Teachers’ attitudes towards tracking: testing the socialization hypothesis

The paper examines how teachers’ attitudes towards tracking (separating pupils into groups with different curricula on the basis of their abilities and results) differ among various generations of teachers. Fundamental and quick changes in the educational system occurred in the Czech Republic after the Velvet Revolution in 1989 as a unified educational system moved to a system strongly accenting tracking practices. We use this ‘policy discontinuity’ to validate teacher socialization theory and test three alternative socialization hypotheses based on different key periods in teachers’ development: the pupil experience hypothesis, the pedagogical preparation hypothesis and the pedagogical experience hypothesis. We work with a data-set from 2009 covering 1002 Czech teachers. The mean tests and the logistic regression analysis support the socialization theory, however only the pedagogical experience hypothesis was found to be most influential.     

A novel way of liver preservation improves rat liver viability upon reperfusion

Background/aim： Currently, the liver is cold-preserved at 0-4 ℃ for experimental and clinical purposes. Here, we investigated whether milder hypothermia during the initial phase of the preservation period was beneficial for liver viability upon reperfusion. Methods： In the first set of experiments, rat livers were preserved either conventionally in clinically used histidine-trypthopan-ketoglutarate （HTK） solution （Group A： 45 min and Group B： 24 h） or by slow cooling HTK solution （from 13 ℃ to 3 ℃） during the initial 45 min of preservation （Group C： 24 h）. In the second set of experiments, additional groups of livers were evaluated： Group BB-preservation according to Group B and Group CC-preservation according to Group C. Further, some livers were preserved at 13 ℃ for 24 h. Livers were then reperfused using a blood-free perfusion model. Results： Bile production was approximately 2-fold greater in Group C compared to Group B. Alanine transaminase （ALT） and aspartate transaminase （AST） release into perfusate were 2-3-fold higher in Group B compared to Group C. No significant differences were found in ALT and AST release between Group C and Group A. Livers in Group CC compared to Group BB exhibited significantly lower portal resistance, greater oxygen consumption and bromosulfophthalein excretion into bile and lower lactate dehydrogenase （LDH） release into perfusate. Histological evaluation of tissue sections in Group BB showed parenchymal dystrophy of hepatocytes, while dystrophy ofhepatocytes was absent in Group CC. Livers preserved at 13 ℃ for 24 h exhibited severe ischemic injury Conclusion： These results suggest that the conventional way of liver preservation is not suitable at least for rat livers and that slow cooling of HTK solution during the initial phase of cold storage can improve liver viability during reperfusion.     

Entrepreneurialism at the University of Zagreb: Managing the Sustainability of Change

This article presents a study of the different aspects of entrepreneurialism at the University of Zagreb in the context of Croatian higher education. The recent history of changes at the University of Zagreb is described using a temporal perspective from the beginning of the development of the European Higher Education Area to the implementation of the Bologna Process in Croatia. The theoretical framework for the study has been Burton Clark's (1998 Clark, B. R. 1998. Creating Entrepreneurial Universities, Oxford: Pergamont and Elsevier Science. Organizational Pathways of Transformation [Google Scholar]) seminal analysis of the main features of academic entrepreneurialism. Each feature: the strengthening of steering capacity, the diversification of financial sources, a stimulated academic heartland, an extended periphery, and integrating entrepreneurial culture have been elaborated using the illustrative examples from university practice and university statistics. The last part of the study gives an overview of the results of the empirical study conducted among university managers, teachers, and students on their perceptions of the university's entrepreneurial culture at the level of the institution as a whole as well as at the level of their respective faculty. In the final conclusions, the main requirements for effective change management within the university context are listed.     

西藏核桃果皮色素的提取与吸光度测定

天然植物色素可以作为研制染料敏化太阳能电池的一种颜料(光敏剂)。西藏核桃果皮富含丰富色素,本文利用萃取、色谱分离技术提取了西藏林芝核桃果皮色素。用蒸馏水从500g干核桃果皮中提取获得了21.03g色素,产率达4.21%。用四氯化碳从500g鲜核桃果皮中提取获得了0.35g色素。利用紫外可见光度计对以上两种萃取流程获得的色素进行了吸光度测定。结果显示核桃果皮色素对波长越短的光吸收能力越强。紫外区有最大的吸光度,然后随着波长的增大,吸光度逐渐变小。为今后研制色素增感型太阳能电池提供了萃取色素颜料技术。     

Approximation based on orthogonal and almost orthogonal functions

In this paper, we define a class of almost orthogonal rational functions of Legendre type in a new manner. Relations of these functions with classical exponentional functions orthogonal over interval (0, ∞), as well as classical polynomials orthogonal over (0, 1) are explained. Defining relations of these functions can be used for designing almost orthogonal filters. These filters are generators of orthogonal signals and can be successfully applied in finding the best signal approximation in the sense of the mean square error. The filters orthogonal property enables building of physical (in this case electrical) models of dynamical systems (the sources of signals to be approximated) either with less components for the same model accuracy or higher accuracy for the same number of components than the other known models. New filters represent further improvement of previously designed filters, by the same authors, in the sense of simplicity, higher accuracy, lesser approximation time and even a possibility to approximate signals generated by systems with built-in imperfections. Series of experiments were performed to analyze the dependence of approximation accuracy and the number of filters sections.     

Development of implanted deaf children’s conversational skills

Previous studies of preverbal development have highlighted the recurrent difficulties experienced by deaf children in acquiring knowledge of the social rules and social skills pertaining to discourse. We expected cochlear implants in children with bilateral profound deafness to improve their use of verbal language, so that their communication skill profile resembled that of younger, hearing children. Using conversation samples taken from videos recorded every 6 months over a 2-year period, we monitored the development of communication skills in a group of 18 prelingually profoundly deaf children (mean implantation age, 3 years and 5 months). Results corroborated our hypothesis that the overall communication performances of children with cochlear implants improve, both quantitatively and qualitatively, as early as the first year post-implantation.     

European cultural statistics in a comparative perspective: index of economic and social condition of culture for the EU countries

In the article, we present the construction of an index of economic and social condition of culture using datasets of Eurostat’s Cultural Statistics Pocketbooks from 2007 and 2011 and Eurostat’s COFOG data. The datasets allow us a broad perspective over a set of more than 200 variables in 12 domains for the EU-27 member states. Using high-dimensionally adjusted factor analysis (Metropolis–Hastings Robbins–Monro algorithm), we construct an index and determine a set of its several dimensions (as seen from the cultural statistics viewpoint). Using cluster analysis, we determine the general similarities and differences among the analysed countries and show several broadly different groupings that roughly, but not exclusively follow the divide speculated in some previous studies. The analysis therefore brings a novel and statistically developed tool to empirically follow the changes in the economic and social condition of culture from the viewpoint of cultural statistics, while the clustering of models has important consequences for empirical cultural policy and has to be verified in future studies.