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11.
Francesco Piraino ?eila Selimovi? Marco Adamo Alessandro Pero Sam Manoucheri Sang Bok Kim Danilo Demarchi Ali Khademhosseini 《Biomicrofluidics》2012,6(4)
The application of microfluidic technologies to stem cell research is of great interest to biologists and bioengineers. This is chiefly due to the intricate ability to control the cellular environment, the reduction of reagent volume, experimentation time and cost, and the high-throughput screening capabilities of microscale devices. Despite this importance, a simple-to-use microfluidic platform for studying the effects of growth factors on stem cell differentiation has not yet emerged. With this consideration, we have designed and characterized a microfluidic device that is easy to fabricate and operate, yet contains several functional elements. Our device is a simple polyester-based microfluidic chip capable of simultaneously screening multiple independent stem cell culture conditions. Generated by laser ablation and stacking of multiple layers of polyester film, this device integrates a 10 × 10 microwell array for cell culture with a continuous perfusion system and a non-linear concentration gradient generator. We performed numerical calculations to predict the gradient formation and calculate the shear stress acting on the cells inside the device. The device operation was validated by culturing murine embryonic stem cells inside the microwells for 5 days. Furthermore, we showed the ability to maintain the pluripotency of stem cell aggregates in response to concentrations of leukemia inhibitory factor ranging from 0 to ∼1000 U/ml. Given its simplicity, fast manufacturing method, scalability, and the cell-compatible nature of the device, it may be a useful platform for long-term stem cell culture and studies. 相似文献
12.
Robert L. Bowman Danilo Baylen 《International journal for the advancement of counseling》1994,17(2):101-108
This article presents a brief introduction to the principles of Buddhism and notes the similarities between Buddhism and Western psychotherapy. Citing the work of Watzlawick, Weakland & Fisch (1974) it is argued that a second-order change model could be constructed based upon Buddhist principles. 相似文献
13.
Nonlinear system identification and prediction is a complex task, and often non-parametric models such as neural networks are used in place of intricate mathematics. To that cause, recently an improved approach to nonlinear system identification using neural networks was presented in Gupta and Sinha (J. Franklin Inst. 336 (1999) 721). Therein a learning algorithm was proposed in which both the slope of the activation function at a neuron, β, and the learning rate, η, were made adaptive. The proposed algorithm assumes that η and β are independent variables. Here, we show that the slope and the learning rate are not independent in a general dynamical neural nétwork, and this should be taken into account when designing a learning algorithm. Further, relationships between η and β are developed which helps reduce the number of degrees of freedom and computational complexity in an optimisation task of training a fully adaptive neural network. Simulation results based on Gupta and Sinha (1999) and the proposed approach support the analysis. 相似文献
14.
The identification of painting techniques is an important aspect of any research related to historical, artistic, and conservation issues in the field of wall paintings conservation. There are a variety of different methodological approaches that can be used to identify wall painting techniques. In this study, the application of optical (PLM) and electron (SEM-EDX) microscopy was explored as they are complementary analytical techniques commonly used for micro-stratigraphic analysis of painted surfaces. Five replicas were prepared according to the technical procedures reported in medieval historical treatises, and the pigment was applied at different time intervals in order to monitor the modifications at the interface between the ground and pictorial layer. The comparison of data from the replicas with samples from Romanesque wall paintings in churches in Southern Switzerland and Northern Lombardy (Italy) allowed for an evaluation of the reliability of the proposed methodology and for the interpretation of the painting techniques. 相似文献
15.
The authors of this article discuss three pedagogical approaches, learning community, community of practice and community learning, and analyse their significance for knowledge acquisition and construction in higher education. The authors also explore the roles of technology in creating adequate environments for educators to implement teaching practices supported by these approaches and explain, through an illustrative course example, how technology and teaching methods can be used together to promote interaction among learners and help them achieve course goals. De la communauté apprenante à l’apprentissage communautaire: la pédagogie’la technologie et l’interactivité Les auteurs de cet article examinent trois approches pédagogiques:la communauté apprenante, la communauté de pratique et l’apprentissage communautaire et analysent leur signification pour l’acquisition et la construction des connaissances dans l’enseignement supérieur. Les auteurs étudient aussi le rôle de la technologie pour créer les environnements adéquats permettant aux éducateurs de mettre en place des pratiques d’enseignement reposant sur ces approches et ils expliquent au moyen d’un exemple de cours significatif,comment la technologie et les méthodes d’enseignement peuvent être utilisées ensemble pour favoriser l’interaction chez les apprenants et les aider à atteindre les objectifs du cours. Von der lernenden Gemeinde zum gemeinsamen Lernen: Pädagogik, Technik und Interaktivität Die Autoren dieses Artikels erörtern drei pädagogische Ansätze: Lerngemeinschaft, Übungsgemeinschaft und lernende Gemeinschaft. Sie analysieren ihre Bedeutung für Wissenserwerb und Aufbau einer höheren Ausbildung. Die Autoren erklären außerdem die Rolle der Technik beim Schaffen von adäquaten Umgebungen für Pädagogen, damit diese von diesen Ansätzen unterstützte Lehrübungen durchführen und durch ein illustratives Kursbeispiel erklären, wie Technologie und Lehrmethoden zusammen verwendet werden können, um Interaktion unter Lernern zu fördern und ihnen zu helfen, Kursziele zu erreichen. 相似文献
16.
