397 research outputs found

    Pre-service teachers' concept image for circle and ellipse

    Get PDF
    Concept image is proposed by Vinner and Tall (1981) to differentiate the elements and relationships that a learner constructs about a concept from formal mathematical definition for the same concept. The answers of 119 University students to an examination question are analysed to establish the concept images they have for circle and ellipse. The results show the difficulty the students have in reasoning with properties at the higher levels of Van Hiele’s (2004) model of geometric thought

    Potential Impact of miR-137 and Its Targets in Schizophrenia

    Get PDF
    The significant impact of microRNAs (miRNAs) on disease pathology is becoming increas- ingly evident. These small non-coding RNAs have the ability to post-transcriptionally silence the expression of thousands of genes. Therefore, dysregulation of even a single miRNA could confer a large polygenic effect. Schizophrenia is a genetically complex illness thought to involve multiple genes each contributing a small risk. Large genome-wide association studies identified miR-137, a miRNA shown to be involved in neuronal maturation, as one of the top risk genes. To assess the potential mechanism of impact of miR-137 in this disorder and identify its targets, we used a combination of literature searches, ingenuity pathway analysis (IPA), and freely accessible bioinformatics resources. Using TargetScan and the schizophrenia gene resource (SZGR) database, we found that in addition to CSMD1, C10orf26, CACNA1C, TCF4, and ZNF804A, five schizophrenia risk genes whose transcripts are also validated miR-137 targets, there are other schizophrenia-associated genes that may be targets of miR-137, including ERBB4, GABRA1, GRIN2A, GRM5, GSK3B, NRG2, and HTR2C. IPA analyses of all the potential targets identified several nervous system (NS) functions as the top canonical pathways including synaptic long-term potentiation, a process implicated in learning and memory mechanisms and recently shown to be altered in patients with schizophrenia. Among the subset of targets involved in NS development and function, the top scoring pathways were ephrin receptor signaling and axonal guidance, processes that are critical for proper circuitry formation and were shown to be disrupted in schizophrenia. These results suggest that miR-137 may indeed play a substantial role in the genetic etiology of schizophrenia by regulating networks involved in neural development and brain function

    Meta Gene Set Enrichment Analyses Link miR-137-regulated Pathways With Schizophrenia Risk

    Get PDF
    Background: A single nucleotide polymorphism (SNP) within MIR137, the host gene for miR-137, has been identified repeatedly as a risk factor for schizophrenia. Previous genetic pathway analyses suggest that potential targets of this microRNA (miRNA) are also highly enriched in schizophrenia-relevant biological pathways, including those involved in nervous system development and function. Methods: In this study, we evaluated the schizophrenia risk of miR-137 target genes within these pathways. Gene set enrichment analysis of pathway-specific miR-137 targets was performed using the stage 1 (21,856 subjects) schizophrenia genome wide association study data from the Psychiatric Genomics Consortium and a small independent replication cohort (244 subjects) from the Mind Clinical Imaging Consortium and Northwestern University. Results: Gene sets of potential miR-137 targets were enriched with variants associated with schizophrenia risk, including target sets involved in axonal guidance signaling, Ephrin receptor signaling, long-term potentiation, PKA signaling, and Sertoli cell junction signaling. The schizophrenia-risk association of SNPs in PKA signaling targets was replicated in the second independent cohort. Conclusions: These results suggest that these biological pathways may be involved in the mechanisms by which this MIR137 variant enhances schizophrenia risk. SNPs in targets and the miRNA host gene may collectively lead to dysregulation of target expression and aberrant functioning of such implicated pathways. Pathway-guided gene set enrichment analyses should be useful in evaluating the impact of other miRNAs and target genes in different diseases

    Genetic Markers of White Matter Integrity in Schizophrenia Revealed by Parallel ICA

