186 research outputs found
Exploring the role of blended learning for teaching and learning effectiveness in institutions of higher learning: An empirical investigation
As the years progress there has been rapid growth in Blended Learning (BL) adoption, but only few research focused on adoption issues related to learners, academic staffs and management. Thus, research is needed to guide universities in strategically examining learners, academic staffs and management adoption of BL. Accordingly, this study develops a model to facilitate university policy makers in their decision making to assess students learning and academic staffs teaching outcome. Furthermore, this study explores on the factors that influence BL adoption in universities, through an empirical study from the perspectives of learners, academic staffs, and management. In particular, it examines the current BL practice adoption effectiveness in universities. Based on extensive review of prior studies, survey questionnaires was designed and distributed to convenience samples of 87 students, academic staffs, and management in 3 Malaysia universities to validate the developed model. Next, Partial Least Square-Structural Equation Modeling (PLS-SEM) was employed to analyze the survey data. Findings reveal that supportive factors, attitude, learning mode, satisfaction, course management, and ease of use positively predict the perception of learners and academic staffs’ to adopt BL. Similarly, findings suggest that the perception of management towards BL adoption is positively determined by the strategy, structure, and support factors. Moreover, findings reveal that the impact of BL on learners’ effectiveness is positively predicted by achievement, engagement, involvement, retention, and cognitive outcome. Additionally, findings suggest that the impact BL on academic staffs’ effectiveness is significantly influence by delivery, performance, evaluation, motivation. Theoretical implications from this study contribute to enhance teaching quality by enriching course management, improving learning content, and facilitate management policies towards effective BL adoption
A managerial perspective on institutions' administration readiness to diffuse blended learning in higher education: concept and evidence
There has been rapid development in Blended Learning (BL) diffusion and prior studies mainly focused on issues related to students and lecturers in improving teaching and learning outcomes, but very few studies focused on institution’s readiness and diffusion issues. Thus, there is need for institutional-based research to guide universities, colleges, and polytechnics to strategically diffuse BL. Accordingly, this study develops a model to investigate the variables and associated factors that influence institutions' administration readiness to diffuse BL initiatives based on Diffusion of Innovation (DoI) theory and institutional BL adoption framework that comprises of mature implementation stage of BL. Quantitative research approach was employed and data was collected using online survey questionnaire from 223 e-learning administrators/managers in Malaysia universities, colleges, and polytechnics. Next, Partial Least Square-Structural Equation Modeling (PLS-SEM) technique was employed for data analysis. Results indicate that institutional structure, resource support, technology infrastructure, management strategies, and ethical considerations are key variables that positively predict administration readiness to diffuse BL initiatives in higher education. Additional results from Importance Performance Map Analysis (IPMA) in PLS-SEM suggest that institutional structure has the strongest effect on administrators’ readiness to diffuse BL and is also the most important variable that influences BL diffusion in institutions. Theoretically, findings from this study provide insights on how institutions’ administration perception and acceptance of BL approach can be enhanced. Practically, the developed model can be employed as a readiness tool to assess institutions current state in implementing BL environment and further provides a road map for future improvement
A managerial perspective on institutions' administration readiness to diffuse blended learning in higher education: concept and evidence
There has been rapid development in Blended Learning (BL) diffusion and prior studies mainly focused on issues related to students and lecturers in improving teaching and learning outcomes, but very few studies focused on institution?s readiness and diffusion issues. Thus, there is need for institutional-based research to guide universities, colleges, and polytechnics to strategically diffuse BL. Accordingly, this study develops a model to investigate the variables and associated factors that influence institutions' administration readiness to diffuse BL initiatives based on Diffusion of Innovation (DoI) theory and institutional BL adoption framework that comprises of mature implementation stage of BL. Quantitative research approach was employed and data was collected using online survey questionnaire from 223 e-learning administrators/managers in Malaysia universities, colleges, and polytechnics. Next, Partial Least Square-Structural Equation Modeling (PLS-SEM) technique was employed for data analysis. Results indicate that institutional structure, resource support, technology infrastructure, management strategies, and ethical considerations are key variables that positively predict administration readiness to diffuse BL initiatives in higher education. Additional results from Importance Performance Map Analysis (IPMA) in PLS-SEM suggest that institutional structure has the strongest effect on administrators? readiness to diffuse BL and is also the most important variable that influences BL diffusion in institutions. Theoretically, findings from this study provide insights on how institutions? administration perception and acceptance of BL approach can be enhanced. Practically, the developed model can be employed as a readiness tool to assess institutions current state in implementing BL environment and further provides a road map for future improvement