Danilo Yanich 《Journal of Media Economics》2013,26(3):162-180
The Federal Communications Commission (FCC) uses three principles to regulate the broadcast industry in the United States: competition, diversity, and localism. The least studied of which is localism. As the management and ownership of local TV stations becomes more consolidated, the author examines what effect, if any, that consolidation has on the presentation of local content on television newscasts. 相似文献
17.
Danilo Bersani Pier Paolo Lottici Antonella Casoli Diego Cauzzi 《Journal of Cultural Heritage》2008,9(1):97-102
During the restoration plan of the famous painting “Madonna col Bambino e S. Giovannino” by Sandro Botticelli, located in the Museo Civico of Piacenza (Italy), a study on painting materials was carried out. The pigments, the binders and the materials used for the application of ground and priming layers were studied using micro-Raman spectroscopy, gas chromatography coupled with mass spectrometry (GC/MS), optical and electronic microscopies. Gypsum and anhydrite were found in the ground layer, while carbon black and lead white were used in the priming layers. The precious pigments of the artist's palette and the binders used (egg and animal glue) were determined. 相似文献
18.
Danilo R. Streck 《International Journal of Lifelong Education》2015,34(1):32-46
The purpose of this paper is to identify the presence of emotions in the constitution of popular education in Latin America, thus contributing to understand popular education as a thinking-feeling practice. It starts from the assumption that emotions are also historical and cultural expressions that mark societies and their understanding of education. In the chronicles of Guaman Poma de Ayala, one can see signs of the resistance to the conquest and of the ambivalence that characterizes coloniality; in Juana Inés de la Cruz, one hears the voice of a woman who breaks the silence; in Paulo Freire, lovingness and indignation are constitutive elements of his liberating pedagogy. In history, some emotions, such as honour, lose their strength or have their meaning changed; others, such as solidarity and insurgency, appear as possibilities of transformation in new times. The study attempts to contribute to the understanding of the complex relation between rationality and emotions in education. 相似文献
19.
Teresa Cerchiara Giuseppe Chidichimo Maria Caterina Gallucci Rita Ferraro Danilo Vuono Alfonso Nastro 《Journal of Cultural Heritage》2009,10(3):396-402
One of the problems in the field of cultural heritage is the degradation of artworks and especially paintings. They appear very sensitive to environmental conditions. In this work, Spanish broom canvas is proposed as a novel painting support. In order to assess the deterioration properties of this new type of canvas, three degradation processes (exposure to wet atmosphere, to acidic attack and to UV light) were simulated and investigated. The deterioration state of the samples was monitored with Infrared Spectroscopy (FT-IR) and Thermogravimetric Analysis (TGA). The structure of the canvas was also analyzed by Scanning Electron Microscopy (SEM). These techniques were successfully applied to study the occurrence significant changes of samples. The exposure to acidic and UV attack produced deep changes on the samples (only on the canvas surface in the case of UV light), while no significant effect was identified on the sample after the exposure to wet atmosphere. The results obtained from Spanish broom canvas are reported in comparison to flax canvas. 相似文献
20.
ABSTRACTOne of the aims of the European Protocol in Preventive Conservation (EPICO) research programme was to implement a simple and flexible assessment method applicable to the majority of historic houses. We present results to verify statistical methods for the application in the assessment of heterogeneous in collections historic houses. For a collection with less than five hundred objects, a complete inventory by two people is possible, in order to collect information about the objects and their condition. A sample is representative when it has the same characteristics as the population studied. In the case of a very small population it is difficult to obtain representative results: here the sample should be almost equal to the total population. Therefore significant work must be done prior to assessment to properly identify the characteristics of the mother population. In the absence of sufficient representativeness, the results obtained from a sample cannot be generalized to the population being studied. 相似文献