首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
青年教师是高等院校未来的主力军,学校可持续发展的后备力量,是学校事业发展的希望,因此,提高青年教师的教学水平至关重要。大学青年教师在专业技能、思想政治素质、业务水平、掌握阅读专业书刊能力、自身的教学经验和反思等方面具有良好的基础,但在教育学、心理学、一般教学方法、学习情况分析等方面不够深入了解,因此需要对大学青年教师进行严格系统性培养,本文针对青年教师一对一导师制专业技能培训、观摩教学、继续教育培训等方面进行阐述,旨在为青年教师早日进入角色,尽快胜任教育教学工作提供参考。  相似文献   

2.
Despite the importance of the theory of evolution to scientific knowledge, a number of misconceptions continue to be found among teachers and undergraduate students. The aim of the present study was to describe and characterise knowledge about evolution among 120 freshman undergraduate students of two natural sciences programmes (environmental biology and veterinary medicine), 80 pre-service science teachers (elementary and biology) and 45 in-service teachers (elementary and biology high school) in Santiago, Chile. The research was carried out based on an eight-question questionnaire about evolution acceptance and understanding. The instrument included seven Likert-scale questions and one open-ended question. An analysis of the data revealed that more than 70% of teachers (pre-service and in-service) and undergraduate students recognised the theory of evolution as established scientific knowledge. When participants discussed the mechanism of evolution in the open-ended question, the most prevalent responses from students and teachers (33%) explained evolution as need-driven changes for survival purposes. Only 13% of the responses could be considered Darwinian, and 10% of responses included more than one view of evolution. The Darwinian responses generally included three important aspects: variation, inheritance and differential reproduction. The implications for biology teacher education are also discussed in this study.  相似文献   

3.
Although all disinfectant tests have the same final purpose, namely measuring the antimicrobial activity of a chemical substance or preparation, a large number of testing methods has been described. They are subdivided into suspension tests, carrier and surface disinfection tests and other practice-mimicking tests. The suspension tests comprise qualitative and quantitative suspension tests, and, as derived tests, the determination of the phenol coefficient and capacity tests. There is an essential difference between a carrier test and a surface disinfectant test: in the former case the carrier is submerged in the disinfectant solution during the whole exposure time, whereas in the latter case the disinfectant is applied on the carrier for the application time and thereafter the carrier is drying during the exposure.The basic principle now widely accepted is that the antimicrobial efficiency of a disinfectant is examined at three stages of testing.The first stage concerns laboratory tests in which it is verified whether a chemical compound or a preparation possesses antimicrobial activity. For these preliminary screening tests, suspension tests are considered.In the second stage of tests, disinfection procedures and not disinfectants are examined. It is determined under which conditions and at which use-dilution for a given application the preparation is active: the tests simulate real-life situations; such tests are carrier tests for the disinfection of materials by submersion and surface disinfection tests.The last stage takes place in the field, and comprises the in-loco or in-situ tests with as variants the in-use tests, which examine whether, after a normal period of use, germs are still killed by the disinfectant solution.It is the task of the European and international standardization organisations to develop new standards and to elaborate tests, which predict the effectiveness of a preparation in practice under variable circumstances.  相似文献   

4.
Amphipods are widely used in both acute and chronic (sub-lethal) sediment tests. Acute sediment tests provide relatively rapid results, but may fail to detect moderately toxic contaminants that are bound to the sediment, whereas chronic life-cycle tests are rarely performed as they are time consuming and expensive. Observations during chronic testing of oil-contaminated sediment suggested that there may be a link between the behavior of the marine amphipod Corophium volutator and reduction in growth rate. Behavior tests were performed with six individual amphipods per treatment using sediment spiked with weathered Forties oil with burrowing time, re-emergence from sediment, and activity prior to burrowing as endpoints. Further behavior tests were used to predict the chronic toxicity of sediments spiked with three crude oils each with a dominant unresolved complex mixture of hydrocarbons (UCM). The effect of sediment type on behavior was also investigated. The results suggested that although the behavior test could not be used alone as a viable alternative to sediment toxicity tests, it could prove useful as an adjunct to acute tests, and help select sediments that deserve further investigation.  相似文献   

