Research on Reform in Mathematics Education, 1993-2000

Proponents and opponents of reform of mathematics education all cite the research base in support of their positions. This article reports the results of a review of studies that contained empirical evidence of the effects of reform or the difficulty of implementing reform that were published between 1993 and 2000. The studies reviewed indicate that implementation of math reform contributes to student achievement, but evidence abounds of superficial implementation and barriers to enactment. There are well-documented strategies for reducing these barriers, the most promising strategies being inservice that simultaneously focuses on teachers' practice and their cognition about mathematics teaching.Promoteurs et adversaires d'une réforme en enseignement des mathématiques puisent tous dans la recherche pour appuyer leurs points de vue. Cet article présente le résultat d'une analyse d'études empiriques publiées entre 1993 et 2000 et qui évoquent les effets d'une réforme ou la difficulté d'en mettre une en application. Selon les études analysées, la mise en œuvre d'une réforme en enseignement des mathématiques contribue aux réalisations des élèves. Toutefois, énormément d'articles évoquent une mise en œuvre superficielle et des obstacles à la réforme. Parmi les stratégies bien documentées pour minimiser ces obstacles, celles qui promettent le plus impliquent une formation pour enseignants en cours d'emploi qui touche à la fois les méthodes des enseignants et leurs connaissances sur l'enseignement des mathématiques

T regulatory cells and attenuated bleomycin-induced fibrosis in lungs of CCR7-/- mice

Abstract Background C-C chemokine receptor (CCR)7 is a regulator of dendritic cell and T cell migration, and its role in tissue wound healing has been investigated in various disease models. We have previously demonstrated that CCR7 and its ligand, chemokine (C-C motif) ligand (CCL)21, modulates wound repair in pulmonary fibrosis (PF) but the mechanism of this is unknown. The objective of this study was to investigate whether the absence of CCR7 protects against bleomycin (BLM)-induced PF. CCR7-/- mice failed to mount a fibrotic pulmonary response as assessed by histologic collagen staining and quantification by hydroxyproline. We hypothesized that the prominent characteristics of CCR7-/- mice, including elevated levels of cytokine and chemokine mediators and the presence of bronchus-associated lymphoid tissue (BALT) might be relevant to the protective phenotype. Results Pulmonary fibrosis was induced in CCR7+/+ and CCR7-/- mice via a single intratracheal injection of BLM. We found that the lung cytokine/chemokine milieu associated with the absence of CCR7 correlated with an increase in BALT, and might be attributable to regulatory T cell (Treg) homeostasis and trafficking within the lungs and lymph nodes. In response to BLM challenge, CCR7-/- mice exhibited an early, steady increase in lung CD4+ T cells and increased CD4+ CD25+ FoxP3+ Tregs in the lungs 21 days after challenge. These findings are consistent with increased lung expression of interleukin-2 and indoleamine 2,3-dioxygenase in CCR7-/- mice, which promote Treg expansion. Conclusions Our study demonstrates that the protective phenotype associated with BLM-treated CCR7-/- mice correlates with the presence of BALT and the anchoring of Tregs in the lungs of CCR7-/- mice. These data provide novel evidence to support the further investigation of CCR7-mediated Treg trafficking in the modulation of BLM-induced PF.http://deepblue.lib.umich.edu/bitstream/2027.42/112768/1/13069_2010_Article_33.pd

Interleukin-33 contributes to both M1 and M2 chemokine marker expression in human macrophages

Abstract Background Interleukin-33 is a member of the IL-1 cytokine family whose functions are mediated and modulated by the ST2 receptor. IL-33-ST2 expression and interactions have been explored in mouse macrophages but little is known about the effect of IL-33 on human macrophages. The expression of ST2 transcript and protein levels, and IL-33-mediated effects on M1 (i.e. classical activation) and M2 (i.e. alternative activation) chemokine marker expression in human bone marrow-derived macrophages were examined. Results Human macrophages constitutively expressed the membrane-associated (i.e. ST2L) and the soluble (i.e. sST2) ST2 receptors. M2 (IL-4 + IL-13) skewing stimuli markedly increased the expression of ST2L, but neither polarizing cytokine treatment promoted the release of sST2 from these cells. When added to naïve macrophages alone, IL-33 directly enhanced the expression of CCL3. In combination with LPS, IL-33 blocked the expression of the M2 chemokine marker CCL18, but did not alter CCL3 expression in these naive cells. The addition of IL-33 to M1 macrophages markedly increased the expression of CCL18 above that detected in untreated M1 macrophages. Similarly, alternatively activated human macrophages treated with IL-33 exhibited enhanced expression of CCL18 and the M2 marker mannose receptor above that detected in M2 macrophages alone. Conclusions Together, these data suggest that primary responses to IL-33 in bone marrow derived human macrophages favors M1 chemokine generation while its addition to polarized human macrophages promotes or amplifies M2 chemokine expression.http://deepblue.lib.umich.edu/bitstream/2027.42/78250/1/1471-2172-11-52.xmlhttp://deepblue.lib.umich.edu/bitstream/2027.42/78250/2/1471-2172-11-52.pdfPeer Reviewe