    Get PDF
    It is becoming a consensus that white matter integrity is compromised in schizophrenia (SZ), however the underlying genetics remains elusive. Evidence suggests a polygenic basis of the disorder, which involves various genetic variants with modest individual effect sizes. In this work, we used a multivariate approach, parallel independent component analysis (P-ICA), to explore the genetic underpinnings of white matter abnormalities in SZ. A pre-filtering step was first applied to locate 6527 single nucleotide polymorphisms (SNPs) discriminating patients from controls with a nominal uncorrected p-value of 0.01. These potential susceptibility loci were then investigated for associations with fractional anisotropy (FA) images in a cohort consisting of 73 SZ patients and 87 healthy controls (HC). A significant correlation (r = −0.37, p = 1.25 × 10−6 ) was identified between one genetic factor and one FA component after controlling for scanning site, ethnicity, age, and sex. The identified FA-SNP association remained stable in a 10-fold validation. A 5000-run permutation test yielded a p-value of 2.00 × 10−4 . The FA component reflected decreased white matter integrity in the forceps major for SZ patients. The SNP component was overrepresented in genes whose products are involved in corpus callosum morphology (e.g., CNTNAP2, NPAS3, and NFIB) as well as canonical pathways of synaptic long term depression and protein kinase A signaling. Taken together, our finding delineates a part of genetic architecture underlying SZ-related FA reduction, emphasizing the important role of genetic variants involved in neural development

    Two distinct signalling cascades target the NF-κB regulatory factor c-IAP1 for degradation

    Get PDF
    c-IAP1 (cellular inhibitor of apoptosis 1) has recently emerged as a negative regulator of the non-canonical NF-κB (nuclear factor κB) signalling cascade. Whereas synthetic IAP inhibitors have been shown to trigger the autoubiquitination and degradation of c-IAP1, less is known about the physiological mechanisms by which c-IAP1 stability is regulated. In the present paper, we describe two distinct cellular processes that lead to the targeted loss of c-IAP1. Recruitment of a TRAF2 (tumour necrosis factor receptor-associated factor 2)–c-IAP1 complex to the cytoplasmic domain of the Hodgkin's/anaplastic large-cell lymphoma-associated receptor, CD30, leads to the targeting and degradation of the TRAF2–c-IAP1 heterodimer through a mechanism requiring the RING (really interesting new gene) domain of TRAF2, but not c-IAP1. In contrast, the induced autoubiquitination of c-IAP1 by IAP antagonists causes the selective loss of c-IAP1, but not TRAF2, thereby releasing TRAF2. Thus c-IAP1 can be targeted for degradation by two distinct processes, revealing the critical importance of this molecule as a regulator of numerous intracellular signalling cascades

    Genes influence the amplitude and timing of brain hemodynamic responses

    Get PDF
    In functional magnetic resonance imaging (fMRI), the hemodynamic response function (HRF) reflects regulation of regional cerebral blood flow in response to neuronal activation. The HRF varies significantly between individuals. This study investigated the genetic contribution to individual variation in HRF using fMRI data from 125 monozygotic (MZ) and 149 dizygotic (DZ) twin pairs. The resemblance in amplitude, latency, and duration of the HRF in six regions in the frontal and parietal lobes was compared between MZ and DZ twin pairs. Heritability was estimated using an ACE (Additive genetic, Common environmental, and unique Environmental factors) model. The genetic influence on the temporal profile and amplitude of HRF was moderate to strong (24%-51%). The HRF may be used in the genetic analysis of diseases with a cerebrovascular etiology. (C) 2015 Elsevier Inc. All rights reserved

