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Sample records for narrow leaf1 gene

  1. Mutation of the Rice Narrow leaf1 Gene, Which Encodes a Novel Protein, Affects Vein Patterning and Polar Auxin Transport1[OA

    PubMed Central

    Qi, Jing; Qian, Qian; Bu, Qingyun; Li, Shuyu; Chen, Qian; Sun, Jiaqiang; Liang, Wenxing; Zhou, Yihua; Chu, Chengcai; Li, Xugang; Ren, Fugang; Palme, Klaus; Zhao, Bingran; Chen, Jinfeng; Chen, Mingsheng; Li, Chuanyou

    2008-01-01

    The size and shape of the plant leaf is an important agronomic trait. To understand the molecular mechanism governing plant leaf shape, we characterized a classic rice (Oryza sativa) dwarf mutant named narrow leaf1 (nal1), which exhibits a characteristic phenotype of narrow leaves. In accordance with reduced leaf blade width, leaves of nal1 contain a decreased number of longitudinal veins. Anatomical investigations revealed that the culms of nal1 also show a defective vascular system, in which the number and distribution pattern of vascular bundles are altered. Map-based cloning and genetic complementation analyses demonstrated that Nal1 encodes a plant-specific protein with unknown biochemical function. We provide evidence showing that Nal1 is richly expressed in vascular tissues and that mutation of this gene leads to significantly reduced polar auxin transport capacity. These results indicate that Nal1 affects polar auxin transport as well as the vascular patterns of rice plants and plays an important role in the control of lateral leaf growth. PMID:18562767

  2. Natural Variation in the Flag Leaf Morphology of Rice Due to a Mutation of the NARROW LEAF 1 Gene in Oryza sativa L.

    PubMed

    Taguchi-Shiobara, Fumio; Ota, Tatsuya; Ebana, Kaworu; Ookawa, Taiichiro; Yamasaki, Masanori; Tanabata, Takanari; Yamanouchi, Utako; Wu, Jianzhong; Ono, Nozomi; Nonoue, Yasunori; Nagata, Kazufumi; Fukuoka, Shuichi; Hirabayashi, Hideyuki; Yamamoto, Toshio; Yano, Masahiro

    2015-10-01

    We investigated the natural variations in the flag leaf morphology of rice. We conducted a principal component analysis based on nine flag leaf morphology traits using 103 accessions from the National Institute of Agrobiological Sciences Core Collection. The first component explained 39% of total variance, and the variable with highest loading was the width of the flag leaf (WFL). A genome-wide association analysis of 102 diverse Japanese accessions revealed that marker RM6992 on chromosome 4 was highly associated with WFL. In analyses of progenies derived from a cross between Takanari and Akenohoshi, the most significant quantitative trait locus (QTL) for WFL was in a 10.3-kb region containing the NARROW LEAF 1 (NAL1) gene, located 0.4 Mb downstream of RM6992. Analyses of chromosomal segment substitution lines indicated that a mutation (G1509A single-nucleotide mutation, causing an R233H amino acid substitution in NAL1) was present at the QTL. This explained 13 and 20% of total variability in WFL and the distance between small vascular bundles, respectively. The mutation apparently occurred during rice domestication and spread into japonica, tropical japonica, and indica subgroups. Notably, one accession, Phulba, had a NAL1 allele encoding only the N-terminal, or one-fourth, of the wild-type peptide. Given that the Phulba allele and the histidine-type allele showed essentially the same phenotype, the histidine-type allele was regarded as malfunctional. The phenotypes of transgenic plants varied depending on the ratio of histidine-type alleles to arginine-type alleles, raising the possibility that H(233)-type products function differently from and compete with R(233)-type products.

  3. Natural Variation in the Flag Leaf Morphology of Rice Due to a Mutation of the NARROW LEAF 1 Gene in Oryza sativa L.

    PubMed Central

    Taguchi-Shiobara, Fumio; Ota, Tatsuya; Ebana, Kaworu; Ookawa, Taiichiro; Yamasaki, Masanori; Tanabata, Takanari; Yamanouchi, Utako; Wu, Jianzhong; Ono, Nozomi; Nonoue, Yasunori; Nagata, Kazufumi; Fukuoka, Shuichi; Hirabayashi, Hideyuki; Yamamoto, Toshio; Yano, Masahiro

    2015-01-01

    We investigated the natural variations in the flag leaf morphology of rice. We conducted a principal component analysis based on nine flag leaf morphology traits using 103 accessions from the National Institute of Agrobiological Sciences Core Collection. The first component explained 39% of total variance, and the variable with highest loading was the width of the flag leaf (WFL). A genome-wide association analysis of 102 diverse Japanese accessions revealed that marker RM6992 on chromosome 4 was highly associated with WFL. In analyses of progenies derived from a cross between Takanari and Akenohoshi, the most significant quantitative trait locus (QTL) for WFL was in a 10.3-kb region containing the NARROW LEAF 1 (NAL1) gene, located 0.4 Mb downstream of RM6992. Analyses of chromosomal segment substitution lines indicated that a mutation (G1509A single-nucleotide mutation, causing an R233H amino acid substitution in NAL1) was present at the QTL. This explained 13 and 20% of total variability in WFL and the distance between small vascular bundles, respectively. The mutation apparently occurred during rice domestication and spread into japonica, tropical japonica, and indica subgroups. Notably, one accession, Phulba, had a NAL1 allele encoding only the N-terminal, or one-fourth, of the wild-type peptide. Given that the Phulba allele and the histidine-type allele showed essentially the same phenotype, the histidine-type allele was regarded as malfunctional. The phenotypes of transgenic plants varied depending on the ratio of histidine-type alleles to arginine-type alleles, raising the possibility that H233-type products function differently from and compete with R233-type products. PMID:26275424

  4. Maize YABBY Genes drooping leaf1 and drooping leaf2 Regulate Plant Architecture[OPEN

    PubMed Central

    Briggs, Sarah; Bradbury, Peter J.

    2017-01-01

    Leaf architecture directly influences canopy structure, consequentially affecting yield. We discovered a maize (Zea mays) mutant with aberrant leaf architecture, which we named drooping leaf1 (drl1). Pleiotropic mutations in drl1 affect leaf length and width, leaf angle, and internode length and diameter. These phenotypes are enhanced by natural variation at the drl2 enhancer locus, including reduced expression of the drl2-Mo17 allele in the Mo17 inbred. A second drl2 allele, produced by transposon mutagenesis, interacted synergistically with drl1 mutants and reduced drl2 transcript levels. The drl genes are required for proper leaf patterning, development and cell proliferation of leaf support tissues, and for restricting auricle expansion at the midrib. The paralogous loci encode maize CRABS CLAW co-orthologs in the YABBY family of transcriptional regulators. The drl genes are coexpressed in incipient and emergent leaf primordia at the shoot apex, but not in the vegetative meristem or stem. Genome-wide association studies using maize NAM-RIL (nested association mapping-recombinant inbred line) populations indicated that the drl loci reside within quantitative trait locus regions for leaf angle, leaf width, and internode length and identified rare single nucleotide polymorphisms with large phenotypic effects for the latter two traits. This study demonstrates that drl genes control the development of key agronomic traits in maize. PMID:28698237

  5. Maize YABBY genes drooping leaf1 and drooping leaf2 affect agronomic traits by regulating leaf architecture

    USDA-ARS?s Scientific Manuscript database

    Leaf architectural traits, such as length, width and angle, directly influence canopy structure and light penetration, photosynthate production and overall yield. We discovered and characterized a maize (Zea mays) mutant with aberrant leaf architecture we named drooping leaf1 (drl1), as leaf blades ...

  6. Overexpression of a Homeobox Gene, LeT6, Reveals Indeterminate Features in the Tomato Compound Leaf1

    PubMed Central

    Janssen, Bart-Jan; Lund, Lance; Sinha, Neelima

    1998-01-01

    The cultivated tomato (Lycopersicon esculentum) has a unipinnate compound leaf. In the developing leaf primordium, major leaflet initiation is basipetal, and lobe formation and early vascular differentiation are acropetal. We show that engineered alterations in the expression of a tomato homeobox gene, LeT6, can cause dramatic changes in leaf morphology. The morphological states are variable and unstable and the phenotypes produced indicate that the tomato leaf has an inherent level of indeterminacy. This is manifested by the production of multiple orders of compounding in the leaf, by numerous shoot, inflorescence, and floral meristems on leaves, and by the conversion of rachis-petiolule junctions into “axillary” positions where floral buds can arise. Overexpression of a heterologous homeobox transgene, kn1, does not produce such phenotypic variability. This indicates that LeT6 may differ from the heterologous kn1 gene in the effects manifested on overexpression, and that 35S-LeT6 plants may be subject to alterations in expression of both the introduced and endogenous LeT6 genes. The expression patterns of LeT6 argue in favor of a fundamental role for LeT6 in morphogenesis of leaves in tomato and also suggest that variability in homeobox gene expression may account for some of the diversity in leaf form seen in nature. PMID:9662520

  7. Analysis of the rice mutant dwarf and gladius leaf 1. Aberrant katanin-mediated microtubule organization causes up-regulation of gibberellin biosynthetic genes independently of gibberellin signaling.

    PubMed

    Komorisono, Masahiko; Ueguchi-Tanaka, Miyako; Aichi, Ikuko; Hasegawa, Yasuko; Ashikari, Motoyuki; Kitano, Hidemi; Matsuoka, Makoto; Sazuka, Takashi

    2005-08-01

    Molecular genetic studies of plant dwarf mutants have indicated that gibberellin (GA) and brassinosteroid (BR) are two major factors that determine plant height; dwarf mutants that are caused by other defects are relatively rare, especially in monocot species. Here, we report a rice (Oryza sativa) dwarf mutant, dwarf and gladius leaf 1 (dgl1), which exhibits only minimal response to GA and BR. In addition to the dwarf phenotype, dgl1 produces leaves with abnormally rounded tip regions. Positional cloning of DGL1 revealed that it encodes a 60-kD microtubule-severing katanin-like protein. The protein was found to be important in cell elongation and division, based on the observed cell phenotypes. GA biosynthetic genes are up-regulated in dgl1, but the expression of BR biosynthetic genes is not enhanced. The enhanced expression of GA biosynthetic genes in dgl1 is not caused by inappropriate GA signaling because the expression of these genes was repressed by GA3 treatment, and degradation of the rice DELLA protein SLR1 was triggered by GA3 in this mutant. Instead, aberrant microtubule organization caused by the loss of the microtubule-severing function of DGL1 may result in enhanced expression of GA biosynthetic genes in that enhanced expression was also observed in a BR-deficient mutant with aberrant microtubule organization. These results suggest that the function of DGL1 is important for cell and organ elongation in rice, and aberrant DGL1-mediated microtubule organization causes up-regulation of gibberellin biosynthetic genes independently of gibberellin signaling.

  8. Two WUSCHEL-related homeobox genes, narrow leaf2 and narrow leaf3, control leaf width in rice.

    PubMed

    Ishiwata, Aiko; Ozawa, Misa; Nagasaki, Hiroshi; Kato, Makio; Noda, Yusaku; Yamaguchi, Takahiro; Nosaka, Misuzu; Shimizu-Sato, Sae; Nagasaki, Akie; Maekawa, Masahiko; Hirano, Hiro-Yuki; Sato, Yutaka

    2013-05-01

    Leaf shape is one of the key determinants of plant architecture. Leaf shape also affects the amount of sunlight captured and influences photosynthetic efficiency; thus, it is an important agronomic trait in crop plants. Understanding the molecular mechanisms governing leaf shape is a central issue of plant developmental biology and agrobiotechnology. Here, we characterized the narrow-leaf phenotype of FL90, a linkage tester line of rice (Oryza sativa). Light and scanning electron microscopic analyses of FL90 leaves revealed defects in the development of marginal regions and a reduction in the number of longitudinal veins. The narrow-leaf phenotype of FL90 shows a two-factor recessive inheritance and is caused by the loss of function of two WUSCHEL-related homeobox genes, NAL2 and NAL3 (NAL2/3), which are duplicate genes orthologous to maize NS1 and NS2 and to Arabidopsis PRS. The overexpression of NAL2/3 in transgenic rice plants results in wider leaves containing increased numbers of veins, suggesting that NAL2/3 expression regulates leaf width. Thus, NAL2/3 can be used to modulate leaf shape and improve agronomic yield in crop plants.

  9. Narrow grass hedges reduce tylosin and associated antimicrobial resistance genes in agricultural runoff

    USDA-ARS?s Scientific Manuscript database

    Agricultural runoff from areas receiving livestock manure can potentially contaminate surface water with antimicrobials and antimicrobial resistance genes (ARGs). The objective of this study was to investigate the effectiveness of narrow grass hedges (NGHs) on reducing the transport of antimicrobial...

  10. Functions of Multiple Genes Encoding ADP-Glucose Pyrophosphorylase Subunits in Maize Endosperm, Embryo, and Leaf1[C][W][OPEN

    PubMed Central

    Huang, Binquan; Hennen-Bierwagen, Tracie A.; Myers, Alan M.

    2014-01-01

    ADP-glucose pyrophosphorylase (AGPase) provides the nucleotide sugar ADP-glucose and thus constitutes the first step in starch biosynthesis. The majority of cereal endosperm AGPase is located in the cytosol with a minor portion in amyloplasts, in contrast to its strictly plastidial location in other species and tissues. To investigate the potential functions of plastidial AGPase in maize (Zea mays) endosperm, six genes encoding AGPase large or small subunits were characterized for gene expression as well as subcellular location and biochemical activity of the encoded proteins. Seven transcripts from these genes accumulate in endosperm, including those from shrunken2 and brittle2 that encode cytosolic AGPase and five candidates that could encode subunits of the plastidial enzyme. The amino termini of these five polypeptides directed the transport of a reporter protein into chloroplasts of leaf protoplasts. All seven proteins exhibited AGPase activity when coexpressed in Escherichia coli with partner subunits. Null mutations were identified in the genes agpsemzm and agpllzm and shown to cause reduced AGPase activity in specific tissues. The functioning of these two genes was necessary for the accumulation of normal starch levels in embryo and leaf, respectively. Remnant starch was observed in both instances, indicating that additional genes encode AGPase large and small subunits in embryo and leaf. Endosperm starch was decreased by approximately 7% in agpsemzm- or agpllzm- mutants, demonstrating that plastidial AGPase activity contributes to starch production in this tissue even when the major cytosolic activity is present. PMID:24381067

  11. Wolverine gene flow across a narrow climatic niche.

    PubMed

    Schwartz, Michael K; Copeland, Jeffrey P; Anderson, Neil J; Squires, John R; Inman, Robert M; McKelvey, Kevin S; Pilgrim, Kristy L; Waits, Lisette P; Cushman, Samuel A

    2009-11-01

    Wolverines (Gulo gulo) are one of the rarest carnivores in the contiguous United States. Effective population sizes in Montana, Idaho, and Wyoming, where most of the wolverines in the contiguous United States exist, were calculated to be 35 (credible limits, 28 52) suggesting low abundance. Landscape features that influence wolverine population substructure and gene flow are largely unknown. Recent work has identified strong associations between areas with persistent spring snow and wolverine presence and range. We tested whether a dispersal model in which wolverines prefer to disperse through areas characterized by persistent spring snow cover produced least-cost paths among all individuals that correlated with genetic distance among individuals. Models simulating large preferences for dispersing within areas characterized by persistent spring snow explained the data better than a model based on Euclidean distance. Partial Mantel tests separating Euclidean distance from spring snow-cover-based effects indicated that Euclidean distance was not significant in describing patterns of genetic distance. Because these models indicated that successful dispersal paths followed areas characterized by spring snow cover, we used these understandings to derive empirically based least-cost corridor maps in the U.S. Rocky Mountains. These corridor maps largely explain previously published population subdivision patterns based on mitochondrial DNA and indicate that natural colonization of the southern Rocky Mountains by wolverines will be difficult but not impossible.

  12. The narrow sheath duplicate genes: sectors of dual aneuploidy reveal ancestrally conserved gene functions during maize leaf development.

    PubMed Central

    Scanlon, M J; Chen, K D; McKnight CC, I V

    2000-01-01

    The narrow sheath mutant of maize displays a leaf and plant stature phenotype controlled by the duplicate factor mutations narrow sheath1 and narrow sheath2. Mutant leaves fail to develop a lateral domain that includes the leaf margins. Genetic data are presented to show that the narrow sheath mutations map to duplicated chromosomal regions, reflecting an ancestral duplication of the maize genome. Genetic and cytogenetic evidence indicates that the original mutation at narrow sheath2 is associated with a chromosomal inversion on the long arm of chromosome 4. Meristematic sectors of dual aneuploidy were generated, producing plants genetically mosaic for NARROW SHEATH function. These mosaic plants exhibited characteristic half-plant phenotypes, in which leaves from one side of the plant were of nonmutant morphology and leaves from the opposite side were of narrow sheath mutant phenotype. The data suggest that the narrow sheath duplicate genes may perform ancestrally conserved, redundant functions in the development of a lateral domain in the maize leaf. PMID:10880496

  13. Laser microdissection of narrow sheath mutant maize uncovers novel gene expression in the shoot apical meristem.

    PubMed

    Zhang, Xiaolan; Madi, Shahinez; Borsuk, Lisa; Nettleton, Dan; Elshire, Robert J; Buckner, Brent; Janick-Buckner, Diane; Beck, Jon; Timmermans, Marja; Schnable, Patrick S; Scanlon, Michael J

    2007-06-01

    Microarrays enable comparative analyses of gene expression on a genomic scale, however these experiments frequently identify an abundance of differentially expressed genes such that it may be difficult to identify discrete functional networks that are hidden within large microarray datasets. Microarray analyses in which mutant organisms are compared to nonmutant siblings can be especially problematic when the gene of interest is expressed in relatively few cells. Here, we describe the use of laser microdissection microarray to perform transcriptional profiling of the maize shoot apical meristem (SAM), a ~100-microm pillar of organogenic cells that is required for leaf initiation. Microarray analyses compared differential gene expression within the SAM and incipient leaf primordium of nonmutant and narrow sheath mutant plants, which harbored mutations in the duplicate genes narrow sheath1 (ns1) and narrow sheath2 (ns2). Expressed in eight to ten cells within the SAM, ns1 and ns2 encode paralogous WUSCHEL1-like homeobox (WOX) transcription factors required for recruitment of leaf initials that give rise to a large lateral domain within maize leaves. The data illustrate the utility of laser microdissection-microarray analyses to identify a relatively small number of genes that are differentially expressed within the SAM. Moreover, these analyses reveal potentially conserved WOX gene functions and implicate specific hormonal and signaling pathways during early events in maize leaf development.

  14. Laser Microdissection of Narrow Sheath Mutant Maize Uncovers Novel Gene Expression in the Shoot Apical Meristem

    PubMed Central

    Zhang, Xiaolan; Madi, Shahinez; Borsuk, Lisa; Nettleton, Dan; Elshire, Robert J; Buckner, Brent; Janick-Buckner, Diane; Beck, Jon; Timmermans, Marja; Schnable, Patrick S; Scanlon, Michael J

    2007-01-01

    Microarrays enable comparative analyses of gene expression on a genomic scale, however these experiments frequently identify an abundance of differentially expressed genes such that it may be difficult to identify discrete functional networks that are hidden within large microarray datasets. Microarray analyses in which mutant organisms are compared to nonmutant siblings can be especially problematic when the gene of interest is expressed in relatively few cells. Here, we describe the use of laser microdissection microarray to perform transcriptional profiling of the maize shoot apical meristem (SAM), a ~100-μm pillar of organogenic cells that is required for leaf initiation. Microarray analyses compared differential gene expression within the SAM and incipient leaf primordium of nonmutant and narrow sheath mutant plants, which harbored mutations in the duplicate genes narrow sheath1 (ns1) and narrow sheath2 (ns2). Expressed in eight to ten cells within the SAM, ns1 and ns2 encode paralogous WUSCHEL1-like homeobox (WOX) transcription factors required for recruitment of leaf initials that give rise to a large lateral domain within maize leaves. The data illustrate the utility of laser microdissection-microarray analyses to identify a relatively small number of genes that are differentially expressed within the SAM. Moreover, these analyses reveal potentially conserved WOX gene functions and implicate specific hormonal and signaling pathways during early events in maize leaf development. PMID:17571927

  15. Narrow grass hedges reduce tylosin and associated antimicrobial resistance genes in agricultural runoff.

    PubMed

    Soni, Bhavneet; Bartelt-Hunt, Shannon L; Snow, Daniel D; Gilley, John E; Woodbury, Bryan L; Marx, David B; Li, Xu

    2015-05-01

    Agricultural runoff from areas receiving livestock manure can potentially contaminate surface water with antimicrobials and antimicrobial resistance genes (ARGs). The objective of this study was to investigate the effectiveness of narrow grass hedges (NGHs) on reducing the transport of antimicrobials and ARGs in runoff after land application of swine manure slurry. Plot-scale rainfall simulation tests were conducted on 0.75 m by 4.0 m plots designed to test three treatment factors: manure amendment (control plots receiving no manure vs. amended plots receiving manure based on 3 times N requirement), NGH (plots with a NGH vs. plots without a NGH), and rainfall events (days 1-3). Runoff generated during three 30-min simulated rainfall events was sampled and analyzed for antimicrobials and ARGs. Manure amendment was responsible for the presence of antimicrobial tylosin ( < 0.0001) and tylosin resistance gene (B) ( < 0.0001) in runoff. Narrow grass hedges proved to be effective in reducing tylosin ( < 0.0001) and (B) ( < 0.0347) in runoff. Manure amendment was responsible for the introduction of tylosin ( < 0.0482) and (B) ( = 0.0128) into the soil; however, it had no significant impact on the abundance of the 16S rRNA gene in soil. Results from this study suggest that NGHs could be a best management practice to control the transport of antimicrobials and ARGs in agricultural runoff.

  16. Characterization and gene cloning of the rice (Oryza sativa L.) dwarf and narrow-leaf mutant dnl3.

    PubMed

    Shi, L; Wei, X J; Adedze, Y M N; Sheng, Z H; Tang, S Q; Hu, P S; Wang, J L

    2016-09-16

    The dwarf and narrow-leaf rice (Oryza sativa L.) mutant dnl3 was isolated from the Japonica cultivar Zhonghua 11 (wild-type). dnl3 exhibited pleiotropic developmental defects. The narrow-leaf phenotype resulted from a marked reduction in the number of vascular bundles, while the dwarf stature was caused by the formation of foreshortened internodes and a reduced number of parenchyma cells. The suggestion that cell division is impaired in the mutant was consistent with the transcriptional behavior of various genes associated with cell division. The mutant was less responsive to exogenously supplied gibberellic acid than the wild-type, and profiling the transcription of genes involved in gibberellin synthesis and response revealed that a lesion in the mutant affected gibberellin signal transduction. The dnl3 phenotype was inherited as a single-dominant gene, mapping within a 19.1-kb region of chromosome 12, which was found to harbor three open reading frames. Resequencing the open reading frames revealed that the mutant carried an allele at one of the three genes that differed from the wild-type sequence by 2-bp deletions; this gene encoded a cellulose synthase-like D4 (CSLD4) protein. Therefore, OsCSLD4 is a candidate gene for DNL3. DNL3 was expressed in all of the rice organs tested at the heading stage, particularly in the leaves, roots, and culms. These results suggest that DNL3 plays important roles in rice leaf morphogenesis and vegetative development.

  17. Identifying Stable Reference Genes for qRT-PCR Normalisation in Gene Expression Studies of Narrow-Leafed Lupin (Lupinus angustifolius L.).

    PubMed

    Taylor, Candy M; Jost, Ricarda; Erskine, William; Nelson, Matthew N

    2016-01-01

    Quantitative Reverse Transcription PCR (qRT-PCR) is currently one of the most popular, high-throughput and sensitive technologies available for quantifying gene expression. Its accurate application depends heavily upon normalisation of gene-of-interest data with reference genes that are uniformly expressed under experimental conditions. The aim of this study was to provide the first validation of reference genes for Lupinus angustifolius (narrow-leafed lupin, a significant grain legume crop) using a selection of seven genes previously trialed as reference genes for the model legume, Medicago truncatula. In a preliminary evaluation, the seven candidate reference genes were assessed on the basis of primer specificity for their respective targeted region, PCR amplification efficiency, and ability to discriminate between cDNA and gDNA. Following this assessment, expression of the three most promising candidates [Ubiquitin C (UBC), Helicase (HEL), and Polypyrimidine tract-binding protein (PTB)] was evaluated using the NormFinder and RefFinder statistical algorithms in two narrow-leafed lupin lines, both with and without vernalisation treatment, and across seven organ types (cotyledons, stem, leaves, shoot apical meristem, flowers, pods and roots) encompassing three developmental stages. UBC was consistently identified as the most stable candidate and has sufficiently uniform expression that it may be used as a sole reference gene under the experimental conditions tested here. However, as organ type and developmental stage were associated with greater variability in relative expression, it is recommended using UBC and HEL as a pair to achieve optimal normalisation. These results highlight the importance of rigorously assessing candidate reference genes for each species across a diverse range of organs and developmental stages. With emerging technologies, such as RNAseq, and the completion of valuable transcriptome data sets, it is possible that other potentially more

  18. Identifying Stable Reference Genes for qRT-PCR Normalisation in Gene Expression Studies of Narrow-Leafed Lupin (Lupinus angustifolius L.)

    PubMed Central

    Erskine, William; Nelson, Matthew N.

    2016-01-01

    Quantitative Reverse Transcription PCR (qRT-PCR) is currently one of the most popular, high-throughput and sensitive technologies available for quantifying gene expression. Its accurate application depends heavily upon normalisation of gene-of-interest data with reference genes that are uniformly expressed under experimental conditions. The aim of this study was to provide the first validation of reference genes for Lupinus angustifolius (narrow-leafed lupin, a significant grain legume crop) using a selection of seven genes previously trialed as reference genes for the model legume, Medicago truncatula. In a preliminary evaluation, the seven candidate reference genes were assessed on the basis of primer specificity for their respective targeted region, PCR amplification efficiency, and ability to discriminate between cDNA and gDNA. Following this assessment, expression of the three most promising candidates [Ubiquitin C (UBC), Helicase (HEL), and Polypyrimidine tract-binding protein (PTB)] was evaluated using the NormFinder and RefFinder statistical algorithms in two narrow-leafed lupin lines, both with and without vernalisation treatment, and across seven organ types (cotyledons, stem, leaves, shoot apical meristem, flowers, pods and roots) encompassing three developmental stages. UBC was consistently identified as the most stable candidate and has sufficiently uniform expression that it may be used as a sole reference gene under the experimental conditions tested here. However, as organ type and developmental stage were associated with greater variability in relative expression, it is recommended using UBC and HEL as a pair to achieve optimal normalisation. These results highlight the importance of rigorously assessing candidate reference genes for each species across a diverse range of organs and developmental stages. With emerging technologies, such as RNAseq, and the completion of valuable transcriptome data sets, it is possible that other potentially more

  19. Narrowing down the distal border of the copy number variable beta-defensin gene cluster on human 8p23.

    PubMed

    Taudien, Stefan; Huse, Klaus; Groth, Marco; Platzer, Matthias

    2014-02-19

    Copy number variation (CNV) in the range from 2 to 12 per diploid genome is an outstanding feature of the beta-defensin gene (DEFB) cluster on human chromosome 8p23.1 numerously demonstrated by different methods. So far, CNV was proven for a 115 kb region between DEFB4 and 21 kb proximal of DEFB107 but the borders for the entire CNV repeat unit are still unknown. Our study aimed to narrow down the distal border of the DEFB cluster. We established tests for length polymorphisms based on amplification and capillary electrophoresis with laser-induced fluorescence (CE-LIF) analysis of seven insertion/deletion (indel) containing regions spread over the entire cluster. The tests were carried out with 25 genomic DNAs with different previously determined cluster copy numbers. CNV was demonstrated for six indels between ~1 kb distal of DEFB108P and 10 kb proximal of DEFB107. In contrast, the most distal indel is not affected by CNV. Our analysis fixes the minimal length of proven CNV to 157 kb including DEFB108P but excluding DEFB109P. The distal border between CNV and non-CNV part of the DEF cluster is located in the 59 kb interval chr8:7,171,082-7,230,128.

  20. Is Perceptual Narrowing Too Narrow?

    ERIC Educational Resources Information Center

    Cashon, Cara H.; Denicola, Christopher A.

    2011-01-01

    There is a growing list of examples illustrating that infants are transitioning from having earlier abilities that appear more "universal," "broadly tuned," or "unconstrained" to having later abilities that appear more "specialized," "narrowly tuned," or "constrained." Perceptual narrowing, a well-known phenomenon related to face, speech, and…

  1. Impact of molecular weight in four-branched star vectors with narrow molecular weight distribution on gene delivery efficiency.

    PubMed

    Nemoto, Yasushi; Borovkov, Alexey; Zhou, Yue-Min; Takewa, Yoshiaki; Tatsumi, Eisuke; Nakayama, Yasuhide

    2009-12-01

    A series of star-shaped cationic polymers, termed star vectors (SVs), has been developed as effective nonviral gene delivery carriers. In this study, we separated SVs into several fractions having different molecular weights with very narrow molecular weight distributions in order to examine in detail the influence of the molecular weight of the SVs on the gene transfection efficiency. As a model compound for several types of SVs, 4-branched poly(N,N-dimethylaminopropyl acrylamide) having a molecular weight (M(n)) of approximately 35 kDa and polydispersity of 1.6 was prepared by iniferter-based radical polymerization. The SVs were separated using size-exclusion chromatography to obtain seven fractions having M(n) ranging from 27 kDa to 73 kDa with polydispersity ranging from 1.1 to 1.2. All the fractionated SVs have similar pH of 10.2-10.4 and were able to interact with and condense luciferase-encoding plasmid deoxyribonucleic acid (DNA) to yield SV/DNA polyplexes. A water-soluble tetrazolium-1 (WST) assay showed that all SVs had minimal cellular cytotoxicity under an N/P charge ratio of 10. The critical micellar concentration decreased with an increase in the M(n) of the fractionated SVs; however, the particle size of the polyplexes, exclusion activity of ethidium bromide, and zeta-potential of the polyplexes increased. An in vitro evaluation using COS-1 cells at an N/P ratio of 10 showed that transfection activity increased almost linearly with M(n). The highest transfection activity was obtained for SVs with the highest M(n) (73 kDa), which was over 7 times that for the SVs with the lowest M(n) (27 kDa), the nonfractionated original SV, or PEI standard. The transfection efficiency was more correlated with the amphiphilicity or hydrophobicity of the SVs and the surface potential and condensate density of the polyplexes than with the particle size.

  2. Transcriptome sequencing of different narrow-leafed lupin tissue types provides a comprehensive uni-gene assembly and extensive gene-based molecular markers

    PubMed Central

    Kamphuis, Lars G; Hane, James K; Nelson, Matthew N; Gao, Lingling; Atkins, Craig A; Singh, Karam B

    2015-01-01

    Narrow-leafed lupin (NLL; Lupinus angustifolius L.) is an important grain legume crop that is valuable for sustainable farming and is becoming recognized as a human health food. NLL breeding is directed at improving grain production, disease resistance, drought tolerance and health benefits. However, genetic and genomic studies have been hindered by a lack of extensive genomic resources for the species. Here, the generation, de novo assembly and annotation of transcriptome datasets derived from five different NLL tissue types of the reference accession cv. Tanjil are described. The Tanjil transcriptome was compared to transcriptomes of an early domesticated cv. Unicrop, a wild accession P27255, as well as accession 83A:476, together being the founding parents of two recombinant inbred line (RIL) populations. In silico predictions for transcriptome-derived gene-based length and SNP polymorphic markers were conducted and corroborated using a survey assembly sequence for NLL cv. Tanjil. This yielded extensive indel and SNP polymorphic markers for the two RIL populations. A total of 335 transcriptome-derived markers and 66 BAC-end sequence-derived markers were evaluated, and 275 polymorphic markers were selected to genotype the reference NLL 83A:476 × P27255 RIL population. This significantly improved the completeness, marker density and quality of the reference NLL genetic map. PMID:25060816

  3. Transcriptome sequencing of different narrow-leafed lupin tissue types provides a comprehensive uni-gene assembly and extensive gene-based molecular markers.

    PubMed

    Kamphuis, Lars G; Hane, James K; Nelson, Matthew N; Gao, Lingling; Atkins, Craig A; Singh, Karam B

    2015-01-01

    Narrow-leafed lupin (NLL; Lupinus angustifolius L.) is an important grain legume crop that is valuable for sustainable farming and is becoming recognized as a human health food. NLL breeding is directed at improving grain production, disease resistance, drought tolerance and health benefits. However, genetic and genomic studies have been hindered by a lack of extensive genomic resources for the species. Here, the generation, de novo assembly and annotation of transcriptome datasets derived from five different NLL tissue types of the reference accession cv. Tanjil are described. The Tanjil transcriptome was compared to transcriptomes of an early domesticated cv. Unicrop, a wild accession P27255, as well as accession 83A:476, together being the founding parents of two recombinant inbred line (RIL) populations. In silico predictions for transcriptome-derived gene-based length and SNP polymorphic markers were conducted and corroborated using a survey assembly sequence for NLL cv. Tanjil. This yielded extensive indel and SNP polymorphic markers for the two RIL populations. A total of 335 transcriptome-derived markers and 66 BAC-end sequence-derived markers were evaluated, and 275 polymorphic markers were selected to genotype the reference NLL 83A:476 × P27255 RIL population. This significantly improved the completeness, marker density and quality of the reference NLL genetic map. © 2014 CSIRO. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  4. Structure, expression profile and phylogenetic inference of chalcone isomerase-like genes from the narrow-leafed lupin (Lupinus angustifolius L.) genome

    PubMed Central

    Przysiecka, Łucja; Książkiewicz, Michał; Wolko, Bogdan; Naganowska, Barbara

    2015-01-01

    Lupins, like other legumes, have a unique biosynthesis scheme of 5-deoxy-type flavonoids and isoflavonoids. A key enzyme in this pathway is chalcone isomerase (CHI), a member of CHI-fold protein family, encompassing subfamilies of CHI1, CHI2, CHI-like (CHIL), and fatty acid-binding (FAP) proteins. Here, two Lupinus angustifolius (narrow-leafed lupin) CHILs, LangCHIL1 and LangCHIL2, were identified and characterized using DNA fingerprinting, cytogenetic and linkage mapping, sequencing and expression profiling. Clones carrying CHIL sequences were assembled into two contigs. Full gene sequences were obtained from these contigs, and mapped in two L. angustifolius linkage groups by gene-specific markers. Bacterial artificial chromosome fluorescence in situ hybridization approach confirmed the localization of two LangCHIL genes in distinct chromosomes. The expression profiles of both LangCHIL isoforms were very similar. The highest level of transcription was in the roots of the third week of plant growth; thereafter, expression declined. The expression of both LangCHIL genes in leaves and stems was similar and low. Comparative mapping to reference legume genome sequences revealed strong syntenic links; however, LangCHIL2 contig had a much more conserved structure than LangCHIL1. LangCHIL2 is assumed to be an ancestor gene, whereas LangCHIL1 probably appeared as a result of duplication. As both copies are transcriptionally active, questions arise concerning their hypothetical functional divergence. Screening of the narrow-leafed lupin genome and transcriptome with CHI-fold protein sequences, followed by Bayesian inference of phylogeny and cross-genera synteny survey, identified representatives of all but one (CHI1) main subfamilies. They are as follows: two copies of CHI2, FAPa2 and CHIL, and single copies of FAPb and FAPa1. Duplicated genes are remnants of whole genome duplication which is assumed to have occurred after the divergence of Lupinus, Arachis, and Glycine

  5. DNA as patentable subject matter and a narrow framework for addressing the perceived problems caused by gene patents.

    PubMed

    Schilling, Stephen H

    2011-12-01

    Concerns about the alleged harmful effects of gene patents--including hindered research and innovation and impeded patient access to high-quality genetic diagnostic tests--have resulted in overreactions from the public and throughout the legal profession. These overreactions are exemplified by Association for Molecular Pathology v. U.S. Patent and Trademark Office, a 2010 case in the Southern District of New York that held that isolated DNA is unpatentable subject matter under 35 U.S.C. § 101. The problem with these responses is that they fail to adequately consider the role that gene patents and patents on similar biomolecules play in facilitating investment in the costly and risky developmental processes required to transform the underlying inventions into marketable products. Accordingly, a more precisely refined solution is advisable. This Note proposes a narrowly tailored set of solutions to address the concerns about gene patents without destroying the incentives for companies to create and commercialize inventions derived from these and similar patents.

  6. Characterization of Rolled and Erect Leaf 1 in regulating leave morphology in rice

    PubMed Central

    Chen, Qiaoling; Xie, Qingjun; Gao, Ju; Wang, Wenyi; Sun, Bo; Liu, Bohan; Zhu, Haitao; Peng, Haifeng; Zhao, Haibing; Liu, Changhong; Wang, Jiang; Zhang, Jingliu; Zhang, Guiquan; Zhang, Zemin

    2015-01-01

    Leaf morphology, particularly in crop, is one of the most important agronomic traits because it influences the yield through the manipulation of photosynthetic capacity and transpiration. To understand the regulatory mechanism of leaf morphogenesis, an Oryza sativa dominant mutant, rolled and erect leaf 1 (rel1) has been characterized. This mutant has a predominant rolled leaf, increased leaf angle, and reduced plant height phenotype that results in a reduction in grain yield. Electron microscope observations indicated that the leaf incurvations of rel1 dominant mutants result from the alteration of the size and number of bulliform cells. Molecular cloning revealed that the rel1 dominant mutant phenotype is caused by the activation of the REL1 gene, which encodes a novel unknown protein, despite its high degree of conservation among monocot plants. Moreover, the downregulation of the REL1 gene in the rel1 dominant mutant restored the phenotype of this dominant mutant. Alternatively, overexpression of REL1 in wild-type plants induced a phenotype similar to that of the dominant rel1 mutant, indicating that REL1 plays a positive role in leaf rolling and bending. Consistent with the observed rel1 phenotype, the REL1 gene was predominantly expressed in the meristem of various tissues during plant growth and development. Nevertheless, the responsiveness of both rel1 dominant mutants and REL1-overexpressing plants to exogenous brassinosteroid (BR) was reduced. Moreover, transcript levels of BR response genes in the rel1 dominant mutants and REL1-overexpressing lines were significantly altered. Additionally, seven REL1-interacting proteins were also identified from a yeast two-hybrid screen. Taken together, these findings suggest that REL1 regulates leaf morphology, particularly in leaf rolling and bending, through the coordination of BR signalling transduction. PMID:26142419

  7. Ecological differentiation, lack of hybrids involving diploids, and asymmetric gene flow between polyploids in narrow contact zones of Senecio carniolicus (syn. Jacobaea carniolica, Asteraceae).

    PubMed

    Hülber, Karl; Sonnleitner, Michaela; Suda, Jan; Krejčíková, Jana; Schönswetter, Peter; Schneeweiss, Gerald M; Winkler, Manuela

    2015-03-01

    Areas of immediate contact of different cytotypes offer a unique opportunity to study evolutionary dynamics within heteroploid species and to assess isolation mechanisms governing coexistence of cytotypes of different ploidy. The degree of reproductive isolation of cytotypes, that is, the frequency of heteroploid crosses and subsequent formation of viable and (partly) fertile hybrids, plays a crucial role for the long-term integrity of lineages in contact zones. Here, we assessed fine-scale distribution, spatial clustering, and ecological niches as well as patterns of gene flow in parental and hybrid cytotypes in zones of immediate contact of di-, tetra-, and hexaploid Senecio carniolicus (Asteraceae) in the Eastern Alps. Cytotypes were spatially separated also at the investigated microscale; the strongest spatial separation was observed for the fully interfertile tetra- and hexaploids. The three main cytotypes showed highly significant niche differences, which were, however, weaker than across their entire distribution ranges in the Eastern Alps. Individuals with intermediate ploidy levels were found neither in the diploid/tetraploid nor in the diploid/hexaploid contact zones indicating strong reproductive barriers. In contrast, pentaploid individuals were frequent in the tetraploid/hexaploid contact zone, albeit limited to a narrow strip in the immediate contact zone of their parental cytotypes. AFLP fingerprinting data revealed introgressive gene flow mediated by pentaploid hybrids from tetra- to hexaploid individuals, but not vice versa. The ecological niche of pentaploids differed significantly from that of tetraploids but not from hexaploids.

  8. Ecological differentiation, lack of hybrids involving diploids, and asymmetric gene flow between polyploids in narrow contact zones of Senecio carniolicus (syn. Jacobaea carniolica, Asteraceae)

    PubMed Central

    Hülber, Karl; Sonnleitner, Michaela; Suda, Jan; Krejčíková, Jana; Schönswetter, Peter; Schneeweiss, Gerald M; Winkler, Manuela

    2015-01-01

    Areas of immediate contact of different cytotypes offer a unique opportunity to study evolutionary dynamics within heteroploid species and to assess isolation mechanisms governing coexistence of cytotypes of different ploidy. The degree of reproductive isolation of cytotypes, that is, the frequency of heteroploid crosses and subsequent formation of viable and (partly) fertile hybrids, plays a crucial role for the long-term integrity of lineages in contact zones. Here, we assessed fine-scale distribution, spatial clustering, and ecological niches as well as patterns of gene flow in parental and hybrid cytotypes in zones of immediate contact of di-, tetra-, and hexaploid Senecio carniolicus (Asteraceae) in the Eastern Alps. Cytotypes were spatially separated also at the investigated microscale; the strongest spatial separation was observed for the fully interfertile tetra- and hexaploids. The three main cytotypes showed highly significant niche differences, which were, however, weaker than across their entire distribution ranges in the Eastern Alps. Individuals with intermediate ploidy levels were found neither in the diploid/tetraploid nor in the diploid/hexaploid contact zones indicating strong reproductive barriers. In contrast, pentaploid individuals were frequent in the tetraploid/hexaploid contact zone, albeit limited to a narrow strip in the immediate contact zone of their parental cytotypes. AFLP fingerprinting data revealed introgressive gene flow mediated by pentaploid hybrids from tetra- to hexaploid individuals, but not vice versa. The ecological niche of pentaploids differed significantly from that of tetraploids but not from hexaploids. PMID:25859328

  9. Genetic analysis of rice mutants responsible for narrow leaf phenotype and reduced vein number.

    PubMed

    Kubo, Fumika Clara; Yasui, Yukiko; Kumamaru, Toshihiro; Sato, Yutaka; Hirano, Hiro-Yuki

    2017-03-17

    Leaves are a major site for photosynthesis and a key determinant of plant architecture. Rice produces thin and slender leaves, which consist of the leaf blade and leaf sheath separated by the lamina joint. Two types of vasculature, the large and small vascular bundles, run in parallel, together with a strong structure, the midrib. In this paper, we examined the function of four genes that regulate the width of the leaf blade and the vein number: NARROW LEAF1 (NAL1), NAL2, NAL3 and NAL7. We backcrossed original mutants of these genes with the standard wild-type rice, Taichung 65. We then compared the effect of each mutation on similar genetic backgrounds and examined genetic interactions of these genes. The nal1 single mutation and the nal2 nal3 double mutation showed a severe effect on leaf width, resulting in very narrow leaves. Although vein number was also reduced in the nal1 and nal2 nal3 mutants, the small vein number was more strongly reduced than the large vein number. In contrast, the nal7 mutation showed a milder effect on leaf width and vein number, and both the large and small veins were similarly affected. Thus, the genes responsible for narrow leaf phenotype seem to play distinct roles. The nal7 mutation showed additive effects on both leaf width and vein number, when combined with the nal1 single or the nal2 nal3 double mutation. In addition, observations of inner tissues revealed that cell differentiation was partially compromised in the nal2 nal3 nal7 mutant, consistent with the severe reduction in leaf width in this triple mutant.

  10. Consequences of transforming narrow leafed lupin (Lupinus angustifolius [L.]) with an ipt gene under control of a flower-specific promoter.

    PubMed

    Atkins, Craig A; Emery, R J Neil; Smith, Penelope M C

    2011-12-01

    Phenotypes of five transgenic lines of narrow-leafed lupin (Lupinus angustifolius [L] cv Merrit) stably transformed with the isopentenyl pyrophosphate transferase (ipt) gene from Agrobacterium tumefaciens coupled to a flower-specific promoter (TP12) from Nicotiana tabacum [L.] are described. Expression of the transgene was detected in floral tissues and in shoot apical meristems on all orders of inflorescence. In each transgenic line there was significant axillary bud outgrowth at all nodes on the main stem with pronounced branch development from the more basal nodes in three of the lines. The lowest basal branches developed in a manner similar to the upper stem axillary branches on cv Merrit and bore fruits, which, in two lines, contained a significant yield of filled seeds at maturity. Senescence of the cotyledons was delayed in all lines with green cotyledons persisting beyond anthesis in one case. IPT expression increased cytokinin (CK) levels in flowers, meristem tissues and phloem exudates in a form specific manner, which was suggestive of localized flower and meristem production with significant long-distance re-distribution in phloem. The total number of fruits formed (pod set) on some transgenic lines was increased compared to cv Merrit. Grain size compared to cv Merrit was not significantly altered in transgenic lines.

  11. The E6-Ap ubiquitin-protein ligase (UBE3A) gene is localized within a narrowed Angelman syndrome critical region.

    PubMed

    Sutcliffe, J S; Jiang, Y H; Galijaard, R J; Matsuura, T; Fang, P; Kubota, T; Christian, S L; Bressler, J; Cattanach, B; Ledbetter, D H; Beaudet, A L

    1997-04-01

    Angelman syndrome (AS) and Prader-Willi syndrome (PWS) are distinct clinical phenotypes resulting from maternal and paternal deficiencies, respectively, in human chromosome 15qll-q13. Although several imprinted, paternally expressed transcripts have been identified within the PWS candidate region, no maternally expressed gene has yet been identified within the AS candidate region. We have developed an integrated physical map spanning the PWS and AS candidate regions and localized two breakpoints, including a cryptic t(14;15) translocation associated with AS and a non-AS 15q deletion, which substantially narrow the AS candidate region to approximately 250 kb. Mapping data indicate that the entire transcriptional unit of the E6-AP ubiquitin-protein ligase (UBE3A) gene lies within the AS region. The UBE3A locus expresses a transcript of approximately 5 kb at low to moderate levels in all tissues tested. The mouse homolog of UBE3A was cloned and sequenced revealing a high degree of conservation at nucleotide and protein levels. Northern and RT-PCR analysis of Ube3a expression in mouse tissues from animals with segmental, paternal uniparental disomy failed to detect substantially reduced or absent expression compared to control animals, failing to provide any evidence for maternal-specific expression from this locus. Recent identification of de novo truncating mutations in UBE3A taken with these observations indicates that mutations in UBE3A can lead to AS and suggests that this locus may encode both imprinted and biallelically expressed products.

  12. Narrowness and Liberality

    ERIC Educational Resources Information Center

    Agresto, John

    2003-01-01

    John Agresto, whose task has been to rebuild the war-ravaged infrastructure of a Middle-Eastern university system, is discouraged to see that narrow expertise is the only goal of education there, to the utter exclusion of intellectual breadth. He comments that, although it is not that bad in the U.S., he feels that doctoral programs as currently…

  13. Identification of a key recombinant narrows the CADASIL gene region to 8 cM and argues against allelism of CADASIL and familial hemiplegic migraine

    SciTech Connect

    Dichgans, M.; Mayer, M.; Straube, A.

    1996-02-15

    This article reports on new information regarding the genetic mapping of the human CADASIL gene region. Previously, the gene had been mapped to human chromosome 19q12. Using the identification of a chromosomal crossover, the region has been refined to an 8-cM interval. 11 refs., 2 figs., 1 tab.

  14. Albino Leaf1 That Encodes the Sole Octotricopeptide Repeat Protein Is Responsible for Chloroplast Development1[OPEN

    PubMed Central

    Tan, Jianjie; Xing, Yi; Liu, Changhong; Chen, Qiaoling; Zhu, Haitao; Wang, Jiang; Zhang, Jingliu; Zhang, Guiquan

    2016-01-01

    Chloroplast, the photosynthetic organelle in plants, plays a crucial role in plant development and growth through manipulating the capacity of photosynthesis. However, the regulatory mechanism of chloroplast development still remains elusive. Here, we characterized a mutant with defective chloroplasts in rice (Oryza sativa), termed albino leaf1 (al1), which exhibits a distinct albino phenotype in leaves, eventually leading to al1 seedling lethality. Electronic microscopy observation demonstrated that the number of thylakoids was reduced and the structure of thylakoids was disrupted in the al1 mutant during rice development, which eventually led to the breakdown of chloroplast. Molecular cloning revealed that AL1 encodes the sole octotricopeptide repeat protein (RAP) in rice. Genetic complementation of Arabidopsis (Arabidopsis thaliana) rap mutants indicated that the AL1 protein is a functional RAP. Further analysis illustrated that three transcript variants were present in the AL1 gene, and the altered splices occurred at the 3′ untranslated region of the AL1 transcript. In addition, our results also indicate that disruption of the AL1 gene results in an altered expression of chloroplast-associated genes. Consistently, proteomic analysis demonstrated that the abundance of photosynthesis-associated proteins is altered significantly, as is that of a group of metabolism-associated proteins. More specifically, we found that the loss of AL1 resulted in altered abundances of ribosomal proteins, suggesting that RAP likely also regulates the homeostasis of ribosomal proteins in rice in addition to the ribosomal RNA. Taken together, we propose that AL1, particularly the AL1a and AL1c isoforms, plays an essential role in chloroplast development in rice. PMID:27208287

  15. [Narrow lumbar canal].

    PubMed

    Deshayes, P; Louvel, J P

    1992-03-01

    The diagnosis of spinal stenosis can be strongly suspected when the following symptoms are present: limbs neuralgias with a poorly defined location, paresthesias in several dermatomas neurogenic intermittent claudication. Myelography coupled with scan yields the best information about morphology, levels of stenosis and narrowing factors, bone bridges ligaments and discal structures. If surgery is decided after failure of medical treatment to improve the patient's condition, the choice will be best guided by the myeloscan analysis.

  16. Genomic amplification in retinoblastoma narrowed to 0.6 megabase on chromosome 6p containing a kinesin-like gene, RBKIN.

    PubMed

    Chen, Danian; Pajovic, Sanja; Duckett, Allison; Brown, Vivette D; Squire, Jeremy A; Gallie, Brenda L

    2002-02-15

    All retinoblastomas (RBs) show genomic changes in addition to loss of both RB1 alleles. Quantitative-multiplex PCR analysis identified in 41 of 70 (59%) RBs a 0.6-Mb minimal region of chromosome 6p22 gain from which we cloned the human kinesin gene, RBKIN/KIF13A, by rapid amplification of retinal cDNA. RBKIN is expressed ubiquitously in adult tissues, at low levels in fetal tissues, and at high levels in RB. Antisense RBKIN oligonucleotide reduced the growth rate of RB cell lines. RBKIN and/or another closely linked gene are candidate oncogenes contributing to malignant progression of RB.

  17. Perceptual narrowing: retrospect and prospect.

    PubMed

    Flom, Ross

    2014-11-01

    Research is reviewed demonstrating perceptual narrowing across a variety of domains. Research is also reviewed showing that the temporal window of perceptual narrowing can be extended and, in some cases, perceptual narrowing can be reversed. Research is also reviewed highlighting the neurophysiological correlates of perceptual narrowing as well as some of the individual neurophysiological differences associated with perceptual narrowing. Various methodological issues associated with perceptual narrowing are also discussed. The broader purpose of this paper, however, is to argue that the term perceptual narrowing fails to capture the dynamic nature of this perceptual process. Finally, it is argued that just as other concepts associated with experience and development are refined and modified as new evidence emerges, likewise we need to evaluate and refine how we conceptualize perceptual narrowing.

  18. Effective Population Size, Gene Flow, and Species Status in a Narrow Endemic Sunflower, Helianthus neglectus, Compared to Its Widespread Sister Species, H. petiolaris

    PubMed Central

    Raduski, Andrew R.; Rieseberg, Loren H.; Strasburg, Jared L.

    2010-01-01

    Species delimitation has long been a difficult and controversial process, and different operational criteria often lead to different results. In particular, investigators using phenotypic vs. molecular data to delineate species may recognize different boundaries, especially if morphologically or ecologically differentiated populations have only recently diverged. Here we examine the genetic relationship between the widespread sunflower species Helianthus petiolaris and its narrowly distributed sand dune endemic sister species H. neglectus using sequence data from nine nuclear loci. The two species were initially described as distinct based on a number of minor morphological differences, somewhat different ecological tolerances, and at least one chromosomal rearrangement distinguishing them; but detailed molecular data has not been available until now. We find that, consistent with previous work, H. petiolaris is exceptionally genetically diverse. Surprisingly, H. neglectus harbors very similar levels of genetic diversity (average diversity across loci is actually slightly higher in H. neglectus). It is extremely unlikely that such a geographically restricted species could maintain these levels of genetic variation in isolation. In addition, the two species show very little evidence of any genetic divergence, and estimates of interspecific gene flow are comparable to gene flow estimates among regions within H. petiolaris. These results indicate that H. petiolaris and H. neglectus likely do not represent two distinct, isolated gene pools; H. neglectus is probably more accurately thought of as a geographically restricted, morphologically and ecologically distinct subspecies of H. petiolaris rather than a separate species. PMID:20386650

  19. Narrow Angle movie

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This brief three-frame movie of the Moon was made from three Cassini narrow-angle images as the spacecraft passed by the Moon on the way to its closest approach with Earth on August 17, 1999. The purpose of this particular set of images was to calibrate the spectral response of the narrow-angle camera and to test its 'on-chip summing mode' data compression technique in flight. From left to right, they show the Moon in the green, blue and ultraviolet regions of the spectrum in 40, 60 and 80 millisecond exposures, respectively. All three images have been scaled so that the brightness of Crisium basin, the dark circular region in the upper right, is the same in each image. The spatial scale in the blue and ultraviolet images is 1.4 miles per pixel (2.3 kilometers). The original scale in the green image (which was captured in the usual manner and then reduced in size by 2x2 pixel summing within the camera system) was 2.8 miles per pixel (4.6 kilometers). It has been enlarged for display to the same scale as the other two. The imaging data were processed and released by the Cassini Imaging Central Laboratory for Operations (CICLOPS) at the University of Arizona's Lunar and Planetary Laboratory, Tucson, AZ.

    Photo Credit: NASA/JPL/Cassini Imaging Team/University of Arizona

    Cassini, launched in 1997, is a joint mission of NASA, the European Space Agency and Italian Space Agency. The mission is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Space Science, Washington DC. JPL is a division of the California Institute of Technology, Pasadena, CA.

  20. A Narrow Segment of Maternal Uniparental Disomy of Chromosome 7q31-qter in Silver-Russell Syndrome Delimits a Candidate Gene Region

    PubMed Central

    Hannula, Katariina; Lipsanen-Nyman, Marita; Kontiokari, Tero; Kere, Juha

    2001-01-01

    Maternal uniparental disomy of chromosome 7 (matUPD7), the inheritance of both chromosomes from only the mother, is observed in ∼10% of patients with Silver-Russell syndrome (SRS). It has been suggested that at least one imprinted gene that regulates growth and development resides on human chromosome 7. To date, three imprinted genes—PEG1/MEST, γ2-COP, and GRB10—have been identified on chromosome 7, but their role in the etiology of SRS remains uncertain. In a systematic screening with microsatellite markers, for matUPD7 cases among patients with SRS, we identified a patient who had a small segment of matUPD7 and biparental inheritance of the remainder of chromosome 7. Such a pattern may be explained by somatic recombination in the zygote. The matUPD7 segment at 7q31-qter extends for 35 Mb and includes the imprinted gene cluster of PEG1/MEST and γ2-COP at 7q32. GRB10 at 7p11.2-p12 is located within a region of biparental inheritance. Although partial UPD has previously been reported for chromosomes 6, 11, 14, and 15, this is the first report of a patient with SRS who has segmental matUPD7. Our findings delimit a candidate imprinted region sufficient to cause SRS. PMID:11112662

  1. NFC - Narrow Field Camera

    NASA Astrophysics Data System (ADS)

    Koukal, J.; Srba, J.; Gorková, S.

    2015-01-01

    We have been introducing a low-cost CCTV video system for faint meteor monitoring and here we describe the first results from 5 months of two-station operations. Our system called NFC (Narrow Field Camera) with a meteor limiting magnitude around +6.5mag allows research on trajectories of less massive meteoroids within individual parent meteor showers and the sporadic background. At present 4 stations (2 pairs with coordinated fields of view) of NFC system are operated in the frame of CEMeNt (Central European Meteor Network). The heart of each NFC station is a sensitive CCTV camera Watec 902 H2 and a fast cinematographic lens Meopta Meostigmat 1/50 - 52.5 mm (50 mm focal length and fixed aperture f/1.0). In this paper we present the first results based on 1595 individual meteors, 368 of which were recorded from two stations simultaneously. This data set allows the first empirical verification of theoretical assumptions for NFC system capabilities (stellar and meteor magnitude limit, meteor apparent brightness distribution and accuracy of single station measurements) and the first low mass meteoroid trajectory calculations. Our experimental data clearly showed the capabilities of the proposed system for low mass meteor registration and for calculations based on NFC data to lead to a significant refinement in the orbital elements for low mass meteoroids.

  2. SEMI-ROLLED LEAF1 Encodes a Putative Glycosylphosphatidylinositol-Anchored Protein and Modulates Rice Leaf Rolling by Regulating the Formation of Bulliform Cells1[W][OA

    PubMed Central

    Xiang, Jing-Jing; Zhang, Guang-Heng; Qian, Qian; Xue, Hong-Wei

    2012-01-01

    Leaf rolling is an important agronomic trait in rice (Oryza sativa) breeding and moderate leaf rolling maintains the erectness of leaves and minimizes shadowing between leaves, leading to improved photosynthetic efficiency and grain yields. Although a few rolled-leaf mutants have been identified and some genes controlling leaf rolling have been isolated, the molecular mechanisms of leaf rolling still need to be elucidated. Here we report the isolation and characterization of SEMI-ROLLED LEAF1 (SRL1), a gene involved in the regulation of leaf rolling. Mutants srl1-1 (point mutation) and srl1-2 (transferred DNA insertion) exhibit adaxially rolled leaves due to the increased numbers of bulliform cells at the adaxial cell layers, which could be rescued by complementary expression of SRL1. SRL1 is expressed in various tissues and is expressed at low levels in bulliform cells. SRL1 protein is located at the plasma membrane and predicted to be a putative glycosylphosphatidylinositol-anchored protein. Moreover, analysis of the gene expression profile of cells that will become epidermal cells in wild type but probably bulliform cells in srl1-1 by laser-captured microdissection revealed that the expression of genes encoding vacuolar H+-ATPase (subunits A, B, C, and D) and H+-pyrophosphatase, which are increased during the formation of bulliform cells, were up-regulated in srl1-1. These results provide the transcript profile of rice leaf cells that will become bulliform cells and demonstrate that SRL1 regulates leaf rolling through inhibiting the formation of bulliform cells by negatively regulating the expression of genes encoding vacuolar H+-ATPase subunits and H+-pyrophosphatase, which will help to understand the mechanism regulating leaf rolling. PMID:22715111

  3. Early Experience & Multisensory Perceptual Narrowing

    PubMed Central

    Lewkowicz, David J.

    2014-01-01

    Perceptual narrowing is a reflection of early experience and contributes in key ways to perceptual and cognitive development. In general, findings have shown that unisensory perceptual sensitivity in early infancy is broadly tuned such that young infants respond to, and discriminate, native as well as non-native sensory inputs, whereas older infants only respond to native inputs. Recently, my colleagues and I discovered that perceptual narrowing occurs at the multisensory processing level as well. The present article reviews this new evidence and puts it in the larger context of multisensory perceptual development and the role that perceptual experience plays in it. Together, the evidence on unisensory and multisensory narrowing shows that early experience shapes the emergence of perceptual specialization and expertise. PMID:24435505

  4. Bacterial motion in narrow capillaries

    PubMed Central

    Ping, Liyan; Wasnik, Vaibhav; Emberly, Eldon

    2014-01-01

    Motile bacteria often have to pass through small tortuous pores in soil or tissue of higher organisms. However, their motion in this prevalent type of niche is not fully understood. Here, we modeled it with narrow glass capillaries and identified a critical radius (Rc) for bacterial motion. Near the surface of capillaries narrower than that, the swimming trajectories are helices. In larger capillaries, they swim in distorted circles. Under non-slip condition, the peritrichous Escherichia coli swam in left-handed helices with an Rc of ∼10 μm near glass surface. However, slipping could occur in the fast monotrichous Pseudomonas fluorescens, when a speed threshold was exceeded, and thus both left-handed and right-handed helices were executed in glass capillaries. In the natural non-cylindrical pores, the near-surface trajectories would be spirals and twisted loops. Engaging in such motions reduces the bacterial migration rate. With a given pore size, the run length and the tumbling angle of the bacterium determine the probability and duration of their near-surface motion. Shear flow and chemotaxis potentially enhance it. Based on this observation, the puzzling previous observations on bacterial migration in porous environments can be interpreted. PMID:25764548

  5. Driven tracers in narrow channels

    NASA Astrophysics Data System (ADS)

    Cividini, J.; Mukamel, D.; Posch, H. A.

    2017-01-01

    Steady-state properties of a driven tracer moving in a narrow two-dimensional (2D) channel of quiescent medium are studied. The tracer drives the system out of equilibrium, perturbs the density and pressure fields, and gives the bath particles a nonzero average velocity, creating a current in the channel. Three models in which the confining effect of the channel is probed are analyzed and compared in this study: the first is the simple symmetric exclusion process (SSEP), for which the stationary density profile and the pressure on the walls in the frame of the tracer are computed. We show that the tracer acts like a dipolar source in an average velocity field. The spatial structure of this 2D strip is then simplified to a one-dimensional (1D) SSEP, in which exchanges of position between the tracer and the bath particles are allowed. Using a combination of mean-field theory and exact solution in the limit where no exchange is allowed gives good predictions of the velocity of the tracer and the density field. Finally, we show that results obtained for the 1D SSEP with exchanges also apply to a gas of overdamped hard disks in a narrow channel. The correspondence between the parameters of the SSEP and of the gas of hard disks is systematic and follows from simple intuitive arguments. Our analytical results are checked numerically.

  6. Cryogenic Detectors (Narrow Field Instruments)

    NASA Astrophysics Data System (ADS)

    Hoevers, H.; Verhoeve, P.

    Two cryogenic imaging spectrometer arrays are currently considered as focal plane instruments for XEUS. The narrow field imager 1 (NFI 1) will cover the energy range from 0.05 to 3 keV with an energy resolution of 2 eV, or better, at 500 eV. A second narrow field imager (NFI 2) covers the energy range from 1 to 15 keV with an energy resolution of 2 eV (at 1 keV) and 5 eV (at 7 keV), creating some overlap with part of the NFI 1 energy window. Both narrow field imagers have a 0.5 arcmin field of view. Their imaging capabilities are matched to the XEUS optics of 2 to 5 arcsec leading to 1 arcsec pixels. The detector arrays will be cooled by a closed cycle system comprising a mechanical cooler with a base temperature of 2.5 K and either a low temperature 3He sorption pump providing the very low temperature stage and/or an Adiabatic Demagnetization Refrigerator (ADR). The ADR cooler is explicitly needed to cool the NFI 2 array. The narrow field imager 1} Currently a 48 times 48 element array of superconducting tunnel junctions (STJ) is envisaged. Its operating temperature is in the range between 30 and 350 mK. Small, single Ta STJs (20-50 mum on a side) have shown 3.5 eV (FWHM) resolution at E = 525 eV and small arrays have been successfully demonstrated (6 times 6 pixels), or are currently tested (10 times 12 pixels). Alternatively, a prototype Distributed Read-Out Imaging Device (DROID), consisting of a linear superconducting Ta absorber of 20 times 100 mum2, including a 20 times 20 mum STJ for readout at either end, has shown a measured energy resolution of 2.4 eV (FWHM) at E = 500 eV. Simulations involving the diffusion properties as well as loss and tunnel rates have shown that the performance can be further improved by slight modifications in the geometry, and that the size of the DROIDS can be increased to 0.5-1.0 mm without loss in energy resolution. The relatively large areas and good energy resolution compared to single STJs make DROIDS good candidates for the

  7. Narrow gap electronegative capacitive discharges

    SciTech Connect

    Kawamura, E.; Lieberman, M. A.; Lichtenberg, A. J.

