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Sample records for enhancer element located

  1. Arousal-Enhanced Location Memory for Pictures

    ERIC Educational Resources Information Center

    Mather, Mara; Nesmith, Kathryn

    2008-01-01

    Four experiments revealed arousal-enhanced location memory for pictures. After an incidental encoding task, participants were more likely to remember the locations of positive and negative arousing pictures than the locations of non-arousing pictures, indicating better binding of location to picture. This arousal-enhanced binding effect did not…

  2. A CAR-responsive enhancer element locating approximately 31 kb upstream in the 5'-flanking region of rat cytochrome P450 (CYP) 3A1 gene.

    PubMed

    Gamou, Toshie; Habano, Wataru; Terashima, Jun; Ozawa, Shogo

    2015-04-01

    Constitutive androstane receptor (CAR) is one of the principal regulators of hepatic cytochrome P450s (CYPs) 3A (CYP3A). cDNA-mediated expression of a mature rat CAR (rCAR) into rat hepatoma cells induced CYP3A1 and CYP2B mRNAs. Aberrant rCAR failed in these inductions. Three important human CYP3A4 regulatory elements (REs), proximal ER6 (proER6), xenobiotic responsive enhancer module (XREM) and constitutive liver enhancer module (CLEM), support constitutive and inducible expression of CYP3As mediated by CAR and pregnane X receptor (PXR). NHR-scan software predicted proER6, XREM and CLEM at -255 b, -8 kb and -11.5 kb, respectively of CYP3A4, but neither XREM nor CLEM was predicted in rat CYP3A. A luciferase reporter construct carrying a 5'-flanking sequence of CYP3A1 (-31,739 to -31,585 from its transcription initiation site) revealed important for the rCAR-dependent transactivation of CYP3A1. This region includes two putative binding motifs of nuclear receptors (DR4 and DR2), a putative hepatocyte nuclear factor-1 binding motif (HNF1), nuclear factor-kappa B binding motif (NFκB), activator protein 1 binding motif (AP-1), and ecotropic viral integration site 1 binding motif (Evi1). We hereby conclude DR4 and/or DR2 motifs being primarily responsible and HNF1 being synergistically functioning elements for the rCAR-mediated transcription of CYP3A1. Copyright © 2015 The Japanese Society for the Study of Xenobiotics. Published by Elsevier Ltd. All rights reserved.

  3. The First Rule of Plant Transposable Element Silencing: Location, Location, Location

    PubMed Central

    Sigman, Meredith J.; Slotkin, R. Keith

    2016-01-01

    Transposable elements (TEs) are mobile units of DNA that comprise large portions of plant genomes. Besides creating mutations via transposition and contributing to genome size, TEs play key roles in chromosome architecture and gene regulation. TE activity is repressed by overlapping mechanisms of chromatin condensation, epigenetic transcriptional silencing, and targeting by small interfering RNAs. The specific regulation of different TEs, as well as their different roles in chromosome architecture and gene regulation, is specified by where on the chromosome the TE is located: near a gene, within a gene, in a pericentromere/TE island, or at the centromere core. In this Review, we investigate the silencing mechanisms responsible for inhibiting TE activity for each of these chromosomal contexts, emphasizing that chromosomal location is the first rule dictating the specific regulation of each TE. PMID:26869697

  4. An evaluation of root ZX and elements diagnostic apex locators.

    PubMed

    Tselnik, Marat; Baumgartner, J Craig; Marshall, J Gordon

    2005-07-01

    The purpose of this study was to compare the accuracy of the Root ZX and Elements Diagnostic electronic apex locators under clinical conditions. Thirty-six teeth planned for extraction were used. Each tooth was decoronated, coronally flared with Orifice Shapers, and irrigated with 2.6% sodium hypochlorite. Working lengths were measured with K-files using both electronic apex locators. The files were cemented at the last measured working length and the teeth were extracted. The apical 4-mm of each canal were exposed and photographed under 15x and 30x magnification. Images of each apex were projected and the distance from the file tip to the minor diameter was determined. The mean distances from the file tip to the minor diameter were 0.346 mm for the Elements Diagnostic and 0.410-mm for the Root ZX beyond the minor constriction. In locating the minor constriction the Root ZX was accurate 75% of the time to +/-0.5 mm, 83.3% +/-0.75 mm, and 88.9% to +/-1 mm. The Elements Diagnostic was accurate 75% of the time to +/-0.5 mm, 88.9% to +/-0.75 mm, and 91.7% to +/-1 mm. There was no statistically significant difference between the accuracy of the two electronic apex locators in locating the minor diameter (p < 0.05).

  5. Transcriptional regulation of the apolipoprotein A-IV gene involves synergism between a proximal orphan receptor response element and a distant enhancer located in the upstream promoter region of the apolipoprotein C-III gene.

    PubMed Central

    Ktistaki, E; Lacorte, J M; Katrakili, N; Zannis, V I; Talianidis, I

    1994-01-01

    Apolipoprotein A-IV expression is limited to intestinal and hepatic cells, suggesting a tissue specific transcriptional regulation of its gene. To investigate the mechanism controlling apo A-IV transcription we have analysed its promoter region by in vitro DNA binding and transient transfection experiments. DNase I footprinting analysis of the proximal promoter with rat liver nuclear extracts revealed four protected regions: AIVA (-32 to -22), AIVB (-84 to -42), AIVC (-148 to -92) and AIVD (-274 to -250). Element AIVC which is necessary for maximal promoter activity, binds HNF-4, Arp-1 and Ear-3 with similar affinity in a mutually exclusive manner. HNF-4 transactivated chimeric constructs containing intact AIVC site in the context of either the apo A-IV promoter or the heterologous thymidine kinase minimal promoter, while Arp-1 and Ear-3 repressed this activation. Increasing amounts of HNF-4 alleviated Arp-1 or Ear-3 mediated repression, suggesting that the observed opposing effects is a result of direct competition of these factors for the same recognition site. In transient transfection assays the apo A-IV promoter region (-700 to +10) had a very low activity in cells of hepatic (HepG2) and intestinal (CaCo2) origin. This activity was increased 13 to 18-fold when the upstream elements of the distantly linked apo C-III gene were fused to the proximal promoter. Results obtained with different 5' and 3' deletion constructs indicated that the cis-acting elements F to J between the nucleotides -500 and -890 of the apo C-III promoter were absolutely necessary to drive maximal enhancement in HepG2 and CaCo2 cells. The apo C-III upstream elements enhanced the activity of the minimal AdML promoter or the apo A-IV site C mutant less efficiently than the intact apo A-IV or AdML promoter constructs containing single HNF-4 sites. The findings suggest that the enhancer effect is mediated by synergistic interactions between the trans-acting factors which recognize the apo C

  6. Transcriptional regulation of the apolipoprotein A-IV gene involves synergism between a proximal orphan receptor response element and a distant enhancer located in the upstream promoter region of the apolipoprotein C-III gene.

    PubMed

    Ktistaki, E; Lacorte, J M; Katrakili, N; Zannis, V I; Talianidis, I

    1994-11-11

    Apolipoprotein A-IV expression is limited to intestinal and hepatic cells, suggesting a tissue specific transcriptional regulation of its gene. To investigate the mechanism controlling apo A-IV transcription we have analysed its promoter region by in vitro DNA binding and transient transfection experiments. DNase I footprinting analysis of the proximal promoter with rat liver nuclear extracts revealed four protected regions: AIVA (-32 to -22), AIVB (-84 to -42), AIVC (-148 to -92) and AIVD (-274 to -250). Element AIVC which is necessary for maximal promoter activity, binds HNF-4, Arp-1 and Ear-3 with similar affinity in a mutually exclusive manner. HNF-4 transactivated chimeric constructs containing intact AIVC site in the context of either the apo A-IV promoter or the heterologous thymidine kinase minimal promoter, while Arp-1 and Ear-3 repressed this activation. Increasing amounts of HNF-4 alleviated Arp-1 or Ear-3 mediated repression, suggesting that the observed opposing effects is a result of direct competition of these factors for the same recognition site. In transient transfection assays the apo A-IV promoter region (-700 to +10) had a very low activity in cells of hepatic (HepG2) and intestinal (CaCo2) origin. This activity was increased 13 to 18-fold when the upstream elements of the distantly linked apo C-III gene were fused to the proximal promoter. Results obtained with different 5' and 3' deletion constructs indicated that the cis-acting elements F to J between the nucleotides -500 and -890 of the apo C-III promoter were absolutely necessary to drive maximal enhancement in HepG2 and CaCo2 cells. The apo C-III upstream elements enhanced the activity of the minimal AdML promoter or the apo A-IV site C mutant less efficiently than the intact apo A-IV or AdML promoter constructs containing single HNF-4 sites. The findings suggest that the enhancer effect is mediated by synergistic interactions between the trans-acting factors which recognize the apo C

  7. Saccade execution suppresses discrimination at distractor locations rather than enhancing the saccade goal location.

    PubMed

    Khan, Aarlenne Z; Blohm, Gunnar; Pisella, Laure; Munoz, Douglas P

    2015-06-01

    As we have limited processing abilities with respect to the plethora of visual information entering our brain, spatial selection mechanisms are crucial. These mechanisms result in both enhancing processing at a location of interest and in suppressing processing at other locations; together, they enable successful further processing of locations of interest. It has been suggested that saccade planning modulates these spatial selection mechanisms; however, the precise influence of saccades on the distribution of spatial resources underlying selection remains unclear. To this end, we compared discrimination performance at different locations (six) within a work space during different saccade tasks. We used visual discrimination performance as a behavioral measure of enhancement and suppression at the different locations. A total of 14 participants performed a dual discrimination/saccade countermanding task, which allowed us to specifically isolate the consequences of saccade execution. When a saccade was executed, discrimination performance at the cued location was never better than when fixation was maintained, suggesting that saccade execution did not enhance processing at a location more than knowing the likelihood of its appearance. However, discrimination was consistently lower at distractor (uncued) locations in all cases where a saccade was executed compared with when fixation was maintained. Based on these results, we suggest that saccade execution specifically suppresses distractor locations, whereas attention shifts (with or without an accompanying saccade) are involved in enhancing perceptual processing at the goal location.

  8. Enhancing Students' Socialization: Key Elements. ERIC Digest.

    ERIC Educational Resources Information Center

    Brophy, Jere

    Coping with students who display social adjustment problems can be frustrating. However, teachers can take actions toward minimizing classroom conflicts by socializing students into a classroom environment conducive to learning. Modeling prosocial behavior is the most basic element for enhancing student socialization. In situations in which…

  9. 49 CFR 236.560 - Contact element, mechanical trip type; location with respect to rail.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Contact element, mechanical trip type; location... Instructions; Locomotives § 236.560 Contact element, mechanical trip type; location with respect to rail. Contact element of automatic train stop device of the mechanical trip type shall be maintained at a height...

  10. 49 CFR 236.560 - Contact element, mechanical trip type; location with respect to rail.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Contact element, mechanical trip type; location... Instructions; Locomotives § 236.560 Contact element, mechanical trip type; location with respect to rail. Contact element of automatic train stop device of the mechanical trip type shall be maintained at a height...

  11. 49 CFR 236.560 - Contact element, mechanical trip type; location with respect to rail.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Contact element, mechanical trip type; location... Instructions; Locomotives § 236.560 Contact element, mechanical trip type; location with respect to rail. Contact element of automatic train stop device of the mechanical trip type shall be maintained at a height...

  12. 49 CFR 236.560 - Contact element, mechanical trip type; location with respect to rail.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Contact element, mechanical trip type; location... Instructions; Locomotives § 236.560 Contact element, mechanical trip type; location with respect to rail. Contact element of automatic train stop device of the mechanical trip type shall be maintained at a height...

  13. 49 CFR 236.560 - Contact element, mechanical trip type; location with respect to rail.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Contact element, mechanical trip type; location... Instructions; Locomotives § 236.560 Contact element, mechanical trip type; location with respect to rail. Contact element of automatic train stop device of the mechanical trip type shall be maintained at a height...

  14. The Mobile Element Locator Tool (MELT): Population-scale mobile element discovery and biology.

    PubMed

    Gardner, Eugene J; Lam, Vincent K; Harris, Daniel N; Chuang, Nelson T; Scott, Emma C; Pittard, William S; Mills, Ryan E; Devine, Scott E

    2017-08-30

    Mobile element insertions (MEIs) represent ~25% of all structural variants in human genomes. Moreover, when they disrupt genes, MEIs can influence human traits and diseases. Therefore, MEIs should be fully discovered along with other forms of genetic variation in whole genome sequencing (WGS) projects involving population genetics, human diseases, and clinical genomics. Here, we describe the Mobile Element Locator Tool (MELT), which was developed as part of the 1000 Genomes Project to perform MEI discovery on a population scale. Using both Illumina WGS data and simulations, we demonstrate that MELT outperforms existing MEI discovery tools in terms of speed, scalability, specificity and sensitivity, while also detecting a broader spectrum of MEI-associated features. Several run modes were developed to perform MEI discovery on local and cloud systems. In addition to using MELT to discover MEIs in modern humans as part of the 1000 Genomes Project, we also used it to discover MEIs in chimpanzees and ancient (Neanderthal and Denisovan) hominids. We detected diverse patterns of MEI stratification across these populations that likely were caused by: i) diverse rates of MEI production from source elements, ii) diverse patterns of MEI inheritance, and iii) the introgression of ancient MEIs into modern human genomes. Overall, our study provides the most comprehensive map of MEIs to date spanning chimpanzees, ancient hominids, and modern humans, and reveals new aspects of MEI biology in these lineages. We also demonstrate that MELT is a robust platform for MEI discovery and analysis in a variety of experimental settings. Published by Cold Spring Harbor Laboratory Press.

  15. Enhancer Complexes Located Downstream of Both Human Immunoglobulin Cα Genes

    PubMed Central

    Mills, Frederick C.; Harindranath, Nagaradona; Mitchell, Mary; Max, Edward E.

    1997-01-01

    To investigate regulation of human immunoglobulin heavy chain expression, we have cloned DNA downstream from the two human Cα genes, corresponding to the position in the mouse IgH cluster of a locus control region (LCR) that includes an enhancer which regulates isotype switching. Within 25 kb downstream of both the human immunoglobulin Cα1 and Cα2 genes we identified several segments of DNA which display B lymphoid–specific DNase I hypersensitivity as well as enhancer activity in transient transfections. The corresponding sequences downstream from each of the two human Cα genes are nearly identical to each other. These enhancers are also homologous to three regions which lie in similar positions downstream from the murine Cα gene and form the murine LCR. The strongest enhancers in both mouse and human have been designated HS12. Within a 135-bp core homology region, the human HS12 enhancers are ∼90% identical to the murine homolog and include several motifs previously demonstrated to be important for function of the murine enhancer; additional segments of high sequence conservation suggest the possibility of previously unrecognized functional motifs. On the other hand, certain functional elements in the murine enhancer, including a B cell–specific activator protein site, do not appear to be conserved in human HS12. The human homologs of the murine enhancers designated HS3 and HS4 show lower overall sequence conservation, but for at least two of the functional motifs in the murine HS4 (a κB site and an octamer motif  ) the human HS4 homologs are exactly conserved. An additional hypersensitivity site between human HS3 and HS12 in each human locus displays no enhancer activity on its own, but includes a region of high sequence conservation with mouse, suggesting the possibility of another novel functional element. PMID:9294139

  16. Arbitrary spot location diffractive beam-splitting elements.

    PubMed

    Bühling, Sven; Wyrowski, Frank

    2002-12-01

    Diffractive beam-splitting elements are typically designed for replicating beams on positions belonging to an equidistant grid in the spatial spectrum. The parameter of the output grid follows directly from the period of the beam-splitter transmission through the grating equation. Our objective is to develop design strategies allowing a more accurate positioning of the replicated beams. Issues occurring when the output grid parameter is decreased below the output beam width are discussed and shown to be avoidable. Furthermore, a design algorithm is introduced, which permits an arbitrary positioning of the replicated beams. This algorithm is constructed for high computational efficiency by utilizing fast Fourier transform operations in the major part of its iterations.

  17. Finite element analysis enhancement of cryogenic testing

    NASA Astrophysics Data System (ADS)

    Thiem, Clare D.; Norton, Douglas A.

    1991-12-01

    Finite element analysis (FEA) of large space optics enhances cryogenic testing by providing an analytical method by which to ensure that a test article survives proposed testing. The analyses presented in this paper were concerned with determining the reliability of a half meter mirror in an environment where the exact environmental profile was unknown. FEA allows the interaction between the test object and the environment to be simulated to detect potential problems prior to actual testing. These analyses examined worse case scenerios related to cooling the mirror, its structural integrity for the proposed test environment, and deformation of the reflective surface. The FEA was conducted in-house on the System's Reliability Division's VAX 11-750 and Decstation 3100 using Engineering Mechanics Research Corporation's numerically integrated elements for systems analysis finite element software. The results of the analyses showed that it would take at least 48 hours to cool the mirror to its desired testing temperature. It was also determined that the proposed mirror mount would not cause critical concentrated thermal stresses that would fracture the mirror. FEA and actual measurements of the front reflective face were compared and good agreement between computer simulation and physical tests were seen. Space deployment of large optics requires lightweight mirrors which can perform under the harsh conditions of space. The physical characteristics of these mirrors must be well understood in order that their deployment and operation are successful. Evaluating design approaches by analytical simulation, like FEA, verifies the reliability and structural integrity of a space optic during design prior to prototyping and testing. Eliminating an optic's poor design early in its life saves money, materials, and human resources while ensuring performance.

  18. Suitability of air sampling locations downstream of bends and static mixing elements.

    PubMed

    McFarland, A R; Gupta, R; Anand, N K

    1999-12-01

    The revised standard for sampling effluent air from stacks and ducts of the nuclear industry places limits on the non-uniformity of velocity and contaminant profiles at the sampling location; namely, the coefficients of variation must not exceed 20% over an area that encompasses at least the center 2/3 of the cross sectional area. Tests were conducted to characterize the degree of mixing at downstream locations as affected by several types of flow disturbances, including 90 degree elbows and commercial static mixing devices. Flow straighteners were incorporated into the ducting upstream of the mixer to be tested to simulate the dampening of flow turbulence that might occur because of upstream HEPA filters. The coefficients of variation of velocity and tracer gas concentration measured in a straight tube at a distance of 3 diameters downstream from a 90 degree elbow were 17% and 69%, respectively. The mixing is impacted by the upstream flow turbulence. Without a flow straightener, the tracer gas concentration coefficient of variation was reduced to 33% at the 3-diameter location. The use of static mixing elements can greatly enhance the mixing process. A ring placed just downstream of a 90 degree elbow, which blocks the outer 56% of the cross sectional area, results in a coefficient of variation of 19% for tracer gas concentration at the 3-diameter location. Pressure loss across the elbow with the ring is about nine times that of the basic elbow. One of the commercially available static mixers provides coefficients of variation that are less than 10% for both velocity and tracer gas concentration at 4 diameters downstream from the mixer with a pressure loss that is only about 3.5 times as large as that of a 90 degree elbow.

  19. Google Earth locations of USA and seafloor hydrothermal vents with associated rare earth element data

    DOE Data Explorer

    Andrew Fowler

    2016-02-10

    Google Earth .kmz files that contain the locations of geothermal wells and thermal springs in the USA, and seafloor hydrothermal vents that have associated rare earth element data. The file does not contain the actual data, the actual data is available through the GDR website in two tier 3 data sets entitled "Compilation of Rare Earth Element Analyses from US Geothermal Fields and Mid Ocean Ridge (MOR) Hydrothermal Vents" and "Rare earth element content of thermal fluids from Surprise Valley, California"

  20. A reciprocal space approach for locating symmetry elements in Patterson superposition maps

    SciTech Connect

    Hendrixson, T.

    1990-09-21

    A method for determining the location and possible existence of symmetry elements in Patterson superposition maps has been developed. A comparison of the original superposition map and a superposition map operated on by the symmetry element gives possible translations to the location of the symmetry element. A reciprocal space approach using structure factor-like quantities obtained from the Fourier transform of the superposition function is then used to determine the best'' location of the symmetry element. Constraints based upon the space group requirements are also used as a check on the locations. The locations of the symmetry elements are used to modify the Fourier transform coefficients of the superposition function to give an approximation of the structure factors, which are then refined using the EG relation. The analysis of several compounds using this method is presented. Reciprocal space techniques for locating multiple images in the superposition function are also presented, along with methods to remove the effect of multiple images in the Fourier transform coefficients of the superposition map. In addition, crystallographic studies of the extended chain structure of (NHC{sub 5}H{sub 5})SbI{sub 4} and of the twinning method of the orthorhombic form of the high-{Tc} superconductor YBa{sub 2}Cu{sub 3}O{sub 7-x} are presented. 54 refs.

  1. Spatial Attention Enhances Perceptual Processing of Single-Element Displays

    NASA Technical Reports Server (NTRS)

    Bacon, William; Johnston, James C.; Remington, Roger W.; Null, Cynthia H. (Technical Monitor)

    1994-01-01

    Shiu and Pashler (1993) reported that precueing masked, single-element displays had negligible effects on identification accuracy. They argued that spatial attention does not actually enhance stimulus perceptibility, but only reduces decision noise. Alternatively, such negative results may arise if cues are sub-optimal, or if masks place an insufficient premium on timely deployment of attention. We report results showing that valid cueing enhances processing of even single-element displays. Spatial attention does indeed enhance perceptual processes.

  2. Spatial Attention Enhances Perceptual Processing of Single-Element Displays

    NASA Technical Reports Server (NTRS)

    Bacon, William; Johnston, James C.; Remington, Roger W.; Null, Cynthia H. (Technical Monitor)

    1994-01-01

    Shiu and Pashler (1993) reported that precueing masked, single-element displays had negligible effects on identification accuracy. They argued that spatial attention does not actually enhance stimulus perceptibility, but only reduces decision noise. Alternatively, such negative results may arise if cues are sub-optimal, or if masks place an insufficient premium on timely deployment of attention. We report results showing that valid cueing enhances processing of even single-element displays. Spatial attention does indeed enhance perceptual processes.

  3. Ex vivo accuracy of three electronic apex locators: Root ZX, Elements Diagnostic Unit and Apex Locator and ProPex.

    PubMed

    Plotino, G; Grande, N M; Brigante, L; Lesti, B; Somma, F

    2006-05-01

    To compare ex vivo the accuracy of three electronic apex locators (EALs): Root ZX, Elements Diagnostic Unit and Apex Locator and ProPex. Electronic working length determination was carried out in 40 extracted teeth using an ex vivo model. After access preparation, a first operator determined the reference length (AL) for each tooth under a 30x stereomicroscope using the apical constriction as the apical landmark. All teeth were then measured with each EAL and the results obtained were compared with the corresponding AL. The AL was subtracted from the electronically determined distance. The measurements exceeding the AL were recorded as positive (long) and the measurements short of the AL were recorded as negative. Data were analyzed using the Friedman Test and Tukey multiple range test for nonparametric correlation amongst groups. Statistical significance was considered at P < 0.05. Comparing the differences between measurements obtained with the three EALs and those obtained with the stereomicroscope, the percentage of measurements within +/-0.5 mm of the AL was 97.37% (84.22% within 0.5 mm short of AL) for the Root ZX, 94.28% (88.57% within 0.5 mm short of AL) for the Elements and 100% (35.9% within 0.5 mm short of AL) for the ProPex. The mean difference between the AL and the lengths measured by the Root ZX, the Elements and the ProPex were, respectively, -0.157 +/- 0.228, -0.103 +/- 0.359 and 0.307 +/- 0.271 mm. The results of the present study confirm that the EALs determined the canal length within +/-0.5 mm from the apical constriction in the majority of cases. The majority of the ProPex readings were long.

  4. Location and characterization of two widely separated glucocorticoid response elements in the phosphoenolpyruvate carboxykinase gene

    SciTech Connect

    Petersen, D.D.; Magnuson, M.A.; Granner, D.K.

    1988-01-01

    Chimeric genes were constructed by fusion of various regions of the 5'-flanking sequence from the phosphoenolpyruvate carboxykinase (GTP) (PEPCK) gene to the chloramphenicol acetyltransferase-coding sequence and to simian virus 40 splice and polyadenylation sequences. These were used to demonstrate that two glucocorticoid regulatory elements (GREs) combine to confer glucocorticoid responsiveness upon the PEPCK gene in H4IIE hepatoma cells. Both elements, distal one whose 5' boundary is located between -1264 and -1111 base pairs and a proximal one located between -468 and -420 base pairs relative to the transcription initiation site, act independently, in various positions and orientations, and upon the heterologous thymidine kinase promoter. Each element accounts for half of the maximal response of the chimeric genes. Therefore, two widely separated enhancerlike elements contribute equally to the response of the PEPCK gene to glucocorticoid hormones. Neither of the PEPCK GREs contains the TGTTCT consensus sequence associated with most other GREs.

  5. Location and characterization of two widely separated glucocorticoid response elements in the phosphoenolpyruvate carboxykinase gene.

    PubMed Central

    Petersen, D D; Magnuson, M A; Granner, D K

    1988-01-01

    Chimeric genes were constructed by fusion of various regions of the 5'-flanking sequence from the phosphoenolpyruvate carboxykinase (GTP) (PEPCK) gene to the chloramphenicol acetyltransferase-coding sequence and to simian virus 40 splice and polyadenylation sequences. These were used to demonstrate that two glucocorticoid regulatory elements (GREs) combine to confer glucocorticoid responsiveness upon the PEPCK gene in H4IIE hepatoma cells. Both elements, a distal one whose 5' boundary is located between -1264 and -1111 base pairs and a proximal one located between -468 and -420 base pairs relative to the transcription initiation site, act independently, in various positions and orientations, and upon the heterologous thymidine kinase promoter. Each element accounts for half of the maximal response of the chimeric genes. Therefore, two widely separated enhancerlike elements contribute equally to the response of the PEPCK gene to glucocorticoid hormones. Neither of the PEPCK GREs contains the TGTTCT consensus sequence associated with most other GREs. Images PMID:3422101

  6. An insulator element located at the cyclin B1 interacting protein 1 gene locus is highly conserved among mammalian species.

    PubMed

    Yoshida, Wataru; Tomikawa, Junko; Inaki, Makoto; Kimura, Hiroshi; Onodera, Masafumi; Hata, Kenichiro; Nakabayashi, Kazuhiko

    2015-01-01

    Insulators are cis-elements that control the direction of enhancer and silencer activities (enhancer-blocking) and protect genes from silencing by heterochromatinization (barrier activity). Understanding insulators is critical to elucidate gene regulatory mechanisms at chromosomal domain levels. Here, we focused on a genomic region upstream of the mouse Ccnb1ip1 (cyclin B1 interacting protein 1) gene that was methylated in E9.5 embryos of the C57BL/6 strain, but unmethylated in those of the 129X1/SvJ and JF1/Ms strains. We hypothesized the existence of an insulator-type element that prevents the spread of DNA methylation within the 1.8 kbp segment, and actually identified a 242-bp and a 185-bp fragments that were located adjacent to each other and showed insulator and enhancer activities, respectively, in reporter assays. We designated these genomic regions as the Ccnb1ip1 insulator and the Ccnb1ip1 enhancer. The Ccnb1ip1 insulator showed enhancer-blocking activity in the luciferase assays and barrier activity in the colony formation assays. Further examination of the Ccnb1ip1 locus in other mammalian species revealed that the insulator and enhancer are highly conserved among a wide variety of species, and are located immediately upstream of the transcriptional start site of Ccnb1ip1. These newly identified cis-elements may be involved in transcriptional regulation of Ccnb1ip1, which is important in meiotic crossing-over and G2/M transition of the mitotic cell cycle.

  7. An Insulator Element Located at the Cyclin B1 Interacting Protein 1 Gene Locus Is Highly Conserved among Mammalian Species

    PubMed Central

    Yoshida, Wataru; Tomikawa, Junko; Inaki, Makoto; Kimura, Hiroshi; Onodera, Masafumi; Hata, Kenichiro; Nakabayashi, Kazuhiko

    2015-01-01

    Insulators are cis-elements that control the direction of enhancer and silencer activities (enhancer-blocking) and protect genes from silencing by heterochromatinization (barrier activity). Understanding insulators is critical to elucidate gene regulatory mechanisms at chromosomal domain levels. Here, we focused on a genomic region upstream of the mouse Ccnb1ip1 (cyclin B1 interacting protein 1) gene that was methylated in E9.5 embryos of the C57BL/6 strain, but unmethylated in those of the 129X1/SvJ and JF1/Ms strains. We hypothesized the existence of an insulator-type element that prevents the spread of DNA methylation within the 1.8 kbp segment, and actually identified a 242-bp and a 185-bp fragments that were located adjacent to each other and showed insulator and enhancer activities, respectively, in reporter assays. We designated these genomic regions as the Ccnb1ip1 insulator and the Ccnb1ip1 enhancer. The Ccnb1ip1 insulator showed enhancer-blocking activity in the luciferase assays and barrier activity in the colony formation assays. Further examination of the Ccnb1ip1 locus in other mammalian species revealed that the insulator and enhancer are highly conserved among a wide variety of species, and are located immediately upstream of the transcriptional start site of Ccnb1ip1. These newly identified cis-elements may be involved in transcriptional regulation of Ccnb1ip1, which is important in meiotic crossing-over and G2/M transition of the mitotic cell cycle. PMID:26110280

  8. Discrete elements within the SV40 enhancer region display different cell-specific enhancer activities.

    PubMed Central

    Ondek, B; Shepard, A; Herr, W

    1987-01-01

    The SV40 enhancer contains three genetically defined elements, called A, B and C, that can functionally compensate for one another. By using short, synthetic DNA oligonucleotides, we show that each of these elements can act autonomously as an enhancer when present as multiple tandem copies. Analysis of a progressive series of B element oligomers shows a single element is ineffective as an enhancer and that the activity of two or more elements increases with copy number. Assay in five different cell lines of two separate enhancers containing six tandem copies of either the B or C element shows that these elements possess different cell-specific activities. Parallel oligomer enhancer constructs containing closely spaced double point mutations display no enhancer activity in any of the cell lines tested, indicating that these elements represent single units of enhancer function. These elements contain either a 'core' or 'octamer' consensus sequence but these consensus sequences alone are not sufficient for enhancer activity. The different cell-specific activities of the B and C elements are consistent with functional interactions with different trans-acting factors. We discuss how tandem duplication of such dissimilar elements, as in the wild-type SV40 72-bp repeats, can serve to expand the conditions under which an enhancer can function. Images Fig. 2. Fig. 3. Fig. 4. PMID:3036487

  9. Finite element models predict the location of microdamage in cancellous bone following uniaxial loading.

    PubMed

    Goff, M G; Lambers, F M; Sorna, R M; Keaveny, T M; Hernandez, C J

    2015-11-26

    High-resolution finite element models derived from micro-computed tomography images are often used to study the effects of trabecular microarchitecture and loading mode on tissue stress, but the degree to which existing finite element methods correctly predict the location of tissue failure is not well characterized. In the current study, we determined the relationship between the location of highly strained tissue, as determined from high-resolution finite element models, and the location of tissue microdamage, as determined from three-dimensional fluoroscopy imaging, which was performed after the microdamage was generated in-vitro by mechanical testing. Fourteen specimens of human vertebral cancellous bone were assessed (8 male donors, 2 female donors, 47-78 years of age). Regions of stained microdamage, were 50-75% more likely to form in highly strained tissue (principal strains exceeding 0.4%) than elsewhere, and generally the locations of the regions of microdamage were significantly correlated (p<0.05) with the locations of highly strained tissue. This spatial correlation was stronger for the largest regions of microdamage (≥1,000,000μm(3) in volume); 87% of large regions of microdamage were located near highly strained tissue. Together, these findings demonstrate that there is a strong correlation between regions of microdamage and regions of high strain in human cancellous bone, particularly for the biomechanically more important large instances of microdamage.

  10. Characterization of the enhancer element of the Danio rerio minor globin gene locus.

    PubMed

    Nefedochkina, Anastasia V; Petrova, Natalia V; Ioudinkova, Elena S; Kovina, Anastasia P; Iarovaia, Olga V; Razin, Sergey V

    2016-04-01

    In Danio rerio, the alpha- and beta-globin genes are present in two clusters: a major cluster located on chromosome 3 and a minor cluster located on chromosome 12. In contrast to the segregated alpha- and beta-globin gene domains of warm-blooded animals, in Danio rerio, each cluster contains both alpha- and beta-globin genes. Expression of globin genes present in the major cluster is controlled by an erythroid-specific enhancer similar to the major regulatory element of mammalian and avian alpha-globin gene domains. The enhancer controlling expression of the globin genes present in the minor locus has not been identified yet. Based on the distribution of epigenetic marks, we have selected two genomic regions that might harbor an enhancer of the minor locus. Using transient transfection of constructs with a reporter gene, we have demonstrated that a ~500-bp DNA fragment located ~1.7 Kb upstream of the αe4 gene possesses an erythroid-specific enhancer active with respect to promoters present in both the major and the minor globin gene loci of Danio rerio. The identified enhancer element harbors clustered binding sites for GATA-1, NF-E2, and EKLF similar to the enhancer of the major globin locus on chromosome 3. Both enhancers appear to have emerged as a result of independent evolution of a duplicated regulatory element present in an ancestral single alpha-/beta-globin locus that existed before teleost-specific genome duplication.

  11. Modulation of tissue repair by regeneration enhancer elements.

    PubMed

    Kang, Junsu; Hu, Jianxin; Karra, Ravi; Dickson, Amy L; Tornini, Valerie A; Nachtrab, Gregory; Gemberling, Matthew; Goldman, Joseph A; Black, Brian L; Poss, Kenneth D

    2016-04-14

    How tissue regeneration programs are triggered by injury has received limited research attention. Here we investigate the existence of enhancer regulatory elements that are activated in regenerating tissue. Transcriptomic analyses reveal that leptin b (lepb) is highly induced in regenerating hearts and fins of zebrafish. Epigenetic profiling identified a short DNA sequence element upstream and distal to lepb that acquires open chromatin marks during regeneration and enables injury-dependent expression from minimal promoters. This element could activate expression in injured neonatal mouse tissues and was divisible into tissue-specific modules sufficient for expression in regenerating zebrafish fins or hearts. Simple enhancer-effector transgenes employing lepb-linked sequences upstream of pro- or anti-regenerative factors controlled the efficacy of regeneration in zebrafish. Our findings provide evidence for 'tissue regeneration enhancer elements' (TREEs) that trigger gene expression in injury sites and can be engineered to modulate the regenerative potential of vertebrate organs.

  12. 20 CFR 655.535 - The second attestation element for locations in Alaska: Employment of United States longshore...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 3 2014-04-01 2014-04-01 false The second attestation element for locations... Alaska Exception § 655.535 The second attestation element for locations in Alaska: Employment of United States longshore workers. (a) The second attestation element shall be satisfied when the employer...

  13. 20 CFR 655.535 - The second attestation element for locations in Alaska: Employment of United States longshore...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 3 2013-04-01 2013-04-01 false The second attestation element for locations... Alaska Exception § 655.535 The second attestation element for locations in Alaska: Employment of United States longshore workers. (a) The second attestation element shall be satisfied when the employer...

  14. 20 CFR 655.535 - The second attestation element for locations in Alaska: Employment of United States longshore...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 3 2012-04-01 2012-04-01 false The second attestation element for locations... Alaska Exception § 655.535 The second attestation element for locations in Alaska: Employment of United States longshore workers. (a) The second attestation element shall be satisfied when the employer...

  15. 20 CFR 655.535 - The second attestation element for locations in Alaska: Employment of United States longshore...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false The second attestation element for locations... Alaska Exception § 655.535 The second attestation element for locations in Alaska: Employment of United States longshore workers. (a) The second attestation element shall be satisfied when the employer...

  16. Enhanced separation of rare earth elements

    SciTech Connect

    Lyon, K.; Greenhalgh, M.; Herbst, R. S.; Garn, T.; Welty, A.; Soderstrom, M. D.; Jakovljevic, B.

    2016-09-01

    Industrial rare earth separation processes utilize PC88A, a phosphonic acid ligand, for solvent extraction separations. The separation factors of the individual rare earths, the equipment requirements, and chemical usage for these flowsheets are well characterized. Alternative ligands such as Cyanex® 572 and the associated flowsheets are being investigated at the pilot scale level to determine if significant improvements to the current separation processes can be realized. These improvements are identified as higher separation factors, reduced stage requirements, or reduced chemical consumption. Any of these improvements can significantly affect the costs associated with these challenging separation proccesses. A mid/heavy rare earth element (REE) separations flowsheet was developed and tested for each ligand in a 30 stage mixer-settler circuit to compare the separation performance of PC88A and Cyanex® 572. The ligand-metal complex strength of Cyanex® 572 provides efficient extraction of REE while significantly reducing the strip acid requirements. Reductions in chemical consumption have a significant impact on process economics for REE separations. Partitioning results summarized Table 1 indicate that Cyanex® 572 offers the same separation performance as PC88A while reducing acid consumption by 30% in the strip section for the mid/heavy REE separation. Flowsheet Effluent Compositions PC88A Cyanex® 572 Raffinate Mid REE Heavy REE 99.40% 0.60% 99.40% 0.60% Rich Mid REE Heavy REE 2.20% 97.80% 0.80% 99.20% Liquor Strip Acid Required 3.4 M 2.3 M Table 1 – Flowsheet results comparing separation performance of PC88A and Cyanex® 572 for a mid/heavy REE separation.

  17. Isomers and Enhanced Stability of Superheavy Elements

    NASA Astrophysics Data System (ADS)

    Kondev, Filip; Anl, Lbnl, Anu, Csnsm, Llnl, Usna, U. Of Edinburgh, U. Of Jyväskylä, U. Of Massachusetts, Lowell Collaboration

    2014-09-01

    There has been continuing activity addressing the complex question of whether excited isomeric states would lead to enhanced stability of superheavy nuclei, given changes in the fission barriers, α-decay probabilities and the effects of nuclear structure (such as K-hindrance). Recently, we have carried out new studies of the 254Rf isotope using the 50Ti + 206Pb reaction at Argonne National Laboratory and Lawrence Berkeley National Laboratory. A digital data acquisition system was deployed in both experiments, which allowed the identification of implant and decay events that were separated by time as short as hundreds of nanoseconds. Two isomeric states were discovered in 254Rf with half-lives of ~4 μs and ~300 μs, the latter being an order of magnitude longer lived than the ground state. In addition, K-isomers in 244Cm and 246Cm were also studied following β- decays of 244Am (Kπ = 6+) and 246Am (Kπ = 7-) mass-separated sources, respectively. The emphasis was on elucidating details of the level schemes, which allowed reliable values for the strength of the K-forbidden transitions to be determined and compared with systematics in other regions of the nuclear chart. There has been continuing activity addressing the complex question of whether excited isomeric states would lead to enhanced stability of superheavy nuclei, given changes in the fission barriers, α-decay probabilities and the effects of nuclear structure (such as K-hindrance). Recently, we have carried out new studies of the 254Rf isotope using the 50Ti + 206Pb reaction at Argonne National Laboratory and Lawrence Berkeley National Laboratory. A digital data acquisition system was deployed in both experiments, which allowed the identification of implant and decay events that were separated by time as short as hundreds of nanoseconds. Two isomeric states were discovered in 254Rf with half-lives of ~4 μs and ~300 μs, the latter being an order of magnitude longer lived than the ground state. In

  18. Dual functionality of cis-regulatory elements as developmental enhancers and Polycomb response elements.

    PubMed

    Erceg, Jelena; Pakozdi, Tibor; Marco-Ferreres, Raquel; Ghavi-Helm, Yad; Girardot, Charles; Bracken, Adrian P; Furlong, Eileen E M

    2017-03-15

    Developmental gene expression is tightly regulated through enhancer elements, which initiate dynamic spatio-temporal expression, and Polycomb response elements (PREs), which maintain stable gene silencing. These two cis-regulatory functions are thought to operate through distinct dedicated elements. By examining the occupancy of the Drosophila pleiohomeotic repressive complex (PhoRC) during embryogenesis, we revealed extensive co-occupancy at developmental enhancers. Using an established in vivo assay for PRE activity, we demonstrated that a subset of characterized developmental enhancers can function as PREs, silencing transcription in a Polycomb-dependent manner. Conversely, some classic Drosophila PREs can function as developmental enhancers in vivo, activating spatio-temporal expression. This study therefore uncovers elements with dual function: activating transcription in some cells (enhancers) while stably maintaining transcriptional silencing in others (PREs). Given that enhancers initiate spatio-temporal gene expression, reuse of the same elements by the Polycomb group (PcG) system may help fine-tune gene expression and ensure the timely maintenance of cell identities. © 2017 Erceg et al.; Published by Cold Spring Harbor Laboratory Press.

  19. Micro-PIXE analysis of trace element concentrations of natural rubies from different locations in Myanmar

    NASA Astrophysics Data System (ADS)

    Sanchez, J. L.; Osipowicz, T.; Tang, S. M.; Tay, T. S.; Win, T. T.

    1997-07-01

    The trace element concentrations found in geological samples can shed light on the formation process. In the case of gemstones, which might be of artificial or natural origin, there is also considerable interest in the development of methods that provide identification of the origin of a sample. For rubies, trace element concentrations present in natural samples were shown previously to be significant indicators of the region of origin [S.M. Tang et al., Appl. Spectr. 42 (1988) 44, and 43 (1989) 219]. Here we report the results of micro-PIXE analyses of trace element (Ti, V, Cr, Fe, Cu and Ga) concentrations of a large set ( n = 130) of natural rough rubies from nine locations in Myanmar (Burma). The resulting concentrations are subjected to statistical analysis. Six of the nine groups form clusters when the data base is evaluated using tree clustering and principal component analysis.

  20. On location of piezoelectric element in a smart-structure: numerical investigation and experiment

    NASA Astrophysics Data System (ADS)

    Oshmarin, D.; Iurlov, M.

    2017-06-01

    In this paper, based on some example problems it was demonstrated that in examining the possibilities of smart structure applications, the matter of considerable researchers’ concern is the problem of location of piezoelectric elements in the structure to allow effective realization of its smart functions in the framework of the specified strategy of structure control and target purposes (vibration damping, defectoscopy, etc.) The numerical and experimental investigations have shown that for structures with the elements made of piezoelectric materials, it is more convenient to use as a parameter, specifying the best location of the piezoelectric element for damping the vibrations at the prescribed frequency, the coefficient of electromechanical coupling, which is evaluated by the values of eigenfrequencies of the structure in the short-circuit and open-circuit regimes. The values of eigenfrequencies of vibrations are evaluated by solving the problem of natural vibrations of electromechanical systems by the finite element method using the applied ANSYS package. The investigation were conducted for a thin-walled aluminum shell in the form of half-cylinder.

  1. An autoregulatory enhancer element of the Drosophila homeotic gene Deformed.

    PubMed

    Bergson, C; McGinnis, W

    1990-12-01

    The stable determination of different anterior-posterior regions of the Drosophila embryo is controlled by the persistent expression of homeotic selector genes. One mechanism that has been proposed to explain the persistent expression of the homeotic gene Deformed is an autoactivation circuit that would be used once Deformed expression had been established by earlier acting patterning genes. Here we show that a large cis-regulatory element mapping approximately 5 kb upstream of the Deformed transcription start has the properties predicted for a Deformed autoregulatory enhancer. This element provides late, spatially localized expression in the epidermal cells of the maxillary and mandibular segments which is wholly dependent upon endogenous Deformed function. In addition, the autoregulatory enhancer can be activated ectopically in embryos and in imaginal disc cells by ectopic expression of Deformed protein. Deletion analysis of the autoregulatory element indicates that it contains compartment specific sub-elements similar to those of other homeotic loci.

  2. Trace element fingerprinting of cockle (Cerastoderma edule) shells can reveal harvesting location in adjacent areas

    PubMed Central

    Ricardo, Fernando; Génio, Luciana; Costa Leal, Miguel; Albuquerque, Rui; Queiroga, Henrique; Rosa, Rui; Calado, Ricardo

    2015-01-01

    Determining seafood geographic origin is critical for controlling its quality and safeguarding the interest of consumers. Here, we use trace element fingerprinting (TEF) of bivalve shells to discriminate the geographic origin of specimens. Barium (Ba), manganese (Mn), magnesium (Mg), strontium (Sr) and lead (Pb) were quantified in cockle shells (Cerastoderma edule) captured with two fishing methods (by hand and by hand-raking) and from five adjacent fishing locations within an estuarine system (Ria de Aveiro, Portugal). Results suggest no differences in TEF of cockle shells captured by hand or by hand-raking, thus confirming that metal rakes do not act as a potential source of metal contamination that could somehow bias TEF results. In contrast, significant differences were recorded among locations for all trace elements analysed. A Canonical Analysis of Principal Coordinates (CAP) revealed that 92% of the samples could be successfully classified according to their fishing location using TEF. We show that TEF can be an accurate, fast and reliable method to determine the geographic origin of bivalves, even among locations separated less than 1 km apart within the same estuarine system. Nonetheless, follow up studies are needed to determine if TEF can reliably discriminate between bivalves originating from different ecosystems. PMID:26149418

  3. Trace element fingerprinting of cockle (Cerastoderma edule) shells can reveal harvesting location in adjacent areas.

    PubMed

    Ricardo, Fernando; Génio, Luciana; Costa Leal, Miguel; Albuquerque, Rui; Queiroga, Henrique; Rosa, Rui; Calado, Ricardo

    2015-07-07

    Determining seafood geographic origin is critical for controlling its quality and safeguarding the interest of consumers. Here, we use trace element fingerprinting (TEF) of bivalve shells to discriminate the geographic origin of specimens. Barium (Ba), manganese (Mn), magnesium (Mg), strontium (Sr) and lead (Pb) were quantified in cockle shells (Cerastoderma edule) captured with two fishing methods (by hand and by hand-raking) and from five adjacent fishing locations within an estuarine system (Ria de Aveiro, Portugal). Results suggest no differences in TEF of cockle shells captured by hand or by hand-raking, thus confirming that metal rakes do not act as a potential source of metal contamination that could somehow bias TEF results. In contrast, significant differences were recorded among locations for all trace elements analysed. A Canonical Analysis of Principal Coordinates (CAP) revealed that 92% of the samples could be successfully classified according to their fishing location using TEF. We show that TEF can be an accurate, fast and reliable method to determine the geographic origin of bivalves, even among locations separated less than 1 km apart within the same estuarine system. Nonetheless, follow up studies are needed to determine if TEF can reliably discriminate between bivalves originating from different ecosystems.

  4. Location, Location, Location!

    ERIC Educational Resources Information Center

    Ramsdell, Kristin

    2004-01-01

    Of prime importance in real estate, location is also a key element in the appeal of romances. Popular geographic settings and historical periods sell, unpopular ones do not--not always with a logical explanation, as the author discovered when she conducted a survey on this topic last year. (Why, for example, are the French Revolution and the…

  5. Location, Location, Location!

    ERIC Educational Resources Information Center

    Ramsdell, Kristin

    2004-01-01

    Of prime importance in real estate, location is also a key element in the appeal of romances. Popular geographic settings and historical periods sell, unpopular ones do not--not always with a logical explanation, as the author discovered when she conducted a survey on this topic last year. (Why, for example, are the French Revolution and the…

  6. Investigating the Microscopic Location of Trace Elements in High-Alpine Glacier Ice

    NASA Astrophysics Data System (ADS)

    Avak, Sven Erik; Birrer, Mario; Laurent, Oscar; Guillong, Marcel; Wälle, Markus; Jenk, Theo Manuel; Bartels-Rausch, Thorsten; Schwikowski, Margit; Eichler, Anja

    2017-04-01

    Past changes in atmospheric pollution can be reconstructed from high-alpine ice core trace element records (Schwikowski et al., 2004). Percolation of meltwater alters the information originally stored in these environmental archives. Eichler et al. (2001) suggested that the preservation of major ions with respect to meltwater percolation depends on their location in the crystal ice lattice, i.e. grain boundaries versus grain interiors. Other studies have also focused on the effect of meltwater on organic pollutant concentrations as well as on stable isotope profiles in ice cores, whereas no information exists about trace elements. Here, we investigate for the first time the effect of the microscopic location of anthropogenic, dust and volcanic related trace elements on the behavior during meltwater percolation by using two different approaches. On the one hand we assess the microscopic location of trace elements indirectly by analyzing trace element concentrations in a high-alpine ice core, which has been shown to be affected by an inflow of meltwater, using discrete inductively coupled plasma mass spectrometry (ICP-MS). Impurities located at grain boundaries are prone to be removed by meltwater and tend to be depleted in the affected section of the record whereas those incorporated into the ice interior are preserved and not disturbed in the record. In the second approach we work towards a direct quantification of differences in concentrations of trace elements between ice grain boundaries and grain interiors in samples both from unaffected and affected sections of this ice core. Therefore we use cryocell laser ablation (LA) ICP-MS, which is the method of choice for the direct in situ chemical analysis of trace elements at a sub-millimeter resolution in glacier ice (Reinhardt et al., 2001, Della Lunga et al., 2014, Sneed et al., 2015). We will present first results of both approaches with regard to the evaluation of the potential of trace elements as environmental

  7. Syringe filtration methods for examining dissolved and colloidal trace element distributions in remote field locations

    NASA Technical Reports Server (NTRS)

    Shiller, Alan M.

    2003-01-01

    It is well-established that sampling and sample processing can easily introduce contamination into dissolved trace element samples if precautions are not taken. However, work in remote locations sometimes precludes bringing bulky clean lab equipment into the field and likewise may make timely transport of samples to the lab for processing impossible. Straightforward syringe filtration methods are described here for collecting small quantities (15 mL) of 0.45- and 0.02-microm filtered river water in an uncontaminated manner. These filtration methods take advantage of recent advances in analytical capabilities that require only small amounts of waterfor analysis of a suite of dissolved trace elements. Filter clogging and solute rejection artifacts appear to be minimal, although some adsorption of metals and organics does affect the first approximately 10 mL of water passing through the filters. Overall the methods are clean, easy to use, and provide reproducible representations of the dissolved and colloidal fractions of trace elements in river waters. Furthermore, sample processing materials can be prepared well in advance in a clean lab and transported cleanly and compactly to the field. Application of these methods is illustrated with data from remote locations in the Rocky Mountains and along the Yukon River. Evidence from field flow fractionation suggests that the 0.02-microm filters may provide a practical cutoff to distinguish metals associated with small inorganic and organic complexes from those associated with silicate and oxide colloids.

  8. Syringe filtration methods for examining dissolved and colloidal trace element distributions in remote field locations

    NASA Technical Reports Server (NTRS)

    Shiller, Alan M.

    2003-01-01

    It is well-established that sampling and sample processing can easily introduce contamination into dissolved trace element samples if precautions are not taken. However, work in remote locations sometimes precludes bringing bulky clean lab equipment into the field and likewise may make timely transport of samples to the lab for processing impossible. Straightforward syringe filtration methods are described here for collecting small quantities (15 mL) of 0.45- and 0.02-microm filtered river water in an uncontaminated manner. These filtration methods take advantage of recent advances in analytical capabilities that require only small amounts of waterfor analysis of a suite of dissolved trace elements. Filter clogging and solute rejection artifacts appear to be minimal, although some adsorption of metals and organics does affect the first approximately 10 mL of water passing through the filters. Overall the methods are clean, easy to use, and provide reproducible representations of the dissolved and colloidal fractions of trace elements in river waters. Furthermore, sample processing materials can be prepared well in advance in a clean lab and transported cleanly and compactly to the field. Application of these methods is illustrated with data from remote locations in the Rocky Mountains and along the Yukon River. Evidence from field flow fractionation suggests that the 0.02-microm filters may provide a practical cutoff to distinguish metals associated with small inorganic and organic complexes from those associated with silicate and oxide colloids.

  9. The role of motion and number of element locations in mirror symmetry perception.

    PubMed

    Sharman, Rebecca J; Gheorghiu, Elena

    2017-04-04

    The human visual system has specialised mechanisms for encoding mirror-symmetry and for detecting symmetric motion-directions for objects that loom or recede from the observers. The contribution of motion to mirror-symmetry perception has never been investigated. Here we examine symmetry detection thresholds for stationary (static and dynamic flicker) and symmetrically moving patterns (inwards, outwards, random directions) with and without positional symmetry. We also measured motion detection and direction-discrimination thresholds for horizontal (left, right) and symmetrically moving patterns with and without positional symmetry. We found that symmetry detection thresholds were (a) significantly higher for static patterns, but there was no difference between the dynamic flicker and symmetrical motion conditions, and (b) higher than motion detection and direction-discrimination thresholds for horizontal or symmetrical motion, with or without positional symmetry. In addition, symmetrical motion was as easy to detect or discriminate as horizontal motion. We conclude that whilst symmetrical motion per se does not contribute to symmetry perception, limiting the lifetime of pattern elements does improve performance by increasing the number of element-locations as elements move from one location to the next. This may be explained by a temporal integration process in which weak, noisy symmetry signals are combined to produce a stronger signal.

  10. The role of motion and number of element locations in mirror symmetry perception

    PubMed Central

    Sharman, Rebecca J.; Gheorghiu, Elena

    2017-01-01

    The human visual system has specialised mechanisms for encoding mirror-symmetry and for detecting symmetric motion-directions for objects that loom or recede from the observers. The contribution of motion to mirror-symmetry perception has never been investigated. Here we examine symmetry detection thresholds for stationary (static and dynamic flicker) and symmetrically moving patterns (inwards, outwards, random directions) with and without positional symmetry. We also measured motion detection and direction-discrimination thresholds for horizontal (left, right) and symmetrically moving patterns with and without positional symmetry. We found that symmetry detection thresholds were (a) significantly higher for static patterns, but there was no difference between the dynamic flicker and symmetrical motion conditions, and (b) higher than motion detection and direction-discrimination thresholds for horizontal or symmetrical motion, with or without positional symmetry. In addition, symmetrical motion was as easy to detect or discriminate as horizontal motion. We conclude that whilst symmetrical motion per se does not contribute to symmetry perception, limiting the lifetime of pattern elements does improve performance by increasing the number of element-locations as elements move from one location to the next. This may be explained by a temporal integration process in which weak, noisy symmetry signals are combined to produce a stronger signal. PMID:28374760

  11. KENNEDY SPACE CENTER, FLA. - An overview of the Space Station Processing Facility shows workstands and ISS elements. The most recent additions are the Japanese Experiment Module (JEM)’s pressurized module and the Italian-built Node 2. The pressurized module is the first element of the JEM, Japan’s primary contribution to the Space Station, to be delivered to KSC. It will enhance the unique research capabilities of the orbiting complex by providing an additional shirt-sleeve environment for astronauts to conduct science experiments. Node 2 will be installed on the end of the U.S. Lab and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, later, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS.

    NASA Image and Video Library

    2003-06-06

    KENNEDY SPACE CENTER, FLA. - An overview of the Space Station Processing Facility shows workstands and ISS elements. The most recent additions are the Japanese Experiment Module (JEM)’s pressurized module and the Italian-built Node 2. The pressurized module is the first element of the JEM, Japan’s primary contribution to the Space Station, to be delivered to KSC. It will enhance the unique research capabilities of the orbiting complex by providing an additional shirt-sleeve environment for astronauts to conduct science experiments. Node 2 will be installed on the end of the U.S. Lab and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, later, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS.

  12. KENNEDY SPACE CENTER, FLA. - A view of the Space Station Processing Facility shows workstands and ISS elements. The most recent additions are the Japanese Experiment Module (JEM)’s pressurized module and the Italian-built Node 2. The pressurized module is the first element of the JEM, Japan’s primary contribution to the Space Station, to be delivered to KSC. It will enhance the unique research capabilities of the orbiting complex by providing an additional shirt-sleeve environment for astronauts to conduct science experiments. Node 2 will be installed on the end of the U.S. Lab and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, later, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS.

    NASA Image and Video Library

    2003-06-06

    KENNEDY SPACE CENTER, FLA. - A view of the Space Station Processing Facility shows workstands and ISS elements. The most recent additions are the Japanese Experiment Module (JEM)’s pressurized module and the Italian-built Node 2. The pressurized module is the first element of the JEM, Japan’s primary contribution to the Space Station, to be delivered to KSC. It will enhance the unique research capabilities of the orbiting complex by providing an additional shirt-sleeve environment for astronauts to conduct science experiments. Node 2 will be installed on the end of the U.S. Lab and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, later, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS.

  13. Using physics-based priors in a Bayesian algorithm to enhance infrasound source location

    NASA Astrophysics Data System (ADS)

    Marcillo, Omar; Arrowsmith, Stephen; Whitaker, Rod; Anderson, Dale; Nippress, Alexandra; Green, David N.; Drob, Douglas

    2014-01-01

    We show improvements in the precision of the Bayesian infrasound source localization (BISL) method by incorporating semi-empirical model-based prior information. Given a set of backazimuths and delay times at ≥2 arrays, BISL scans a parameter space (that comprises the horizontal coordinates, celerity and origin time) for the most likely solution. A key element of BISL is its flexibility; the method allows the incorporation of prior information to constrain the parameters. Our research focuses on generating model-based propagation catalogues using a comprehensive set of atmospheric scenarios, extracting celerity distributions based on range and azimuth from the catalogues and using these distributions as prior probability density functions to enhance the location solution from BISL. To illustrate the improvements in source location precision, we compare the BISL results computed using uniform celerity distribution priors with those using enhanced priors; as applied to: (1) a set of events recorded across a regional network and (2) a large accidental chemical explosion recorded by six infrasound arrays in Eurasia. Finally, we discuss efforts to improve the numerical implementation of BISL by expanding the parameter space to cover a richer set of parameters that can include station-specific celerity distributions.

  14. Disease-associated variants in different categories of disease located in distinct regulatory elements

    PubMed Central

    2015-01-01

    Background The invention of high throughput sequencing technologies has led to the discoveries of hundreds of thousands of genetic variants associated with thousands of human diseases. Many of these genetic variants are located outside the protein coding regions, and as such, it is challenging to interpret the function of these genetic variants by traditional genetic approaches. Recent genome-wide functional genomics studies, such as FANTOM5 and ENCODE have uncovered a large number of regulatory elements across hundreds of different tissues or cell lines in the human genome. These findings provide an opportunity to study the interaction between regulatory elements and disease-associated genetic variants. Identifying these diseased-related regulatory elements will shed light on understanding the mechanisms of how these variants regulate gene expression and ultimately result in disease formation and progression. Results In this study, we curated and categorized 27,558 Mendelian disease variants, 20,964 complex disease variants, 5,809 cancer predisposing germline variants, and 43,364 recurrent cancer somatic mutations. Compared against nine different types of regulatory regions from FANTOM5 and ENCODE projects, we found that different types of disease variants show distinctive propensity for particular regulatory elements. Mendelian disease variants and recurrent cancer somatic mutations are 22-fold and 10- fold significantly enriched in promoter regions respectively (q<0.001), compared with allele-frequency-matched genomic background. Separate from these two categories, cancer predisposing germline variants are 27-fold enriched in histone modification regions (q<0.001), 10-fold enriched in chromatin physical interaction regions (q<0.001), and 6-fold enriched in transcription promoters (q<0.001). Furthermore, Mendelian disease variants and recurrent cancer somatic mutations share very similar distribution across types of functional effects. We further found that

  15. Disease-associated variants in different categories of disease located in distinct regulatory elements.

    PubMed

    Ma, Meng; Ru, Ying; Chuang, Ling-Shiang; Hsu, Nai-Yun; Shi, Li-Song; Hakenberg, Jörg; Cheng, Wei-Yi; Uzilov, Andrew; Ding, Wei; Glicksberg, Benjamin S; Chen, Rong

    2015-01-01

    The invention of high throughput sequencing technologies has led to the discoveries of hundreds of thousands of genetic variants associated with thousands of human diseases. Many of these genetic variants are located outside the protein coding regions, and as such, it is challenging to interpret the function of these genetic variants by traditional genetic approaches. Recent genome-wide functional genomics studies, such as FANTOM5 and ENCODE have uncovered a large number of regulatory elements across hundreds of different tissues or cell lines in the human genome. These findings provide an opportunity to study the interaction between regulatory elements and disease-associated genetic variants. Identifying these diseased-related regulatory elements will shed light on understanding the mechanisms of how these variants regulate gene expression and ultimately result in disease formation and progression. In this study, we curated and categorized 27,558 Mendelian disease variants, 20,964 complex disease variants, 5,809 cancer predisposing germline variants, and 43,364 recurrent cancer somatic mutations. Compared against nine different types of regulatory regions from FANTOM5 and ENCODE projects, we found that different types of disease variants show distinctive propensity for particular regulatory elements. Mendelian disease variants and recurrent cancer somatic mutations are 22-fold and 10- fold significantly enriched in promoter regions respectively (q<0.001), compared with allele-frequency-matched genomic background. Separate from these two categories, cancer predisposing germline variants are 27-fold enriched in histone modification regions (q<0.001), 10-fold enriched in chromatin physical interaction regions (q<0.001), and 6-fold enriched in transcription promoters (q<0.001). Furthermore, Mendelian disease variants and recurrent cancer somatic mutations share very similar distribution across types of functional effects. We further found that regulatory regions are

  16. Heating Location Control of HIFU Treatment Enhanced with Microbubbles

    NASA Astrophysics Data System (ADS)

    Nishihara, T.; Utashiro, H.; Ichiyanagi, M.; Yoshinaka, K.; Takagi, S.; Matsumoto, Y.

    2011-09-01

    High-intensity focused ultrasound (HIFU) treatment using ultrasound contrast microbubbles for enhancing the heating effect has been developed with the aim of realising a less invasive tumor therapy. The focused sound waves result in an increase in temperature and increased thermal absorption, which necroses tumor cells. In addition, microbubbles are used as contrast agents for ultrasound imaging, and, in a previous study, we used microbubbles to enhance the heating effect. However, when microbubbles exist in the ultrasound pathway, they disturb ultrasound propagation and distort the acoustic field. Distortion of the acoustic field leads to defocusing and causes unexpected damage to tissue in the body. The objective of the present study is to propose a method by which to destroy microbubbles in the ultrasound pathway and to focus the thermal energy only at the focal point. The proposed method consists of two steps. The first step is to use repetitive high-intensity, short-burst waves (20 waves) to destroy the microbubbles in the pathway. In the second step, low amplitude continuous waves are sent in order to heat the focal point. This method was successful for a gel containing microbubbles with a void fraction on the order of 10-4. The results of the present study indicate that more microbubbles were destroyed as the non-exposure time and the pulse number were increased during the first step.

  17. Considering Affective Responses towards Environments for Enhancing Location Based Services

    NASA Astrophysics Data System (ADS)

    Huang, H.; Gartner, G.; Klettner, S.; Schmidt, M.

    2014-04-01

    A number of studies in the field of environmental psychology show that humans perceive and evaluate their surroundings affectively. Some places are experienced as unsafe, while some others as attractive and interesting. Experiences from daily life show that many of our daily behaviours and decision-making are often influenced by this kind of affective responses towards environments. Location based services (LBS) are often designed to assist and support people's behaviours and decision-making in space. In order to provide services with high usefulness (usability and utility), LBS should consider these kinds of affective responses towards environments. This paper reports on the results of a research project, which studies how people's affective responses towards environments can be modelled and acquired, as well as how LBS can benefit by considering these affective responses. As one of the most popular LBS applications, mobile pedestrian navigation systems are used as an example for illustration.

  18. Failure location prediction by finite element analysis for an additive manufactured mandible implant.

    PubMed

    Huo, Jinxing; Dérand, Per; Rännar, Lars-Erik; Hirsch, Jan-Michaél; Gamstedt, E Kristofer

    2015-09-01

    In order to reconstruct a patient with a bone defect in the mandible, a porous scaffold attached to a plate, both in a titanium alloy, was designed and manufactured using additive manufacturing. Regrettably, the implant fractured in vivo several months after surgery. The aim of this study was to investigate the failure of the implant and show a way of predicting the mechanical properties of the implant before surgery. All computed tomography data of the patient were preprocessed to remove metallic artefacts with metal deletion technique before mandible geometry reconstruction. The three-dimensional geometry of the patient's mandible was also reconstructed, and the implant was fixed to the bone model with screws in Mimics medical imaging software. A finite element model was established from the assembly of the mandible and the implant to study stresses developed during mastication. The stress distribution in the load-bearing plate was computed, and the location of main stress concentration in the plate was determined. Comparison between the fracture region and the location of the stress concentration shows that finite element analysis could serve as a tool for optimizing the design of mandible implants. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

  19. Experimental and Computational Investigation of Lift-Enhancing Tabs on a Multi-Element Airfoil

    NASA Technical Reports Server (NTRS)

    Ashby, Dale L.

    1996-01-01

    An experimental and computational investigation of the effect of lift-enhancing tabs on a two-element airfoil has been conducted. The objective of the study was to develop an understanding of the flow physics associated with lift-enhancing tabs on a multi-element airfoil. An NACA 63(2)-215 ModB airfoil with a 30% chord fowler flap was tested in the NASA Ames 7- by 10-Foot Wind Tunnel. Lift-enhancing tabs of various heights were tested on both the main element and the flap for a variety of flap riggings. A combination of tabs located at the main element and flap trailing edges increased the airfoil lift coefficient by 11% relative to the highest lift coefficient achieved by any baseline configuration at an angle of attack of 0 deg, and C(sub 1max) was increased by 3%. Computations of the flow over the two-element airfoil were performed using the two-dimensional incompressible Navier-Stokes code INS2D-UP. The computed results predicted all of the trends observed in the experimental data quite well. In addition, a simple analytic model based on potential flow was developed to provide a more detailed understanding of how lift-enhancing tabs work. The tabs were modeled by a point vortex at the air-foil or flap trailing edge. Sensitivity relationships were derived which provide a mathematical basis for explaining the effects of lift-enhancing tabs on a multi-element airfoil. Results of the modeling effort indicate that the dominant effects of the tabs on the pressure distribution of each element of the airfoil can be captured with a potential flow model for cases with no flow separation.

  20. TE-Locate: A Tool to Locate and Group Transposable Element Occurrences Using Paired-End Next-Generation Sequencing Data

    PubMed Central

    Platzer, Alexander; Nizhynska, Viktoria; Long, Quan

    2012-01-01

    Transposable elements (TEs) are common mobile DNA elements present in nearly all genomes. Since the movement of TEs within a genome can sometimes have phenotypic consequences, an accurate report of TE actions is desirable. To this end, we developed TE-Locate, a computational tool that uses paired-end reads to identify the novel locations of known TEs. TE-Locate can utilize either a database of TE sequences, or annotated TEs within the reference sequence of interest. This makes TE-Locate useful in the search for any mobile sequence, including retrotransposed gene copies. One major concern is to act on the correct hierarchy level, thereby avoiding an incorrect calling of a single insertion as multiple events of TEs with high sequence similarity. We used the (super)family level, but TE-Locate can also use any other level, right down to the individual transposable element. As an example of analysis with TE-Locate, we used the Swedish population in the 1,001 Arabidopsis genomes project, and presented the biological insights gained from the novel TEs, inducing the association between different TE superfamilies. The program is freely available, and the URL is provided in the end of the paper. PMID:24832231

  1. TE-Locate: A Tool to Locate and Group Transposable Element Occurrences Using Paired-End Next-Generation Sequencing Data.

    PubMed

    Platzer, Alexander; Nizhynska, Viktoria; Long, Quan

    2012-09-12

    Transposable elements (TEs) are common mobile DNA elements present in nearly all genomes. Since the movement of TEs within a genome can sometimes have phenotypic consequences, an accurate report of TE actions is desirable. To this end, we developed TE-Locate, a computational tool that uses paired-end reads to identify the novel locations of known TEs. TE-Locate can utilize either a database of TE sequences, or annotated TEs within the reference sequence of interest. This makes TE-Locate useful in the search for any mobile sequence, including retrotransposed gene copies. One major concern is to act on the correct hierarchy level, thereby avoiding an incorrect calling of a single insertion as multiple events of TEs with high sequence similarity. We used the (super)family level, but TE-Locate can also use any other level, right down to the individual transposable element. As an example of analysis with TE-Locate, we used the Swedish population in the 1,001 Arabidopsis genomes project, and presented the biological insights gained from the novel TEs, inducing the association between different TE superfamilies. The program is freely available, and the URL is provided in the end of the paper.

  2. Elemental abundances of flaring solar plasma - Enhanced neon and sulfur

    NASA Technical Reports Server (NTRS)

    Schmelz, J. T.

    1993-01-01

    Elemental abundances of two flares observed with the SMM Flat Crystal Spectrometer are compared and contrasted. The first had a gradual rise and a slow decay, while the second was much more impulsive. Simultaneous spectra of seven bright soft X-ray resonance lines provide information over a broad temperature range and are available throughout both flares, making these events unique in the SMM data base. For the first flare, the plasma seemed to be characterized by coronal abundances but, for the second, the plasma composition could not be coronal, photospheric, or a linear combination of both. A good differential emission measure fit required enhanced neon such that Ne/O = 0.32 +/- 0.02, a value which is inconsistent with the current models of coronal abundances based on the elemental first-ionization potential. Similar values of enhanced neon are found for flaring plasma observed by the SMM gamma-ray spectrometer, in (He-3)-rich solar energetic particle events, and in the decay phase of several long duration soft X-ray events. Sulfur is also enhanced in the impulsive flare, but not as dramatically as neon. These events are compared with two models which attempt to explain the enhanced values of neon and sulfur.

  3. Elemental abundances of flaring solar plasma - Enhanced neon and sulfur

    NASA Technical Reports Server (NTRS)

    Schmelz, J. T.

    1993-01-01

    Elemental abundances of two flares observed with the SMM Flat Crystal Spectrometer are compared and contrasted. The first had a gradual rise and a slow decay, while the second was much more impulsive. Simultaneous spectra of seven bright soft X-ray resonance lines provide information over a broad temperature range and are available throughout both flares, making these events unique in the SMM data base. For the first flare, the plasma seemed to be characterized by coronal abundances but, for the second, the plasma composition could not be coronal, photospheric, or a linear combination of both. A good differential emission measure fit required enhanced neon such that Ne/O = 0.32 +/- 0.02, a value which is inconsistent with the current models of coronal abundances based on the elemental first-ionization potential. Similar values of enhanced neon are found for flaring plasma observed by the SMM gamma-ray spectrometer, in (He-3)-rich solar energetic particle events, and in the decay phase of several long duration soft X-ray events. Sulfur is also enhanced in the impulsive flare, but not as dramatically as neon. These events are compared with two models which attempt to explain the enhanced values of neon and sulfur.

  4. Harvest locations of goose barnacles can be successfully discriminated using trace elemental signatures

    NASA Astrophysics Data System (ADS)

    Albuquerque, Rui; Queiroga, Henrique; Swearer, Stephen E.; Calado, Ricardo; Leandro, Sérgio M.

    2016-06-01

    European Union regulations state that consumers must be rightfully informed about the provenance of fishery products to prevent fraudulent practices. However, mislabeling of the geographical origin is a common practice. It is therefore paramount to develop forensic methods that allow all players involved in the supply chain to accurately trace the origin of seafood. In this study, trace elemental signatures (TES) of the goose barnacle Pollicipes pollicipes, collected from ten sites along the Portuguese coast, were employed to discriminate individual’s origin. Barium (Ba), boron (B), cadmium (Cd), chromium (Cr), lithium (Li), magnesium (Mg), manganese (Mn), phosphorous (P), lead (Pb), strontium (Sr) and zinc (Zn) - were quantified using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). Significant differences were recorded among locations for all elements. A regularized discriminant analysis (RDA) revealed that 83% of all individuals were correctly assigned. This study shows TES can be a reliable tool to confirm the geographic origin of goose barnacles at fine spatial resolution. Although additional studies are required to ascertain the reliability of TES on cooked specimens and the temporal stability of the signature, the approach holds great promise for the management of goose barnacles fisheries, enforcement of conservation policies and assurance in accurate labeling.

  5. Harvest locations of goose barnacles can be successfully discriminated using trace elemental signatures

    PubMed Central

    Albuquerque, Rui; Queiroga, Henrique; Swearer, Stephen E.; Calado, Ricardo; Leandro, Sérgio M.

    2016-01-01

    European Union regulations state that consumers must be rightfully informed about the provenance of fishery products to prevent fraudulent practices. However, mislabeling of the geographical origin is a common practice. It is therefore paramount to develop forensic methods that allow all players involved in the supply chain to accurately trace the origin of seafood. In this study, trace elemental signatures (TES) of the goose barnacle Pollicipes pollicipes, collected from ten sites along the Portuguese coast, were employed to discriminate individual’s origin. Barium (Ba), boron (B), cadmium (Cd), chromium (Cr), lithium (Li), magnesium (Mg), manganese (Mn), phosphorous (P), lead (Pb), strontium (Sr) and zinc (Zn) - were quantified using Inductively Coupled Plasma−Mass Spectrometry (ICP-MS). Significant differences were recorded among locations for all elements. A regularized discriminant analysis (RDA) revealed that 83% of all individuals were correctly assigned. This study shows TES can be a reliable tool to confirm the geographic origin of goose barnacles at fine spatial resolution. Although additional studies are required to ascertain the reliability of TES on cooked specimens and the temporal stability of the signature, the approach holds great promise for the management of goose barnacles fisheries, enforcement of conservation policies and assurance in accurate labeling. PMID:27292413

  6. Harvest locations of goose barnacles can be successfully discriminated using trace elemental signatures.

    PubMed

    Albuquerque, Rui; Queiroga, Henrique; Swearer, Stephen E; Calado, Ricardo; Leandro, Sérgio M

    2016-06-13

    European Union regulations state that consumers must be rightfully informed about the provenance of fishery products to prevent fraudulent practices. However, mislabeling of the geographical origin is a common practice. It is therefore paramount to develop forensic methods that allow all players involved in the supply chain to accurately trace the origin of seafood. In this study, trace elemental signatures (TES) of the goose barnacle Pollicipes pollicipes, collected from ten sites along the Portuguese coast, were employed to discriminate individual's origin. Barium (Ba), boron (B), cadmium (Cd), chromium (Cr), lithium (Li), magnesium (Mg), manganese (Mn), phosphorous (P), lead (Pb), strontium (Sr) and zinc (Zn) - were quantified using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). Significant differences were recorded among locations for all elements. A regularized discriminant analysis (RDA) revealed that 83% of all individuals were correctly assigned. This study shows TES can be a reliable tool to confirm the geographic origin of goose barnacles at fine spatial resolution. Although additional studies are required to ascertain the reliability of TES on cooked specimens and the temporal stability of the signature, the approach holds great promise for the management of goose barnacles fisheries, enforcement of conservation policies and assurance in accurate labeling.

