Dynamics of a periodically driven chain of coupled nonlinear oscillators     

Paweł Fritzkowski  Roman Starosta  Grażyna Sypniewska-Kamińska  Jan Awrejcewicz 《浙江大学学报(A卷英文版)》2017,18(7):497-510

A 1D chain of coupled oscillators is considered, including the Duffing-type nonlinearity, viscous damping, and kinematic harmonic excitation. The equations of motion are presented in a non-dimensional form. The approximate equations for the vibrational amplitudes and phases are derived by means of the classical averaging method. A simple analysis of the resulting equations allows one to determine the conditions for the two basic synchronous steady-states of the system: the in-phase and anti-phase motions. The relations between the required excitation frequency and the natural frequencies of the abbreviated (linear) system are discussed. The validity of these predictions is examined by a series of numerical experiments. The effect of the model parameters on the rate of synchronization is analyzed. For the purpose of systematic numerical studies, the cross-correlation of time-series is used as a measure of the phase adjustment between particular oscillators. Finally, some essential issues that arise in case of the mechanical system with dry friction are indicated.  相似文献   

Overweight and obesity versus concentrations of VEGF-A,sVEGFR-1, and sVEGFR-2 in plasma of patients with lower limb chronic ischemia     

Radosław Wieczór  Anna Maria Wieczór  Grażyna Gadomska  Katarzyna Stankowska  Jacek Fabisiak  Karol Suppan  Grzegorz Pulkowski  Jacek Budzyński  Danuta Rość 《Journal of Zhejiang University. Science. B》2016,17(11):842-849

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Propolis modulates vitronectin, laminin, and heparan sulfate/heparin expression during experimental burn healing     

Pawe? Olczyk  Katarzyna Komosińska-Vassev  Katarzyna Winsz-Szczotka  Ewa M. Ko?ma  Grzegorz Wisowski  Jerzy Stojko  Katarzyna Klimek  Krystyna Olczyk 《Journal of Zhejiang University. Science. B》2012,13(11):932-941

Objective

This study was aimed at assessing the dynamics of vitronectin (VN), laminin (LN), and heparan sulfate/heparin (HS/HP) content changes during experimental burn healing.

Methods

VN, LN, and HS/HP were isolated and purified from normal and injured skin of domestic pigs, on the 3rd, 5th, 10th, 15th, and 21st days following thermal damage. The wounds were treated with apitherapeutic agent (propolis), silver sulfadiazine (SSD), physiological salt solution, and propolis vehicle. VN and LN were quantified using an immunoenzymatic assay and HS/HP was estimated by densitometric analysis.

Results

Propolis treatment stimulated significant increases in VN, LN, and HS/HP contents during the initial phase of study, followed by a reduction in the estimated extracellular matrix molecules. Similar patterns, although less extreme, were observed after treatment with SSD.

Conclusions

The beneficial effects of propolis on experimental wounds make it a potential apitherapeutic agent in topical burn management.  相似文献   

Flipped spotters learning model: An innovative student activity-based strategy. A preparation tool for anatomy practical examinations in medical education     

Marcelina Łopińska  Jerzy Stanisław Gielecki  Anna Żurada 《Anatomical sciences education》2022,15(5):886-897

The flipped spotters learning model is a modern student activity-based and learner-centered method in medical education. The aim of the study was to determine if the flipped spotters learning model improves students' learning. Participants were 1214 medical students of Polish (PD) and English (ED) divisions between 2013 and 2019 academic years at the University of Warmia and Mazury in Olsztyn, Poland. They were divided into a traditional group (control group) and a flipped spotters learning group (treatment group). Each flipped spotters learning group was asked to label anatomical structures on various specimens according to the structures name list prepared by the teacher on the multiple stations. The flipped spotters learning group leaders were instructed to take pictures with the appropriately marked structures on each of the human body prosections. After completion of the class, each flipped spotters team received photos for evaluation. In the flipped spotters learning model, the students strengthened their skills and knowledge by matching specimens independently as a form of practical laboratory activities. Students' performance in gross anatomy practical examinations between the group utilizing the flipped spotters learning model, and the group with the traditional teaching model was compared. Students participating in the treatment group achieved, on average 9.9 percentage points higher among PD students, and 13.0 percentage points higher among ED students than the control group in all nine practical examinations (the effect size ranging from 0.47 to 0.95). The results suggest the positive impact of flipped spotters model on improving student's performance in the practical examinations.  相似文献   

Trust and Mistrust in Sources of Scientific Information on Climate Change and Vaccines     

Rowland  Jussara  Estevens  João  Krzewińska  Aneta  Warwas  Izabela  Delicado  Ana 《Science & Education》2022,31(5):1399-1424

Science & Education - Public trust in science and expertise remains a contentious issue. When public trust is analysed, it often simplifies a complex process of information retrieval and...  相似文献   

Selected aspects of conditions in the use of new media as an important part of the training of teachers in the Czech Republic and Poland - differences,risks and threats     

Łukasz Tomczyk  Rene Szotkowski  Artur Fabiś  Arkadiusz Wąsiński  Štefan Chudý  Pavel Neumeister 《Education and Information Technologies》2017,22(3):747-767