    2013-10-15

    Narrow gap electronegative (EN) capacitive discharges are widely used in industry and have unique features not found in conventional discharges. In this paper, plasma parameters are determined over a range of decreasing gap length L from values for which an electropositive (EP) edge exists (2-region case) to smaller L-values for which the EN region connects directly to the sheath (1-region case). Parametric studies are performed at applied voltage V{sub rf}=500 V for pressures of 10, 25, 50, and 100 mTorr, and additionally at 50 mTorr for 1000 and 2000 V. Numerical results are given for a parallel plate oxygen discharge using a planar 1D3v (1 spatial dimension, 3 velocity components) particle-in-cell (PIC) code. New interesting phenomena are found for the case in which an EP edge does not exist. This 1-region case has not previously been investigated in detail, either numerically or analytically. In particular, attachment in the sheaths is important, and the central electron density n{sub e0} is depressed below the density n{sub esh} at the sheath edge. The sheath oscillations also extend into the EN core, creating an edge region lying within the sheath and not characterized by the standard diffusion in an EN plasma. An analytical model is developed using minimal inputs from the PIC results, and compared to the PIC results for a base case at V{sub rf}=500 V and 50 mTorr, showing good agreement. Selected comparisons are made at the other voltages and pressures. A self-consistent model is also developed and compared to the PIC results, giving reasonable agreement.

  8. Infants Experience Perceptual Narrowing for Nonprimate Faces

    ERIC Educational Resources Information Center

    Simpson, Elizabeth A.; Varga, Krisztina; Frick, Janet E.; Fragaszy, Dorothy

    2011-01-01

    Perceptual narrowing--a phenomenon in which perception is broad from birth, but narrows as a function of experience--has previously been tested with primate faces. In the first 6 months of life, infants can discriminate among individual human and monkey faces. Though the ability to discriminate monkey faces is lost after about 9 months, infants…

  9. Infants Experience Perceptual Narrowing for Nonprimate Faces

    ERIC Educational Resources Information Center

    Simpson, Elizabeth A.; Varga, Krisztina; Frick, Janet E.; Fragaszy, Dorothy

    2011-01-01

    Perceptual narrowing--a phenomenon in which perception is broad from birth, but narrows as a function of experience--has previously been tested with primate faces. In the first 6 months of life, infants can discriminate among individual human and monkey faces. Though the ability to discriminate monkey faces is lost after about 9 months, infants…

  10. Narrow band gap amorphous silicon semiconductors

    DOEpatents

    Madan, A.; Mahan, A.H.

    1985-01-10

    Disclosed is a narrow band gap amorphous silicon semiconductor comprising an alloy of amorphous silicon and a band gap narrowing element selected from the group consisting of Sn, Ge, and Pb, with an electron donor dopant selected from the group consisting of P, As, Sb, Bi and N. The process for producing the narrow band gap amorphous silicon semiconductor comprises the steps of forming an alloy comprising amorphous silicon and at least one of the aforesaid band gap narrowing elements in amount sufficient to narrow the band gap of the silicon semiconductor alloy below that of amorphous silicon, and also utilizing sufficient amounts of the aforesaid electron donor dopant to maintain the amorphous silicon alloy as an n-type semiconductor.

  11. Multilayer dielectric narrow band mangin mirror

    NASA Astrophysics Data System (ADS)

    Ahmed, K.; Khan, A. N.; Rauf, A.; Gul, A.

    2014-06-01

    The design of multilayer stack of dielectric films for narrow band mirror is developed using thin film coating software. The proposed design is materialized by employing thin film coating (PVD) method and reflectance in narrow band spectrum range is achieved. Thickness of high and low refractive index material is taken precisely up to nanometer level. The curved coated substrate is cemented with another K9 matching substrate that forms a Mangin mirror for wavelength 650nm. Narrow band mirrors with reflectivity more than 90% has been produced by properly stacking of 21 layers and advantage of the use of this type of mirror as an interference filter is discussed.

  12. Reconditioning of Cassini Narrow-Angle Camera

    NASA Image and Video Library

    2002-07-23

    These five images of single stars, taken at different times with the narrow-angle camera on NASA Cassini spacecraft, show the effects of haze collecting on the camera optics, then successful removal of the haze by warming treatments.

  13. Narrow deeply bound K- atomic states

    NASA Astrophysics Data System (ADS)

    Friedman, E.; Gal, A.

    1999-07-01

    Using optical potentials fitted to a comprehensive set of strong interaction level shifts and widths in K- atoms, we predict that the K- atomic levels which are inaccessible in the atomic cascade process are generally narrow, spanning a range of widths about 50-1500 keV over the entire periodic table. The mechanism for this narrowing is different from the mechanism for narrowing of pionic atom levels. Examples of such `deeply bound' K- atomic states are given, showing that in many cases these states should be reasonably well resolved. Several reactions which could be used to form these `deeply bound' states are mentioned. Narrow deeply bound states are expected also in overlinep atoms.

  14. Frequency-narrowed diode array bar.

    PubMed

    Babcock, Earl; Chann, Bien; Nelson, Ian A; Walker, Thad G

    2005-05-20

    We describe a method to frequency narrow multielement high-power diode bars. Using a commercial 60-W, 49-element, 1-cm-long diode array bar at 795 nm running at 45 W, we narrow the linewidth from 1000 to 64 GHz with only a loss of 33% in output power. The resulting laser light is well suited for spin-exchange optical pumping of noble gas nuclei.

  15. Hot Wax Sweeps Debris From Narrow Passages

    NASA Technical Reports Server (NTRS)

    Ricklefs, Steven K.

    1990-01-01

    Safe and effective technique for removal of debris and contaminants from narrow passages involves entrainment of undesired material in thermoplastic casting material. Semisolid wax slightly below melting temperature pushed along passage by pressurized nitrogen to remove debris. Devised to clean out fuel passages in main combustion chamber of Space Shuttle main engine. Also applied to narrow, intricate passages in internal-combustion-engine blocks, carburetors, injection molds, and other complicated parts.

  16. Narrowing of intersensory speech perception in infancy

    PubMed Central

    Pons, Ferran; Lewkowicz, David J.; Soto-Faraco, Salvador; Sebastián-Gallés, Núria

    2009-01-01

    The conventional view is that perceptual/cognitive development is an incremental process of acquisition. Several striking findings have revealed, however, that the sensitivity to non-native languages, faces, vocalizations, and music that is present early in life declines as infants acquire experience with native perceptual inputs. In the language domain, the decline in sensitivity is reflected in a process of perceptual narrowing that is thought to play a critical role during the acquisition of a native-language phonological system. Here, we provide evidence that such a decline also occurs in infant response to multisensory speech. We found that infant intersensory response to a non-native phonetic contrast narrows between 6 and 11 months of age, suggesting that the perceptual system becomes increasingly more tuned to key native-language audiovisual correspondences. Our findings lend support to the notion that perceptual narrowing is a domain-general as well as a pan-sensory developmental process. PMID:19541648

  17. Discovery of a narrow line quasar

    NASA Technical Reports Server (NTRS)

    Stocke, J.; Liebert, J.; Maccacaro, T.; Griffiths, R. E.; Steiner, J. E.

    1982-01-01

    A stellar object is reported which, while having X-ray and optical luminosities typical of quasars, has narrow permitted and forbidden emission lines over the observed spectral range. The narrow-line spectrum is high-excitation, the Balmer lines seem to be recombinational, and a redder optical spectrum than that of most quasars is exhibited, despite detection as a weak radio source. The object does not conform to the relationships between H-beta parameters and X-ray flux previously claimed for a large sample of the active galactic nuclei. Because reddish quasars with narrow lines, such as the object identified, may not be found by the standard techniques for the discovery of quasars, the object may be a prototype of a new class of quasars analogous to high-luminosity Seyfert type 2 galaxies. It is suggested that these objects cannot comprise more than 10% of all quasars.

  18. Microlayer during boiling in narrow slot channels

    NASA Astrophysics Data System (ADS)

    Diev, Mikhail D.; Leontiev, Alexander I.

    1997-01-01

    An international space station Alpha will have a two-phase thermal control system. Boiling of a liquid ammonia will be a process of heat collection in evaporative heat exchangers. Unfortunately, only little data is available for boiling heat transfer in microgravity. Geometries of boiling channels working good in normal gravity are not appropriate in microgravity, and special means should be worked out to avoid some undesired events. From this point of view, the narrow slot channels may be assumed as a promising geometry for microgravity operation. During boiling in narrow slots, the vapor bubbles are flattened between the channel walls. The vapor phase and the channel wall are separated by a thin liquid film which is known as a microlayer. The paper presents the experimental results compared to the theoretical analysis, the paper also shows the narrow slot channels as a perspective configuration for microgravity applications.

  19. Congenital narrowing of the cervical spinal canal.

    PubMed Central

    Kessler, J T

    1975-01-01

    The clinical and laboratory findings in six patients with congenital narrowing of the cervical spinal canal and neurological symptoms are described. A variable age of onset and an entirely male occurrence were found. Signs and symptoms of spinal cord dysfunction predominated in all but one patient. Symptoms were produced in five patients by increased physical activity alone. Congenital narrowing of the cervical spinal canal may result in cord compression without a history of injury and occasionally without evidence of significant bony degenerative changes. The clinical features may be distinguishable from those found in cervical spondylosis without congenital narrowing. Intermittent claudication of the cervical spinal cord appears to be an important feature of this syndrome. Surgery improved four out of five people. PMID:1219087

  20. Does interest broaden or narrow attentional scope?

    PubMed

    Sung, Billy; Yih, Jennifer

    2015-08-10

    Theory proposes that interest is a positive emotion that may either broaden attention to facilitate processing of new information, or narrow attention to preserve engagement with new information. To our knowledge, no research has directly examined the effect of interest on attentional scope. Across four experiments, we show that traits associated with the propensity to experience interest-specifically, trait curiosity and internal boredom proneness-are associated with a narrower scope of attention. We also find that, instead of broadening, interest actually narrows attentional scope in comparison to a neutral state and awe. Challenging the conventional notion that all positive emotions broaden cognition and attention, our findings suggest that specific emotions influence attention in ways that extend beyond a general emotional valence effect.

  1. Efficient, Narrow-Pass-Band Optical Filters

    NASA Technical Reports Server (NTRS)

    Sandford, Stephen P.

    1996-01-01

    Optical filters with both narrow pass bands and high efficiencies fabricated to design specifications. Offer tremendous improvements in performance for number of optical (including infrared) systems. In fiber-optic and free-space communication systems, precise frequency discrimination afforded by narrow pass bands of filters provide higher channel capacities. In active and passive remote sensors like lidar and gas-filter-correlation radiometers, increased efficiencies afforded by filters enhance detection of small signals against large background noise. In addition, sizes, weights, and power requirements of many optical and infrared systems reduced by taking advantage of gains in signal-to-noise ratios delivered by filters.

  2. Narrow vision after view-broadening travel.

    PubMed

    Melo, Mariana de Mendonça; Ciriano, Jose P Martinez; van Genderen, Perry J J

    2008-01-01

    Loss of vision is a threatening presentation of disease. We describe a case of acute idiopathic blind spot enlargement in a 26-year-old male traveler who presented with narrow vision after a journey to Indonesia. Although the patient used mefloquine at time of presentation, we were unable to retrieve sound data incriminating mefloquine in this rare eye disorder.

  3. Narrow-headed garter snake (Thamnophis rufipunctatus)

    USGS Publications Warehouse

    Nowak, Erika M.

    2006-01-01

    The narrow-headed garter snake is a harmless, nonvenomous snake that is distinguished by its elongated, triangular-shaped head and the red or dark spots on its olive to tan body. Today, the narrow-headed garter snake is a species of special concern in the United States because of its decline over much of its historic range. Arizona's Oak Creek has historically contained the largest population of narrow-headed garter snakes in the United States. The U.S. Geological Survey (USGS) and the Arizona Game and Fish Department jointly funded research by USGS scientists in Oak Creek to shed light on the factors causing declining population numbers. The research resulted in better understanding of the snake's habitat needs, winter and summer range, and dietary habits. Based on the research findings, the U.S. Forest Service has developed recommendations that visitors and local residents can adopt to help slow the decline of the narrow-headed garter snake in Oak Creek.

  4. Narrow-Band Applications of Communications Satellites.

    ERIC Educational Resources Information Center

    Cowlan, Bert; Horowitz, Andrew

    This paper attempts to describe the advantages of "narrow-band" applications of communications satellites for education. It begins by discussing the general controversy surrounding the use of satellites in education, by placing the concern within the larger context of the general debate over the uses of new technologies in education, and by…

  5. Narrow band binary phase locked loops

    NASA Technical Reports Server (NTRS)

    Burhans, R. W.

    1976-01-01

    Very high Q digital filtering circuits for audio frequencies in the range of 1Hz to 15 KHz are implemented in simple CMOS hardware using a binary local reference clock frequency. The circuits have application to VLF navigation receivers and other narrow band audio range tracking problems.

  6. Narrow-Band Applications of Communications Satellites.

    ERIC Educational Resources Information Center

    Cowlan, Bert; Horowitz, Andrew

    This paper attempts to describe the advantages of "narrow-band" applications of communications satellites for education. It begins by discussing the general controversy surrounding the use of satellites in education, by placing the concern within the larger context of the general debate over the uses of new technologies in education, and by…

  7. Wolverine gene flow across a narrow climatic niche

    Treesearch

    Michael K. Schwartz; Jeffrey P. Copeland; Neil J. Anderson; John R. Squires; Robert M. Inman; Kevin S. Mckelvey; Kristy L. Pilgrim; Lisette P. Waits; Samuel A. Cushman

    2009-01-01

    Wolverines (Gulo gulo) are one of the rarest carnivores in the contiguous United States. Effective population sizes in Montana, Idaho, and Wyoming, where most of the wolverines in the contiguous United States exist, were calculated to be 35 (credible limits, 28-52) suggesting low abundance. Landscape features that influence wolverine population...

  8. Powerful narrow linewidth random fiber laser

    NASA Astrophysics Data System (ADS)

    Ye, Jun; Xu, Jiangming; Zhang, Hanwei; Zhou, Pu

    2017-03-01

    In this paper, we demonstrate a narrow linewidth random fiber laser, which employs a tunable pump laser to select the operating wavelength for efficiency optimization, a narrow-band fiber Bragg grating (FBG) and a section of single mode fiber to construct a half-open cavity, and a circulator to separate pump light input and random lasing output. Spectral linewidth down to 42.31 GHz is achieved through filtering by the FBG. When 8.97 W pump light centered at the optimized wavelength 1036.5 nm is launched into the half-open cavity, 1081.4 nm random lasing with the maximum output power of 2.15 W is achieved, which is more powerful than the previous reported results.

  9. Exciton absorption in narrow armchair graphene nanoribbons

    NASA Astrophysics Data System (ADS)

    Monozon, B. S.; Schmelcher, P.

    2016-11-01

    We develop an analytical approach to the exciton optical absorption for narrow gap armchair graphene nanoribbons (AGNR). We focus on the regime of dominant size quantization in combination with the attractive electron-hole interaction. An adiabatic separation of slow and fast motions leads via the two-body Dirac equation to the isolated and coupled subband approximations. Discrete and continuous exciton states are in general coupled and form quasi-Rydberg series of purely discrete and resonance type character. The corresponding oscillator strengths and widths are derived. We show that the exciton peaks are blue-shifted, become broader and increase in magnitude upon narrowing the ribbon. At the edge of a subband the singularity related to the 1D density of states is transformed into finite absorption via the presence of the exciton. Our analytical results are in good agreement with those obtained by other methods including numerical approaches. Estimates of the expected experimental values are provided for realistic AGNR.

  10. Creep turns linear in narrow ferromagnetic nanostrips.

    PubMed

    Leliaert, Jonathan; Van de Wiele, Ben; Vansteenkiste, Arne; Laurson, Lasse; Durin, Gianfranco; Dupré, Luc; Van Waeyenberge, Bartel

    2016-02-04

    The motion of domain walls in magnetic materials is a typical example of a creep process, usually characterised by a stretched exponential velocity-force relation. By performing large-scale micromagnetic simulations, and analyzing an extended 1D model which takes the effects of finite temperatures and material defects into account, we show that this creep scaling law breaks down in sufficiently narrow ferromagnetic strips. Our analysis of current-driven transverse domain wall motion in disordered Permalloy nanostrips reveals instead a creep regime with a linear dependence of the domain wall velocity on the applied field or current density. This originates from the essentially point-like nature of domain walls moving in narrow, line- like disordered nanostrips. An analogous linear relation is found also by analyzing existing experimental data on field-driven domain wall motion in perpendicularly magnetised media.

  11. Powerful narrow linewidth random fiber laser

    NASA Astrophysics Data System (ADS)

    Ye, Jun; Xu, Jiangming; Zhang, Hanwei; Zhou, Pu

    2016-11-01

    In this paper, we demonstrate a narrow linewidth random fiber laser, which employs a tunable pump laser to select the operating wavelength for efficiency optimization, a narrow-band fiber Bragg grating (FBG) and a section of single mode fiber to construct a half-open cavity, and a circulator to separate pump light input and random lasing output. Spectral linewidth down to 42.31 GHz is achieved through filtering by the FBG. When 8.97 W pump light centered at the optimized wavelength 1036.5 nm is launched into the half-open cavity, 1081.4 nm random lasing with the maximum output power of 2.15 W is achieved, which is more powerful than the previous reported results.

  12. Creep turns linear in narrow ferromagnetic nanostrips

    NASA Astrophysics Data System (ADS)

    Leliaert, Jonathan; van de Wiele, Ben; Vansteenkiste, Arne; Laurson, Lasse; Durin, Gianfranco; Dupré, Luc; van Waeyenberge, Bartel

    2016-02-01

    The motion of domain walls in magnetic materials is a typical example of a creep process, usually characterised by a stretched exponential velocity-force relation. By performing large-scale micromagnetic simulations, and analyzing an extended 1D model which takes the effects of finite temperatures and material defects into account, we show that this creep scaling law breaks down in sufficiently narrow ferromagnetic strips. Our analysis of current-driven transverse domain wall motion in disordered Permalloy nanostrips reveals instead a creep regime with a linear dependence of the domain wall velocity on the applied field or current density. This originates from the essentially point-like nature of domain walls moving in narrow, line- like disordered nanostrips. An analogous linear relation is found also by analyzing existing experimental data on field-driven domain wall motion in perpendicularly magnetised media.

  13. Creep turns linear in narrow ferromagnetic nanostrips

    PubMed Central

    Leliaert, Jonathan; Van de Wiele, Ben; Vansteenkiste, Arne; Laurson, Lasse; Durin, Gianfranco; Dupré, Luc; Van Waeyenberge, Bartel

    2016-01-01

    The motion of domain walls in magnetic materials is a typical example of a creep process, usually characterised by a stretched exponential velocity-force relation. By performing large-scale micromagnetic simulations, and analyzing an extended 1D model which takes the effects of finite temperatures and material defects into account, we show that this creep scaling law breaks down in sufficiently narrow ferromagnetic strips. Our analysis of current-driven transverse domain wall motion in disordered Permalloy nanostrips reveals instead a creep regime with a linear dependence of the domain wall velocity on the applied field or current density. This originates from the essentially point-like nature of domain walls moving in narrow, line- like disordered nanostrips. An analogous linear relation is found also by analyzing existing experimental data on field-driven domain wall motion in perpendicularly magnetised media. PMID:26843125

  14. Narrow linewidth single frequency microfiber laser.

    PubMed

    Fan, Wei; Gan, Jiulin; Zhang, Zhishen; Wei, Xiaoming; Xu, Shanhui; Yang, Zhongmin

    2012-10-15

    A compact 2 kHz linewidth single frequency microfiber ring laser is demonstrated. Microfiber, with a diameter of 1.88 μm, which is drawn from an Er(3+)/Yb(3+) co-doped phosphate glass fiber, serves as the gain medium. By using this microfiber, a double-knot resonator with a total length of 1.75 mm is constructed. Based on this resonator, a narrow linewidth single frequency laser with output power higher than 0.95 μW is obtained at the wavelength of 1536.1 nm. The linewidth of this microfiber laser is as narrow as 2 kHz, and the side-mode-suppression ratio is higher than 38 dB.

  15. Multiwatts narrow linewidth fiber Raman amplifiers.

    PubMed

    Feng, Yan; Taylor, Luke; Bonaccini Calia, Domenico

    2008-07-21

    Up to 4.8 W, approximately 10 MHz, 1178 nm laser is obtained by Raman amplification of a distributed feedback diode laser in standard single mode fibers pumped by an 1120 nm Yb fiber laser. More than 10% efficiency and 27 dB amplification is achieved, limited by onset of stimulated Brillouin scattering. The ratio of Raman to Brillouin gain coefficient of a fiber is identified as a figure of merit for building a narrow linewidth fiber Raman amplifier.

  16. The s-physics of narrow samples

    NASA Astrophysics Data System (ADS)

    Roth, Yehuda

    1993-01-01

    The physical properties of neutral particles confined to a three-dimensional narrow sample with a nonconstant width and with no potential in the narrow dimension is explored. We investigate the nature of those particles through the eyes of a two-dimensional slow observer (s-observer) who averages over a time and distance scale much longer and larger than the typical time and length scales associated with the narrow coordinate, respectively. This averaging process provides us, in a sense, with a new language (an s-physics) for describing the particle behaviour (s-particles). In this context it is shown that the width variation is responsible for the occurrence of a time-dependent potential in an s-Hamiltonian, and that it causes the s-particles to be correlated with a virtual s-state. The two s-particle states are for that case enforced to possess fermion or boson symmetry. In the case of a clean sample (i.e. the particles collide with the walls only) it is shown that the potential causes the system to exhibit a characteristic classical behaviour. This means that there is a solution for an s-Schrödinger equation, in which the s-particle density behaves as a rigid body accelerated according to Newton's second law. For a system which is ballistic in the narrow coordinate only, it is shown that the first-order correction to the Born-Oppenheimer-approximation Hamiltonian is a power-operator-like term. The correlations in that approximation depend on the distance between the s-particles only.

  17. Fine Mapping and Candidate Gene Analysis of the Leaf-Color Gene ygl-1 in Maize

    PubMed Central

    Guan, Haiying; Xu, Xiangbo; He, Chunmei; Liu, Chunxiao; Liu, Qiang; Dong, Rui; Liu, Tieshan; Wang, Liming

    2016-01-01

    A novel yellow-green leaf mutant yellow-green leaf-1 (ygl-1) was isolated in self-pollinated progenies from the cross of maize inbred lines Ye478 and Yuanwu02. The mutant spontaneously showed yellow-green character throughout the lifespan. Meanwhile, the mutant reduced contents of chlorophyll and Car, arrested chloroplast development and lowered the capacity of photosynthesis compared with the wild-type Lx7226. Genetic analysis revealed that the mutant phenotype was controlled by a recessive nuclear gene. The ygl-1 locus was initially mapped to an interval of about 0.86 Mb in bin 1.01 on the short arm of chromosome 1 using 231 yellow-green leaf individuals of an F2 segregating population from ygl-1/Lx7226. Utilizing four new polymorphic SSR markers, the ygl-1 locus was narrowed down to a region of about 48 kb using 2930 and 2247 individuals of F2 and F3 mapping populations, respectively. Among the three predicted genes annotated within this 48 kb region, GRMZM2G007441, which was predicted to encode a cpSRP43 protein, had a 1-bp nucleotide deletion in the coding region of ygl-1 resulting in a frame shift mutation. Semi-quantitative RT-PCR analysis revealed that YGL-1 was constitutively expressed in all tested tissues and its expression level was not significantly affected in the ygl-1 mutant from early to mature stages, while light intensity regulated its expression both in the ygl-1 mutant and wild type seedlings. Furthermore, the mRNA levels of some genes involved in chloroplast development were affected in the six-week old ygl-1 plants. These findings suggested that YGL-1 plays an important role in chloroplast development of maize. PMID:27100184

  18. Fine Mapping and Candidate Gene Analysis of the Leaf-Color Gene ygl-1 in Maize.

    PubMed

    Guan, Haiying; Xu, Xiangbo; He, Chunmei; Liu, Chunxiao; Liu, Qiang; Dong, Rui; Liu, Tieshan; Wang, Liming

    2016-01-01

    A novel yellow-green leaf mutant yellow-green leaf-1 (ygl-1) was isolated in self-pollinated progenies from the cross of maize inbred lines Ye478 and Yuanwu02. The mutant spontaneously showed yellow-green character throughout the lifespan. Meanwhile, the mutant reduced contents of chlorophyll and Car, arrested chloroplast development and lowered the capacity of photosynthesis compared with the wild-type Lx7226. Genetic analysis revealed that the mutant phenotype was controlled by a recessive nuclear gene. The ygl-1 locus was initially mapped to an interval of about 0.86 Mb in bin 1.01 on the short arm of chromosome 1 using 231 yellow-green leaf individuals of an F2 segregating population from ygl-1/Lx7226. Utilizing four new polymorphic SSR markers, the ygl-1 locus was narrowed down to a region of about 48 kb using 2930 and 2247 individuals of F2 and F3 mapping populations, respectively. Among the three predicted genes annotated within this 48 kb region, GRMZM2G007441, which was predicted to encode a cpSRP43 protein, had a 1-bp nucleotide deletion in the coding region of ygl-1 resulting in a frame shift mutation. Semi-quantitative RT-PCR analysis revealed that YGL-1 was constitutively expressed in all tested tissues and its expression level was not significantly affected in the ygl-1 mutant from early to mature stages, while light intensity regulated its expression both in the ygl-1 mutant and wild type seedlings. Furthermore, the mRNA levels of some genes involved in chloroplast development were affected in the six-week old ygl-1 plants. These findings suggested that YGL-1 plays an important role in chloroplast development of maize.

  19. Spinal canal narrowing during simulated frontal impact.

    PubMed

    Ivancic, Paul C; Panjabi, Manohar M; Tominaga, Yasuhiro; Pearson, Adam M; Elena Gimenez, S; Maak, Travis G

    2006-06-01

    Between 23 and 70% of occupants involved in frontal impacts sustain cervical spine injuries, many with neurological involvement. It has been hypothesized that cervical spinal cord compression and injury may explain the variable neurological profile described by frontal impact victims. The goals of the present study, using a biofidelic whole cervical spine model with muscle force replication, were to quantify canal pinch diameter (CPD) narrowing during frontal impact and to evaluate the potential for cord compression. The biofidelic model and a sled apparatus were used to simulate frontal impacts at 4, 6, 8, and 10 g horizontal accelerations of the T1 vertebra. The CPD was measured in the intact specimen in the neutral posture (neutral posture CPD), under static sagittal pure moments of 1.5 Nm (pre-impact CPD), during dynamic frontal impact (dynamic impact CPD), and again under static pure moments following each impact (post-impact CPD). Frontal impact caused significant (P<0.05) dynamic CPD narrowing at C0-dens, C2-C3, and C6-C7. The narrowest dynamic CPD was observed at C0-dens during the 10 g impact and was 25.9% narrower than the corresponding neutral posture CPD. Interpretation of the present results indicate that the neurological symptomatology reported by frontal impact victims is most likely not due to cervical spinal cord compression. Cord compression due to residual spinal instability is also not likely.

  20. The mechanism of water diffusion in narrow carbon nanotubes.

    PubMed

    Striolo, Alberto

    2006-04-01

    Carbon nanotubes show exceptional physical properties that render them promising candidates as building blocks for nanostructured materials. Many ambitious applications, ranging from gene therapy to membrane separations, require the delivery of fluids, in particular aqueous solutions, through the interior of carbon nanotubes. To foster these and other applications, it is necessary to understand the thermodynamic and transport properties of water confined within long narrow carbon nanotubes. Previous theoretical work considered either short carbon nanotubes or short periods of time. By conducting molecular dynamics simulations in the microcanonical ensemble for water confined in infinitely long carbon nanotubes of diameter 1.08 nm, we show here that confined water molecules diffuse through a fast ballistic motion mechanism for up to 500 ps at room temperature. By comparing the results obtained for the diffusion of water to those obtained for the diffusion of a reference Lennard-Jones fluid, we prove here that long-lasting hydrogen bonds are responsible for the ballistic diffusion of water clusters in narrow carbon nanotubes, as opposed to spatial mismatches between pore-fluid and fluid-fluid attractive interactions which, as shown previously by others, are responsible for the concerted motion of simple fluids in molecular sieves. Additionally we prove here for the first time that, despite the narrow diameter of the carbon nanotubes considered which may suggest the existence of single-file diffusion, when the trajectories of confined water are studied at time scales in excess of 500 ps, a Fickian-type diffusion mechanism prevails. Our results are important for designing nano fluidic apparatuses to develop, for example, novel drug-delivery devices.

  1. Ultra-narrow laser linewidth measurement

    NASA Astrophysics Data System (ADS)

    Chen, Xiaopei

    In this report, we give a deeper investigation of the loss-compensated recirculating delayed self-heterodyne interferometer (LC-RDSHI) for ultra-narrow linewidth measurement, including the theoretical analysis, experimental implementation, further modification on the system and more applications. Recently, less than 1kHz linewidth fiber lasers have been commercialized. But even the manufacturers face a challenge on accurately measuring the linewidth of such lasers. There is a need to develop more accurate methods to characterize ultra-narrow laser linewidth and frequency noises. Compared with other currently available linewidth measurement techniques, the loss-compensated recirculating delayed-heterodyne interferometer (LC-RDSHI) technique is the most promising one. It overcomes the bottle-neck of the high resolution requirement on the delayed self-heterodyne interferometer (DSHI) by using a short length of fiber delay line. This method does not need another narrower and more stable laser as the reference which is the necessary component in heterodyne detection. The laser spectral lineshape can be observed directly instead of complicated interpretation in frequency discriminator techniques. The theoretical analysis of a LC-RDSHI gives us a guidance on choosing the optimal parameters of the system and assists us to interpret the recorded spectral lineshape. Laser linewidth as narrow as 700Hz has been proved to be measurable by using the LC-RDSHI method. The non-linear curve fitting of Voigt lineshape to separate Lorentzian and Gaussian components was investigated. Voigt curve fitting results give us a clear view on laser frequency noises and laser linewidth nature. It is also shown that for a ultra-narrow linewidth laser, simply taking 20dB down from the maximum value of the beat spectrum and dividing by 2 99 will over estimate the laser linewidth and coherent length. Besides laser linewidth measurement in the frequency domain, we also implemented time

  2. The Interplay between Carbon Availability and Growth in Different Zones of the Growing Maize Leaf1[OPEN

    PubMed Central

    Arrivault, Stéphanie; Lohse, Marc A.; Feil, Regina; Krohn, Nicole; Encke, Beatrice; Nunes-Nesi, Adriano; Fernie, Alisdair R.; Stitt, Mark

    2016-01-01

    Plants assimilate carbon in their photosynthetic tissues in the light. However, carbon is required during the night and in nonphotosynthetic organs. It is therefore essential that plants manage their carbon resources spatially and temporally and coordinate growth with carbon availability. In growing maize (Zea mays) leaf blades, a defined developmental gradient facilitates analyses in the cell division, elongation, and mature zones. We investigated the responses of the metabolome and transcriptome and polysome loading, as a qualitative proxy for protein synthesis, at dusk, dawn, and 6, 14, and 24 h into an extended night, and tracked whole-leaf elongation over this time course. Starch and sugars are depleted by dawn in the mature zone, but only after an extension of the night in the elongation and division zones. Sucrose (Suc) recovers partially between 14 and 24 h into the extended night in the growth zones, but not the mature zone. The global metabolome and transcriptome track these zone-specific changes in Suc. Leaf elongation and polysome loading in the growth zones also remain high at dawn, decrease between 6 and 14 h into the extended night, and then partially recover, indicating that growth processes are determined by local carbon status. The level of Suc-signaling metabolite trehalose-6-phosphate, and the trehalose-6-phosphate:Suc ratio are much higher in growth than mature zones at dusk and dawn but fall in the extended night. Candidate genes were identified by searching for transcripts that show characteristic temporal response patterns or contrasting responses to carbon starvation in growth and mature zones. PMID:27582314

  3. Are Quantity-Distances Narrowing in?

    DTIC Science & Technology

    2010-07-01

    REPORT TYPE N/A 3 . DATES COVERED - 4. TITLE AND SUBTITLE Are Quantity-Distances Narrowing in? 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c...adopt AASTP-1 and AASTP-5 for ammunition storage /1/, /2 /. Quantity-Distance History The history of QD goes far back, see e.g. / 3 /, /4/, /5...6 3 /. Reference / / quotes /7 /: “Act for preventing the Mischiefs which may happen by keeping too great Quantities of gunpowder in or near

  4. Narrow electron injector for ballistic electron spectroscopy

    SciTech Connect

    Kast, M.; Pacher, C.; Strasser, G.; Gornik, E.

    2001-06-04

    A three-terminal hot electron transistor is used to measure the normal energy distribution of ballistic electrons generated by an electron injector utilizing an improved injector design. A triple barrier resonant tunneling diode with a rectangular transmission function acts as a narrow (1 meV) energy filter. An asymmetric energy distribution with its maximum on the high-energy side with a full width at half maximum of {Delta}E{sub inj}=10 meV is derived. {copyright} 2001 American Institute of Physics.

  5. Global viscous overstabilities in narrow rings

    NASA Astrophysics Data System (ADS)

    Longaretti, Pierre-Yves; French, Richard G.; Nicholson, Philip D.

    2016-10-01

    Local viscous overstabilities have been the focus of a number of theoretical analyses in the last decades due to the rôle they are believed to play in the creation of the small scale structure of broad ring systems (Saturn, Uranus). Global viscous overstabilities have also been investigated in the 1980s and 1990s as a potential source of narrow ring eccentricities (Longaretti and Rappaport, 1995, Icarus, 116, 376).An important feature of global viscous overstabilities is that they produce slow relative librating or circulating motions of narrow ring edges; they may also produce slowly librating or circulating components of edge modes. This process is potentially relevant to explain the occurrence of unusually large apsidal shifts observed in some saturnian ringlets and may also explain the existence of the free m=2 B ring edge mode that is slowly circulating with respect to the component forced by Mimas.The time-scale of such motions is primarily controlled by the ring self-gravity and can be analytically quantified in a two-streamline analysis which yields a characteristic libration/circulation frequency Ωl = (n/π)(Mr/Mp)(a/δa)2H(q2) where n is the mean motion, Mr the ringlet or pertubed region mass, Mp the planet mass, a the semi-major axis, δa the narrow ringlet or pertubed region width and H(q2) a dimensionless factor of order unity that depends on the streamline compression parameter q. The related time-scale is of the order of a few years to a few tens of years depending on the surface density and ringlet/perturbed region geometry. Preliminary data analyzes indicate that the Maxwell and Huyghens ringlets are probably librating with periods consistent with this two-streamline estimate.The talk will briefly present the physics of global viscous overstabilities as well as more detailed applications to narrow rings, and if time permits, to edge modes.

  6. Narrow field electromagnetic sensor system and method

    DOEpatents

    McEwan, Thomas E.

    1996-01-01

    A narrow field electromagnetic sensor system and method of sensing a characteristic of an object provide the capability to realize a characteristic of an object such as density, thickness, or presence, for any desired coordinate position on the object. One application is imaging. The sensor can also be used as an obstruction detector or an electronic trip wire with a narrow field without the disadvantages of impaired performance when exposed to dirt, snow, rain, or sunlight. The sensor employs a transmitter for transmitting a sequence of electromagnetic signals in response to a transmit timing signal, a receiver for sampling only the initial direct RF path of the electromagnetic signal while excluding all other electromagnetic signals in response to a receive timing signal, and a signal processor for processing the sampled direct RF path electromagnetic signal and providing an indication of the characteristic of an object. Usually, the electromagnetic signal is a short RF burst and the obstruction must provide a substantially complete eclipse of the direct RF path. By employing time-of-flight techniques, a timing circuit controls the receiver to sample only the initial direct RF path of the electromagnetic signal while not sampling indirect path electromagnetic signals. The sensor system also incorporates circuitry for ultra-wideband spread spectrum operation that reduces interference to and from other RF services while allowing co-location of multiple electronic sensors without the need for frequency assignments.

  7. Narrow field electromagnetic sensor system and method

    DOEpatents

    McEwan, T.E.

    1996-11-19

    A narrow field electromagnetic sensor system and method of sensing a characteristic of an object provide the capability to realize a characteristic of an object such as density, thickness, or presence, for any desired coordinate position on the object. One application is imaging. The sensor can also be used as an obstruction detector or an electronic trip wire with a narrow field without the disadvantages of impaired performance when exposed to dirt, snow, rain, or sunlight. The sensor employs a transmitter for transmitting a sequence of electromagnetic signals in response to a transmit timing signal, a receiver for sampling only the initial direct RF path of the electromagnetic signal while excluding all other electromagnetic signals in response to a receive timing signal, and a signal processor for processing the sampled direct RF path electromagnetic signal and providing an indication of the characteristic of an object. Usually, the electromagnetic signal is a short RF burst and the obstruction must provide a substantially complete eclipse of the direct RF path. By employing time-of-flight techniques, a timing circuit controls the receiver to sample only the initial direct RF path of the electromagnetic signal while not sampling indirect path electromagnetic signals. The sensor system also incorporates circuitry for ultra-wideband spread spectrum operation that reduces interference to and from other RF services while allowing co-location of multiple electronic sensors without the need for frequency assignments. 12 figs.

  8. Narrow resonances and short-range interactions

    NASA Astrophysics Data System (ADS)

    Gelman, Boris A.

    2009-09-01

    Narrow resonances in systems with short-range interactions are discussed in an effective field theory (EFT) framework. An effective Lagrangian is formulated in the form of a combined expansion in powers of a momentum Q≪Λ—a short-distance scale—and an energy difference δɛ=|E-ɛ0|≪ɛ0—a resonance peak energy. At leading order in the combined expansion, a two-body scattering amplitude is the sum of a smooth background term of order Q0 and a Breit-Wigner term of order Q2(δɛ)-1 which becomes dominant for δɛ≲Q3. Such an EFT is applicable to systems in which short-distance dynamics generates a low-lying quasistationary state. The EFT is generalized to describe a narrow low-lying resonance in a system of charged particles. It is shown that in the case of Coulomb repulsion, a two-body scattering amplitude at leading order in a combined expansion is the sum of a Coulomb-modified background term and a Breit-Wigner amplitude with parameters renormalized by Coulomb interactions.

  9. Narrow resonances and short-range interactions

    SciTech Connect

    Gelman, Boris A.

    2009-09-15

    Narrow resonances in systems with short-range interactions are discussed in an effective field theory (EFT) framework. An effective Lagrangian is formulated in the form of a combined expansion in powers of a momentum Q<<{lambda}--a short-distance scale--and an energy difference {delta}{epsilon}=|E-{epsilon}{sub 0}|<<{epsilon}{sub 0}--a resonance peak energy. At leading order in the combined expansion, a two-body scattering amplitude is the sum of a smooth background term of order Q{sup 0} and a Breit-Wigner term of order Q{sup 2}({delta}{epsilon}){sup -1} which becomes dominant for {delta}{epsilon} < or approx. Q{sup 3}. Such an EFT is applicable to systems in which short-distance dynamics generates a low-lying quasistationary state. The EFT is generalized to describe a narrow low-lying resonance in a system of charged particles. It is shown that in the case of Coulomb repulsion, a two-body scattering amplitude at leading order in a combined expansion is the sum of a Coulomb-modified background term and a Breit-Wigner amplitude with parameters renormalized by Coulomb interactions.

  10. Studies of narrow autoionizing resonances in gadolinium

    SciTech Connect

    Bushaw, Bruce A.; Nortershauser, W.; Blaum, K.; Wendt, Klaus

    2003-06-30

    The autoionization (AI) spectrum of gadolinium between the first and second limits has been investigated by triple-resonance excitation with high-resolution cw lasers. A large number of narrow AI resonances have been observed and assigned total angular momentum J values. The resonances are further divided into members of AI Rydberg series converging to the second limit or other ''interloping'' levels. Fine structure in the Rydberg series has been identified and interpreted in terms of Jc j coupling. A number of detailed studies have been performed on the interloping resonances: These include lifetime determination by lineshape analysis, isotope shifts, hyperfine structure, and photoionization saturation parameters. The electronic structure of the interloping levels is discussed in terms of these studies. Linewidths generally decrease with increasing total angular momentum and the J = 7 resonances are extremely narrow with Lorentzian widths ranging from < 1 MHz up to 157 MHz. The strongest resonances are found to have cross-sections of {approx}10-12 cm{sup 2} and photoionization can be saturated with powers available from cw diode lasers.

  11. 2. Photocopied July 1971 from photostat Jordan Narrows Folder #1, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Photocopied July 1971 from photostat Jordan Narrows Folder #1, Engineering Department, Utah Power and Light Co., Salt Lake City, Utah. JORDAN NARROWS STATION. PLAN AND SECTION. - Salt Lake City Water & Electrical Power Company, Jordan Narrows Hydroelectric Plant, Jordan River, Riverton, Salt Lake County, UT

  12. 33 CFR 117.561 - Kent Island Narrows.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Kent Island Narrows. 117.561... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.561 Kent Island Narrows. The draw of the U.S. Route 50/301 bridge, mile 1.0, Kent Island Narrows, operates as follows: (a) From November 1...

  13. 33 CFR 117.561 - Kent Island Narrows.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Kent Island Narrows. 117.561... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.561 Kent Island Narrows. The draw of the U.S. Route 50/301 bridge, mile 1.0, Kent Island Narrows, operates as follows: (a) From November 1...

  14. 33 CFR 117.561 - Kent Island Narrows.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Kent Island Narrows. 117.561... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.561 Kent Island Narrows. The draw of the U.S. Route 50/301 bridge, mile 1.0, Kent Island Narrows, operates as follows: (a) From November 1...

  15. 33 CFR 117.561 - Kent Island Narrows.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Kent Island Narrows. 117.561... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.561 Kent Island Narrows. The draw of the U.S. Route 50/301 bridge, mile 1.0, Kent Island Narrows, operates as follows: (a) From November 1...

  16. 33 CFR 117.561 - Kent Island Narrows.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Kent Island Narrows. 117.561... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.561 Kent Island Narrows. The draw of the U.S. Route 50/301 bridge, mile 1.0, Kent Island Narrows, operates as follows: (a) From November 1...

  17. Promoting L2 Vocabulary Learning through Narrow Reading

    ERIC Educational Resources Information Center

    Kang, Eun Young

    2015-01-01

    Krashen (2004) has advocated that narrow reading, i.e., reading a series of texts addressing one specific topic, is an effective method to grow vocabulary. While narrow reading has been championed to have many advantages for L2 vocabulary learning, there remains a relative dearth of empirical studies that test the impact of narrow reading on L2…

  18. Narrow UV Absorption Line Outflows from Quasars

    NASA Astrophysics Data System (ADS)

    Hamann, F.; Simon, L.; Rodriguez Hidalgo, P.; Capellupo, D.

    2012-08-01

    Narrow absorption line (NAL) outflows are an important yet poorly understood part of the quasar outflow phenomenon. We discuss one particular NAL outflow that has high speeds, time variability, and moderate ionizations like typical BAL flows, at an estimated location just ˜5 pc from the quasar. It also has a total column density and line widths (internal velocity dispersions) ˜100 times smaller than BALs, with no substantial X-ray absorption. We argue that radiative shielding (in the form of an X-ray/warm absorber) is not critical for the outflow acceleration and that the moderate ionizations occur in dense substructures that have an overall small volume filling factor in the flow. We also present new estimates of the overall incidence of quasar outflow lines; e.g., ˜43% of bright quasars have a C IV NAL outflow while ˜68% have a C IV outflow line of any variety (NAL, BAL, or mini-BAL).

  19. Narrow-angle astrometry with PRIMA

    NASA Astrophysics Data System (ADS)

    Sahlmann, J.; Ségransan, D.; Mérand, A.; Zimmerman, N.; Abuter, R.; Chazelas, B.; Delplancke, F.; Henning, T.; Kaminski, A.; Köhler, R.; Launhardt, R.; Mohler, M.; Pepe, F.; Queloz, D.; Quirrenbach, A.; Reffert, S.; Schmid, C.; Schuhler, N.; Schulze-Hartung, T.

    2012-07-01

    The Extrasolar Planet Search with PRIMA project (ESPRI) aims at characterising and detecting extrasolar planets by measuring the host star's reflex motion using the narrow-angle astrometry capability of the PRIMA facility at the Very Large Telescope Interferometer. A first functional demonstration of the astrometric mode was achieved in early 2011. This marked the start of the astrometric commissioning phase with the purpose of characterising the instrument's performance, which ultimately has to be sufficient for exoplanet detection. We show results obtained from the observation of bright visual binary stars, which serve as test objects to determine the instrument's astrometric precision, its accuracy, and the plate scale. Finally, we report on the current status of the ESPRI project, in view of starting its scientific programme.

  20. Diluted magnetic semiconductors with narrow band gaps

    NASA Astrophysics Data System (ADS)

    Gu, Bo; Maekawa, Sadamichi

    2016-10-01

    We propose a method to realize diluted magnetic semiconductors (DMSs) with p - and n -type carriers by choosing host semiconductors with a narrow band gap. By employing a combination of the density function theory and quantum Monte Carlo simulation, we demonstrate such semiconductors using Mn-doped BaZn2As2 , which has a band gap of 0.2 eV. In addition, we found a nontoxic DMS Mn-doped BaZn2Sb2 , of which the Curie temperature Tc is predicted to be higher than that of Mn-doped BaZn2As2 , the Tc of which was up to 230 K in a recent experiment.

  1. Gated Narrow Escape Time for Molecular Signaling

    NASA Astrophysics Data System (ADS)

    Reingruber, Jürgen; Holcman, David

    2009-10-01

    The mean time for a diffusing ligand to activate a target protein located on the surface of a microdomain can regulate cellular signaling. When the ligand switches between various states induced by chemical interactions or conformational changes, while target activation occurs in only one state, this activation time is affected. We investigate this dynamics using new equations for the sojourn times spent in each state. For two states, we obtain exact solutions in dimension one, and asymptotic ones confirmed by Brownian simulations in dimension 3. We find that the activation time is quite sensitive to changes of the switching rates, which can be used to modulate signaling. Interestingly, our analysis reveals that activation can be fast although the ligand spends most of the time “hidden” in the nonactivating state. Finally, we obtain a new formula for the narrow escape time in the presence of switching.

  2. Nondecaying hydrodynamic interactions along narrow channels

    NASA Astrophysics Data System (ADS)

    Misiunas, Karolis; Pagliara, Stefano; Lauga, Eric; Lister, John R.; Keyser, Ulrich

    Particle-particle interactions are of paramount importance in every multi-body system as they determine the collective behaviour and coupling strength. Many well-known interactions like electro-static, van der Waals or screened Coulomb, decay exponentially or with negative powers of the particle spacing r. Similarly, hydrodynamic interactions between particles undergoing Brownian motion decay as 1 / r in bulk, and are assumed to decay in small channels. Such interactions are ubiquitous in biological and technological systems. Here we confine two particles undergoing Brownian motion in narrow, microfluidic channels and study their coupling through hydrodynamic interactions. Our experiments show that the hydrodynamic particle-particle interactions are distance-independent in these channels. This finding is of fundamental importance for the interpretation of experiments where dense mixtures of particles or molecules diffuse through finite length, water-filled channels or pore networks.

  3. Robotic chair at steep and narrow stairways

    NASA Astrophysics Data System (ADS)

    Imazato, Masahiro; Yamaguchi, Masahiro; Moromugi, Shunji; Ishimatsu, Takakazu

    2007-12-01

    A robotic chair is developed to support mobility of elderly and disabled people living in the house where steep and narrow stairways are installed. In order to deal with such mobility problem the developed robotic chair has a compact original configuration. The robotic chair vertically moves by actuation of electric cylinders and horizontally moves by push-pull operation given by a care-giver. In order to navigate safely every action of the chair is checked by the operator. Up-and-down motions of the robotic chair on the stairway are executed through combinations of motor and cylinder actuations. Performance of the robotic chair was evaluated through two kinds of experiments. The excellent ability of the robotic chair could be confirmed through these experiments.

  4. Line Narrowing Parameter Measurement by Modulation Spectroscopy

    NASA Technical Reports Server (NTRS)

    Dharamsi, Amin N.

    1998-01-01

    Accurate Characterization of Oxygen A-Band Line Parameters by Wavelength Modulation Spectroscopy with tunable diode lasers is an ongoing research at Old Dominion University, under sponsorship from NASA Langley research Center. The work proposed here will be undertaken under the guidance of Dr. William Chu and Dr. Lamont Poole of the Aerosol Research Branch at NASA Langley-Research Center in Hampton, Virginia. The research was started about two years ago and utilizes wavelength modulation absorption spectroscopy with higher harmonic detection, a technique that we developed at Old Dominion University, to obtain the absorption line characteristics of the Oxygen A-band rovibronic lines. Accurate characterization of this absorption band is needed for processing of data that will be obtained in experiments such as the NASA Stratospheric Aerosol and Gas Experiment III (SAGE III) as part of the US Mission to Planet Earth. The research work for Summer Fellowship undertook a measurement of the Dicke line-narrowing parameters of the Oxygen A-Band lines by using wavelength modulation spectroscopy. Our previous theoretical results had indicated that such a measurement could be done sensitively and in a convenient fashion by using this type of spectroscopy. In particular, theoretical results had indicated that the signal magnitude would depend on pressure in a manner that was very sensitive to the narrowing parameter. One of the major tasks undertaken during the summer of 1998 was to establish experimentally that these theoretical predictions were correct. This was done successfully and the results of the work are being prepared for publication. Experimental Results were obtained in which the magnitude of the signal was measured as a function of pressure, for various harmonic detection orders (N = 1, 2, 3, 4, 5). A comparison with theoretical results was made, and it was shown that the agreement between theory and experiment was very good. More importantly, however, it was shown

  5. Line Narrowing Parameter Measurement by Modulation Spectroscopy

    NASA Technical Reports Server (NTRS)

    Dharamsi, Amin N.

    1998-01-01

    Accurate Characterization of Oxygen A-Band Line Parameters by Wavelength Modulation Spectroscopy with tunable diode lasers is an ongoing research at Old Dominion University, under sponsorship from NASA Langley research Center. The work proposed here will be undertaken under the guidance of Dr. William Chu and Dr. Lamont Poole of the Aerosol Research Branch at NASA Langley-Research Center in Hampton, Virginia. The research was started about two years ago and utilizes wavelength modulation absorption spectroscopy with higher harmonic detection, a technique that we developed at Old Dominion University, to obtain the absorption line characteristics of the Oxygen A-band rovibronic lines. Accurate characterization of this absorption band is needed for processing of data that will be obtained in experiments such as the NASA Stratospheric Aerosol and Gas Experiment III (SAGE III) as part of the US Mission to Planet Earth. The research work for Summer Fellowship undertook a measurement of the Dicke line-narrowing parameters of the Oxygen A-Band lines by using wavelength modulation spectroscopy. Our previous theoretical results had indicated that such a measurement could be done sensitively and in a convenient fashion by using this type of spectroscopy. In particular, theoretical results had indicated that the signal magnitude would depend on pressure in a manner that was very sensitive to the narrowing parameter. One of the major tasks undertaken during the summer of 1998 was to establish experimentally that these theoretical predictions were correct. This was done successfully and the results of the work are being prepared for publication. Experimental Results were obtained in which the magnitude of the signal was measured as a function of pressure, for various harmonic detection orders (N = 1, 2, 3, 4, 5). A comparison with theoretical results was made, and it was shown that the agreement between theory and experiment was very good. More importantly, however, it was shown

  6. DICOM extensions for narrow-band networks.

    PubMed

    Riesmeier, J; Eichelberg, M; Lemoine, D; Punys, V; Balogh, N; Jensch, P

    2000-01-01

    DICOM is today's de-facto standard for exchanging medical images. Since new image acquisition devices produce more and more image and non-image data, image compression has become an important part of the standard. However, the compression of non-pixel data also stored in DICOM data sets has been disregarded up to now. In the scope of an EU research project we have examined a large amount of real-world DICOM images to test whether or not there is a potential for compressing the non-pixel attributes. Especially for use with narrow-band networks extensions as proposed in this paper could be a solution to save valuable bandwidth.

  7. Magnetization in narrow ribbons: curvature effects

    NASA Astrophysics Data System (ADS)

    Gaididei, Yuri; Goussev, Arseni; Kravchuk, Volodymyr P.; Pylypovskyi, Oleksandr V.; Robbins, J. M.; Sheka, Denis D.; Slastikov, Valeriy; Vasylkevych, Sergiy

    2017-09-01

    A ribbon is a surface swept out by a line segment turning as it moves along a central curve. For narrow magnetic ribbons, for which the length of the line segment is much less than the length of the curve, the anisotropy induced by the magnetostatic interaction is biaxial, with a hard axis normal to the ribbon and an easy axis along the central curve. The micromagnetic energy of a narrow ribbon reduces to that of a one-dimensional ferromagnetic wire, but with curvature, torsion and local anisotropy modified by the rate of turning. These general results are applied to two examples, namely a helicoid ribbon, for which the central curve is a straight line, and a Möbius ribbon, for which the central curve is a circle about which the line segment executes a {{180}\\circ} twist. In both examples, for large positive tangential anisotropy, the ground state magnetization lies tangent to the central curve. As the tangential anisotropy is decreased, the ground state magnetization undergoes a transition, acquiring an in-surface component perpendicular to the central curve. For the helicoid ribbon, the transition occurs at vanishing anisotropy, below which the ground state is uniformly perpendicular to the central curve. The transition for the Möbius ribbon is more subtle; it occurs at a positive critical value of the anisotropy, below which the ground state is nonuniform. For the helicoid ribbon, the dispersion law for spin wave excitations about the tangential state is found to exhibit an asymmetry determined by the geometric and magnetic chiralities.

  8. An Instability in Narrow Planetary Rings

    NASA Astrophysics Data System (ADS)

    Weiss, J. W.; Stewart, G. R.

    2003-08-01

    We will present our work investigating the behavior of narrow planetary rings with low dispersion velocities. Such narrow a ring will be initially unstable to self-gravitational collapse. After the collapse, the ring is collisionally very dense. At this stage, it is subject to a new instability. Waves appear on the inner and outer edges of the ring within half of an orbital period. The ring then breaks apart radially, taking approximately a quarter of an orbital period of do so. As clumps of ring particles expand radially away from the dense ring, Kepler shear causes these clumps to stretch out azimuthally, and eventually collapse into a new set of dense rings. Small-scale repetitions of the original instability in these new rings eventually leads to a stabilized broad ring with higher dispersion velocities than the initial ring. Preliminary results indicate that this instability may be operating on small scales in broad rings in the wake-like features seen by Salo and others. Some intriguing properties have been observed during this instability. The most significant is a coherence in the epicyclic phases of the particles. Both self-gravity and collisions in the ring operated to create and enforce this coherence. The coherence might also be responsible for the instability to radial expansion. We also observe that guiding centers of the particles do not migrate to the center of the ring during the collapse phase of the ring. In fact, guiding centers move radially away from the core of the ring during this phase, consistent with global conservation of angular momentum. We will show the results of our simulations to date, including movies of the evolution of various parameters. (Audiences members wanting popcorn are advised to bring their own.) This work is supported by a NASA Graduate Student Research Program grant and by the Cassini mission.

  9. The effect of narrow provider networks on health care use.

    PubMed

    Atwood, Alicia; Lo Sasso, Anthony T

    2016-12-01

    Network design is an often overlooked aspect of health insurance contracts. Recent policy factors have resulted in narrower provider networks. We provide plausibly causal evidence on the effect of narrow network plans offered by a large national health insurance carrier in a major metropolitan market. Our econometric design exploits the fact that some firms offer a narrow network plan to their employees and some do not. Our results show that narrow network health plans lead to reductions in health care utilization and spending. We find evidence that narrow networks save money by selecting lower cost providers into the network.

  10. The Narrow-Line Region of Narrow-Line Seyfert 1 Galaxies

    NASA Astrophysics Data System (ADS)

    Rodríguez-Ardila, A.; Binette, Luc; Pastoriza, Miriani G.; Donzelli, Carlos J.

    2000-08-01

    This work studies the optical emission-line properties and physical conditions of the narrow-line region (NLR) of seven narrow-line Seyfert 1 galaxies (NLS1's) for which high signal-to-noise ratio spectroscopic observations were available. The resolution is 340 km s-1 (at Hα) over the wavelength interval 3700-9500 Å, enabling us to separate the broad and narrow components of the permitted emission lines. Our results show that the flux carried out by the narrow component of Hβ is, on average, 50% of the total line flux. As a result, the [O III] λ5007/Hβ ratio emitted in the NLR varies from 1 to 5, instead of the universally adopted value of 10. This has strong implications for the required spectral energy distribution that ionizes the NLR gas. Photoionization models that consider a NLR composed of a combination of matter-bounded and ionization-bounded clouds are successful at explaining the low [O III] λ5007/Hβ ratio and the weakness of low-ionization lines of NLS1's. Variation of the relative proportion of these two type of clouds nicely reproduces the dispersion of narrow-line ratios found among the NLS1 sample. Assuming similar physical model parameters of both NLS1's and the normal Seyfert 1 galaxy NGC 5548, we show that the observed differences of emission-line ratios between these two groups of galaxies can be explained, to a first approximation, in terms of the shape of the input ionizing continuum. Narrow emission-line ratios of NLS1's are better reproduced by a steep power-law continuum in the EUV-soft X-ray region, with spectral index α~-2. Flatter spectral indices (α~-1.5) match the observed line ratios of NGC 5548 but are unable to provide a good match to the NLS1 ratios. This result is consistent with ROSAT observations of NLS1's, which show that these objects are characterized by steeper power-law indices than those of Seyfert 1 galaxies with strong broad optical lines. Based on observations made at CASLEO. Complejo Astronómico El Leoncito

  11. Diffusion in narrow channels on curved manifolds

    NASA Astrophysics Data System (ADS)

    Chacón-Acosta, Guillermo; Pineda, Inti; Dagdug, Leonardo

    2013-12-01

    In this work, we derive a general effective diffusion coefficient to describe the two-dimensional (2D) diffusion in a narrow and smoothly asymmetric channel of varying width, embedded on a curved surface, in the simple diffusion of non-interacting, point-like particles under no external field. To this end, we extend the generalization of the Kalinay-Percus' projection method [J. Chem. Phys. 122, 204701 (2005); Kalinay-Percus', Phys. Rev. E 74, 041203 (2006)] for the asymmetric channels introduced in [L. Dagdug and I. Pineda, J. Chem. Phys. 137, 024107 (2012)], to project the anisotropic two-dimensional diffusion equation on a curved manifold, into an effective one-dimensional generalized Fick-Jacobs equation that is modified according to the curvature of the surface. For such purpose we construct the whole expansion, writing the marginal concentration as a perturbation series. The lowest order in the perturbation parameter, which corresponds to the Fick-Jacobs equation, contains an additional term that accounts for the curvature of the surface. We explicitly obtain the first-order correction for the invariant effective concentration, which is defined as the correct marginal concentration in one variable, and we obtain the first approximation to the effective diffusion coefficient analogous to Bradley's coefficient [Phys. Rev. E 80, 061142 (2009)] as a function of the metric elements of the surface. In a straightforward manner, we study the perturbation series up to the nth order, and derive the full effective diffusion coefficient for two-dimensional diffusion in a narrow asymmetric channel, with modifications according to the metric terms. This expression is given as D(ξ )=D_0/w^' (ξ )}√{g_1/g_2} lbrace arctan [√{g_2/g_1}(y^' }_0(ξ )+w^' }(ξ )/2)]-arctan [√{g_2/g_1}(y^' }_0(ξ )-w^' }(ξ )/2)] rbrace, which is the main result of our work. Finally, we present two examples of symmetric surfaces, namely, the sphere and the cylinder, and we study certain

  12. Spectral narrowing of solid state lasers by narrow-band PTR Bragg mirrors

    NASA Astrophysics Data System (ADS)

    Chung, T.; Rapaport, A.; Chen, Y.; Smirnov, V.; Hemmer, M.; Glebov, L. B.; Richardson, M. C.; Bass, M.

    2006-05-01

    Dramatic spectral narrowing of normally broad band lasers, Ti:Sapphire,Cr:LiSAF, and alexandrite was achieved by simply replacing the output mirror with a reflective, volumetric Bragg grating recorded in photo thermal refractive (PTR) glass. The output power of each laser was changed very slightly from that obtained using dielectric coated output mirrors with the same output coupling as the Bragg grating while spectral brightness increased by about three orders of magnitude.

  13. The Meteorological Setting of Narrow Bipolar Events

    NASA Astrophysics Data System (ADS)

    Stanley, M. A.; Suszcynsky, D. M.; Heavner, M. J.

    2003-12-01

    Narrow Bipolar Events (NBEs) are an impulsive form of electrical breakdown in storms which emits strong VHF radiation. It is well known that these events can be readily detected by VHF receivers in orbit and thus may provide a highly practical means to globally monitor storm activity. However, relatively little is known about how NBEs relate to the convective phase of storms and of how good a predictor they are of severe weather events such as large hail, damaging winds, and tornadoes. On June 10, 2002, numerous energetic NBEs were detected over Kansas by the Los Alamos National Laboratory Edot array, which is primarily located in Florida. These NBEs were also detected by a VHF receiver on-board the SVN 54 GPS satellite. The NBEs were associated with severe thunderstorms which produced softball size hail exceeding 11 centimeters in diameter and a weak F0 tornado. In another case study, several F2 tornadic Florida storms were analyzed for March, 2001. Unlike the Kansas storms, the NBEs of the Florida tornadic storms were spread out over a much wider area and exhibited considerable variability in both frequency of occurrence and predominant polarity of vertical charge transfer. To further explore the significance of the NBE rate variability, we will analyze NEXRAD radar volume scans in conjunction with Edot 3-dimensional locations to better understand how NBEs correlate with the thunderstorm life-cycle.

  14. Tunable pulsed narrow bandwidth light source

    DOEpatents

    Powers, Peter E.; Kulp, Thomas J.

    2002-01-01

    A tunable pulsed narrow bandwidth light source and a method of operating a light source are provided. The light source includes a pump laser, first and second non-linear optical crystals, a tunable filter, and light pulse directing optics. The method includes the steps of operating the pump laser to generate a pulsed pump beam characterized by a nanosecond pulse duration and arranging the light pulse directing optics so as to (i) split the pulsed pump beam into primary and secondary pump beams; (ii) direct the primary pump beam through an input face of the first non-linear optical crystal such that a primary output beam exits from an output face of the first non-linear optical crystal; (iii) direct the primary output beam through the tunable filter to generate a sculpted seed beam; and direct the sculpted seed beam and the secondary pump beam through an input face of the second non-linear optical crystal such that a secondary output beam characterized by at least one spectral bandwidth on the order of about 0.1 cm.sup.-1 and below exits from an output face of the second non-linear optical crystal.

  15. Spoof surface plasmons guided by narrow grooves

    NASA Astrophysics Data System (ADS)

    Schnitzer, Ory

    2017-08-01

    An approximate description of surface waves propagating along periodically grooved surfaces is intuitively developed in the limit where the grooves are narrow relative to the period. Considering acoustic and electromagnetic waves guided by rigid and perfectly conducting gratings, respectively, the wave field is obtained by interrelating elementary approximations obtained in three overlapping spatial domains. Specifically, above the grating and on the scale of the period the grooves are effectively reduced to point resonators characterized by their dimensions as well as the geometry of their apertures. Along with this descriptive physical picture emerges an analytical dispersion relation, which agrees remarkably well with exact calculations and improves on preceding approximations. Scalings and explicit formulas are obtained by simplifying the theory in three distinguished propagation regimes, namely where the Bloch wave number is respectively smaller than, close to, or larger than that corresponding to a groove resonance. Of particular interest is the latter regime where the field within the grooves is resonantly enhanced and the field above the grating is maximally localized, attenuating on a length scale comparable with the period.

  16. Narrow bandpass cryogenic filter for microwave measurements

    NASA Astrophysics Data System (ADS)

    Ivanov, B. I.; Klimenko, D. N.; Sultanov, A. N.; Il'ichev, E.; Meyer, H.-G.

    2013-05-01

    An ultra-wide stopband hairpin bandpass filter with integrated nonuniform transmission lines was designed and fabricated for highly sensitive measurements at cryogenic temperatures down to millikelvin and a frequency range of 10 Hz-10 GHz. The scattering matrices of the filter were characterized at T = 4.2 K. The filter provides a stopband from 10 Hz to 2.2 GHz and from 2.3 GHz to 10 GHz with more than 50 dB and 40 dB of amplitude suppression, respectively. The center frequency of the passband is f0 = 2.25 GHz with a bandwidth Δf = 80 MHz. The maximum insertion loss in the passband is 4 dB. The filter has a 50 Ω input and output impedance, SubMiniature version A connector termination, and significantly reduced form factor. The wide stopband frequency range and narrow passband in conjunction with small dimensions make the filter suitable to use it as a part of a high sensitive readout for superconducting quantum circuits, such as superconducting quantum bits and cryogenic parametric amplifiers.

