Le teorie di Vygotskij e Feuerstein per il XXI secolo

There is a certain mystery in the current popularity of Vygotsky’s and Feuerstein’s ideas. On the surface, this growing interest is paradoxical – the ideas that emerged in Russia in the 1920s and in Israel of the 1960s are supposed to be light years behind the concerns of Western psychologists and educators of the 21st century. What then makes Vygotsky’s and Feuerstein’s ideas so contemporary? The article suggests that the current popularity of these ideas is related to the almost perfect match between “answers” given by Vygotsky and Feuerstein to the “questions” that, often without any direct impact of their theories, had emerged in Western psychology and education at the end of the 20th century. The discussion is focused around three key issues: Cultural difference, dynamic assessment, and the relationships between cognition and education.C'è un certo mistero intorno all’attuale popolarità delle idee di Vygotskij e Feuerstein. Di primo acchito quest’interesse crescente sembrerebbe paradossale, dato che le idee emerse negli anni ‘20 in Russia e negli anni ’60 in Israele dovrebbero essere anni indietro rispetto alle preoccupazioni degli psicologi e degli educatori occidentali del XXI secolo. Cos'è allora che rende le idee di Vygotskij e Feuerstein così contemporanee? Questo articolo suggerisce che la popolarità di queste idee sia da mettere in relazione al perfetto abbinamento esistente tra le “risposte” date da Vygotskij e Feuerstein alle “domande” che, spesso senza alcun impatto diretto delle loro teorie, sono emerse nella psicologia e nelle scienze dell’educazione occidentale alla fine del XX secolo. La discussione si focalizza orienta a tre aree: le differenze culturali, la valutazione dinamica, e la relazione tra cognizione ed educazione

Explosive Vaporization of Water and Isopropyl Alcohol on a Flat Microheater

This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.The MEMS control systems, such as ink jet printers, optical switches and valves, use the explosive vaporization of metastable liquid for the rapid phase change. The initial stage of explosive vaporization of water, isopropyl alcohol and ethanol has been studied experimentally on the surface of a thin-film microheater, covered with the submicron silicon-carbide layer. In experiments, the multilayer thin-film resistor of the Think Jet printhead with 100 × 110 μm2 surface area was used. Applying the optical method, we investigated the patterns of the liquid–vapor phase transition under pulse heating and obtained the characteristics of nucleation at the rate of temperature growth of up to 800 MK/s. Pulsed laser illumination was applied for the high-speed photography of liquid vaporization. Data for the vapor-covered surface area vs. time depending on the supplied heat flux and the heating time are reported. The theoretical model of explosive vaporization on a flat heater has been developed and numerical simulations have been performed for water and isopropyl alcohol nucleation on the multi-layer microheater. Comparison of calculation results with experimental data is discussed in this paper

Alterations in ZENK and glucagon RNA transcript expression during increased ocular growth in chickens

Purpose: To examine in detail the time-course of changes in Zif268, Egr-1, NGFI-A, and Krox-24 (ZENK) and pre-proglucagon (PPG) RNA transcript levels in the chick retina during periods of increased ocular growth induced by form-deprivation and negative-lens wear. To further elucidate the role of ZENK in the modulation of ocular growth, we investigated the effect of intravitreal injections of the muscarinic antagonist atropine and the dopamine agonist 2-amino-6,7-dihydroxy-1,2,3,4-tetrahydronaphthalene hydrobromide (ADTN), both of which block the development of experimental myopia, on the expression of ZENK in eyes fitted with negative-lenses. Methods: Myopia was induced by fitting translucent diffusers or -10D polymethyl methacrylate (PMMA) lenses over one eye of the chicken. At times from 1 h to 10 days after fitting of the diffusers or negative lenses, retinal RNA transcript levels of the selected genes were determined by semi-quantitative real-time reverse transcriptase polymerase chain reaction (RT-PCR). For the pharmacology experiments, -10D lenses were fitted over the left eye of chicks for a period of 1h. Intravitreal injections of atropine (10 μl-25 mM), ADTN (10 μl-10 mM), or a vehicle solution were made immediately before fitting of the lenses. Results: ZENK RNA transcript levels were rapidly and persistently down-regulated following the attachment of the optical devices over the eye. With a delay relative to ZENK, PPG transcript levels were also down-regulated. Induced changes in gene expression were similar for both form-deprivation and negative-lens wear. When atropine or ADTN were administered immediately before lens attachment, the rapid down-regulation in ZENK RNA transcript levels normally seen following 1 h of negative-lens wear was not seen, and ZENK transcript levels rose above those values seen in control eyes. However, injection of atropine or ADTN into untreated eyes had no effect on ZENK transcript levels. Conclusions: Both form-deprivation and negative-lens wear modulated the retinal expression of ZENK and PPG RNA transcripts, with a similar time-course and strength of response. The ability of the tested drugs to prevent the down-regulation of ZENK in both lens-induced myopia (LIM) and form-deprivation myopia (FDM) suggests that atropine and ADTN act directly and rapidly on retinal circuits to enhance sensitivity early in the signaling process. These findings suggest that very similar molecular pathways are involved in the changes in eye growth in response to form-deprivation and negative lenses at 1 h after the fitting of optical devices

