43 research outputs found

    Facilitando a mobilização de redes de conhecimento: as reformas políticas, parcerias e formação de professores

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    Educational researchers and policy-makers are now expected by funding agencies and their institutions to innovate the multidirectional ways in which our production of knowledge can impact the classrooms of teachers (practitioners), while also integrating their experiential knowledge into the landscape of our research. In this article, we draw on the curriculum implementation literature to complicate our understandings of knowledge mobilization (KMb). Policy implementation, we suggest, can be understood as one specific type of KMb. We draw on different models for KMb and curriculum implementation and develop a relational model for KMb. Utilizing our model we critically reflect on the specific successes and challenges encountered while establishing, building, and sustaining the capacity of our KMb network. Our findings suggest that faculties of education are uniquely positioned to act as secondary brokers for the implementation of policy reforms within public education systems. To this end, we discuss how a relational KMb network is a “best practice” for establishing and sustaining partnerships among policy makers, educational researchers, and public school practitioners.Los organismos de financiación y sus instituciones esperan que investigadores educativos y responsables de decisiones políticas en el área innoven  la forma multidireccional en la que la producción de conocimiento puede afectar a las aulas de los docentes, y al mismo tiempo integrar su conocimiento experiencial en el modelo de la investigación. En este artículo, nos basamos en la literatura la implementación del currículo de reflexionar sobre nuestro entendimiento de la movilización de los conocimientos (por su sigla en inglés KMB). La implementación de políticas, se sugiere, se puede entender como un tipo específico de KMB. Nos basamos en diferentes modelos para la aplicación KMB e implementación curricular y desarrollamos un modelo relacional para KMB. Utilizando nuestro modelo reflexionamos críticamente sobre los éxitos y desafíos específicos encontrados mientras se establece, la construcción y el mantenimiento de la capacidad de nuestra red de KMB. Nuestros hallazgos sugieren que las facultades de educación están en una posición única para actuar como agentes secundarios en la implementación de reformas de política dentro de los sistemas de educación pública. Con este fin, se discute cómo una red KMB relacional es una "mejor práctica" para el establecimiento y mantenimiento de alianzas entre responsables políticos, los investigadores de la educación, y los profesionales de las escuelas públicas. Agências de fomento e instituições de ensino esperam que os pesquisadores em educação assim como os que decidem políticas na área inovem na forma multidirecional  que a produção de conhecimento na pode afetar o professor em sala de aula, e ao mesmo tempo integrar os conhecimentos experienciais no modelo de pesquisa. Neste artigo, nós confiamos na implementação do currículo literatura para refletir sobre a nossa compreensão da mobilização de conhecimentos (a sigla KMB). Implementação de políticas, sugere-se, pode ser entendida como um tipo específico de KMB. Contamos com diferentes modelos de candidatura e curriculum implementação KMB e desenvolver um modelo relacional para KMB. Usando nosso modelo, para refletir criticamente sobre os sucessos e desafios específicos encontrados ao estabelecer, construir e manter a capacidade de nossa rede de KMB. Nossos resultados sugerem que as escolas de educação estão em uma posição única para atuar como agentes secundários na aplicação de reformas políticas no seio das redes públicas de ensino. Para este fim, discutimos como uma rede relacional KMB é um "melhores práticas" para a criação e manutenção de parcerias entre os que decidem políticas, investigadores e profissionais de educação nas escolas públicas

    Environmental impact assessment of wheat straw based alkyl polyglucosides produced using novel chemical approaches