  7. Visual processing at goal and effector locations is dynamically enhanced during motor preparation.

    PubMed

    Mason, Luke; Linnell, Karina J; Davis, Rob; Van Velzen, José

    2015-08-15

    Previous theoretical and experimental works has shown that preparing to act causes enhanced perceptual processing at movement-relevant locations. Up until now, this has focused almost exclusively on the goal of an action, neglecting the role of the effector. We addressed this by measuring changes in visual processing across time during motor preparation at both goal and effector locations. We compared event related potentials (ERPs) elicited by task-irrelevant visual probe stimuli at both goal and effector locations during motor preparation. Participants were instructed to place their hands on two starting positions (effector locations) and an auditory tone instructed them to immediately move to one of two target buttons (goal locations). Probe stimuli were presented in the interval between the offset of the cue and the execution of the movement at either a goal or an effector location. Probes were presented randomly at either 100ms, 200ms or 300ms after the auditory cue. Analysis of the visual N1 ERP showed enhanced visual processing at moving vs. not-moving goal locations across all three SOAs. At effector locations, enhanced processing for the moving vs. not-moving effector was only observed during the middle (200ms) SOA. These results demonstrate, for the first time, simultaneous perceptual enhancement of goal and effector locations during motor preparation. We interpret these results as reflecting a temporally and spatially specific dynamic attentional map of the environment that adapts to maximise efficiency of movement by selectively weighting processing of multiple functional components of action in parallel.

  8. An AP-2 element acts synergistically with the cyclic AMP- and Phorbol ester-inducible enhancer of the human proenkephalin gene

    SciTech Connect

    Hyman, S.E.; Comb, M.; Pearlberg, J.; Goodman, H.M.

    1989-01-01

    An enhancer with two DNA elements, one containing the sequence CGTCA, is required for cyclic AMP-and phorbol ester-inducible transcription of the human proenkephalin gene. The authors report that an AP-2 element located adjacent to the enhancer acts synergistically with it to confer maximal response to cyclic AMP and phorbol esters.

  9. Nanoparticle location and material dependent dose enhancement in X-ray radiation therapy

    PubMed Central

    Hossain, Mainul

    2012-01-01

    Nanoparticles of high atomic number (Z) materials can act as radiosensitizers to enhance radiation dose delivered to tumors. An analytical approach is used to calculate dose enhancements to tumor endothelial cells and their nuclei for a series of nanoparticles (bismuth, gold and platinum) located at different locations relative to nuclei by considering contributions from both photoelectrons and Auger electrons. The ratio of the dose delivered to cells with and without the nanoparticles is known as the dose enhancement factor (DEF). DEFs depend on material composition, size and location of nanoparticles with respect to the cell and the nucleus. Energy of irradiating X-ray beam affects X-ray absorption by nanoparticles and plays an important role in dose enhancements. For diagnostic X-ray sources, bismuth nanoparticles provide higher dose enhancements than gold and platinum nanoparticles for a given nanoparticle size, concentration and location. The highest DEFs are achieved for nanoparticles located closest to the nucleus where energy depositions from short range Auger electrons are maximum. With nanoparticles ranging in diameter between 2-400 nm, the dose enhancement increases with decrease in particle size. The results are useful in finding optimized conditions for nanoparticle enhanced X-ray radiation therapy of cancer. PMID:23393610

  10. Mutations in ash1 and trx enhance P-element-dependent silencing in Drosophila melanogaster.

    PubMed

    McCracken, Allen; Locke, John

    2016-08-01

    In Drosophila melanogaster, the mini-w(+) transgene in Pci is normally expressed throughout the adult eye; however, when other P or KP elements are present, a variegated-eye phenotype results, indicating random w(+) silencing during development called P-element-dependent silencing (PDS). Mutant Su(var)205 and Su(var)3-7 alleles act as haplo-suppressors/triplo-enhancers of this variegated phenotype, indicating that these heterochromatic modifiers act dose dependently in PDS. Previously, we recovered a spontaneous mutation of P{lacW}ci(Dplac) called P{lacW}ci(DplacE1) (E1) that variegated in the absence of P elements, presumably due to the insertion of an adjacent gypsy element. From a screen for genetic modifiers of E1 variegation, we describe here the isolation of five mutations in ash1 and three in trx that enhance the E1 variegated phenotype in a dose-dependent and cumulative manner. These mutant alleles enhance PDS at E1, and in E1/P{lacW}ci(Dplac), but suppress position effect variegation (PEV) at In(1)w(m)(4). This opposite action is consistent with a model where ASH1 and TRX mark transcriptionally active chromatin domains. If ASH1 or TRX function is lost or reduced, heterochromatin can spread into these domains creating a sink that diverts heterochromatic proteins from other variegating locations, which then may express a suppressed phenotype.

  11. Experimental Study of Lift-Enhancing Tabs on a Two-Element Airfoil

    NASA Technical Reports Server (NTRS)

    Storms, Bruce L.; Ross, James C.

    1995-01-01

    The results of a wind-tunnel test are presented for a two-dimensional NASA 63(sub 2)-215 Mod B airfoil with a 30% chord single-slotted flap. The use of lift-enhancing tabs (similar to Gurney flaps) on the lower surface near the trailing edge of both elements was investigated on four nap configurations. A combination of vortex generators on the flap and lift-enhancing tabs was also investigated. Measurements of surface-pressure distributions and wake profiles were used to determine the aerodynamic performance of each configuration. By reducing flow separation on the flap, a lift-enhancing tab at the main-element trailing edge increased the maximum lift by 10.3% for the 42-deg flap case. The tab had a lesser effect at a moderate flap deflection (32 deg) and adversely affected the performance at the smallest flap deflection (22 deg). A tab located near the flap trailing edge produced an additional lift increment for all flap deflections. The application of vortex generators to the flap eliminated lift-curve hysteresis and reduced flow separation on two configurations with large flap deflections (greater than 40 deg). A maximum-lift coefficient of 3.32 (17% above the optimum baseline) was achieved with the combination of lift-enhancing tabs on both elements and vortex generators on the flap.

  12. Multiple sequence elements facilitate Chp Rho GTPase subcellular location, membrane association, and transforming activity.

    PubMed

    Chenette, Emily J; Mitin, Natalia Y; Der, Channing J

    2006-07-01

    Cdc42 homologous protein (Chp) is a member of the Rho family of small GTPases and shares significant sequence and functional similarity with Cdc42. However, unlike classical Rho GTPases, we recently found that Chp depends on palmitoylation, rather than prenylation, for association with cellular membranes. Because palmitoylation alone is typically not sufficient to promote membrane association, we evaluated the possibility that other carboxy-terminal residues facilitate Chp subcellular association with membranes. We found that Chp membrane association and transforming activity was dependent on the integrity of a stretch of basic amino acids in the carboxy terminus of Chp and that the basic amino acids were not simply part of a palmitoyl acyltransferase recognition motif. We also determined that the 11 carboxy-terminal residues alone were sufficient to promote Chp plasma and endomembrane association. Interestingly, stimulation with tumor necrosis factor-alpha activated only endomembrane-associated Chp. Finally, we found that Chp membrane association was not disrupted by Rho guanine nucleotide dissociation inhibitory proteins, which are negative regulators of Cdc42 membrane association and biological activity. In summary, the unique carboxy-terminal sequence elements that promote Chp subcellular location and function expand the complexity of mechanisms by which the cellular functions of Rho GTPases are regulated.

  13. Multiple Sequence Elements Facilitate Chp Rho GTPase Subcellular Location, Membrane Association, and Transforming Activity

    PubMed Central

    Chenette, Emily J.; Mitin, Natalia Y.

    2006-01-01

    Cdc42 homologous protein (Chp) is a member of the Rho family of small GTPases and shares significant sequence and functional similarity with Cdc42. However, unlike classical Rho GTPases, we recently found that Chp depends on palmitoylation, rather than prenylation, for association with cellular membranes. Because palmitoylation alone is typically not sufficient to promote membrane association, we evaluated the possibility that other carboxy-terminal residues facilitate Chp subcellular association with membranes. We found that Chp membrane association and transforming activity was dependent on the integrity of a stretch of basic amino acids in the carboxy terminus of Chp and that the basic amino acids were not simply part of a palmitoyl acyltransferase recognition motif. We also determined that the 11 carboxy-terminal residues alone were sufficient to promote Chp plasma and endomembrane association. Interestingly, stimulation with tumor necrosis factor-α activated only endomembrane-associated Chp. Finally, we found that Chp membrane association was not disrupted by Rho guanine nucleotide dissociation inhibitory proteins, which are negative regulators of Cdc42 membrane association and biological activity. In summary, the unique carboxy-terminal sequence elements that promote Chp subcellular location and function expand the complexity of mechanisms by which the cellular functions of Rho GTPases are regulated. PMID:16641371

  14. Modelling elemental carbon at regional, urban and traffic locations in The Netherlands

    NASA Astrophysics Data System (ADS)

    Keuken, M. P.; Zandveld, P.; Jonkers, S.; Moerman, M.; Jedynska, A. D.; Verbeek, R.; Visschedijk, A.; Elshout van den, S.; Panteliadis, P.; Velders, G. J. M.

    2013-07-01

    The annual concentration of elemental carbon (EC) has been derived for The Netherlands in 2011. National emissions contribute 55% to the average EC concentration in the Netherlands. About 65% of the national contribution comes from emissions from road traffic and about 35% from other mobile sources (15%), households (14%), shipping (4%) and other combustion sources (2%). Conversion factors were established to compare different methods of EC measurement such as Black Smoke, Black Carbon and thermal analysis. The measured regional and urban background concentrations and variability were 0.5 ± 0.1 and 0.9 ± 0.1 μg EC per m3, respectively. The ratios between modelled and measured regional and urban background concentrations were 1.6 ± 0.5 and 1.8 ± 0.4, respectively. The modelled values are likely to be overestimated. The modelled and measured traffic contributions to EC concentrations near motorways and in street canyons were in the range 1.1-1.3 μg m-3 with total EC concentrations of 2.0 and 2.2 μg m-3, respectively. Our study showed that EC concentrations near intense traffic are increased with a factor 2-4 as compared to the urban and regional background, respectively. Consequently there is a similar variation in exposure and potential health effects in the population. More measurements of EC are required to improve modelling of EC concentrations in particular at urban background and near traffic locations.

  15. Enhanced associative memory for colour (but not shape or location) in synaesthesia.

    PubMed

    Pritchard, Jamie; Rothen, Nicolas; Coolbear, Daniel; Ward, Jamie

    2013-05-01

    People with grapheme-colour synaesthesia have been shown to have enhanced memory on a range of tasks using both stimuli that induce synaesthesia (e.g. words) and, more surprisingly, stimuli that do not (e.g. certain abstract visual stimuli). This study examines the latter by using multi-featured stimuli consisting of shape, colour and location conjunctions (e.g. shape A+colour A+location A; shape B+colour B+location B) presented in a recognition memory paradigm. This enables distractor items to be created in which one of these features is 'unbound' with respect to the others (e.g. shape A+colour B+location A; shape A+colour A+location C). Synaesthetes had higher recognition rates suggesting an enhanced ability to bind certain visual features together into memory. Importantly, synaesthetes' false alarm rates were lower only when colour was the unbound feature, not shape or location. We suggest that synaesthetes are "colour experts" and that enhanced perception can lead to enhanced memory in very specific ways; but, not for instance, an enhanced ability to form associations per se. The results support contemporary models that propose a continuum between perception and memory.

  16. Method of locating a leaking fuel element in a fast breeder power reactor

    DOEpatents

    Honekamp, John R.; Fryer, Richard M.

    1978-01-01

    Leaking fuel elements in a fast reactor are identified by measuring the ratio of .sup.134 Xe to .sup.133 Xe in the reactor cover gas following detection of a fuel element leak, this ratio being indicative of the power and burnup of the failed fuel element. This procedure can be used to identify leaking fuel elements in a power breeder reactor while continuing operation of the reactor since the ratio measured is that of the gases stored in the plenum of the failed fuel element. Thus, use of a cleanup system for the cover gas makes it possible to identify sequentially a multiplicity of leaking fuel elements without shutting the reactor down.

  17. Single-Shell Tanks Leak Integrity Elements/ SX Farm Leak Causes and Locations - 12127

    SciTech Connect

    Girardot, Crystal; Harlow, Don; Venetz, Theodore; Washenfelder, Dennis; Johnson, Jeremy

    2012-07-01

    Washington River Protection Solutions, LLC (WRPS) developed an enhanced single-shell tank (SST) integrity project in 2009. An expert panel on SST integrity was created to provide recommendations supporting the development of the project. One primary recommendation was to expand the leak assessment reports (substitute report or LD-1) to include leak causes and locations. The recommendation has been included in the M-045-91F Hanford Federal Facility Agreement and Consent Order (Tri-Party Agreement) as one of four targets relating to SST leak integrity. The 241-SX Farm (SX Farm) tanks with leak losses were addressed on an individual tank basis as part of LD-1. Currently, 8 out of 23 SSTs that have been reported to having a liner leak are located in SX Farm. This percentage was the highest compared to other tank farms which is why SX Farm was analyzed first. The SX Farm is comprised of fifteen SSTs built 1953-1954. The tanks are arranged in rows of three tanks each, forming a cascade. Each of the SX Farm tanks has a nominal 1-million-gal storage capacity. Of the fifteen tanks in SX Farm, an assessment reported leak losses for the following tanks: 241-SX-107, 241-SX-108, 241-SX-109, 241-SX- 111, 241-SX-112, 241-SX-113, 241-SX-114 and 241-SX-115. The method used to identify leak location consisted of reviewing in-tank and ex-tank leak detection information. This provided the basic data identifying where and when the first leaks were detected. In-tank leak detection consisted of liquid level measurement that can be augmented with photographs which can provide an indication of the vertical leak location on the sidewall. Ex-tank leak detection for the leaking tanks consisted of soil radiation data from laterals and dry-wells near the tank. The in-tank and ex-tank leak detection can provide an indication of the possible leak location radially around and under the tank. Potential leak causes were determined using in-tank and ex-tank information that is not directly related to

  18. SINGLE-SHELL TANKS LEAK INTEGRITY ELEMENTS/SX FARM LEAK CAUSES AND LOCATIONS - 12127

    SciTech Connect

    VENETZ TJ; WASHENFELDER D; JOHNSON J; GIRARDOT C

    2012-01-25

    Washington River Protection Solutions, LLC (WRPS) developed an enhanced single-shell tank (SST) integrity project in 2009. An expert panel on SST integrity was created to provide recommendations supporting the development of the project. One primary recommendation was to expand the leak assessment reports (substitute report or LD-1) to include leak causes and locations. The recommendation has been included in the M-045-9IF Hanford Federal Facility Agreement and Consent Order (Tri-Party Agreement) as one of four targets relating to SST leak integrity. The 241-SX Farm (SX Farm) tanks with leak losses were addressed on an individual tank basis as part of LD-1. Currently, 8 out of 23 SSTs that have been reported to having a liner leak are located in SX Farm. This percentage was the highest compared to other tank farms which is why SX Farm was analyzed first. The SX Farm is comprised of fifteen SSTs built 1953-1954. The tanks are arranged in rows of three tanks each, forming a cascade. Each of the SX Farm tanks has a nominal I-million-gal storage capacity. Of the fifteen tanks in SX Farm, an assessment reported leak losses for the following tanks: 241-SX-107, 241-SX-108, 241-SX-109, 241-SX-111, 241-SX-112, 241-SX-113, 241-SX-114 and 241-SX-115. The method used to identify leak location consisted of reviewing in-tank and ex-tank leak detection information. This provided the basic data identifying where and when the first leaks were detected. In-tank leak detection consisted of liquid level measurement that can be augmented with photographs which can provide an indication of the vertical leak location on the sidewall. Ex-tank leak detection for the leaking tanks consisted of soil radiation data from laterals and drywells near the tank. The in-tank and ex-tank leak detection can provide an indication of the possible leak location radially around and under the tank. Potential leak causes were determined using in-tank and ex-tank information that is not directly related to

  19. Dispersive Elements for Enhanced Laser Gyroscopy and Cavity Stabilization

    NASA Technical Reports Server (NTRS)

    Smith, David D.; Chang, Hongrok; Diels, J. C.

    2007-01-01

    We analyze the effect of a highly dispersive element placed inside a modulated optical cavity on the frequency and amplitude of the modulation to determine the conditions for cavity self-stabilization and enhanced gyroscopic sensitivity. We find an enhancement in the sensitivity of a laser gyroscope to rotation for normal dispersion, while anomalous dispersion can be used to self-stabilize an optical cavity. Our results indicate that atomic media, even coherent superpositions in multilevel atoms, are of limited use for these applications, because the amplitude and phase filters work against one another, i.e., decreasing the modulation frequency increases its amplitude and vice-versa. On the other hand, for optical resonators the dispersion reversal associated with critical coupling enables the amplitude and phase filters to work together. We find that for over-coupled resonators, the absorption and normal dispersion on-resonance increase the contrast and frequency of the beat-note, respectively, resulting in a substantial enhancement of the gyroscopic response. Under-coupled resonators can be used to stabilize the frequency of a laser cavity, but result in a concomitant increase in amplitude fluctuations. As a more ideal solution we propose the use of a variety of coupled-resonator-induced transparency that is accompanied by anomalous dispersion.

  20. Variation in the genomic locations and sequence conservation of STAR elements among staphylococcal species provides insight into DNA repeat evolution

    PubMed Central

    2012-01-01

    Background Staphylococcus aureus Repeat (STAR) elements are a type of interspersed intergenic direct repeat. In this study the conservation and variation in these elements was explored by bioinformatic analyses of published staphylococcal genome sequences and through sequencing of specific STAR element loci from a large set of S. aureus isolates. Results Using bioinformatic analyses, we found that the STAR elements were located in different genomic loci within each staphylococcal species. There was no correlation between the number of STAR elements in each genome and the evolutionary relatedness of staphylococcal species, however higher levels of repeats were observed in both S. aureus and S. lugdunensis compared to other staphylococcal species. Unexpectedly, sequencing of the internal spacer sequences of individual repeat elements from multiple isolates showed conservation at the sequence level within deep evolutionary lineages of S. aureus. Whilst individual STAR element loci were demonstrated to expand and contract, the sequences associated with each locus were stable and distinct from one another. Conclusions The high degree of lineage and locus-specific conservation of these intergenic repeat regions suggests that STAR elements are maintained due to selective or molecular forces with some of these elements having an important role in cell physiology. The high prevalence in two of the more virulent staphylococcal species is indicative of a potential role for STAR elements in pathogenesis. PMID:23020678

  1. Variation in the genomic locations and sequence conservation of STAR elements among staphylococcal species provides insight into DNA repeat evolution.

    PubMed

    Purves, Joanne; Blades, Matthew; Arafat, Yasrab; Malik, Salman A; Bayliss, Christopher D; Morrissey, Julie A

    2012-09-28

    Staphylococcus aureus Repeat (STAR) elements are a type of interspersed intergenic direct repeat. In this study the conservation and variation in these elements was explored by bioinformatic analyses of published staphylococcal genome sequences and through sequencing of specific STAR element loci from a large set of S. aureus isolates. Using bioinformatic analyses, we found that the STAR elements were located in different genomic loci within each staphylococcal species. There was no correlation between the number of STAR elements in each genome and the evolutionary relatedness of staphylococcal species, however higher levels of repeats were observed in both S. aureus and S. lugdunensis compared to other staphylococcal species. Unexpectedly, sequencing of the internal spacer sequences of individual repeat elements from multiple isolates showed conservation at the sequence level within deep evolutionary lineages of S. aureus. Whilst individual STAR element loci were demonstrated to expand and contract, the sequences associated with each locus were stable and distinct from one another. The high degree of lineage and locus-specific conservation of these intergenic repeat regions suggests that STAR elements are maintained due to selective or molecular forces with some of these elements having an important role in cell physiology. The high prevalence in two of the more virulent staphylococcal species is indicative of a potential role for STAR elements in pathogenesis.

  2. Enhancement of the visibility of objects located below the surface of a scattering medium

    DOEpatents

    Demos, Stavros

    2013-11-19

    Techniques are provided for enhancing the visibility of objects located below the surface of a scattering medium such as tissue, water and smoke. Examples of such an object include a vein located below the skin, a mine located below the surface of the sea and a human in a location covered by smoke. The enhancement of the image contrast of a subsurface structure is based on the utilization of structured illumination. In the specific application of this invention to image the veins in the arm or other part of the body, the issue of how to control the intensity of the image of a metal object (such as a needle) that must be inserted into the vein is also addressed.

  3. Determination of the Optimal Chromosomal Location(s) for a DNA Element in Escherichia coli Using a Novel Transposon-mediated Approach.

    PubMed

    Frimodt-Møller, Jakob; Charbon, Godefroid; Krogfelt, Karen A; Løbner-Olesen, Anders

    2017-09-11

    The optimal chromosomal position(s) of a given DNA element was/were determined by transposon-mediated random insertion followed by fitness selection. In bacteria, the impact of the genetic context on the function of a genetic element can be difficult to assess. Several mechanisms, including topological effects, transcriptional interference from neighboring genes, and/or replication-associated gene dosage, may affect the function of a given genetic element. Here, we describe a method that permits the random integration of a DNA element into the chromosome of Escherichia coli and select the most favorable locations using a simple growth competition experiment. The method takes advantage of a well-described transposon-based system of random insertion, coupled with a selection of the fittest clone(s) by growth advantage, a procedure that is easily adjustable to experimental needs. The nature of the fittest clone(s) can be determined by whole-genome sequencing on a complex multi-clonal population or by easy gene walking for the rapid identification of selected clones. Here, the non-coding DNA region DARS2, which controls the initiation of chromosome replication in E. coli, was used as an example. The function of DARS2 is known to be affected by replication-associated gene dosage; the closer DARS2 gets to the origin of DNA replication, the more active it becomes. DARS2 was randomly inserted into the chromosome of a DARS2-deleted strain. The resultant clones containing individual insertions were pooled and competed against one another for hundreds of generations. Finally, the fittest clones were characterized and found to contain DARS2 inserted in close proximity to the original DARS2 location.

  4. 20 CFR 655.536 - The third attestation element for locations in Alaska: No intention or design to influence...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Longshore Activities in U.S. Ports Alaska Exception § 655.536 The third attestation element for locations in... attest that use of alien crewmembers to perform the longshore activity specified on the Form ETA 9033-A... longshore activity specified on the Form ETA 9033-A was not intended nor designed to influence an...

  5. Comparative analysis of bleeding risk by the location and shape of arachnoid cysts: a finite element model analysis.

    PubMed

    Lee, Chang-Hyun; Han, In Seok; Lee, Ji Yeoun; Phi, Ji Hoon; Kim, Seung-Ki; Kim, Young-Eun; Wang, Kyu-Chang

    2017-01-01

    Although arachnoid cysts (ACs) are observed in various locations, only sylvian ACs are mainly regarded to be associated with bleeding. The reason for this selective association of sylvian ACs with bleeding is not understood well. This study is to investigate the effect of the location and shape of ACs on the risk of bleeding. A developed finite element model of the head/brain was modified for models of sylvian, suprasellar, and posterior fossa ACs. A spherical AC was placed at each location to compare the effect of AC location. Bowl-shaped and oval-shaped AC models were developed to compare the effect by shape. The shear force on the spot-weld elements (SFSW) was measured between the dura and the outer wall of the ACs or the comparable arachnoid membrane in the normal model. All AC models revealed higher SFSW than comparable normal models. By location, sylvian AC displayed the highest SFSW for frontal and lateral impacts. By shape, small outer wall AC models showed higher SFSW than large wall models in sylvian area and lower SFSW than large ones in posterior fossa. In regression analysis, the presence of AC was the only independent risk of bleeding. The bleeding mechanism of ACs is very complex, and the risk quantification failed to show a significant role of location and shape of ACs. The presence of AC increases shear force on impact condition and may be a risk factor of bleeding, and sylvian location of AC may not have additive risks of AC bleeding.

  6. Closed-form analytical solutions of the time difference of arrival source location problem for minimal element monitoring arrays.

    PubMed

    Spencer, Steven J

    2010-05-01

    Closed-form analytical solutions are found for the time difference of arrival (TDOA) source location problem. Solutions are found for both two-dimensional (2D) and three-dimensional (3D) source location by formulating the TDOA equations in, respectively, polar and spherical coordinate systems, with the radial direction coincident with the assumed geodesic path of signal propagation to a reference sensor. Quadratic equations for TDOA 2D and 3D source location based on the spherical intersection (SX) scheme, in some cases permitting dual physical solutions, are found for three and four sensor element monitoring arrays, respectively. A method of spherical intersection subarrays (SXSAs) is developed to derive from these quadratic equations globally unique closed-form analytical solutions for TDOA 2D and 3D source location, for four and five sensor element monitoring arrays, respectively. Errors in 2D source location for introduced bias in time differences of arrival are shown to have a strong geometrical dependence. The SXSA and SX methods perform well in terms of accuracy and precision at high levels of arrival time bias for both 2D and 3D source location and are much more efficient than nonlinear least-squares schemes. The SXSA scheme may have particular applicability to accurately solving source location problems in demanding real-time situations.

  7. RibEx: a web server for locating riboswitches and other conserved bacterial regulatory elements.

    PubMed

    Abreu-Goodger, Cei; Merino, Enrique

    2005-07-01

    We present RibEx (riboswitch explorer), a web server capable of searching any sequence for known riboswitches as well as other predicted, but highly conserved, bacterial regulatory elements. It allows the visual inspection of the identified motifs in relation to attenuators and open reading frames (ORFs). Any of the ORF's or regulatory elements' sequence can be obtained with a click and submitted to NCBI's BLAST. Alternatively, the genome context of all other genes regulated by the same element can be explored with our genome context tool (GeConT). RibEx is available at http://www.ibt.unam.mx/biocomputo/ribex.html.

  8. The muscle creatine kinase gene is regulated by multiple upstream elements, including a muscle-specific enhancer

    SciTech Connect

    Jaynes, J.B.; Johnson, J.E.; Buskin, J.N.; Gartside, C.L.; Hauschka, S.D.

    1988-01-01

    Muscle creatine kinase (MCK) is induced to high levels during skeletal muscle differentiation. The authors examined the upstream regulatory elements of the mouse MCK gene which specify its activation during myogenesis in culture. Fusion genes containing up to 3,300 nucleotides (nt) of MCK 5' flanking DNA in various positions and orientations relative to the bacterial chloramphenicol acetyltransferase (CAT) structural gene were transfected into cultured cells. Transient expression of CAT was compared between proliferating and differentiated MM14 mouse myoblasts and with nonmyogenic mouse L cells. The major effector of high-level expression was found to have the properties of a transcriptional enhancer. This element, located between 1,050 and 1,256 nt upstream of the transcription start site, was also found to have a major influence on the tissue and differentiation specificity of MCK expression; it activated either the MCK promoter or heterologous promoters only in differentiated muscle cells. Comparisons of viral and cellular enhancer sequences with the MCK enhancer revealed some similarities to essential regions of the simian virus 40 enhancer as well as to a region of the immunoglobulin heavy-chain enhancer, which has been implicated in tissue-specific protein binding. Even in the absence of the enhancer, low-level expression from a 776-nt MCK promoter retained differentiation specificity. In addition to positive regulatory elements, our data provide some evidence for negative regulatory elements with activity in myoblasts. These may contribute to the cell type and differentiation specificity of MCK expression.

  9. Two locations, two times, and the element set. [applicable to orbit determination of artificial satellites

    NASA Technical Reports Server (NTRS)

    Taff, L. G.; Randall, P. M. S.

    1985-01-01

    A robust analytical formulation is developed to apply classical initial orbital determination to artificial satellites whose locations are uncertain to about 1 cu km and separated in time by no more than 30 min. An analytical simplification reduces Gauss's method, iteration on the semilatus rectum, iteration on the true anomaly, and the Lambert-Euler technique, to the solution of a single equation in one unknown, instead of the usual coupled triplet of three equations in three unknowns. The method is demonstrated for all common artificial satellite orbits over a variety of time intervals between the two location vectors, and for a varied set of position and distance errors.

  10. Integrated Nondestructive Evaluation and Finite Element Analysis Predicts Crack Location and Shape

    NASA Technical Reports Server (NTRS)

    Abdul-Azia, Ali; Baaklini, George Y.; Trudell, Jeffrey J.

    2002-01-01

    This study describes the finite-element analyses and the NDE modality undertaken on two flywheel rotors that were spun to burst speed. Computed tomography and dimensional measurements were used to nondestructively evaluate the rotors before and/or after they were spun to the first crack detection. Computed tomography data findings of two- and three-dimensional crack formation were used to conduct finite-element (FEA) and fracture mechanics analyses. A procedure to extend these analyses to estimate the life of these components is also outlined. NDE-FEA results for one of the rotors are presented in the figures. The stress results, which represent the radial stresses in the rim, clearly indicate that the maximum stress region is within the section defined by the computed tomography scan. Furthermore, the NDE data correlate well with the FEA results. In addition, the measurements reported show that the NDE and FEA data are in parallel.

  11. Time elements for enhanced performance of the Dromo orbit propagator

    SciTech Connect

    Baù, Giulio; Bombardelli, Claudio E-mail: claudio.bombardelli@upm.es

    2014-09-01

    We propose two time elements for the orbit propagator named Dromo. One is linear and the other constant with respect to the independent variable, which coincides with the osculating true anomaly in the Keplerian motion. They are defined from a generalized Kepler's equation written for negative values of the total energy and, unlike the few existing time elements of this kind, are free of singularities. To our knowledge it is the first time that a constant time element is associated with a second-order Sundman time transformation. Numerical tests to assess the performance of the Dromo method equipped with a time element show the remarkable improvement in accuracy for the perturbed bounded motion around the Earth compared to the case in which the physical time is a state variable. Moreover, the method is competitive with and even better than other efficient sets of elements. Finally, we also derive a time element for a null and positive total energy.

  12. Elemental characterization of urban particulates at receptor locations in Abuja, north-central Nigeria

    NASA Astrophysics Data System (ADS)

    Abiye, Olawale Emmanuel; Obioh, Imoh B.; Ezeh, Godwin C.

    2013-12-01

    The rising population and increasing urban infrastructures of Abuja have led to increased pressure on the urban environment. Two decades after putting the city of Abuja to use, there is yet no information on the air quality status of the city. Hence, this study was conducted in order to assess the mass concentration and elemental characterization of airborne particulate matter in Abuja, north-central Nigeria. Sampling of PM2.5: aerodynamic diameter ≤2.5 μm and PM10: aerodynamic diameter ≤10 μm were carried out in five urban sites within the city from April, 2009 to May, 2010. "Gent" stacked filter unit sampler equipped with a double stage filters in series was employed for sample collection. Charged helium (4He+) Particle Induced X-ray Emission technique of 2500 keV particle energy and Genie 2000 software were used for spectra acquisition while elemental characterization was achieved using Gupixwin software in order to determine the concentration of eighteen elements (Si, S, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Sn, Ba, Ta and Pb). Mass concentrations range between 7-86 μg m-3 and 22-343 μg m-3 for PM2.5 and PM10 respectively. Crustal elements (Si, Ca, and Fe) were found to be predominant in PM10 than in PM2.5 fraction with very high values. Positive correlation r > 0.90 and r > 0.53 to 0.90 exist between metals (V, Co, Ni, Cd, Zn and Pb). PM2.5/PM10 mass ratios were well within the range specified by WHO for developing urban scenario.

  13. Optical signal processing of video surveillance for recognizing and measurement location railway infrastructure elements

    NASA Astrophysics Data System (ADS)

    Diyazitdinov, Rinat R.; Vasin, Nikolay N.

    2016-03-01

    Processing of optical signals, which are received from CCD sensors of video cameras, allows to extend the functionality of video surveillance systems. Traditional video surveillance systems are used for saving, transmitting and preprocessing of the video content from the controlled objects. Video signal processing by analytics systems allows to get more information about object's location and movement, the flow of technological processes and to measure other parameters. For example, the signal processing of video surveillance systems, installed on carriage-laboratories, are used for getting information about certain parameters of the railways. Two algorithms for video processing, allowing recognition of pedestrian crossings of the railways, as well as location measurement of the so-called "Anchor Marks" used to control the mechanical stresses of continuous welded rail track are described in this article. The algorithms are based on the principle of determining the region of interest (ROI), and then the analysis of the fragments inside this ROI.

  14. Quasi-optimal locations of piezo-elements on a rectangular plate

    NASA Astrophysics Data System (ADS)

    Koszewnik, Andrzej; Gosiewski, Zdzisław

    2016-07-01

    The optimal location of piezo-actuators and piezo-sensors for the vibration control of a rectangular plate with SFSF (Simply Supported - Free - Simply Supported - Free) boundary conditions is presented in the paper. Based on bending moments, Mx(x,y) and My(x,y), the modal control forces generated by the piezo-stripes are calculated for the first five mode shapes. Calculations are carried out for different locations of two piezo-strips directed along the X and Y axes. The obtained results are used to define performance indexes of modal control forces for the two considered directions of vibration. In a similar way the modal unit elongations of the piezo-sensors are calculated for two different orientations of the piezos on the plate. Based on these results the objective cost functions J_{ɛ - odd} and J_{ɛ - even} are defined separately for odd and even modes. The quasi-optimal locations of the piezo-actuators and piezo-sensors are determined by maximizing the proposed cost functions. After analytical and numerical investigations the process of the full model identification is carried out at the laboratory stand. A chirp signal is applied in the identification process. The rectangular plate is excited with the chirp force while output signals are measured by the piezo-sensors oriented in the perpendicular directions X and Y. In such a way two mathematical models are obtained to control the vibration of the plate separately for odd and even natural modes.-1

  15. Elemental analysis and radiation hazards parameters of bauxite located in Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Alashrah, S.; E Taher, A.

    2017-04-01

    Since Bauxite has been widely used in industry and in scientific investigations for producing Aluminum, it is important to measure the radionuclides concentrations to determine the health effect. The Bauxite mine is located in Az Zabirah city in Saudi Arabia. The concentrations of the radionuclides in the bauxite samples were measured using γ-ray spectrometer NaI (Tl). The average and range values of the concentrations of 226Ra, 232Th and 40K were 102.2 (141.1-62.7), 156.3 (202.8-102.8) and 116.8 (191.7- 48.9) Bq/kg respectively. These results were compared with the reported ranges in the literature from other locations around the world. The radiation hazard parameters; radium equivalent activity, annual dose, external hazard were also calculated and compared with the recommended levels by International Commission on Radiological Protection (ICRP-60) and united nations scientific committee on the effects of atomic radiation UNSCEAR reports. There are no studies for the natural radioactivity in the bauxite mine in Az Zabirah city, so these results are a start to establishing a database in this location.

  16. Enhanced Raman scattering of graphene by silver nanoparticles with different densities and locations

    NASA Astrophysics Data System (ADS)

    Sun, Hai-Bin; Fu, Can; Xia, Yan-Jie; Zhang, Chong-Wu; Du, Jiang-Hui; Yang, Wen-Chao; Guo, Peng-Fei; Xu, Jun-Qi; Wang, Chun-Lei; Jia, Yong-Lei; Liu, Jiang-Feng

    2017-02-01

    Graphene–metal nanoparticle heterojunctions greatly improve the surface-enhanced Raman scattering (SERS) by strong light–graphene interactions. In this work, to enhance the Raman scattering, Ag nanoparticles (NPs) underneath and on top of the graphene were used. Then, Raman scattering of graphene is significantly enhanced approximately 67-fold, and the enhancement factor of the graphene G peak increases with the Ag NP density at the same location. In addition, an obvious red-shift and broadening of the resonance peak of Ag NPs is presented, which may be correlated to the strength of Raman enhancement, the coupling of the deposited Ag NPs and the graphene. Further, graphene–Ag NP heterojunctions can be used as SERS substrates to obtain the strongest Raman signals of the rhodamine (R6G) molecules and the weakest photoluminescence (PL) background from the Ag NPs. Based on the tunable Raman enhancement, graphene–Ag NPs offer a promising platform for engineering SERS substrates to obtain highly sensitive detection of trace levels of analyte molecules.

  17. Enhanced phytoextraction of germanium and rare earth elements - a rhizosphere-based approach

    NASA Astrophysics Data System (ADS)

    Wiche, Oliver

    2016-04-01

    Germanium (Ge) and rare earth elements (REEs) are economically valuable raw materials that have become an integral part of our modern high tech society. While most of these elements are not actually rare in terms of general amounts in the earth's crust, they are rarely found in sufficient abundances in single locations for their mining to be economically viable. The average concentration of Ge in soils is estimated at 1.6 μg g-1. The REEs comprise a group of 16 elements including La, the group of lanthanides and Y that are abundant in the earth crust with concentrations varying from 35 μg g-1 (La), 40 μg g-1 (Nd), 6 μg g-1 (Gd) and 3.5 μg g-1 (Er) to 0.5 μg g-1 in Tm. Thus, a promising chance to improve supply of these elements could be phytomining. Unfortunately, bioavailability of Ge and REEs in soils appears to be low, in particular in neutral or alkaline soils. A sequential dissolution analysis of 120 soil samples taken from the A-horizons of soils in the area of Freiberg (Saxony, Germany) revealed that only 0.2% of total Ge and about 0.5% of La, Nd, Gd and Er of bulk concentrations were easily accessible by leaching with NH4-acetate (pH 7). Most of the investigated elements were bound to Fe-/Mn-oxides and silicates and were therefore only poorly available for plant uptake. Here we report an environmentally friendly approach for enhanced phytoextraction of Ge and REEs from soils using mixed cultures of plant species with efficient mechanisms for the acquisition of nutrients in the rhizosphere. The rhizosphere is characterized as the zone in soil sourrounding a plant root that consists of a gradient in chemical, physical and biological soil properties driven by rhizodeposits like carboxylates and protons. Some species like white lupin (Lupinus albus) are able to excrete large amounts of organic acid anions(predominantly citrate and malate) and show a particularly high potential for the acidification of the rhizosphere. In our experiments, mixed cultures

  18. Identifier (ID) elements are not preferentially located to brain-specific genes: high ID element representation in other tissue-specific- and housekeeping genes of the rat.

    PubMed

    Goldman, Andrés; Capoano, Carlos A; González-López, Evangelina; Geisinger, Adriana

    2014-01-01

    BC1 is a short non-coding RNA from rodents, which is transcribed by RNA pol III. Its RNA is highly abundant in the brain, where it exerts a post-transcriptional regulatory role in dendrites. Upon transcription, retroposition and insertion, BC1 gives rise to a subclass of short interspersed repetitive sequences (SINEs) named identifier (ID) elements. IDs can become integrated inside non-coding regions of RNA pol II transcription units, and - although challenged by a couple of reports - their preferential location to brain-specific genes has been long proposed. Furthermore, an additional, cis-regulatory role in the control of brain-specific pol II-directed transcripts has been suggested for these sequences. In this work we used Northern blot and in silico analyses to examine IDs' location among pol II transcription units in different tissues, and in housekeeping genes. ID sequences appeared distributed in a similar fashion within tissue-specific hnRNA populations of the brain, testis and liver, and within housekeeping primary transcripts as well. Moreover, when the lengths of the unprocessed transcripts were considered, ID representation was higher in housekeeping ones. On the other hand, ID elements appeared similarly distributed among the different gene regions, with the obvious exclusion of those sequences where strict constraints for proper gene expression exist. Altogether, the widespread distribution of ID elements in all the analyzed genes - including housekeeping - and in all gene regions, suggests a random location, raising questions about the specific cis-regulatory role of those sequences. © 2013 Elsevier B.V. All rights reserved.

  19. Relation between the location of elements in the periodic table and various organ-uptake rates.

    PubMed

    Ando, A; Ando, I; Hiraki, T; Hisada, K

    1989-01-01

    Fifty four elements and 65 radioactive compounds were examined to determine the organ uptake rates for rats 3, 24 and 48 h after i.v. injection of these compounds. They were prepared as carrier free nuclides, or containing a small amount of stable nuclide. Generally speaking, behaviors of K, Rb, Cs and Tl in all the organs were very similar to one another, but they differed from that of Na. Bivalent hard acids were avidly taken up into bone; therefore, uptake rates in soft tissues were very small. Hard acids of tri-, quadri- and pentavalence which were taken up into the soft tissue organs decreased more slowly from these organs than other ions. Soft acids such as Hg2+ were bound very firmly to the component in the kidney. Anions (with few exceptions), GeCl4 and SbCl3 were rapidly excreted in urine, so that the uptake rates in organs were low.

  20. KENNEDY SPACE CENTER, FLA. - Astronaut Soichi Noguchi (right), with the National Space Development Agency of Japan (NASDA), is inside the Japanese Experiment Module (JEM), undergoing a Multi-Element Integrated Test (MEIT) in the Space Station Processing Facility. Noguchi is assigned to mission STS-114 as a mission specialist. Node 2 attaches to the end of the U.S. Lab on the ISS and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. The JEM, developed by NASDA, is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments.

    NASA Image and Video Library

    2003-09-03

    KENNEDY SPACE CENTER, FLA. - Astronaut Soichi Noguchi (right), with the National Space Development Agency of Japan (NASDA), is inside the Japanese Experiment Module (JEM), undergoing a Multi-Element Integrated Test (MEIT) in the Space Station Processing Facility. Noguchi is assigned to mission STS-114 as a mission specialist. Node 2 attaches to the end of the U.S. Lab on the ISS and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. The JEM, developed by NASDA, is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments.

  1. KENNEDY SPACE CENTER, FLA. - Astronaut Soichi Noguchi, with the National Space Development Agency of Japan (NASDA), works at a console during a Multi-Element Integrated Test (MEIT) of the U.S. Node 2 and the Japanese Experiment Module (JEM). Noguchi is assigned to mission STS-114 as a mission specialist. Node 2 attaches to the end of the U.S. Lab on the ISS and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. The JEM, developed by NASDA, is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments.

    NASA Image and Video Library

    2003-09-03

    KENNEDY SPACE CENTER, FLA. - Astronaut Soichi Noguchi, with the National Space Development Agency of Japan (NASDA), works at a console during a Multi-Element Integrated Test (MEIT) of the U.S. Node 2 and the Japanese Experiment Module (JEM). Noguchi is assigned to mission STS-114 as a mission specialist. Node 2 attaches to the end of the U.S. Lab on the ISS and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. The JEM, developed by NASDA, is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments.

  2. KENNEDY SPACE CENTER, FLA. - Technicians in the Space Station Processing Facility work on a Multi-Element Integrated Test (MEIT) of the U.S. Node 2 and the Japanese Experiment Module (JEM). Node 2 attaches to the end of the U.S. Lab on the ISS and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. The JEM, developed by the National Space Development Agency of Japan (NASDA), is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments.

    NASA Image and Video Library

    2003-09-03

    KENNEDY SPACE CENTER, FLA. - Technicians in the Space Station Processing Facility work on a Multi-Element Integrated Test (MEIT) of the U.S. Node 2 and the Japanese Experiment Module (JEM). Node 2 attaches to the end of the U.S. Lab on the ISS and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. The JEM, developed by the National Space Development Agency of Japan (NASDA), is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments.

  3. KENNEDY SPACE CENTER, FLA. - Astronaut Soichi Noguchi, with the National Space Development Agency of Japan (NASDA), rests inside the Japanese Experiment Module (JEM), undergoing a Multi-Element Integrated Test (MEIT) in the Space Station Processing Facility. Noguchi is assigned to mission STS-114 as a mission specialist. Node 2 attaches to the end of the U.S. Lab on the ISS and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. The JEM, developed by NASDA, is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments.

    NASA Image and Video Library

    2003-09-03

    KENNEDY SPACE CENTER, FLA. - Astronaut Soichi Noguchi, with the National Space Development Agency of Japan (NASDA), rests inside the Japanese Experiment Module (JEM), undergoing a Multi-Element Integrated Test (MEIT) in the Space Station Processing Facility. Noguchi is assigned to mission STS-114 as a mission specialist. Node 2 attaches to the end of the U.S. Lab on the ISS and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. The JEM, developed by NASDA, is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments.

  4. KENNEDY SPACE CENTER, FLA. - Workers in the Space Station Processing Facility look over paperwork during a Multi-Element Integrated Test (MEIT) of the U.S. Node 2 and the Japanese Experiment Module (JEM). Node 2 attaches to the end of the U.S. Lab on the ISS and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. The JEM, developed by the National Space Development Agency of Japan (NASDA), is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments.

    NASA Image and Video Library

    2003-09-03

    KENNEDY SPACE CENTER, FLA. - Workers in the Space Station Processing Facility look over paperwork during a Multi-Element Integrated Test (MEIT) of the U.S. Node 2 and the Japanese Experiment Module (JEM). Node 2 attaches to the end of the U.S. Lab on the ISS and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. The JEM, developed by the National Space Development Agency of Japan (NASDA), is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments.

  5. KENNEDY SPACE CENTER, FLA. - Astronaut Soichi Noguchi, with the National Space Development Agency of Japan (NASDA), signals success during a Multi-Element Integrated Test (MEIT ) of the Japanese Experiment Module (JEM) in the Space Station Processing Facility. Noguchi is assigned to mission STS-114 as a mission specialist. Node 2 attaches to the end of the U.S. Lab on the ISS and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. The JEM, developed by NASDA, is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments.

    NASA Image and Video Library

    2003-09-03

    KENNEDY SPACE CENTER, FLA. - Astronaut Soichi Noguchi, with the National Space Development Agency of Japan (NASDA), signals success during a Multi-Element Integrated Test (MEIT ) of the Japanese Experiment Module (JEM) in the Space Station Processing Facility. Noguchi is assigned to mission STS-114 as a mission specialist. Node 2 attaches to the end of the U.S. Lab on the ISS and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. The JEM, developed by NASDA, is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments.

  6. KENNEDY SPACE CENTER, FLA. - Workers in the Space Station Processing Facility observe consoles during a Multi-Element Integrated Test (MEIT) of the U.S. Node 2 and the Japanese Experiment Module (JEM). Node 2 attaches to the end of the U.S. Lab on the ISS and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. The JEM, developed by the National Space Development Agency of Japan (NASDA), is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments.

    NASA Image and Video Library

    2003-09-03

    KENNEDY SPACE CENTER, FLA. - Workers in the Space Station Processing Facility observe consoles during a Multi-Element Integrated Test (MEIT) of the U.S. Node 2 and the Japanese Experiment Module (JEM). Node 2 attaches to the end of the U.S. Lab on the ISS and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. The JEM, developed by the National Space Development Agency of Japan (NASDA), is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments.

  7. KENNEDY SPACE CENTER, FLA. - Astronaut Soichi Noguchi, with the National Space Development Agency of Japan (NASDA), is inside the Japanese Experiment Module (JEM), undergoing a Multi-Element Integrated Test (MEIT) in the Space Station Processing Facility. Noguchi is assigned to mission STS-114 as a mission specialist. Node 2 attaches to the end of the U.S. Lab on the ISS and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. The JEM, developed by NASDA, is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments.

    NASA Image and Video Library

    2003-09-03

    KENNEDY SPACE CENTER, FLA. - Astronaut Soichi Noguchi, with the National Space Development Agency of Japan (NASDA), is inside the Japanese Experiment Module (JEM), undergoing a Multi-Element Integrated Test (MEIT) in the Space Station Processing Facility. Noguchi is assigned to mission STS-114 as a mission specialist. Node 2 attaches to the end of the U.S. Lab on the ISS and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. The JEM, developed by NASDA, is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments.

  8. KENNEDY SPACE CENTER, FLA. - Workers in the Space Station Processing Facility are lined up at consoles during a Multi-Element Integrated Test (MEIT ) of the Japanese Experiment Module (JEM) and U.S. Node 2. Node 2 attaches to the end of the U.S. Lab on the ISS and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. The JEM, developed by NASDA, is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments.

    NASA Image and Video Library

    2003-09-03

    KENNEDY SPACE CENTER, FLA. - Workers in the Space Station Processing Facility are lined up at consoles during a Multi-Element Integrated Test (MEIT ) of the Japanese Experiment Module (JEM) and U.S. Node 2. Node 2 attaches to the end of the U.S. Lab on the ISS and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. The JEM, developed by NASDA, is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments.

  9. Bmp2 Transcription in Osteoblast Progenitors Is Regulated by a Distant 3′ Enhancer Located 156.3 Kilobases from the Promoter▿ †

    PubMed Central

    Chandler, Ronald L.; Chandler, Kelly J.; McFarland, Karen A.; Mortlock, Douglas P.

    2007-01-01

    Bone morphogenetic protein 2 (encoded by Bmp2) has been implicated as an important signaling ligand for osteoblast differentiation and bone formation and as a genetic risk factor for osteoporosis. To initially survey a large genomic region flanking the mouse Bmp2 gene for cis-regulatory function, two bacterial artificial chromosome (BAC) clones that extend far upstream and downstream of the gene were engineered to contain a lacZ reporter cassette and tested in transgenic mice. Each BAC clone directs a distinct subset of normal Bmp2 expression patterns, suggesting a modular arrangement of distant Bmp2 regulatory elements. Strikingly, regulatory sequences required for Bmp2 expression in differentiating osteoblasts, as well as tooth buds, hair placodes, kidney, and other tissues, are located more than 53 kilobases 3′ to the promoter. By testing BACs with engineered deletions across this distant 3′ region, we parsed these regulatory elements into separate locations and more closely refined the location of the osteoblast progenitor element. Finally, a conserved osteoblast progenitor enhancer was identified within a 656-bp sequence located 156.3 kilobases 3′ from the promoter. The identification of this enhancer should permit further investigation of upstream regulatory mechanisms that control Bmp2 transcription during osteoblast differentiation and are relevant to further studies of Bmp2 as a candidate risk factor gene for osteoporosis. PMID:17283059

  10. Prediction of coronary plaque location on arteries having myocardial bridge, using finite element models.

    PubMed

    Nikolić, Dalibor; Radović, Miloš; Aleksandrić, Srđan; Tomašević, Miloje; Filipović, Nenad

    2014-11-01

    This study was performed to evaluate the influences of the myocardial bridges on the plaque initializations and progression in the coronary arteries. The wall structure is changed due to the plaque presence, which could be the reason for multiple heart malfunctions. Using simplified parametric finite element model (FE model) of the coronary artery having myocardial bridge and analyzing different mechanical parameters from blood circulation through the artery (wall shear stress, oscillatory shear index, residence time), we investigated the prediction of "the best" position for plaque progression. We chose six patients from the angiography records and used data from DICOM images to generate FE models with our software tools for FE preprocessing, solving and post-processing. We found a good correlation between real positions of the plaque and the ones that we predicted to develop at the proximal part of the myocardial bridges with wall shear stress, oscillatory shear index and residence time. This computer model could be additional predictive tool for everyday clinical examination of the patient with myocardial bridge.

  11. Comparative structure, proximal promoter elements, and chromosome location of the human eosinophil major basic protein genes.

    PubMed

    Plager, D A; Weiler, D A; Loegering, D A; Johnson, W B; Haley, L; Eddy, R L; Shows, T B; Gleich, G J

    2001-02-01

    Human eosinophil major basic protein (MBP) is strongly implicated as a mediator of disease, especially bronchial asthma. We recently isolated a highly divergent human homologue of MBP (MBPH). Given human MBP's importance in disease and the restricted expression of it and human MBPH, we isolated the 4.6-kb human MBPH gene (HGMW-approved symbol PRG3). Comparisons among the human MBP (PRG2), human MBPH, and murine MBP-1 (mMBP-1; Prg2) genes suggest that the human MBP and mMBP-1 genes are more closely related than either is to the human MBPH gene. Proximal promoters of these three genes show conservation of potential binding sites for IK2 and STAT and of a known GATA site. However, a known C/EBP site is altered in the human MBPH gene's proximal promoter. The human MBP and MBPH genes localized to chromosome 11 in the centromere to 11q12 region. Thus, the human MBP and MBPH genes have diverged considerably, probably following a gene duplication event. Furthermore, the identified conserved and distinct proximal promoter elements likely contribute to the eosinophil-restricted and relatively reduced transcription of the human MBPH gene. Copyright 2001 Academic Press.

  12. Transposable element insertion location bias and the dynamics of gene drive in mosquito populations.

    PubMed

    Rasgon, J L; Gould, F

    2005-10-01

    Some vector-borne disease control strategies using transgenic mosquitoes require transgene spread to high frequency in populations. Transposable elements (TEs) are DNA sequences that replicate and transpose within the genomes of other organisms and may therefore be represented in the next generation in higher frequencies than predicted by Mendelian segregation. This over-representation has allowed some TEs to spread through natural populations. Transgenes incorporated within a TE sequence are expected to be driven into populations as long as there is a positive balance between fitness costs and over-representation. Models have been used to examine parameters that affect this balance but did not take into account biased insertion of TEs to linked sites in the genome. A simulation model was created to examine the impact of insertion bias on TE spread in mosquito populations. TEs that induce no fitness costs are predicted to increase in frequency over a wide range of parameter values but spread is slower for lower levels of transposition and non-local movement. If TEs are costly, high proportions of local movement can slow or halt spread. To function as a robust transgene drive mechanism a TE should replicate and transpose > 10%/insert/generation, induce < 1% fitness cost/insert, and move preferentially to unlinked sites in the genome.

  13. [Relation between location of elements in periodic table and affinity for the malignant tumor (author's transl)].

    PubMed

    Ando, A; Hisada, K; Ando, I

    1977-10-01

    Affinity of many inorganic compounds for the malignant tumor was examined, using the rats which were subcutaneously transplanted with Yoshida sarcoma. And the relations between the uptake rate into the malignant tumor and in vitro binding power to the protein were investigated in these compounds. In these experiments, the bipositive ions and anions had not affinity for the tumor tissue with a few exceptions. On the other hand, Hg, Au and Bi, which have strong binding power to the protein, showed high uptake rate into the malignant tumor. As Hg++, Au+ and Bi+++ are soft acids according to classification of Lewis acids, it was thought that these elements would bind strongly to soft base (R-SH, R-S-) present in the tumor tissue. In many hard acids (according to classification of Lewis acids), the uptake rate into the tumor was shown as a function of ionic potentials (valency/ionic radii) of the metal ions. It is presumed that the chemical bond of these hard acids in the tumor tissue is ionic bond to hard base (R-COO-, R-PO3(2-), R-SO3-, R-NH2).

  14. Relation between the location of elements in the periodic table and tumor-uptake rate.

    PubMed

    Ando, A; Ando, I; Hiraki, T; Hisada, K

    1985-01-01

    The bipositive ions and anions, with few exceptions, indicated a low tumor uptake rate. On the other hand, compounds of Hg, Au and Bi, which have a strong binding power to protein, showed a high tumor uptake rate. As Hg2+, Au+ and Bi3+ are soft acids according to the classification of Lewis acids, it was thought that these ions would bind strongly to soft bases (R-SH, R-S-) present in tumor tissue. For many hard acids such as 85Sr2+, 67Ga3+, 181Hf4+, and 95Nb5+, tumor uptake rates are shown as a function of ionic potentials (valency/ionic radii) of the metal ions. Considering the present data and previously reported results, it was presumed that hard acids of trivalence, quadrivalence and pentavalence would replace calcium in the calcium salts of hard bases (calcium salts of acid mucopolysaccharides, etc.). Ionic potentials of alkaline metals and Tl were small, but the tumor-uptake rate of these elements indicated various values. As Ge and Sb are bound by covalent bonds to chloride, GeCl4 and SbCl3 behaved differently from many metallic compounds in tumor tissue.

  15. [Relations between location of elements in periodic table and affinity for the kidneys (author's transl)].

    PubMed

    Ando, A; Hisada, K; Ando, I

    1977-10-01

    The distribution of many inorganic compounds in rats was investigated in order to evaluate kidney affinity of inorganic compounds. In these experiments, 30%, 10-20% and 4-10% of administered dose was localized in the kidneys in 203Hg-acetate and 203 Bi-acetate, in H198AuCl4, 103PdCl2, 201TlCl, 210Pd(NO3)2 and H2(127M)TeO3, and in Na2(51)CrO4, 54MnCl2, (114m)InCl3 and 7BeCl2, respectively. Some bipositive ions and anions was hardly taken up into the kidneys. And in many hard acids according to classification of Lewis acids, the uptake rate into the kidneys was usually small. On the other hand, Hg, Au and Bi, which have strong binding power to the protein, showed high uptake rate in the kidneys. As Hg++, Au+ and Bi+++ was soft acids according to classification of Lewis acids, it was thought that these elements would bind strongly to soft base (RSH, RS-) present in the kidney.

  16. Isotopes and trace elements as geo-location markers for biosecurity: determining the origin of exotic pests.

    NASA Astrophysics Data System (ADS)

    Holder, Peter W.; Armstrong, Karen; Clough, Tim; Frew, Russell; van Hale, Robert; Baker, Joel A.; Millet, Marc-Alban

    2010-05-01

    Background. The benefits of accurate point of origin discrimination in biosecurity include achieving appropriate operational responses in exotic pest eradication and post-border incursion campaigns, and identifying risk pathways. Reading natural abundance biogeochemical markers via mass spectrometry methods is a powerful tool for tracing ecological pathways and provenance determination of agricultural products and items of forensic interest. However, the application of these methods to trace insects - man's most damaging competitors - has been underutilised to date and our understanding in this field is still in a phase of basic development. Stable isotope ratio analyses using δ2H, δ13C have given spatial resolution in the monarch butterfly, single host system in eastern North America. Subsequently, the same method was employed in an attempt to determine the origin of important biosecurity pests in New Zealand. However, the results were contentious as the accuracy and limitations of the method in a biosecurity application were unknown. Further investigation has shown the value of existing invertebrate stable isotope geo-location methodology (i.e., using only two light elements) is tenuous in the biosecurity context, where the sample sizes are usually only one or two insects, and the specimens are generally polyphagous and accidentally introduced, and so from an unknown and unpredictable place, point in time and host: The spatial distribution of 2H in New Zealand may not be reliable over insect life-span time-scales; and fractional variables are un-quantified and potentially overwhelm any New Zealand signal. Further, the geo-location value of 13C is uncertain, especially for polyphagous insects. Research aims. The internationally distributed Helicoverpa armigera [Noctuidae] is being used to examine the processes fundamental to the location-to-plant-to-insect biogeochemical profile imprinting in phytophagous insects, including the turn over of elements in adult

  17. True-3D Accentuating of Grids and Streets in Urban Topographic Maps Enhances Human Object Location Memory

    PubMed Central

    Edler, Dennis; Bestgen, Anne-Kathrin; Kuchinke, Lars; Dickmann, Frank

    2015-01-01

    Cognitive representations of learned map information are subject to systematic distortion errors. Map elements that divide a map surface into regions, such as content-related linear symbols (e.g. streets, rivers, railway systems) or additional artificial layers (coordinate grids), provide an orientation pattern that can help users to reduce distortions in their mental representations. In recent years, the television industry has started to establish True-3D (autostereoscopic) displays as mass media. These modern displays make it possible to watch dynamic and static images including depth illusions without additional devices, such as 3D glasses. In these images, visual details can be distributed over different positions along the depth axis. Some empirical studies of vision research provided first evidence that 3D stereoscopic content attracts higher attention and is processed faster. So far, the impact of True-3D accentuating has not yet been explored concerning spatial memory tasks and cartography. This paper reports the results of two empirical studies that focus on investigations whether True-3D accentuating of artificial, regular overlaying line features (i.e. grids) and content-related, irregular line features (i.e. highways and main streets) in official urban topographic maps (scale 1/10,000) further improves human object location memory performance. The memory performance is measured as both the percentage of correctly recalled object locations (hit rate) and the mean distances of correctly recalled objects (spatial accuracy). It is shown that the True-3D accentuating of grids (depth offset: 5 cm) significantly enhances the spatial accuracy of recalled map object locations, whereas the True-3D emphasis of streets significantly improves the hit rate of recalled map object locations. These results show the potential of True-3D displays for an improvement of the cognitive representation of learned cartographic information. PMID:25679208

  18. True-3D accentuating of grids and streets in urban topographic maps enhances human object location memory.

    PubMed

    Edler, Dennis; Bestgen, Anne-Kathrin; Kuchinke, Lars; Dickmann, Frank

    2015-01-01

    Cognitive representations of learned map information are subject to systematic distortion errors. Map elements that divide a map surface into regions, such as content-related linear symbols (e.g. streets, rivers, railway systems) or additional artificial layers (coordinate grids), provide an orientation pattern that can help users to reduce distortions in their mental representations. In recent years, the television industry has started to establish True-3D (autostereoscopic) displays as mass media. These modern displays make it possible to watch dynamic and static images including depth illusions without additional devices, such as 3D glasses. In these images, visual details can be distributed over different positions along the depth axis. Some empirical studies of vision research provided first evidence that 3D stereoscopic content attracts higher attention and is processed faster. So far, the impact of True-3D accentuating has not yet been explored concerning spatial memory tasks and cartography. This paper reports the results of two empirical studies that focus on investigations whether True-3D accentuating of artificial, regular overlaying line features (i.e. grids) and content-related, irregular line features (i.e. highways and main streets) in official urban topographic maps (scale 1/10,000) further improves human object location memory performance. The memory performance is measured as both the percentage of correctly recalled object locations (hit rate) and the mean distances of correctly recalled objects (spatial accuracy). It is shown that the True-3D accentuating of grids (depth offset: 5 cm) significantly enhances the spatial accuracy of recalled map object locations, whereas the True-3D emphasis of streets significantly improves the hit rate of recalled map object locations. These results show the potential of True-3D displays for an improvement of the cognitive representation of learned cartographic information.

  19. Pitx1 Broadly Associates with Limb Enhancers and is Enriched on Hindlimb cis-Regulatory Elements

    PubMed Central

    Infante, Carlos R.; Park, Sungdae; Mihala, Alexandra; Kingsley, David M.; Menke, Douglas B.

    2013-01-01

    Extensive functional analyses have demonstrated that the pituitary homeodomain transcription factor Pitx1 plays a critical role in specifying hindlimb morphology in vertebrates. However, much less is known regarding the target genes and cis-regulatory elements through which Pitx1 acts. Earlier studies suggested that the hindlimb transcription factors Tbx4, HoxC10, and HoxC11 might be transcriptional targets of Pitx1, but definitive evidence for direct regulatory interactions has been lacking. Using ChIP-Seq on embryonic mouse hindlimbs, we have pinpointed the genome-wide location of Pitx1 binding sites during mouse hindlimb development and identified potential gene targets for Pitx1. We determined that Pitx1 binding is significantly enriched near genes involved in limb morphogenesis, including Tbx4, HoxC10, and HoxC11. Notably, Pitx1 is bound to the previously identified HLEA and HLEB hindlimb enhancers of the Tbx4 gene and to a newly identified Tbx2 hindlimb enhancer. Moreover, Pitx1 binding is significantly enriched on hindlimb relative to forelimb-specific cis-regulatory features that are differentially marked by H3K27ac. However, our analysis revealed that Pitx1 also strongly associates with many functionally verified limb enhancers that exhibit similar levels of activity in the embryonic mesenchyme of forelimbs and hindlimbs. We speculate that Pitx1 influences hindlimb morphology both through the activation of hindlimb specific enhancers as well as through the hindlimb-specific modulation of enhancers that are active in both sets of limbs. PMID:23201014

  20. A sequence level model of an intact locus predicts the location and function of nonadditive enhancers

    PubMed Central

    Reinitz, John

    2017-01-01

    Metazoan gene expression is controlled through the action of long stretches of noncoding DNA that contain enhancers—shorter sequences responsible for controlling a single aspect of a gene’s expression pattern. Models built on thermodynamics have shown how enhancers interpret protein concentration in order to determine specific levels of gene expression, but the emergent regulatory logic of a complete regulatory locus shows qualitative and quantitative differences from isolated enhancers. Such differences may arise from steric competition limiting the quantity of DNA that can simultaneously influence the transcription machinery. We incorporated this competition into a mechanistic model of gene regulation, generated efficient algorithms for this computation, and applied it to the regulation of Drosophila even-skipped (eve). This model finds the location of enhancers and identifies which factors control the boundaries of eve expression. This model predicts a new enhancer that, when assayed in vivo, drives expression in a non-eve pattern. Incorporation of chromatin accessibility eliminates this inconsistency. PMID:28715438

  1. Baseline System Costs for 50.0 MW Enhanced Geothermal System -- A Function of: Working Fluid, Technology, and Location, Location, Location

    SciTech Connect

    Dunn, Paul; Selman, Nancy; Volpe, Anthony Della; Moss, Deborah; Mobley, Rick; Dickey, Halley; Unruh, Jeffery; Hitchcock, Chris; Tanguay, Jasmine; Butler, Steven; Stacey, Robert; Robertson-Tait, Ann; Pruess, Karsten; Gutoski, Greg; Fay, Jamie M.; Stitzer, John T.; Oglesby, Ken

    2012-04-30

    Substantial unexploited opportunity exists for the US, and the world, in Enhanced Geothermal Systems (EGS). As a result of US DOE investment, new drilling technology, new power generation equipment and cycles enable meaningful power production, in a compact and modular fashion; at lower and lower top side EGS working fluid temperatures and in a broader range of geologies and geographies. This cost analysis effort supports the expansion of Enhanced Geothermal Systems (EGS), furthering DOE strategic themes of energy security and sub goal of energy diversity; reducing the Nation's dependence on foreign oil while improving the environment.

  2. Synergistic enhansons located within an acute phase responsive enhancer modulate glucocorticoid induction of angiotensinogen gene transcription.

    PubMed

    Brasier, A R; Ron, D; Tate, J E; Habener, J F

    1990-12-01

    The hepatic transcription of the angiotensinogen gene is regulated by both glucocorticoids and cytokines generated as products of the acute phase reaction. We have identified a multimodular enhancer in the 5'-flanking region of the rat angiotensinogen gene that mediates these responses and consists of an acute phase response element (APRE) flanked on both sides by adjacent glucocorticoid response element consensus motifs (GREs). Induction of transcription by the cytokine interleukin-1 (IL-1) is glucocorticoid dependent and mediated through the APRE. The APRE binds in a mutually exclusive manner a cytokine/phorbol ester-inducible protein (BPi), indistinguishable from nuclear factor kB, and a family of constitutive liver proteins (BPcs) related to the heat-stable transcription factor C/EBP. Using mutated 5'-flanking sequences of the angiotensinogen gene fused to a firefly luciferase reporter gene transfected into hepatoblastoma (HepG2) cells, we have mapped enhanson sequences required for the transcriptional response to glucocorticoids. Two functionally distinct GREs are identified by deletion and site-directed mutagenesis, both of which mediate glucocorticoid-stimulated transcription in vivo. Glucocorticoid-induced transcription mediated by the angiotensinogen gene enhancer is, furthermore, dependent on the occupancy of the APRE by either the BPi or a member of the BPc family because a mutant APRE that binds neither BPi nor BPc exhibits an attenuated glucocorticoid responsiveness. Mutant APREs that permit exclusive binding of either BPi or BPc synergistically transmit the glucocorticoid response mediated by one or the other of the adjacent GREs. Thus, the induction of angiotensinogen gene transcription involves interaction between the glucocorticoid receptor and either one of the APRE-binding proteins: either the cytokine-inducible NFkB or the constitutive family of C/EBP-like proteins, bound to adjacent enhansons in a mutually synergistic enhancer complex.

  3. Quantitative analysis of polycomb response elements (PREs) at identical genomic locations distinguishes contributions of PRE sequence and genomic environment

    PubMed Central

    2011-01-01

    Background Polycomb/Trithorax response elements (PREs) are cis-regulatory elements essential for the regulation of several hundred developmentally important genes. However, the precise sequence requirements for PRE function are not fully understood, and it is also unclear whether these elements all function in a similar manner. Drosophila PRE reporter assays typically rely on random integration by P-element insertion, but PREs are extremely sensitive to genomic position. Results We adapted the ΦC31 site-specific integration tool to enable systematic quantitative comparison of PREs and sequence variants at identical genomic locations. In this adaptation, a miniwhite (mw) reporter in combination with eye-pigment analysis gives a quantitative readout of PRE function. We compared the Hox PRE Frontabdominal-7 (Fab-7) with a PRE from the vestigial (vg) gene at four landing sites. The analysis revealed that the Fab-7 and vg PREs have fundamentally different properties, both in terms of their interaction with the genomic environment at each site and their inherent silencing abilities. Furthermore, we used the ΦC31 tool to examine the effect of deletions and mutations in the vg PRE, identifying a 106 bp region containing a previously predicted motif (GTGT) that is essential for silencing. Conclusions This analysis showed that different PREs have quantifiably different properties, and that changes in as few as four base pairs have profound effects on PRE function, thus illustrating the power and sensitivity of ΦC31 site-specific integration as a tool for the rapid and quantitative dissection of elements of PRE design. PMID:21410956

  4. Levels and spatial distribution of airborne chemical elements in a heavy industrial area located in the north of Spain.

    PubMed

    Lage, J; Almeida, S M; Reis, M A; Chaves, P C; Ribeiro, T; Garcia, S; Faria, J P; Fernández, B G; Wolterbeek, H T

    2014-01-01

    The adverse health effects of airborne particles have been subjected to intense investigation in recent years; however, more studies on the chemical characterization of particles from pollution emissions are needed to (1) identify emission sources, (2) better understand the relative toxicity of particles, and (3) pinpoint more targeted emission control strategies and regulations. The main objective of this study was to assess the levels and spatial distribution of airborne chemical elements in a heavy industrial area located in the north of Spain. Instrumental and biomonitoring techniques were integrated and analytical methods for k0 instrumental neutron activation analysis and particle-induced x-ray emission were used to determine element content in aerosol filters and lichens. Results indicated that in general local industry contributed to the emissions of As, Sb, Cu, V, and Ni, which are associated with combustion processes. In addition, the steelwork emitted significant quantities of Fe and Mn and the cement factory was associated with Ca emissions. The spatial distribution of Zn and Al also indicated an important contribution of two industries located outside the studied area.

  5. Simple Syringe Filtration Methods for Reliably Examining Dissolved and Colloidal Trace Element Distributions in Remote Field Locations

    NASA Astrophysics Data System (ADS)

    Shiller, A. M.

    2002-12-01

    Methods for obtaining reliable dissolved trace element samples frequently utilize clean labs, portable laminar flow benches, or other equipment not readily transportable to remote locations. In some cases unfiltered samples can be obtained in a remote location and transported back to a lab for filtration. However, this may not always be possible or desirable. Additionally, methods for obtaining information on colloidal composition are likewise frequently too cumbersome for remote locations as well as being time-consuming. For that reason I have examined clean methods for collecting samples filtered through 0.45 and 0.02 micron syringe filters. With this methodology, only small samples are collected (typically 15 mL). However, with the introduction of the latest generation of ICP-MS's and microflow nebulizers, sample requirements for elemental analysis are much lower than just a few years ago. Thus, a determination of a suite of first row transition elements is frequently readily obtainable with samples of less than 1 mL. To examine the "traditional" (<0.45 micron) dissolved phase, 25 mm diameter polypropylene syringe filters and all polyethylene/polypropylene syringes are utilized. Filters are pre-cleaned in the lab using 40 mL of approx. 1 M HCl followed by a clean water rinse. Syringes are pre-cleaned by leaching with hot 1 M HCl followed by a clean water rinse. Sample kits are packed in polyethylene bags for transport to the field. Results are similar to results obtained using 0.4 micron polycarbonate screen filters, though concentrations may differ somewhat depending on the extent of sample pre-rinsing of the filter. Using this method, a multi-year time series of dissolved metals in a remote Rocky Mountain stream has been obtained. To examine the effect of colloidal material on dissolved metal concentrations, 0.02 micron alumina syringe filters have been utilized. Other workers have previously used these filters for examining colloidal Fe distributions in lake

  6. Reconfiguration of nucleosome-depleted regions at distal regulatory elements accompanies DNA methylation of enhancers and insulators in cancer

    PubMed Central

    Taberlay, Phillippa C.; Statham, Aaron L.; Kelly, Theresa K.

    2014-01-01

    It is well established that cancer-associated epigenetic repression occurs concomitant with CpG island hypermethylation and loss of nucleosomes at promoters, but the role of nucleosome occupancy and epigenetic reprogramming at distal regulatory elements in cancer is still poorly understood. Here, we evaluate the scope of global epigenetic alterations at enhancers and insulator elements in prostate and breast cancer cells using simultaneous genome-wide mapping of DNA methylation and nucleosome occupancy (NOMe-seq). We find that the genomic location of nucleosome-depleted regions (NDRs) is mostly cell type specific and preferentially found at enhancers in normal cells. In cancer cells, however, we observe a global reconfiguration of NDRs at distal regulatory elements coupled with a substantial reorganization of the cancer methylome. Aberrant acquisition of nucleosomes at enhancer-associated NDRs is associated with hypermethylation and epigenetic silencing marks, and conversely, loss of nucleosomes with demethylation and epigenetic activation. Remarkably, we show that nucleosomes remain strongly organized and phased at many facultative distal regulatory elements, even in the absence of a NDR as an anchor. Finally, we find that key transcription factor (TF) binding sites also show extensive peripheral nucleosome phasing, suggesting the potential for TFs to organize NDRs genome-wide and contribute to deregulation of cancer epigenomes. Together, our findings suggest that “decommissioning” of NDRs and TFs at distal regulatory elements in cancer cells is accompanied by DNA hypermethylation susceptibility of enhancers and insulator elements, which in turn may contribute to an altered genome-wide architecture and epigenetic deregulation in malignancy. PMID:24916973

  7. Characterization of enhancer elements and their mutations in the long terminal repeat of feline endogenous RD-114 proviruses.