  17. Diging simulation of a narrow trench

    NASA Astrophysics Data System (ADS)

    Anghelache, D. G.; Goanta, A. M.

    2016-08-01

    In this paper, we realized digging process simulation for a narrow trench using special equipment located at a mini excavator. These types of machines digging perform the longitudinal direction to the direction of travel, making trenches with widths of 0.4 m and depths of 3.5 -7.0 m. These are necessary for the location of underground cables or draining water in agriculture. For Parametric modelling of parts included in ensemble has used software from Siemens NX 7.5, we produce sketches of each piece, using following commands: Sketch, Profile (Line), Arc, Circle, Quick Trim Quick Extend, Constraints. Depending on the layout of each piece can also use other commands such as: Chamfer, Rotate, Mirror Curve, Offset Curve, etc. After completion of sketch and dimensioning commands was: Extrude, Revolve, and at this stage the play may various modifications such as drilling, removal of certain volumes of piece showing various forms or change the appearance of surfaces (thread cutting, bevelling). This paper was realized with this parametric modelling software because presents major advantages including: control over the design, making design speed and increasing productivity; increasing product quality, reducing design risk recovery and time work, less human effort and reduced financial resources throughout the process.

  18. Reconditioning of Cassini Narrow-Angle Camera

    NASA Technical Reports Server (NTRS)

    2002-01-01

    These five images of single stars, taken at different times with the narrow-angle camera on NASA's Cassini spacecraft, show the effects of haze collecting on the camera's optics, then successful removal of the haze by warming treatments.

    The image on the left was taken on May 25, 2001, before the haze problem occurred. It shows a star named HD339457.

    The second image from left, taken May 30, 2001, shows the effect of haze that collected on the optics when the camera cooled back down after a routine-maintenance heating to 30 degrees Celsius (86 degrees Fahrenheit). The star is Maia, one of the Pleiades.

    The third image was taken on October 26, 2001, after a weeklong decontamination treatment at minus 7 C (19 F). The star is Spica.

    The fourth image was taken of Spica January 30, 2002, after a weeklong decontamination treatment at 4 C (39 F).

    The final image, also of Spica, was taken July 9, 2002, following three additional decontamination treatments at 4 C (39 F) for two months, one month, then another month.

    Cassini, on its way toward arrival at Saturn in 2004, is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini mission for NASA's Office of Space Science, Washington, D.C.

  19. Polarization and spectral action of narrow slit

    NASA Astrophysics Data System (ADS)

    Oleksyuk, M. V.; Felde, Ch. V.; Polyanskii, P. V.

    2012-01-01

    Experimental study of diffraction of coherent (laser, completely polarized) and incoherent (temporal, polychromatic, unpolarized) light radiation at slits whose width is restricted by a few wavelengths is made. It is shown that for diffraction at the edge of metallic half-plane screen, the angular dependences of diffraction field intensity are considerably different for orientation of the electric field vector parallel and perpendicular to the screen edge, so that metallic screen causes polarization action on the probing beam. It is shown that as the width of a slit formed by two metallic half-planes becomes less than ten wavelengths (being left larger than a wavelength), as the polarization effect is considerable even for the forward direction, i.e. for the zero diffraction angle. It causes also spectral effect, if polychromatic radiation diffracts at narrow slit at metallic screen. Namely, one observes pronounced blue shift of the maximum of the spectral distribution of the forward diffracted polychromatic ('white-light') beam. We apply for the first time the Berry's chromascopic technique for experimental data processing to elucidate such diffraction induced spectral changes.

  20. Polarization and spectral action of narrow slit

    NASA Astrophysics Data System (ADS)

    Oleksyuk, M. V.; Felde, Ch. V.; Polyanskii, P. V.

    2011-09-01

    Experimental study of diffraction of coherent (laser, completely polarized) and incoherent (temporal, polychromatic, unpolarized) light radiation at slits whose width is restricted by a few wavelengths is made. It is shown that for diffraction at the edge of metallic half-plane screen, the angular dependences of diffraction field intensity are considerably different for orientation of the electric field vector parallel and perpendicular to the screen edge, so that metallic screen causes polarization action on the probing beam. It is shown that as the width of a slit formed by two metallic half-planes becomes less than ten wavelengths (being left larger than a wavelength), as the polarization effect is considerable even for the forward direction, i.e. for the zero diffraction angle. It causes also spectral effect, if polychromatic radiation diffracts at narrow slit at metallic screen. Namely, one observes pronounced blue shift of the maximum of the spectral distribution of the forward diffracted polychromatic ('white-light') beam. We apply for the first time the Berry's chromascopic technique for experimental data processing to elucidate such diffraction induced spectral changes.

  1. Genes

    MedlinePlus

    ... Search Search MedlinePlus GO GO About MedlinePlus Site Map FAQs Customer Support Health Topics Drugs & Supplements Videos & Tools Español You Are Here: Home → Medical Encyclopedia → Genes URL of this page: //medlineplus.gov/ency/article/ ...

  2. Narrowing of the ITCZ in a warming climate: Physical mechanisms

    NASA Astrophysics Data System (ADS)

    Byrne, Michael P.; Schneider, Tapio

    2016-11-01

    The Intertropical Convergence Zone (ITCZ) narrows in response to global warming in both observations and climate models. However, a physical understanding of this narrowing is lacking. Here we show that the narrowing of the ITCZ in simulations of future climate is related to changes in the moist static energy (MSE) budget. MSE advection by the mean circulation and MSE divergence by transient eddies tend to narrow the ITCZ, while changes in net energy input to the atmosphere and the gross moist stability tend to widen the ITCZ. The narrowing tendency arises because the meridional MSE gradient strengthens with warming, whereas the largest widening tendency is due to increasing shortwave heating of the atmosphere. The magnitude of the ITCZ narrowing depends strongly on the gross moist stability and clouds, emphasizing the need to better understand these fundamental processes in the tropical atmosphere.

  3. Propagation Characteristics of Narrow X-Ray Pulses

    DTIC Science & Technology

    1975-05-01

    NARROW X-RAY PULSES \\4 [’ AD -v Heber D. Jones Donald Eccleshall Judith K. Temperley May 1975 KÄVA?1^ ^US Government ancles only; Test and...Characteristics of Narrow X-Ray Pulses 7. AUTHORf«) lieber D, Jones, Donald Eccleshall, and Judith K. Temperley 9 PERFORMING OROANI Z...narrow pulse of x-rays is such that the absorption of later x-rays which follow the same path is greatly reduced. Various processes which

  4. 39. Photocopy of photograph. NARROW GAUGE LOCOMOTIVE AND ORE CARS, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    39. Photocopy of photograph. NARROW GAUGE LOCOMOTIVE AND ORE CARS, 1910. (From the Bethlehem Steel Corporation collection, Seattle, WA) - Irondale Iron & Steel Plant, Port Townsend, Jefferson County, WA

  5. Complete mitochondrial genome of the Endangered Narrow Sawfish Anoxypristis cuspidata (Rajiformes: Pristidae).

    PubMed

    Chen, Xiao; Kyne, Peter M; Pillans, Richard D; Feutry, Pierre

    2016-11-01

    In this study, we describe the first complete mitochondrial sequence for the Endangered Narrow Sawfish Anoxypristis cuspidata. It is 17,243 bp in length and contains 13 protein-coding genes, two rRNA genes, 22 tRNA genes, and a control region with the common vertebrate mitogenomic organization. A total of 30 bp overlaps and 28 bp short intergenic spaces are located between all genes. The overall base composition is 32.7% A, 25.7% C, 12.9% G, and 28.6% T. Two start codons (ATG and GTG) and two stop codons (TAG and TAA/T) were used in all protein-coding genes. The origin of L-strand replication (OL) sequence (38 bp) formed a hairpin structure (13 bp stem and 12 bp loop) to initiate the replication of L-strand.

  6. Vortex formation in magnetic narrow rings

    NASA Astrophysics Data System (ADS)

    Bland, J. A. C.

    2002-03-01

    Underlying the current interest in magnetic elements is the possibility such systems provide both for the study of fundamental phenomena in magnetism (such as domain wall trapping and spin switching) and for technological applications, such as high density magnetic storage or magnetic random access memories (MRAM). One key issue is to control the magnetic switching precisely. To achieve this one needs first to have a well defined and reproducible remanent state, and second the switching process itself must be simple and reproducible. Among the many studied geometries, rings are shown to exhibit several advantages over other geometries, in that they show relatively simple stable magnetic states at remanence, with fast and simple magnetisation switching mechanisms. This is borne out of our systematic investigation of the magnetic properties of epitaxial and polycrystalline Co rings, where both the static, dynamic and transport properties have been studied. Magnetic measurements and micromagnetic simulations show that for appropriate ring structures a two step switching process occurs at high fields, indicating the existence of two different stable states. In addition to the vortex state, which occurs at intermediate fields, we have identified a new bi-domain state, which we term the `onion state', corresponding to opposite circulation of the magnetisation in each half of the ring. The magnetic elements were fabricated using a new technique based on the pre-patterning of Si ring structures and subsequent epitaxial growth of Cu/Co/Cu sandwich films on top of the Si elements. This technique has allowed the growth of epitaxial fcc Co(001) structures and in contrast to conventional lithographic methods, no damage to the magnetic layer structure is introduced by the patterning process [1,2]. We have studied the magnetic switching properties of arrays of narrow Co(100) epitaxial ring magnets, with outer diameters between 1 μm and 2 μm, varying inner diameters and varying

  7. 1. Photocopied July 1971 from Photo 745, Jordan Narrows Folder ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Photocopied July 1971 from Photo 745, Jordan Narrows Folder #1, Engineering Department, Utah Power and Light Co., Salt Lake City, Utah. JORDAN STATION, JULY 2, 1909. GENERAL VIEW. - Salt Lake City Water & Electrical Power Company, Jordan Narrows Hydroelectric Plant, Jordan River, Riverton, Salt Lake County, UT

  8. 3. Photocopied July 1971 from Photo 741, Jordan Narrows Folder ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. Photocopied July 1971 from Photo 741, Jordan Narrows Folder #1, Engineering Department, Utah Power and Light Co., Salt Lake City, Utah. INTERIOR VIEW, JULY 2, 1909. - Salt Lake City Water & Electrical Power Company, Jordan Narrows Hydroelectric Plant, Jordan River, Riverton, Salt Lake County, UT

  9. The Case for the Narrow View of Reading

    ERIC Educational Resources Information Center

    Kamhi, Alan G.

    2009-01-01

    Purpose: This prologue reiterates the case for the narrow view of reading as a solution to the persistently high levels of reading failure that occurs in our schools and provides a brief summary of the 5 response articles. Method: The arguments that support the narrow view of reading are presented and the respondents are introduced. Conclusion:…

  10. Bayesian Face Recognition and Perceptual Narrowing in Face-Space

    ERIC Educational Resources Information Center

    Balas, Benjamin

    2012-01-01

    During the first year of life, infants' face recognition abilities are subject to "perceptual narrowing", the end result of which is that observers lose the ability to distinguish previously discriminable faces (e.g. other-race faces) from one another. Perceptual narrowing has been reported for faces of different species and different races, in…

  11. Bayesian Face Recognition and Perceptual Narrowing in Face-Space

    ERIC Educational Resources Information Center

    Balas, Benjamin

    2012-01-01

    During the first year of life, infants' face recognition abilities are subject to "perceptual narrowing", the end result of which is that observers lose the ability to distinguish previously discriminable faces (e.g. other-race faces) from one another. Perceptual narrowing has been reported for faces of different species and different races, in…

  12. Channel Narrowing and Channel Reset: Effects of a Large Flood on the Vegetated, Narrowing Rio Grande

    NASA Astrophysics Data System (ADS)

    Dean, D. J.; Schmidt, J. C.

    2009-12-01

    In September 2008, heavy precipitation from a tropical storm in the Sierra Madre Occidental, MX, produced large amounts of stream flow to the Rio Conchos and lower Rio Grande. This flood was well publicized in the media due to the widespread flooding in Ojinaga, Chih., and Presidio, TX. Gage records indicate that this flood had an approximate recurrence of 15 years as measured on the Rio Grande near Presidio. Nevertheless, flood stages were the highest ever recorded and resulted from a significant loss of channel capacity due to channel narrowing that had occurred during the previous 18 years. Measurements from aerial photographs indicate that channel width had decreased between 35 and 50% between 1990 and 2008 during regional drought. During this period of low stream flow, invasion by non-native riparian vegetation (Tamarix spp., Arundo donax) helped trap sediment and promote floodplain accretion. Our resurveys of the channel indicate that the 2008 flood was a reset event and that the channel was re-widened by 32 to 48%. Repeated, oblique photographs showed significant channel migration and large scale floodplain stripping during this flood. These results show that although riparian vegetation may actively promote channel narrowing and floodplain accretion, moderately large floods may cause large scale bank erosion, floodplain stripping, and vegetation removal in alluvial valleys subject to large-scale invasion by nonnative plants.

  13. "Narrow" graphene nanoribbons made easier by partial hydrogenation.

    PubMed

    Xiang, Hongjun; Kan, Erjun; Wei, Su-Huai; Whangbo, Myung-Hwan; Yang, Jinlong

    2009-12-01

    It is highly desirable to produce narrow-width graphene nanoribbons (GNRs) with smooth edges in large scale. In an attempt to solve this difficult problem, we examined the hydrogenation of GNRs on the basis of first principles density functional calculations. Our study shows that narrow GNRs can be readily obtained from wide GNRs by partial hydrogenation. The hydrogenation of GNRs starts from the edges of GNRs and proceeds gradually toward the middle of the GNRs so as to maximize the number of carbon-carbon pi-pi bonds, hence effectively leading to narrower GNRs. Furthermore, the partially hydrogenated wide GNRs have similar electronic and magnetic properties as those of the narrow GNRs representing their graphene parts. Therefore, partial hydrogenation of wide GNRs should be a practical and reliable method to produce narrow GNRs in large scale.

  14. Narrowing and genomic annotation of the commonly deleted region of the 5q- syndrome

    SciTech Connect

    Boultwood, Jacqueline; Fidler, Carrie; Strickson, Amanda J.; Watkins, Fiona; Gama, Susana; Kearney, Lyndal; Tosi, Sabrina; Kasprzyk, Arek; Cheng, Jan-Fang; Jaju, Rina J.; Wainscoat, James S.

    2002-01-15

    The 5q syndrome is the most distinct of the myelodysplastic syndromes, and the molecular basis for this disorder remains unknown. We describe the narrowing of the common deleted region (CDR) of the 5q syndrome to the approximately 1.5-megabases interval at 5q32 flanked by D5S413 and the GLRA1 gene. The Ensemblgene prediction program has been used for the complete genomic annotation of the CDR. The CDR is gene rich and contains 24 known genes and 16 novel (predicted) genes. Of 40 genes in the CDR, 33 are expressed in CD34 cells and, therefore, represent candidate genes since they are expressed within the hematopoietic stem/progenitor cell compartment. A number of the genes assigned to the CDR represent good candidates for the 5q syndrome, including MEGF1, G3BP, and several of the novel gene predictions. These data now afford a comprehensive mutational/expression analysis of all candidate genes assigned to the CDR.

  15. Young's interference fringes with narrow-band light.

    PubMed

    Wolf, E

    1983-05-01

    The changes in the interference pattern in Young's interference experiment, produced by placing two identical narrow-band filters in front of the pinholes, are analyzed. It is shown theoretically that, in general, the fringes will not become sharp (i.e., their maximum visibility will not tend to unity) even when the filters have arbitrarily narrow passbands. The analysis brings out a relationship between the complex degree of coherence in the space-time and the space-frequency domains. When the passbands of the filters are narrow enough, the filtered light is found to be cross-spectrally pure.

  16. Ring resonator based narrow-linewidth semiconductor lasers

    NASA Technical Reports Server (NTRS)

    Ksendzov, Alexander (Inventor)

    2005-01-01

    The present invention is a method and apparatus for using ring resonators to produce narrow linewidth hybrid semiconductor lasers. According to one embodiment of the present invention, the narrow linewidths are produced by combining the semiconductor gain chip with a narrow pass band external feedback element. The semi conductor laser is produced using a ring resonator which, combined with a Bragg grating, acts as the external feedback element. According to another embodiment of the present invention, the proposed integrated optics ring resonator is based on plasma enhanced chemical vapor deposition (PECVD) SiO.sub.2 /SiON/SiO.sub.2 waveguide technology.

  17. Narrow-band generation in random distributed feedback fiber laser.

    PubMed

    Sugavanam, Srikanth; Tarasov, Nikita; Shu, Xuewen; Churkin, Dmitry V

    2013-07-15

    Narrow-band emission of spectral width down to ~0.05 nm line-width is achieved in the random distributed feedback fiber laser employing narrow-band fiber Bragg grating or fiber Fabry-Perot interferometer filters. The observed line-width is ~10 times less than line-width of other demonstrated up to date random distributed feedback fiber lasers. The random DFB laser with Fabry-Perot interferometer filter provides simultaneously multi-wavelength and narrow-band (within each line) generation with possibility of further wavelength tuning.

  18. The Narrow-Band Model and Semi-Conductor Theory

    ERIC Educational Resources Information Center

    Tanner, B. K.

    1976-01-01

    Applies the narrow-band model to the instruction of intrinsic and extrinsic semiconductors along with the phenomenon of compensation. Advocates the model for undergraduate instruction due to its intuitive appeal and mathematical simplicity. (CP)

  19. A narrow clear zone over Florida and the Atlantic Ocean

    NASA Technical Reports Server (NTRS)

    Negri, A. J.; Morris, K. R.

    1980-01-01

    A narrow cloud-free zone of large longitudinal extent was observed in visible and infrared satellite imagery on September 21, 1978. An attempt to explain the zone in terms of subsidence induced by a transverse frontal circulation is presented.

  20. 33 CFR 83.09 - Narrow channels (Rule 9).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Narrow channels (Rule 9). (a) Keeping near to outer limit of channel or fairway which lies on vessel's... keep as near to the outer limit of the channel or fairway which lies on her starboard side as is safe...

  1. 33 CFR 83.09 - Narrow channels (Rule 9).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Narrow channels (Rule 9). (a) Keeping near to outer limit of channel or fairway which lies on vessel's... keep as near to the outer limit of the channel or fairway which lies on her starboard side as is safe...

  2. Novel bioequivalence approach for narrow therapeutic index drugs.

    PubMed

    Yu, L X; Jiang, W; Zhang, X; Lionberger, R; Makhlouf, F; Schuirmann, D J; Muldowney, L; Chen, M-L; Davit, B; Conner, D; Woodcock, J

    2015-03-01

    Narrow therapeutic index drugs are defined as those drugs where small differences in dose or blood concentration may lead to serious therapeutic failures and/or adverse drug reactions that are life-threatening or result in persistent or significant disability or incapacity. The US Food and Drug Administration proposes that the bioequivalence of narrow therapeutic index drugs be determined using a scaling approach with a four-way, fully replicated, crossover design study in healthy subjects that permits the simultaneous equivalence comparison of the mean and within-subject variability of the test and reference products. The proposed bioequivalence limits for narrow therapeutic index drugs of 90.00%-111.11% would be scaled based on the within-subject variability of the reference product. The proposed study design and data analysis should provide greater assurance of therapeutic equivalence of narrow therapeutic index drug products.

  3. The Narrow-Band Model and Semi-Conductor Theory

    ERIC Educational Resources Information Center

    Tanner, B. K.

    1976-01-01

    Applies the narrow-band model to the instruction of intrinsic and extrinsic semiconductors along with the phenomenon of compensation. Advocates the model for undergraduate instruction due to its intuitive appeal and mathematical simplicity. (CP)

  4. The case for the narrow view of reading.

    PubMed

    Kamhi, Alan G

    2009-04-01

    This prologue reiterates the case for the narrow view of reading as a solution to the persistently high levels of reading failure that occurs in our schools and provides a brief summary of the 5 response articles. The arguments that support the narrow view of reading are presented and the respondents are introduced. Although the contributors to this clinical forum may have different views, we all are working toward a common goal: improving the literacy levels of children in our schools.

  5. Gap narrowing in charged and doped silicon nanoclusters

    NASA Astrophysics Data System (ADS)

    Titov, Andrey; Michelini, Fabienne; Raymond, Laurent; Kulatov, Erkin; Uspenskii, Yurii A.

    2010-12-01

    The gap narrowing in charged Si35H36 and n -type doped Si34DH36 ( D=P , As, Sb, S, Se, and Te) clusters is studied within the GW approximation, including energy dependence of the dielectric matrix and local-field effects. It is shown that the density functional theory does not properly describe the gap narrowing in clusters, as it was found earlier in bulk Si. The main mechanisms of this effect in clusters are the same as in bulk Si: (i) the screened exchange interaction between additional electrons and (ii) the extra screening of the Coulomb interaction by additional electrons. At the same time, our calculations show that the carrier-induced gap narrowing has peculiar features in the clusters. A much weaker screening of the electron-electron interaction strongly increases the first and decreases the second mechanism of gap narrowing in Si clusters as compared to bulk Si. We find also that the gap-narrowing effect is more pronounced in doped clusters than in charged ones due to the charge localization near impurity ions. The electronic spectrum of the charged and doped Si clusters with one electron is spin split. The local-density approximation calculation greatly underestimates the value of the spin splitting. A calculation performed with the screened Hartree-Fock method shows that the splitting is large. It considerably narrows the gap and brings important spin effects into cluster properties.

  6. Ocular Biometrics of Myopic Eyes With Narrow Angles.

    PubMed

    Chong, Gabriel T; Wen, Joanne C; Su, Daniel Hsien-Wen; Stinnett, Sandra; Asrani, Sanjay

    2016-02-01

    The purpose of this study was to compare the ocular biometrics between myopic patients with and without narrow angles. Patients with a stable myopic refraction (myopia worse than -1.00 D spherical equivalent) were prospectively recruited. Angle status was assessed using gonioscopy and biometric measurements were performed using an anterior segment optical coherence tomography and an IOLMaster. A total of 29 patients (58 eyes) were enrolled with 13 patients (26 eyes) classified as having narrow angles and 16 patients (32 eyes) classified as having open angles. Baseline demographics of age, sex, and ethnicity did not differ significantly between the 2 groups. The patients with narrow angles were on average older than those with open angles but the difference did not reach statistical significance (P=0.12). The central anterior chamber depth was significantly less in the eyes with narrow angles (P=0.05). However, the average lens thickness, although greater in the eyes with narrow angles, did not reach statistical significance (P=0.10). Refractive error, axial lengths, and iris thicknesses did not differ significantly between the 2 groups (P=0.32, 0.47, 0.15). Narrow angles can occur in myopic eyes. Routine gonioscopy is therefore recommended for all patients regardless of refractive error.

  7. Narrow- and Broad-Host-Range Symbiotic Plasmids of Rhizobium spp. Strains That Nodulate Phaseolus vulgaris

    PubMed Central

    Brom, Susana; Martinez, Esperanza; Dávila, Guillermo; Palacios, Rafael

    1988-01-01

    Agrobacterium transconjugants containing symbiotic plasmids from different Rhizobium spp. strains that nodulate Phaseolus vulgaris were obtained. All transconjugants conserved the parental nodulation host range. Symbiotic (Sym) plasmids of Rhizobium strains isolated originally from P. vulgaris nodules, which had a broad nodulation host range, and single-copy nitrogenase genes conferred a Fix+ phenotype to the Agrobacterium transconjugants. A Fix− phenotype was obtained with Sym plasmids of strains isolated from P. vulgaris nodules that had a narrow host range and reiterated nif genes, as well as with Sym plasmids of strains isolated from other legumes that presented single nif genes and a broad nodulation host range. This indicates that different types of Sym plasmids can confer the ability to establish an effective symbiosis with P. vulgaris. Images PMID:16347637

  8. Bayesian face recognition and perceptual narrowing in face-space.

    PubMed

    Balas, Benjamin

    2012-07-01

    During the first year of life, infants' face recognition abilities are subject to 'perceptual narrowing', the end result of which is that observers lose the ability to distinguish previously discriminable faces (e.g. other-race faces) from one another. Perceptual narrowing has been reported for faces of different species and different races, in developing humans and primates. Though the phenomenon is highly robust and replicable, there have been few efforts to model the emergence of perceptual narrowing as a function of the accumulation of experience with faces during infancy. The goal of the current study is to examine how perceptual narrowing might manifest as statistical estimation in 'face-space', a geometric framework for describing face recognition that has been successfully applied to adult face perception. Here, I use a computer vision algorithm for Bayesian face recognition to study how the acquisition of experience in face-space and the presence of race categories affect performance for own and other-race faces. Perceptual narrowing follows from the establishment of distinct race categories, suggesting that the acquisition of category boundaries for race is a key computational mechanism in developing face expertise. © 2012 Blackwell Publishing Ltd.

  9. Diffusion in narrow domains and application to phototransduction

    NASA Astrophysics Data System (ADS)

    Reingruber, Jürgen; Holcman, David

    2009-03-01

    The mean time for a Brownian particle to find a small target inside a narrow domain is a key parameter for many chemical reactions occurring in cellular microstructures. Although current estimations are given for a large class of domains, they cannot be used for narrow domains often encountered in cellular biology, such as the synaptic cleft, narrow compartments in the outer segment of vertebrate photoreceptors, or neuron-glia contact. We compute here the mean time for a Brownian particle to hit a small target placed on the surface of a narrow cylinder. We then use this result to estimate the rate constant of cyclic-GMP (cGMP) hydrolysis by the activated enzyme phosphodiesterase (PDE) in the narrow microdomains that build up the outer segment of a rod photoreceptor. By controlling the cGMP concentration, PDE activity is at the basis of the early photoresponse chemical reaction cascade. Our approach allows us to compute the cGMP rate constant as a function of biophysical parameters.

  10. Nasal base narrowing: the alar flap advancement technique.

    PubMed

    Ismail, Ahmed Soliman

    2011-01-01

    To evaluate the role of creating an alar-based advancement flap in narrowing the nasal base and correcting excessive alar flare. Case series with chart review. This is a retrospective record review study. The study included 35 cases presenting with a wide nasal base and excessive alar flaring. The surgical procedure combined the alar base reduction with alar flare excision by creating a single laterally based alar flap. Any caudal septal deformities and any nasal tip modification procedures were corrected before the nasal base narrowing. The mean follow-up period was 23 months. The mean alar flap narrowing was 6.3 mm, whereas the mean width of sill narrowing was 2.9 mm. This single laterally based advancement alar flap resulted in a more conservative external resection, thus avoiding alar wedge overresection or blunting of the alar-facial crease. No cases of postoperative bleeding, infection, or keloid were encountered, and the external alar wedge excision healed with no apparent scar that was hidden in the depth of the alar-facial crease. The risk of notching of the alar rim at the sill incision is reduced by adopting a 2-layer closure of the vestibular floor. The alar base advancement flap is an effective technique in narrowing both the nasal base and excessive alar flare. It adopts a single skin excision to correct the 2 deformities while commonly feared complications were avoided.

  11. Bayesian Face Recognition and Perceptual Narrowing in Face-Space

    PubMed Central

    Balas, Benjamin

    2012-01-01

    During the first year of life, infants’ face recognition abilities are subject to “perceptual narrowing,” the end result of which is that observers lose the ability to distinguish previously discriminable faces (e.g. other-race faces) from one another. Perceptual narrowing has been reported for faces of different species and different races, in developing humans and primates. Though the phenomenon is highly robust and replicable, there have been few efforts to model the emergence of perceptual narrowing as a function of the accumulation of experience with faces during infancy. The goal of the current study is to examine how perceptual narrowing might manifest as statistical estimation in “face space,” a geometric framework for describing face recognition that has been successfully applied to adult face perception. Here, I use a computer vision algorithm for Bayesian face recognition to study how the acquisition of experience in face space and the presence of race categories affect performance for own and other-race faces. Perceptual narrowing follows from the establishment of distinct race categories, suggesting that the acquisition of category boundaries for race is a key computational mechanism in developing face expertise. PMID:22709406

  12. Cavity linewidth narrowing with dark-state polaritons

    NASA Astrophysics Data System (ADS)

    Gong-Wei, Lin; Jie, Yang; Yue-Ping, Niu; Shang-Qing, Gong

    2016-01-01

    We present a quantum-theoretical treatment of cavity linewidth narrowing with intracavity electromagnetically induced transparency (EIT). By means of intracavity EIT, the photons in the cavity are in the form of cavity polaritons: bright-state polariton and dark-state polariton. Strong coupling of the bright-state polariton to the excited state induces an effect known as vacuum Rabi splitting, whereas the dark-state polariton decoupled from the excited state induces a narrow cavity transmission window. Our analysis would provide a quantum theory of linewidth narrowing with a quantum field pulse. Project supported by the National Natural Science Foundation of China (Grants Nos. 11204080, 11274112, 91321101, and 61275215) and the Fundamental Research Fund for the Central Universities of China (Grants No. WM1313003).

  13. Prospects for a narrow line MOT in YO

    NASA Astrophysics Data System (ADS)

    Collopy, Alejandra L.; Hummon, Matthew T.; Yeo, Mark; Yan, Bo; Ye, Jun

    2015-05-01

    In addition to being suitable for laser cooling and trapping in a magneto-optical trap (MOT) using a relatively broad (∼ 5 MHz) transition, the molecule YO possesses a narrow-line transition. This forbidden transition between the {{X}2}Σ and A{{\\prime }2}{{Δ }3/2} states has linewidth ∼ 2π × 160 kHz. After cooling in a MOT on the 614 nm {{X}2}Σ to {{A}2}{{\\Pi }1/2} (orange) transition, the narrow 690 nm (red) transition can be used to further cool the sample, requiring only minimal additions to the first stage system. We estimate that the narrow line cooling stage will bring the temperature from ∼1 mK to ∼10 μK, significantly advancing the frontier on direct cooling achievable for molecules.

  14. CT demonstration of pharyngeal narrowing in adult obstructive sleep apnea

    SciTech Connect

    Bohlman, M.E.; Haponik, E.F.; Smith, P.L.; Allen, R.P.; Bleecker, E.R.; Goldman, S.M.

    1983-03-01

    Sleep apnea is a major cause of daytime hypersomnolence. Among the proposed etiologies, focal obstruction of the airways at the level of the pharynx has been suggested but not proven. Using computed tomography, the cross-sectional area of the airway can be readily assessed. Thirty-three adults with clinically proven sleep apnea and 12 normal adults underwent systematic computed tomography of the neck. Significant airway narrowing was demonstrated in all the patients with obstructive sleep apnea, whereas no such narrowing was seen in the controls. In 11, the narrowing was at a single level, whereas in 22 patients two or more levels were affected. This study has shown that a structurally abnormal airway may serve as an anatomic substrate for the development of sleep apnea. On the basis of this evidence, uvulopalatopharyngoplasty has been performed in two patients with relief of symptoms in one.

  15. Temporal intensity interferometry for characterization of very narrow spectral lines

    NASA Astrophysics Data System (ADS)

    Tan, P. K.; Kurtsiefer, C.

    2017-08-01

    Some stellar objects exhibit very narrow spectral lines in the visible range additional to their blackbody radiation. Natural lasing has been suggested as a mechanism to explain narrow lines in Wolf-Rayet stars. However, the spectral resolution of conventional astronomical spectrographs is still about two orders of magnitude too low to test this hypothesis. We want to resolve the linewidth of narrow spectral emissions in starlight. A combination of spectral filtering with single-photon-level temporal correlation measurements breaks the resolution limit of wavelength-dispersing spectrographs by moving the linewidth measurement into the time domain. We demonstrate in a laboratory experiment that temporal intensity interferometry can determine a 20-MHz-wide linewidth of Doppler-broadened laser light and identify a coherent laser light contribution in a blackbody radiation background.

  16. The detection of gratings in narrow-band visual noise*

    PubMed Central

    Carter, Barbara E.; Henning, G. Bruce

    1971-01-01

    1. The detectability of sinusoidal gratings comprised of either one or many cycles was measured in veiling luminances the spatial frequencies of which were either narrow- or broad-band. 2. In narrow-band noise, the single-cycle grating was detected with approximately 0·6 log units less contrast than the many-cycle grating. On the other hand when both broad-band and narrow-band noise were present, there was no measurable difference in the detectability of the two types of grating. 3. The results are interpreted as supporting the hypothesis of Campbell & Robson (1968) that spatially varying luminance patterns are processed by mechanisms selectively sensitive to limited ranges of spatial frequencies. PMID:5158393

  17. Ultra-narrow linewidth measurement based on Voigt profile fitting.

    PubMed

    Chen, Mo; Meng, Zhou; Wang, Jianfei; Chen, Wei

    2015-03-09

    We study the method of Voigt profile fitting for ultra-narrow linewidth measurement. It filters out the effect of the spectrum broadening due to the 1/f frequency noise and extracts out the Lorentzian lineshape from the measured spectrum. The resolution is thus greatly promoted than the direct measurement from the self-heterodyne technique. We apply this method to an ultra-narrow-linewidth (~40 Hz by heterodyne beat technique) Brillouin/erbium fiber laser. The linewidth estimated from Voigt fitting method is indicated to be more accurate. In contrast, the linewidths estimated direct from the 3-dB and the 20-dB heterodyne-spectrum width are far over the true linewidth of the BEFL. The Voigt fitting method provides an efficient tool for ultra-narrow-linewidth measurement. And compared with heterodyne beat technique, it is applicable for all types of lasers.

  18. Narrow linewidth operation of buried-heterostructure photonic crystal nanolaser.

    PubMed

    Kim, Jimyung; Shinya, Akihiko; Nozaki, Kengo; Taniyama, Hideaki; Chen, Chin-Hui; Sato, Tomonari; Matsuo, Shinji; Notomi, Masaya

    2012-05-21

    We investigate the spectral linewidth of a monolithic photonic crystal nanocavity laser. The nanocavity laser is based on a buried heterostructure cavity in which an ultra-small InGaAsP active region is embedded in an InP photonic crystal. Although it was difficult to achieve narrow linewidth operation in previously reported photonic crystal nanocavity lasers, we have successfully demonstrated a linewidth of 143.5 MHz, which is far narrower than the cold cavity linewidth and the narrowest value yet reported for nanolasers and photonic crystal lasers. The narrow linewidth is accompanied by a low power consumption and an ultrasmall footprint, thus making this particular laser especially suitable for use as an integrated multi-purpose sensor.

  19. Frequency narrowing of a 25 W broad area diode laser

    NASA Astrophysics Data System (ADS)

    Sell, J. F.; Miller, W.; Wright, D.; Zhdanov, B. V.; Knize, R. J.

    2009-02-01

    We report on the spectral narrowing of a high powered (25 W) broad area diode laser using an external cavity with a holographic diffraction grating. In a Littman-Metcalf configuration, the external cavity is able to reduce the linewidth of the diode laser to primarily a single longitudinal mode (1.8 MHz) for output powers of ≤10 W at 852 nm. Many physics applications could benefit from such high powered, narrow linewidth lasers; however both the frequency stability and the spatial profile of the output beam show room for improvement.

  20. Narrow-band imaging bronchoscopy in tracheobronchial amyloidosis.

    PubMed

    Serrano-Fernández, Martha L; Alvarez-Maldonado, Pablo; Aristi-Urista, Gerardo; Valero-Gómez, Alfredo; Cicero-Sabido, Raúl; Redondo, Carlos Núñez-Pérez

    2014-07-01

    Primary tracheobronchial amyloidosis (TBA) is a rare disease characterized by extracellular focal or diffuse submucosal deposits of amyloid proteins. Various types of endobronchial lesions have been described in TBA when bronchoscopy is performed using white light. Narrow-band imaging bronchoscopy has been mainly employed for detecting preneoplastic and neoplastic endobronchial lesions as it provides more detailed images of the microvasculature reflective of an altered angiogenesis process. Here, we describe bronchoscopic findings with white light and narrow-band imaging in 2 patients presenting with central airway obstructive disease later confirmed as having primary TBA.

  1. Inscription of narrow bandwidth Bragg gratings in polymer optical fibers

    NASA Astrophysics Data System (ADS)

    Marques, Carlos A. F.; Bilro, Lúcia B.; Alberto, Nélia J.; Webb, David J.; Nogueira, Rogério N.

    2013-07-01

    We report on the inscription and characterization of narrow bandwidth fiber Bragg gratings (FBGs) in different spectral regions using polymer optical fibers (POFs). Narrow bandwidth FBGs are increasingly essential for optical filtering in POF transmission systems and photonic applications. Long FBGs with resonance wavelengths of around 600, 850 and 1550 nm were inscribed in several types of polymer optical fibers using a scanning technique with a short optical path. The technique allowed the inscription in relatively short periods of time. The achieved 3 dB bandwidth varied from 0.22 down to 0.045 nm considering FBG lengths of 10 and 25 mm, respectively.

  2. Linewidth-narrowing phenomena with intersubband cavity polaritons

    NASA Astrophysics Data System (ADS)

    Murphy, Francis J.; Bak, Alexey O.; Matthews, Mary; Dupont, Emmanuel; Amrania, Hemmel; Phillips, Chris C.

    2014-05-01

    Absorption spectra of strongly coupled intersubband cavity polaritons have been measured, using a tunable midinfrared quantum cascade laser, with high angular and spectral resolution. Pronounced linewidth narrowing of the polaritons around the anticrossing was found, with polariton linewidths narrower (4.2 meV) than both the bare intersubband transition linewidth and empty cavity linewidth (6.2 and 6 meV, respectively), at room temperature. This is due to variations in the degree of spatial averaging of the in-plane quantum-well disorder as the polariton's extended coherence length is increased by the photonic coupling over the value corresponding to the bare intersubband transition coherence length.

  3. Observation of anomalous leakage increase of narrow and short BCPMOS

    NASA Astrophysics Data System (ADS)

    Xu, Y. Z.; Pohland, O.; Cai, C.; Puchner, H.

    2004-07-01

    Leakage performance of BCPMOS (Buried channel PMOS) is investigated by experimentally varying the LDD implant conditions. An anomalous leakage increase with Boron LDD implant is observed for a small geometry (narrow and short) PMOS. Experimental results indicate that the increase of leakage current for narrow and short channel PMOS can be explained by boron piling up at the edge of STI isolation and from source/drain towards the middle of channel. Further confirmation of boron piling up is proven by the surface channel NMOS threshold voltage. Based on the leakage sensitivity, BCPMOS LDD is optimized to reduce leakage current for the small geometry transistors.

  4. Search for narrow resonances lighter than ϒ mesons

    NASA Astrophysics Data System (ADS)

    Aaltonen, T.; Adelman, J.; Akimoto, T.; Álvarez González, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Apresyan, A.; Arisawa, T.; Artikov, A.; Ashmanskas, W.; Attal, A.; Aurisano, A.; Azfar, F.; Badgett, W.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Barria, P.; Bartsch, V.; Bauer, G.; Beauchemin, P.-H.; Bedeschi, F.; Beecher, D.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Beringer, J.; Bhatti, A.; Binkley, M.; Bisello, D.; Bizjak, I.; Blair, R. E.; Blocker, C.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Boisvert, V.; Bolla, G.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brau, B.; Bridgeman, A.; Brigliadori, L.; Bromberg, C.; Brubaker, E.; Budagov, J.; Budd, H. S.; Budd, S.; Burke, S.; Burkett, K.; Busetto, G.; Bussey, P.; Buzatu, A.; Byrum, K. L.; Cabrera, S.; Calancha, C.; Campanelli, M.; Campbell, M.; Canelli, F.; Canepa, A.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Carron, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cavalli-Sforza, M.; Cerri, A.; Cerrito, L.; Chang, S. H.; Chen, Y. C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Chlebana, F.; Cho, K.; Chokheli, D.; Chou, J. P.; Choudalakis, G.; Chuang, S. H.; Chung, K.; Chung, W. H.; Chung, Y. S.; Chwalek, T.; Ciobanu, C. I.; Ciocci, M. A.; Clark, A.; Clark, D.; Compostella, G.; Convery, M. E.; Conway, J.; Cordelli, M.; Cortiana, G.; Cox, C. A.; Cox, D. J.; Crescioli, F.; Cuenca Almenar, C.; Cuevas, J.; Culbertson, R.; Cully, J. C.; Dagenhart, D.; Datta, M.; Davies, T.; de Barbaro, P.; de Cecco, S.; Deisher, A.; de Lorenzo, G.; Dell'Orso, M.; Deluca, C.; Demortier, L.; Deng, J.; Deninno, M.; Derwent, P. F.; di Canto, A.; di Giovanni, G. P.; Dionisi, C.; di Ruzza, B.; Dittmann, J. R.; D'Onofrio, M.; Donati, S.; Dong, P.; Donini, J.; Dorigo, T.; Dube, S.; Efron, J.; Elagin, A.; Erbacher, R.; Errede, D.; Errede, S.; Eusebi, R.; Fang, H. C.; Farrington, S.; Fedorko, W. T.; Feild, R. G.; Feindt, M.; Fernandez, J. P.; Ferrazza, C.; Field, R.; Flanagan, G.; Forrest, R.; Frank, M. J.; Franklin, M.; Freeman, J. C.; Furic, I.; Gallinaro, M.; Galyardt, J.; Garberson, F.; Garcia, J. E.; Garfinkel, A. F.; Garosi, P.; Genser, K.; Gerberich, H.; Gerdes, D.; Gessler, A.; Giagu, S.; Giakoumopoulou, V.; Giannetti, P.; Gibson, K.; Gimmell, J. L.; Ginsburg, C. M.; Giokaris, N.; Giordani, M.; Giromini, P.; Giunta, M.; Giurgiu, G.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldschmidt, N.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; González, O.; Gorelov, I.; Goshaw, A. T.; Goulianos, K.; Gresele, A.; Grinstein, S.; Grosso-Pilcher, C.; Group, R. C.; Grundler, U.; Guimaraes da Costa, J.; Gunay-Unalan, Z.; Haber, C.; Hahn, K.; Hahn, S. R.; Halkiadakis, E.; Han, B.-Y.; Han, J. Y.; Happacher, F.; Hara, K.; Hare, D.; Hare, M.; Harper, S.; Harr, R. F.; Harris, R. M.; Hartz, M.; Hatakeyama, K.; Hays, C.; Heck, M.; Heijboer, A.; Heinrich, J.; Henderson, C.; Herndon, M.; Heuser, J.; Hewamanage, S.; Hidas, D.; Hill, C. S.; Hirschbuehl, D.; Hocker, A.; Hou, S.; Houlden, M.; Hsu, S.-C.; Huffman, B. T.; Hughes, R. E.; Husemann, U.; Hussein, M.; Huston, J.; Incandela, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E. J.; Jha, M. K.; Jindariani, S.; Johnson, W.; Jones, M.; Joo, K. K.; Jun, S. Y.; Jung, J. E.; Junk, T. R.; Kamon, T.; Kar, D.; Karchin, P. E.; Kato, Y.; Kephart, R.; Ketchum, W.; Keung, J.; Khotilovich, V.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, H. W.; Kim, J. E.; Kim, M. J.; Kim, S. B.; Kim, S. H.; Kim, Y. K.; Kimura, N.; Kirsch, L.; Klimenko, S.; Knuteson, B.; Ko, B. R.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Korytov, A.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Krop, D.; Krumnack, N.; Kruse, M.; Krutelyov, V.; Kubo, T.; Kuhr, T.; Kulkarni, N. P.; Kurata, M.; Kwang, S.; Laasanen, A. T.; Lami, S.; Lammel, S.; Lancaster, M.; Lander, R. L.; Lannon, K.; Lath, A.; Latino, G.; Lazzizzera, I.; Lecompte, T.; Lee, E.; Lee, H. S.; Lee, S. W.; Leone, S.; Lewis, J. D.; Lin, C.-S.; Linacre, J.; Lindgren, M.; Lipeles, E.; Lister, A.; Litvintsev, D. O.; Liu, C.; Liu, T.; Lockyer, N. S.; Loginov, A.; Loreti, M.; Lovas, L.; Lucchesi, D.; Luci, C.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lyons, L.; Lys, J.; Lysak, R.; MacQueen, D.; Madrak, R.; Maeshima, K.; Makhoul, K.; Maki, T.; Maksimovic, P.; Malde, S.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Margaroli, F.; Marino, C.; Marino, C. P.; Martin, A.; Martin, V.; Martínez, M.; Martínez-Ballarín, R.; Maruyama, T.; Mastrandrea, P.; Masubuchi, T.; Mathis, M.; Mattson, M. E.; Mazzanti, P.; McFarland, K. S.; McIntyre, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Menzione, A.; Merkel, P.; Mesropian, C.; Miao, T.; Miladinovic, N.; Miller, R.; Mills, C.; Milnik, M.; Mitra, A.; Mitselmakher, G.; Miyake, H.; Moggi, N.; Moon, C. S.; Moore, R.; Morello, M. J.; Morlock, J.; Movilla Fernandez, P.; Mülmenstädt, J.; Mukherjee, A.; Muller, Th.; Mumford, R.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Nagano, A.; Naganoma, J.; Nakamura, K.; Nakano, I.; Napier, A.; Necula, V.; Nett, J.; Neu, C.; Neubauer, M. S.; Neubauer, S.; Nielsen, J.; Nodulman, L.; Norman, M.; Norniella, O.; Nurse, E.; Oakes, L.; Oh, S. H.; Oh, Y. D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Osterberg, K.; Pagan Griso, S.; Palencia, E.; Papadimitriou, V.; Papaikonomou, A.; Paramonov, A. A.; Parks, B.; Pashapour, S.; Patrick, J.; Pauletta, G.; Paulini, M.; Paus, C.; Peiffer, T.; Pellett, D. E.; Penzo, T. A.; Phillips, J.; Piacentino, G.; Pianori, E.; Pinera, L.; Pitts, K.; Plager, C.; Pondrom, L.; Poukhov, O.; Pounder, N.; Prakoshyn, F.; Pronko, A.; Proudfoot, J.; Ptohos, F.; Pueschel, E.; Punzi, G.; Pursley, J.; Rademacker, J.; Rahaman, A.; Ramakrishnan, V.; Ranjan, N.; Redondo, I.; Renton, P.; Renz, M.; Rescigno, M.; Richter, S.; Rimondi, F.; Ristori, L.; Robson, A.; Rodrigo, T.; Rodriguez, T.; Rogers, E.; Rolli, S.; Roser, R.; Rossi, M.; Rossin, R.; Roy, P.; Ruiz, A.; Russ, J.; Rusu, V.; Rutherford, B.; Saarikko, H.; Safonov, A.; Sakumoto, W. K.; Saltó, O.; Santi, L.; Sarkar, S.; Sartori, L.; Sato, K.; Savoy-Navarro, A.; Schlabach, P.; Schmidt, A.; Schmidt, E. E.; Schmidt, M. A.; Schmidt, M. P.; Schmitt, M.; Schwarz, T.; Scodellaro, L.; Scribano, A.; Scuri, F.; Sedov, A.; Seidel, S.; Seiya, Y.; Semenov, A.; Sexton-Kennedy, L.; Sforza, F.; Sfyrla, A.; Shalhout, S. Z.; Shears, T.; Shepard, P. F.; Shimojima, M.; Shiraishi, S.; Shochet, M.; Shon, Y.; Shreyber, I.; Sinervo, P.; Sisakyan, A.; Slaughter, A. J.; Slaunwhite, J.; Sliwa, K.; Smith, J. R.; Snider, F. D.; Snihur, R.; Soha, A.; Somalwar, S.; Sorin, V.; Spreitzer, T.; Squillacioti, P.; Stanitzki, M.; St. Denis, R.; Stelzer, B.; Stelzer-Chilton, O.; Stentz, D.; Strologas, J.; Strycker, G. L.; Suh, J. S.; Sukhanov, A.; Suslov, I.; Suzuki, T.; Taffard, A.; Takashima, R.; Takeuchi, Y.; Tanaka, R.; Tecchio, M.; Teng, P. K.; Terashi, K.; Thom, J.; Thompson, A. S.; Thompson, G. A.; Thomson, E.; Tipton, P.; Ttito-Guzmán, P.; Tkaczyk, S.; Toback, D.; Tokar, S.; Tollefson, K.; Tomura, T.; Tonelli, D.; Torre, S.; Torretta, D.; Totaro, P.; Tourneur, S.; Trovato, M.; Tsai, S.-Y.; Tu, Y.; Turini, N.; Ukegawa, F.; Vallecorsa, S.; van Remortel, N.; Varganov, A.; Vataga, E.; Vázquez, F.; Velev, G.; Vellidis, C.; Vidal, M.; Vidal, R.; Vila, I.; Vilar, R.; Vine, T.; Vogel, M.; Volobouev, I.; Volpi, G.; Wagner, P.; Wagner, R. G.; Wagner, R. L.; Wagner, W.; Wagner-Kuhr, J.; Wakisaka, T.; Wallny, R.; Wang, S. M.; Warburton, A.; Waters, D.; Weinberger, M.; Weinelt, J.; Whitehouse, B.; Whiteson, D.; Wicklund, A. B.; Wicklund, E.; Wilbur, S.; Williams, G.; Williams, H. H.; Wilson, P.; Winer, B. L.; Wittich, P.; Wolbers, S.; Wolfe, C.; Wright, T.; Wu, X.; Würthwein, F.; Xie, S.; Yagil, A.; Yamamoto, K.; Yamaoka, J.; Yang, U. K.; Yang, Y. C.; Yao, W. M.; Yeh, G. P.; Yi, K.; Yoh, J.; Yorita, K.; Yoshida, T.; Yu, G. B.; Yu, I.; Yu, S. S.; Yun, J. C.; Zanello, L.; Zanetti, A.; Zhang, X.; Zheng, Y.; Zucchelli, S.

    2009-07-01

    We report a search for narrow resonances, produced in pbar{p} collisions at sqrt{s}=1.96 TeV, that decay into muon pairs with invariant mass between 6.3 and 9.0 GeV/ c 2. The data, collected with the CDF II detector at the Fermilab Tevatron collider, correspond to an integrated luminosity of 630 pb-1. We use the dimuon invariant mass distribution to set 90% upper credible limits of about 1% to the ratio of the production cross section times muonic branching fraction of possible narrow resonances to that of the ϒ(1S) meson.

  5. Characterization and mapping of LanrBo: a locus conferring anthracnose resistance in narrow-leafed lupin (Lupinus angustifolius L.).

    PubMed

    Fischer, Kristin; Dieterich, Regine; Nelson, Matthew N; Kamphuis, Lars G; Singh, Karam B; Rotter, Björn; Krezdorn, Nicolas; Winter, Peter; Wehling, Peter; Ruge-Wehling, Brigitte

    2015-10-01

    A novel and highly effective source of anthracnose resistance in narrow-leafed lupin was identified. Resistance was shown to be governed by a single dominant locus. Molecular markers have been developed, which can be used for selecting resistant genotypes in lupin breeding. A screening for anthracnose resistance of a set of plant genetic resources of narrow-leafed lupin (Lupinus angustifolius L.) identified the breeding line Bo7212 as being highly resistant to anthracnose (Colletotrichum lupini). Segregation analysis indicated that the resistance of Bo7212 is inherited by a single dominant locus. The corresponding resistance gene was given the designation LanrBo. Previously published molecular anchor markers allowed us to locate LanrBo on linkage group NLL-11 of narrow-leafed lupin. Using information from RNAseq data obtained with inoculated resistant vs. susceptible lupin entries as well as EST-sequence information from the model genome Lotus japonicus, additional SNP and EST markers linked to LanrBo were derived. A bracket of two LanrBo-flanking markers allows for precise marker-assisted selection of the novel resistance gene in narrow-leafed lupin breeding programs.

  6. Integration of Lupinus angustifolius L. (narrow-leafed lupin) genome maps and comparative mapping within legumes.

    PubMed

    Wyrwa, Katarzyna; Książkiewicz, Michał; Szczepaniak, Anna; Susek, Karolina; Podkowiński, Jan; Naganowska, Barbara

    2016-09-01

    Narrow-leafed lupin (Lupinus angustifolius L.) has recently been considered a reference genome for the Lupinus genus. In the present work, genetic and cytogenetic maps of L. angustifolius were supplemented with 30 new molecular markers representing lupin genome regions, harboring genes involved in nitrogen fixation during the symbiotic interaction of legumes and soil bacteria (Rhizobiaceae). Our studies resulted in the precise localization of bacterial artificial chromosomes (BACs) carrying sequence variants for early nodulin 40, nodulin 26, nodulin 45, aspartate aminotransferase P2, asparagine synthetase, cytosolic glutamine synthetase, and phosphoenolpyruvate carboxylase. Together with previously mapped chromosomes, the integrated L. angustifolius map encompasses 73 chromosome markers, including 5S ribosomal DNA (rDNA) and 45S rDNA, and anchors 20 L. angustifolius linkage groups to corresponding chromosomes. Chromosomal identification using BAC fluorescence in situ hybridization identified two BAC clones as narrow-leafed lupin centromere-specific markers, which served as templates for preliminary studies of centromere composition within the genus. Bioinformatic analysis of these two BACs revealed that centromeric/pericentromeric regions of narrow-leafed lupin chromosomes consisted of simple sequence repeats ordered into tandem repeats containing the trinucleotide and pentanucleotide simple sequence repeats AGG and GATAC, structured into long arrays. Moreover, cross-genus microsynteny analysis revealed syntenic patterns of 31 single-locus BAC clones among several legume species. The gene and chromosome level findings provide evidence of ancient duplication events that must have occurred very early in the divergence of papilionoid lineages. This work provides a strong foundation for future comparative mapping among legumes and may facilitate understanding of mechanisms involved in shaping legume chromosomes.

  7. Relational Themes in Counseling Supervision: Broadening and Narrowing Processes

    ERIC Educational Resources Information Center

    Gazzola, Nicola; Theriault, Anne

    2007-01-01

    This study investigated the experiences of broadening (i.e., thinking and acting creatively and being open to exploring new ways of being) and narrowing (i.e., the experience of perceiving one's choices as limited) in the supervisory process with the aim of identifying key relational themes from the perspective of supervisees. We interviewed 10…

  8. Revisiting the Case for Narrow Reading with English Language Learners

    ERIC Educational Resources Information Center

    Hansen, Laurie E.; Collins, Penelope

    2015-01-01

    This study investigated children's access to books, narrow independent reading volume, and growth in vocabulary knowledge and comprehension. Two hundred-twenty English language learners and native-English speaking children from diverse socioeconomic backgrounds were given measures of vocabulary and literacy in the fall and spring of fourth grade.…

  9. 9. INTERIOR LIVING ROOM DETAIL OF ONE OF TWO NARROW ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. INTERIOR LIVING ROOM DETAIL OF ONE OF TWO NARROW 4-LIGHT OVER 4-LIGHT, DOUBLE-HUNG, WOOD-FRAMED WINDOWS ON EITHER SIDE OF FRONT DOOR SHOWING EXPOSED COUNTERBALANCE CABLE. VIEW TO SOUTHWEST. - Bishop Creek Hydroelectric System, Plant 4, Worker Cottage, Bishop Creek, Bishop, Inyo County, CA

  10. The Tacoma Narrows Bridge Collapse on Film and Video

    ERIC Educational Resources Information Center

    Olson, Don; Hook, Joseph; Doescher, Russell; Wolf, Steven

    2015-01-01

    This month marks the 75th anniversary of the Tacoma Narrows Bridge collapse. During a gale on Nov. 7, 1940, the bridge exhibited remarkable oscillations before collapsing spectacularly (Figs. 1-5). Physicists over the years have spent a great deal of time and energy studying this event. By using open-source analysis tools and digitized footage of…

  11. INTERIOR VIEW OF THE KITCHEN. NOTE THE NARROW DOOR OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR VIEW OF THE KITCHEN. NOTE THE NARROW DOOR OF THE FORMER COOLER (LEFT), SINGLE-LIGHT OVER THREE-PANEL DOOR TO THE SERVICE PORCH (CENTER), AND BUILT-IN SPICE RACK (RIGHT). VIEW FACING EAST. - Hickam Field, NCO Housing Type 1, 211 Tenth Street, Honolulu, Honolulu County, HI

  12. 33 CFR 162.240 - Tongass Narrows, Alaska; navigation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Tongass Narrows, Alaska; navigation. 162.240 Section 162.240 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY INLAND WATERWAYS NAVIGATION REGULATIONS § 162.240...

  13. 33 CFR 162.240 - Tongass Narrows, Alaska; navigation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Tongass Narrows, Alaska; navigation. 162.240 Section 162.240 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY INLAND WATERWAYS NAVIGATION REGULATIONS § 162.240...

  14. 33 CFR 162.240 - Tongass Narrows, Alaska; navigation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Tongass Narrows, Alaska; navigation. 162.240 Section 162.240 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY INLAND WATERWAYS NAVIGATION REGULATIONS § 162.240...

  15. Narrow grass hedge effects on nutrient transport following compost application

    USDA-ARS?s Scientific Manuscript database

    The use of stiff-stemmed grass hedges can be a valuable soil conservation measure. A study was conducted to measure the effectiveness of a narrow grass hedge, planted on the contour along the hillslope, in reducing runoff nutrient transport from plots with a range of soil nutrient values. Composted ...

  16. Interior direct view of unit narrow kitchen with highlevel barred ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior direct view of unit narrow kitchen with high-level barred windows at 2nd floor of Building 7, looking south - North Beach Place, 431 Bay Street, 530 Francisco Street, 431 Bay Street, 530 Francisco Street, San Francisco, San Francisco County, CA

  17. INTERIOR VIEW OF THE SOUTH ROOM. DOOR TO THE NARROW ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR VIEW OF THE SOUTH ROOM. DOOR TO THE NARROW CORRIDOR IS ON THE LEFT, DOOR TO THE NORTH ROOM IS ON THE RIGHT. VIEW FACING WEST - U.S. Naval Base, Pearl Harbor, Ford Island 5-Inch Antiaircraft Battery, Battery Command Center, Ford Island, Pearl City, Honolulu County, HI

  18. INTERIOR VIEW OF NARROW CORRIDOR. NOTE THE ENTRY STAIRWAY (STAIRS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR VIEW OF NARROW CORRIDOR. NOTE THE ENTRY STAIRWAY (STAIRS COVERED WITH EARTH) LEADING UP TO GROUND LEVEL ON THE LEFT. VIEW FACING WEST - U.S. Naval Base, Pearl Harbor, Ford Island 5-Inch Antiaircraft Battery, Battery Command Center, Ford Island, Pearl City, Honolulu County, HI

  19. A "Narrowing of Inquiry" in American Moral Psychology and Education

    ERIC Educational Resources Information Center

    Richardson, Michael J.; Slife, Brent D.

    2013-01-01

    We explore the possibility that a priori philosophical commitments continue to result in a narrowing of inquiry in moral psychology and education where theistic worldviews are concerned. Drawing from the theories of Edward L. Thorndike and John Dewey, we examine naturalistic philosophical commitments that influenced the study of moral psychology…

  20. World Food Resources and Population: The Narrowing Margin.

    ERIC Educational Resources Information Center

    Brown, Lester R.

    1981-01-01

    This bulletin examines the narrowing margin between global food production and population growth. Between 1950 and 1971, world grain production nearly doubled and per capita production increased 31 percent. During the 1970s, gains in output barely kept pace with population growth, consumption per person declined in sub-Saharan Africa and parts of…

  1. Career Attainment among Healthcare Executives: Is the Gender Gap Narrowing?

    ERIC Educational Resources Information Center

    Branin, Joan Julia

    2009-01-01

    Health care occupations are expected to be among the fastest growing professions in the next ten years. With such incredible growth expected in employment and wages, and with women's participation in the industry remaining strong, are women in the health care industry, particularly those in health care administration, experiencing a narrowing of…

  2. High average power, narrow band 248 nm alexandrite laser system

    SciTech Connect

    Kuper, J.W.; Chin, T.C.; Papanestor, P.A.

    1994-12-31

    A compact line-narrowed 248 nm solid state laser source operating at 15 mJ {at} 100 Hz PRF was demonstrated. Constraints due to thermal loading of components were addressed. Tradeoffs between pulse energy and repetition rate were investigated. A method for overcoming thermal dephasing in the THG material was achieved by scanning a slab shaped crystal.

  3. World Food Resources and Population: The Narrowing Margin.

    ERIC Educational Resources Information Center

    Brown, Lester R.

    1981-01-01

    This bulletin examines the narrowing margin between global food production and population growth. Between 1950 and 1971, world grain production nearly doubled and per capita production increased 31 percent. During the 1970s, gains in output barely kept pace with population growth, consumption per person declined in sub-Saharan Africa and parts of…

  4. Vascular narrowing in pulmonary arterial hypertension is heterogeneous: rethinking resistance.

    PubMed

    Rol, Nina; Timmer, Esther M; Faes, Theo J C; Noordegraaf, Anton Vonk; Grünberg, Katrien; Bogaard, Harm-Jan; Westerhof, Nico

    2017-03-01

    In idiopathic pulmonary arterial hypertension (PAH), increased pulmonary vascular resistance is associated with structural narrowing of small (resistance) vessels and increased vascular tone. Current information on pulmonary vascular remodeling is mostly limited to averaged increases in wall thickness, but information on number of vessels affected and internal diameter decreases for vessels of different sizes is limited. Our aim was to quantify numbers of affected vessels and their internal diameter decrease for differently sized vessels in PAH in comparison with non-PAH patients. Internal and external diameters of transversally cut vessels were measured in five control subjects and six PAH patients. Resistance vessels were classified in Strahler orders, internal diameters 13 μm (order 1) to 500 μm (order 8). The number fraction, that is, percentage of affected vessels, and the internal diameter fraction, that is, percentage diameter of normal diameter, were calculated. In PAH, not all resistance vessels are affected. The number fraction is about 30%, that is, 70% of vessels have diameters not different from vessels of control subjects. Within each order, the decrease in diameter of affected vessels is variable with an averaged diameter fraction of 50-70%. Narrowing of resistance vessels is heterogeneous: not all vessels are narrowed, and the decrease in internal diameters, even within a single order, vary largely. This heterogeneous narrowing alone cannot explain the large resistance increase in PAH We suggest that rarefaction could be an important contributor to the hemodynamic changes.

  5. Moving beyond Idealistically Narrow Discourses in Citizenship Education

    ERIC Educational Resources Information Center

    Fischman, Gustavo E.; Haas, Eric

    2014-01-01

    The main goal of this article is to provide conceptual guidelines to move the pedagogical debate in the field of citizenship education beyond idealistically narrow models. We begin by providing an overview of key shortcomings presented in most citizenship education programs, specifically in the United States of America. The second section presents…

  6. Narrow line cooling and momentum-space crystals

    SciTech Connect

    Loftus, Thomas H.; Ido, Tetsuya; Boyd, Martin M.; Ludlow, Andrew D.; Ye Jun

    2004-12-01

    Narrow line laser cooling is advancing the frontier for experiments ranging from studies of fundamental atomic physics to high precision optical frequency standards. In this paper, we present an extensive description of the systems and techniques necessary to realize 689 nm {sup 1}S{sub 0}-{sup 3}P{sub 1} narrow line cooling of atomic {sup 88}Sr. Narrow line cooling and trapping dynamics are also studied in detail. By controlling the relative size of the power broadened transition linewidth and the single-photon recoil frequency shift, we show that it is possible to smoothly bridge the gap between semiclassical and quantum mechanical cooling. Novel semiclassical cooling processes, some of which explicitly depend on the relative size of gravity and the radiative force, are also explored. Moreover, for laser frequencies tuned above the atomic resonance, we demonstrate momentum-space crystals containing up to 26 well defined lattice points. Gravitationally assisted cooling is also achieved with blue-detuned light. Theoretically, we find the blue detuned dynamics are universal to Doppler limited systems. This paper offers the most comprehensive study of narrow line laser cooling to date.

