276 research outputs found

    Sociocultural theory for academic literacy research involving argumentation in institutions of higher learning

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    Researchers in the field of academic literacy, specifically those focused on the first-year level in universities, are often required to articulate the theoretical framework that informs their critical orientation. In this process, an indication of the researcher’s ontological view of the nature of academic literacy practices should also be declared. Ontologically, this study questions whether academic literacy constitutes a mechanistic technology or a socially emergent mode of arguing in higher education. This article reviews concepts and theories that warrant the second stance and a sociocultural paradigm of academic literacy research. A sociocultural explanatory framework incorporates human identities and cultures into analyses of the ways that humans employ language in universities. This framework accentuates the influences of social context and power relationships in the designation of acceptable modes of argumentation in the university. The results of the study indicate that theoretical discussions in academic literacy research are epistemic and ontological in nature. Theoretical frameworks are epistemic constructs as they reflect a researcher’s conceptual understanding of the field of academic literacy. Conceptual paradigms are also ontological constructs due to their exposure of the researcher’s understanding of the nature of academic literacy practices as an element of human existence. The study concludes by articulating a seven-point ontology that researchers can apply towards theoretically framing their own studies in the field of academic literacy and argumentation

    Private Cell Retrieval from Data Warehouses

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    © 2015 IEEE. Publicly accessible data warehouses are an indispensable resource for data analysis. However, they also pose a significant risk to the privacy of the clients, since a data warehouse operator may follow the client's queries and infer what the client is interested in. Private information retrieval (PIR) techniques allow the client to retrieve a cell from a data warehouse without revealing to the operator which cell is retrieved and, therefore, protects the privacy of the client's queries. However, PIR cannot be used to hide online analytical processing (OLAP) operations performed by the client, which may disclose the client's interest. This paper presents a solution for private cell retrieval from a data warehouse on the basis of the Paillier cryptosystem. By our solution, the client can privately perform OLAP operations on the data warehouse and retrieve one (or more) cell without revealing any information about which cell is selected. In addition, we propose a solution for private block download on the basis of the Paillier cryptosystem. Our private block download allows the client to download an encrypted block from a data warehouse without revealing which block in a cloaking region is downloaded and improves the feasibility of our private cell retrieval. Our solutions ensure both the server's privacy and the client's privacy. Our experiments have shown that our solutions are practical

    NIVEL DE CONOCIMIENTO Y ACTITUDES SOBRE LA DONACIÓN Y TRASPLANTE DE ÓRGANOS Y TEJIDOS DE LOS MÉDICOS E INTERNOS DE MEDICINA DEL HOSPITAL MILITAR CENTRAL - JULIO 2016

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    Objetivos: Determinar la asociación entre el nivel de conocimiento y las actitudes sobre la donación y trasplante de órganos y tejidos de los médicos e internos de medicina del Hospital Militar Central – Julio 2016. Métodos: Estudio observacional, analítico, no experimental, transversal. El tamaño de la población fue de 218 participantes entre médicos e internos de medicina del Hospital Militar Central. Se empleó una encuesta validada. Para el análisis estadístico de la relación de variables se utilizó el OR y el Chi-cuadrado. Y el análisis de datos se realizó por medio del programa estadístico SPSS. Resultados: Se encontró que un 57.8% de los encuestados tuvo un nivel de conocimiento alto, mientras un 58.3% tuvo actitudes favorables frente a la donación y trasplante de órganos y tejidos. Asimismo, se halló que la mayoría de los encuestados que tienen entre 41 a 60 años tienen un nivel de conocimiento alto 77.5% y 80% tienen una actitud favorable. De los encuestados, 88.07% son católicos de los cuales 61.5% tienen una actitud favorable, sin embargo, de los que pertenecen a otra religión 65.4% tienen una actitud desfavorable. La mayoría de encuestados fueron médicos con un 57.8% donde 69% tuvo un nivel de conocimiento alto y 68.3% tuvieron una actitud favorable. Conclusión: El tener un alto nivel de conocimiento está relacionado a tener actitudes favorables respecto a la donación y trasplante de órganos y tejido obteniendo un OR de 2,9, con un intervalo de confianza [1,658 -5,072] Existe una asociación estadísticamente significativa. DOI: https://doi.org/10.25176/RFMH.v17.n3.119

    Factors limiting complete tumor ablation by radiofrequency ablation

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    The purpose of this study was to determine radiological or physical factors to predict the risk of residual mass or local recurrence of primary and secondary hepatic tumors treated by radiofrequency ablation (RFA). Eighty-two patients, with 146 lesions (80 hepatocellular carcinomas, 66 metastases), were treated by RFA. Morphological parameters of the lesions included size, location, number, ultrasound echogenicity, computed tomography density, and magnetic resonance signal intensity were obtained before and after treatment. Parameters of the generator were recorded during radiofrequency application. The recurrence-free group was statistically compared to the recurrence and residual mass groups on all these parameters. Twenty residual masses were detected. Twenty-nine lesions recurred after a mean follow-up of 18 months. Size was a predictive parameter. Patients\u27 sex and age and the echogenicity and density of lesions were significantly different for the recurrence and residual mass groups compared to the recurrence-free group (p < 0.05). The presence of an enhanced ring on the magnetic resonance control was more frequent in the recurrence and residual mass groups. In the group of patients with residual lesions, analysis of physical parameters showed a significant increase (p < 0.05) in the time necessary for the temperature to rise. In conclusion, this study confirms risk factors of recurrence such as the size of the tumor and emphasizes other factors such as a posttreatment enhanced ring and an increase in the time necessary for the rise in temperature. These factors should be taken into consideration when performing RFA and during follow-up

