Yangxueqingnao particles inhibit rat vascular smooth muscle cell proliferation induced by lysophosphatidic acid

Objective: To observe the effect of Yangxueqingnao particles on rat vascular smooth muscle cell (VSMC) proliferation induced by lysophosphatidic acid (LPA). Methods: The amount of3H-TdR (3H-thymidine) admixed in cultured rat VSMC was measured and mitogen-activated protein kinase (MAPK) activity and lipid peroxidation end product malondialdehyde (MDA)content of the VSMC were assayed. Results: 1×10-9, 1×10-8, 1×10-7 mol/L LPA in a concentration dependent manner, induced the amount of 3H-TdR admixed, MAP kinase activity, and MDA content of the cultured rat VSMC to increase. However, 5%, 10%,and 15% Yangxueqingnao serum preincubation resulted in a decrease of 23.0%, 42.0%, and 52.0% (P＜0.01) respectively in the amount of 3H-TdR admixed, a decline in VSMC MAP kinase activity of 13.9% (P＜0.05), 29.6% (P＜0.01), and 48.9% (P＜0.01)respectively, and also, a decrease in MDA content of VSMC of 19.4%, 24.7%, and 43.2% (P＜0.01) respectively, in the 1×10-7mol/L LPA-treated VSMC. Conclusions: LPA activates the proliferation and lipid peroxidation of VSMC in a concentration dependent manner. The LPA-induced VSMC proliferation is related to the activity of MAP kinases, enzymes involved in an intracellular signalling pathway. The results of the present study showed that Yangxueqingnao particles can effectively inhibit LPA-induced VSMC proliferation, MAP kinase activation, and reduce lipid peroxidative lesion.     

Validation of a self-perceived media competence instrument for pre-service teachers / Validación de un instrumento de autopercepción de competencia mediática para docentes en formación

Abstract

Key to guaranteeing the fundamental human rights of freedom of expression and information is the development of media competence, particularly in schools. Training teachers in the area of media competence is particularly important for developing these skills in the broader citizenry. In order to provide educators and educational policymakers with a useful diagnostic tool, we have designed a self-perception questionnaire. The questionnaire was applied to a sample of Peruvian education students (N = 501). On the one hand, the results confirm the construct’s coherence, validity and instrumental reliability. On the other hand, they allow us to propose a theoretically based update to the way in which this construct is interpreted and applied, confirming the multidimensionality of media competence. Finally, we use this empirical evidence to discuss the integral, transversal and ecological status of media competence.     

The inadequacy of individual educational program (IEP) goals for high school students with word-level reading difficulties

This investigation analyzed goals from the Individual Educational Programs (IEPs) of 54 high school students with diagnosed reading disabilities in basic skills (decoding and/or word identification). Results showed that for 73% of the students, the IEPs written when they were in high school failed to specify any objectives regarding their acute difficulties with basic skills. IEPs from earlier points in the students’ educations were also reviewed, as available. For 23 of the students, IEPs were present in the students’ files for three time points: elementary school (ES), middle school (MS), and high school (HS). Another 20 students from the sample of 54 had IEPs available for two time points (HS and either MS or ES). Comparisons with the IEPs from younger years showed a pattern of decline from ES to MS to HS in the percentage of IEPs that commented on or set goals pertaining to weaknesses in decoding. These findings suggest that basic skills deficits that persist into the upper grade levels are not being sufficiently targeted for remediation, and help explain why older students frequently fail to resolve their reading problems.     

Enhancing cellular immune response to HBV M DNA vaccine in mice by codelivery of interleukin-18 recombinant

Objective: To investigate the effect of interleukin-18 (IL-18) on immune response induced by plasmid encoding hepatitis B virus middle protein antigen and to explore new strategies for prophylactic and therapeutic HBV DNA vaccines. Methods: BALB/c mice were immunized with pCMV-M alone or co-immunized with pcDNA3-18 and pCMV-M and then their sera were collected for analysing anti-HBsAg antibody by ELISA; splenocytes were isolated for detecting specific CTL response and cytokine assay in vitro. Results: The anti-HBs antibody level of mice co-immunized with pcDNA3-18 and pCMV-M was slightly higher than that of mice immunized with pCMV-M alone, but there was not significantly different (P>0.05). Compared with mice injected with pCMV-M, the specific CTL cytotoxity activity of mice immunized with pcDNA3-18 and pCMV-M was significantly enhanced (P<0.05) and the level of IFN-γ in supernatant of splenocytes cultured with HBsAg in vitro was significantly elevated (P<0.05) while the level of IL-4 had no significant difference (P>0.05). Conclusion: The plasmid encoding IL-18 together with HBV M gene DNA vaccines may enhance specific TH1 cells and CTL cellular immune response induced in mice, so that IL-18 is a promising immune adjuvant.     