    PubMed Central

    Ghosh, A K; Roy-Burman, P

    1989-01-01

    To locate the enhancer regions of the feline endogenous RD-114 long terminal repeat (LTR), we examined expression of the chloramphenicol acetyltransferase gene driven by various segments of the U3 region from two different proviral loci (CRL3 and CR1). Transient expression assays demonstrated that the primary signal sequence for transcription enhancement was located within the 63-base-pair (bp) element of the CRL3 DNA occurring between positions -184 and -121 from the CAP site (+1), whereas the similar region of CR1 was almost inactive. This element from both CRL3 and CR1 contained a single 30-bp sequence (direct repeat [DR]-B2) found in duplicate tandem copies in the LTR of the infectious RD-114 provirus. Two 9-bp inverted repeats marked the DR-B unit of the active element, and a prominent base deletion in one of these repeats in CR1 DNA appeared to be related to loss of enhancer activity. Another segment of CRL3 (-296 to -184), also displaying enhancer function, contained tandem repeated sequences (DR-A1 and DR-A2). The Dr-A2 unit, which lacked the 5' 20-bp sequence of the 47-pb DR-A1, could not function as an enhancer by itself, but it contributed to enhancer effects in cooperation with either the DR-A1 or DR-B2 region. The CR1 LTR contained a single DR-A1 sequence with extensive mutations, and the region (-313 to -181) containing this DR-A1 unit was nonfunctional, similar to the DR-B2 region of CR1. Site-directed mutagenesis analysis of another enhancer element, an octamer motif occurring between CAAT and TATA boxes of all RD-114 LTRs sequenced, revealed that this element was necessary for full enhancer function of the U3 region but with a variable effect, depending on the cell types in which chloramphenicol acetyltransferase expression was determined. Images PMID:2778873

  8. Enhanced pre-computed finite element models for surgical simulation.

    PubMed

    Zhong, Hualiang; Wachowiak, Mark P; Peters, Terry M

    2005-01-01

    Soft tissue modeling is an important component in effective surgical simulation systems. A pre-computed finite element method based on elastic models is well suited to modeling soft tissue deformation. This paper addresses two principal issues: the flexibility of the pre-computed FE method and the approximation approach to non-linear elastic models. We describe a dynamic mechanism of the reconfiguration of the contacted nodes and the fixed boundary, without re-computing the inverse of the global stiffness matrix. The flexibility of the pre-computed models is described for both linear and non-linear elastic models.

  9. Identification and characterization of a neuroretina-specific enhancer element in the quail Pax-6 (Pax-QNR) gene.

    PubMed Central

    Plaza, S; Dozier, C; Langlois, M C; Saule, S

    1995-01-01

    Using nuclear run-on assays, we showed that the tissue-specific expression of quail Pax-6 (Pax-QNR) P0-initiated mRNAs is due in part to regulation of the gene at the transcriptional level. Regulatory sequences governing neuroretina-specific expression of the P0-initiated mRNAs were investigated. By using reporter-based expression assays, we characterized a region within the Pax-QNR gene, located 7.5 kbp downstream from the P0 promoter, that functions as an enhancer in neuroretina cells but not in nonexpressing P0-initiated mRNA cells (quail embryo cells and quail retinal pigment epithelial cells). This enhancer element functioned in a position- and orientation-independent manner both on the Pax-QNR P0 promoter and the heterologous thymidine kinase promoter. Moreover, this enhancer element exhibited a developmental stage-specific activity during embryonic neuroretina development: in contrast to activity at day E7, the enhancer activity was very weak at day E5. This paralleled the level of expression of P0-initiated mRNAs observed at the same stages. Using footprinting, gel retardation, and Southwestern (DNA-protein) analysis, we demonstrated the existence of four neuroretina-specific nuclear protein-binding sites, involving multiple unknown factors. In addition we showed that the quail enhancer element is structurally and functionally conserved in mice. All of these results strongly suggest that this enhancer element may contribute to the neuroretina-specific transcriptional regulation of the Pax-6 gene in vivo. PMID:7529875

  10. Enhanced production of recombinant proteins with Corynebacterium glutamicum by deletion of insertion sequences (IS elements).

    PubMed

    Choi, Jae Woong; Yim, Sung Sun; Kim, Min Jeong; Jeong, Ki Jun

    2015-12-29

    In most bacteria, various jumping genetic elements including insertion sequences elements (IS elements) cause a variety of genetic rearrangements resulting in harmful effects such as genome and recombinant plasmid instability. The genetic stability of a plasmid in a host is critical for high-level production of recombinant proteins, and in this regard, the development of an IS element-free strain could be a useful strategy for the enhanced production of recombinant proteins. Corynebacterium glutamicum, which is a workhorse in the industrial-scale production of various biomolecules including recombinant proteins, also has several IS elements, and it is necessary to identify the critical IS elements and to develop IS element deleted strain. From the cultivation of C. glutamicum harboring a plasmid for green fluorescent protein (GFP) gene expression, non-fluorescent clones were isolated by FACS (fluorescent activated cell sorting). All the isolated clones had insertions of IS elements in the GFP coding region, and two major IS elements (ISCg1 and ISCg2 families) were identified. By co-cultivating cells harboring either the isolated IS element-inserted plasmid or intact plasmid, it was clearly confirmed that cells harboring the IS element-inserted plasmids became dominant during the cultivation due to their growth advantage over cells containing intact plasmids, which can cause a significant reduction in recombinant protein production during cultivation. To minimize the harmful effects of IS elements on the expression of heterologous genes in C. glutamicum, two IS element free C. glutamicum strains were developed in which each major IS element was deleted, and enhanced productivity in the engineered C. glutamicum strain was successfully demonstrated with three models: GFP, poly(3-hydroxybutyrate) [P(3HB)] and γ-aminobutyrate (GABA). Our findings clearly indicate that the hopping of IS elements could be detrimental to the production of recombinant proteins in C

  11. Unsupervised video-based lane detection using location-enhanced topic models

    NASA Astrophysics Data System (ADS)

    Sun, Hao; Wang, Cheng; Wang, Boliang; El-Sheimy, Naser

    2010-10-01

    An unsupervised learning algorithm based on topic models is presented for lane detection in video sequences observed by uncalibrated moving cameras. Our contributions are twofold. First, we introduce the maximally stable extremal region (MSER) detector for lane-marking feature extraction and derive a novel shape descriptor in an affine invariant manner to describe region shapes and a modified scale-invariant feature transform descriptor to capture feature appearance characteristics. MSER features are more stable compared to edge points or line pairs and hence provide robustness to lane-marking variations in scale, lighting, viewpoint, and shadows. Second, we proposed a novel location-enhanced probabilistic latent semantic analysis (pLSA) topic model for simultaneous lane recognition and localization. The proposed model overcomes the limitation of a pLSA model for effective topic localization. Experimental results on traffic sequences in various scenarios demonstrate the effectiveness and robustness of the proposed method.

  12. Enhanced apoptotic propensity in diabetic cardiac mitochondria: influence of subcellular spatial location

    PubMed Central

    Williamson, Courtney L.; Dabkowski, Erinne R.; Baseler, Walter A.; Croston, Tara L.; Alway, Stephen E.

    2010-01-01

    Cardiovascular complications, such as diabetic cardiomyopathy, account for the majority of deaths associated with diabetes mellitus. Mitochondria are particularly susceptible to the damaging effects of diabetes mellitus and have been implicated in the pathogenesis of diabetic cardiomyopathy. Cardiac mitochondria consist of two spatially distinct subpopulations, termed subsarcolemmal mitochondria (SSM) and interfibrillar mitochondria (IFM). The goal of this study was to determine whether subcellular spatial location is associated with apoptotic propensity of cardiac mitochondrial subpopulations during diabetic insult. Swiss Webster mice were subjected to intraperitoneal injection of streptozotocin or citrate saline vehicle. Ten weeks following injection, diabetic hearts displayed increased caspase-3 and caspase-9 activities, indicating enhanced apoptotic signaling (P < 0.05, for both). Mitochondrial size (forward scatter) and internal complexity (side scatter) were decreased in diabetic IFM (P < 0.05, for both) but not in diabetic SSM. Mitochondrial membrane potential (ΔΨm) was lower in diabetic IFM (P < 0.01) but not in diabetic SSM. Mitochondrial permeability transition pore (mPTP) opening was increased in diabetic compared with control IFM (P < 0.05), whereas no differences were observed in diabetic compared with control SSM. Examination of mPTP constituents revealed increases in cyclophilin D in diabetic IFM. Furthermore, diabetic IFM possessed lower cytochrome c and BcL-2 levels and increased Bax levels (P < 0.05, for all 3). No significant changes in these proteins were observed in diabetic SSM compared with control. These results indicate that diabetes mellitus is associated with an enhanced apoptotic propensity in IFM, suggesting a differential apoptotic susceptibility of distinct mitochondrial subpopulations based upon subcellular location. PMID:19966057

  13. KENNEDY SPACE CENTER, FLA. - Various elements intended for the International Space Station are lined up in the Space Station Processing Facility. The newest to arrive at KSC are in the rear: at left, the U.S. Node 2, and next to it at right, the Japanese Experiment Module (JEM). The two elements are undergoing a Multi-Element Integrated Test (MEIT). Node 2 attaches to the end of the U.S. Lab on the ISS and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. Developed by the National Space Development Agency of Japan (NASDA), the JEM is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments.

    NASA Image and Video Library

    2003-09-03

    KENNEDY SPACE CENTER, FLA. - Various elements intended for the International Space Station are lined up in the Space Station Processing Facility. The newest to arrive at KSC are in the rear: at left, the U.S. Node 2, and next to it at right, the Japanese Experiment Module (JEM). The two elements are undergoing a Multi-Element Integrated Test (MEIT). Node 2 attaches to the end of the U.S. Lab on the ISS and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. Developed by the National Space Development Agency of Japan (NASDA), the JEM is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments.

  14. KENNEDY SPACE CENTER, FLA. - Various elements intended for the International Space Station are lined up in the Space Station Processing Facility. The newest to arrive at KSC are in the rear: at left, the U.S. Node 2, and at right, the Japanese Experiment Module (JEM). The two elements are undergoing a Multi-Element Integrated Test (MEIT). Node 2 attaches to the end of the U.S. Lab on the ISS and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. Developed by the National Space Development Agency of Japan (NASDA), the JEM is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments.

    NASA Image and Video Library

    2003-08-27

    KENNEDY SPACE CENTER, FLA. - Various elements intended for the International Space Station are lined up in the Space Station Processing Facility. The newest to arrive at KSC are in the rear: at left, the U.S. Node 2, and at right, the Japanese Experiment Module (JEM). The two elements are undergoing a Multi-Element Integrated Test (MEIT). Node 2 attaches to the end of the U.S. Lab on the ISS and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. Developed by the National Space Development Agency of Japan (NASDA), the JEM is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments.

  15. Comparative Study of Antenna Elements for TDRSS Enhanced Multiple Access System

    NASA Technical Reports Server (NTRS)

    Kory, Carol L.; Lambert, Kevin; Acosta, Roberto; Nessel, James

    2006-01-01

    We compare three antennas, which are candidates for the TDRSS-Continuation enhanced MA array antenna elements. Measured and simulated data show very good agreement for all antenna elements. All of the antennas meet the specifications with the exception of the SBA isolation. However, improvements can likely be made with further design efforts.

  16. East Asia Dust Source Location Using the Naval Research Laboratory's 1-km Dust Enhancement Product

    NASA Astrophysics Data System (ADS)

    Walker, A. L.; Curtis, C. A.; Miller, S. D.; Richardson, K.; Westphal, D. L.

    2011-12-01

    In the effort to predict dust storms and their effects on local, regional and global scales an often cited uncertainty is the precise location of dust sources. Many approaches have been used to identify major dust source regions in East Asia. These approaches include analysis of station data for frequency of dust storms, drifting dust, dusty day, wind speed, and PM10 total suspended particulates. Some approaches emphasize the location of land surface type (Gobi, sandy desert, and loess) and geomorphological setting/features (basins, plateaus, alluvial fans, dry rivers, or oases). Other approaches use remote sensing to locate areas of high dust activity using the Total Ozone Mapping Spectrometer Aerosol Index (TOMS AI) data, to correlate Normalized Difference Vegetation Index (NDVI) vegetation cover with dust storm frequency, or to track dust storm event origination by analyzing Moderate Resolution Imaging Spectroradiometer (MODIS) images. It is also customary for researchers to combine two or more of these approaches to identify dust source regions. In this paper we use a novel approach to locate dust sources in East Asia. Utilizing the Naval Research Laboratory's satellite derived 1-km Dust Enhancement Product (DEP) imagery we can readily distinguish elevated dust over land from other components of the scene and individual dust plumes are readily seen. The high resolution of the DEP allows the many small, eroding point sources (measuring 1-10s km across) that form individual plumes to be located. Five years (2007 - 2011) of East Asia DEP imagery have been analyzed. Dust source frequency plots will be shown highlighting the most active dust source areas in East Asia. Our results show the most active point sources are located along the slopes and around the rim of large basins. Within basins, on plateaus and in valleys point sources are concentrated in smaller depressions relative to the surrounding topography. Point sources are also associated with the action of

  17. Ligands located within a cholesterol domain enhance gene delivery to the target tissue

    PubMed Central

    Xu, Long; Betker, Jamie; Yin, Hao; Anchordoquy, Thomas J.

    2012-01-01

    Targeted gene delivery provides enormous potential for clinical treatment of many incurable diseases. Liposomes formulated with targeting ligands have been tested extensively both in vitro and in vivo, and many studies have strived to identify more efficacious ligands. However, the environment of the ligand within the delivery vehicle is generally not considered, and this study assesses the effect of ligand micoenvironment by utilizing a lipoplex possessing a cholesterol domain. Our recent work has shown that the presence of the targeting ligand within the cholesterol domain promotes more productive transfection in cultured cells. In the present study, lipoplexes having the identical lipid composition were formulated with different conjugates of the folate ligand such that the ligand was included in, or excluded from, the cholesterol domain. The effect of locating the ligand within the cholesterol domain was then tested in a xenograft tumor model in mice. Lipoplexes that included the ligand within the cholesterol domain showed significantly higher luciferase expression and plasmid accumulation in tumors as compared to lipoplexes in which the ligand was excluded from the domain. These results demonstrate that the microenvironment of the ligand can affect gene delivery to tumors, and show that ligand-mediated delivery can be enhanced by locating targeting ligands within a cholesterol domain. PMID:22440429

  18. Convective Enhancement of Icing Roughness Elements in Stagnation Region Flows

    NASA Technical Reports Server (NTRS)

    Hughes, Michael T.; McClain, Stephen T.; Vargas, Mario; Broeren, Andy

    2015-01-01

    To improve existing ice accretion simulation codes, more data regarding ice roughness and its effects on convective heat transfer are required. To build on existing research on this topic, this study used the Vertical Icing Studies Tunnel (VIST) at NASA Glenn Research to model realistic ice roughness in the stagnation region of a NACA 0012 airfoil. Using the VIST, a test plate representing the leading 2% chord of the airfoil was subjected to flows of 7.62 m/s (25 ft/s), 12.19 m/s (40 ft/s), and 16.76 m/s (55 ft/s). The test plate was fitted with 3 surfaces, each with a different representation of ice roughness: 1) a control surface with no ice roughness, 2) a surface with ice roughness with element height scaled by 10x and streamwise rough zone width from the stagnation point scaled by 10x, and 3) a surface with ice roughness with element height scaled by 10x and streamwise rough zone width from the stagnation point scaled by 25x. Temperature data from the tests were recorded using an infrared camera and thermocouples imbedded in the test plate. From the temperature data, a convective heat transfer coefficient map was created for each case. Additional testing was also performed to validate the VIST's flow quality. These tests included five-hole probe and hot-wire probe velocity traces to provide flow visualization and to study boundary layer formation on the various test surfaces. The knowledge gained during the experiments will help improve ice accretion codes by providing heat transfer coefficient validation data and by providing flow visualization data helping understand current and future experiments performed in the VIST.

  19. Urban Enhancement of PM10 Bioaerosol Tracers Relative to Background Locations in the Midwestern United States

    PubMed Central

    Rathnayake, Chathurika M.; Metwali, Nervana; Baker, Zach; Jayarathne, Thilina; Kostle, Pamela A.; Thorne, Peter S.; O’Shaughnessy, Patrick T.; Stone, Elizabeth A.

    2016-01-01

    Bioaerosols are well-known immune-active particles that exacerbate respiratory diseases. Human exposures to bioaerosols and their resultant health impacts depend on their ambient concentrations, seasonal and spatial variation, and co-pollutants, which are not yet widely characterized. In this study, chemical and biological tracers of bioaerosols were quantified in respirable particulate matter (PM10) collected at three urban and three background sites in the Midwestern United States across four seasons in 2012. Endotoxins from gram negative bacteria (and a few gram positive bacteria), water-soluble proteins, and tracers for fungal spores (fungal glucans, arabitol and mannitol) were ubiquitous and showed significant seasonal variation and dependence on temperature. Fungal spores were elevated in spring and peaked in summer, following the seasonal growing cycle, while endotoxins peaked in autumn during the row crop harvesting season. Paired comparisons of bioaerosols in urban and background sites revealed significant urban enhancements in PM10, fungal glucans, endotoxins and water-soluble proteins relative to background locations, such that urban populations have a greater outdoor exposure to bioaerosols. These bioaerosols contribute, in part, to the urban excesses in PM10. Higher bioaerosol mass fractions in urban areas relative to background sites indicate that urban areas serve as a source of bioaerosols. Similar urban enhancements in water-soluble calcium and its correlation with bioaerosol tracers point towards wind-blown soil as an important source of bioaerosols in urban areas. PMID:27672535

  20. A Collaborative Location Based Travel Recommendation System through Enhanced Rating Prediction for the Group of Users

    PubMed Central

    Ravi, Logesh; Vairavasundaram, Subramaniyaswamy

    2016-01-01

    Rapid growth of web and its applications has created a colossal importance for recommender systems. Being applied in various domains, recommender systems were designed to generate suggestions such as items or services based on user interests. Basically, recommender systems experience many issues which reflects dwindled effectiveness. Integrating powerful data management techniques to recommender systems can address such issues and the recommendations quality can be increased significantly. Recent research on recommender systems reveals an idea of utilizing social network data to enhance traditional recommender system with better prediction and improved accuracy. This paper expresses views on social network data based recommender systems by considering usage of various recommendation algorithms, functionalities of systems, different types of interfaces, filtering techniques, and artificial intelligence techniques. After examining the depths of objectives, methodologies, and data sources of the existing models, the paper helps anyone interested in the development of travel recommendation systems and facilitates future research direction. We have also proposed a location recommendation system based on social pertinent trust walker (SPTW) and compared the results with the existing baseline random walk models. Later, we have enhanced the SPTW model for group of users recommendations. The results obtained from the experiments have been presented. PMID:27069468

  1. Urban enhancement of PM10 bioaerosol tracers relative to background locations in the Midwestern United States

    NASA Astrophysics Data System (ADS)

    Rathnayake, Chathurika M.; Metwali, Nervana; Baker, Zach; Jayarathne, Thilina; Kostle, Pamela A.; Thorne, Peter S.; O'Shaughnessy, Patrick T.; Stone, Elizabeth A.

    2016-05-01

    Bioaerosols are well-known immune-active particles that exacerbate respiratory diseases. Human exposures to bioaerosols and their resultant health impacts depend on their ambient concentrations, seasonal and spatial variation, and copollutants, which are not yet widely characterized. In this study, chemical and biological tracers of bioaerosols were quantified in respirable particulate matter (PM10) collected at three urban and three background sites in the Midwestern United States across four seasons in 2012. Endotoxins from Gram-negative bacteria (and a few Gram-positive bacteria), water-soluble proteins, and tracers for fungal spores (fungal glucans, arabitol, and mannitol) were ubiquitous and showed significant seasonal variation and dependence on temperature. Fungal spores were elevated in spring and peaked in summer, following the seasonal growing cycle, while endotoxins peaked in autumn during the row crop harvesting season. Paired comparisons of bioaerosols in urban and background sites revealed significant urban enhancements in PM10, fungal glucans, endotoxins, and water-soluble proteins relative to background locations, such that urban populations have a greater outdoor exposure to bioaerosols. These bioaerosols contribute, in part, to the urban excesses in PM10. Higher bioaerosol mass fractions in urban areas relative to background sites indicate that urban areas serve as a source of bioaerosols. Similar urban enhancements in water-soluble calcium and its correlation with bioaerosol tracers point toward windblown soil as an important source of bioaerosols in urban areas.

  2. Enhancing bioplastic-substrate interaction via pore induction and directed migration of enzyme location.

    PubMed

    Lele, Bhalchandra S; Papworth, Glenn; Katsemi, Vicky; Rüterjans, Heinz; Martyano, Igor; Klabunde, Kenneth J; Russell, Alan J

    2004-06-20

    We demonstrate two novel approaches to enhance interactions of polymer-immobilized biomolecules with their substrates. In the first approach, diisopropylfluorophosphatase (DFPase) containing poly(urethane) (PU) coatings were made microporous by incorporating, then extracting, poly(ethylene glycol)-based diesters as porogens. Incorporation of 2% w/w porogen increased the effective diffusion coefficient of diisopropylfluorophosphate (DFP) through the coatings by 30% and increased the apparent turnover number of immobilized DFPase 3-fold. In the second approach, prior to immobilization, hydrophobic modification of DFPase was achieved through its conjugation with a dimer/trimer mixture of a uretdione based on 1,6-diisocyanatohexane. When the hydrophobically modified DFPase was immobilized in coatings, catalytic activity was 4-fold higher than that of the equivalent, immobilized, native DFPase. This activity enhancement was independent of the presence or absence of pores. Confocal microscopy images of coatings containing fluorescently labeled lysozyme show that the native enzyme is distributed uniformly over the entire thickness of the coatings. Hydrophobically modified and fluorescently labeled lysozyme is accumulated only in the upper 10 microm cross-sectional layer of a 100 microm-thick coating. Interactions of bioplastics with their substrates are tunable either by pore induction in a polymer or by directed migration of the hydrophobically modified biomolecule to the desired location. The latter approach has broad implications, including overcoming mass transfer limitations experienced by immobilized biocatalysts.

  3. A Collaborative Location Based Travel Recommendation System through Enhanced Rating Prediction for the Group of Users.

    PubMed

    Ravi, Logesh; Vairavasundaram, Subramaniyaswamy

    2016-01-01

    Rapid growth of web and its applications has created a colossal importance for recommender systems. Being applied in various domains, recommender systems were designed to generate suggestions such as items or services based on user interests. Basically, recommender systems experience many issues which reflects dwindled effectiveness. Integrating powerful data management techniques to recommender systems can address such issues and the recommendations quality can be increased significantly. Recent research on recommender systems reveals an idea of utilizing social network data to enhance traditional recommender system with better prediction and improved accuracy. This paper expresses views on social network data based recommender systems by considering usage of various recommendation algorithms, functionalities of systems, different types of interfaces, filtering techniques, and artificial intelligence techniques. After examining the depths of objectives, methodologies, and data sources of the existing models, the paper helps anyone interested in the development of travel recommendation systems and facilitates future research direction. We have also proposed a location recommendation system based on social pertinent trust walker (SPTW) and compared the results with the existing baseline random walk models. Later, we have enhanced the SPTW model for group of users recommendations. The results obtained from the experiments have been presented.

  4. Finite Element Analysis Enhancement or B-25 Container Dynamic Compaction

    SciTech Connect

    Jones, W.E.

    2002-12-19

    The document describes initial structural finite element modeling for dynamic compaction of B-25 containers buried in Engineered Trench number 1 at the U.S. Department of Energy's Savannah River Site (SRS), Aiken, South Carolina. Dynamic compaction is the practice of dropping a heavy weight to compact material that has been placed in the subsurface for disposal. B-25s placed in Engineered Trench number 1 contain low-level radioactive waste. Dynamic compaction of buried B-25s is an option that could mitigate subsidence of the cap that is eventually constructed over an engineered trench disposal site. The objective of numerical modeling of the Engineered trench system was to evaluate the response of B-25 Containers to dynamic compaction, eventually incorporating dynamic compaction behavior with various degrees of B-25 corrosion. Understanding the structural behavior of buried B-25s over time is important for anticipating and dealing with subsidence. Subsidence may compromise the long-term integrity of the caps placed over the buried waste to limit downward water and contaminant movement through the material.

  5. Locating AED Enabled Medical Drones to Enhance Cardiac Arrest Response Times.

    PubMed

    Pulver, Aaron; Wei, Ran; Mann, Clay

    2016-01-01

    Out-of-hospital cardiac arrest (OOHCA) is prevalent in the United States. Each year between 180,000 and 400,000 people die due to cardiac arrest. The automated external defibrillator (AED) has greatly enhanced survival rates for OOHCA. However, one of the important components of successful cardiac arrest treatment is emergency medical services (EMS) response time (i.e., the time from EMS "wheels rolling" until arrival at the OOHCA scene). Unmanned Aerial Vehicles (UAV) have regularly been used for remote sensing and aerial imagery collection, but there are new opportunities to use drones for medical emergencies. The purpose of this study is to develop a geographic approach to the placement of a network of medical drones, equipped with an automated external defibrillator, designed to minimize travel time to victims of out-of-hospital cardiac arrest. Our goal was to have one drone on scene within one minute for at least 90% of demand for AED shock therapy, while minimizing implementation costs. In our study, the current estimated travel times were evaluated in Salt Lake County using geographical information systems (GIS) and compared to the estimated travel times of a network of AED enabled medical drones. We employed a location model, the Maximum Coverage Location Problem (MCLP), to determine the best configuration of drones to increase service coverage within one minute. We found that, using traditional vehicles, only 4.3% of the demand can be reached (travel time) within one minute utilizing current EMS agency locations, while 96.4% of demand can be reached within five minutes using current EMS vehicles and facility locations. Analyses show that using existing EMS stations to launch drones resulted in 80.1% of cardiac arrest demand being reached within one minute Allowing new sites to launch drones resulted in 90.3% of demand being reached within one minute. Finally, using existing EMS and new sites resulted in 90.3% of demand being reached while greatly reducing

  6. A sequence homologous to kappa-deleting element is located 5 prime to the human J sub K locus

    SciTech Connect

    Kennedy, M.A.; Morris, C.M.; Fitzgerald, P.H. )

    1989-01-25

    The human kappa deleting element (Kde) mediates loss of CK and JK genes in B cells. A probe for Kde detects two genomic sequences on Southern blots. The Kde is located 24kb 3{prime} to CK, but the position of the homologous sequence is unknown. The authors in situ hybridized m141-2 to metaphase cells of JC11, a B-cell line bearing a t(2;14)(p11;q32) in which the chromosome 2 breakpoint is within JK or the VK-JK intron. Three peaks of labelled sites were obtained. Southern analysis of BamH1 digested DNA showed that Kde (14kb) and the homologous sequence (3kb) were both intact. Kde accounts for hybridization to 14q+ and the 2p- signal presumably derives from the related sequence. This locates the sequence homologous to Kde upstream from JK, possibly within the VK cluster, and may reflect transposition or some other duplicative event as proposed for the evolution of other regions of the kappa locus.

  7. Criticality safety evaluation for the Advanced Test Reactor enhanced low enriched uranium fuel elements

    SciTech Connect

    Montierth, Leland M.

    2016-07-19

    The Global Threat Reduction Initiative (GTRI) convert program is developing a high uranium density fuel based on a low enriched uranium (LEU) uranium-molybdenum alloy. Testing of prototypic GTRI fuel elements is necessary to demonstrate integrated fuel performance behavior and scale-up of fabrication techniques. GTRI Enhanced LEU Fuel (ELF) elements based on the ATR-Standard Size elements (all plates fueled) are to be fabricated for testing in the Advanced Test Reactor (ATR). While a specific ELF element design will eventually be provided for detailed analyses and in-core testing, this criticality safety evaluation (CSE) is intended to evaluate a hypothetical ELF element design for criticality safety purposes. Existing criticality analyses have analyzed Standard (HEU) ATR elements from which controls have been derived. This CSE documents analysis that determines the reactivity of the hypothetical ELF fuel elements relative to HEU ATR elements and whether the existing HEU ATR element controls bound the ELF element. The initial calculations presented in this CSE analyzed the original ELF design, now referred to as Mod 0.1. In addition, as part of a fuel meat thickness optimization effort for reactor performance, other designs have been evaluated. As of early 2014 the most current conceptual designs are Mk1A and Mk1B, that were previously referred to as conceptual designs Mod 0.10 and Mod 0.11, respectively. Revision 1 evaluates the reactivity of the ATR HEU Mark IV elements for a comparison with the Mark VII elements.

  8. The MES-1 murine enhancer element is closely associated with the heterogeneous 5' ends of two divergent transcription units.

    PubMed Central

    Williams, T J; Fried, M

    1986-01-01

    The location in the mouse genome of the 149-base pair MES-1 element, previously isolated by its ability to restore expression to an enhancerless selectable gene, was analyzed. The active moiety of the single-copy MES-1 element is located between the 5' ends of two divergent transcription units, SURF-1 and SURF-2, both of which specify more than one mRNA species by differential splicing. The heterogeneous 5' ends of the SURF transcripts are separated by only 50 to 75 base pairs, and this sequence possesses a high G + C content (65%) and contains neither the TATA and CAAT box motifs normally associated with many highly expressed genes nor the GC box motif (Sp1-binding site) associated with a number of housekeeping genes. Although MES-1 appears to have enhancerlike properties when linked to heterologous genes, its normal genomic location suggests that it functions as a bidirectional promoter. Thus, MES-1 may represent a new class of enhancer-promoter element. Images PMID:3025660

  9. Study of Co-Located and Distant Collaboration with Symbolic Support via a Haptics-Enhanced Virtual Reality Task

    ERIC Educational Resources Information Center

    Yeh, Shih-Ching; Hwang, Wu-Yuin; Wang, Jin-Liang; Zhan, Shi-Yi

    2013-01-01

    This study intends to investigate how multi-symbolic representations (text, digits, and colors) could effectively enhance the completion of co-located/distant collaborative work in a virtual reality context. Participants' perceptions and behaviors were also studied. A haptics-enhanced virtual reality task was developed to conduct…

  10. Study of Co-Located and Distant Collaboration with Symbolic Support via a Haptics-Enhanced Virtual Reality Task

    ERIC Educational Resources Information Center

    Yeh, Shih-Ching; Hwang, Wu-Yuin; Wang, Jin-Liang; Zhan, Shi-Yi

    2013-01-01

    This study intends to investigate how multi-symbolic representations (text, digits, and colors) could effectively enhance the completion of co-located/distant collaborative work in a virtual reality context. Participants' perceptions and behaviors were also studied. A haptics-enhanced virtual reality task was developed to conduct…

  11. Computational analysis of enhanced magnetic bioseparation in microfluidic systems with flow-invasive magnetic elements.

    PubMed

    Khashan, S A; Alazzam, A; Furlani, E P

    2014-06-16

    A microfluidic design is proposed for realizing greatly enhanced separation of magnetically-labeled bioparticles using integrated soft-magnetic elements. The elements are fixed and intersect the carrier fluid (flow-invasive) with their length transverse to the flow. They are magnetized using a bias field to produce a particle capture force. Multiple stair-step elements are used to provide efficient capture throughout the entire flow channel. This is in contrast to conventional systems wherein the elements are integrated into the walls of the channel, which restricts efficient capture to limited regions of the channel due to the short range nature of the magnetic force. This severely limits the channel size and hence throughput. Flow-invasive elements overcome this limitation and enable microfluidic bioseparation systems with superior scalability. This enhanced functionality is quantified for the first time using a computational model that accounts for the dominant mechanisms of particle transport including fully-coupled particle-fluid momentum transfer.

  12. Finite element simulation of location- and time-dependent mechanical behavior of chondrocytes in unconfined compression tests.

    PubMed

    Wu, J Z; Herzog, W

    2000-03-01

    Experimental evidence suggests that cells are extremely sensitive to their mechanical environment and react directly to mechanical stimuli. At present, it is technically difficult to measure fluid pressure, stress, and strain in cells, and to determine the time-dependent deformation of chondrocytes. For this reason, there are no data in the published literature that show the dynamic behavior of chondrocytes in articular cartilage. Similarly, the dynamic chondrocyte mechanics have not been calculated using theoretical models that account for the influence of cell volumetric fraction on cartilage mechanical properties. In the present investigation, the location- and time-dependent stress-strain state and fluid pressure distribution in chondrocytes in unconfined compression tests were simulated numerically using a finite element method. The technique involved two basic steps: first, cartilage was approximated as a macroscopically homogenized material and the mechanical behavior of cartilage was obtained using the homogenized model; second, the solution of the time-dependent displacements and fluid pressure fields of the homogenized model was used as the time-dependent boundary conditions for a microscopic submodel to obtain average location- and time-dependent mechanical behavior of cells. Cells and extracellular matrix were assumed to be biphasic materials composed of a fluid phase and a hyperelastic solid phase. The hydraulic permeability was assumed to be deformation dependent and the analysis was performed using a finite deformation approach. Numerical tests were made using configurations similar to those of experiments described in the literature. Our simulations show that the mechanical response of chondrocytes to cartilage loading depends on time, fluid boundary conditions, and the locations of the cells within the specimen. The present results are the first to suggest that chondrocyte deformation in a stress-relaxation type test may exceed the imposed system

  13. Modeling insights into the locations of density enhancements from the Enceladus water vapor jets

    NASA Astrophysics Data System (ADS)

    Hurley, Dana M.; Perry, Mark E.; Waite, J. Hunter

    2015-11-01

    Monte Carlo modeling of the vapor erupting from Enceladus' south polar region is presented to demonstrate the influence of physical characteristics of the emitted vapor on the distribution of particles at altitude. The modeled sources include localized jets and eruptions distributed along the surface features labeled "tiger stripes." The modeling reveals that density enhancements are displaced from the source location caused not only by the angle of emission but also by superposition of material from nearby sources. The altitude of the superposition is mass dependent and contributes to differences observed in the mass 28 and mass 44 channels of the Cassini Ion and Neutral Mass Spectrometer (INMS) during Enceladus encounters. INMS data are well modeled using only the tiger stripe sources; however, certain regions require additional sources to reproduce some features of the data. In particular, an excess source is required for 44 unified atomic mass unit (u) on the Saturn-facing hemisphere of Baghdad Sulcus. It is apparent in three parallel Cassini flybys. A relative decrease in the source rate is observed for mass 28 u for E14. The more diffuse nature of the 28 u INMS observations compared to the more collimated structure of the 44 u INMS observations is consistent with increased thermal spreading for low-mass constituents of the plume.

  14. Enhancer and promoter elements directing activation and glucocorticoid repression of the. cap alpha. /sub 1/-fetoprotein gene in hepatocytes

    SciTech Connect

    Guertin, M.; La Rue, H.; Bernier, D.; Wrange, O.; Chevrette, M.; Gingras, M.C.; Belanger, L.

    1988-04-01

    Mutations were introduced in 7 kilobases of 5'-flanking rat ..cap alpha../sub 1/-fetoprotein (AFP) genomic DNA, linked to the chloramphenicol acetyltransferase gene. AFP promoter activity and its repression by a glucocorticoid hormone were assessed by stable and transient expression assays. Stable transfection assays were more sensitive and accurate than transient expression assays in a Morris 7777 rat hepatoma recipient (Hepa7.6), selected for its strong AFP repression by dexamethasone. The segment of DNA encompassing a hepatocyte-constitutive chromatin DNase I-hypersensitive site at -3.7 kilobases and a liver developmental stage-specific site at -2.5 kilobases contains interacting enhancer elements sufficient for high AFP promoter activity in Hepa7.6 or HepG2 cells. Deletions and point mutations define an upstream promoter domain of AFP gene activation, operating with at least three distinct promoter-activating elements, PEI at -65 base pairs, PEII at -120 base pairs, and DE at -160 base pairs. PEI and PEII share homologies with albumin promoter sequences, PEII is a near-consensus nuclear factor I recognition sequence, and DE overlaps a glucocorticoid receptor recognition sequence. An element conferring glucocorticoid repression of AFP gene activity is located in the upstream AFP promoter domain. Receptor-binding assays indicate that this element is the glucocorticoid receptor recognition sequence which overlaps with promoter-activating element DE.

  15. A Meiotic Drive Element in the Maize Pathogen Fusarium verticillioides Is Located Within a 102 kb Region of Chromosome V

    PubMed Central

    Pyle, Jay; Patel, Tejas; Merrill, Brianna; Nsokoshi, Chabu; McCall, Morgan; Proctor, Robert H.; Brown, Daren W.; Hammond, Thomas M.

    2016-01-01

    Fusarium verticillioides is an agriculturally important fungus because of its association with maize and its propensity to contaminate grain with toxic compounds. Some isolates of the fungus harbor a meiotic drive element known as Spore killer (SkK) that causes nearly all surviving meiotic progeny from an SkK × Spore killer-susceptible (SkS) cross to inherit the SkK allele. SkK has been mapped to chromosome V but the genetic element responsible for meiotic drive has yet to be identified. In this study, we used cleaved amplified polymorphic sequence markers to genotype individual progeny from an SkK × SkS mapping population. We also sequenced the genomes of three progeny from the mapping population to determine their single nucleotide polymorphisms. These techniques allowed us to refine the location of SkK to a contiguous 102 kb interval of chromosome V, herein referred to as the Sk region. Relative to SkS genotypes, SkK genotypes have one extra gene within this region for a total of 42 genes. The additional gene in SkK genotypes, herein named SKC1 for Spore Killer Candidate 1, is the most highly expressed gene from the Sk region during early stages of sexual development. The Sk region also has three hyper-variable regions, the longest of which includes SKC1. The possibility that SKC1, or another gene from the Sk region, is an essential component of meiotic drive and spore killing is discussed. PMID:27317777

  16. A family of transposable elements co-opted into developmental enhancers in the mouse neocortex.

    PubMed

    Notwell, James H; Chung, Tisha; Heavner, Whitney; Bejerano, Gill

    2015-03-25

    The neocortex is a mammalian-specific structure that is responsible for higher functions such as cognition, emotion and perception. To gain insight into its evolution and the gene regulatory codes that pattern it, we studied the overlap of its active developmental enhancers with transposable element (TE) families and compared this overlap to uniformly shuffled enhancers. Here we show a striking enrichment of the MER130 repeat family among active enhancers in the mouse dorsal cerebral wall, which gives rise to the neocortex, at embryonic day 14.5. We show that MER130 instances preserve a common code of transcriptional regulatory logic, function as enhancers and are adjacent to critical neocortical genes. MER130, a nonautonomous interspersed TE, originates in the tetrapod or possibly Sarcopterygii ancestor, which far predates the appearance of the neocortex. Our results show that MER130 elements were recruited, likely through their common regulatory logic, as neocortical enhancers.

  17. Elemental Fluorine-18 Gas: Enhanced Production and Availability

    SciTech Connect

    VanBrocklin, Henry F.

    2011-12-01

    The overall objective of this project was to develop an efficient, reproducible and reliable process for the preparation of fluorine-18 labeled fluorine gas ([¹⁸F]F₂) from readily available cyclotron-produced [¹⁸F]fluoride ion. The two step process entailed the production of [¹⁸F]fluoromethane with subsequent conversion to [¹⁸F]F₂ by electric discharge of [¹⁸F]fluoromethane in the presence of carrier nonradioactive F₂ gas. The specific goals of this project were i) to optimize the preparation of [¹⁸F]fluoromethane from [¹⁸F]fluoride ion; ii) to develop a prototype automated system for the production of [¹⁸F]F₂ from [¹⁸F]fluoride ion and iii) develop a compact user friendly automated system for the preparation of [¹⁸F]F₂ with initial synthesis of fluorine-18 labeled radiotracers. Over the last decade there has been an increased interest in the production of "non-standard" positron-emitting isotopes for the preparation of new radiotracers for a variety of applications including medical imaging and therapy. The increased availability of these isotopes from small biomedical cyclotrons has prompted their use in labeling radiotracers. In much the same way the production of [¹⁸F]F₂ gas has been known for several decades. However, access to [¹⁸F]F₂ gas has been limited to those laboratories with the means (e.g. F₂ targetry for the cyclotron) and the project-based need to work with [¹⁸F]F₂ gas. Relatively few laboratories, compared to those that produce [¹⁸F]fluoride ion on a daily basis, possess the capability to produce and use [¹⁸F]F₂ gas. A simplified, reliable system employing [¹⁸F]fluoride ion from cyclotron targetry systems that are already in place coupled with on-demand production of the [¹⁸F]F₂ gas would greatly enhance its availability. This would improve the availability of [¹⁸F]F₂ gas and promote further work with a valuable precursor. The major goals of the project were accomplished

  18. A phorbol ester response element within the human T-cell receptor beta-chain enhancer.

    PubMed Central

    Prosser, H M; Wotton, D; Gegonne, A; Ghysdael, J; Wang, S; Speck, N A; Owen, M J

    1992-01-01

    The activity of the T-cell receptor beta-chain gene enhancer is increased by activators of the protein kinase C pathway during T-cell activation. Analysis of mutant enhancer constructs identified two elements, beta E2 and beta E3, conferring phorbol ester inducibility. Multimerized beta E2 acted in isolation as a phorbol ester-responsive element. Both beta E2 and beta E3, which contain a consensus Ets-binding site, were shown to bind directly to the product of the c-ets-1 protooncogene. Both regions also bound a second factor, core-binding factor. Mutation of the beta E2 Ets site abolished the inducibility of the beta E2 multimer. beta E2 and beta E3 Ets site mutations also profoundly affected activity and inducibility of the enhancer. In contrast, enhancer activity but not its inducibility was affected by mutation of the beta E2 core-binding factor site. Cotransfection studies showed that Ets-1 specifically repressed activity of the multimerized beta E2 element and the complete T-cell receptor beta-chain enhancer. These data show that the T-cell receptor beta-chain enhancer responds to protein kinase C-mediated activation signals via a functional domain, composed of two elements, which contains binding sites for Ets transcription factors and which is negatively regulated by Ets-1. Images PMID:1409722

  19. Modeling of dynamic crack branching by enhanced extended finite element method

    NASA Astrophysics Data System (ADS)

    Xu, Dandan; Liu, Zhanli; Liu, Xiaoming; Zeng, Qinglei; Zhuang, Zhuo

    2014-08-01

    The conventional extended finite element method (XFEM) is enhanced in this paper to simulate dynamic crack branching, which is a top challenge issue in fracture mechanics and finite element method. XFEM uses the enriched shape functions with special characteristics to represent the discontinuity in computation field. In order to describe branched cracks, it is necessary to set up the additional enrichment. Here we have developed two kinds of branched elements, namely the "element crossed by two separated cracks" and "element embedded by a junction". Another series of enriched degrees of freedom are introduced to seize the additional discontinuity in the elements. A shifted enrichment scheme is used to avoid the treatment of blending element. Correspondingly a new mass lumping method is developed for the branched elements based on the kinetic conservation. The derivation of the mass matrix of a four-node quadrilateral element which contains two strong discontinuities is specially presented. Then by choosing crack speed as the branching criterion, the branching process of a single mode I crack is simulated. The results including the branching angle and propagation routes are compared with that obtained by the conventionally used element deletion method.

  20. Finite Element Method Simulation of the Field Distribution for AFM Tip-Enhanced Surface- Enhanced Raman Scanning Microscopy

    SciTech Connect

    Micic, Miodrag; Klymyshyn, Nicholas A.; Suh, Yung D.; Lu, H. Peter

    2003-02-20

    We simulate field enhancement distributions encountered in atomic force microscopy (AFM) tip-induced surface enhanced Raman spectroscopy (SERS) experiments (AFM_SERS) by using the frequency-domain three-dimensional finite element method simulation (FEM) to solve Maxwell?s equations of electric field distributions. This paper reports on a numerical simulation of an electromagnetic field enhancement in the vicinity of a metallic atomic force microscopy 9AFM) tip positioned in a close proximity to metallic nanoparticles. We simulated the experimental configurations of involving an AFM metallic tip, one or two silver nanoparticles, and a laser beam of various incident angles under different geometric arrangements. Maximum electric field enhancement is discussed in terms of the relative position of the tip and nanoparticles, as well as the direction of excitation laser propagation. Our results suggest new approaches for using the AFM-SERS tip enhanced near-field imaging samples on surfaces.

  1. Perceived location specificity in perceptual separation-induced but not fear conditioning-induced enhancement of prepulse inhibition in rats.

    PubMed

    Lei, Ming; Luo, Lu; Qu, Tianshu; Jia, Hongxiao; Li, Liang

    2014-08-01

    Prepulse inhibition (PPI) is the suppression of the startle reflex when the startling stimulus is shortly preceded by a non-startling stimulus (the prepulse). Previous studies have shown that both fear conditioning of a prepulse and precedence-effect-induced perceptual separation between the conditioned prepulse and a noise masker facilitate selective attention to the prepulse and consequently enhance PPI with a remarkable prepulse-feature specificity. This study investigated whether the two types of attentional enhancements of PPI in rats also exhibit a prepulse-location specificity. The results showed that when a prepulse was delivered by each of the two spatially separated loudspeakers, fear conditioning of the prepulse at a particularly perceived location (left or right to the tested rat) enhanced PPI without exhibiting any perceived-location specificity. However, when a noise masker was presented, the precedence-effect-induced perceptual separation between the conditioned prepulse and the noise masker further enhanced PPI when the prepulse was perceived as coming from the location that was conditioned but not the location without being conditioned. Moreover, both conditioning-induced and perceptual separation-induced PPI enhancements were eliminated by extinction learning, whose effect could be blocked by systemic injection of the selective antagonist of metabotropic glutamate receptor subtype 5 (mGluR5), 2-methyl-6-(phenylethynyl)-pyridine (MPEP). Thus, fear conditioning of a prepulse perceived at a particular location not only facilitates selective attention to the conditioned prepulse but also induces a learning-based spatial gating effect on the spatial unmasking of the conditioned prepulse, leading to that the perceptual separation-induced PPI enhancement becomes perceived-location specific. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Enhanced secondary organic aerosols during fog episodes over typical location in Indo-Gangetic region

    NASA Astrophysics Data System (ADS)

    Kaul, D. S.; Tripathi, S. N.; Gupta, T.

    2011-12-01

    This study examines the reason of enhanced SOA yield during foggy days and hypothesizes likely production of SOA through aqueous phase chemistry during fog episodes. PM1 samples were collected from January 16, 2010 to February 20, 2010 at Kanpur to study the secondary organic aerosol (SOA) production during clear and foggy days. Of the 180 samples collected, 56 were from foggy days. Micro-Pulse Lidar Network (MPLNET), a part of National Aeronautic Space Administration (NASA), was used for identification of fog duration. Organic Carbon (OC), Elemental Carbon (EC) and water soluble organic carbon analysis were carried out by a EC-OC analyzer and a TOC analyzer, respectively. Trace gases and solar flux measurement were carried out by gas analyzers and a pyranometer (a part of NASA), respectively to identify the photo-chemical activity. Meteorological data were measured by atmospheric weather station. SOA was estimated during foggy and clear days using tracer method. Enhanced SOA was observed during foggy days, production of SOA was highest in the afternoon and lower during morning and evening. Peak of OC/EC ratio during foggy days occurred earlier indicating role of aqueous phase chemistry in addition to gas-particle portioning which is the prevalent mechanism of SOA production during clear days. The possible contribution of biomass burning to SOA which could otherwise confound the SOA estimate during foggy days was also examined by biomass tracer, potassium ion. The influence of biomass to SOA during foggy days was found to be negligible. This is so because organic carbon from biomass origin is highly hygroscopic and is scavenged by the fog droplets. The lesser average concentration of water soluble organic carbon during foggy days support the scavenging and removal of the biomass originated organic carbon. Evaporation of individual fog and subsequent increase of OC/EC ratio further supported the aqueous phase production of SOA. The temperature and relative humidity

  3. Enhanced light element imaging in atomic resolution scanning transmission electron microscopy.

    PubMed

    Findlay, S D; Kohno, Y; Cardamone, L A; Ikuhara, Y; Shibata, N

    2014-01-01

    We show that an imaging mode based on taking the difference between signals recorded from the bright field (forward scattering region) in atomic resolution scanning transmission electron microscopy provides an enhancement of the detectability of light elements over existing techniques. In some instances this is an enhancement of the visibility of the light element columns relative to heavy element columns. In all cases explored it is an enhancement in the signal-to-noise ratio of the image at the light column site. The image formation mechanisms are explained and the technique is compared with earlier approaches. Experimental data, supported by simulation, are presented for imaging the oxygen columns in LaAlO₃. Case studies looking at imaging hydrogen columns in YH₂ and lithium columns in Al₃Li are also explored through simulation, particularly with respect to the dependence on defocus, probe-forming aperture angle and detector collection aperture angles. © 2013 Elsevier B.V. All rights reserved.

  4. Hydrogen atom donor compounds as contrast enhancers for black-and-white photothermographic and thermographic elements

    DOEpatents

    Harring, Lori S.; Simpson, Sharon M.; Sansbury, Francis H.

    1997-01-01

    Hydrogen atom donor compounds are useful as contrast enhancers when used in combination with (i) hindered phenol developers, and (ii) trityl hydrazide and/or formyl-phenyl hydrazine co-developers, to produce ultra-high contrast black-and-white photothermographic and thermographic elements. The photothermographic and thermographic elements may be used as a photomask in a process where there is a subsequent exposure of an ultraviolet or short wavelength visible radiation-sensitive imageable medium.

  5. Demystifying the secret mission of enhancers: linking distal regulatory elements to target genes

    PubMed Central

    Yao, Lijing; Berman, Benjamin P.; Farnham, Peggy J.

    2015-01-01

    Abstract Enhancers are short regulatory sequences bound by sequence-specific transcription factors and play a major role in the spatiotemporal specificity of gene expression patterns in development and disease. While it is now possible to identify enhancer regions genomewide in both cultured cells and primary tissues using epigenomic approaches, it has been more challenging to develop methods to understand the function of individual enhancers because enhancers are located far from the gene(s) that they regulate. However, it is essential to identify target genes of enhancers not only so that we can understand the role of enhancers in disease but also because this information will assist in the development of future therapeutic options. After reviewing models of enhancer function, we discuss recent methods for identifying target genes of enhancers. First, we describe chromatin structure-based approaches for directly mapping interactions between enhancers and promoters. Second, we describe the use of correlation-based approaches to link enhancer state with the activity of nearby promoters and/or gene expression. Third, we describe how to test the function of specific enhancers experimentally by perturbing enhancer–target relationships using high-throughput reporter assays and genome editing. Finally, we conclude by discussing as yet unanswered questions concerning how enhancers function, how target genes can be identified, and how to distinguish direct from indirect changes in gene expression mediated by individual enhancers. PMID:26446758

  6. Two enhancers and one silencer located in the introns of regA control somatic cell differentiation in Volvox carteri

    PubMed Central

    Stark, Klaus; Kirk, David L.; Schmitt, Rüdiger

    2001-01-01

    The regA gene plays a central role in germ-soma differentiation of Volvox carteri by suppressing all reproductive functions in somatic cells. Here we show that the minimal promoter of regA consists of only 42 bp immediately upstream of the transcription start site, and that it contains no discernible regulatory elements. However, introns 3 and 5 are both required for regA expression in somatic cells, and intron 7 is essential for silencing regA in gonidia (asexual reproductive cells). A regA gene lacking intron 7 rescues the normal phenotype of mutant somatic cells, but also results in gonidia that reproduce only weakly and soon die out. The same phenotype is observed when a regA gene containing intron 7 is placed under control of a constitutive promoter, suggesting that the silencing activity of intron 7 is promoter specific. Intron 7 is unusual in that it contains a potential ORF that is in frame with exons 7 and 8, and some transcripts are produced in which intron 7 is retained. However, a regulatory role for the intron 7 translation product can be ruled out, because a construct in which intron 7 must be translated, and one in which it cannot be translated, both result in wild-type development of both cell types. Furthermore, intron 7 is unable to act in trans to silence regA, but is able to exert its normal effect when placed in a different location within the gene. Therefore, it appears that intron 7 functions in gonidia as a classical cell-type-specific and promoter-specific enhancer, of the inhibitory type that is often referred to as a silencer. PMID:11390364

  7. Identification of minute damage in composite bridge structures equipped with fiber optic sensors using the location of neutral axis and finite element analysis

    NASA Astrophysics Data System (ADS)

    Li, Xi; Glisic, Branko

    2016-04-01

    By definition, the neutral axis of a loaded composite beam structure is the curve along which the section experiences zero bending strain. When no axial loading is present, the location of the neutral axis passes through the centroid of stiffness of the beam cross-section. In the presence of damage, the centroid of stiffness, as well as the neutral axis, shift from the healthy position. The concept of neutral axis can be widely applied to all beam-like structures. According to literature, a change in location of the neutral axis can be associated with damage in the corresponding cross-section. In this paper, the movement of neutral axis near locations of minute damage in a composite bridge structure was studied using finite element analysis and experimental results. The finite element model was developed based on a physical scale model of a composite simply-supported structure with controlled minute damage in the reinforced concrete deck. The structure was equipped with long-gauge fiber optic strain and temperature sensors at a healthy reference location as well as two locations of damage. A total of 12 strain sensors were installed during construction and used to monitor the structure during various loading events. This paper aims to explain previous experimental results which showed that the observed positions of neutral axis near damage locations were higher than the predicted healthy locations in some loading events. Analysis has shown that finite element analysis has potential to simulate and explain the physical behavior of the test structure.

  8. Analysis of organic and elemental carbon in heating and non-heating periods in four locations of Beijing.

    PubMed

    Sun, Fengbin; Lun, Xiaoxiu; Liu, Xuhui; Mo, Li; Li, Renna; Zhang, Hongxia; Chen, Jungang; Cao, Yingying; Shi, Fangtian; Yu, Xinxiao

    2016-01-01

    The concentrations of elemental carbon (EC) and organic carbon (OC) in PM2.5 atmospheric aerosol were measured at four different sites in Beijing: Beijing Olympic Forest Park (OF), Jiufeng National Forest Park (JF), Beijing Forestry University campus lawn (G), and roads near the Beijing Forestry University (S). The winter heating period concentrations were 30-45% higher than the spring non-heating period. Possible reasons for this could be the severe convective weather in spring due to the temperate monsoon, deposition of PM2.5 to plants in spring, stable atmospheric conditions in winter, and/or a greater number of sources of carbonaceous aerosols in winter. The proportion of total carbon (i.e. EC + OC) in PM2.5 in Beijing is high. The OC/EC value was 2.45 (OF) and 2.39 (JF) in winter and 1.6 (OF) and 1.43 (JF) in spring. These ratios and the high correlation of OC with EC in the winter samples indicate a strong primary source of OC. Eight carbon fractions from the four different sampling locations were analysed, and the OC1-4 values were found to vary considerably. In winter, the OC1 values from all four sites were higher than the spring values. Although there were differences at each site, the percentages of OC2, OC3, EC1-OP, and EC2 were the largest. Secondary organic carbon (SOC) formed during long-range transport from the emission sources to the monitoring sites, and the increase of OC2 and OC3 concentrations could be associated with SOC.

  9. Student Voice in a Chinese Context: Investigating the Key Elements of Leadership That Enhance Student Voice

    ERIC Educational Resources Information Center

    Cheng, Annie Yan Ni

    2012-01-01

    This study examines the issues surrounding "student voice" in a specific Chinese context, and assesses the key elements of leadership that could enhance student voice in that context. It reports the results of a research conducted in a community-based educational centre in Hong Kong that provides after-school educational and social…

  10. Elements of Collaborative Discussion and Shared Problem Solving in a Voice-Enhanced Multiplayer Game

    ERIC Educational Resources Information Center

    Bluemink, Johanna; Jarvela, Sanna

    2011-01-01

    This study focuses on investigating the nature of small-group collaborative interaction in a voice-enhanced multiplayer game called "eScape". The aim was to analyse the elements of groups' collaborative discussion and to explore the nature of the players' shared problem solving activity during the solution critical moments in the game. The data…

  11. Hypoxia inducible factor-1 mediates the expression of the immune checkpoint HLA-G in glioma cells through hypoxia response element located in exon 2

    PubMed Central

    Yaghi, Layale; Poras, Isabelle; Simoes, Renata T.; Donadi, Eduardo A.; Tost, Jörg; Daunay, Antoine; de Almeida, Bibiana Sgorla; Carosella, Edgardo D.; Moreau, Philippe

    2016-01-01

    HLA-G is an immune checkpoint molecule with specific relevance in cancer immunotherapy. It was first identified in cytotrophoblasts, protecting the fetus from maternal rejection. HLA-G tissue expression is very restricted but induced in numerous malignant tumors such as glioblastoma, contributing to their immune escape. Hypoxia occurs during placenta and tumor development and was shown to activate HLA-G. We aimed to elucidate the mechanisms of HLA-G activation under conditions combining hypoxia-mimicking treatment and 5-aza-2′deoxycytidine, a DNA demethylating agent used in anti-cancer therapy which also induces HLA-G. Both treatments enhanced the amount of HLA-G mRNA and protein in HLA-G negative U251MG glioma cells. Electrophoretic Mobility Shift Assays and luciferase reporter gene assays revealed that HLA-G upregulation depends on Hypoxia Inducible Factor-1 (HIF-1) and a hypoxia responsive element (HRE) located in exon 2. A polymorphic HRE at −966 bp in the 5′UT region may modulate the magnitude of the response mediated by the exon 2 HRE. We suggest that therapeutic strategies should take into account that HLA-G expression in response to hypoxic tumor environment is dependent on HLA-G gene polymorphism and DNA methylation state at the HLA-G locus. PMID:27577073

  12. Hypoxia inducible factor-1 mediates the expression of the immune checkpoint HLA-G in glioma cells through hypoxia response element located in exon 2.

    PubMed

    Yaghi, Layale; Poras, Isabelle; Simoes, Renata T; Donadi, Eduardo A; Tost, Jörg; Daunay, Antoine; de Almeida, Bibiana Sgorla; Carosella, Edgardo D; Moreau, Philippe

    2016-09-27

    HLA-G is an immune checkpoint molecule with specific relevance in cancer immunotherapy. It was first identified in cytotrophoblasts, protecting the fetus from maternal rejection. HLA-G tissue expression is very restricted but induced in numerous malignant tumors such as glioblastoma, contributing to their immune escape. Hypoxia occurs during placenta and tumor development and was shown to activate HLA-G. We aimed to elucidate the mechanisms of HLA-G activation under conditions combining hypoxia-mimicking treatment and 5-aza-2'deoxycytidine, a DNA demethylating agent used in anti-cancer therapy which also induces HLA-G. Both treatments enhanced the amount of HLA-G mRNA and protein in HLA-G negative U251MG glioma cells. Electrophoretic Mobility Shift Assays and luciferase reporter gene assays revealed that HLA-G upregulation depends on Hypoxia Inducible Factor-1 (HIF-1) and a hypoxia responsive element (HRE) located in exon 2. A polymorphic HRE at -966 bp in the 5'UT region may modulate the magnitude of the response mediated by the exon 2 HRE. We suggest that therapeutic strategies should take into account that HLA-G expression in response to hypoxic tumor environment is dependent on HLA-G gene polymorphism and DNA methylation state at the HLA-G locus.

  13. Fluid rare earth element anlayses from geothermal wells located on the Reykjanes Peninsula, Iceland and Middle Valley seafloor hydrothermal system on the Juan de Fuca Ridge.

    DOE Data Explorer

    Andrew Fowler

    2015-05-01

    Results for fluid rare earth element analyses from four Reykjanes peninsula high-temperature geothermal fields. Data for fluids from hydrothermal vents located 2400 m below sea level from Middle Valley on the Juan de Fuca Ridge are also included. Data have been corrected for flashing. Samples preconcentrated using a chelating resin with IDA functional group (InertSep ME-1). Analyzed using an Element magnetic sector inductively coupled plasma mass spectrometry (ICP-MS).

  14. Enhancement of antibody class switch recombination by the cumulative activity of four separate elements1

    PubMed Central

    Dunnick, Wesley A.; Shi, Jian; Zerbato, Jennifer M.; Fontaine, Clinton A.; Collins, John T.

    2011-01-01

    Class switch recombination of antibody isotype is mediated by a recombinational DNA deletion event, and must be robustly upregulated during antigen-driven differentiation of B cells. The enhancer region 3′ of the Cα gene is important for the upregulation of switch recombination. Using a transgene of the entire heavy chain constant region locus, we now demonstrate that it is the four 3′ enhancer elements themselves (a total of 4.7 kb) that are responsible for the upregulation, rather than the 24 kb of DNA in between them. Neither allelic exclusion nor transgenic μ expression is reduced by deletion of the four 3′ enhancers. We also test deletions of two or three of the 3′ enhancers, and show that deletion of more 3′ enhancers results in a progressive reduction in both switch recombination and germline transcription of all heavy chain genes. Nevertheless, we find evidence for special roles for some 3′ enhancers--different heavy chain genes are affected by different 3′ enhancer deletions. Thus, we find that the dramatic induction of class switch recombination during antigen-driven differentiation is the result of an interaction among four separated regulatory elements. PMID:21949022

  15. Novel approach in radionuclide tumor therapy: dose enhancement by high Z-element contrast agents.

    PubMed

    Aziz, Emad F; Bugaj, Joseph E; Caglar, Gül; Dinkelborg, Ludger M; Lawaczeck, Rüdiger

    2006-06-01

    The aim of this study was to first calculate the dose-enhancement effect from internalized radiation by the presence of exogenous contrast media using Monte Carlo simulations, and then provide in vitro proof-of-concept for this novel method of radiation-dose enhancement. The Monte Carlo program EGSnrc (Electron Gamma Shower) was used to simulate the interaction of internalizing radiation with iodine (I) or gadolinium (Gd) containing contrast media. Experimentally, the doseenhancement effect induced by I or Gd was evaluated in cell culture assays using internalizing peptides chelated with beta- emitting radionuclides and clinically available contrast media. Monte Carlo simulations predicted significant enhancement (approximately 70-340%) of radiation dose in the presence of high Zelement contrast media. This enhancement is radiation and Z-element dependent. Calculations showed that in the presence of contrast media, low-energy radionuclides favor localization of secondary particles, whereas higher energy beta- emitters localize radiation by reducing the pathway of the primary beta-particle. The dose enhancement was verified in vitro in two cell lines. Monte Carlo simulations in parallel with in vitro studies provide proof-of-principle for dose enhancement that occurs when utilizing an internalized source of radiation followed by the addition of exogenous contrast media. This dose enhancement is both radiation and Z-element dependent.

  16. Identifying transcription start sites and active enhancer elements using BruUV-seq.

    PubMed

    Magnuson, Brian; Veloso, Artur; Kirkconnell, Killeen S; de Andrade Lima, Leonardo Carmo; Paulsen, Michelle T; Ljungman, Emily A; Bedi, Karan; Prasad, Jayendra; Wilson, Thomas E; Ljungman, Mats

    2015-12-11

    BruUV-seq utilizes UV light to introduce transcription-blocking DNA lesions randomly in the genome prior to bromouridine-labeling and deep sequencing of nascent RNA. By inhibiting transcription elongation, but not initiation, pre-treatment with UV light leads to a redistribution of transcription reads resulting in the enhancement of nascent RNA signal towards the 5'-end of genes promoting the identification of transcription start sites (TSSs). Furthermore, transcripts associated with arrested RNA polymerases are protected from 3'-5' degradation and thus, unstable transcripts such as putative enhancer RNA (eRNA) are dramatically increased. Validation of BruUV-seq against GRO-cap that identifies capped run-on transcripts showed that most BruUV-seq peaks overlapped with GRO-cap signal over both TSSs and enhancer elements. Finally, BruUV-seq identified putative enhancer elements induced by tumor necrosis factor (TNF) treatment concomitant with expression of nearby TNF-induced genes. Taken together, BruUV-seq is a powerful new approach for identifying TSSs and active enhancer elements genome-wide in intact cells.

  17. Identifying transcription start sites and active enhancer elements using BruUV-seq

    PubMed Central

    Magnuson, Brian; Veloso, Artur; Kirkconnell, Killeen S.; Lima, Leonardo Carmo de Andrade; Paulsen, Michelle T.; Ljungman, Emily A.; Bedi, Karan; Prasad, Jayendra; Wilson, Thomas E.; Ljungman, Mats

    2015-01-01

    BruUV-seq utilizes UV light to introduce transcription-blocking DNA lesions randomly in the genome prior to bromouridine-labeling and deep sequencing of nascent RNA. By inhibiting transcription elongation, but not initiation, pre-treatment with UV light leads to a redistribution of transcription reads resulting in the enhancement of nascent RNA signal towards the 5′-end of genes promoting the identification of transcription start sites (TSSs). Furthermore, transcripts associated with arrested RNA polymerases are protected from 3′–5′ degradation and thus, unstable transcripts such as putative enhancer RNA (eRNA) are dramatically increased. Validation of BruUV-seq against GRO-cap that identifies capped run-on transcripts showed that most BruUV-seq peaks overlapped with GRO-cap signal over both TSSs and enhancer elements. Finally, BruUV-seq identified putative enhancer elements induced by tumor necrosis factor (TNF) treatment concomitant with expression of nearby TNF-induced genes. Taken together, BruUV-seq is a powerful new approach for identifying TSSs and active enhancer elements genome-wide in intact cells. PMID:26656874

  18. Alloying element's substitution in titanium alloy with improved oxidation resistance and enhanced magnetic properties

    NASA Astrophysics Data System (ADS)

    Yu, Ang-Yang; Wei, Hua; Hu, Qing-Miao; Yang, Rui

    2017-01-01

    First-principles method is used to characterize segregation and magnetic properties of alloyed Ti/TiO2interface. We calculate the segregation energy of the doped Ti/TiO2 interface to investigate alloying atom's distribution. The oxidation resistance of Ti/TiO2 interface is enhanced by elements Fe and Ni but reduced by element Co. Magnetism could be produced by alloying elements such as Co, Fe and Ni in the bulk of titanium and the surface of Ti at Ti/TiO2 interface. The presence of these alloying elements could transform the non-magnetic titanium alloys into magnetic systems. We have also calculated the temperature dependence of magnetic permeability for the doped and pure Ti/TiO2 interfaces. Alloying effects on the Curie temperature of the Ti/TiO2 interface have been elaborated.

  19. Investigation of deformation of elements of three-dimensional reinforced concrete structures located in the soil, interacting with each other through rubber gaskets

    NASA Astrophysics Data System (ADS)

    Berezhnoi, D. V.; Balafendieva, I. S.; Sachenkov, A. A.; Sekaeva, L. R.

    2017-06-01

    In work the technique of calculation of elements of three-dimensional reinforced concrete substructures located in a soil, interacting with each other through rubber linings is realized. To describe the interaction of deformable structures with the ground, special “semi-infinite” finite elements are used. A technique has been implemented that allows one to describe the contact interaction of three-dimensional structures by means of a special contact finite element with specific properties. The obtained numerical results are compared with the experimental data, their good agreement is noted.

  20. Seeing and Feeling for Self and Other: Proprioceptive Spatial Location Determines Multisensory Enhancement of Touch

    ERIC Educational Resources Information Center

    Cardini, Flavia; Haggard, Patrick; Ladavas, Elisabetta

    2013-01-01

    We have investigated the relation between visuo-tactile interactions and the self-other distinction. In the Visual Enhancement of Touch (VET) effect, non-informative vision of one's own hand improves tactile spatial perception. Previous studies suggested that looking at "another"person's hand could also enhance tactile perception, but did not…

  1. Seeing and Feeling for Self and Other: Proprioceptive Spatial Location Determines Multisensory Enhancement of Touch

    ERIC Educational Resources Information Center

    Cardini, Flavia; Haggard, Patrick; Ladavas, Elisabetta

    2013-01-01

    We have investigated the relation between visuo-tactile interactions and the self-other distinction. In the Visual Enhancement of Touch (VET) effect, non-informative vision of one's own hand improves tactile spatial perception. Previous studies suggested that looking at "another"person's hand could also enhance tactile perception, but did not…

  2. Incomplete reporting of enhanced recovery elements and its impact on achieving quality improvement

    PubMed Central

    Day, Ryan W.; Fielder, Sharon; Calhoun, John; Kehlet, Henrik

    2015-01-01

    BACKGROUND Enhanced recovery (ER) protocols are widely used in surgical practice. As protocols are multidisciplinary with multiple components, it is difficult to compare and contrast reports. The present study therefore examined compliance and transferability to clinical practice among ER publications related to colorectal surgery. METHODS PubMed, EMBASE and Cochrane databases were searched for current colorectal ER manuscripts. Each publication was assessed for the number of ER elements, whether the element was sufficiently explained so that it could be transferred to clinical practice, and the compliance with the ER element. RESULTS Some 50 publications met the reporting criteria for inclusion. There were 22 ERAS elements described altogether. The median number of elements included in each publication was 9 with median number of included patients of 130. The most frequent elements included in ER pathways were early postoperative diet advancement in 49 (98%) and early mobilisation in 47 (94%). Early diet advancement was sufficiently explained in 43 (86%) publications but just 22 (45%) reported compliance. The explanation for early mobilisation was satisfactory in 41 (82%) publications but only 14 (30%) reported compliance. Other ERAS elements had similar rates of explanation and compliance. The most frequently analysed outcome measures were morbidity 49 (98%), length of stay 47 (94%), and mortality in 45 (90%) of publications. CONCLUSIONS The current standard of reporting is frequently incomplete. In order to transfer knowledge and facilitate implementation of pathways that demonstrate improvements in perioperative care and recovery, a consistent structured reporting platform is needed. PMID:26364714

  3. Optimal MRI sequence for identifying occlusion location in acute stroke: which value of time-resolved contrast-enhanced MRA?

    PubMed

    Le Bras, A; Raoult, H; Ferré, J-C; Ronzière, T; Gauvrit, J-Y

    2015-06-01

    Identifying occlusion location is crucial for determining the optimal therapeutic strategy during the acute phase of ischemic stroke. The purpose of this study was to assess the diagnostic efficacy of MR imaging, including conventional sequences plus time-resolved contrast-enhanced MRA in comparison with DSA for identifying arterial occlusion location. Thirty-two patients with 34 occlusion levels referred for thrombectomy during acute cerebral stroke events were consecutively included from August 2010 to December 2012. Before thrombectomy, we performed 3T MR imaging, including conventional 3D-TOF and gradient-echo T2 sequences, along with time-resolved contrast-enhanced MRA of the extra- and intracranial arteries. The 3D-TOF, gradient-echo T2, and time-resolved contrast-enhanced MRA results were consensually assessed by 2 neuroradiologists and compared with prethrombectomy DSA results in terms of occlusion location. The Wilcoxon test was used for statistical analysis to compare MR imaging sequences with DSA, and the κ coefficient was used to determine intermodality agreement. The occlusion level on the 3D-TOF and gradient-echo T2 images differed significantly from that of DSA (P < .001 and P = .002, respectively), while no significant difference was observed between DSA and time-resolved contrast-enhanced MRA (P = .125). κ coefficients for intermodality agreement with DSA (95% CI, percentage agreement) were 0.43 (0.3%-0.6; 62%), 0.32 (0.2%-0.5; 56%), and 0.81 (0.6%-1.0; 88%) for 3D-TOF, gradient-echo T2, and time-resolved contrast-enhanced MRA, respectively. The time-resolved contrast-enhanced MRA sequence proved reliable for identifying occlusion location in acute stroke with performance superior to that of 3D-TOF and gradient-echo T2 sequences. © 2015 by American Journal of Neuroradiology.

  4. A retroviral promoter and a cellular enhancer define a bipartite element which controls env ERVWE1 placental expression.

    PubMed

    Prudhomme, Sarah; Oriol, Guy; Mallet, François

    2004-11-01

    The HERV-W family contains hundreds of loci diversely expressed in several physiological and pathological contexts. A unique locus termed ERVWE1 encodes an envelope glycoprotein (syncytin) involved in hominoid placental physiology. Here we show that syncytin expression is regulated by a bipartite element consisting of a cyclic AMP (cAMP)-inducible long terminal repeat (LTR) retroviral promoter adjacent to a cellular enhancer conferring a high level of expression and placental tropism. Deletion mutant analysis showed that the ERVWE1 5' LTR contains binding sites essential for basal placental activity in the region from positions +1 to +125. The region from positions +125 to +310 represents a cAMP-responsive core HERV-W promoter active in all cell types. Site-directed mutagenesis analysis highlighted the complexity of U3 regulation. ERVWE1 placenta-specific positive (e.g., T240) and negative (e.g., G71) regulatory sites were identified, as were essential sites required for basic activity (e.g., A247). The flanking sequences of the ERVWE1 provirus contain several putative regulatory elements. The upstream HERV-H and HERV-P LTRs were found to be inactive. Conversely, the 436-bp region located between the HERV-P LTR and ERVWE1 was shown to be an upstream regulatory element (URE) which is significantly active in placenta cells. This URE acts as a tissue-specific enhancer. Genetic and functional analyses of hominoid UREs revealed large differences between UREs of members of the Hominidae and the Hylobatidae. These data allowed the identification of a positive regulatory region from positions -436 to -128, a mammalian apparent LTR retrotransposon negative regulatory region from positions -128 to -67, and a trophoblast-specific enhancer (TSE) from positions -67 to -35. Putative AP-2, Sp-1, and GCMa binding sites are essential constituents of the 33-bp TSE.