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    This paper evaluates and quantifies the environmental performance of alkyl polyglucosides sourced from wheat straw (WS-APG), a low-cost and low-ecological impact agricultural residue, compared to that of their commercial counterpart, which is sourced from palm kernel oil and wheat grain (PW-APG). Escalating pressure to consider the environmental sustainability of fossil derived surfactant consumption has driven biosurfactants to become the product of choice within the surfactant market, and a class of ‘plant’ based non-ionic surfactants called alkyl polyglucosides (APG) are particularly prevalent. However, the existing food based feedstock of APG such as coconut oil, palm oil, wheat and corn (in addition to being expensive) will potentially undermine the claimed ‘sustainability’ of the APG products (i.e. the ‘food vs. chemical’ issue). Here, we present the “cradle-to-gate” life cycle impact assessment of a suggested alternative, hybridised APG synthesis technique where the Fisher glycosidation method is supplemented by novel, green chemistry based techniques. This evaluation provides a quantitative insight into direct GHG intensity and other ecological impact indicators, including land use, waste generation and energy consumption. Upon evaluation, the wheat straw-derived pathway delivered GHG-emission savings in the range of 84–98%, compared to that of the palm kernel–wheat grain pathway. Waste generated from the production of unit mass of the product amounted to 0.43 kg and 10.73 kg per kg of WS-APG and PW-APG, respectively. In addition to the above mentioned facts, the ‘cradle–gate’ stages of WS-APG production were also found to consume relatively lower amounts of water and fossil-derived energy. In conclusion, of the two APG production pathways, the suggested ‘hybrid’ pathway using an agricultural residue, wheat straw, was found to be sustainable and to demonstrate better environmental performance

    Challenge clusters facing LCA in environmental decision-making—what we can learn from biofuels

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    Purpose Bioenergy is increasingly used to help meet greenhouse gas (GHG) and renewable energy targets. However, bioenergy’s sustainability has been questioned, resulting in increasing use of life cycle assessment (LCA). Bioenergy systems are global and complex, and market forces can result in significant changes, relevant to LCA and policy. The goal of this paper is to illustrate the complexities associated with LCA, with particular focus on bioenergy and associated policy development, so that its use can more effectively inform policymakers. Methods The review is based on the results from a series of workshops focused on bioenergy life cycle assessment. Expert submissions were compiled and categorized within the first two workshops. Over 100 issues emerged. Accounting for redundancies and close similarities in the list, this reduced to around 60 challenges, many of which are deeply interrelated. Some of these issues were then explored further at a policyfacing workshop in London, UK. The authors applied a rigorous approach to categorize the challenges identified to be at the intersection of biofuels/bioenergy LCA and policy. Results and discussion The credibility of LCA is core to its use in policy. Even LCAs that comply with ISO standards and policy and regulatory instruments leave a great deal of scope for interpretation and flexibility. Within the bioenergy sector, this has led to frustration and at times a lack of obvious direction. This paper identifies the main challenge clusters: overarching issues, application and practice and value and ethical judgments. Many of these are reflective of the transition from application of LCA to assess individual products or systems to the wider approach that is becoming more common. Uncertainty in impact assessment strongly influences planning and compliance due to challenges in assigning accountability, and communicating the inherent complexity and uncertainty within bioenergy is becoming of greater importance. Conclusions The emergence of LCA in bioenergy governance is particularly significant because other sectors are likely to transition to similar governance models. LCA is being stretched to accommodate complex and broad policy-relevant questions, seeking to incorporate externalities that have major implications for long-term sustainability. As policy increasingly relies on LCA, the strains placed on the methodology are becoming both clearer and impedimentary. The implications for energy policy, and in particular bioenergy, are large

    Model for the Peptide-Free Conformation of Class II MHC Proteins

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    Background: Major histocompatibility complex proteins are believed to undergo significant conformational changes concomitant with peptide binding, but structural characterization of these changes has remained elusive. Methodology/Principal Findings: Here we use molecular dynamics simulations and experimental probes of protein conformation to investigate the peptide-free state of class II MHC proteins. Upon computational removal of the bound peptide from HLA-DR1-peptide complex, the a50-59 region folded into the P1-P4 region of the peptide binding site, adopting the same conformation as a bound peptide. Strikingly, the structure of the hydrophobic P1 pocket is maintained by engagement of the side chain of Phe a54. In addition, conserved hydrogen bonds observed in crystal structures between the peptide backbone and numerous MHC side chains are maintained between the a51-55 region and the rest of the molecule. The model for the peptide-free conformation was evaluated using conformationally-sensitive antibody and superantigen probes predicted to show no change, moderate change, or dramatic changes in their interaction with peptide-free DR1 and peptide-loaded DR1. The binding observed for these probes is in agreement with the movements predicted by the model. Conclusion/Significance: This work presents a molecular model for peptide-free class II MHC proteins that can help to interpret the conformational changes known to occur within the protein during peptide binding and release, and ca

