2,050 research outputs found

    Evaluation of Heat Transfer and Thermal Stability of Supercritical JP-7 Fuel

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    A series of electrically heated tube experiments was conducted to investigate the potential of JP-7 as a coolant under conditions relevant to a Mach 8 propulsion system. The heat transfer capabilities, carbon deposition, and material compatibility of JP-7 at surface temperatures up to 1700 F (927 C) were tested in 0.125 in. diameter tubes of 304 SS, Inconel 617, Haynes 188, Haynes 230, and 50150 Moly-Rhenium. The heat transfer to the coolant was modeled well by a Dittus-Boelter correlation at lower heat fluxes. At higher heat fluxes, audible instabilities were observed and corresponded to a significant enhancement in the coolant heat transfer. The carbon deposition rates in these tests were comparable to those in previous experiments at lower heat fluxes and much longer residence times. This result suggests that alternative paths of the deposition mechanism may be enhanced under high heat flux test conditions. Microscopic investigation of the post test tubes indicated that there was a significant layer of ordered carbon deposits that had not been seen in the tests at lower heat flux

    Legal Terms of Use and Public Genealogy Websites

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    Public genealogy websites, to which individuals upload family history, genealogy, and sometimes individual genetic data, have been used in an increasing number of public health, epidemiological, and genetic studies. Yet there is little awareness among researchers of the legal rules that govern the use of these online resources. We analyzed the online Terms of Use (TOU) applicable to 17 popular genealogy websites and found that none of them expressly permit scientific research, while at least 13 contain restrictions that may limit or prohibit scientific research using data obtained from those sites. In order to ensure that researchers who use genealogy and other data from these sites for public health and other scientific research purposes do not inadvertently breach applicable TOUs, we recommend that genealogy website operators consider revising their TOUs to permit this activity

    Perceptions of Immigration Among Nonmetropolitan Nebraskans: Nebraska Rural Poll Research Report 19-2

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    The percent of Nebraska’s population that is foreign born has steadily increased during the past decade. In fact, its growth in foreign born population since 2010 ranks in the top 10 among all states. Given these changes, are rural Nebraskans aware of recent immigrants in their community? How do they perceive immigrants and their impacts on rural Nebraska? How do they view various immigration policies? This paper provides a detailed analysis of these questions. This report details 1,776 responses to the 2019 Nebraska Rural Poll, the 24th annual effort to understand rural Nebraskans’ perceptions. Respondents were asked a series of questions about immigration. Trends for some of the questions are examined by comparing data from the 2006 Rural Poll. In addition, comparisons are made among different respondent subgroups, that is, comparisons by age, occupation, region, etc. Based on these analyses, some key findings emerged

    Community Involvement and Leadership in Nonmetropolitan Nebraska: Rural Poll Research Report 19-1

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    Community leadership and involvement are important parts of community development. Rural communities rely on volunteers for many community development activities as well as local leadership positions. In smaller communities in particular, community members often take on multiple roles. Given these challenges, how involved are rural Nebraskans in community and political activities? How do they feel about the leadership in their community? How often do they have social interactions with others during a typical month? This paper provides a detailed analysis of these questions. This report details 1,776 responses to the 2019 Nebraska Rural Poll, the 24th annual effort to understand rural Nebraskans’ perceptions. Respondents were asked a series of questions about their community involvement and community leadership. Trends for some of the questions are examined by comparing data from the 2015 Rural Poll. In addition, comparisons are made among different respondent subgroups, that is, comparisons by age, occupation, region, etc. Based on these analyses, some key findings emerged

    Exploring the Nebraska Rural Poll, 2020

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    The Nebraska Rural Poll was initiated in 1996. Over the past 24 years, input has been gathered from over 64,000 nonmetropolitan Nebraskans. 102 separate reports have been produced covering 31 unique topics Trend Analysis Subgroup Comparisons Some questions have been repeated at various intervals of tim

    Trends in Well-Being in Nonmetropolitan Nebraska: Nebraska Rural Poll Research Report 19-3

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    Nebraska’s economy remained strong in the beginning of 2019. However, the continued weakness of the agriculture sector had the possibility of hampering the state’s economic growth. In addition, the March flooding had the potential for negative economic effects. Given these challenges, how do rural Nebraskans feel about their community? Are they satisfied with the services provided by their community? How do rural Nebraskans believe they are doing and how do they view their future? How satisfied are they with various items that influence their well-being? Have these views changed over the past 24 years? This paper provides a detailed analysis of these questions. This report details 1,776 responses to the 2019 Nebraska Rural Poll, the 24th annual effort to understand rural Nebraskans’ perceptions. Respondents were asked a series of questions about their community and well-being. Trends for some of the questions are examined by comparing data from the 23 previous polls to this year’s results. In addition, comparisons are made among different respondent subgroups, that is, comparisons by age, occupation, region, etc. Based on these analyses, some key findings emerged

    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

    Widespread winners and narrow-ranged losers: land use homogenizes biodiversity in local assemblages worldwide

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    Human use of the land (for agriculture and settlements) has a substantial negative effect on biodiversity globally. However, not all species are adversely affected by land use, and indeed, some benefit from the creation of novel habitat. Geographically rare species may be more negatively affected by land use than widespread species, but data limitations have so far prevented global multi-clade assessments of land-use effects on narrow-ranged and widespread species. We analyse a large, global database to show consistent differences in assemblage composition. Compared with natural habitat, assemblages in disturbed habitats have more widespread species on average, especially in urban areas and the tropics. All else being equal, this result means that human land use is homogenizing assemblage composition across space. Disturbed habitats show both reduced abundances of narrow-ranged species and increased abundances of widespread species. Our results are very important for biodiversity conservation because narrow-ranged species are typically at higher risk of extinction than widespread species. Furthermore, the shift to more widespread species may also affect ecosystem functioning by reducing both the contribution of rare species and the diversity of species’ responses to environmental changes among local assemblages

    Alterations of immune response of non-small lung cancer with azacytidine

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    Innovative therapies are needed for advanced Non-Small Cell Lung Cancer (NSCLC). We have undertaken a genomics based, hypothesis driving, approach to query an emerging potential that epigenetic therapy may sensitize to immune checkpoint therapy targeting PD-L1/PD-1 interaction. NSCLC cell lines were treated with the DNA hypomethylating agent azacytidine (AZA - Vidaza) and genes and pathways altered were mapped by genome-wide expression and DNA methylation analyses. AZA-induced pathways were analyzed in The Cancer Genome Atlas (TCGA) project by mapping the derived gene signatures in hundreds of lung adeno (LUAD) and squamous cell carcinoma (LUSC) samples. AZA up-regulates genes and pathways related to both innate and adaptive immunity and genes related to immune evasion in a several NSCLC lines. DNA hypermethylation and low expression of IRF7, an interferon transcription factor, tracks with this signature particularly in LUSC. In concert with these events, AZA up-regulates PD-L1 transcripts and protein, a key ligand-mediator of immune tolerance. Analysis of TCGA samples demonstrates that a significant proportion of primary NSCLC have low expression of AZA-induced immune genes, including PD-L1. We hypothesize that epigenetic therapy combined with blockade of immune checkpoints - in particular the PD-1/PD-L1 pathway - may augment response of NSCLC by shifting the balance between immune activation and immune inhibition, particularly in a subset of NSCLC with low expression of these pathways. Our studies define a biomarker strategy for response in a recently initiated trial to examine the potential of epigenetic therapy to sensitize patients with NSCLC to PD-1 immune checkpoint blockade
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