Land degradation,government subsidy,and smallholders’ conservation decision: the case of the loess plateau in China     

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   

Metaphors we’re colonised by? The case of data-driven educational technologies in Brazil     

Giselle Martins dos Santos Ferreira  Luiz Alexandre da Silva Rosado  Márcio Silveira Lemgruber  Jaciara de Sá Carvalho 《Learning, Media and Technology》2020,45(1):46-60

ABSTRACT

This article discusses issues concerning the spread of data-driven educational technologies in Brazil. Here, as elsewhere, educational technology continues to be promoted optimistically as the bearer of a panacea for historically-rooted social problems. Whilst some of these technologies have indeed contributed to important widening-participation programmes in the last two decades, widespread advocacy of technological ‘solutionism’, reflected in gradually stronger policy demands for efficiencies to be improved through ‘innovation’, has supported a relentless marketisation of the country’s educational systems. As transnational corporations position themselves to take control of key areas of these systems, threatening to restructure the whole sector, data-driven educational technologies provide the latest example in a series of ‘new’ ideas offered in an ever-expanding market. Based on the notion of ‘conceptual metaphors’, which encapsulate specific ways of perceiving, thinking and relating with the world, this article examines key metaphors underpinning discourses surrounding data-driven educational technologies in Brazil. In particular, the article analyses ways in which these specific metaphors may be promoting perspectives that ignore difference and obscure broader questions concerning education, thus contributing to the reproduction of previously existing problems and supporting new forms of colonisation.  相似文献   

China’s graduate students need better education in scientific writing and publishing     

Chun-jie?Zhang  Yuan?ZhuEmail author 《Journal of Zhejiang University. Science. B》2016,17(5):409-412

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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   

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

Catone WV  Brady SA 《Annals of dyslexia》2005,55(1):53-78

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   

Investigation on apoptosis of neuronal cells induced by Amyloid beta-Protein     

罗本燕  徐增斌  陈智  陈峰  唐敏 《浙江大学学报(A卷英文版)》2004,5(8):989-994

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   

African Oral Traditions: Riddles Among The Haya of Northwestern Tanzania     

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.

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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.

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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.

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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.

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What's wrong? Understanding beginners' problems with Prolog     

Maarten W. Van Someren 《Instructional Science》1990,19(4-5):257-282

This paper reviews psychological research on programming and applies it to the problems of learning and teaching Prolog. We present a psychological model that explains how a certain class of errors in programs comes about. The model fits quite well with the results of a small sample of students and problems. The problems that underlie these and other errors seem to be (a) the complexity of the Prolog primitives (unification and backtracking) and (b) the misfit between students' naive solutions to a problem and the constructs that are available in Prolog (e.g. iterative solutions do not map easily to recursive programs). This suggests that learning Prolog could be helped by (1) coherent and detailed instruction about how Prolog works, (2) emphasis on finding recursive solutions that do not rely on primitives such as assignment and (3) instruction in programming techniques that allow students to implement procedural solutions.  相似文献   

知识产权特征新论——兼析知识产权与有形财产权的区别   总被引：1，自引：0，他引：1  

江滢  郑友德 《华中科技大学学报(社会科学版)》2001,15(4):16-20

知识产权本质上是一种无形财产权,本文通过对知识产权与有形财产权之比较,论述了知识产权的四方面特征,即客体的无形性、相对垄断性、法律效力在时空上的有限性及权利保护范围的不确定性.  相似文献   

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

陈建忠  朱海红  刘克洲  陈智 《浙江大学学报(A卷英文版)》2004,5(4):467-471

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.  相似文献