5.
Randomization tests allow the formulation and statistical testing of null hypotheses about the quality of entire data sets or the quality of fit between the data and particular phylogenetic hypotheses. Randomization tests of phylogenetic hypotheses based on the concepts of split support and split conflict are described here, as are tests where splits, rather than the data, are randomly permuted. These tree-independent randomization tests are explored through their application to phylogenetic data for caecilian amphibians. Of these tests, split support randomization tests appear to be the most promising tools for phylogeneticists. These tests seem quite conservative, are applicable to nonpolar data and unordered multistate characters, and do not have the problems of nonindependence that affect split conflict and hierarchy tests. Unlike split conflict tests, their power does not appear to be correlated with split size. However, all tests are sensitive to taxonomic scope. Split support tests may help discern data that are likely to be affected by the problems of long-branches effects. Comparison of test results for mutually incompatible splits may help identify the presence of strong misleading signals in phylogenetic data. Significant split support could be a prerequisite for considering phylogenetic hypotheses to be well supported by the data, and split support randomization tests might be usefully applied prior to or as part of tree construction.  相似文献   

6.
This article develops criteria for the selection, professional development, and assessment of cooperating teachers through four “notions.” These notions suggest that cooperating teachers might (1) possess knowledge of educational theory and practice; (2) understand the importance of context in education; (3) understand narrative's role in the process of learning to teach; and (4) critically reflect on teaching practice. We explore these notions as qualities that may guide cooperating teachers’ work in facilitating student teachers’ development. We discuss specific ideas and strategies for mentoring and modeling within various theoretical frameworks and selected research that supports each notion. Throughout the article, we outline policy and practice implications for music teacher preparation programs, including aligning them with current accreditation standards and assessments.  相似文献   

7.
HOW TO ESTIMATE AND USE THE VARIANCE OF d' FROM DIFFERENCE TESTS   总被引:1,自引:0,他引:1  
d' is an estimate of δ, a measure of the degree of sensory difference between two products, that can be obtained easily using tables, from the proportion of difference tests performed correctly. Tables of δ are available for the 2-AFC, 3-AFC, triangular and duo-trio tests. Tables for calculating the variance of d' for these tests are provided in this paper. They can be used for comparison of d's, especially for those obtained from different difference tests. A simple procedure is described here for computing values for the variance of d'. Having obtained the variance, confidence intervals for d' can be obtained, tests of significance for d' can be made as well as tests of whether two or more d's are significantly different. The formula and tables for the number of judgments required for the estimation of δ are given also in this paper.  相似文献   

8.
Microarray-based clinical tests have become powerful tools in the diagnosis and treatment of diseases. In contrast to traditional DNA-based tests that largely focus on single genes associated with rare conditions, microarray-based tests are ideal for the study of diseases with underlying complex genetic causes. Several microarray based tests have been translated into clinical practice such as MammaPrint and AmpliChip CYP450. Additional cancer-related microarray-based tests are either in the process of FDA review or under active development, including Tissue of Tumor Origin and AmpliChip p53. All diagnostic microarray testing is ordered by physicians and tested by a Clinical Laboratories Improvement Amendment-certified (CLIA) reference laboratory. Recently, companies offering consumer based microarray testing have emerged. Individuals can order tests online and service providers deliver the results directly to the clients via a password-protected secure website. Navigenics, 23andMe and deCODE Genetics represent pioneering companies in this field. Although the progress of these microarray-based tests is extremely encouraging with the potential to revolutionize the recognition and treatment of common diseases, these tests are still in their infancy and face technical, clinical and marketing challenges. In this article, we review microarray-based tests which are currently approved or under review by the FDA, as well as the consumer-based testing. We also provide a summary of the challenges and strategic solutions in the development and clinical use of the microarray-based tests. Finally, we present a brief outlook for the future of microarray-based clinical applications.  相似文献   

9.
10.
Two nonparametric tests are proposed for the comparison of a paired sample of response curves with T congruent time points. The first procedure rank transforms each curve and tests the homogeneity of the resulting pair of averaged rank vectors. The second procedure rank transforms each pair of curves and tests the homogeneity of the related pair of averaged rank vectors. The first test detects only pure interactions; the second test checks if any difference exists between the rank curves. Both tests are presented in finite and asymptotic as well as in combined (by T singular tests) and multivariate form.  相似文献   

