2,748 research outputs found

    RNA Polymerase-Binding and Transcription Initiation Sites Upstream of the Methyl Reductase Operon of Methanococcus vannielii

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    RNA Polymerase, purified from Methanococcus vannielii, was shown by exonuclease III footprinting to bind to a 49-base-pair (bp) region of DNA in the intergenic region upstream of mcrB. Sl nuclease protection experiments demonstrated that transcription Initiation in vivo occurs within this region at 32 or 33 bp 5' to the A T G translation initiation codon of mcrB and 19 or 20 bp 3' to a T A T A box

    The effects of an experimental programme to support students’ autonomy on the overt behaviours of physical education teachers

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    Although the benefits of autonomy supportive behaviours are now well established in the literature, very few studies have attempted to train teachers to offer a greater autonomy support to their students. In fact, none of these studies has been carried out in physical education (PE). The purpose of this study is to test the effects of an autonomy-supportive training on overt behaviours of teaching among PE teachers. The experimental group included two PE teachers who were first educated on the benefits of an autonomy supportive style and then followed an individualised guidance programme during the 8 lessons of a teaching cycle. Their behaviours were observed and rated along 3 categories (i.e., autonomy supportive, neutral and controlling) and were subsequently compared to those of three teachers who formed the control condition. The results showed that teachers in the experimental group used more autonomy supportive and neutral behaviours than those in the control group, but no difference emerged in relation to controlling behaviours. We discuss the implications for schools of our findings

    Structure and sequence divergence of two archaebacterial genes.

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    Expression of Insulinlike Growth Factor (IGF) and IGF-Binding Protein Genes in Human Lung Tumor Cell Lines

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    Background: The presence of multiple, low-molecular-weight, insulinlike growth factor (IGF)-binding proteins in lung tumor cell-conditioned medium and lung cancer patient serum has been recently reported. Purpose: To begin to elucidate the genetic basis for these observations, the present study examines the expression by lung tumor cell lines of three IGF-binding protein genes, namely, IGFBP-1, IGFBP-2, and IGFBP-3. Since IGF-binding proteins are thought to modulate the biologic action of the IGFs, the relationship between the expression of IGF-binding protein genes and the genes encoding IGF-I and IGF-II also has been investigated. Methods: Gene expression was studied in four small-cell lung cancer (SCLC) and three non—small-cell lung cancer (NSCLC) cell lines using Northern blot analysis and reverse transcriptase polymerase chain reaction (RT-PCR) for IGFBP-1. Results: IGFBP-1 gene expression was detected by Northern blot analysis in one NSCLC cell line only. However, RT-PCR revealed that the IGFBP-1 gene was expressed in all four SCLC cell lines and in two of the three NSCLC lines. Northern blot analysis of IGFBP-2 gene expression demonstrated that all lung tumor cell lines expressed this gene. A low level of IGFBP-3 gene expression was detected in one SCLC cell line and in all three NSCLC cell lines. All lung tumor cell lines expressed the IGF-II gene as determined by Northern blot analysis. In marked contrast, none of the lines showed evidence of IGF-I gene expression using this method. However, RT-PCR revealed a low level of IGF-I gene expression in one SCLC and one NSCLC cell line only. Conclusions: These observations indicate 1) that IGF-binding proteins secreted by lung tumors are encoded by at least three different genes; 2) that there may be a close association between IGF-II and IGFBP-2 gene expression, such that, where there is production of IGF-II, IGFBP-2 is the principal BP; and 3) that the IGF-II gene is more widely expressed than the IGF-I gene in human lung tumor cell lines. [J Natl Cancer Institute 84: 628-634, 1992

    Expanding Autonomy Psychological Need States From Two (Satisfaction, Frustration) to Three (Dissatisfaction): A Classroom-Based Intervention Study

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    We propose that students experience "autonomy dissatisfaction" when the learning environment is indifferent to their psychological need for autonomy. We hypothesized that (a) students could distinguish this newly proposed need state from both autonomy satisfaction and autonomy frustration, (b) autonomy dissatisfaction would explain unique and rather substantial variance in students' classroom disengagement, and (c) a full understanding of the psychological need for autonomy necessitates expanding the current emphasis from two need states (satisfaction, frustration) to three (dissatisfaction). In the experimental condition, 20 secondaryschool physical education (PE) teachers learned how to teach in an autonomy-supportive way; in the control condition, 17 PE teachers taught using "practice as usual." Their 2,669 students (1,180 females, 1,489 males) self-reported their autonomy satisfaction, autonomy dissatisfaction, autonomy frustration, engagement, and disengagement throughout a semester. Objective raters scored the manipulation check (teachers' autonomysupportive instructional behaviors) and the engagement-disengagement outcome measure. Autonomy dissatisfaction longitudinally increased in the control group and longitudinally decreased in the experimental group. Most importantly, intervention-enabled decreases in autonomy dissatisfaction decreased students' end-ofsemester disengagement, even after controlling for midsemester changes in autonomy satisfaction and autonomy frustration. We discuss the theoretical and practical benefits of adding autonomy dissatisfaction to the self-determination theory explanatory framework
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