3,705 research outputs found
School Culture and Its Effect on Extracurricular Participation in Hong Kong
Abstract Extracurricular participation has displayed positive effects on student development; it is, therefore, worthwhile to investigate the factors that influence studentsâ willingness and ability to participate in extracurricular activities held by the school. Through a qualitative research design, this study hopes to reveal how school culture and other factors influence extracurricular participation among local high school students in Hong Kong. Focus groups were conducted with students from three local schools, and teachers and administrative staff were interviewed when available. The study focused on four main themes: school and student profile, participation requirements, activity availability, and school mission and academic emphasis. Hand coding and data analysis suggest that principal and school attitudes influenced the activities available, while timing and activity arrangement significantly affected student participation. Overall, there were mixed opinions toward extracurricular activities
Effectiveness of Resin Infiltration and Mi Paste Cpp-Acp in Masking White Spot Lesions
The development of decalcification around orthodontic brackets and bands, commonly called white spot lesions (WSLs), is often observed in patients with poor oral hygiene during treatment (Behnan et al., 2010, Rodgers et al., 2010). In many instances, these WSLs continue to be visible after the removal of fixed appliances and after natural remineralization. The purpose of this in vitro study was to compare the effectiveness of two treatment modalities, resin infiltration (RI) and Casein Phosphopeptide Amorphous Calcium Phosphate (CPP-ACP), at improving the light reflectivity and thus the appearance of WSLs using spectrophotometric analysis. Sixty extracted human third molars were partially demineralized to create artificial WSLs and randomly divided into a control (artificial saliva) and two treatment groups. A spectrophotometer (VITA EasyshadeĂÂź compact) was used before and after treatment to quantify the amount of light (L*) reflected from the surfaces of each tooth specimen. All three groups showed statistically significant improvements in reflectivity, as indicated by the increase in L* after treatment. However, there were no statistically significant differences among the study groups. In conclusion, both treatment modalities and the control were effective at masking WSLs
An examination of persistence in charitable giving to education through the 2002 economic downturn
Using three waves of the Center on Philanthropy Panel Study, a module of the Panel Study of Income Dynamics, ïŹ elded by the Institute for Social Research at the University of Michigan, we examine characteristics of donors who gave to any level of education in each of the years studied (2000, 2002 and 2004). We ïŹ nd that these persistent donors to education are more likely to have higher income (average of US $ 142 603 in 2000) and higher levels of education (bachelor â s degree or above) than are less frequent education donors and non-donors to education. There is some support for a positive association between persistent giving to education and the number and age of children in the household. There is strong support for positive association between educational attainment and persistence in giving to education and in giving to other secular causes. Implications for fundraising practice and further research topics are discussed
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Structure in Category-Based Induction
We investigated category-based inference tasics, contrasting the predictions of structural alignment theory as applied to categorization with those of feature-overlap models of similarity. We provide evidence for the differential level of importance of causal information in category-based inference tasks, as predicted by the systematicity principle (Centner, 1983). Our basic paradigm consists of a task in which participants decide between inferences based on shared causal antecedents or shared attributes. Experiment I demonstrated a preference for the causal inference when the target animal shares one attribute with one of the base animals and one causal antecedent with the other base. In Experiment 2, we found that this preference holds even when the target animal shares greater attribute similarity with the noncausal base (i.e., the target shares two attributes with one base and one causal antecedent with the other). Experiment 2 also served to demonstrate that this result can indeed be attributed to the influence of causal structure, and not to surface stimulus properties, such as sentence length. Overall, the results agreed with the predictions of structural alignment theory and were inconsistent with a feature-overlap account
Forward Genetic Dissection of Biofilm Development by Fusobacterium nucleatum: Novel Functions of Cell Division Proteins FtsX and EnvC.
Fusobacterium nucleatum is a key member of the human oral biofilm. It is also implicated in preterm birth and colorectal cancer. To facilitate basic studies of fusobacterial virulence, we describe here a versatile transposon mutagenesis procedure and a pilot screen for mutants defective in biofilm formation. Out of 10 independent biofilm-defective mutants isolated, the affected genes included the homologs of the Escherichia coli cell division proteins FtsX and EnvC, the electron transport protein RnfA, and four proteins with unknown functions. Next, a facile new gene deletion method demonstrated that nonpolar, in-frame deletion of ftsX or envC produces viable bacteria that are highly filamentous due to defective cell division. Transmission electron and cryo-electron microscopy revealed that the ÎftsX and ÎenvC mutant cells remain joined with apparent constriction, and scanning electron microscopy (EM) uncovered a smooth cell surface without the microfolds present in wild-type cells. FtsX and EnvC proteins interact with each other as well as a common set of interacting partners, many with unknown function. Last, biofilm development is altered when cell division is blocked by MinC overproduction; however, unlike the phenotypes of ÎftsX and ÎenvC mutants, a weakly adherent biofilm is formed, and the wild-type rugged cell surface is maintained. Therefore, FtsX and EnvC may perform novel functions in Fusobacterium cell biology. This is the first report of an unbiased approach to uncover genetic determinants of fusobacterial biofilm development. It points to an intriguing link among cytokinesis, cell surface dynamics, and biofilm formation, whose molecular underpinnings remain to be elucidated.IMPORTANCE Little is known about the virulence mechanisms and associated factors in F. nucleatum, due mainly to the lack of convenient genetic tools for this organism. We employed two efficient genetic strategies to identify F. nucleatum biofilm-defective mutants, revealing FtsX and EnvC among seven biofilm-associated factors. Electron microscopy established cell division defects of the ÎftsX and ÎenvC mutants, accompanied with a smooth cell surface, unlike the microfold, rugged appearance of wild-type bacteria. Proteomic studies demonstrated that FtsX and EnvC interact with each other as well as a set of common and unique interacting proteins, many with unknown functions. Importantly, blocking cell division by MinC overproduction led to formation of a weakly adherent biofilm, without alteration of the wild-type cell surface. Thus, this work links cell division and surface dynamics to biofilm development and lays a foundation for future genetic and biochemical investigations of basic cellular processes in this clinically significant pathogen
Streaming Enrollment in Early Child Care Centers Using Stable Matching
From the Washington University Office of Undergraduate Research Digest (WUURD), Vol. 13, 05-01-2018. Published by the Office of Undergraduate Research. Joy Zalis Kiefer, Director of Undergraduate Research and Associate Dean in the College of Arts & Sciences; Lindsey Paunovich, Editor; Helen Human, Programs Manager and Assistant Dean in the College of Arts and Sciences Mentor(s): John McCarth
Germline and Somatic DNA Damage Repair Gene Mutations and Overall Survival in Metastatic Pancreatic Adenocarcinoma Patients Treated with FOLFIRINOX
Purpose: Pancreatic ductal adenocarcinoma (PDAC) is a lethal cancer with lack of predictive biomarkers. We conducted a study to assess DNA damage repair (DDR) gene mutations as a predictive biomarker in PDAC patients treated with FOLFIRINOX.