The contribution of epistemology to curriculum construction in the sciences

Summary The paper focuses upon curriculum planning in the scientific disciplines at university level, although it is claimed the argument may be of wider applicability. Drawing upon the writings of philosophers of education from several decades ago (notably Schwab and Scheffler) whose work is too often overlooked in contemporary debates about the curriculum, and using illustrative examples from the author’s own experience, it is argued that too often the focus of science curriculum planning is the “rhetoric of conclusions” or the “substantive structure” — the current state of knowledge at the forefront of the respective disciplines — to the neglect of what Schwab called the “syntactical structure” of the sciences (which roughly approximates their epistemology). This aspect of these disciplines is essential for the general student trying to become familiar with the nature of science as a broad field of knowledge, for prospective teachers, and — contra Scheffler’s view — for students who aim at careers as researchers.

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Zusammenfassung Der Beitrag der Epistemologie zur Curriuculumkonstruktion in den Naturwissenschaften Der Aufsatz fokussiert auf die Curriculumplanung für den naturwissenschaftlichen Unterricht in der universit?ren Lehrerausbildung, wenngleich behauptet wird, dass dieses Argument weitreichendere Anwendbarkeit besitzt. Der Text knüpft an erziehungswissenschaftlichen Schriften (insbesondere von Schwab und Scheffler) an, deren Ver?ffentlichung zwar einige Dekaden zurückliegt, deren Beitrag in den aktuellen Debatten aber oft übersehen wird. Darüber hinaus werden einige illustrative Beispiele aus dem Erfahrungsschatz des Autors genutzt, um zu zeigen, dass der Fokus der Curriculumplanung für die Naturwissenschaften — dem augenblicklichen Wissensstand der zu berücksichtigenden Disziplinen zufolge — zu oft in einer „Rhetorik der Schlussfolgerung“ oder „substantivischen Struktur“ besteht, was dazu führt, dass das, was Schwab die „syntaktische Struktur“ der Naturwissenschaften nennt (und ihrer Epistemologie ziemlich nahe kommt), vernachl?ssigt wird. Dieser Aspekt jener Disziplinen ist besonders wichtig für Studierende, die allgemeinbildend vertraut werden m?chten mit den Naturwissenschaften, für angehende Lehrer und — entgegen Schefflers Ansicht — für Studenten, die eine Karriere als Forscher anstreben.

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“When walking in quicksand country, carry a stout pole — it will help you get out should you need to. As soon as you start to sink, lay the pole on the surface of the quicksand. Flop onto your back on top of the pole. Work the pole to a new position: under your hips and at right angles to your spine. Take the shortest route to firmer ground, moving slowly.” Piven/Borgenicht 1999, p. 18

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This paper was presented at the conference Silence Between the Disciplines, Berlin-Brandenburg Academy of Sciences, Berlin, October 2002.     

Connectedness among taiwanese middle school students: a validation study of the hemingway measure of adolescent connectedness

Theories of adolescent connectedness suggest that adolescents strive to become connected by engaging with and valuing the people, activities, and worlds in their social ecology. The purpose of this study was to examine the psychometric properties of a measure designed to assess these worlds of connectedness among 320 junior high school students in Taiwan. The subscales and composite scales evidenced satisfactory reliability and concurrent validity. A hypothesized three-factor, higher order structural model of connectedness was cross-validated. Girls were generally more connected than boys. Both connectedness to school and to friends explained more variance in connectedness to self than did family connectedness. There was mixed support for separation-individuation processes. The measure appears promising in terms of future research on adolescent social development in the Asia Pacific.     

求解化学反应动力学参数的一种方法

反应级数的确定在化学动力学研究中非常重要,现给出了利用计算机和用微分法确定反应级数的方法.为了使编程的程序简短、高效,采用MATLAB语言作为编程语言.     

Books and articles of academic interest

Books and articles of academic interest