614 research outputs found

    BIM Adoption in the Cambodian Construction Industry: Key Drivers and Barriers

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    Critical issues surrounding the promotion and adoption of building information modeling (BIM) for construction projects are largely country-specific due to contextual socio-cultural, economic, and regulatory environments impacting construction operations and outcomes. There is little information on BIM adoption issues specific to the Cambodian construction industry (‘the industry’). This paper aims to narrow existing knowledge by investigating key drivers for, and barriers to the adoption of BIM in the industry. Using descriptive survey method, feedback was received from contractors and architects that were registered with their respective trade and professional associations in the industry. The multi-attribute method and the Statistical Package for the Social Sciences (SPSS)-based Kendall’s coefficient of concordance (W) test were used to analyze the empirical datasets. Results showed that out of the 13 significant drivers identified in the study, the most influential comprised the technology’s ability to remarkably enhance project visualization and schedule performance; this is followed by awareness that the technology is redefining how project information is created and shared among stakeholders and therefore the future of the industry that cannot be ignored. On the other hand, the most constraining barrier to the adoption of the technology, out of 19 significant barriers, related to strong industry resistance to change, especially reluctance to change from 2D drafting to 3D modeling; other highly rated barriers included the high initial cost of the software and the shortage of professionals with BIM skills. Implementation of the study findings could support greater uptake of the technology and the leveraging of its key benefits to improving project success and the growth of the Cambodian construction industry, as well as those of other developing economies that share similar socio-cultural, economic, and regulatory environments

    Ab Initio Structural Energetics of Beta-Si3N4 Surfaces

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    Motivated by recent electron microscopy studies on the Si3N4/rare-earth oxide interfaces, the atomic and electronic structures of bare beta-Si3N4 surfaces are investigated from first principles. The equilibrium shape of a Si3N4 crystal is found to have a hexagonal cross section and a faceted dome-like base in agreement with experimental observations. The large atomic relaxations on the prismatic planes are driven by the tendency of Si to saturate its dangling bonds, which gives rise to resonant-bond configurations or planar sp^2-type bonding. We predict three bare surfaces with lower energies than the open-ring (10-10) surface observed at the interface, which indicate that non-stoichiometry and the presence of the rare-earth oxide play crucial roles in determining the termination of the Si3N4 matrix grains.Comment: 4 Pages, 4 Figures, 1 tabl

    The impact assessment of cage aquaculture on benthic communities along the south eastern Black Sea

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    The present study was conducted to examine the impact of cage aquaculture on benthic communities in coastal areas (depth 25 to 50 m) from fish farming operations located along the southeastern Black Sea (Ordu-Perşembe, Trabzon-Yomra and Rize central). Sampling was conducted seasonally from April 2007 to 2009. Sediment samples were taken using Ekman Grab (box core- 0.04 m2). Temperature, salinity, and water velocity were periodically measured to determine influencing sedimentary organic matter in the sediment, oxygenation, and anoxic conditions. In addition, grain size of sediment, organic carbon content, and distribution of benthic communities were investigated. In order to determine benthic impact of fish farms on the region, Shannon – Wiener diversity index (H’), AMBI (AZTI Marine Biotic Index) and M-AMBI (Multivariate- Marine Biotic Index) indices were used. Results of current study showed that benthic zone ecological quality of stations with number 01, 02, 03, and 04 at Ordu-Perşembefish-farming habitat was found to be very low. In autumn 2008, there were 3 species which belonged to Capitella capitata (844 individuals/m2), Capitella sp. (133 individuals/m2), and Heteromastus filliformis (311 individuals/m2) at OP-01 station. In addition, the impact of Trabzon-Yomra fish-farming activity on benthic communities was low. The degree of exposure for Rize fish-farming area in all seasons was quite low, which was not a significant negative impact

    Age-Specific Signatures of Glioblastoma at the Genomic, Genetic, and Epigenetic Levels

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    Age is a powerful predictor of survival in glioblastoma multiforme (GBM) yet the biological basis for the difference in clinical outcome is mostly unknown. Discovering genes and pathways that would explain age-specific survival difference could generate opportunities for novel therapeutics for GBM. Here we have integrated gene expression, exon expression, microRNA expression, copy number alteration, SNP, whole exome sequence, and DNA methylation data sets of a cohort of GBM patients in The Cancer Genome Atlas (TCGA) project to discover age-specific signatures at the transcriptional, genetic, and epigenetic levels and validated our findings on the REMBRANDT data set. We found major age-specific signatures at all levels including age-specific hypermethylation in polycomb group protein target genes and the upregulation of angiogenesis-related genes in older GBMs. These age-specific differences in GBM, which are independent of molecular subtypes, may in part explain the preferential effects of anti-angiogenic agents in older GBM and pave the way to a better understanding of the unique biology and clinical behavior of older versus younger GBMs

