120 research outputs found
chroGPS, a global chromatin positioning system for the functional analysis and visualization of the epigenome
Get PDFDevelopment of tools to jointly visualize the genome and the epigenome remains a challenge. chroGPS is a computational approach that addresses this question. chroGPS uses multidimensional scaling techniques to represent similarity between epigenetic factors, or between genetic elements on the basis of their epigenetic state, in 2D/3D reference maps. We emphasize biological interpretability, statistical robustness, integration of genetic and epigenetic data from heterogeneous sources, and computational feasibility. Although chroGPS is a general methodology to create reference maps and study the epigenetic state of any class of genetic element or genomic region, we focus on two specific kinds of maps: chroGPSfactors, which visualizes functional similarities between epigenetic factors, and chroGPSgenes, which describes the epigenetic state of genes and integrates gene expression and other functional data. We use data from the modENCODE project on the genomic distribution of a large collection of epigenetic factors in Drosophila, a model system extensively used to study genome organization and function. Our results show that the maps allow straightforward visualization of relationships between factors and elements, capturing relevant information about their functional properties that helps to interpret epigenetic information in a functional context and derive testable hypotheses
Emancipatiebeleid tussen geleefde droom en onvoltooide daad
No full textThe author also comments on the interview with D’Ancona and Bussemaker. He enumerates the similarities between them: their enthusiasm and their struggles to ‘frame’ the problem of emancipation in a correct way. Both make a distinction between the substance and the process of emancipation policy, making it all the more surprising, he argues, that so little has been done in the past years to establish new institutions and to generate continuity. Lack of consensus between political parties about the way forward has generated an incremental way of policy making, resulting in a patchwork of regulations, which are often very confusing to the public. Schippers, furthermore, draws attention to the differences between the interviewees in view of the work/care problem ‐ sharing between partners or stimulating the commercialisation of care work
Exceptional graphs with smallest eigenvalue -2 and related problems
No full textThis paper summarizes the known results on graphs with smallest eigenvalue around -2, and completes the theory by proving a number of new results, giving comprehensive tables of the finitely many exceptions, and posing some new problems. Then the theory is applied to characterize a class of distance-regular graphs of large diameter by their intersection array
Emancipatiebeleid tussen geleefde droom en onvoltooide daad
No full textThe author also comments on the interview with D’Ancona and Bussemaker. He enumerates the similarities between them: their enthusiasm and their struggles to ‘frame’ the problem of emancipation in a correct way. Both make a distinction between the substance and the process of emancipation policy, making it all the more surprising, he argues, that so little has been done in the past years to establish new institutions and to generate continuity. Lack of consensus between political parties about the way forward has generated an incremental way of policy making, resulting in a patchwork of regulations, which are often very confusing to the public. Schippers, furthermore, draws attention to the differences between the interviewees in view of the work/care problem ‐ sharing between partners or stimulating the commercialisation of care work
A New Type of Tackmeter
No full textAbstract
A new type of tackmeter is described. Strips of the material to be tested are used for tack measurements. The instrument compresses and separates the strips under conditions which can be arbitrarily selected. The tackmeter is of rugged design for simple handling and ease of operation. The test results are recorded on a chart, enabling easy reading of the results. A description of the tackmeter and the testing procedure is given. The accuracy of the measurement is briefly discussed. Among the factors affecting the measurement are the thickness of the sample, compression conditions and aging of the surface. Some test results obtained with factory-made plies and compounds with varying black loadings are given.</jats:p
Sonolysis of Per- And Poly Fluoroalkyl Substances (PFAS): A meta-analysis
No full text•PFAS sonolysis parameter meta-analysis.•Optimum pH, frequency and temperature derived for PFOX sonolysis.•Degradation occurs via adsorption bubble and headgroup removal.•PFOA/S sonolysis produces only CO2, H2, H+, and F-•Oxidative agents alter degradation mechanism.Human ingestion of Per- and Polyfluoroalkyl Substances (PFAS) from contaminated food and water is linked to the development of several cancers, birth defects and other illnesses. The complete mineralisation of aqueous PFAS by ultrasound (sonolysis) into harmless inorganics has been demonstrated in many studies. However, the range and interconnected nature of reaction parameters (frequency, power, temperature etc.), and variety of reaction metrics used, limits understanding of degradation mechanisms and parametric trends. This work summarises the state-of-the-art for PFAS sonolysis, considering reaction mechanisms, kinetics, intermediates, products, rate limiting steps, reactant and product measurement techniques, and effects of co-contaminants. A meta-analysis showed that mid-high frequency (100-1,000 kHz) sonolysis mechanisms are similar, regardless of reaction conditions, while the low frequency (20-100 kHz) mechanisms are specific to oxidative species added, less well understood, and generally slower than mid-high frequency mechanisms. Arguments suggest that PFAS degradation occurs via adsorption (not absorption) at the bubble interface, followed by headgroup cleavage. Further mechanistic steps toward mineralisation remain to be proven. For the first time, complete stoichiometric reaction equations are derived for PFOA and PFOS sonolysis, which add H2 as a reaction product and consider CO an intermediate. Fluorinated intermediate products are derived for common, and more novel PFAS, and a naming system proposed for novel perfluoroether carboxylates. The meta-analysis also revealed the transition between pseudo first and zero order PFOA/S kinetics commonly occurs at 15-40 µM. Optimum values of; ultrasonic frequency (300 – 500 kHz), concentration (>15-40 μM), temperature (≈20°C), and pH range (3.2 – 4) for rapid PFOX degradation are derived by evaluation of prior works, while optimum values for dilution of PFAS containing firefighting foams and applied power require further work. Rate limiting steps are debated and F- is shown to be rate enhancing, while SO42- and CO2 by products are theorised to be rate limiting. Sonolysis was compared to other PFAS destructive technologies and shown to be the only treatment which fully mineralises PFAS, degrades different PFAS in order of decreasing hydrophobicity, is parametrically well studied and has low-moderate energy requirements (several kWh g-1 PFAS). It is concluded that sonolysis of PFAS in environmental samples would be well incorporated within a treatment train for improved efficiency
Collaborative Design of a Business Jet Family Using the AGILE 4.0 MBSE Environment
Get PDFThis paper presents the collaborative model-based design of a business jet family. In family design, a trade-off is made between aircraft performance, reducing fuel burn, and commonality, reducing manufacturing costs. The family is designed using Model-Based Systems Engineering (MBSE) methods developed in the AGILE 4.0 project. The EC-funded AGILE 4.0 project extends the scope of the preliminary aircraft design process to also include systems engineering phases and new design domains like manufacturing, maintenance, and certification. Stakeholders, needs, requirements, and architecture models of the business jet family are presented. Then, the collaborative Multidisciplinary Design Analysis and Optimization (MDAO) capabilities are used to integrate various aircraft design disciplines, including overall aircraft design, onboard systems design, wing structural sizing, tailplane sizing, mission analysis, and cost estimation. Decisions regarding the degree of commonality are implemented by optionally fixing the design of a shared component when sizing an aircraft
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