  5. A Retroviral Promoter and a Cellular Enhancer Define a Bipartite Element Which Controls env ERVWE1 Placental Expression

    PubMed Central

    Prudhomme, Sarah; Oriol, Guy; Mallet, François

    2004-01-01

    The HERV-W family contains hundreds of loci diversely expressed in several physiological and pathological contexts. A unique locus termed ERVWE1 encodes an envelope glycoprotein (syncytin) involved in hominoid placental physiology. Here we show that syncytin expression is regulated by a bipartite element consisting of a cyclic AMP (cAMP)-inducible long terminal repeat (LTR) retroviral promoter adjacent to a cellular enhancer conferring a high level of expression and placental tropism. Deletion mutant analysis showed that the ERVWE1 5′ LTR contains binding sites essential for basal placental activity in the region from positions +1 to +125. The region from positions +125 to +310 represents a cAMP-responsive core HERV-W promoter active in all cell types. Site-directed mutagenesis analysis highlighted the complexity of U3 regulation. ERVWE1 placenta-specific positive (e.g., T240) and negative (e.g., G71) regulatory sites were identified, as were essential sites required for basic activity (e.g., A247). The flanking sequences of the ERVWE1 provirus contain several putative regulatory elements. The upstream HERV-H and HERV-P LTRs were found to be inactive. Conversely, the 436-bp region located between the HERV-P LTR and ERVWE1 was shown to be an upstream regulatory element (URE) which is significantly active in placenta cells. This URE acts as a tissue-specific enhancer. Genetic and functional analyses of hominoid UREs revealed large differences between UREs of members of the Hominidae and the Hylobatidae. These data allowed the identification of a positive regulatory region from positions −436 to −128, a mammalian apparent LTR retrotransposon negative regulatory region from positions −128 to −67, and a trophoblast-specific enhancer (TSE) from positions −67 to −35. Putative AP-2, Sp-1, and GCMa binding sites are essential constituents of the 33-bp TSE. PMID:15507602

  6. Computational Analysis of Enhanced Magnetic Bioseparation in Microfluidic Systems with Flow-Invasive Magnetic Elements

    PubMed Central

    Khashan, S. A.; Alazzam, A.; Furlani, E. P.

    2014-01-01

    A microfluidic design is proposed for realizing greatly enhanced separation of magnetically-labeled bioparticles using integrated soft-magnetic elements. The elements are fixed and intersect the carrier fluid (flow-invasive) with their length transverse to the flow. They are magnetized using a bias field to produce a particle capture force. Multiple stair-step elements are used to provide efficient capture throughout the entire flow channel. This is in contrast to conventional systems wherein the elements are integrated into the walls of the channel, which restricts efficient capture to limited regions of the channel due to the short range nature of the magnetic force. This severely limits the channel size and hence throughput. Flow-invasive elements overcome this limitation and enable microfluidic bioseparation systems with superior scalability. This enhanced functionality is quantified for the first time using a computational model that accounts for the dominant mechanisms of particle transport including fully-coupled particle-fluid momentum transfer. PMID:24931437

  7. Enhanced analgesic effects of tramadol and common trace element coadministration in mice.

    PubMed

    Alexa, Teodora; Marza, Aurelia; Voloseniuc, Tudor; Tamba, Bogdan

    2015-10-01

    Chronic pain is managed mostly by the daily administration of analgesics. Tramadol is one of the most commonly used drugs, marketed in combination with coanalgesics for enhanced effect. Trace elements are frequent ingredients in dietary supplements and may enhance tramadol's analgesic effect either through synergic mechanisms or through analgesic effects of their own. Swiss Weber male mice were divided into nine groups and were treated with a combination of the trace elements Mg, Mn, and Zn in three different doses and a fixed dose of tramadol. Two groups served as positive (tramadol alone) and negative (saline) controls. Nociceptive assessment by tail-flick (TF) and hot-plate (HP) tests was performed at baseline and at 15, 30, 45, and 60 min after intraperitoneal administration. Response latencies were recorded and compared with the aid of ANOVA testing. All three trace elements enhanced tramadol's analgesic effect, as assessed by TF and HP test latencies. Coadministration of these trace elements led to an increase of approximately 30% in the average pain inhibition compared with the tramadol-alone group. The most effective doses were 0.6 mg/kg b.w. for Zn, 75 mg/kg b.w. for Mg, and 7.2 mg/kg b.w. for Mn. Associating trace elements such as Zn, Mg, and Mn with the standard administration of tramadol increases the drug's analgesic effect, most likely a consequence of their synergic action. These findings impact current analgesic treatment because the addition of these trace elements may reduce the tramadol dose required to obtain analgesia. © 2015 Wiley Periodicals, Inc.

  8. Transcriptional regulation by activation and repression elements located at the 5'-noncoding region of the human alpha9 nicotinic receptor subunit gene.

    PubMed

    Valor, Luis M; Castillo, Mar; Ortiz, José A; Criado, Manuel

    2003-09-26

    The alpha9 subunit is a component of the neuronal nicotinic acetylcholine receptor gene superfamily that is expressed in very restricted locations. The promoter of the human gene has been analyzed in the human neuroblastoma SH-SY5Y, where alpha9 subunit expression was detected, and in C2C12 cells that do not express alpha9. A proximal promoter region (from -322 to +113) showed maximal transcriptional activity in SH-SY5Y cells, whereas its activity in C1C12 cells was much lower. Two elements unusually located at the 5'-noncoding region exhibited opposite roles. A negative element located between +15 and +48 appears to be cell-specific because it was effective in C2C12 but not in SH-SY5Y cells, where it was counterbalanced by the presence of the promoter region 5' to the initiation site. An activating element located between +66 and +79 and formed by two adjacent Sox boxes increased the activity of the alpha9 promoter about 4-fold and was even able to activate other promoters. This element interacts with Sox proteins, probably through a cooperative mechanism in which the two Sox boxes are necessary. We propose that the Sox complex provides an initial scaffold that facilitates the recruiting of the transcriptional machinery responsible for alpha9 subunit expression.

  9. Experimental and computational investigation of lift-enhancing tabs on a multi-element airfoil

    NASA Technical Reports Server (NTRS)

    Ashby, Dale

    1996-01-01

    An experimental and computational investigation of the effect of lift enhancing tabs on a two-element airfoil was conducted. The objective of the study was to develop an understanding of the flow physics associated with lift enhancing tabs on a multi-element airfoil. A NACA 63(sub 2)-215 ModB airfoil with a 30 percent chord Fowler flap was tested in the NASA Ames 7 by 10 foot wind tunnel. Lift enhancing tabs of various heights were tested on both the main element and the flap for a variety of flap riggings. Computations of the flow over the two-element airfoil were performed using the two-dimensional incompressible Navier-Stokes code INS2D-UP. The computer results predict all of the trends in the experimental data quite well. When the flow over the flap upper surface is attached, tabs mounted at the main element trailing edge (cove tabs) produce very little change in lift. At high flap deflections. however, the flow over the flap is separated and cove tabs produce large increases in lift and corresponding reductions in drag by eliminating the separated flow. Cove tabs permit high flap deflection angles to be achieved and reduce the sensitivity of the airfoil lift to the size of the flap gap. Tabs attached to the flap training edge (flap tabs) are effective at increasing lift without significantly increasing drag. A combination of a cove tab and a flap tab increased the airfoil lift coefficient by 11 percent relative to the highest lift tab coefficient achieved by any baseline configuration at an angle of attack of zero percent and the maximum lift coefficient was increased by more than 3 percent. A simple analytic model based on potential flow was developed to provide a more detailed understanding of how lift enhancing tabs work. The tabs were modeled by a point vortex at the training edge. Sensitivity relationships were derived which provide a mathematical basis for explaining the effects of lift enhancing tabs on a multi-element airfoil. Results of the modeling

  10. A novel regulatory element (E77) isolated from CHO‐K1 genomic DNA enhances stable gene expression in Chinese hamster ovary cells

    PubMed Central

    Kang, Shin‐Young; Kim, Yeon‐Gu; Kang, Seunghee; Lee, Hong Weon

    2016-01-01

    Abstract Vectors flanked by regulatory DNA elements have been used to generate stable cell lines with high productivity and transgene stability; however, regulatory elements in Chinese hamster ovary (CHO) cells, which are the most widely used mammalian cells in biopharmaceutical production, are still poorly understood. We isolated a novel gene regulatory element from CHO‐K1 cells, designated E77, which was found to enhance the stable expression of a transgene. A genomic library was constructed by combining CHO‐K1 genomic DNA fragments with a CMV promoter‐driven GFP expression vector, and the E77 element was isolated by screening. The incorporation of the E77 regulatory element resulted in the generation of an increased number of clones with high expression, thereby enhancing the expression level of the transgene in the stable transfectant cell pool. Interestingly, the E77 element was found to consist of two distinct fragments derived from different locations in the CHO genome shotgun sequence. High and stable transgene expression was obtained in transfected CHO cells by combining these fragments. Additionally, the function of E77 was found to be dependent on its site of insertion and specific orientation in the vector construct. Our findings demonstrate that stable gene expression mediated by the CMV promoter in CHO cells may be improved by the isolated novel gene regulatory element E77 identified in the present study. PMID:26762773

  11. A novel regulatory element (E77) isolated from CHO-K1 genomic DNA enhances stable gene expression in Chinese hamster ovary cells.

    PubMed

    Kang, Shin-Young; Kim, Yeon-Gu; Kang, Seunghee; Lee, Hong Weon; Lee, Eun Gyo

    2016-05-01

    Vectors flanked by regulatory DNA elements have been used to generate stable cell lines with high productivity and transgene stability; however, regulatory elements in Chinese hamster ovary (CHO) cells, which are the most widely used mammalian cells in biopharmaceutical production, are still poorly understood. We isolated a novel gene regulatory element from CHO-K1 cells, designated E77, which was found to enhance the stable expression of a transgene. A genomic library was constructed by combining CHO-K1 genomic DNA fragments with a CMV promoter-driven GFP expression vector, and the E77 element was isolated by screening. The incorporation of the E77 regulatory element resulted in the generation of an increased number of clones with high expression, thereby enhancing the expression level of the transgene in the stable transfectant cell pool. Interestingly, the E77 element was found to consist of two distinct fragments derived from different locations in the CHO genome shotgun sequence. High and stable transgene expression was obtained in transfected CHO cells by combining these fragments. Additionally, the function of E77 was found to be dependent on its site of insertion and specific orientation in the vector construct. Our findings demonstrate that stable gene expression mediated by the CMV promoter in CHO cells may be improved by the isolated novel gene regulatory element E77 identified in the present study.

  12. Horizontal Saccadic Eye Movements Enhance the Retrieval of Landmark Shape and Location Information

    ERIC Educational Resources Information Center

    Brunye, Tad T.; Mahoney, Caroline R.; Augustyn, Jason S.; Taylor, Holly A.

    2009-01-01

    Recent work has demonstrated that horizontal saccadic eye movements enhance verbal episodic memory retrieval, particularly in strongly right-handed individuals. The present experiments test three primary assumptions derived from this research. First, horizontal eye movements should facilitate episodic memory for both verbal and non-verbal…

  13. Enhanced Associative Memory for Colour (but Not Shape or Location) in Synaesthesia

    ERIC Educational Resources Information Center

    Pritchard, Jamie; Rothen, Nicolas; Coolbear, Daniel; Ward, Jamie

    2013-01-01

    People with grapheme-colour synaesthesia have been shown to have enhanced memory on a range of tasks using both stimuli that induce synaesthesia (e.g. words) and, more surprisingly, stimuli that do not (e.g. certain abstract visual stimuli). This study examines the latter by using multi-featured stimuli consisting of shape, colour and location…

  14. Enhancement of Beaconless Location-Based Routing with Signal Strength Assistance for Ad-Hoc Networks

    NASA Astrophysics Data System (ADS)

    Chen, Guowei; Itoh, Kenichi; Sato, Takuro

    Routing in Ad-hoc networks is unreliable due to the mobility of the nodes. Location-based routing protocols, unlike other protocols which rely on flooding, excel in network scalability. Furthermore, new location-based routing protocols, like, e. g. BLR [1], IGF [2], & CBF [3] have been proposed, with the feature of not requiring beacons in MAC-layer, which improve more in terms of scalability. Such beaconless routing protocols can work efficiently in dense network areas. However, these protocols' algorithms have no ability to avoid from routing into sparse areas. In this article, historical signal strength has been added as a factor into the BLR algorithm, which avoids routing into sparse area, and consequently improves the global routing efficiency.

  15. Synergistic interactions between two distinct elements of a regulated splicing enhancer.

    PubMed

    Lynch, K W; Maniatis, T

    1995-02-01

    Regulated alternative splicing of doublesex (dsx) pre-mRNA requires a splicing enhancer designated the dsx repeat element (dsxRE) that contains six copies of a 13-nucleotide repeat sequence. Previous studies have shown that the activity of the dsxRE requires the splicing regulators Transformer (Tra) and Transformer 2 (Tra2), and one or more members of the SR family of general splicing factors. In this paper we identify a purine-rich enhancer (PRE) sequence within the dsxRE, and show that this element functionally synergizes with the repeat sequences. In vitro binding studies show that the PRE is required for specific binding of Tra2 to the dsxRE, and that Tra and SR proteins bind cooperatively to the dsxRE in the presence or absence of the PRE. Thus positive control of dsx pre-mRNA splicing requires the Tra- and Tra2-dependent assembly of a multiprotein complex on at least two distinct enhancer elements.

  16. Enhancing effect of marine oligotrophy on environmental concentrations of particle-reactive trace elements

    SciTech Connect

    Jeffree, R.A.; Szymczak, R.

    2000-05-15

    A biogeochemical model has been previously developed that explains the inverse and nonlinear relationship between Po-210 concentration in zooplankton and their biomass, under oligotrophic conditions in French Polynesia. In this study the model structure was reviewed to determine a set of biogeochemical behaviors of Po-210, proposed to be critical to its environmental enhancement under oligotrophy: this set was then used to identify 25 other elements with comparable behaviors to Po-210. Field investigation in the Timor Sea showed that four of these a priori identified elements, viz. Cd, Co, Pb, and Mn as well as Cr and Ni, showed elevated water concentrations with reduced particle removal rates in the euphotic zone, results that are consistent with those previously obtained for Po-210 and the proposed explanatory model. These findings point to the enhanced susceptibility to contamination with particle-reactive elements of oligotrophic marine systems, whose degree and geographic extent may be enhanced by projected increases in sea surface temperatures from global warming.

  17. Viral expression cassette elements to enhance transgene target specificity and expression in gene therapy.

    PubMed

    Powell, Sara Kathleen; Rivera-Soto, Ricardo; Gray, Steven James

    2015-01-01

    Over the last five years, the number of clinical trials involving AAV (adeno-associated virus) and lentiviral vectors continue to increase by about 150 trials each year. For continued success, AAV and lentiviral expression cassettes need to be designed to meet each disease's specific needs. This review discusses how viral vector expression cassettes can be engineered with elements to enhance target specificity and increase transgene expression. The key differences relating to target specificity between ubiquitous and tissue-specific promoters are discussed, as well as how endogenous miRNAs and their target sequences have been used to restrict transgene expression. Specifically, relevant studies indicating how cis-acting elements such as introns, WPRE, polyadenylation signals, and the CMV enhancer are highlighted to show their utility for enhancing transgene expression in gene therapy applications. All discussion bears in mind that expression cassettes have space constraints. In conclusion, this review can serve as a menu of vector genome design elements and their cost in terms of space to thoughtfully engineer viral vectors for gene therapy.

  18. Mutations that alter a repeated ACCA element located at the 5' end of the Potato virus X genome affect RNA accumulation.

    PubMed

    Park, Mi-Ri; Kwon, Sun-Jung; Choi, Hong-Soo; Hemenway, Cynthia L; Kim, Kook-Hyung

    2008-08-15

    The repeated ACCA or AC-rich sequence and structural (SL1) elements in the 5' non-translated region (NTR) of the Potato virus X (PVX) RNA play vital roles in the PVX life cycle by controlling translation, RNA replication, movement, and assembly. It has already been shown that the repeated ACCA or AC-rich sequence affect both gRNA and sgRNA accumulation, while not affecting minus-strand RNA accumulation, and are also required for host protein binding. The functional significance of the repeated ACCA sequence elements in the 5' NTR region was investigated by analyzing the effects of deletion and site-directed mutations on PVX replication in Nicotiana benthamiana plants and NT1 protoplasts. Substitution (ACCA into AAAA or UUUU) mutations introduced in the first (nt 10-13) element in the 5' NTR of the PVX RNA significantly affected viral replication, while mutations introduced in the second (nt 17-20) and third (nt 20-23) elements did not. The fourth (nt 29-32) ACCA element weakly affected virus replication, whereas mutations in the fifth (nt 38-41) significantly reduced virus replication due to the structure disruption of SL1 by AAAA and/or UUUU substitutions. Further characterization of the first ACCA element indicated that duplication of ACCA at nt 10-13 (nt 10-17, ACCAACCA) caused severe symptom development as compared to that of wild type, while deletion of the single element (nt 10-13), DeltaACCA) or tripling of this element caused reduced symptom development. Single- and double-nucleotide substitutions introduced into the first ACCA element revealed the importance of CC located at nt positions 11 and 12. Altogether, these results indicate that the first ACCA element is important for PVX replication.

  19. Cholinergic enhancement differentially modulates neural response to encoding during face identity and face location working memory tasks.

    PubMed

    Handjaras, Giacomo; Ricciardi, Emiliano; Szczepanik, Joanna; Pietrini, Pietro; Furey, Maura L

    2013-09-01

    Potentiation of cholinergic transmission influences stimulus processing by enhancing signal detection through suppression and/or filtering out of irrelevant information (bottom-up modulation) and with top-down task-oriented executive mechanisms based on the recruitment of prefrontal and parietal attentional systems. The cholinergic system also plays a critical role in working memory (WM) processes and preferentially modulates WM encoding, likely through stimulus-processing mechanisms. Previous research reported increased brain responses in visual extrastriate cortical regions during cholinergic enhancement in the encoding phase of WM, independently addressing object and spatial encoding. The current study used functional magnetic resonance imaging to determine the effects of cholinergic enhancement on encoding of key visual processing features. Subjects participated in two scanning sessions, one during an intravenous (i.v.) infusion of saline and the other during an infusion of the acetylcholinesterase inhibitor physostigmine. In each scan session, subjects alternated between a face identity recognition and a spatial location WM. Enhanced cholinergic function increased neural activity in the ventral stream during encoding of face identity and in the dorsal stream during encoding of face location. Conversely, a reduction in brain response was found for scrambled sensorimotor control images. The cholinergic effects on neural activity in the ventral stream during encoding of face identity were stronger than those observed in the dorsal stream during encoding of face location, likely as a consequence of the role of acetylcholine in establishing the inherently relevant nature of face identity. Despite the limited sample-size, the results suggest the stimulus-dependent role of cholinergic system in signal detection, as they show that cholinergic potentiation enhances neural activity in regions associated with early perceptual processing in a selective manner depending on

  20. Multi-organ segmentation from multi-phase abdominal CT via 4D graphs using enhancement, shape and location optimization.

    PubMed

    Linguraru, Marius George; Pura, John A; Chowdhury, Ananda S; Summers, Ronald M

    2010-01-01

    The interpretation of medical images benefits from anatomical and physiological priors to optimize computer-aided diagnosis (CAD) applications. Diagnosis also relies on the comprehensive analysis of multiple organs and quantitative measures of soft tissue. An automated method optimized for medical image data is presented for the simultaneous segmentation of four abdominal organs from 4D CT data using graph cuts. Contrast-enhanced CT scans were obtained at two phases: non-contrast and portal venous. Intra-patient data were spatially normalized by non-linear registration. Then 4D erosion using population historic information of contrast-enhanced liver, spleen, and kidneys was applied to multi-phase data to initialize the 4D graph and adapt to patient specific data. CT enhancement information and constraints on shape, from Parzen windows, and location, from a probabilistic atlas, were input into a new formulation of a 4D graph. Comparative results demonstrate the effects of appearance and enhancement, and shape and location on organ segmentation.

  1. Electromagnetic Ion Cyclotron Wave Triggering by Solar Wind Dynamic Pressure Enhancements at Multiple Locations

    NASA Astrophysics Data System (ADS)

    Cho, J.; Lee, D. Y.; Kim, H.

    2016-12-01

    Electromagnetic Ion cyclotron (EMIC) waves are one of the key plasma waves which play a critical role in the magnetosphere by interacting with charged particles. One of the generation mechanisms of EMIC waves is magnetospheric compression due to impact of enhanced solar wind dynamic pressure Pdyn. With the multi-satellite (the Van Allen Probes and two GOES satellites) observations in the inner magnetosphere and ground-based magnetometers, we examine two EMIC wave events that are triggered by Pdyn enhancements under prolonged northward IMF quiet time preconditions. For both events, the impact of enhanced Pdyn causes EMIC waves at multiple points. However, we find a strong spatial dependence of EMIC wave triggering and the accompanied wave properties. For Event 1, a satellite near noon observes no dramatic EMIC waves. In contrast, three other satellites are situated at a nearly same dawn side zone but at slightly different L shells and see notable EMIC waves but in different frequencies relative to local ion gyrofrequencies. These waves are found inside or outer edge of the plasmasphere. For Event 2, the satellites are situated at three different MLT zones, late afternoon-dusk, early evening-pre-midnight, and post-midnight, when they see the triggered EMIC waves. They are again found at different frequencies relative to local ion gyrofrequencies, and all outside the plasmasphere. Furthermore, the triggered EMIC waves for both events are observed from high-latitude ground stations in Antarctica. The results in this work imply that triggering of EMIC waves by enhanced Pdyn can occur at multiple points but with different wave properties, which must be due to different local plasma and magnetic conditions.

  2. Identifying elements of the plumbing system beneath Kilauea Volcano, Hawaii, from the source locations of very-long-period signals

    USGS Publications Warehouse

    Almendros, J.; Chouet, B.; Dawson, P.; Bond, T.

    2002-01-01

    We analyzed 16 seismic events recorded by the Hawaiian broad-band seismic network at Kilauca Volcano during the period September 9-26, 1999. Two distinct types of event are identified based on their spectral content, very-long-period (VLP) waveform, amplitude decay pattern and particle motion. We locate the VLP signals with a method based on analyses of semblance and particle motion. Different source regions are identified for the two event types. One source region is located at depths of ~1 km beneath the northeast edge of the Halemaumau pit crater. A second region is located at depths of ~8 km below the northwest quadrant of Kilauea caldera. Our study represents the first time that such deep sources have been identified in VLP data at Kilauea. This discovery opens the possibility of obtaining a detailed image of the location and geometry of the magma plumbing system beneath this volcano based on source locations and moment tensor inversions of VLP signals recorded by a permanent, large-aperture broad-band network.

  3. 20 CFR 655.534 - The first attestation element for locations in Alaska: Bona fide request for dispatch of United...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... in Alaska: Bona fide request for dispatch of United States longshore workers. 655.534 Section 655.534...: Bona fide request for dispatch of United States longshore workers. (a) The first attestation element... workers pursuant to § 655.537(a)(1)(i) of this part, an employer need not request dispatch of...

  4. 20 CFR 655.534 - The first attestation element for locations in Alaska: Bona fide request for dispatch of United...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... in Alaska: Bona fide request for dispatch of United States longshore workers. 655.534 Section 655.534...: Bona fide request for dispatch of United States longshore workers. (a) The first attestation element... workers pursuant to § 655.537(a)(1)(i) of this part, an employer need not request dispatch of...

  5. 20 CFR 655.534 - The first attestation element for locations in Alaska: Bona fide request for dispatch of United...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... in Alaska: Bona fide request for dispatch of United States longshore workers. 655.534 Section 655.534...: Bona fide request for dispatch of United States longshore workers. (a) The first attestation element... workers pursuant to § 655.537(a)(1)(i) of this part, an employer need not request dispatch of...

  6. 20 CFR 655.534 - The first attestation element for locations in Alaska: Bona fide request for dispatch of United...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... in Alaska: Bona fide request for dispatch of United States longshore workers. 655.534 Section 655.534...: Bona fide request for dispatch of United States longshore workers. (a) The first attestation element... workers pursuant to § 655.537(a)(1)(i) of this part, an employer need not request dispatch of...

  7. 20 CFR 655.534 - The first attestation element for locations in Alaska: Bona fide request for dispatch of United...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... in Alaska: Bona fide request for dispatch of United States longshore workers. 655.534 Section 655.534...: Bona fide request for dispatch of United States longshore workers. (a) The first attestation element... workers pursuant to § 655.537(a)(1)(i) of this part, an employer need not request dispatch of...

  8. A meiotic drive element in the maize pathogen Fusarium verticillioides is located within a 102-kb region of chromosome V

    USDA-ARS?s Scientific Manuscript database

    Fusarium verticillioides is an agriculturally important fungus because of its association with maize and its propensity to contaminate grain with toxic compounds. Some isolates of the fungus harbor a meiotic drive element known as Spore killer (SkK) that causes nearly all surviving meiotic progeny f...

  9. Quantitatively Measured Anatomic Location and Volume of Optic Disc Drusen: An Enhanced Depth Imaging Optical Coherence Tomography Study.

    PubMed

    Malmqvist, Lasse; Lindberg, Anne-Sofie Wessel; Dahl, Vedrana Andersen; Jørgensen, Thomas Martini; Hamann, Steffen

    2017-05-01

    Optic disc drusen (ODD) are found in up to 2.4% of the population and are known to cause visual field defects. The purpose of the current study was to investigate how quantitatively estimated volume and anatomic location of ODD influence optic nerve function. Anatomic location, volume of ODD, and peripapillary retinal nerve fiber layer and macular ganglion cell layer thickness were assessed in 37 ODD patients using enhanced depth imaging optical coherence tomography. Volume of ODD was calculated by manual segmentation of ODD in 97 B-scans per eye. Anatomic characteristics were compared with optic nerve function using automated perimetric mean deviation (MD) and multifocal visual evoked potentials. Increased age (P = 0.015); larger ODD volume (P = 0.002); and more superficial anatomic ODD location (P = 0.007) were found in patients with ODD visible by ophthalmoscopy compared to patients with buried ODD. In a multivariate analysis, a worsening of MD was significantly associated with larger ODD volume (P < 0.0001). No association was found between MD and weighted anatomic location, age, and visibility by ophthalmoscopy. Decreased ganglion cell layer thickness was significantly associated with worse MD (P = 0.025) and had a higher effect on MD when compared to retinal nerve fiber layer thickness. Large ODD volume is associated with optic nerve dysfunction. The worse visual field defects associated with visible ODD should only be ascribed to larger ODD volume and not to a more superficial anatomic ODD location.

  10. Dissection of a Ciona regulatory element reveals complexity of cross-species enhancer activity

    PubMed Central

    Chen, Wei-Chung; Pauls, Stefan; Bacha, Jamil; Elgar, Greg; Loose, Matthew; Shimeld, Sebastian M.

    2014-01-01

    Vertebrate genomes share numerous conserved non-coding elements, many of which function as enhancer elements and are hypothesised to be under evolutionary constraint due to a need to be bound by combinations of sequence-specific transcription factors. In contrast, few such conserved elements can be detected between vertebrates and their closest invertebrate relatives. Despite this lack of sequence identity, cross-species transgenesis has identified some cases where non-coding DNA from invertebrates drives reporter gene expression in transgenic vertebrates in patterns reminiscent of the expression of vertebrate orthologues. Such instances are presumed to reflect the presence of conserved suites of binding sites in the regulatory regions of invertebrate and vertebrate orthologues, such that both regulatory elements can correctly interpret the trans-activating environment. Shuffling of binding sites has been suggested to lie behind loss of sequence conservation; however this has not been experimentally tested. Here we examine the underlying basis of enhancer activity for the Ciona intestinalis βγ-crystallin gene, which drives expression in the lens of transgenic vertebrates despite the Ciona lineage predating the evolution of the lens. We construct an interactive gene regulatory network (GRN) for vertebrate lens development, allowing network interactions to be robustly catalogued and conserved network components and features to be identified. We show that a small number of binding motifs are necessary for Ciona βγ-crystallin expression, and narrow down the likely factors that bind to these motifs. Several of these overlap with the conserved core of the vertebrate lens GRN, implicating these sites in cross species function. However when we test these motifs in a transgenic vertebrate they prove to be dispensable for reporter expression in the lens. These results show that current models depicting cross species enhancer function as dependent on conserved binding

  11. Cast Iron Inoculation Enhanced by Supplementary Oxy-sulfides Forming Elements

    NASA Astrophysics Data System (ADS)

    Riposan, Iulian; Stan, Stelian; Uta, Valentin; Stefan, Ion

    2017-08-01

    Inoculation is one of the most important metallurgical treatments applied to the molten cast iron immediately prior to casting, to promote solidification without excessive eutectic undercooling, which favors carbides formation usually with undesirable graphite morphologies. The paper focused on the separate addition of an inoculant enhancer alloy [S, O, oxy-sulfides forming elements] with a conventional Ca-FeSi alloy, in the production of gray and ductile cast irons. Carbides formation tendency decreased with improved graphite characteristics as an effect of the [Ca-FeSi + Enhancer] inoculation combination, when compared to other Ca/Ca, Ba/Ca, RE-FeSi alloy treatments. Adding an inoculant enhancer greatly enhances inoculation, lowers inoculant consumption up to 50% or more and avoids the need to use more costly inoculants, such as a rare earth bearing alloy. The Inoculation Specific Factor [ISF] was developed as a means to more realistically measure inoculant treatment efficiency. It compares the ratio between the improved characteristic level and total inoculant consumption for this effect. Addition of any of the commercial inoculants plus the inoculant enhancer offered outstanding inoculation power [increased ISF] even at higher solidification cooling rates, even though the total enhancer addition was at a small fraction of the amount of commercial inoculant used.

  12. KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, the U.S. Node 2 (center) and the Japanese Experiment Module (JEM), background right, await a Multi-Element Integrated Test (MEIT). Node 2 attaches to the end of the U.S. Lab on the International Space Station and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. The National Space Development Agency of Japan (NASDA) developed their laboratory at the Tsukuba Space Center near Tokyo. It is the first element, named "Kibo" (Hope), to be delivered to KSC. The JEM is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments.

    NASA Image and Video Library

    2003-08-27

    KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, the U.S. Node 2 (center) and the Japanese Experiment Module (JEM), background right, await a Multi-Element Integrated Test (MEIT). Node 2 attaches to the end of the U.S. Lab on the International Space Station and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. The National Space Development Agency of Japan (NASDA) developed their laboratory at the Tsukuba Space Center near Tokyo. It is the first element, named "Kibo" (Hope), to be delivered to KSC. The JEM is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments.

  13. Neuroimaging reveals enhanced activation in a reach-selective brain area for objects located within participants' typical hand workspaces.

    PubMed

    Gallivan, Jason P; McLean, Adam; Culham, Jody C

    2011-11-01

    In recent years, there has been growing excitement within cognitive neuroscience about the concept of embodiment: How do the capabilities and limitations of our physical bodies affect neural representations in the brain? Neuropsychological and neurophysiological studies show clear evidence that short-term visuomotor experience can influence the encoding of the space around the body in parietal cortex. For example, tool-use may expand the neural representation of peripersonal space. But how is this initial spatial representation influenced by a lifetime of object-related interactions? To examine this question we used functional magnetic resonance imaging (fMRI) to investigate the neural effects of an individual's hand preferences for acting within peripersonal space. Left- and right-handed participants viewed real-world objects at different locations accessible by either the left hand, right hand, or neither hand. The superior parieto-occipital cortex (SPOC), an area most often implicated in reaching actions, showed enhanced visual responses for objects located within the range of space in which each group typically acts. Specifically, in right-handers, who strongly prefer grasping with the right hand, SPOC showed strongest activation for objects located within the range of space for the right hand only. In contrast, in left-handers, who use their two hands comparably often in visuomotor tasks, SPOC showed strongest activation for objects located within the range of space of either hand. These findings show that, even in the absence of overt responses, real 3D objects located in the individual's typical workspace for hand actions automatically invoke enhanced responses in associated visuomotor areas of the brain.

  14. Geo-Located Tweets. Enhancing Mobility Maps and Capturing Cross-Border Movement

    PubMed Central

    Blanford, Justine I.; Huang, Zhuojie; Savelyev, Alexander; MacEachren, Alan M.

    2015-01-01

    Capturing human movement patterns across political borders is difficult and this difficulty highlights the need to investigate alternative data streams. With the advent of smart phones and the ability to attach accurate coordinates to Twitter messages, users leave a geographic digital footprint of their movement when posting tweets. In this study we analyzed 10 months of geo-located tweets for Kenya and were able to capture movement of people at different temporal (daily to periodic) and spatial (local, national to international) scales. We were also able to capture both long and short distances travelled, highlighting regional connections and cross-border movement between Kenya and the surrounding countries. The findings from this study has broad implications for studying movement patterns and mapping inter/intra-region movement dynamics. PMID:26086772

  15. Enhancing the validity of foster care follow-up studies through multiple alumni location strategies.

    PubMed

    Williams, Jason; McWilliams, Alisa; Mainieri, Tina; Pecora, Peter J; La Belle, Karin

    2006-01-01

    While family-based placement prevention services, family reunification programs, subsidized guardianship, and aggressive adoption programs are reducing the numbers of children spending long periods of time in substitute care, a significant number of America's children will come of age in foster care. Agencies and policymakers should use research and evaluation to assess the effectiveness of foster care in nurturing healthy adults and to explore ways to improve services. Outcome studies that have focused on locating and interviewing young or middle-aged adults emancipated from foster care have been hampered by modest response rates, limiting the field's ability to evaluate the efficacy of foster care programs. This article describes a set of strategies that were used to achieve higher response rates in two recent follow-up studies.

  16. Boundary element method applied to a gas-fired pin-fin-enhanced heat pipe

    SciTech Connect

    Andraka, C.E.; Knorovsky, G.A.; Drewien, C.A.

    1998-02-01

    The thermal conduction of a portion of an enhanced surface heat exchanger for a gas fired heat pipe solar receiver was modeled using the boundary element and finite element methods (BEM and FEM) to determine the effect of weld fillet size on performance of a stud welded pin fin. A process that could be utilized by others for designing the surface mesh on an object of interest, performing a conversion from the mesh into the input format utilized by the BEM code, obtaining output on the surface of the object, and displaying visual results was developed. It was determined that the weld fillet on the pin fin significantly enhanced the heat performance, improving the operating margin of the heat exchanger. The performance of the BEM program on the pin fin was measured (as computational time) and used as a performance comparison with the FEM model. Given similar surface element densities, the BEM method took longer to get a solution than the FEM method. The FEM method creates a sparse matrix that scales in storage and computation as the number of nodes (N), whereas the BEM method scales as N{sup 2} in storage and N{sup 3} in computation.

  17. Analysis of core promoter sequences located downstream from the TATA element in the hsp70 promoter from Drosophila melanogaster.

    PubMed

    Wu, C H; Madabusi, L; Nishioka, H; Emanuel, P; Sypes, M; Arkhipova, I; Gilmour, D S

    2001-03-01

    TFIID recognizes multiple sequence elements in the hsp70 promoter of Drosophila. Here, we investigate the function of sequences downstream from the TATA element. A mutation in the initiator was identified that caused an eightfold reduction in binding of TFIID and a fourfold reduction in transcription in vitro. Another mutation in the +24 to +29 region was somewhat less inhibitory, but a mutation in the +14 to +19 region had essentially no effect. The normal promoter and the mutants in the initiator and the +24 to +29 region were transformed into flies by P element-mediated transformation. The initiator mutation reduced expression an average of twofold in adult flies, whereas the mutation in the +24 to +29 region had essentially no effect. In contrast, a promoter combining the two mutations was expressed an average of sixfold less than the wild type. The results suggest that the initiator and the +24 to +29 region could serve overlapping functions in vivo. Protein-DNA cross-linking was used to identify which subunits of TFIID contact the +24 to +29 region and the initiator. No specific subunits were found to cross-link to the +24 to +29 region. In contrast, the initiator cross-linked exclusively to dTAF230. Remarkably, dTAF230 cross-links approximately 10 times more efficiently to the nontranscribed strand than to the transcribed strand at the initiator.

  18. Evidence for enhanced bioavailability of trace elements in the marine ecosystem of Deception Island, a volcano in Antarctica.

    PubMed

    Deheyn, Dimitri D; Gendreau, Philippe; Baldwin, Roberta J; Latz, Michael I

    2005-07-01

    This study assessed whether trace elements present at Deception Island, an active submarine volcano in the Antarctic Peninsula, show enhanced biological availability to the local marine community. Using a weak acid extraction method to dissolve organic material and leach associated but not constitutive trace elements of sediments, fifteen elements were measured from seafloor sediment, seawater particulates, and tissues of benthic (bivalves, brittlestars, sea urchins) and pelagic (demersal and pelagic fishes, krill) organisms collected in the flooded caldera. The highest element concentrations were associated with seafloor sediment, the lowest with seawater particulates and organism tissues. In the case of Ag and Se, concentrations were highest in organism tissue, indicating contamination through the food chain and biomagnification of those elements. The elements Al, Fe, Mn, Sr, Ti, and to a lesser extent Zn, were the most concentrated of the trace elements for all sample types. This indicates that the whole ecosystem of Deception Island is contaminated with trace elements from local geothermal activity, which is also reflected in the pattern of element contamination in organisms. Accordingly, element concentrations were higher in organisms collected at Deception Island compared to those from the neighboring non-active volcanic King George Island, suggesting that volcanic activity enhances bioavailability of trace elements to marine organisms. Trace element concentrations were highest in digestive tissue of organisms, suggesting that elements at Deception Island are incorporated into the marine food web mainly through a dietary route.

  19. A Distribution-class Locational Marginal Price (DLMP) Index for Enhanced Distribution Systems

    NASA Astrophysics Data System (ADS)

    Akinbode, Oluwaseyi Wemimo

    The smart grid initiative is the impetus behind changes that are expected to culminate into an enhanced distribution system with the communication and control infrastructure to support advanced distribution system applications and resources such as distributed generation, energy storage systems, and price responsive loads. This research proposes a distribution-class analog of the transmission LMP (DLMP) as an enabler of the advanced applications of the enhanced distribution system. The DLMP is envisioned as a control signal that can incentivize distribution system resources to behave optimally in a manner that benefits economic efficiency and system reliability and that can optimally couple the transmission and the distribution systems. The DLMP is calculated from a two-stage optimization problem; a transmission system OPF and a distribution system OPF. An iterative framework that ensures accurate representation of the distribution system's price sensitive resources for the transmission system problem and vice versa is developed and its convergence problem is discussed. As part of the DLMP calculation framework, a DCOPF formulation that endogenously captures the effect of real power losses is discussed. The formulation uses piecewise linear functions to approximate losses. This thesis explores, with theoretical proofs, the breakdown of the loss approximation technique when non-positive DLMPs/LMPs occur and discusses a mixed integer linear programming formulation that corrects the breakdown. The DLMP is numerically illustrated in traditional and enhanced distribution systems and its superiority to contemporary pricing mechanisms is demonstrated using price responsive loads. Results show that the impact of the inaccuracy of contemporary pricing schemes becomes significant as flexible resources increase. At high elasticity, aggregate load consumption deviated from the optimal consumption by up to about 45 percent when using a flat or time-of-use rate. Individual load

  20. Location-Enhanced Activity Recognition in Indoor Environments Using Off the Shelf Smart Watch Technology and BLE Beacons

    PubMed Central

    Filippoupolitis, Avgoustinos; Oliff, William; Takand, Babak; Loukas, George

    2017-01-01

    Activity recognition in indoor spaces benefits context awareness and improves the efficiency of applications related to personalised health monitoring, building energy management, security and safety. The majority of activity recognition frameworks, however, employ a network of specialised building sensors or a network of body-worn sensors. As this approach suffers with respect to practicality, we propose the use of commercial off-the-shelf devices. In this work, we design and evaluate an activity recognition system composed of a smart watch, which is enhanced with location information coming from Bluetooth Low Energy (BLE) beacons. We evaluate the performance of this approach for a variety of activities performed in an indoor laboratory environment, using four supervised machine learning algorithms. Our experimental results indicate that our location-enhanced activity recognition system is able to reach a classification accuracy ranging from 92% to 100%, while without location information classification accuracy it can drop to as low as 50% in some cases, depending on the window size chosen for data segmentation. PMID:28555022

  1. Location-Enhanced Activity Recognition in Indoor Environments Using Off the Shelf Smart Watch Technology and BLE Beacons.

    PubMed

    Filippoupolitis, Avgoustinos; Oliff, William; Takand, Babak; Loukas, George

    2017-05-27

    Activity recognition in indoor spaces benefits context awareness and improves the efficiency of applications related to personalised health monitoring, building energy management, security and safety. The majority of activity recognition frameworks, however, employ a network of specialised building sensors or a network of body-worn sensors. As this approach suffers with respect to practicality, we propose the use of commercial off-the-shelf devices. In this work, we design and evaluate an activity recognition system composed of a smart watch, which is enhanced with location information coming from Bluetooth Low Energy (BLE) beacons. We evaluate the performance of this approach for a variety of activities performed in an indoor laboratory environment, using four supervised machine learning algorithms. Our experimental results indicate that our location-enhanced activity recognition system is able to reach a classification accuracy ranging from 92% to 100%, while without location information classification accuracy it can drop to as low as 50% in some cases, depending on the window size chosen for data segmentation.

  2. Changing within-trial array location and target object position enhances rats' (Rattus norvegicus) missing object recognition accuracy.

    PubMed

    Arain, Marium; Parameswaran, Varakini; Cohen, Jerome

    2012-09-01

    Six rats were trained to find a previously missing target or 'jackpot' object in a square array of four identical or different objects (the test segment of a trial) after first visiting and collecting sunflower seeds from under the other three objects (the study segment of a trial). During training, objects' local positions within the array and their global positions within the larger foraging array were varied over trials but were not changed between segments within a trial. Following this training, rats were tested on their accuracy for finding the target object when a trial's test array was sometimes moved to a different location in the foraging arena or when the position of the target object within the test array had been changed. Either of these manipulations initially slightly reduced rats' accuracy for finding the missing object but then enhanced it. Relocating test arrays of identical objects enhanced rats' performance only after 10-min inter-segment intervals (ISIs). Relocating test arrays of different objects enhanced rats' performance only after 2-min ISIs. Rats also improved their performance when they encountered the target object in a new position in test arrays of different objects. This enhancement effect occurred after either 2- or 30-min ISIs. These findings suggest that rats separately retrieved a missing (target) object's spatial and non-spatial information when they were relevant but not when they were irrelevant in a trial. The enhancement effects provide evidence for rats' limited retrieval capacity in their visuo-spatial working memory.

  3. Enhanced Recovery after Urological Surgery: A Contemporary Systematic Review of Outcomes, Key Elements, and Research Needs.

    PubMed

    Azhar, Raed A; Bochner, Bernard; Catto, James; Goh, Alvin C; Kelly, John; Patel, Hiten D; Pruthi, Raj S; Thalmann, George N; Desai, Mihir

    2016-07-01

    Enhanced Recovery after Surgery (ERAS) programs are multimodal care pathways that aim to decrease intra-operative blood loss, decrease postoperative complications, and reduce recovery times. To overview the use and key elements of ERAS pathways, and define needs for future clinical trials. A comprehensive systematic MEDLINE search was performed for English language reports published before May 2015 using the terms "postoperative period," "postoperative care," "enhanced recovery after surgery," "enhanced recovery," "accelerated recovery," "fast track recovery," "recovery program," "recovery pathway", "ERAS," and "urology" or "cystectomy" or "urologic surgery." We identified 18 eligible articles. Patient counseling, physical conditioning, avoiding excessive alcohol and smoking, and good nutrition appeared to protect against postoperative complications. Fasting from solid food for only 6h and perioperative liquid-carbohydrate loading up to 2h prior to surgery appeared to be safe and reduced recovery times. Restricted, balanced, and goal-directed fluid replacement is effective when individualized, depending on patient morbidity and surgical procedure. Decreased intraoperative blood loss may be achieved by several measures. Deep vein thrombosis prophylaxis, antibiotic prophylaxis, and thermoregulation were found to help reduce postsurgical complications, as was a multimodal approach to postoperative nausea, vomiting, and analgesia. Chewing gum, prokinetic agents, oral laxatives, and an early resumption to normal diet appear to aid faster return to normal bowel function. Further studies should compare anesthetic protocols, refine analgesia, and evaluate the importance of robot-assisted surgery and the need/timing for drains and catheters. ERAS regimens are multidisciplinary, multimodal pathways that optimize postoperative recovery. This review provides an overview of the use and key elements of Enhanced Recovery after Surgery programs, which are multimodal

  4. Molecular genetic analysis of Drosophila eyes absent mutants reveals an eye enhancer element.

    PubMed Central

    Zimmerman, J E; Bui, Q T; Liu, H; Bonini, N M

    2000-01-01

    The eyes absent (eya) gene is critical for normal eye development in Drosophila and is highly conserved to vertebrates. To define regions of the gene critical for eye function, we have defined the mutations in the four viable eya alleles. Two of these mutations are eye specific and undergo transvection with other mutations in the gene. These were found to be deletion mutations that remove regulatory sequence critical for eye cell expression of the gene. Two other viable alleles cause a reduced eye phenotype and affect the function of the gene in additional tissues, such as the ocelli. These mutations were found to be insertion mutations of different transposable elements within the 5' UTR of the transcript. Detailed analysis of one of these revealed that the transposable element has become subject to regulation by eye enhancer sequences of the eya gene, disrupting normal expression of EYA in the eye. More extended analysis of the deletion region in the eye-specific alleles indicated that the deleted region defines an enhancer that activates gene expression in eye progenitor cells. This enhancer is responsive to ectopic expression of the eyeless gene. This analysis has defined a critical regulatory region required for proper eye expression of the eya gene. PMID:10628984

  5. An overview of sheet metal forming simulations with enhanced assumed strain elements

    SciTech Connect

    Valente, R. A. F.; Sousa, R. J. A. de; Cardoso, R. P. R.; Simoes, F.; Gracio, J.; Jorge, R. M. N.; Yoon, J. W.

    2007-05-17

    Sheet metal forming operations are characterized by extreme shape changes in initially flat or pre-formed blanks, thus needing complex and robust simulation tools for their correct virtual analysis. Among numerical approaches, finite element procedures are one of the most common techniques in modelling and simulation of such manufacturing applications. However, reliable simulations of complex parts' sheet forming must be able to correctly reproduce the deformation patterns involved but also accurately predict the appearance of defects after or during forming stages. Among the most common defects in the forming of metallic parts, spring-back and wrinkling are of crucial importance in manufacturing viewpoint. Spring-back appearance can be traced to the onset of traction instabilities when the tools depart the blank due to a rearrangement of stress fields after forming (or forming stages) and so, the unloaded blank reaches a new equilibrium. On the other side, wrinkling defects can be seen as compressive dominated defects and, in this sense, be dealt with as buckling-type structural instabilities. In this work, a class of solid-shell finite elements, based on distinct features but relying on the enhanced assumed strain approach, are tested in the simulation of sheet metal forming operation in metallic components. Results obtained from these elements, specially designed to treat transverse shear and volumetric locking effects, are then compared with well-established references in the literature, including experimental and numerical studies, where, for the latter case, shell finite elements are dominantly used.

  6. Enhanced Low-Enriched Uranium Fuel Element for the Advanced Test Reactor

    SciTech Connect

    Pope, M. A.; DeHart, M. D.; Morrell, S. R.; Jamison, R. K.; Nef, E. C.; Nigg, D. W.

    2015-03-01

    Under the current US Department of Energy (DOE) policy and planning scenario, the Advanced Test Reactor (ATR) and its associated critical facility (ATRC) will be reconfigured to operate on low-enriched uranium (LEU) fuel. This effort has produced a conceptual design for an Enhanced LEU Fuel (ELF) element. This fuel features monolithic U-10Mo fuel foils and aluminum cladding separated by a thin zirconium barrier. As with previous iterations of the ELF design, radial power peaking is managed using different U-10Mo foil thicknesses in different plates of the element. The lead fuel element design, ELF Mk1A, features only three fuel meat thicknesses, a reduction from the previous iterations meant to simplify manufacturing. Evaluation of the ELF Mk1A fuel design against reactor performance requirements is ongoing, as are investigations of the impact of manufacturing uncertainty on safety margins. The element design has been evaluated in what are expected to be the most demanding design basis accident scenarios and has met all initial thermal-hydraulic criteria.

  7. An Oncogenic Super-Enhancer Formed Through Somatic Mutation of a Noncoding Intergenic Element

    PubMed Central

    Mansour, Marc R.; Abraham, Brian J; Anders, Lars; Berezovskaya, Alla; Gutierrez, Alejandro; Durbin, Adam D; Etchin, Julia; Lawton, Lee; Sallan, Stephen E.; Silverman, Lewis B.; Loh, Mignon L.; Hunger, Stephen P.; Sanda, Takaomi; Young, Richard A.; Look, A. Thomas

    2016-01-01

    In certain human cancers, the expression of critical oncogenes is driven from large regulatory elements, called super-enhancers, which recruit much of the cell’s transcriptional apparatus and are defined by extensive acetylation of histone H3 lysine 27 (H3K27ac). In a subset of T-cell acute lymphoblastic leukemia (T-ALL) cases, we found that heterozygous somatic mutations are acquired that introduce binding motifs for the MYB transcription factor in a precise noncoding site, which creates a super-enhancer upstream of the TAL1 oncogene. MYB binds to this new site and recruits it’s H3K27 acetylase binding partner CBP, as well as core components of a major leukemogenic transcriptional complex that contains RUNX1, GATA-3, and TAL1 itself. Additionally, most endogenous super-enhancers found in T-ALL cells are occupied by MYB and CBP, suggesting a general role for MYB in super-enhancer initiation. Thus, this study identifies a genetic mechanism responsible for the generation of oncogenic super-enhancers in malignant cells. PMID:25394790

  8. Drosophila gypsy insulator and yellow enhancers regulate activity of yellow promoter through the same regulatory element.

    PubMed

    Melnikova, Larisa; Kostuchenko, Margarita; Silicheva, Margarita; Georgiev, Pavel

    2008-04-01

    There is ample evidence that the enhancers of a promoterless yellow locus in one homologous chromosome can activate the yellow promoter in the other chromosome where the enhancers are inactive or deleted, which is indicative of a high specificity of the enhancer-promoter interaction in yellow. In this paper, we have found that the yellow sequence from -100 to -69 is essential for stimulation of the heterologous eve (TATA-containing) and white (TATA-less) promoters by the yellow enhancers from a distance. However, the presence of this sequence is not required when the yellow enhancers are directly fused to the heterologous promoters or are activated by the yeast GAL4 activator. Unexpectedly, the same promoter proximal region defines previously described promoter-specific, long-distance repression of the yellow promoter by the gypsy insulator on the mod(mdg4) ( u1 ) background. These finding suggest that proteins bound to the -100 to -69 sequence are essential for communication between the yellow promoter and upstream regulatory elements.

  9. Enhancement of impedance change at low frequency in a thin-film magnetoimpedance element

    NASA Astrophysics Data System (ADS)

    Kikuchi, Hiroaki; Kamata, Shingo; Sumida, Chihiro; Nakai, Tomoo; Hashi, Shuichiro; Ishiyama, Kazushi

    2016-12-01

    In this paper, we found an atypical profile on the frequency dependence of a thin-film magnetoimpedance element having a narrow width and a thickness of several microns in the lower frequency region, although a typical magnetoimpedance shows a single peak above the 100 MHz region. The observed peak achieves higher intensity and frequency with increasing applied bias DC magnetic field, and disappears at the higher applied field. Since the sensitivity of the element for the applied magnetic field maintains nearly the same level as that in the high frequency region, the existence of the peak in the low frequency region brings us a possibility to realize a thin-film magnetic field sensor with higher sensitivity operating in the low frequency region. We confirmed experimentally that the enhancement of impedance change in low frequency is attributed to a large permeability change in the low frequency region, which may contribute to the domain wall resonance.

  10. Luminous exothermic hollow optical elements for enhancement of biofilm growth and activity.

    PubMed

    Zhong, Nianbing; Zhao, Mingfu; Zhong, Lianchao; Li, Shan; Luo, Binbin; Tang, Bin; Song, Tao; Shi, Shenghui; Hu, Xinyu; Xin, Xin; Wu, Ruohua; Cen, Yanyan; Wang, Zhengkun

    2017-03-20

    In this work, we present a luminous-exothermic hollow optical element (LEHOE) that performs spectral beam splitting in the visible spectral range for the enhancement of biofilm growth and activity. The LEHOE is composed of a four-layer structure with a fiber core (air), cladding (SiO2), coating I (LaB6 film), and coating II (SiO2-Agarose-Medium film). To clarify the physical, optical and photothermal conversion properties of the LEHOE, we determined the surface morphology and composition of the coating materials, and examined the luminous intensity and heating rate at the LEHOE surface. The biofilm activity on the biocompatible LEHOE is far greater than that of commercial fibers, and the biofilm weight on the LEHOE is 4.5 × that of the uncoated hollow optical element.

  11. Whistler wave radiation from a pulsed loop antenna located in a cylindrical duct with enhanced plasma density

    SciTech Connect

    Kudrin, Alexander V.; Shkokova, Natalya M.; Ferencz, Orsolya E.; Zaboronkova, Tatyana M.

    2014-11-15

    Pulsed radiation from a loop antenna located in a cylindrical duct with enhanced plasma density is studied. The radiated energy and its distribution over the spatial and frequency spectra of the excited waves are derived and analyzed as functions of the antenna and duct parameters. Numerical results referring to the case where the frequency spectrum of the antenna current is concentrated in the whistler range are reported. It is shown that under ionospheric conditions, the presence of an artificial duct with enhanced density can lead to a significant increase in the energy radiated from a pulsed loop antenna compared with the case where the same source is immersed in the surrounding uniform magnetoplasma. The results obtained can be useful in planning active ionospheric experiments with pulsed electromagnetic sources operated in the presence of artificial field-aligned plasma density irregularities that are capable of guiding whistler waves.

  12. Histone H3 K27 acetylation marks a potent enhancer element on the adipogenic master regulator gene Pparg2

    PubMed Central

    Ramlee, Muhammad Khairul; Zhang, Qiongyi; Idris, Muhammad; Peng, Xu; Sim, Choon Kiat; Han, Weiping; Xu, Feng

    2014-01-01

    PPARγ2 is expressed almost exclusively in adipose tissue and plays a central role in adipogenesis. Despite intensive studies over the last 2 decades, the mechanism regulating the expression of the Pparg2 gene, especially the role of cis-regulatory elements, is still not completely understood. Here, we report a comprehensive investigation of the enhancer elements within the murine Pparg2 gene. Utilizing the combined techniques of sequence conservation analysis and chromatin marker examination, we identified a potent enhancer element that augmented the expression of a reporter gene under the control of the Pparg2 promoter by 20-fold. This enhancer element was first identified as highly conserved non-coding sequence 10 (CNS10) and was later shown to be enriched with the enhancer marker H3 K27 acetylation. Further studies identified a binding site for p300 as the essential enhancer element in CNS10. Moreover, p300 physically binds to CNS10 and is required for the enhancer activity of CNS10. The depletion of p300 by siRNA resulted in significantly impaired activation of Pparg2 at the early stages of 3T3-L1 adipogenesis. In summary, our study identified a novel enhancer element on the murine Pparg2 gene and suggested a novel mechanism for the regulation of Pparg2 expression by p300 in 3T3-L1 adipogenesis. PMID:25485585

  13. Histone H3 K27 acetylation marks a potent enhancer element on the adipogenic master regulator gene Pparg2.

    PubMed

    Ramlee, Muhammad Khairul; Zhang, Qiongyi; Idris, Muhammad; Peng, Xu; Sim, Choon Kiat; Han, Weiping; Xu, Feng

    2014-01-01

    PPARγ2 is expressed almost exclusively in adipose tissue and plays a central role in adipogenesis. Despite intensive studies over the last 2 decades, the mechanism regulating the expression of the Pparg2 gene, especially the role of cis-regulatory elements, is still not completely understood. Here, we report a comprehensive investigation of the enhancer elements within the murine Pparg2 gene. Utilizing the combined techniques of sequence conservation analysis and chromatin marker examination, we identified a potent enhancer element that augmented the expression of a reporter gene under the control of the Pparg2 promoter by 20-fold. This enhancer element was first identified as highly conserved non-coding sequence 10 (CNS10) and was later shown to be enriched with the enhancer marker H3 K27 acetylation. Further studies identified a binding site for p300 as the essential enhancer element in CNS10. Moreover, p300 physically binds to CNS10 and is required for the enhancer activity of CNS10. The depletion of p300 by siRNA resulted in significantly impaired activation of Pparg2 at the early stages of 3T3-L1 adipogenesis. In summary, our study identified a novel enhancer element on the murine Pparg2 gene and suggested a novel mechanism for the regulation of Pparg2 expression by p300 in 3T3-L1 adipogenesis.

  14. Magnetometer-enhanced personal locator for tunnels and GPS-denied outdoor environments

    NASA Astrophysics Data System (ADS)

    Kwanmuang, Surat; Ojeda, Lauro; Borenstein, Johann

    2011-06-01

    This paper describes recent advances with our earlier developed Personal Dead-reckoning (PDR) system for GPS-denied environments. The PDR system uses a foot-mounted Inertial Measurement Unit (IMU) that also houses a three axismagnetometer. In earlier work we developed methods for correcting the drift errors in the accelerometers, thereby allowing very accurate measurements of distance traveled. In addition, we developed a powerful heuristic method for correcting heading errors caused by gyro drift. The heuristics exploit the rectilinear features found in almost all manmade structures and therefore limit this technology to indoor use only. Most recently we integrated a three-axis magnetometer with the IMU, using a Kalman Filter. While it is well known that the ubiquitous magnetic disturbances found in most modern buildings render magnetometers almost completely useless indoors, these sensors are nonetheless very effective in pristine outdoor environments as well as in some tunnels and caves. The present paper describes the integrated magnetometer/IMU system and presents detailed experimental results. Specifically, the paper reports results of an objective test conducted by Firefighters of California's CAL-FIRE. In this particular test, two firefighters in full operational gear and one civilian hiked up a two-mile long mountain trail over rocky, sometimes steeply inclined terrain, each wearing one of our magnetometer-enhanced PDR systems but not using any GPS. During the hour-long hike the average position error was about 20 meters and the maximum error was less than 45 meters, which is about 1.4% of distance traveled for all three PDR systems.

  15. Water-enhanced interdiffusion of major elements between natural shoshonite and high-K rhyolite melts

    NASA Astrophysics Data System (ADS)

    González-García, Diego; Behrens, Harald; Petrelli, Maurizio; Vetere, Francesco; Morgavi, Daniele; Zhang, Chao; Perugini, Diego

    2017-09-01

    The interdiffusion of six major elements (Si, Ti, Fe, Mg, Ca, K) between natural shoshonite and a high-K calc-alkaline rhyolite (Vulcano island, Aeolian archipelago, Italy) has been experimentally measured by the diffusion couple technique at 1200{\\deg}C, pressures from 50 to 500 MPa and water contents from 0.3 (nominally dry) to 2 wt%. The experiments were carried out in an internally heated pressure vessel, and major element profiles were later acquired by electron probe microanalysis. The concentration-distance profiles are evaluated using a concentration-dependent diffusivity approach. Effective binary diffusion coefficients for four intermediate silica contents are obtained by the Sauer-Freise modified Boltzmann-Matano method. At the experimental temperature and pressures, the diffusivity of all studied elements notably increases with dissolved H2O content. Particularly, diffusion is up to 1.4 orders of magnitude faster in a melt containing 2 wt.% H2O than in nominally dry melts. This effect is slightly enhanced in the more mafic compositions. Uphill diffusion was observed for Al, while all other elements can be described by the concept of effective binary interdiffusion. Ti is the slowest diffusing element through all experimental conditions and compositions, followed by Si. Fe, Mg, Ca and K diffuse at similar rates but always more rapidly than Si and Ti. This trend suggests a strong coupling between melt components. Since effects of composition (including water content) are dominant, a pressure effect on diffusion cannot be clearly resolved in the experimental pressure range.

  16. Enhanced signal processing algorithms for buried unexploded ordnance detection and location estimation with magnetometer and electromagnetic induction measurements

    SciTech Connect

    Witten, A.

    1993-09-01

    Enhanced signal processing algorithms have been developed for the detection and location of buried unexploded ordnance using magnetometry and electromagnetic induction (EMI) measurements. These signal processing algorithms are related to those used to image with geophysical diffraction tomography (GDT) employing wave-based measurements. The underlying relationship of GDT is the Generalized Projection Slice Theorem (GPST) that relates the spatial Fourier transform of acquired data to the spatial Fourier transform of subsurface inhomogeneities of one higher dimension. This relationship can be used to simulate data templates for known targets and, by virtue of the shift property of Fourier transforms, a data simulation need only be computed for one reference target location. All other target locations are generated by an appropriate phase shift. These data templates can be correlated with acquired data to determine the spatial distribution of probable target location. This approach to target detection and location estimation, referred to as a maximum likelihood estimation, can be used to produce an {open_quotes}image{close_quotes} of the likelihood of a specified target`s position. For non wave-based methods, the relationship between data and target characteristics is not strictly associated with Fourier transforms. In the case of magnetometry, the appropriate GPST requires a Fourier-Laplace transform of the target characteristics while the EMI GPST is based on an integral transform with a complex wavenumber. Nevertheless, the shift rule for integral transforms can be invoked to yield GPST`s for these tools and the associated computationally efficient maximum likelihood estimators. The EMI detection algorithm was applied to data acquired at a known underground storage tank site and the algorithms for both magnetometry and EMI were applied to data acquired at the Magnetic Range of the Naval EOD Tech Center in Indian Head, Maryland.

  17. Gold nanoparticle dimer plasmonics: finite element method calculations of the electromagnetic enhancement to surface-enhanced Raman spectroscopy.

    PubMed

    McMahon, Jeffrey M; Henry, Anne-Isabelle; Wustholz, Kristin L; Natan, Michael J; Freeman, R Griffith; Van Duyne, Richard P; Schatz, George C

    2009-08-01

    Finite element method calculations were carried out to determine extinction spectra and the electromagnetic (EM) contributions to surface-enhanced Raman spectroscopy (SERS) for 90-nm Au nanoparticle dimers modeled after experimental nanotags. The calculations revealed that the EM properties depend significantly on the junction region, specifically the distance between the nanoparticles for spacings of less than 1 nm. For extinction spectra, spacings below 1 nm lead to maxima that are strongly red-shifted from the 600-nm plasmon maximum associated with an isolated nanoparticle. This result agrees qualitatively well with experimental transmission electron microscopy images and localized surface plasmon resonance spectra that are also presented. The calculations further revealed that spacings below 0.5 nm, and especially a slight fusing of the nanoparticles to give tiny crevices, leads to EM enhancements of 10(10) or greater. Assuming a uniform coating of SERS molecules around both nanoparticles, we determined that regardless of the separation, the highest EM fields always dominate the SERS signal. In addition, we determined that for small separations less than 3% of the molecules always contribute to greater than 90% of the signal.

  18. Analysis of Vertebral Bone Strength, Fracture Pattern, and Fracture Location: A Validation Study Using a Computed Tomography-Based Nonlinear Finite Element Analysis

    PubMed Central

    Imai, Kazuhiro

    2015-01-01

    Finite element analysis (FEA) is an advanced computer technique of structural stress analysis developed in engineering mechanics. Because the compressive behavior of vertebral bone shows nonlinear behavior, a nonlinear FEA should be utilized to analyze the clinical vertebral fracture. In this article, a computed tomography-based nonlinear FEA (CT/FEA) to analyze the vertebral bone strength, fracture pattern, and fracture location is introduced. The accuracy of the CT/FEA was validated by performing experimental mechanical testing with human cadaveric specimens. Vertebral bone strength and the minimum principal strain at the vertebral surface were accurately analyzed using the CT/FEA. The experimental fracture pattern and fracture location were also accurately simulated. Optimization of the element size was performed by assessing the accuracy of the CT/FEA, and the optimum element size was assumed to be 2 mm. It is expected that the CT/FEA will be valuable in analyzing vertebral fracture risk and assessing therapeutic effects on osteoporosis. PMID:26029476

  19. Three-dimensional analysis using finite element method of anterior teeth inclination and center of resistance location.

    PubMed

    Geramy, Allahyar; Sodagar, Ahmad; Hassanpour, Mehdi

    2014-01-01

    To locate the centre of resistance of consolidated units of four and six anterior teeth during retraction. Twelve three-dimensional (3D) models were designed in SolidWorks of the anterior segment with four and six teeth and their supporting structure. A proper force system was applied in each model to retract the teeth bodily. The exact location of the centre of resistances (CRes) was determined. It was found that the path of CRes change in four-tooth and six-tooth units according to the anterior teeth torque. A posterior shift of the CRes by increasing the inclination of teeth was shown. However, vertical position has a fluctuant behaviour. First it moves apically, then it moves incisally. Furthermore, results suggest that in en masse retraction, translation can be achieved with a smaller amount of moment-to-force ratio than in four-incisor retraction. In other words, for bodily retraction of anterior incisor segments, we should apply force in a more apical position. Different anterior torques between 7 and 35 degrees, cannot affect the CRes position dramatically. The area of CRes shifting is 0.92 mm (anterioposteriorly) x 0.74 mm (superior-inferiorly) in the six-tooth unit in the teeth model and 0.85 mm (anterioposteriorly) x 0.82 mm (superior-inferiorly) in the teeth and bone model. In the four-tooth model, the area of CRes shifting is 0.97 mm (anterioposteriorly) x 0.93 mm (superior-inferiorly) in tooth model and 0.77 mm (anterioposteriorly) x 0.87 mm (superior-inferiorly) in the teeth and bone model.

  20. New insights on the transcriptional regulation of CD69 gene through a potent enhancer located in the conserved non-coding sequence 2.

    PubMed

    Laguna, Teresa; Notario, Laura; Pippa, Raffaella; Fontela, Miguel G; Vázquez, Berta N; Maicas, Miren; Aguilera-Montilla, Noemí; Corbí, Ángel L; Odero, María D; Lauzurica, Pilar

    2015-08-01

    The CD69 type II C-type lectin is one of the earliest indicators of leukocyte activation acting in lymphocyte migration and cytokine secretion. CD69 expression in hematopoietic lineage undergoes rapid changes depending on the cell-lineage, the activation state or the localization of the cell where it is expressed, suggesting a complex and tightly controlled regulation. Here we provide new insights on the transcriptional regulation of CD69 gene in mammal species. Through in silico studies, we analyzed several regulatory features of the 4 upstream conserved non-coding sequences (CNS 1-4) previously described, confirming a major function of CNS2 in the transcriptional regulation of CD69. In addition, multiple transcription binding sites are identified in the CNS2 region by DNA cross-species conservation analysis. By functional approaches we defined a core region of 226bp located within CNS2 as the main enhancer element of CD69 transcription in the hematopoietic cells analyzed. By chromatin immunoprecipitation, binding of RUNX1 to the core-CNS2 was shown in a T cell line. In addition, we found an activating but not essential role of RUNX1 in CD69 gene transcription by site-directed mutagenesis and RNA silencing, probably through the interaction with this potent enhancer specifically in the hematopoietic lineage. In summary, in this study we contribute with new evidences to the landscape of the transcriptional regulation of the CD69 gene. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. A Fine-Grained and Privacy-Preserving Query Scheme for Fog Computing-Enhanced Location-Based Service.

    PubMed

    Yang, Xue; Yin, Fan; Tang, Xiaohu

    2017-07-11

    Location-based services (LBS), as one of the most popular location-awareness applications, has been further developed to achieve low-latency with the assistance of fog computing. However, privacy issues remain a research challenge in the context of fog computing. Therefore, in this paper, we present a fine-grained and privacy-preserving query scheme for fog computing-enhanced location-based services, hereafter referred to as FGPQ. In particular, mobile users can obtain the fine-grained searching result satisfying not only the given spatial range but also the searching content. Detailed privacy analysis shows that our proposed scheme indeed achieves the privacy preservation for the LBS provider and mobile users. In addition, extensive performance analyses and experiments demonstrate that the FGPQ scheme can significantly reduce computational and communication overheads and ensure the low-latency, which outperforms existing state-of-the art schemes. Hence, our proposed scheme is more suitable for real-time LBS searching.

  2. A Fine-Grained and Privacy-Preserving Query Scheme for Fog Computing-Enhanced Location-Based Service

    PubMed Central

    Yin, Fan; Tang, Xiaohu

    2017-01-01

    Location-based services (LBS), as one of the most popular location-awareness applications, has been further developed to achieve low-latency with the assistance of fog computing. However, privacy issues remain a research challenge in the context of fog computing. Therefore, in this paper, we present a fine-grained and privacy-preserving query scheme for fog computing-enhanced location-based services, hereafter referred to as FGPQ. In particular, mobile users can obtain the fine-grained searching result satisfying not only the given spatial range but also the searching content. Detailed privacy analysis shows that our proposed scheme indeed achieves the privacy preservation for the LBS provider and mobile users. In addition, extensive performance analyses and experiments demonstrate that the FGPQ scheme can significantly reduce computational and communication overheads and ensure the low-latency, which outperforms existing state-of-the art schemes. Hence, our proposed scheme is more suitable for real-time LBS searching. PMID:28696395

  3. REAL TIME CONTINUOUS MEASUREMENTS OF [CO2] AND δ13C AT MULTIPLE LOCATIONS USING CAVITY ENHANCED LASER ABSORPTION

    NASA Astrophysics Data System (ADS)

    McAlexander, W. I.; Rau, G. H.; Dobeck, L.; Spangler, L.

    2009-12-01

    A commercial instrument (Los Gatos Research, model 908-0003) utilizing Cavity Enhanced Laser Absorption Spectroscopy was deployed in 2009 at the ZERT carbon release site (Bozeman, MT) for real time measurement of above-ground CO2 concentration and isotope ratio (δ13C). An automated switching system sampled 13 different locations in the field, as well as two known references, over an 8 day period. Real-time Keeling plots were constructed showing distinct signatures of soil (-27.0 ‰) and fossil (-56.0 ‰) sources compared to background air (-8.2 ‰). Instrument performance gave 0.2 ‰ precision with only 100 seconds of averaging per inlet. Sequential sampling of the various inlets gave a temporal and physical mapping of the CO2 release plume that is difficult to obtain using more conventional techniques. The figures show the nature and quality of the data from one of the locations. Details concerning instrument performance, systematics, calibration, and data processing will be discussed. Fig1: Time chart of CO2 concentration and isotope ratio δ13C from one of 13 sample inlet locations at ZERT release field, July, 2009. Fig2: Keeling plot of data from Fig1 illustrating the two source mixing of soil (-27 ‰) and fossil (-56 ‰) CO2 with background air.

  4. Strain of passive elements during force enhancement by stretch in frog muscle fibres.

    PubMed Central

    Edman, K A; Tsuchiya, T

    1996-01-01

    1. The force enhancement during and after stretch (0.15 micron per sarcomere) was studied during fused tetani of single fibres isolated from the anterior tibialis muscle of Rana temporaria (0.5-3.6 degrees C; sarcomere length, 2.05-2.65 microns). Changes in length were recorded simultaneously from the fibre as a whole (puller movement) and from marked segments (approximately 0.5 mm in length) of the same fibre. 2. The residual force enhancement after stretch (recorded at the end of a long tetanus) was found to be linearly related to the slow component of tension rise during the stretch ramp. 3. The fibres were released to shorten against a very small load at different times after stretch (load clamp). The shortening records derived after a preceding stretch exhibited a larger and steeper initial transient than that recorded in an isometric tetanus without stretch. The excess length change (LS; nanometres per half-sarcomere) recorded during the initial transient increased with the amplitude of stretch and was linearly related to the force enhancement produced by the stretch (FE; % of maximum tetanic tension) according to the following regression: LS = 0.200 FE + 8.65 (P < 0.001). The length changes recorded from the whole fibre agreed well with measurements from individual segments. 4. Slack-test measurements confirmed the existence of a large initial transient phase when the fibre was released to shorten after a preceding stretch. The excess length change determined from the slack tests agreed closely with the values derived from load-clamp recordings. 5. The results support the view that stretching a muscle fibre during tetanus leads to strain of elastic elements and, presumably, to variation of filament overlap due to non-uniform distribution of the length change within the fibre volume. Regions with greater filament overlap are likely to generate the long-lasting extra force referred to as 'residual force enhancement after stretch'. The elastic elements

  5. Dependence of radiation belt enhancements on the radial extent of Pc5 waves and the plasmapause location

    NASA Astrophysics Data System (ADS)

    Georgiou, M.; Daglis, I. A.; Zesta, E.; Balasis, G.; Katsavrias, C.; Mann, I. R.; Tsinganos, K.

    2014-12-01

    Low-energy electrons are accelerated to relativistic energies through different mechanisms, transporting them across their drift shells to the outer radiation belt. Among the different acceleration mechanisms, radial diffusion describes the result of ULF magnetic field pulsations resonantly interacting with radiation belt electrons. In this paper, the radial positioning of the relativistic electron population during 39 intense and moderate magnetic storms is examined against that of ULF Pc5 wave power and the plasmapause location. The relativistic electron population of the outer radiation belt appeared enhanced in the 2 - 6 MeV electron flux data from SAMPEX and in > 2 MeV electron flux data from the geosynchronous GOES satellites following 27 of the magnetic storms. We compared relativistic electrons observations with concurrent radial distribution of wave power enhancements at Pc5 frequencies as detected by the IMAGE and CARISMA magnetometer arrays, as well as by additional magnetic stations collaborating in SuperMAG. We discuss the growth and decay characteristics of Pc5 waves in association with the plasmapause location, determined from IMAGE EUV observations, as the controlling factor for wave power penetration deep into the magnetosphere. We show that, during magnetic storms characterized by increased post-storm fluxes, Pc5 wave power penetrates to L shells of 4 and lower. On the other hand, magnetic storms which were characterised by loss of electrons were related to low Pc5 wave activity, which was not intensified at low L shells. These observations provide support for the hypothesis that enhanced Pc5 wave activity deep into the magnetosphere during the main and recovery phase can discriminate between storms that result in increases of electron fluxes from those that do not. The work leading to this paper has received funding from the European Union's Seventh Framework Programme (FP7-SPACE-2011-1) under grant agreement no. 284520 for the MAARBLE

  6. Hair sampling location in harbor seals (Phoca vitulina) affects selenium and mercury concentrations: implications for study design of trace element determination in pinnipeds.