    Genomic Hotspots for Adaptation: The Population Genetics of Müllerian Mimicry in the Heliconius melpomene Clade

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    Wing patterning in Heliconius butterflies is a longstanding example of both Müllerian mimicry and phenotypic radiation under strong natural selection. The loci controlling such patterns are “hotspots” for adaptive evolution with great allelic diversity across different species in the genus. We characterise nucleotide variation, genotype-by-phenotype associations, linkage disequilibrium, and candidate gene expression at two loci and across multiple hybrid zones in Heliconius melpomene and relatives. Alleles at HmB control the presence or absence of the red forewing band, while alleles at HmYb control the yellow hindwing bar. Across HmYb two regions, separated by ∼100 kb, show significant genotype-by-phenotype associations that are replicated across independent hybrid zones. In contrast, at HmB a single peak of association indicates the likely position of functional sites at three genes, encoding a kinesin, a G-protein coupled receptor, and an mRNA splicing factor. At both HmYb and HmB there is evidence for enhanced linkage disequilibrium (LD) between associated sites separated by up to 14 kb, suggesting that multiple sites are under selection. However, there was no evidence for reduced variation or deviations from neutrality that might indicate a recent selective sweep, consistent with these alleles being relatively old. Of the three genes showing an association with the HmB locus, the kinesin shows differences in wing disc expression between races that are replicated in the co-mimic, Heliconius erato, providing striking evidence for parallel changes in gene expression between Müllerian co-mimics. Wing patterning loci in Heliconius melpomene therefore show a haplotype structure maintained by selection, but no evidence for a recent selective sweep. The complex genetic pattern contrasts with the simple genetic basis of many adaptive traits studied previously, but may provide a better model for most adaptation in natural populations that has arisen over millions rather than tens of years

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

    Structure of MHC class I-like MILL2 reveals heparan-sulfate binding and interdomain flexibility

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    The MILL family, composed of MILL1 and MILL2, is a group of nonclassical MHC class I molecules that occur in some orders of mammals. It has been reported that mouse MILL2 is involved in wound healing; however, the molecular mechanisms remain unknown. Here, we determine the crystal structure of MILL2 at 2.15 Å resolution, revealing an organization similar to classical MHC class I. However, the α1-α2 domains are not tightly fixed on the α3-β2m domains, indicating unusual interdomain flexibility. The groove between the two helices in the α1-α2 domains is too narrow to permit ligand binding. Notably, an unusual basic patch on the α3 domain is involved in the binding to heparan sulfate which is essential for MILL2 interactions with fibroblasts. These findings suggest that MILL2 has a unique structural architecture and physiological role, with binding to heparan sulfate proteoglycans on fibroblasts possibly regulating cellular recruitment in biological events

    Crystal structures of two H-2Db/glycopeptide complexes suggest a molecular basis for CTL cross-reactivity.

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    Two synthetic O-GlcNAc-bearing peptides that elicit H-2Db-restricted glycopeptide-specific cytotoxic T cells (CTL) have been shown to display nonreciprocal patterns of cross-reactivity. Here, we present the crystal structures of the H-2Db glycopeptide complexes to 2.85 A resolution or better. In both cases, the glycan is solvent exposed and available for direct recognition by the T cell receptor (TCR). We have modeled the complex formed between the MHC-glycopeptide complexes and their respective TCRs, showing that a single saccharide residue can be accommodated in the standard TCR-MHC geometry. The models also reveal a possible molecular basis for the observed cross-reactivity patterns of the CTL clones, which appear to be influenced by the length of the CDR3 loop and the nature of the immunizing ligand
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