1,721 research outputs found

    Optimal location of tsunami warning buoys and sea level monitoring stations in the mediterranean sea

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    The present study determines the optimal location of detection components of a tsunami warning system in the Mediterranean region given the existing and planned infrastructure. Specifically, we examine the locations of existing tsunameters DART buoys and coastal sea-level monitoring stations to see if additional buoys and stations will improve the proportion of the coastal population that may receive a warning ensuring a timely response. A spreadsheet model is used to examine this issue. Based on the historical record of tsunamis and assuming international cooperation in tsunami detection, it is demonstrated that the existing network of sea level stations and tsunameters enable around ninety percent of the coastal population of the Mediterranean Sea to receive a 15 minute warning. Improvement in this result can be achieved through investment in additional real-time, coastal, sea level monitoring stations. This work was undertaken as a final year undergraduate research project

    RAB25 expression is epigenetically downregulated in oral and oropharyngeal squamous cell carcinoma with lymph node metastasis

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    Oral and oropharyngeal squamous cell carcinoma (OOSCC) have a low survival rate, mainly due to metastasis to the regional lymph nodes. For optimal treatment of these metastases, a neck dissection is required; however, inaccurate detection methods results in under- and over-treatment. New DNA prognostic methylation biomarkers might improve lymph node metastases detection. To identify epigenetically regulated genes associated with lymph node metastases, genome-wide methylation analysis was performed on 6 OOSCC with (pN+) and 6 OOSCC without (pN0) lymph node metastases and combined with a gene expression signature predictive for pN+ status in OOSCC. Selected genes were validated using an independent OOSCC cohort by immunohistochemistry and pyrosequencing, and on data retrieved from The Cancer Genome Atlas. A two-step statistical selection of differentially methylated sequences revealed 14 genes with increased methylation status and mRNA downregulation in pN+ OOSCC. RAB25, a known tumor suppressor gene, was the highest-ranking gene in the discovery set. In the validation sets, both RAB25 mRNA (P = 0.015) and protein levels (P = 0.012) were lower in pN+ OOSCC. RAB25 mRNA levels were negatively correlated with RAB25 methylation levels (P < 0.001) but RAB25 protein expression was not. Our data revealed that promoter methylation is a mechanism resulting in downregulation of RAB25 expression in pN+ OOSCC and decreased expression is associated with lymph node metastasis. Detection of RAB25 methylation might contribute to lymph node metastasis diagnosis and serve as a potential new therapeutic target in OOSCC

    Online management of text production from pictures:a comparison between fifth graders and undergraduate students

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    This study was designed to enhance our understanding of the online management of writing processes by two groups of writers with a different level of expertise, and to explore the impact of this online management on text quality. To this aim, fifth graders (mean age 10.5 years) and undergraduate students (mean age 22.6 years) were asked to compose a narrative from a visual source of images, while their handwriting activity and eye movements were recorded by means of Eye & Pen software and a digitizing tablet. Results showed that fifth graders and undergraduate students used different strategies to engage in high-level source-based text elaboration processes throughout their writing. The main differences concerned the density of source consultation during prewriting, on the one hand, and during pauses, on the other hand. Relationships between these characteristics of online management and text quality were minimal in fifth graders, while in undergraduate students they were more substantial as in the case of syntactic complexity. These findings suggest that with age, the online management of writing becomes more closely related to text quality. In line with a capacity view of writing, it is also concluded that the online management of writing processes of fifth graders is highly constrained by a lack of fluent text production skills which ultimately affects their text quality

    Immune related endonucleases and GTPases are not associated with tumor response in patients with advanced non-small cell lung cancer treated with checkpoint inhibitors