    Crop Updates 2008 - Cereals

    Get PDF
    This session covers twenty four papers from different authors: WHEAT AGRONOMY 1. Wheat variety performance in the Northern Agricultural Region in 2007, Christine Zaicou, Department of Agriculture and Food 2. Wheat variety performance on the Central Agricultural Region in 2007, Shahajahan Miyan, Department of Agriculture and Food 3. Response of wheat varieties to sowing time in the Great Southern and Lakes Region in 2007, Brenda Shackley and Steve Penny, Department of Agriculture and Food 4. Wheat variety performance in the South Coastal Region in 2007, Sarah Ellis, Department of Agriculture and Food 5. Flowering dates of wheat varieties in Western Australia in 2007, Darshan Sharma, Brenda Shackley and Christine Zaicou, Department of Agriculture and Food BARLEY AGRONOMY 6. Barley variety options for Western Australia, Blakely Paynter, Andrea Hills and Jeff Russell, Department of Agriculture and Food 7. Vlaming A – the newest malting barley variety, Blakely Paynter, Jeff Russell and Andrea Hills, Department of Agriculture and Food 8. Barley yields higher in wide rows with stubble retained in a very dry season at Merredin, Glen Riethmuller, Bill Bowden and Paul Blackwell, Department of Agriculture and Food HERBICIDE TOLERANCE 9. Herbicide tolerance of current/new wheat varieties, Dr Harmohinder Dhammu, Department of Agriculture and Food 10. Herbicide tolerance of new oat varieties, Dr Harmohinder Dhammu, Vince Lambert, and Chris Roberts,Department of Agriculture and Food NUTRITION 11. Managing nitrogen inputs in malting barley, Andrea Hills and Blakely Paynter, Department of Agriculture and Food 12. Decision tools for optimal N on cereal crops, David and Sally Cox, Jeremy Lemon* and Andrea Hills*, *Department of Agriculture and Food 13. Wheat varieties respond differently to potassium application on potassium responsive soils, Paul Damon and Zed Rengel, Faculty of Natural and Agricultural Sciences, University of Western Australia DISEASES 14. Leaf disease management in continuous barley in the northern and central grainbelt of WA, Geoff Thomas, Ciara Beard, Anne Smith, Kith Jayasena and Sean Kelly, Department of Agriculture and Food 15. Temperature and moisture requirements of leaf, stem and stripe rusts of wheat, Geoff Thomas, Rob Loughman and Bill MacLeod, Department of Agriculture and Food 16. Fungicide options for controlling diseases in oats, Raj Malik and Blakely Paynter, Department of Agriculture and Food 17. Survey of wheat root diseases under intensive cereal production in Western Australia during 2005-2007, Ravjit Khangura, William MacLeod, Vivien Vanstone, Colin Hanbury, Mehreteab Aberra, Gordon MacNish and Robert Loughman, Department of Agriculture and Food 18. Epidemiology studies on Wheat Streak Mosaic Virus in 2007, Brenda Coutts, Geoff Strickland, Monica Kehoe, Dustin Severtson and Roger Jones, Department of Agriculture and Food 19. Bacterial diseases that affect WA export hay quality, Dominie Wright and Megan Jordan, Department of Agriculture and Food SOIL 20. Hardpan penetration ability of drought-stressed wheat under pot and field conditions, Xinhua He1, Eli Manyol1, Song-Ai Nio1, Imran Malik1, Tina Botwright-Acuña1,2and Len Wade1,3,1School of Plant Biology, University of Western Australia, 2Tasmanian Institute of Agricultural Research, University of Tasmania, TAS, 3E.H. Graham Centre, Charles Sturt University, NSW HARVEST MANAGEMENT 21. Calculating the risk – the SEPWA Harvest Calculator, Nigel Metz, South East Premium Wheat Growers Association 22. The relationship between grain moisture and atmospheric conditions in cereal crop harvesting on the South Coast of WA, Nigel Metz, South East Premium Wheat Growers Association (SEPWA) MARKETS 23. Varietal accreditation for Australian Barley, Linda Price, Barley Australia STATISTICAL METHODS 24. Applying data mining tools to improve grain quality for growers, Dean Diepeveen1, Leisa Armstrong2, Peter Clarke1, Doug Abrecht1, Rudi Appels2 and Matthew Bellgard3,1Department of Agriculture and Food, Western Australia 2Edith Cowan University, Western Australia, 3Centre of Comparative Genomics, Murdoch Universit
    corecore