149 research outputs found

    Core Concepts for Future Cataloguers

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    The Linked Open Bibliographic Data project at UCL is developing an Open Educational Resource to enable the teaching and learning of BIBFRAME, the new RDF-based framework designed to take over from MARC. A new bibliographic dataset based on BIBFRAME, which will be linked with other online datasets, has been created for that purpose. The learning resource, which will be publicly available under an open licence on completion, will allow learners to access, explore, query and update the dataset through an intuitive interface built on top of the SPARQL query language. This masterclass shares experience in converting MARC records to BIBFRAME using the Library of Congress’s conversion tools [http://bibframe.org/tools/]. More fundamentally, it provides examples of how our model for Cataloguing is changing from linking record:record to field:field. Using publication data from library academics, we’ll look at what’s new in BIBFRAME and why this matters. Finally, we’ll discuss the extent to which those responsible for inputting data may (or may not) need to get to grips with the new data structure and ways that the enthusiastic can keep up

    Graduate studies on optoelectronics in Argentina: an experience

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    The number of graduate programs in Optoelectronics in Argentina is scarce. The current Optics and Photonics Education Directory lists only three programs. One of them was launched in 2001 in the Facultad de Ingeniería (College of Engineering), Universidad de Buenos Aires (UBA). This was the first graduate program in the field, leading to a Master Degree in Optoelectronics. This decision arose from the demand of telecommunications industries and several estate- or private-funded research institutions working with us in the fields of lasers, optics, remote sensing, etc. A great bonus was the steady work, during several decades, of research groups in the College on the development of different type of lasers and optical non destructive tests and their engineering applications. As happened in many engineering graduate programs in Argentina at that time, few non full-time students could finish their studies, which called for 800 hours of traditional lecture-recitation classes, and the Master Thesis. In recent years Argentine Education authorities downsized the Master programs to 700 hours of blended learning and we redesigned the Graduate Optoelectronic Engineering Program to meet the challenge, dividing it in two successive one year programs, the first aimed at a professional training for almost immediate insertion in the labor market (called Especialización en Ingeniería Optoelectrónica), and the second (called Maestría en Ingeniería Optoelectrónica y Fotónica) aimed at a more academic and research target to comply with the UBA standards for Master degrees. The present work is a presentation of the new program design, which has begun in the current year. © (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.Fil: Fernández, Juan Carlos. Universidad de Buenos Aires. Facultad de Ingeniería; ArgentinaFil: Garea, María T.. Universidad de Buenos Aires. Facultad de Ingeniería; ArgentinaFil: Isaurralde, Silvia. Universidad de Buenos Aires. Facultad de Ingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Perez, Liliana Ines. Universidad de Buenos Aires. Facultad de Ingeniería; ArgentinaFil: Raffo, Carlos A.. Universidad de Buenos Aires. Facultad de Ingeniería; Argentin

    In silico evaluation of ultrafiltration and nanofiltration membrane cascades for continuous fractionation of protein hydrolysate from tuna processing byproduct

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    The present work proposes the design of cascades that integrate ultrafiltration (UF) and nanofiltration (NF) membranes to separate the different protein fractions from the protein hydrolysate obtained after hydrolysis of tuna byproducts. Experimental data (permeate flux and rejection of protein fractions under different applied pressures) previously obtained and published by this research group were fitted to empirical models, which were the basis for a process simulation model. High recovery rates (0.9) in the UF stages implied high process yields by reduced desired fraction losses, while similar recovery rates in the NF stages were required for high product purity. However, the applied pressures were not so influential over the performance of the system. Optimization problems were solved to identify the optimal design and operation conditions to maximize the product purity or the process yield. Maximal purity of the preferred 1-4 kDa fraction (49.3% from 19.0% in feed stream) obtained by the configuration with 3 UF stages and another 3 NF stages implied 2 and 5 bar pressures applied in the UF and NF stages, respectively, while 0.9 was the optimal recovery rate value for all the stages. These maximal purity conditions resulted in 62.6% process yield, defined as the percentage of the 1-4 kDa fraction in the feed stream recovered in the product stream. In addition, multiobjective optimization of the process was also carried out to obtain the Pareto graphs that represent the counterbalance between maximal yields and purities

    Work in Progress: the Linked Open Bibliographic Data Project

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    Reports on the first stage of a project to create an Open Educational Resource for the teaching of new cataloguing format BIBFRAME. Collaborative creation of knowledge with students is a key aspect of the project, and this is discussed in the context of UCL's Connected Curriculum

    Histone deacetylases as new therapy targets for platinum-resistant epithelial ovarian cancer

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    Introduction: In developed countries, ovarian cancer is the fourth most common cancer in women. Due to the nonspecific symptomatology associated with the disease many patients with ovarian cancer are diagnosed late, which leads to significantly poorer prognosis. Apart from surgery and radiotherapy, a substantial number of ovarian cancer patients will undergo chemotherapy and platinum based agents are the mainstream first-line therapy for this disease. Despite the initial efficacy of these therapies, many women relapse; therefore, strategies for second-line therapies are required. Regulation of DNA transcription is crucial for tumour progression, metastasis and chemoresistance which offers potential for novel drug targets. Methods: We have reviewed the existing literature on the role of histone deacetylases, nuclear enzymes regulating gene transcription. Results and conclusion: Analysis of available data suggests that a signifant proportion of drug resistance stems from abberant gene expression, therefore HDAC inhibitors are amongst the most promising therapeutic targets for cancer treatment. Together with genetic testing, they may have a potential to serve as base for patient-adapted therapies

    Histone deacetylase inhibition results in a common metabolic profile associated with HT29 differentiation

