243 research outputs found

    Student Voice e didattica partecipativa: un valore aggiunto per l\u2019innovazione scolastica

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    Following Student Voice approach, a democratic participation is an essential point of a \u201cnew\u201d educational approach that requires a review of teaching methods, wich encourages cooperation and inclusion, listening to students\u2019 voice and students\u2019participation in the decision making processes involving their education. In this framework we carried out a participatory action research in an upper secondary school. Twenty of the third and fourth year students took part in the activity with the specific aim of proposing some elements to innovate the Pedagogy curriculum. The project allowed us to reach the established aims and to authorise students to experience new positioning in the school. In this article, we present and discuss students\u2019 suggestions to improve their participation in the realisation of the Pedagogy curriculum

    Hierarchy of bounding surfaces in aeolian sandstones of the Jurassic Tordillo Formation (Neuquén Basin, Argentina)

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    The Tordillo Formation is a continental clastic unit deposited in the Neuquén Basin during the Late Jurassic. This paper discusses the stratigraphy of the succession outcropping at the Quebrada del Sapo, with emphasis on the origin, dimensions and hierarchy of bounding surfaces of aeolian deposits. Field survey, supported by the measurement of three detailed stratigraphic sections and line drawings of photographic panels allow the identification of four unconformity bounded units within the succession, informally named as T1, T2, T3 and T4. Units T1 and T3 are composed of conglomerates and pebbly sandstones deposited by density flows in a lacustrine environment. Paleocurrents indicate a source area located in the northeast while the presence of angular sandstone blocks suggests resedimentation processes. T2 and T4 units are composed of fine to medium grained sandstones of aeolian origin, characterized by large scale dunes and minor dry interdunes. Both units have sharp bases, and overlie a deflation surface characterized by the presence of ventifacts. Paleocurrents suggest a paleowind direction from the southwest. Internal bounding surfaces show a hierarchy of at least four discrete surfaces which were numbered according to their crescent extension. Type 1 surfaces are related to the normal advance of the dune front. Type 2 are reactivation surfaces within a single dune set. Type 3 surfaces relate to set superposition. Type 4 surfaces are related to extensive deflation of the dune complex, and define at least nine elementary aeolian sequences in the T4 unit

    Genetic structure and variability within and among populations of the fat-tailed Barbarine sheep breed using microsatellites markers

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    This study investigates the genetic diversity and the structure of the most dominant native fat-tailed Tunisian sheep breed (Barbarine, BAR) using microsatellite markers. Blood samples from 183 BAR animals, belonging to 4 subpopulations according to phenotypic traits, were collected across all regions in Tunisia. BAR animals and 31 Appenninica Italian sheep breed (APP) used as an out-group were genotyped at 17 microsatellites loci. A total of 270 alleles were identified with average gene diversity equal to 0.812. The mean observed heterozygosity (0.745) and allelic richness (8.09) estimates were high within BAR breed highlighting notable levels of genetic diversity. The low FIS (0.078) and FIT (0.084) values indicate low level of inbreeding within this breed while a low FST estimate (0.007) shows that the subpopulations are not genetically differentiated. The clustering analysis performed with ‘structure’ detected the absence of substructures and the clear uniqueness of the BAR. Tomiuk and Loeschcke’s DTL genetic distance values confirmed the distinction between APP and BAR breeds. Results arising from our microsatellites analysis represent a starting point for the valorization of this indigenous Tunisian sheep breed. A suggestion was made to monitor its genetic variability and for the preservation of this breed for the next generations.Keywords: Tunisian Barbarine sheep breed, microsatellite markers, genetic variability, population structureAfrican Journal of Biotechnology, Vol. 13(1), pp. 44-54, 1 January, 201

    A functional biological network centered on XRCC3: a new possible marker of chemoradiotherapy resistance in rectal cancer patients