11.
Numerous reports in the literature indicate that various noninvasive vascular techniques can now be used to evaluate atherosclerosis at the carotid bifurcation. This article reviews noninvasive screening techniques currently available and being developed. Particular emphasis has been placed on the practicality of these techniques as well as their limitations. Our conclusions are that noninvasive techniques cannot be used as definitive screening tests for cerebrovascular disease. Although these tests are frequently useful when positive, the false negative rate of these tests would appear to be significant and variable in different hands. Nonstenotic ulcers are usually not detected and total occlusion often not differentiated from stenosis. These tests should be viewed as the beginning rather than the end result of a developing field. At present, contrast arteriography remains the definitive test to evaluate the presence and significance of extracranial cerebrovascular disease.  相似文献   

12.
P. Leeuwangh 《Hydrobiologia》1978,59(2):145-148
The possible role of Daphnia species in toxicity tests is discussed. In screening tests, effluent monitoring tests and legal tests daphnids are recommended as useful test organisms. They also may help to establish concentration limits for chemical water pollution (water quality criteria). As biological indicator organisms their use is limited.  相似文献   

13.
Research into the human genome has undoubtedly opened up a new perspective in medicine. The ability to identify the cause of specific diseases, especially neurodegenerative diseases, will definitively change the concepts of disease and treatment, while advances such as antibiotic therapy and anesthesia will be relegated to history. However, the arrival of genome medicine poses major bioethical challenges, many of which remain to be resolved. We review the applicability, results and consequences of predictions based on genetic tests for presymptomatic Alzheimer's disease, as well as the dilemmas and contradictions that are already arising as a result of the commercialization of predictive tests for public use with little or no medical supervision. Given that there is currently no effective treatment of Alzheimer?s disease, the greatest challenge and contradiction lies in managing the results of predictive tests. There are no indications for the performance of predictive genetic tests in late or sporadic Alzheimer's disease or for counselling of persons requesting these tests. The PICOGEN program provides a safe, effective, reliable and satisfactory option for persons requesting these tests who meet the inclusion criteria. Currently, caution should be the norm when considering the performance of predictive tests in presymptomatic dementia.  相似文献   

14.
Research into the human genome has undoubtedly opened up a new perspective in medicine. The ability to identify the cause of specific diseases, especially neurodegenerative diseases, will definitively change the concepts of disease and treatment, while advances such as antibiotic therapy and anesthesia will be relegated to history. However, the arrival of genome medicine poses major bioethical challenges, many of which remain to be resolved. We review the applicability, results and consequences of predictions based on genetic tests for presymptomatic Alzheimer's disease, as well as the dilemmas and contradictions that are already arising as a result of the commercialization of predictive tests for public use with little or no medical supervision. Given that there is currently no effective treatment of Alzheime?s disease, the greatest challenge and contradiction lies in managing the results of predictive tests. There are no indications for the performance of predictive genetic tests in late or sporadic Alzheimer's disease or for counselling of persons requesting these tests. The PICOGEN program provides a safe, effective, reliable and satisfactory option for persons requesting these tests who meet the inclusion criteria. Currently, caution should be the norm when considering the performance of predictive tests in presymptomatic dementia.  相似文献   

15.
Precedence tests are simple yet robust nonparametric procedures useful for comparing two or more distributions. In this paper precedence-type tests are considered when the data contain some censored observations. Generalizing the precedence statistic for uncensored data, the precedence tests for censored data are based on the Kaplan-Meier estimators of the respective distribution functions and the corresponding quantile functions. The literature is reviewed for some two-sample as well as some multi-sample problems.  相似文献   

16.
A comparison of current serologic tests for syphilis shows that treponemal tests are preferable to reagin tests in detecting specific antibodies, but that reagin tests are best for determining the response to treatment. The newly developed fta-absorption technique is suggested as a reliable, inexpensive test for treponemal antibodies.  相似文献   