    PubMed

    McHuron, Elizabeth A; Harvey, James T; Castellini, J Margaret; O'Hara, Todd M

    2012-11-01

    Hair is used to determine trace elements exposure and status of pinnipeds because it is an excretory route for many elements and can be collected non-lethally. Despite increased use, there have been few studies on how sampling designs and procedures (e.g., hair type, collection site) affect results. The objective of this study was to determine whether concentrations of an essential (selenium; Se) and non-essential element (mercury; Hg) differed between hair samples collected from two body locations on harbor seals (Phoca vitulina). Concentrations of Se and total Hg (THg) differed between mid-dorsal midline and neck samples, and although the absolute differences were relatively small (Δ(absolute) Se = 0.69 μg g(-1), Δ(absolute) THg = 2.86 μg g(-1)), the relative differences were large (Δ(relative) Se = 49%, Δ(relative) THg = 17%). These differences highlight the need to standardize the collection site for trace element determination in pinnipeds.

  7. Wall thickness measurement using resonant phenomena of circumferential Lamb waves generated by plural transducer elements located evenly on girth

    NASA Astrophysics Data System (ADS)

    Nishino, Hideo; Iwata, Kodai; Ishikawa, Masashi

    2016-07-01

    We present a novel method of measuring the pipe wall thickness using the resonance of the circumferential (C-) Lamb wave generated by a piezoelectric ring-shaped sensor (PS). The PS is a special device for an axially propagating torsional wave; however, the C-Lamb waves are generated simultaneously as spurious signals owing to the structure of the PS. Particularly under resonant conditions, the C-Lamb waves are dominantly generated, distorting the axially propagating wave. In this method, these troublesome spurious signals are used effectively for the measurement of the wall thickness under the PS location that is a dead zone of the PS itself. The method can compensate for its drawback, namely, the dead zone problem, without using additional instruments. In this study, the mechanisms of the generation and resonance of the C-Lamb waves were first explained. Secondly, the principle of the wall thickness estimation utilizing the resonance of the C-Lamb waves was proposed. Finally, experimental verifications were carried out. The estimated wall thicknesses agreed very well (maximum 1.5% error) with those measured by a micrometer caliper under suitable resonant conditions.

  8. Subject-specific finite element models implementing a maximum principal strain criterion are able to estimate failure risk and fracture location on human femurs tested in vitro.

    PubMed

    Schileo, Enrico; Taddei, Fulvia; Cristofolini, Luca; Viceconti, Marco

    2008-01-01

    No agreement on the choice of the failure criterion to adopt for the bone tissue can be found in the literature among the finite element studies aiming at predicting fracture risk of bones. The use of stress-based criteria seems to prevail on strain-based ones, while basic bone biomechanics suggest using strain parameters to describe failure. The aim of the present combined experimental-numerical study was to verify, using subject-specific finite element models able to accurately predict strains, if a strain-based failure criterion could identify the failure patterns of bones. Three cadaver femurs were CT-scanned and subsequently fractured in a clinically relevant single-stance loading scenario. Load-displacement curves and high-speed movies were acquired to define the failure load and the location of fracture onset, respectively. Subject-specific finite element models of the three femurs were built from CT data following a validated procedure. A maximum principal strain criterion was implemented in the finite element models, and two stress-based criteria selected for comparison. The failure loads measured were applied to the models, and the computed risks of fracture were compared to the results of the experimental tests. The proposed principal strain criterion managed to correctly identify the level of failure risk and the location of fracture onset in all the modelled specimens, while Von Mises or maximum principal stress criteria did not give significant information. A maximum principal strain criterion can thus be defined a suitable candidate for the in vivo risk factor assessment on long bones.

  9. Functional analysis of a bacitracin resistance determinant located on ICECp1, a novel Tn916-like element from a conjugative plasmid in Clostridium perfringens.

    PubMed

    Han, Xiaoyan; Du, Xiang-Dang; Southey, Luke; Bulach, Dieter M; Seemann, Torsten; Yan, Xu-Xia; Bannam, Trudi L; Rood, Julian I

    2015-11-01

    Bacitracins are mixtures of structurally related cyclic polypeptides with antibiotic properties. They act by interfering with the biosynthesis of the bacterial cell wall. In this study, we analyzed an avian necrotic enteritis strain of Clostridium perfringens that was resistant to bacitracin and produced NetB toxin. We identified a bacitracin resistance locus that resembled a bacitracin resistance determinant from Enterococcus faecalis. It contained the structural genes bcrABD and a putative regulatory gene, bcrR. Mutagenesis studies provided evidence that both bcrA and bcrB are essential for bacitracin resistance, and that evidence was supported by the results of experiments in which the introduction of both the bcrA and bcrB genes into a bacitracin-susceptible C. perfringens strain was required to confer bacitracin resistance. The wild-type strain was shown to contain at least three large, putatively conjugative plasmids, and the bcrRABD locus was localized to an 89.7-kb plasmid, pJIR4150. This plasmid was experimentally shown to be conjugative and was sequenced. The sequence revealed that it also carries a tpeL toxin gene and is related to the pCW3 family of conjugative antibiotic resistance and toxin plasmids from C. perfringens. The bcr genes were located on a genetic element, ICECp1, which is related to the Tn916 family of integrative conjugative elements (ICEs). ICECp1 appears to be the first Tn916-like element shown to confer bacitracin resistance. In summary, we identified in a toxin-producing C. perfringens strain a novel mobile bacitracin resistance element which was experimentally shown to be essential for bacitracin resistance and is carried by a putative ICE located on a conjugative plasmid.

  10. First comprehensive study on total contents and hot water extractable fraction of selected elements in 19 medicinal plants from various locations in Nyamira County, Kenya.

    PubMed

    Nischwitz, Volker; Mogwasi, Richard; Zor, Salim; Getenga, Zachary; Kariuki, David K; Günther, Klaus

    2017-01-01

    A large number of medicinal plants is traditionally known in Kenya and used for treatment of various diseases, for example diabetes, where metals are supposed to be involved in pathogenesis and therapy. Therefore, detailed investigation of the concentration of a large number of metals in medicinal plants is required for improved understanding and optimisation of the therapeutic role of metals and also to exclude potentially toxic effects. Our study focused on the determination of 30 selected elements in 19 medicinal plant species each collected from 3 sampling locations in Nyamira County, Kenya. The obtained comprehensive data set showed large variability and multivariate data analysis revealed that the differences in the elemental composition were stronger dependent on the plant species than on the sampling location. In addition, hot water extractions were performed to mimic the traditional preparation of medicine from the plants. It was found that the mean extraction efficiencies were below 20% except for B, Mg, P, K, Mn, Co, Ni, Cu, Zn, Rb, Mo, Cd and Tl, which are mostly essential elements apart from Cd and Tl. Sequential (ultra)filtration of the extracts was applied as novel approach for molecular size-fractionation of the extracted elemental species. The results indicate more than 50% low molecular weight species (<3kDa) for Mg, Mn, Co, Ni and Zn while predominantly larger size-fractions (>3kDa up to<5μm) were detected for V, Cu, Al and Fe. Copyright © 2016 Elsevier GmbH. All rights reserved.

  11. Enhanced Recovery after Urological Surgery: A Contemporary Systematic Review of Outcomes, Key Elements, and Research Needs

    PubMed Central

    Azhar, Raed A.; Bochner, Bernard; Catto, James; Goh, Alvin C.; Kelly, John; Patel, Hiten D.; Pruthi, Raj S.; Thalmann, George N.; Desai, Mihir

    2017-01-01

    Context Enhanced Recovery after Surgery (ERAS) programs are multimodal care pathways that aim to decrease intra-operative blood loss, decrease postoperative complications, and reduce recovery times. Objective To overview the use and key elements of ERAS pathways, and define needs for future clinical trials. Evidence acquisition A comprehensive systematic MEDLINE search was performed for English language reports published before May 2015 using the terms “postoperative period,” “postoperative care,” “enhanced recovery after surgery,” “enhanced recovery,” “accelerated recovery,” “fast track recovery,” “recovery program,” “recovery pathway”,“ERAS ” , and “urology” or “cystectomy” or “urologic surgery.” Evidence synthesis We identified 18 eligible articles. Patient counseling, physical conditioning, avoiding excessive alcohol and smoking, and good nutrition appeared to protect against postoperative complications. Fasting from solid food for only 6 h and perioperative liquid – carbohydrate loading up to 2 h prior to surgery appeared to be safe and reduced recovery times. Restricted, balanced, and goal-directed fluid replacement is effective when individualized, depending on patient morbidity and surgical procedure. Decreased intraoperative blood loss may be achieved by several measures. Deep vein thrombosis prophylaxis, antibiotic prophylaxis, and thermoregulation were found to help reduce postsurgical complications, as was a multimodal approach to postoperative nausea, vomiting, and analgesia. Chewing gum, prokinetic agents, oral laxatives, and an early resumption to normal diet appear to aid faster return to normal bowel function. Further studies should compare anesthetic protocols, refine analgesia, and evaluate the importance of robot-assisted surgery and the need/timing for drains and catheters. Conclusions ERAS regimens are multidisciplinary, multimodal pathways that optimize postoperative recovery. Patient summary

  12. The C/ebp-Atf response element (CARE) location reveals two distinct Atf4-dependent, elongation-mediated mechanisms for transcriptional induction of aminoacyl-tRNA synthetase genes in response to amino acid limitation.

    PubMed

    Shan, Jixiu; Zhang, Fan; Sharkey, Jason; Tang, Tiffany A; Örd, Tönis; Kilberg, Michael S

    2016-11-16

    The response to amino acid (AA) limitation of the entire aminoacyl-tRNA synthetase (ARS) gene family revealed that 16/20 of the genes encoding cytoplasmic-localized enzymes are transcriptionally induced by activating transcription factor 4 (Atf4) via C/ebp-Atf-Response-Element (CARE) enhancers. In contrast, only 4/19 of the genes encoding mitochondrial-localized ARSs were weakly induced. Most of the activated genes have a functional CARE near the transcription start site (TSS), but for others the CARE is downstream. Regardless of the location of CARE enhancer, for all ARS genes there was constitutive association of RNA polymerase II (Pol II) and the general transcription machinery near the TSS. However, for those genes with a downstream CARE, Atf4, C/ebp-homology protein (Chop), Pol II and TATA-binding protein exhibited enhanced recruitment to the CARE during AA limitation. Increased Atf4 binding regulated the association of elongation factors at both the promoter and the enhancer regions, and inhibition of cyclin-dependent kinase 9 (CDK9), that regulates these elongation factors, blocked induction of the AA-responsive ARS genes. Protein pull-down assays indicated that Atf4 directly interacts with CDK9 and its associated protein cyclin T1. The results demonstrate that AA availability modulates the ARS gene family through modulation of transcription elongation. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

  13. The C/ebp-Atf response element (CARE) location reveals two distinct Atf4-dependent, elongation-mediated mechanisms for transcriptional induction of aminoacyl-tRNA synthetase genes in response to amino acid limitation

    PubMed Central

    Shan, Jixiu; Zhang, Fan; Sharkey, Jason; Tang, Tiffany A.; Örd, Tönis; Kilberg, Michael S.

    2016-01-01

    The response to amino acid (AA) limitation of the entire aminoacyl-tRNA synthetase (ARS) gene family revealed that 16/20 of the genes encoding cytoplasmic-localized enzymes are transcriptionally induced by activating transcription factor 4 (Atf4) via C/ebp-Atf-Response-Element (CARE) enhancers. In contrast, only 4/19 of the genes encoding mitochondrial-localized ARSs were weakly induced. Most of the activated genes have a functional CARE near the transcription start site (TSS), but for others the CARE is downstream. Regardless of the location of CARE enhancer, for all ARS genes there was constitutive association of RNA polymerase II (Pol II) and the general transcription machinery near the TSS. However, for those genes with a downstream CARE, Atf4, C/ebp-homology protein (Chop), Pol II and TATA-binding protein exhibited enhanced recruitment to the CARE during AA limitation. Increased Atf4 binding regulated the association of elongation factors at both the promoter and the enhancer regions, and inhibition of cyclin-dependent kinase 9 (CDK9), that regulates these elongation factors, blocked induction of the AA-responsive ARS genes. Protein pull-down assays indicated that Atf4 directly interacts with CDK9 and its associated protein cyclin T1. The results demonstrate that AA availability modulates the ARS gene family through modulation of transcription elongation. PMID:27471030

  14. Genome-wide identification of novel intergenic enhancer-like elements: implications in the regulation of transcription in Plasmodium falciparum.

    PubMed

    Ubhe, Suyog; Rawat, Mukul; Verma, Srikant; Anamika, Krishanpal; Karmodiya, Krishanpal

    2017-08-23

    The molecular mechanisms of transcriptional regulation are poorly understood in Plasmodium falciparum. In addition, most of the genes in Plasmodium falciparum are transcriptionally poised and only a handful of cis-regulatory elements are known to operate in transcriptional regulation. Here, we employed an epigenetic signature based approach to identify significance of previously uncharacterised intergenic regions enriched with histone modification marks leading to discovery of enhancer-like elements. We found that enhancer-like elements are significantly enriched with H3K4me1, generate unique non-coding bi-directional RNAs and majority of them can function as cis-regulators. Furthermore, functional enhancer reporter assay demonstrates that the enhancer-like elements regulate transcription of target genes in Plasmodium falciparum. Our study also suggests that the Plasmodium genome segregates functionally related genes into discrete housekeeping and pathogenicity/virulence clusters, presumably for robust transcriptional control of virulence/pathogenicity genes. This report contributes to the understanding of parasite regulatory genomics by identification of enhancer-like elements, defining their epigenetic and transcriptional features and provides a resource of functional cis-regulatory elements that may give insights into the virulence/pathogenicity of Plasmodium falciparum.

  15. Ab initio search for cohesion-enhancing impurity elements at grain boundaries in molybdenum and tungsten

    NASA Astrophysics Data System (ADS)

    Scheiber, D.; Pippan, R.; Puschnig, P.; Romaner, L.

    2016-12-01

    We report high throughput density functional theory (DFT) calculations to simulate segregation of s- and p-elements in Mo and W. First, the preference of solutes for interstitial or substitutional positions in the bulk is evaluated and then the segregation energies for the solutes to interstitial and different substitutional sites at a grain boundary (GB) and a free surface (FS) are computed. We show that several solutes change their site preference from substitutional to interstitial position upon segregation to the GB. With the segregation energies to GB and FS, the changes in cohesion can be calculated and GB cohesion enhancing solutes can be identified. The results show striking similarity for both W and Mo. In addition, we collected the available literature data from experimental and theoretical side, which we consequently compare to our results. From our results and the comparison to literature, we identify B, C and Be as potential alloying additions for an increased GB cohesion in Mo and W.

  16. Determination of Reduced Number and Suitable Locations of Fuzzy Logic Controlled Braking Resistors for Transient Stability Enhancement

    NASA Astrophysics Data System (ADS)

    Ali, Mohd. Hasan; Murata, Toshiaki; Tamura, Junji

    Braking resistor is known to be a very powerful tool for transient stability improvement in electric power systems. Usually, in a large power system braking resistors are placed at each generator terminal bus which requires a high installation as well as operation cost. Also, heavy computation is required for the controllers used for the switching of the resistors. From these viewpoints, this paper directs to the study of installation of reduced number of fuzzy logic controlled braking resistors at suitable locations for transient stability enhancement. Groups of coherent generators in the power system are determined. Then one braking resistor is installed in each of the coherent group and at each of the remaining generator terminal bus. Thus, the number of braking resistors is reduced and hence the installation and operation cost as well as computational burden for the controllers are minimized. The suitable location for the braking resistor in each coherent group of generators is determined according to the values of the transient stability index as calculated for a 3LG (Three-phase-to-ground) fault at the points near the generators of the coherent group without considering the braking resistors in the system. The effectiveness of the proposed method is demonstrated through EMTP simulations for the IEEJ West-10 machine model system.

  17. New water soluble phosphonate and polycarboxylate complexants for enhanced f element separations

    SciTech Connect

    Nash, K.L.; Rickert, P.G.; Lessmann, E.P.; Mendoza, M.D.; Feil, J.F.; Sullivan, J.C.

    1994-08-01

    While lipophilic extractant molecules and ion exchange polymeric materials are clearly essential to efficient separation of metal ions by solvent extraction or ion exchange, the most difficult separations often could not be accomplished without the use of water soluble complexants. This report focuses on recent developments in design, synthesis and characterization of phosphonic acid and polycarboxylic acid ligands for enhanced f element separations. Emphasis is on the basic solution chemistry and crystal structures of complexes of the f elements with selected amino-derivatives of methanediphosphonic acid and with tetrahydrofuran-2,3,4,5-tetracarboxylic acid. The former series of compounds exhibit high affinity for lanthanides and actinides in acidic solutions. The latter ligand exhibits an unusual (and very useful) ``anti-selectivity`` for uranyl ion in a solvent extraction process, which permits efficient separation of uranyl from more radioactive components of nuclear wastes. Most of the observed effects can be explained through examination of the structure of the ligand, and comparison of the spectroscopic and thermodynamic parameters for complexation of various metal ions.

  18. Antenna Gain Enhancement and Beamshaping using a Diffractive Optical Element (DOE) Lens

    NASA Astrophysics Data System (ADS)

    Torbitt, Christopher

    Dielectric and metamaterial lenses have been designed for gain enhancement and beam shaping. The motivation for this work came from a commercially available slotted waveguide antenna with a dielectric lens that shapes the beam and enhances the gain only in the azimuth plane. When two of these antennas, each with a dielectric lens, are stacked as an array to form the sum and difference patterns the elevation plane gain is low and the beam width too wide to be acceptable for radar applications. The objective of the present work is to design a diffractive optical element (DOE) lens for gain enhancement gain and beam shaping. As compared to other available lenses it is much thinner, lighter and easily machined. The DOE lens is made from rexolite which has a dielectric constant of 2.53. The DOE lens is composed of a series of zones which focus the light at a certain focal length. The phase is the same everywhere on each zone at the focal point. The phase difference between neighboring zones is 2pi, resulting in a constructive interference at the focus. These zones are able to focus the radiation from an antenna in order to enhance the gain and shape the beam. The design parameters include the lens diameter, number of zones, the center zone thickness for a particular frequency and refractive index of the dielectric material. A comprehensive study has been performed in CST Microwave Studio to illustrate the properties of the DOE lens. The focusing property for image formation is verified by a plane wave excitation. Lenses have been designed and tested at different frequencies and with varying design parameters. Gain enhancement and beam shaping are illustrated by modeling the DOE lens in CST and placing it in front of different antennas. This work presents lenses for 10GHz and 40GHz horn antennas, a 3GHz slotted waveguide antenna array, and a 10GHz microstrip patch arrays. Beam shaping and focusing is clearly illustrated for each type of antenna. It is seen that the size

  19. An enhanced Kurtogram method for fault diagnosis of rolling element bearings

    NASA Astrophysics Data System (ADS)

    Wang, Dong; Tse, Peter W.; Tsui, Kwok Leung

    2013-02-01

    The Kurtogram is based on the kurtosis of temporal signals that are filtered by the short-time Fourier transform (STFT), and has proved useful in the diagnosis of bearing faults. To extract transient impulsive signals more effectively, wavelet packet transform is regarded as an alternative method to STFT for signal decomposition. Although kurtosis based on temporal signals is effective under some conditions, its performance is low in the presence of a low signal-to-noise ratio and non-Gaussian noise. This paper proposes an enhanced Kurtogram, the major innovation of which is kurtosis values calculated based on the power spectrum of the envelope of the signals extracted from wavelet packet nodes at different depths. The power spectrum of the envelope of the signals defines the sparse representation of the signals and kurtosis measures the protrusion of the sparse representation. This enhanced Kurtogram helps to determine the location of resonant frequency bands for further demodulation with envelope analysis. The frequency signatures of the envelope signal can then be used to determine the type of fault that has affected a bearing by identifying its characteristic frequency. In many cases, discrete frequency noise always exists and may mask the weak bearing faults. It is usually preferable to remove such discrete frequency noise by using autoregressive filtering before the enhanced Kurtogram is performed. At last, we used a number of simulated bearing fault signals and three real bearing fault signals obtained from an experimental motor to validate the efficiency of these proposed modifications. The results show that both the proposed method and the enhanced Kurtogram are effective in the detection of various bearing faults.

  20. Excitation of whistler waves below the lower hybrid frequency by a loop antenna located in an enhanced density duct

    NASA Astrophysics Data System (ADS)

    Kudrin, Alexander V.; Ostafiychuk, Oleg M.; Zaboronkova, Tatyana M.

    2017-08-01

    Whistler wave radiation from a loop antenna located in a cylindrical duct with enhanced plasma density is considered in the case where the wave frequency is less than the lower hybrid frequency. Using the full-wave formulation, the total radiation resistance and the partial radiation resistances corresponding to guided eigenmodes of such a duct and unguided waves radiating to the background magnetoplasma are calculated and analyzed as functions of the plasma and source parameters. The emphasis is placed on the radiation characteristics of the considered source in the presence of an artificial near-antenna duct that can be created during active experiments in the ionosphere. Conditions are revealed under which the total radiation resistance is predominantly determined by the excitation of the eigenmodes of the duct. It is shown that the presence of an enhanced density duct can lead to a notable increase in the radiation resistance of a loop antenna in the discussed frequency range even if the duct is rather narrow and capable of guiding only a single low-order eigenmode. The results obtained can be helpful in understanding the basic features of excitation of the ducted whistlers and planning the related ionospheric and laboratory experiments.

  1. To feed or not to feed: plant factors located in the epidermis, mesophyll, and sieve elements influence pea aphid's ability to feed on legume species.

    PubMed

    Schwarzkopf, Alexander; Rosenberger, Daniel; Niebergall, Martin; Gershenzon, Jonathan; Kunert, Grit

    2013-01-01

    The pea aphid (Acyrthosiphon pisum Harris), a legume specialist, encompasses at least 11 genetically distinct sympatric host races. Each host race shows a preference for a certain legume species. Six pea aphid clones from three host races were used to localize plant factors influencing aphid probing and feeding behavior on four legume species. Aphid performance was tested by measuring survival and growth. The location of plant factors influencing aphid probing and feeding was determined using the electrical penetration graph (EPG) technique. Every aphid clone performed best on the plant species from which it was originally collected, as well as on Vicia faba. On other plant species, clones showed intermediate or poor performance. The most important plant factors influencing aphid probing and feeding behavior were localized in the epidermis and sieve elements. Repetitive puncturing of sieve elements might be relevant for establishing phloem feeding, since feeding periods appear nearly exclusively after these repetitive sieve element punctures. A combination of plant factors influences the behavior of pea aphid host races on different legume species and likely contributes to the maintenance of these races.

  2. KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, astronaut Soichi Noguchi (right), with the National Space Development Agency of Japan (NASDA), stands inside the Japanese Experiment Module (JEM) that is undergoing a Multi-Element Integrated Test (MEIT) with the U.S. Node 2. The JEM, developed by NASDA, is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments. Noguchi is assigned to mission STS-114 as a mission specialist. Node 2 provides attach locations for the Japanese laboratory, as well as European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. Installation of the module will complete the U.S. Core of the ISS.

    NASA Image and Video Library

    2003-09-03

    KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, astronaut Soichi Noguchi (right), with the National Space Development Agency of Japan (NASDA), stands inside the Japanese Experiment Module (JEM) that is undergoing a Multi-Element Integrated Test (MEIT) with the U.S. Node 2. The JEM, developed by NASDA, is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments. Noguchi is assigned to mission STS-114 as a mission specialist. Node 2 provides attach locations for the Japanese laboratory, as well as European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. Installation of the module will complete the U.S. Core of the ISS.

  3. KENNEDY SPACE CENTER, FLA. - Astronaut Soichi Noguchi (left), with the National Space Development Agency of Japan (NASDA), works at a console during a Multi-Element Integrated Test (MEIT) of the U.S. Node 2 and the Japanese Experiment Module (JEM) in the Space Station Processing Facility. The JEM, developed by NASDA, is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments. Noguchi is assigned to mission STS-114 as a mission specialist. Node 2 provides attach locations for the Japanese laboratory, as well as European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. Installation of the module will complete the U.S. Core of the ISS.

    NASA Image and Video Library

    2003-09-03

    KENNEDY SPACE CENTER, FLA. - Astronaut Soichi Noguchi (left), with the National Space Development Agency of Japan (NASDA), works at a console during a Multi-Element Integrated Test (MEIT) of the U.S. Node 2 and the Japanese Experiment Module (JEM) in the Space Station Processing Facility. The JEM, developed by NASDA, is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments. Noguchi is assigned to mission STS-114 as a mission specialist. Node 2 provides attach locations for the Japanese laboratory, as well as European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. Installation of the module will complete the U.S. Core of the ISS.

  4. KENNEDY SPACE CENTER, FLA. - Astronaut Soichi Noguchi (left), with the National Space Development Agency of Japan (NASDA), points to data on the console during a Multi-Element Integrated Test (MEIT) of the U.S. Node 2 and the Japanese Experiment Module (JEM) in the Space Station Processing Facility. The JEM, developed by NASDA, is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments. Noguchi is assigned to mission STS-114 as a mission specialist. Node 2 provides attach locations for the Japanese laboratory, as well as European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. Installation of the module will complete the U.S. Core of the ISS.

    NASA Image and Video Library

    2003-09-03

    KENNEDY SPACE CENTER, FLA. - Astronaut Soichi Noguchi (left), with the National Space Development Agency of Japan (NASDA), points to data on the console during a Multi-Element Integrated Test (MEIT) of the U.S. Node 2 and the Japanese Experiment Module (JEM) in the Space Station Processing Facility. The JEM, developed by NASDA, is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments. Noguchi is assigned to mission STS-114 as a mission specialist. Node 2 provides attach locations for the Japanese laboratory, as well as European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. Installation of the module will complete the U.S. Core of the ISS.

  5. Principal locations of major-ion, trace-element, nitrate, and Escherichia coli loading to Emigration Creek, Salt Lake County, Utah, October 2005

    USGS Publications Warehouse

    Kimball, Briant A.; Runkel, Robert L.; Walton-Day, Katherine

    2008-01-01

    Housing development and recreational activity in Emigration Canyon have increased substantially since 1980, perhaps causing an observed decrease in water quality of this northern Utah stream located near Salt Lake City. To identify reaches of the stream that contribute to water-quality degradation, a tracer-injection and synoptic-sampling study was done to quantify mass loading of major ions, trace elements, nitrate, and Escherichia coli (E. coli) to the stream. The resulting mass-loading profiles for major ions and trace elements indicate both geologic and anthropogenic inputs to the stream, principally from tributary and spring inflows to the stream at Brigham Fork, Burr Fork, Wagner Spring, Emigration Tunnel Spring, Blacksmith Hollow, and Killyon Canyon. The pattern of nitrate loading does not correspond to the major-ion and trace-element loading patterns. Nitrate levels in the stream did not exceed water-quality standards at the time of synoptic sampling. The majority of nitrate mass loading can be considered related to anthropogenic input, based on the field settings and trends in stable isotope ratios of nitrogen. The pattern of E. coli loading does not correspond to the major-ion, trace-element, or nitrate loading patterns. The majority of E. coli loading was related to anthropogenic sources based on field setting, but a considerable part of the loading also comes from possible animal sources in Killyon Canyon, in Perkins Flat, and in Rotary Park. In this late summer sampling, E. coli concentrations only exceeded water-quality standards in limited sections of the study reach. The mass-loading approach used in this study provides a means to design future studies and to evaluate the loading on a catchment scale.

  6. Identification of a new hybrid serum response factor and myocyte enhancer factor 2-binding element in MyoD enhancer required for MyoD expression during myogenesis.

    PubMed

    L'honore, Aurore; Rana, Vanessa; Arsic, Nikola; Franckhauser, Celine; Lamb, Ned J; Fernandez, Anne

    2007-06-01

    MyoD is a critical myogenic factor induced rapidly upon activation of quiescent satellite cells, and required for their differentiation during muscle regeneration. One of the two enhancers of MyoD, the distal regulatory region, is essential for MyoD expression in postnatal muscle. This enhancer contains a functional divergent serum response factor (SRF)-binding CArG element required for MyoD expression during myoblast growth and muscle regeneration in vivo. Electrophoretic mobility shift assay, chromatin immunoprecipitation, and microinjection analyses show this element is a hybrid SRF- and MEF2 Binding (SMB) sequence where myocyte enhancer factor 2 (MEF2) complexes can compete out binding of SRF at the onset of differentiation. As cells differentiate into postmitotic myotubes, MyoD expression no longer requires SRF but instead MEF2 binding to this dual-specificity element. As such, the MyoD enhancer SMB element is the site for a molecular relay where MyoD expression is first initiated in activated satellite cells in an SRF-dependent manner and then increased and maintained by MEF2 binding in differentiated myotubes. Therefore, SMB is a DNA element with dual and stage-specific binding activity, which modulates the effects of regulatory proteins critical in controlling the balance between proliferation and differentiation.

  7. The neuron-restrictive silencer element: A dual enhancer/silencer crucial for patterned expression of a nicotinic receptor gene in the brain

    PubMed Central

    Bessis, Alain; Champtiaux, Nicolas; Chatelin, Laurent; Changeux, Jean-Pierre

    1997-01-01

    The neuron-restrictive silencer element (NRSE) has been identified in several neuronal genes and confers neuron specificity by silencing transcription in nonneuronal cells. NRSE is present in the promoter of the neuronal nicotinic acetylcholine receptor β2-subunit gene that determines its neuron-specific expression in the nervous system. Using transgenic mice, we show that NRSE may either silence or enhance transcription depending on the cellular context within the nervous system. In vitro in neuronal cells, NRSE activates transcription of synthetic promoters when located downstream in the 5′ untranslated region, or at less than 50 bp upstream from the TATA box, but switches to a silencer when located further upstream. In contrast, in nonneuronal cells NRSE always functions as a silencer. Antisense RNA inhibition shows that the NRSE-binding protein REST contributes to the activation of transcription in neuronal cells. PMID:9159173

  8. GABA acting on GABAB receptors located in a medullary pain facilitatory area enhances nociceptive behaviors evoked by intraplantar formalin injection.

    PubMed

    Martins, Isabel; Carvalho, Paulina; de Vries, Martin G; Teixeira-Pinto, Armando; Wilson, Steven P; Westerink, Ben H C; Tavares, Isaura

    2015-08-01

    The dorsal reticular nucleus (DRt) plays a key role in facilitation of nociceptive transmission at the spinal cord. In this study, we evaluated the mechanisms involved in GABA-mediated control of the DRt focusing on the role of local GABAB receptors. First, we used in vivo microdialysis to study the release of GABA in the DRt during the course of the formalin test. An increase of GABA levels in comparison with baseline values was detected in the second phase of the test. Because we previously showed that GABAB receptors are expressed by opioidergic DRt neurons, which respond to nociceptive stimuli and inhibit spinally projecting DRt neurons involved in descending pronociception, we then interfered with local GABAB receptors using gene transfer and pharmacological approaches. Lentiviral-mediated knockdown of GABAB1a expression decreased nociceptive responses during the second phase of the test. Local administration of the GABAB receptor antagonist CGP 35348 also decreased nociceptive responses in the second phase of the test, whereas the opposite was detected after injection of the GABAB agonist baclofen. Finally, we determined the GABAergic afferents of the DRt, namely those arising from its main brain afferents, which are located at the telencephalon and diencephalon. For that purpose, we combined retrograde tract-tracing from the DRt with immunodetection of glutamate decarboxylase, the GABA-synthesizing enzyme. The higher numbers of retrogradely labelled glutamate decarboxylase-immunoreactive neurons were located at insular, somatosensory, and motor cortices. Collectively, the results suggest that GABA acting on GABAB receptors may enhance pain facilitation from the DRt during inflammatory pain.

  9. A conserved RNA structural element within the hepatitis B virus post-transcriptional regulatory element enhance nuclear export of intronless transcripts and repress the splicing mechanism.

    PubMed

    Visootsat, Akasit; Payungporn, Sunchai; T-Thienprasert, Nattanan P

    2015-12-01

    Hepatitis B virus (HBV) infection is a primary cause of hepatocellular carcinoma and liver cirrhosis worldwide. To develop novel antiviral drugs, a better understanding of HBV gene expression regulation is vital. One important aspect is to understand how HBV hijacks the cellular machinery to export unspliced RNA from the nucleus. The HBV post-transcriptional regulatory element (HBV PRE) has been proposed to be the HBV RNA nuclear export element. However, the function remains controversial, and the core element is unclear. This study, therefore, aimed to identify functional regulatory elements within the HBV PRE and investigate their functions. Using bioinformatics programs based on sequence conservation and conserved RNA secondary structures, three regulatory elements were predicted, namely PRE 1151-1410, PRE 1520-1620 and PRE 1650-1684. PRE 1151-1410 significantly increased intronless and unspliced luciferase activity in both HepG2 and COS-7 cells. Likewise, PRE 1151-1410 significantly elevated intronless and unspliced HBV surface transcripts in liver cancer cells. Moreover, motif analysis predicted that PRE 1151-1410 contains several regulatory motifs. This study reported the roles of PRE 1151-1410 in intronless transcript nuclear export and the splicing mechanism. Additionally, these results provide knowledge in the field of HBV RNA regulation. Moreover, PRE 1151-1410 may be used to enhance the expression of other mRNAs in intronless reporter plasmids.

  10. Enhanced seamount location database for the western and central Pacific Ocean: Screening and cross-checking of 20 existing datasets

    NASA Astrophysics Data System (ADS)

    Allain, Valérie; Kerandel, Julie-Anne; Andréfouët, Serge; Magron, Franck; Clark, Malcolm; Kirby, David S.; Muller-Karger, Frank E.

    2008-08-01

    Seamounts are habitats of considerable interest in terms of conservation and biodiversity, and in terms of fisheries for bentho-pelagic and pelagic species. Twenty previously compiled datasets including seamount/underwater feature lists, bathymetric maps and emerged feature maps from different sources (ship-derived and satellite altimetry-derived) at different spatial scales (from individual cruise to worldwide satellite data) were gathered in order to compile an enhanced list of underwater features for parts of the western and central Pacific Ocean (WCPO). The KL04 dataset [Kitchingman, A., and Lai, S., 2004. Inferences on potential seamount locations from mid-resolution bathymetric data. Fisheries Centre Research Reports 12 (5), 7-12], listing seamount positions and depths as calculated from satellite altimetry-derived bathymetry, provided the baseline data for this study as it covered the entire region of interest and included summit depth information. All KL04 potential seamounts were cross-checked with other datasets to remove any atolls and islands that had been incorrectly classified as seamounts, to add seamounts undetected by KL04, to update the overall database (geolocation, depth, elevation, and name) and to compile a 12-class typology of the different types of underwater features. Of the 4626 potential seamounts identified in KL04, 719 were multiple identifications of the same large underwater features and 373 (10%) were actually emerged banks, atolls and islands, leaving 3534 actual underwater features. Conversely, 487 underwater features were documented in other datasets but not registered by KL04. The screening of all the potential WCPO seamounts produced a final list of 4021 underwater features with agreed upon position and information. This enhanced list should have many applications in oceanography, biodiversity conservation and studies of the influence of seamounts on pelagic ecosystems and fisheries.

  11. Recognition of enhancer element-specific histone methylation by TIP60 in transcriptional activation

    PubMed Central

    Jeong, Kwang Won; Kim, Kyunghwan; Situ, Alan Jialun; Ulmer, Tobias S.; An, Woojin; Stallcup, Michael R.

    2011-01-01

    Many coregulator proteins are recruited by DNA-bound transcription factors to remodel chromatin and activate transcription. However, mechanisms for coordinating actions of multiple coregulator proteins are poorly understood. We demonstrate that multiple protein-protein interactions by protein acetyltransferase TIP60 are required for estrogen-induced transcription of a subset of estrogen receptor (ER) α target genes in human cells. Estrogen-induced recruitment of TIP60 requires direct binding of TIP60 to ERα and the action of chromatin remodeling ATPase BRG1, leading to increased recruitment of histone methyltransferase MLL1 and increased monomethylation of histone H3 at Lys4. TIP60 recruitment also requires preferential binding of the TIP60 chromodomain to histone H3 containing monomethylated Lys4, which marks active and poised enhancer elements. After recruitment, TIP60 increases acetylation of histone H2A at Lys5. Thus, complex cooperation of TIP60 with ERα and other chromatin remodeling enzymes is required for estrogen-induced transcription. PMID:22081016

  12. Structural and functional characterization of a transcription-enhancing sequence element in the rbcL gene of the Chlamydomonas chloroplast genome.

    PubMed

    Anthonisen, Inger Lill; Kasai, Seitaro; Kato, Ko; Salvador, Maria Luisa; Klein, Uwe

    2002-08-01

    The structure and function of a transcription-enhancing sequence element in the coding region of the Chlamydomonas reinhardtii rbcL gene was analyzed in Chlamydomonas chloroplast transformants in vivo. The enhancer sequence is contained within a DNA segment extending from position +108 to position +143, relative to the start site of rbcL gene transcription. The sequence remains functional when inverted or when placed 34 bp closer to or 87 bp further downstream of the basic rbcL promoter. However, it does not function from a site about 250 bp downstream of its original location. Besides promoting transcription initiation from the rbcL promoter, the element is able to augment transcription from the promoter of the Chlamydomonas chloroplast atpB gene, but has an inhibitory effect on transcription from the promoter of the chloroplast ribosomal RNA genes. The results suggest that the enhancer-like sequence acts upon transcription initiation in a position-specific and promoter type-specific manner.

  13. Coordinately Co-opted Multiple Transposable Elements Constitute an Enhancer for wnt5a Expression in the Mammalian Secondary Palate

    PubMed Central

    Kimura-Yoshida, Chiharu; Yan, Kuo; Bormuth, Olga; Ding, Qiong; Nakanishi, Akiko; Sasaki, Takeshi; Hirakawa, Mika; Sumiyama, Kenta; Furuta, Yasuhide; Tarabykin, Victor; Matsuo, Isao; Okada, Norihiro

    2016-01-01

    Acquisition of cis-regulatory elements is a major driving force of evolution, and there are several examples of developmental enhancers derived from transposable elements (TEs). However, it remains unclear whether one enhancer element could have been produced via cooperation among multiple, yet distinct, TEs during evolution. Here we show that an evolutionarily conserved genomic region named AS3_9 comprises three TEs (AmnSINE1, X6b_DNA and MER117), inserted side-by-side, and functions as a distal enhancer for wnt5a expression during morphogenesis of the mammalian secondary palate. Functional analysis of each TE revealed step-by-step retroposition/transposition and co-option together with acquisition of a binding site for Msx1 for its full enhancer function during mammalian evolution. The present study provides a new perspective suggesting that a huge variety of TEs, in combination, could have accelerated the diversity of cis-regulatory elements involved in morphological evolution. PMID:27741242

  14. Earthworm Activity and the Potential for Enhanced Leaching of Inorganic Elements in Soils

    NASA Astrophysics Data System (ADS)

    Gruau, G.; Ablain, F.; Cluzeau, D.

    2002-12-01

    The potential influence of earthworms on the mobility of soil inorganic constituents was experimentally investigated. Six 20 cm long and 15 cm i.d. columns were packed with soil (loamy material, Paris basin, France). Three earthworm specimens - Lombricus terrestris - were introduced into 3 of the 6 columns (earthworm treatment or ET), the remaing 3 being used to study changes in water composition and solute fluxes without earthworms (control treatment or CT). The 6 columns were operated for 8 weeks and were subjected to 100 ml addition of distilled water at 1, 8, 15, 22, 29, 36, 43 and 50 days. Effluents were collected weekly, filtered and analysed for their Dissolved Organic Carbon (DOC) as well as Si, Na, K, Mg, Ca, Fe, Mn, Al, Sr, Ba, Cu, Zn, Cr, Cd, REE and U concentrations. Replicates yielded extremely consistent results, with standard deviations generally lower than 10%. Effluent volumes were greatest during ET simulations (28% difference on a cumulative basis), which can be attributed to the construction by Lombricus terrestris of permanent vertical burrows into the soil columns. Different temporal chemical trends were observed depending on whether earthworms were present or not. During ET simulations, a washout phenomenon occurred for DOC, Ca, Mg, Fe, Ba, Sr, Cu and U during the startup outflow period (week 2). This washout was followed by a period of apparent equilibrium with concentrations in ET effluents remaining roughly constant for all solutes except REE, Zn and to a lesser extent Mn. No such washout nor equilibrium period was observed during CT simulations. Instead, concentrations in Ca, Mg, Fe, Ba, Sr, Cr and Cu decreased from week 2 to week 8, while those in other solutes increased from week 2 to week 5, then declining untill week 8. For many elements (not all), final (equilibrium?) concentrations (8 weeks simulation) were highest in ET effluents (e.g. 17% higher for Ca and Na; 30% higher for Zn), despite the enhanced infiltration rate (and thus

  15. Understanding rhizosphere processes to enhance phytoextraction of germanium and rare earth elements

    NASA Astrophysics Data System (ADS)

    Wiche, Oliver

    2017-04-01

    Germanium (Ge) and rare earth elements (REEs) are economically valuable raw materials that are not actually rare in terms of concentrations in soils but they are hardly available for plant uptake due to interactions with organic matter (SOM), secondary soil constituents such as Fe/Mn oxides and P bearing soil fractions. Processes in the rhizosphere might influence availability of Ge and REEs in the soil-plant system, since lowering of the pH and presence of carboxylates and siderophores (small molecules that strongly chelate Fe and other elements) strongly influences the chemical speciation of Ge and REEs in soil and consequently this comprehensive knowledge helps us to improve phytomining. In a series of field and greenhouse experiments 16 plant species from the functional groups of grasses, herbs and legumes were tested with regard to their accumulation efficiency of Ge and REEs in shoots. Subsequently, we conducted mixed culture experiments in which inefficient species (e.g. cereals like Avena sativa, Hordeum vulgare, Panicum miliaceum) were cultivated in mixed cultures with efficient species (Lupinus albus, Lupinus angustifolius). Based on the plant concentrations a principal component analysis (PCA) was performed to identify significant factors that explain the accumulation behavior of different plant species with regard to Ge, REEs, Si, Fe and Mn. In this analysis Mn was used to identify plant species with efficient mechanisms to access sparingly available P-resources in soils. Particularly in nonmycorrhizal species concentrations of Mn in leaves often indicate a carboxylate based P-mobilising strategy. Herbaceous plant species accumulated significantly higher amounts of REEs while grasses accumulated significantly higher amounts of Ge. Concentrations of Ge in shoots of grasses correlated significantly positive with Si, but negatively with concentrations of Mn. Indeed, the results of the PCA clearly show that plants with high Mn concentrations tend to have

  16. Finite Element Method Simulations of the Near-Field Enhancement at the Vicinity of Fractal Rough Metallic Surfaces

    SciTech Connect

    Micic, Miodrag; Klymyshyn, Nicholas A.; Lu, H PETER.

    2004-03-04

    Near-field optical enhancement at metal surfaces and methods such as surface plasmon resonance (SPR), surface-enhanced Raman scattering (SERS), fluorescent quenching and enhancement, and various near-field scanning microscopies (NSOM) all depend on a metals surface properties, mainly on its morphology and SPR resonant frequency. We report on simulations of the influence of different surface morphologies on electromagnetic field enhancements at the rough surfaces of noble metals and also evaluate the optimal conditions for the generation of a surface-enhanced Raman signal of absorbed species on a metallic substrate. All simulations were performed with a classical electrodynamics approach using the full set of Maxwells equations, which were solved with the three-dimensional finite element method (FEM). Two different classes of surfaces where modeled using fractals, representing diffusion limited aggregation growth dendritic structures, such as one on the surface of electrodes, and second one representing the sponge-like structure used to model surfaces of particles with high porosity, such as metal coated catalyst supports. The simulations depict the high inhomogeneity of an enhanced electromagnetic field as both a field enhancement and field attenuation near the surface. While the diffusion limited aggregation dendritical fractals enhanced the near-field electromagnetic field, the sponge fractals significantly reduced the local electromagnetic field intensity. Moreover, the fractal orders of the fractal objects did not significantly alter the total enhancement, and the distribution of a near-field enhancement was essentially invariant to the changes in the angle of an incoming laser beam.

  17. In situ detection of a heat-shock regulatory element binding protein using a soluble synthetic enhancer sequence.

    PubMed Central

    Harel-Bellan, A; Brini, A T; Ferris, D K; Robin, P; Farrar, W L

    1989-01-01

    In various studies, enhancer binding proteins have been successfully absorbed out by competing sequences inserted into plasmids, resulting in the inhibition of the plasmid expression. Theoretically, such a result could be achieved using synthetic enhancer sequences not inserted into plasmids. In this study, a double stranded DNA sequence corresponding to the human heat shock regulatory element was chemically synthesized. By in vitro retardation assays, the synthetic sequence was shown to bind specifically a protein in extracts from the human T cell line Jurkat. When the synthetic enhancer was electroporated into Jurkat cells, not only the enhancer was shown to remain undegraded into the cells for up to 2 days, but also it was shown to bind intracellularly a protein. The binding was specific and was modulated upon heat shock. Furthermore, the binding protein was shown to be of the expected molecular weight by UV crosslinking. However, when the synthetic enhancer element was co-electroporated with an HSP 70-CAT reporter construct, the expression of the reporter plasmid was consistently enhanced in the presence of the exogenous synthetic enhancer. Images PMID:2740211

  18. The enhanced locating performance of an integrated cross-correlation and genetic algorithm for radio monitoring systems.

    PubMed

    Chang, Yao-Tang; Wu, Chi-Lin; Cheng, Hsu-Chih

    2014-04-24

    The rapid development of wireless broadband communication technology has affected the location accuracy of worldwide radio monitoring stations that employ time-difference-of-arrival (TDOA) location technology. In this study, TDOA-based location technology was implemented in Taiwan for the first time according to International Telecommunications Union Radiocommunication (ITU-R) recommendations regarding monitoring and location applications. To improve location accuracy, various scenarios, such as a three-dimensional environment (considering an unequal locating antenna configuration), were investigated. Subsequently, the proposed integrated cross-correlation and genetic algorithm was evaluated in the metropolitan area of Tainan. The results indicated that the location accuracy at a circular error probability of 50% was less than 60 m when a multipath effect was present in the area. Moreover, compared with hyperbolic algorithms that have been applied in conventional TDOA-based location systems, the proposed algorithm yielded 17-fold and 19-fold improvements in the mean difference when the location position of the interference station was favorable and unfavorable, respectively. Hence, the various forms of radio interference, such as low transmission power, burst and weak signals, and metropolitan interference, was proved to be easily identified, located, and removed.

  19. The Enhanced Locating Performance of an Integrated Cross-Correlation and Genetic Algorithm for Radio Monitoring Systems

    PubMed Central

    Chang, Yao-Tang; Wu, Chi-Lin; Cheng, Hsu-Chih

    2014-01-01

    The rapid development of wireless broadband communication technology has affected the location accuracy of worldwide radio monitoring stations that employ time-difference-of-arrival (TDOA) location technology. In this study, TDOA-based location technology was implemented in Taiwan for the first time according to International Telecommunications Union Radiocommunication (ITU-R) recommendations regarding monitoring and location applications. To improve location accuracy, various scenarios, such as a three-dimensional environment (considering an unequal locating antenna configuration), were investigated. Subsequently, the proposed integrated cross-correlation and genetic algorithm was evaluated in the metropolitan area of Tainan. The results indicated that the location accuracy at a circular error probability of 50% was less than 60 m when a multipath effect was present in the area. Moreover, compared with hyperbolic algorithms that have been applied in conventional TDOA-based location systems, the proposed algorithm yielded 17-fold and 19-fold improvements in the mean difference when the location position of the interference station was favorable and unfavorable, respectively. Hence, the various forms of radio interference, such as low transmission power, burst and weak signals, and metropolitan interference, was proved to be easily identified, located, and removed. PMID:24763254

  20. Blue eye color in humans may be caused by a perfectly associated founder mutation in a regulatory element located within the HERC2 gene inhibiting OCA2 expression.

    PubMed

    Eiberg, Hans; Troelsen, Jesper; Nielsen, Mette; Mikkelsen, Annemette; Mengel-From, Jonas; Kjaer, Klaus W; Hansen, Lars

    2008-03-01

    The human eye color is a quantitative trait displaying multifactorial inheritance. Several studies have shown that the OCA2 locus is the major contributor to the human eye color variation. By linkage analysis of a large Danish family, we finemapped the blue eye color locus to a 166 Kbp region within the HERC2 gene. By association analyses, we identified two SNPs within this region that were perfectly associated with the blue and brown eye colors: rs12913832 and rs1129038. Of these, rs12913832 is located 21.152 bp upstream from the OCA2 promoter in a highly conserved sequence in intron 86 of HERC2. The brown eye color allele of rs12913832 is highly conserved throughout a number of species. As shown by a Luciferase assays in cell cultures, the element significantly reduces the activity of the OCA2 promoter and electrophoretic mobility shift assays demonstrate that the two alleles bind different subsets of nuclear extracts. One single haplotype, represented by six polymorphic SNPs covering half of the 3' end of the HERC2 gene, was found in 155 blue-eyed individuals from Denmark, and in 5 and 2 blue-eyed individuals from Turkey and Jordan, respectively. Hence, our data suggest a common founder mutation in an OCA2 inhibiting regulatory element as the cause of blue eye color in humans. In addition, an LOD score of Z = 4.21 between hair color and D14S72 was obtained in the large family, indicating that RABGGTA is a candidate gene for hair color.

  1. The influence of contact ratio and its location on the primary stability of cementless total hip arthroplasty: A finite element analysis.

    PubMed

    Reimeringer, M; Nuño, N

    2016-05-03

    Cementless hip stems are fixed to the surrounding bone by means of press-fit. To ensure a good press-fit, current surgical technique specifies an under-reaming of the bone cavity using successively larger broaches. Nevertheless, this surgical technique is inaccurate. Several studies show that the contact ratio (percentage of stem interface in contact with bone) achieved after surgery can vary between 20% and 95%. Therefore, this study aimed to investigate the influence of the contact ratio and its location on the primary stability of a cementless total hip arthroplasty using finite element analysis. A straight tapered femoral stem implanted in a composite bone was subjected to stair climbing. Micromotion of 7600 nodes at the stem-bone interface was computed for different configurations of contact ratios between 2% and 98%) along the hip stem. Considering the 15 configurations evaluated, the average micromotion ranges between 27μm and 54μm. The percentage of the porous interface of the stem having micromotion below 40μm that allows bone ingrowth range between 25-57%. The present numerical study shows that full contact (100%) between stem and bone is not necessary to obtain a good primary stability. The stem primary stability is influenced by both the contact ratio and its location. Several configurations with contact ratio lower than 100% and involving either the proximal or the cortical contact provide better primary stability than the full contact configuration. However, with contact ratio lower than 40%, the stem should be in contact with cortical bone to ensure a good primary stability.

  2. A Novel Four-Node Quadrilateral Smoothing Element for Stress Enhancement and Error Estimation

    NASA Technical Reports Server (NTRS)

    Tessler, A.; Riggs, H. R.; Dambach, M.

    1998-01-01

    A four-node, quadrilateral smoothing element is developed based upon a penalized-discrete-least-squares variational formulation. The smoothing methodology recovers C1-continuous stresses, thus enabling effective a posteriori error estimation and automatic adaptive mesh refinement. The element formulation is originated with a five-node macro-element configuration consisting of four triangular anisoparametric smoothing elements in a cross-diagonal pattern. This element pattern enables a convenient closed-form solution for the degrees of freedom of the interior node, resulting from enforcing explicitly a set of natural edge-wise penalty constraints. The degree-of-freedom reduction scheme leads to a very efficient formulation of a four-node quadrilateral smoothing element without any compromise in robustness and accuracy of the smoothing analysis. The application examples include stress recovery and error estimation in adaptive mesh refinement solutions for an elasticity problem and an aerospace structural component.

  3. A gene-type-specific enhancer regulates the carbamyl phosphate synthetase I promoter by cooperating with the proximal GAG activating element.

    PubMed Central

    Goping, I S; Lamontagne, S; Shore, G C; Nguyen, M

    1995-01-01

    The rat carbamyl phosphate synthetase I gene is expressed in two cell types: hepatocytes and epithelial cells of the intestinal mucosa. The proximal promoter contains a single activating element, GAG, two repressor elements (sites I and III) and an anti-repressor element (site II). Although these elements together exhibit the potential for complex regulation, they are unable to confer tissue-specific promoter activity. Here we have identified a cell-type-specific enhancer that lies 10 kilobases upstream of the promoter. Unexpectedly, the enhancer also functioned in a gene-type-specific manner. The enhancer stimulated promoter activity exclusively through the proximal GAG element. Abrogation of GAG, either directly by mutation of GAG or indirectly by sites I and III repressors, abolished enhancer activation. Conversely, activation of the heterologous thymidine kinase promoter by the enhancer required the introduction of GAG. The requirement for GAG, therefore, functions to constrain the enhancer to a specific target promoter. PMID:7784176

  4. A zinc-dependent DNA-binding activity co-operates with cAMP-responsive-element-binding protein to activate the human thyroglobulin enhancer.

    PubMed Central

    Berg, V; Vassart, G; Christophe, D

    1997-01-01

    Footprinting experiments involving the human thyroglobulin gene enhancer and thyroid nuclear extracts revealed a protected region called X2, containing an incomplete cAMP-responsive element (CRE). Band-shift experiments identified two binding activities recognizing the X2 element: a CRE-binding protein (CREB)/activating transcription factor (ATF) relative that binds the half CRE motif and a second factor that interacts with a G-rich motif located just upstream from the CRE. The first factor appears to be CREB itself, as indicated by the supershifting when using an antibody directed against CREB, and the second DNA-binding activity involved was shown to be zinc-dependent and exhibited an apparent molecular mass of 42-44 kDa in South-Western blotting experiments. This factor may represent a novel entity, which we named CAF, for 'CREB Associated Factor'. Three copies of X2 sequence conferred a strong cAMP-dependent transcriptional activation to a heterologous promoter in transient transfection assay in cAMP-stimulated primary thyrocytes and HeLa cells. Transfection experiments of constructs containing the X2 element mutated in either the CRE or the G-rich site showed that both motifs were required for this transcription activating function. Moreover, the combination of several individual X2 elements mutated in either the CRE or the G-rich motif did not exhibit full transcriptional activity. This suggests that, in the context of the X2 element, CREB requires a close interaction with CAF to achieve both basal and cAMP-dependent transcriptional activation. PMID:9163323

  5. Teacher Self-Efficacy Enhancement and School Location: Implication for Students' Achievement in Economics in Senior Secondary School in Ibadan, Oyo State, Nigeria

    ERIC Educational Resources Information Center

    Durowoju, Esther O.; Onuka, Adams O. U.

    2015-01-01

    The paper investigated the effect of teacher self-efficacy enhancement and school location on students' achievement in Economics in Senior Secondary School in Ibadan Metropolis of Oyo State, Nigeria. Three hypotheses were tested at 0.05 level of significance. Multi-stage sampling technique was adopted in the study. Four Local Government Areas (two…

  6. A Mammalian Conserved Element Derived from SINE Displays Enhancer Properties Recapitulating Satb2 Expression in Early-Born Callosal Projection Neurons

    PubMed Central

    Nakanishi, Akiko; Sasaki, Takeshi; Yan, Kuo; Tarabykin, Victor; Vigier, Lisa; Sumiyama, Kenta; Hirakawa, Mika; Nishihara, Hidenori; Pierani, Alessandra; Okada, Norihiro

    2011-01-01

    Short interspersed repetitive elements (SINEs) are highly repeated sequences that account for a significant proportion of many eukaryotic genomes and are usually considered “junk DNA”. However, we previously discovered that many AmnSINE1 loci are evolutionarily conserved across mammalian genomes, suggesting that they may have acquired significant functions involved in controlling mammalian-specific traits. Notably, we identified the AS021 SINE locus, located 390 kbp upstream of Satb2. Using transgenic mice, we showed that this SINE displays specific enhancer activity in the developing cerebral cortex. The transcription factor Satb2 is expressed by cortical neurons extending axons through the corpus callosum and is a determinant of callosal versus subcortical projection. Mouse mutants reveal a crucial function for Sabt2 in corpus callosum formation. In this study, we compared the enhancer activity of the AS021 locus with Satb2 expression during telencephalic development in the mouse. First, we showed that the AS021 enhancer is specifically activated in early-born Satb2+ neurons. Second, we demonstrated that the activity of the AS021 enhancer recapitulates the expression of Satb2 at later embryonic and postnatal stages in deep-layer but not superficial-layer neurons, suggesting the possibility that the expression of Satb2 in these two subpopulations of cortical neurons is under genetically distinct transcriptional control. Third, we showed that the AS021 enhancer is activated in neurons projecting through the corpus callosum, as described for Satb2+ neurons. Notably, AS021 drives specific expression in axons crossing through the ventral (TAG1−/NPY+) portion of the corpus callosum, confirming that it is active in a subpopulation of callosal neurons. These data suggest that exaptation of the AS021 SINE locus might be involved in enhancement of Satb2 expression, leading to the establishment of interhemispheric communication via the corpus callosum, a eutherian

  7. An isolation-enhanced quad-element antenna using suspended solid wires for LTE small-cell base stations

    NASA Astrophysics Data System (ADS)

    Chen, Yen-Sheng; Zhou, Huang-Cheng

    2017-05-01

    This paper presents a multiple-input-multiple-output (MIMO) antenna that has four-unit elements enabled by an isolation technique for long-term evolution (LTE) small-cell base stations. While earlier studies on MIMO base-station antennas cope with either a lower LTE band (698-960 MHz) or an upper LTE band (1710-2690 MHz), the proposed antenna meets the full LTE specification, yet it uses the maximum number of unit elements to increase channel capacity. The antenna configuration is optimized for good impedance matching and high radiation efficiency. In particular, as the spacing between unit elements is so small that severe mutual coupling occurs, we propose a simple structure with extremely low costs to enhance the isolation. By using suspended solid wires interconnecting the position having strong coupled current of two adjacent elements, an isolation enhancement of 37 dB is achieved. Although solid wires inherently aim at direct-current applications, this work successfully employs such a low-cost technique to microwave antenna development. Experimental results have validated the design guidelines and the proposed configuration, showing that antenna performances including impedance matching, isolation, radiation features, signal correlation, and channel capacity gain are highly desired for LTE small-cell base stations.

  8. Genetic variation in T-box binding element functionally affects SCN5A/SCN10A enhancer.

    PubMed

    van den Boogaard, Malou; Wong, L Y Elaine; Tessadori, Federico; Bakker, Martijn L; Dreizehnter, Lisa K; Wakker, Vincent; Bezzina, Connie R; 't Hoen, Peter A C; Bakkers, Jeroen; Barnett, Phil; Christoffels, Vincent M

    2012-07-01

    The contraction pattern of the heart relies on the activation and conduction of the electrical impulse. Perturbations of cardiac conduction have been associated with congenital and acquired arrhythmias as well as cardiac arrest. The pattern of conduction depends on the regulation of heterogeneous gene expression by key transcription factors and transcriptional enhancers. Here, we assessed the genome-wide occupation of conduction system-regulating transcription factors TBX3, NKX2-5, and GATA4 and of enhancer-associated coactivator p300 in the mouse heart, uncovering cardiac enhancers throughout the genome. Many of the enhancers colocalized with ion channel genes repressed by TBX3, including the clustered sodium channel genes Scn5a, essential for cardiac function, and Scn10a. We identified 2 enhancers in the Scn5a/Scn10a locus, which were regulated by TBX3 and its family member and activator, TBX5, and are functionally conserved in humans. We also provided evidence that a SNP in the SCN10A enhancer associated with alterations in cardiac conduction patterns in humans disrupts TBX3/TBX5 binding and reduces the cardiac activity of the enhancer in vivo. Thus, the identification of key regulatory elements for cardiac conduction helps to explain how genetic variants in noncoding regulatory DNA sequences influence the regulation of cardiac conduction and the predisposition for cardiac arrhythmias.

  9. The upstream muscle-specific enhancer of the rat muscle creatine kinase gene is composed of multiple elements.

    PubMed Central

    Horlick, R A; Benfield, P A

    1989-01-01

    A series of constructs that links the rat muscle creatine kinase promoter to the bacterial chloramphenicol acetyltransferase gene was generated. These constructs were introduced into differentiating mouse C2C12 myogenic cells to localize sequences that are important for up-regulation of the creatine kinase gene during myogenic differentiation. A muscle-specific enhancer element responsible for induction of chloramphenicol acetyltransferase expression during myogenesis was localized to a 159-base-pair region from 1,031 to 1,190 base pairs upstream of the transcription start site. Analysis of transient expression experiments using promoters mutated by deletion indicated the presence of multiple functional domains within this muscle-specific regulatory element. A DNA fragment spanning this region was used in DNase I protection experiments. Nuclear extracts derived from C2 myotubes protected three regions (designated E1, E2, and E3) on this fragment from digestion, which indicated there may be three or more trans-acting factors that interact with the creatine kinase muscle enhancer. Gel retardation assays revealed that factors able to bind specifically to E1, E2, and E3 are present in a wide variety of tissues and cell types. Transient expression assays demonstrated that elements in regions E1 and E3, but not necessarily E2, are required for full enhancer activity. Images PMID:2761536

  10. Accumulation of antimony and other potentially toxic elements in plants around a former antimony mine located in the Ribes Valley (Eastern Pyrenees)

    NASA Astrophysics Data System (ADS)

    Bech, Jaume; Corrales, Isabel; Duran, Paola; Roca, Núria; Tume, Pedro; Barceló, Juan; Poschenrieder, Charlotte

    2010-05-01

    Soil contamination by antimony is of increasing environmental concern due to the use of this amphoterous p-block element in many industrial applications such as flame retardant, electronics, alloys, rubber and textile industries. However, little is still known about the response of plants to antimony. Here we report on the accumulation of antimony and other potentially toxic elements (mainly As, Pb and Cu) in plants growing around a former antimony mine in the ribes Valley located in the Eastern Pyrenees (424078E, 4686100N alt. 1145 m.a.s.l) that was operating approximately between the years 1870 to 1960. The ore mineral veins are included in quartz gangue. The main ores were: Sulphides: Stibnite (Sb2S3), Pyrite (FeS2), Sphalerite (ZnS), Arsenopyrite (FeAs), Galenite (PbS), Chalcopyrite (CuFeS2), Tetrahydrite (Cu5Sb2S3). Sulphosals: Boulangerite (5PbS•2Sb2S3), Jamesonite (4PbS•FeS•3Sb2S3), Zinckenite (6PbS•7Sb2S3), Plagionite (5PbS•4Sb2S3), Bournonite PbCu (Sb,As)S3, Pyrargirite (Ag3SbS3). Soil and plant samples were taken at five locations with different levels of Sb, As, and polymetallic contamination. Both pseudototal (aqua regia soluble) and extractable (EDTA) concentrations of metals from sites with low (sites 1 and 2), moderate (site 3 and 4) and high (sites 5 and 6) pollutant burdens were studied. The range of agua regia and EDTA values in mgkg-1 is as follows: Sb 8-2904 and 0.88-44; As: 33-16186 and 3.2-167; Pb: 79-4794 and 49-397; Cu: 66-712 and 48-56 mg•kg-1, respectively). While sites 1 to 4 had alkaline soil pH (7.4-8.7), sites 5 and 6 were acidic with values of 6 and 4.6, respectively. Different herbaceous plant species (Poa annua, Echium vulgare, Sonchus asper, Barbera verna among others) at the low and moderately polluted sites were able to efficiently restrict Sb and As transport to shoots showing average concentration ranges between 5.5 and 23 mg/kg As and 1.21 mg/kg and 4.9 mg/kg Sb. However, at the highly polluted acidic sites (5 and

  11. A proposed method for enhanced eigen-pair extraction using finite element methods: Theory and application

    NASA Technical Reports Server (NTRS)

    Jara-Almonte, J.; Mitchell, L. D.

    1988-01-01

    The paper covers two distinct parts: theory and application. The goal of this work was the reduction of model size with an increase in eigenvalue/vector accuracy. This method is ideal for the condensation of large truss- or beam-type structures. The theoretical approach involves the conversion of a continuum transfer matrix beam element into an 'Exact' dynamic stiffness element. This formulation is implemented in a finite element environment. This results in the need to solve a transcendental eigenvalue problem. Once the eigenvalue is determined the eigenvectors can be reconstructed with any desired spatial precision. No discretization limitations are imposed on the reconstruction. The results of such a combined finite element and transfer matrix formulation is a much smaller FEM eigenvalue problem. This formulation has the ability to extract higher eigenvalues as easily and as accurately as lower eigenvalues. Moreover, one can extract many more eigenvalues/vectors from the model than the number of degrees of freedom in the FEM formulation. Typically, the number of eigenvalues accurately extractable via the 'Exact' element method are at least 8 times the number of degrees of freedom. In contrast, the FEM usually extracts one accurate (within 5 percent) eigenvalue for each 3-4 degrees of freedom. The 'Exact' element results in a 20-30 improvement in the number of accurately extractable eigenvalues and eigenvectors.

  12. Measurements of atmospheric elemental and oxidized mercury and dry deposition to a surrogate surface at a coastal estuary location in Central California

    NASA Astrophysics Data System (ADS)

    Cook, D.; Weiss-Penzias, P. S.; Flegal, A. R.; Paytan, A.; Gustin, M. S.

    2009-12-01

    Atmospheric deposition is recognized as a potentially major source of mercury (Hg) to aquatic ecosystems. Hg deposition occurs with precipitation (wet), but also without precipitation (dry) mainly due to the high surface reactivity of the various species of gaseous oxidized mercury (GOM) (HgCl2, HgBr2, HgO, etc.). In some areas where rainfall is sparse or seasonal, dry deposition can be the dominant mechanism of removal of atmospheric Hg and a potential source to aquatic systems. As part of a larger study to quantify inputs of total Hg and monomethyl mercury sources to estuaries along the West Coast of the U.S., the objective of these measurements was to evaluate the atmospheric component of Hg input in order to construct an Hg mass balance for these locations. Measurements of gaseous elemental Hg (GEM), GOM, and deposition of GOM were carried out during the fall of 2009 at Elkhorn Slough on the Monterey Bay, Central California. GEM and GOM were measured with a Tekran 2537/1130 automated system and GOM deposition was measured by deploying a novel passive technique which involves collecting and analyzing ion-exchange membranes for total Hg. These membranes have been shown to take up and retain GOM and not GEM, thereby providing an estimate of dry deposition without the use of micrometeorological models. In this work, preliminary data will be presented and compared with other available data for the region to assess the importance of Hg dry deposition on total Hg input to Elkhorn Slough.

  13. Genetic and biochemical analysis of cis regulatory elements within the keratinocyte enhancer region of the human papillomavirus type 31 upstream regulatory region during different stages of the viral life cycle.

    PubMed

    Sen, Ellora; Alam, Samina; Meyers, Craig

    2004-01-01

    Using linker scanning mutational analysis, we recently identified potential cis regulatory elements contained within the 5' upstream regulatory region (URR) domain and auxiliary enhancer (AE) region of the human papillomavirus type 31 (HPV31) URR involved in the regulation of E6/E7 promoter activity at different stages of the viral life cycle. For the present study, we extended the linker scanning mutational analysis to identify potential cis elements located in the keratinocyte enhancer (KE) region (nucleotides 7511 to 7762) of the HPV31 URR and to characterize cellular factors that bind to these elements under conditions representing different stages of the viral life cycle. The linker scanning mutational analysis identified viral cis elements located in the KE region that regulate transcription in the presence and absence of any viral gene products or viral DNA replication and determine the role of host tissue differentiation on viral transcriptional regulation. Using electrophoretic mobility shift assays, we illustrated defined reorganization in the composition of cellular transcription factors binding to the same cis regulatory elements at different stages of the HPV differentiation-dependent life cycle. Our studies provide an extensive map of functional elements in the KE region of the HPV31 URR, identify cis regulatory elements that exhibit significant transcription regulatory potential, and illustrate changes in specific protein-DNA interactions at different stages of the viral life cycle. The variable recruitment of transcription factors to the same cis element under different cellular conditions may represent a mechanism underlying the tight link between keratinocyte differentiation and E6/E7 expression.

  14. Negative regulatory element associated with potentially functional promoter and enhancer elements in the long terminal repeats of endogenous murine leukemia virus-related proviral sequences

    SciTech Connect

    Ch'ang, L.Y.; Yang, W.K.; Myer, F.E.; Yang, D.M.

    1989-06-01

    Three series of recombinant DNA clones were constructed, with the bacterial chloramphenical acetyltransferase (CAT) gene as a quantitative indicator, to examine the activities of promoter and enhancer sequence elements in the 5' long terminal repeat (LTR) of murine leukemia virus (MuLV)-related proviral sequences isolated from the mouse genome. Transient CAT expression was determined in mouse NIH 3T3, human HT1080, and mink CCL64 cultured cells transfected with the LTR-CAT constructs. The 700-base pair (bp) LTRs of three polytropic MuLV-related proviral clones and the 750-bp LTRs of four modified polytropic proviral clones, in complete structures either with or without the adjacent downstream sequences, all showed very little or negligible activities for CAT expression, while ecotropic MuLV LTRs were highly active. The MuLV-related LTRs were divided into three portions and examined separately. The 3' portion of the MuLV-related LTRs that contains the CCAAC and TATAA boxes was found to be a functional promoter, being about one-half to one-third as active as the corresponding portion of the ecotropic MuLV LTRs. A MboI-Bg/II fragment, representing the distinct 190- to 200-pb inserted segment in the middle, was found to be a potential enhancer, especially when examined in combination with the simian virus 40 promoter in CCL64 cells. A PstI-MboI fragment of the 5' portion, which contains the protein-binding motifs on the enhancer segment as well as the upstream LTF sequences, showed moderate enhancer activities in CCL6 cells but was virtually inactive in NIH 3T3 cells and HT1080 cells; addition of this fragment to the ecotropic LTR-CAT constructs depressed CAT expression.

  15. Expression of zebrafish pax6b in pancreas is regulated by two enhancers containing highly conserved cis-elements bound by PDX1, PBX and PREP factors.

    PubMed

    Delporte, François M; Pasque, Vincent; Devos, Nathalie; Manfroid, Isabelle; Voz, Marianne L; Motte, Patrick; Biemar, Frédéric; Martial, Joseph A; Peers, Bernard

    2008-05-16

    PAX6 is a transcription factor playing a crucial role in the development of the eye and in the differentiation of the pancreatic endocrine cells as well as of enteroendocrine cells. Studies on the mouse Pax6 gene have shown that sequences upstream from the P0 promoter are required for expression in the lens and the pancreas; but there remain discrepancies regarding the precise location of the pancreatic regulatory elements. Due to genome duplication in the evolution of ray-finned fishes, zebrafish has two pax6 genes, pax6a and pax6b. While both zebrafish pax6 genes are expressed in the developing eye and nervous system, only pax6b is expressed in the endocrine cells of the pancreas. To investigate the cause of this differential expression, we used a combination of in silico, in vivo and in vitro approaches. We show that the pax6b P0 promoter targets expression to endocrine pancreatic cells and also to enteroendocrine cells, retinal neurons and the telencephalon of transgenic zebrafish. Deletion analyses indicate that strong pancreatic expression of the pax6b gene relies on the combined action of two conserved regulatory enhancers, called regions A and C. By means of gel shift assays, we detected binding of the homeoproteins PDX1, PBX and PREP to several cis-elements of these regions. In constrast, regions A and C of the zebrafish pax6a gene are not active in the pancreas, this difference being attributable to sequence divergences within two cis-elements binding the pancreatic homeoprotein PDX1. Our data indicate a conserved role of enhancers A and C in the pancreatic expression of pax6b and emphasize the importance of the homeoproteins PBX and PREP cooperating with PDX1, in activating pax6b expression in endocrine pancreatic cells. This study also provides a striking example of how adaptative evolution of gene regulatory sequences upon gene duplication progressively leads to subfunctionalization of the paralogous gene pair.

  16. The transcription factor c-Myc enhances KIR gene transcription through direct binding to an upstream distal promoter element

    PubMed Central

    Cichocki, Frank; Hanson, Rebecca J.; Lenvik, Todd; Pitt, Michelle; McCullar, Valarie; Li, Hongchuan; Anderson, Stephen K.

    2009-01-01

    The killer cell immunoglobulin-like receptor (KIR) repertoire of natural killer (NK) cells determines their ability to detect infected or transformed target cells. Although epigenetic mechanisms play a role in KIR gene expression, work in the mouse suggests that other regulatory elements may be involved at specific stages of NK-cell development. Here we report the effects of the transcription factor c-Myc on KIR expression. c-Myc directly binds to, and promotes transcription from, a distal element identified upstream of most KIR genes. Binding of endogenous c-Myc to the distal promoter element is significantly enhanced upon interleukin-15 (IL-15) stimulation in peripheral blood NK cells and correlates with an increase in KIR transcription. In addition, the overexpression of c-Myc during NK-cell development promotes transcription from the distal promoter element and contributes to the overall transcription of multiple KIR genes. Our data demonstrate the significance of the 5′ promoter element upstream of the conventional KIR promoter region and support a model whereby IL-15 stimulates c-Myc binding at the distal KIR promoter during NK-cell development to promote KIR transcription. This finding provides a direct link between NK-cell activation signals and KIR expression required for acquisition of effector function during NK-cell education. PMID:18987359

  17. Cell-specific activity of the constituent elements of the simian virus 40 enhancer

    SciTech Connect

    Nomiyama, H.; Fromental, C.; Xiao, J.H.; Chambon, P.

