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61.
In five conditioned taste aversion experiments with rats, summation, retardation, and preference tests were used to assess the effects of extinguishing a conditioned saccharin aversion for three or nine trials. In Experiment 1, a summation test showed that saccharin aversion extinguished over nine trials reduced the aversion to a merely conditioned flavor (vinegar), whereas three saccharin extinction trials did not subsequently influence the vinegar aversion. Experiment 2 clarified that result, with unpaired controls equated on flavor exposure prior to testing; the results with those controls suggested that the flavor extinguished for nine trials produced generalization decrement during testing. In Experiment 3, the saccharin aversion reconditioned slowly after nine extinction trials, but not after three. Those results suggested the development of latent inhibition after more than three extinction trials. Preference tests comparing saccharin consumption with a concurrently available fluid (water in Experiment 4, saline in Experiment 5) showed that the preference for saccharin was greater after nine extinction trials than after three. However, saccharin preference after nine extinction trials was not greater, as compared with that for either latent inhibition controls (Experiments 4 and 5) or a control given equated exposures to saccharin and trained to drink saline at a high rate prior to testing (Experiment 5). Concerns about whether conditioned inhibition has been demonstrated in any flavor aversion procedure are discussed. Our findings help explain both successes and failures in demonstrating postextinction conditioned response recovery effects reported in the conditioned taste aversion literature, and they can be explained using a memory interference account. 相似文献
62.
Whereas emerging technologies, such as touchscreen tablets, are bringing sensorimotor interaction back into mathematics learning activities, existing educational theory is not geared to inform or analyze passages from action to concept. We present case studies of tutor–student behaviors in an embodied-interaction learning environment, the Mathematical Imagery Trainer. Drawing on ecological dynamics—a blend of dynamical-systems theory and ecological psychology—we explain and demonstrate that: (a) students develop sensorimotor schemes as solutions to interaction problems; (b) each scheme is oriented on an attentional anchor—a real or imagined object, area, or other aspect or behavior of the perceptual manifold that emerges to facilitate motor-action coordination; and (c) when symbolic artifacts are introduced into the arena, they may both mediate new affordances for students’ motor-action control and shift their discourse into explicit mathematical re-visualization of the environment. Symbolic artifacts are ontological hybrids evolving from things with which you act to things with which you think. Students engaged in embodied-interaction learning activities are first attracted to symbolic artifacts as prehensible environmental features optimizing their grip on the world, yet in the course of enacting the improved control routines, the artifacts become frames of reference for establishing and articulating quantitative systems known as mathematical reasoning. 相似文献
63.
师生冲突的概念界定与分类探究——基于刘易斯·科塞的冲突分类理论 总被引:15,自引:0,他引:15
论文通过借鉴和辨析社会学理论中的冲突概念,对师生冲突概念作出界定。根据美国当代社会学家刘易斯·科塞的冲突分类理论,对学校师生冲突进行分类研究。在此基础上提出了三个观点:学校师生冲突的多数属于非现实性冲突;师生结构由紧密走向松散是师生冲突增多的重要原因;师生冲突具有一定的正面功能。 相似文献
64.
石敏俊 《浙江大学学报(A卷英文版)》2004,5(12):1533-1542
Land degradation is one of the severe environmental problems in China. In order to combat land degradation, a soil conservation program was introduced since 2000 to reduce soil erosion by converting slope-cultivated land into forestry and pasture. This paper represents the first systematic attempt to investigate the impact of the soil conservation program on land degradation in the loess plateau. The results indicate that the soil conservation program to convert slope fields into forest or pasture is an effective way to combat soil erosion. However, a subsidy that is higher than profit of land use activity of slope fields before their conversion into forest and pasture is needed to encourage farmers to join the conservation program. A policy measure to encourage and assist farmers to develop sedentary livestock by using crops produced from fields as well as fodder and forage grass from the converted slope fields might contribute to combat soil erosion. Increase in off-farm job opportunities may encourage households to reduce cultivation in slope fields. That implies a policy measure to encourage rural urbanization might contribute to combat soil erosion. 相似文献
65.
66.
Yangxueqingnao particles inhibit rat vascular smooth muscle cell proliferation induced by lysophosphatidic acid 总被引:1,自引:0,他引:1
Cai W Xu Y Chen JZ Huang SR Lu ZY Wang ZK 《Journal of Zhejiang University. Science. B》2005,6(9):892-896
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. 相似文献
67.
Julio-César Mateus Wilson Hernández-Breña Mònica Figueras-Maz 《Cultura y Educación》2019,31(2):436-464
AbstractKey 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. 相似文献
68.
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. 相似文献
69.