Role of leukocyte cell-derived chemotaxin 2 as a biomarker in hepatocellular carcinoma
We sought to identify a secreted biomarker for β-catenin activation commonly seen in hepatocellular carcinoma (HCC). By examination of our previously published genearray of hepatocyte-specific β-catenin knockout (KO) livers, we identified secreted factors whose expression may be β-catenin-dependent. We verified expression and secretion of the leading factor in HCC cells transfected with mutated (Hep3BS33Y)-β- catenin. Serum levels of biomarker were next investigated in a mouse model of HCC with β-catenin gene (Ctnnb1) mutations and eventually in HCC patients. Leukocyte cell-derived chemotaxin-2 (LECT2) expression was decreased in KO livers. Hep3BS33Y expressed and secreted more LECT2 in media as compared to Hep3BWT. Mice developing HCC with Ctnnb1 mutations showed significantly higher serum LECT2 levels. However patients with CTNNB1 mutations showed LECT2 levels of 54.28±22.32 ng/mL (Mean ± SD; n = 8) that were insignificantly different from patients with non-neoplastic chronic liver disease (32.8±21.1 ng/mL; n = 15) or healthy volunteers (33.2±7.2 ng/mL; n = 11). Intriguingly, patients without β-catenin mutations showed significantly higher serum LECT2 levels (54.26 ± 22.25 ng/mL; n = 46). While β-catenin activation was evident in a subset of non-mutant β-catenin HCC group with high LECT2 expression, serum LECT2 was unequivocally similar between β-catenin-active and -normal group. Further analysis showed that LECT2 levels greater than 50 ng/ml diagnosed HCC in patients irrespective of β-catenin mutations with specificity of 96.1% and positive predictive value of 97.0%. Thus, LECT2 is regulated by β-catenin in HCC in both mice and men, but serum LECT2 reflects β-catenin activity only in mice. Serum LECT2 could be a potential biomarker of HCC in patients. © 2014 Okabe et al
CD133 antigen expression in ovarian cancer
<p>Abstract</p> <p>Background</p> <p>Much attention has been recently focused on the role of cancer stem cells (CSCs) in the initiation and progression of solid malignancies. Since CSCs are able to proliferate and self-renew extensively, thus sustaining tumor growth, the identification of CSCs through their antigenic profile might have relevant clinical implications. In this context, CD133 antigen has proved to be a marker of tumor cells with stemness features in several human malignancies.</p> <p>The aim of the study was to investigate the clinical role of the immunohistochemically assessed expression of CD133 in a large single Institution series of ovarian cancer patients.</p> <p>Methods</p> <p>The study included 160 cases admitted to the Gynecologic Oncology Unit, Catholic University of Campobasso and Rome. CD133 antigen was identified by the monoclonal mouse anti-CD133-1 antibody (clone CD133 Miltenyi biotec).</p> <p>Results</p> <p>In the overall series CD133 positive tumor cells were observed in 50/160 (31.2%) cases. A <it>diffuse cytoplasmic </it>pattern was identified in 30/50 (60.0%), while an <it>apical cytoplasmic </it>pattern was found in 20/50 (40.0%) of CD133 positive tumors.</p> <p>As of September 2008, the median follow up was 37 months (range: 2–112). During the follow up period, progression and death of disease were observed in 123 (76.9%), and 88 (55.0%) cases, respectively. There was no difference in TTP between cases with negative (median TTP = 23 months) versus positive CD133 expression (median TTP = 24 months) (p value = 0.3). Similar results were obtained for OS. When considering the TTP and OS curves according to the pattern of CD133 expression, a trend to a worse prognosis for cases with <it>diffuse cytoplasmic </it>versus the <it>apical cytoplasmic </it>pattern was documented, although the statistical significance was not reached.</p> <p>Conclusion</p> <p>The immunohistochemical assessment of CD133 expression seems not to provide additional prognostic information in ovarian cancer patients. The role of the different pattern of CD133 immunoreaction deserves further investigation in a larger series.</p
Folliculin mutations are not associated with severe COPD
<p>Abstract</p> <p>Background</p> <p>Rare loss-of-function folliculin (<it>FLCN</it>) mutations are the genetic cause of Birt-Hogg-Dubé syndrome, a monogenic disorder characterized by spontaneous pneumothorax, fibrofolliculomas, and kidney tumors. Loss-of-function folliculin mutations have also been described in pedigrees with familial spontaneous pneumothorax. Because the majority of patients with folliculin mutations have radiographic evidence of pulmonary cysts, folliculin has been hypothesized to contribute to the development of emphysema.</p> <p>To determine whether folliculin sequence variants are risk factors for severe COPD, we genotyped seven previously reported Birt-Hogg-Dubé or familial spontaneous pneumothorax associated folliculin mutations in 152 severe COPD probands participating in the Boston Early-Onset COPD Study. We performed bidirectional resequencing of all 14 folliculin exons in a subset of 41 probands and subsequently genotyped four identified variants in an independent sample of345 COPD subjects from the National Emphysema Treatment Trial (cases) and 420 male smokers with normal lung function from the Normative Aging Study (controls).</p> <p>Results</p> <p>None of the seven previously reported Birt-Hogg-Dubé or familial spontaneous pneumothorax mutations were observed in the 152 severe, early-onset COPD probands. Exon resequencing identified 31 variants, including two non-synonymous polymorphisms and two common non-coding polymorphisms. No significant association was observed for any of these four variants with presence of COPD or emphysema-related phenotypes.</p> <p>Conclusion</p> <p>Genetic variation in folliculin does not appear to be a major risk factor for severe COPD. These data suggest that familial spontaneous pneumothorax and COPD have distinct genetic causes, despite some overlap in radiographic characteristics.</p
