2,940 research outputs found

    The transition from school to university in mathematics education research: new trends and ideas from a systematic literature review

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    Investigating the transition between educational levels is one of the main themes for the future of mathematics education. In particular, the transition from secondary school to STEM degrees is problematic for the widespread students' difficulties and significant for the implications that it has on students' futures. Knowing and understanding the past is key to imagine the future of a research field. For this reason, this paper reports a systematic review of the literature on the secondary-tertiary transition in Mathematics Education from 2008 to 2021. We constructed two corpuses: one from the proceedings of three international conferences in mathematics education (PME, ICME, and INDRUM) and the other from peer reviewed research papers and book chapters returned by the databases ERIC and Google Scholar. A clear evolution in perspectives since 2008 emerges from the analysis of the two corpuses: the research focus changed from a purely cognitive to a more holistic one, including socio-cultural and - to a lesser extent - affective issues. To this end, a variety of research methods were used, and specific theoretical models were developed in the considered papers. The analysis also highlights a worrisome trend of underrepresentation: very little research comes from large geographical areas such as South America or Africa. We argue that this gap in representation is problematic as research on secondary tertiary transition concerns also consideration of socio-cultural and contextual factors

    Growth by insertion: The family of bacterial DDxP proteins

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    We have identified a variety of proteins in species of the Legionella, Aeromonas, Pseudomonas, Vibrio, Nitrosomonas, Nitrosospira, Variovorax, Halomonas, and Rhizobia genera, which feature repetitive modules of different length and composition, invariably ending at the COOH side with Asp–Asp–x–Pro (DDxP) motifs. DDxP proteins range in size from 900 to 6200 aa (amino acids), and contain 1 to 5 different module types, present in one or multiple copies. We hypothesize that DDxP proteins were modeled by the action of specific endonucleases inserting DNA segments into genes encoding DDxP motifs. Target site duplications (TSDs) formed upon repair of staggered ends generated by endonuclease cleavage would explain the DDxP motifs at repeat ends. TSDs acted eventually as targets for the insertion of more modules of the same or different types. Repeat clusters plausibly resulted from amplification of both repeat and flanking TSDs. The proposed growth shown by the insertion model is supported by the identification of homologous proteins lacking repeats in Pseudomonas and Rhizobium. The 85 DDxP repeats identified in this work vary in length, and can be sorted into short (136–215 aa) and long (243–304 aa) types. Conserved Asp–Gly–Asp–Gly–Asp motifs are located 11–19 aa from the terminal DDxP motifs in all repeats, and far upstream in most long repeats

    Detection of a misaligned broken pipe by electromagnetic interaction

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    The study we are presenting concerns electromagnetic scattering of a plane wave due to the presence of a misaligned broken pipe buried in a half-space occupied by cement and by asphalt/ground, for civil-engineering applications

    Characterization of two new alleles at the goat CSN1S2 locus.

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    Two novel alleles at the goat CSN1S2 locus have been identified: CSN1S2(F) and CSN1S2(D). Sequence analyses revealed that the CSN1S2(F) allele is characterized by a G --> A transition at the 13th nucleotide in exon 3 changing the seventh amino acid of the mature protein from Val to Ile. The CSN1S2(D) allele, apparently associated with a decreased synthesis of alpha s2-casein, is characterized by a 106-bp deletion, involving the last 11 bp of the exon 11 and the first 95 bp of the following intron. Methods (PCR-RFLP and PCR) for identification of carriers of these alleles have been developed

    The nero lucano pig breed: Recovery and variability

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    The Nero Lucano (NL) pig is a black coat colored breed characterized by a remarkable ability to adapt to the difficult territory and climatic conditions of Basilicata region in Southern Italy. In the second half of the twentieth century, technological innovation, agricultural evolution, new breeding methods and the demand for increasingly lean meat brought the breed almost to extinction. Only in 2001, thanks to local institutions such as: the Basilicata Region, the University of Basilicata, the Regional Breeders Association and the Medio Basento mountain community, the NL pig returned to populate the area with the consequent possibility to appreciate again its specific cured meat products. We analyzed the pedigrees recorded by the breeders and the Illumina Porcine SNP60 BeadChip genotypes in order to obtain the genetic structure of the NL pig. Results evidenced that this population is characterized by long mean generation intervals (up to 3.5 yr), low effective population size (down to 7.2) and high mean inbreeding coefficients (FMOL = 0.53, FROH = 0.39). This picture highlights the low level of genetic variability and the critical issues to be faced for the complete recovery of this population

    Integrating mitigation and adaptation in climate and land use policies in Brazil: a policy document analysis

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    This paper investigates climate policy integration and coherence in land use policies in Brazil. Unlike other policy analyses a key aim is to assess ‘internal policy coherence’ in the climate change domain, or the extent to which positive and negative interactions between mitigation and adaptation are taken into account in policy formulation. The paper is based on a systematic content analysis of major federal level climate change and land use policies. The results indicate a stronger focus on climate change mitigation compared to adaptation in all land uses. Integrated approaches that consider mutually supportive mitigation and adaptation actions are called for in key climate change policies, but so far such linkages remain largely unexplored in sectoral policies. While some progress in this regard occurred in the agricultural sector, this has not translated into actual policy actions that are of use to small-scale producers. In the forest domain the focus remains almost exclusively on climate change mitigation. Three main recommendations are drawn. First, more knowledge about locally specific climate change impacts, resilience, capacity and measures for climate change adaptation is needed in order to increase the opportunities to pursue mutually beneficial approaches to climate change mitigation, adaptation and development, in particular in the forestry sector. Second, policy makers need to address more explicitly potential trade-offs between mitigation and adaptation in both policy formulation and implementation. Third, policy action on how to achieve mutually beneficial outcomes and avoid trade-offs between mitigation and adaptation needs to be operationalised into concrete policy objectives within sectoral policies and into practices that apply not just to agriculture and livestock systems, but to forested landscapes as well
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