Alterations in ZENK and glucagon RNA transcript expression during increased ocular growth in chickens

Purpose: To examine in detail the time-course of changes in Zif268, Egr-1, NGFI-A, and Krox-24 (ZENK) and pre-proglucagon (PPG) RNA transcript levels in the chick retina during periods of increased ocular growth induced by form-deprivation and negative-lens wear. To further elucidate the role of ZENK in the modulation of ocular growth, we investigated the effect of intravitreal injections of the muscarinic antagonist atropine and the dopamine agonist 2-amino-6,7-dihydroxy-1,2,3,4-tetrahydronaphthalene hydrobromide (ADTN), both of which block the development of experimental myopia, on the expression of ZENK in eyes fitted with negative-lenses.\ud \ud Methods: Myopia was induced by fitting translucent diffusers or −10D polymethyl methacrylate (PMMA) lenses over one eye of the chicken. At times from 1 h to 10 days after fitting of the diffusers or negative lenses, retinal RNA transcript levels of the selected genes were determined by semi-quantitative real-time reverse transcriptase polymerase chain reaction (RT–PCR). For the pharmacology experiments, −10D lenses were fitted over the left eye of chicks for a period of 1h. Intravitreal injections of atropine (10 μl–25 mM), ADTN (10 μl–10 mM), or a vehicle solution were made immediately before fitting of the lenses.\ud \ud Results: ZENK RNA transcript levels were rapidly and persistently down-regulated following the attachment of the optical devices over the eye. With a delay relative to ZENK, PPG transcript levels were also down-regulated. Induced changes in gene expression were similar for both form-deprivation and negative-lens wear. When atropine or ADTN were administered immediately before lens attachment, the rapid down-regulation in ZENK RNA transcript levels normally seen following 1 h of negative-lens wear was not seen, and ZENK transcript levels rose above those values seen in control eyes. However, injection of atropine or ADTN into untreated eyes had no effect on ZENK transcript levels.\ud \ud Conclusions: Both form-deprivation and negative-lens wear modulated the retinal expression of ZENK and PPG RNA transcripts, with a similar time-course and strength of response. The ability of the tested drugs to prevent the down-regulation of ZENK in both lens-induced myopia (LIM) and form-deprivation myopia (FDM) suggests that atropine and ADTN act directly and rapidly on retinal circuits to enhance sensitivity early in the signaling process. These findings suggest that very similar molecular pathways are involved in the changes in eye growth in response to form-deprivation and negative lenses at 1 h after the fitting of optical devices

Numerical simulation of deformation behavior of aluminum alloy sheets under processing by groove pressing method

The results of theoretical estimation of capabilities of the material structure modification of 1560 aluminum alloy sheets under processing by severe plastic deformation are presented in this paper. Severe plastic deformation of flat specimens is effected by the constrained groove pressing method in original dies with trapezoidal teeth. The numerical simulation results of the sheet specimen treatment process by severe plastic deformation were used for dies designing. The stress-strain state of flat aluminum alloy specimens and the steel dies at high processing temperature, support reaction force during pressing and the degrees of plastic strain accumulation at the optimum mode of pressing were estimated. The main numerical result is the value of accumulated plastic strain in the specimen per one pressing cycle which is about 1.14. Large degrees of strain are the reasons of grain structure and material texture changes, which leads to inevitable change of its physical-mechanical properties. Increasing the number of pressing cycles leads to proportional increase of the degree of accumulated plastic strain

Analysis of Complement Expression in Light-Induced Retinal Degeneration: Synthesis and Deposition of C3 by Microglia/Macrophages Is Associated with Focal Photoreceptor Degeneration

Purpose. To investigate the expression and localization of complement system mRNA and protein in a light-induced model of progressive retinal degeneration. Methods. Sprague-Dawley (SD) rats were exposed to 1000 lux of bright continuous light (BCL) for u