On complexity reduction of concept lattices: three counterexamples     

Michal Krupka 《Information Retrieval》2012,15(2):151-156

We discuss the paper by Cheung and Vogel, Inf Retr 8(2), pp 285–299 (2005). We introduce some counterexamples showing that the theoretical results, the paper is based upon, are incorrect.  相似文献   

Whole‐word shape effect in dyslexia     

Michal Lavidor 《Journal of Research in Reading》2011,34(4):443-454

The research question here was whether whole‐word shape cues might facilitate reading in dyslexia following reports of how normal‐reading children benefit from using this cue when learning to read. We predicted that adults with dyslexia would tend to rely more on orthographic rather than other cues when reading, and therefore would be more affected by word shape manipulations. This prediction was tested in a lexical decision task on words with a flat or a non‐flat outline (i.e. without or with letters with ascending/descending features). We found that readers with dyslexia were significantly faster when reading non‐flat compared with flat words, while typical readers did not benefit from whole‐word shape cues. The interaction of participants' group and word shape was not modulated by word frequency; that is word outline shape facilitated reading for both rare and frequent words. Our results suggest that enhanced sensitivity to orthographic cues is developed in some cases of dyslexia when normal, phonology‐based word recognition processing is not exploited.  相似文献   

MATHEMATICS EDUCATORS’ VIEWS ON THE ROLE OF MATHEMATICS LEARNING IN DEVELOPING DEDUCTIVE REASONING     

Michal Ayalon  Ruhama Even 《International Journal of Science and Mathematics Education》2010,8(6):1131-1154

This study examines the views of people involved in mathematics education regarding the commonly stated goal of using mathematics learning to develop deductive reasoning that is usable outside of mathematical contexts. The data source includes 21 individual semi-structured interviews. The findings of the study show that the interviewees ascribed different meanings to the above-stated goal. Moreover, none of them said that it is possible to develop formal logic-based reasoning useful outside of mathematics, but for different reasons. Three distinct views were identified: the intervention–argumentation view, the reservation–deductive view, and the spontaneity–systematic view. Each interviewee’s view was interrelated with the interviewee’s approach to deductive reasoning and its nature in mathematics and outside it.  相似文献   

Multi-function microsystem for cells migration analysis and evaluation of photodynamic therapy procedure in coculture     

Elzbieta Jastrzebska  Ilona Grabowska-Jadach  Michal Chudy  Artur Dybko  Zbigniew Brzozka 《Biomicrofluidics》2012,6(4)

Cell migration is an important physiological process, which is involved in cancer metastasis. Therefore, the investigation of cell migration may lead to the development of novel therapeutic approaches. In this study, we have successfully developed a microsystem for culture of two cell types (non-malignant and carcinoma) and for analysis of cell migration dependence on distance between them. Finally, we studied quantitatively the influence of photodynamic therapy (PDT) procedures on the viability of pairs of non-malignant (MRC5 or Balb/3T3) and carcinoma (A549) cells coculture. The proposed geometry of the microsystem allowed for separate introduction of two cell lines and analysis of cells migration dependence on distance between the cells. We found that a length of connecting microchannel has an influence on cell migration and viability of non-malignant cells after PDT procedure. Summarizing, the developed microsystem can constitute a new tool for carrying out experiments, which offers a few functions: cell migration analysis, carcinoma and non-malignant cells coculture, and evaluation of PDT procedure in the various steps of cell migration.  相似文献   

Individual differences in reading comprehension gains from assisted reading practice: pre existing conditions, vocabulary acquisition, and amounts of practice     

Michal Shany  Andrew Biemiller 《Reading and writing》2010,23(9):1071-1083

We conducted a study of the effects of assisted reading practice (Shany & Biemiller, 1995). In this paper we examined the original data to find factors affecting gains in reading comprehension. We contrasted 14 children who had below median gains in reading comprehension and 15 who had above median gains. There were no significant correlations between pre-program language and reading measures and reading comprehension gains. High comprehension gainers made significantly larger gains in vocabulary. In the previous report on this research, we found that reading practice had large beneficial impact on reading comprehension. In this study we also found that children who gained significantly more vocabulary had also significantly higher gains in reading comprehension. Implications are discussed.  相似文献   

The “over-educated” Kibbutz: Shifting relations between social reproduction and individual development on the Kibbutz     

Zelda F. Gamson  Michal Palgi 《Interchange》1982,13(1):55-67

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STUDENTS’ OPPORTUNITIES TO ENGAGE IN TRANSFORMATIONAL ALGEBRAIC ACTIVITY IN DIFFERENT BEGINNING ALGEBRA TOPICS AND CLASSES     