    Search for the best indicators for the presence of a VPS13B gene mutation and confirmation of diagnostic criteria in a series of 34 patients genotyped for suspected Cohen syndrome

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    BACKGROUND: Cohen syndrome is a rare autosomal recessive inherited disorder that results from mutations of the VPS13B gene. Clinical features consist of a combination of mental retardation, facial dysmorphism, postnatal microcephaly, truncal obesity, slender extremities, joint hyperextensibility, myopia, progressive chorioretinal dystrophy, and intermittent neutropenia.PATIENTS AND METHODS: The aim of the study was to determine which of the above clinical features were the best indicators for the presence of VPS13B gene mutations in a series of 34 patients with suspected Cohen syndrome referred for molecular analysis of VPS13B. RESULTS: 14 VPS13B gene mutations were identified in 12 patients, and no mutation was found in 22 patients. The presence of chorioretinal dystrophy (92% vs 32%, p=0.0023), intermittent neutropenia (92% vs 5%, p<0.001), and postnatal microcephaly (100% vs 48%, p=0.0045) was significantly higher in the group of patients with a VPS13B gene mutation compared to the group of patients without a mutation. All patients with VPS13B mutations had chorioretinal dystrophy and/or intermittent neutropenia. The Kolehmainen diagnostic criteria provided 100% sensibility and 77% specificity when applied to this series. CONCLUSION: From this study and a review of more than 160 genotyped cases from the literature, it is concluded that, given the large size of the gene, VPS13B screening is not indicated in the absence of chorioretinal dystrophy or neutropenia in patients aged over 5 years. The follow-up of young patients could be a satisfactory alternative unless there are some reproductive issues

    The yield of essential oils in Melaleuca alternifolia (Myrtaceae) is regulated through transcript abundance of genes in the MEP pathway

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    Medicinal tea tree (Melaleuca alternifolia) leaves contain large amounts of an essential oil, dominated by monoterpenes. Several enzymes of the chloroplastic methylerythritol phosphate (MEP) pathway are hypothesised to act as bottlenecks to the production of monoterpenes. We investigated, whether transcript abundance of genes encoding for enzymes of the MEP pathway were correlated with foliar terpenes in M. alternifolia using a population of 48 individuals that ranged in their oil concentration from 39 -122 mg x g DM(-1). Our study shows that most genes in the MEP pathway are co-regulated and that the expression of multiple genes within the MEP pathway is correlated with oil yield. Using multiple regression analysis, variation in expression of MEP pathway genes explained 87% of variation in foliar monoterpene concentrations. The data also suggest that sesquiterpenes in M. alternifolia are synthesised, at least in part, from isopentenyl pyrophosphate originating from the plastid via the MEP pathway

    Identifying Human Disease Genes through Cross-Species Gene Mapping of Evolutionary Conserved Processes

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    Understanding complex networks that modulate development in humans is hampered by genetic and phenotypic heterogeneity within and between populations. Here we present a method that exploits natural variation in highly diverse mouse genetic reference panels in which genetic and environmental factors can be tightly controlled. The aim of our study is to test a cross-species genetic mapping strategy, which compares data of gene mapping in human patients with functional data obtained by QTL mapping in recombinant inbred mouse strains in order to prioritize human disease candidate genes.We exploit evolutionary conservation of developmental phenotypes to discover gene variants that influence brain development in humans. We studied corpus callosum volume in a recombinant inbred mouse panel (C57BL/6J×DBA/2J, BXD strains) using high-field strength MRI technology. We aligned mouse mapping results for this neuro-anatomical phenotype with genetic data from patients with abnormal corpus callosum (ACC) development.).This approach that exploits highly diverse mouse strains provides an efficient and effective translational bridge to study the etiology of human developmental disorders, such as autism and schizophrenia

    Role of Plant-Specific N-Terminal Domain of Maize CK2β1 Subunit in CK2β Functions and Holoenzyme Regulation

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    Protein kinase CK2 is a highly pleiotropic Ser/Thr kinase ubiquituous in eukaryotic organisms. CK2 is organized as a heterotetrameric enzyme composed of two types of subunits: the catalytic (CK2α) and the regulatory (CK2β). The CK2β subunits enhance the stability, activity and specificity of the holoenzyme, but they can also perform functions independently of the CK2 tetramer. CK2β regulatory subunits in plants differ from their animal or yeast counterparts, since they present an additional specific N-terminal extension of about 90 aminoacids that shares no homology with any previously characterized functional domain. Sequence analysis of the N-terminal domain of land plant CK2β subunit sequences reveals its arrangement through short, conserved motifs, some of them including CK2 autophosphorylation sites. By using maize CK2β1 and a deleted version (ΔNCK2β1) lacking the N-terminal domain, we have demonstrated that CK2β1 is autophosphorylated within the N-terminal domain. Moreover, the holoenzyme composed with CK2α1/ΔNCK2β1 is able to phosphorylate different substrates more efficiently than CK2α1/CK2β1 or CK2α alone. Transient overexpression of CK2β1 and ΔNCK2β1 fused to GFP in different plant systems show that the presence of N-terminal domain enhances aggregation in nuclear speckles and stabilizes the protein against proteasome degradation. Finally, bimolecular fluorescence complementation (BiFC) assays show the nuclear and cytoplasmic location of the plant CK2 holoenzyme, in contrast to the individual CK2α/β subunits mainly observed in the nucleus. All together, our results support the hypothesis that the plant-specific N-terminal domain of CK2β subunits is involved in the down-regulation of the CK2 holoenzyme activity and in the stabilization of CK2β1 protein. In summary, the whole amount of data shown in this work suggests that this domain was acquired by plants for regulatory purposes
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