Blending critical thinking skills with the teaching of subject matter: Case of a geography lesson in a Malawi School

Critical thinking skills are essential in education. Unfortunately, education policymakers and curriculum developers in Malawi have not given a   concerted effort to promoting critical thinking skills in schools. OSISA has indicated that there is no clear evidence in the Malawi primary and   secondary school curricula that promoting critical thinking is considered   important. In this paper, we examine the definitions of critical thinking,   creative thinking, reflective thinking and we are of the view that there is a level of overlap amongst them. We also look at how the behaviours of   egocentrism and sociocentrism can undermine critical thinking. The study draws on Piaget and Vygotsky’s theory of (social) constructivism to advance approaches and practices that teachers can employ to promote critical   thinking in learners. We develop a lesson plan that incorporates critical  thinking skills and show how teachers can correct egocentric and    sociocentric tendencies that might impede critical thinking in learners. We  claim that students equipped with critical thinking skills can contribute   intellectually, socially, culturally and economically to society.Key words: critical thinking, social constructivism, lesson plan, egocentric, sociocentri

No Evidence of Human Papillomavirus in Patients with Breast Cancer in Hong Kong, Southern China

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A three-miRNA signature as promising non-invasive diagnostic marker for gastric cancer

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MicroRNA-143 is downregulated in breast cancer and regulates DNA methyltransferases 3A in breast cancer cells

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Differential expression of microRNAs in plasma of patients with colorectal cancer: A potential marker for colorectal cancer screening

Objective: MicroRNAs (miRNAs) have been shown to offer great potential in the diagnosis of cancer. We investigated whether plasma miRNAs could discriminate between patients with and without colorectal cancer (CRC). Methods: This study was divided into three phases: (1) marker discovery using real-time PCR-based miRNA profiling on plasma, corresponding cancerous and adjacent non-cancerous colonic tissues of five patients with CRC, along with plasma from five healthy individuals as controls; (2) marker selection and validation by real-time quantitative RT-PCR on a small set of plasma; and (3) independent validation on a large set of plasma from 90 patients with CRC, 20 patients with gastric cancer, 20 patients with inflammatory bowel disease (IBD) and 50 healthy controls. Results: Of the panel of 95 miRNAs analysed, five were upregulated both in plasma and tissue samples. All the five miRNAs were validated on the plasma of 25 patients with CRC and 20 healthy controls. Both miR-17-3p and miR-92 were significantly elevated in the patients with CRC (p<0.0005). The plasma levels of these markers were significantly reduced after surgery in 10 patients with CRC (p<0.05). Further validation with an independent set of plasma samples (n=180) indicated that miR-92 differentiates CRC from gastric cancer, IBD and normal subjects. This marker yielded a receiver operating characteristic curve area of 88.5%. At a cut-off of 240 (relative expression in comparison to RNU6B snRNA), the sensitivity was 89% and the specificity was 70% in discriminating CRC from control subjects. Conclusion: MiR-92 is significantly elevated in plasma of patients with CRC and can be a potential non-invasive molecular marker for CRC screening.published_or_final_versio

Circulating microRNAs as Specific Biomarkers for Breast Cancer Detection

Background: We previously showed microRNAs (miRNAs) in plasma are potential biomarkers for colorectal cancer detection. Here, we aimed to develop specific blood-based miRNA assay for breast cancer detection. Methodology/Principal Findings: TaqMan-based miRNA profiling was performed in tumor, adjacent non-tumor, corresponding plasma from breast cancer patients, and plasma from matched healthy controls. All putative markers identified were verified in a training set of breast cancer patients. Selected markers were validated in a case-control cohort of 170 breast cancer patients, 100 controls, and 95 other types of cancers and then blindly validated in an independent set of 70 breast cancer patients and 50 healthy controls. Profiling results showed 8 miRNAs were concordantly up-regulated and 1 miRNA was concordantly down-regulated in both plasma and tumor tissue of breast cancer patients. Of the 8 up-regulated miRNAs, only 3 were significantly elevated (p<0.0001) before surgery and reduced after surgery in the training set. Results from the validation cohort showed that a combination of miR-145 and miR-451 was the best biomarker (p<0.0001) in discriminating breast cancer from healthy controls and all other types of cancers. In the blind validation, these plasma markers yielded Receiver Operating Characteristic (ROC) curve area of 0.931. The positive predictive value was 88% and the negative predictive value was 92%. Altered levels of these miRNAs in plasma have been detected not only in advanced stages but also early stages of tumors. The positive predictive value for ductal carcinoma in situ (DCIS) cases was 96%. Conclusions: These results suggested that these circulating miRNAs could be a potential specific biomarker for breast cancer screening. © 2013 Ng et al.published_or_final_versio

Hf-based high-k materials for Si nanocrystal floating gate memories

Pure and Si-rich HfO2 layers fabricated by radio frequency sputtering were utilized as alternative tunnel oxide layers for high-k/Si-nanocrystals-SiO2/SiO2 memory structures. The effect of Si incorporation on the properties of Hf-based tunnel layer was investigated. The Si-rich SiO2 active layers were used as charge storage layers, and their properties were studied versus deposition conditions and annealing treatment. The capacitance-voltage measurements were performed to study the charge trapping characteristics of these structures. It was shown that with specific deposition conditions and annealing treatment, a large memory window of about 6.8 V is achievable at a sweeping voltage of ± 6 V, indicating the utility of these stack structures for low-operating-voltage nonvolatile memory devices

A Toolkit and Robust Pipeline for the Generation of Fosmid-Based Reporter Genes in C. elegans

Engineering fluorescent proteins into large genomic clones, contained within BACs or fosmid vectors, is a tool to visualize and study spatiotemporal gene expression patterns in transgenic animals. Because these reporters cover large genomic regions, they most likely capture all cis-regulatory information and can therefore be expected to recapitulate all aspects of endogenous gene expression. Inserting tags at the target gene locus contained within genomic clones by homologous recombination (“recombineering”) represents the most straightforward method to generate these reporters. In this methodology paper, we describe a simple and robust pipeline for recombineering of fosmids, which we apply to generate reporter constructs in the nematode C. elegans, whose genome is almost entirely covered in an available fosmid library. We have generated a toolkit that allows for insertion of fluorescent proteins (GFP, YFP, CFP, VENUS, mCherry) and affinity tags at specific target sites within fosmid clones in a virtually seamless manner. Our new pipeline is less complex and, in our hands, works more robustly than previously described recombineering strategies to generate reporter fusions for C. elegans expression studies. Furthermore, our toolkit provides a novel recombineering cassette which inserts a SL2-spliced intercistronic region between the gene of interest and the fluorescent protein, thus creating a reporter controlled by all 5′ and 3′ cis-acting regulatory elements of the examined gene without the direct translational fusion between the two. With this configuration, the onset of expression and tissue specificity of secreted, sub-cellular compartmentalized or short-lived gene products can be easily detected. We describe other applications of fosmid recombineering as well. The simplicity, speed and robustness of the recombineering pipeline described here should prompt the routine use of this strategy for expression studies in C. elegans