Michal Ayalon  Ruhama Even 《International Journal of Science and Mathematics Education》2015,13(2):285-307

This study compares students’ opportunities to engage in transformational (rule-based) algebraic activity between 2 classes taught by the same teacher and across 2 topics in beginning algebra: forming and investigating algebraic expressions and equivalence of algebraic expressions. It comprises 2 case studies; each involves a teacher teaching in two 7th grade classes. All 4 classes used the same textbook. Analysis of classroom videotapes (15–19 lessons in each class) revealed that the opportunities to engage in transformational algebraic activity related to forming and investigating algebraic expressions were similar in each teacher’s 2 classes. By contrast, substantial differences were found between 1 teacher’s classes with regard to the opportunities to engage in transformational algebraic activity related to equivalence of algebraic expressions. The discussion highlights the contribution of the interplay among the mathematical topic, the teacher, and the class to shaping students’ learning opportunities. Specifically, the mathematical topic appeared to play a prominent role in certain situations, with the topic involving deductive reasoning generating high variation in classes of 1 teacher but not in the other’s.  相似文献   

Determination of Acid β-Galactosidase Activity: Methodology and Perspectives     

Radoslaw Kwapiszewski  Justyna Szczudlowska  Karina Kwapiszewska  Michal Chudy  Zbigniew Brzozka 《Indian journal of clinical biochemistry : IJCB》2014,29(1):57-62

Early, accurate diagnosis of lysosomal storage disorders is a major challenge, even for trained specialists. Finding innovative, accurate diagnostic methods, and high throughput, cost-effective tools are crucial to medical progress and will contribute to improved quality of life. The goal of this work was to improve currently used protocols to determine activity of acid β-galactosidase, and discuss the possibility analysing lysosomal enzymes with microfluidic systems. A principle of the determination of β-galactosidase activity was fluorometric measurement of a deprotonated form of 4-methylumbelliferone released in the enzymatic reaction. Measurements were performed using Jurkat T cells as a source of the enzyme. We observed the temperature-dependent substrate inhibition effect and determined the substrate (4-MU-β-d-galactopyranoside) concentration which should be used to determine acid β-galactosidase activity at 37 °C (0.8 mM) and at room temperature (0.6 mM). We proved that the sample incubation time may be significantly reduced to only a few minutes. We also showed that the amount of alkaline buffer used to stop the enzymatic reaction may be minimized and even, in some cases, eliminated. The presented results show how the sensitivity of the available methods to diagnose patients suffer from gangliosidosis GM1 or Morquio B disease can be improved. The proposed method may be easily implemented with microfluidic systems, which currently are promising tools for point-of-care applications.  相似文献   

Detection of immunoglobulins in a laser induced fluorescence system utilizing polydimethysiloxane microchips with advanced surface and optical properties     

Schrott W  Nebyla M  Přibyl M  Snita D 《Biomicrofluidics》2011,5(1):14101

We developed an automated laser induced fluorescence system utilizing microfluidic chips for detection and quantification of immunoglobulins. Microchips were fabricated from polydimethysiloxane (PDMS) using the so-called "prepolymerization technique." The microchip structure helped minimize the effects of PDMS autofluorescence and light scattering. Furthermore, a thin and uniform PDMS layer forming the top of the microchip enabled proper focusing and collection of the excitation beam and the emitted fluorescence, respectively. The developed system was tested for the detection of mouse immunoglobulins. The capturing antibodies were immobilized on internal microchannel walls in the form of a polyelectrolyte. We clearly show that this immobilization technique, if correctly realized, gives results with high reproducibility. After sample incubation and washing, secondary antibodies labeled by fluorescein isothiocyanate were introduced into microchannels to build a detectable complex. We show that mouse antibodies can be quantified in a wide concentration range, 0.01-100 μg ml(-1). The lower detection limit was below 0.001 μg ml(-1) (6.7 pM). The developed laser induced fluorescence (LIF) apparatus is relatively cheap and easy to construct. The total cost of the developed LIF detector is lower than a typical price of plate readers. If compared to classical ELISA (enzyme linked immunosorbent assay) plate systems, the detection of immunoglobulins or other proteins in the developed PDMS microfluidic device brings other important benefits such as reduced time demands (10 min incubation) and low reagent consumption (less than 1 μl). The cost of the developed PDMS chips is comparable with the price of commercial ELISA plates. The main troubleshooting related to the apparatus development is also discussed in order to help potential constructors.  相似文献   

Emerging issues in early childhood education,part 1     

Alice Sterling Honig 《Early Childhood Education Journal》1986,13(3):6-11

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