  7. Acute and chronic response to CRT in narrow QRS patients.

    PubMed

    Donahue, Tim; Niazi, Imran; Leon, Angel; Stucky, Michael; Herrmann, Keith

    2012-04-01

    Previous studies suggest that CRT may benefit narrow QRS patients with mechanical dyssynchrony (MD). We conducted an acute and chronic study, evaluating the response of heart failure patients with a narrow QRS to cardiac resynchronization therapy (CRT). ESTEEM-CRT was a multi-center, single-arm, feasibility study that evaluated ICD-indicated, medically-optimized patients with EF ≤ 35%, NYHA class III heart failure, QRS duration <120 ms, and MD as defined by the standard deviation of time to peak systolic velocity of 12 segments (Ts-SD). Sixty-eight patients received a CRT defibrillator, exercise testing, and echo exams, and 47 of these patients underwent invasive hemodynamic testing at implant. Follow-up was at 6 and 12 months. The average maximal improvement in LV dP/dt(max) was minor (2 ± 2%). NYHA and quality of life scores were substantially improved at 6 and 12 months (P < 0.001), while exercise capacity and LV volumes were unchanged. The echo indices of MD were difficult to collect, discordant, and failed to predict clinical outcomes. ESTEEM-CRT patients with a narrow QRS and MD as defined in this study did not improve as measured by acute hemodynamics, chronic exercise performance, or reverse remodeling. These multi-center results support the notion that dyssynchrony indices are ineffective or at least require greater refinement for the selection of narrow QRS patients for CRT.

  8. Narrow deeply bound K- and p atomic states

    NASA Astrophysics Data System (ADS)

    Friedman, E.; Gal, A.

    2000-01-01

    Examples of recently predicted narrow `deeply bound' K- and p atomic states are shown. The saturation of widths for strong absorptive potentials due to the induced repulsion, and the resulting suppression of atomic wave functions within the nucleus, are demonstrated. Production reactions for K- atomic states using φ(1020) decay, and the (p,p) reaction for p atomic states, are discussed.

  9. Is the Achievement Gap in Indiana Narrowing? Special Report

    ERIC Educational Resources Information Center

    Spradlin, Terry E.; Kirk, Ryan; Walcott, Crystal; Kloosterman, Peter; Zaman, Khadija; McNabb, Sarah; Zapf, Jason

    2005-01-01

    In this Special Report, the Center for Evaluation and Education Policy at Indiana University examines the factors that contribute to student achievement gaps, defines the scope of the achievement gaps that exist in Indiana, evaluates whether these gaps are narrowing or will persist as Neal suggests, and offers strategies that have been identified…

  10. Large Aperture, Narrow-Band Detectors for Optical Communication Systems.

    DTIC Science & Technology

    The patent application provides a sensitive detector means for the reception and detection of optical communication signals which are accompanied by...onto a detector. A provision of a large aperture narrow-band detector for optical communication systems is made for receiving and detecting optical ... communication with self-filtering to selectively detect the information while discriminating or rejecting background radiation.

  11. The Tacoma Narrows Bridge Collapse on Film and Video

    ERIC Educational Resources Information Center

    Olson, Don; Hook, Joseph; Doescher, Russell; Wolf, Steven

    2015-01-01

    This month marks the 75th anniversary of the Tacoma Narrows Bridge collapse. During a gale on Nov. 7, 1940, the bridge exhibited remarkable oscillations before collapsing spectacularly (Figs. 1-5). Physicists over the years have spent a great deal of time and energy studying this event. By using open-source analysis tools and digitized footage of…

  12. 33 CFR 162.240 - Tongass Narrows, Alaska; navigation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Tongass Narrows, Alaska; navigation. 162.240 Section 162.240 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY INLAND WATERWAYS NAVIGATION REGULATIONS § 162.240 Tongass...

  13. 33 CFR 162.240 - Tongass Narrows, Alaska; navigation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Tongass Narrows, Alaska; navigation. 162.240 Section 162.240 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY INLAND WATERWAYS NAVIGATION REGULATIONS § 162.240 Tongass...

  14. Narrow-Band WGM Optical Filters With Tunable FSRs

    NASA Technical Reports Server (NTRS)

    Mohageg, Makan; Matsko, Andrey; Savchenkov, Anatoliy; Maleki, Lute; Iltchenko, Vladimir; Strekalov, Dmitry

    2007-01-01

    Optical resonators of the whispering-gallery-mode (WGM) type featuring DC-tunable free spectral ranges (FSRs) have been demonstrated. By making the FSR tunable, one makes it possible to adjust, during operation, the frequency of a microwave signal generated by an optoelectronic oscillator in which an WGM optical resonator is utilized as a narrow-band filter.

  15. Moving beyond Idealistically Narrow Discourses in Citizenship Education

    ERIC Educational Resources Information Center

    Fischman, Gustavo E.; Haas, Eric

    2014-01-01

    The main goal of this article is to provide conceptual guidelines to move the pedagogical debate in the field of citizenship education beyond idealistically narrow models. We begin by providing an overview of key shortcomings presented in most citizenship education programs, specifically in the United States of America. The second section presents…

  16. Genome degradation in Brucella ovis corresponds with narrowing of its host range and tissue tropism.

    PubMed

    Tsolis, Renee M; Seshadri, Rekha; Santos, Renato L; Sangari, Felix J; Lobo, Juan M García; de Jong, Maarten F; Ren, Qinghu; Myers, Garry; Brinkac, Lauren M; Nelson, William C; Deboy, Robert T; Angiuoli, Samuel; Khouri, Hoda; Dimitrov, George; Robinson, Jeffrey R; Mulligan, Stephanie; Walker, Richard L; Elzer, Philip E; Hassan, Karl A; Paulsen, Ian T

    2009-01-01

    Brucella ovis is a veterinary pathogen associated with epididymitis in sheep. Despite its genetic similarity to the zoonotic pathogens B. abortus, B. melitensis and B. suis, B. ovis does not cause zoonotic disease. Genomic analysis of the type strain ATCC25840 revealed a high percentage of pseudogenes and increased numbers of transposable elements compared to the zoonotic Brucella species, suggesting that genome degradation has occurred concomitant with narrowing of the host range of B. ovis. The absence of genomic island 2, encoding functions required for lipopolysaccharide biosynthesis, as well as inactivation of genes encoding urease, nutrient uptake and utilization, and outer membrane proteins may be factors contributing to the avirulence of B. ovis for humans. A 26.5 kb region of B. ovis ATCC25840 Chromosome II was absent from all the sequenced human pathogenic Brucella genomes, but was present in all of 17 B. ovis isolates tested and in three B. ceti isolates, suggesting that this DNA region may be of use for differentiating B. ovis from other Brucella spp. This is the first genomic analysis of a non-zoonotic Brucella species. The results suggest that inactivation of genes involved in nutrient acquisition and utilization, cell envelope structure and urease may have played a role in narrowing of the tissue tropism and host range of B. ovis.

  17. Establishing the phylogenetic origin, history, and age of the narrow endemic Viola guadalupensis (Violaceae).

    PubMed

    Marcussen, Thomas; Blaxland, Kim; Windham, Michael D; Haskins, Kristin E; Armstrong, Fred

    2011-12-01

    Climate change and shifts in land use are two major threats to biodiversity and are likely to disproportionately impact narrow endemics. Understanding their origins and the extent of their genetic diversity will enable land managers to better conserve these unique, highly localized gene pools. Viola guadalupensis is a narrow endemic of the Guadalupe Mountains (west Texas, USA). Its affinities within Viola section Chamaemelanium have been the subject of some debate. Furthermore, the polyploid and presumably reticulate relationships within this section remain largely unknown. We counted chromosomes for V. guadalupensis. Phylogenies for the chloroplast trnL-F region and the low-copy nuclear gene GPI for 24 Viola taxa were generated and used to produce a polyploid phylogenetic network. Divergence dates were obtained by fossil calibration. Meiotic chromosome counts revealed that V. guadalupensis is tetraploid (n = 12), and the presence of two GPI homoeologs further suggested allotetraploidy. Phylogenetic reconstructions showed that it originated through hybridization between unidentified members of subsection Canadenses (paternal parent) and subsection Nuttallianae (maternal parent). A fossil-calibrated relaxed clock dating analysis of GPI estimated the maximum age of V. guadalupensis to be 8.6 (5.7-11.6) Myr, suggesting the species evolved after the Guadalupe Mountains formed 12-13 Ma. Viola guadalupensis originated by intersubsectional hybridization followed by polyploidization. Within section Chamaemelanium, this phenomenon has occurred repeatedly in the last 9 Myr (at least for V. bakeri, V. douglasii, V. glabella, and V. sempervirens). Consequences for the systematics of the section are discussed.

  18. Genome Degradation in Brucella ovis Corresponds with Narrowing of Its Host Range and Tissue Tropism

    PubMed Central

    Tsolis, Renee M.; Seshadri, Rekha; Santos, Renato L.; Sangari, Felix J.; Lobo, Juan M. García; de Jong, Maarten F.; Ren, Qinghu; Myers, Garry; Brinkac, Lauren M.; Nelson, William C.; DeBoy, Robert T.; Angiuoli, Samuel; Khouri, Hoda; Dimitrov, George; Robinson, Jeffrey R.; Mulligan, Stephanie; Walker, Richard L.; Elzer, Philip E.; Hassan, Karl A.; Paulsen, Ian T.

    2009-01-01

    Brucella ovis is a veterinary pathogen associated with epididymitis in sheep. Despite its genetic similarity to the zoonotic pathogens B. abortus, B. melitensis and B. suis, B. ovis does not cause zoonotic disease. Genomic analysis of the type strain ATCC25840 revealed a high percentage of pseudogenes and increased numbers of transposable elements compared to the zoonotic Brucella species, suggesting that genome degradation has occurred concomitant with narrowing of the host range of B. ovis. The absence of genomic island 2, encoding functions required for lipopolysaccharide biosynthesis, as well as inactivation of genes encoding urease, nutrient uptake and utilization, and outer membrane proteins may be factors contributing to the avirulence of B. ovis for humans. A 26.5 kb region of B. ovis ATCC25840 Chromosome II was absent from all the sequenced human pathogenic Brucella genomes, but was present in all of 17 B. ovis isolates tested and in three B. ceti isolates, suggesting that this DNA region may be of use for differentiating B. ovis from other Brucella spp. This is the first genomic analysis of a non-zoonotic Brucella species. The results suggest that inactivation of genes involved in nutrient acquisition and utilization, cell envelope structure and urease may have played a role in narrowing of the tissue tropism and host range of B. ovis. PMID:19436743

  19. A spectrophotometric atlas of Narrow-Line Seyfert 1 galaxies

    NASA Astrophysics Data System (ADS)

    Véron-Cetty, M.-P.; Véron, P.; Gonçalves, A. C.

    2001-06-01

    We have compiled a list of 83 objects classified as Narrow-Line Seyfert 1 galaxies (NLS1s) or known to have a broad Balmer component narrower than 2 000 km s-1. Of these, 19 turned out to have been spectroscopically misidentified in previous studies; only 64 of the selected objects are genuine NLS1s. We have spectroscopically observed 59 of them and tried to characterize their Narrow and Broad-Line Regions (NLR and BLR) by fitting the emission-lines with Gaussian and/or Lorentzian profiles. In most cases, the broad Balmer components are well fitted by a single Lorentzian profile, confirming previous claims that Lorentzian rather than Gaussian profiles are better suited to reproduce the shape of the NLS1s broad emission lines. This has consequences concerning their FWHMs and line ratios: when the broad Balmer components are fitted with a Lorentzian, most narrow line regions have line ratios typical of Seyfert 2s while, when a Gaussian profile is used for fitting the broad Balmer components, the line ratios are widely scattered in the usual diagnostic diagrams (Veilleux & Osterbrock \\cite{vei87}); moreover, the FWHM of the best fitting Lorentzian is systematically smaller than the FWHM of the Gaussian. We find that, in general, the [O III] lines have a relatively narrow Gaussian profile ( ~ 200-500 km s-1 FWHM) with often, in addition, a second broad ( ~ 500-1 800 km s-1 FWHM), blueshifted Gaussian component. We do not confirm that the [O III] lines are weak in NLS1s. As previously suggested, there is a continuous transition of all properties between NLS1s and classical Broad-Line Seyfert 1 Galaxies (BLS1s) and the limit of 2000 km s-1 used to separate the two species is arbitrary; R4570, the ratio of the Fe II to the Hβ fluxes, could be a physically more meaningful parameter to distinguish them.

  20. A narrow band pattern-matching model of vowel perception.

    PubMed

    Hillenbrand, James M; Houde, Robert A

    2003-02-01

    The purpose of this paper is to propose and evaluate a new model of vowel perception which assumes that vowel identity is recognized by a template-matching process involving the comparison of narrow band input spectra with a set of smoothed spectral-shape templates that are learned through ordinary exposure to speech. In the present simulation of this process, the input spectra are computed over a sufficiently long window to resolve individual harmonics of voiced speech. Prior to template creation and pattern matching, the narrow band spectra are amplitude equalized by a spectrum-level normalization process, and the information-bearing spectral peaks are enhanced by a "flooring" procedure that zeroes out spectral values below a threshold function consisting of a center-weighted running average of spectral amplitudes. Templates for each vowel category are created simply by averaging the narrow band spectra of like vowels spoken by a panel of talkers. In the present implementation, separate templates are used for men, women, and children. The pattern matching is implemented with a simple city-block distance measure given by the sum of the channel-by-channel differences between the narrow band input spectrum (level-equalized and floored) and each vowel template. Spectral movement is taken into account by computing the distance measure at several points throughout the course of the vowel. The input spectrum is assigned to the vowel template that results in the smallest difference accumulated over the sequence of spectral slices. The model was evaluated using a large database consisting of 12 vowels in /hVd/ context spoken by 45 men, 48 women, and 46 children. The narrow band model classified vowels in this database with a degree of accuracy (91.4%) approaching that of human listeners.

  1. A narrow band pattern-matching model of vowel perception

    NASA Astrophysics Data System (ADS)

    Hillenbrand, James M.; Houde, Robert A.

    2003-02-01

    The purpose of this paper is to propose and evaluate a new model of vowel perception which assumes that vowel identity is recognized by a template-matching process involving the comparison of narrow band input spectra with a set of smoothed spectral-shape templates that are learned through ordinary exposure to speech. In the present simulation of this process, the input spectra are computed over a sufficiently long window to resolve individual harmonics of voiced speech. Prior to template creation and pattern matching, the narrow band spectra are amplitude equalized by a spectrum-level normalization process, and the information-bearing spectral peaks are enhanced by a ``flooring'' procedure that zeroes out spectral values below a threshold function consisting of a center-weighted running average of spectral amplitudes. Templates for each vowel category are created simply by averaging the narrow band spectra of like vowels spoken by a panel of talkers. In the present implementation, separate templates are used for men, women, and children. The pattern matching is implemented with a simple city-block distance measure given by the sum of the channel-by-channel differences between the narrow band input spectrum (level-equalized and floored) and each vowel template. Spectral movement is taken into account by computing the distance measure at several points throughout the course of the vowel. The input spectrum is assigned to the vowel template that results in the smallest difference accumulated over the sequence of spectral slices. The model was evaluated using a large database consisting of 12 vowels in /hVd/ context spoken by 45 men, 48 women, and 46 children. The narrow band model classified vowels in this database with a degree of accuracy (91.4%) approaching that of human listeners.

  2. Increased coherence time in narrowed bath states in quantum dots

    NASA Astrophysics Data System (ADS)

    Gravert, Lars B.; Lorenz, Peter; Nase, Carsten; Stolze, Joachim; Uhrig, Götz S.

    2016-09-01

    We study the influence of narrowed distributions of the nuclear Overhauser field on the decoherence of a central electron spin in quantum dots. We describe the spin dynamics in quantum dots by the central spin model. We use analytic solutions for uniform couplings and the time dependent density-matrix renormalization group (tDMRG) for nonuniform couplings. With these tools we calculate the dynamics of the central spin for large baths of nuclear spins with or without external magnetic field applied to the central spin. The focus of our study is the influence of initial mixtures with narrowed distributions of the Overhauser field and of applied magnetic fields on the decoherence of the central spin.

  3. Period Effects, Cohort Effects, and the Narrowing Gender Wage Gap

    PubMed Central

    Campbell, Colin; Pearlman, Jessica

    2015-01-01

    Despite the abundance of sociological research on the gender wage gap, questions remain. In particular, the role of cohorts is under investigated. Using data from the Current Population Survey, we use Age-Period-Cohort analysis to uniquely estimate age, period, and cohort effects on the gender wage gap. The narrowing of the gender wage gap that occurred between 1975 and 2009 is largely due to cohort effects. Since the mid-1990s, the gender wage gap has continued to close absent of period effects. While gains in female wages contributed to declines in the gender wage gap for cohorts born before 1950, for later cohorts the narrowing of the gender wage gap is primarily a result of declines in male wages. PMID:24090861

  4. Period effects, cohort effects, and the narrowing gender wage gap.

    PubMed

    Campbell, Colin; Pearlman, Jessica

    2013-11-01

    Despite the abundance of sociological research on the gender wage gap, questions remain. In particular, the role of cohorts is under investigated. Using data from the Current Population Survey, we use age-period-cohort analysis to uniquely estimate age, period, and cohort effects on the gender wage gap. The narrowing of the gender wage gap that occurred between 1975 and 2009 is largely due to cohort effects. Since the mid-1990s, the gender wage gap has continued to close absent of period effects. While gains in female wages contributed to declines in the gender wage gap for cohorts born before 1950, for later cohorts the narrowing of the gender wage gap is primarily a result of declines in male wages.

  5. Undersea narrow-beam optical communications field demonstration

    NASA Astrophysics Data System (ADS)

    Hamilton, Scott A.; DeVoe, Cathy E.; Fletcher, Andrew S.; Gaschits, Igor D.; Hakimi, Farhad; Hardy, Nicholas D.; Howe, Thomas; Mittleman, Nathan; Rao, Hemonth G.; Scheinbart, Marvin S.; Yarnall, Timothy M.

    2017-05-01

    Optical propagation through the ocean encounters significant absorption and scattering; the impact is exponential signal attenuation and temporal broadening, limiting the maximum link range and the achievable data rate, respectively. MIT Lincoln Laboratory is developing narrow-beam lasercom for the undersea environment, where a collimated transmit beam is precisely pointed to the receive terminal. This approach directly contrasts with the more commonly demonstrated approach, where the transmit light is sent over a wide angle, avoiding precise pointing requirements but reducing the achievable range and data rate. Two advantages of narrow-beam lasercom are the maximization of light collected at the receiver and the ability to mitigate the impact of background light by spatial filtering. Precision pointing will be accomplished by bi-directional transmission and tracking loops on each terminal, a methodology used to great effect in atmospheric and space lasercom systems. By solving the pointing and tracking problem, we can extend the link range and increase the data throughput.

  6. Transport and Mixing of Pollutants In A Narrow Alpine Valley

    NASA Astrophysics Data System (ADS)

    Kerbiriou, M. A.; Chollet, J. P.; Staquet, C.

    Atmospheric dynamics in narrow valleys often lead to the formation of bottom and capping inversion layers, whose features depend upon the geometry and the soil char- acteristics of the topography. The altitude and thickness of such stable layers evolve during a diurnal cycle under the effect of solar radiation. Therefore, the layers strongly influence the transport and dispersion of pollutants emitted at the bottom of the val- ley. We conducted a numerical study of the processes leading to the formation and destruction of such inversion layers in a narrow alpine valley, using the ARPS 4.5.1 code. We shall present considerations on the energy balance between the ground and the above atmosphere in this case. We shall also address the effect of such layers on the dispersion of pollutants, using lagrangian tracors, and we will show some prelim- inary results about the transport and mixing throughout the layers during one diurnal cycle.

  7. Narrow groove welding gas diffuser assembly and welding torch

    DOEpatents

    Rooney, Stephen J.

    2001-01-01

    A diffuser assembly is provided for narrow groove welding using an automatic gas tungsten arc welding torch. The diffuser assembly includes a manifold adapted for adjustable mounting on the welding torch which is received in a central opening in the manifold. Laterally extending manifold sections communicate with a shield gas inlet such that shield gas supplied to the inlet passes to gas passages of the manifold sections. First and second tapered diffusers are respectively connected to the manifold sections in fluid communication with the gas passages thereof. The diffusers extend downwardly along the torch electrode on opposite sides thereof so as to release shield gas along the length of the electrode and at the distal tip of the electrode. The diffusers are of a transverse width which is on the order of the thickness of the electrode so that the diffusers can, in use, be inserted into a narrow welding groove before and after the electrode in the direction of the weld operation.

  8. Narrow groove welding gas diffuser assembly and welding torch

    SciTech Connect

    Rooney, Stephen J.

    2000-02-04

    A diffuser assembly is provided for narrow groove welding using an automatic gas tungsten arc welding torch. The diffuser assembly includes manifold adapted for adjustable mounting on the welding torch which is received in a central opening in the manifold. Laterally extending manifold sections communicate with a shield gas inlet such that shield gas supplied to the inlet passes to gas passages of the manifold sections. First and second tapered diffusers are respectively connected to the manifold sections in fluid communication with the gas passages thereof. The diffusers extend downwardly along the torch electrode on opposite sides thereof so as to release shield gas along the length of the electrode and at the distal tip of the electrode. The diffusers are of a transverse width which is on the order of the thickness of the electrode so that the diffusers can, in use, be inserted into a narrow welding groove before and after the electrode in the direction of the weld operation.

  9. Domain wall pinning in ultra-narrow electromigrated break junctions.

    PubMed

    Reeve, Robert M; Loescher, André; Mawass, Mohamad-Assaad; Hoffmann-Vogel, Regina; Kläui, Mathias

    2014-11-26

    The study of magnetic domain walls in constrained geometries is an important topic, yet when dealing with extreme nanoscale magnetic systems artefacts can often dominate the measurements and obscure the effects of intrinsic magnetic origin. In this work we study the evolution of domain wall depinning in electromigrated ferromagnetic junctions which are both initially fabricated and subsequently tailored in-situ in clean ultra-high vacuum conditions. Carefully designed Ni(80)Fe(20) (Permalloy) notched half-ring structures are fabricated and investigated as a function of constriction width by tailoring the size of the contact using controlled in-situ electromigration. It is found that the domain wall pinning strength is increased on reducing the contact size in line with a reduction of the wall energy in narrower constrictions. Furthermore, the angular dependency and symmetry of the depinning field is measured to determine the full pinning potential for a domain wall in a system with a narrow constriction.

  10. Model of Layered Weld Formation Under Narrow Gap Pulse Welding

    NASA Astrophysics Data System (ADS)

    Krampit, A. G.

    2016-04-01

    The model parameters of narrow gap pulse welding can be divided into input, internal and output ones. The breadth of gap, that is, clearance breadth between upright edges is one of key parameters securing high quality of a weld joint. The paper presents theoretical outcomes for the model of layered weld formation under narrow gap pulse welding. Based on these studies is developed model of processes, which occur in the weld pool under pulse grove welding. It comprises the scheme of liquid metal motion in the weld pool, scheme of fusion with the side edge and in the bottom part, and the scheme of welding current impulse effect on the structure of a weld joint.

  11. NARROW ATOMIC FEATURES FROM RAPIDLY SPINNING NEUTRON STARS

    SciTech Connect

    Bauboeck, Michi; Psaltis, Dimitrios; Oezel, Feryal E-mail: dpsaltis@email.arizona.edu

    2013-04-01

    Neutron stars spinning at moderate rates ({approx}300-600 Hz) become oblate in shape and acquire a nonzero quadrupole moment. In this paper, we calculate the profiles of atomic features from such neutron stars using a ray-tracing algorithm in the Hartle-Thorne approximation. We show that line profiles acquire cores that are much narrower than the widths expected from pure Doppler effects for a large range of observer inclinations. As a result, the effects of both the oblateness and the quadrupole moments of neutron stars need to be taken into account when aiming to measure neutron-star radii from rotationally broadened lines. Moreover, the presence of these narrow cores substantially increases the likelihood of detecting atomic lines from rapidly spinning neutron stars.

  12. Magnetic Field Generation During the Collision of Narrow Plasma Clouds

    NASA Astrophysics Data System (ADS)

    Sakai, Jun-ichi; Kazimura, Yoshihiro; Haruki, Takayuki

    1999-06-01

    We investigate the dynamics of the collision of narrow plasma clouds,whose transverse dimension is on the order of the electron skin depth.A 2D3V (two dimensions in space and three dimensions in velocity space)particle-in-cell (PIC) collisionless relativistic code is used toshow the generation of a quasi-staticmagnetic field during the collision of narrow plasma clouds both inelectron-ion and electron-positron (pair) plasmas. The localizedstrong magnetic fluxes result in the generation of the charge separationwith complicated structures, which may be sources of electromagneticas well as Langmuir waves. We also present one applicationof this process, which occurs during coalescence of magnetic islandsin a current sheet of pair plasmas.

  13. Noise measurement on thermal systems with narrow band

    NASA Astrophysics Data System (ADS)

    Burks, Stephen D.; Haefner, David P.; Doe, Joshua M.

    2016-05-01

    Thermal systems with a narrow spectral bandpass and mid-wave thermal imagers are useful for a variety of imaging applications. Additionally, the sensitivity for these classes of systems is increasing along with an increase in performance requirements when evaluated in a lab. Unfortunately, the uncertainty in the blackbody temperature along with the temporal instability of the blackbody could lead to uncontrolled laboratory environmental effects which could increase the measured noise. If the temporal uncertainty and accuracy of a particular blackbody is known, then confidence intervals could be adjusted for source accuracy and instability. Additionally, because thermal currents may be a large source of temporal noise in narrow band systems, a means to mitigate them is presented and results are discussed.

  14. 980 nm narrow linewidth Yb-doped phosphate fiber laser

    NASA Astrophysics Data System (ADS)

    Li, Pingxue; Yao, Yifei; Hu, Haowei; Chi, Junjie; Yang, Chun; Zhao, Ziqiang; Zhang, Guangju

    2014-12-01

    A narrow-linewidth ytterbium (Yb)-doped phosphate fiber laser based on fiber Bragg grating (FBG) operating around 980 nm is reported. Two different kinds of cavity are applied to obtain the 980 nm narrow-linewidth output. One kind of the cavity consists of a 0.35 nm broadband lindwidth high-reflection FBG and the Yb-doped phosphate fiber end with 0° angle, which generates a maximum output power of 25 mW. The other kind of resonator is composed of a single mode Yb-doped phosphate fiber and a pair of FBGs. Over 10.7 mW stable continuous wave are obtained with two longitudinal modes at 980 nm. We have given a detailed analysis and discussion for the results.

  15. 4. Overhead view showing the 1927 bridge (narrow bridgeleft side) ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. Overhead view showing the 1927 bridge (narrow bridge-left side) and 1959 bridge (right side) across Carquinez Strait. Town of Crockett is on south bank (bottom of image). C&H sugar factory is along the strait to the east (right) side of the 1959 bridge. The toll plaza is at the top of the image on the 1959 bridge side. - Carquinez Bridge, Spanning Carquinez Strait at Interstate 80, Vallejo, Solano County, CA

  16. Analysis of ultra-narrow ferromagnetic domain walls

    SciTech Connect

    Jenkins, Catherine; Paul, David

    2012-01-10

    New materials with high magnetic anisotropy will have domains separated by ultra-narrow ferromagnetic walls with widths on the order of a few unit cells, approaching the limit where the elastic continuum approximation often used in micromagnetic simulations is accurate. The limits of this approximation are explored, and the static and dynamic interactions with intrinsic crystalline defects and external driving elds are modeled. The results developed here will be important when considering the stability of ultra-high-density storage media.

  17. Generation of narrow peaks in spectroscopy of charged particles

    NASA Astrophysics Data System (ADS)

    Dubbers, Dirk; Schmidt, Ulrich

    2016-11-01

    In spectroscopy of charged particles, narrow peaks may appear in continuous spectra if magnetic transport of the particles is involved. These artefacts, which so far have escaped the attention of investigators, can develop whenever geometric detection efficiency is less than 100%. As such peaks may be misinterpreted as new physics, their generation is investigated, both analytically and experimentally, for various detector configurations, including those used in searches for the spontaneous decay of the vacuum in heavy-ion collisions.

  18. Photoluminescence from narrow InAs-AlSb quantum wells

    NASA Technical Reports Server (NTRS)

    Brar, Berinder; Kroemer, Herbert; Ibbetson, James; English, John H.

    1993-01-01

    We report on photoluminescence spectra from narrow InAs-AlSb quantum wells. Strong, clearly resolved peaks for well widths from 2 to 8 monolayers were observed. Transmission electron micrographs show direct evidence for the structural quality of the quantum well structures. The transition energies of the narrowest wells suggest a strong influence of the AlSb X-barrier on the electronic states in the conduction band.

  19. 28. ROOM 211, VIEW TO THE SOUTHEAST. THE LONG NARROW ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    28. ROOM 211, VIEW TO THE SOUTHEAST. THE LONG NARROW SPACE HAS EXPOSED TRUSSWORK IN UNPAINTED WOOD AS DID ALL UPSTAIRS ROOMS IN THEIR ORIGINAL CONDITION. CLERESTORY WINDOWS ARE INTERSPERSED WITH VENTS ALONG BOTH LONG SIDES OF THE ROOM. WALLS HAVE WIDE WOOD PANELING THAT IS PAINTED, FLOORS ARE WOOD. DOORWAY IN SOUTHWEST WALL LEADS TO UNFINISHED ATTIC SPACE. - Presidio of San Francisco, Cavalry Stables, Cowles Street, between Lincoln Boulevard & McDowell Street, San Francisco, San Francisco County, CA

  20. The Structure of A Pacific Narrow Cold Frontal Rainband

    NASA Technical Reports Server (NTRS)

    Jorgensen, David P.; Pu, Zhaoxia; Persson, Ola; Tao, Wei-Kuo; Starr, David OC. (Technical Monitor)

    2002-01-01

    A NOAA P-3 instrumented aircraft observed an intense, fast-moving narrow cold frontal Farmhand as it approached the Pacific Northwest coast on 19 February 2001 during the Pacific Coastal Jets Experiment. Pseudo-dual-Doppler analyses performed on the airborne Doppler radar data while the frontal system was well offshore indicated that a narrow ribbon of very high radar reflectively convective cores characterized the Farmhand at low levels with echo tops to approximately 4-5 km. The NCFR exhibited gaps in its narrow ribbon of high reflectively, probably as a result of hydrodynamic instability all no its advancing cold pool leading edge. In contrast to some earlier studies of cold frontal rainbands, density current theory described well the motion of the overall front. The character of the updraft structure associated with the heavy rainfall at its leading edge varied across the gap region. The vertical shear of the cross-frontal low-level ambient flow exerted a strong influence on the updraft character, consistent with theoretical arguments developed for squall lines describing the balance of vorticity at the leading edge. In short regions south of the gaps the vertical wind shear was strongest with the updrafts and rain shafts more intense, narrower, and more erect or even downshear tilted. North of the gaps the wind shear weakened with less intense Dihedrals which tilted upshear with a broader band of rainfall. Simulations using a nonhydrostatic mesoscale nested grid model are used to investigate the gap regions, particularly the balance of cold pool induced to pre-frontal ambient shears at the leading edge. Observations confirm the model results that the updraft character depends on the balance of vorticity at the leading edge. Downshear-tilted updrafts imply that convection south of the gap regions would weaken with time relative to the frontal segments north of the gaps since inflow air would be affected by passage through the heavy rain region before ascent

  1. Critical Heat Flux in Inclined Rectangular Narrow Gaps

    SciTech Connect

    Jeong J. Kim; Yong H. Kim; Seong J. Kim; Sang W. Noh; Kune Y. Suh; Joy L. Rempe; Fan-Bill Cheung; Sang B. Kim

    2004-06-01

    In light of the TMI-2 accident, in which the reactor vessel lower head survived the attack by molten core material, the in-vessel retention strategy was suggested to benefit from cooling the debris through a gap between the lower head and the core material. The GAMMA 1D (Gap Apparatus Mitigating Melt Attack One Dimensional) tests were conducted to investigate the critical heat flux (CHF) in narrow gaps with varying surface orientations. The CHF in an inclined gap, especially in case of the downward-facing narrow gap, is dictated by bubble behavior because the departing bubbles are squeezed. The orientation angle affects the bubble layer and escape of the bubbles from the narrow gap. The test parameters include gap sizes of 1, 2, 5 and 10 mm and the open periphery, and the orientation angles range from the fully downward-facing (180o) to the vertical (90o) position. The 15 ×35 mm copper test section was electrically heated by the thin film resistor on the back. The heater assembly was installed to the tip of the rotating arm in the heated water pool at the atmospheric pressure. The bubble behavior was photographed utilizing a high-speed camera through the Pyrex glass spacer. It was observed that the CHF decreased as the surface inclination angle increased and as the gap size decreased in most of the cases. However, the opposing results were obtained at certain surface orientations and gap sizes. Transition angles, at which the CHF changed in a rapid slope, were also detected, which is consistent with the existing literature. A semi-empirical CHF correlation was developed for the inclined narrow rectangular channels through dimensional analysis. The correlation provides with best-estimate CHF values for realistically assessing the thermal margin to failure of the lower head during a severe accident involving relocation of the core material.

  2. de Gennes Narrowing Describes the Relative Motion of Protein Domains

    NASA Astrophysics Data System (ADS)

    Hong, Liang; Smolin, Nikolai; Smith, Jeremy C.

    2014-04-01

    The relative motion of structural domains is essential for the biological function of many proteins. Here, by analyzing neutron scattering data and performing molecular dynamics simulations, we find that interdomain motion in several proteins obeys the principle of de Gennes narrowing, in which the wave vector dependence of the interdomain diffusion coefficient is inversely proportional to the interdomain structure factor. Thus, the rate of interdomain motion is inversely proportional to the probability distribution of the spatial configurations of domains.

  3. Whittier Narrows Flood Control Basin Historic Resources Survey,

    DTIC Science & Technology

    1976-10-15

    noted, had "a good growth of cottonwoods, willows, and other trees, thickets of blackberries , and innumerable wild grape vines; and ...near- by there...leather, tallow for candles, soap, woolens, furniture, tools, utensils, wines, dried fruits and vegetables. At its peak over 20,000 head of cattle bore...Whittier Narrows. Workman prospered as he acquired in time 3,000 head of cattle, 600 horses, developed wheat arowing, vineyards and fruit orchards

  4. Spectral manifestations of polarization action of narrow slit

    NASA Astrophysics Data System (ADS)

    Felde, Ch. V.; Oleksyuk, M. V.; Polyanskii, P. V.

    2013-06-01

    Experimental study of quasimonochromatic and polychromatic ("white-light") radiation, that diffracts on very narrow (in order of several wavelength) slit in metallic screen is represented. It is shown that for monochromatic light slit acts similarly to linear analyzer. And for polychromatic light polarization action of a slit is accompanied with a spectral effect, viz. considerable predomination of blue component in total radiation. The chromascopic technique is applied for analyzing this spectral effect.

  5. Photonic bandgap narrowing in conical hollow core Bragg fibers

    SciTech Connect

    Ozturk, Fahri Emre; Yildirim, Adem; Kanik, Mehmet; Bayindir, Mehmet

    2014-08-18

    We report the photonic bandgap engineering of Bragg fibers by controlling the thickness profile of the fiber during the thermal drawing. Conical hollow core Bragg fibers were produced by thermal drawing under a rapidly alternating load, which was applied by introducing steep changes to the fiber drawing speed. In conventional cylindrical Bragg fibers, light is guided by omnidirectional reflections from interior dielectric mirrors with a single quarter wave stack period. In conical fibers, the diameter reduction introduced a gradient of the quarter wave stack period along the length of the fiber. Therefore, the light guided within the fiber encountered slightly smaller dielectric layer thicknesses at each reflection, resulting in a progressive blueshift of the reflectance spectrum. As the reflectance spectrum shifts, longer wavelengths of the initial bandgap cease to be omnidirectionally reflected and exit through the cladding, which narrows the photonic bandgap. A narrow transmission bandwidth is particularly desirable in hollow waveguide mid-infrared sensing schemes, where broadband light is coupled to the fiber and the analyte vapor is introduced into the hollow core to measure infrared absorption. We carried out sensing simulations using the absorption spectrum of isopropyl alcohol vapor to demonstrate the importance of narrow bandgap fibers in chemical sensing applications.

  6. Riparian deforestation, stream narrowing, and loss of stream ecosystem services

    PubMed Central

    Sweeney, Bernard W.; Bott, Thomas L.; Jackson, John K.; Kaplan, Louis A.; Newbold, J. Denis; Standley, Laurel J.; Hession, W. Cully; Horwitz, Richard J.

    2004-01-01

    A study of 16 streams in eastern North America shows that riparian deforestation causes channel narrowing, which reduces the total amount of stream habitat and ecosystem per unit channel length and compromises in-stream processing of pollutants. Wide forest reaches had more macroinvertebrates, total ecosystem processing of organic matter, and nitrogen uptake per unit channel length than contiguous narrow deforested reaches. Stream narrowing nullified any potential advantages of deforestation regarding abundance of fish, quality of dissolved organic matter, and pesticide degradation. These findings show that forested stream channels have a wider and more natural configuration, which significantly affects the total in-stream amount and activity of the ecosystem, including the processing of pollutants. The results reinforce both current policy of the United States that endorses riparian forest buffers as best management practice and federal and state programs that subsidize riparian reforestation for stream restoration and water quality. Not only do forest buffers prevent nonpoint source pollutants from entering small streams, they also enhance the in-stream processing of both nonpoint and point source pollutants, thereby reducing their impact on downstream rivers and estuaries. PMID:15381768

  7. Riparian deforestation, stream narrowing, and loss of stream ecosystem services.

    PubMed

    Sweeney, Bernard W; Bott, Thomas L; Jackson, John K; Kaplan, Louis A; Newbold, J Denis; Standley, Laurel J; Hession, W Cully; Horwitz, Richard J

    2004-09-28

    A study of 16 streams in eastern North America shows that riparian deforestation causes channel narrowing, which reduces the total amount of stream habitat and ecosystem per unit channel length and compromises in-stream processing of pollutants. Wide forest reaches had more macroinvertebrates, total ecosystem processing of organic matter, and nitrogen uptake per unit channel length than contiguous narrow deforested reaches. Stream narrowing nullified any potential advantages of deforestation regarding abundance of fish, quality of dissolved organic matter, and pesticide degradation. These findings show that forested stream channels have a wider and more natural configuration, which significantly affects the total in-stream amount and activity of the ecosystem, including the processing of pollutants. The results reinforce both current policy of the United States that endorses riparian forest buffers as best management practice and federal and state programs that subsidize riparian reforestation for stream restoration and water quality. Not only do forest buffers prevent nonpoint source pollutants from entering small streams, they also enhance the in-stream processing of both nonpoint and point source pollutants, thereby reducing their impact on downstream rivers and estuaries.

  8. Searching for Variability of NV Intrinsic Narrow Absorption Line Systems

    NASA Astrophysics Data System (ADS)

    Rodruck, Michael; Charlton, Jane C.; Ganguly, Rajib

    2017-01-01

    The majority of quasar absorption line systems with NV detected are found within the associated region (within 5000km/s of the quasar redshift) and many/most are believed to be related to the quasar accretion disk wind or outflows. The most definite evidence that these NV absorbers are "intrinsic" is partial covering of the quasar continuum source and/or broad line region. Over 50 quasars containing NV narrow absorption lines have observations obtained at different times with the Keck/HIRES and the VLT/UVES spectrographs at high resolution. The interval between these observations range from months to a decade in the quasar rest frame. While variability is common for intrinsic broad and mini-broad absorption lines, intrinsic narrow absorption lines have been found to be less likely to vary, though systematic studies with large, high quality datasets have been limited. The variability timescales are useful for deriving gas densities and thus the distances from the central engines. This is important in mapping the quasar surroundings, understanding the accretion disk wind mechanism, and assessing the effect the wind has on the galaxy surroundings. We report on the results of a systematic study of variability of NV NALs, exploiting the overlap of targets for observations in the archives of Keck and VLT, and discuss the consequences for interpretation of the origin of intrinsic narrow absorption lines.

  9. Narrow-band Jovian Kilometric Radiation: a New Radio Component

    NASA Technical Reports Server (NTRS)

    Kaiser, M. L.; Desch, M. D.

    1980-01-01

    A new component of Jupiter's radio spectrum is investigated. The component emits in a very narrow bandwidth (less than or equal to 40 kHz) near 100 kHz. Its waveform is a very smooth and gradual rise and subsequent fall in intensity, usually over two hours. The emission is polarized with left hand polarization associated with the Jovian northern magnetic hemisphere and right hand with the south. The emissions deviation from a strict system 3 rotation period repetition rate is examined. The emission source of the narrow band component which rotates 3 to 5 percent slower than all other forms of Jovian radio emission is determined from propagation considerations, coupled with the observed lack of corotation, to a source region near the equatorial plane at the outer edge of the Io plasma torus. The narrow band KOM (nKOM) form is examined using observations from the PRA instrument. The spectrum and occurrence statistics are described and contrasted with the tapered or broadband KOM (bKOM) characteristics.

  10. Social anxiety and narrowed attentional breadth toward faces.

    PubMed

    Yoon, K Lira; Vidaurri, Desirae N; Joormann, Jutta; De Raedt, Rudi

    2015-12-01

    The amount of information that can be perceived and processed will be partly determined by attentional breadth (i.e., the scope of attention), which might be narrowed in social anxiety due to a negative attentional bias. The current study examined the effects of stimulus valence on socially anxious individuals' attentional breadth. Seventy-three undergraduate students completed a computerized dual-task experiment during which they were simultaneously presented with a facial picture at the center of the screen and a black circle (i.e., a target) at the periphery. Participants' task was to indicate the gender of the model in the picture and the location of the peripheral target. The peripheral target was presented either close to or far from the central picture. Higher levels of social anxiety were significantly associated with greater difficulties detecting the target presented far from the central facial pictures, suggesting that social anxiety is associated with narrowed attentional breadth around social cues. Narrowing of attentional breadth among socially anxious individuals might hamper their ability to process all available social cues, thereby perpetuating social anxiety. (c) 2015 APA, all rights reserved).

  11. Infrared Perfect Ultra-narrow Band Absorber as Plasmonic Sensor

    NASA Astrophysics Data System (ADS)

    Wu, Dong; Liu, Yumin; Li, Ruifang; Chen, Lei; Ma, Rui; Liu, Chang; Ye, Han

    2016-11-01

    We propose and numerically investigate a novel perfect ultra-narrow band absorber based on a metal-dielectric-metal-dielectric-metal periodic structure working at near-infrared region, which consists of a dielectric layer sandwiched by a metallic nanobar array and a thin gold film over a dielectric layer supported by a metallic film. The absorption efficiency and ultra-narrow band of the absorber are about 98 % and 0.5 nm, respectively. The high absorption is contributed to localized surface plasmon resonance, which can be influenced by the structure parameters and the refractive index of dielectric layer. Importantly, the ultra-narrow band absorber shows an excellent sensing performance with a high sensitivity of 2400 nm/RIU and an ultra-high figure of merit of 4800. The FOM of refractive index sensor is significantly improved, compared with any previously reported plasmonic sensor. The influences of structure parameters on the sensing performance are also investigated, which will have a great guiding role to design high-performance refractive index sensors. The designed structure has huge potential in sensing application.

  12. [Cardiac resynchronization therapy in patients with narrow QRS].

    PubMed

    Chapurnykh, A V; Mochalova, O V; Solov'eva, N V; Riabov, A S; Solov'ev, O V; Nazarov, D E

    2011-01-01

    Conduction delay affecting 30-50% of patients with NYHA class III-IV heart failure (HF) mainly results from left bundle branch block and leads to deterioration of cardiac contractility through intra- and interventricular dyssynchrony. Cardiac resynchronization therapy (CRT) has class I recommendation for the treatment of patients with severe systolic HF who have left ventricular ejection fraction less or equal to 35%, QRS duration greater than or equal to 120 ms. Nevertheless some studies have shown that systolic asynchrony is present in 27-43% of HF patients with narrow QRS complexes (defined as <120 ms). We present here results of CRT in 20 patients (13 male, 7 female). Main indication for CRT was ventricular dyssynchrony during basic cardiac rhythm or cardiac pacing independently of QRS width. In 4 patients width of QRS complex was less than 120 ms, in 3 QRS varied from 120 to 149 ms pts and in 13 it was equal to or exceeded 150 ms. CRT in patients with narrow QRS resulted in clinical improvement associated with increase of cardiac contractility and decrease of left ventricular end systolic volume. This allows to conclude that CRT can be beneficial for HF patients with narrow QRS and ventricular dyssynchrony.

  13. Identification of chromosome regions controlling seed storage proteins of narrow-leafed lupin (Lupinus angustifolius).

    PubMed

    Li, Xin; Islam, Shahidul; Yang, Huaan; Ma, Wujun; Yan, Guijun

    2013-05-01

    Narrow-leafed lupin (Lupinus angustifolius L.) is a valuable legume crop for animal feed and human health food because of its high proteins content. However, the genetics of seed storage proteins is unclear, limiting further improvement of protein quantity and quality. In this study, matrix-assisted laser desorption/ionization time of flight mass spectrometry was used for the first time to analyze lupin seed storage proteins and the spectra generated was treated as markers to investigate the chromosome locations controlling seed storage proteins in the narrow-leafed lupin. In a recombinant inbred line population of 89 individuals, 48 polymorphic protein peaks were identified and seven of which were successfully mapped onto four existing linkage groups: two on NLL-04, three on NLL-05, one on NLL-07 and one on NLL-14, with LOD values ranging from 2.6 to 7.7 confirming a significant linkage. Most protein-based markers showed distorted segregation and were failed to be integrated into the reference map. Among them, 31 were grouped into six clusters and the other ten were totally unlinked. This study provides a significant clue to study the comparative genomics/proteomics among legumes as well as for protein marker-assisted breeding. The distribution pattern of genes controlling seed storage protein revealed in this study probably exists universally among legumes or even all plants and animals. Whether genes controlling seed storage protein share the same gene expression pattern controlling other enzymes and what is the mechanism behind it are the questions which remain to be answered in the future.

  14. Narrowing the DiGeorge Region (DGCR) using DGS-VCFS associated translocation breakpoints

    SciTech Connect

    Li, M.; Budarf, M.L.; Sellinger, B.

    1994-09-01

    The initial evidence linking 22q11 with DiGeorge syndrome (DGS) came from identification of DGS patients with unbalanced translocations resulting in loss of 22pter{r_arrow}q11. Molecular detection of 22q11.2 deletions in over 85% of our DGS and VCFS patient population confirms the role of 22q11 haploinsufficiency in the etiology of these two disorders. In the present study, DGS/VCFS-associated translocations are used to further refine the DGS minimal critical region. We obtained previously described cell lines: GM5878 [t(10;22)], GM5401 [t(4;22)], GM0980 [t(11;22)], and LGL6012 [t(20;22)]. Lymphoblastoid cell lines were established from two new unbalanced translocations, [t(15;22)(p11;q11)] and [t(12;22)(p13.31;q11.2)] and from a family with balanced and unbalanced forms of a t(X;22)(p22.31;q11). All probands are missing 22pter{r_arrow}q11 and have mild dysmorphia, short stature, frequent infections and developmental delay. Cleft palate was also seen in the two sibs resulting from malsegregation of the t(X;22)mat. These seven breakpoints were positioned by FISH utilizing cosmids from 22q11.2. The cosmids include the loci D22S75 (N25), D22S66 (160b), and D22S259 (R32) which we have previously used to define the DGS/VCFS commonly deleted region. The t(12;22) and t(20;22) breakpoints map distal to R32. Four translocation breakpoints map between N25 and R32: CEN - N25 - t(15;22) - t(11;22) - t(10;22) - 160b - t(4;22) - R32 - TEL. The t(X;22) breakpoint lies between the proximal flanking locus D22S36 (pH11) and N25, suggesting that genes critical to the phenotype may lie between these markers. However, the der(X) is inactivated in both sibs, raising the possibility that spreading of inactivation to the translocated, 22-derived segment may silence gene(s) distal to the breakpoint. Thus, the DGCR has been narrowed to a region between D22S36 and the t(15;22) breakpoint. This enables us to narrow the search for the critical gene(s) deleted in patients with DGS and VCFS.

  15. Nasal base narrowing: the combined alar base excision technique.

    PubMed

    Foda, Hossam M T

    2007-01-01

    To evaluate the role of the combined alar base excision technique in narrowing the nasal base and correcting excessive alar flare. The study included 60 cases presenting with a wide nasal base and excessive alar flaring. The surgical procedure combined an external alar wedge resection with an internal vestibular floor excision. All cases were followed up for a mean of 32 (range, 12-144) months. Nasal tip modification and correction of any preexisting caudal septal deformities were always completed before the nasal base narrowing. The mean width of the external alar wedge excised was 7.2 (range, 4-11) mm, whereas the mean width of the sill excision was 3.1 (range, 2-7) mm. Completing the internal excision first resulted in a more conservative external resection, thus avoiding any blunting of the alar-facial crease. No cases of postoperative bleeding, infection, or keloid formation were encountered, and the external alar wedge excision healed with an inconspicuous scar that was well hidden in the depth of the alar-facial crease. Finally, the risk of notching of the alar rim, which can occur at the junction of the external and internal excisions, was significantly reduced by adopting a 2-layered closure of the vestibular floor (P = .01). The combined alar base excision resulted in effective narrowing of the nasal base with elimination of excessive alar flare. Commonly feared complications, such as blunting of the alar-facial crease or notching of the alar rim, were avoided by using simple modifications in the technique of excision and closure.

  16. Antilisterial Bacteriocin from Lactobacillus rhamnosus CJNU 0519 Presenting a Narrow Antimicrobial Spectrum

    PubMed Central

    2015-01-01

    A lactic acid bacterium presenting antimicrobial activity against a Lactobacillus acidophilus strain used for eradication of acid inhibition was isolated from a natural cheese. The 16S rRNA gene sequence of the isolate best matched with a strain of L. rhamnosus and was designated L. rhamnosus CJNU 0519. The antimicrobial activity of the partially purified bacteriocin of CJNU 0519 was abolished when treated with a protease, indicating the protein nature of the bacteriocin. The partially purified bacteriocin (rhamnocin 519) displayed a narrow antimicrobial activity against L. acidophilus, Listeria monocytogenes, and Staphylococcus aureus among several tested bacterial and yeast strains. Rhamnocin 519 in particular showed strong bactericidal action against L. monocytogenes. PMID:26761811

  17. Control of flux by narrow passages and hidden targets in cellular biology.

    PubMed

    Holcman, D; Schuss, Z

    2013-07-01

    Critical biological processes, such as synaptic plasticity and transmission, activation of genes by transcription factors, or double-strained DNA break repair, are controlled by diffusion in structures that have both large and small spatial scales. These may be small binding sites inside or on the surface of the cell, or narrow passages between subcellular compartments. The great disparity in spatial scales is the key to controlling cell function by structure. We report here recent progress on resolving analytical and numerical difficulties in extracting properties from experimental data, from biophysical models, and from Brownian dynamics simulations of diffusion in multi-scale structures. This progress is achieved by developing an analytical approximation methodology for solving the model equations. The reported results are applied to analysis and simulations of subcellular processes and to the quantification of their biological functions.

  18. Coupling Through Tortuous Path Narrow Slot Apertures into Complex Cavitivies

    SciTech Connect

    Jedlicka, Russell P.; Castillo, Steven P.; Warne, Larry K.

    1999-07-26

    A hybrid FEM/MoM model has been implemented to compute the coupling of fields into a cavity through narrow slot apertures having depth. The model utilizes the slot model of Warne and Chen [23]-[29] which takes into account the depth of the slot, wall losses, and inhomogeneous dielectrics in the slot region. The cavity interior is modeled with the mixed-order, covariant-projection hexahedral elements of Crowley [32]. Results are given showing the accuracy and generality of the method for modeling geometrically complex slot-cavity combinations.

  19. Forced motion of an elastic filament through a narrow tube

    NASA Astrophysics Data System (ADS)

    Freund, L. B.

    2015-12-01

    A polymer filament consisting of many similar molecules linked in a one-dimensional array is very flexible. As a result, shapes with a relatively large curvature can be accommodated elastically. When loosely confined in a thermal environment, such a flexible strand may become tangled owing to its flexibility. When confined within a narrow "tube" over its full length, a flexible molecule may behave quite differently. Here, we consider the qualitative nature of deformation of an individual filament when confined within a tube. Commonly the tube is formed within the cluster by a large number of surrounding filaments of the same type.

  20. Narrow-line magneto-optical trap for dysprosium atoms.

    PubMed

    Maier, T; Kadau, H; Schmitt, M; Griesmaier, A; Pfau, T

    2014-06-01

    We present our technique to create a magneto-optical trap (MOT) for dysprosium atoms using the narrow-line cooling transition at 626 nm to achieve suitable conditions for direct loading into an optical dipole trap. The MOT is loaded from an atomic beam via a Zeeman slower using the strongest atomic transition at 421 nm. With this combination of two cooling transitions we can trap up to 2.0·10(8) atoms at temperatures down to 6 μK. This cooling approach is simpler than present work with ultracold dysprosium and provides similar starting conditions for a transfer to an optical dipole trap.

  1. The Meteorology of Storms that Produce Narrow Bipolar Events

    NASA Technical Reports Server (NTRS)

    Lang, Timothy; McCaul, Bill; Fuchs, Brody; Cummer, Steve

    2013-01-01

    Narrow Bipolar Event's (NBE) are compact (< 2 km), powerful (> 10 kW in VHF), and impulsive (approx 10 micro s) electrical discharges in thunderstorms, also known as compact intracloud discharges (CIDs). Can be either positive or negative polarity and have distinctive broadband waveform signatures sometimes confused for +CGs in the past by NLDN and other networks. NBEs are related to lightning but are likely optically "dark". As revealed by VHF sensors (both satellite and ground): (1) The most powerful lightning-­-related VHF sources observed (2) Tend to occur at the beginning of intracloud discharges (3) Difficult to estimate altitude properly due to receiver saturation.

  2. Torsional instability in suspension bridges: The Tacoma Narrows Bridge case

    NASA Astrophysics Data System (ADS)

    Arioli, Gianni; Gazzola, Filippo

    2017-01-01

    All attempts of aeroelastic explanations for the torsional instability of suspension bridges have been somehow criticised and none of them is unanimously accepted by the scientific community. We suggest a new nonlinear model for a suspension bridge and we perform numerical experiments with the parameters corresponding to the collapsed Tacoma Narrows Bridge. We show that the thresholds of instability are in line with those observed the day of the collapse. Our analysis enables us to give a new explanation for the torsional instability, only based on the nonlinear behavior of the structure.

  3. Venus - Complex Network of Narrow Fractures Near Hestia Rupes Region

    NASA Image and Video Library

    1996-10-23

    This image from NASA Magellan spacecraft covers region near Hestia Rupes on the northwestern corner of Aphrodite Terra. The complex network of narrow (<1 kilometer) fractures in the center of the image extends for approximately 50 kilometers (31 miles). This network exhibits tributary-like branches similar to those observed in river systems on Earth. However, the angular intersections of tributaries suggest tectonic control. These features appear to be due to drainage of lava along preexisting fractures and subsequent collapse of the surface. The underlying tectonic fabric can be observed in the northeast trending ridges which predate the plains. http://photojournal.jpl.nasa.gov/catalog/PIA00469

  4. Tunable polarization plasma channel undulator for narrow bandwidth photon emission

    DOE PAGES

    Rykovanov, S. G.; Wang, J. W.; Kharin, V. Yu.; ...

    2016-09-09

    The theory of a plasma undulator excited by a short intense laser pulse in a parabolic plasma channel is presented. The undulator fields are generated either by the laser pulse incident off-axis and/or under the angle with respect to the channel axis. Linear plasma theory is used to derive the wakefield structure. It is shown that the electrons injected into the plasma wakefields experience betatron motion and undulator oscillations. Optimal electron beam injection conditions are derived for minimizing the amplitude of the betatron motion, producing narrow-bandwidth undulator radiation. Polarization control is readily achieved by varying the laser pulse injection conditions.

  5. Are Narrow Line Seyfert 1 Galaxies Viewed Pole-on?

    DTIC Science & Technology

    2011-04-01

    0.2’’ respectively. Figure 1 displays the position of each slit over a Barbosa et al. (2009) GMOS IFU image of the [S III] flux (which originates...C. Winge, H. Schmitt: Gemini/ GMOS IFU gas velocity ’tomography’ of the narrow line region of nearby active galaxies, MNRAS, 396 (2009) 2. [2] D...1995) 81. 4 P o S ( N L S 1 ) 0 5 0 Are NLS1s Pole-on? Travis C. Fischer 5 Figure 1: NGC 4051 GMOS IFU image showing integrated [SIII] flux

  6. Bayesian-Augmented Identification of Stars in a Narrow View

    NASA Technical Reports Server (NTRS)

    Clouse, Daniel; Padgett, Curtis

    2004-01-01

    An algorithm for the identification of stars from a charge-coupled-device (CCD) image of a star field has been extended for use with narrower field-of-view images. Previously, the algorithm had been shown to be effective at a field of view of 8 degrees. This work augments the earlier algorithm using Bayesian decision theory. The new algorithm is shown to be capable of effective star identification down to a field of view of 2 degrees. The algorithm was developed for use in estimating the attitude of a spacecraft and could be used on Earth to help in the identification of stars and other celestial objects for astronomical observations.

  7. Masas de agujeros negros en Narrow Line Seyfert 1

    NASA Astrophysics Data System (ADS)

    Schmidt, E.; Ferreiro, D.; Oio, G.; Vega, L.; Donoso, L.

    We describe two of the ways to estimate black hole masses in AGN, and then we estimate the black hole masses of 13 Narrow Line Seyfert 1 galaxies with the two methods: virial masses, using the correlation found by Greene & Ho (2005, ApJ, 630, 122); and the correlation found by Tremaine et al. (2002, ApJ, 574, 740). For this work we analyzed the optical spectroscopy data we obtained from CASLEO (San Juan). We compare the results obtained through both methods. FULL TEXT IN SPANISH

  8. Tunable polarization plasma channel undulator for narrow bandwidth photon emission

    NASA Astrophysics Data System (ADS)

    Rykovanov, S. G.; Wang, J. W.; Kharin, V. Yu.; Lei, B.; Schroeder, C. B.; Geddes, C. G. R.; Esarey, E.; Leemans, W. P.

    2016-09-01

    The theory of a plasma undulator excited by a short intense laser pulse in a parabolic plasma channel is presented. The undulator fields are generated either by the laser pulse incident off-axis and/or under the angle with respect to the channel axis. Linear plasma theory is used to derive the wakefield structure. It is shown that the electrons injected into the plasma wakefields experience betatron motion and undulator oscillations. Optimal electron beam injection conditions are derived for minimizing the amplitude of the betatron motion, producing narrow-bandwidth undulator radiation. Polarization control is readily achieved by varying the laser pulse injection conditions.

  9. Active Narrow-Band Vibration Isolation of Large Engineering Structures

    NASA Technical Reports Server (NTRS)

    Rahman, Zahidul; Spanos, John

    1994-01-01

    We present a narrow-band tracking control method using a variant of the Least Mean Squares (LMS) algorithm to isolate slowly changing periodic disturbances from engineering structures. The advantage of the algorithm is that it has a simple architecture and is relatively easy to implement while it can isolate disturbances on the order of 40-50 dB over decades of frequency band. We also present the results of an experiment conducted on a flexible truss structure. The average disturbance rejection achieved is over 40 dB over the frequency band of 5 Hz to 50 Hz.

  10. Theory of polaron bandwidth narrowing in organic molecular crystals

    NASA Astrophysics Data System (ADS)

    Hannewald, K.; Stojanović, V. M.; Schellekens, J. M.; Bobbert, P. A.; Kresse, G.; Hafner, J.

    2004-02-01

    We present a theoretical description of polaron bandwidth narrowing in organic molecular crystals. Based on a solution of a Holstein-Peierls model for tightly bound electrons interacting with phonons, an explicit expression for the temperature dependence of the electronic bandwidths is found. This formula generalizes the result of Holstein polaron theory by treating local and nonlocal electron-phonon coupling on equal footing. The usefulness of the method is demonstrated by model studies for oligo-acene crystals from which microscopic insight into the relevance of the different coupling mechanisms is obtained.

  11. Emerging role of narrow band imaging in duodenum

    PubMed Central

    Dutta, Amit Kumar; Chacko, Ashok

    2015-01-01

    Endoscopy using magnification narrow band imaging (mNBI) allows detailed assessment of mucosal surface and vascular pattern. This may help in better identification and prediction of the nature of the lesion. The role of this technology in duodenum is still evolving. Studies have shown that mNBI has high accuracy in predicting villous atrophy in the duodenum. Limited data suggests that this technique can provide additional information on duodenal polyps, nodules and ampullary tumour which can help guide their management. In this paper we describe the technique for duodenal assessment using NBI and review the existing literature evaluating its role in diagnosis of various duodenal pathologies. PMID:26566428

  12. A narrow, mid-mantle plume below southern Africa

    NASA Astrophysics Data System (ADS)

    Sun, Daoyuan; Helmberger, Don; Gurnis, Michael

    2010-05-01

    New waveform tomographic evidence displays a narrow plume-like feature emitting from the top of the large African low-velocity structure in the lower mantle. A detailed SKS wavefield is assembled for a segment along the structure's southern edge by combining multiple events recorded by a seismic array in the Kaapvaal region of southern Africa. With a new processing technique that emphases multi-pathing, we locate a relatively jagged, sloping wall 1000 km high with low velocities near it's basal edge. Forward modeling indicates that the plume's diameter is less than 150 km and consistent with an iso-chemical, low-viscosity plume conduit.

  13. Narrow-band tunable alexandrite laser with passive Q switching

    SciTech Connect

    Tyryshkin, I S; Ivanov, N A; Khulugurov, V M

    1998-06-30

    An alexandrite laser with a self-injection of narrow-band radiation into its cavity was developed. A Fabry - Perot interferometer and a diffraction grating were used as dispersive components in an additional cavity. The cavity was switched by an LiF crystal with F{sub 3}{sup -} colour centres. The laser generated a single pulse of {approx} 180 ns duration and of 1.5 mJ energy, and with a spectrum 5 x 10{sup -3} cm{sup -1} wide. The laser emitted in the spectral range 720 - 780 nm. (lasers, active media)

  14. Taylor dispersion of colloidal particles in narrow channels

    NASA Astrophysics Data System (ADS)

    Sané, Jimaan; Padding, Johan T.; Louis, Ard A.

    2015-09-01

    We use a mesoscopic particle-based simulation technique to study the classic convection-diffusion problem of Taylor dispersion for colloidal discs in confined flow. When the disc diameter becomes non-negligible compared to the diameter of the pipe, there are important corrections to the original Taylor picture. For example, the colloids can flow more rapidly than the underlying fluid, and their Taylor dispersion coefficient is decreased. For narrow pipes, there are also further hydrodynamic wall effects. The long-time tails in the velocity autocorrelation functions are altered by the Poiseuille flow.

  15. Synthesis of very narrow multilayer graphene nanoribbon with turbostratic stacking

    NASA Astrophysics Data System (ADS)

    Negishi, R.; Yamamoto, K.; Kitakawa, H.; Fukumori, M.; Tanaka, H.; Ogawa, T.; Kobayashi, Y.

    2017-05-01

    A multilayer graphene nanoribbon (GNR) less than 20 nm wide was synthesized by overlayer growth of graphene on a GNR template. First, very narrow template GNRs with widths of approximately 10 nm were prepared by unzipping from double-walled carbon nanotubes. Additional 4-5 layers of graphene were then formed on the pristine GNR template by chemical vapor deposition. Raman spectroscopy revealed that the synthesized multilayer GNR had turbostratic stacking without any structural correlation between the graphene layers. A large on/off ratio and a high on-current were observed in field effect transistors fabricated using the synthesized multilayer GNR channel.

  16. Initiation of granular surface flows in a narrow channel

    NASA Astrophysics Data System (ADS)

    Jop, Pierre; Forterre, Yoël; Pouliquen, Olivier

    2007-08-01

    We experimentally investigate how a long granular pile confined in a narrow channel destabilizes when it is inclined above the angle of repose. A uniform flow then develops, which is localized at the free surface. It first accelerates before reaching a steady uniform regime. During this process, an apparent erosion is observed and the thickness of the flowing layer increases. We precisely study the evolution of the vertical velocity profile in this transient regime. The measurements are compared with the prediction of a viscoplastic model [Jop et al., Nature 441, 727 (2006)].

  17. An Injection-seeded Narrow Linewidth Singly Resonant ZGP OPO

    NASA Technical Reports Server (NTRS)

    Yu, Jirong; Barnes, Norman P.; Lee, Hyung R.; Bai, Yingxin

    2006-01-01

    Injection seeding of a singly resonant ZnGeP2 (ZGP) mid-infrared optical parametric oscillator (OPO) using a continuous wave 3.39 micrometers laser and a tunable near-infrared laser has been demonstrated. This ZGP OPO utilizes a bow-tie shape cavity with a partially reflective mirror for injection seeding at the signal wavelength. It produces high energy pulses in the mid-IR range from 4-10 micrometers. The injection seeded OPO provides a narrow idler wavelength linewidth of approximately 1 nm, limited by the measurement resolution of the monochromator.

