提高学生数学成绩——数学课堂教学建议

过去三十年来有关数学教育的研究数量急剧增长 .这些研究结果 ,以及在其他领域 ,比如认识心理学上的相关研究结果 ,都被用来确认成功的教学策略和实践 .数学的教和学是复杂的任务 .很难确认一个单一教学行为的变化对学生学习的影响 .这是因为与之相联的其他教学活动 ,以及教学进行时的情景同时也对学生学习有影响 .这些研究结果表明 ,当教师努力想改进自己的数学教学行为时 ,某些教学策略和方法值得仔细地考虑 .对要了解下述建议的读者来说 ,很清楚 ,许多教学行为都是相关的 .有相当一批不同的教学行为已被确认为是有效的教学行为 ,因此许多…     

Scaling behavior of nucleotide cluster in DNA sequences

In this paper we study the scaling behavior of nucleotide cluster in 11 chromosomes of Encephalitozoon cuniculi Genome. The statistical distribution of nucleotide clusters for 11 chromosomes is characterized by the scaling behavior of P（S） ∝ e^-αs＇ where S represents nucleotide cluster size. The cluster-size distribution P（S1＋S2） with the total size of sequential C-G cluster and A-T cluster S1＋S2 were also studied. P（S1＋S2） follows exponential decay. There does not exist the case of large C-G cluster following large A-T cluster or large A-T cluster following large C-G cluster. We also discuss the relatively random walk length function L（n） and the local compositional complexity of nucleotide sequences based on a new model. These investigations may provide some insight into nucleotide cluster of DNA sequence.     

Children with autism illuminate the role of social intention in word learning

To what extent do children with autism (AD) versus typically developing children (TD) rely on attentional and intentional cues to learn words? Four experiments compared 17 AD children (M age=5.08 years) with 17 language- and 17 mental-age-matched TD children (M ages=2.57 and 3.12 years, respectively) on nonverbal enactment and word-learning tasks. Results revealed variability in all groups, but particularly within the AD group. Performance on intention tasks was the most powerful predictor of vocabulary in the AD group but not in the TD groups. These findings suggest that word learning cannot be explained exclusively by either attentional or intentional processes, and they provide evidence of a special role for intentional understanding in the vocabulary development of AD children.     

A semester-long student-directed research project involving enzyme immunoassay: appropriate for immunology, endocrinology, or neuroscience courses

The following project aimed at promoting integrated and long-lasting learning is described for an Immunology course, but it may be adapted to other disciplines. Students were asked to develop and carry out a research project to examine the relationship between immune function and stress. The experiments were required to include the assessment of salivary cortisol and salivary IgA (sIgA) with enzyme immunoassays. All other aspects of the experiments were developed by student groups with appropriate guidance from the instructor. Data are presented for one group project that assessed the effect of music on cortisol and sIgA. Overall levels of sIgA and cortisol were consistent with reported values. Students found a significant decrease in cortisol over time. Additionally, there was a trend that supported the overall student hypothesis regarding the effect of stress and immune function. Compared with the same Immunology course that included an instructor-designed experiment using enzyme immunoassays for cortisol and sIgA, several assessments (e.g., final grades and comments on student evaluations) show that overall learning seemed to be much better in the course with the student-directed research project.     

Effect of high glucose levels on the calcification of vascular smooth muscle cells by inducing osteoblastic differentiation and intracellular calcium deposition via BMP-2/Cbfα-1 pathway

In this paper,we investigate the effect and the possible mechanism of high glucose levels on the calcification of human aortic smooth muscle cells (HASMCs).HASMCs were divided into four groups: normal glucose group (NG),osmolality control group (OC),high glucose group (HG,HASMCs culture medium containing 30 mmol/L glucose),and high glucose plus recombinant human Noggin protein (bone morphogenetic protein-2 (BMP-2) antagonist) group (HN).The mRNA levels and the protein expressions of BMP-2 and core binding factor alpha-1 (Cbfα-1) were measured by real-time quantitative polymerase chain reaction (PCR) and Western blot.After induced by 10 mmol/L β-glycerol phosphoric acid,cells were harvested for assessments of alkaline phosphatase (ALP) activities at Days 1,2,and 3,and intracellular calcium contents at Days 7 and 14,respectively.High glucose levels increased the mRNA levels and the protein expressions of BMP-2 and Cbfα-1 (P0.05).The expression of Cbfα-1 was partially blocked by Noggin protein (P0.05),while BMP-2 was not (P0.05).After being induced by β-glycerol phosphoric acid,high glucose levels increased the ALP activity [(48.63±1.03) vs.(41.42±2.28) U/mg protein,Day 3;P0.05] and the intracellular calcium content [(2.76±0.09) vs.(1.75±0.07) μmol/mg protein,Day 14;P0.05] in a time-dependent manner when compared with the NG group,while the ALP activity could not be blocked by Noggin protein [(48.63±1.03) vs.(47.37±0.97) U/mg protein,Day 3;P0.05].These results show that high glucose levels can evoke the calcification of HASMCs by inducing osteoblastic trans-differentiation and intracellular calcium deposition via the BMP-2/Cbfα-1 pathway,which can be partially blocked by Noggin protein.     

