Contributions and Obstacles of Contexts in the Development of Mathematical Knowledge     

Carlo Dapueto  Laura Parenti 《Educational Studies in Mathematics》1999,39(1-3):1-21

A framework for discussing (through the concepts of ‘model’ and ‘field of experience’) the nature of the relationships between contexts and the formation of mathematical knowledge is proposed, and some educational, cultural and cognitive problems of situated teaching-learning are tackled within it. This framework is supported and illustrated with references to the curricular innovation and educational research carried out by the Genoa group, of which the authors are members. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

The Brazilian book publishing industry and its current challenges     

Carlo?CarrenhoEmail author 《Publishing Research Quarterly》2005,21(3):77-92

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A Fight for the Soul of Public Education: The Story of the Chicago Teachers Strike,edited by Steven K. Ashby and Robert Bruno,ILR Press,Ithaca, NY, 2016, 328 pp., $34.98 (hardcover), ISBN-10: 1501704915     

Matthew Di Carlo 《Journal of School Choice》2018,12(1):149-151

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Experimenting ‘learn by doing’ and ‘learn by failing’     

Rossella Pozzi  Carlo Noè  Tommaso Rossi 《European Journal of Engineering Education》2015,40(1):68-80

According to the literature, in recent years, developing experiential learning has fulfilled the requirement of a deep understanding of lean philosophy by engineering students, demonstrating the advantages and disadvantages of some of the key principles of lean manufacturing. On the other hand, the literature evidences how some kinds of game-based experiential learning overlook daily difficulties, which play a central role in manufacturing systems. To fill the need of a game overcoming such lack of vision, an innovative game direct in-field, named Kart Factory, has been developed. Actual production shifts are simulated, while keeping all the elements peculiar to a real production set (i.e. complexity, effort, safety). The working environment is a real pedal car assembly department, the products to be assembled have relevant size and weight (i.e. up to 35 kg approximately), and the provided tools are real production equipment (e.g. keys, screwdrivers, trans-pallets, etc.). Due to the need to maximise the impact on students, a labour-intensive process characterises the production department. The whole training process is based on three educational principles: Experience Value Principle, Error Value Principle, and Team Value Principle. As the ‘learn by doing’ and ‘learn by failing’ are favoured, the theory follows the practice, while crating the willingness to ‘do’ instead of just designing or planning. The gathered data prove the Kart Factory's effectiveness in reaching a good knowledge of lean concepts, notwithstanding the students’ initial knowledge level.  相似文献   

Communication between Children with Deafness,Blindness and Deafblindness and their Social Partners: An Intersubjective Developmental Perspective     

Saskia Damen  Marleen J. Janssen  Wied A. J. J. M. Ruijssenaars  Carlo Schuengel 《International Journal of Disability, Development & Education》2015,62(2):215-243

Trevarthen’s theory of innate intersubjectivity is relevant to understanding communication problems in children with sensory disabilities. Trevarthen and Aitken used the term “intersubjectivity” to describe “the ability of humans to detect and change each other’s minds and behavior”. When children lack auditory and/or visual means of interaction, they may not be able to fully develop intersubjectivity, which impedes the development of more complex interpersonal communication. This article presents a review of 31 studies about intersubjectivity in children with sensory disabilities. The results indicate that the intersubjective development of children with sensory disabilities is often delayed. The studies also describe similar strategies for mediating intersubjectivity in children with sensory disabilities and in typical children, but say that specific adaptations may be needed. From an intersubjectivity perspective, symbolic communication delays in children with sensory disabilities may be improved through specific, purposeful forms of social interaction.  相似文献   

High efficiency vortex trapping of circulating tumor cells     

Manjima Dhar  Jessica Wong  Armin Karimi  James Che  Corinne Renier  Melissa Matsumoto  Melanie Triboulet  Edward B. Garon  Jonathan W. Goldman  Matthew B. Rettig  Stefanie S. Jeffrey  Rajan P. Kulkarni  Elodie Sollier  Dino Di Carlo 《Biomicrofluidics》2015,9(6)