  18. Narrow linewidth Brillouin laser based on chalcogenide photonic chip.

    PubMed

    Kabakova, Irina V; Pant, Ravi; Choi, Duk-Yong; Debbarma, Sukhanta; Luther-Davies, Barry; Madden, Stephen J; Eggleton, Benjamin J

    2013-09-01

    We present, to the best of our knowledge, the first demonstration of a narrow linewidth, waveguide-based Brillouin laser that is enabled by large Brillouin gain of a chalcogenide chip. The waveguides are equipped with vertical tapers for low-loss coupling. Due to optical feedback for the Stokes wave, the lasing threshold is reduced to 360 mW, which is five times lower than the calculated single-pass Brillouin threshold for the same waveguide. The slope efficiency of the laser is found to be 30%, and the linewidth of 100 kHz is measured using a self-heterodyne method.

  19. Million-line failure distributions for narrow interconnects

    SciTech Connect

    Bartelt, M.C.; Hoyt, J.J.; Bartelt, N.C.; Dike, J.J.; Wolfer, W.G.

    1997-12-01

    The authors examine the distribution of failure times in a simple and computationally efficient, yet reasonably authentic, model of interconnect reliability that allows consideration of statistically significant samples. The model includes an approximate description of the distribution of grain sizes and texture in narrow interconnects, an effective treatment of stress evolution associated with mass transport along grain boundaries, and local relaxation of stresses due to void formation. Failure time distributions for populations of idealized structures are analyzed to aid in interpretation of model behavior.

  20. Fast IMRT with narrow high energy scanned photon beams.

    PubMed

    Andreassen, Björn; Strååt, Sara Janek; Holmberg, Rickard; Näfstadius, Peder; Brahme, Anders

    2011-08-01

    Since the first publications on intensity modulated radiation therapy (IMRT) in the early 1980s almost all efforts have been focused on fairly time consuming dynamic or segmental multileaf collimation. With narrow fast scanned photon beams, the flexibility and accuracy in beam shaping increases, not least in combination with fast penumbra trimming multileaf collimators. Previously, experiments have been performed with full range targets, generating a broad bremsstrahlung beam, in combination with multileaf collimators or material compensators. In the present publication, the first measurements with fast narrow high energy (50 MV) scanned photon beams are presented indicating an interesting performance increase even though some of the hardware used were suboptimal. Inverse therapy planning was used to calculate optimal scanning patterns to generate dose distributions with interesting properties for fast IMRT. To fully utilize the dose distributional advantages with scanned beams, it is necessary to use narrow high energy beams from a thin bremsstrahlung target and a powerful purging magnet capable of deflecting the transmitted electron beam away from the generated photons onto a dedicated electron collector. During the present measurements the scanning system, purging magnet, and electron collimator in the treatment head of the MM50 racetrack accelerator was used with 3-6 mm thick bremsstrahlung targets of beryllium. The dose distributions were measured with diodes in water and with EDR2 film in PMMA. Monte Carlo simulations with GEANT4 were used to study the influence of the electrons transmitted through the target on the photon pencil beam kernel. The full width at half-maximum (FWHM) of the scanned photon beam was 34 mm measured at isocenter, below 9.5 cm of water, 1 m from the 3 mm Be bremsstrahlung target. To generate a homogeneous dose distribution in a 10 x 10 cm2 field, the authors used a spot matrix of 100 equal intensity beam spots resulting in a

  1. Radiative recombination of hot carriers in narrow-gap semiconductors

    SciTech Connect

    Pavlov, N. V.; Zegrya, G. G.

    2012-01-15

    The mechanism of the radiative recombination of hot carriers in narrow-gap semiconductors is analyzed using the example of indium antimonide. It is shown that the CHCC Auger recombination process may lead to pronounced carrier heating at high excitation levels. The distribution functions and concentrations of hot carriers are determined. The radiative recombination rate of hot carriers and the radiation gain coefficient are calculated in terms of the Kane model. It is demonstrated that the radiative recombination of hot carriers will make a substantial contribution to the total radiative recombination rate at high carrier concentrations.

  2. Fatigue failure of materials under narrow band random vibrations. I.

    NASA Technical Reports Server (NTRS)

    Huang, T. C.; Hubbard, R. B.; Lanz, R. W.

    1971-01-01

    A novel approach for the study of fatigue failure of materials under the multifactor influence of narrow band random vibrations is developed. The approach involves the conduction of an experiment in conjunction with various statistical techniques. Three factors including two statistical properties of the excitation or response are considered and varied simultaneously. A minimum of 6 tests for 3 variables is possible for a fractional f actorial design. The four coefficients of the predicting equation can be independently estimated. A look at 3 predicting equations shows the predominant effect of the root mean square stress of the first order equation.

  3. Variability Studies of Narrow Line Seyfert 1 Galaxy

    NASA Technical Reports Server (NTRS)

    Marshall, Hermann

    1994-01-01

    I supported the data reduction and analysis. We found that the source was not as variable as other soft AGN such as the narrow line Sy 1 galaxies (NLSls). The NLSls vary on time scales of days, while the ROSAT data for this target was fairly constant over a week at a time. Thus, it was very important to have a light curve that spanned 60 days as was the case for these ROSAT observations because the power spectral distribution can be established to very low frequencies that are rarely measured.

  4. Narrow line diode laser stacks for DPAL pumping

    NASA Astrophysics Data System (ADS)

    Koenning, Tobias; Irwin, David; Stapleton, Dean; Pandey, Rajiv; Guiney, Tina; Patterson, Steve

    2014-02-01

    Diode pumped alkali metal vapor lasers (DPALs) offer the promise of scalability to very high average power levels while maintaining excellent beam quality, making them an attractive candidate for future defense applications. A variety of gain media are used and each requires a different pump wavelength: near 852nm for cesium, 780nm for rubidium, 766nm for potassium, and 670nm for lithium atoms. The biggest challenge in pumping these materials efficiently is the narrow gain media absorption band of approximately 0.01nm. Typical high power diode lasers achieve spectral widths around 3nm (FWHM) in the near infrared spectrum. With state of the art locking techniques, either internal to the cavity or externally mounted gratings, the spectral width can typically be reduced to 0.5nm to 1nm for kW-class, high power stacks. More narrow spectral width has been achieved at lower power levels. The diode's inherent wavelength drift over operating temperature and output power is largely, but not completely, eliminated. However, standard locking techniques cannot achieve the required accuracy on the location of the spectral output or the spectral width for efficient DPAL pumping. Actively cooled diode laser stacks with continuous wave output power of up to 100W per 10mm bar at 780nm optimized for rubidium pumping will be presented. Custom designed external volume holographic gratings (VHGs) in conjunction with optimized chip material are used to narrow and stabilize the optical spectrum. Temperature tuning on a per-bar-level is used to overlap up to fifteen individual bar spectra into one narrow peak. At the same time, this tuning capability can be used to adjust the pump wavelength to match the absorption band of the active medium. A spectral width of <0.1nm for the entire stack is achieved at <1kW optical output power. Tuning of the peak wavelength is demonstrated for up to 0.15nm. The technology can easily be adapted to other diode laser wavelengths to pump different materials.

  5. Active Narrow-Band Vibration Isolation of Large Engineering Structures

    NASA Technical Reports Server (NTRS)

    Rahman, Zahidul; Spanos, John

    1994-01-01

    We present a narrow-band tracking control method using a variant of the Least Mean Squares (LMS) algorithm to isolate slowly changing periodic disturbances from engineering structures. The advantage of the algorithm is that it has a simple architecture and is relatively easy to implement while it can isolate disturbances on the order of 40-50 dB over decades of frequency band. We also present the results of an experiment conducted on a flexible truss structure. The average disturbance rejection achieved is over 40 dB over the frequency band of 5 Hz to 50 Hz.

  6. Propagation of narrow laser beams in a resonantly absorbing medium

    SciTech Connect

    Petrushevich, Yu V; Starostin, Andrei N

    2000-03-31

    The propagation of a narrow laser beam in a resonantly absorbing medium is analysed. Qualitatively different patterns of the dynamics of a radiation pulse travelling in a medium (depending on conditions of the problem) were obtained by a real three-dimensional nonstationary numerical simulation. The diffraction spreading of a pulse, its compression due to self-focusing, and chaotic beam splitting caused by the development of instability were observed. The simulation results are compared with the experimental data published in the literature. A qualitative agreement is obtained with the observations and conclusions made earlier. (nonlinear optical phenomena and devices)

  7. The Narrow-Field Telescope Science Case: A Proposal

    NASA Astrophysics Data System (ADS)

    Richer, M. G.

    2007-06-01

    Based upon the capabilities that are likely to be available from space and terrestrial observatories around 2015-2020 and the traditional interests of the Mexican astronomical community, I propose that the narrow-field telescope (NFT) be dedicated to high resolution spectroscopy covering wavelengths from the optical to the mid-infrared and adaptive optics imaging and spectroscopy (medium to high spectral resolution) in the near-infrared. These capabilities would permit studying the processes responsible for galaxy evolution after the epoch of mass assembly: the development of galactic structure, star formation, stellar structure and mass distributions, the kinematics and chemical composition of stars and the interstellar medium (ISM).

  8. Small ICBM area narrowing report. Executive summary. Summary report

    SciTech Connect

    Not Available

    1986-01-01

    This Area Narrowing Report Summarizes the results of the Comprehensive Siting Analysis Process for the Hard Mobile Launcher in Random Movement, Hard Mobile Launcher at Minuteman Facilities, and Hard Silo in Patterned Array basing modes of the Small Intercontinental Ballistic Missile (ICBM) system. Specifically, this report provides an overview of the system description; discusses technical, operational, legal, and policy siting criteria; describes the rationale and process for elimination of potential locations; and identifies potential locations for each basing mode that remain under consideration for deployment of the system.

  9. Oscillatory quantum interference effects in narrow-gap semiconductor heterostructures

    NASA Astrophysics Data System (ADS)

    Lillianfeld, R. B.; Kallaher, R. L.; Heremans, J. J.; Chen, Hong; Goel, N.; Chung, S. J.; Santos, M. B.; Van Roy, W.; Borghs, G.

    2010-01-01

    We investigate quantum interference phenomena in narrow bandgap semiconductors under strong spin-orbit interaction, by measuring the magnetoresistance across mesoscopic closed-path structures fabricated in two-dimensional electron systems. We discuss our results in terms of four quantum interference effects brought about by geometric phases acquired by the electron wave functions: the Aharonov-Bohm phase, the Altshuler-Aronov-Spivak effect, the Berry's phase due to the evolution of the spin degree of freedom, and the Aharonov-Casher phase.

  10. When alcohol narrows the field of focal attention.

    PubMed

    Harvey, Alistair J

    2016-01-01

    The aim of this study was to measure the extent to which alcohol intoxication restricts the scope of attention in the visual field. A group of intoxicated (n = 31; mean BAC ≈ .08%) and placebo control (n = 31; mean BAC ≈ .00%) participants were required to correctly identify visual probes while performing two verbal categorization tasks: one designed to widen the scope of visual attention on to each stimulus word, the other to narrow attention on to the central letter of each word. Response times to surprise probes interpolated between categorization trials were measured and these catch trials could appear in any of the stimulus word letter positions. As predicted by alcohol myopia theory (AMT), which assumes that the drug narrows focal attention, intoxicated participants made slower responses than the sober controls to probes displayed in non-central letter positions, although right-field probe reaction times (RTs) were slower than those for left-field targets. This response asymmetry and the wider theoretical implications of these findings are discussed.

  11. Linewidth Narrowing for 31Phosphorus MRI of Bones

    NASA Astrophysics Data System (ADS)

    Frey, Merideth; Barrett, Sean

    2011-03-01

    Bone is a particularly challenging tissue to study with conventional MRI given the relatively low water density and wider linewidths of its solid components. Recent fundamental research in quantum computing gave rise to a new NMR pulse sequence that can be used to narrow the broad NMR spectrum of solids. Here we narrow the spectrum of the 31 P in natural bone mineral (by a factor of up to 1600x). This technique offers a new route to do high spatial resolution, 3D 31 P MRI of bone which complements conventional MRI and x-ray based techniques to study bone physiology and structure. Thus far we have used our pulse sequence to do high spatial resolution (sub-250 μ m)3 3 D 31 P MRI of ex vivo dry bovine cortical bones, wet procine rib bones, and wet rabbit femoral bones at 4T. We have also explored the use of compressive sampling to push imaging time down to less than two hours without distracting artifacts. F. W. Wehrli, J. MRI 25, 390 (2007); S. Anumula et al., Bone 42, 405 (2008); D. Idiyatullin et al., J. Mag Res 193, 267 (2008); E.E. Sigmund et al., NMR Biomed 22, 436 (2009); Y. Wu et al., J. MRI 31, 954 (2010)

  12. Formation of wind-driven ice bridges in narrow straits

    NASA Astrophysics Data System (ADS)

    Rallabandi, Bhargav; Zheng, Zhong; Winton, Michael; Stone, Howard A.

    2016-11-01

    An ice bridge is a static arch made of tightly packed ice that can be formed when sea ice flows through a narrow strait between landmasses. The formation of a stable ice arch prevents the further flow of sea ice into warmer oceans, and therefore plays an important role in the regulation of the local climate and ecology and to an extent, the mass balance of Arctic ice. While ice bridges are a seasonal phenomenon in many parts of the Canadian Archipelago, the process of their formation and breakup is poorly understood. Using thin-layer theory along with dynamic sea ice models widely used in climate modeling, we develop a reduced-order description of wind-driven ice bridge formation in long, narrow straits. Our theory predicts a critical static condition for arrested flow that involves the ice properties (thickness and compactness), the geometry of the channel, and the magnitude of the wind stress. Further, we show that in a channel of varying shape and under a constant wind stress, a spatially uniform ice field evolves towards a steady state with discontinuities in its properties, consistent with observed mechanisms of ice bridge formation. The reduced-order model thus provides a predictive tool for the flow and stoppage of sea ice in straits.

  13. Electronic characterization of defects in narrow gap semiconductors

    NASA Technical Reports Server (NTRS)

    Patterson, James D.

    1993-01-01

    The study of point defects in semiconductors has a long and honorable history. In particular, the detailed understanding of shallow defects in common semiconductors traces back to the classic work of Kohn and Luttinger. However, the study of defects in narrow gap semiconductors represents a much less clear story. Here, both shallow defects (caused by long range potentials) and deep defects (from short range potentials) are far from being completely understood. In this study, all results are calculational and our focus is on the chemical trend of deep levels in narrow gap semiconductors. We study substitutional (including antisite), interstitial and ideal vacancy defects. For substitutional and interstitial impurities, the efects of relaxation are included. For materials like Hg(1-x)Cd(x)Te, we study how the deep levels vary with x, of particular interest is what substitutional and interstitial atoms yield energy levels in the gap i.e. actually produce deep ionized levels. Also, since the main technique utilized is Green's functions, we include some summary of that method.

  14. Black Hole-Bulge Relation for Narrow-Line Objects

    NASA Astrophysics Data System (ADS)

    Bian, Wei-Hao; Zhao, Yong-Heng

    2003-02-01

    It has been thought that narrow-line Seyfert 1 galaxies are likely to be in the early stages of the evolution of active galaxies. To test this suggestion, the ratios of the central massive black hole (MBH) mass to the bulge mass (Mbh/Mbulge) were estimated for 22 Narrow Line AGNs (NL AGNs). It is found that NL AGNs appear to have genuinely lower MBH/Bulge mass ratio (Mbh/Mbulge). The mean log (Mbh/Mbulge) for 22 NL AGNs is -3.9 ± 0.07, which is an order of magnitude lower than that for Broad Line AGNs and quiescent galaxies. We suggest a nonlinear MBH/Bulge relation and find there exists a relation between the Mbh / Mbulge and the velocity dispersion, σ, derived from the [O III ] width. A scenario of MBH growth for NL AGNs is one of our interpretations of the nonline ar MBH/Bulge relation. The MBH growth timescales for 22 NL AGNs were calculated, with a mean value (1.29 ± 0.24) × 108 yr. Another plausible interpretation is also possible: that NL AGNs occur in low-Mbulge galaxies and that in such galaxies Mbh/Mbulge is lower than that in galaxies with a higher Mbulge, if we consider that NL AGNs already have their ``final'' Mbh/Mbulge. More information of the bulge in NL AGNs is needed to clarify the black hole-bulge relation.

  15. Thermal Design of the Cassini Narrow Angle Camera

    NASA Technical Reports Server (NTRS)

    Hoffman, Pamela

    1994-01-01

    The Narrow Angle Camera (NAC) is one of two cameras in the Imaging Science Subsystem (ISS) on the Cassini Spacecraft (S/C), the second camera is a Voyager-inherited Wide Angle Camera (WAC). Cassini is currently planned to be launched in October 1997 and will arrive at Saturn for a four year tour in June 2004. The Narrow Angle Optics are a Ritchey Chretien type Optics, has a focal length of 2000 mm, a relative aperture of f/10.5, a spectral range of 200 to 1100 nm, 24 filters, a pixel field of view of 6.0 microradian/pixel, and has a field of view of 3.5 x 3.5 degrees. The sensor is a Charged Couple Device (CCD), 1024 x 1024 pixels with a pixel size of 12 x 12 um, a full well greater than 50,000 e-, on chip processing of up to 800,000 e- pixel summation, a dark current of less than 0.1 e-/pixel/sec at operating temperature, and a charge transfer efficiency of 0.99999 at operating temperature...

  16. Dynamics of an oscillating bubble in a narrow gap.

    PubMed

    Azam, Fahad Ibn; Karri, Badarinath; Ohl, Siew-Wan; Klaseboer, Evert; Khoo, Boo Cheong

    2013-10-01

    The complex dynamics of a single bubble of a few millimeters in size oscillating inside a narrow fluid-filled gap between two parallel plates is studied using high-speed videography. Two synchronized high-speed cameras were used to observe both the side and front views of the bubble. The front-view images show bubble expansion and collapse with the formation of concentric dark and bright rings. The simultaneous recordings reveal the mechanism behind these rings. The side-view images reveal two different types of collapse behavior of the bubble including a previously unreported collapse phenomenon that is observed as the gap width is changed. At narrow widths, the bubble collapses towards the center of the gap; when the width is increased, the bubble splits before collapsing towards the walls. The bubble dynamics is also observed to be unaffected by the hydrophobic or hydrophilic nature of the plate surface due to the presence of a thin film of liquid between each of the plates and the bubble throughout the bubble lifetime. It is revealed that such systems do not behave as quasi-two-dimensional systems; three-dimensional effects are important.

  17. Subwavelength-Sized Narrow-Band Anechoic Waveguide Terminations

    NASA Astrophysics Data System (ADS)

    Santillán, Arturo; Ćrenlund, Emil; Bozhevolnyi, Sergey I.

    2016-11-01

    We propose and demonstrate the use of a pair of detuned acoustic resonators to efficiently absorb narrow-band sound waves in a terminated waveguide. The suggested configuration is relatively simple and advantageous for usage at low frequencies, since the dimensions of the resonators are very small compared to the wavelength. We present a theoretical description based on lumped parameters to calculate the absorption coefficient, which agrees very well with experimental data. The experimental results verify that the anechoic (reflection approximately -38 dB ) narrow-band (Δ f /f ˜0.1 ) termination with deeply subwavelength (<λ /10 ) sizes can be realized at a target frequency, suggesting thereby applications for noise control and sensing. As an illustration of possible applications for sound absorption in a room, we demonstrate by use of numerical simulations that a given axial resonant excitation in a room can be practically eliminated. Thus, a reduction of approximately 24 dB in the average acoustic energy is achieved in the room when using only four Helmholtz resonators. We also discuss various scenarios of noise control in rooms.

  18. Superscattering-enhanced narrow band forward scattering antenna

    NASA Astrophysics Data System (ADS)

    Hu, De-Jiao; Zhang, Zhi-You; Du, Jing-Lei

    2015-10-01

    We present a narrow band forward scattering optical antenna which is based on the excitation of distinctive whispering gallery modes (WGMs). The antenna is composed of three coaxial cylinder layers: a dielectric layer is sandwiched between a metallic core and cladding. Owing to the destructive interference between the scattering of the outer metallic cladding and the WGM in the backward direction, the power flow in the forward direction is increased. Simulation and analysis show that in proper geometry conditions, the cavity can be tuned into a superscattering state. At this state, both the zeroth and the first order of WGM are excited and contribute to the total scattering. It is shown that the power ratio (power towards backward divided by power towards forward) can be enhanced to about 27 times larger than that for a non-resonant position by the superscattering. Owing to the confinement of the cladding to WGMs, the wavelength range of effective forward scattering is considerably narrow (about 15 nm). Project supported by the National Natural Science Foundation of China (Grant No. 61377054), the Collaborative Innovation Foundation of Sichuan University, China (Grant No. XTCX 2013002), and the International Cooperation and Exchange of Science and Technology Project in Sichuan Province, China (Grant No. 2013HH0010).

  19. Pathogenesis of laryngeal narrowing in patients with multiple system atrophy

    PubMed Central

    Isono, Shiroh; Shiba, Keisuke; Yamaguchi, Mika; Tanaka, Atsuko; Hattori, Takamichi; Konno, Akiyoshi; Nishino, Takashi

    2001-01-01

    We do not fully understand the pathogenesis of nocturnal laryngeal stridor in patients with multiple system atrophy (MSA). Recent studies suggest that inspiratory thyroarytenoid (TA) muscle activation has a role in the development of the stridor.The breathing pattern and firing timing of TA muscle activation were determined in ten MSA patients, anaesthetized with propofol and breathing through the laryngeal mask airway, while the behaviour of the laryngeal aperture was being observed endoscopically.Two distinct breathing patterns, i.e. no inspiratory flow limitation (no-IFL) and IFL, were identified during the measurements. During IFL, significant laryngeal narrowing was observed leading to an increase in laryngeal resistance and end-tidal carbon dioxide concentration. Development of IFL was significantly associated with the presence of phasic inspiratory activation of TA muscle. Application of continuous positive airway pressure suppressed the TA muscle activation.The results indicate that contraction of laryngeal adductors during inspiration narrows the larynx leading to development of inspiratory flow limitation accompanied by stridor in patients with MSA under general anaesthesia. PMID:11579172

  20. Domestication does not narrow MHC diversity in Sus scrofa.

    PubMed

    Moutou, Katerina A; Koutsogiannouli, Evagelia A; Stamatis, Costas; Billinis, Charalambos; Kalbe, Claudia; Scandura, Massimo; Mamuris, Zissis

    2013-03-01

    The Major Histocompatibility Complex (MHC) is a multigene family of outstanding polymorphism. MHC molecules bind antigenic peptides in the peptide-binding region (PBR) that consists of five binding pockets (P). In this study, we compared the genetic diversity of domestic pigs to that of the modern representatives of their wild ancestors, the wild boar, in two MHC loci, the oligomorphic DQA and the polymorphic DRB1. MHC nucleotide polymorphism was compared with the actual functional polymorphism in the PBR and the binding pockets P1, P4, P6, P7, and P9. The analysis of approximately 200 wild boars collected throughout Europe and 120 domestic pigs from four breeds (three pureblood, Pietrain, Leicoma, and Landrace, and one mixed Danbred) revealed that wild boars and domestic pigs share the same levels of nucleotide and amino acid polymorphism, allelic richness, and heterozygosity. Domestication did not appear to act as a bottleneck that would narrow MHC diversity. Although the pattern of polymorphism was uniform between the two loci, the magnitude of polymorphism was different. For both loci, most of the polymorphism was located in the PBR region and the presence of positive selection was supported by a statistically significant excess of nonsynonymous substitutions over synonymous substitutions in the PBR. P4 and P6 were the most polymorphic binding pockets. Functional polymorphism, i.e., the number and the distribution of pocket variants within and among populations, was significantly narrower than genetic polymorphism, indicative of a hierarchical action of selection pressures on MHC loci.

  1. Detecting dark matter substructure with narrow line lensing

    NASA Astrophysics Data System (ADS)

    Nierenberg, Anna

    2014-10-01

    The abundance of low mass halos is one of the key predictions of LCDM and remains at apparent odds with observations of luminous structure. Strong gravitational lensing provides a straightforward means of testing this theory as it enables the detection of dark matter subhalos at cosmological distances, without requiring the structure to contain any baryons at all. The fluxes of strongly lensed, parsec scale sources in particular, are excellent probes as they are extremely sensitive to the presence of low mass subhalos, while still being extended enough to remain unaffected by microlensing by stars which is a dominant contaminant for smaller sources. Traditionally this field has been limited to the analysis of the small number of strongly lensed, radio-loud quasars. Quasar narrow-line emission offers an alternative to radio. It is also parsec scale and microlensing free, but has the benefit of detectable in a much larger sample of systems. This proposal will combine milliarcsecond astrometry, and percent level photometry attainable with WFC3 IR grism, in order to measure spatially resolved narrow line lensing in six new systems, which cannot be studied from the ground. We have demonstrated that data of this quality can be used to detect subhalos as small as a million solar masses. This proposal will double the sample of systems which can be used to detect dark, low mass substructure using flux ratio anomalies.

  2. Critical Heat Flux In Inclined Rectangular Narrow Long Channel

    SciTech Connect

    J. L. Rempe; S. W. Noh; Y. H. Kim; K. Y. Suh; F.B.Cheung; S. B. Kim

    2005-05-01

    In the TMI-2 accident, the lower part of the reactor pressure vessel had been overheated and then rather rapidly cooled down, as was later identified in a vessel investigation project. This accounted for the possibility of gap cooling feasibility. For this reason, several investigations were performed to determine the critical heat flux (CHF) from the standpoint of invessel retention. The experiments are conducted to investigate the general boiling phenomena, and the triggering mechanism for the CHF in a narrow gap using a 5 x 105 mm2 crevice type heater assembly and de-mineralized water. The test parameters include the gap size of 5 mm, and the surface orientation angles from the downward facing position (180o) to the vertical position (90o). The orientation angle affects the bubble layer and escape from the narrow gap. The CHF is less than that in a shorter channel, compared with the previous experiments having a heated length of 35 mmin the copper test section.

  3. An evaluation of the narrowing gender gap in DUI arrests.

    PubMed

    Robertson, Angela A; Liew, Hui; Gardner, Sheena

    2011-07-01

    Although males account for the vast majority of those convicted of driving under the influence of alcohol and/or other drugs (DUI), female DUI convictions have increased over the past two decades. In this study, we examined the ratio of males-to-females who were court-mandated between the years 1992 and 2008 to attend the Mississippi Alcohol Safety Education Program (MASEP), a DUI intervention program in Mississippi. The data for this study came from MASEP records; the Behavioral Risk Factor Surveillance System (BRFSS); the Uniform Crime Reports (UCR); the Treatment Episode Data Set (TEDS); the National Household Travel Survey (NHTS); and National Highway Traffic Safety Administration (NHTSA), an agency within the US Department of Transportation. Augmented Dickey-Fuller (ADF) tests were used to assess the nature (i.e., convergence, divergence, or stability) of this trend and to identify predictors. The results showed that, over the 17-year period, the gender gap in DUI convictions, self-reported history of prior arrest, official drug arrests, and substance abuse treatment admissions has narrowed considerably. Results from the autoregressive integrated moving average (ARIMA) models show that three factors account for increases in the proportion of women mandated to attend MASEP: self-reported arrest prior to the DUI conviction, female admissions to substance abuse treatment, and annual miles driven. Changes in both women's behavior and law enforcement practices have increased female exposure to DUI arrests and narrowed the gender gap in DUI convictions.

  4. Spectral narrowing in gases using femtosecond laser pulses

    NASA Astrophysics Data System (ADS)

    Karpate, Tanvi; Dharmadhikari, A. K.; Dharmadhikari, J. A.; Mathur, D.

    2017-05-01

    Filamentation in gases due to high power femtosecond pulses results from the combined action of the optical Kerr effect (giving rise to self-focusing) and plasma formation (giving rise to defocusing) that confines optical energy in a small region over a distance longer than the Rayleigh range. Since the discovery of N2 as a potential gain medium, which subsequently led to the formation of nitrogen lasers, it has held a keen interest due to its potential in achieving lasing by remote excitation. Recently, Yamanouchi and coworkers demonstrated lasing action in N2 in the forward as well the backward directions along the femtosecond pulse propagation. In the present work, we have focused on excitation of N2 + (corresponding to the 391nm spectral feature) and have measured spectral narrowing. We have investigated the influence exerted by the incident pulse power and gas pressure for incident pulses of durations 40 fs and 10 fs in forward and backward detection modes. Spectral narrowing that occurs for N2 gas at 391 nm shows a dependence on the incident pulse duration. Pressure threshold for different incident powers for lasing has been established. Increase in the signal intensity on varying the incident power is ascribed to amplified spontaneous emission (ASE). White-light-seeded lasing in N2 + is generated by a Ti:sapphire femtosecond laser for different focusing. The lasing lines peak over the trail of the incident broadband spectra.

  5. Analysis of Red Blood Cell Behavior in a Narrow Tube

    NASA Astrophysics Data System (ADS)

    Hosaka, Haruki; Omori, Toshihiro; Imai, Yohsuke; Yamaguchi, Takami; Ishikawa, Takuji

    2012-11-01

    Red Blood Cell (RBC) is a main component of blood accounting for 40 percent in volume, and enclosed by a twodimensional hyper elastic membrane. RBCs strongly influence rheological properties and mass transport of blood. The deformation of RBCs in capillary and at narrowing is also important in considering mechano-transduction of RBCs and hemolysis, though it has not been clarified in detail. Thus, in this study, we investigated the behavior of a RBC flowing in a narrow tube. To carry out the fluid-structure interaction analysis, we coupled a boundary element method to analyze the velocity of the internal and external fluid with a finite element method to analyze the deformation of the membrane. The boundary element method has good calculation accuracy and its computational cost is low because three-dimensional flow filed can be calculated by a two-dimensional computational mesh. The background flow in a tube is pressure-driven Poiseuille flow. Additionally, to reduce the computational time, we implemented massive parallel computation by using GPUs. The results show that the deformation of a RBC is strongly affected by the Capillary number, which is the ratio of viscous force to the elastic force, radius of the tube, and the initial orientation.

  6. Channel narrowing and vegetation development following a great plains flood

    USGS Publications Warehouse

    Friedman, J.M.; Osterkamp, W.R.; Lewis, W.M.

    1996-01-01

    Streams in the plains of eastern Colorado are prone to intense floods following summer thunderstorms. Here, and in other semiarid and arid regions, channel recovery after a flood may take several decades. As a result, flood history strongly influences spatial and temporal variability in bottomland vegetation. Interpretation of these patterns must be based on understanding the long-term response of bottomland morphology and vegetation to specific floods. A major flood in 1965 on Plum Creek, a perennial sandbed stream, removed most of the bottomland vegetatiqn and transformed the single-thread stream into a wider, braided channel. Channel narrowing began in 1973 and continues today. In 1991, we determined occurrences of 150 vascular plant species in 341 plots (0.5 m2) along a 7-km reach of Plum Creek near Louviers, Colorado. We related patterns of vegetation to elevation, litter cover, vegetative cover, sediment particle size, shade, and year of formation of the underlying surface (based on age of the excavated root flare of the oldest woody plants). Geomorphic investigation determined that Plum Creek fluvial surfaces sort into five groups by year of formation: terraces of fine sand formed before 1965; terraces of coarse sand deposited by the 1965 flood; stable bars formed by channel narrowing during periods of relatively high bed level (1973-1986); stable bars similarly formed during a recent period of low bed level (1987-1990); and the present channel bed (1991). Canonical correspondence analysis indicates a strong influence of elevation and litter cover, and lesser effects of vegetative cover, shade, and sediment particle size. However, the sum of all canonical eigenvalues explained by these factors is less than that explained by an analysis including only the dummy variables that define the five geomorphically determined age groups. The effect of age group is significant even when all five other environmental variables are specified as covariables. Therefore, the

  7. Grassy Narrows Reserve: Mercury Pollution, Social Disruption, and Natural Resources: A Question of Autonomy.

    ERIC Educational Resources Information Center

    Vecsey, Christopher

    1987-01-01

    Presents chronological socio-economic account of Grassy Narrows Reserve, focusing on the 1962-1970 mercury pollution that poisoned the reserve's river system and on resulting negotiations between the Ojibway people of Grassy Narrows, the government, and the polluting company. Examines the question of Grassy Narrows people gaining autonomy over the…

  8. Grassy Narrows Reserve: Mercury Pollution, Social Disruption, and Natural Resources: A Question of Autonomy.

    ERIC Educational Resources Information Center

    Vecsey, Christopher

    1987-01-01

    Presents chronological socio-economic account of Grassy Narrows Reserve, focusing on the 1962-1970 mercury pollution that poisoned the reserve's river system and on resulting negotiations between the Ojibway people of Grassy Narrows, the government, and the polluting company. Examines the question of Grassy Narrows people gaining autonomy over the…

  9. 76 FR 60733 - Drawbridge Operation Regulations; Narrow Bay, Smith Point, NY

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-30

    ... SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulations; Narrow Bay, Smith Point, NY AGENCY... the Smith Point Bridge, 6.1, across Narrow Bay, between Smith Point and Fire Island, New York. The.... SUPPLEMENTARY INFORMATION: The Smith Point Bridge, across Narrow Bay, mile 6.1, between Smith Point and Fire...

  10. Tracking photosynthetic efficiency with narrow-band spectroradiometry

    NASA Technical Reports Server (NTRS)

    Gamon, John A.; Field, Christopher B.

    1992-01-01

    Narrow-waveband spectroradiometry presents the possibility of detecting subtle signals closely related to the current physiological state of vegetation. One such signal related to the epoxidation state of the xanthophyll cycle pigments, violaxanthin, antheraxanthin, and zeaxanthin is discussed. Recent advances in plant ecophysiology demonstrated a close relationship between these pigments and the regulatory state of photosystem 2 in photosynthesis. Our recent field studies of sunflower (Helianthus annuus) and oak (Quercus agrifolia) demonstrated that a 'xanthophyll signal' can be isolated from the diurnal reflectance spectra of intact canopies. Furthermore, the xanthophyll signal can be used to derive a 'physiological reflectance index' (PRI) that closely correlates with the actual photosynthetic efficiency (defined as the photosynthetic rate divided by the incident PAR) in closed canopies. If these signals were detectable in Airborne Visible/Infrared Imaging Spectrometers (AVIRIS) images, they could lead to improved remote estimates of photosynthetic fluxes.

  11. Ciliochoroidal melanomas treated with a narrow medical proton beam

    SciTech Connect

    Brovkina, A.F.; Zarubei, G.D.

    1986-03-01

    We treated 63 patients with intraocular melanomas by means of a narrow medical proton beam. Tumors were irradiated with 2,500 rad at each of four to five sessions, with an interval of one to two days between sessions. The melanomas ranged in diameter from 8 to 20 mm and were from 3.0 to 13.7 mm in thickness. Patients were followed up for three months to seven years. In 11 cases, the tumor was fully resorbed. Complications included radiation cataract, postradiation glaucoma, radiation retinopathy, and exudative retinal detachment. In 12 cases, enucleation was performed because tumor growth persisted. Four patients died during follow-up period because of metastasis. The eye was preserved in 47 cases.

  12. High unexpected genetic diversity of a narrow endemic terrestrial mollusc.

    PubMed

    Madeira, Pedro M; Chefaoui, Rosa M; Cunha, Regina L; Moreira, Francisco; Dias, Susana; Calado, Gonçalo; Castilho, Rita

    2017-01-01

    The Iberian Peninsula has an extensive record of species displaying strong genetic structure as a result of their survival in isolated pockets throughout the Pleistocene ice ages. We used mitochondrial and nuclear sequence data to analyze phylogeographic patterns in endemic land snails from a valley of central Portugal (Vale da Couda), putatively assigned to Candidula coudensis, that show an exceptionally narrow distributional range. The genetic survey presented here shows the existence of five main mitochondrial lineages in Vale da Couda that do not cluster together suggesting independent evolutionary histories. Our results also indicate a departure from the expectation that species with restricted distributions have low genetic variability. The putative past and contemporary models of geographic distribution of Vale da Couda lineages are compatible with a scenario of species co-existence in more southern locations during the last glacial maximum (LGM) followed by a post-LGM northern dispersal tracking the species optimal thermal, humidity and soil physical conditions.

  13. High unexpected genetic diversity of a narrow endemic terrestrial mollusc

    PubMed Central

    Madeira, Pedro M.; Chefaoui, Rosa M.; Cunha, Regina L.; Moreira, Francisco; Dias, Susana; Calado, Gonçalo

    2017-01-01

    The Iberian Peninsula has an extensive record of species displaying strong genetic structure as a result of their survival in isolated pockets throughout the Pleistocene ice ages. We used mitochondrial and nuclear sequence data to analyze phylogeographic patterns in endemic land snails from a valley of central Portugal (Vale da Couda), putatively assigned to Candidula coudensis, that show an exceptionally narrow distributional range. The genetic survey presented here shows the existence of five main mitochondrial lineages in Vale da Couda that do not cluster together suggesting independent evolutionary histories. Our results also indicate a departure from the expectation that species with restricted distributions have low genetic variability. The putative past and contemporary models of geographic distribution of Vale da Couda lineages are compatible with a scenario of species co-existence in more southern locations during the last glacial maximum (LGM) followed by a post-LGM northern dispersal tracking the species optimal thermal, humidity and soil physical conditions. PMID:28321363

  14. Density Fluctuations of Hard-Sphere Fluids in Narrow Confinement

    SciTech Connect

    Nygård, Kim; Sarman, Sten; Hyltegren, Kristin; Chodankar, Shirish; Perret, Edith; Buitenhuis, Johan; van der Veen, J. Friso; Kjellander, Roland

    2016-02-16

    Spatial confinement induces microscopic ordering of fluids, which in turn alters many of their dynamic and thermodynamic properties. However, the isothermal compressibility has hitherto been largely overlooked in the literature, despite its obvious connection to the underlying microscopic structure and density fluctuations in confined geometries. Here, we address this issue by probing density profiles and structure factors of hard-sphere fluids in various narrow slits, using x-ray scattering from colloid-filled nanofluidic containers and integral-equation-based statistical mechanics at the level of pair distributions for inhomogeneous fluids. Most importantly, we demonstrate that density fluctuations and isothermal compressibilities in confined fluids can be obtained experimentally from the long-wavelength limit of the structure factor, providing a formally exact and experimentally accessible connection between microscopic structure and macroscopic, thermodynamic properties. Our approach will thus, for example, allow direct experimental verification of theoretically predicted enhanced density fluctuations in liquids near solvophobic interfaces.

  15. Long-pulse-width narrow-bandwidth solid state laser

    DOEpatents

    Dane, C. Brent; Hackel, Lloyd A.

    1997-01-01

    A long pulse laser system emits 500-1000 ns quasi-rectangular pulses at 527 nm with near diffraction-limited divergence and near transform-limited bandwidth. The system consists of one or more flashlamp-pumped Nd:glass zig-zag amplifiers, a very low threshold stimulated-Brillouin-scattering (SBS) phase conjugator system, and a free-running single frequency Nd:YLF master oscillator. Completely passive polarization switching provides eight amplifier gain passes. Multiple frequency output can be generated by using SBS cells having different pressures of a gaseous SBS medium or different SBS materials. This long pulse, low divergence, narrow-bandwidth, multi-frequency output laser system is ideally suited for use as an illuminator for long range speckle imaging applications. Because of its high average power and high beam quality, this system has application in any process which would benefit from a long pulse format, including material processing and medical applications.

  16. Long-pulse-width narrow-bandwidth solid state laser

    DOEpatents

    Dane, C.B.; Hackel, L.A.

    1997-11-18

    A long pulse laser system emits 500-1000 ns quasi-rectangular pulses at 527 nm with near diffraction-limited divergence and near transform-limited bandwidth. The system consists of one or more flashlamp-pumped Nd:glass zig-zag amplifiers, a very low threshold stimulated-Brillouin-scattering (SBS) phase conjugator system, and a free-running single frequency Nd:YLF master oscillator. Completely passive polarization switching provides eight amplifier gain passes. Multiple frequency output can be generated by using SBS cells having different pressures of a gaseous SBS medium or different SBS materials. This long pulse, low divergence, narrow-bandwidth, multi-frequency output laser system is ideally suited for use as an illuminator for long range speckle imaging applications. Because of its high average power and high beam quality, this system has application in any process which would benefit from a long pulse format, including material processing and medical applications. 5 figs.

  17. Narrow sidebranch arrays for low frequency duct noise control.

    PubMed

    Tang, S K

    2012-11-01

    The present study investigates the sound transmission loss across a section of an infinitely long duct where one or more narrow sidebranch tubes are installed flushed with the duct wall. The finite-element method is used to compute the wave propagation characteristics, and a simplified theoretical analysis is carried out at the same time to explain the wave mechanism at frequencies of high sound reduction. Results show that the high sound transmission loss at a particular frequency is due to the concerted actions of three consecutive sidebranch tubes with the most upstream one in the resonant state. The expansion chamber effect of the setup also plays a role in enhancing sound attenuation at non-resonance frequencies. Broadband performance of the device can be greatly enhanced by appropriate arrangements of tube lengths and/or by coupling arrays on the two sides of the duct.

  18. Statistics of narrow-band partially polarized light

    NASA Astrophysics Data System (ADS)

    Charnotskii, Mikhail

    2017-09-01

    A complete single-point statistical description of a narrow-band partially polarized optical field is developed in terms of the 2D period-averaged probability density function (PA-PDF) of the electrical field vector. This statistic can be measured using the coherent (heterodyne) detection. PA-PDF carries more information about the partially polarized light than the traditional Stokes vector. For a simple Gaussian partially polarized field the PA-PDF depends on 13 real parameters in contrast to the four parameters of the Stokes vector or coherence tensor. We show on several examples that the polarization state of the wave, as described by PA-PDF can vary significantly even while Stokes vector remains fixed.

  19. Wide color gamut LCDs with narrow green emitting films

    NASA Astrophysics Data System (ADS)

    He, Juan; Chen, Haiwei; Chen, Hao; Wang, Yanan; Chen, Jiangshan; Zhu, Ruidong; Wu, Shin-Tson; Dong, Yajie

    2017-02-01

    We demonstrate a series of ultrastable, highly luminescent CH3NH3PbBr3 (MAPbBr3) green emitting organic-inorganic perovskites (OIP) - polymer composite films achieved by a simple yet general strategy, to be used together with red emitters as down-converters for blue LEDs in display technology. These composite films exhibit high photoluminescence quantum yield (PLQY) of up to 48%, high color purity with FWHM (full width at half maximum) as narrow as 18 nm. When combined with blue LED and CdSe-based quantum dots-polymer films or red phosphors as LCD backlight, we can achieve a relatively wide color gamut in Rec. 2020 color space.

  20. Prediction of narrow N* and {Lambda}* with hidden charm

    SciTech Connect

    Wu Jiajun; Molina, R.; Oset, E.; Zou, B. S.

    2011-10-24

    The interaction between various charmed mesons and charmed baryons, such as D-bar{Sigma}{sub c}-D-bar{Lambda}{sub c}, D-bar*{Sigma}{sub c}-D-bar*{Lambda}{sub c}, and related strangeness channels, are studied within the framework of the coupled channel unitary approach with the local hidden gauge formalism. Six narrow N* and {Lambda}* resonances are dynamically generated with mass above 4 GeV and width smaller than 100 MeV. These predicted new resonances definitely cannot be accommodated by quark models with three constituent quarks. We make estimates of production cross sections of these predicted resonances in p-barp collisions for PANDA at the forthcoming FAIR facility.

  1. FORMATION OF THE TERRESTRIAL PLANETS FROM A NARROW ANNULUS

    SciTech Connect

    Hansen, Brad M. S.

    2009-09-20

    We show that the assembly of the solar system terrestrial planets can be successfully modeled with all of the mass initially confined to a narrow annulus between 0.7 and 1.0 AU. With this configuration, analogs of Mercury and Mars often form from the collisional evolution of material diffusing out of the annulus under the scattering of the forming Earth and Venus analogs. The final systems also possess eccentricities and inclinations that match the observations, without recourse to dynamical friction from remnant small body populations. Finally, the characteristic assembly timescale for Earth analogs is rapid in this model and consistent with cosmochemical models based on the {sup 182}Hf-{sup 182}W isotopes. The agreement between this model and the observations suggests that terrestrial planet systems may also be formed in 'planet traps', as has been proposed recently for the cores of giant planets in our solar system and others.

  2. Search for narrow resonances below the Upsilon mesons

    SciTech Connect

    Apollinari, G.; Barone, M.; Carithers, W.; Dell'Orso, M.; Dorigo, T.; Fiori, I; Franklin, M.; Giannetti, P.; Giromini, P.; Happacher, F.; Miscetti, S.; Parri, A.; Ptohos, F.; Velev, G.; /Frascati /Fermilab /Harvard U. /LBL, Berkeley /INFN, Pisa /Pisa U. /Pisa, Scuola Normale Superiore /Padua U. /INFN, Padua

    2005-07-01

    The authors have investigated the invariant mass spectrum of dimuons collected by the CDF experiment during the 1992-1995 run of the Fermilab Tevatron collider to improve the limit on the existence of narrow resonances set by the experiments at the SPEAR e{sup +}e{sup -} collider. In the mass range 6.3-9.0 GeV/c{sup 2} they derive an average 90% upper credible limit of 8 eV to the leptonic width of possible resonances. This limit is much worse at the mass of 7.2 GeV/c{sup 2} due to an excess of 250 {+-} 61 events with a width consistent with the detector resolution.

  3. Shining a new narrow band of light on old problems.

    PubMed

    Chan, Daniel K; Wang, Kenneth K

    2014-06-01

    Improvements in narrow band imaging (NBI) may provide an improved view of colonic mucosa for detection of polyps and adenomas. In this issue, Leung et al. report findings to suggest that this next-generation NBI technology is superior to conventional high-definition white light endoscopy in polyp detection. These findings are based on brighter illumination, which has been a problem with older generations of NBI, which did not increase polyp detection but were useful for polyp characterization. Although these findings are very promising for this new role of second-generation NBI in polyp detection, the study must be viewed with consideration of the history of the older NBI system, the analysis of which through multiple positive and negative studies ultimately led to the conclusion that it was not beneficial for detection.

  4. Narrow-field radiometry in a quasi-isotropic atmosphere

    NASA Technical Reports Server (NTRS)

    Holmes, A.; Palmer, J. M.; Tomasko, M. G.

    1979-01-01

    If a radiometer having a narrow field of view is used to measure the radiance of a source such as a quasi-isotropic atmosphere, a knowledge of the out-of-field responsivity is critical. For example, if a radiometer with a field of view of 5 deg (full-angle) has a relative responsivity of 0.0001 for the out-of-field radiation, the contribution of the out-of-field radiation (assuming an isotropic source subtending 2 steradians) is 10.5% of the total signal. Either the stray light suppression of the radiometer must be extremely high or methods of determining the out-of-field response must be developed. A description of one method of determining the effect of out-of-field response and its application to a planetary atmospheric radiometer is presented.

  5. Relativistic jets in Narrow-Line Seyfert 1

    NASA Astrophysics Data System (ADS)

    Foschini, L.; Angelakis, E.; Bonnoli, G.; Calderone, G.; Colpi, M.; D'Ammando, F.; Donato, D.; Falcone, A.; Fuhrmann, L.; Ghisellini, G.; Ghirlanda, G.; Hauser, M.; Kovalev, Y. Y.; Maraschi, L.; Nieppola, E.; Richards, J.; Stamerra, A.; Tagliaferri, G.; Tavecchio, F.; Thompson, D. J.; Tibolla, O.; Tramacere, A.; Wagner, S.

    2011-02-01

    Narrow-Line Seyfert 1 (NLS1) class of active galactic nuclei (AGNs) is generally radio-quiet, but a small percent of them are radio-loud. The recent discovery by Fermi/LAT of high-energy γ-ray emission from 4 NLS1s proved the existence of relativistic jets in these systems. It is therefore important to study this new class of γ-ray emitting AGNs. Here we report preliminary results about the observations of the July 2010 γ-ray outburst of PMN J0948+0022, when the source flux exceeded for the first time 10-6 ph cm-2 s-1 (E > 100 MeV).

  6. PCF based high power narrow line width pulsed fiber laser

    NASA Astrophysics Data System (ADS)

    Chen, H.; Yan, P.; Xiao, Q.; Wang, Y.; Gong, M.

    2012-09-01

    Based on semiconductor diode seeded multi-stage cascaded fiber amplifiers, we have obtained 88-W average power of a 1063-nm laser with high repetition rate of up to 1.5 MHz and a constant 2-ns pulse duration. No stimulated Brillouin scattering pulse or optical damage occurred although the maximum pulse peak power has exceeded 112 kW. The output laser exhibits excellent beam quality (M2x = 1.24 and M2y = 1.18), associated with a spectral line width as narrow as 0.065 nm (FWHM). Additionally, we demonstrate high polarization extinction ratio of 18.4 dB and good pulse stabilities superior to 1.6 % (RMS).

  7. Neutral and positively charged excitons in narrow quantum ring

    SciTech Connect

    Porras Monroy, L. C.; Rodríguez-Prada, F. A.; Mikhailov, I. D.

    2014-05-15

    We study theoretically quantized states of a neutral and a positively charged exciton (trion X{sup +}) confined in a heterostructure with the ring-like geometry. In order to assess the experimentally relevant domain of parameters, we adopt a simple model of a narrow ring when 3D wave equations for the neutral and positively charged excitons can be separated. By using the Fourier series method, we have calculated the energy spectra of excitons complexes in a quantum ring as a function of the electron-to-hole mass ratio, the ring radius, and the magnetic field strength. The quantum-size effect and the size-dependent magnetic oscillations of energy levels of excitons' complexes spectra have been revealed.

  8. Single-Frequency Narrow Linewidth 2 Micron Fiber Laser

    NASA Technical Reports Server (NTRS)

    Jiang, Shibin (Inventor); Spiegelberg, Christine (Inventor); Luo, Tao (Inventor)

    2006-01-01

    A compact single frequency, single-mode 2 .mu.m fiber laser with narrow linewidth, <100 kHz and preferably <100 kHz, is formed with a low phonon energy glass doped with triply ionized rare-earth thulium and/or holmium oxide and fiber gratings formed in sections of passive silica fiber and fused thereto. Formation of the gratings in passive silica fiber both facilitates splicing to other optical components and reduces noise thus improving linewidth. An increased doping concentration of 0.5 to 15 wt. % for thulium, holmium or mixtures thereof produces adequate gain, hence output power levels for fiber lengths less than 5 cm and preferably less than 3 cm to enable single-frequency operation.

  9. Narrow-field imaging of the lunar sodium exosphere

    NASA Technical Reports Server (NTRS)

    Stern, S. Alan; Flynn, Brian C.

    1995-01-01

    We present the first results of a new technique for imaging the lunar Na atmosphere. The technique employs high resolution, a narrow bandpass, and specific observing geometry to suppress scattered light and image lunar atmospheric Na I emission down to approximately 50 km altitude. Analysis of four latitudinally dispersed images shows that the lunar Na atmosphere exhibits intersting latitudinal and radial dependencies. Application of a simple Maxwellian collisionless exosphere model indicates that: (1) at least two thermal populations are required to adequately fit the soldium's radial intensity behavior, and (2) the fractional abundances and temperatures of the two components vary systematically with latitude. We conclude that both cold (barometric) and hot (suprathermal) Na may coexist in the lunar atmosphere, either as distinct components or as elements of a continuum of populations ranging in temperature from the local surface temperature up to or exceeding escape energies.

  10. Plasmonic nanochannel structure for narrow-band selective thermal emitter

    NASA Astrophysics Data System (ADS)

    Wang, Zhiyu; Clark, J. Kenji; Huang, Li-Chung; Ho, Ya-Lun; Delaunay, Jean-Jacques

    2017-06-01

    A plasmonic structure consisting of a periodic arrangement of vertical silicon nanochannels connected by U-shaped gold layers is demonstrated as a spectrally selective thermal emitter. The plasmonic nanochannel structure sustains a coupled mode between a surface plasmon polariton and a stationary surface plasmon resonance, which induces a strong and sharp resonance observed in the form of a reflectance dip in the far field. Upon heating the structure, a strong and narrow-bandwidth thermal emittance peak is observed with a maximum emittance value of 0.72 and a full-width-at-half-maximum of 248 nm at a wavelength of 5.66 μm, which corresponds to the reflectance dip wavelength. Moreover, we demonstrate the control of the emission peak wavelength by varying the period of the structure. The plasmonic nanochannel structure realizes a small-size and selective infrared thermal emitter, which is expected to be applicable as an infrared light source.

  11. High Intensity Laser Interactions with Narrow Gap Semiconductors

    NASA Astrophysics Data System (ADS)

    Hasselback, Michael Peter

    1995-01-01

    Two-photon absorption in solids is a well known and thoroughly characterized nonlinear optical process. Higher order multi-photon absorption however, has received comparatively little study. In this dissertation, results of experiments with bulk, narrow gap semiconductors InSb and InAs are reported. By performing Z-scans and pump-probe measurements at different laser wavelengths and sample temperatures, various nonlinear optical processes are identified. Data obtained with InAs is consistent with photocarrier generation by three and four-photon absorption. It is believed this is the first direct evidence of four-photon absorption in a semiconductor. Leakage two-photon is observed with InSb at 15K. This novel effect arises from dynamic band un-blocking caused by laser heating of conduction electrons. All phenomena are excited with picosecond CO_2 laser pulses at irradiances below the material damage threshold. Physical models describing the observations are presented.

  12. Friction-factor characteristics for narrow channels with honeycomb surfaces

    NASA Technical Reports Server (NTRS)

    Ha, T. W.; Morrison, G. L.; Childs, D. W.

    1992-01-01

    The experimental determination of friction-factors for the flow of air in a narrow channel lined with various honeycomb geometries has been carried out. Test results show that, generally, the friction-factor is nearly constant or slightly decreases as the Reynolds number increases, a characteristic common to turbulent flow in pipes. However, in some test geometries this trend is remarkably different. The friction factor dramatically drops and then rises as the Reynolds number increases. This phenomenon can be characterized as a 'friction-factor jump'. Further investigations of the acoustic spectrum and friction-factor measurements for a broad range of Reynolds numbers indicate that the 'friction-factor jump' phenomenon is accompanied by an onset of a normal mode resonance excited coherent flow fluctuation structure, which occurs at Reynolds number of the order of 10,000. The purpose of this paper is to explain the friction-factor-jump phenomenon and friction-factor characteristics.

  13. Narrow Band Imaging: Technology Basis and Research and Development History.

    PubMed

    Gono, Kazuhiro

    2015-11-01

    The first launch of narrow band imaging (NBI) was in 2005. Since then, in most countries where gastrointestinal endoscopies are performed, NBI is the most commonly used optical digital method of performing image-enhanced endoscopy. Thanks to the outstanding efforts of many endoscopists, many clinical studies have been performed and clinical evidence has been gathered. In Japan, since 2010, NBI has been reimbursed under the Japanese national health insurance system. This is owing to the establishment of clinical evidence by physicians. However, even though endoscope systems with NBI function have been widely used outside of Japan, dissemination of knowledge on how to use NBI is insufficient. In this review paper, the technology basis of NBI and its research and development history are described. I hope this information will be helpful for updating physicians' knowledge of NBI.

  14. Flow-induced polymer translocation through narrow and patterned channels.

    PubMed

    Nikoubashman, Arash; Likos, Christos N

    2010-08-21

    We consider linear and branched polymers driven through narrow and patterned channels by imposing a Poiseuille flow on the ambient solvent. We establish, by means of scaling arguments, that the translocation probability of dendrimers through the pore is independent of the number of monomers and that it takes place above a viscosity-dependent critical external current. When the channel walls are smooth, the translocation times of linear and branched polymers with the same monomer number are very similar. However, for walls that are decorated with attractive patches, dramatic differences show up: whereas a dendrimer successively docks at the patches and "walks" from one to the next, being carried away by the solvent flow, linear chains spread themselves along the channel wall without achieving translocation within simulation times. Our findings are relevant for, e.g., drug delivery through dendritic carrier molecules in capillary arterioles.

  15. Narrow band 3 × 3 Mueller polarimetric endoscopy

    PubMed Central

    Qi, Ji; Ye, Menglong; Singh, Mohan; Clancy, Neil T.; Elson, Daniel S.

    2013-01-01

    Mueller matrix polarimetric imaging has shown potential in tissue diagnosis but is challenging to implement endoscopically. In this work, a narrow band 3 × 3 Mueller matrix polarimetric endoscope was designed by rotating the endoscope to generate 0°, 45° and 90° linearly polarized illumination and positioning a rotating filter wheel in front of the camera containing three polarisers to permit polarization state analysis for backscattered light. The system was validated with a rotating linear polarizer and a diffuse reflection target. Initial measurements of 3 × 3 Mueller matrices on a rat are demonstrated, followed by matrix decomposition into the depolarization and retardance matrices for further analysis. Our work shows the feasibility of implementing polarimetric imaging in a rigid endoscope conveniently and economically in order to reveal diagnostic information. PMID:24298405

  16. Quantum phase slip phenomenon in ultra-narrow superconducting nanorings

    PubMed Central

    Arutyunov, Konstantin Yu.; Hongisto, Terhi T.; Lehtinen, Janne S.; Leino, Leena I.; Vasiliev, Alexander L.

    2012-01-01

    The smaller the system, typically - the higher is the impact of fluctuations. In narrow superconducting wires sufficiently close to the critical temperature Tc thermal fluctuations are responsible for the experimentally observable finite resistance. Quite recently it became possible to fabricate sub-10 nm superconducting structures, where the finite resistivity was reported within the whole range of experimentally obtainable temperatures. The observation has been associated with quantum fluctuations capable to quench zero resistivity in superconducting nanowires even at temperatures T→0. Here we demonstrate that in tiny superconducting nanorings the same phenomenon is responsible for suppression of another basic attribute of superconductivity - persistent currents - dramatically affecting their magnitude, the period and the shape of the current-phase relation. The effect is of fundamental importance demonstrating the impact of quantum fluctuations on the ground state of a macroscopically coherent system, and should be taken into consideration in various nanoelectronic applications. PMID:22389762

  17. Flow regimes and heat transfer in vertical narrow annuli

    SciTech Connect

    Ulke, A.; Goldberg, I.

    1993-11-01

    In shell side boiling heat exchangers narrow crevices that are formed between the tubes and the tube support structure provide areas for local thermal-hydraulic conditions which differ significantly from bulk fluid conditions. Understanding of the processes of boiling and dryout in flow restricted crevices can help in designing of tube support geometries to minimize the likelihood of tube support plate and tube corrosion observed in commercial power plant steam generators. This paper describes a one dimensional thermal-hydraulic model of a vertical crevice between a tube and a support plate with cylindrical holes. The annulus formed by the support plate hole and an eccentrically located tube has been represented by vertical strips. The formation, growth and collapse of a steam bubble in each strip has been determined. Based on the bubble history, and flow regimes characterized by ``isolated`` bubbles, ``coalesced`` bubbles and liquid deficient regions have been defined.

  18. The audiovisual temporal binding window narrows in early childhood.

    PubMed

    Lewkowicz, David J; Flom, Ross

    2014-01-01

    Binding is key in multisensory perception. This study investigated the audio-visual (A-V) temporal binding window in 4-, 5-, and 6-year-old children (total N = 120). Children watched a person uttering a syllable whose auditory and visual components were either temporally synchronized or desynchronized by 366, 500, or 666 ms. They were asked whether the voice and face went together (Experiment 1) or whether the desynchronized videos differed from the synchronized one (Experiment 2). Four-year-olds detected the 666-ms asynchrony, 5-year-olds detected the 666- and 500-ms asynchrony, and 6-year-olds detected all asynchronies. These results show that the A-V temporal binding window narrows slowly during early childhood and that it is still wider at 6 years of age than in older children and adults.

  19. Narrow linewidth Yb-doped fiber laser at 1120 nm.

    PubMed

    Xiaojuan, Liu; Shenggui, Fu; Liping, Guo; Kezhen, Han

    2013-03-20

    A 974 nm laser diode pumped 1120 nm ytterbium (Yb)-doped fiber laser with all fiber components has been experimentally demonstrated. The resonator is composed of a normal single-mode Yb-doped fiber 1 m long and a pair of fiber Bragg gratings. Up to 21.6 mW of continuous-wave output power is generated when the launched pump power is 161 mW with an optical-to-optical conversion efficiency of 13.4%. The central wavelength is 1120.89 nm with a linewidth as narrow as 0.02 nm. Additionally, a similar fiber laser with a 2 m long gain medium displays a broadened linewidth. The results of the two fiber lasers are compared and discussed in the paper.

  20. The Tacoma Narrows Bridge Collapse on Film and Video

    NASA Astrophysics Data System (ADS)

    Olson, Don; Hook, Joseph; Doescher, Russell; Wolf, Steven

    2015-11-01

    This month marks the 75th anniversary of the Tacoma Narrows Bridge collapse. During a gale on Nov. 7, 1940, the bridge exhibited remarkable oscillations before collapsing spectacularly (Figs. 1-5). Physicists over the years have spent a great deal of time and energy studying this event. By using open-source analysis tools and digitized footage of the disaster, physics students in both high school and college can continue in this tradition. Students can watch footage of "Galloping Gertie," ask scientific questions about the bridge's collapse, analyze data, and draw conclusions from that analysis. Students should be encouraged to pursue their own investigations, but the question that drove our inquiry was this: "When physics classes watch modern video showing the oscillations and the free fall of the bridge fragments, are these scenes sped up, slowed down, or at the correct speed compared to what was observed by the eyewitnesses on Nov. 7, 1940?"

  1. Concurrent bandgap narrowing and polarization enhancement in epitaxial ferroelectric nanofilms

    NASA Astrophysics Data System (ADS)

    Tyunina, Marina; Yao, Lide; Chvostova, Dagmar; Dejneka, Alexandr; Kocourek, Tomas; Jelinek, Miroslav; Trepakov, Vladimir; van Dijken, Sebastiaan

    2015-04-01

    Perovskite-type ferroelectric (FE) crystals are wide bandgap materials with technologically valuable optical and photoelectric properties. Here, versatile engineering of electronic transitions is demonstrated in FE nanofilms of KTaO3, KNbO3 (KNO), and NaNbO3 (NNO) with a thickness of 10-30 unit cells. Control of the bandgap is achieved using heteroepitaxial growth of new structural phases on SrTiO3 (001) substrates. Compared to bulk crystals, anomalous bandgap narrowing is obtained in the FE state of KNO and NNO films. This effect opposes polarization-induced bandgap widening, which is typically found for FE materials. Transmission electron microscopy and spectroscopic ellipsometry measurements indicate that the formation of higher-symmetry structural phases of KNO and NNO produces the desirable red shift of the absorption spectrum towards visible light, while simultaneously stabilizing robust FE order. Tuning of optical properties in FE films is of interest for nanoscale photonic and optoelectronic devices.

  2. The hydrogen line spectra of narrow-line radio galaxies

    NASA Astrophysics Data System (ADS)

    Ferland, G. J.; Osterbrock, D. E.

    1985-02-01

    The results of the first detection of Ly-alpha in a narrow-line radio galaxy are reported. Nearly simultaneous optical and UV observations of 3C 192 and 3C 223 allow the measurement of both Balmer and Lyman decrements. These line ratios are approximate functions of the interstellar reddening and of a parameter which is proportional to the amount of H I collisional excitation present. The reddening of 3C 192 is slightly larger than that due to the Galaxy, although 3C 223 may have a larger value. Both galaxies have intrinsic Balmer and Lyman decrements which are significantly steeper than case B, suggesting that the gas is photoionized by a fairly hard X-ray continuum. The deduced values of L-alpha/H-beta and H-alpha/H-beta compare favorably with predictions of recent models.

  3. The hydrogen line spectra of narrow-line radio galaxies

    NASA Technical Reports Server (NTRS)

    Ferland, G. J.; Osterbrock, D. E.

    1985-01-01

    The results of the first detection of Ly-alpha in a narrow-line radio galaxy are reported. Nearly simultaneous optical and UV observations of 3C 192 and 3C 223 allow the measurement of both Balmer and Lyman decrements. These line ratios are approximate functions of the interstellar reddening and of a parameter which is proportional to the amount of H I collisional excitation present. The reddening of 3C 192 is slightly larger than that due to the Galaxy, although 3C 223 may have a larger value. Both galaxies have intrinsic Balmer and Lyman decrements which are significantly steeper than case B, suggesting that the gas is photoionized by a fairly hard X-ray continuum. The deduced values of L-alpha/H-beta and H-alpha/H-beta compare favorably with predictions of recent models.