    1987-11-01

    The authors have compared the activation of transcription from the early promoter of simian virus 40 brought about by the enhancer during transient expression in several cell lines. The enhancer stimulated RNA synthesis approximately 400-, 100-, 100-, and 300-fold in human HeLa cells, the mouse plasmacytoma B cells MPC11, and the nondifferentiated and retinoic acid-differentiated mouse embryonal carcinoma F9 cells, respectively. The contribution to enhancer activity of its multiple constituent motifs has been investigated in the different cell types using the pA series of recombinants mutated throughout the enhancer. A comparison of the activity of these recombinants in the four cell lines indicates that the activity of the various enhancer motifs is cell specific. The activity of a given motif in a given cell line correlates well with the known presence in this cell line of a protein(s) that binds specifically to that motif in vitro.

  18. EWS-FLI1 utilizes divergent chromatin remodeling mechanisms to directly activate or repress enhancer elements in Ewing sarcoma

    PubMed Central

    Rheinbay, Esther; Boulay, Gaylor; Suvà, Mario L.; Rossetti, Nikki E.; Boonseng, Wannaporn E.; Oksuz, Ozgur; Cook, Edward B.; Formey, Aurélie; Patel, Anoop; Gymrek, Melissa; Thapar, Vishal; Deshpande, Vikram; Ting, David T.; Hornicek, Francis J.; Nielsen, G. Petur; Stamenkovic, Ivan; Aryee, Martin J.

    2015-01-01

    Summary The aberrant transcription factor EWS-FLI1 drives Ewing sarcoma yet its molecular function is incompletely understood. We find that EWS-FLI1 reprograms gene regulatory circuits in Ewing sarcoma by directly inducing or repressing enhancers. At GGAA repeat elements, which lack evolutionary conservation and regulatory potential in other cell types, EWS-FLI1 multimers induce chromatin opening and create de novo enhancers that physically interact with target promoters. Conversely, EWS-FLI1 inactivates conserved enhancers containing canonical ETS motifs by displacing wild type ETS transcription factors. These divergent chromatin-remodeling patterns repress tumor suppressors and mesenchymal lineage regulators, while activating oncogenes and new potential therapeutic targets, such as the kinase VRK1. Our findings demonstrate how EWS-FLI1 establishes an oncogenic regulatory program governing both tumor survival and differentiation. PMID:25453903

  19. Discrete-Roughness-Element-Enhanced Swept-Wing Natural Laminar Flow at High Reynolds Numbers

    NASA Technical Reports Server (NTRS)

    Malik, Mujeeb; Liao, Wei; Li, Fei; Choudhari, Meelan

    2015-01-01

    Nonlinear parabolized stability equations and secondary-instability analyses are used to provide a computational assessment of the potential use of the discrete-roughness-element technology for extending swept-wing natural laminar flow at chord Reynolds numbers relevant to transport aircraft. Computations performed for the boundary layer on a natural-laminar-flow airfoil with a leading-edge sweep angle of 34.6 deg, freestream Mach number of 0.75, and chord Reynolds numbers of 17 × 10(exp 6), 24 × 10(exp 6), and 30 × 10(exp 6) suggest that discrete roughness elements could delay laminar-turbulent transition by about 20% when transition is caused by stationary crossflow disturbances. Computations show that the introduction of small-wavelength stationary crossflow disturbances (i.e., discrete roughness element) also suppresses the growth of most amplified traveling crossflow disturbances.

  20. Multiple enhancers located in a 1-Mb region upstream of POU3F4 promote expression during inner ear development and may be required for hearing

    PubMed Central

    Naranjo, Silvia; Voesenek, Krysta; de la Calle-Mustienes, Elisa; Robert-Moreno, Alex; Kokotas, Haris; Grigoriadou, Maria; Economides, John; Van Camp, Guy; Hilgert, Nele; Moreno, Felipe; Alsina, Berta; Petersen, Michael B.; Kremer, Hannie

    2010-01-01

    POU3F4 encodes a POU-domain transcription factor required for inner ear development. Defects in POU3F4 function are associated with X-linked deafness type 3 (DFN3). Multiple deletions affecting up to ~900-kb upstream of POU3F4 are found in DFN3 patients, suggesting the presence of essential POU3F4 enhancers in this region. Recently, an inner ear enhancer was reported that is absent in most DFN3 patients with upstream deletions. However, two indications suggest that additional enhancers in the POU3F4 upstream region are required for POU3F4 function during inner ear development. First, there is at least one DFN3 deletion that does not eliminate the reported enhancer. Second, the expression pattern driven by this enhancer does not fully recapitulate Pou3f4 expression in the inner ear. Here, we screened a 1-Mb region upstream of the POU3F4 gene for additional cis-regulatory elements and searched for novel DFN3 mutations in the identified POU3F4 enhancers. We found several novel enhancers for otic vesicle expression. Some of these also drive expression in kidney, pancreas and brain, tissues that are known to express Pou3f4. In addition, we report a new and smallest deletion identified so far in a DFN3 family which eliminates 3.9 kb, comprising almost exclusively the previous reported inner ear enhancer. We suggest that multiple enhancers control the expression of Pou3f4 in the inner ear and these may contribute to the phenotype observed in DFN3 patients. In addition, the novel deletion demonstrates that the previous reported enhancer, although not sufficient, is essential for POU3F4 function during inner ear development. Electronic supplementary material The online version of this article (doi:10.1007/s00439-010-0864-x) contains supplementary material, which is available to authorized users. PMID:20668882

  1. One-dimensional plasmonic hotspots located between silver nanowire dimers evaluated by surface-enhanced resonance Raman scattering

    NASA Astrophysics Data System (ADS)

    Itoh, Tamitake; Yamamoto, Yuko S.; Kitahama, Yasutaka; Balachandran, Jeyadevan

    2017-03-01

    Hotspots of surface-enhanced resonance Raman scattering (SERRS) are localized within 1 nm at gaps or crevices of plasmonic nanoparticle dimers. We demonstrate SERRS hotspots with volumes that are extended in one dimension tens of thousand times compared to standard zero-dimensional hotspots using crevices of plasmonic nanowire dimers. According to the polarization measurements, a plasmon resonance in the direction along the dimer width generates SERRS hotspots. SERRS images show oscillating patterns between edges of the hotspot. The SERRS intensity becomes the strongest at the edges, indicating that Fabry-Perot-type resonance of surface plasmons is involved in the Raman enhancement. These optical properties of the SERRS hotspots are quantitatively reproduced by numerical calculations based on the electromagnetic (EM) mechanism. EM coupling energy between dye molecule excitons and plasmons is evaluated using spectral changes in plasmon resonance reflected in a loss of SERRS activity at the hotspots. The coupling energies are consistent with the calculated EM enhancement factors.

  2. Common Elements Enhance or Retard Negative Patterning Discrimination Learning Depending on Modality of Stimuli

    ERIC Educational Resources Information Center

    Redhead, Edward S.; Curtis, Cheryl

    2013-01-01

    Human contingency learning studies were used to compare the predictions of configural and elemental theories. In two experiments, participants were required to learn which stimuli were associated with an increase in core temperature of a fictitious nuclear plant. Experiments investigated the rate at which a simple negative patterning…

  3. Common Elements Enhance or Retard Negative Patterning Discrimination Learning Depending on Modality of Stimuli

    ERIC Educational Resources Information Center

    Redhead, Edward S.; Curtis, Cheryl

    2013-01-01

    Human contingency learning studies were used to compare the predictions of configural and elemental theories. In two experiments, participants were required to learn which stimuli were associated with an increase in core temperature of a fictitious nuclear plant. Experiments investigated the rate at which a simple negative patterning…

  4. [Investigation of enhancing effect for hydride generation-atomic fluorescence of transition metal elements].

    PubMed

    Sun, Han-Wen; Suo, Ran

    2008-11-01

    A mechanism of hydride generation based on disassembly reaction of hydrogen-transferred interim state [M(BH4)m]* was developed by investigating the effect of reaction medium acidity on hydride generation. The effects of Co2+ and Ni2+, phenanthroline and 8-hydroxyquinoline on hydride generation-atomic fluorescence signals of Zn, Cd, Cu and Ni were studied, respectively, and their enhancing mechnism was discussed. The enhancing effect Co2+ and Ni2+ on the fluorescence signals of Zn and Cd was due to the increase in transmission efficiency of hydride of Zn and Cd. There was a synergic enhancing effect between phenanthroline or 8-hydroxyquinoline and Co2+ on the fluorescence signals of Zn and Cd, however no synergic enhancing effect between phenanthroline and 8-hydroxyquinoline on the fluorescence signals of Zn and Cd. The simulative action of cationic surfactant, anion surfactant and non-ionic surfactant surfactant to hydride generation was investigated. It is shown that both cationic surfactant and non-ionic surfactant have obvious enhancing effect on the fluorescence signals of analytes because of the decrease in surface tension of reaction solution. The release characteristics of hydride from the absorption solution containing surfactant was ulteriorly examined by using graphite furnace atomic absorption spectrometry, and the mechanism of enhancing effect of surfactant on hydride generation and transmission was proposed.

  5. From adjacent activation in Escherichia coli and DNA cyclization to eukaryotic enhancers: the elements of a puzzle.

    PubMed

    Amouyal, Michèle

    2014-01-01

    Deoxyribonucleic acid cyclization, Escherichia coli lac repressor binding to two spaced lac operators and repression enhancement can be successfully used for a better understanding of the conditions required for interaction between eukaryotic enhancers and the machinery of transcription initiation. Chronologically, the DNA looping model has first accounted for the properties initially defining enhancers, i.e., independence of action with distance or orientation with respect to the start of transcription. It has also predicted enhancer activity or its disruption at short distance (site orientation, alignment between promoter and enhancer sites), with high-order complexes of protein, or with transcription factor concentrations close or different from the wild-type situation. In another step, histones have been introduced into the model to further adapt it to eukaryotes. They in fact favor DNA cyclization in vitro. The resulting DNA compaction might explain the difference counted in base pairs in the distance of action between eukaryotic transcription enhancers and prokaryotic repression enhancers. The lac looping system provides a potential tool for analysis of this discrepancy and of chromatin state directly in situ. Furthermore, as predicted by the model, the contribution of operators O2 and O3 to repression of the lac operon clearly depends on the lac repressor level in the cell and is prevented in strains overproducing lac repressor. By extension, gene regulation especially that linked to cell fate, should also depend on transcription factor levels, providing a potential tool for cellular therapy. In parallel, a new function of the O1-O3 loop completes the picture of lac repression. The O1-O3 loop would at the same time ensure high efficiency of repression, inducibility through the low-affinity sites and limitation of the level of repressor through self-repression of the lac repressor. Last, the DNA looping model can be successfully adapted to the enhancer

  6. From adjacent activation in Escherichia coli and DNA cyclization to eukaryotic enhancers: the elements of a puzzle

    PubMed Central

    Amouyal, Michèle

    2014-01-01

    Deoxyribonucleic acid cyclization, Escherichia coli lac repressor binding to two spaced lac operators and repression enhancement can be successfully used for a better understanding of the conditions required for interaction between eukaryotic enhancers and the machinery of transcription initiation. Chronologically, the DNA looping model has first accounted for the properties initially defining enhancers, i.e., independence of action with distance or orientation with respect to the start of transcription. It has also predicted enhancer activity or its disruption at short distance (site orientation, alignment between promoter and enhancer sites), with high-order complexes of protein, or with transcription factor concentrations close or different from the wild-type situation. In another step, histones have been introduced into the model to further adapt it to eukaryotes. They in fact favor DNA cyclization in vitro. The resulting DNA compaction might explain the difference counted in base pairs in the distance of action between eukaryotic transcription enhancers and prokaryotic repression enhancers. The lac looping system provides a potential tool for analysis of this discrepancy and of chromatin state directly in situ. Furthermore, as predicted by the model, the contribution of operators O2 and O3 to repression of the lac operon clearly depends on the lac repressor level in the cell and is prevented in strains overproducing lac repressor. By extension, gene regulation especially that linked to cell fate, should also depend on transcription factor levels, providing a potential tool for cellular therapy. In parallel, a new function of the O1–O3 loop completes the picture of lac repression. The O1–O3 loop would at the same time ensure high efficiency of repression, inducibility through the low-affinity sites and limitation of the level of repressor through self-repression of the lac repressor. Last, the DNA looping model can be successfully adapted to the enhancer

  7. Location, Location, Location: Where Do Location-Based Services Fit into Your Institution's Social Media Mix?

    ERIC Educational Resources Information Center

    Nekritz, Tim

    2011-01-01

    Foursquare is a location-based social networking service that allows users to share their location with friends. Some college administrators have been thinking about whether and how to take the leap into location-based services, which are also known as geosocial networking services. These platforms, which often incorporate gaming elements like…

  8. Location, Location, Location: Where Do Location-Based Services Fit into Your Institution's Social Media Mix?

    ERIC Educational Resources Information Center

    Nekritz, Tim

    2011-01-01

    Foursquare is a location-based social networking service that allows users to share their location with friends. Some college administrators have been thinking about whether and how to take the leap into location-based services, which are also known as geosocial networking services. These platforms, which often incorporate gaming elements like…

  9. Post-Training Intrahippocampal Inhibition of Class I Histone Deacetylases Enhances Long-Term Object-Location Memory

    ERIC Educational Resources Information Center

    Hawk, Joshua D.; Florian, Cedrick; Abel, Ted

    2011-01-01

    Long-term memory formation involves covalent modification of the histone proteins that package DNA. Reducing histone acetylation by mutating histone acetyltransferases impairs long-term memory, and enhancing histone acetylation by inhibiting histone deacetylases (HDACs) improves long-term memory. Previous studies using HDAC inhibitors to enhance…

  10. Evaluation of aircraft microwave data for locating zones for well stimulation and enhanced gas recovery. [Arkansas Arkoma Basin

    NASA Technical Reports Server (NTRS)

    Macdonald, H.; Waite, W.; Elachi, C.; Babcock, R.; Konig, R.; Gattis, J.; Borengasser, M.; Tolman, D.

    1980-01-01

    Imaging radar was evaluated as an adjunct to conventional petroleum exploration techniques, especially linear mapping. Linear features were mapped from several remote sensor data sources including stereo photography, enhanced LANDSAT imagery, SLAR radar imagery, enhanced SAR radar imagery, and SAR radar/LANDSAT combinations. Linear feature maps were compared with surface joint data, subsurface and geophysical data, and gas production in the Arkansas part of the Arkoma basin. The best LANDSAT enhanced product for linear detection was found to be a winter scene, band 7, uniform distribution stretch. Of the individual SAR data products, the VH (cross polarized) SAR radar mosaic provides for detection of most linears; however, none of the SAR enhancements is significantly better than the others. Radar/LANDSAT merges may provide better linear detection than a single sensor mapping mode, but because of operator variability, the results are inconclusive. Radar/LANDSAT combinations appear promising as an optimum linear mapping technique, if the advantages and disadvantages of each remote sensor are considered.

  11. Post-Training Intrahippocampal Inhibition of Class I Histone Deacetylases Enhances Long-Term Object-Location Memory

    ERIC Educational Resources Information Center

    Hawk, Joshua D.; Florian, Cedrick; Abel, Ted

    2011-01-01

    Long-term memory formation involves covalent modification of the histone proteins that package DNA. Reducing histone acetylation by mutating histone acetyltransferases impairs long-term memory, and enhancing histone acetylation by inhibiting histone deacetylases (HDACs) improves long-term memory. Previous studies using HDAC inhibitors to enhance…

  12. Enhanced methods for assessment of the trace element composition of Iron Age bone.

    PubMed

    Shafer, Martin M; Siker, Malika; Overdier, Joel T; Ramsl, Peter C; Teschler-Nicola, Maria; Farrell, Philip M

    2008-08-15

    Modern, ultra-trace, analytical methods, coupled with magnetic sector ICP-MS (HR-ICP-MS), were applied to the determination of a large suite of major and trace elements in Iron Age bones. The high sensitivity and un-paralleled signal-to-noise characteristics of HR-ICP-MS enabled the accurate measurement of Ag, Al, As, Ba, Ca, Cd, Ce, Co, Cr, Cu, Fe, La, Li, Mg, Mn, Ni, P, Pb, Pt, Rb, Sr, U, V, and Zn in small bone sections (<75 mg). Critically, the HR-ICP-MS effectively addressed molecular interferences, which would likely have compromised data generated with quadrupole-based ICP-MS instruments. Contamination and diagenetic alteration of ancient bone are grave concerns, which if not properly addressed, may result in serious misinterpretation of data from bone archives. Analytical procedures and several chemical and statistical methods (Principal Components Analysis - PCA) were studied to assess their utility in identifying and correcting bone contamination and diagenetic alteration. Uncertainties in bone (femur) sampling were characterized for each element and longitudinal variation was found to be the dominant source of sampling variability. However the longitudinal variation in most trace elements levels was relatively modest, ranging between 9 and 17% RSD. Bone surface contamination was evaluated using sequential acid leaching. Calcium-normalized metal levels in brief, timed, dilute nitric acid leaches were compared with similarly normalized interior core metal levels to assess the degree of surface enrichment. A select group of metals (Mn, Co, Ni, Ag, Cd, and Pt) were observed to be enriched by up to a factor of 10 in the bone surface, indicating that that these elements may have a higher contamination component. However, the results of sequential acid leaching experiments indicated that the single acid leaching step was effective in removing most surface-enriched contaminants. While the leaching protocol was effective in removing contaminants associated with

  13. Enhanced 911/global position system wizard: a telemedicine application for the prevention of severe hypoglycemia--monitor, alert, and locate.

    PubMed

    Dassau, Eyal; Jovanovic, Lois; Doyle, Francis J; Zisser, Howard C

    2009-11-01

    Intensive insulin therapy has an inherent risk of hypoglycemia that can lead to loss of consciousness, cardiac arrhythmia, seizure, and death ("dead-in-bed syndrome"). This risk of hypoglycemia is a major concern for patients, families, and physicians. The need for an automated system that can alert in the event of severe hypoglycemia is evident. In engineering systems, where there is a risk of malfunction of the primary control system, alert and safety mechanisms are implemented in layers of protection. This concept has been adopted in the proposed system that integrates a hypoglycemia prediction algorithm with a global position system (GPS) locator and short message service such that the current glucose value with the rate of change (ROC) and the location of the subject can be communicated to a predefined list. Furthermore, if the system is linked to the insulin pump, it can suspend the pump or decrease the basal insulin infusion rate to prevent the pending event. The system was evaluated on clinical datasets of glucose tracings from the DexCom Seven system. Glucose tracings were analyzed for hypoglycemia events and then a text message was broadcast to a predefined list of people who were notified with the glucose value, ROC, GPS coordinates, and a Google map of the location. In addition to providing a safety layer to a future artificial pancreas, this system also can be easily implemented in current continuous glucose monitors to help provide information and alerts to people with diabetes.

  14. Does computerized working memory training with game elements enhance motivation and training efficacy in children with ADHD?

    PubMed

    Prins, Pier J M; Dovis, Sebastiaan; Ponsioen, Albert; ten Brink, Esther; van der Oord, Saskia

    2011-03-01

    This study examined the benefits of adding game elements to standard computerized working memory (WM) training. Specifically, it examined whether game elements would enhance motivation and training performance of children with ADHD, and whether it would improve training efficacy. A total of 51 children with ADHD aged between 7 and 12 years were randomly assigned to WM training in a gaming format or to regular WM training that was not in a gaming format. Both groups completed three weekly sessions of WM training. Children using the game version of the WM training showed greater motivation (i.e., more time training), better training performance (i.e., more sequences reproduced and fewer errors), and better WM (i.e., higher scores on a WM task) at post-training than children using the regular WM training. Results are discussed in terms of executive functions and reinforcement models of ADHD. It is concluded that WM training with game elements significantly improves the motivation, training performance, and working memory of children with ADHD. The findings of this study are encouraging and may have wide-reaching practical implications in terms of the role of game elements in the design and implementation of new intervention efforts for children with ADHD.

  15. Endogenous retroviruses function as species-specific enhancer elements in the placenta

    PubMed Central

    Chuong, Edward B.; Rumi, M. A. Karim; Soares, Michael J.; Baker, Julie C.

    2013-01-01

    The mammalian placenta is remarkably distinct between species, suggesting a history of rapid evolutionary diversification1. To gain insight into the molecular drivers of placental evolution, we compared biochemically predicted enhancers between mouse and rat trophoblast stem cells (TSCs) and find that species-specific enhancers are highly enriched for endogenous retroviruses (ERVs) on a genome-wide level. One of these ERV families, RLTR13D5, contributes hundreds of mouse-specific H3K4me1/H3K27ac-defined enhancers that functionally bind Cdx2, Eomes, and Elf5 - core factors that define the TSC regulatory network. Furthermore, we demonstrate that RLTR13D5 is capable of driving gene expression in rat placental cells. Comparison with other tissues revealed that species-specific ERV enhancer activity is generally restricted to hypomethylated tissues, suggesting that tissues permissive to ERV activity gain access to an otherwise silenced source of regulatory variation. Overall, our results implicate ERV enhancer cooption as a mechanism underlying the striking evolutionary diversification of placental development. PMID:23396136

  16. Enhancer connectome in primary human cells identifies target genes of disease-associated DNA elements.

    PubMed

    Mumbach, Maxwell R; Satpathy, Ansuman T; Boyle, Evan A; Dai, Chao; Gowen, Benjamin G; Cho, Seung Woo; Nguyen, Michelle L; Rubin, Adam J; Granja, Jeffrey M; Kazane, Katelynn R; Wei, Yuning; Nguyen, Trieu; Greenside, Peyton G; Corces, M Ryan; Tycko, Josh; Simeonov, Dimitre R; Suliman, Nabeela; Li, Rui; Xu, Jin; Flynn, Ryan A; Kundaje, Anshul; Khavari, Paul A; Marson, Alexander; Corn, Jacob E; Quertermous, Thomas; Greenleaf, William J; Chang, Howard Y

    2017-09-25

    The challenge of linking intergenic mutations to target genes has limited molecular understanding of human diseases. Here we show that H3K27ac HiChIP generates high-resolution contact maps of active enhancers and target genes in rare primary human T cell subtypes and coronary artery smooth muscle cells. Differentiation of naive T cells into T helper 17 cells or regulatory T cells creates subtype-specific enhancer-promoter interactions, specifically at regions of shared DNA accessibility. These data provide a principled means of assigning molecular functions to autoimmune and cardiovascular disease risk variants, linking hundreds of noncoding variants to putative gene targets. Target genes identified with HiChIP are further supported by CRISPR interference and activation at linked enhancers, by the presence of expression quantitative trait loci, and by allele-specific enhancer loops in patient-derived primary cells. The majority of disease-associated enhancers contact genes beyond the nearest gene in the linear genome, leading to a fourfold increase in the number of potential target genes for autoimmune and cardiovascular diseases.

  17. Multi-grid finite element method used for enhancing the reconstruction accuracy in Cerenkov luminescence tomography

    NASA Astrophysics Data System (ADS)

    Guo, Hongbo; He, Xiaowei; Liu, Muhan; Zhang, Zeyu; Hu, Zhenhua; Tian, Jie

    2017-03-01

    Cerenkov luminescence tomography (CLT), as a promising optical molecular imaging modality, can be applied to cancer diagnostic and therapeutic. Most researches about CLT reconstruction are based on the finite element method (FEM) framework. However, the quality of FEM mesh grid is still a vital factor to restrict the accuracy of the CLT reconstruction result. In this paper, we proposed a multi-grid finite element method framework, which was able to improve the accuracy of reconstruction. Meanwhile, the multilevel scheme adaptive algebraic reconstruction technique (MLS-AART) based on a modified iterative algorithm was applied to improve the reconstruction accuracy. In numerical simulation experiments, the feasibility of our proposed method were evaluated. Results showed that the multi-grid strategy could obtain 3D spatial information of Cerenkov source more accurately compared with the traditional single-grid FEM.

  18. Enhancing Surface Finish of Additively Manufactured Titanium and Cobalt Chrome Elements Using Laser Based Finishing

    NASA Astrophysics Data System (ADS)

    Gora, Wojciech S.; Tian, Yingtao; Cabo, Aldara Pan; Ardron, Marcus; Maier, Robert R. J.; Prangnell, Philip; Weston, Nicholas J.; Hand, Duncan P.

    Additive manufacturing (AM) offers the possibility of creating a complex free form object as a single element, which is not possible using traditional mechanical machining. Unfortunately the typically rough surface finish of additively manufactured parts is unsuitable for many applications. As a result AM parts must be post-processed; typically mechanically machined and/or and polished using either chemical or mechanical techniques (both of which have their limitations). Laser based polishing is based on remelting of a very thin surface layer and it offers potential as a highly repeatable, higher speed process capable of selective area polishing, and without any waste problems (no abrasives or liquids). In this paper an in-depth investigation of CW laser polishing of titanium and cobalt chrome AM elements is presented. The impact of different scanning strategies, laser parameters and initial surface condition on the achieved surface finish is evaluated.

  19. Great thermoelectric power factor enhancement of CoSb{sub 3} through the lightest metal element filling

    SciTech Connect

    Zhang Jianjun; Xu Bo; Wang Limin; Yu Dongli; Liu Zhongyuan; He Julong; Tian Yongjun

    2011-02-14

    Lithium, the lightest metal element with a small ionic radius, is successfully filled into the voids of CoSb{sub 3} by utilizing the high pressure synthesis technique. The synthesized Li{sub 0.4}Co{sub 4}Sb{sub 12} shows the largest thermoelectric power factor of 6000 {mu}W m{sup -1} K{sup -2} among all elemental filled CoSb{sub 3} materials. This significantly enhanced thermoelectric power factor is attributed to the large carrier mobility of Li{sub 0.4}Co{sub 4}Sb{sub 12}, 61 cm{sup 2} V{sup -1} s{sup -1}, featuring a good electron crystal property for the Li-filled CoSb{sub 3} samples.

  20. Enhancing biogas production from vinasse in sugarcane biorefineries: Effects of urea and trace elements supplementation on process performance and stability.

    PubMed

    Janke, Leandro; Leite, Athaydes F; Batista, Karla; Silva, Witan; Nikolausz, Marcell; Nelles, Michael; Stinner, Walter

    2016-10-01

    In this study, the effects of nitrogen, phosphate and trace elements supplementation were investigated in a semi-continuously operated upflow anaerobic sludge blanket system to enhance process stability and biogas production from sugarcane vinasse. Phosphate in form of KH2PO4 induced volatile fatty acids accumulation possibly due to potassium inhibition of the methanogenesis. Although nitrogen in form of urea increased the reactor's alkalinity, the process was overloaded with an organic loading rate of 6.1gCODL(-1)d(-1) and a hydraulic retention time of 3.6days. However, by supplementing urea and trace elements a stable operation even at an organic loading rate of 9.6gCODL(-1)d(-1) and a hydraulic retention time of 2.5days was possible, resulting in 79% higher methane production rate with a stable specific methane production of 239mLgCOD(-1).

  1. Sonication enhances polyphenolic compounds, sugars, carotenoids and mineral elements of apple juice.

    PubMed

    Abid, Muhammad; Jabbar, Saqib; Wu, Tao; Hashim, Malik Muhammad; Hu, Bing; Lei, Shicheng; Zeng, Xiaoxiong

    2014-01-01

    A study was initiated with the objective of evaluating the effects of sonication treatment on quality characteristics of apple juice such as polyphenolic compounds (chlorogenic acid, caffeic acid, catechin, epicatechin and phloridzin), sugars (fructose, glucose and sucrose), mineral elements (Na, K, Ca, P, Mg, Cu and Zn), total carotenoids, total anthocyanins, viscosity and electrical conductivity. The fresh apple juice samples were sonicated for 0, 30 and 60 min at 20 °C (frequency 25 kHz and amplitude 70%), respectively. As results, the contents of polyphenolic compounds and sugars significantly increased (P<0.05) but the increases were more pronounced in juice samples sonicated for 30 min whereas, total carotenoids, mineral elements (Na, K and Ca) and viscosity significantly increased (P<0.05) in samples treated for 60 min sonication. Losses of some mineral elements (P, Mg and Cu) also occurred. Total anthocyanins, Zn and electrical conductivity did not undergo any change in the sonicated samples. Findings of the present study suggest that sonication technique may be applied to improve phytonutrients present naturally in apple juice. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Enhanced detection of rolling element bearing fault based on stochastic resonance

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaofei; Hu, Niaoqing; Cheng, Zhe; Hu, Lei

    2012-11-01

    Early bearing faults can generate a series of weak impacts. All the influence factors in measurement may degrade the vibration signal. Currently, bearing fault enhanced detection method based on stochastic resonance(SR) is implemented by expensive computation and demands high sampling rate, which requires high quality software and hardware for fault diagnosis. In order to extract bearing characteristic frequencies component, SR normalized scale transform procedures are presented and a circuit module is designed based on parameter-tuning bistable SR. In the simulation test, discrete and analog sinusoidal signals under heavy noise are enhanced by SR normalized scale transform and circuit module respectively. Two bearing fault enhanced detection strategies are proposed. One is realized by pure computation with normalized scale transform for sampled vibration signal, and the other is carried out by designed SR hardware with circuit module for analog vibration signal directly. The first strategy is flexible for discrete signal processing, and the second strategy demands much lower sampling frequency and less computational cost. The application results of the two strategies on bearing inner race fault detection of a test rig show that the local signal to noise ratio of the characteristic components obtained by the proposed methods are enhanced by about 50% compared with the band pass envelope analysis for the bearing with weaker fault. In addition, helicopter transmission bearing fault detection validates the effectiveness of the enhanced detection strategy with hardware. The combination of SR normalized scale transform and circuit module can meet the need of different application fields or conditions, thus providing a practical scheme for enhanced detection of bearing fault.

  3. Post-Zygotic and Inter-Individual Structural Genetic Variation in a Presumptive Enhancer Element of the Locus between the IL10Rβ and IFNAR1 Genes

    PubMed Central

    Prakash, Kancherla Reddy; Przerada, Szymon; Paprocka, Hanna; Zywicka, Anna; Westerman, Maxwell P.; Pedersen, Nancy L.; O'Hanlon, Terrance P.; Rider, Lisa G.; Miller, Frederick W.; Srutek, Ewa; Jankowski, Michal; Zegarski, Wojciech; Piotrowski, Arkadiusz; Absher, Devin; Dumanski, Jan P.

    2013-01-01

    Although historically considered as junk-DNA, tandemly repeated sequence motifs can affect human phenotype. For example, variable number tandem repeats (VNTR) with embedded enhancers have been shown to regulate gene transcription. The post-zygotic variation is the presence of genetically distinct populations of cells in an individual derived from a single zygote, and this is an understudied aspect of genome biology. We report somatically variable VNTR with sequence properties of an enhancer, located upstream of IFNAR1. Initially, SNP genotyping of 63 monozygotic twin pairs and multiple tissues from 21 breast cancer patients suggested a frequent post-zygotic mosaicism. The VNTR displayed a repeated 32 bp core motif in the center of the repeat, which was flanked by similar variable motifs. A total of 14 alleles were characterized based on combinations of segments, which showed post-zygotic and inter-individual variation, with up to 6 alleles in a single subject. Somatic variation occurred in ∼24% of cases. In this hypervariable region, we found a clustering of transcription factor binding sites with strongest sequence similarity to mouse Foxg1 transcription factor binding motif. This study describes a VNTR with sequence properties of an enhancer that displays post-zygotic and inter-individual genetic variation. This element is within a locus containing four related cytokine receptors: IFNAR2, IL10Rβ, IFNAR1 and IFNGR2, and we hypothesize that it might function in transcriptional regulation of several genes in this cluster. Our findings add another level of complexity to the variation among VNTR-based enhancers. Further work may unveil the normal function of this VNTR in transcriptional control and its possible involvement in diseases connected with these receptors, such as autoimmune conditions and cancer. PMID:24023707

  4. Mutations in ACTRT1 and its enhancer RNA elements lead to aberrant activation of Hedgehog signaling in inherited and sporadic basal cell carcinomas.

    PubMed

    Bal, Elodie; Park, Hyun-Sook; Belaid-Choucair, Zakia; Kayserili, Hülya; Naville, Magali; Madrange, Marine; Chiticariu, Elena; Hadj-Rabia, Smail; Cagnard, Nicolas; Kuonen, Francois; Bachmann, Daniel; Huber, Marcel; Le Gall, Cindy; Côté, Francine; Hanein, Sylvain; Rosti, Rasim Özgür; Aslanger, Ayca Dilruba; Waisfisz, Quinten; Bodemer, Christine; Hermine, Olivier; Morice-Picard, Fanny; Labeille, Bruno; Caux, Frédéric; Mazereeuw-Hautier, Juliette; Philip, Nicole; Levy, Nicolas; Taieb, Alain; Avril, Marie-Françoise; Headon, Denis J; Gyapay, Gabor; Magnaldo, Thierry; Fraitag, Sylvie; Crollius, Hugues Roest; Vabres, Pierre; Hohl, Daniel; Munnich, Arnold; Smahi, Asma

    2017-09-04

    Basal cell carcinoma (BCC), the most common human cancer, results from aberrant activation of the Hedgehog signaling pathway. Although most cases of BCC are sporadic, some forms are inherited, such as Bazex-Dupré-Christol syndrome (BDCS)-a cancer-prone genodermatosis with an X-linked, dominant inheritance pattern. We have identified mutations in the ACTRT1 gene, which encodes actin-related protein T1 (ARP-T1), in two of the six families with BDCS that were examined in this study. High-throughput sequencing in the four remaining families identified germline mutations in noncoding sequences surrounding ACTRT1. These mutations were located in transcribed sequences encoding enhancer RNAs (eRNAs) and were shown to impair enhancer activity and ACTRT1 expression. ARP-T1 was found to directly bind to the GLI1 promoter, thus inhibiting GLI1 expression, and loss of ARP-T1 led to activation of the Hedgehog pathway in individuals with BDCS. Moreover, exogenous expression of ACTRT1 reduced the in vitro and in vivo proliferation rates of cell lines with aberrant activation of the Hedgehog signaling pathway. In summary, our study identifies a disease mechanism in BCC involving mutations in regulatory noncoding elements and uncovers the tumor-suppressor properties of ACTRT1.

  5. Synthesis of trace element Si and Sr codoping hydroxyapatite with non-cytotoxicity and enhanced cell proliferation and differentiation.

    PubMed

    Gao, Jianyong; Wang, Ming; Shi, Chao; Wang, Liping; Wang, Dalin; Zhu, Yingchun

    2016-11-01

    The main inorganic minerals in natural bones are non-stoichiometric hydroxyapatite (HA, Ca10[PO4]6[OH]2) doped with various trace elements, which may possess important biochemical effects. To investigate the functions of Sr and Si elements in human hard tissues, non-doped HA, trace Si doped HA, Si and Sr codoped HA with the concentration of natural bones are synthesized by hydrothermal method in this study. The samples are characterized by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscope (SEM). The biological activities are evaluated via cytotoxicity study, adhesion and proliferation of osteoblast measurement, and alkaline phosphatase (ALP) assay. All the synthesized materials are HA phase, which have hierarchical structures with oriented HA nanorods assembled into the platy particles. These materials are non-cytotoxic against L929 cells line even at 400 μg/ml powder suspension. The results clearly indicate that the proliferation of L929 cells increases with trace elements doping from trace Si-HA to Si + Sr-HA. The adhesion and proliferation of osteoblast measurement illustrates that proliferation of osteoblasts advances about 1.3 times for Si-HA and about 1.8 times for Si + Sr-HA compared with undoped HA. In general, Si-HA with trace Si element shows enhanced cell differentiation, and Si + Sr-HA dual-doped with Si and Sr elements presents increased biological activity compared with Si-HA.

  6. Large enhancement of superconducting transition temperature in single-element superconducting rhenium by shear strain

    NASA Astrophysics Data System (ADS)

    Mito, Masaki; Matsui, Hideaki; Tsuruta, Kazuki; Yamaguchi, Tomiko; Nakamura, Kazuma; Deguchi, Hiroyuki; Shirakawa, Naoki; Adachi, Hiroki; Yamasaki, Tohru; Iwaoka, Hideaki; Ikoma, Yoshifumi; Horita, Zenji

    2016-11-01

    Finding a physical approach for increasing the superconducting transition temperature (Tc) is a challenge in the field of material science. Shear strain effects on the superconductivity of rhenium were investigated using magnetic measurements, X-ray diffraction, transmission electron microscopy, and first-principles calculations. A large shear strain reduces the grain size and simultaneously expands the unit cells, resulting in an increase in Tc. Here we show that this shear strain approach is a new method for enhancing Tc and differs from that using hydrostatic strain. The enhancement of Tc is explained by an increase in net electron–electron coupling rather than a change in the density of states near the Fermi level. The shear strain effect in rhenium could be a successful example of manipulating Bardeen–Cooper–Schrieffer-type Cooper pairing, in which the unit cell volumes are indeed a key parameter.

  7. Large enhancement of superconducting transition temperature in single-element superconducting rhenium by shear strain.

    PubMed

    Mito, Masaki; Matsui, Hideaki; Tsuruta, Kazuki; Yamaguchi, Tomiko; Nakamura, Kazuma; Deguchi, Hiroyuki; Shirakawa, Naoki; Adachi, Hiroki; Yamasaki, Tohru; Iwaoka, Hideaki; Ikoma, Yoshifumi; Horita, Zenji

    2016-11-04

    Finding a physical approach for increasing the superconducting transition temperature (Tc) is a challenge in the field of material science. Shear strain effects on the superconductivity of rhenium were investigated using magnetic measurements, X-ray diffraction, transmission electron microscopy, and first-principles calculations. A large shear strain reduces the grain size and simultaneously expands the unit cells, resulting in an increase in Tc. Here we show that this shear strain approach is a new method for enhancing Tc and differs from that using hydrostatic strain. The enhancement of Tc is explained by an increase in net electron-electron coupling rather than a change in the density of states near the Fermi level. The shear strain effect in rhenium could be a successful example of manipulating Bardeen-Cooper-Schrieffer-type Cooper pairing, in which the unit cell volumes are indeed a key parameter.

  8. Large enhancement of superconducting transition temperature in single-element superconducting rhenium by shear strain

    PubMed Central

    Mito, Masaki; Matsui, Hideaki; Tsuruta, Kazuki; Yamaguchi, Tomiko; Nakamura, Kazuma; Deguchi, Hiroyuki; Shirakawa, Naoki; Adachi, Hiroki; Yamasaki, Tohru; Iwaoka, Hideaki; Ikoma, Yoshifumi; Horita, Zenji

    2016-01-01

    Finding a physical approach for increasing the superconducting transition temperature (Tc) is a challenge in the field of material science. Shear strain effects on the superconductivity of rhenium were investigated using magnetic measurements, X-ray diffraction, transmission electron microscopy, and first-principles calculations. A large shear strain reduces the grain size and simultaneously expands the unit cells, resulting in an increase in Tc. Here we show that this shear strain approach is a new method for enhancing Tc and differs from that using hydrostatic strain. The enhancement of Tc is explained by an increase in net electron–electron coupling rather than a change in the density of states near the Fermi level. The shear strain effect in rhenium could be a successful example of manipulating Bardeen–Cooper–Schrieffer-type Cooper pairing, in which the unit cell volumes are indeed a key parameter. PMID:27811983

  9. Enhancement of X-ray Energy Deposition via Heavy Element Sensitization in Biological Environments

    NASA Astrophysics Data System (ADS)

    Lim, Sara; Pradhan, Anil; Nahar, Sultana; Barth, Rolf

    2015-05-01

    Energy (dose) deposition by low vs. high energy x-rays (LEX & HEX), approximately E ~ 100 keV and E > 1 MeV respectively, was studied in biological matter sensitized with heavy elements (high-Z or HZ) to improve radiation therapy of cancer. Computations and simulations show that LEX interact favorably with HZ sensitizers by depositing more dose than HEX. LEX photons effectively photoionize deep inner electronic shells and release cell-killing Auger electrons near malignant cells embedded with HZ atoms. HEX photons predominantly Compton scatter with little interaction, even with HZ elements. Monte Carlo simulations show that in comparison to unsensitized tissue, LEX irradiation of HZ-sensitized models resulted in up to a factor of 2 increase in dose deposition relative to HEX. To validate the studies, in vitro experiments were performed using 2 distinct cancer cell types treated with Pt-based sensitizers, then irradiated with a LEX 160 KV x-ray source and a HEX 6 MV LINAC employed in radiation therapy. The experiments support numerical simulations, and demonstrate several factors lower survival of HZ-sensitized cells irradiated with LEX compared with HEX.

  10. Adsorption enhancement of elemental mercury onto sulphur-functionalized silica gel adsorbents.

    PubMed

    Johari, Khairiraihanna; Saman, Norasikin; Mat, Hanapi

    2014-01-01

    In this study, elemental mercury (EM) adsorbents were synthesized using tetraethyl orthosilicate (TEOS) and 3-mercaptopropyl trimethoxysilane as silica precursors. The synthesized silica gel (SG)-TEOS was further functionalized through impregnation with elemental sulphur and carbon disulphide (CS2). The SG adsorbents were then characterized by using scanning electron microscope, Fourier transform infra-red spectrophotometer, nitrogen adsorption/desorption, and energy-dispersive X-ray diffractometer. The EM adsorption of the SG adsorbents was determined using fabricated fixed-bed adsorber. The EM adsorption results showed that the sulphur-functionalized SG adsorbents had a greater Hgo breakthrough adsorption capacity, confirming that the presence of sulphur in silica matrices can improve Hgo adsorption performance due to their high affinity towards mercury. The highest Hgo adsorption capacity was observed for SG-TEOS(CS2) (82.62 microg/g), which was approximately 2.9 times higher than SG-TEOS (28.47 microg/g). The rate of Hgo adsorption was observed higher for sulphur-impregnated adsorbents, and decreased with the increase in the bed temperatures.

  11. Surface-enhanced raman detection of 2,4-dinitrotoluene impurity vapor as a marker to locate landmines.

    PubMed

    Sylvia, J M; Janni, J A; Klein, J D; Spencer, K M

    2000-12-01

    Time, cost, and casualties associated with demining efforts underscore the need for improved detection techniques. Reduction in the number of false positives by directly detecting the explosive material, rather than casing material, is desirable. The desired field sensor must, at a minimum, demonstrate reproducibility, the necessary level of sensitivity, portability, instrumental stability, and fast system response times. Ideally, vibrational spectroscopic techniques have the potential to remove false positives, since every chemical has a unique bond structure. Herein, we demonstrate the capabilities of surface-enhanced Raman spectroscopy to detect the chemical vapor signature emanating from buried TNT-based landmines. We present reproducible results obtained from blind tests controlled by the Defense Advanced Research Projects Agency (DARPA) that demonstrate vapor detection of 2,4-dinitrotoluene at concentration levels of 5 ppb or less. The results presented used acquisition times of 30 s on a fieldable system and showed that SERS can be a significant improvement over current landmine detection methods.

  12. Probabilistic cost-benefit analysis of enhanced safety features for strategic nuclear weapons at a representative location

    SciTech Connect

    Stephens, D.R.; Hall, C.H.; Holman, G.S.; Graham, K.F.; Harvey, T.F.; Serduke, F.J.D.

    1993-10-01

    We carried out a demonstration analysis of the value of developing and implementing enhanced safety features for nuclear weapons in the US stockpile. We modified an approach that the Nuclear Regulatory Commission (NRC) developed in response to a congressional directive that NRC assess the ``value-impact`` of regulatory actions for commercial nuclear power plants. Because improving weapon safety shares some basic objectives with NRC regulations, i.e., protecting public health and safety from the effects of accidents involving radioactive materials, we believe the NRC approach to be appropriate for evaluating weapons-safety cost-benefit issues. Impact analysis includes not only direct costs associated with retrofitting the weapon system, but also the expected costs (or economic risks) that are avoided by the action, i.e., the benefits.

  13. Finite element modeling of quasi-brittle cracks in 2D and 3D with enhanced strain accuracy

    NASA Astrophysics Data System (ADS)

    Cervera, M.; Barbat, G. B.; Chiumenti, M.

    2017-07-01

    This paper discusses the finite element modeling of cracking in quasi-brittle materials. The problem is addressed via a mixed strain/displacement finite element formulation and an isotropic damage constitutive model. The proposed mixed formulation is fully general and is applied in 2D and 3D. Also, it is independent of the specific finite element discretization considered; it can be equally used with triangles/tetrahedra, quadrilaterals/hexahedra and prisms. The feasibility and accuracy of the method is assessed through extensive comparison with experimental evidence. The correlation with the experimental tests shows the capacity of the mixed formulation to reproduce the experimental crack path and the force-displacement curves with remarkable accuracy. Both 2D and 3D examples produce results consistent with the documented data. Aspects related to the discrete solution, such as convergence regarding mesh resolution and mesh bias, as well as other related to the physical model, like structural size effect and the influence of Poisson's ratio, are also investigated. The enhanced accuracy of the computed strain field leads to accurate results in terms of crack paths, failure mechanisms and force displacement curves. Spurious mesh dependency suffered by both continuous and discontinuous irreducible formulations is avoided by the mixed FE, without the need of auxiliary tracking techniques or other computational schemes that alter the continuum mechanical problem.

  14. Folding of the natural hammerhead ribozyme is enhanced by interaction of auxiliary elements

    PubMed Central

    PENEDO, J. CARLOS; WILSON, TIMOTHY J.; JAYASENA, SUMEDHA D.; KHVOROVA, ANASTASIA; LILLEY, DAVID M.J.

    2004-01-01

    It has been shown that the activity of the hammerhead ribozyme at μM magnesium ion concentrations is markedly increased by the inclusion of loops in helices I and II. We have studied the effect of such loops on the magnesium ion-induced folding of the ribozyme, using fluorescence resonance energy transfer. We find that with the loops in place, folding into the active conformation occurs in a single step, in the μM range of magnesium ion concentration. Disruption of the loop–loop interaction leads to a reversion to two-step folding, with the second stage requiring mM concentrations of magnesium ion. Sodium ions also promote the folding of the natural form of the ribozyme at high concentrations, but the folding occurs as a two-stage process. The loops clearly act as important auxiliary elements in the function of the ribozyme, permitting folding to occur efficiently under physiological conditions. PMID:15100442

  15. The Use of Finite Element Analysis to Enhance Research and Clinical Practice in Orthopedics.

    PubMed

    Pfeiffer, Ferris M

    2016-02-01

    Finite element analysis (FEA) is a very powerful tool for the evaluation of biomechanics in orthopedics. Finite element (FE) simulations can effectively and efficiently evaluate thousands of variables (such as implant variation, surgical techniques, and various pathologies) to optimize design, screening, prediction, and treatment in orthopedics. Additionally, FEA can be used to retrospectively evaluate and troubleshoot complications or failures to prevent similar future occurrences. Finally, FE simulations are used to evaluate implants, procedures, and techniques in a time- and cost-effective manner. In this work, an overview of the development of FE models is provided and an example application is presented to simulate knee biomechanics for a specimen with medial meniscus insufficiency. FE models require the development of the geometry of interest, determination of the material properties of the tissues simulated, and an accurate application of a numerical solver to produce an accurate solution and representation of the field variables. The objectives of this work are to introduce the reader to the application of FEA in orthopedic analysis of the knee joint. A brief description of the model development process as well as a specific application to the investigation of knee joint stability in geometries with normal or compromised medial meniscal attachment is included. Significant increases in stretch of the anterior cruciate ligament were predicted in specimens with medial meniscus insufficiency (such behavior was confirmed in corresponding biomechanical testing). It can be concluded from this work that FE analysis of the knee can provide significant new information with which more effective clinical decisions can be made.

  16. Fault feature extraction and enhancement of rolling element bearing in varying speed condition

    NASA Astrophysics Data System (ADS)

    Ming, A. B.; Zhang, W.; Qin, Z. Y.; Chu, F. L.

    2016-08-01

    In engineering applications, the variability of load usually varies the shaft speed, which further degrades the efficacy of the diagnostic method based on the hypothesis of constant speed analysis. Therefore, the investigation of the diagnostic method suitable for the varying speed condition is significant for the bearing fault diagnosis. In this instance, a novel fault feature extraction and enhancement procedure was proposed by the combination of the iterative envelope analysis and a low pass filtering operation in this paper. At first, based on the analytical model of the collected vibration signal, the envelope signal was theoretically calculated and the iterative envelope analysis was improved for the varying speed condition. Then, a feature enhancement procedure was performed by applying a low pass filter on the temporal envelope obtained by the iterative envelope analysis. Finally, the temporal envelope signal was transformed to the angular domain by the computed order tracking and the fault feature was extracted on the squared envelope spectrum. Simulations and experiments were used to validate the efficacy of the theoretical analysis and proposed procedure. It is shown that the computed order tracking method is recommended to be applied on the envelope of the signal in order to avoid the energy spreading and amplitude distortion. Compared with the feature enhancement method performed by the fast kurtogram and corresponding optimal band pass filtering, the proposed method can efficiently extract the fault character in the varying speed condition with less amplitude attenuation. Furthermore, do not involve the center frequency estimation, the proposed method is more concise for engineering applications.

  17. Temporal predictability enhances judgements of causality in elemental causal induction from both observation and intervention.

    PubMed

    Greville, W James; Buehner, Marc J

    2016-01-01

    When the temporal interval or delay separating cause and effect is consistent over repeated instances, it becomes possible to predict when the effect will follow from the cause, hence temporal predictability serves as an appropriate term for describing consistent cause-effect delays. It has been demonstrated that in instrumental action-outcome learning tasks, enhancing temporal predictability by holding the cause-effect interval constant elicits higher judgements of causality compared to conditions involving variable temporal intervals. Here, we examine whether temporal predictability exerts a similar influence when causal learning takes place through observation rather than intervention through instrumental action. Four experiments demonstrated that judgements of causality were higher when the temporal interval was constant than when it was variable, and that judgements declined with increasing variability. We further found that this beneficial effect of predictability was stronger in situations where the effect base-rate was zero (Experiments 1 and 3). The results therefore clearly indicate that temporal predictability enhances impressions of causality, and that this effect is robust and general. Factors that could mediate this effect are discussed.

  18. Conserved elements within first intron of aquaporin-5 (Aqp5) function as transcriptional enhancers

    PubMed Central

    Flodby, Per; Zhou, Beiyun; Ann, David K.; Kim, Kwang-Jin; Minoo, Parviz; Crandall, Edward D.; Borok, Zea

    2007-01-01

    A 4.3-kb rat aquaporin-5 (Aqp5) promoter that directs lung and salivary cell-specific expression in vitro directs low level expression of a GFP reporter in lungs of transgenic mice. Alignment of rat, mouse and human AQP5 genomic sequences identified a highly conserved region in the 3′ portion of intron 1, here termed ci1. To investigate the role of ci1 in Aqp5 expression, transient transfections were undertaken in AQP5-expressing mouse lung epithelial (MLE-15) and rat salivary (Pa-4) cells and AQP5-non-expressing NIH/3T3 cells. A 536 bp ci1 fragment enhanced transcriptional activity of the rat Aqp5 minimal promoter specifically in MLE-15 cells in an orientation-independent manner. Enhancer activity was Aqp5 promoter-specific, since no increase in activity was detected with the TK promoter. These results suggest that expression of transgenes in mouse lungs under direction of the 4.3 kb rat Aqp5 promoter may be augmented by inclusion of ci1 in transgenic constructs. PMID:17339032

  19. A novel strategy to identify the location of necessary and sufficient cis-acting regulatory mRNA elements in trypanosomes.

    PubMed

    Webb, Helena; Burns, Roisin; Kimblin, Nicola; Ellis, Louise; Carrington, Mark

    2005-07-01

    Expression of nearly all protein coding genes in trypanosomes is regulated post-transcriptionally, predominantly at the level of mRNA half-life. The identification of cis-acting elements involved in mRNA stability has been hindered by a lack of ability to screen for loss-of-regulation mutants. The method described in this article allows the region containing the necessary and sufficient elements within a mRNA to be identified and uses antibiotic resistance genes as both selectable markers and reporters. In the case of unstable mRNAs, the strategy can be extended by performing a screen for spontaneous loss-of-function mutants in regulatory parts of a mRNA. The method was validated by using the GPI-PLC mRNA, which is unstable in procyclic form trypanosomes and showed that the 3'UTR of the GPI-PLC mRNA contains all elements required for developmentally regulated instability. Loss-of-instability mutants all contained deletions within the 2300-nucleotide-long 3'UTR, and their analysis showed that a deletion including the last 800 nt of the gene stabilized the mRNA. The method is nonpresumptive, allows far more rapid screening for cis-elements than existing procedures, and has the advantage of identifying functional mutants. It is applicable to all eukaryotes using polycistronic transcription.

  20. Migration of trace elements from basalt substrate to co-located vegetation (lichens and mosses) at the Wudalianchi volcanos, Northeast China

    NASA Astrophysics Data System (ADS)

    Bao, Yuan; Ju, Yiwen; Li, Boping; Sun, Yimin

    2016-03-01

    Vegetation (e.g., lichens and mosses) living on the basalt substrate have potential to accumulate trace elements in their tissues. Here, we analyze the trace elements in basalt (collected from major volcanic center to jet plate places, representing four different eruption phases) and adjacent lichens and mosses to assess their elemental source-receptor relation. The results indicate that As, Sr, Mo, Cd, and Ba are enriched in basalt, and depleted in lichens and mosses. However, Zn, Hg, and Pb are enriched in lichens and mosses and depleted in basalt. Moreover, with the increase of basalt age, Cr, Mn, Fe, Ni, and Cu are gradually enriched in lichen and moss, but gradually depleted in basalt. Compared with transition metals, large ion lithophiles, the platinum group, and rare earth elements, Cr, Co, Cu, Zn, and Os are more easily absorbed by No. 1 lichen. Specifically, S is highly assimilated in vegetation, with a highest value of 166, followed by I, C, Pb, Zn, and Hg. In addition, the hydrogen and oxygen isotopic compositions of water samples suggest that the surface water in the Wenbo area came from meteoric waters in summer with a high humidity, while the underground water in the Beiyaoquan area came from meteoric waters in winter with a low humidity.

  1. Maternal separation enhances object location memory and prevents exercise-induced MAPK/ERK signalling in adult Sprague–Dawley rats

    PubMed Central

    Bugarith, Kishor; Russell, Vivienne A

    2012-01-01

    Early life stress increases the risk of developing psychopathology accompanied by reduced cognitive function in later life. Maternal separation induces anxiety-like behaviours and is associated with impaired memory. On the other hand, exercise has been shown to diminish anxiety-like behaviours and improve cognitive function. The effects of maternal separation and exercise on anxiety, memory and hippocampal proteins were investigated in male Sprague–Dawley rats. Maternal separation produced anxiety-like behaviours which were reversed by exercise. Maternal separation also enhanced object location memory which was not affected by exercise. Exercise did, however, increase synaptophysin and phospho-extracellular signal-regulated kinase (p-ERK) in the hippocampus of non-separated rats and this effect was not observed in maternally separated rats. These findings show that maternal separation selectively enhanced n memory and prevented activation of the MAPK/ERK signalling pathway in the adult rat hippocampus. PMID:22476924

  2. Maternal separation enhances object location memory and prevents exercise-induced MAPK/ERK signalling in adult Sprague-Dawley rats.

    PubMed

    Makena, Nokuthula; Bugarith, Kishor; Russell, Vivienne A

    2012-09-01

    Early life stress increases the risk of developing psychopathology accompanied by reduced cognitive function in later life. Maternal separation induces anxiety-like behaviours and is associated with impaired memory. On the other hand, exercise has been shown to diminish anxiety-like behaviours and improve cognitive function. The effects of maternal separation and exercise on anxiety, memory and hippocampal proteins were investigated in male Sprague-Dawley rats. Maternal separation produced anxiety-like behaviours which were reversed by exercise. Maternal separation also enhanced object location memory which was not affected by exercise. Exercise did, however, increase synaptophysin and phospho-extracellular signal-regulated kinase (p-ERK) in the hippocampus of non-separated rats and this effect was not observed in maternally separated rats. These findings show that maternal separation selectively enhanced n memory and prevented activation of the MAPK/ERK signalling pathway in the adult rat hippocampus.

  3. Enhanced focus steering abilities of multi-element therapeutic arrays operating in nonlinear regimes

    SciTech Connect

    Yuldashev, P. Ilyin, S.; Gavrilov, L.; Sapozhnikov, O.; Khokhlova, V.; Kreider, W.

    2015-10-28

    Steering abilities of a typical HIFU therapeutic array operated in linear and nonlinear regimes were compared using numerical simulation with the 3D Westervelt equation. The array included 256 elements of 1.2 MHz frequency and 6.6 mm diameter distributed in a quasi-random pattern over a spherical shell with a 130 mm aperture and a focal length of 120 mm. In the case of linear focusing, thermal effects are proportional to the intensity level and the criterion for safe array operation is that the intensity in the grating lobes should be less than 10% of the intensity in the main focus. In the case of nonlinear focusing, the heating effect is no longer proportional to intensity; therefore the heat deposition rate was chosen as the relevant metric, using the same 10% threshold for the secondary lobe in comparison with the focal maximum. When steering the focus, the same linearly predicted intensity level at the main focus was maintained by increasing the array power. Numerical simulations of the acoustic field were performed for nonlinear propagation both in water and in tissue. It was shown that for shock-forming conditions in the main focus, the steering range of safe electronic focusing is larger than that for linear propagation conditions. Nonlinear sonication regimes therefore can be used to enlarge tissue volumes that can be sonicated using electronic steering of the focus of HIFU arrays.

  4. Unusual seeding mechanism for enhanced performance in solid-phase magnetic extraction of Rare Earth Elements

    PubMed Central

    Polido Legaria, Elizabeth; Rocha, Joao; Tai, Cheuk-Wai; Kessler, Vadim G.; Seisenbaeva, Gulaim A.

    2017-01-01

    Due to the increasing demand of Rare Earth Elements (REE or RE), new and more efficient techniques for their extraction are necessary, suitable for both mining and recycling processes. Current techniques such as solvent extraction or solid adsorbents entail drawbacks such as using big volumes of harmful solvents or limited capacity. Hybrid nanoadsorbents based on SiO2 and highly stable γ-Fe2O3-SiO2 nanoparticles, proved recently to be very attractive for adsorption of REE, yet not being the absolute key to solve the problem. In the present work, we introduce a highly appealing new approach in which the nanoparticles, rather than behaving as adsorbent materials, perform as inducers of crystallization for the REE in the form of hydroxides, allowing their facile and practically total removal from solution. This induced crystallization is achieved by tuning the pH, offering an uptake efficiency more than 20 times higher than previously reported (up to 900 mg RE3+/g vs. 40 mg RE3+/g). The obtained phases were characterized by SEM-EDS, TEM, STEM and EFTEM and 13C and 29Si solid state NMR. Magnetic studies showed that the materials possessed enough magnetic properties to be easily removed by a magnet, opening ways for an efficient and industrially applicable separation technique. PMID:28266566

  5. Unusual seeding mechanism for enhanced performance in solid-phase magnetic extraction of Rare Earth Elements

    NASA Astrophysics Data System (ADS)

    Polido Legaria, Elizabeth; Rocha, Joao; Tai, Cheuk-Wai; Kessler, Vadim G.; Seisenbaeva, Gulaim A.

    2017-03-01

    Due to the increasing demand of Rare Earth Elements (REE or RE), new and more efficient techniques for their extraction are necessary, suitable for both mining and recycling processes. Current techniques such as solvent extraction or solid adsorbents entail drawbacks such as using big volumes of harmful solvents or limited capacity. Hybrid nanoadsorbents based on SiO2 and highly stable γ-Fe2O3-SiO2 nanoparticles, proved recently to be very attractive for adsorption of REE, yet not being the absolute key to solve the problem. In the present work, we introduce a highly appealing new approach in which the nanoparticles, rather than behaving as adsorbent materials, perform as inducers of crystallization for the REE in the form of hydroxides, allowing their facile and practically total removal from solution. This induced crystallization is achieved by tuning the pH, offering an uptake efficiency more than 20 times higher than previously reported (up to 900 mg RE3+/g vs. 40 mg RE3+/g). The obtained phases were characterized by SEM-EDS, TEM, STEM and EFTEM and 13C and 29Si solid state NMR. Magnetic studies showed that the materials possessed enough magnetic properties to be easily removed by a magnet, opening ways for an efficient and industrially applicable separation technique.

  6. Shape memory alloy smart knee spacer to enhance knee functionality: model design and finite element analysis.

    PubMed

    Gautam, Arvind; Rani, A Bhargavi; Callejas, Miguel A; Acharyya, Swati Ghosh; Acharyya, Amit; Biswas, Dwaipayan; Bhandari, Vasundhra; Sharma, Paresh; Naik, Ganesh R

    2016-08-01

    In this paper we introduce Shape Memory Alloy (SMA) for designing the tibial part of Total Knee Arthroplasty (TKA) by exploiting the shape-memory and pseudo-elasticity property of the SMA (e.g. NiTi). This would eliminate the drawbacks of the state-of-the art PMMA based knee-spacer including fracture, sustainability, dislocation, tilting, translation and subluxation for tackling the Osteoarthritis especially for the aged people of 45-plus or the athletes. In this paper a Computer Aided Design (CAD) model using SolidWorks for the knee-spacer is presented based on the proposed SMA adopting the state-of-the art industry-standard geometry that is used in the PMMA based spacer design. Subsequently Ansys based Finite Element Analysis is carried out to measure and compare the performance between the proposed SMA based model with the state-of-the art PMMA ones. 81% more bending is noticed in the PMMA based spacer compared to the proposed SMA that would eventually cause fracture and tilting or translation of spacer. Permanent shape deformation of approximately 58.75% in PMMA based spacer is observed compared to recoverable 11% deformation in SMA when same load is applied on both separately.

  7. A distal intergenic region controls pancreatic endocrine differentiation by acting as a transcriptional enhancer and as a polycomb response element.

    PubMed

    van Arensbergen, Joris; Dussaud, Sebastien; Pardanaud-Glavieux, Corinne; García-Hurtado, Javier; Sauty, Claire; Guerci, Aline; Ferrer, Jorge; Ravassard, Philippe

    2017-01-01

    Lineage-selective expression of developmental genes is dependent on the interplay between activating and repressive mechanisms. Gene activation is dependent on cell-specific transcription factors that recognize transcriptional enhancer sequences. Gene repression often depends on the recruitment of Polycomb group (PcG) proteins, although the sequences that underlie the recruitment of PcG proteins, also known as Polycomb response elements (PREs), remain poorly understood in vertebrates. While distal PREs have been identified in mammals, a role for positive-acting enhancers in PcG-mediated repression has not been described. Here we have used a highly efficient procedure based on lentiviral-mediated transgenesis to carry out in vivo fine-mapping of, cis-regulatory sequences that control lineage-specific activation of Neurog3, a master regulator of pancreatic endocrine differentiation. Our findings reveal an enhancer region that is sufficient to drive correct spacio-temporal expression of Neurog3 and demonstrate that this same region serves as a PRE in alternative lineages where Neurog3 is inactive.

  8. A distal intergenic region controls pancreatic endocrine differentiation by acting as a transcriptional enhancer and as a polycomb response element

    PubMed Central

    Pardanaud-Glavieux, Corinne; García-Hurtado, Javier; Sauty, Claire; Guerci, Aline; Ferrer, Jorge

    2017-01-01

    Lineage-selective expression of developmental genes is dependent on the interplay between activating and repressive mechanisms. Gene activation is dependent on cell-specific transcription factors that recognize transcriptional enhancer sequences. Gene repression often depends on the recruitment of Polycomb group (PcG) proteins, although the sequences that underlie the recruitment of PcG proteins, also known as Polycomb response elements (PREs), remain poorly understood in vertebrates. While distal PREs have been identified in mammals, a role for positive-acting enhancers in PcG-mediated repression has not been described. Here we have used a highly efficient procedure based on lentiviral-mediated transgenesis to carry out in vivo fine-mapping of, cis-regulatory sequences that control lineage-specific activation of Neurog3, a master regulator of pancreatic endocrine differentiation. Our findings reveal an enhancer region that is sufficient to drive correct spacio-temporal expression of Neurog3 and demonstrate that this same region serves as a PRE in alternative lineages where Neurog3 is inactive. PMID:28225770

  9. The mouse albumin enhancer contains a negative regulatory element that interacts with a novel DNA-binding protein.

    PubMed Central

    Herbst, R S; Boczko, E M; Darnell, J E; Babiss, L E

    1990-01-01

    The far-upstream mouse albumin enhancer (-10.5 to -8.43 kilobases) has both positive and negative regulatory domains which contribute to the rate and tissue specificity of albumin gene transcription. (R. S. Herbst, N. Friedman, J. E. Darnell, Jr., and L. E. Babiss, Proc. Natl. Acad. Sci. USA 86:1553-1557). In this work, the negative regulatory region has been functionally localized to sequences -8.7 to -8.43 kilobases upstream of the albumin gene cap site. In the absence of the albumin-modulating region (in which there are binding sites for the transcription factor C/EBP), the negative region can suppress a neighboring positive-acting element, thereby interfering with albumin enhancer function. The negative region is also capable of negating the positive action of the heterologous transthyretin enhancer in an orientation-independent fashion. Within this negative-acting region we can detect two DNA-binding sites, both of which are recognized by a protein present in all cell types tested. This DNA-binding activity is not competed for by any of a series of known DNA-binding sites, and hence this new protein is a candidate for a role in suppressing the albumin gene in nonhepatic cells. Images PMID:2370857

  10. Understanding the Importance of Context: A Qualitative Study of a Location-Based Exergame to Enhance School Childrens Physical Activity

    PubMed Central

    Jepson, Ruth; Macvean, Andrew; Gray, Stuart

    2016-01-01

    Many public health interventions are less effective than expected in ‘real life settings’, yet little work is undertaken to understand the reasons why. The effectiveness of complex public health interventions can often be traced back to a robust programme theory (how and why an intervention brings about a change in outcome(s)) and assumptions that are made about the context in which it is implemented. Understanding whether effectiveness (or lack thereof) is due to the intervention or the context is hugely helpful in decisions about whether to a) modify the intervention; b) modify the context; c) stop providing the intervention. Exergames–also known as Active Video Games or AVGS–are video games which use the player's bodily movements as input and have potential to increase physical activity in children. However, the results of a recent pilot randomised controlled trial (RCT) of a location-based exergame (FitQuest) in a school setting were inconclusive; no significant effect was detected for any of the outcome measures. The aim of this study was to explore whether the programme theory for FitQuest was correct with respect to how and why it would change children’s perceptions of physical activity (PA) and exercise self-efficacy in the school setting. A further aim was to investigate the features of the school setting (context) that may impact on FitQuest’s implementation and effectiveness. Qualitative data (gathered during the RCT) were gathered from interviews with teachers and children, and observation of sessions using FitQuest. Thematic analysis indicated that whilst children enjoyed playing the game, engaged with goal setting within the game context and undertook low to vigorous physical activity, there were significant contextual factors that prevented it from being played as often as intended. These included environmental factors (e.g. size of the playground), school factors (cancellations due to other activities), school technology policy (rules

  11. Understanding the Importance of Context: A Qualitative Study of a Location-Based Exergame to Enhance School Childrens Physical Activity.

    PubMed

    Robertson, Judy; Jepson, Ruth; Macvean, Andrew; Gray, Stuart

    2016-01-01

    Many public health interventions are less effective than expected in 'real life settings', yet little work is undertaken to understand the reasons why. The effectiveness of complex public health interventions can often be traced back to a robust programme theory (how and why an intervention brings about a change in outcome(s)) and assumptions that are made about the context in which it is implemented. Understanding whether effectiveness (or lack thereof) is due to the intervention or the context is hugely helpful in decisions about whether to a) modify the intervention; b) modify the context; c) stop providing the intervention. Exergames-also known as Active Video Games or AVGS-are video games which use the player's bodily movements as input and have potential to increase physical activity in children. However, the results of a recent pilot randomised controlled trial (RCT) of a location-based exergame (FitQuest) in a school setting were inconclusive; no significant effect was detected for any of the outcome measures. The aim of this study was to explore whether the programme theory for FitQuest was correct with respect to how and why it would change children's perceptions of physical activity (PA) and exercise self-efficacy in the school setting. A further aim was to investigate the features of the school setting (context) that may impact on FitQuest's implementation and effectiveness. Qualitative data (gathered during the RCT) were gathered from interviews with teachers and children, and observation of sessions using FitQuest. Thematic analysis indicated that whilst children enjoyed playing the game, engaged with goal setting within the game context and undertook low to vigorous physical activity, there were significant contextual factors that prevented it from being played as often as intended. These included environmental factors (e.g. size of the playground), school factors (cancellations due to other activities), school technology policy (rules relating to

  12. Expression of zebrafish pax6b in pancreas is regulated by two enhancers containing highly conserved cis-elements bound by PDX1, PBX and PREP factors

    PubMed Central

    Delporte, François M; Pasque, Vincent; Devos, Nathalie; Manfroid, Isabelle; Voz, Marianne L; Motte, Patrick; Biemar, Frédéric; Martial, Joseph A; Peers, Bernard

    2008-01-01

    Background PAX6 is a transcription factor playing a crucial role in the development of the eye and in the differentiation of the pancreatic endocrine cells as well as of enteroendocrine cells. Studies on the mouse Pax6 gene have shown that sequences upstream from the P0 promoter are required for expression in the lens and the pancreas; but there remain discrepancies regarding the precise location of the pancreatic regulatory elements. Results Due to genome duplication in the evolution of ray-finned fishes, zebrafish has two pax6 genes, pax6a and pax6b. While both zebrafish pax6 genes are expressed in the developing eye and nervous system, only pax6b is expressed in the endocrine cells of the pancreas. To investigate the cause of this differential expression, we used a combination of in silico, in vivo and in vitro approaches. We show that the pax6b P0 promoter targets expression to endocrine pancreatic cells and also to enteroendocrine cells, retinal neurons and the telencephalon of transgenic zebrafish. Deletion analyses indicate that strong pancreatic expression of the pax6b gene relies on the combined action of two conserved regulatory enhancers, called regions A and C. By means of gel shift assays, we detected binding of the homeoproteins PDX1, PBX and PREP to several cis-elements of these regions. In constrast, regions A and C of the zebrafish pax6a gene are not active in the pancreas, this difference being attributable to sequence divergences within two cis-elements binding the pancreatic homeoprotein PDX1. Conclusion Our data indicate a conserved role of enhancers A and C in the pancreatic expression of pax6b and emphasize the importance of the homeoproteins PBX and PREP cooperating with PDX1, in activating pax6b expression in endocrine pancreatic cells. This study also provides a striking example of how adaptative evolution of gene regulatory sequences upon gene duplication progressively leads to subfunctionalization of the paralogous gene pair. PMID

  13. 5-Hydroxymethylcytosine localizes to enhancer elements and is associated with survival in glioblastoma patients

    PubMed Central

    Johnson, Kevin C.; Houseman, E. Andres; King, Jessica E.; von Herrmann, Katharine M.; Fadul, Camilo E.; Christensen, Brock C.

    2016-01-01

    Glioblastomas exhibit widespread molecular alterations including a highly distorted epigenome. Here, we resolve genome-wide 5-methylcytosine and 5-hydroxymethylcytosine in glioblastoma through parallel processing of DNA with bisulfite and oxidative bisulfite treatments. We apply a statistical algorithm to estimate 5-methylcytosine, 5-hydroxymethylcytosine and unmethylated proportions from methylation array data. We show that 5-hydroxymethylcytosine is depleted in glioblastoma compared with prefrontal cortex tissue. In addition, the genomic localization of 5-hydroxymethylcytosine in glioblastoma is associated with features of dynamic cell-identity regulation such as tissue-specific transcription and super-enhancers. Annotation of 5-hydroxymethylcytosine genomic distribution reveal significant associations with RNA regulatory processes, immune function, stem cell maintenance and binding sites of transcription factors that drive cellular proliferation. In addition, model-based clustering results indicate that patients with low-5-hydroxymethylcytosine patterns have significantly poorer overall survival. Our results demonstrate that 5-hydroxymethylcytosine patterns are strongly related with transcription, localizes to disease-critical genes and are associated with patient prognosis. PMID:27886174

  14. Bioactive glass-derived trabecular coating: a smart solution for enhancing osteointegration of prosthetic elements.

    PubMed

    Vitale-Brovarone, Chiara; Baino, Francesco; Tallia, Francesca; Gervasio, Cristina; Verné, Enrica

    2012-10-01

    In this work, the use of foam-like glass-ceramic scaffolds as trabecular coatings on ceramic prosthetic devices to enhance implant osteointegration is proposed. The feasibility of this innovative device was explored in a simplified, flat geometry: glass-ceramic scaffolds, prepared by polymeric sponge replication and mimicking the trabecular architecture of cancellous bone, were joined to alumina square substrates by a dense glass coating (interlayer). The role played by different formulations of starting glasses was examined, with particular care to the effect on the mechanical properties and bioactivity of the final coating. Microindentations at the coating/substrate interface and tensile tests were performed to evaluate the bonding strength between the sample's components. In vitro bioactive behaviour was assessed by soaking in simulated body fluid and evaluating the apatite formation on the surface and inside the pores of the trabecular coating. The concepts disclosed in the present study can have a significant impact in the field of implantable devices, suggesting a valuable alternative to traditional, often invasive bone-prosthesis fixation.

  15. The solar elemental abundances problem: Large enhancements in photoionization and bound-free opacity

    NASA Astrophysics Data System (ADS)

    Pradhan, A.; Nahar, S.

