required for regulation of CHS1. Conclusion: Cell wall glycosidases, Dfg5 and Dcw1, regulate chitin synthesis via expression of chitin synthases, which lead to differential chitin accumulation and a defect in cell separation.**To request an accessible version of the file(s) associated with this item, contact [email protected]. Please include the item's persistent URL [http://hdl.handle.net/. . .] in your request.*