The writing performance of elementary students receiving Strategic and Interactive Writing Instruction

Strategic and Interactive Writing Instruction (SIWI) has led to improved writing and language outcomes among deaf and hard of hearing (d/hh) middle grades students. The purpose of this study was to examine the effects of SIWI on the written expression of d/hh elementary students across recount/ personal narrative, information report, and persuasive genres. Five multiple-probe case studies demonstrate a relationship between implementation of SIWI and improvements in genre-related writing performance. The effect of instruction was most immediately demonstrated with information reports and persuasive writing, whereas several sessions of recount instruction were needed for students to satisfy performance criteria. Additionally, pre and post data from a larger group of students (N=31) were compared. Wilcoxon Signed-Rank test statistics were statistically significant for each genre with medium to high effect sizes. Data suggest SIWI as a promising practice with elementary students, and comments regarding further development and research are provided

Lab-in-a-Cell: a microfluidic chip to study a single living cell

Introduction: The application of microchip techniques has really entered life science and has started to serve as a driving force for discovery in cell biology, neurobiology, pharmacology and tissue engineering. As the field of cellomics is expected to become a very important one, a chip to perform single cell analysis will be developed. Therefore, the chip has to consist of a sorting unit, sampling unit and a connection to an analysing unit. Methods: The research is divided in autofluorescence (AF) cell detection, electroporation, needle puncture and picosampling. AF cell detection and localization has been performed on a microfluidic glass chip using granulocytes and red blood cells. For electroporation, cells are trapped and electrodes generating a high electrical field create pores in the cell membrane. Further, siliconnitride microneedles (260nm thick) have been made to analyse needle puncture through a cell membrane. Results: With confocal microscopy, it is possible to sort red blood cells from granulocytes on a microfluidic glass chip on the basis of their intrinsic AF. Further, non-viable cells were distinguished from viable cells due to a lower AF intensity. For the sampling unit, an electroporation device and sharp needles have been made to be able to manipulate a cell. Extraction of cell fluid from oocytes has been performed. Conclusion: Our results show the possibility to manipulate and analyse single living cells on chip. All units have to be organised on one fluidic-chip to be able to perform single cell analysis. Precise control of biochemical cellular environment and analysis of the composition of single cells will lead to Lab-in-a-Cel

'Het beste uit studenten': onderzoek naar de werking van het Sirius Programma om excellentie in het hoger onderwijs te bevorderen

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Viability analysis and apoptosis induction of breast cancer cells in a microfluidic device: effect of cytostatic drugs

Breast cancer is the leading cause of cancer deaths among non-smoking women worldwide. At the moment the treatment regime is such that patients receive different chemotherapeutic and/or hormonal treatments dependent on the hormone receptor status, the menopausal status and age. However, in vitro sensitivity testing of tumor biopsies could rationalize and improve the choice of chemo- and hormone therapy. Lab-on-a-Chip devices, using microfluidic techniques, make detailed cellular analysis possible using fewer cells, enabling working with a patients’ own cells and performing chemo- and hormone sensitivity testing in an ex vivo setting. This article describes the development of two microfluidic devices made in poly(dimethylsiloxane) (PDMS) to validate the cell culture properties and analyze the chemosensitivity of MCF-7 cells (estrogen receptor positive human breast cancer cells) in response to the drug staurosporine (SSP). In both cases, cell viability was assessed using the life-stain Calcein-AM (CAAM) and the death dye propidium iodide (PI). MCF-7 cells could be statically cultured for up to 7 days in the microfluidic chip. A 30 min flow with SSP and a subsequent 24 h static incubation in the incubator induced apoptosis in MCF-7 cells, as shown by a disappearance of the aggregate-like morphology, a decrease in CAAM staining and an increase in PI staining. This work provides valuable leads to develop a microfluidic chip to test the chemosensitivity of tumor cells in response to therapeutics and in this way improve cancer treatment towards personalized medicine