17.
Scientific discovery requires both abstract, theoretically defined concepts and discovery operations formed by sets of rules that permit the empirical detection of instances of those concepts. In this paper, I examine the ontological status of discovery operations and the tests employed to evaluate them in evolutionary biology. Attention is drawn to the distinction between nomothetic (universal, predictive) and ideographic (historical, retrodictive) discovery operations, and between complementary and exclusive discovery operations. Three types of tests of discovery operations are commonly employed in evolutionary biology. Theoretical tests aim to show that a discovery operation is inconsistent with accepted, well-corroborated, empirical theories. Empirical tests evaluate the performance of competing discovery operations in terms of their results when applied to the same empirical data sets. Philosophical tests aim to show that an operation is inconsistent with logical and epistemological principles. Appropriately designed theoretical and philosophical tests of ideographic discovery operations may be scientifically valid. Empirical tests, however, are incapable of evaluating the scientific merits of competing discovery operations. Nonetheless, empirical comparisons (not tests ) of competing discovery operations may provide insight into the ways discovery operations may be misleading and therefore may play an important role in stimulating critical debate and eventually establishing a scientifically optimal operation. In practice, theoretical and philosophical tests are often combined to test competing discovery operations as rigorously as possible.  相似文献   

18.
Rosenbaum PR 《Biometrics》2007,63(4):1164-1171
A small literature discusses locally most powerful rank tests when only a fraction of treated subjects respond to treatment. The ranks used in these tests are very different from conventional ranks, being relatively flat for low responses and then rising steeply, and the associated tests are much more powerful than conventional rank tests when, indeed, only a small fraction of treated subjects exhibit dramatic responses. Because the tests are derived from considerations of local power, they do not yield a plausible family of models for effect, and therefore they do not yield confidence intervals for the magnitude of effect formed by inverting the tests. There is a similarity between these tests and another family of tests, originally motivated by different considerations involving peak performance in small subsets. Exploiting this similarity, a method for obtaining confidence statements is proposed. In the case of observational studies, sensitivity to unobserved bias from nonrandom assignment of treatments is also examined. Two examples are used as illustrations: (i) a study of smoking during pregnancy and its effects on birth weight, in which smokers are matched to six controls, and (ii) a matched pair study of damage to DNA among workers at aluminum production plants.  相似文献   

19.
The terms death (as an irreversible occurrence), necrosis and apoptosis are well defined and generally accepted in cell biology. Procedures and terminology related to estimation of different forms of cell mortality are, however, less clear and exact. Evaluation of the rate of mortality is important for numerous biological processes such as growth, atrophy, regeneration and neoplasia. Procedures used for assessing cell mortality include: 1. dye exclusion tests which were shown to be inadequate in apoptosis; 2. release of radioactive markers, also inadequate, as they occur also in life during shedding of membranes and cleavage of cell parts; 3. morphological and histochemical procedures which show only relatively late changes (autolysis) in cells which have not yet been completely obliterated; 4. absence of synthetic activities, which do not necessarily indicate death (e.g. mature erythrocytes); 5. colony forming capacity in cultures, which are considered by most authors as the most useful tests for assessing the effects of cytotoxic treatments. These tests do not, however, assess viability, but rather reproductive capacity. In all these tests, delayed changes in vitality can be determined by repeated or continuous testing. The following new terms are proposed and related to presently available tests. Aposchisis--for cleavage of cell parts not necessarily associated with cell death. N-mortality--for necrosis type of mortality estimated by the dye exclusion tests. A-mortality--for apoptosis type of mortality, which cannot be directly estimated at present. Acarpy--for loss of reproductive capacity of cells which is assessed by the colony forming tests.  相似文献   

20.
This study investigated biology teachers’ (N = 148) understanding of models and modelling (MoMo), their model-related teaching activities and relations between the two. A framework which distinguishes five aspects of MoMo in science (nature of models, multiple models, purpose of models, testing models and changing models) served as a theoretical background. Teachers’ understanding of MoMo was assessed using constructed-response items which were analysed qualitatively based on a coding scheme. The biology teachers mainly expressed a limited understanding of models as copies or idealised depictions used to show or to explain something. Model-related teaching activities were assessed through rating-scale items. The findings propose that models are primarily generated in biology lessons to show or to explain something but are rarely contrasted with other models, evaluated and modified. Significant correlations between teachers’ understanding of the aspect testing models and their intensity of model-related teaching activities were found. This suggests that the aspect testing models is a key aspect of promoting teaching activities related to MoMo in biology lessons. The findings are discussed with respect to relevant literature about MoMo in science education and educational implications are provided.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号