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    Immune related endonucleases have recently been described as potential therapeutic targets and predictors of response to treatment with immune checkpoint inhibitors (ICI). The aim is to evaluate the association between the expression of 5 biomarkers involved in the immune response (CD73, CD39, VISTA, Arl4d and Cytohesin-3) in parallel with the more common ICI-predictive markers, PD-L1 expression and Tumor Mutation Burden (TMB) with response to ICI therapy in an advanced non-small cell lung cancer (NSCLC) cohort. METHODS: Patients with advanced NSCLC treated with ICI single agent were divided into responders and non-responders according to RECIST v1.1 and duration of response (DOR) criteria. Immunohistochemistry was performed on pretreatment tumor tissue samples for PD-L1, CD73, CD39, VISTA, Arl4d, and Cytohesin-3 expression. TMB was estimated with NEOplus v2 RUO (NEO New Oncology GmbH) hybrid capture next generation sequencing assay. Resistance mutations in STK11/KEAP1 and positive predictive mutations in ARID1A/POLE were also evaluated. RESULTS: Included were 56 patients who were treated with ICI single agent. The median progression-free and overall survival for the whole cohort was 3.0 (95% CI, 2.4-3.6) and 15 (95% CI, 9.7-20.2) months, respectively. The distribution of CD73 in tumor cells and CD39, VISTA, Arl4d and Cytohesin-3 expression in immune cells were not different between responders and non-responders. Also, PD-L1 and TMB were not predictive for response. The frequency of STK11, KEAP1 and ARID1A mutations was low and only observed in the non-responder group. CONCLUSION: Separate and combined expression of 5 biomarkers involved in the immune response (CD73, CD39, VISTA, Arl4d, and Cytohesin-3) was not associated with response in our cohort of advanced NSCLC patients receiving single agent ICI. To confirm our findings the analysis of independent larger cohorts is warranted

    Modeling BCR-ABL and MLL-AF9 leukemia in a human bone marrow-like scaffold based xenograft model

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    While NOD-SCID IL2RÎł(-/-) (NSG) xenograft mice are currently the most frequently used model to study human leukemia in vivo, the absence of a human niche severely hampers faithful recapitulation of the disease. We used NSG mice in which ceramic scaffolds seeded with human mesenchymal stromal cells were implanted to generate a human bone marrow (huBM-sc)-like niche. We observed that, in contrast to the murine bone marrow (mBM) niche, expression of BCR-ABL or MLL-AF9 was sufficient to induce both primary AML and ALL. Stemness was preserved within the human niches as demonstrated by serial transplantation assays. Efficient engraftment of AML MLL-AF9 and blast-crisis CML patient cells was also observed, whereby the immature blast-like phenotype was maintained in the huBM-sc niche, but to a much lesser extent in mBM niches. We compared transcriptomes of leukemias derived from mBM niches versus leukemias from huBM-like scaffold-based niches, which revealed striking differences in expression of genes associated with hypoxia, mitochondria and metabolism. Finally, we utilized the huBM-sc MLL-AF9 B-ALL model to evaluate the efficacy of the I-BET151 inhibitor in vivo. In conclusion, we have established human niche models in which the myeloid and lymphoid features of BCR-ABL(+) and MLL-AF9(+) leukemias can be studied in detail. Accepted article preview online 29 April 2016; Advance online publication 17 May 2016This work was supported by grants from the Dutch Cancer Society (2009-4411; VU2011-5127) and by the EU (ITN EuroCSC). I-BET151 was kindly provided by Nicholas Smithers (GSK R&D, UK)

    Imagining worse than reality: comparing beliefs and intentions between disaster evacuees and survey respondents

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    We often credit disasters, and their coverage in the media, with changes in the public perception of risk associated with low-probability, high-consequence events (LPHCs). With a change in perceptions, we also expect changes in beliefs, preferences, and behaviors. Do beliefs and behaviors change in different ways for people who live through these LPHC critical events, as opposed to people who observe them? This study compares hypothetical hurricanes with actual hurricane effects in a survey quasi-experiment. Findings indicate that hypothetical disasters induce stronger reactions than those experienced in the natural world, as Hurricane Katrina bystanders imagine themselves incurring much higher damages, and being much less likely to return to live in their hurricane-damaged homes, than actual Hurricane Katrina evacuees. Ultimately, respondents considering a hypothetical low-probability, high-consequence event exhibit exaggerated beliefs and opposite decisions of those who actually lived through one of these events. Results underline the importance of examining the differences between public perceptions and experiential reality

    On a new iterative method for solving linear systems and comparison results

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    AbstractIn Ujević [A new iterative method for solving linear systems, Appl. Math. Comput. 179 (2006) 725–730], the author obtained a new iterative method for solving linear systems, which can be considered as a modification of the Gauss–Seidel method. In this paper, we show that this is a special case from a point of view of projection techniques. And a different approach is established, which is both theoretically and numerically proven to be better than (at least the same as) Ujević's. As the presented numerical examples show, in most cases, the convergence rate is more than one and a half that of Ujević
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