Circulating tumor cells (CTCs) are important biomarkers for monitoring tumor dynamics and efficacy of cancer therapy. Several technologies have been demonstrated to isolate CTCs with high efficiency but achieve a low purity from a large background of blood cells. We have previously shown the ability to enrich CTCs with high purity from large volumes of blood through selective capture in microvortices using the Vortex Chip. The device consists of a narrow channel followed by a series of expansion regions called reservoirs. Fast flow in the narrow entry channel gives rise to inertial forces, which direct larger cells into trapping vortices in the reservoirs where they remain circulating in orbits. By studying the entry and stability of particles following entry into reservoirs, we discover that channel cross sectional area plays an important role in controlling the size of trapped particles, not just the orbital trajectories. Using these design modifications, we demonstrate a new device that is able to capture a wider size range of CTCs from clinical samples, uncovering further heterogeneity. This simple biophysical method opens doors for a range of downstream interventions, including genetic analysis, cell culture, and ultimately personalized cancer therapy.  相似文献   

Repeated sprint ability in young basketball players: one vs. two changes of direction (Part 2)     

Giuseppe Attene  Guillaume Laffaye  Anis Chaouachi  Fabio Pizzolato  Gian Mario Migliaccio 《Journal of sports sciences》2015,33(15):1553-1563

The aim of this study was to compare the training effects based on repeated sprint ability (RSA) (with one change of direction) with an intensive repeated sprint ability (IRSA) (with two changes of direction) on jump performance and aerobic fitness. Eighteen male basketball players were assigned to repeated sprint ability and intensive repeated sprint ability training groups (RSAG and IRSAG). RSA, IRSA, squat jump (SJ), countermovement jump (CMJ) and Yo-Yo intermittent recovery level 1 test were assessed before and after four training weeks. The RSA and IRSA trainings consisted of three sets of six sprints (first two weeks) and eight sprints (second two weeks) with 4-min sets recovery and 20-s of sprints recovery. Four weeks of training led to an overall improvement in most of the measures of RSA, but little evidence of any differences between the two training modes. Jump performance was enhanced: CMJ of 7.5% (P < 0.0001) and 3.1% (P = 0.016) in IRSAG and RSAG respectively. While SJ improved of 5.3% (P = 0.003) for IRSAG and 3.4% (P = 0.095) for RSAG. Conversely the Yo-Yo distance increased 21% (P = 0.301) and 34% (P = 0.017) in IRSAG and RSAG respectively. Therefore, short-term repeated sprint training with one/two changes of direction promotes improvements in both RSA and IRSA respectively but the better increase on jump performance shown a few changes on sprint and endurance performances.  相似文献   

A low-cost method for estimating energy expenditure during soccer refereeing     

Luca Paolo Ardigò  Johnny Padulo  Andrea Zuliani  Carlo Capelli 《Journal of sports sciences》2015,33(17):1853-1858

This study aimed to apply a validated bioenergetics model of sprint running to recordings obtained from commercial basic high-sensitivity global positioning system receivers to estimate energy expenditure and physical activity variables during soccer refereeing. We studied five Italian fifth division referees during 20 official matches while carrying the receivers. By applying the model to the recorded speed and acceleration data, we calculated energy consumption during activity, mass-normalised total energy consumption, total distance, metabolically equivalent distance and their ratio over the entire match and the two halves. Main results were as follows: (match) energy consumption = 4729 ± 608 kJ, mass normalised total energy consumption = 74 ± 8 kJ · kg^?1, total distance = 13,112 ± 1225 m, metabolically equivalent distance = 13,788 ± 1151 m and metabolically equivalent/total distance = 1.05 ± 0.05. By using a very low-cost device, it is possible to estimate the energy expenditure of soccer refereeing. The provided predicting mass-normalised total energy consumption versus total distance equation can supply information about soccer refereeing energy demand.  相似文献   