Objective: To construct a PC12 cell strain with neuronal differentiation, and observe the apoptosis and pro-liferation activity effects induced these cells by Amyloid beta-Protein (Aβ-43). Methods: 1) PC12 cells in logarithmicgrowth phase were subcultured for 24 h. After the culture fluid was changed, the cells were treated with Rat-β-NGF andcultured for 9 days. 2) Neuronal differentiation of PC12 cells in logarithmic growth phase were divided into four groups:control group (0), experimental group (1), experimental group (2) and experimental group (3). The concentrations of Aβ inthe four groups were 0 μmol/L, 1.25 μ mol/L, 2.5 μ mol/L and 5 μmol/L, respectively. The cells were harvested at 24, 48 and72 h later and stained with AnnexinV-FITC/PI after centrifugation and washing. Then flow cytometry was conducted toexamine the apoptosis percentage. 3) NGF-induced PC12 cells were selected and Aβ with different concentrations wasadded. The final concentrations of Aβ were 0 μmol/L, 1.25 μmol/L, 2.5 μmol/L and 5 μ mol/L, respectively. After the cellswere incubated in an atmosphere of 5% CO2 at 37 ℃ in an incubator for 72 h, the OD values were examined. Results: 1)Neuronal differentiated PC 12 cell lines were successfully established. 2) Flow cytometric examination indicated that Aβ(1.25, 2.5, and 5.0 μmol/L) could effectively induce apoptosis of neuronal-differented cells at the 24 h, 48 h and 72 h timepoints. 3) Aβ (0-5.00 μ mol/L) had no obvious effect on proliferation or restraining of the neuronal differentiation of thePC 12 cells after a 72 h interacting process. Conclusion: This investigation revealed successful neuronal differentiation of thePC12 cell strain. The induction of apoptosis of the neurocytes by various concentrations of Aβ was observed and the in-fluence of Aβ on induced proliferation of PC 12 cells by Rat-β-NGF was revealed. This study -05 provide basis for futureresearch on the molecular cure of AD and interdiction of AD evolution. 相似文献
70.
Johnson?M.?IshengomaEmail author 《International Review of Education/Internationale Zeitschrift für Erziehungswissenschaft/Revue internationale l'éducation》2005,51(2-3):139-153
This study argues for the integration of African oral traditions and other elements of traditional learning into the modern school curriculum. It thus contributes to supporting the increased relevance of education to local communities. In particular, using the example of riddles collected from one of the main ethnic groups in Northwestern Tanzania, the Haya people, the present study challenges the views of those social and cultural anthropologists who hold that African riddles have no substantially meaningful educational value. Instead, it is maintained that riddles make an important contribution to children’s full participation in the social, cultural, political, and economic life of African communities, especially by fostering critical thinking and transmitting indigenous knowledge.
Zusammenfassung MÜNDLICHE TRADITIONEN IN AFRIKA: DER ERZIEHERISCHE WERT VON RÄTSELN BEI DEN HAYA IM NORDWESTLICHEN TANSANIA – Diese Studie argumentiert für die Einbeziehung afrikanischer mündlicher Traditionen und anderer Elemente traditionellen Lernens in den modernen schulischen Lehrplan. Sie fördert somit die gestiegene Bedeutung der Bildung für die örtlichen Gemeinschaften. Insbesondere begegnet die vorliegende Studie, indem sie das Beispiel von Rätseln gebraucht, die bei einer der Hauptvolksgruppen im nordwestlichen Tansania, dem Volk der Haya, gesammelt wurden, den Ansichten derjenigen Sozial- und Kulturanthropologen, die behaupten, dass afrikanische Rätsel keinen wesentlich bedeutungsvollen erzieherischen Wert haben. Stattdessen wird die These aufgestellt, dass Rätsel einen wichtigen Beitrag zur vollständigen Teilnahme von Kindern am gesellschaftlichen, kulturellen, politischen sowie wirtschaftlichen Leben afrikanischer Gemeinschaften leisten, besonders durch die Förderung von kritischem Denken und die Weitergabe des Wissens der Eingeborenen.
Resumen TRADICIONES ORALES AFRICANAS: EL VALOR EDUCATIVO DE LAS ADIVINANZAS PARA EL PUEBLO DE LOS HAYA EN EL NOROESTE DE TANZANÍA – Con este trabajo, el autor aboga por una integración de tradiciones orales africanas y de otros elementos de aprendizaje tradicional en los actuales planes de estudios de las escuelas. Al mismo tiempo, hace énfasis en la creciente relevancia que la educación tiene para las comunidades locales. Con este estudio, el autor desafía la posición de aquellos antropólogos sociales y culturales que sostienen que las adivinanzas africanas no tienen ningún valor educativo digno de mención, ante todo presentando el ejemplo de adivinanzas que ha recopilado entre los miembros del pueblo de los haya, uno de los principales grupos étnicos del noroeste de Tanzanía. Por lo contrario, el autor afirma que las adivinanzas promueven en gran medida la participación plena de los niños en la vida social, cultural, política y económica de las comunidades africanas, ante todo porque incentivan el pensamiento crítico y transmiten conocimientos indígenas.
Résumé TRADITIONS ORALES AFRICAINES : LA VALEUR ÉDUCATIVE DES ÉNIGMES CHEZ LES HAYAS DE LA TANZANIE DU NORD-OUEST – Cette étude argumente en faveur de l’intégration des traditions orales africaines et autres éléments de l’apprentissage traditionnel dans le programme d’étude de l’école moderne. Elle contribue ainsi à soutenir la pertinance accrue de l’éducation au sein des communautés locales. En particulier, utilisant l’exemple des énigmes recueillies chez l’un des principaux groupes ethniques de la Tanzanie du Nord-Ouest, le peuple Haya, l’étude présente conteste les vues de ces anthropologues sociaux et culturels qui soutiennent que les énigmes africaines n’ont pas de valeur éducative substantiellement significative. Au lieu de cela, on maintient que les énigmes apportent une contribution importante à la pleine participation des enfants à la vie sociale, culturelle, politique et économique des communautés africaines, spécialement en ce qu’elles favorisent la pensée critique et transmettent les connaissances indigènes.相似文献