  4. Differential diagnosis of regular, narrow-QRS tachycardias.

    PubMed

    Katritsis, Demosthenes G; Josephson, Mark E

    2015-07-01

    We present an update on clinical and electrophysiological criteria used for the differential diagnosis of regular supraventricular tachycardias. Although several electrocardiographic clues may assist in the differential diagnosis, this is usually accomplished at electrophysiology study, and most often, the differential diagnosis is between atrioventricular nodal reentrant tachycardia, atrioventricular reentrant tachycardia due to a concealed accessory pathway, and atrial tachycardia. Atrial and ventricular pacing maneuvers during sinus rhythm or tachycardia have been used with various success rates. In clinical practice, these techniques cannot be applied to all cases, and multiple criteria must be used for the differential diagnosis of narrow-complex tachycardias with atypical characteristics. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  5. Automated IFU Analysis: Narrow Line Region Outflows In Mrk 3

    NASA Astrophysics Data System (ADS)

    Fischer, Travis C.; Crenshaw, D. Michael; Pope, Crystal

    2015-08-01

    As Integral Field Unit (IFU) observations and large spectral surveys continue to become more prevalent, the handling of thousands of spectra has become common place. Establishing a method that will easily allow for multiple-component analysis of emission-line features, as often seen in the Narrow-Line Regions (NLRs) of nearby Active Galactic Nuclei (AGN), in an automated fashion would be of great use to the community. We present such an analysis for the NLR kinematics in the Type 2 Seyfert AGN Mrk 3, based on observations from the Gemini Near Infrared Integral Field Spectrograph (NIFS). By incorporating Bayesian model selection into our analysis, the fitting of multiple kinematic components is performed while simultaneously determining the correct number of components in each spectrum, streamlining the line measurements for a large number of spectra into a single process.

  6. Electronic publication and the narrowing of science and scholarship.

    PubMed

    Evans, James A

    2008-07-18

    Online journals promise to serve more information to more dispersed audiences and are more efficiently searched and recalled. But because they are used differently than print-scientists and scholars tend to search electronically and follow hyperlinks rather than browse or peruse-electronically available journals may portend an ironic change for science. Using a database of 34 million articles, their citations (1945 to 2005), and online availability (1998 to 2005), I show that as more journal issues came online, the articles referenced tended to be more recent, fewer journals and articles were cited, and more of those citations were to fewer journals and articles. The forced browsing of print archives may have stretched scientists and scholars to anchor findings deeply into past and present scholarship. Searching online is more efficient and following hyperlinks quickly puts researchers in touch with prevailing opinion, but this may accelerate consensus and narrow the range of findings and ideas built upon.

  7. Density Fluctuations of Hard-Sphere Fluids in Narrow Confinement

    NASA Astrophysics Data System (ADS)

    Nygârd, Kim; Sarman, Sten; Hyltegren, Kristin; Chodankar, Shirish; Perret, Edith; Buitenhuis, Johan; van der Veen, J. Friso; Kjellander, Roland

    2016-01-01

    Spatial confinement induces microscopic ordering of fluids, which in turn alters many of their dynamic and thermodynamic properties. However, the isothermal compressibility has hitherto been largely overlooked in the literature, despite its obvious connection to the underlying microscopic structure and density fluctuations in confined geometries. Here, we address this issue by probing density profiles and structure factors of hard-sphere fluids in various narrow slits, using x-ray scattering from colloid-filled nanofluidic containers and integral-equation-based statistical mechanics at the level of pair distributions for inhomogeneous fluids. Most importantly, we demonstrate that density fluctuations and isothermal compressibilities in confined fluids can be obtained experimentally from the long-wavelength limit of the structure factor, providing a formally exact and experimentally accessible connection between microscopic structure and macroscopic, thermodynamic properties. Our approach will thus, for example, allow direct experimental verification of theoretically predicted enhanced density fluctuations in liquids near solvophobic interfaces.

  8. Leo Szilard: Physics, Politics, and the Narrow Margin of Hope.

    NASA Astrophysics Data System (ADS)

    Lanouette, William

    1998-04-01

    Leo Szilard (1898-1964) was a creative physicist and biologist. But concern about how scientific discoveries might affect humanity also led him to seek political solutions to enlarge the benefits and limit the damage caused by his work. This disposition to save the world came to Szilard by the age of 10, when he read The Tragedy of Man, a Hungarian epic poem in which humanity faces extinction yet continues to survive by maintaining a narrow margin of hope. With this hope Szilard brought about improbable scientific and political feats (such as the nuclear chain reaction and the Moscow-Washington Hotline). This talk focuses on Szilard's many attempts in 1945 to prevent the atomic bombing of Japan. William Lanouette, a writer and public policy analyst, is the author of Genius in the Shadows: A Biography of Leo Szilard, The Man Behind the Bomb. (University of Chicago Press, 1994)

  9. Shearing flow from transient bubble oscillations in narrow gaps

    NASA Astrophysics Data System (ADS)

    Mohammadzadeh, Milad; Li, Fenfang; Ohl, Claus-Dieter

    2017-01-01

    The flow driven by a rapidly expanding and collapsing cavitation bubble in a narrow cylindrical gap is studied with the volume of fluid method. The simulations reveal a developing plug flow during the early expansion followed by flow reversal at later stages. An adverse pressure gradient leads to boundary layer separation and flow reversal, causing large shear stress near the boundaries. Analytical solution to a planar pulsating flow shows qualitative agreement with the CFD results. The shear stress close to boundaries has implications to deformable objects located near the bubble: Experiments reveal that thin, flat biological cells entrained in the boundary layer become stretched, while cells with a larger cross section are mainly transported with the flow.

  10. Patterns of granular convection and separation in narrow vibration bed

    NASA Astrophysics Data System (ADS)

    Liu, Chuanping; Wu, Ping; Wang, Li; Tong, Lige; Yin, Shaowu

    2017-06-01

    Granular convection/separation of single and binary component particles are studied in a narrow vibration bed, respectively. With filling the single light particles (molecular sieve beads), the bed exhibits five different states successively by increasing the vibration frequency f from 15Hz to 70 Hz (vibration strength Γ>3), as the global convection, symmetrical heap, unsymmetrical heap, local convection and pseudo solid. Comparatively, the granular bed of the single heavy particles (steel beads) is only in pseudo solid state at the above vibration condition. By filling binary component particles (molecular sieve and same size steel beads) instead of the single component, the bed shows similar convection state with that of the single molecular sieve beads, and the heavy steel beads are aggregated in the centre of convention roll as a core. Varying the initial distribution of binary component particles, the final convection and separation are not influenced, although the aggregation process of steel beads changes.

  11. Observations of the cavitating jet in a narrow watercourse

    SciTech Connect

    Soyama, H.; Ikohagi, T.; Oba, R.

    1994-12-31

    Highspeed submerged water-jets ar very often successfully applied for peening and cleaning. And such a jet-working-capacity closely depends on the shedding of cavitation clouds. In order to make clear the shedding mechanism of the clouds, the authors systematically observe the aspects of a two-dimensional jet in a 0.35mm-thin narrow watercourse, ejecting from the nozzle whose throat is 4mm long and 1mm wide. The cavitating jet is carefully observed by means of a highspeed photography and a digital image processing technique. The cavitating jet is very rapidly changing with time, and the clouds associated with the highly erosive cavitation are periodically shedding, whose frequency is about 800 Hz. The vortex cavitation around the jet is also shedding in 3kHz. The acceleration levels associated with high cavitation-erosion-energy are also measured.

  12. Keeping the Edges Sharp II: Honing Simulations of Narrow Rings

    NASA Astrophysics Data System (ADS)

    Rimlinger, Thomas; Hamilton, Douglas; Hahn, Joseph M.

    2016-05-01

    It has long been believed that shepherd satellites are necessary to keep narrow rings confined. While a pair of nearby satellites brackets Saturn’s F ring and Uranus’ Epsilon ring, dozens of other ringlets observed around the outer three planets seem to be unattended. Hamilton et al. (this meeting) have argued analytically that eccentric or inclined rings can maintain their sharp edges for millions or even billions of years despite continually dissipating energy. Here, we present numerical integrations showing isolated eccentric ringlets that do not spread; our model includes only the gravity from an oblate planet, ring self-gravity, and viscosity. We use the symplectic integrator epi_int written by Hahn & Spitale (2013).For narrow rings, the weak perturbation forces that we study act on secular rather than orbital timescales. Therefore, we find that we can use an unusually long timestep, in which these weak forces are applied once every ~30 orbits, with good energy and angular momentum conservation. Long timesteps allow us to run simulations that might otherwise take hours or even days in a matter of minutes. We present comparisons between simulations with identical initial conditions but varying timesteps to show that our approach is appropriate for this class of problems. This technique of speeding up numerical integrations works for any symplectic integrator, requiring only that the forces be weak and that the timescale of interest be long. Problems well suited to this approach (those with only secular and drag forces) include tidally-damped exoplanets and dust grains subject to radiation pressure and Poynting-Robertson drag.

  13. Narrow-line fiber-coupled modules for DPAL pumping

    NASA Astrophysics Data System (ADS)

    Koenning, Tobias; McCormick, Dan; Irvin, David; Stapleton, Dean; Guiney, Tina; Patterson, Steve

    2015-03-01

    Recent advances in high power diode laser technologies have enabled advanced research on diode pumped alkali metal vapor lasers (DPALs). Due to their low quantum defect, DPALs offer the promise of scalability to very high average power levels while maintaining excellent beam quality. Research is being conducted on a variety of gain media species, requiring different pump wavelengths: near 852nm for cesium, 780nm for rubidium, 766nm for potassium, and 670nm for lithium atoms. The biggest challenge in pumping these materials efficiently is the narrow gain media absorption band of approximately 0.01nm. Typical high power diode lasers achieve spectral widths around 3nm (FWHM) in the near infrared spectrum. Gratings may be used internal or external to the cavity to reduce the spectral width to 0.5nm to 1nm for high power diode laser modules. Recently, experimental results have shown narrower line widths ranging from picometers (pm) at very low power levels to sub-100 picometers for water cooled stacks around 1kW of output power. The focus of this work is a further reduction in the spectral line width of high power diode laser bars emitting at 766nm, with full applicability to other wavelengths of interest. One factor limiting the reduction of the spectral line width is the optical absorption induced thermal gradient inside the volume Bragg grating (VBG). Simulated profiles and demonstrated techniques to minimize thermal gradients will be presented. To enable the next stage of DPAL research, a new series of fiber coupled modules is being introduced featuring greater than 400W from a 600μm core fiber of 0.22NA. The modules achieve a spectral width of <<0.1nm and wavelength tunability of +/- 0.15nm.

  14. Narrow-track wheeled agricultural tractor parameter variation.

    PubMed

    Guzzomi, A; Rondelli, V

    2013-10-01

    Despite a general consensus among farmers, manufacturers, and researchers that wheeled agricultural tractor design has changed over time, there is little published evidence. There is debate as to whether the standardized rollover protective structure (ROPS) energy and force requirements, based on a tractor reference mass and pertaining to studies conducted more than 40 years ago, are appropriate for modern tractors. This article investigated the physical parameters of 326 modern narrow-track tractors, measured according to OECD Code 6 over 16 years (1993 to 2008 inclusive): 252 (-77%) were fixed-chassis tractors and 74 (-23%) were articulated. To understand the significance of design changes, the data were analyzed with respect to time and as a function of tractor mass. Articulated and fixed-chassis data were treated separately. The time data allowed qualitative analysis, while the mass data allowed quantitative analysis. The parameters show some changes over time and clearly indicate differences between articulated and fixed-chassis types. The parameter changes, along with the differences between types, may have important safety ramifications for ROPS energy absorption requirements, and these aspects are discussed. Regression lines with R2 values were fitted to the mass-related data for fixed-chassis and articulated tractors to determine the suitability of fit. The mass relations also displayed differences between fixed-chassis and articulated tractors. Thus, the most significant recommendation from this study is that the standardized testing procedure for narrow-track wheeled agricultural tractor category should be split into two groups: fixed-chassis and articulated.

  15. II-VI Narrow-Bandgap Semiconductors for Optoelectronics

    NASA Astrophysics Data System (ADS)

    Baker, Ian

    The field of narrow-gap II-VI materials is dominated by the compound semiconductor mercury cadmium telluride, (Hg1-x Cd x Te or MCT), which supports a large industry in infrared detectors, cameras and infrared systems. It is probably true to say that HgCdTe is the third most studied semiconductor after silicon and gallium arsenide. Hg1-x Cd x Te is the material most widely used in high-performance infrared detectors at present. By changing the composition x the spectral response of the detector can be made to cover the range from 1 μm to beyond 17 μm. The advantages of this system arise from a number of features, notably: close lattice matching, high optical absorption coefficient, low carrier generation rate, high electron mobility and readily available doping techniques. These advantages mean that very sensitive infrared detectors can be produced at relatively high operating temperatures. Hg1-x Cd x Te multilayers can be readily grown in vapor-phase epitaxial processes. This provides the device engineer with complex doping and composition profiles that can be used to further enhance the electro-optic performance, leading to low-cost, large-area detectors in the future. The main purpose of this chapter is to describe the applications, device physics and technology of II-VI narrow-bandgap devices, focusing on HgCdTe but also including Hg1-x Mn x Te and Hg1-x Zn x Te. It concludes with a review of the research and development programs into third-generation infrared detector technology (so-called GEN III detectors) being performed in centers around the world.

  16. A Narrow Quantitative Trait Locus in C. elegans Coordinately Affects Longevity, Thermotolerance, and Resistance to Paraquat

    PubMed Central

    Vertino, Anthony; Ayyadevara, Srinivas; Thaden, John J.; Reis, Robert J. Shmookler

    2011-01-01

    By linkage mapping of quantitative trait loci, we previously identified at least 11 natural genetic variants that significantly modulate Caenorhabditis elegans life-span (LS), many of which would have eluded discovery by knock-down or mutation screens. A region on chromosome IV between markers stP13 and stP35 had striking effects on longevity in three inter-strain crosses (each P < 10−9). In order to define the limits of that interval, we have now constructed two independent lines by marker-based selection during 20 backcross generations, isolating the stP13–stP35 interval from strain Bergerac-BO in a CL2a background. These congenic lines differed significantly from CL2a in LS, assayed in two environments (each P < 0.001). We then screened for exchange of flanking markers to isolate recombinants that partition this region, because fine-mapping the boundaries for overlapping heteroallelic spans can greatly narrow the implicated interval. Recombinants carrying the CL2a allele at stP35 were consistently long-lived compared to those retaining the Bergerac-BO allele (P < 0.001), and more resistant to temperature elevation and paraquat (each ∼1.7-fold, P < 0.0001), but gained little protection from ultraviolet or peroxide stresses. Two rounds of recombinant screening, followed by fine-mapping of break-points and survival testing, narrowed the interval to 0.18 Mb (13.35–13.53 Mb) containing 26 putative genes and six small-nuclear RNAs – a manageable number of targets for functional assessment. PMID:22303358

  17. Gene diversity and genetic structure in a narrow endemic, torrey pine (Pinus torreyana Parry ex Carr.)

    Treesearch

    F. Thomas Ledig; M. Thompson Conkle

    1983-01-01

    Recent reviews have suggested that tree species are the most variable of organisms, as measured by proportion of polymorphic loci or average heterozygosity (Hamrick, 1979; Hamrick et al., 1979). Average heterozygosity is greater than 0.30 for several conifers. By contrast, annual herbaceous species have a mean heterozygosity of 0.13 (Hamrick et al., 1979).

  18. Whispering-Gallery-Mode Tunable Narrow-Band-Pass Filter

    NASA Technical Reports Server (NTRS)

    Savchenkov, Anatoliy; Iltchenko, Vladimir; Matsko, Andrey; Maleki, Lute

    2004-01-01

    An experimental tunable, narrow-band-pass electro-optical filter is based on a whispering-gallery resonator. This device is a prototype of tunable filters needed for the further development of reconfigurable networking wavelength-division multiplexers and communication systems that utilize radio-frequency (more specifically, microwave) subcarrier signals on optical carrier signals. The characteristics of whispering-gallery resonators that make them attractive for such applications include high tuning speed, compactness, wide tuning range, low power consumption, and compatibility with single-mode optical fibers. In addition, relative to Fabry-Perot resonators, these devices offer advantages of greater robustness and lower cost. As described in several prior NASA Tech Briefs articles, a whispering-gallery resonator is a spheroidal, disk-like, or toroidal body made of a highly transparent material. It is so named because it is designed to exploit whispering-gallery electromagnetic modes, which are waveguide modes that propagate circumferentially and are concentrated in a narrow toroidal region centered on the equatorial plane and located near the outermost edge. The experimental whispering-gallery tunable filter (see figure) is made from a disk of Z-cut LiNbO3 of 4.8-mm diameter and 0.17-mm thickness. The perimeter of the disk is rounded to a radius of curvature of 100 m. Metal coats on the flat faces of the disk serve as electrodes for exploiting the electro-optical effect in LiNbO3 for tuning. There is no metal coat on the rounded perimeter region, where the whispering-gallery modes propagate. Light is coupled from an input optical fiber into the whispering-gallery modes by means of a diamond prism. Another diamond prism is used to couple light from the whispering-gallery modes to an output optical fiber. This device is designed and operated to exploit transverse magnetic (TM) whispering- gallery modes, rather than transverse electric (TE) modes because the

  19. The Characteristics of Broad and Narrow Focal Zone Lithotripters

    NASA Astrophysics Data System (ADS)

    Pishchalnikov, Yuri A.; McAteer, James A.; VonDerHaar, R. Jason; Pishchalnikova, Irina V.; Williams, James C.

    2008-09-01

    The focal width of a lithotripter is a measure of the diameter of its focal zone, the region where acoustic pressures are at least half the maximum positive pressure generated at a given power level. Different lithotripters have different focal widths. The Dornier HM3, for example, has a focal width of ˜10-12 mm and for many years this was the widest focal zone among clinical machines. Electromagnetic lithotripters tend to have narrower focal zones, in the range of ˜4-6 mm. Recent studies suggesting that focal width plays an important role in stone breakage prompted this assessment of two electromagnetic lithotripters. Acoustical mapping using a fiber optic probe hydrophone (FOPH-500) and breakage of U-30 gypsum model stones were used to compare a conventional lithotripter (Dornier DoLi-50) and a broad focal zone device (XiXin XX-ES). FOPH mapping characterized the focal width of the DoLi to be about 5mm and that of the XX-ES to be much wider (˜18 mm). For stone breakage experiments the DoLi was fired at power level 3 (mid-range) and the XX-ES was operated at the recommended clinical setting of 9.3 kV. Both lithotripters were fired at 60 SW/min. U-30 model stones held in a 2mm mesh basket were positioned at the clinical target point on the acoustic axis and at 5mm steps laterally, and the number of SW's to complete fragmentation was counted. Breakage on-axis was similar for the two machines (DoLi 676±105 SW's versus XX-ES 644±123 SW's, p>0.6), but at 15mm the DoLi required nearly twice the number of SW's as the XX-ES (DoLi 3006±780 SW's versus 1726±972 SW's, p<0.006). This demonstrates that a broad focal zone lithotripter is more effective in breaking stones off axis and supports the idea that focal width is an important feature, likely to be relevant in the clinical setting where respiratory motion may limit the effectiveness of narrow focal zone machines.

  20. Identification of the Novel Narrow-Spectrum β-Lactamase SCO-1 in Acinetobacter spp. from Argentina▿

    PubMed Central

    Poirel, Laurent; Corvec, Stéphane; Rapoport, Melina; Mugnier, Pauline; Petroni, Alejandro; Pasteran, Fernando; Faccone, Diego; Galas, Marcelo; Drugeon, Henri; Cattoir, Vincent; Nordmann, Patrice

    2007-01-01

    By studying the β-lactamase content of several Acinetobacter spp. isolates from Argentina, producing the expanded-spectrum β-lactamases (ESBL) VEB-1a or PER-2, a novel Ambler class A β-lactamase gene was identified. It encoded the narrow-spectrum β-lactamase SCO-1, whose activity was inhibited by clavulanic acid. SCO-1 hydrolyzes penicillins at a high level and cephalosporins and carbapenems at a very low level. β-Lactamase SCO-1 was identified from unrelated VEB-1a-positive or PER-2-positive Acinetobacter spp. isolates recovered from three hospitals. The blaSCO-1 gene was apparently located on a plasmid of ca. 150 kb from all cases but was not associated with any ESBL-encoding gene. The G+C content of the blaSCO gene was 52%, a value that does not correspond to that of the A. baumannii genome (39%). β-Lactamase SCO-1 shares 47% amino acid identity with CARB-5 and ca. 40% with the enzymes TEM, SHV, and CTX-M. A gene encoding a putative resolvase was identified downstream of the blaSCO-1 gene, but its precise way of acquisition remains to be determined. PMID:17420213

  1. Associations between Narrow Angle and Adult Anthropometry: The Liwan Eye Study

    PubMed Central

    Jiang, Yuzhen; He, Mingguang; Friedman, David S.; Khawaja, Anthony P.; Lee, Pak Sang; Nolan, Winifred P.; Yin, Qiuxia; Foster, Paul J.

    2015-01-01

    Purpose To assess the associations between narrow angle and adult anthropometry. Methods Chinese adults aged 50 years and older were recruited from a population-based survey in the Liwan District of Guangzhou, China. Narrow angle was defined as the posterior trabecular meshwork not visible under static gonioscopy in at least three quadrants (i.e. a circumference of at least 270°). Logistic regression models were used to examine the associations between narrow angle and anthropomorphic measures (height, weight and body mass index, BMI). Results Among the 912 participants, lower weight, shorter height, and lower BMI were significantly associated with narrower angle width (tests for trend: mean angle width in degrees vs weight p<0.001; vs height p<0.001; vs BMI p = 0.012). In univariate analyses, shorter height, lower weight and lower BMI were all significantly associated with greater odds of narrow angle. The crude association between height and narrow angle was largely attributable to a stronger association with age and sex. Lower BMI and weight remained significantly associated with narrow angle after adjustment for height, age, sex, axial ocular biometric measures and education. In analyses stratified by sex, the association between BMI and narrow angle was only observed in women. Conclusion Lower BMI and weight were associated with significantly greater odds of narrow angle after adjusting for age, education, axial ocular biometric measures and height. The odds of narrow angle increased 7% per 1 unit decrease in BMI. This association was most evident in women. PMID:24707840

  2. "Sawfish" systolic narrowing of the left anterior descending coronary artery: an angiographic sign of hypertrophic cardiomyopathy.

    PubMed

    Brugada, P; Bär, F W; de Zwaan, C; Roy, D; Green, M; Wellens, H J

    1982-10-01

    The morphologic characteristics at coronary arteriography of systolic narrowing of the left anterior descending coronary artery (LAD) were evaluated in 14 patients. Six patients had systolic narrowing of the LAD not associated with other cardiac abnormalities (group A) and eight patients had systolic narrowing of the LAD associated with hypertrophic cardiomyopathy (group B). Patients in group A showed a smooth and progressive constriction of the vessel up to the point of maximal stenosis, giving it a "rat-tail" appearance. There was no systolic narrowing of septal branches or of other epicardial vessels in this group. In patients of group B, systolic narrowing of the LAD had a "saw-fish" appearance. Seven patients had systolic narrowing of the septal branches, and five had systolic narrowing of other epicardial vessels. These data indicate that systolic narrowing of the LAD in patients with hypertrophic cardiomyopathy differs angiographically from systolic narrowing due to an intramural course of a part of the vessel (as in group A patients). We postulate that in patients with hypertropic cardiomyopathy, fiber hypertrophy and disarray in the vicinity of the coronary vessels is responsible for the morphology and the widespread distribution of systolic narrowing.

  3. Giant Hall Photoconductivity in Narrow-Gapped Dirac Materials.

    PubMed

    Song, Justin C W; Kats, Mikhail A

    2016-12-14

    Carrier dynamics acquire a new character in the presence of Bloch-band Berry curvature, which naturally arises in gapped Dirac materials (GDMs). Here, we argue that photoresponse in GDMs with small band gaps is dramatically enhanced by Berry curvature. This manifests in a giant and saturable Hall photoconductivity when illuminated by circularly polarized light. Unlike Hall motion arising from a Lorentz force in a magnetic field, which impedes longitudinal carrier motion, Hall photoconductivity arising from Berry curvature can boost longitudinal carrier transport. In GDMs, this results in a helicity-dependent photoresponse in the Hall regime, where photoconductivity is dominated by its Hall component. We find that the induced Hall conductivity per incident irradiance is enhanced by up to 6 orders of magnitude when moving from the visible regime (with corresponding band gaps) to the far infrared. These results suggest that narrow-gap GDMs are an ideal test-bed for the unique physics that arise in the presence of Berry curvature and open a new avenue for infrared and terahertz optoelectronics.

  4. The Meteorology of Storms that Produce Narrow Bipolar Events

    NASA Technical Reports Server (NTRS)

    Lang, Timothy J.; McCaul, Eugene W.; Cummer, Steven A.

    2013-01-01

    Narrow Bipolar Events (NBEs) are compact intracloud discharges that produce the most powerful lightning-related radio frequency signals that have been observed. However, their luminosity is below the threshold for detectability from current and past spaceborne optical sensors. NBEs have been loosely associated with convective intensity, but their occurrence tends to be highly localized in time and space within a thunderstorm, and there remain many questions about whether and to what extent they are significantly related to meteorological processes within thunderstorms. Using the North Alabama Lightning Mapping Array (NALMA), the National Lightning Detection Network, and available Doppler and polarimetric radar data, case studies will be presented for storm events that produced large numbers of NBEs (10s-100s) during their lifetimes. NBEs are documented via a method that identifies high peak power (>40-50 dBW) initial VHF sources within a specific altitude band in the upper levels of thunderstorms. The production of NBEs, including spatial and temporal variability, will be compared to the radar-inferred kinematic and microphysical structure and evolution of thunderstorms, as well as their NALMA- and NLDN-inferred electrical characteristics. The results should provide new insights into the relationships between NBEs and thunderstorm processes.

  5. Effect of Regulatory Architecture on Broad versus Narrow Sense Heritability

    PubMed Central

    Wang, Yunpeng; Vik, Jon Olav; Omholt, Stig W.; Gjuvsland, Arne B.

    2013-01-01

    Additive genetic variance (VA) and total genetic variance (VG) are core concepts in biomedical, evolutionary and production-biology genetics. What determines the large variation in reported VA/VG ratios from line-cross experiments is not well understood. Here we report how the VA/VG ratio, and thus the ratio between narrow and broad sense heritability (h2/H2), varies as a function of the regulatory architecture underlying genotype-to-phenotype (GP) maps. We studied five dynamic models (of the cAMP pathway, the glycolysis, the circadian rhythms, the cell cycle, and heart cell dynamics). We assumed genetic variation to be reflected in model parameters and extracted phenotypes summarizing the system dynamics. Even when imposing purely linear genotype to parameter maps and no environmental variation, we observed quite low VA/VG ratios. In particular, systems with positive feedback and cyclic dynamics gave more non-monotone genotype-phenotype maps and much lower VA/VG ratios than those without. The results show that some regulatory architectures consistently maintain a transparent genotype-to-phenotype relationship, whereas other architectures generate more subtle patterns. Our approach can be used to elucidate these relationships across a whole range of biological systems in a systematic fashion. PMID:23671414

  6. Electronically steerable ultrasound-driven long narrow air stream

    NASA Astrophysics Data System (ADS)

    Hasegawa, Keisuke; Qiu, Liwei; Noda, Akihito; Inoue, Seki; Shinoda, Hiroyuki

    2017-08-01

    Acoustic streaming, which is the unidirectional movement of a medium driven by its internal intense acoustic vibrations, has been known for more than a century. Despite the long history of research, there have been no scientific reports on the creation of long stretching steerable airflows in an open space, generated by ultrasound. Here, we demonstrated the creation of a narrow, straight flow in air to a distance of 400 mm from an ultrasound phased array emitting a Bessel beam. We also demonstrated that the direction of the flow could be controlled by appropriately tuning the wavefronts of the emission from the phased array. Unlike conventional airflows such as those generated by jets or fans, which decelerate and spread out as they travel farther, the flow that we created proceeded while being accelerated by the kinetic energy supplied from the ultrasound beam and keeping the diameter as small as the wavelength. A flow of 3 m/s with a 10 mm diameter extended for several hundreds of millimeters in a room that was large enough to be regarded as an open-boundary environment. These properties of the generated flow will enable fine and rapid control of three-dimensional airflow distributions.

  7. Large-scale solution synthesis of narrow graphene nanoribbons

    NASA Astrophysics Data System (ADS)

    Vo, Timothy H.; Shekhirev, Mikhail; Kunkel, Donna A.; Morton, Martha D.; Berglund, Eric; Kong, Lingmei; Wilson, Peter M.; Dowben, Peter A.; Enders, Axel; Sinitskii, Alexander

    2014-02-01

    According to theoretical studies, narrow graphene nanoribbons with atomically precise armchair edges and widths of <2 nm have a bandgap comparable to that in silicon (1.1 eV), which makes them potentially promising for logic applications. Different top-down fabrication approaches typically yield ribbons with width >10 nm and have limited control over their edge structure. Here we demonstrate a novel bottom-up approach that yields gram quantities of high-aspect-ratio graphene nanoribbons, which are only ~1 nm wide and have atomically smooth armchair edges. These ribbons are shown to have a large electronic bandgap of ~1.3 eV, which is significantly higher than any value reported so far in experimental studies of graphene nanoribbons prepared by top-down approaches. These synthetic ribbons could have lengths of >100 nm and self-assemble in highly ordered few-micrometer-long ‘nanobelts’ that can be visualized by conventional microscopy techniques, and potentially used for the fabrication of electronic devices.

  8. Entanglement, excitations, and correlation effects in narrow zigzag graphene nanoribbons

    NASA Astrophysics Data System (ADS)

    Hagymási, I.; Legeza, Ö.

    2016-10-01

    We investigate the low-lying excitation spectrum and ground-state properties of narrow graphene nanoribbons with zigzag edge configurations. Nanoribbons of comparable widths have been synthesized very recently [P. Ruffieux et al., Nature (London) 531, 489 (2016)], 10.1038/nature17151, and their descriptions require more sophisticated methods since in this regime conventional methods, like mean-field or density-functional theory with local-density approximation, fail to capture the enhanced quantum fluctuations. Using the unbiased density-matrix renormalization-group algorithm, we calculate the charge gaps with high accuracy for different widths and interaction strengths and compare them with mean-field results. It turns out that the gaps are much smaller in the former case due to the proper treatment of quantum fluctuations. Applying the elements of quantum information theory, we also reveal the entanglement structure inside a ribbon and examine the spectrum of subsystem density matrices to understand the origin of entanglement. We examine the possibility of magnetic ordering and the effect of magnetic field. Our findings are relevant for understanding the gap values in different recent experiments and the deviations between them.

  9. Concurrent bandgap narrowing and polarization enhancement in epitaxial ferroelectric nanofilms

    PubMed Central

    Yao, Lide; Chvostova, Dagmar; Dejneka, Alexandr; Kocourek, Tomas; Jelinek, Miroslav; Trepakov, Vladimir; van Dijken, Sebastiaan

    2015-01-01

    Perovskite-type ferroelectric (FE) crystals are wide bandgap materials with technologically valuable optical and photoelectric properties. Here, versatile engineering of electronic transitions is demonstrated in FE nanofilms of KTaO3, KNbO3 (KNO), and NaNbO3 (NNO) with a thickness of 10–30 unit cells. Control of the bandgap is achieved using heteroepitaxial growth of new structural phases on SrTiO3 (001) substrates. Compared to bulk crystals, anomalous bandgap narrowing is obtained in the FE state of KNO and NNO films. This effect opposes polarization-induced bandgap widening, which is typically found for FE materials. Transmission electron microscopy and spectroscopic ellipsometry measurements indicate that the formation of higher-symmetry structural phases of KNO and NNO produces the desirable red shift of the absorption spectrum towards visible light, while simultaneously stabilizing robust FE order. Tuning of optical properties in FE films is of interest for nanoscale photonic and optoelectronic devices. PMID:27877779

  10. 37 GHz observations of narrow-line Seyfert 1 galaxies

    NASA Astrophysics Data System (ADS)

    Lähteenmäki, A.; Järvelä, E.; Hovatta, T.; Tornikoski, M.; Harrison, D. L.; López-Caniego, M.; Max-Moerbeck, W.; Mingaliev, M.; Pearson, T. J.; Ramakrishnan, V.; Readhead, A. C. S.; Reeves, R. A.; Richards, J. L.; Sotnikova, Y.; Tammi, J.

    2017-07-01

    Observations performed at Metsähovi Radio Observatory at 37 GHz are presented for a sample of 78 radio-loud and radio-quiet narrow-line Seyfert 1 (NLS1) galaxies, together with additional lower and higher frequency radio data from RATAN-600, Owens Valley Radio Observatory, and the Planck satellite. Most of the data have been gathered between February 2012 and April 2015 but for some sources even longer light curves exist. The detection rate at 37 GHz is around 19%, which is comparable to other populations of active galactic nuclei presumed to be faint at radio frequencies, such as BL Lac objects. Variability and spectral indices are determined for sources with enough detections. Based on the radio data, many NLS1 galaxies show a blazar-like radio spectra exhibiting significant variability. The spectra at a given time are often inverted or convex. The source of the high-frequency radio emission in NLS1 galaxies, detected at 37 GHz, is most probably a relativistic jet rather than star formation. Jets in NLS1 galaxies are therefore expected to be a much more common phenomenon than earlier assumed. Full Table 7 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/603/A100

  11. Narrower bottlenecks could be more efficient for concentrating choanoflagellates

    NASA Astrophysics Data System (ADS)

    Sparacino, J.; Miño, G.; Koehl, M. A. R.; King, N.; Stocker, R.; Banchio, A. J.; Marconi, V. I.

    2015-11-01

    In evolutionary biology choanoflagellates are broadly investigated as the closest living relatives of the animal ancestors. Under diverse environmental cues, choanoflagellate Salpingoeca rosetta can differentiate in two types of solitary swimming cells: slow and fast microswimmers. Here we present a first phenomenological 2D-model for the choanoflagellates dynamics confined into a flat device divided by a wall of asymmetric microconstrictions. The model allow us to optimize the geometry of the microchannels for directing and concentrating cell populations under strict control. We solve our set of dynamical equations using Langevin dynamics. Experimental parameters for the motility of the slow and fast cells were measured and used for our numerical estimations of the directed transport efficiency, otherwise we have no adjustable parameters. We find remarkable differences in the rectification results for slow and fast choanoflagellates, which give us a strategy to develop a suitable microfluidic sorting device. For a given population velocity, narrower bottlenecks, of similar size to the cell dimension, show to be more efficient as concentrator of populations. Experiments and simulations are in good agreement.

  12. Radio properties of narrow-lined Seyfert 1 galaxies

    NASA Technical Reports Server (NTRS)

    Ulvestad, James S.; Antonucci, Robert R. J.; Goodrich, Robert W.

    1995-01-01

    We have observed seven narrow-linedd Seyfert 1 (NLS1) galaxies and one high-ionization Seyfert 2 galaxy with the Very Large Array (VLA). Combining these observations with published data, we summarize the radio properties of the NLS1 galaxies for which spectropolarimetry was reported by Goodrich. Fifteen of these 17 objects now have published radio observations of high sensitivity, and only nine of those have been detected. For a Hubble parameter of 75 km/s/Mpc, the 6 cm radio powers range from 10(exp 20) to 10(exp 23) W/Hz, within the range previously found for other types of Seyfert galaxy. The median radio size of the nine VLA-detected galaxies is no larger than 300 pc, similar to the median size found by Ulvestad & Wilson for a distance-limited sample of Seyfert galaxies. Of the six NLS1 galaxies known to have significant intrinsic optical polarization, three have measurable radio axes. Two of those three galaxies have radio major axes close to 90 deg from their polarization position angles, while the third has an inner radio axis that may be nearly parallel to the polarization position angle. The former relationship is expected for a Seyfert 1 in a unified model of Seyfert galaxies, assuming no intrinsic continuum polarization.

  13. Narrow-band Imagery of the ISM using the RCT

    NASA Astrophysics Data System (ADS)

    Walter, D. K.; Gelderman, R.; Guinan, E.; Howell, S.; Mattox, J. R.; McGruder, C. H., III; Davis, D.; Everett, M.

    2003-05-01

    We present the first results of imaging the Interstellar Medium (ISM) using narrow-band filters with the Robotically Controlled Telescope (RCT). The RCT is the recently refurbished 1.3-meter telescope at the Kitt Peak National Observatory. Details regarding the RCT can be found elsewhere at this meeting (Gelderman, R. et al.). Our filters are centered on diagnostic, nebular emission lines of the ions H+, He+, S+, N+ and O++. Objects of interest in the galactic and extragalactic ISM were observed including the starburst galaxy NGC 4449. Ionization ratio maps include [OIII]/Hβ, [NII]/Hα and the C(Hβ) extinction map from the ratio of Hα/Hβ. Electron densities are derived from the ratio of images taken through filters centered on the sulfur lines at 671.7 and 673.1 nm. Refurbishment of the RCT has been made possible by NASA NAG 58-762. Funding for filters and additional equipment has been made possible by NASA OSS NAG 5-10145 and NASA MU-SPIN NCC 5-534.

  14. Modeling the Mechanosensitivity of Neutrophils Passing through a Narrow Channel.

    PubMed

    Wu, Tenghu; Feng, James J

    2015-12-01

    Recent experiments have found that neutrophils may be activated after passing through microfluidic channels and filters. Mechanical deformation causes disassembly of the cytoskeleton and a sudden drop of the elastic modulus of the neutrophil. This fluidization is followed by either activation of the neutrophil with protrusion of pseudopods or a uniform recovery of the cytoskeleton network with no pseudopod. The former occurs if the neutrophil traverses the narrow channel at a slower rate. We propose a chemo-mechanical model for the fluidization and activation processes. Fluidization is treated as mechanical destruction of the cytoskeleton by sufficiently rapid bending. Loss of the cytoskeleton removes a pathway by which cortical tension inhibits the Rac protein. As a result, Rac rises and polarizes through a wave-pinning mechanism if the chemical reaction rate is fast enough. This leads to recovery and reinforcement of the cytoskeleton at the front of the neutrophil, and hence protrusion and activation. Otherwise the Rac signal returns to a uniform pre-deformation state and no activation occurs. Thus, mechanically induced neutrophil activation is understood as the competition between two timescales: that of chemical reaction and that of mechanical deformation. The model captures the main features of the experimental observation.

  15. Indian power generation market: Narrowing the gap between supply & demand

    SciTech Connect

    Wilson, R.

    1997-01-01

    It is estimated that per capita consumption of electricity in India is less than 350 kWh per year, an extremely low level by world standards. India accounts for 16% of the world`s population, but only 3% of world energy consumption. Massive investments, as much as US $10 billion over the next five years, are needed to narrow the gap between supply and demand. Power sector policy reforms dating back to 1991 have encouraged private investors, but the lndian bureaucracy itself still bubbles with protectionist leanings and corruption, resulting in delays and inefficiencies. Stakes in the Indian power sector are so high, however, that investor interest is still keen. Most predict better than double-digit growth in the Indian energy sector through 2000. Those who have been persistent in courting the India power sector will eventually reap the rewards. This paper describes some of the projects in the works at present and the companies and equipment manufacturers involved. 6 figs.

  16. Role of narrow band imaging in endoscopic submucosal dissection

    PubMed Central

    Nonaka, Kouichi; Nishimura, Makoto; Kita, Hiroto

    2012-01-01

    Narrow band imaging (NBI) is a new image enhancement system employing optic digital methods to enhance images of blood vessels on mucosal surfaces, allowing improved visualization of mucosal surface structures. Studies have progressed over the last several years, and the clinical usefulness has been demonstrated. NBI has become frequently applied for preoperative diagnosis before endoscopic submucosal dissection (ESD) of digestive tract cancers, as well as for assessment of the range of ESD for en-bloc resection of large lesions. Consensus has been reached with regard to the usefulness of NBI for detecting micro-lesions of esophageal squamous cell carcinoma indicated for ESD, for the diagnosis of the range and depth. NBI has also been attracting attention for diagnosing gastric cancer based on the observation of micro blood vessels on the mucosal surface and mucosal surface microstructures. The usefulness of NBI has been reported in relation to various aspects of colon cancer, including diagnoses of the presence, quality, range, and depth of lesions. However, as NBI has not surpassed diagnostic methods based on magnifying observation combined with the established and widely employed dye method, its role in ESD is limited at present. Although NBI is very useful for the diagnosis of digestive tract cancers, comprehensive endoscopic diagnosis employing the combination of conventional endoscopy including dye spraying, EUS, and NBI may be important and essential for ESD. PMID:23125896

  17. Numerical Simulation for Mechanism of Airway Narrowing in Asthma

    NASA Astrophysics Data System (ADS)

    Bando, Kiyoshi; Yamashita, Daisuke; Ohba, Kenkichi

    A calculation model is proposed to examine the generation mechanism of the numerous lobes on the inner-wall of the airway in asthmatic patients and to clarify luminal occlusion of the airway inducing breathing difficulties. The basement membrane in the airway wall is modeled as a two-dimensional thin-walled shell having inertia force due to the mass, and the smooth muscle contraction effect is replaced by uniform transmural pressure applied to the basement membrane. A dynamic explicit finite element method is used as a numerical simulation method. To examine the validity of the present model, simulation of an asthma attack is performed. The number of lobes generated in the basement membrane increases when transmural pressure is applied in a shorter time period. When the remodeling of the basement membrane occurs characterized by thickening and hardening, it is demonstrated that the number of lobes decreases and the narrowing of the airway lumen becomes severe. Comparison of the results calculated by the present model with those measured for animal experiments of asthma will be possible.

  18. Capping Layer Effects on Electromigration in Narrow Cu Lines

    SciTech Connect

    Hu, C.-K.; Rosenberg, R.

    2004-12-08

    Electromigration in narrow (bamboo-like) Cu Damascene lines capped with either a CoWP, Ta/TaN, SiNx, or SiCxNyHz layer is reviewed. A thin CoWP or Ta/TaN cap on top of the Cu line surface significantly reduces interface diffusion and improves the electromigration lifetime when compared with lines capped with SiNx or SiCxNyHz. Activation energies for electromigration were found to be 1.9-2.4 eV, 1.4 eV, and 0.85-1.1 eV for the Cu lines capped with CoWP, Ta/TaN, and SiNx or SiCxNyHz, respectively. Relationships between line width, diffusion path, void nucleation sites and lifetime are presented. Resistance changes in the CoWP coated lines were related to the solubility and diffusivity of Co in Cu such that void growth caused by electromigration was detectable only as a significant resistance increase over that caused by the Co. The solubility and diffusivity of Co in Cu was determined from line resistance measurements of thermally annealed Cu lines with CoWP caps. The activation energy of Co diffusion in Cu lines was found to be 2.2 eV, and the solubility limit of Co in Cu was found to be 18e(-0.57eV/kT) atomic percent.

  19. Simulation of Micro Bubble in a Narrow Tube

    NASA Astrophysics Data System (ADS)

    Ye, Tao; Bull, Joseph L.

    2003-11-01

    We are investigating a new gas embolotherapy technique that involves acoustically vaporizing perfluorocarbon liquid droplets to form gas bubbles, which are large enough to occlude flow in arterioles and capillaries with the goal of starving tumors. The bubbles typically originate as 6 micrometer, liquid droplets that are small enough to pass through capillaries. These droplets can be observed using ultrasound imaging and then vaporized by a high intensity ultrasound field when they are at the desired location. Vaporization close to the tumor will minimize the infarction of healthy tissue, but poses the risk of vessel rupture and subsequent hemorrhage if the bubbles are formed in too small of vessels. Mechanical stresses induced by bubble growth and collapse need to be determined in order to prevent rupture of the blood vessel or endothelial cell injury. In this study, the physics of the micro-scale bubble growth/collapse in a narrow tube with a flexible wall is investigated using direct numerical simulation. The computational method is a novel shape-interface, moving boundary method for solving full Navier-Stokes equations of multi-phase fluid flows with dynamic interfaces. Dimensionless parameters are varied to examine the effects of viscosity, surface tension, and bubble pressure. Our simulations reveal that normal and shear stress on the vessel wall reach peak values at different stages with peak magnitude of normal stress far greater than that of shear stress. The initial phase of the bubble expansion is the most dangerous period for the vessel in all cases.

  20. Flight Calibration of the LROC Narrow Angle Camera

    NASA Astrophysics Data System (ADS)

    Humm, D. C.; Tschimmel, M.; Brylow, S. M.; Mahanti, P.; Tran, T. N.; Braden, S. E.; Wiseman, S.; Danton, J.; Eliason, E. M.; Robinson, M. S.

    2016-04-01

    Characterization and calibration are vital for instrument commanding and image interpretation in remote sensing. The Lunar Reconnaissance Orbiter Camera Narrow Angle Camera (LROC NAC) takes 500 Mpixel greyscale images of lunar scenes at 0.5 meters/pixel. It uses two nominally identical line scan cameras for a larger crosstrack field of view. Stray light, spatial crosstalk, and nonlinearity were characterized using flight images of the Earth and the lunar limb. These are important for imaging shadowed craters, studying ˜1 meter size objects, and photometry respectively. Background, nonlinearity, and flatfield corrections have been implemented in the calibration pipeline. An eight-column pattern in the background is corrected. The detector is linear for DN = 600--2000 but a signal-dependent additive correction is required and applied for DN<600. A predictive model of detector temperature and dark level was developed to command dark level offset. This avoids images with a cutoff at DN=0 and minimizes quantization error in companding. Absolute radiometric calibration is derived from comparison of NAC images with ground-based images taken with the Robotic Lunar Observatory (ROLO) at much lower spatial resolution but with the same photometric angles.

  1. Use of narrow band imaging in assessing duodenal villous atrophy.

    PubMed

    Goswami, Amitava; Dadhich, Sunil; Bhargava, Narendra

    2014-09-01

    Narrow band imaging endoscopy with magnification (NBI-ME) has already been established in Barrett's esophagus, stomach, and colonic mucosa, but limited work has been done in the mucosal evaluation of duodenum. A study was done to determine the correlation between NBI and histology in grading villous architecture in varied etiology. A prospective observational study comprising 105 subjects with suspected malabsorption. The presence of a diagnosed celiac disease, severe life threatening comorbidity, or pregnancy was considered as exclusion criteria. Standard endoscopy (SE), NBI-ME, multiple duodenal biopsies with histopathological examination were done in all. Fifty-one patients had celiac disease while 54 patients comprised mainly functional dyspepsia, iron deficiency anemia, tropical malabsorption syndrome, and irritable bowel syndrome. Four NBI-ME image subtypes of villous morphology have been proposed (NBI type I/II/III/IV). NBI-ME had 95 % sensitivity, 90.2 % specificity, 91.2 % positive predictive value, and 94.2 % negative predictive value for diagnosing altered villous morphology. Intraobserver kappa agreement coefficient (κ) for NBI-ME was 0.83 while interobserver agreement was 0.89 (95 % CI 0.8-0.97). NBI-ME has good performance characteristics and very good kappa intra/interobserver agreement coefficient for varied subtypes of villous morphology. NBI-ME is most useful for obtaining a targeted biopsy which can be missed by conventional white light endoscopy.

  2. Narrow-band ELF events observed from South Pole Station

    NASA Astrophysics Data System (ADS)

    Heavisides, J.; Weaver, C.; Lessard, M.; Weatherwax, A. T.

    2012-12-01

    Extremely Low Frequency (ELF) waves are typically in the range of 3 Hz - 3 kHz and can play a role in acceleration and pitch-angle scattering of energetic particles in the radiation belts. Observations of a not uncommon, but not well studied ELF phenomenon are presented with ground-based data from South Pole Station. The narrow-band waves last approximately one or two minutes maintaining bandwidth over the course of the event, begin around 100 Hz, decrease to about 70 Hz, and typically show a higher frequency harmonic. The waves have only been documented at four locations - Heacock, 1974 (Alaska); Sentman and Ehring, 1994 (California); Wang et al, 2005 and Wang et al, 2011 (Taiwan); and Kim et al, 2006 (South Pole). The waves observed at the South Pole are not detected when the Sun drops below a 10 degree elevation angle, which is not true for the other locations. We extend the study of Kim et al, 2006, and explore possible generation mechanisms including sunlit ionosphere and ion cyclotron wave modes, as well as correspondence with energetic particle precipitation.

  3. Measurement and visualization of impingement cooling in narrow channels

    NASA Astrophysics Data System (ADS)

    Kaiser, E.

    Experimental measurement techniques such as naphthalene sublimation, liquid crystal thermography and real-time holographic interferometry are standard. Their application in narrow channels causes problems and is therefore limited. The channel width must not change too much because the naphthalene sublimation and the liquid crystal coating necessary for the thermography may cause non-negotiable variations. The interferometry fails in turbulent flow area. The diffraction along the channel edges is an additional difficulty. A comparison of the results obtained from the application of all three techniques, which has not been considered in earlier publications, is made here. The methods were used to measure and visualize the heat transfer characteristics of an array of 1.2mm diameter impinging jets in an enclosed channel (>=2.2mm) with single-sided flow-off at Reynolds numbers of about Rez 20,000. Scale-up ratios as low as 2.4 have been used in order to maintain similarity as it has not been previously reported. The naphthalene technique provided a high spatially resolved measurement of the Sherwood number along a downstream line. The liquid crystal thermography technique provided 2D contours of the Nusselt number. The temperature distribution within dead water zones was visualized with holographic interferometry. The cross-flow effects caused a shift in the stagnation point and a monotone decrease in the Nusselt number in the downstream direction.

  4. Increasing antimicrobial resistance and narrowing therapeutics in typhoidal salmonellae.

    PubMed

    Kaurthe, Jaspal

    2013-03-01

    Multidrug-resistant typhoid fever (MDRTF) is a major public health problem in developing countries and is an emerging problem in the developed world. Because of the difficulties in preventing typhoid by public health measures or immunization in developing countries, great reliance is placed on antimicrobial chemotherapy. The treatment should commence as soon as the clinical diagnosis is made rather than after the results of antimicrobial susceptibility tests but the existence of MDRTF poses a serious clinical dilemma in the selection of empiric antimicrobial therapy. With the widespread emergence and spread of strains resistant to chloramphenicol, ampicillin and trimethoprim, ciprofloxacin became the drug of choice for the treatment of typhoid fever. However, of late the efficacy of fluoroquinolones too has been questioned, mainly due to increasing reports of increasing defervescence time and poor patient response. This indicates that the organism has begun to develop resistance to fluoroquinolones, and is corroborated by a steady increase in Minimum Inhibitory Concentration (MIC) of ciprofloxacin. The therapeutics of ciprofloxacin-resistant enteric fever narrows down to third- and fourth-generation cephalosporins and azithromycin. However, the emergence of extended-spectrum b-lactamases (ESBLs) in typhoidal Salmonellae poses a new challenge and would greatly limit the therapeutic options leaving only tigecycline and carbepenems as secondary antimicrobial drugs. This increasing resistance is alarming and emphasizes the need of effective preventive measures to control typhoid and to limit the unnecessary use of antibiotics.

  5. Narrow lines from alpha-alpha reactions. [in Galaxy

    NASA Technical Reports Server (NTRS)

    Kozlovsky, B.; Ramaty, R.

    1977-01-01

    Intensities and spectral shapes of the prompt gamma-ray lines of Li-7 at 0.431 MeV and Be-7 at 0.478 MeV and of the delayed 0.478-MeV line, all resulting from alpha-alpha reactions, are calculated using recent direct measurements of the cross sections for the alpha-alpha reactions. It is found that the intensities of these lines are comparable to that of the 4.44-MeV line of C-12, so that the investigated lines should be observable in large solar flares, provided their Doppler widths are not excessively large. An evaluation of the shapes of the prompt lines indicates that for an isotropic distribution of energetic alpha-particles, the two lines merge into a broad feature which essentially cannot be distinguished from the continuum. A situation in which the delayed 0.478-MeV line could be very narrow is considered.

  6. Grouping behavior of coaxial settling particles in a narrow channel.

    PubMed

    Nie, Deming; Lin, Jianzhong; Chen, Rongqian

    2016-01-01

    Using numerical simulations, we studied the grouping behaviors of particles settling along their line of centers in narrow channels having a Reynolds number range of 5 ≤ Re ≤ 50. The calculations are based on our previously developed lattice Boltzmann direct-forcing-fictitious-domain method. We report the grouping behavior and investigate the dependence on the number of particles n, the initial interparticle separation h_{0}, and the Reynolds number Re. In particular, the mode of grouping is found to be independent of the number of particles when the Reynolds numbers is small. The two lowermost particles always come together first and form a vertical doublet and then the next two lowest particles form another doublet, and so on. Therefore, we observe n/2 doublets or (n-1)/2 doublets when n is even or odd, respectively. The uppermost particle is always left behind when n is odd. Furthermore, the separation between these doublets remains constant, displaying a power-law dependence decreasing from top to bottom.

  7. Extreme ultraviolet narrow band emission from electron cyclotron resonance plasmas.

    PubMed

    Zhao, H Y; Zhao, H W; Sun, L T; Zhang, X Z; Wang, H; Ma, B H; Li, X X; Zhu, Y H; Sheng, L S; Zhang, G B; Tian, Y C

    2008-02-01

    Extreme ultraviolet lithography (EUVL) is considered as the most promising solution at and below dynamic random access memory 32 nm half pitch among the next generation lithography, and EUV light sources with high output power and sufficient lifetime are crucial for the realization of EUVL. However, there is no EUV light source completely meeting the requirements for the commercial application in lithography yet. Therefore, ECR plasma is proposed as a novel concept EUV light source. In order to investigate the feasibility of ECR plasma as a EUV light source, the narrow band EUV power around 13.5 nm emitted by two highly charged ECR ion sources -- LECR2M and SECRAL -- was measured with a calibrated EUV power measurement tool. Since the emission lines around 13.5 nm can be attributed to the 4d-5p transitions of Xe XI or the 4d-4f unresolved transition array of Sn VIII-XIII, xenon plasma was investigated. The dependence of the EUV throughput and the corresponding conversion efficiency on the parameters of the ion source, such as the rf power and the magnetic confinement configurations, were preliminarily studied.

  8. Dielectric response of polar liquids in narrow slit pores.

    PubMed

    Froltsov, Vladimir A; Klapp, Sabine H L

    2007-03-21

    Based on molecular dynamics (MD) simulations and a simple (Stockmayer) model we investigate the static and dynamic dielectric response of polar liquids confined to narrow slit pores. The MD simulations are used to calculate the time-dependent polarization fluctuations along directions parallel and perpendicular to the walls, from which the components of the frequency-dependent dielectric tensor can be derived via linear response theory. Our numerical results reveal that the system's response is strongly anisotropic. The parallel dielectric function, epsilonparallel(omega), has Debye-like character very similar to the corresponding isotropic bulk function, epsilonbulk(omega), at the same chemical potential. Indeed, the main confinement effect on epsilonparallel(omega) consists in a shift toward smaller values relative to the bulk function. On the other hand, in the perpendicular direction we observe a characteristic peak in the absorption part of the dielectric function, epsilonperpendicular(omega). This peak is absent in the bulk system and reflects strongly pronounced, damped oscillations in the polarization fluctuations normal to the walls. We discuss two possible origins of the oscillations (and the resulting absorption peak), that is collective oscillations of dipoles in clusters formed parallel to the walls, and the existence of a "dipolaron mode" previously observed in MD simulations of bulk polar fluids.

  9. Anisotropic dynamics of dipolar liquids in narrow slit pores.

    PubMed

    Froltsov, Vladimir A; Klapp, Sabine H L

    2006-04-07

    We report molecular dynamics simulation results for Stockmayer fluids confined to narrow slitlike pores with structureless, nonconducting walls. The translational and rotational dynamics of the dipolar particles have been investigated by calculating autocorrelation functions, diffusion coefficients, and relaxation times for various pore widths (five or less particle diameters) and directions parallel and perpendicular to the walls. The dynamic properties of the confined systems are compared to bulk properties, where corresponding bulk and pore states at the same temperature and chemical potential are determined in parallel grand canonical Monte Carlo simulations. We find that the dynamic behavior inside the pore depends on the distance from the walls and can be strongly anisotropic even in globally isotropic systems. This concerns especially the particles in the surface layers close to the walls, where the single particle and collective dipolar relaxation resemble that of true two-dimensional dipolar fluids with different in-plane and out-of-plane relaxations. On the other hand, bulklike relaxation is observed in the pore center of sufficiently wide pores.

  10. Testing Different Survey Techniques to Model Architectonic Narrow Spaces

    NASA Astrophysics Data System (ADS)

    Mandelli, A.; Fassi, F.; Perfetti, L.; Polari, C.

    2017-08-01

    In the architectural survey field, there has been the spread of a vast number of automated techniques. However, it is important to underline the gap that exists between the technical specification sheet of a particular instrument and its usability, accuracy and level of automation reachable in real cases scenario, especially speaking about Cultural Heritage (CH) field. In fact, even if the technical specifications (range, accuracy and field of view) are known for each instrument, their functioning and features are influenced by the environment, shape and materials of the object. The results depend more on how techniques are employed than the nominal specifications of the instruments. The aim of this article is to evaluate the real usability, for the 1:50 architectonic restitution scale, of common and not so common survey techniques applied to the complex scenario of dark, intricate and narrow spaces such as service areas, corridors and stairs of Milan's cathedral indoors. Tests have shown that the quality of the results is strongly affected by side-issues like the impossibility of following the theoretical ideal methodology when survey such spaces. The tested instruments are: the laser scanner Leica C10, the GeoSLAM ZEB1, the DOT DPI 8 and two photogrammetric setups, a full frame camera with a fisheye lens and the NCTech iSTAR, a panoramic camera. Each instrument presents advantages and limits concerning both the sensors themselves and the acquisition phase.

  11. Mechanical filtering for narrow-band hearing in the weta.

    PubMed

    Lomas, Kathryn; Montealegre-Z, Fernando; Parsons, Stuart; Field, Larry H; Robert, Daniel

    2011-03-01

    This paper constitutes a major attempt to associate tympanic deflections with the mechanoreceptor organ location in an acoustic insect. The New Zealand tree weta (Hemideina thoracica) has tympanal ears located on each of the prothoracic tibiae. The tympana exhibit a sclerotized oval plate, membranous processes bulging out from the tibial cuticle and many loosely suspended ripples. We used microscanning laser Doppler vibrometry to determine how such a tympanal membrane vibrates in response to sound and whether the sclerotized region plays a role in hearing. The tympanum displays a single resonance at the calling frequency of the male, an unusual example of an insect tympana acting as a narrow bandpass filter. Both tympana resonate in phase with the stimulus and with each other. Histological sections show that the tympanal area is divided into two distinct regions, as in other ensiferans. An oval plate lies in the middle of a thickened region and is surrounded by a transparent and uniformly thin region. It is hinged dorsally to the tympanal rim and thus resembles the model of a 'hinged flap'. The thickened region appears to act as a damping mass on the oscillation of the thin region, and vibration displacement is reduced in this area. The thinner area vibrates with higher amplitude, inducing mechanical pressure on the dorsal area adjacent to the crista acustica. We present a new model showing how the thickened region might confer a mechanical gain onto the activation of the crista acustica sensory neurons during the sound-induced oscillations.

  12. Mass Outflow in the Narrow Line Region of Markarian 573

    NASA Astrophysics Data System (ADS)

    Revalski, Mitchell; Crenshaw, D. Michael; Fischer, Travis C.; Kraemer, Steven B.; Schmitt, Henrique R.

    2016-01-01

    We present our progress toward determining the mass outflow rate in the narrow emission line region (NLR) of the Seyfert 2 galaxy Markarian 573. Mass outflows in Active Galactic Nuclei (AGN) drive gas away from the central supermassive black hole (SMBH) into the circumnuclear environment, and may play an important role in regulating the growth of the SMBH, and its coevolution with the host galaxy bulge. Recent work by Crenshaw et al. (2015, ApJ, 799, 83) found that the mass outflow rate in the NLR of NGC 4151 is too large for the outflowing mass to have originated only from the central region, indicating a significant amount of gas is picked up by the outflow as it travels away from the nucleus. Using archival spectra taken with the Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS), we are working to determine the mass outflow rates in a sample of 10 Seyfert galaxies to determine if correlations exist between their outflows and other properties including galaxy luminosity. To accomplish this, we will analyze the emission line spectra using photoionization models to determine the mass of the outflowing gas. Combining this information with previous kinematic modeling from Fischer et al. (2013, ApJS, 209, 1), we can determine the mass outflow rates and kinetic luminosities as a function of radius from the nucleus. These quantities will provide a direct comparison between observation and theoretical feedback models, allowing us to determine the significance of these outflows in regulating AGN feedback.

  13. Flow of interacting colloidal suspensions through a narrow channel

    NASA Astrophysics Data System (ADS)

    Cruz Hidalgo, Raul; Arietaleaniz, Sara; Pagonabarraga, Ignacio

    In this work we numerically study the constitutive behavior of interacting colloidal suspensions at intermediate and high concentrations. The influence of the interaction potential strength on the system's response is examined, in suspensions flowing through narrow channels at low Reynold's numbers. Using Lattice Boltzmann methods, we analyze the rheological response of a colloidal suspension once the steady state is established. In dilute suspensions we always recover a newtonian behavior. At higher volume fractions, the range and strength of the interaction potential has a stronger impact in the behavior of the suspension. While for short range potentials, the non-newtonian response mostly depends on colloid concentration and confinement distance, for a Lennard-Jones potential we identify two rheological responses depending on the potential strength, ξLJ, at a given concentration. For weak ξLJ the effective viscosity, ηeff , decreases until a minimum is reached. On the contrary, at large values of ξLJ the effective viscosity ηeff increases when increasing the strength of interaction. This behavior has been correlated with the local structure of this complex fluid.

  14. Narrow band gap conjugated polymers for emergent optoelectronic technologies

    NASA Astrophysics Data System (ADS)

    Azoulay, Jason D.; Zhang, Benjamin A.; London, Alexander E.

    2015-09-01

    Conjugated organic molecules effectively produce and harvest visible light and find utility in a variety of emergent optoelectronic technologies. There is currently interest in expanding the scope of these materials to extend functionality into the infrared (IR) spectral regions and endow functionality relevant in emergent technologies. Developing an understanding of the interplay between chemical and electronic structure in these systems will require control of the frontier orbital energetics (separation, position, and alignment), ground state electronic configurations, interchain arrangements, solid-state properties, and many other molecular features with synthetic precision that has yet to be demonstrated. Bridgehead imine substituted 4H-cyclopenta[2,1-b:3,4-b']dithiophene (CPDT) structural units, in combination with strong acceptors with progressively delocalized π-systems, afford modular donor-acceptor copolymers with broad and long wavelength absorption that spans technologically relevant wavelength (λ) ranges from 0.7 < λ < 3.2 μm.1 Here we demonstrate that electronic and structural manipulation play a major role in influencing the energetics of these systems and ultimately controlling the band gap of the materials. These results bear implication in the development of very narrow band gap systems where precise control will be necessary for achieving desired properties such as interactions with longer wavelength light.

  15. The Use of Narrow Diameter Implants in the Molar Area

    PubMed Central

    Saad, M.; Assaf, A.; Gerges, E.

    2016-01-01

    Implant rehabilitations in the posterior jaw are influenced by many factors such as the condition of the remaining teeth, the force factors related to the patient, the quality of the bone, the maintenance of the hygiene, the limited bone height, the type and extent of edentulism, and the nature of the opposing arch. The gold standard is to place a regular diameter implant (>3.7 mm) or a wide one to replace every missing molar. Unfortunately, due to horizontal bone resorption, this option is not possible without lateral bone augmentation. In this situation, narrow diameter implant (NDI < 3.5 mm) could be the alternative to lateral bone augmentation procedures. This paper presents a clinical study where NDIs were used for the replacement of missing molars. They were followed up to 11 years. Special considerations were observed and many parameters were evaluated. NDI could be used to replace missing molar in case of moderate horizontal bone resorption if strict guidelines are respected. Yet, future controlled prospective clinical trials are required to admit their use as scientific evidence. PMID:27293436

  16. Modular design of long narrow scintillating cells for ILC detector

    SciTech Connect

    Beznosko, D.; Blazey, G.; Dyshkant, A.; Maloney, J.; Rykalin, V.; Schellpfeffer, J.; /Fermilab

    2005-09-01

    The experimental results for the narrow scintillating elements with effective area about 20 cm{sup 2} are reported. The elements were formed from the single piece of scintillator and were read out via wavelength shifting fibers with the MRS (Metal/Resistor/Semiconductor) photodiodes on both ends of each fiber. The formation of the cells from the piece of scintillator by using grooves is discussed. The cell performance was tested using the radioactive source by measuring the PMT current and a single rate after amplifier and discrimination with threshold at about three photo electrons in each channel and quad coincidences (double coincidences between sensors on each fiber and double coincidences between two neighboring fibers). This result is of high importance for large multi-channel systems, i.e. module may be used as an active element for calorimeter or muon system for the design of the future electron-positron linear collider detector because cell effective area can be smoothly enlarged or reduced (to 4 cm{sup 2} definitely).

