Attitudes to risk management in space projects

This paper aims to examine the personalities of people currently working in the delivery of space projects. The study employed an online survey which included twenty-fi ve Likert scale questions based on risk decision scenarios and personality questions. A total of 50 responses were collected from people with experience in the delivery of space projects. The results of this study suggest that people who have experience in space project delivery have a high level and long term view, are fair and pleasing, extroverted and logical decision takers, prefer to freeze scope and respect deadlines and to make team consensus decisions. The results also show that the respondents are prepared to make risky decisions depending on the situation and case

Critical success factors for the construction industry

This study aims to identify the critical success factors for projects in the construction industry. A list of factors were identified from the existing literature and grouped into categories. The authors added project risk management and requirements management to the list of categories to test the hypothesis that these should also be considered as critical success factors in the construction industry. The study identified 58 success factors classified into 11 groups, which were tested using an elicitation technique. Forty-nine responses were collected from project managers, who had an average or 15 years of project management experience and had participated in more than 15 projects. Once the data was collected, the authors adopted the use of the relative importance index to rank the categories. From the results, the top five most important are (1) Project Organization, (2) Project Manager Competence, (3) Project Risk Management, (4) Project Team Competence and (5) Requirements Management. This lead to the conclusion that both project risk management and requirements management should be considered as critical success factors. Further analysis of the data highlights the importance of scope management and soft skills in Requirements Management and Project Risk Management respectively

Critical success factors for projects in the space sector

The paper identifies the critical success factors for space projects. A list of factors was synthesized from existing literature, and risk management and requirements management were added as the authors felt that these had particular significance in the space sector. The paper identifies 58 success factors that were then classified into 11 groups. These factors were then tested within the space industry using an elicitation technique, the data obtained was then analysed to test a number of research hypotheses. It is concluded that both requirements management and project risk management should be considered as critical success factors. The paper also uses the relative importance index approach to rank the classified categories based on their perceived importance

Plant-RRBS, a bisulfite and next-generation sequencing-based methylome profiling method enriching for coverage of cytosine positions

Background: Cytosine methylation in plant genomes is important for the regulation of gene transcription and transposon activity. Genome-wide methylomes are studied upon mutation of the DNA methyltransferases, adaptation to environmental stresses or during development. However, from basic biology to breeding programs, there is a need to monitor multiple samples to determine transgenerational methylation inheritance or differential cytosine methylation. Methylome data obtained by sodium hydrogen sulfite (bisulfite)-conversion and next-generation sequencing (NGS) provide genome- wide information on cytosine methylation. However, a profiling method that detects cytosine methylation state dispersed over the genome would allow high-throughput analysis of multiple plant samples with distinct epigenetic signatures. We use specific restriction endonucleases to enrich for cytosine coverage in a bisulfite and NGS-based profiling method, which was compared to whole-genome bisulfite sequencing of the same plant material. Methods: We established an effective methylome profiling method in plants, termed plant-reduced representation bisulfite sequencing (plant-RRBS), using optimized double restriction endonuclease digestion, fragment end repair, adapter ligation, followed by bisulfite conversion, PCR amplification and NGS. We report a performant laboratory protocol and a straightforward bioinformatics data analysis pipeline for plant-RRBS, applicable for any reference-sequenced plant species. Results: As a proof of concept, methylome profiling was performed using an Oryza sativa ssp. indica pure breeding line and a derived epigenetically altered line (epiline). Plant-RRBS detects methylation levels at tens of millions of cytosine positions deduced from bisulfite conversion in multiple samples. To evaluate the method, the coverage of cytosine positions, the intra-line similarity and the differential cytosine methylation levels between the pure breeding line and the epiline were determined. Plant-RRBS reproducibly covers commonly up to one fourth of the cytosine positions in the rice genome when using MspI-DpnII within a group of five biological replicates of a line. The method predominantly detects cytosine methylation in putative promoter regions and not-annotated regions in rice. Conclusions: Plant-RRBS offers high-throughput and broad, genome- dispersed methylation detection by effective read number generation obtained from reproducibly covered genome fractions using optimized endonuclease combinations, facilitating comparative analyses of multi-sample studies for cytosine methylation and transgenerational stability in experimental material and plant breeding populations

Comparison of sequencing-based methods to profile DNA methylation and identification of monoallelic epigenetic modifications.