    2016-05-01

    Aimed at solving the outstanding problem of solar opacity and radiation transport, we report substantial photoabsorption in the high-energy regime due to atomic core photo-excitations not heretofore considered. In an extensive R-Matrix calculations of unprecedented complexity for an important iron ion Fe XVII, with a wave function expansion of 99 Fe XVIII core states from n <= 4 complexes (equivalent to 218 fine structure levels), we find: i) up to orders of magnitude enhancement in background photoionization cross sections, in addition to strongly peaked photo-excitation-of-core resonances not considered in current opacity models, and ii) demonstrate convergence with respect to successive core excitations. These findings may explain the ``higher-than-predicted'' monochromatic iron opacity measured recently at the Sandia Z-pinch fusion device at solar interior conditions. The findings will also impact the total atomic photoabsorption and radiation transport in laboratory and astrophysical plasmas, such as UV emission from host stars of extra-solar planets. Support: NSF, DOE, Ohio Supercomputer Center, Columbus, OH.

  16. An enhanced lumped element electrical model of a double barrier memristive device

    NASA Astrophysics Data System (ADS)

    Solan, Enver; Dirkmann, Sven; Hansen, Mirko; Schroeder, Dietmar; Kohlstedt, Hermann; Ziegler, Martin; Mussenbrock, Thomas; Ochs, Karlheinz

    2017-05-01

    The massive parallel approach of neuromorphic circuits leads to effective methods for solving complex problems. It has turned out that resistive switching devices with a continuous resistance range are potential candidates for such applications. These devices are memristive systems—nonlinear resistors with memory. They are fabricated in nanotechnology and hence parameter spread during fabrication may aggravate reproducible analyses. This issue makes simulation models of memristive devices worthwhile. Kinetic Monte-Carlo simulations based on a distributed model of the device can be used to understand the underlying physical and chemical phenomena. However, such simulations are very time-consuming and neither convenient for investigations of whole circuits nor for real-time applications, e.g. emulation purposes. Instead, a concentrated model of the device can be used for both fast simulations and real-time applications, respectively. We introduce an enhanced electrical model of a valence change mechanism (VCM) based double barrier memristive device (DBMD) with a continuous resistance range. This device consists of an ultra-thin memristive layer sandwiched between a tunnel barrier and a Schottky-contact. The introduced model leads to very fast simulations by using usual circuit simulation tools while maintaining physically meaningful parameters. Kinetic Monte-Carlo simulations based on a distributed model and experimental data have been utilized as references to verify the concentrated model.

  17. Development and application of a new Silent reporter system to quantitate the activity of enhancer elements in the type II Collagen Gene.

    PubMed

    Ito, Kazuo; Shinomura, Tamayuki

    2016-07-01

    Type II collagen is a major component of cartilage, which provide structural stiffness to the tissue. As a sufficient amount of type II collagen is critical for maintaining the biomechanical properties of cartilage, its expression is tightly regulated in chondrocytes. Therefore, it is essential to elucidate in detail the transcriptional mechanism that controls expression of type II collagen, in particular by two enhancer elements we recently discovered. To systematically analyze and compare enhancer activities, we developed a novel reporter assay system that exploits site-specific integration of promoter and enhancer elements to activate a transcriptionally silent reporter gene. Using this system, we found that the enhancer elements have distinct characteristics, with one exhibiting additive effects and the other exhibiting synergistic effects when repeated in tandem. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Space bandwidth product enhancement of holographic display using high-order diffraction guided by holographic optical element.

    PubMed

    Li, Gang; Jeong, Jinsoo; Lee, Dukho; Yeom, Jiwoon; Jang, Changwon; Lee, Seungjae; Lee, Byoungho

    2015-12-28

    A space bandwidth product (SBP) enhancement method for holographic display using high-order diffraction of a spatial light modulator (SLM) is proposed. Among numerous high order diffraction terms, the plus-minus first and the zeroth are adopted and guided by holographic optical elements (HOEs) to an identical direction with the same intensity. By using a set of electro-shutters synchronized with corresponding order component, the system acts as if three SLMs are tiled in the horizontal direction. To confirm the feasibility of using HOE as the guiding optics for the system, several optical characteristics of the recording material are measured before using them. Furthermore, a computer generated hologram algorithm is proposed for compensating the wavefront distortion caused by use of the HOE. The demonstrated system achieves a three-fold increase in SBP of a single SLM. The results are verified experimentally.

  19. Enhanced carcinogenicity by coexposure to arsenic and iron and a novel remediation system for the elements in well drinking water.

    PubMed

    Kumasaka, Mayuko Y; Yamanoshita, Osamu; Shimizu, Shingo; Ohnuma, Shoko; Furuta, Akio; Yajima, Ichiro; Nizam, Saika; Khalequzzaman, Md; Shekhar, Hossain U; Nakajima, Tamie; Kato, Masashi

    2013-03-01

    Various carcinomas including skin cancer are explosively increasing in arsenicosis patients who drink arsenic-polluted well water, especially in Bangladesh. Although well drinking water in the cancer-prone areas contains various elements, very little is known about the effects of elements except arsenic on carcinogenicity. In order to clarify the carcinogenic effects of coexposure to arsenic and iron, anchorage-independent growth and invasion in human untransformed HaCaT and transformed A431 keratinocytes were examined. Since the mean ratio of arsenic and iron in well water was 1:10 in cancer-prone areas of Bangladesh, effects of 1 μM arsenic and 10 μM iron were investigated. Iron synergistically promoted arsenic-mediated anchorage-independent growth in untransformed and transformed keratinocytes. Iron additionally increased invasion in both types of keratinocytes. Activities of c-SRC and ERK that regulate anchorage-independent growth and invasion were synergistically enhanced in both types of keratinocytes. Our results suggest that iron promotes arsenic-mediated transformation of untransformed keratinocytes and progression of transformed keratinocytes. We then developed a low-cost and high-performance adsorbent composed of a hydrotalcite-like compound for arsenic and iron. The adsorbent rapidly reduced concentrations of both elements from well drinking water in cancer-prone areas of Bangladesh to levels less than those in WHO health-based guidelines for drinking water. Thus, we not only demonstrated for the first time increased carcinogenicity by coexposure to arsenic and iron but also proposed a novel remediation system for well drinking water.

  20. Phase field modeling of brittle fracture for enhanced assumed strain shells at large deformations: formulation and finite element implementation

    NASA Astrophysics Data System (ADS)

    Reinoso, J.; Paggi, M.; Linder, C.

    2017-02-01

    Fracture of technological thin-walled components can notably limit the performance of their corresponding engineering systems. With the aim of achieving reliable fracture predictions of thin structures, this work presents a new phase field model of brittle fracture for large deformation analysis of shells relying on a mixed enhanced assumed strain (EAS) formulation. The kinematic description of the shell body is constructed according to the solid shell concept. This enables the use of fully three-dimensional constitutive models for the material. The proposed phase field formulation integrates the use of the (EAS) method to alleviate locking pathologies, especially Poisson thickness and volumetric locking. This technique is further combined with the assumed natural strain method to efficiently derive a locking-free solid shell element. On the computational side, a fully coupled monolithic framework is consistently formulated. Specific details regarding the corresponding finite element formulation and the main aspects associated with its implementation in the general purpose packages FEAP and ABAQUS are addressed. Finally, the applicability of the current strategy is demonstrated through several numerical examples involving different loading conditions, and including linear and nonlinear hyperelastic constitutive models.

  1. Phase field modeling of brittle fracture for enhanced assumed strain shells at large deformations: formulation and finite element implementation

    NASA Astrophysics Data System (ADS)

    Reinoso, J.; Paggi, M.; Linder, C.

    2017-06-01

    Fracture of technological thin-walled components can notably limit the performance of their corresponding engineering systems. With the aim of achieving reliable fracture predictions of thin structures, this work presents a new phase field model of brittle fracture for large deformation analysis of shells relying on a mixed enhanced assumed strain (EAS) formulation. The kinematic description of the shell body is constructed according to the solid shell concept. This enables the use of fully three-dimensional constitutive models for the material. The proposed phase field formulation integrates the use of the (EAS) method to alleviate locking pathologies, especially Poisson thickness and volumetric locking. This technique is further combined with the assumed natural strain method to efficiently derive a locking-free solid shell element. On the computational side, a fully coupled monolithic framework is consistently formulated. Specific details regarding the corresponding finite element formulation and the main aspects associated with its implementation in the general purpose packages FEAP and ABAQUS are addressed. Finally, the applicability of the current strategy is demonstrated through several numerical examples involving different loading conditions, and including linear and nonlinear hyperelastic constitutive models.

  2. Interfamilial recombination between viruses led to acquisition of a novel translation-enhancing RNA element that allows resistance breaking

    PubMed Central

    Miras, Manuel; Sempere, Raquel N.; Kraft, Jelena J.; Miller, W. Allen; Aranda, Miguel A.; Truniger, Veronica

    2015-01-01

    Summary Many plant viruses depend on functional RNA elements, called 3′-UTR cap-independent translation enhancers (3′-CITEs), for translation of their RNAs. In this manuscript we provide direct proof for the existing hypothesis that 3′-CITEs are modular and transferable by recombination in nature, and that this is associated with an advantage for the created virus. By characterizing a newly identified Melon necrotic spot virus (MNSV; Tombusviridae) isolate, which is able to overcome eukaryotic translation initiation factor 4E (eIF4E)-mediated resistance, we found that it contains a 55 nucleotide insertion in its 3′-UTR. We provide strong evidence that this insertion was acquired by interfamilial recombination with the 3′-UTR of an Asiatic Cucurbit aphid-borne yellows virus (CABYV; Luteoviridae). By constructing chimeric viruses, we showed that this recombined sequence is responsible for resistance breaking. Analysis of the translational efficiency of reporter constructs showed that this sequence functions as a novel 3′-CITE in both resistant and susceptible plants, being essential for translation control in resistant plants. In conclusion, we showed that a recombination event between two clearly identified viruses from different families led to the transfer of exactly the sequence corresponding to a functional RNA element, giving rise to a new isolate with the capacity to infect an otherwise non-susceptible host. PMID:24372390

  3. Interfamilial recombination between viruses led to acquisition of a novel translation-enhancing RNA element that allows resistance breaking.

    PubMed

    Miras, Manuel; Sempere, Raquel N; Kraft, Jelena J; Miller, W Allen; Aranda, Miguel A; Truniger, Veronica

    2014-04-01

    Many plant viruses depend on functional RNA elements, called 3'-UTR cap-independent translation enhancers (3'-CITEs), for translation of their RNAs. In this manuscript we provide direct proof for the existing hypothesis that 3'-CITEs are modular and transferable by recombination in nature, and that this is associated with an advantage for the created virus. By characterizing a newly identified Melon necrotic spot virus (MNSV; Tombusviridae) isolate, which is able to overcome eukaryotic translation initiation factor 4E (eIF4E)-mediated resistance, we found that it contains a 55 nucleotide insertion in its 3'-UTR. We provide strong evidence that this insertion was acquired by interfamilial recombination with the 3'-UTR of an Asiatic Cucurbit aphid-borne yellows virus (CABYV; Luteoviridae). By constructing chimeric viruses, we showed that this recombined sequence is responsible for resistance breaking. Analysis of the translational efficiency of reporter constructs showed that this sequence functions as a novel 3'-CITE in both resistant and susceptible plants, being essential for translation control in resistant plants. In conclusion, we showed that a recombination event between two clearly identified viruses from different families led to the transfer of exactly the sequence corresponding to a functional RNA element, giving rise to a new isolate with the capacity to infect an otherwise nonsusceptible host. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  4. The CCAAT/enhancer-binding protein-ATF response elements-luciferase mouse model, an innovative tool to monitor the integrated stress response pathway in vivo.

    PubMed

    Bruhat, Alain; Fafournoux, Pierre

    2017-05-01

    The article highlights the recent development of an ATF4 (activating transcription factor) inducible luciferase (LUC) mouse model to monitor the integrated stress response pathway (ISR) in vivo. The ISR pathway plays a key role in cellular adaptation to stress and is dysregulated in numerous diseases. The core event in this pathway is the phosphorylation of eukaryotic translation initiation factor 2 α, which leads to the recruitment of the transcription factor ATF4 to specific CCAAT/enhancer-binding protein-ATF response elements (CAREs) located in the promoters of target genes. To monitor the modulation of this pathway in the whole animal and at tissue and cellular levels, we generated a CARE-driven LUC mouse model. We validated the relevance of this model to study stress-related pathologies and recently observed the correlation between the ISR pathway induction in muscle and the occurrence of stress-induced skeletal muscle atrophy. The CARE-LUC mouse model represents an innovative tool for investigating the role of the ISR pathway in physiology and disease and opens new avenues for the development of drugs that could modify this important pathway in stress-related human diseases.

  5. Highly sensitive object location in tissue models with linear in-phase and anti-phase multi-element optical arrays in one and two dimensions.

    PubMed Central

    Chance, B; Kang, K; He, L; Weng, J; Sevick, E

    1993-01-01

    Based upon previous observations of low-frequency photon diffusion waves within highly scattering tissue, this paper explores the "near-field" phenomena of such waves of approximately 10-cm wavelength with 200-MHz phase modulation equipment. Multiple-element source arrays consist of laser diode sources modulated at 180 degrees out of phase with respect to the other sources. The diffusing waves originating from the out-of-phase sources give, in the midplane, an amplitude null and a sharp phase transition. These may be observed in a highly scattering intralipid medium simulating the breast or brain (0.5% intralipid), 3-5 cm from the transmitting laser diodes. In the plane containing the array, there is a high sensitivity for a small volume of a hidden absorber (indocyanine green) deep within a highly scattering medium; 20 pmol in a volume of 70 microliters can be detected. Two-dimensional arrays consisting of four or more elements in two orthogonal planes give sensitivity on both axes similar to the one-dimensional array. Measurements show that in the presence of a light-absorbing object, the amplitude null and the interference plane becomes a curved surface which is deflected toward the heterogeneity. The degree of deflection is related to the volume and the absorption characteristics of the heterogeneity and provides detection of the heterogeneity, and thereby may provide localization information for the detection of small tumors within the human breast, or stroke volumes, aneurysms, and tumors in the human brain. PMID:8475092

  6. Enhancing Transgene Expression from Recombinant AAV8 Vectors in Different Tissues Using Woodchuck Hepatitis Virus Post-Transcriptional Regulatory Element

    PubMed Central

    Wang, Lizheng; Wang, Zixuan; Zhang, Fangfang; Zhu, Rui; Bi, Jinpeng; Wu, Jiaxin; Zhang, Haihong; Wu, Hui; Kong, Wei; Yu, Bin; Yu, Xianghui

    2016-01-01

    Adeno-associated virus (AAV) vectors have been utilized extensively in gene therapy and gene function studies, as strong transgene expression is a prerequisite for positive outcomes. AAV8 was reported as the most efficient AAV serotype for transduction of the liver, brain and muscle compared with other serotypes. However, AAV8-mediated transduction of human hepatocytes is rather poor with approximately 20-fold lower efficiency compared with that of mouse hepatocytes. Therefore, we applied the woodchuck hepatitis virus post-transcriptional regulatory element (WPRE) to enhance AAV8-mediated transgene expression driven by a combination promoter (CAG promoter) with a CMV-IE enhancer and chicken beta-actin promoter for a more efficient viral vector. Transgene expression from recombinant AAV8 (rAAV8) vectors harboring a red fluorescent protein (RFP) reporter gene with or without WPRE were evaluated in vitro and in vivo. The results demonstrated that WPRE improved AAV8-mediated RFP expression in different cell lines with clear increases of transgene expression in the liver, brain or muscle of animals. The findings of this study will help to substantially reduce the quantity of viral particles that must be injected in order to reach a therapeutic level of transgene expression in gene therapy. Consequently, such dose reductions may lessen the potential risks associated with high doses of viral vectors. PMID:27076785

  7. Gift from statistical learning: Visual statistical learning enhances memory for sequence elements and impairs memory for items that disrupt regularities.

    PubMed

    Otsuka, Sachio; Saiki, Jun

    2016-02-01

    Prior studies have shown that visual statistical learning (VSL) enhances familiarity (a type of memory) of sequences. How do statistical regularities influence the processing of each triplet element and inserted distractors that disrupt the regularity? Given that increased attention to triplets induced by VSL and inhibition of unattended triplets, we predicted that VSL would promote memory for each triplet constituent, and degrade memory for inserted stimuli. Across the first two experiments, we found that objects from structured sequences were more likely to be remembered than objects from random sequences, and that letters (Experiment 1) or objects (Experiment 2) inserted into structured sequences were less likely to be remembered than those inserted into random sequences. In the subsequent two experiments, we examined an alternative account for our results, whereby the difference in memory for inserted items between structured and random conditions is due to individuation of items within random sequences. Our findings replicated even when control letters (Experiment 3A) or objects (Experiment 3B) were presented before or after, rather than inserted into, random sequences. Our findings suggest that statistical learning enhances memory for each item in a regular set and impairs memory for items that disrupt the regularity. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Kinetics and mechanism of the enhanced reductive degradation of nitrobenzene by elemental iron in the presence of ultrasound

    SciTech Connect

    Hung, H.M.; Ling, F.H.; Hoffmann, M.R.

    2000-05-01

    Sonolysis, reduction by elemental iron (Fe{sup 0}), and a combination of the two processes were used to facilitate the degradation of nitrobenzene (NB) and aniline (AN) in water. The rates of reduction of nitrobenzene by Fe{sup 0} are enhanced in the presence of ultrasound. The first-order rate constant, K{sub US}, for nitrobenzene degradation by ultrasound is 1.8 x 10{sup {minus}3} min{sup {minus}1}, while in the presence of Fe{sup 0}, the rate was found to be substantially faster. The observation of similar degradation rates for aniline in each system suggests that the sonication process was not affected by the presence of Fe{sup 0}. The observed rate enhancements for the degradation of nitrobenzene can be attributed primarily to the continuous cleaning and chemical activation of the Fe{sup 0} surfaces by acoustic cavitation and to accelerated mass transport rates of reactants, intermediates, and products between the solution phase and the Fe{sup 0} surface. The relative concentrations of nitrosobenzene and aniline, the principal reaction intermediates generated by Fe{sup 0} reduction, are altered substantially in the presence of ultrasound.

  9. Detection of mercury ions using silver telluride nanoparticles as a substrate and recognition element through surface-enhanced Raman scattering

    NASA Astrophysics Data System (ADS)

    Wang, Chia-Wei; Lin, Zong-Hong; Roy, Prathik; Chang, Huan-Tsung

    2013-10-01

    In this paper we unveil a new sensing strategy for sensitive and selective detection of Hg2+ through surface-enhanced Raman scattering (SERS) using Ag2Te nanoparticles (NPs) as a substrate and recognition element and rhodamine 6G (R6G) as a reporter. Ag2Te NPs prepared from tellurium dioxide and silver nitrate and hydrazine in aqueous solution containing sodium dodecyl sulfate at 90ºC with an average size of 26.8 ± 4.1 nm (100 counts) have strong SERS activity. The Ag2Te substrate provides strong SERS signals of R6G with an enhancement factor of 3.6 × 105 at 1360 cm-1, which is comparable to Ag NPs. After interaction of Ag2Te NPs with Hg2+, some HgTe NPs are formed, leading to decreases in the SERS signal of R6G, mainly because HgTe NPs relative to Ag2Te NPs have weaker SERS activity. Under optimum conditions, this SERS approach using Ag2Te as substrates is selective for the detection of Hg2+, with a limit of detection of 3 nM and linearity over 10-150 nM. The practicality of this approach has been validated for the determination of the concentrations of spiked Hg2+ in a pond water sample.

  10. A mammary cell-specific enhancer in mouse mammary tumor virus DNA is composed of multiple regulatory elements including binding sites for CTF/NFI and a novel transcription factor, mammary cell-activating factor.

    PubMed Central

    Mink, S; Härtig, E; Jennewein, P; Doppler, W; Cato, A C

    1992-01-01

    Mouse mammary tumor virus (MMTV) is a milk-transmitted retrovirus involved in the neoplastic transformation of mouse mammary gland cells. The expression of this virus is regulated by mammary cell type-specific factors, steroid hormones, and polypeptide growth factors. Sequences for mammary cell-specific expression are located in an enhancer element in the extreme 5' end of the long terminal repeat region of this virus. This enhancer, when cloned in front of the herpes simplex thymidine kinase promoter, endows the promoter with mammary cell-specific response. Using functional and DNA-protein-binding studies with constructs mutated in the MMTV long terminal repeat enhancer, we have identified two main regulatory elements necessary for the mammary cell-specific response. These elements consist of binding sites for a transcription factor in the family of CTF/NFI proteins and the transcription factor mammary cell-activating factor (MAF) that recognizes the sequence G Pu Pu G C/G A A G G/T. Combinations of CTF/NFI- and MAF-binding sites or multiple copies of either one of these binding sites but not solitary binding sites mediate mammary cell-specific expression. The functional activities of these two regulatory elements are enhanced by another factor that binds to the core sequence ACAAAG. Interdigitated binding sites for CTF/NFI, MAF, and/or the ACAAAG factor are also found in the 5' upstream regions of genes encoding whey milk proteins from different species. These findings suggest that mammary cell-specific regulation is achieved by a concerted action of factors binding to multiple regulatory sites. Images PMID:1328867

  11. Shared Enhancer Activity in the Limbs and Phallus and Functional Divergence of a Limb-Genital cis-Regulatory Element in Snakes.

    PubMed

    Infante, Carlos R; Mihala, Alexandra G; Park, Sungdae; Wang, Jialiang S; Johnson, Kenji K; Lauderdale, James D; Menke, Douglas B

    2015-10-12

    The amniote phallus and limbs differ dramatically in their morphologies but share patterns of signaling and gene expression in early development. Thus far, the extent to which genital and limb transcriptional networks also share cis-regulatory elements has remained unexplored. We show that many limb enhancers are retained in snake genomes, suggesting that these elements may function in non-limb tissues. Consistent with this, our analysis of cis-regulatory activity in mice and Anolis lizards reveals that patterns of enhancer activity in embryonic limbs and genitalia overlap heavily. In mice, deletion of HLEB, an enhancer of Tbx4, produces defects in hindlimbs and genitalia, establishing the importance of this limb-genital enhancer for development of these different appendages. Further analyses demonstrate that the HLEB of snakes has lost hindlimb enhancer function while retaining genital activity. Our findings identify roles for Tbx4 in genital development and highlight deep similarities in cis-regulatory activity between limbs and genitalia.

  12. Location Privacy

    NASA Astrophysics Data System (ADS)

    Meng, Xiaofeng; Chen, Jidong

    With rapid development of sensor and wireless mobile devices, it is easy to access mobile users' location information anytime and anywhere. On one hand, LBS is becoming more and more valuable and important. On the other hand, location privacy issues raised by such applications have also gained more attention. However, due to the specificity of location information, traditional privacy-preserving techniques in data publishing cannot be used. In this chapter, we will introduce location privacy, and analyze the challenges of location privacy-preserving, and give a survey of existing work including the system architecture, location anonymity and query processing.

  13. Location | FNLCR

    Cancer.gov

    The Frederick National Laboratory for Cancer Research campus is located 50 miles northwest of Washington, D.C., and 50 miles west of Baltimore, Maryland, in Frederick, Maryland. Satellite locations include leased and government facilities extending s

  14. Automatic vehicle location system

    NASA Technical Reports Server (NTRS)

    Hansen, G. R., Jr. (Inventor)

    1973-01-01

    An automatic vehicle detection system is disclosed, in which each vehicle whose location is to be detected carries active means which interact with passive elements at each location to be identified. The passive elements comprise a plurality of passive loops arranged in a sequence along the travel direction. Each of the loops is tuned to a chosen frequency so that the sequence of the frequencies defines the location code. As the vehicle traverses the sequence of the loops as it passes over each loop, signals only at the frequency of the loop being passed over are coupled from a vehicle transmitter to a vehicle receiver. The frequencies of the received signals in the receiver produce outputs which together represent a code of the traversed location. The code location is defined by a painted pattern which reflects light to a vehicle carried detector whose output is used to derive the code defined by the pattern.

  15. Transposable Elements and DNA Methylation Create in Embryonic Stem Cells Human-Specific Regulatory Sequences Associated with Distal Enhancers and Noncoding RNAs

    PubMed Central

    Glinsky, Gennadi V.

    2015-01-01

    Despite significant progress in the structural and functional characterization of the human genome, understanding of the mechanisms underlying the genetic basis of human phenotypic uniqueness remains limited. Here, I report that transposable element-derived sequences, most notably LTR7/HERV-H, LTR5_Hs, and L1HS, harbor 99.8% of the candidate human-specific regulatory loci (HSRL) with putative transcription factor-binding sites in the genome of human embryonic stem cells (hESC). A total of 4,094 candidate HSRL display selective and site-specific binding of critical regulators (NANOG [Nanog homeobox], POU5F1 [POU class 5 homeobox 1], CCCTC-binding factor [CTCF], Lamin B1), and are preferentially located within the matrix of transcriptionally active DNA segments that are hypermethylated in hESC. hESC-specific NANOG-binding sites are enriched near the protein-coding genes regulating brain size, pluripotency long noncoding RNAs, hESC enhancers, and 5-hydroxymethylcytosine-harboring regions immediately adjacent to binding sites. Sequences of only 4.3% of hESC-specific NANOG-binding sites are present in Neanderthals’ genome, suggesting that a majority of these regulatory elements emerged in Modern Humans. Comparisons of estimated creation rates of novel TF-binding sites revealed that there was 49.7-fold acceleration of creation rates of NANOG-binding sites in genomes of Chimpanzees compared with the mouse genomes and further 5.7-fold acceleration in genomes of Modern Humans compared with the Chimpanzees genomes. Preliminary estimates suggest that emergence of one novel NANOG-binding site detectable in hESC required 466 years of evolution. Pathway analysis of coding genes that have hESC-specific NANOG-binding sites within gene bodies or near gene boundaries revealed their association with physiological development and functions of nervous and cardiovascular systems, embryonic development, behavior, as well as development of a diverse spectrum of pathological conditions

  16. Control elements targeting Tgfb3 expression to the palatal epithelium are located intergenically and in introns of the upstream Ift43 gene

    PubMed Central

    Lane, Jamie; Yumoto, Kenji; Pisano, Justin; Azhar, Mohamad; Thomas, Penny S.; Kaartinen, Vesa

    2014-01-01

    Tgfb3 is strongly and specifically expressed in the epithelial tips of pre-fusion palatal shelves where it plays a critical non-redundant role in palatal fusion in both medial edge epithelial (MEE) cells and in a thin layer of flattened peridermal cells that covers the MEE. It is not known how Tgfb3 expression is regulated in these specific cell types. Using comparative genomics and transgenic reporter assays, we have identified cis-regulatory elements that could control Tgfb3 expression during palatogenesis. Our results show that a 61-kb genomic fragment encompassing the Tgfb3 gene drives remarkably specific reporter expression in the MEE and adjacent periderm. Within this fragment, we identified two small, non-coding, evolutionarily conserved regions in intron 2 of the neighboring Ift43 gene, and a larger region in the intervening sequence between the Ift43 and Tgfb3 genes, each of which could target reporter activity to the tips of pre-fusion/fusing palatal shelves. Identification of the cis-regulatory sequences controlling spatio-temporal Tgfb3 expression in palatal shelves is a key step toward understanding upstream regulation of Tgfb3 expression during palatogenesis and should enable the development of improved tools to investigate palatal epithelial fusion. PMID:25071603

  17. Specific binding of Synechococcus sp. strain PCC 7942 proteins to the enhancer element of psbAII required for high-light-induced expression.

    PubMed Central

    Li, R; Dickerson, N S; Mueller, U W; Golden, S S

    1995-01-01

    The psbAII gene of the cyanobacterium Synechococcus sp. strain PCC 7942 is a member of a three-gene family that encodes the D1 protein of the photosystem II reaction center. Transcription of psbAII is rapidly induced when the light intensity reaching the culture increases from 125 microE.m-2.s-1 (low light) to 750 microE.m-2.s-1 (high light). The DNA segment upstream of psbAII that corresponds to the untranslated leader of its major transcript has enhancer activity and confers high-light induction. We show that one or more soluble proteins from PCC 7942 specifically bind to this region of psbAII (designated the enhancer element). In vivo footprinting showed protein binding to the enhancer element in high-light-exposed cell samples but not in those maintained at low light, even though in vitro mobility shifts were detectable with extracts from low- or high-light-grown cells. When 12 bp were deleted from the psbAII enhancer element, protein binding was impaired and high-light induction of both transcriptional and translational psbAII-lacZ reporters was significantly reduced. This finding indicates that protein binding to this region is required for high-light induction of psbAII. The mutant element also showed impaired enhancer activity when combined with a heterologous promoter. PMID:7836280

  18. Caffeine suppresses exercise-enhanced long-term and location memory in middle-aged rats: Involvement of hippocampal Akt and CREB signaling.

    PubMed

    Cechella, José L; Leite, Marlon R; da Rocha, Juliana T; Dobrachinski, Fernando; Gai, Bibiana M; Soares, Félix A A; Bresciani, Guilherme; Royes, Luiz F F; Zeni, Gilson

    2014-11-05

    The cognitive function decline is closely related with brain changes generated by age. The ability of caffeine and exercise to prevent memory impairment has been reported in animal models and humans. The purpose of the present study was to investigate whether swimming exercise and caffeine administration enhance memory in middle-aged Wistar rats. Male Wistar rats (18months) received caffeine at a dose of 30mg/kg, 5days per week by a period of 4weeks. Animals were subjected to swimming training with a workload (3% of body weight, 20min per day for 4weeks). After 4weeks, the object recognition test (ORT) and the object location test (OLT) were performed. The results of this study demonstrated that caffeine suppressed exercise-enhanced long-term (ORT) and spatial (OLT) memory in middle-aged and this effect may be related to a decrease in hippocampal p-CREB signaling. This study also provided evidence that the effects of this protocol on memory were not accompanied by alterations in the levels of activated Akt. The [(3)H] glutamate uptake was reduced in hippocampus of rats administered with caffeine and submitted to swimming protocol.

  19. Post-transcriptional regulation of cytokine genes in fish: A role for conserved AU-rich elements located in the 3'-untranslated region of their mRNAs.

    PubMed

    Roca, Francisco J; Cayuela, María L; Secombes, Chris J; Meseguer, José; Mulero, Victoriano

    2007-01-01

    The overproduction of cytokines, such us interleukin-1beta (IL-1beta) and tumor necrosis factor alpha (TNFalpha), contributes to the pathological complications observed in many inflammatory diseases caused by bacterial endotoxins. The synthesis of these cytokines is tightly regulated at both transcriptional and post-transcriptional levels. Post-transcriptional regulation of gene expression depends on specific cis-acting sequences and trans-acting factors. Thus, the presence of adenylate- and uridylate-rich (AU-rich) elements (AREs) has been described in the 3'-untranslated regions (UTRs) of many unstable mammalian mRNAs. Although, it represents the most widespread, phylogenetically conserved and efficient determinant of mRNA stability among those so far characterized in mammalian cells, no studies are available on the functional relevance of this sequence in non-mammalian vertebrates. In this contribution, we study the enzymatic activity of various luciferase reporter constructs, containing or lacking the 3'UTR of IL-1beta and TNFalpha from different fish species, and report the finding that bony fish AREs are able to decrease luciferase activity but are less potent than their mammalian counterparts. Surprisingly, the 3'UTR of the IL-1beta from the cartilaginous fish small spotted catshark had the greatest ability to decrease luciferase activity. Lastly, the functional significance of the above was confirmed by measuring the half-life of IL-1beta and TNFalpha mRNAs in gilthead seabream leukocytes by blocking transcription with actinomycin D. Both cytokine mRNAs were unstable with an estimated half-life of about 45 min in control and activated cells.

  20. Time-resolved measurements of black carbon light absorption enhancement in urban and near-urban locations of southern Ontario, Canada

    NASA Astrophysics Data System (ADS)

    Chan, T. W.; Brook, J. R.; Smallwood, G. J.; Lu, G.

    2011-10-01

    In this study a photoacoustic spectrometer (PA), a laser-induced incandescence instrument system (LII) and an Aerosol Mass Spectrometer were operated in parallel for in-situ measurements of black carbon (BC) light absorption enhancement. Results of a thermodenuder experiment using ambient particles in Toronto are presented first to show that LII measurements of BC are not influenced by the presence of non-refractory material thus providing true atmospheric BC mass concentrations. In contrast, the PA response is enhanced when the non-refractory material is internally mixed with the BC particles. Through concurrent measurements using the LII and PA the specific absorption cross-section (SAC) can be quantified with high time resolution (1 min). Comparisons of ambient PA and LII measurements from four different locations (suburban Toronto; a street canyon with diesel bus traffic in Ottawa; adjacent to a commuter highway in Ottawa and; regional background air in and around Windsor, Ontario), show that different impacts from emission sources and/or atmospheric processes result in different particle light absorption enhancements and hence variations in the SAC. The diversity of measurements obtained, including those with the thermodenuder, demonstrated that it is possible to identify measurements where the presence of externally-mixed non-refractory particles obscures direct observation of the effect of coating material on the SAC, thus allowing this effect to be measured with more confidence. Depending upon the time and location of measurement (urban, rural, close to and within a lake breeze frontal zone), 30 min average SAC varies between 9 ± 2 and 43 ± 4 m2 g-1. Causes of this variation, which were determined through the use of meteorological and gaseous measurements (CO, SO2, O3), include the particle emission source, airmass source region, the degree of atmospheric processing. Observations from this study also show that the active surface area of the BC aggregate

  1. Rolling element bearing defect detection using the generalized synchrosqueezing transform guided by time-frequency ridge enhancement.

    PubMed

    Li, Chuan; Sanchez, Vinicio; Zurita, Grover; Cerrada Lozada, Mariela; Cabrera, Diego

    2016-01-01

    Healthy rolling element bearings are vital guarantees for safe operation of the rotating machinery. Time-frequency (TF) signal analysis is an effective tool to detect bearing defects under time-varying shaft speed condition. However, it is a challenging work dealing with defective characteristic frequency and rotation frequency simultaneously without a tachometer. For this reason, a technique using the generalized synchrosqueezing transform (GST) guided by enhanced TF ridge extraction is suggested to detect the existence of the bearing defects. The low frequency band and the resonance band are first chopped from the Fourier spectrum of the bearing vibration measurements. The TF information of the lower band component and the resonance band envelope are represented using short-time Fourier transform, where the TF ridge are extracted by harmonic summation search and ridge candidate fusion operations. The inverse of the extracted TF ridge is subsequently used to guide the GST mapping the chirped TF representation to the constant one. The rectified TF pictures are then synchrosqueezed as sharper spectra where the rotation frequency and the defective characteristic frequency can be identified, respectively. Both simulated and experimental signals were used to evaluate the present technique. The results validate the effectiveness of the suggested technique for the bearing defect detection. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  2. Elemental analysis by surface-enhanced Laser-Induced Breakdown Spectroscopy combined with liquid-liquid microextraction

    NASA Astrophysics Data System (ADS)

    Aguirre, M. A.; Legnaioli, S.; Almodóvar, F.; Hidalgo, M.; Palleschi, V.; Canals, A.

    2013-01-01

    In this work, the possibility of using Laser-Induced Breakdown Spectrometry (LIBS) combined with liquid-liquid microextraction techniques is evaluated as a simple and fast method for trace elemental analysis. Two different strategies for LIBS analysis of manganese contained in microdroplets of extraction solvent (Triton X-114) are studied: (i) analysis by direct laser irradiation of microdroplets; and (ii) analysis by laser irradiation of microdroplets dried on metallic substrates (surface-enhanced LIBS — SENLIBS). Experiments were carried out using synthetic samples with different concentrations of manganese in a 10% w/w Triton X-114 matrix. The analysis by direct laser irradiation of microdroplets showed low precision, sensitivity and poor linearity across the concentration range evaluated (R2 < 0.95). On the other hand, the SENLIBS method of analysis improved the sensitivity, the precision and the linearity of the calibration curve with respect to the direct analysis of microdroplets. In comparison with experimental results obtained by direct analysis, SENLIBS also allowed several replicate measurements to be carried out in a single microdroplet. The limit of detection obtained was 6 μg g- 1 of Mn.

  3. Enhanced phosphorylation of cyclic AMP response element binding protein in Brain of mice following repetitive hypoxic exposure

    SciTech Connect

    Gao Yanan; Gao Ge; Long Caixia; Han Song; Zu Pengyu; Fang Li . E-mail: lfang@utmb.edu; Li Junfa . E-mail: junfali@cpums.edu.cn

    2006-02-10

    Cerebral ischemic/hypoxic preconditioning (I/HPC) is a phenomenon of endogenous protection that renders Brain tolerant to sustained ischemia/hypoxia. This profound protection induced by I/HPC makes it an attractive target for developing potential clinical therapeutic approaches. However, the molecular mechanism of I/HPC is unclear. Cyclic AMP (cAMP) response element binding protein (CREB), a selective nuclear transcriptional factor, plays a key role in the neuronal functions. Phosphorylation of CREB on Ser-133 may facilitate its transcriptional activity in response to various stresses. In the current study, we observed the changes in CREB phosphorylation (Ser-133) and protein expression in Brain of auto-hypoxia-induced HPC mice by using Western blot analysis. We found that the levels of phosphorylated CREB (Ser-133), but not protein expression of CREB, increased significantly (p < 0.05) in the hippocampus and the frontal cortex of mice after repetitive hypoxic exposure (H2-H4, n = 6 for each group), when compared to that of the normoxic (H0, n = 6) or hypoxic exposure once group (H1, n = 6). In addition, a significant enhancement (p < 0.05) of CREB phosphorylation (Ser-133) could also be found in the nuclear extracts from the whole hippocampus of hypoxic preconditioned mice (H2-H4, n = 6 for each group). These results suggest that the phosphorylation of CREB might be involved in the development of cerebral hypoxic preconditioning.

  4. THE BINARY FREQUENCY OF r-PROCESS-ELEMENT-ENHANCED METAL-POOR STARS AND ITS IMPLICATIONS: CHEMICAL TAGGING IN THE PRIMITIVE HALO OF THE MILKY WAY

    SciTech Connect

    Hansen, Terese; Andersen, Johannes; Nordstroem, Birgitta; Buchhave, Lars A.; Beers, Timothy C. E-mail: ja@astro.ku.dk E-mail: beers@pa.msu.edu

    2011-12-10

    A few rare halo giants in the range [Fe/H] {approx_equal} -2.9 {+-} 0.3 exhibit r-process element abundances that vary as a group by factors up to [r/Fe] {approx}80, relative to those of the iron peak and below. Yet, the astrophysical production site of these r-process elements remains unclear. We report initial results from four years of monitoring the radial velocities of 17 r-process-enhanced metal-poor giants to detect and characterize binaries in this sample. We find three (possibly four) spectroscopic binaries with orbital periods and eccentricities that are indistinguishable from those of Population I binaries with giant primaries, and which exhibit no signs that the secondary components have passed through the asymptotic giant branch stage of evolution or exploded as supernovae. The other 14 stars in our sample appear to be single-including the prototypical r-process-element-enhanced star CS 22892-052, which is also enhanced in carbon, but not in s-process elements. We conclude that the r-process (and potentially carbon) enhancement of these stars was not a local event due to mass transfer or winds from a binary companion, but was imprinted on the natal molecular clouds of these (single and binary) stars by an external source. These stars are thus spectacular chemical tracers of the inhomogeneous nature of the early Galactic halo system.

  5. A modular system of DNA enhancer elements mediates tissue-specific activation of transcription by high dietary zinc in C. elegans

    PubMed Central

    Roh, Hyun Cheol; Dimitrov, Ivan; Deshmukh, Krupa; Zhao, Guoyan; Warnhoff, Kurt; Cabrera, Daniel; Tsai, Wendy; Kornfeld, Kerry

    2015-01-01

    Zinc is essential for biological systems, and aberrant zinc metabolism is implicated in a broad range of human diseases. To maintain homeostasis in response to fluctuating levels of dietary zinc, animals regulate gene expression; however, mechanisms that mediate the transcriptional response to fluctuating levels of zinc have not been fully defined. Here, we identified DNA enhancer elements that mediate intestine-specific transcriptional activation in response to high levels of dietary zinc in C. elegans. Using bioinformatics, we characterized an evolutionarily conserved enhancer element present in multiple zinc-inducible genes, the high zinc activation (HZA) element. The HZA was consistently adjacent to a GATA element that mediates expression in intestinal cells. Functional studies using transgenic animals demonstrated that this modular system of DNA enhancers mediates tissue-specific transcriptional activation in response to high levels of dietary zinc. We used this information to search the genome and successfully identified novel zinc-inducible genes. To characterize the mechanism of enhancer function, we demonstrated that the GATA transcription factor ELT-2 and the mediator subunit MDT-15 are necessary for zinc-responsive transcriptional activation. These findings define new mechanisms of zinc homeostasis and tissue-specific regulation of transcription. PMID:25552416

  6. A modular system of DNA enhancer elements mediates tissue-specific activation of transcription by high dietary zinc in C. elegans.

    PubMed

    Roh, Hyun Cheol; Dimitrov, Ivan; Deshmukh, Krupa; Zhao, Guoyan; Warnhoff, Kurt; Cabrera, Daniel; Tsai, Wendy; Kornfeld, Kerry

    2015-01-01

    Zinc is essential for biological systems, and aberrant zinc metabolism is implicated in a broad range of human diseases. To maintain homeostasis in response to fluctuating levels of dietary zinc, animals regulate gene expression; however, mechanisms that mediate the transcriptional response to fluctuating levels of zinc have not been fully defined. Here, we identified DNA enhancer elements that mediate intestine-specific transcriptional activation in response to high levels of dietary zinc in C. elegans. Using bioinformatics, we characterized an evolutionarily conserved enhancer element present in multiple zinc-inducible genes, the high zinc activation (HZA) element. The HZA was consistently adjacent to a GATA element that mediates expression in intestinal cells. Functional studies using transgenic animals demonstrated that this modular system of DNA enhancers mediates tissue-specific transcriptional activation in response to high levels of dietary zinc. We used this information to search the genome and successfully identified novel zinc-inducible genes. To characterize the mechanism of enhancer function, we demonstrated that the GATA transcription factor ELT-2 and the mediator subunit MDT-15 are necessary for zinc-responsive transcriptional activation. These findings define new mechanisms of zinc homeostasis and tissue-specific regulation of transcription. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

  7. Pectobacterium atrosepticum and Pectobacterium carotovorum Harbor Distinct, Independently Acquired Integrative and Conjugative Elements Encoding Coronafacic Acid that Enhance Virulence on Potato Stems.

    PubMed

    Panda, Preetinanda; Vanga, Bhanupratap R; Lu, Ashley; Fiers, Mark; Fineran, Peter C; Butler, Ruth; Armstrong, Karen; Ronson, Clive W; Pitman, Andrew R

    2016-01-01

    Integrative and conjugative elements (ICEs) play a central role in the evolution of bacterial virulence, their transmission between bacteria often leading to the acquisition of virulence factors that alter host range or aggressiveness. Much is known about the functions of the virulence determinants that ICEs harbor, but little is understood about the cryptic effects of ICEs on their host cell. In this study, the importance of horizontally acquired island 2 (HAI2), an ICE in the genome of Pectobacterium atrosepticum SCRI1043, was studied using a strain in which the entire ICE had been removed by CRISPR-Cas-mediated genome editing. HAI2 encodes coronafacic acid, a virulence factor that enhances blackleg disease of potato stems caused by P. atrosepticum SCRI1043. As expected, deletion of HAI2 resulted in reduced blackleg symptoms in potato stems. A subsequent screen for HAI2-related ICEs in other strains of the Pectobacterium genus revealed their ubiquitous nature in P. atrosepticum. Yet, HAI2-related ICEs were only detected in the genomes of a few P. carotovorum strains. These strains were notable as blackleg causing strains belonging to two different subspecies of P. carotovorum. Sequence analysis of the ICEs in different strains of both P. atrosepticum and P. carotovorum confirmed that they were diverse and were present in different locations on the genomes of their bacterial host, suggesting that the cfa cluster was probably acquired independently on a number of occasions via chromosomal insertion of related ICEs. Excision assays also demonstrated that the ICEs in both P. atrosepticum and P. carotovorum are mobilized from the host chromosome. Thus, the future spread of these ICEs via lateral gene transfer might contribute to an increase in the prevalence of blackleg-causing strains of P. carotovorum.

  8. Pectobacterium atrosepticum and Pectobacterium carotovorum Harbor Distinct, Independently Acquired Integrative and Conjugative Elements Encoding Coronafacic Acid that Enhance Virulence on Potato Stems

    PubMed Central

    Panda, Preetinanda; Vanga, Bhanupratap R.; Lu, Ashley; Fiers, Mark; Fineran, Peter C.; Butler, Ruth; Armstrong, Karen; Ronson, Clive W.; Pitman, Andrew R.

    2016-01-01

    Integrative and conjugative elements (ICEs) play a central role in the evolution of bacterial virulence, their transmission between bacteria often leading to the acquisition of virulence factors that alter host range or aggressiveness. Much is known about the functions of the virulence determinants that ICEs harbor, but little is understood about the cryptic effects of ICEs on their host cell. In this study, the importance of horizontally acquired island 2 (HAI2), an ICE in the genome of Pectobacterium atrosepticum SCRI1043, was studied using a strain in which the entire ICE had been removed by CRISPR-Cas-mediated genome editing. HAI2 encodes coronafacic acid, a virulence factor that enhances blackleg disease of potato stems caused by P. atrosepticum SCRI1043. As expected, deletion of HAI2 resulted in reduced blackleg symptoms in potato stems. A subsequent screen for HAI2-related ICEs in other strains of the Pectobacterium genus revealed their ubiquitous nature in P. atrosepticum. Yet, HAI2-related ICEs were only detected in the genomes of a few P. carotovorum strains. These strains were notable as blackleg causing strains belonging to two different subspecies of P. carotovorum. Sequence analysis of the ICEs in different strains of both P. atrosepticum and P. carotovorum confirmed that they were diverse and were present in different locations on the genomes of their bacterial host, suggesting that the cfa cluster was probably acquired independently on a number of occasions via chromosomal insertion of related ICEs. Excision assays also demonstrated that the ICEs in both P. atrosepticum and P. carotovorum are mobilized from the host chromosome. Thus, the future spread of these ICEs via lateral gene transfer might contribute to an increase in the prevalence of blackleg-causing strains of P. carotovorum. PMID:27065965

  9. Systematic analysis of enhancer and critical cis-acting RNA elements in the protein-encoding region of the hepatitis C virus genome.

    PubMed

    Chu, Derrick; Ren, Songyang; Hu, Stacy; Wang, Wei Gang; Subramanian, Aparna; Contreras, Deisy; Kanagavel, Vidhya; Chung, Eric; Ko, Justine; Amirtham Jacob Appadorai, Ranjit Singh; Sinha, Sanjeev; Jalali, Ziba; Hardy, David W; French, Samuel W; Arumugaswami, Vaithilingaraja

    2013-05-01

    Hepatitis C virus (HCV) causes chronic hepatitis, cirrhosis, and liver cancer. cis-acting RNA elements of the HCV genome are critical for translation initiation and replication of the viral genome. We hypothesized that the coding regions of nonstructural proteins harbor enhancer and essential cis-acting replication elements (CRE). In order to experimentally identify new cis RNA elements, we utilized an unbiased approach to introduce synonymous substitutions. The HCV genome coding for nonstructural proteins (nucleotide positions 3872 to 9097) was divided into 17 contiguous segments. The wobble nucleotide positions of each codon were replaced, resulting in 33% to 41% nucleotide changes. The HCV genome containing one of each of 17 mutant segments (S1 to S17) was tested for genome replication and infectivity. We observed that silent mutations in segment 13 (S13) (nucleotides [nt] 7457 to 7786), S14 (nt 7787 to 8113), S15 (nt 8114 to 8440), S16 (nt 8441 to 8767), and S17 (nt 8768 to 9097) resulted in impaired genome replication, suggesting CRE structures are enriched in the NS5B region. Subsequent high-resolution mutational analysis of NS5B (nt 7787 to 9289) using approximately 51-nucleotide contiguous subsegment mutant viruses having synonymous mutations revealed that subsegments SS8195-8245, SS8654-8704, and SS9011-9061 were required for efficient viral growth, suggesting that these regions act as enhancer elements. Covariant nucleotide substitution analysis of a stem-loop, JFH-SL9098, revealed the formation of an extended stem structure, which we designated JFH-SL9074. We have identified new enhancer RNA elements and an extended stem-loop in the NS5B coding region. Genetic modification of enhancer RNA elements can be utilized for designing attenuated HCV vaccine candidates.

  10. The murine alpha B-crystallin/small heat shock protein enhancer: identification of alpha BE-1, alpha BE-2, alpha BE-3, and MRF control elements.

    PubMed

    Gopal-Srivastava, R; Piatigorsky, J

    1993-11-01

    The murine alpha B-crystallin gene (a member of the small heat shock protein family) is expressed constitutively at high levels in the lens and at lower levels in many other tissues, including skeletal muscle. We have previously used the herpes simplex virus thymidine kinase promoter fused to the human growth hormone gene to identify an alpha B-crystallin enhancer at positions -427 to -259 that has high activity in muscle and low activity in lens cell lines. In the study reported here, we performed DNase I footprinting, transfection, mutagenesis, and electrophoretic mobility shift experiments using the murine C2C12 muscle and alpha TN4-1 lens cell lines and the rabbit N/N1003A lens cell line to identify sequences responsible for activity of this enhancer. Enhancer activity in both the muscle and lens cells was dependent on novel elements called alpha BE-1 (-407 to -397), alpha BE-2 (-360 to -327), and alpha BE-3 (-317 to -306). These elements were also weakly occupied by nuclear proteins in L929 cells, which appear to express the alpha B-crystallin gene at a very low level (detectable only by the polymerase chain reaction). A fourth element containing a consensus muscle regulatory factor-binding site called MRF (-300 to -288) was occupied and used only by the C2C12 muscle cells. Cotransfection in NIH 3T3 cells and antibody-gel shift experiments using C2C12 nuclear extracts indicated that MyoD, myogen, or a similar member of this family can activate the alpha B-crystallin enhancer by interaction with the MRF site. Taken together, we conclude that the alpha BE-1, alpha BE-2, and alpha BE-3 elements are shared by both lens and muscle cells, but the MRF element is used only in muscle cells, providing the first example of a muscle-specific control element in a crystallin gene.

  11. Investigation of the effects of cell model and subcellular location of gold nanoparticles on nuclear dose enhancement factors using Monte Carlo simulation

    SciTech Connect

    Cai, Zhongli; Chattopadhyay, Niladri; Kwon, Yongkyu Luke; Pignol, Jean-Philippe; Lechtman, Eli; Reilly, Raymond M.

    2013-11-15

    Purpose: The authors’ aims were to model how various factors influence radiation dose enhancement by gold nanoparticles (AuNPs) and to propose a new modeling approach to the dose enhancement factor (DEF).Methods: The authors used Monte Carlo N-particle (MCNP 5) computer code to simulate photon and electron transport in cells. The authors modeled human breast cancer cells as a single cell, a monolayer, or a cluster of cells. Different numbers of 5, 30, or 50 nm AuNPs were placed in the extracellular space, on the cell surface, in the cytoplasm, or in the nucleus. Photon sources examined in the simulation included nine monoenergetic x-rays (10–100 keV), an x-ray beam (100 kVp), and {sup 125}I and {sup 103}Pd brachytherapy seeds. Both nuclear and cellular dose enhancement factors (NDEFs, CDEFs) were calculated. The ability of these metrics to predict the experimental DEF based on the clonogenic survival of MDA-MB-361 human breast cancer cells exposed to AuNPs and x-rays were compared.Results: NDEFs show a strong dependence on photon energies with peaks at 15, 30/40, and 90 keV. Cell model and subcellular location of AuNPs influence the peak position and value of NDEF. NDEFs decrease in the order of AuNPs in the nucleus, cytoplasm, cell membrane, and extracellular space. NDEFs also decrease in the order of AuNPs in a cell cluster, monolayer, and single cell if the photon energy is larger than 20 keV. NDEFs depend linearly on the number of AuNPs per cell. Similar trends were observed for CDEFs. NDEFs using the monolayer cell model were more predictive than either single cell or cluster cell models of the DEFs experimentally derived from the clonogenic survival of cells cultured as a monolayer. The amount of AuNPs required to double the prescribed dose in terms of mg Au/g tissue decreases as the size of AuNPs increases, especially when AuNPs are in the nucleus and the cytoplasm. For 40 keV x-rays and a cluster of cells, to double the prescribed x-ray dose (NDEF = 2

  12. A T-cell specific transcriptional enhancer element 3 prime of C sub. alpha. in the human T-cell receptor. alpha. locus

    SciTech Connect

    Ho, Icheng; Yang, Lihsuan; Morle, G.; Leiden, J.M. )

    1989-09-01

    A transcriptional enhancer element has been identified 4.5 kilobases 3{prime} of C{sub {alpha}} (constant region {alpha} chain) in the human T-cell receptor (TCR) {alpha}-chain locus. This enhancer is active on both a TCR V{sub {alpha}} (variable region {alpha} chain) promoter and the minimal simian virus 40 promoter in TCR {alpha}/{beta} Jurkat and EL4 cells but is inactive on a V{sub {alpha}} promoter TCR {gamma}/{delta} PEER and Molt-13 cells, clone 13 B cells, and HeLa fibroblasts. The enhancer has been localized to a 116-base-pair BstXI/Dra I restriction enzyme fragment, which lacks immunoglobulin octamer and {kappa}B enhancer motifs but does contain a consensus cAMP-response element (CRE). DNase I footprint analyses demonstrated that the minimal enhancer contains two binding sites for Jurkat nuclear proteins. One of these sites corresponds to the CRE, while the other does not correspond to a known transcriptional enhancer motif. These data support a model in which TCR {alpha} gene transcription is regulated by a unique set of cis-acting sequences and trans-acting factors, which are differentially active in cells of the TCR {alpha}/{beta} lineage. In addition, the TCR {alpha} enhancer may play a role in activating oncogene expression in T-lymphoblastoid tumors that have previously been shown to display chromosomal translocations into the human TCR {alpha} locus.

  13. Expression of human LINE-1 elements in enhanced by isochromosome 12p; evidence from testicular germ cell tumors and the Pallister-Killian syndrome

    SciTech Connect

    Swergold, D.

    1994-09-01

    Expression of the human LINE-1 (L1Hs) transposable element is restricted to a narrow range of cell types. Specific expression of either endogenous elements or transfected recombinant elements has been reported primarily in tumors and cell lines of germ cell origin, including the NTera2D1, 2102EP, and JEG3 cell lines. These tumors and cell lines often contain one or more copies of isochromosome 12p, or translocations of 12p. Another human condition, the Pallister-Killian syndrome, is also characterized by the mosaic presence of an isochromosome 12p in patient`s cells. M28, a previously described somatic hybrid cell line, contains a human isochromosone 12p derived from fibroblasts of a patient with Pallister-Killian syndrome in a mouse LMTK-background. I asked whether the M28 cell line would exhibit enhanced expression of endogenous or transfected L1Hs elements. Expression of transfected recombinant L1Hs elements was 10-20 fold higher in M28 than in LMTK-cells. Expression of L1Hs elements was not increased in the GM10868A somatic cell hybrid line which contains a complete human chromosome 12 in a Chinese Hamster Ovary background. Somatic cell hybrid lines containing various human chromosomes in a LMTK-background also exhibited no enhanced L1Hs expression. P40, the protein encoded by the L1Hs first open reading frame, was detected in NTera2D1 but not in non-transfected M28 cells. Preliminary promoter deletion experiments indicate that similar, but non-identical regions of the L1Hs 5{prime} UTR, contribute to high level expression in the NTera2D1 and the M28 cell lines. These data suggest that the enhanced expression of human LINE-1 elements in tumors of germ cell origin is due in part to the presence of the isochromosome 12p.

  14. Exon 10 skipping in ACAT1 caused by a novel c.949G>A mutation located at an exonic splice enhancer site.

    PubMed

    Otsuka, Hiroki; Sasai, Hideo; Nakama, Mina; Aoyama, Yuka; Abdelkreem, Elsayed; Ohnishi, Hidenori; Konstantopoulou, Vassiliki; Sass, Jörn Oliver; Fukao, Toshiyuki

    2016-11-01

    Beta-ketothiolase deficiency, also known as mitochondrial acetoacetyl-CoA thiolase (T2) deficiency, is an autosomal recessive disease caused by mutations in the acetyl‑CoA acetyltransferase 1 (ACAT1) gene. A German T2‑deficient patient that developed a severe ketoacidotic episode at the age of 11 months, was revealed to be a compound heterozygote of a previously reported null mutation, c.472A>G (p.N158D) and a novel mutation, c.949G>A (p.D317N), in ACAT1. The c.949G>A mutation was suspected to cause aberrant splicing as it is located within an exonic splicing enhancer sequence (c. 947CTGACGC) that is a potential binding site for serine/arginine‑rich splicing factor 1. A mutation in this sequence, c.951C>T, results in exon 10 skipping. A minigene construct was synthesized that included exon 9‑truncated intron 9‑exon 10‑truncated intron 10‑exon 11, and the splicing of this minigene revealed that the c.949G>A mutant construct caused exon 10 skipping in a proportion of the transcripts. Furthermore, additional substitution of G for C at the first nucleotide of exon 10 (c.941G>C) abolished the effect of the c.949G>A mutation. Transient expression analysis of the c.949G>A mutant cDNA revealed no residual T2 activity in the mutated D317N enzyme. Therefore, c.949G>A (D317N) is a pathogenic missense mutation, and diminishes the effect of an exonic splicing enhancer and causes exon 10 skipping. The present study demonstrates that a missense mutation, or even a synonymous substitution, may disrupt enzyme function by interference with splicing.

  15. A novel polymorphic CAAT/enhancer-binding protein beta element in the FasL gene promoter alters Fas ligand expression: a candidate background gene in African American systemic lupus erythematosus patients.

    PubMed

    Wu, Jianming; Metz, Christine; Xu, Xiulong; Abe, Riichiro; Gibson, Andrew W; Edberg, Jeffrey C; Cooke, Jennifer; Xie, Fenglong; Cooper, Glinda S; Kimberly, Robert P

    2003-01-01

    A single-nucleotide polymorphism (SNP), identified at nucleotide position -844 in the 5' promoter of the FasL gene, lies within a putative binding motif for CAAT/enhancer-binding protein beta (C/EBPbeta). Electrophoretic mobility shift and supershift assays confirmed that this element binds specifically to C/EBPbeta and demonstrated that the two alleles of this element have different affinities for C/EBPbeta. In luciferase reporter assays, the -844C genotype had twice the basal activity of the -844T construct, and basal expression of Fas ligand (FasL) on peripheral blood fibrocytes was also significantly higher in -844C than in -844T homozygous donors. FasL is located on human chromosome 1q23, a region that shows linkage to the systemic lupus autoimmune phenotype. Analysis of 211 African American systemic lupus erythematosus patients revealed enrichment of the -844C homozygous genotype in these systemic lupus erythematosus patients compared with 150 ethnically matched normal controls (p = 0.024). The -844C homozygous genotype may lead to the increased expression of FasL, to altered FasL-mediated signaling in lymphocytes, and to enhanced risk for autoimmunity. This functionally significant SNP demonstrates the potential importance of SNPs in regulatory regions and suggests that differences in the regulation of FasL expression may contribute to the development of the autoimmune phenotype.

  16. Differential dimerization of variants linked to enhanced S-cone sensitivity syndrome (ESCS) located in the NR2E3 ligand-binding domain.

    PubMed

    von Alpen, Désirée; Tran, Hoai Viet; Guex, Nicolas; Venturini, Giulia; Munier, Francis L; Schorderet, Daniel F; Haider, Neena B; Escher, Pascal

    2015-06-01

    NR2E3 encodes the photoreceptor-specific nuclear hormone receptor that acts as a repressor of cone-specific gene expression in rod photoreceptors, and as an activator of several rod-specific genes. Recessive variants located in the ligand-binding domain (LBD) of NR2E3 cause enhanced short wavelength sensitive- (S-) cone syndrome (ESCS), a retinal degeneration characterized by an excess of S-cones and non-functional rods. We analyzed the dimerization properties of NR2E3 and the effect of disease-causing LBD missense variants by bioluminescence resonance energy transfer (BRET(2) ) protein interaction assays. Homodimerization was not affected in presence of p.A256V, p.R039G, p.R311Q, and p.R334G variants, but abolished in presence of p.L263P, p.L336P, p.L353V, p.R385P, and p.M407K variants. Homology modeling predicted structural changes induced by NR2E3 LBD variants. NR2E3 LBD variants did not affect interaction with CRX, but with NRL and rev-erbα/NR1D1. CRX and NRL heterodimerized more efficiently together, than did either with NR2E3. NR2E3 did not heterodimerize with TLX/NR2E1 and RXRα/NR2C1. The identification of a new compound heterozygous patient with detectable rod function, who expressed solely the p.A256V variant protein, suggests a correlation between LBD variants able to form functional NR2E3 dimers and atypical mild forms of ESCS with residual rod function.

  17. Differential dimerization of variants linked to enhanced S-Cone Sensitivity Syndrome (ESCS) located in the NR2E3 ligand-binding domain

    PubMed Central

    von Alpen, Désirée; Tran, H. Viet; Guex, Nicolas; Venturini, Giulia; Munier, Francis L.; Schorderet, Daniel F.; Haider, Neena B.; Escher, Pascal

    2016-01-01

    NR2E3 encodes the photoreceptor-specific nuclear hormone receptor that acts as a repressor of cone-specific gene expression in rod photoreceptors, and as an activator of several rod-specific genes. Recessive variants located in the ligand-binding domain (LBD) of NR2E3 cause enhanced short wavelength sensitive- (S-) cone syndrome (ESCS), a retinal degeneration characterized by an excess of Scones and non-functional rods. We analyzed the dimerization properties of NR2E3 and the effect of disease-causing LBD missense variants by bioluminescence resonance energy transfer (BRET2) protein interaction assays. Homodimerization was not affected in presence of p.A256V, p.R039G, p.R311Q and p.R334G variants, but abolished in presence of p.L263P, p.L336P, p.L353V, p.R385P and p.M407K variants. Homology modeling predicted structural changes induced by NR2E3 LBD variants. NR2E3 LBD variants did not affect interaction with CRX, but with NRL and rev-erbα/NR1D1. CRX and NRL heterodimerized more efficiently together, than did either with NR2E3. NR2E3 did not heterodimerize with TLX/NR2E1 and RXRα/NR2C1. The identification of a new compound heterozygous patient with detectable rod function, who expressed solely the p.A256V variant protein, suggests a correlation between LBD variants able to form functional NR2E3 dimers and atypical mild forms of ESCS with residual rod function. PMID:25703721

  18. Replacement of the human cytomegalovirus promoter with fish enhancer and core elements to control the expression of the G gene of viral haemorrhagic septicemia virus (VHSV).

    PubMed

    Martinez-Lopez, A; Chinchilla, B; Encinas, P; Gomez-Casado, E; Estepa, A; Coll, J M

    2012-12-15

    This work explores some of the possibilities to replace human cytomegalovirus (CMV) core and/or enhancer promoter control elements to create new expression vectors for use with fish. The work is relevant to fish vaccination, since DNA vaccines use eukaryotic expression plasmids controlled by the human cytomegalovirus (CMV) promoter to be effective against novirhabdoviruses, such as viral haemorrhagic septicemia virus (VHSV), one of the most devastating fish viral European diseases. To reduce possible homologous recombination with fish genome, core and enhancer sequences from fish origin, such as trout interferon-inducible myxovirus protein (Mx), zebrafish retrovirus long terminal repeat (LTR) and carp β-actin (AE6), were combined with those of CMV to design alternative hybrid promoters. The substitution of CMV core and/or enhancer with the corresponding elements of Mx or the LTR core maintained a similar in vitro protein G expression level than that obtained by using the CMV promoter. Vectors using the dsRNA-inducible Mx enhancer followed either by the LTR or the AE6 cores showed the highest in vitro protein G expression levels. Furthermore, synthetic constructs using the Mx enhancer maintained their polyI:C induction capabilities despite the core used. Some of these hybrid promoters might contribute to the development of all-fish-vectors for DNA vaccines while others might be useful for more basic studies.

  19. The role of proximal-enhancer elements in the glucocorticoid regulation of carbamoylphosphate synthetase gene transcription from the upstream response unit.

    PubMed

    Schoneveld, Onard J L M; Gaemers, Ingrid C; Hoogenkamp, Maarten; Lamers, Wouter H

    2005-11-01

    As part of the urea cycle, carbamoylphosphate synthetase (CPS) converts toxic ammonia resulting from amino-acid catabolism into urea. Liver-specific and glucocorticoid-dependent expression of the gene involves a distal enhancer, a promoter-proximal enhancer, and the minimal promoter itself. When challenged with glucocorticoids, the glucocorticoid-responsive unit (GRU) in the distal enhancer of the carbamoylphosphate-synthetase gene can only activate gene expression if, in addition to the minimal promoter, the proximal enhancer is present. Here, we identify and characterise two elements in the proximal CPS enhancer that are involved in glucocorticoid-dependent gene activation mediated by the GRU. A purine-rich stretch forming a so-called GAGA-box and a glucocorticoid-response element (GRE) are both crucial for the efficacy of the GRU and appear to constitute a promoter-proximal response unit that activates the promoter. The glucocorticoid response of the CPS gene is, therefore, dependent on the combined action of a distal and a promoter-proximal response unit.

  20. A unique enhancer element for the trans activator (p40 sup tax ) of human T-cell leukemia virus type I that is distinct from cyclic AMP- and 12-O-tetradecanoylphobol-13-acetate-responsive elements

    SciTech Connect

    Fujisawa, Junichi; Toita, Masami; Yoshida, Mitsuaki )

    1989-08-01

    The trans activator (p40{sup tax}) of human T-cell leukemia virus type I (HTLV-I) is a transcriptional factor that activates the long terminal repeat (LTR) of HTLV-I and interleukin-2 receptor {alpha}. The authors examined the HTLV-I enhancer responsible for tax-mediated trans activation and identified (A/T)(G/C)(G/C)CNNTGACG(T/A) as a plausible tax-responsive element (TRE). The putative TRE in the LTR was found to be different from the elements required for activation by cyclic AMP and 12-O-tetradecanoylphorbol-13-acetate, although these elements overlapped each other. The TRE was also different from a binding site of N-{kappa}B-like factor that was identified was identified in the interleukin-2 receptor {alpha} promoter and human immunodeficiency virus LTR as a TRE. The latter result was further demonstrated by the failure of the NF-{kappa}B sequence to compete with the TRE of the LTR in a protein-binding assay. These findings indicate that tax function and its cascade can modulate activities of various enhancer sequences, which are probably regulated by distinct DNA-binding factors.

  1. The atomic-scale mechanism for the enhanced glass-forming-ability of a Cu-Zr based bulk metallic glass with minor element additions

    NASA Astrophysics Data System (ADS)

    Wang, Q.; Liu, C. T.; Yang, Y.; Liu, J. B.; Dong, Y. D.; Lu, J.

    2014-04-01

    It is known that the glass forming-ability (GFA) of bulk metallic glasses (BMGs) can be greatly enhanced via minor element additions. However, direct evidence has been lacking to reveal its structural origin despite different theories hitherto proposed. Through the high-resolution transmission-electron-microscopy (HRTEM) analysis, here we show that the content of local crystal-like orders increases significantly in a Cu-Zr-Al BMG after a 2-at% Y addition. Contrasting the previous studies, our current results indicate that the formation of crystal-like order at the atomic scale plays an important role in enhancing the GFA of the Cu-Zr-Al base BMG.

  2. FEM (finite element method) thermal modeling and thermal hydraulic performance of an enhanced thermal conductivity UO2/BeO composite fuel

    SciTech Connect

    Zhou, Wenzhong

    2011-03-24

    An enhanced thermal conductivity UO2-BeO composite nuclear fuel was studied. A methodology to generate ANSYS (an engineering simulation software) FEM (Finite Element Method) thermal models of enhanced thermal conductivity oxide nuclear fuels was developed. The results showed significant increase in the fuel thermal conductivities and have good agreement with the measured ones. The reactor performance analysis showed that the decrease in centerline temperature was 250-350K for the UO2-BeO composite fuel, and thus we can improve nuclear reactors' performance and safety, and high-level radioactive waste generation.

  3. Correlation between local structure and glass forming ability enhanced by similar element substitution in (La-Ce)-Co-Al bulk metallic glasses

    NASA Astrophysics Data System (ADS)

    Li, Xuan; Zhang, Tao

    2017-08-01

    Similar element substitution is an effective strategy to develop bulk metallic glasses (BMGs) with high glass forming ability (GFA). However, the relationship between the local structure and the GFA enhancement has not been clarified when similar element is introduced. In this paper, the local structures of the ternary La65Co25Al10 and pseudo-ternary (La0.7Ce0.3)65Co25Al10 BMGs were studied by ab-initio molecular dynamics. Partial pair correlation function, bond angle distribution, coordination number, solute-solute avoidance, Voronoi polyhedron, and free volume were used to characterize the local structure. After partial substitution of Ce for La, the (La0.7Ce0.3)65Co25Al10 BMG exhibited higher degree of solute-solute avoidance, more icosahedral-like Voronoi polyhedrons, and less free volume, which may be the structural origin of the higher GFA induced by similar element substitution.

  4. Mutations in CG8878, a Novel Putative Protein Kinase, Enhance P Element Dependent Silencing (PDS) and Position Effect Variegation (PEV) in Drosophila melanogaster

    PubMed Central

    McCracken, Allen; Locke, John

    2014-01-01

    Genes in multicellular organisms are expressed as part of a developmental program that is largely dependent on self-perpetuating higher-order chromatin states. The mechanism of establishing and maintaining these epigenetic events is well studied in Drosophila. The first known example of an epigenetic effect was that of (PEV) in Drosophila, which has been shown to be due to gene silencing via heterochromatin formation. We are investigating a process similar to Position Effect Variegation (PEV) using a mini-w transgene, called Pci, inserted in the upstream regulatory region of ci. The mini-white+ transgene in Pci is expressed throughout the adult eye; however, when other P or KP elements are present, a variegated eye phenotype results indicating random w+ silencing during development. This P element dependent silencing (PDS) can be modified by the haplo-suppressors/triplo-enhancers, Su(var)205 and Su(var)3–7, indicating that these heterochromatic modifiers also act dose dependently in PDS. Here we use a spontaneous derivative mutation of Pci called PciE1 (E1) that variegates like PDS in the absence of P elements, presumably due to an adjacent gypsy element insertion, to screen for second-site modifier mutations that enhance variable silencing of white+ in E1. We isolated 7 mutations in CG8878, an essential gene, that enhance the E1 variegated phenotype. CG8878, a previously uncharacterized gene, potentially encodes a serine/threonine kinase whose closest Drosophila paralogue, ballchen (nhk-1), phosphorylates histones. These mutant alleles enhance both PDS at E1 and Position Effect Variegation (PEV) at wm4, indicating a previously unknown common silencing mechanism between the two. PMID:24614804

  5. Glucocorticoid receptor-mediated suppression of the interleukin 2 gene expression through impairment of the cooperativity between nuclear factor of activated T cells and AP-1 enhancer elements

    PubMed Central

    1992-01-01

    The immunosuppressant hormone dexamethasone (Dex) interferes with T cell-specific signals activating the enhancer sequences directing interleukin 2 (IL-2) transcription. We report that the Dex-dependent downregulation of 12-O-tetradecanoyl-phorbol-13-acetate (TPA) and calcium ionophore-induced activity of the IL-2 enhancer are mediated by glucocorticoid receptor (GR) via a process that requires intact NH2- and COOH-terminal and DNA-binding domains. Functional analysis of chloramphenicol acetyltransferase (CAT) vectors containing internal deletions of the -317 to +47 bp IL-2 enhancer showed that the GR- responsive elements mapped to regions containing nuclear factor of activated T cells protein (NFAT) (-279 to -263 bp) and AP-1 (-160 to - 150 bp) motifs. The AP-1 motif binds TPA and calcium ionophore-induced nuclear factor(s) containing fos protein. TPA and calcium ionophore- induced transcriptional activation of homo-oligomers of the NFAT element were not inhibited by Dex, while AP-1 motif concatemers were not stimulated by TPA and calcium ionophore. When combined, NFAT and AP- 1 motifs significantly synergized in directing CAT transcription. Such a synergism was impaired by specific mutations affecting the trans- acting factor binding to either NFAT or AP-1 motifs. In spite of the lack of hormone regulation of isolated cis elements, TPA/calcium ionophore-mediated activation of CAT vectors containing a combination of the NFAT and the AP-1 motifs became suppressible by Dex. Our results show that the IL-2-AP-1 motif confers GR sensitivity to a flanking region containing a NFAT element and suggest that synergistic cooperativity between the NFAT and AP-1 sites allows GR to mediate the Dex inhibition of IL-2 gene transcription. Therefore, a Dex-modulated second level of IL-2 enhancer regulation, based on a combinatorial modular interplay, appears to be present. PMID:1740658

  6. Targeted Deletion of the Antisilencer/Enhancer (ASE) Element from Intron 1 of the Myelin Proteolipid Protein Gene (Plp1) in Mouse Reveals that the Element Is Dispensable for Plp1 Expression in Brain during Development and Remyelination

    PubMed Central

    Pereira, Glauber B.; Meng, Fanxue; Kockara, Neriman T.; Yang, Baoli; Wight, Patricia A.