    8q Gain Has No Additional Predictive Value in <i>SF3B1</i><sup>MUT</sup> Uveal Melanoma but Is Predictive for a Worse Prognosis in Patients with <i>BAP1</i><sup>MUT</sup> Uveal Melanoma

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    Purpose: Gain of chromosome 8q has been associated with poor prognosis in uveal melanoma (UM), and an increase in the absolute number of 8q-copies correlated with an even shorter survival. Splicing factor 3b subunit 1 (SF3B1)-mutated (SF3B1 MUT) tumors display structural chromosomal anomalies and frequently show a partial gain of chromosome 8qter. A recent subset of SF3B1 MUT UM with early-onset metastases has been identified, prompting the investigation of the relationship between survival, 8q gain, and SF3B1 MUT UM. Design: Retrospective cohort study. Subjects: Patients diagnosed with UM who underwent enucleation or received a biopsy at the Erasmus MC Cancer Institute or the Rotterdam Eye Hospital, The Netherlands were included. Methods: Fifty-nine patients with SF3B1 MUT tumors and 211 patients with BRCA1 associated protein 1 (BAP1)-mutated (BAP1 MUT) tumors were included in this study. Copy number status and gene expression were assessed using either a single nucleotide polymorphism array, fluorescence in situ hybridization, and karyotyping, or a combination of these techniques. Disease-free survival was determined and a cut-off of 60 months was used to define early-onset metastatic disease. Main Outcome Measures: Disease-free survival. Results: Forty-eight patients with SF3B1 MUT UM (81%) had chromosome 8q gain (3 copies, 78%; 4 copies, 22%). Kaplan–Meier analysis of SF3B1 MUT UM did not indicate a difference in survival in patients with or without gain of 8q (P = 0.99). Furthermore, the number of 8q copies was not associated with survival when comparing early (P = 0.97) versus late (P = 0.23) metastases group. In contrast, the presence of 8q gain (86%) was correlated with a decreased survival in BAP1 MUT UM (P = 0.013). Conclusions: We did not find a correlation between 8q gain and early-onset metastasis in SF3B1 MUT tumors. Gain of 8q has no additional predictive value in SF3B1 MUT tumors. In contrast, 8q gain is predictive of a worse prognosis in patients with BAP1 MUT tumors. Thus, gain of chromosome 8q has additional predictive value for BAP1 MUT tumors, but not for SF3B1 MUT tumors. Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article.</p

    8q Gain Has No Additional Predictive Value in <i>SF3B1</i><sup>MUT</sup> Uveal Melanoma but Is Predictive for a Worse Prognosis in Patients with <i>BAP1</i><sup>MUT</sup> Uveal Melanoma

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    Purpose: Gain of chromosome 8q has been associated with poor prognosis in uveal melanoma (UM), and an increase in the absolute number of 8q-copies correlated with an even shorter survival. Splicing factor 3b subunit 1 (SF3B1)-mutated (SF3B1 MUT) tumors display structural chromosomal anomalies and frequently show a partial gain of chromosome 8qter. A recent subset of SF3B1 MUT UM with early-onset metastases has been identified, prompting the investigation of the relationship between survival, 8q gain, and SF3B1 MUT UM. Design: Retrospective cohort study. Subjects: Patients diagnosed with UM who underwent enucleation or received a biopsy at the Erasmus MC Cancer Institute or the Rotterdam Eye Hospital, The Netherlands were included. Methods: Fifty-nine patients with SF3B1 MUT tumors and 211 patients with BRCA1 associated protein 1 (BAP1)-mutated (BAP1 MUT) tumors were included in this study. Copy number status and gene expression were assessed using either a single nucleotide polymorphism array, fluorescence in situ hybridization, and karyotyping, or a combination of these techniques. Disease-free survival was determined and a cut-off of 60 months was used to define early-onset metastatic disease. Main Outcome Measures: Disease-free survival. Results: Forty-eight patients with SF3B1 MUT UM (81%) had chromosome 8q gain (3 copies, 78%; 4 copies, 22%). Kaplan–Meier analysis of SF3B1 MUT UM did not indicate a difference in survival in patients with or without gain of 8q (P = 0.99). Furthermore, the number of 8q copies was not associated with survival when comparing early (P = 0.97) versus late (P = 0.23) metastases group. In contrast, the presence of 8q gain (86%) was correlated with a decreased survival in BAP1 MUT UM (P = 0.013). Conclusions: We did not find a correlation between 8q gain and early-onset metastasis in SF3B1 MUT tumors. Gain of 8q has no additional predictive value in SF3B1 MUT tumors. In contrast, 8q gain is predictive of a worse prognosis in patients with BAP1 MUT tumors. Thus, gain of chromosome 8q has additional predictive value for BAP1 MUT tumors, but not for SF3B1 MUT tumors. Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article.</p
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