Experimental Design: Indiana University Simon Cancer Center pancreatic cancer database was used to identify patients with metastatic PDAC, treated with FOLFIRINOX and had tissue available for DNA sequencing. Baseline demographic, clinical, and pathologic information was gathered. DNA isolation and targeted sequencing was performed using the Ion AmpliSeq protocol. Overall survival (OS) analysis was conducted using KaplanâMeier, logistic regression and Cox proportional hazard methods. Multivariate models were adjusted for age, gender, margin status, CA 19-9, adjuvant chemotherapy, tumor and nodal stage.
Results: Overall, 36 patients were sequenced. DDR gene mutations were found in 12 patients. Mutations were seen in BRCA1 (N = 7), BRCA2 (N = 5), PALB2 (N = 3), MSH2 (N = 1), and FANCF (N = 1) of all the DDR genes sequenced. Median age was 65.5 years, 58% were male, 97.2% were Caucasian and 51.4% had any family history of cancer. The median OS was near significantly superior in those with DDR gene mutations present vs. absent [14 vs. 5 months; HR, 0.58; 95% confidence interval (CI), 0.29â1.14; log-rank P = 0.08]. Multivariate logistic (OR, 1.47; 95% CI, 1.04â2.06; P = 0.04) and Cox regression (HR, 0.37; 95% CI, 0.15â0.94; P = 0.04) showed presence of DDR gene mutations was associated with improved OS.
Conclusions: In a single institution, retrospective study, we found that the presence of DDR gene mutations are associated with improved OS in PDAC patients treated with FOLFIRINOX
Physical Layer Algorithm and Hardware Verification of MIMO Relays Using Cooperative Partial Detection
Cooperative communication with multi-antenna relays can significantly increase the reliability and speed. However, cooperative MIMO detection would impose considerable complexity overhead onto the relay if a full detect-and-forward (FDF) strategy is employed. In order to address this challenge, we propose a novel cooperative partial detection (CPD) strategy to partition the detection task between the relay and the destination. CPD utilizes the inherent structure of the tree-based sphere detectors, and modifies the tree traversal so that instead of visiting all the levels of the tree, only a subset of the levels, thus a subset of the transmitted streams, are visited. Based on this methodology, the destination combines the source signal and the partial relay signal to perform the detection step. We show, in both simulation and hardware
verification on the WARP platform, that using the CPD approach, the relay can avoid the considerable overhead of MIMO detection while helping the source-destination link to improve its performance.XilinxAzimuth SystemsNational Science Foundatio
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Enhancing Myoblast Fusion for Therapy of Muscular Dystrophies
Skeletal muscle is a major organ comprising 30-40% of the human body mass. The coordination of processes resulting in mature muscle requires many genes, and their loss can result in debilitating muscle disorders. Of the strategies being developed to cure muscle diseases, enhancement of the natural process of muscle cell fusion in existing or introduced myogenic cells has great therapeutic potential. In this work, we determined whether a drug that stimulates proliferation and fusion of myoblasts could alleviate murine Duchenne muscular dystrophy. We also studied the necessity of a gene that is upregulated in early fusing human myoblast cultures and its role in muscle disease development
Vascular endothelium plays a key role in directing pulmonary epithelial cell differentiation.
The vascular endothelium is critical for induction of appropriate lineage differentiation in organogenesis. In this study, we report that dysfunctional pulmonary endothelium, resulting from the loss of matrix Gla protein (MGP), causes ectopic hepatic differentiation in the pulmonary epithelium. We demonstrate uncontrolled induction of the hepatic growth factor (HGF) caused by dysregulated cross talk between pulmonary endothelium and epithelium in Mgp-null lungs. Elevated HGF induced hepatocyte nuclear factor 4 α (Hnf4a), which competed with NK2 homeobox 1 (Nkx2.1) for binding to forkhead box A2 (Foxa2) to drive hepatic differentiation in Mgp-null airway progenitor cells. Limiting endothelial HGF reduced Hnf4a, abolished interference of Hnf4a with Foxa2, and reduced hepatic differentiation in Mgp-null lungs. Together, our results suggest that endothelial-epithelial interactions, maintained by MGP, are essential in pulmonary cell differentiation
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