  17. Probing Quasar Winds Using Intrinsic Narrow Absorption Lines

    NASA Astrophysics Data System (ADS)

    Culliton, Christopher S.; Charlton, Jane C.; Eracleous, Michael; Roberts, Amber; Ganguly, Rajib; Misawa, Toru; Muzahid, Sowgat

    2017-01-01

    Quasar outflows are important for understanding the accretion and growth processes of the central black hole. Furthermore, outflows potentially have a role in providing feedback to the galaxy, and halting star formation and infall of gas. The geometry and density of these outflows remain unknown, especially as a function of ionization and velocity. Having searched ultraviolet spectra at both high redshift (VLT/UVES; 1.4narrow absorption lines (NALs) that are intrinsic to (physically associated with) the quasar. We identify intrinsic NALs with a wide range of properties, including ejection velocity, coverage fraction, and ionization level. We also consider the incidence of intrinsic absorbers as a function of quasar properties (optical, radio and X-ray fluxes), and find that radio properties and quasar orientation are influential in determining if a quasar is likely to host an intrinsic system. We find that there is a continuum of properties within the intrinsic NAL sample, rather than discrete families, ranging from partially covered CIV systems with black Lya and with a separate low ionization gas phase to partially covered NV systems with partially covered Lya and without detected low ionization gas. Additionally, we construct a model describing the spatial distributions, geometries, and varied ionization structures of intrinsic NALs.

  18. Assembly auxiliary system for narrow cabins of spacecraft

    NASA Astrophysics Data System (ADS)

    Liu, Yi; Li, Shiqi; Wang, Junfeng

    2015-09-01

    Due to the narrow space and complex structure of spacecraft cabin, the existing asssembly systems can not well suit for the assembly process of cabin products. This paper aims to introduce an assembly auxiliary system for cabin products. A hierarchical-classification method is proposed to re-adjust the initial assembly relationship of cabin into a new hierarchical structure for efficient assembly planning. An improved ant colony algorithm based on three assembly principles is established for searching a optimizational assembly sequence of cabin parts. A mixed reality assembly environment is constructed with enhanced information to promote interaction efficiency of assembly training and guidance. Based on the machine vision technology, the inspection of left redundant objects and measurement of parts distance in inner cabin are efficiently performed. The proposed system has been applied to the assembly work of a spacecraft cabin with 107 parts, which includes cabin assembly planning, assembly training and assembly quality inspection. The application result indicates that the proposed system can be an effective assistant tool to cabin assembly works and provide an intuitive and real assembly experience for workers. This paper presents an assembly auxiliary system for spacecraft cabin products, which can provide technical support to the spacecraft cabin assembly industry.

  19. Source characteristics of Jovian narrow-band kilometric radio emissions

    NASA Astrophysics Data System (ADS)

    Reiner, M. J.; Fainberg, J.; Stone, R. G.; Kaiser, M. L.; Desch, M. D.; Manning, R.; Zarka, P.; Pedersen, B.-M.

    1993-07-01

    New observations of Jovian narrow-band kilometric (nKOM) radio emissions were made by the Unified Radio and Plasma Wave (URAP) experiment on the Ulysses spacecraft during the Ulysses-Jupiter encounter in early February 1992. These observations have demonstrated the unique capability of the URAP instrument for determining both the direction and polarization of nKOM radio sources. An important result is the discovery that nKOM radio emission originates from a number of distinct sources located at different Jovian longitudes and at the inner and outermost regions of the Io plasma torus. These sources have been tracked for several Jovian rotations, yielding their corotational lags, their spatial and temporal evolution, and their radiation characteristics at both low latitudes far from Jupiter and at high latitudes near the planet. Both right-hand and left-hand circularly polarized nKOM sources were observed. The polarizations observed for sources in the outermost regions of the torus seem to favor extraordinary mode emission.

  20. Magnetic Counterpart of Persistent Photoconductivity in Narrow-Gap Semiconductors

    NASA Astrophysics Data System (ADS)

    Vasil'ev, Alexander; Voloshok, Tatyana; Warchulska, Jolanta; Kageyama, Hiroshi

    2001-08-01

    At low temperatures, some ionic, covalent and mixed bonding compounds, as well as semiconducting heterostructures and quantum wells exhibit persistent photoconductivity. This term is used to describe the striking phenomenon in which the conductivity of these compounds and/or structures is observed to be greatly enhanced by visible or infrared illumination and the low resistance state is maintained for a long time after switching off the illumination. To describe this effect in variously doped ionic-covalent semiconductors, models of repulsive barriers for both electron emission and capture were introduced based primarily on the assumption of dopants displacement in the host's crystal lattice. Here we report on the magnetic counterpart of this phenomenon, which however does not exactly meet the expectations based on transport measurements. It was found that the magnetic response of AIVBVI narrow-gap semiconductors doped with CIII impurities possesses features of both relaxation phenomena and light-induced phase transition. Exposure of PbTe:Ga, PbTe:In and Pb0.75Sn0.25Te:In single crystals to white-light illumination at low temperatures resulted initially in an increase of the diamagnetic response and then in the appearance of a sharp paramagnetic peak upon heating.

  1. Broadband Absorbing Exciton-Plasmon Metafluids with Narrow Transparency Windows.

    PubMed

    Yang, Jihua; Kramer, Nicolaas J; Schramke, Katelyn S; Wheeler, Lance M; Besteiro, Lucas V; Hogan, Christopher J; Govorov, Alexander O; Kortshagen, Uwe R

    2016-02-10

    Optical metafluids that consist of colloidal solutions of plasmonic and/or excitonic nanomaterials may play important roles as functional working fluids or as means for producing solid metamaterial coatings. The concept of a metafluid employed here is based on the picture that a single ballistic photon, propagating through the metafluid, interacts with a large collection of specifically designed optically active nanocrystals. We demonstrate water-based metafluids that act as broadband electromagnetic absorbers in a spectral range of 200-3300 nm and feature a tunable narrow (∼100 nm) transparency window in the visible-to-near-infrared region. To define this transparency window, we employ plasmonic gold nanorods. We utilize excitonic boron-doped silicon nanocrystals as opaque optical absorbers ("optical wall") in the UV and blue-green range of the spectrum. Water itself acts as an opaque "wall" in the near-infrared to infrared. We explore the limits of the concept of a "simple" metafluid by computationally testing and validating the effective medium approach based on the Beer-Lambert law. According to our simulations and experiments, particle aggregation and the associated decay of the window effect are one example of the failure of the simple metafluid concept due to strong interparticle interactions.

  2. Propagation modeling results for narrow-beam undersea laser communications

    NASA Astrophysics Data System (ADS)

    Fletcher, Andrew S.; Hardy, Nicholas D.; Hamilton, Scott A.

    2016-03-01

    Communication links through ocean waters are challenging due to undersea propagation physics. Undersea optical communications at blue or green wavelengths can achieve high data rates (megabit- to gigabit-per-second class links) despite the challenging undersea medium. Absorption and scattering in ocean waters attenuate optical signals and distort the waveform through dense multipath. The exponential propagation loss and the temporal spread due to multipath limit the achievable link distance and data rate. In this paper, we describe the Monte Carlo modeling of the undersea scattering and absorption channel. We model photon signal attenuation levels, spatial photon distributions, time of arrival statistics, and angle of arrival statistics for a variety of lasercom scenarios through both clear and turbid water environments. Modeling results inform the design options for an undersea optical communication system, particularly illustrating the advantages of narrow-beam lasers compared to wide beam methods (e.g. LED sources). The modeled pupil plane and focal plane photon arrival distributions enable beam tracking techniques for robust pointing solutions, even in highly scattering harbor waters. Laser communication with collimated beams maximizes the photon transfer through the scattering medium and enables spatial and temporal filters to minimize waveform distortion and background interference.

  3. Smooth DNA Transport through a Narrowed Pore Geometry

    PubMed Central

    Carson, Spencer; Wilson, James; Aksimentiev, Aleksei; Wanunu, Meni

    2014-01-01

    Voltage-driven transport of double-stranded DNA through nanoscale pores holds much potential for applications in quantitative molecular biology and biotechnology, yet the microscopic details of translocation have proven to be challenging to decipher. Earlier experiments showed strong dependence of transport kinetics on pore size: fast regular transport in large pores (> 5 nm diameter), and slower yet heterogeneous transport time distributions in sub-5 nm pores, which imply a large positional uncertainty of the DNA in the pore as a function of the translocation time. In this work, we show that this anomalous transport is a result of DNA self-interaction, a phenomenon that is strictly pore-diameter dependent. We identify a regime in which DNA transport is regular, producing narrow and well-behaved dwell-time distributions that fit a simple drift-diffusion theory. Furthermore, a systematic study of the dependence of dwell time on DNA length reveals a single power-law scaling of 1.37 in the range of 35–20,000 bp. We highlight the resolution of our nanopore device by discriminating via single pulses 100 and 500 bp fragments in a mixture with >98% accuracy. When coupled to an appropriate sequence labeling method, our observation of smooth DNA translocation can pave the way for high-resolution DNA mapping and sizing applications in genomics. PMID:25418307

  4. The mouse atherosclerosis locus at chromosome 10 (Ath11) acts early in lesion formation with subcongenic strains delineating two narrowed regions

    PubMed Central

    Wolfrum, Susanne; Rodríguez, José M.; Tan, Marietta; Chen, Kwan Y.; Teupser, Daniel; Breslow, Jan L.

    2010-01-01

    Objective Ath11, an atherosclerosis susceptibility locus on proximal chromosome 10 (0–21cM) revealed in a cross between apolipoprotein E deficient C57BL/6 (B6) and FVB mice, was recently confirmed in congenic mice. The objectives of this study were to assess how Ath11 affects lesion development and morphology, to determine aortic gene expression in congenics, and to narrow the congenic interval. Methods and Results Assessing lesion area over time in congenic mice showed that homozygosity for the FVB allele increased lesion area at 6 weeks persisting through to 24 weeks of age. Staining of aortic root sections at 16 weeks did not reveal obvious differences between congenics. Aortic expression-array analysis at 6 weeks revealed 97 >2 fold regulated genes, including one gene in the QTL interval, Aldh8a1, and two gene clusters regulated by Hnf4α and Esr1. Analysis of lesion area in 11 subcongenic strains revealed two narrowed regions, 10a (21 genes) acting in females and 10b (7 genes) acting in both genders. Conclusions Ath11 appears to act early in lesion formation with significant effects on aortic gene expression. This QTL is genetically complex containing a female specific region 10a from 0 to 7.3 Mb, and a gender independent region 10b from 20.1 to 21.9 Mb. PMID:20466976

  5. Terahertz plasmonic laser radiating in an ultra-narrow beam

    SciTech Connect

    Wu, Chongzhao; Khanal, Sudeep; Reno, John L.; Kumar, Sushil

    2016-07-07

    Plasmonic lasers (spasers) generate coherent surface plasmon polaritons (SPPs) and could be realized at subwavelength dimensions in metallic cavities for applications in nanoscale optics. Plasmonic cavities are also utilized for terahertz quantum-cascade lasers (QCLs), which are the brightest available solid-state sources of terahertz radiation. A long standing challenge for spasers that are utilized as nanoscale sources of radiation, is their poor coupling to the far-field radiation. Unlike conventional lasers that could produce directional beams, spasers have highly divergent radiation patterns due to their subwavelength apertures. Here, we theoretically and experimentally demonstrate a new technique for implementing distributed feedback (DFB) that is distinct from any other previously utilized DFB schemes for semiconductor lasers. The so-termed antenna-feedback scheme leads to single-mode operation in plasmonic lasers, couples the resonant SPP mode to a highly directional far-field radiation pattern, and integrates hybrid SPPs in surrounding medium into the operation of the DFB lasers. Experimentally, the antenna-feedback method, which does not require the phase matching to a well-defined effective index, is implemented for terahertz QCLs, and single-mode terahertz QCLs with a beam divergence as small as 4°×4° are demonstrated, which is the narrowest beam reported for any terahertz QCL to date. Moreover, in contrast to a negligible radiative field in conventional photonic band-edge lasers, in which the periodicity follows the integer multiple of half-wavelengths inside the active medium, antenna-feedback breaks this integer limit for the first time and enhances the radiative field of the lasing mode. Terahertz lasers with narrow-beam emission will find applications for integrated as well as standoff terahertz spectroscopy and sensing. Furthermore, the antenna-feedback scheme is generally applicable to any plasmonic laser with a Fabry–Perot cavity

  6. Terahertz plasmonic laser radiating in an ultra-narrow beam

    DOE PAGES

    Wu, Chongzhao; Khanal, Sudeep; Reno, John L.; ...

    2016-07-07

    Plasmonic lasers (spasers) generate coherent surface plasmon polaritons (SPPs) and could be realized at subwavelength dimensions in metallic cavities for applications in nanoscale optics. Plasmonic cavities are also utilized for terahertz quantum-cascade lasers (QCLs), which are the brightest available solid-state sources of terahertz radiation. A long standing challenge for spasers that are utilized as nanoscale sources of radiation, is their poor coupling to the far-field radiation. Unlike conventional lasers that could produce directional beams, spasers have highly divergent radiation patterns due to their subwavelength apertures. Here, we theoretically and experimentally demonstrate a new technique for implementing distributed feedback (DFB) thatmore » is distinct from any other previously utilized DFB schemes for semiconductor lasers. The so-termed antenna-feedback scheme leads to single-mode operation in plasmonic lasers, couples the resonant SPP mode to a highly directional far-field radiation pattern, and integrates hybrid SPPs in surrounding medium into the operation of the DFB lasers. Experimentally, the antenna-feedback method, which does not require the phase matching to a well-defined effective index, is implemented for terahertz QCLs, and single-mode terahertz QCLs with a beam divergence as small as 4°×4° are demonstrated, which is the narrowest beam reported for any terahertz QCL to date. Moreover, in contrast to a negligible radiative field in conventional photonic band-edge lasers, in which the periodicity follows the integer multiple of half-wavelengths inside the active medium, antenna-feedback breaks this integer limit for the first time and enhances the radiative field of the lasing mode. Terahertz lasers with narrow-beam emission will find applications for integrated as well as standoff terahertz spectroscopy and sensing. Furthermore, the antenna-feedback scheme is generally applicable to any plasmonic laser with a Fabry–Perot cavity

  7. Alcohol advertising and public health: systems perspectives versus narrow perspectives.

    PubMed

    Petticrew, M; Shemilt, I; Lorenc, T; Marteau, T M; Melendez-Torres, G J; O'Mara-Eves, A; Stautz, K; Thomas, J

    2017-03-01

    Alcohol consumption is influenced by a complex causal system of interconnected psychological, behavioural, social, economic, legal and environmental factors. These factors are shaped by governments (eg, licensing laws and taxation), by consumers (eg, patterns of alcohol consumption drive demand) and by alcohol industry practices, such as advertising. The marketing and advertising of alcoholic products contributes to an 'alcogenic environment' and is a modifiable influence on alcohol consumption and harm. The public health perspective is that there is sufficient evidence that alcohol advertising influences consumption. The alcohol industry disputes this, asserting that advertising only aims to help consumers choose between brands. We review the evidence from recent systematic reviews, including their theoretical and methodological assumptions, to help understand what conclusions can be drawn about the relationships between alcohol advertising, advertising restrictions and alcohol consumption. A wide evidence base needs to be drawn on to provide a system-level overview of the relationship between alcohol advertising, advertising restrictions and consumption. Advertising aims to influence not just consumption, but also to influence awareness, attitudes and social norms; this is because advertising is a system-level intervention with multiple objectives. Given this, assessments of the effects of advertising restrictions which focus only on sales or consumption are insufficient and may be misleading. For this reason, previous systematic reviews, such as the 2014 Cochrane review on advertising restrictions (Siegfried et al) contribute important, but incomplete representations of 'the evidence' needed to inform the public health case for policy decisions on alcohol advertising. We conclude that an unintended consequence of narrow, linear framings of complex system-level issues is that they can produce misleading answers. Systems problems require systems perspectives

  8. Terahertz plasmonic lasers with narrow beams and large tunability

    NASA Astrophysics Data System (ADS)

    Jin, Yuan; Wu, Chongzhao; Reno, John L.; Kumar, Sushil

    2017-02-01

    Plasmonic lasers generate coherent long-range or localized surface-plasmon-polaritons (SPPs), where the SPP mode exists at the interface of the metal (or a metallic nanoparticle) and a dielectric. Metallic-cavities sup- porting SPP modes are also utilized for terahertz quantum-cascade lasers (QCLs). Due to subwavelength apertures, plasmonic lasers have highly divergent radiation patterns. Recently, we theoretically and experimentally demonstrated a new technique for implementing distributed-feedback (DFB), which is termed as an antenna- feedback scheme, to establish a hybrid SPP mode in the surrounding medium of a plasmonic laser's cavity with a large wavefront. This technique allows such lasers to radiate in narrow beams without requirement of any specific design considerations for phase-matching. Experimental demonstration is done for terahertz QCLs that show beam-divergence as small as 4-degrees. The antenna-feedback scheme has a characteristic feature in that refractive-index of the laser's surrounding medium affects its radiative frequency in the same vein as refractive- index of the cavity. Hence, any perturbations in the refractive-index of the surrounding medium could lead to large modulation in the laser's emission frequency. Along this line, we report 57 GHz reversible, continuous, and mode-hop-free tuning of such QCLs operating at 78 K based on post-process deposition/etching of a dielectric on an already mounted QCL chip. This is the largest tuning range achieved for terahertz QCLs when operating much above the temperature of liquid-Helium. We review the aforementioned experimental results and discuss methods to increase optical power output from terahertz QCLs with antenna-feedback. Peak power output of 13 mW is realized for a 3.3 THz QCL operating in a Stirling cooler at 54 K. A new dual-slit photonic structure based on antenna-feedback scheme is proposed to further improve output power as well as provide enhanced tunability.

  9. Mathematical modeling and numerical computation of narrow escape problems

    NASA Astrophysics Data System (ADS)

    Cheviakov, Alexei F.; Reimer, Ashton S.; Ward, Michael J.

    2012-02-01

    The narrow escape problem refers to the problem of calculating the mean first passage time (MFPT) needed for an average Brownian particle to leave a domain with an insulating boundary containing N small well-separated absorbing windows, or traps. This mean first passage time satisfies the Poisson partial differential equation subject to a mixed Dirichlet-Neumann boundary condition on the domain boundary, with the Dirichlet condition corresponding to absorbing traps. In the limit of small total trap size, a common asymptotic theory is presented to calculate the MFPT in two-dimensional domains and in the unit sphere. The asymptotic MFPT formulas depend on mutual trap locations, allowing for global optimization of trap locations. Although the asymptotic theory for the MFPT was developed in the limit of asymptotically small trap radii, and under the assumption that the traps are well-separated, a comprehensive study involving comparison with full numerical simulations shows that the full numerical and asymptotic results for the MFPT are within 1% accuracy even when total trap size is only moderately small, and for traps that may be rather close together. This close agreement between asymptotic and numerical results at finite, and not necessarily asymptotically small, values of the trap size clearly illustrates one of the key side benefits of a theory based on a systematic asymptotic analysis. In addition, for the unit sphere, numerical results are given for the optimal configuration of a collection of traps on the surface of a sphere that minimizes the average MFPT. The case of N identical traps and a pattern of traps with two different sizes are considered. The effect of trap fragmentation on the average MFPT is also discussed.

  10. NARROW-K-BAND OBSERVATIONS OF THE GJ 1214 SYSTEM

    SciTech Connect

    Colón, Knicole D.; Gaidos, Eric

    2013-10-10

    GJ 1214 is a nearby M dwarf star that hosts a transiting super-Earth-size planet, making this system an excellent target for atmospheric studies. Most studies find that the transmission spectrum of GJ 1214b is flat, which favors either a high mean molecular weight or cloudy/hazy hydrogen (H) rich atmosphere model. Photometry at short wavelengths (<0.7 μm) and in the K band can discriminate the most between these different atmosphere models for GJ 1214b, but current observations do not have sufficiently high precision. We present photometry of seven transits of GJ 1214b through a narrow K-band (2.141 μm) filter with the Wide Field Camera on the 3.8 m United Kingdom Infrared Telescope. Our photometric precision is typically 1.7 × 10{sup –3} (for a single transit), comparable with other ground-based observations of GJ 1214b. We measure a planet-star radius ratio of 0.1158 ± 0.0013, which, along with other studies, also supports a flat transmission spectrum for GJ 1214b. Since this does not exclude a scenario where GJ 1214b has an H-rich envelope with heavy elements that are sequestered below a cloud/haze layer, we compare K-band observations with models of H{sub 2} collision-induced absorption in an atmosphere for a range of temperatures. While we find no evidence for deviation from a flat spectrum (slope s = 0.0016 ± 0.0038), an H{sub 2}-dominated upper atmosphere (<60 mbar) cannot be excluded. More precise observations at <0.7 μm and in the K band, as well as a uniform analysis of all published data, would be useful for establishing more robust limits on atmosphere models for GJ 1214b.

  11. Electrostatic field changes and durations of narrow bipolar events

    NASA Astrophysics Data System (ADS)

    Karunarathne, S.; Marshall, T. C.; Stolzenburg, M.; Karunarathna, N.

    2016-09-01

    Using an array of 10 sensors, electric field change measurements of 35 positive narrow bipolar events (NBEs) were obtained at close range (≤10 km). At the closest sensor all 35 NBEs had a net electrostatic change (ΔEfast) associated with the main bipolar pulse with amplitudes of 0.4 to 16.3 V/m (not range normalized). At the closest sensor the bipolar pulse of each of the 35 NBEs was followed by a relatively long, slow electrostatic change (ΔEslow) with amplitudes of 0.1 to 43.4 V/m and durations of 0.7 to 33.7 ms. For ΔEfast, estimated 3-D charge moments for 10 NBEs ranged from 0.46 C km to 1.81 C km with an average and standard deviation of (1.09 ± 0.36) C km. Seven 3-D charge moments were essentially vertically oriented, and the other three moments were tilted at 10°-20° from vertical. The 10 3-D charge moments were overlaid on vertical radar cross sections; 6 NBEs occurred in weak reflectivity near the upper reflectivity boundary; the other 4 NBEs occurred near the top of the high-reflectivity core of the thunderclouds. For ΔEslow, we estimated 3-D charge moments for only three NBEs; they ranged from 1.11 C km to 2.69 C km with an average of (1.83 ± 0.80) C km. A two current transmission line model matched the bipolar pulse and the following slow change (ΔEslow) of one NBE reasonably well. The slow change mechanism may be different from the NBE mechanism and similar to the initial E-change before typical lightning flashes.

  12. The Origin of Narrow Band Cyclotron Wave Emissions Called Chorus

    NASA Astrophysics Data System (ADS)

    Skoug, Ruth Marie

    1995-01-01

    On May 6, 1993, a sounding rocket experiment designed to study microburst electron precipitation was launched from Poker Flat, Alaska, into a morningside auroral event. This was the first sounding rocket to simultaneously detect microburst electrons and associated very low frequency (VLF) waves. Both microbursts and narrow band VLF chorus (risers) were observed throughout the flight. Waves and electron bursts were observed in association with each other, but no one-to-one correlations were seen between the two phenomena. The association between waves and particles suggests that both phenomena may be produced by a wave -particle interaction. This dissertation discusses the design of the VLF wave antenna, a magnetic search coil, and the analysis of data from this instrument. The data are compared to chorus production theories to determine the source location and mechanism of the observed waves. In this work, the observed chorus emissions are interpreted in terms of a cyclotron resonance interaction. This is the first comprehensive test of the cyclotron resonance theory applied to chorus associated with microburst precipitation. The frequency range of the risers and the observed electron energy range agree with those required to satisfy the cyclotron resonance condition. Using a criterion derived from the conservation of energy during an interaction, it is determined that a cold plasma cyclotron resonance interaction could have produced only the lower frequency portions of the observed chorus risers. We present an extension of the cyclotron resonance theory which uses a warm plasma model of the wave-particle interaction. This model assumes a two-component plasma, with an isotropic cold component and a bi-Maxwellian warm component. The addition of the warm component produces sufficient changes in the wave dispersion relation that the interaction can produce the highest frequencies observed in our data set. As predicted by theory, an anisotropic plasma is required to

  13. Detection of joint space narrowing in hand radiographs

    NASA Astrophysics Data System (ADS)

    Kauffman, Joost A.; Slump, Cornelis H.; Bernelot Moens, Hein J.

    2006-03-01

    Radiographic assessment of joint space narrowing in hand radiographs is important for determining the progression of rheumatoid arthritis in an early stage. Clinical scoring methods are based on manual measurements that are time consuming and subjected to intra-reader and inter-reader variance. The goal is to design an automated method for measuring the joint space width with a higher sensitivity to change1 than manual methods. The large variability in joint shapes and textures, the possible presence of joint damage, and the interpretation of projection images make it difficult to detect joint margins accurately. We developed a method that uses a modified active shape model to scan for margins within a predetermined region of interest. Possible joint space margin locations are detected using a probability score based on the Mahalanobis distance. To prevent the detection of false edges, we use a dynamic programming approach. The shape model and the Mahalanobis scoring function are trained with a set of 50 hand radiographs, in which the margins have been outlined by an expert. We tested our method on a test set of 50 images. The method was evaluated by calculating the mean absolute difference with manual readings by a trained person. 90% of the joint margins are detected within 0.12 mm. We found that our joint margin detection method has a higher precision considering reproducibility than manual readings. For cases where the joint space has disappeared, the algorithm is unable to estimate the margins. In these cases it would be necessary to use a different method to quantify joint damage.

  14. Recovering physical properties from narrow-band photometry

    NASA Astrophysics Data System (ADS)

    Schoenell, W.; Cid Fernandes, R.; Benítez, N.; Vale Asari, N.

    2013-05-01

    Our aim in this work is to answer, using simulated narrow-band photometry data, the following general question: What can we learn about galaxies from these new generation cosmological surveys? For instance, can we estimate stellar age and metallicity distributions? Can we separate star-forming galaxies from AGN? Can we measure emission lines, nebular abundances and extinction? With what precision? To accomplish this, we selected a sample of about 300k galaxies with good S/N from the SDSS and divided them in two groups: 200k objects and a template library of 100k. We corrected the spectra to z = 0 and converted them to filter fluxes. Using a statistical approach, we calculated a Probability Distribution Function (PDF) for each property of each object and the library. Since we have the properties of all the data from the STARLIGHT-SDSS database, we could compare them with the results obtained from summaries of the PDF (mean, median, etc). Our results shows that we retrieve the weighted average of the log of the galaxy age with a good error margin (σ ≈ 0.1 - 0.2 dex), and similarly for the physical properties such as mass-to-light ratio, mean stellar metallicity, etc. Furthermore, our main result is that we can derive emission line intensities and ratios with similar precision. This makes this method unique in comparison to the other methods on the market to analyze photometry data and shows that, from the point of view of galaxy studies, future photometric surveys will be much more useful than anticipated.

  15. How narrow is the spectrum of submaximal speeds in swimming?

    PubMed

    Greco, Camila C; de Oliveira, Mariana F M; Caputo, Fabrizio; Denadai, Benedito S; Dekerle, Jeanne

    2013-05-01

    The purpose of this study was to identify the boundary of submaximal speed zones (i.e., exercise intensity domains) between maximal aerobic speed (S-400) and lactate threshold (LT) in swimming. A 400-m all-out test, a 7 × 200 m incremental step test, and two to four 30-minute submaximal tests were performed by 12 male endurance swimmers (age = 24.5 ± 9.6 years; body mass = 71.3 ± 9.8 kg) to determine S-400, speed corresponding to LT, and maximal lactate steady state (MLSS). S-400 was 1.30 ± 0.09 m·s (400 m-5:08 minutes:seconds). The speed at LT (1.08 ± 0.02 m·s; 83.1 ± 2.2 %S-400) was lower than the speed at MLSS (1.14 ± 0.02 m·s; 87.5 ± 1.9 %S-400). Maximal lactate steady state occurred at 26 ± 10% of the difference between the speed at LT and S-400. Mean blood lactate values at the speeds corresponding to LT and MLSS were 2.45 ± 1.13 mmol·L and 4.30 ± 1.32 mmol·L, respectively. The present findings demonstrate that the range of intensity zones between LT and MLSS (i.e., heavy domain) and between MLSS and S-400 (i.e., severe domain) are very narrow in swimming with LT occurring at 83% S-400 in trained swimmers. Precision and sensitivity of the measurement of aerobic indexes (i.e., LT and MLSS) should be considered when conducting exercise training and testing in swimming.

  16. World food resources and population: the narrowing margin.

    PubMed

    Brown, L R

    1981-09-01

    This bulletin examines the narrowing margin between global food production and population growth. Between 1950 and 1971, world grain production nearly doubled and per capita production increased 31%. During the 1970s, gains in output barely kept pace with population growth, consumption/person declined in sub-Saharan Africa and parts of Asia, food prices were volatile, and over 100 food deficit countries came to depend on the exportable surplus of North America, now the only major grain exporting region. The world fish catch levelled off in the early 1970s and beef production, still dependent mainly on grassland grazing, levelled off in the mid-1970s. With little new land left to plow, satisfying increased food demand now depends on sharp increases in yields on existing crop land. Worldwide, this effort is hampered by loss of topsoil and irrigated land, conversion of cropland to nonfarm uses, rising energy costs, inefficient agrarian structures, particularly in the Soviet Union, the falling yield response to chemical fertilizers in agriculturally advanced countries, and the emerging competition between food and agriculturally based energy crops. Green Revolution successes in some developing countries deomonstrate that, given the right inputs, 3rd world farmers can increase crop yields dramatically. Feeding the world's poor also requires more equitable income and food distribution, including a reduction in the proportion of grain and fish consumed indirectly as livestock products by the affluent. Most important in meeting food needs on a finite planet is braking population growth. The author concludes that every effort should be made to stabilize world production at abour 6 billion by 2020, rather than 10.5 billion by 2110, as is now projected by the UN.

  17. Illegal "no prescription" internet access to narrow therapeutic index drugs.

    PubMed

    Liang, Bryan A; Mackey, Tim K; Lovett, Kimberly M

    2013-05-01

    Narrow therapeutic index (NTI) drugs, because of proximity of therapeutic amounts to toxic amounts, require close professional oversight, particularly when switching formulations. However, safe use may be compromised by unsupervised switching through access to online "no prescription" Web sites. We assessed no prescription online availability of NTI drugs, using an academically published list (core NTI drugs). Using the Google search term "buy DRUG no prescription," we reviewed the first 5 search result pages for marketing of no prescription NTI drugs. We further assessed if National Association of Boards of Pharmacy (NABP) Not Recommended vendors were marketing NTI drugs. Searches were conducted from November 3, 2012 to January 3, 2013. For core NTI drugs, we found 13 of 14 NTI drugs (92%) marketed as available without prescription, all from NABP Not Recommended vendors. On the basis of these initial findings, we expanded our core list to 12 additional NTI drugs; 11 of 12 of these drugs (92%) were available from no prescription Web sites. Overall, 24 of 26 NTI drugs (92%) were illegally marketed as available online without the need for a prescription. Suspect online NTI drug access from no prescription vendors represents a significant patient safety risk because of potential patient drug switching and risk of counterfeit versions. Further, state health care exchanges with coverage limitations may drive patients to seek formulations online. Food and Drug Administration harmonization with tighter international NTI drug standards should be considered, and aggressive action against suspect online marketers should be a regulatory and public health priority. Copyright © 2013 Elsevier HS Journals, Inc. All rights reserved.

  18. [Results of peripheral iridectomy in narrow-angle glaucoma and of prophylactic iridectomy (author's transl)].

    PubMed

    Lerche, W; Kayser, O N

    1980-01-01

    During a period of three years 79 eyes with narrow-angle glucoma were operated on, and prophylactic iridectomy was performed in 55 eyes. In this way, narrow-angle glaucoma in the fellow eye, which frequently occurs, was prevented. There are less postoperative complications with therapeutic and prophylactic peripheral iridectomy than with filtering operations. In view of the pathogenesis of narrow-angle glaucoma peripheral iridectomy is the most economical and effective procedure for preventing another attack and narrow-angle glaucoma in the fellow eye.

  19. Bandwidth-narrowed Bragg gratings inscribed in double-cladding fiber by femtosecond laser.

    PubMed

    Shi, Jiawei; Li, Yuhua; Liu, Shuhui; Wang, Haiyan; Liu, Ningliang; Lu, Peixiang

    2011-01-31

    Bragg gratings with the bandwidth(FWHM) narrowed up to 79 pm were inscribed in double-cladding fiber with femtosecond radiation and a phase mask followed by an annealing treatment. With the annealing temperature below a critical value, the bandwidth of Bragg gratings induced by Type I-IR and Type II-IR index change was narrowed without the reduction of reflectivity. The bandwidth narrowing is due to the profile transformation of the refractive index modulation caused by the annealing treatment. This mechanism was verified by comparing bandwidth narrowing processes of FBGs written with different power densities.

  20. Chromosome-encoded narrow-spectrum Ambler class A beta-lactamase GIL-1 from Citrobacter gillenii.

    PubMed

    Naas, Thierry; Aubert, Daniel; Ozcan, Ayla; Nordmann, Patrice

    2007-04-01

    A novel beta-lactamase gene was cloned from the whole-cell DNA of an enterobacterial Citrobacter gillenii reference strain that displayed a weak narrow-spectrum beta-lactam-resistant phenotype and was expressed in Escherichia coli. It encoded a clavulanic acid-inhibited Ambler class A beta-lactamase, GIL-1, with a pI value of 7.5 and a molecular mass of ca. 29 kDa. GIL-1 had the highest percent amino acid sequence identity with TEM-1 and SHV-1, 77%, and 67%, respectively, and only 46%, 31%, and 32% amino acid sequence identity with CKO-1 (C. koseri), CdiA1 (C. diversus), and SED-1 (C. sedlaki), respectively. The substrate profile of the purified GIL-1 was similar to that of beta-lactamases TEM-1 and SHV-1. The blaGIL-1 gene was chromosomally located, as revealed by I-CeuI experiments, and was constitutively expressed at a low level in C. gillenii. No gene homologous to the regulatory ampR genes of chromosomal class C beta-lactamases was found upstream of the blaGIL-1 gene, which fits the noninducibility of beta-lactamase expression in C. gillenii. Rapid amplification of DNA 5' ends analysis of the promoter region revealed putative promoter sequences that diverge from what has been identified as the consensus sequence in E. coli. The blaGIL-1 gene was part of a 5.5-kb DNA fragment bracketed by a 9-bp duplication and inserted between the d-lactate dehydrogenase gene and the ydbH genes; this DNA fragment was absent in other Citrobacter species. This work further illustrates the heterogeneity of beta-lactamases in Citrobacter spp., which may indicate that the variability of Citrobacter species is greater than expected.

  1. Ethical reasons for narrowing the scope of biotech patents.

    PubMed

    Andreassen, Tom

    2015-11-01

    Patents on biotech products have a scope that goes well beyond what is covered by the most widely applied ethical justifications of intellectual property. Neither natural rights theory from Locke, nor public interest theory of IP rights justifies the wide scope of legal protection. The article takes human genes as an example, focusing on the component that is not invented but persists as unaltered gene information even in the synthetically produced complementary DNA, the cDNA. It is argued that patent on cDNA holds this information captive, or illegitimately appropriates it in limiting other researchers and inventors' opportunity to explore new functions and uses based on this non-invented information. A tighter connection between legal IP protection and the use description stated in the patent claim is suggested. By binding protection to the product's foreseeable functions and use, instead of the product itself and all future uses of it, legitimacy of biotech product patents is restored.

  2. Porcine arthrogryposis multiplex congenita (AMC): new diagnostic test and narrowed candidate region.

    PubMed

    Haubitz, Monika; Neuenschwander, Stefan; Vögeli, Peter

    2012-12-01

    In the Swiss Large White pig population a genetically caused arthrogryposis multiplex congenita (AMC) variant was identified. The disease is autosomal recessively inherited and is a fatal defect. Affected piglets are of normal size, but show malformed and permanently contracted joints in their legs. Often the spinal cord is curved and the lower jaw is shortened. Originally, AMC was mapped to a 5 Mb region on pig chromosome 5 (SSC5) between microsatellite markers SW152 and SW904. In order to detect unaffected carriers a diagnostic test using markers within the candidate region was developed. However, two independent recombination events occurred in a diseased and in a healthy piglet. Therefore, we selected 24 consecutive markers (3 microsatellites, 19 SNPs and 2 indels) in the candidate region, and determined the haplotypes in the two pedigrees with the recombinations. The parents and five offspring were investigated. In consequence, we were able to narrow down the candidate region and map AMC between SNPs ALGA0032767 and DRGA0006010 on SSC5 which span around 2.32 Mb. The candidate region shares homology to human chromosome 12. However, we are still lacking good candidate genes. A PCR-RFLP was developed and is used as an improved genetic test for AMC. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. A narrow hybrid zone between two Cottus species in Wills Creek, Potomac drainage.

    PubMed

    Kinziger, A P; Raesly, R L

    2001-01-01

    We describe a narrow hybrid zone between the mottled sculpin (Cottus b. bairdi) and the Blue Ridge sculpin (C. caeruleomentum). Seven characters (dorsal fin rays, pectoral fin rays, caudal base band condition, male spawning coloration, and one frequency and two fixed allozyme differences) distinguish the two taxa in the hybrid zone. C. caeruleomentum and C. b. bairdi diverged in these characters in allopatry as indicated by their distribution on opposite sides of the Atlantic-Ohio divide. However, a stream capture placed these two taxa in secondary contact in Wills Creek, Potomac drainage (Atlantic slope). Allozyme data indicate the presence of post-F(1) hybrids in the zone of secondary contact. Changes in allozymes, morphology, and spawning coloration along a transect in Wills Creek reveal the hybrid zone is less than 20 river kilometers in length. Estimates of root mean square dispersal and gene flow tentatively suggest that selection is operating in the Wills Creek hybrid zone. C. b. bairdi and C. caeruleomentum are maintaining their identity in seven distinguishing characters on opposite ends of the hybrid zone revealing these two taxa are independent evolutionary lineages.

  4. Electronic characterization of defects in narrow gap semiconductors

    NASA Technical Reports Server (NTRS)

    Patterson, James D.

    1994-01-01

    We use a Green's function technique to calculate the position of deep defects in narrow gap semiconductors. We consider substitutional (including antisite), vacancy, and interstitial (self and foreign) deep defects. We also use perturbation theory to look at the effect of nonparabolic bands on shallow defect energies and find nonparabolicity can increase the binding by 10 percent or so. We consider mercury cadmium telluride (MCT), mercury zinc telluride (MZT), and mercury zinc selenide (MZS). For substitutional and interstitial defects we look at the situation with and without relaxation. For substitutional impurities in MCT, MZT, and MZS, we consider x (the concentration of Cd or Zn) in the range 0.1 less than x less than 0.3 and also consider appropriate x so E(sub g) = 0.1 eV for each of the three compounds. We consider several cation site s-like deep levels and anion site p-like levels. For E(sub g) = 0.1 eV, we also consider the effects of relaxation. Similar comments apply to the interstitial deep levels whereas no relaxation is considered for the ideal vacancy model. Relaxation effects can be greater for the interstitial than the substitutional cases. Specific results are given in figures and tables and comparison to experiment is made in a limited number of cases. We find, for example, that I, Se, S, Rn, and N are possible cation site, s-like deep levels in MCT and Zn and Mg are for anion site, p-like levels (both levels for substitutional cases). The corresponding cation and anion site levels for interstitial deep defects are (Au, Ag, Hg, Cd, Cu, Zn) and (N, Ar, O, F). For the substitutional cases we have some examples of relaxation moving the levels into the band gap, whereas for the interstitial case we have examples where relaxation moves it out of the band gap. Future work involves calculating the effects of charge state interaction and seeing the effect of relaxation on vacancy levels.

  5. Revisiting "Narrow Bipolar Event" intracloud lightning using the FORTE satellite

    NASA Astrophysics Data System (ADS)

    Jacobson, A. R.; Light, T. E. L.

    2012-02-01

    The lightning stroke called a "Narrow Bipolar Event", or NBE, is an intracloud discharge responsible for significant charge redistribution. The NBE occurs within 10-20 μs, and some associated process emits irregular bursts of intense radio noise, fading at shorter timescales, sporadically during the charge transfer. In previous reports, the NBE has been inferred to be quite different from other forms of lightning strokes, in two ways: First, the NBE has been inferred to be relatively dark (non-luminous) compared to other lightning strokes. Second, the NBE has been inferred to be isolated within the storm, usually not participating in flashes, but when it is in a flash, the NBE has been inferred to be the flash initiator. These two inferences have sufficiently stark implications for NBE physics that they should be subjected to further independent test, with improved statistics. We attempt such a test with both optical and radio data from the FORTE satellite, and with lightning-stroke data from the Los Alamos Sferic Array. We show rigorously that by the metric of triggering the PDD optical photometer aboard the FORTE satellite, NBE discharges are indeed less luminous than ordinary lightning. Referred to an effective isotropic emitter at the cloud top, NBE light output is inferred to be less than ~3 × 108 W. To address isolation of NBEs, we first expand the pool of geolocated intracloud radio recordings, by borrowing geolocations from either the same flash's or the same storm's other recordings. In this manner we generate a pool of ~2 × 105 unique and independent FORTE intracloud radio recordings, whose slant range from the satellite can be inferred. We then use this slant range to calculate the Effective Radiated Power (ERP) at the radio source, in the passband 26-49 MHz. Stratifying the radio recordings by ERP into eight bins, from a lowest bin (<5 kW) to a highest bin (>140 kW), we document a trend for the radio recordings to become more isolated in time as the

  6. Optogenetic Central Amygdala Stimulation Intensifies and Narrows Motivation for Cocaine.

    PubMed

    Warlow, Shelley M; Robinson, Mike J F; Berridge, Kent C

    2017-08-30

    Addiction is often characterized by intense motivation for a drug, which may be narrowly focused at the expense of other rewards. Here, we examined the role of amygdala-related circuitry in the amplification and narrowing of motivation focus for intravenous cocaine. We paired optogenetic channelrhodopsin (ChR2) stimulation in either central nucleus of amygdala (CeA) or basolateral amygdala (BLA) of female rats with one particular nose-poke porthole option for earning cocaine infusions (0.3 mg/kg, i.v.). A second alternative porthole earned identical cocaine but without ChR2 stimulation. Consequently, CeA rats quickly came to pursue their CeA ChR2-paired cocaine option intensely and exclusively, elevating cocaine intake while ignoring their alternative cocaine alone option. By comparison, BLA ChR2 pairing failed to enhance cocaine motivation. CeA rats also emitted consummatory bites toward their laser-paired porthole, suggesting that higher incentive salience made that cue more attractive. A separate progressive ratio test of incentive motivation confirmed that CeA ChR2 amplified rats' motivation, raising their breakpoint effort price for cocaine by 10-fold. However, CeA ChR2 laser on its own lacked any reinforcement value: laser by itself was never self-stimulated, not even by the same rats in which it amplified motivation for cocaine. Conversely, CeA inhibition by muscimol/baclofen microinjections prevented acquisition of cocaine self-administration and laser preference, whereas CeA inhibition by optogenetic halorhodopsin suppressed cocaine intake, indicating that CeA circuitry is needed for ordinary cocaine motivation. We conclude that CeA ChR2 excitation paired with a cocaine option specifically focuses and amplifies motivation to produce intense pursuit and consumption focused on that single target.SIGNIFICANCE STATEMENT In addiction, intense incentive motivation often becomes narrowly focused on a particular drug of abuse. Here we show that pairing central

  7. Physical Conditions in the Narrow Line Region of M51

    NASA Astrophysics Data System (ADS)

    Bradley, L. D., II; Kaiser, M. E.; Baan, W. A.

    2001-12-01

    We present long-slit Space Telescope Imaging Spectrograph (STIS) and Very Large Array (VLA) observations of the near-nuclear region of M51 obtained to study the kinematic and ionization structure of multiple emission line clouds in the narrow line region (NLR). The STIS spectra were obtained at a single position angle (166o) which intersects the nucleus and several NLR clouds. Low-dispersion G430L and G750L spectra provide continuous wavelength coverage from 2900 Å to 1 micron, while G430M spectra of [OIII] (66 km s-1 resolution) were used to more precisely determine the velocity structure of the emission-line clouds. The VLA radio continuum observations obtained at 3.6 cm with a resolution of 0.24'' complement our high spatial resolution (0.1\\arcsec) HST/STIS spectra. M51 possesses a biconical ionization cone (Ford et al. 1985, Cecil 1988) typical of Seyferts and Liners. This near-nuclear emission is comprised of multiple knots spanning 3.0" (122 pc) with cloud separations ranging from 0.1" (4 pc) to 0.75" (31 pc). Our 3.6 cm radio observations exhibit elongated nuclear emission with a similar PA. In agreement with earlier lower resolution 6 cm data (Crane & van der Hulst 1992), a weak radio jet, ~2.5" in extent, connects the near-nuclear emission with a diffuse (lobe) structure which spans ~4'' (163 pc). Close to the northern edge of this diffuse structure lies a radio knot which is identified with the extra-nuclear cloud (XNC) detected in Hα + [NII] and [OIII] imaging (Ford et al. 1985; Grillmair et al. 1997) and the X-ray (Terashima & Wilson 2001). We also detect weak radio emission extending to the north of the nucleus roughly opposite the southern jet. This northern 10μ Jy radio contour encompasses the [OIII] emission structure ~1.2'' north of the nucleus. Cloud velocities, velocity dispersions, emission line flux ratios, and photoionization modelling will be presented and discussed to explore the physical conditions (reddening, temperature, density, and

  8. Genes and Gene Therapy

    MedlinePlus

    ... correctly, a child can have a genetic disorder. Gene therapy is an experimental technique that uses genes to ... or prevent disease. The most common form of gene therapy involves inserting a normal gene to replace an ...

  9. Magnetic Fields Sculpt Narrow Jets From Dying Star

    NASA Astrophysics Data System (ADS)

    2006-03-01

    Molecules spewed outward from a dying star are confined into narrow jets by a tightly-wound magnetic field, according to astronomers who used the National Science Foundation's Very Long Baseline Array (VLBA) radio telescope to study an old star about 8,500 light-years from Earth. Magnetic Field Around Jet Artist's Conception Shows Tightly-Wound Magnetic Field Confining Jet CREDIT: NRAO/AUI/NSF (Click on image for larger version) The star, called W43A, in the constellation Aquila, is in the process of forming a planetary nebula, a shell of brightly-glowing gas lit by the hot ember into which the star will collapse. In 2002, astronomers discovered that the aging star was ejecting twin jets of water molecules. That discovery was a breakthrough in understanding how many planetary nebulae are formed into elongated shapes. "The next question was, what is keeping this outpouring of material confined into narrow jets? Theoreticians suspected magnetic fields, and we now have found the first direct evidence that a magnetic field is confining such a jet," said Wouter Vlemmings, a Marie Curie Fellow working at the Jodrell Bank Observatory of the University of Manchester in England. "Magnetic fields previously have been detected in jets emitted by quasars and protostars, but the evidence was not conclusive that the magnetic fields were actually confining the jets. These new VLBA observations now make that direct connection for the very first time," Vlemmings added. By using the VLBA to study the alignment, or polarization, of radio waves emitted by water molecules in the jets, the scientists were able to determine the strength and orientation of the magnetic field surrounding the jets. "Our observations support recent theoretical models in which magnetically-confined jets produce the sometimes-complex shapes we see in planetary nebulae," said Philip Diamond, also of Jodrell Bank Observatory. During their "normal" lives, stars similar to our Sun are powered by the nuclear fusion

  10. [Clinical features of narrow-angle glaucoma in the native residents of Turkmenistan].

    PubMed

    Orazmukhammedov, Iu G

    1991-01-01

    The author analyzes the specific clinical features of narrow-angle glaucoma in the native residents of Turkmenistan and in the residents of a european origin. He has found some specific anatomic and functional features that may be considered as factors predisposing to the development of narrow-angle glaucoma in Turkmenistan natives.

  11. Brief Daily Exposures to Asian Females Reverses Perceptual Narrowing for Asian Faces in Caucasian Infants

    ERIC Educational Resources Information Center

    Anzures, Gizelle; Wheeler, Andrea; Quinn, Paul C.; Pascalis, Olivier; Slater, Alan M.; Heron-Delaney, Michelle; Tanaka, James W.; Lee, Kang

    2012-01-01

    Perceptual narrowing in the visual, auditory, and multisensory domains has its developmental origins during infancy. The current study shows that experimentally induced experience can reverse the effects of perceptual narrowing on infants' visual recognition memory of other-race faces. Caucasian 8- to 10-month-olds who could not discriminate…

  12. 78 FR 50377 - Narrow Woven Ribbons With Woven Selvedge From Taiwan: Final Results of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-19

    ...On May 21, 2013, the Department of Commerce (the Department) published the preliminary results of the second administrative review of the antidumping duty order on narrow woven ribbons with woven selvedge (narrow woven ribbons) from Taiwan. The period of review (POR) is September 1, 2011, through August 31, 2012. We received no comments from interested parties. Therefore, the final results do......

  13. Looking through an Adolescent Literacy Lens at the Narrow View of Reading

    ERIC Educational Resources Information Center

    Ehren, Barbara J.

    2009-01-01

    Purpose: This commentary is a personal reaction to A. G. Kamhi's (2007) article on the "narrow view" of reading and his suggestion that this view be adopted as a way to address the reading problems of children and adolescents. Method: In this article, I consider the narrow view of reading from an adolescent literacy perspective and discuss the…

  14. Brief Daily Exposures to Asian Females Reverses Perceptual Narrowing for Asian Faces in Caucasian Infants

    ERIC Educational Resources Information Center

    Anzures, Gizelle; Wheeler, Andrea; Quinn, Paul C.; Pascalis, Olivier; Slater, Alan M.; Heron-Delaney, Michelle; Tanaka, James W.; Lee, Kang

    2012-01-01

    Perceptual narrowing in the visual, auditory, and multisensory domains has its developmental origins during infancy. The current study shows that experimentally induced experience can reverse the effects of perceptual narrowing on infants' visual recognition memory of other-race faces. Caucasian 8- to 10-month-olds who could not discriminate…

  15. A narrow ESR signal and mesophase transformations in the heat treatment of coals and pitches

    SciTech Connect

    Farber, M.S.

    1982-01-01

    The author discusses changes in the EPR spectrum when coal, pitch and its fractions are heated directly in the spectrometer resonator. It is shown that the high temperature maximum of EPR signals is determined to a significant extent by the narrow signal. This suggests that the narrow signal spectrum is related to the mesophase structures during the synthesis process.

  16. Narrowing the Gap in Outcomes for Vulnerable Groups: A Review of the Research Evidence

    ERIC Educational Resources Information Center

    Kendall, Sally; Straw, Suzanne; Jones, Megan; Springate, Iain; Grayson, Hilary

    2008-01-01

    This report presents findings from a review of the best evidence on narrowing the gap in outcomes across the five Every Child Matters (ECM) areas for vulnerable groups in the context of improving outcomes for all. The review was commissioned to prepare the ground for work on "Narrowing the Gap" with participating local authorities (LAs).…

  17. Narrowing the Achievement Gap: A Case Study of an Urban School

    ERIC Educational Resources Information Center

    Lugo, Rosalinda

    2010-01-01

    The goal of this case study was to identify the cultural norms, practices, and programs of an urban school that narrowed the achievement gap. The reason for identifying these factors in a successful school was to add to the body of literature regarding the achievement gap and what a struggling school was able to do to narrow the gap. This case…

  18. Narrowing the Gap in Outcomes: Early Years (0-5 Years)

    ERIC Educational Resources Information Center

    Springate, Ian; Atkinson, Mary; Straw, Suzanne; Lamont, Emily; Grayson, Hilary

    2008-01-01

    This report was commissioned by the Local Government Association (LGA) to inform the Department for Children, Schools and Families (DCSF) and LGA work on "Narrowing the Gap." It focuses on early years' provision and presents findings from a review of the best evidence on narrowing the gap in outcomes across the five Every Child Matters…

  19. 78 FR 23845 - Drawbridge Operation Regulations; Narrow Bay, Smith Point, NY

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-23

    ... SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulations; Narrow Bay, Smith Point, NY AGENCY... the Smith Point Bridge, mile 6.1, across Narrow Bay, between Smith Point and Fire Island, New York. The deviation is necessary to facilitate the Smith Point Triathlon. This deviation allows the bridge...

  20. Features of the potential barrier and current flow in the narrow Schottky diodes

    NASA Astrophysics Data System (ADS)

    Mamedov, R. K.

    2013-08-01

    This paper presents some specific characteristics of the potential barrier and the current flow in the narrow Au-nGaAs Schottky diodes (SDs), in which an additional electric field (AEF) directly measured by atomic-force microscopy. Show that there existing a potential barrier in the narrow SD is formed by the superposition of the space charge field and the AEF in the near-contact area of the semiconductor. Dependence of the potential barrier height of the voltage narrow SD has about the same character in both forward and reverse directions. Forward I-V characteristics narrow Au-nGaAs SD width of 1, 2 and 3 μm represented by straight lines in the semi-logarithmic scale in a wide current range of about nine order and ideality factor is close to unity. The reverse current of the same narrow SD in the initial reverse voltage is virtually absent and with increasing voltage increases linearly in the order of 3-5 in the semi-logarithmic scale. The correlation between the numerical values of electrophysical parameters of the forward and reverse current-voltage characteristics of narrow SD was founded. Energy diagram of the narrow SD was created and its corresponding energy parameters were evaluated. It has been shown that the conductivity in the narrow Au-nGaAs SD qualitatively and quantitatively well described by energy model real metal-semiconductor contacts with AEF.

  1. 33 CFR 162.255 - Wrangell Narrows, Alaska; use, administration, and navigation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Wrangell Narrows, Alaska; use... § 162.255 Wrangell Narrows, Alaska; use, administration, and navigation. (a) Definitions. (1) The term... 9 feet or less (northbound, read down; southbound, read up): East of Battery Islets: East of...

  2. Geographical Structuring of Genetic Diversity Across the Whole Distribution Range of Narcissus longispathus, a Habitat-specialist, Mediterranean Narrow Endemic

    PubMed Central

    Medrano, Mónica; Herrera, Carlos M.

    2008-01-01

    Background and Aims High mountain ranges of the Mediterranean Basin harbour a large number of narrowly endemic plants. In this study an investigation is made of the levels and partitioning of genetic diversity in Narcissus longispathus, a narrow endemic of south-eastern Spanish mountains characterized by a naturally fragmented distribution due to extreme specialization on a rare habitat type. By using dense sampling of populations across the species' whole geographical range, genetic structuring at different geographical scales is also examined. Methods Using horizontal starch-gel electrophoresis, allozyme variability was screened at 19 loci for a total of 858 individuals from 27 populations. The data were analysed by means of standard statistical approaches in order to estimate gene diversity and the genetic structure of the populations. Key Results Narcissus longispathus displayed high levels of genetic diversity and extensive diversification among populations. At the species level, the percentage of polymorphic loci was 68 %, with average values of 2·1, 0·11 and 0·14 for the number of alleles per locus, observed heterozygosity and expected heterozygosity, respectively. Southern and more isolated populations tended to have less genetic variability than northern and less-isolated populations. A strong spatial patterning of genetic diversity was found at the various spatial scales. Gene flow/drift equilibrium occurred over distances <4 km. Beyond that distance divergence was relatively more influenced by drift. The populations studied seem to derive from three panmictic units or ‘gene pools’, with levels of admixture being greatest in the central and south-eastern portions of the species' range. Conclusions In addition to documenting a case of high genetic diversity in a narrow endemic plant with naturally fragmented populations, the results emphasize the need for dense population sampling and examination of different geographical scales for understanding

  3. Geographical structuring of genetic diversity across the whole distribution range of Narcissus longispathus, a habitat-specialist, Mediterranean narrow endemic.

    PubMed

    Medrano, Mónica; Herrera, Carlos M

    2008-08-01

    High mountain ranges of the Mediterranean Basin harbour a large number of narrowly endemic plants. In this study an investigation is made of the levels and partitioning of genetic diversity in Narcissus longispathus, a narrow endemic of south-eastern Spanish mountains characterized by a naturally fragmented distribution due to extreme specialization on a rare habitat type. By using dense sampling of populations across the species' whole geographical range, genetic structuring at different geographical scales is also examined. Using horizontal starch-gel electrophoresis, allozyme variability was screened at 19 loci for a total of 858 individuals from 27 populations. The data were analysed by means of standard statistical approaches in order to estimate gene diversity and the genetic structure of the populations. Narcissus longispathus displayed high levels of genetic diversity and extensive diversification among populations. At the species level, the percentage of polymorphic loci was 68 %, with average values of 2.1, 0.11 and 0.14 for the number of alleles per locus, observed heterozygosity and expected heterozygosity, respectively. Southern and more isolated populations tended to have less genetic variability than northern and less-isolated populations. A strong spatial patterning of genetic diversity was found at the various spatial scales. Gene flow/drift equilibrium occurred over distances <4 km. Beyond that distance divergence was relatively more influenced by drift. The populations studied seem to derive from three panmictic units or 'gene pools', with levels of admixture being greatest in the central and south-eastern portions of the species' range. In addition to documenting a case of high genetic diversity in a narrow endemic plant with naturally fragmented populations, the results emphasize the need for dense population sampling and examination of different geographical scales for understanding population genetic structure in habitat specialists

  4. Joint space narrowing after partial medial meniscectomy in the anterior cruciate ligament-intact knee.

    PubMed

    Shelbourne, K Donald; Dickens, Jonathan F

    2007-09-01

    Osteoarthritis of the knee is common after total medial meniscectomy. In anterior cruciate ligament-intact knees, the reported outcomes of partial medial meniscectomy are variable. Radiographic assessment using a posteroanterior weight-bearing view is a reliable tool for detecting minor medial joint space narrowing, which may be an early sign of osteoarthritis. Studies that assessed the effect of partial medial meniscectomy found a low percentage of patients with >50% joint narrowing at 10 to 15 years after surgery. Digital radiography, using a posteroanterior weight-bearing view, is a highly sensitive method for observing minor joint space narrowing in the involved knee. A recent study showed that 88% of patients who underwent partial medial meniscectomy had joint space narrowing of <2 mm, and none had narrowing >or=2 mm, at a mean follow-up of 12 years. Subjective results after partial medial meniscectomy are favorable, with 88% to 95% of patients reporting good to excellent results.

  5. Experimental analysis of emission linewidth narrowing in a pulsed KGd(WO ₄) ₂ Raman laser.

    PubMed

    Savitski, Vasili G

    2014-09-08

    The linewidth of a KGd(WO ₄) ₂ (KGW) intracavity pumped Raman laser is analyzed experimentally for different configurations of the Raman and pump laser resonators: with narrow and broadband pump emission profiles, with and without linewidth narrowing elements in the Raman laser resonator, with and without injection seeding into the Raman cavity. The benefits of a narrow linewidth pump source in combination with linewidth narrowing elements in the Raman laser cavity for the efficient linewidth narrowing of the Raman laser emission are explained. 20 kW peak-power pulses at 1156 nm with 0.43 cm⁻¹ emission linewidth are demonstrated from an injection seeded KGW Raman laser.

  6. kW-level narrow linewidth fiber amplifier seeded by a fiber Bragg grating based oscillator.

    PubMed

    Hao, Jinping; Zhao, Hong; Zhang, Dayong; Zhang, Liming; Zhang, Kun

    2015-05-20

    This paper demonstrates an all-fiber narrow linewidth amplifier with a seed based on narrow linewidth fiber Bragg gratings (FBGs). The fiber amplifier achieves a narrow bandwidth output of 823 W, with an opto-optic efficiency of 84.5%. The pair of FBGs in the seed configuration helps to assure a narrow linewidth of the laser as 0.08 nm. In the laser profile, we introduce a cladding stripper with a sectional structure, which realizes high pump power leakage with high efficiency. The paper also discusses the impact of seed linewidth and fiber length on the SBS threshold in a narrow bandwidth laser. Based on this analysis, we discovered ways to inhibit SBS onset and scale power output.

  7. Oxidation reduction is a key process for successful treatment of psoriasis by narrow-band UVB phototherapy.

    PubMed

    Gu, Xiaolian; Nylander, Elisabet; Coates, Philip J; Nylander, Karin

    2015-02-01

    Narrow-band UVB (NB-UVB) phototherapy is commonly used for treatment of psoriasis, though the mechanisms underlying its efficacy have not been completely elucidated. We used gene expression profiling to characterise gene expression in lesional epidermis from psoriasis patients in the middle and late stages of NB-UVB photo-therapy. Increased melanogenesis gene expression was the earliest response to phototherapy. At the end of treatment, genes responding to phototherapy and correlated to treatment outcome were involved in oxidation reduction, growth and mitochondria organisation. Particularly, SPATA18, a key regulator of mitochondrial quality, was significantly down-regulated in psoriasis (p < 0.05). Poly(dA:dT) and poly(I:C) stimulation increased SPATA18 level in primary keratinocytes, indicating the importance of mitochondria quality control under innate immune induced oxidative stress. Normalised SPATA18 expression after phototherapy indicates improved mitochondrial quality control and restored cellular redox status. Our data suggest that oxidation reduction is critical for the resolution of psoriatic plaques following NB-UVB phototherapy.

  8. A temperature-induced narrow DNA curvature range sustains the maximum activity of a bacterial promoter in vitro.

    PubMed

    Prosseda, Gianni; Mazzola, Alessia; Di Martino, Maria Letizia; Tielker, Denis; Micheli, Gioacchino; Colonna, Bianca

    2010-04-06

    Among the molecular strategies bacteria have set up to quickly match their transcriptional program to new environments, changes in sequence-mediated DNA curvature play a crucial role. Bacterial promoters, especially those of mesophilic bacteria, are in general preceded by a curved region. The marked thermosensitivity of curved DNA stretches allows bacteria to rapidly sense outer temperature variations and affects transcription by favoring the binding of activators or repressors. Curved DNA is also able to influence the transcriptional activity of a bacterial promoter directly, without the involvement of trans-acting regulators. This study attempts to quantitatively analyze the role of DNA curvature in thermoregulated gene expression using a real-time in vitro transcription model system based on a specific fluorescence molecular beacon. By analyzing the temperature-dependent expression of a reporter gene in a construct carrying a progressively decreasing bent sequence upstream from the promoter, we show that with a decrease in temperature a narrow curvature range accounts for a significant enhancement of promoter activity. This strengthens the view that DNA curvature-mediated regulation of gene expression is likely a strategy offering fine-tuning control possibilities and that, considering the widespread presence of curved sequences upstream from bacterial promoters, it may represent one of the most primitive forms of gene regulation.

  9. Unequal Contribution of Widespread and Narrow-Ranged Species to Botanical Diversity Patterns

    PubMed Central

    Raes, Niels; Wieringa, Jan J.; Sosef, Marc S. M.