The paper presents the complex problems of preparation of pedagogy students to work as teachers in the context of their readiness to use ICT in the didactic process. The complexity of this subject matter has been proved by the current, ongoing, discussion about the direction of the expected transformations of contemporary schools and the prospective teachers education system in the age of prevalent digitization. Considering the complexity of conditions, the main research problem has been formulated as follows: Conditions of what type affect the preparation of prospective teachers to use new media in learning and teaching process?. Thus, the empirical analysis conducted in the paper focuses on the following issues: the style of using new media by students, identification of students’ attitudes towards media, subjective (from the students’ point of view) assessment of how university level schools are prepared to shape modern media competences among their students and self-evaluation of media and IT competences in the group of prospective teachers. Czech and Polish students, despite being the so called digital natives, do not present homogeneous styles of using new media. They also reveal different attitudes toward applying digital solutions to the didactic process. Factors such as: low evaluation of one’s own competences or lack of evaluation in this area, lack of creative approach to the use of new media, lack of education in the area of new applications, lack of skills necessary to handle basic digital tools (e.g. interactive board, e-learning platforms) negatively affect, in most cases, the attitude toward the active use of ICT tools in future didactic work. On the basis of the gathered empirical data and inductive qualitative analysis a typology of students attitudes toward new media was developed. It consists of four categories: techno-optimist, techno-realist, techno-pessimist and techno-ignorant. The whole of analyses has the character of comparative research and involves two neighboring countries of the Visegrad Group: Poland (N?=?466) and Czech Republic (N?=?168).  相似文献   

Heuristic learning and programmed learning     

Wincenty Okoń 《International Review of Education/Internationale Zeitschrift für Erziehungswissenschaft/Revue internationale l'éducation》1969,15(4):407-421

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“I understand why people need to ease their emotions”: Exploring mindfulness and emotions in a conceptual physics classroom of an elementary teacher education program     

Małgorzata Powietrzyńska  Al-Karim H. Gangji 《Cultural Studies of Science Education》2016,11(3):693-712

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General Film Histories     

Michael Wood  Adam Garbicz  Jacek Klinowski  Tino Balio  Charles Higham  John Douglas Eames 《Communication Booknotes Quarterly》2013,44(4):40-41

Michael Wood's America in the Movies, or "Santa Maria, It Had Slipped My Mind" (New York: Basic Books, 1975---$10.00)

Adam Garbicz and Jacek Klinowski's Cinema, The Magic Vehicle: A Guide to its Achievement (Metuchen, N.J.: Scarecrow Press, 1975---$18.50)

Tino Balio's United Artists: The Company Built by the Stars (Madison: University of Wisconsin Press, 1975-- $15.00)

Charles Higham's Warner Brothers (New Y( Scribner's, 1975---$9.95)

John Douglas Eames' The MGM Story: The Complete History of Fifty Roaring Years (New York: Crown, 1975---$25.00)

Rochelle Larkin's Hail, Columbia (New Rochelle, N.Y.: Arlington House, 1975---$17.95)

Datid E. Scherman (ed.) Life Goes to the Movies (New York: Time-Life Books, 1975-- $19.95)

Paul Trent's Those Fabulous Movie Years: The 30s (New York: Crown, 1975---$14.95)

Griffith and Mayer's The Movies (New York: Simon and Schuster, 1969)

Sidney Skolsky's Don't Get Me Wrong-- I Love Hollywood (New York: Putnam's, 1975---$8.95)

Leo Handel's Hollywood Looks at its Audience: A Report of Film Audience Research (originally issued by the University of Illinois Press in 1950)  相似文献   

An Investigation of Student Response to a Potential Tuition Cap Increase at Casper College     

Elizabeth Davis  Thomas Aitchison  Eric Allen  Carrie Gomez  Sheree Laird  Kaja Raczyńska 《Community College Journal of Research & Practice》2013,37(2):192-198

Wyoming Community College Commission policy currently states any student enrolled for more than 12 credit hours will be charged tuition for only 12 credit hours. This policy is referred to as the tuition cap. In November 2010, the commission discussed increasing the tuition cap to 15 credits. An increase from 12 to 15 credits would have represented a 25% increase in tuition for students enrolled for 15 or more credits. Casper College president Dr. Walter Nolte commissioned a study to examine the impact such an increase would have on Casper College and its students. A survey instrument was designed to determine if students carrying more than 12 credit hours would reduce their enrollment credits and what sources of funding they would seek to defray the increased cost. Using a multistage sampling design, a sample of 67 Casper College course sections was selected to respond to the survey. The data were analyzed with logistic regression models, and the estimates were adjusted using sampling weights and a finite population correction. Analysis indicated that 42% of Casper College students would reduce their credit hours by an average of 3.3 credits. Approximately 58% of students would seek additional scholarships and 63% would seek increased work hours. The results of the study were presented to the Wyoming Community College Commission on October 28, 2011. In December 2011, the Commission announced a decision not to increase the tuition cap.  相似文献