Contamination of lithium heparin blood by K2-ethylenediaminetetraacetic acid (EDTA): an experimental evaluation     

Gabriel Lima-Oliveira  Gian Luca Salvagno  Elisa Danese  Giorgio Brocco  Gian Cesare Guidi  Giuseppe Lippi 《Biochemia medica : ?asopis Hrvatskoga dru?tva medicinskih biokemi?ara / HDMB》2014,24(3):359-367

Introduction:

The contamination of serum or lithium heparin blood with ethylenediaminetetraacetic acid (EDTA) salts may affect accuracy of some critical analytes and jeopardize patient safety. The aim of this study was to evaluate the effect of lithium heparin sample contamination with different amounts of K₂EDTA.

Materials and methods:

Fifteen volunteers were enrolled among the laboratory staff. Two lithium heparin tubes and one K₂EDTA tube were collected from each subject. The lithium-heparin tubes of each subject were pooled and divided in 5 aliquots. The whole blood of K₂EDTA tube was then added in scalar amount to autologous heparinised aliquots, to obtained different degrees of K₂EDTA blood volume contamination (0%; 5%; 13%; 29%; 43%). The following clinical chemistry parameters were then measured in centrifuged aliquots: alanine aminotranspherase (ALT), bilirubin (total), calcium, chloride, creatinine, iron, lactate dehydrogenase (LD), lipase, magnesium, phosphate, potassium, sodium.

Results:

A significant variation starting from 5% K₂EDTA contamination was observed for calcium, chloride, iron, LD, magnesium (all decreased) and potassium (increased). The variation of phosphate and sodium (both increased) was significant after 13% and 29% K₂EDTA contamination, respectively. The values of ALT, bilirubin, creatinine and lipase remained unchanged up to 43% K₂EDTA contamination. When variations were compared with desirable quality specifications, the bias was significant for calcium, chloride, LD, magnesium and potassium (from 5% K₂EDTA contamination), sodium, phosphate and iron (from 29% K₂EDTA contamination).

Conclusions:

The concentration of calcium, magnesium, potassium, chloride and LD appears to be dramatically biased by even modest K₂EDTA contamination (i.e., 5%). The values of iron, phosphate, and sodium are still reliable up to 29% K₂EDTA contamination, whereas ALT, bilirubin, creatinine and lipase appear overall less vulnerable towards K₂EDTA contamination.  相似文献   

Avoidance to wipe alcohol before venipuncture is not a source of spurious hemolysis     

Gian Luca Salvagno  Elisa Danese  Gabriel Lima-Oliveira  Gian Cesare Guidi  Giuseppe Lippi 《Biochemia medica : ?asopis Hrvatskoga dru?tva medicinskih biokemi?ara / HDMB》2013,23(2):201-205

Background

It is still uncertain whether or not avoidance to let disinfectant alcohol dry at the site of venipuncture is a source of spurious hemolysis when drawing venous blood.

Methods:

In a consecutive series of 52 outpatients referred for routine laboratory testing, venous blood was drawn by direct venipuncture with (odd group) or without (pair group) wiping 70% isopropyl alcohol at the site of venipuncture. A 3.5 mL evacuated tube with clot activator and gel separator was drawn from a vein of the upper limb, serum was immediately separated with standard centrifugation and tested for potassium, lactate dehydrogenase (LD), aspartate aminotransferase (AST) and hemolysis index (HI) on Roche Cobas.

Results:

No specimen was discarded for unsatisfactory venipuncture. No differences for age and gender were observed between groups. As regards the four parameters investigated, no significant differences could be observed between patients in whom blood was drawn with or without letting the alcohol dry. It is also noteworthy that no sample in both groups exceeded the conventional sample rejection threshold of cell-free hemoglobin.

Conclusions:

The results of our prospective, randomized study attest that failure to wipe alcohol at the site of venipuncture should not be considered as a potential source of spurious hemolysis when drawing blood.  相似文献