1,961 research outputs found

    Discharge Coefficient Performance of Venturi, Standard Concentric Orifice Plate, V-Cone, and Wedge Flow Meters at Small Reynolds Numbers

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    The relationship between the Reynolds number (Re) and discharge coefficients (C) was investigated through differential pressure flow meters. The focus of the study was directed toward very small Reynolds numbers commonly associated with pipeline transportation of viscous fluids. There is currently a relatively small amount of research that has been performed in this area for the Venturi, standard orifice plate, V-cone, and wedge flow meters. The Computational Fluid Dynamics (CFD) program FLUENT© was used to perform the research, while GAMBIT© was used as the preprocessing tool for the flow meter models created. Heavy oil and water were used separately as the two flowing fluids to obtain a wide range of Reynolds numbers with high precision. Multiple models were used with varying characteristics, such as pipe size and meter geometry, to obtain a better understanding of the C vs. Re relationship. All of the simulated numerical models were compared to physical data to determine the accuracy of the models. The study indicates that the various discharge coefficients decrease rapidly as the Reynolds number approaches 1 for each of the flow meters; however, the Reynolds number range in which the discharge coefficients were constant varied with meter design. The standard orifice plate does not follow the general trend in the discharge coefficient curve that the other flow meters do; instead as the Re decreases, the C value increases to a maximum before sharply dropping off. Several graphs demonstrating the varying relationships and outcomes are presented. The primary focus of this research was to obtain further understanding of discharge coefficient performance versus Reynolds number for differential producing flow meters at very small Reynolds numbers

    Using Balloon Launches as a Precursor to Small Satellite High School Education

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    In August 2017, Destination SPACE (Satellite Program for Aerospace-Centered Education) launched its pilot run of Satellite Week, a camp where high school students learned about satellites and remote sensing through constructing small weather stations and launching them on low altitude balloons in Asheville, North Carolina. The payloads, designed and produced by XinaBox, represented ThinSats, a variation of a Pocket CubeSat small satellite. Students learned about calibration, data acquisition, analysis, and interpretation, as well as how weather balloons are used prior to the launch of a rocket. The students will continue to use these skills as they enter the ThinSat Program, an after school program where they will conduct both low and high altitude balloon launches and ultimately design and build their own ThinSat. Destination SPACE is manifested for launch on the second stage of an Orbital ATK supply rocket to the International Space Station in October 2018. Destination SPACE’s ThinSat Program is developed in collaboration with Twiggs Space Lab and Virginia Commercial Space

    ARC (NSC 188491) has identical activity to Sangivamycin (NSC 65346) including inhibition of both P-TEFb and PKC

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    <p>Abstract</p> <p>Background</p> <p>The nucleoside analog, ARC (NSC 188491) is a recently characterized transcriptional inhibitor that selectively kills cancer cells and has the ability to perturb angiogenesis <it>in vitro</it>. In this study, the mechanism of action of ARC was further investigated by comparing <it>in vitro </it>and <it>in vivo </it>activity with other anti-neoplastic purines.</p> <p>Methods</p> <p>Structure-based homology searches were used to identify those compounds with similarity to ARC. Comparator compounds were then evaluated alongside ARC in the context of viability, cell cycle and apoptosis assays to establish any similarities. Following this, biological overlap was explored in detail using gene-expression analysis and kinase inhibition assays.</p> <p>Results</p> <p>Results demonstrated that sangivamycin, an extensively characterized pro-apoptotic nucleoside isolated from <it>Streptomyces</it>, had identical activity to ARC in terms of 1) cytotoxicity assays, 2) ability to induce a G<sub>2</sub>/M block, 3) inhibitory effects on RNA/DNA/protein synthesis, 4) transcriptomic response to treatment, 5) inhibition of protein kinase C, 6) inhibition of positive transcription elongation factor b (P-TEFb), 7) inhibition of VEGF secretion, and 8) activity within hollow fiber assays. Extending ARC activity to PKC inhibition provides a molecular basis for ARC cancer selectivity and anti-angiogenic effects. Furthermore, functional overlap between ARC and sangivamycin suggests that development of ARC may benefit from a retrospective of previous sangivamycin clinical trials. However, ARC was found to be inactive in several xenograft models, likely a consequence of rapid serum clearance.</p> <p>Conclusion</p> <p>Overall, these data expand on the biological properties of ARC but suggest additional studies are required before it can be considered a clinical trials candidate.</p

    Immunizations with pneumococcal surface protein A and pneumolysin are protective against pneumonia in a murine model of pulmonary infection with Streptococcus pneumoniae

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    Intranasal infection of mice with certain strains of capsular group 19 Streptococcus pneumoniae can result in focal pneumonia in the absence of bacteremia. Using this model of murine pneumonia, we demonstrated that immunization with recombinant forms of either pneumococcal surface protein A (PspA) or PdB (a genetically detoxified derivative of pneumolysin) elicited significant protection against focal pulmonary infection. This may be the first demonstration that a proposed vaccine antigen can protect against pneumococcal pneumonia. The best protection was obtained by immunizing mice with a mixture of PspA and PdB, indicating that the protection elicited by these antigens can complement each other. This result is in agreement with previous studies that used pneumococcal sepsis and nasal colonization models and demonstrate that the best protein vaccines for prevention of infection may be those that include more than one protection-eliciting pneumococcal protein.David E. Briles, Susan K. Hollingshead, James C. Paton, Edwin W. Ades, Lea Novak, Frederik W. van Ginkel, and William H. Benjamin, Jr