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    Preoperative chemoradiotherapy is widely used to improve local control of disease, sphincter preservation and to improve survival in patients with locally advanced rectal cancer. Patients enrolled in the present study underwent preoperative chemoradiotherapy, followed by surgical excision. Response to chemoradiotherapy was evaluated according to Mandard's Tumor Regression Grade (TRG). TRG 3, 4 and 5 were considered as partial or no response while TRG 1 and 2 as complete response. From pretherapeutic biopsies of 84 locally advanced rectal carcinomas available for the analysis, only 42 of them showed 70% cancer cellularity at least. By determining gene expression profiles, responders and non-responders showed significantly different expression levels for 19 genes (P < 0.001). We fitted a logistic model selected with a stepwise procedure optimizing the Akaike Information Criterion (AIC) and then validated by means of leave one out cross validation (LOOCV, accuracy = 95%). Four genes were retained in the achieved model: ZNF160, XRCC3, HFM1 and ASXL2. Real time PCR confirmed that XRCC3 is overexpressed in responders group and HFM1 and ASXL2 showed a positive trend. In vitro test on colon cancer resistant/susceptible to chemoradioterapy cells, finally prove that XRCC3 deregulation is extensively involved in the chemoresistance mechanisms. Protein-protein interactions (PPI) analysis involving the predictive classifier revealed a network of 45 interacting nodes (proteins) with TRAF6 gene playing a keystone role in the network. The present study confirmed the possibility that gene expression profiling combined with integrative computational biology is useful to predict complete responses to preoperative chemoradiotherapy in patients with advanced rectal cance

    Noninvasive biomarkers of colorectal cancer: role in diagnosis and personalised treatment perspectives

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    Colorectal cancer (CRC) is the third leading cause of cancer-related deaths worldwide. It has been estimated that more than one-third of patients are diagnosed when CRC has already spread to the lymph nodes. One out of five patients is diagnosed with metastatic CRC. The stage of diagnosis influences treatment outcome and survival. Notwithstanding the recent advances in multidisciplinary management and treatment of CRC, patients are still reluctant to undergo screening tests because of the associated invasiveness and discomfort (e.g., colonoscopy with biopsies). Moreover, the serological markers currently used for diagnosis are not reliable and, even if they were useful to detect disease recurrence after treatment, they are not always detected in patients with CRC (e.g., CEA). Recently, translational research in CRC has produced a wide spectrum of potential biomarkers that could be useful for diagnosis, treatment, and follow-up of these patients. The aim of this review is to provide an overview of the newer noninvasive or minimally invasive biomarkers of CRC. Here, we discuss imaging and biomolecular diagnostics ranging from their potential usefulness to obtain early and less-invasive diagnosis to their potential implementation in the development of a bespoke treatment of CRC

    Unc5B Interacts with FLRT3 and Rnd1 to Modulate Cell Adhesion in Xenopus Embryos

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    The FLRT family of transmembrane proteins has been implicated in the regulation of FGF signalling, neurite outgrowth, homotypic cell sorting and cadherin-mediated adhesion. In an expression screen we identified the Netrin receptors Unc5B and Unc5D as high-affinity FLRT3 interactors. Upon overexpression, Unc5B phenocopies FLRT3 and both proteins synergize in inducing cell deadhesion in Xenopus embryos. Morpholino knock-downs of Unc5B and FLRT3 synergistically affect Xenopus development and induce morphogenetic defects. The small GTPase Rnd1, which transmits FLRT3 deadhesion activity, physically and functionally interacts with Unc5B, and mediates its effect on cell adhesion. The results suggest that FLRT3, Unc5B and Rnd1 proteins interact to modulate cell adhesion in early Xenopus development

    Lrp4 Modulates Extracellular Integration of Cell Signaling Pathways in Development

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    The extent to which cell signaling is integrated outside the cell is not currently appreciated. We show that a member of the low-density receptor-related protein family, Lrp4 modulates and integrates Bmp and canonical Wnt signalling during tooth morphogenesis by binding the secreted Bmp antagonist protein Wise. Mouse mutants of Lrp4 and Wise exhibit identical tooth phenotypes that include supernumerary incisors and molars, and fused molars. We propose that the Lrp4/Wise interaction acts as an extracellular integrator of epithelial-mesenchymal cell signaling. Wise, secreted from mesenchyme cells binds to BMP's and also to Lrp4 that is expressed on epithelial cells. This binding then results in the modulation of Wnt activity in the epithelial cells. Thus in this context Wise acts as an extracellular signaling molecule linking two signaling pathways. We further show that a downstream mediator of this integration is the Shh signaling pathway
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