Depending on the kindness of strangers: current national data initiatives and developmental research

This article provides a brief review of current large-scale, longitudinal data collection initiatives focusing on children. These studies will be available for secondary data analyses in the twenty-first century. In addition to child outcome data, process-oriented information is being collected on child-parent interactions, quality of child care, elementary school teacher reports and classroom observations, accessibility and use of health, educational and social services, parental mental health, family violence, fathering, parental residence patterns, income and income sources, child support, employment patterns, and community characteristics. Several of these studies are randomized trials of the efficacy of early childhood intervention services and housing mobility programs. The usefulness of these efforts for exploring policy-relevant issues (child support enforcement, work requirements for welfare recipients, antipoverty strategies, housing subsidies and relocation, availability of child care, child-care subsidies) are discussed.     

The Swedish WAIS-R factor structure and cognitive profiles for adults with dyslexia

Factor analysis of the Swedish version of the Wechsler Adult Intelligence Scale-Revised (WAIS-R) on a group of 88 adult individuals with dyslexia showed a three-factor structure with a verbal comprehension (VC) factor, a perceptual organization (PO) factor, and a freedom from distractibility (FD) factor. The results of this factor analysis support earlier findings from factor analyses of adults in the original U.S. normative sample and in different clinical groups. The profile of scores for the sample of individuals with dyslexia showed the expected pattern, with PO highest and FD lowest. The predicted pattern was also observed using Bannatyne's recategorization of WAIS-R subtests. As has been true for other typical and exceptional samples, women scored significantly higher than men on the Digit Symbol subtest. Related to this gender difference, Digit Symbol scores proved to be sensitive to problems associated with dyslexia only for men with dyslexia. Also, education level was shown to be related to verbal (V)-performance (P) IQ discrepancy, with larger P > V differences observed for participants with fewer years of formal schooling. Regardless of these gender and education differences, the characteristic factor score and Bannatyne patterns were identified for both men and women and for three different subsamples categorized by educational level.     

The similarity of siblings' attachments to their mother

Do siblings develop similar attachment relationships with their mother? Attachment theory suggests that brothers and sisters growing up in the same family are likely to relate in similar ways to their parents, at least when parental attachment representations and interactive styles remain stable across time. In the current study, sibling attachment data from three research groups (from Pennsylvania State University, Leiden University, and the University of Western Ontario) have been pooled to assemble a sufficiently large sample of observations (N = 138 sibling pairs) for a detailed comparison of sibling attachment relationships. Spacing between the births, differences in maternal sensitivity, and gender of siblings were examined as possible sources of concordance of nonconcordance. Attachment security (including disorganized attachment) of each sibling was assessed with the Strange Situation procedure between 12 and 14 months after birth. Maternal sensitivity was observed with the same rating scale in a laboratory play session in one of the studies and in home observations in the others. Sibling relationships were found to be significantly concordant when classified as secure/nonsecure (62% concordance, p < .01, 1-tailed, intraclass correlation = .23) but not when further subcategorized. Maternal insensitivity to both siblings (shared environment) was associated with concordance of sibling nonsecurity. Siblings of the same gender were more likely to form concordant relationships with their mother (68%; p < .01, 1-tailed, intraclass correlation = .37) than those of opposite gender. Same-sex sibling concordance was comparable to the concordance found for monozygotic twins in earlier studies. Genetic factors may, therefore, play a relatively small role in the development of attachment.     

Children's Difficulties in Text Comprehension: Assessing Causal Issues

In this article we consider the difficulties of children who have a specific reading comprehension problem. Our earlier work has shown that good and poor comprehenders differ, in particular, in their ability to make inferences, integrate information in text, understand story structure, and monitor their understanding. We outline some studies that illustrate the poor comprehenders' problems and present two studies that use a comprehension-age match design to explore the direction of causality between comprehension skill and other abilities. We also present data from the first and second stages of a longitudinal study, when the children were 7 to 8 and 8 to 9 years old. Multiple regression analyses show that a number of factors predict significant variance in comprehension skill even after "general ability" factors such as IQ and vocabulary have been taken into account. These findings suggest that, not only can children have comprehension problems in the absence of word recognition problems, but that distinctly different skills predict variance in word recognition and variance in comprehension. The data support the view that single-word reading skills and the ability to build integrated text representations make independent contributions to overall reading ability. We discuss the implications of these findings for our understanding of children's problems in text comprehension, for deaf readers, and for remediation.     

日美课程改革的比较分析——美国学者谈日本教育改革

二战后受美国的影响,日本现行的课程模式是在美国初、中等教育课程结构的基础之上建立起来的。但是,日本课程结构的核心精华却有着丰富悠久的历史。它具有强烈的美学意识和热爱大自然的传统观念,并受到诸如日本神道教、佛教、孔子之道等各种不同道教思想的影响。如今人们访问日本学校不难发现这些特点随处可见。只有通过对这些方面的了解,人们才有可能较详尽地理解日本的教育改革。目前在任何一个国家都明显地表现出经济、社会、文化和政治对课程结构所产生的影响。在日本由于课程编制是由中央集权直接控制的,因而更加容易看到这些影响。