    2012-01-01

    Myelin proteolipid protein gene (Plp1) expression is temporally regulated in brain, which peaks during the active myelination period of CNS development. Previous studies with Plp1-lacZ transgenic mice demonstrated that (mouse) Plp1 intron 1 DNA is required for high levels of expression in oligodendrocytes. Deletion-transfection analysis revealed the intron contains a single positive regulatory element operative in the N20.1 oligodendroglial cell line, which was named ASE (antisilencer/enhancer) based on its functional properties in these cells. To investigate the role of the ASE in vivo, the element was deleted from the native gene in mouse using a Cre/lox strategy. While removal of the ASE from Plp1-lacZ constructs profoundly decreased expression in transfected oligodendroglial cell lines (N20.1 and Oli-neu), the element was dispensable to achieve normal levels of Plp1 gene expression in mouse during development (except perhaps at postnatal day 15) and throughout the remyelination period following cuprizone-induced (acute) demyelination. Thus, it is possible that the ASE is nonfunctional in vivo, or that loss of the ASE from the native gene in mouse can be compensated for by the presence of other regulatory elements within the Plp1 gene. PMID:23157328

  7. Point mutations in the Moloney murine leukemia virus enhancer identify a lymphoid-specific viral core motif and 1,3-phorbol myristate acetate-inducible element.

    PubMed Central

    Speck, N A; Renjifo, B; Hopkins, N

    1990-01-01

    The transcriptional enhancer of the Moloney murine leukemia virus (MoMLV) is organized as a 75-base-pair repeat, and in each copy of the repeat there are multiple binding sites for nuclear factors. We have introduced point mutations into each of the known nuclear factor-binding sites in the MoMLV enhancer, in both copies of the direct repeat, and have analyzed the transcriptional activity conferred by the mutated enhancers by transient-expression assays in both hematopoietic and nonhematopoietic cell lines. Mutation of individual binding sites in the MoMLV enhancer has moderate effects (less than 2-fold to 20-fold) on transcription in six independent cell lines. Several mutations decreased transcription from the MoMLV enhancer ubiquitously (the leukemia virus factor b site and the glucocorticoid response element), whereas others affected transcription specifically in lymphoid cell lines (core motif) or, more significantly, in fibroblasts (nuclear factor 1 site). The transcriptional activity of the MoMLV enhancer can be induced 8- to 10-fold by 1,3-phorbol myristate acetate in Jurkat T cells. Mutations in any of three adjacent binding sites (leukemia virus factor b and c sites and the core motif) within a 28-base-pair region in the center of the direct repeat sequence of the MoMLV enhancer completely attenuate the response to 1,3-phorbol myristate acetate. Images PMID:2104942

  8. Effects of a low severity prescribed fire on water-soluble elements in ash from a cork oak (Quercus suber) forest located in the northeast of the Iberian Peninsula

    USGS Publications Warehouse

    Pereira, P.; beda, X.; Martin, D.; Mataix-Solera, J.; Guerrero, C.

    2011-01-01

    Wildfire is the major disturbance in Mediterranean forests. Prescribed fire can be an alternative to reduce the amount of fuel and hence decrease the wildfire risk. However the effects of prescribed fire must be studied, especially on ash properties, because ash is an important nutrient source for ecosystem recovery. The aim of this study is to determine the effects of a low severity prescribed fire on water-soluble elements in ash including pH, electrical conductivity (EC), calcium (Ca), magnesium (Mg), sodium (Na), potassium (K), aluminum (Al), manganese (Mn), iron (Fe), zinc (Zn), silica (SiO2) and total sulphur (TS). A prescribed fire was conducted in a cork oak (Quercus suber) (Q.S) forest located in the northeast part of the Iberian Peninsula. Samples were collected from a flat plot of 40??70m mainly composed of Q.S and Quercus robur (Q.R) trees. In order to understand the effects of the prescribed fire on the soluble elements in ash, we conducted our data analysis on three data groups: all samples, only Q.S samples and only Q.R samples. All three sample groups exhibited a significant increase in pH, EC (p<0.001), water-soluble Ca, Mg, Na, SiO2 and TS and a decrease in water-soluble Mn, Fe and Zn. Differences were identified between oak species for water-soluble K, Al and Fe. In Q.S samples we registered a significant increase in the first two elements p<0.001 and p<0.01, respectively, and a non-significant impact in the third, at p<0.05. In Q.R data we identified a non-significant impact on water-soluble K and Al and a significant decrease in water-soluble Fe (p<0.05). These differences are probably due to vegetation characteristics and burn severity. The fire induced a higher variability in the ash soluble elements, especially in Q.S samples, that at some points burned with higher severity. The increase of pH, EC, Ca, Mg, Na and K will improve soil fertility, mainly in the study area where soils are acidic. The application of this low severity prescribed

  9. Effects of a low severity prescribed fire on water-soluble elements in ash from a cork oak (Quercus suber) forest located in the northeast of the Iberian Peninsula.

    PubMed

    Pereira, Paulo; Ubeda, Xavier; Martin, Deborah; Mataix-Solera, Jorge; Guerrero, César

    2011-02-01

    Wildfire is the major disturbance in Mediterranean forests. Prescribed fire can be an alternative to reduce the amount of fuel and hence decrease the wildfire risk. However the effects of prescribed fire must be studied, especially on ash properties, because ash is an important nutrient source for ecosystem recovery. The aim of this study is to determine the effects of a low severity prescribed fire on water-soluble elements in ash including pH, electrical conductivity (EC), calcium (Ca), magnesium (Mg), sodium (Na), potassium (K), aluminum (Al), manganese (Mn), iron (Fe), zinc (Zn), silica (SiO(2)) and total sulphur (TS). A prescribed fire was conducted in a cork oak (Quercus suber) (Q.S) forest located in the northeast part of the Iberian Peninsula. Samples were collected from a flat plot of 40×70m mainly composed of Q.S and Quercus robur (Q.R) trees. In order to understand the effects of the prescribed fire on the soluble elements in ash, we conducted our data analysis on three data groups: all samples, only Q.S samples and only Q.R samples. All three sample groups exhibited a significant increase in pH, EC (p<0.001), water-soluble Ca, Mg, Na, SiO(2) and TS and a decrease in water-soluble Mn, Fe and Zn. Differences were identified between oak species for water-soluble K, Al and Fe. In Q.S samples we registered a significant increase in the first two elements p<0.001 and p<0.01, respectively, and a non-significant impact in the third, at p<0.05. In Q.R data we identified a non-significant impact on water-soluble K and Al and a significant decrease in water-soluble Fe (p<0.05). These differences are probably due to vegetation characteristics and burn severity. The fire induced a higher variability in the ash soluble elements, especially in Q.S samples, that at some points burned with higher severity. The increase of pH, EC, Ca, Mg, Na and K will improve soil fertility, mainly in the study area where soils are acidic. The application of this low severity

  10. Highly conserved elements discovered in vertebrates are present in non-syntenic loci of tunicates, act as enhancers and can be transcribed during development

    PubMed Central

    Sanges, Remo; Hadzhiev, Yavor; Gueroult-Bellone, Marion; Roure, Agnes; Ferg, Marco; Meola, Nicola; Amore, Gabriele; Basu, Swaraj; Brown, Euan R.; De Simone, Marco; Petrera, Francesca; Licastro, Danilo; Strähle, Uwe; Banfi, Sandro; Lemaire, Patrick; Birney, Ewan; Müller, Ferenc; Stupka, Elia

    2013-01-01

    Co-option of cis-regulatory modules has been suggested as a mechanism for the evolution of expression sites during development. However, the extent and mechanisms involved in mobilization of cis-regulatory modules remains elusive. To trace the history of non-coding elements, which may represent candidate ancestral cis-regulatory modules affirmed during chordate evolution, we have searched for conserved elements in tunicate and vertebrate (Olfactores) genomes. We identified, for the first time, 183 non-coding sequences that are highly conserved between the two groups. Our results show that all but one element are conserved in non-syntenic regions between vertebrate and tunicate genomes, while being syntenic among vertebrates. Nevertheless, in all the groups, they are significantly associated with transcription factors showing specific functions fundamental to animal development, such as multicellular organism development and sequence-specific DNA binding. The majority of these regions map onto ultraconserved elements and we demonstrate that they can act as functional enhancers within the organism of origin, as well as in cross-transgenesis experiments, and that they are transcribed in extant species of Olfactores. We refer to the elements as ‘Olfactores conserved non-coding elements’. PMID:23393190

  11. Enhancement of the Excitation Efficiency of a Torsional Wave PPM EMAT Array for Pipe Inspection by Optimizing the Element Number of the Array Based on 3-D FEM

    PubMed Central

    Wang, Yugang; Wu, Xinjun; Sun, Pengfei; Li, Jian

    2015-01-01

    Electromagnetic acoustic transducers (EMATs) can generate non-dispersive T(0,1) mode guided waves in a metallic pipe for nondestructive testing (NDT) by using a periodic permanent magnet (PPM) EMAT circular array. In order to enhance the excitation efficiency of the sensor, the effects of varying the number of elements of the array on the excitation efficiency is studied in this paper. The transduction process of the PPM EMAT array is studied based on 3-D finite element method (FEM). The passing signal amplitude of the torsional wave is obtained to represent the excitation efficiency of the sensor. Models with different numbers of elements are established and the results are compared to obtain an optimal element number. The simulation result is verified by experiments. It is shown that after optimization, the amplitudes of both the passing signal and defect signal with the optimal element number are increased by 29%, which verifies the feasibility of this optimal method. The essence of the optimization is to find the best match between the static magnetic field and the eddy current field in a limited circumferential space to obtain the maximum circumferential Lorentz force. PMID:25654722

  12. Enhancement of the excitation efficiency of a torsional wave PPM EMAT array for pipe inspection by optimizing the element number of the array based on 3-D FEM.

    PubMed

    Wang, Yugang; Wu, Xinjun; Sun, Pengfei; Li, Jian

    2015-02-03

    Electromagnetic acoustic transducers (EMATs) can generate non-dispersive T(0,1) mode guided waves in a metallic pipe for nondestructive testing (NDT) by using a periodic permanent magnet (PPM) EMAT circular array. In order to enhance the excitation efficiency of the sensor, the effects of varying the number of elements of the array on the excitation efficiency is studied in this paper. The transduction process of the PPM EMAT array is studied based on 3-D finite element method (FEM). The passing signal amplitude of the torsional wave is obtained to represent the excitation efficiency of the sensor. Models with different numbers of elements are established and the results are compared to obtain an optimal element number. The simulation result is verified by experiments. It is shown that after optimization, the amplitudes of both the passing signal and defect signal with the optimal element number are increased by 29%, which verifies the feasibility of this optimal method. The essence of the optimization is to find the best match between the static magnetic field and the eddy current field in a limited circumferential space to obtain the maximum circumferential Lorentz force.

  13. Evaluation of Dietary Supplement Contamination by Xenobiotic and Essential Elements Using Microwave-Enhanced Sample Digestion and Inductively Coupled Plasma-Mass Spectrometry.

    PubMed

    Zinn, Gregory M; Rahman, G M Mizanur; Faber, Scott; Wolle, Mesay Mulugeta; Pamuku, Matt; Kingston, H M Skip

    2016-01-01

    Dietary supplements were analyzed by evaluating the elemental content in six widely consumed products manufactured by four well-known companies. The elements included the neurotoxic and carcinogenic elements cadmium, mercury, aluminum, lead, arsenic, and antimony, as well as the essential elements zinc, selenium, chromium, iron, and copper, which were often not listed as ingredients on the product labels. Contamination from either xenobiotic or essential elements was found in all samples analyzed. The samples were prepared using US Environmental Protection Agency (EPA) Method 3052, microwave-enhanced digestion. The resulting digests were analyzed by Inductively Coupled Plasma-Mass Spectrometry based on EPA Method 6020B. The analytical protocols were validated by analyzing a multivitamin standard reference material, the National Institute of Standards and Technology Standard Reference Material 3280. The application of EPA standard methods demonstrated their utility in making accurate and precise measurements in complex matrices with multiple ingredients and excipients. In the future, the use of these methods could provide a uniform quality assurance protocol that can be implemented along with other industry guidelines to improve the production of dietary supplements.

  14. Developmental activation of the lysozyme gene in chicken macrophage cells is linked to core histone acetylation at its enhancer elements

    PubMed Central

    Myers, Fiona A.; Lefevre, Pascal; Mantouvalou, Evangelia; Bruce, Kimberley; Lacroix, Claire; Bonifer, Constanze; Thorne, Alan W.; Crane-Robinson, Colyn

    2006-01-01

    Native chromatin IP assays were used to define changes in core histone acetylation at the lysozyme locus during developmental maturation of chicken macrophages and stimulation to high-level expression by lipo-polysaccharide. In pluripotent precursors the lysozyme gene (Lys) is inactive and there is no acetylation of core histones at the gene, its promoter or at the upstream cis-control elements. In myeloblasts, where there is a very low level of Lys expression, H4 acetylation appears at the cis-control elements but not at the Lys gene or its promoter: neither H3 nor H2B become significantly acetylated in myeloblasts. In mature macrophages, Lys expression increases 5-fold: H4, H2B and H2A.Z are all acetylated at the cis-control elements but H3 remains unacetylated except at the −2.4 S silencer. Stimulation with LPS increases Lys expression a further 10-fold: this is accompanied by a rise in H3 acetylation throughout the cis-control elements; H4 and H2B acetylation remain substantial but acetylation at the Lys gene and its promoter remains low. Acetylation is thus concentrated at the cis-control elements, not at the Lys gene or its immediate promoter. H4 acetylation precedes H3 acetylation during development and H3 acetylation is most directly linked to high-level Lys expression. PMID:16914441

  15. Enhancer/Suppressor mutator (En/Spm)-like transposable elements of cassava (Manihot esculenta) are transcriptionally inactive.

    PubMed

    Gbadegesin, M A; Beeching, J R

    2010-04-13

    Transposable elements contribute to the size, structure, variation, and diversity of the genome and have major effects on gene function. Sequencing projects have revealed the diversity of transposable elements in many organisms and have shown that they constitute a high percentage of the genome. PCR-based techniques using degenerate primers designed from conserved enzyme domains of transposable elements can provide quick and extensive surveys, making study of diversity and abundance and their applications possible in species where full genome sequence data are not yet available. We studied cassava (Manihot esculenta) En/Spm-like transposons (Meens) with regard to genomic distribution, sequence diversity and methylation status. Cassava transposase fragments characteristic of En/Spm-like transposons were isolated, cloned and characterized. Sequence analysis showed that cassava En/Spm-like elements are highly conserved, with overall identity in the range of 68-98%. Southern hybridization supports the presence of multiple copies of En/Spm-like transposons integrated in the genome of all cassava cultivars that we tested. Hybridization patterns of HpaII- and MspI-digested cassava genomic DNA revealed highly methylated sequences. There were no clear differences in hybridization pattern between the cultivars. We did not detect RNA transcripts of Meens by Northern procedures. We examined the possibility of recent transposition activities of the cassava En/Spm-like elements.

  16. Improved recombinant antibody production by CHO cells using a production enhancer DNA element with repeated transgene integration at a predetermined chromosomal site.

    PubMed

    Kawabe, Yoshinori; Inao, Takanori; Komatsu, Shodai; Huang, Guan; Ito, Akira; Omasa, Takeshi; Kamihira, Masamichi

    2017-03-01

    Chinese hamster ovary (CHO) cells are one of the most useful host cell lines for the production of biopharmaceutical proteins. Although a series of production processes have been refined to improve protein productivity and cost performance, establishing producer cells is still time-consuming and labor-intensive. Recombinase-mediated site-specific gene integration into a predetermined chromosomal locus may enable predictable protein expression, reducing the laborious process of cell screening. We previously developed an accumulative site-specific gene integration system (AGIS) using Cre recombinase and mutated loxP sites for transgene integration and amplification in the CHO cell genome. Epigenetic modifier elements such as insulators are effective DNA cis-regulatory elements for stabilizing transgene expression. Here, we attempted to enhance transgene expression in recombinant CHO cells generated by AGIS using a production enhancer DNA element (PE) derived from the CHO genome. The PE was introduced into an expression unit for a recombinant scFv-Fc antibody. The effect on scFv-Fc productivity of PE position and orientation within the transgene was evaluated, while keeping the background chromosomal structure constant. For the optimal PE arrangement, scFv-Fc productivity was enhanced 2.6-fold compared with an expression unit without a PE. The enhancing effect of the PE on transgene expression was also observed when two or three PE-flanked expression units were inserted as tandem repeats. These results indicate that AGIS using the PE-flanked expression unit is a promising approach for establishing producer cell lines for biopharmaceutical protein production.

  17. Location of atypical femoral fracture can be determined by tensile stress distribution influenced by femoral bowing and neck-shaft angle: a CT-based nonlinear finite element analysis model for the assessment of femoral shaft loading stress.

    PubMed

    Oh, Yoto; Fujita, Koji; Wakabayashi, Yoshiaki; Kurosa, Yoshiro; Okawa, Atsushi

    2017-09-27

    Loading stress due to individual variations in femoral morphology is thought to be strongly associated with the pathogenesis of atypical femoral fracture (AFF). In Japan, studies on AFF regarding pathogenesis in the mid-shaft are well-documented and a key factor in the injury is thought to be femoral shaft bowing deformity. Thus, we developed a CT-based finite element analysis (CT/FEA) model to assess distribution of loading stress in the femoral shaft. A multicenter prospective study was performed at 12 hospitals in Japan from August 2015 to February 2017. We assembled three study groups-the mid-shaft AFF group (n=12), the subtrochanteric AFF group (n=10), and the control group (n=11)-and analyzed femoral morphology and loading stress in the femoral shaft by nonlinear CT/FEA. Femoral bowing in the mid-shaft AFF group was significantly greater (lateral bowing, p<0.0001; anterior bowing, p<0.01). Femoral neck-shaft angle in the subtrochanteric AFF group was significantly smaller (p<0.001). On CT/FEA, both the mid-shaft and subtrochanteric AFF group showed maximum tensile stress located adjacent to the fracture site. Quantitatively, there was a correlation between femoral bowing and the ratio of tensile stress, which was calculated between the mid-shaft and subtrochanteric region (lateral bowing, r=0.6373, p<0.0001; anterior bowing, r=-0.5825, p<0.001). CT/FEA demonstrated that tensile stress by loading stress can cause AFF. The location of AFF injury could be determined by individual stress distribution influenced by femoral bowing and neck-shaft angle. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Partial extinction of a conditioned context enhances preference for elements previously associated with cocaine but not with chocolate.

    PubMed

    Orsini, C; Bonito-Oliva, A; Montanari, C; Conversi, D; Cabib, S

    2013-08-15

    Drug-associated stimuli are crucial to reinstatement of drug-seeking after periods of abstinence, representing a central problem in treatment of addiction. The present study investigated the influence of partial extinction of the conditioned context on the expression of conditioned place preference (CPP). Mice of the inbred DBA/2J strain were conditioned with cocaine or chocolate in a context identified by multiple elements (A+B) and subsequently CPP expression was evaluated in a context containing only one element (A or B) or both (A+B). Cocaine- and chocolate-conditioned mice showed CPP in presence of the original compound stimulus. However, cocaine-conditioned mice did not show CPP when tested in A or B context, while chocolate-conditioned mice did show CPP to single element context. After conditioning mice were exposed to extinction training of the context A or B and then tested for CPP 1 and 9 days after the end of the extinction (days 9 and 18). Cocaine-conditioned mice showed CPP 9 days after extinction while chocolate-conditioned mice were relatively insensitive to the extinction procedure on day 1 after extinction, but they did not show CPP for the partial or the original compound 9 days after extinction. Cocaine-conditioned mice not submitted to the extinction training (simple passage of time) or submitted to a Sham-extinction procedure (saline injections and confinement in a new environment) did not show CPP on day 9 or 18. Cocaine-conditioned mice exposed to extinction training showed increased c-Fos expression in several brain areas in comparison to mice exposed to Sham-extinction. The extinction procedure did not specifically reduce behavioral sensitization. The results suggest that extinction training involving only elements of a drug-associated context can result in increased associative strength of those elements. © 2013.

  19. A new global approach using a network of piezoelectric elements and energy redistribution for enhanced vibration damping of smart structure

    NASA Astrophysics Data System (ADS)

    Wu, Dan; Guyomar, Daniel; Richard, Claude

    2013-04-01

    A new global approach for improved vibration damping of smart structure, based on global energy redistribution by means of a network of piezoelectric elements is proposed. It is basically using semi-active Synchronized Switch Damping technique. SSD technique relies on a cumulative build-up of the voltage resulting from the continuous switching and it was shown that the performance is strongly related to this voltage. The increase of the piezoelectric voltage results in improvement of the damping performance. External voltage sources or improved switching sequences were previously designed to increase this voltage in the case of single piezoelectric element structure configurations. This paper deals with extended structure with many embedded piezoelectric elements. The proposed strategy consist of using an electric network made with non-linear component and switches in order to set up and control a low-loss energy transfer from source piezoelements extracting the vibration energy of the structure and oriented toward a given piezoelement in order to increase its operative energy for improving a given mode damping. This paper presents simulation of a clamped plate with four piezoelectric elements implemented in the Matlab/SimulinkTM environment and SimscapeTM library. The various simulation cases show the relationship between the damping performance on a given targeted mode and the established power flow. SSDD and SSDT are two proposed original networks. Performances are compared to the SSDI baseline. A damping increase of 18dB can be obtained even with a weakly coupled piezoelectric element in the multi-sine excitation case. This result proves the importance of new global non-linear multi-actuator strategies for improved vibration damping of extended smart structure.

  20. Translational enhancement of H-ferritin mRNA by interleukin-1 beta acts through 5' leader sequences distinct from the iron responsive element.

    PubMed Central

    Rogers, J T; Andriotakis, J L; Lacroix, L; Durmowicz, G P; Kasschau, K D; Bridges, K R

    1994-01-01

    Interleukin-1 beta (Il-1 beta), a key cytokine in the acute phase response, elevates hepatic expression of both the heavy (H) and light (L) ferritin subunits without influencing the steady-state levels of either ferritin transcript. Transfection experiments with human hepatoma cells reveal that sequences within the 5' untranslated region (5'UTR) of H-ferritin mRNA confer translational regulation to chimaeric chloramphenicol acetyl transferase (CAT) mRNAs in response to Il-1 beta in the absence of marked changes in CAT mRNA levels. Il-1 beta dependent translational enhancement is mediated by a distinct G + C rich RNA sequence within 70 nucleotides (nt) of the start codon. The upstream Iron Responsive Element RNA stemloop does not confer increased expression to CAT mRNA in Il-1 beta stimulated hepatoma transfectants. A 38 nucleotide consensus sequence within the 5'UTRs of the mRNAs encoding the hepatic acute phase proteins alpha 1-antitrypsin (alpha 1AT), alpha 1-acid glycoprotein (AGP) and haptoglobin (Dente et al., 1985) is similar to sequences in the G + C rich H-ferritin mRNA translational regulatory element. Deletion of three nucleotides from this region of the 61 nt G + C rich element in the H-ferritin mRNA 5' leader eliminates Il-1 beta translational enhancement of the CAT reporter transcripts. Images PMID:8041631

  1. Organic acid enhanced soil risk element (Cd, Pb and Zn) leaching and secondary bioconcentration in water lettuce (Pistia stratiotes L.) in the rhizofiltration process.

    PubMed

    Veseý, Tomás; Tlustos, Pavel; Száková, Jirina

    2012-04-01

    The use of natural chelates to enhance risk element mobility combined with rhizofiltration by free floating macrophytes have not been thoroughly studied in recent years. The aim of this study was to investigate the efficiency of organic acids in soil by conducting flushing experiments to enhance the mobility of Cd, Pb, and Zn from soil to solution. In addition, the bioaccumulation of Cd, Pb, and Zn, in water lettuce (Pistia stratiotes L.) will be studied as they affect the biomass in the rhizofiltration process. The results revealed that citric and tartaric acids mobilised the highest amount of all risk elements. In comparison to control, citric acid mobilised 71%, 181%, and 112% of Cd, Pb, and Zn while tartaric acid mobilised 70%, 155%, and 135% of Cd, Pb, and Zn respectively. The bioconcentration factor was approximately 2-5 times higher for juvenile plants than mature plants for all treatments as well as for both parts (leaves and roots). The risk element translocation into aerial parts decreased with increased time. Juvenile and mature plants proved a high accumulation potential and a 3 week growth period was observed as a sufficient time period to remove more than 80% of Cd, Pb, and Zn.

  2. Analysis of Fibroblast growth factor 15 cis-elements reveals two conserved enhancers which are closely related to cardiac outflow tract development.

    PubMed

    Saitsu, Hirotomo; Shiota, Kohei; Ishibashi, Makoto

    2006-09-01

    Fibroblast growth factor 15 (Fgf15) is expressed in the developing mouse central nervous system and pharyngeal arches. Fgf15 mutant mice showed defects of the cardiac outflow tract probably because of aberrant behavior of the cardiac neural crest cells. In this study, we examined cis-elements of the Fgf15 gene by transient transgenic analysis using lacZ as a reporter. We identified two enhancers: one directed lacZ expression in the hindbrain/spinal cord and the other in the posterior midbrain (pmb), rhombomere1 (r1) and pharyngeal epithelia. Interestingly, human genomic regions which are highly homologous to these two mouse enhancers showed almost the same enhancer activities as those of mice in transgenic mouse embryos, indicating that the two enhancers are conserved between humans and mice. We also showed that the mouse and human pmb/r1 enhancer can regulate lacZ expression in chick embryos in almost the same way as in mouse embryos. We found that the lacZ expression domain with this enhancer was expanded by ectopic Fgf8b expression, suggesting that this enhancer is regulated by Fgf8 signaling. Moreover, over-expression of Fgf15 resulted in up-regulation of Fgf8 expression in the isthmus/r1. These findings suggest that a reciprocal positive regulation exists between Fgf15 and Fgf8 in the isthmus/r1. Together with cardiac outflow tract defects in Fgf15 mutants, the conservation of enhancers in the hindbrain/spinal cord and pharyngeal epithelia suggests that human FGF19 (ortholog of Fgf15) is involved in early development and the distribution of cardiac neural crest cells and is one of the candidate genes for congenital heart defects.

  3. A Sub-Element in PRE enhances nuclear export of intronless mRNAs by recruiting the TREX complex via ZC3H18.

    PubMed

    Chi, Binkai; Wang, Ke; Du, Yanhua; Gui, Bin; Chang, Xingya; Wang, Lantian; Fan, Jing; Chen, She; Wu, Xudong; Li, Guohui; Cheng, Hong

    2014-06-01

    Viral RNA elements that facilitate mRNA export are useful tools for identifying cellular RNA export factors. Here we show that hepatitis B virus post-transcriptional element (PRE) is one such element, and using PRE several new cellular mRNA export factors were identified. We found that PRE drastically enhances the cytoplasmic accumulation of cDNA transcripts independent of any viral protein. Systematic deletion analysis revealed the existence of a 116 nt functional Sub-Element of PRE (SEP1). The RNP that forms on the SEP1 RNA was affinity purified, in which TREX components as well as several other proteins were identified. TREX components and the SEP1-associating protein ZC3H18 are required for SEP1-mediated mRNA export. Significantly, ZC3H18 directly binds to the SEP1 RNA, interacts with TREX and is required for stable association of TREX with the SEP1-containing mRNA. Requirements for SEP1-mediated mRNA export are similar to those for splicing-dependent mRNA export. Consistent with these similarities, several SEP1-interacting proteins, including ZC3H18, ARS2, Acinus and Brr2, are required for efficient nuclear export of polyA RNAs. Together, our data indicate that SEP1 enhances mRNA export by recruiting TREX via ZC3H18. The new mRNA export factors that we identified might be involved in cap- and splicing-dependent TREX recruitment to cellular mRNAs.

  4. A Sub-Element in PRE enhances nuclear export of intronless mRNAs by recruiting the TREX complex via ZC3H18

    PubMed Central

    Chi, Binkai; Wang, Ke; Du, Yanhua; Gui, Bin; Chang, Xingya; Wang, Lantian; Fan, Jing; Chen, She; Wu, Xudong; Li, Guohui; Cheng, Hong

    2014-01-01

    Viral RNA elements that facilitate mRNA export are useful tools for identifying cellular RNA export factors. Here we show that hepatitis B virus post-transcriptional element (PRE) is one such element, and using PRE several new cellular mRNA export factors were identified. We found that PRE drastically enhances the cytoplasmic accumulation of cDNA transcripts independent of any viral protein. Systematic deletion analysis revealed the existence of a 116 nt functional Sub-Element of PRE (SEP1). The RNP that forms on the SEP1 RNA was affinity purified, in which TREX components as well as several other proteins were identified. TREX components and the SEP1-associating protein ZC3H18 are required for SEP1-mediated mRNA export. Significantly, ZC3H18 directly binds to the SEP1 RNA, interacts with TREX and is required for stable association of TREX with the SEP1-containing mRNA. Requirements for SEP1-mediated mRNA export are similar to those for splicing-dependent mRNA export. Consistent with these similarities, several SEP1-interacting proteins, including ZC3H18, ARS2, Acinus and Brr2, are required for efficient nuclear export of polyA RNAs. Together, our data indicate that SEP1 enhances mRNA export by recruiting TREX via ZC3H18. The new mRNA export factors that we identified might be involved in cap- and splicing-dependent TREX recruitment to cellular mRNAs. PMID:24782531

  5. Gata4 expression in lateral mesoderm is downstream of BMP4 and isactivated directly by Forkhead and GATA transcription factors through adistal enhancer element

    SciTech Connect

    Rojas, Anabel; De Val, Sarah; Heidt, Analeah B.; Xu, Shan-Mei; Bristow, James; Black, Brian L.

    2005-05-20

    The GATA family of zinc-finger transcription factors plays key roles in the specification and differentiation of multiple cell types during development. GATA4 is an early regulator of gene expression during the development of endoderm and mesoderm, and genetic studies in mice have demonstrated that GATA4 is required for embryonic development.Despite the importance of GATA4 in tissue specification and differentiation, the mechanisms by which Gata4 expression is activated and the transcription factor pathways upstream of GATA4 remain largely undefined. To identify transcriptional regulators of Gata4 in the mouse,we screened conserved noncoding sequences from the mouse Gata4 gene for enhancer activity in transgenic embryos. Here, we define the regulation of a distal enhancer element from Gata4 that is sufficient to direct expression throughout the lateral mesoderm, beginning at 7.5 days of mouse embryonic development. The activity of this enhancer is initially broad but eventually becomes restricted to the mesenchyme surrounding the liver. We demonstrate that the function of this enhancer in transgenic embryos is dependent upon highly conserved Forkhead and GATA transcription factor binding sites, which are bound by FOXF1 and GATA4,respectively. Furthermore, the activity of the Gata4 lateral mesoderm enhancer is attenuated by the BMP antagonist Noggin, and the enhancer is not activated in Bmp4-null embryos. Thus, these studies establish that Gata4 is a direct transcriptional target of Forkhead and GATA transcription factors in the lateral mesoderm, and demonstrate that Gata4lateral mesoderm enhancer activation requires BMP4, supporting a model in which GATA4 serves as a downstream effector of BMP signaling in the lateral mesoderm.

  6. Design and technical evaluation of an enhanced location-awareness service enabler for spatial disorientation management of elderly with mild cognitive impairment.

    PubMed

    Moreno, Pedro A; Hernando, M Elena; Gómez, Enrique J

    2015-01-01

    The progressive ageing of population has turned the mild cognitive impairment (MCI) into a prevalent disease suffered by elderly. Consequently, the spatial disorientation has become a significant problem for older people and their caregivers. The ambient-assisted living applications are offering location-based services for empowering elderly to go outside and encouraging a greater independence. Therefore, this paper describes the design and technical evaluation of a location-awareness service enabler aimed at supporting and managing probable wandering situations of a person with MCI. Through the presence capabilities of the IP multimedia subsystem (IMS) architecture, the service will alert patient's contacts if a hazardous situation is detected depending on his location. Furthermore, information about the older person's security areas has been included in the user profile managed by IMS. In doing so, the service enabler introduced contribute to "context-awareness" paradigm allowing the adaptation and personalization of services depending on user's context and specific conditions or preferences.

  7. Simulation of the enhancement factor from an individual 3D hemisphere-on-post field emitter by using finite elements method.

    PubMed

    Roveri, D S; Sant'Anna, G M; Bertan, H H; Mologni, J F; Alves, M A R; Braga, E S

    2016-01-01

    This paper presents a 3D computational framework for evaluating electrostatic properties of a single field emitter characterized by the hemisphere-on-post geometry. Numerical simulations employed the finite elements method by using Ansys-Maxwell software. Extensive parametric simulations were focused on the threshold distance from which the emitter field enhancement factor (γ) becomes independent from the anode-substrate gap (G). This investigation allowed demonstrating that the ratio between G and the emitter height (h) is a reliable reference for a broad range of emitter dimensions; furthermore, results permitted establishing G/h ≥ 2.2 as the threshold condition for setting the anode without affecting γ.

  8. Crystallization and preliminary X-ray diffraction analysis of the Pax9 paired domain bound to a DC5 enhancer DNA element.

    PubMed

    Narasimhan, Kamesh; Hilbig, Antonia; Udayasuryan, Barath; Jayabal, Sriram; Kolatkar, Prasanna R; Jauch, Ralf

    2014-10-01

    Pax genes belong to a family of metazoan transcription factors that are known to play a critical role in eye, ear, kidney and neural development. The mammalian Pax family of transcription factors is characterized by a ∼128-amino-acid DNA-binding paired domain that makes sequence-specific contacts with DNA. The diversity in Pax gene activities emerges from complex modes of interaction with enhancer regions and heterodimerization with multiple interaction partners. Based on in vitro optimal binding-site selection studies and enhancer identification assays, it has been suggested that Pax proteins may recognize and bind their target DNA elements with different binding modes/topologies, however this hypothesis has not yet been structurally explored. One of the most extensively studied DNA target elements of the Pax6 paired domain is the eye-lens specific DC5 (δ-crystallin) enhancer element. In order to shed light on Pax6-DC5 DNA interactions, the related paired-domain prototype Pax9 was crystallized with the minimal δ-crystallin DC5 enhancer element and preliminary X-ray diffraction analysis was attempted. A 3.0 Å resolution native data set was collected at the National Synchrotron Light Source (NSLS), Brookhaven from crystals grown in a solution consisting of 10%(w/v) PEG 20K, 20%(v/v) PEG 550 MME, 0.03 M NaNO3, 0.03 M Na2HPO4, 0.03 M NH2SO4, 0.1 M MES/imidazole pH 6.5. The data set was indexed and merged in space group C2221, with unit-cell parameters a = 75.74, b = 165.59, c = 70.14 Å, α = β = γ = 90°. The solvent content in the unit cell is consistent with the presence of one Pax9 paired domain bound to duplex DNA in the asymmetric unit.

  9. Identification of QTLs that enhance the nutritional value of rice grain and limit accumulation of undesirable elements such as arsenic

    USDA-ARS?s Scientific Manuscript database

    Research into the mineral contents of cereal grains and vegetables is motivated by interest in improving their nutritional value. Biofortification refers to natural enhancement of grain/food products through traditional breeding. Since this approach does not require genetic engineering, it is acce...

  10. Organic complexant-enhanced mobility of toxic elements in low-level wastes. Quarterly progress report, January-March 1984

    SciTech Connect

    Swanson, J.L.

    1984-06-01

    The results obtained during the third quarter's activities of a project whose objective is to determine how and to what extent organic complexants affect the mobility of toxic elements in subsurface groundwaters at commercial low-level waste disposal sites are described. This project will study nonradioactive toxic elements as well as elements having radioactive isotopes of importance (e.g. /sup 63/Ni, /sup 239/Pu, /sup 241/Am). Organic complexants used in the nuclear industry are being emphasized, but others are being examined. Generic soil components (e.g. hydrous oxides, silica, clays) are being used so that the results will be broadly applicable. Substantiation of the previously indicated sorption of a Pu(IV)-EDTA complex by hydrous ferric oxide (Fe/sub 2/O/sub 3/.xH/sub 2/O) was obtained by comparing the sorption of EDTA in the presence and absence of Pu. Additional data on the sorption of a Ni-EDTA complex by Fe/sub 2/O/sub 3/.xH/sub 2/O were also obtained. Preliminary Ni sorption data were obtained with other complexants (picolinic acid and citric acid), and another generic soil component (TiO/sub 2/). Sorption of a Ni-EDTA complex by an anion exchange resin was observed. Complexed species are thus likely to be present in the resin wastes from certain reactor decontamination solution clean-up operations. An experimental problem that caused some erroneous results for uncomplexed Ni was discovered and corrected. The filters being used to assure good separation of solid and liquid phases were removing Ni from solution, which skewed some earlier results. 11 references, 13 figures, 2 tables.

  11. One base pair change abolishes the T cell-restricted activity of a kB-like proto-enhancer element from the interleukin 2 promoter.

    PubMed Central

    Briegel, K; Hentsch, B; Pfeuffer, I; Serfling, E

    1991-01-01

    The inducible, T cell-specific enhancers of murine and human Interleukin 2 (Il-2) genes contain the kB-like sequence GGGATTTCACC as an essential cis-acting enhancer motif. When cloned in multiple copies this so-called TCEd (distal T cell element) acts as an inducible proto-enhancer element in E14 T lymphoma cells, but not in HeLa cells. In extracts of induced, Il-2 secreting El4 cells three individual protein factors bind to TCEd DNA. The binding of the most prominent factor, named TCF-1 (T cell factor 1), is correlated with the proto-enhancer activity of TCEd. TCF-1 consists of two polypeptides of about 50 kD and 105 kD; the former seems to be related to the 50 kD polypeptide of NF-kB. Purified NF-kB is also able to bind to the TCEd, but TCF-1 binds stronger than NF-kB to TCEd DNA. The conversion of the TCEd to a 'perfect' NF-kB binding site leads to a tighter binding of NF-kB to TCEd DNA and, as a functional consequence, to the activity of the 'converted' TCEd motifs in HeLa cells. Thus, the substitution of the underlined A residue to a C within the GGGATTTCACC motif abolishes its T cell-restricted activity and leads to its functioning in both El4 cells and HeLa cells. These results indicate that lymphocyte-specific factors binding to the TCEd are involved in the control of T cell specific-transcription of the Il-2 gene. Images PMID:1945879

  12. Sensor systems for precise location of depleted uranium in soil and for enhancing the recovery of both zero valence and uranium oxides

    SciTech Connect

    Etheridge, J.A.; Monts, D.L.; Su, Y.; Waggoner, C.A.

    2007-07-01

    Depleted uranium (DU) has been the primary material used for the past two decades by the US military in armor piercing rounds. Domestic firing ranges that have been used for DU training purposes are located around the country and vary with regard to soil type, depth of vadose zone, and extent of contamination with other types of projectiles. A project is underway to develop a set of sensor systems to locate expended DU rounds and to process soil and debris to recover the material. Reactivity of zero valence DU material, even in dry sandy soils, results in rapid oxidation and diffusion of uranium minerals within the soil column. Detection techniques must be robust for both metallic and uranyl species. Radiological sensor techniques including both gamma spectroscopy and prompt gamma neutron analysis are being used in conjunction with electromagnetic imaging to locate the DU for excavation. Detection limits for both zero valence DU (ZVDU) and oxidized material will be discussed. Applicability of active and passive optical methods, such as spectral imaging and fluorescence spectroscopy, will be discussed as aids for achieving clean soil margins while excavating DU materials. Instrumentation selection for controlling processing equipment used to separate ZVDU and uranyl species from contaminated soil and debris will also be discussed. Preliminary findings for use of sodium iodide detectors and multichannel analyzer software are discussed for locating 25 and 105 mm DU penetrators. Optimum detector height of 15 cm (six inches) and detection depths up to 15 cm are discussed. A comparison of detector response of the Geonics EM61 MKII electromagnetic induction unit for DU and ferrous materials is reported. Difficulty of locating small DU penetrators using the one meter detection coil and differences in detector response for target orientation relative to the detection coil are reported. (authors)

  13. Tandemly Integrated HPV16 Can Form a Brd4-Dependent Super-Enhancer-Like Element That Drives Transcription of Viral Oncogenes

    PubMed Central

    Dooley, Katharine E.; Warburton, Alix

    2016-01-01

    ABSTRACT In cancer cells associated with human papillomavirus (HPV) infections, the viral genome is very often found integrated into the cellular genome. The viral oncogenes E6 and E7 are transcribed from the viral promoter, and integration events that alter transcriptional regulation of this promoter contribute to carcinogenic progression. In this study, we detected highly enriched binding of the super-enhancer markers Brd4, MED1, and H3K27ac, visible as a prominent nuclear focus by immunofluorescence, at the tandemly integrated copies of HPV16 in cells of the cervical neoplasia cell line W12 subclone 20861. Tumor cells are often addicted to super-enhancer-driven oncogenes and are particularly sensitive to disruption of transcription factor binding to the enhancers. Treatment of 20861 cells with bromodomain inhibitors displaced Brd4 from the HPV integration site, greatly decreased E6/E7 transcription, and inhibited cellular proliferation. Thus, Brd4 activates viral transcription at this integration site, and strong selection for E6/E7 expression can drive the formation of a super-enhancer-like element to promote oncogenesis. PMID:27624132

  14. Essential telemedicine elements (tele-ments) for connecting the academic health center and remote community providers to enhance patient care.

    PubMed

    Meyer, Brett C; Clarke, Christopher A; Troke, Tana M; Friedman, Lawrence S

    2012-08-01

    The authors draw on their experience with the University of California, San Diego Medical Center's successful enterprise-level clinical telemedicine program to present a paradigm for other academic health centers (AHCs) that wish to develop such a program. They detail key telemedicine program elements, or "tele-ments," that they consider essential to the development of a centralized, structured telemedicine program and relevant to the development of smaller programs. These tele-ments include an overall organizational vision, a centralized telemedicine infrastructure, telemedicine-specific policies and procedures, medical record documentation, relationships between the AHC clinical hub and its remote (spoke) partners, identification of and training for specialty providers, a business plan based on service agreements and/or insurance billing, and licensure/privileging. They discuss the importance of delaying equipment purchases until a plan is in place for sustaining the telemedicine enterprise and of establishing measures to define success at the outset of program development. In addition, they detail the benefits and concerns associated with telemedicine, provide a comprehensive listing of the roles and responsibilities of providers and staff involved in all aspects of telemedicine, and share samples of their program's informed consent forms and workflow checklists. Their goal is to offer support and guidance to other AHCs entering the telemedicine arena, enabling them to replicate key elements of a successful, enterprise-wide telemedicine infrastructure.

  15. Cooperative binding of estrogen receptor to imperfect estrogen-responsive DNA elements correlates with their synergistic hormone-dependent enhancer activity.

    PubMed

    Martinez, E; Wahli, W

    1989-12-01

    The Xenopus vitellogenin (vit) gene B1 estrogen-inducible enhancer is formed by two closely adjacent 13 bp imperfect palindromic estrogen-responsive elements (EREs), i.e. ERE-2 and ERE-1, having one and two base substitutions respectively, when compared to the perfect palindromic consensus ERE (GGTCANNNTGACC). Gene transfer experiments indicate that these degenerated elements, on their own, have a low or no regulatory capacity at all, but in vivo act together synergistically to confer high receptor- and hormone-dependent transcription activation to the heterologous HSV thymidine kinase promoter. Thus, the DNA region upstream of the vitB1 gene comprising these two imperfect EREs separated by 7 bp, was called the vitB1 estrogen-responsive unit (vitB1 ERU). Using in vitro protein-DNA interaction techniques, we demonstrate that estrogen receptor dimers bind cooperatively to the imperfect EREs of the vitB1 ERU. Binding of a first receptor dimer to the more conserved ERE-2 increases approximately 4- to 8-fold the binding affinity of the receptor to the adjacent less conserved ERE-1. Thus, we suggest that the observed synergistic estrogen-dependent transcription activation conferred by the pair of hormone-responsive DNA elements of the vit B1 ERU is the result of cooperative binding of two estrogen receptor dimers to these two adjacent imperfect EREs.

  16. Sensitive determinations of Cu, Pb, Cd, and Cr elements in aqueous solutions using chemical replacement combined with surface-enhanced laser-induced breakdown spectroscopy.

    PubMed

    Yang, X Y; Hao, Z Q; Li, C M; Li, J M; Yi, R X; Shen, M; Li, K H; Guo, L B; Li, X Y; Lu, Y F; Zeng, X Y

    2016-06-13

    In this study, chemical replacement combined with surface-enhanced laser-induced breakdown spectroscopy (CR-SENLIBS) was for the first time applied to improve the detection sensitivities of trace heavy metal elements in aqueous solutions. Utilizing chemical replacement effect, heavy metal ions in aqueous solution were enriched on the magnesium alloy surface as a solid replacement layer through reacting with the high chemical activity metallic magnesium (Mg) within 1 minute. Unitary and mixed solutions with Cu, Pb, Cd, and Cr elements were prepared to construct calibration curves, respectively. The CR-SENLIBS showed a much better detection sensitivity and accuracy for both unitary and mixed solutions. The coefficients of determination R2 of the calibration curves were above 0.96, and the LoDs were of the same order of magnitude, i.e., in the range of 0.016-0.386 μg/mL for the unitary solution, and in the range of 0.025-0.420 μg/mL for the mixed solution. These results show that CR-SENLIBS is a feasible method for improving the detection sensitivity of trace element in liquid sample, which definitely provides a way for wider application of LIBS in water quality monitoring.

  17. Verification of the in vivo activity of three distinct cis-acting elements within the Gata1 gene promoter-proximal enhancer in mice.

    PubMed

    Shimizu, Ritsuko; Hasegawa, Atsushi; Ottolenghi, Sergio; Ronchi, Antonella; Yamamoto, Masayuki

    2013-11-01

    The transcription factor GATA1 is essential for erythroid and megakaryocytic cell differentiation. Gata1 hematopoietic regulatory domain (G1HRD) has been shown to recapitulate endogenous Gata1 gene expression in transgenic mouse assays in vivo. G1HRD contains a promoter-proximal enhancer composed of a GATA-palindrome motif, four CP2-binding sites and two CACCC boxes. We prepared transgenic reporter mouse lines in which green fluorescent protein and β-galactosidase expression are driven by wild-type G1HRD (as a positive control) and the G1HRD harboring mutations within these cis-acting elements (as the experimental conditions), respectively. Exploiting this transgenic dual reporter (TDR) assay, we show here that in definitive erythropoiesis, G1HRD activity was markedly affected by individual mutations in the GATA-palindrome motif and the CACCC boxes. Mutation of CP2-binding sites also moderately decreased G1HRD activity. The combined mutation of the CP2-binding sites and the GATA-palindrome motif resulted in complete loss of G1HRD activity. In contrast, in primitive erythroid cells, individual mutations of each element did not affect G1HRD activity; G1HRD activity was abolished only when these three mutations were combined. These results thus show that all three elements independently and cooperatively contribute to G1HRD activity in vivo in definitive erythropoiesis, although these are contributing redundantly to primitive erythropoiesis.

  18. Cooperative binding of estrogen receptor to imperfect estrogen-responsive DNA elements correlates with their synergistic hormone-dependent enhancer activity.

    PubMed Central

    Martinez, E; Wahli, W

    1989-01-01

    The Xenopus vitellogenin (vit) gene B1 estrogen-inducible enhancer is formed by two closely adjacent 13 bp imperfect palindromic estrogen-responsive elements (EREs), i.e. ERE-2 and ERE-1, having one and two base substitutions respectively, when compared to the perfect palindromic consensus ERE (GGTCANNNTGACC). Gene transfer experiments indicate that these degenerated elements, on their own, have a low or no regulatory capacity at all, but in vivo act together synergistically to confer high receptor- and hormone-dependent transcription activation to the heterologous HSV thymidine kinase promoter. Thus, the DNA region upstream of the vitB1 gene comprising these two imperfect EREs separated by 7 bp, was called the vitB1 estrogen-responsive unit (vitB1 ERU). Using in vitro protein-DNA interaction techniques, we demonstrate that estrogen receptor dimers bind cooperatively to the imperfect EREs of the vitB1 ERU. Binding of a first receptor dimer to the more conserved ERE-2 increases approximately 4- to 8-fold the binding affinity of the receptor to the adjacent less conserved ERE-1. Thus, we suggest that the observed synergistic estrogen-dependent transcription activation conferred by the pair of hormone-responsive DNA elements of the vit B1 ERU is the result of cooperative binding of two estrogen receptor dimers to these two adjacent imperfect EREs. Images PMID:2583118

  19. Near-road enhancement and solubility of fine and coarse particulate matter trace elements near a major interstate in Detroit, Michigan

    NASA Astrophysics Data System (ADS)

    Oakes, Michelle M.; Burke, Janet M.; Norris, Gary A.; Kovalcik, Kasey D.; Pancras, J. Patrick; Landis, Matthew S.

    2016-11-01

    Communities near major roadways are disproportionately affected by traffic-related air pollution which can contribute to adverse health outcomes. The specific role of particulate matter (PM) from traffic sources is not fully understood due to complex emissions processes and physical/chemical properties of PM in the near-road environment. To investigate the spatial profile and water solubility of elemental PM species near a major roadway, filter-based measurements of fine (PM2.5) and coarse (PM10-2.5) PM were simultaneously collected at multiple distances (10 m, 100 m, and 300 m) from Interstate I-96 in Detroit, Michigan during September-November 2010. Filters were extracted in water, followed by a hot acid extraction, and analyzed by magnetic sector field high resolution inductively coupled plasma mass spectrometry (HR-ICPMS) to quantify water-soluble and acid-soluble trace elements for each PM size fraction. PM2.5 and PM10-2.5 species measured in the near-road samples included elements associated with traffic activity, local industrial sources, and regional pollution. Metals indicative of brake wear (Ba, Cu) were dramatically enriched near the roadway during downwind conditions (factor of 5 concentration increase), with the largest increase within 100 m of the roadway. Moderate near-roadway increases were observed for crustal elements and other traffic-related PM (Fe, Ca), and the lowest increases observed for regional PM species (S). Water solubility varied by PM species and size, and for PM2.5 included highly (S, K, Ca, Mg, Zn, Ba), moderately (Cu, Mn, Sb, Pb), and minimally (Fe, Ti) water-soluble species, with lower water solubility for most species in PM10-2.5. Results from this study indicate that water-soluble PM2.5 and PM10-2.5 metals, particularly from brake/tire wear, were enhanced in the near-roadway environment which may have human health implications.

  20. Plasmon Mapping in Metallic Nanostructures and its Application to Single Molecule Surface Enhanced Raman Scattering: Imaging Electromagnetic Hot-Spots and Analyte Location

    SciTech Connect

    Camden, Jon P

    2013-07-16

    A major component of this proposal is to elucidate the connection between optical and electron excitation of plasmon modes in metallic nanostructures. These accomplishments are reported: developed a routine protocol for obtaining spatially resolved, low energy EELS spectra, and resonance Rayleigh scattering spectra from the same nanostructures.; correlated optical scattering spectra and plasmon maps obtained using STEM/EELS.; and imaged electromagnetic hot spots responsible for single-molecule surface-enhanced Raman scattering (SMSERS).

  1. Insertion of core CpG island element into human CMV promoter for enhancing recombinant protein expression stability in CHO cells.

    PubMed

    Mariati; Yeo, Jessna H M; Koh, Esther Y C; Ho, Steven C L; Yang, Yuansheng

    2014-01-01

    The human cytomegalovirus promoter (hCMV) is susceptible to gene silencing in CHO cells, most likely due to epigenetic events, such as DNA methylation and histone modifications. The core CpG island element (IE) from the hamster adenine phosphoribosyltransferase gene has been shown to prevent DNA methylation. A set of modified hCMV promoters was developed by inserting one or two copies of IE in either forward or reverse orientations either upstream of the hCMV enhancer, between the enhancer and core promoter (CP), or downstream of the CP. The modified hCMV with one copy of IE inserted between the enhancer and core promoter in reverse orientation (MR1) was most effective at enhancing expression stability without compromising expression level when compared with the wild-type (WT) hCMV. A third of 18 EGFP expressing clones generated using MR1 retained 70% of their starting expression level after 8 weeks of culture in the absence of selection pressure, while none of 18 WT hCMV generated clones had expression above 50%. MR1 also improved antibody expression stability of methotrexate (MTX) amplified CHO cell lines. Stably transfected pools generated using MR1 maintained 62% of their original monoclonal antibody titer after 8 weeks of culture in the absence of MTX, compared to only 37% for WT hCMV pools. Low levels of CpG methylation within both WT hCMV and MR1 were observed in all the analyzed cell lines and the methylation levels did not correlate to the expression stability, suggesting IE enhances expression stability by other mechanisms other than preventing methylation. © 2014 American Institute of Chemical Engineers.

  2. [Laser ignition assisted spark-induced breakdown spectroscopy for element analysis of aluminum alloy with enhanced sensitivity].

    PubMed

    Peng, Fei-fei; Zhou, Qi; Chen, Yu-qi; Li, Run-hua

    2013-09-01

    The analytical performance of laser ignition assisted spark-induced breakdown spectroscopy (LI-SIBS) for the analysis of trace metal in aluminum alloy was reported in the present article. In order to improve the analytical performance of spark-induced breakdown spectroscopy, a low energy laser pulse was focused on the surface of the sample to produce plasma between discharge electrodes to trigger high voltage spark discharge. Under current geometrical arrangement, optimized discharge voltage and capacitance were determined, and copper in aluminum alloy was analyzed under optimized experimental condition. The limit of detection of copper in aluminum alloy was determined to be 0.7 ppm. Both signal stability and measurement accuracy for spark-induced breakdown spectroscopy were improved with the assistance of laser ignition. The discharge voltage could be reduced and the spatial resolution could be improved with the assistance of laser ignition at the same time. It was demonstrated that LI-SIBS has the characteristics of high sensitivity, good stability and better spatial resolution and is suitable for trace elements analysis in different alloys.

  3. Determination of trace elements in high purity alumina powder by helium enhanced direct current glow discharge mass spectrometry

    NASA Astrophysics Data System (ADS)

    Jung, Sehoon; Kim, Sunhye; Hinrichs, Joachim

    2016-08-01

    Trace impurities in high purity alumina powder were determined by fast flow direct current glow discharge mass spectrometry (GD-MS). The non-conductive samples were prepared with high purity graphite powder and used as a sample binder and as a secondary cathode. To improve the sensitivity of the GD-MS analysis, helium was introduced as an additional glow discharge gas to argon plasma. The quantification results of the GD-MS measurement were calculated by external calibration with matrix matched certified reference materials. The GD-MS results for the determination of Na, Mg, Si, Ca, Ti, V, Cr, Fe, Cu, Zn and Ga in the alumina samples agreed well with the certified values of a reference material and the results of chemical analysis using wet sample digestion with inductively coupled plasma atomic emission spectrometry (ICP-AES) and inductively coupled plasma mass spectrometry (ICP-MS). The GD-MS analysis is a rapid analysis technique to determine trace elements in non-conductive alumina to below mg·kg- 1 levels.

  4. Enhancement of enzymatic accessibility by fibrillation of woody biomass using batch-type kneader with twin-screw elements.

    PubMed

    Lee, Seung-Hwan; Teramoto, Yoshikuni; Endo, Takashi

    2010-01-01

    Fibrillation of wood cell walls into submicron and/or nanoscale fibers was successfully carried out in the presence of water by using a batch-type kneader with combination-available twin-screw elements. The results obtained are expected to be used for the application of a twin-screw extruder. Two types of screw combinations were used for applying different shearing and distribution forces. Most of the fibers of the fibrillated products had diameters less than 1 microm, and some of them had diameters less than 100 nm. The maximum glucose yield by enzymatic saccharification was found to be 54.2% in the fibrillated products kneaded for 20 min after ball milling for 20 min using a screw combination for applying high shearing force. The fibrillation increased the surface area of cellulose. The glucose yield was improved by cooking the fibrillated products with water at 135 degrees C under 0.25 MPa, revealing that only mechanical kneading appears to have some limitation to expose cellulose for complete enzymatic saccharification.

  5. Gotu Kola (Centella Asiatica) extract enhances phosphorylation of cyclic AMP response element binding protein in neuroblastoma cells expressing amyloid beta peptide.

    PubMed

    Xu, Yanan; Cao, Zhiming; Khan, Ikhlas; Luo, Yuan

    2008-04-01

    Alzheimer's disease (AD) is a progressive neurodegenerative disorder that shows cognitive deficits and memory impairment. Extract from the leaves of Gotu Kola (Centella Asiatica) have been used as an alternative medicine for memory improvement in Indian Ayurvedic system of medicine for a long time. Although several studies have revealed its effect in ameliorating the cognitive impairment in rat models of AD and stimulating property on neuronal dendrites of hippocampal region, the molecular mechanism of Gotu Kola on neuroprotection still remains to be elucidated. In this study, we report that phosphorylation of cyclic AMP response element binding protein (CREB) is enhanced in both a neuroblastoma cell line expressing amyloid beta 1-42 (Abeta) and in rat embryonic cortical primary cell culture. In addition, the contribution of two major single components to the enhanced CREB phosphorylatioin was examined. Furthermore, inhibitors were applied in this study revealing that ERK/RSK signaling pathway might mediate this effect of Gotu Kola extract. Taken together, we provide a possible molecular mechanism for memory enhancing property of Gotu Kola extract for the first time.

  6. Enhanced hydrogen production from water via a photo-catalyzed reaction using chalcogenide d-element nanoparticles induced by UV light.

    PubMed

    El Naggar, Ahmed M A; Nassar, Ibrahim M; Gobara, Heba M

    2013-10-21

    Hydrogen has the potential to meet the requirements as a clean non-fossil fuel in the future. The photocatalytic production of H2 through water splitting has been demonstrated and enormous efforts have been published. The present work is an attempt to enhance the production of H2 during water splitting using synthesized nanoparticles based on chalcogenide d-element semiconductors via a photochemical reaction under UV-light in the presence of methanol as a hole-scavenger. In general, the enhanced activity of a semiconductor is most likely due to the effective charge separation of photo generated electrons and holes in the semiconductors. Hence, the utilization of different semiconductors in combination can consequently provide better hydrogen production. Accordingly in this research work, two different semiconductors, with different concentrations, either used individually or combined together were introduced. They in turn produced a high concentration of H2 as detected and measured using gas chromatography. Herein, data revealed that the nano-structured semiconductors prepared through this work are a promising candidate in the production of an enhanced H2 flux under visible UV radiation.

  7. Enhanced hydrogen production from water via a photo-catalyzed reaction using chalcogenide d-element nanoparticles induced by UV light

    NASA Astrophysics Data System (ADS)

    El Naggar, Ahmed M. A.; Nassar, Ibrahim. M.; Gobara, Heba M.

    2013-09-01

    Hydrogen has the potential to meet the requirements as a clean non-fossil fuel in the future. The photocatalytic production of H2 through water splitting has been demonstrated and enormous efforts have been published. The present work is an attempt to enhance the production of H2 during water splitting using synthesized nanoparticles based on chalcogenide d-element semiconductors via a photochemical reaction under UV-light in the presence of methanol as a hole-scavenger. In general, the enhanced activity of a semiconductor is most likely due to the effective charge separation of photo generated electrons and holes in the semiconductors. Hence, the utilization of different semiconductors in combination can consequently provide better hydrogen production. Accordingly in this research work, two different semiconductors, with different concentrations, either used individually or combined together were introduced. They in turn produced a high concentration of H2 as detected and measured using gas chromatography. Herein, data revealed that the nano-structured semiconductors prepared through this work are a promising candidate in the production of an enhanced H2 flux under visible UV radiation.

  8. Chemically enhanced phytoextraction of risk elements from a contaminated agricultural soil using Zea mays and Triticum aestivum: performance and metal mobilization over a three year period.

    PubMed

    Neugschwandtner, Reinhard W; Tlustos, Pavel; Komárek, Michael; Száková, Jirina; Jakoubková, Lucie

    2012-09-01

    Enhanced phytoextraction using EDTA for the remediation of an agricultural soil contaminated with less mobile risk elements Cd and Pb originating from smelting activities in Príbram (Czech Republic) was assessed on the laboratory and the field scale. EDTA was applied to the first years crop Zea mays. Metal mobilization and metal uptake by the plants in the soil were monitored for two additional years when Triticum aestivum was planted. The application ofEDTA effectively increased water-soluble Cd and Pb concentrations in the soil. These concentrations decreased over time. Anyhow, increased concentrations could be still observed in the third experimental year indicating a low possibility of groundwater pollution after the addition of EDTA during and also after the enhanced phytoextraction process under prevailing climatic conditions. EDTA-applications caused phytotoxicity and thereby decreased biomass production and increased Cd and Pb uptake by the plants. Phytoextraction efficiency and phytoextraction potential were too low for Cd and Pb phytoextraction in the field in a reasonable time frame (as less than one-tenth of a percent of total Cd and Pb could be removed). This strongly indicates that EDTA-enhanced phytoextraction as implemented in this study is not a suitable remediation technique for risk metal contaminated soils.

  9. The impact of enhanced atmospheric carbon dioxide on yield, proximate composition, elemental concentration, fatty acid and vitamin C contents of tomato (Lycopersicon esculentum).

    PubMed

    Khan, Ikhtiar; Azam, Andaleeb; Mahmood, Abid

    2013-01-01

    The global average temperature has witnessed a steady increase during the second half of the twentieth century and the trend is continuing. Carbon dioxide, a major green house gas is piling up in the atmosphere and besides causing global warming, is expected to alter the physico-chemical composition of plants. The objective of this work was to evaluate the hypothesis that increased CO(2) in the air is causing undesirable changes in the nutritional composition of tomato fruits. Two varieties of tomato (Lycopersicon esculentum) were grown in ambient (400 μmol mol(-1)) and elevated (1,000 μmol mol(-1)) concentration of CO(2) under controlled conditions. The fruits were harvested at premature and fully matured stages and analyzed for yield, proximate composition, elemental concentration, fatty acid, and vitamin C contents. The amount of carbohydrates increased significantly under the enhanced CO(2) conditions. The amount of crude protein and vitamin C, two important nutritional parameters, decreased substantially. Fatty acid content showed a mild decrease with a slight increase in crude fiber. Understandably, the effect of enhanced atmospheric CO(2) was more pronounced at the fully matured stage. Mineral contents of the fruit samples changed in an irregular fashion. Tomato fruit has been traditionally a source of vitamin C, under the experimental conditions, a negative impact of enhanced CO(2) on this source of vitamin C was observed. The nutritional quality of both varieties of tomato has altered under the CO(2) enriched atmosphere.

  10. Oxidative mobilization of cerium and uranium and enhanced release of "immobile" high field strength elements from igneous rocks in the presence of the biogenic siderophore desferrioxamine B

    NASA Astrophysics Data System (ADS)

    Kraemer, Dennis; Kopf, Sebastian; Bau, Michael

    2015-09-01

    Polyvalent trace elements such as the high field strength elements (HFSE) are commonly considered rather immobile during low-temperature water-rock interaction. Hence, they have become diagnostic tools that are widely applied in geochemical studies. We present results of batch leaching experiments focused on the mobilization of certain HFSE (Y, Zr, Hf, Th, U and rare earth elements) from mafic, intermediate and felsic igneous rocks in the presence and absence, respectively, of the siderophore desferrioxamine B (DFOB). Our data show that DFOB strongly enhances the mobility of these trace elements during low-temperature water-rock interaction. The presence of DFOB produces two distinct features in the Rare Earths and Yttrium (REY) patterns of leaching solutions, regardless of the mineralogical and chemical composition or the texture of the rock type studied. Bulk rock-normalized REY patterns of leaching solutions with DFOB show (i) a very distinct positive Ce anomaly and (ii) depletion of La and other light REY relative to the middle REY, with a concave downward pattern between La and Sm. These features are not observed in experiments with hydrochloric acid, acetic acid or deionized water. In DFOB-bearing leaching solutions Ce and U are decoupled from and selectively enriched relative to light REY and Th, respectively, due to oxidation to Ce(IV) and U(VI). Oxidation of Ce3+ and U4+ is promoted by the significantly higher stability of the Ce(IV) and U(VI) DFOB complexes as compared to the Ce(III) and U(IV) DFOB complexes. This is similar to the relationship between the Ce(IV)- and Ce(III)-pentacarbonate complexes that cause positive Ce anomalies in alkaline lakes. However, while formation of Ce(IV) carbonate complexes is confined to alkaline environments, Ce(IV) DFOB complexes may produce positive Ce anomalies even in mildly acidic and near-neutral natural waters. Siderophore-promoted dissolution processes also significantly enhance mobility of other 'immobile' HFSE

  11. DIORAMA Location Type User's Guide

    SciTech Connect

    Terry, James Russell

    2015-01-29

    The purpose of this report is to present the current design and implementation of the DIORAMA location type object (LocationType) and to provide examples and use cases. The LocationType object is included in the diorama-app package in the diorama::types namespace. Abstractly, the object is intended to capture the full time history of the location of an object or reference point. For example, a location may be speci ed as a near-Earth orbit in terms of a two-line element set, in which case the location type is capable of propagating the orbit both forward and backward in time to provide a location for any given time. Alternatively, the location may be speci ed as a xed set of geodetic coordinates (latitude, longitude, and altitude), in which case the geodetic location of the object is expected to remain constant for all time. From an implementation perspective, the location type is de ned as a union of multiple independent objects defi ned in the DIORAMA tle library. Types presently included in the union are listed and described in subsections below, and all conversions or transformation between these location types are handled by utilities provided by the tle library with the exception of the \\special-values" location type.

  12. Inhibition of cyclic AMP response element-directed transcription by decoy oligonucleotides enhances tumor-specific radiosensitivity

    SciTech Connect

    Park, Serk In; Park, Sung-Jun; Lee, Junghan; Kim, Hye Eun; Park, Su Jin; Sohn, Jeong-Won; Park, Yun Gyu

    2016-01-15

    The radiation stress induces cytotoxic responses of cell death as well as cytoprotective responses of cell survival. Understanding exact cellular mechanism and signal transduction pathways is important in improving cancer radiotherapy. Increasing evidence suggests that cyclic AMP response element binding protein (CREB)/activating transcription factor (ATF) family proteins act as a survival factor and a signaling molecule in response to stress. We postulated that CREB inhibition via CRE decoy oligonucleotide increases tumor cell sensitization to γ-irradiation-induced cytotoxic stress. In the present study, we demonstrate that CREB phosphorylation and CREB DNA-protein complex formation increased in time- and radiation dose-dependent manners, while there was no significant change in total protein level of CREB. In addition, CREB was phosphorylated in response to γ-irradiation through p38 MAPK pathway. Further investigation revealed that CREB blockade by decoy oligonucleotides functionally inhibited transactivation of CREB, and significantly increased radiosensitivity of multiple human cancer cell lines including TP53- and/or RB-mutated cells with minimal effects on normal cells. We also demonstrate that tumor cells ectopically expressing dominant negative mutant CREB (KCREB) and the cells treated with p38 MAPK inhibitors were more sensitive to γ-irradiation than wild type parental cells or control-treated cells. Taken together, we conclude that CREB protects tumor cells from γ-irradiation, and combination of CREB inhibition plus ionizing radiation will be a promising radiotherapeutic approach. - Highlights: • γ-Irradiation induced CREB phosphorylation and CRE-directed transcription in tumor. • γ-Irradiation-induced transcriptional activation of CREB was via p38 MAPK pathway. • CRE blockade increased radiosensitivity of tumor cells but not of normal cells. • CRE decoy oligonucleotides or p38 MAPK inhibitors can be used as radiosensitizers.

  13. Transposon-mediated enhancer detection reveals the location, morphology and development of the cupular organs, which are putative hydrodynamic sensors, in the ascidian Ciona intestinalis.

    PubMed

    Ohta, Naoyuki; Horie, Takeo; Satoh, Nori; Sasakura, Yasunori

    2010-11-01

    The adult of the ascidian Ciona intestinalis has cupular organs, i.e., putative hydrodynamic sensors, at the atrial epithelium. The cupular organ consists of support cells and sensory neurons, and it extends a gelatinous matrix, known as a cupula, toward the atrial cavity. These characteristics are shared with sensory hair cells in the vertebrate inner ear and lateral line neuromasts in fish and amphibians, which suggests an evolutionary link between the cupular organ and these vertebrate hydrodynamic sensors. In the present study, we have isolated and investigated two transposon-mediated enhancer detection lines that showed GFP expression in support cells of the cupular organs. Using the enhancer detection lines and neuron marker transgenic lines, we describe the position, morphology, and development of the cupular organs. Cupular organs were found at the atrial epithelium, but not in the branchial epithelium. We found that cupular organs are also present along the dorsal fold and the gonoducts. The cells lining the pre-atrial opening in juveniles are presumably precursor cells of the cupular organ. To our knowledge, the present study is the first precise description of the ascidian cupular organ, providing evidence that may help to resolve discrepancies among previous studies on the organ.

  14. The Mitochondrion-Located Protein OsB12D1 Enhances Flooding Tolerance during Seed Germination and Early Seedling Growth in Rice

    PubMed Central

    He, Dongli; Zhang, Hui; Yang, Pingfang

    2014-01-01

    B12D belongs to a function unknown subgroup of the Balem (Barley aleurone and embryo) proteins. In our previous work on rice seed germination, we identified a B12D-like protein encoded by LOC_Os7g41350 (named OsB12D1). OsB12D1 pertains to an ancient protein family with an amino acid sequence highly conserved from moss to angiosperms. Among the six OsB12Ds, OsB12D1 is one of the major transcripts and is primarily expressed in germinating seed and root. Bioinformatics analyses indicated that OsB12D1 is an anoxic or submergence resistance-related gene. RT-PCR results showed OsB12D1 is induced remarkably in the coleoptiles or roots by flooding during seed germination and early seedling growth. The OsB12D1-overexpressed rice seeds could protrude radicles in 8 cm deep water, further exhibiting significant flooding tolerance compared to the wild type. Moreover, this tolerance was not affected by the gibberellin biosynthesis inhibitor paclobutrazol. OsB12D1 was identified in the mitochondrion by subcellular localization analysis and possibly enhances electron transport through mediating Fe and oxygen availability under flooded conditions. This work indicated that OsB12D1 is a promising gene that can help to enhance rice seedling establishment in farming practices, especially for direct seeding. PMID:25089878

  15. Intravenous low-grade endometrial stromal sarcoma with intracardiac extension: A CASE OF inaccurate tumor location on contrast-enhanced computed tomography

    PubMed Central

    NOGAMI, YUYA; YAMAGAMI, WATARU; MAKI, JUNKO; BANNO, KOUJI; SUSUMU, NOBUYUKI; TOMITA, KOICHI; MATSUBARA, KENTARO; OBARA, HIDEAKI; KITAGAWA, YUKO; AOKI, DAISUKE

    2016-01-01

    We herein report a case of low-grade endometrial stromal sarcoma with intracardiac extension in a 58-year-old woman with a uterine tumor with intravascular involvement. The tumor was suspected preoperatively to be an endometrial stromal sarcoma by magnetic resonance imaging. The extent of intravascular involvement was determined to be below the level of the renal veins on preoperative contrast-enhanced computed tomography (CT). However, perioperative echography revealed that the tumor extended to the right atrium. An emergency cardiotomy with extracorporeal circulation was required. The risk of tumor embolism was reduced through transection of the inferior vena cava, but the tumor was difficult to remove completely. Postoperative hormonal therapy reduced the size of the residual tumor and no recurrence was detected for 1 year. The preoperative contrast-enhanced CT was unable to detect the free-floating intravascular tumor. This case illustrates a limitation of CT and indicates that accurate determination of the tumor extent for planning a surgical strategy in similar cases should be performed using multiple imaging methods. PMID:26893856

  16. Robust optimization of well location to enhance hysteretical trapping of CO2: Assessment of various uncertainty quantification methods and utilization of mixed response surface surrogates

    NASA Astrophysics Data System (ADS)

    Babaei, Masoud; Pan, Indranil; Alkhatib, Ali

    2015-12-01

    The paper aims to solve a robust optimization problem (optimization in presence of uncertainty) for finding the optimal locations of a number of CO2 injection wells for geological sequestration of carbon dioxide in a saline aquifer. The parametric uncertainties are the interfacial tension between CO2 and aquifer brine, the Land's trapping coefficient and the boundary aquifer's absolute permeability. The spatial uncertainties are due to the channelized permeability field which exhibits a binary channel-non-channel system. The objective function of the optimization is the amount of residually trapped CO2 due to the hysteresis of the relative permeability curves. A risk-averse value derived from the cumulative density function of the distribution of the amount of trapped gas is chosen as the objective function value. In order to ensure that the uncertainties are effectively taken into account, Monte Carlo simulation and Polynomial Chaos Expansion (PCE)-based methods are used and compared with each other. For different cases of parametric and spatial uncertainties, the most accurate uncertainty quantification (UQ) method is chosen to be integrated within the optimization algorithm. While for parametric uncertainty cases of up to two uncertain variables, PCE-based methods computationally outperform Monte Carlo simulations, it is shown that for the multimodal distributions of the function of trapped gas occurring for the spatial uncertainty case, Monte Carlo simulations are more reliable than PCE-based UQ methods. For the discrete (integer) optimization problem, various mixed response surface surrogate models are tested and the robust optimization resulted in optimal CO2 injection well locations.

  17. Drosophila TDP-43 RNA-Binding Protein Facilitates Association of Sister Chromatid Cohesion Proteins with Genes, Enhancers and Polycomb Response Elements

    PubMed Central

    Misulovin, Ziva; Gause, Maria; Rickels, Ryan A; Shilatifard, Ali

    2016-01-01

    The cohesin protein complex mediates sister chromatid cohesion and participates in transcriptional control of genes that regulate growth and development. Substantial reduction of cohesin activity alters transcription of many genes without disrupting chromosome segregation. Drosophila Nipped-B protein loads cohesin onto chromosomes, and together Nipped-B and cohesin occupy essentially all active transcriptional enhancers and a large fraction of active genes. It is unknown why some active genes bind high levels of cohesin and some do not. Here we show that the TBPH and Lark RNA-binding proteins influence association of Nipped-B and cohesin with genes and gene regulatory sequences. In vitro, TBPH and Lark proteins specifically bind RNAs produced by genes occupied by Nipped-B and cohesin. By genomic chromatin immunoprecipitation these RNA-binding proteins also bind to chromosomes at cohesin-bindin