M. Breitenbach, R. Crameri, and S. B. Lehrer. Fungal Allergy and Pathogenicity .

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43274/1/11046_2004_Article_5122151.pd

Development of a Bioluminescent Sensor of Isothiocyanates through Genetic Modification of Pseudomonas fluorescens and Validation on Crude Plant Materials

Isothiocyanates (ITCs) are produced by roots in a variety of agricultural plants, such as those within the Brassicaceae family. ITCs act as fumigants, and are used to control microbial plant pathogens by adding brassica-origin seed meal to soil prior to replanting. However, there is suggestion that the presence of residual ITCs in soil may inhibit seed germination in recently planted crops. These chemical compounds are difficult to detect, where a biological sensor may be a strategic indicator for when the soil is safe to replant in. Some microbes, including Pseudomonas fluorescens, exhibit resistance to ITCs mediated by an induced biochemical pathway. P. fluorescens is a root-colonizing non-pathogenic microbe, making it an ideal and safe biological sensor for agricultural use. To accomplish this, we linked an ITC-responsive promoter (saxA promoter) to the ilux operon, an enhanced version of the lux operon with an additional FMN reductase. The resulting biosensor was responsive in a dose-dependent manner to the aliphatic ITC, sulforaphane, in the concentration range of 1-100 μM. Further tests were conducted using extracted fluid from plant material of broccoli and daikon for the experimental group, while utilizing clover, alfalfa, and mung bean as a negative control group. The biosensor was responsive to the Brassica-related plants, and did not luminesce in response to the negative control extracts. The biosensor was also responsive to the seed meal of Brassica juncea and Sinapis alba, which are common seed meals used in biofumigation. Future experiments will determine the biosensor’s responsiveness to other ITCs and their precursors, glucosinolates, and detection in seed meal amended soils

Eye position and word identification during reading

College students read text displayed by computer as their eyes were being monitored. On occasional fixations or saccades the text was removed and the subject reported the last word that had been read and tried to guess the next word. Distributions of the location of the last read word with respect to the last fixated word give an indication of what words are being read during a fixation. The data do not support an anticipation model of reading nor the acquisition of peripheral cues concerning upcoming words

The chemokine receptor CCR6 is an important component of the innate immune response

In our initial studies we found that naÏve CCR6-deficient (CCR6 –/– ) C57BL/6 mice possessed significantly lower number of both F4/80 + macrophages and dendritic cells (DC), but higher number of B cells in the peritoneal cavity, as compared to naÏve wild type (WT) controls. Furthermore, peritoneal macrophages isolated from CCR6 –/– mice expressed significantly lower levels of inflammatory cytokines and nitric oxide following lipopolysaccharide (LPS)stimulation, as compared to WT macrophages. In a severe experimental peritonitis model induced by cecal ligation and puncture (CLP), CCR6 –/– mice were protected when compared with WT controls. At 24 h following the induction of peritonitis, CCR6 –/– mice exhibited significantly lower levels of inflammatory cytokines/chemokines in both the peritoneal cavity and blood. Interestingly, DC recruitment into the peritoneal cavity was impaired in CCR6 –/– mice during the evolution of CLP-induced peritonitis. Peritoneal macrophages isolated from surviving CCR6 –/– mice 3 days after CLP-induced peritonitis exhibited an enhanced LPS response compared with similarly treated WT peritoneal macrophages. These data illustrate that CCR6 deficiency alters the innate response via attenuating the hyperactive local and systemic inflammatory response during CLP-induced peritonitis.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/56112/1/2487_ftp.pd