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    Cell differentiation is an orderly process that begins with modifications in gene expression. This process is regulated by the acetylation state of histones. Removal of the acetyl groups of histones by specific enzymes (histone deacetylases, HDAC) usually downregulates expression of genes that can cause cells to differentiate, and pharmacological inhibitors of these enzymes have been shown to induce differentiation in several colon cancer cell lines. Butyrate at high (mM) concentration is both a precursor for acetyl-CoA and a known HDAC inhibitor that induces cell differentiation in colon cells. The dual role of butyrate raises the question whether its effects on HT29 cell differentiation are due to butyrate metabolism or to its HDAC inhibitor activity. To distinguish between these two possibilities, we used a tracer-based metabolomics approach to compare the metabolic changes induced by two different types of HDAC inhibitors (butyrate and the non-metabolic agent trichostatin A) and those induced by other acetyl-CoA precursors that do not inhibit HDAC (caprylic and capric acids). [1,2-13C2]-d-glucose was used as a tracer and its redistribution among metabolic intermediates was measured to estimate the contribution of glycolysis, the pentose phosphate pathway and the Krebs cycle to the metabolic profile of HT29 cells under the different treatments. The results demonstrate that both HDAC inhibitors (trichostatin A and butyrate) induce a common metabolic profile that is associated with histone deacetylase inhibition and differentiation of HT29 cells whereas the metabolic effects of acetyl-CoA precursors are different from those of butyrate. The experimental findings support the concept of crosstalk between metabolic and cell signalling events, and provide an experimental approach for the rational design of new combined therapies that exploit the potential synergism between metabolic adaptation and cell differentiation processes through modification of HDAC activity

    Qualitative and quantitative characterization of a coal power plant waste by TG/DSC/MS, XRF and XRD

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    SO2 removal from coal-fired power plant flue gases can be done by dry, semi-dry or wet desulphurization processes, using limestone or lime-containing products as sorbents. In a Brazilian coal power plant, there is a dry desulphurization unit to capture SO2 with hydrated lime from the combustion gases. A part of the flying ashes produced is mixed with the bottom coal ashes and the spent sulphated product generated after SO2 capture. This residual solid blend is then buried in a non-productive area, from which coal was already extracted and is studied in this work. According to the authors’ experience in the development and characterization of adsorbents for low temperature dry desulphurization processes and in thermogravimetric analysis, this paper shows and discusses a method which was developed to characterize qualitatively and quantitatively the chemical and mineral composition of this waste by using thermogravimetry coupled with mass spectrometry, X-ray fluorescence and X-ray diffraction, to preview new potential industrial applications for this waste.We are thankful to the University of Cantabria for the financial support under the Project: 51.VP61.64005, to the Brazilian Research Council, under the project CNPq no. 407005/2013-7, and to the Brazilian Education Council CAPES

    Interlinkages: Governance for Sustainability Chapter 8

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    The Earth functions as a system: atmosphere, land, water, biodiversity and human society are all linked in a complex web of interactions and feedbacks. Environment and development challenges are interlinked across thematic, institutional and geographic boundaries through social and environmental processes. The state of knowledge on these interlinkages and implications for human well-being are highlighted in the following messages: Environmental change and development challenges are caused by the same sets of drivers. They include population change, economic processes, scientific and technological innovations, distribution patterns, and cultural, social, political and institutional processes

    Fine Mapping of Posttranslational Modifications of the Linker Histone H1 from Drosophila melanogaster

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    The linker histone H1 binds to the DNA in between adjacent nucleosomes and contributes to chromatin organization and transcriptional control. It is known that H1 carries diverse posttranslational modifications (PTMs), including phosphorylation, lysine methylation and ADP-ribosylation. Their biological functions, however, remain largely unclear. This is in part due to the fact that most of the studies have been performed in organisms that have several H1 variants, which complicates the analyses. We have chosen Drosophila melanogaster, a model organism, which has a single H1 variant, to approach the study of the role of H1 PTMs during embryonic development. Mass spectrometry mapping of the entire sequence of the protein showed phosphorylation only in the ten N-terminal amino acids, mostly at S10. For the first time, changes in the PTMs of a linker H1 during the development of a multicellular organism are reported. The abundance of H1 monophosphorylated at S10 decreases as the embryos age, which suggests that this PTM is related to cell cycle progression and/or cell differentiation. Additionally, we have found a polymorphism in the protein sequence that can be mistaken with lysine methylation if the analysis is not rigorous

    Epigenetics provides a new generation of oncogenes and tumour-suppressor genes

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    Cancer is nowadays recognised as a genetic and epigenetic disease. Much effort has been devoted in the last 30 years to the elucidation of the ‘classical' oncogenes and tumour-suppressor genes involved in malignant cell transformation. However, since the acceptance that major disruption of DNA methylation, histone modification and chromatin compartments are a common hallmark of human cancer, epigenetics has come to the fore in cancer research. One piece is still missing from the story: are the epigenetic genes themselves driving forces on the road to tumorigenesis? We are in the early stages of finding the answer, and the data are beginning to appear: knockout mice defective in DNA methyltransferases, methyl-CpG-binding proteins and histone methyltransferases strongly affect the risk of cancer onset; somatic mutations, homozygous deletions and methylation-associated silencing of histone acetyltransferases, histone methyltransferases and chromatin remodelling factors are being found in human tumours; and the first cancer-prone families arising from germline mutations in epigenetic genes, such as hSNF5/INI1, have been described. Even more importantly, all these ‘new' oncogenes and tumour-suppressor genes provide novel molecular targets for designed therapies, and the first DNA-demethylating agents and inhibitors of histone deacetylases are reaching the bedside of patients with haematological malignancies
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