Rapamycin Response in Tumorigenic and Non-Tumorigenic Hepatic Cell Lines
The mTOR inhibitor rapamycin has anti-tumor activity across a variety of human cancers, including hepatocellular carcinoma. However, resistance to its growth inhibitory effects is common. We hypothesized that hepatic cell lines with varying rapamycin responsiveness would show common characteristics accounting for resistance to the drug.We profiled a total of 13 cell lines for rapamycin-induced growth inhibition. The non-tumorigenic rat liver epithelial cell line WB-F344 was highly sensitive while the tumorigenic WB311 cell line, originally derived from the WB-F344 line, was highly resistant. The other 11 cell lines showed a wide range of sensitivities. Rapamycin induced inhibition of cyclin E-dependent kinase activity in some cell lines, but the ability to do so did not correlate with sensitivity. Inhibition of cyclin E-dependent kinase activity was related to incorporation of p27(Kip1) into cyclin E-containing complexes in some but not all cell lines. Similarly, sensitivity of global protein synthesis to rapamycin did not correlate with its anti-proliferative effect. However, rapamycin potently inhibited phosphorylation of two key substrates, ribosomal protein S6 and 4E-BP1, in all cases, indicating that the locus of rapamycin resistance was downstream from inhibition of mTOR Complex 1. Microarray analysis did not disclose a unifying mechanism for rapamycin resistance, although the glycolytic pathway was downregulated in all four cell lines studied.We conclude that the mechanisms of rapamycin resistance in hepatic cells involve alterations of signaling downstream from mTOR and that the mechanisms are highly heterogeneous, thus predicting that maintaining or promoting sensitivity will be highly challenging
Molecular biology of breast cancer metastasis: Genetic regulation of human breast carcinoma metastasis
The present is an overview of recent data that describes the genetic underpinnings of the suppression of cancer metastasis. Despite the explosion of new information about the genetics of cancer, only six human genes have thus far been shown to suppress metastasis functionally. Not all have been shown to be functional in breast carcinoma. Several additional genes inhibit various steps of the metastatic cascade, but do not necessarily block metastasis when tested using in vivo assays. The implications of this are discussed. Two recently discovered metastasis suppressor genes block proliferation of tumor cells at a secondary site, offering a new target for therapeutic intervention
Levels of DNA methylation vary at CpG sites across the BRCA1 promoter, and differ according to triple negative and "BRCA-like" status, in both blood and tumour DNA
Triple negative breast cancer is typically an aggressive and difficult to treat subtype. It is
often associated with loss of function of the BRCA1 gene, either through mutation, loss of
heterozygosity or methylation. This study aimed to measure methylation of the BRCA1
gene promoter at individual CpG sites in blood, tumour and normal breast tissue, to assess
whether levels were correlated between different tissues, and with triple negative receptor
status, histopathological scoring for BRCA-like features and BRCA1 protein expression.
Blood DNA methylation levels were significantly correlated with tumour methylation at 9 of
11 CpG sites examined (p<0.0007). The levels of tumour DNA methylation were significantly
higher in triple negative tumours, and in tumours with high BRCA-like histopathological
scores (10 of 11 CpG sites; p<0.01 and p<0.007 respectively). Similar results were
observed in blood DNA (6 of 11 CpG sites; p<0.03 and 7 of 11 CpG sites; p<0.02 respectively).
This study provides insight into the pattern of CpG methylation across the BRCA1
promoter, and supports previous studies suggesting that tumours with BRCA1 promoter
methylation have similar features to those with BRCA1 mutations, and therefore may be
suitable for the same targeted therapies
Analysis of Pools of Targeted Salmonella Deletion Mutants Identifies Novel Genes Affecting Fitness during Competitive Infection in Mice
Pools of mutants of minimal complexity but maximal coverage of genes of interest facilitate screening for genes under selection in a particular environment. We constructed individual deletion mutants in 1,023 Salmonella enterica serovar Typhimurium genes, including almost all genes found in Salmonella but not in related genera. All mutations were confirmed simultaneously using a novel amplification strategy to produce labeled RNA from a T7 RNA polymerase promoter, introduced during the construction of each mutant, followed by hybridization of this labeled RNA to a Typhimurium genome tiling array. To demonstrate the ability to identify fitness phenotypes using our pool of mutants, the pool was subjected to selection by intraperitoneal injection into BALB/c mice and subsequent recovery from spleens. Changes in the representation of each mutant were monitored using T7 transcripts hybridized to a novel inexpensive minimal microarray. Among the top 120 statistically significant spleen colonization phenotypes, more than 40 were mutations in genes with no previously known role in this model. Fifteen phenotypes were tested using individual mutants in competitive assays of intraperitoneal infection in mice and eleven were confirmed, including the first two examples of attenuation for sRNA mutants in Salmonella. We refer to the method as Array-based analysis of cistrons under selection (ABACUS)
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