Analysis of DNA methylation patterns relies increasingly on sequencing-based profiling methods. The four most frequently used sequencing-based technologies are the bisulfite-based methods MethylC-seq and reduced representation bisulfite sequencing (RRBS), and the enrichment-based techniques methylated DNA immunoprecipitation sequencing (MeDIP-seq) and methylated DNA binding domain sequencing (MBD-seq). We applied all four methods to biological replicates of human embryonic stem cells to assess their genome-wide CpG coverage, resolution, cost, concordance and the influence of CpG density and genomic context. The methylation levels assessed by the two bisulfite methods were concordant (their difference did not exceed a given threshold) for 82% for CpGs and 99% of the non-CpG cytosines. Using binary methylation calls, the two enrichment methods were 99% concordant and regions assessed by all four methods were 97% concordant. We combined MeDIP-seq with methylation-sensitive restriction enzyme (MRE-seq) sequencing for comprehensive methylome coverage at lower cost. This, along with RNA-seq and ChIP-seq of the ES cells enabled us to detect regions with allele-specific epigenetic states, identifying most known imprinted regions and new loci with monoallelic epigenetic marks and monoallelic expression

Genome-scale DNA methylation mapping of clinical samples at single-nucleotide resolution

August 1, 2010Bisulfite sequencing measures absolute levels of DNA methylation at single-nucleotide resolution, providing a robust platform for molecular diagnostics. Here, we optimize bisulfite sequencing for genome-scale analysis of clinical samples. Specifically, we outline how restriction digestion targets bisulfite sequencing to hotspots of epigenetic regulation; we show that 30ng of DNA are sufficient for genome-scale analysis; we demonstrate that our protocol works well on formalinfixed, paraffin-embedded (FFPE) samples; and we describe a statistical method for assessing significance of altered DNA methylation patterns.National Institutes of Health (U.S.) (Grant R01HG004401)National Institutes of Health (U.S.) (Grant U54HG03067)National Institutes of Health (U.S.) (Grant U01ES017155

Long-term outcome of displaced radial neck fractures in adulthood: 16–21 year follow-up of 5 patients treated with radial head excision

Background There have been no reports on the long-term outcome of radial neck Mason type IIIb fractures in adults

Quantum confinement and photoresponsivity ofβ-In2Se3 nanosheets grown by physical vapour transport

We demonstrate that β-In2Se3 layers with thickness ranging from 2.8 to 100 nm can be grown on SiO2/Si, mica and graphite using a physical vapour transport method. The β-In2Se3 layers are chemically stable at room temperature and exhibit a blue-shift of the photoluminescence emission when the layer thickness is reduced, due to strong quantum confinement of carriers by the physical boundaries of the material. The layers are characterised using Raman spectroscopy and x-ray diffraction from which we confirm lattice constants c = 28.31 ± 0.05 Å and a = 3.99 ± 0.02 Å. In addition, these layers show high photoresponsivity of up to ~2 × 103 A W−1 at λ = 633 nm, with rise and decay times of τ r = 0.6 ms and τ d = 2.5 ms, respectively, confirming the potential of the as-grown layers for high sensitivity photodetectors

Widespread recovery of methylation at gametic imprints in hypomethylated mouse stem cells following rescue with DNMT3A2

BACKGROUND: Imprinted loci are paradigms of epigenetic regulation and are associated with a number of genetic disorders in human. A key characteristic of imprints is the presence of a gametic differentially methylated region (gDMR). Previous studies have indicated that DNA methylation lost from gDMRs could not be restored by DNMT1, or the de novo enzymes DNMT3A or 3B in stem cells, indicating that imprinted regions must instead undergo passage through the germline for reprogramming. However, previous studies were non-quantitative, were unclear on the requirement for DNMT3A/B and showed some inconsistencies. In addition, new putative gDMR has recently been described, along with an improved delineation of the existing gDMR locations. We therefore aimed to re-examine the dependence of methylation at gDMRs on the activities of the methyltransferases in mouse embryonic stem cells (ESCs). RESULTS: We examined the most complete current set of imprinted gDMRs that could be assessed using quantitative pyrosequencing assays in two types of ESCs: those lacking DNMT1 (1KO) and cells lacking a combination of DNMT3A and DNMT3B (3abKO). We further verified results using clonal analysis and combined bisulfite and restriction analysis. Our results showed that loss of methylation was approximately equivalent in both cell types. 1KO cells rescued with a cDNA-expressing DNMT1 could not restore methylation at the imprinted gDMRs, confirming some previous observations. However, nearly all gDMRs were remethylated in 3abKO cells rescued with a DNMT3A2 expression construct (3abKO + 3a2). Transcriptional activity at the H19/Igf2 locus also tracked with the methylation pattern, confirming functional reprogramming in the latter. CONCLUSIONS: These results suggested (1) a vital role for DNMT3A/B in methylation maintenance at imprints, (2) that loss of DNMT1 and DNMT3A/B had equivalent effects, (3) that rescue with DNMT3A2 can restore imprints in these cells. This may provide a useful system in which to explore factors influencing imprint reprogramming. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13072-016-0104-2) contains supplementary material, which is available to authorized users