    Immunizations with pneumococcal surface protein A and pneumolysin are protective against pneumonia in a murine model of pulmonary infection with Streptococcus pneumoniae

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    Intranasal infection of mice with certain strains of capsular group 19 Streptococcus pneumoniae can result in focal pneumonia in the absence of bacteremia. Using this model of murine pneumonia, we demonstrated that immunization with recombinant forms of either pneumococcal surface protein A (PspA) or PdB (a genetically detoxified derivative of pneumolysin) elicited significant protection against focal pulmonary infection. This may be the first demonstration that a proposed vaccine antigen can protect against pneumococcal pneumonia. The best protection was obtained by immunizing mice with a mixture of PspA and PdB, indicating that the protection elicited by these antigens can complement each other. This result is in agreement with previous studies that used pneumococcal sepsis and nasal colonization models and demonstrate that the best protein vaccines for prevention of infection may be those that include more than one protection-eliciting pneumococcal protein.David E. Briles, Susan K. Hollingshead, James C. Paton, Edwin W. Ades, Lea Novak, Frederik W. van Ginkel, and William H. Benjamin, Jr

    Pneumococcal surface protein A of invasive Streptococcus pneumoniae isolates from Colombian children.

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    Pneumococcal surface protein A (PspA) elicits protection in mice against fatal bacteremia and sepsis caused by genetically diverse pneumococci and protects against carriage and lung infection. We determined the PspA families of invasive isolates of Streptococcus pneumoniae recovered from Colombian children <5 years of age. That 97.5% of Colombian isolates belong to PspA families 1 and 2 supports the hypothesis that a human PspA vaccine covering a few PspA families could be broadly effective

    Is the War on Poverty attacking mental illness?

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    Based on a 2-year study of Office of Economic Opportunity (OEO) programs in a large urban center, this paper examines the potential of Community Action Centers for serving low-income clients with emotional problems. The processing, referral and follow-up patterns of the indigenous counseling staff are described. Strategies for mental health agencies are developed for enhancing their links with these programs and increasing the impact of the War on Poverty on mental illness .Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44328/1/10597_2005_Article_BF01457167.pd

    Postnatal trajectories of maternal depressive symptoms: Postpartum antecedents and differences in toddler adjustment

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    Infants are uniquely vulnerable to maternal depression’s noxious effects, but few longitudinal studies have tried to identify discrete postnatal trajectories of maternal depressive symptoms (MDS) beginning in infancy. This study extends evidence of heterogeneous change in postnatal MDS by examining their cross‐contextual antecedents in infancy and their consequences for children’s early behavior problems and language skills in late toddlerhood. A community sample of mother–child dyads (N = 235, 72% Caucasian) was assessed when children were 7, 15, and 33 months old. Mothers reported their socioeconomic status (SES), social support, marital relationship quality, family dysfunction, parenting stress, and infants’ functional regulatory problems at 7 months postpartum, and children’s internalizing and externalizing symptoms at 33 months. Children completed a receptive vocabulary assessment at 33 months in the lab. Latent class growth analysis identified three postnatal MDS trajectory classes that fit the data best: low‐decreasing, moderate, and increasing. Psychosocial measures at seven months postpartum primarily predicted membership to these postnatal trajectory classes, which subsequently differed in children’s internalizing, externalizing, and receptive vocabulary in late toddlerhood, controlling for family SES and functional regulatory problems in infancy. We discuss salient antecedents and consequences of postnatal depression for mothers and their offspring.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154920/1/imhj21843_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154920/2/imhj21843.pd

    Relationships between drug activity in NCI preclinical in vitro and in vivo models and early clinical trials

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    An analysis of the activity of compounds tested in pre-clinical in vivo and in vitro assays by the National Cancer Institute's Developmental Therapeutics Program was performed. For 39 agents with both xenograft data and Phase II clinical trials results available, in vivo activity in a particular histology in a tumour model did not closely correlate with activity in the same human cancer histology, casting doubt on the correspondence of the pre-clinical models to clinical results. However, for compounds with in vivo activity in at least one-third of tested xenograft models, there was correlation with ultimate activity in at least some Phase II trials. Thus, an efficient means of predicting activity in vivo models remains desirable for compounds with anti-proliferative activity in vitro. For 564 compounds tested in the hollow fibre assay which were also tested against in vivo tumour models, the likelihood of finding xenograft activity in at least one-third of the in vivo models tested rose with increasing intraperitoneal hollow fibre activity, from 8% for all compounds tested to 20% in agents with evidence of response in more than 6 intraperitoneal fibres (P< 0.0001). Intraperitoneal hollow fibre activity was also found to be a better predictor of xenograft activity than either subcutaneous hollow fibre activity or intraperitoneal plus subcutaneous activity combined. Since hollow fibre activity was a useful indicator of potential in vivo response, correlates with hollow fibre activity were examined for 2304 compounds tested in both the NCI 60 cell line in vitro cancer drug screen and hollow fibre assay. A positive correlation was found for histologic selectivity between in vitro and hollow fibre responses. The most striking correlation was between potency in the 60 cell line screen and hollow fibre activity; 56% of compounds with mean 50% growth inhibition below 10–7.5 M were active in more than 6 intraperitoneal fibres whereas only 4% of compounds with a potency of 10–4 M achieved the same level of hollow fibre activity (P< 0.0001). Structural parameters of the drugs analysed included compound molecular weight and hydrogen-bonding factors, both of which were found to be predictive of hollow fibre activity. © 2001 Cancer Research Campaign www.bjcancer.co
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