    2016-01-01

    In conservation studies, solely widespread species are often used as indicators of diversity patterns, but narrow-ranged species can show different patterns. Here, we assess how well subsets of narrow-ranged, widespread or randomly selected plant species represent patterns of species richness and weighted endemism in Gabon, tropical Africa. Specifically, we assess the effect of using different definitions of widespread and narrow-ranged and of the information content of the subsets. Finally, we test if narrow-ranged species are overrepresented in species-rich areas. Based on distribution models of Gabonese plant species, we defined sequential subsets from narrow-ranged-to-widespread, widespread-to-narrow-ranged, and 100 randomly arranged species sequences using the range sizes of species in tropical Africa and within Gabon. Along these sequences, correlations between subsets and the total species richness and total weighted endemism patterns were computed. Random species subsets best represent the total species richness pattern, whereas subsets of narrow-ranged species best represent the total weighted endemism pattern. For species ordered according to their range sizes in tropical Africa, subsets of narrow-ranged species represented the total species richness pattern better than widespread species subsets did. However, the opposite was true when range sizes were truncated by the Gabonese national country borders. Correcting for the information content of the subset results in a skew of the sequential correlations, its direction depending on the range-size frequency distribution. Finally, we find a strong, positive, non-linear relation between weighted endemism and total species richness. Observed differences in the contribution of narrow-ranged, widespread and randomly selected species to species richness and weighted endemism patterns can be explained by the range-size frequency distribution and the use of different definitions of widespread or narrow-ranged. We

  10. Ultra-thin narrow-band, complementary narrow-band, and dual-band metamaterial absorbers for applications in the THz regime

    NASA Astrophysics Data System (ADS)

    Astorino, Maria Denise; Frezza, Fabrizio; Tedeschi, Nicola

    2017-02-01

    In this paper, ultra-thin narrow-band, complementary narrow-band, and dual-band metamaterial absorbers (MMAs), exploiting the same electric ring resonator configuration, are investigated at normal and oblique incidence for both transverse electric (TE) and transverse magnetic (TM) polarizations, and with different physical properties in the THz regime. In the analysis of the ultra-thin narrow-band MMA, the limit of applicability of the transmission line model has been overcome with the introduction of a capacitance which considers the z component of the electric field. These absorbing structures have shown a wide angular response and a polarization-insensitive behavior due to the introduction of a conducting ground plane and to the four-fold rotational symmetry of the resonant elements around the propagation axis. We have adopted a retrieval procedure to extract the effective electromagnetic parameters of the proposed MMAs and we have compared the simulated and analytical results through the interference theory.

  11. Closing the gap: Avian lineage splits at a young, narrow seaway imply a protracted history of mixed population response.

    PubMed

    Trewick, Steve A; Pilkington, Stephen; Shepherd, Lara D; Gibb, Gillian C; Morgan-Richards, Mary

    2017-08-14

    The evolutionary significance of spatial habitat gaps has been well recognized since Alfred Russel Wallace compared the faunas of Bali and Lombok. Gaps between islands influence population structuring of some species, and flightless birds are expected to show strong partitioning even where habitat gaps are narrow. We examined the population structure of the most numerous living flightless land bird in New Zealand, Weka (Gallirallus australis). We surveyed Weka and their feather lice in native and introduced populations using genetic data gathered from DNA sequences of mitochondrial genes and nuclear β-fibrinogen and five microsatellite loci. We found low genetic diversity among extant Weka population samples. Two genetic clusters were evident in the mtDNA from Weka and their lice, but partitioning at nuclear loci was less abrupt. Many formerly recognized subspecies/species were not supported; instead, we infer one subspecies for each of the two main New Zealand islands. Although currently range restricted, North Island Weka have higher mtDNA diversity than the more wide-ranging southern Weka. Mismatch and neutrality statistics indicate North Island Weka experienced rapid and recent population reduction, while South Island Weka display the signature of recent expansion. Similar haplotype data from a widespread flying relative of Weka and other New Zealand birds revealed instances of North Island-South Island partitioning associated with a narrow habitat gap (Cook Strait). However, contrasting patterns indicate priority effects and other ecological factors have a strong influence on spatial exchange at this scale. © 2017 John Wiley & Sons Ltd.

  12. Distribution and evolution of fusarin mycotoxin biosynthetic genes in Fusarium

    USDA-ARS?s Scientific Manuscript database

    In Fusarium/Gibberella, secondary metabolite biosynthetic (SMB) genes that have a narrow distribution within the genus can have complex evolutionary histories. Whether more widely distributed SMB genes have similarly complex histories is not known. Genes responsible for production of fusarin mycot...

  13. Narrowing the Search After Gravitational-Wave Detections

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-11-01

    Now that were able to detect gravitational waves, the next challenge is to spot electromagnetic signatures associated with gravitational-wave events. A team of scientists has proposed a new algorithm that might narrow the search.Artists illustrations of the stellar-merger model for short gamma-ray bursts. In the model, 1) two neutron stars inspiral, 2) they merge and produce a gamma-ray burst, 3) a small fraction of their mass is flung out and radiates as a kilonova, 4) a massive neutron star or black hole with a disk remains after the event. [NASA, ESA, and A. Feild (STScI)]Light from Neutron-Star MergersJust over a year ago, LIGO detected its first gravitational-wave signal: GW150914, produced when two black holes merged. While we didnt expect to see any sort of light-based signal from this merger, we could expect to see transient electromagnetic signatures in the case of a neutron starblack hole merger or a neutron starneutron star merger in the form of a kilonova or a short gamma-ray burst.While we havent yet detected any mergers involving neutron stars, LIGO has the sensitivity to make these detections in the local universe, and we hope to start seeing them soon! Finding the electromagnetic companions to gravitational-wave signals would be the best way to probe the evolution history of the universe and learn what happens when evolved stars collide. So how do we hunt them down?2D localization maps for LIGOs detection of GW150914 (black contours), as well as the footprints of follow-up observations (red for radio, green for optical/IR, blue for X-ray). [Abbott et al. 2016]Pinpointing a VolumeThe two LIGO detectors can already provide rough 2D localization of where the gravitational-wave signal came from, but the region predicted for GW150914 still covered 600 square degrees, which is a pretty hefty patch of sky! In light of this, the simplest follow-up strategy of tiling large survey observations of the entire predicted region is somewhat impractical and time

  14. Pharma-nutrition interface: the gap is narrowing.

    PubMed

    Georgiou, Niki A; Garssen, Johan; Witkamp, Renger F

    2011-01-25

    The interaction between pharmacology and nutrition science is on the rise. Nutritional status is considered one of the important determinants of health and disease and several diseases of our time have a clear link with lifestyle factors including the diet. There is also increasing realization that a continuum between health and disease often exists without strict boundaries. Understanding the subtle interactions between genes, environment and homeostatic processes is the key in finding effective ways to prevent, treat or manage disease. Both pharmacologists and nutritionists are recognizing that most of the low hanging fruit has been picked, and that the one disease-one target-one drug (or nutrient) concept will provide fewer successes than it did in the past. Instead, complex multi-factorial diseases require multi-pathway understanding and multi-targeting approaches which will often result in compound combinations. Therapeutic synergy between foods and drugs does not necessarily mean that both have the same primary target. There are also examples of nutritional products that effectively contribute to the therapeutic regimen by improving the patients' general condition or by reducing side-effects of drugs. Examples of conditions and diseases that are highlighted in this review include the metabolic syndrome with its co-morbidities, immune-related diseases and HIV. With the aging population there are other fields emerging, including CNS-related diseases and cancer, where we will likely see an increased synergy between the two disciplines that seemed to have lost contact since the times of Hippocrates.

  15. A polycrystalline SiO2 colloidal crystal film with ultra-narrow reflections.

    PubMed

    Fu, Qianqian; Chen, Ang; Shi, Lei; Ge, Jianping

    2015-04-30

    This work reported a high quality photonic crystal film with an ultra-narrow photonic bandgap obtained via a chemical synthetic route. The bandgap is much narrower than that of traditional colloidal crystals, which makes the film qualified for use in optical devices. The narrow PBG originates from not only the high crystallinity and uniform orientations of microcrystals within the film but also the very close refractive indices between the silica and the polymer matrix. Due to the matching of the refractive index, the amorphous contents of the film are optically transparent and do not interfere with the reflection, so that the photonic crystal film is tolerant of the existence of disordered contents.

  16. A technique for production of nanocrystalline cellulose with a narrow size distribution

    SciTech Connect

    Bai, Wen; Holbery, James D.; Li, Kaichang

    2009-02-01

    Nanocrystalline cellulose (NCC) was prepared by sulfuric acid hydrolysis of microcrystalline cellulose. A differential centrifugation technique was studied to obtain NCC whiskers with a narrow size distribution. It was shown that the volume of NCC in different fractions had an inverse relationship with relative centrifugal force (RCF). The length of NCC whiskers was also fractionized by differential RCF. The aspect ratio of NCC in different fractions had a relatively narrow range. This technique provides an easy way of producing NCC whiskers with a narrow size distribution.

  17. Spectrally narrowed lasing of a self-injection KrF excimer laser

    NASA Astrophysics Data System (ADS)

    Shimada, Yasuhiro; Wani, Koichi; Miki, Tadaaki; Kawahara, Hidehito; Mimasu, Mutsumi; Ogata, Yoshiro

    1990-08-01

    Spectrally nantwed lasing of a KrF excimer laser has teen ahieved by a self-injection technique using abeam splitter for power extraction aixi intravity etalons for spectral-narrowing. The laser cavity is divithi into an amplifying branch aix! a spectralnarrowing branch. The spectral bandwidth was narrowed to <3pm FWHM with air-sed etalons placed in the spectral-narrowing branch. A laser propagation model was intrOdUced for describing the laser intensity traveling in the laser cavity. The calculated intensityincident onthe intracavityetalons wassmaller thanthat in theconventional Fabry-Perotcavity withplane-parallel mirrors.

  18. Activin/Nodal Signaling Supports Retinal Progenitor Specification in a Narrow Time Window during Pluripotent Stem Cell Neuralization

    PubMed Central

    Bertacchi, Michele; Lupo, Giuseppe; Pandolfini, Luca; Casarosa, Simona; D’Onofrio, Mara; Pedersen, Roger A.; Harris, William A.; Cremisi, Federico

    2015-01-01

    Summary Retinal progenitors are initially found in the anterior neural plate region known as the eye field, whereas neighboring areas undertake telencephalic or hypothalamic development. Eye field cells become specified by switching on a network of eye field transcription factors, but the extracellular cues activating this network remain unclear. In this study, we used chemically defined media to induce in vitro differentiation of mouse embryonic stem cells (ESCs) toward eye field fates. Inhibition of Wnt/β-catenin signaling was sufficient to drive ESCs to telencephalic, but not retinal, fates. Instead, retinal progenitors could be generated from competent differentiating mouse ESCs by activation of Activin/Nodal signaling within a narrow temporal window corresponding to the emergence of primitive anterior neural progenitors. Activin also promoted eye field gene expression in differentiating human ESCs. Our results reveal insights into the mechanisms of eye field specification and open new avenues toward the generation of retinal progenitors for translational medicine. PMID:26388287

  19. Narrowing the position of the Werner syndrome locus by homozygosity analysis - extension of homozygosity analysis

    SciTech Connect

    Nakura, Jun; Miki, Tetsuro; Ye, Lin

    1996-08-15

    Werner syndrome (WS) is an autosomal recessive disorder characterized by the premature occurrence of many age-related features. Previously, the WS gene (WRN) was mapped between D8S131 and D8S87, in an 8.3-cM interval. In this study, regions of homozygosity in 36 WS patients from inbred families were searched for by genotyping for 35 dinucleotide repeat polymorphic markers to narrow down the W-RN critical region. The region most consistently homozygous in these patients was between the D8S1219/D8S1220 cluster and D8S278, within a 4.4-cM interval. For 16 markers mapped in this interval, 24 WS patients (22 Japanese patients and 2 Caucasian patients) in whom consanguinity failed to be proved were also genotyped, under the assumption that some of these patients might still be from consanguineous marriages. The data were analyzed by Fisher`s exact test with a 2 x 2 contingency table for the 22 Japanese patients, excluding the 2 Caucasian patients. The frequencies of homozygosity in the 22 patients at 10 of 16 markers tested were significantly higher than those detected in the general population. Analysis of homozygosity patterns indicated that the region most consistently homozygous was between D8S1445 and D8S278. Thus the WRN locus is most likely between the two markers D8S1445 and D8S278, in a 1.6-cM interval. 49 refs., 4 tabs.

  20. Strong reproductive isolation and narrow genomic tracts of differentiation among three woodpecker species in secondary contact.

    PubMed

    Grossen, Christine; Seneviratne, Sampath S; Croll, Daniel; Irwin, Darren E

    2016-09-01

    Hybrid zones allow the measurement of gene flow across the genome, producing insight into the genomic architecture of speciation. Such analysis is particularly powerful when applied to multiple pairs of hybridizing species, as patterns of genomic differentiation can then be related to age of the hybridizing species, providing a view into the build-up of differentiation over time. We examined 33 809 single nucleotide polymorphisms (SNPs) in three hybridizing woodpecker species: Red-breasted, Red-naped and Yellow-bellied sapsuckers (Sphyrapicus ruber, Sphyrapicus nuchalis and Sphyrapicus varius), two of which (ruber and nuchalis) are much more closely related than each is to the third (varius). To identify positions of SNPs on chromosomes, we developed a localization method based on comparative genomics. We found narrow clines, bimodal distributions of hybrid indices and genomic regions with decreased rates of introgression. These results suggest moderately strong reproductive isolation among species and selection against specific hybrid genotypes. We found 19 small regions of strong differentiation between species, partly shared among species pairs, but no large regions of differentiation. An association analysis revealed a single strong-effect candidate locus associated with plumage, possibly explaining mismatch among the three species in genomic relatedness and plumage similarity. Our comparative analysis of species pairs of different age and their hybrid zones showed that moderately strong reproductive isolation can occur with little genomic differentiation, but that reproductive isolation is incomplete even with much greater genomic differentiation, implying there are long periods of time when hybridization is possible if diverging populations are in geographic contact. © 2016 John Wiley & Sons Ltd.

  1. Genome-wide association study identified a narrow chromosome 1 region associated with chicken growth traits.

    PubMed

    Xie, Liang; Luo, Chenglong; Zhang, Chengguang; Zhang, Rong; Tang, Jun; Nie, Qinghua; Ma, Li; Hu, Xiaoxiang; Li, Ning; Da, Yang; Zhang, Xiquan

    2012-01-01

    Chicken growth traits are important economic traits in broilers. A large number of studies are available on finding genetic factors affecting chicken growth. However, most of these studies identified chromosome regions containing putative quantitative trait loci and finding causal mutations is still a challenge. In this genome-wide association study (GWAS), we identified a narrow 1.5 Mb region (173.5-175 Mb) of chicken (Gallus gallus) chromosome (GGA) 1 to be strongly associated with chicken growth using 47,678 SNPs and 489 F2 chickens. The growth traits included aggregate body weight (BW) at 0-90 d of age measured weekly, biweekly average daily gains (ADG) derived from weekly body weight, and breast muscle weight (BMW), leg muscle weight (LMW) and wing weight (WW) at 90 d of age. Five SNPs in the 1.5 Mb KPNA3-FOXO1A region at GGA1 had the highest significant effects for all growth traits in this study, including a SNP at 8.9 Kb upstream of FOXO1A for BW at 22-48 d and 70 d, a SNP at 1.9 Kb downstream of FOXO1A for WW, a SNP at 20.9 Kb downstream of ENSGALG00000022732 for ADG at 29-42 d, a SNP in INTS6 for BW at 90 d, and a SNP in KPNA3 for BMW and LMW. The 1.5 Mb KPNA3-FOXO1A region contained two microRNA genes that could bind to messenger ribonucleic acid (mRNA) of IGF1, FOXO1A and KPNA3. It was further indicated that the 1.5 Mb GGA1 region had the strongest effects on chicken growth during 22-42 d.

  2. Genetic structure, introgression, and a narrow hybrid zone between northern and California spotted owls (Strix occidentalis).

    PubMed

    Barrowclough, G F; Groth, J G; Mertz, L A; Gutiérrez, R J

    2005-04-01

    The northern spotted owl (Strix occidentalis caurina) is a threatened subspecies and the California spotted owl (Strix occidentalis occidentalis) is a subspecies of special concern in the western United States. Concern for their continued viability has arisen because of habitat loss caused by timber harvesting. The taxonomic status of the northern subspecies has been the subject of continuing controversy. We investigated the phylogeographical and population genetic structure of northern and California spotted owls with special reference to their region of contact. Mitochondrial DNA (mtDNA) control region sequences confirmed the existence of two well-differentiated lineages connected by a narrow hybrid zone in a region of low population density in north central California. Maximum-likelihood estimates indicated bidirectional gene flow between the lineages but limited introgression outside the region of contact. The lengths of both the mtDNA hybrid zone and the reduced density patch were similar and slightly exceeded estimates of natal dispersal distances. This suggests that the two subspecies were in secondary contact in a hybrid zone trapped by a population density trough. Consequently, the zone of interaction is expected to be geographically stable. We discovered a third, rare clade of haplotypes, which we interpreted to be a result of incomplete lineage sorting; those haplotypes result in a paraphyletic northern spotted owl with respect to the California spotted owl. A congeneric species, the barred owl (Strix varia), occasionally hybridizes with spotted owls; our results indicated an upper bound for the frequency of barred owl mtDNA haplotypes in northern spotted owl populations of 3%.

  3. L,L-diaminopimelate aminotransferase (DapL): a putative target for the development of narrow-spectrum antibacterial compounds

    PubMed Central

    Triassi, Alexander J.; Wheatley, Matthew S.; Savka, Michael A.; Gan, Han Ming; Dobson, Renwick C. J.; Hudson, André O.

    2014-01-01

    Despite the urgent need for sustained development of novel antibacterial compounds to combat the drastic rise in antibiotic resistant and emerging bacterial infections, only a few clinically relevant antibacterial drugs have been recently developed. One of the bottlenecks impeding the development of novel antibacterial compounds is the identification of new enzymatic targets. The nutritionally essential amino acid anabolic pathways, for example lysine biosynthesis, provide an opportunity to explore the development of antibacterial compounds, since human genomes do not possess the genes necessary to synthesize these amino acids de novo. The diaminopimelate (DAP)/lysine (lys) anabolic pathways are attractive targets for antibacterial development since the penultimate lys precursor meso-DAP (m-DAP) is a cross-linking amino acid in the peptidoglycan (PG) cell wall of most Gram-negative bacteria and lys plays a similar role in the PG of most Gram-positive bacteria, in addition to its role as one of the 20 proteogenic amino acids. The L,L-diaminopimelate aminotransferase (DapL) pathway was recently identified as a novel variant of the DAP/lys anabolic pathways. The DapL pathway has been identified in the pathogenic bacteria belonging to the genus; Chlamydia, Leptospira, and Treponema. The dapL gene has been identified in the genomes of 381 or approximately 13% of the 2771 bacteria that have been sequenced, annotated and reposited in the NCBI database, as of May 23, 2014. The narrow distribution of the DapL pathway in the bacterial domain provides an opportunity for the development and or discovery of narrow spectrum antibacterial compounds. PMID:25309529

  4. Natural variation at sympathy for the ligule controls penetrance of the semidominant Liguleless narrow-R mutation in Zea mays.

    PubMed

    Buescher, Elizabeth M; Moon, Jihyun; Runkel, Anne; Hake, Sarah; Dilkes, Brian P

    2014-10-24

    Leaf architecture determines plant structural integrity, light harvesting, and economic considerations such as plant density. Ligules, junctions at the leaf sheath and blade in grasses, protect stalks from environmental stresses and, in conjunction with auricles, controls leaf angle. Previous studies in mutants have recessive liguleless mutants (lg1 and lg2) and dominant mutations in knotted1-like homeobox genes (Lg3-O, Lg4, and Kn1) involved in ligule development. Recently, a new semidominant liguleless mutant, Liguleless narrow (Lgn-R), has been characterized in maize that affects ligule and auricle development and results in a narrow leaf phenotype. We show that quantitative genetic variation affects penetrance of Lgn-R. To examine the genetic architecture underlying Lgn-R expressivity, crosses between Lgn-R/+ mutants in a B73 background and intermated B73 x Mo17 recombinant inbred lines were evaluated in multiple years and locations. A single main-effect quantitative trait locus (QTL) on chromosome 1 (sympathy for the ligule; sol) was discovered with a Mo17-contributed allele that suppressed Lgn-R mutant phenotypes. This QTL has a genetic-interaction with a locus on chromosome 7 (lucifer; lcf) for which the B73-contributed allele increases the ability of the sol(Mo17) allele to suppress Lgn-R. Neither of the genetic intervals likely to contain sol or lcf overlap with any current liguleless genes nor with previously identified genome-wide association QTL connected to leaf architecture. Analysis of phenotypes across environments further identified a genotype by enviroment interaction determining the strength of the sol x lcf interaction. Copyright © 2014 Buescher et al.

  5. L,L-diaminopimelate aminotransferase (DapL): a putative target for the development of narrow-spectrum antibacterial compounds.

    PubMed

    Triassi, Alexander J; Wheatley, Matthew S; Savka, Michael A; Gan, Han Ming; Dobson, Renwick C J; Hudson, André O

    2014-01-01

    Despite the urgent need for sustained development of novel antibacterial compounds to combat the drastic rise in antibiotic resistant and emerging bacterial infections, only a few clinically relevant antibacterial drugs have been recently developed. One of the bottlenecks impeding the development of novel antibacterial compounds is the identification of new enzymatic targets. The nutritionally essential amino acid anabolic pathways, for example lysine biosynthesis, provide an opportunity to explore the development of antibacterial compounds, since human genomes do not possess the genes necessary to synthesize these amino acids de novo. The diaminopimelate (DAP)/lysine (lys) anabolic pathways are attractive targets for antibacterial development since the penultimate lys precursor meso-DAP (m-DAP) is a cross-linking amino acid in the peptidoglycan (PG) cell wall of most Gram-negative bacteria and lys plays a similar role in the PG of most Gram-positive bacteria, in addition to its role as one of the 20 proteogenic amino acids. The L,L-diaminopimelate aminotransferase (DapL) pathway was recently identified as a novel variant of the DAP/lys anabolic pathways. The DapL pathway has been identified in the pathogenic bacteria belonging to the genus; Chlamydia, Leptospira, and Treponema. The dapL gene has been identified in the genomes of 381 or approximately 13% of the 2771 bacteria that have been sequenced, annotated and reposited in the NCBI database, as of May 23, 2014. The narrow distribution of the DapL pathway in the bacterial domain provides an opportunity for the development and or discovery of narrow spectrum antibacterial compounds.

  6. Overlapping microdeletions involving 15q22.2 narrow the critical region for intellectual disability to NARG2 and RORA.

    PubMed

    Yamamoto, Toshiyuki; Mencarelli, Maria Antonietta; Di Marco, Chiara; Mucciolo, Mafalda; Vascotto, Marina; Balestri, Paolo; Gérard, Marion; Mathieu-Dramard, Michèle; Andrieux, Joris; Breuning, Martijn; Hoffer, Mariëtte J V; Ruivenkamp, Claudia A L; Shimada, Shino; Sangu, Noriko; Shimojima, Keiko; Umezu, Ryoji; Kawame, Hiroshi; Matsuo, Mari; Saito, Kayoko; Renieri, Alessandra; Mari, Francesca

    2014-03-01

    Microdeletions in the 15q22 region have not been well documented. We collected genotype and phenotype data from five patients with microdeletions involving 15q22.2, which were between 0.7 Mb and 6.5 Mb in size; two were of de novo origin and one was of familial origin. Intellectual disability and epilepsy are frequently observed in patients with 15q22.2 deletions. Genotype-phenotype correlation analysis narrowed the critical region for such neurologic symptoms to a genomic region of 654 Kb including the NMDA receptor-regulated 2 gene (NARG2) and the PAR-related orphan receptor A gene (RORA), either of which may be responsible for neurological symptoms commonly observed in patients with deletions in this region. The neighboring regions, including the forkhead box B1 gene (FOXB1), may also be related to the additional neurological features observed in the patients with larger deletions. Crown Copyright © 2014. Published by Elsevier Masson SAS. All rights reserved.

  7. Fine mapping and narrowing of the genetic interval of the spinal muscular atrophy region by linkage studies

    SciTech Connect

    Wirth, B.; Voosen, B.; Roehrig, D.; Piechaczek, B.; Ruonk-Schoeneborn, S.; Zerres, K. ); Knapp, M. )

    1993-01-01

    The gene for autosomal recessive proximal spinal muscular atrophy (SMA) has recently been mapped to chromosome 5q12.2-q13, within a genetic distance of about 6 cM, and is proximally flanked by the locus D5S6 and distally by D5S112. Here, we report linkage analyses in 64 SMA families with nine polymorphic markers closely linked to the SMA gene which allowed us to narrow the SMA region to about 4cM and to define a new proximal genetic border by the locus D5S125 EF(TG/AG)[sub n]. Based on haplotype analysis and specific recombination event,the following order of the loci was determined: 5cen- D5S76-D5S6-D5S125-SMA-(5[prime]MAP-1B-3[prime]MApP[center dot]1 B)/D5S112-JK53CAI/2-(D5S39-D5S127)-5qter. The location of the SMA gene between D5Sl25 and MAP[center dot]1B is further supported by multipoint linkage analysis. 18 refs., 3 figs., 4 tabs.

  8. Further improvements in program to calculate electronic properties of narrow band gap materials

    NASA Technical Reports Server (NTRS)

    Patterson, James D.

    1991-01-01

    Research into the properties of narrow band gap materials during the period 15 Jun. to 15 Dec. 1991 is discussed. Abstracts and bibliographies from papers presented during this period are reported. Graphs are provided.

  9. The effect of divided attention on emotion-induced memory narrowing.

    PubMed

    Mickley Steinmetz, Katherine R; Waring, Jill D; Kensinger, Elizabeth A

    2014-01-01

    Individuals are more likely to remember emotional than neutral information, but this benefit does not always extend to the surrounding background information. This memory narrowing is theorised to be linked to the availability of attentional resources at encoding. In contrast to the predictions of this theoretical account, altering participants' attentional resources at encoding by dividing attention did not affect emotion-induced memory narrowing. Attention was divided using three separate manipulations: a digit ordering task (Experiment 1), an arithmetic task (Experiment 2) and an auditory discrimination task (Experiment 3). Across all three experiments, divided attention decreased memory across the board but did not affect the degree of memory narrowing. These findings suggest that theories to explain memory narrowing must be expanded to include other potential mechanisms beyond the limitations of attentional resources.

  10. Rapid water transportation through narrow one-dimensional channels by restricted hydrogen bonds.

    PubMed

    Ohba, Tomonori; Kaneko, Katsumi; Endo, Morinobu; Hata, Kenji; Kanoh, Hirofumi

    2013-01-29

    Water plays an important role in controlling chemical reactions and bioactivities. For example, water transportation through water channels in a biomembrane is a key factor in bioactivities. However, molecular-level mechanisms of water transportation are as yet unknown. Here, we investigate water transportation through narrow and wide one-dimensional (1D) channels on the basis of water-vapor adsorption rates and those determined by molecular dynamics simulations. We observed that water in narrow 1D channels was transported 3-5 times faster than that in wide 1D channels, although the narrow 1D channels provide fewer free nanospaces for water transportation. This rapid transportation is attributed to the formation of fewer hydrogen bonds between water molecules adsorbed in narrow 1D channels. The water-transportation mechanism provides the possibility of rapid communication through 1D channels and will be useful in controlling reactions and activities in water systems.

  11. Booze cues and attentional narrowing: Neural correlates of virtual alcohol myopia.

    PubMed

    Gable, Philip A; Mechin, Nicole C; Neal, Lauren B

    2016-05-01

    Exposure to alcohol cues reduces the breadth of attentional scope, called "virtual myopia." Past researchers have suggested approach motivation as a possible mechanism that underlies this myopia in response to alcohol cues. We expanded on these findings in the current study by identifying the neural underpinnings of the relationship between attentional narrowing, approach motivation, and exposure to alcohol cues. Participants completed 64 trials that consisted of neutral or alcohol-related stimuli followed by a measure of attentional narrowing (i.e., Navons letter task). Electroencephalography (EEG) was recorded during the experiment to assess greater left frontal hemispheric asymmetry, a measure of approach motivation. Results revealed that alcohol cues led to greater "virtual myopia" as measured by narrowed attentional scope. Greater left frontal activation to alcohol cues related to greater myopia, suggesting that approach motivation is associated with virtual myopia. Left frontal activation appears to be a neural correlate of cognitive narrowing related to approach motivation. (PsycINFO Database Record

  12. The Effect of Divided Attention on Emotion-Induced Memory Narrowing

    PubMed Central

    Steinmetz, Katherine R. Mickley; Waring, Jill D.; Kensinger, Elizabeth A.

    2014-01-01

    Individuals are more likely to remember emotional than neutral information, but this benefit does not always extend to the surrounding background information. This memory narrowing is theorized to be linked to the availability of attentional resources at encoding. In contrast to the predictions of this theoretical account, altering participants’ attentional resources at encoding, by dividing attention, did not affect the emotion-induced memory narrowing. Attention was divided using three separate manipulations: a digit ordering task (Experiment 1), an arithmetic task (Experiment 2), and an auditory discrimination task (Experiment 3). Across all three experiments, divided attention decreased memory across-the-board but did not affect the degree of memory narrowing. These findings suggest that theories to explain memory narrowing must be expanded to include other potential mechanisms beyond limitations of attentional resources. PMID:24295041

  13. Ultra-narrow bandpass filters for infrared applications with improved angle of incidence performance

    NASA Astrophysics Data System (ADS)

    Rahmlow, Thomas D.; Fredell, Markus; Chanda, Sheetal; Johnson, Robert

    2016-05-01

    Narrow band-pass optical interference filters are used for a variety of applications to improve signal quality in laser based systems. Applications include LIDAR, sensor processing and free space communications. A narrow band width optical filter allows for passage of the laser signal while rejecting ambient light. The more narrow the bandwidth, the better the signal to noise. However, the bandwidth of a design for a particular application is typically limited by a number of factors including spectral shift over the operational angles of incidence, thermal shift over the range of operating temperature and, in the case of laser communication, rejection of adjacent laser channels. The trade-off of these parameters can significantly impact system design and performance. This paper presents design and material approaches to maximize the performance of narrow bandpass filters in the infrared.

  14. Prognostic implications of coronary artery calcium in the absence of coronary artery luminal narrowing.

    PubMed

    Cho, Iksung; Ó Hartaigh, Bríain; Gransar, Heidi; Valenti, Valentina; Lin, Fay Y; Achenbach, Stephan; Berman, Daniel S; Budoff, Matthew J; Callister, Tracy Q; Al-Mallah, Mouaz H; Cademartiri, Filippo; Chinnaiyan, Kavitha; Chow, Benjamin J W; Dunning, Allison M; DeLago, Augustin; Villines, Todd C; Hadamitzky, Martin; Hausleiter, Joerg; Leipsic, Jonathon; Shaw, Leslee J; Kaufmann, Philipp A; Cury, Ricardo C; Feuchtner, Gudrun; Kim, Yong-Jin; Maffei, Erica; Raff, Gilbert; Pontone, Gianluca; Andreini, Daniele; Chang, Hyuk-Jae; Min, James K

    2017-07-01

    Coronary artery calcium (CAC) scoring is a predictor of future adverse clinical events, and a surrogate measure of overall coronary artery plaque burden. Coronary computed tomographic angiography (CCTA) is a contrast-enhanced method that allows for visualization of plaque as well as whether that plaque causes luminal narrowing. To date, the prognosis of individuals with CAC but without stenosis has not been reported. We explored the prevalence of CAC>0 and its prognostic utility for future mortality for patients without luminal narrowing by CCTA. From 17 sites in 9 countries, we identified patients without known coronary artery disease, who underwent CAC scoring and CCTA, and were followed for >3 years. CCTA was graded for % stenosis according to a modified American Heart Association 16-segment model. We calculated hazard ratios (HR) with 95% confidence intervals (95% CI) for incident mortality and compared risk of death for patients as a function of presence or absence of CAC and presence or absence of luminal narrowing by CCTA. Among 6656 patients who underwent CCTA and CAC scoring, 399 patients (6.0%) had no coronary luminal narrowing but CAC>0. During a median follow-up of 5.1 years (IQR: 3.9-5.9 years), 456 deaths occurred. Compared to individuals without luminal narrowing or CAC, individuals without luminal narrowing but CAC>0 were older, more likely to be male and had higher rates of diabetes, hypertension, and dyslipidemia. Individuals without luminal narrowing but CAC experienced a 2-fold increased risk of mortality, with increasing risk of mortality with higher CAC score. Following adjustment, incident death persisted (HR, 1.8; 95% CI, 1.1-2.9, p = 0.02) among patients without luminal narrowing but with CAC>0 compared with patients whose CACS = 0. Individuals without luminal narrowing but CAC ≥100 had mortality risks similar to individuals with non-obstructive CAD (0 < stenosis<50%) by CCTA [HR 2.5 (95% CI 1.3-4.9) and 2.2 (95% CI 1

  15. Multipoint Pacing versus conventional ICD in Patients with a Narrow QRS complex (MPP Narrow QRS trial): study protocol for a pilot randomized controlled trial.

    PubMed

    Gasparini, Maurizio; Galimberti, Paola; Bragato, Renato; Ghio, Stefano; Raineri, Claudia; Landolina, Maurizio; Chieffo, Enrico; Lunati, Maurizio; Mulargia, Ederina; Proclemer, Alessandro; Facchin, Domenico; Rordorf, Roberto; Vicentini, Alessandro; Marcantoni, Lina; Zanon, Francesco; Klersy, Catherine

    2016-12-03

    Despite an intensive search for predictors of the response to cardiac resynchronization therapy (CRT), the QRS duration remains the simplest and most robust predictor of a positive response. QRS duration of ≥ 130 ms is considered to be a prerequisite for CRT; however, some studies have shown that CRT may also be effective in heart failure (HF) patients with a narrow QRS (<130 ms). Since CRT can now be performed by pacing the left ventricle from multiple vectors via a single quadripolar lead, it is possible that multipoint pacing (MPP) might be effective in HF patients with a narrow QRS. This article reports the design of the MPP Narrow QRS trial, a prospective, randomized, multicenter, controlled feasibility study to investigate the efficacy of MPP using two LV pacing vectors in patients with a narrow QRS complex (100-130 ms). Fifty patients with a standard ICD indication will be enrolled and randomized (1:1) to either an MPP group or a Standard ICD group. All patients will undergo a low-dose dobutamine stress echo test and only those with contractile reserve will be included in the study and randomized. The primary endpoint will be the percentage of patients in each group that have reverse remodeling at 12 months, defined as a reduction in left ventricular end-systolic volume (LVESV) of >15% from the baseline. This feasibility study will determine whether MPP improves reverse remodeling, as compared with standard ICD, in HF patients who have a narrow QRS complex (100-130 ms). ClinicalTrials.gov, NCT02402816 . Registered on 25 March 2015.

  16. Sensor based on Fano resonances of plane metamaterial with narrow slits

    NASA Astrophysics Data System (ADS)

    Huang, Wan-Xia; Guo, Juan-Juan; Wang, Mao-Sheng; Zhao, Guo-Ren

    2017-03-01

    The optical properties of a composite metamaterial composed of narrow slits and nano hole pairs have been investigated experimentally and numerically. The strength of the transmission peak originating from the interference between the coupled surface plasmon polaritons (SPP) of the narrow slit and the SPP modes of the hole array is modulated by the degree of symmetry breaking. Some SPP modes can be inhibited by controlling the spacer layer thickness. Our metamaterial has potential applications in sensing and weak signal detection.

  17. Collisional narrowing in the optically pumped CH3OH and CH3F lasers

    NASA Technical Reports Server (NTRS)

    Lawandy, N. M.; Koepf, G. A.

    1982-01-01

    The gain linewidth of the optically pumped CH3F laser is observed to narrow and rebroaden with the addition of He. In addition, the same effect is observed in the CH3OH laser with the addition of the polyatomic buffer gases SF6 and CS2. These results offer conclusive evidence of the Dicke narrowing phenomena in these inverted pure rotational transitions. The effect is observed using a high harmonic mixing technique in a Schottky barrier diode.

  18. Ship interaction in narrow water channels: A two-lane cellular automata approach

    NASA Astrophysics Data System (ADS)

    Sun, Zhuo; Chen, Zhonglong; Hu, Hongtao; Zheng, Jianfeng

    2015-08-01

    In narrow waterways, closed ships might interact due to hydrodynamic forces. To avoid clashes, different lane-changing rules are required. In this paper, a two-lane cellular automata model is proposed to investigate the traffic flow patterns in narrow water channels. Numerical experiments show that ship interaction can form "lumps" in traffic flow which will significantly depress the flux. We suggest that the lane-changing frequency of fast ships should be limited.

  19. Collisional narrowing in the optically pumped CH3OH and CH3F lasers

    NASA Technical Reports Server (NTRS)

    Lawandy, N. M.; Koepf, G. A.

    1982-01-01

    The gain linewidth of the optically pumped CH3F laser is observed to narrow and rebroaden with the addition of He. In addition, the same effect is observed in the CH3OH laser with the addition of the polyatomic buffer gases SF6 and CS2. These results offer conclusive evidence of the Dicke narrowing phenomena in these inverted pure rotational transitions. The effect is observed using a high harmonic mixing technique in a Schottky barrier diode.

  20. Association between choroidal thickness and anterior chamber segment in eyes with narrow or open-angle

    PubMed Central

    Li, Song-Feng; Wu, Ge-Wei; Chen, Chang-Xi; Shen, Ling; Zhang, Zhi-Bao; Gao, Fei; Wang, Ning-Li

    2016-01-01

    AIM To investigate the relationship between choroidal thickness and anterior chamber segment in subjects with eyes with narrow or open-angle. METHODS The subfoveal choroidal thickness was measured with enhanced depth-imaging optical coherence tomography and anterior chamber parameters were measured with ultrasound biomicroscopy in one eye of 23 subjects with open-angle eyes and 38 subjects with narrow-angle eyes. The mean age was 59.52±7.04y for narrow-angle subjects and 60.76±7.23y for open-angle subjects (P=0.514). Multivariate linear regression analysis was performed to assess the association between choroidal thickness and narrow-angle parameters. RESULTS There were no differences in subfoveal choroidal thickness between open- and narrow-angle subjects (P=0.231). Anterior chamber parameters, including central anterior chamber depth, trabecular iris angle, iris thickness 500 µm from the scleral spur (IT500), and ciliary body thickness at 1 mm and 2 mm from the scleral spur (CBT1, CBT2) showed significant differences between the two groups (P<0.05). Subfoveal choroidal thickness showed negative correlation (β=-0.496, P=0.016) only with anterior chamber depth in the open-angle group and with age (β=-0.442, P=0.003) and IT500 (β=-0.399, P=0.008) in the narrow-angle group. However, subfoveal choroidal thickness was not correlated with trabecular iris angle, anterior chamber depth, ciliary body thickness, or central corneal thickness in the narrow-angle group. CONCLUSION Choroidal thickness does not differ in the two groups and has not correlated with anterior chamber parameters in narrow-angle subjects, suggesting a lack of relationship between choroidal thickness and primary angle-closure glaucoma. PMID:27588269

  1. The effects of narrow and elevated path walking on aperture crossing.

    PubMed

    Hackney, Amy L; Cinelli, Michael E; Denomme, Luke T; Frank, James S

    2015-06-01

    The study investigated the impact that action capabilities have on identifying possibilities for action, particularly how postural threat influences the passability of apertures. To do this, the ability to maintain balance was challenged by manipulating the level of postural threat while walking. First, participants walked along a 7m path and passed through two vertical obstacles spaced 1.1-1.5×the shoulder width apart during normal walking. Next, postural threat was manipulated by having participants complete the task either walking on a narrow, ground level path or on an elevated/narrow path. Despite a decrease in walking speed as well as an increase in trunk sway in both the narrow and elevated/narrow walking conditions, the passability of apertures was only affected when the consequence of instability was greatest. In the elevated/narrow walking condition, individuals maintained a larger critical point (rotated their shoulders for larger aperture widths) compared to normal walking. However, this effect was not observed for the narrow path walking suggesting that the level of postural threat was not enough to impose similar changes to the critical point. Therefore, it appears that manipulating action capabilities by increasing postural threat does indeed influence aperture crossing behavior, however the consequence associated with instability must be high before both gait characteristics and the critical point are affected.

  2. Narrow Networks On The Health Insurance Marketplaces: Prevalence, Pricing, And The Cost Of Network Breadth.

    PubMed

    Dafny, Leemore S; Hendel, Igal; Marone, Victoria; Ody, Christopher

    2017-09-01

    Anecdotal reports and systematic research highlight the prevalence of narrow-network plans on the Affordable Care Act's health insurance Marketplaces. At the same time, Marketplace premiums in the period 2014-16 were much lower than projected by the Congressional Budget Office in 2009. Using detailed data on the breadth of both hospital and physician networks, we studied the prevalence of narrow networks and quantified the association between network breadth and premiums. Controlling for many potentially confounding factors, we found that a plan with narrow physician and hospital networks was 16 percent cheaper than a plan with broad networks for both, and that narrowing the breadth of just one type of network was associated with a 6-9 percent decrease in premiums. Narrow-network plans also have a sizable impact on federal outlays, as they depress the premium of the second-lowest-price silver plan, to which subsidy amounts are linked. Holding all else constant, we estimate that federal subsidies would have been 10.8 percent higher in 2014 had Marketplaces required all plans to offer broad provider networks. Narrow networks are a promising source of potential savings for other segments of the commercial insurance market. Project HOPE—The People-to-People Health Foundation, Inc.

  3. Tolerability of magnifying narrow band imaging endoscopy for esophageal cancer screening

    PubMed Central

    Yamasaki, Yasushi; Takenaka, Ryuta; Hori, Keisuke; Takemoto, Koji; Kawano, Seiji; Kawahara, Yoshiro; Okada, Hiroyuki; Fujiki, Shigeatsu; Yamamoto, Kazuhide

    2015-01-01

    AIM: To compare the tolerability of magnifying narrow band imaging endoscopy for esophageal cancer screening with that of lugol chromoendoscopy. METHODS: We prospectively enrolled and analyzed 51 patients who were at high risk for esophageal cancer. All patients were divided into two groups: a magnifying narrow band imaging group, and a lugol chromoendoscopy group, for comparison of adverse symptoms. Esophageal cancer screening was performed on withdrawal of the endoscope. The primary endpoint was a score on a visual analogue scale for heartburn after the examination. The secondary endpoints were scale scores for retrosternal pain and dyspnea after the examinations, change in vital signs, total procedure time, and esophageal observation time. RESULTS: The scores for heartburn and retrosternal pain in the magnifying narrow band imaging group were significantly better than those in the lugol chromoendoscopy group (P = 0.004, 0.024, respectively, ANOVA for repeated measures). The increase in heart rate after the procedure was significantly greater in the lugol chromoendoscopy group. There was no significant difference between the two groups with respect to other vital sign. The total procedure time and esophageal observation time in the magnifying narrow band imaging group were significantly shorter than those in the lugol chromoendoscopy group (450 ± 116 vs 565 ± 174, P = 0.004, 44 ± 26 vs 151 ± 72, P < 0.001, respectively). CONCLUSION: Magnifying narrow band imaging endoscopy reduced the adverse symptoms compared with lugol chromoendoscopy. Narrow band imaging endoscopy is useful and suitable for esophageal cancer screening periodically. PMID:25759551

  4. Spectrally narrowed edge emission from leaky waveguide modes in organic light-emitting diodes

    SciTech Connect

    Gan, Zhengqing; Tian, Yun; Lynch, David W.; Kang, Ji-hun; Park, Q-Han; and Shinar, Joseph

    2009-11-03

    A dramatic spectral line narrowing of the edge emission at room temperature from tris(quinolinolate) Al (Alq{sub 3}), N,N{prime}-diphenyl-N,N{prime}-bis(1-naphthylphenyl)-1,1{prime}-biphenyl-4,4{prime}-diamine (NPD), 4,4{prime}-bis(2,2{prime}-diphenyl-vinyl)-,1{prime}-biphenyl (DPVBi), and some guest-host small molecular organic light-emitting diodes (OLEDs), fabricated on indium tin oxide (ITO)-coated glass, is described. In all but the DPVBi OLEDs, the narrowed emission band emerges above a threshold thickness of the emitting layer, and narrows down to a full width at half maximum of only 5-10 nm. The results demonstrate that this narrowed emission is due to irregular waveguide modes that leak from the ITO to the glass substrate at a grazing angle. While measurements of variable stripe length l devices exhibit an apparent weak optical gain 0 {le} g {le} 1.86 cm{sup -1}, there is no observable threshold current or bias associated with this spectral narrowing. In addition, in the phosphorescent guest-host OLEDs, there is no decrease in the emission decay time of the narrowed edge emission relative to the broad surface emission. It is suspected that the apparent weak optical gain is due to misalignment of the axis of the waveguided mode and the axis of the collection lens of the probe.

  5. Isolation of a Breast Cancer Tumor Suppressor Gene from Chromosome 3p

    DTIC Science & Technology

    1995-10-01

    regions) of 3p that most consistently undergo LOH in breast cancer and to further narrow the critical region in order to facilitate molecular cloning of...tumorigenesis. In the identification and molecular cloning of tumor suppressor genes, homozygous deletions have played a very major role in directing gene...narrow the critical region in order to facilitate molecular cloning of the disease gene. Fluorescence in situ hybridization will be employed as an

  6. 33 CFR 334.710 - The Narrows and Gulf of Mexico adjacent to Santa Rosa Island, Headquarters Air Armament Center...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false The Narrows and Gulf of Mexico... DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.710 The Narrows and Gulf of Mexico adjacent to... part 329, including the waters of The Narrows and the Gulf of Mexico easterly of the periphery of a...

  7. 33 CFR 334.710 - The Narrows and Gulf of Mexico adjacent to Santa Rosa Island, Headquarters Air Armament Center...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false The Narrows and Gulf of Mexico... DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.710 The Narrows and Gulf of Mexico adjacent to... part 329, including the waters of The Narrows and the Gulf of Mexico easterly of the periphery of a...

  8. 33 CFR 334.710 - The Narrows and Gulf of Mexico adjacent to Santa Rosa Island, Headquarters Air Armament Center...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false The Narrows and Gulf of Mexico... DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.710 The Narrows and Gulf of Mexico adjacent to... part 329, including the waters of The Narrows and the Gulf of Mexico easterly of the periphery of a...

  9. 17 CFR 41.15 - Exclusion from definition of narrow-based security index for indexes composed of debt securities.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... narrow-based security index for indexes composed of debt securities. 41.15 Section 41.15 Commodity and... Indexes § 41.15 Exclusion from definition of narrow-based security index for indexes composed of debt securities. (a) An index is not a narrow-based security index if: (1)(i) Each of the securities of an issuer...

  10. 17 CFR 41.15 - Exclusion from definition of narrow-based security index for indexes composed of debt securities.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... narrow-based security index for indexes composed of debt securities. 41.15 Section 41.15 Commodity and... Indexes § 41.15 Exclusion from definition of narrow-based security index for indexes composed of debt securities. (a) An index is not a narrow-based security index if: (1)(i) Each of the securities of an issuer...

  11. The Effects of Narrow Reading of Authentic Texts on Interest and Reading Ability in English as a Foreign Language

    ERIC Educational Resources Information Center

    Cho, Kyung-Sook; Ahn, Kyoung-Ok; Krashen, Stephen

    2005-01-01

    Narrow reading means reading in only one genre, one subject matter, or the work of one author. The case for narrow reading was first presented over twenty years ago (Krashen, 1981). Narrow reading, it was argued, has the advantage of providing the developing reader with a familiar context, that is, familiar background knowledge that helps make…

  12. Oxygen vacancy induced band gap narrowing of ZnO nanostructures by an electrochemically active biofilm

    NASA Astrophysics Data System (ADS)

    Ansari, Sajid Ali; Khan, Mohammad Mansoob; Kalathil, Shafeer; Nisar, Ambreen; Lee, Jintae; Cho, Moo Hwan

    2013-09-01

    Band gap narrowing is important and advantageous for potential visible light photocatalytic applications involving metal oxide nanostructures. This paper reports a simple biogenic approach for the promotion of oxygen vacancies in pure zinc oxide (p-ZnO) nanostructures using an electrochemically active biofilm (EAB), which is different from traditional techniques for narrowing the band gap of nanomaterials. The novel protocol improved the visible photocatalytic activity of modified ZnO (m-ZnO) nanostructures through the promotion of oxygen vacancies, which resulted in band gap narrowing of the ZnO nanostructure (Eg = 3.05 eV) without dopants. X-ray diffraction, UV-visible diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, electron paramagnetic resonance spectroscopy, Raman spectroscopy, photoluminescence spectroscopy and high resolution transmission electron microscopy confirmed the oxygen vacancy and band gap narrowing of m-ZnO. m-ZnO enhanced the visible light catalytic activity for the degradation of different classes of dyes and 4-nitrophenol compared to p-ZnO, which confirmed the band gap narrowing because of oxygen defects. This study shed light on the modification of metal oxide nanostructures by EAB with a controlled band structure.Band gap narrowing is important and advantageous for potential visible light photocatalytic applications involving metal oxide nanostructures. This paper reports a simple biogenic approach for the promotion of oxygen vacancies in pure zinc oxide (p-ZnO) nanostructures using an electrochemically active biofilm (EAB), which is different from traditional techniques for narrowing the band gap of nanomaterials. The novel protocol improved the visible photocatalytic activity of modified ZnO (m-ZnO) nanostructures through the promotion of oxygen vacancies, which resulted in band gap narrowing of the ZnO nanostructure (Eg = 3.05 eV) without dopants. X-ray diffraction, UV-visible diffuse reflectance spectroscopy, X

  13. Hydrographic surveys of four narrows within the Namakan reservoir system, Voyageurs National Park, Minnesota, 2011

    USGS Publications Warehouse

    Densmore, Brenda K.; Strauch, Kellan R.; Ziegeweid, Jeffrey R.

    2013-01-01

    The U.S. Geological Survey performed multibeam echosounder hydrographic surveys of four narrows in the Namakan reservoir system in August 2011, in cooperation with the International Joint Commission and Environment Canada. The data-collection effort was completed to provide updated and detailed hydrographic data to Environment Canada for inclusion in a Hydrologic Engineering Centers River Analysis System hydraulic model. The Namakan reservoir system is composed of Namakan, Kabetogama, Sand Point, Crane, and Little Vermilion Lakes. Water elevations in the Namakan reservoir system are regulated according to rule curves, or guidelines for water-level management based on the time of year, established by the International Joint Commission. Water levels are monitored by established gages on Crane Lake and the outlet of Namakan Lake at Kettle Falls, but water elevations throughout the system may deviate from these measured values by as much as 0.3 meters, according to lake managers and residents. Deviations from expected water elevations may be caused by between-lake constrictions (narrows). According to the 2000 Rule Curve Assessment Workgroup, hydrologic models of the reservoir system are needed to better understand the system and to evaluate the recent changes made to rule curves in 2000. Hydrographic surveys were performed using a RESON SeaBat™7125 multibeam echosounder system. Surveys were completed at Namakan Narrows, Harrison Narrows, King Williams Narrows, and Little Vermilion Narrows. Hydrographic survey data were processed using Caris HIPSTM and SIPSTM software that interpolated a combined uncertainty and bathymetric estimator (CUBE) surface. Quality of the survey results was evaluated in relation to standards set by the International Hydrographic Organization (IHO) for describing the uncertainty of hydrographic surveys. More than 90 percent of the surveyed areas at the four narrows have resulting bed elevations that meet the IHO “Special Order” quality

  14. Accurate stepping on a narrow path: mechanics, EMG, and motor cortex activity in the cat.

    PubMed

    Farrell, Brad J; Bulgakova, Margarita A; Sirota, Mikhail G; Prilutsky, Boris I; Beloozerova, Irina N

    2015-11-01

    How do cats manage to walk so graciously on top of narrow fences or windowsills high above the ground while apparently exerting little effort? In this study we investigated cat full-body mechanics and the activity of limb muscles and motor cortex during walking along a narrow 5-cm path on the ground. We tested the hypotheses that during narrow walking 1) lateral stability would be lower because of the decreased base-of-support area and 2) the motor cortex activity would increase stride-related modulation because of imposed demands on lateral stability and paw placement accuracy. We measured medio-lateral and rostro-caudal dynamic stability derived from the extrapolated center of mass position with respect to the boundaries of the support area. We found that cats were statically stable in the frontal plane during both unconstrained and narrow-path walking. During narrow-path walking, cats walked slightly slower with more adducted limbs, produced smaller lateral forces by hindlimbs, and had elevated muscle activities. Of 174 neurons recorded in cortical layer V, 87% of forelimb-related neurons (from 114) and 90% of hindlimb-related neurons (from 60) had activities during narrow-path walking distinct from unconstrained walking: more often they had a higher mean discharge rate, lower depth of stride-related modulation, and/or longer period of activation during the stride. These activity changes appeared to contribute to control of accurate paw placement in the medio-lateral direction, the width of the stride, rather than to lateral stability control, as the stability demands on narrow-path and unconstrained walking were similar. Copyright © 2015 the American Physiological Society.

  15. Accurate stepping on a narrow path: mechanics, EMG, and motor cortex activity in the cat

    PubMed Central

    Farrell, Brad J.; Bulgakova, Margarita A.; Sirota, Mikhail G.; Prilutsky, Boris I.

    2015-01-01

    How do cats manage to walk so graciously on top of narrow fences or windowsills high above the ground while apparently exerting little effort? In this study we investigated cat full-body mechanics and the activity of limb muscles and motor cortex during walking along a narrow 5-cm path on the ground. We tested the hypotheses that during narrow walking 1) lateral stability would be lower because of the decreased base-of-support area and 2) the motor cortex activity would increase stride-related modulation because of imposed demands on lateral stability and paw placement accuracy. We measured medio-lateral and rostro-caudal dynamic stability derived from the extrapolated center of mass position with respect to the boundaries of the support area. We found that cats were statically stable in the frontal plane during both unconstrained and narrow-path walking. During narrow-path walking, cats walked slightly slower with more adducted limbs, produced smaller lateral forces by hindlimbs, and had elevated muscle activities. Of 174 neurons recorded in cortical layer V, 87% of forelimb-related neurons (from 114) and 90% of hindlimb-related neurons (from 60) had activities during narrow-path walking distinct from unconstrained walking: more often they had a higher mean discharge rate, lower depth of stride-related modulation, and/or longer period of activation during the stride. These activity changes appeared to contribute to control of accurate paw placement in the medio-lateral direction, the width of the stride, rather than to lateral stability control, as the stability demands on narrow-path and unconstrained walking were similar. PMID:26354314

  16. Poloidal asymmetry in the narrow heat flux feature in the TCV scrape-off layer

    NASA Astrophysics Data System (ADS)

    Tsui, C. K.; Boedo, J. A.; Halpern, F. D.; Loizu, J.; Nespoli, F.; Horacek, J.; Labit, B.; Morales, J.; Reimerdes, H.; Ricci, P.; Theiler, C.; Coda, S.; Duval, B. P.; Furno, I.

    2017-06-01

    Heat flux profiles inferred from a reciprocating probe at the outer midplane of the TCV tokamak during inner wall limited discharges feature radial fall-off lengths that shorten near the last closed flux surface (LCFS) consistent with the so-called narrow feature. The narrow feature is significantly wider on the outboard side compared with that measured on the inner wall by infrared thermography, so it is difficult to discern from the main scrape-off layer feature. After small shifts were applied for alignment, the fraction of the power contained in the narrow feature matches between inboard and outboard measurements, and they scale together with plasma current Ip, suggesting that we are observing the same phenomenon. The outboard side fall-off length within the narrow feature is found to scale closely with the radial correlation length of the edge turbulence as expected if the narrow feature arises due to radially sheared E × B flows. This is found to hold true even for cases where the narrow feature is weak and the fall-off lengths are approaching that of the far scrape-off layer. After the small shifts for alignment, non-zero floating potential profiles were found to match between inboard and outboard sides. A simple model of polarization and diamagnetic cross-field currents is described, which is consistent with the shape of these floating potential profiles. The model predicts that the floating potential at the LCFS must be negative, which supports the argument to shift the upstream measurements. The predicted currents are also consistent with the E × B flows believed to cause the narrow feature. The model is used to predict the magnitude of the floating potential of the LCFS, and the results are found to match measurements for all values of Ip. This paper therefore demonstrates consistency between the measurements of the narrow feature on the inboard and outboard sides of the plasma, as well as consistency between the measurements, non-linear turbulence

  17. Experimental study on narrow linewidth fiber ring laser based on parallel feedback mechanism

    NASA Astrophysics Data System (ADS)

    Wang, Cui-yun; Wang, Da-liang; Wang, Zi-nan; Lu, Ping; Xu, Lian-yu; Yu, Xiao-qi; Jiang, Yun; Zhu, Li-xin; Li, Zheng-bin

    2011-06-01

    Narrow linewidth fiber lasers are intensively studied during these years, for their wide use in coherent optical communication, optical fiber sensing, high-precision spectroscopy and many other industrial and military applications. A usual technique to suppress linewidth is narrow band filtering in the resonating structure of the laser. However, it is hard in fabrication for a tradition optical filter to achieve an ultra narrow pass band such as kilo-Hertz. In this paper, the parallel feedback structure is proposed and experimentally studied. A fiber laser with ultra narrow linewidth (15Hz detected) is achieved in laboratory, basing on the parallel feedback mechanism in a fiber ring cavity. In multimode fiber, each transverse mode has a different propagation constant. Equivalently, when a light beam propagates form single mode fiber to multimode fiber, it will split into a few parallel light paths with different propagation constants. The parallel feedback structure of a fiber ring laser is carried out by introducing one or more pieces of multi-mode fiber into its resonant cavity. Lasing light in the cavity must fit the restrictions of all light paths, thus linewidth of the laser output is suppressed. Ultra narrow linewidth can be achieved by carefully adjusting the amount and length of multi-mode fiber pieces. The narrowest linewidth achieved in laboratory is 15Hz detected by a delayed self-heterodyne interferometer with a 100km fiber delay line. In this work, we focus on pressuring linewidth, and mechanism of selecting and stabilizing mode isn't employed. Therefore, the narrow linewidth fiber laser isn't single-longitudinal-mode (SLM). A similar ring laser structure with bidirectional output is also experimental implemented, achieving a bandwidth of the same order. The bidirectional ring laser is the basic component of a laser gyroscope, and its linewidth is one key limiting factor of the gyroscope accuracy. This narrow linewidth bidirectional ring laser is a

  18. Narrow-linewidth Q-switched random distributed feedback fiber laser.

    PubMed

    Xu, Jiangming; Ye, Jun; Xiao, Hu; Leng, Jinyong; Wu, Jian; Zhang, Hanwei; Zhou, Pu

    2016-08-22

    A narrow-linewidth Q-switched random fiber laser (RFL) based on a half-opened cavity, which is realized by narrow-linewidth fiber Bragg grating (FBG) and a section of 3 km passive fiber, has been proposed and experimentally investigated. The narrow-linewidth lasing is generated by the spectral filtering of three FBGs with linewidth of 1.21 nm, 0.56 nm, and 0.12 nm, respectively. The Q switching of the distributed cavity is achieved by placing an acousto-optical modulator (AOM) between the FBG and the passive fiber. The maximal output powers of the narrow-linewidth RFLs with the three different FBGs are 0.54 W, 0.27 W, and 0.08 W, respectively. Furthermore, the repetition rates of the output pulses are 500 kHz, and the pulse durations are about 500 ns. The corresponding pulse energies are about 1.08 μJ, 0.54 μJ, and 0.16 μJ, accordingly. The linewidth of FBG can influence the output characteristics in full scale. The narrower the FBG, the higher the pump threshold; the lower the output power at the same pump level, the more serious the linewidth broadening; and thus the higher the proportion of the CW-ground exists in the output pulse trains. Thanks to the assistance of the band-pass filter (BPF), the proportion of the CW-ground of narrow-linewidth Q-switched RFL under the relative high-pump-low-output condition can be reduced effectively. The experimental results indicate that it is challenging to demonstrate a narrow-linewidth Q-switched RFL with high quality output. But further power scaling and linewidth narrowing is possible in the case of operating parameters, optimization efforts, and a more powerful pump source. To the best of our knowledge, this is the first demonstration of narrow-linewidth generation in a Q-switched RFL.

  19. The role of vegetation and bed-level fluctuations in the process of channel narrowing

    USGS Publications Warehouse

    Friedman, J.M.; Osterkamp, W.R.; Lewis, W.M.

    1996-01-01

    A catastrophic flood in 1965 on Plum Creek, a perennial sandbed stream in the western Great Plains, removed most of the bottomland vegetation and transformed the single-thalweg stream into a wider, braided channel. Following eight years of further widening associated with minor high flows, a process of channel narrowing began in 1973; narrowing continues today. The history of channel narrowing was reconstructed by counting the annual rings of 129 trees and shrubs along a 5-km reach of Plum Creek near Louviers, Colorado. Sixty-three of these plants were excavated in order to determine the age and elevation of the germination point. The reconstructed record of channel change was verified from historical aerial photographs, and then compared to sediment stratigraphy and records of discharge and bed elevation from a streamflow gaging station in the study reach. Channel narrowing at Plum Creek occurs in two ways. First, during periods of high flow, sand and fine gravel are delivered to the channel, temporarily raising the general bed-level. Subsequently, several years of uninterrupted low flows incise a narrower channel. Second, during years of low flow, vegetation becomes established on the subaerial part of the present channel bed. In both cases, surfaces stabilize as a result of vegetation growth and vertical accretion of sediment.

  20. Electronic structure descriptor for the discovery of narrow-band red-emitting phosphors

    DOE PAGES

    Wang, Zhenbin; Chu, Iek -Heng; Zhou, Fei; ...

    2016-05-09

    Narrow-band red-emitting phosphors are a critical component of phosphor-converted light-emitting diodes for highly efficient illumination-grade lighting. In this work, we report the discovery of a quantitative descriptor for narrow-band Eu2+-activated emission identified through a comparison of the electronic structures of known narrow-band and broad-band phosphors. We find that a narrow emission bandwidth is characterized by a large splitting of more than 0.1 eV between the two highest Eu2+ 4f7 bands. By incorporating this descriptor in a high-throughput first-principles screening of 2259 nitride compounds, we identify five promising new nitride hosts for Eu2+-activated red-emitting phosphors that are predicted to exhibit goodmore » chemical stability, thermal quenching resistance, and quantum efficiency, as well as narrow-band emission. Lastly, our findings provide important insights into the emission characteristics of rare-earth activators in phosphor hosts and a general strategy to the discovery of phosphors with a desired emission peak and bandwidth.« less

  1. Electronic structure descriptor for the discovery of narrow-band red-emitting phosphors

    SciTech Connect

    Wang, Zhenbin; Chu, Iek -Heng; Zhou, Fei; Ong, Shyue Ping

    2016-05-09

    Narrow-band red-emitting phosphors are a critical component of phosphor-converted light-emitting diodes for highly efficient illumination-grade lighting. In this work, we report the discovery of a quantitative descriptor for narrow-band Eu2+-activated emission identified through a comparison of the electronic structures of known narrow-band and broad-band phosphors. We find that a narrow emission bandwidth is characterized by a large splitting of more than 0.1 eV between the two highest Eu2+ 4f7 bands. By incorporating this descriptor in a high-throughput first-principles screening of 2259 nitride compounds, we identify five promising new nitride hosts for Eu2+-activated red-emitting phosphors that are predicted to exhibit good chemical stability, thermal quenching resistance, and quantum efficiency, as well as narrow-band emission. Lastly, our findings provide important insights into the emission characteristics of rare-earth activators in phosphor hosts and a general strategy to the discovery of phosphors with a desired emission peak and bandwidth.

  2. Electronic structure descriptor for the discovery of narrow-band red-emitting phosphors

    SciTech Connect

    Wang, Zhenbin; Chu, Iek -Heng; Zhou, Fei; Ong, Shyue Ping

    2016-05-09

    Narrow-band red-emitting phosphors are a critical component of phosphor-converted light-emitting diodes for highly efficient illumination-grade lighting. In this work, we report the discovery of a quantitative descriptor for narrow-band Eu2+-activated emission identified through a comparison of the electronic structures of known narrow-band and broad-band phosphors. We find that a narrow emission bandwidth is characterized by a large splitting of more than 0.1 eV between the two highest Eu2+ 4f7 bands. By incorporating this descriptor in a high-throughput first-principles screening of 2259 nitride compounds, we identify five promising new nitride hosts for Eu2+-activated red-emitting phosphors that are predicted to exhibit good chemical stability, thermal quenching resistance, and quantum efficiency, as well as narrow-band emission. Lastly, our findings provide important insights into the emission characteristics of rare-earth activators in phosphor hosts and a general strategy to the discovery of phosphors with a desired emission peak and bandwidth.

  3. Short term frequency stability measurement for narrow linewidth laser by time domain self-heterodyne method

    NASA Astrophysics Data System (ADS)

    Lu, Lidong; Sun, Xiaoyan; Bu, Xiande; Li, Binglin

    2016-11-01

    Based on the time delay self-heterodyne method to measure the laser linewidth, the short-term linewidth variation of a narrow linewidth laser is experimentally studied and analyzed, and then a time domain self-heterodyne method is proposed to measure the short-term frequency stability of narrow linewidth laser. The Rayleigh backscattering frequency of a pulsed light propagating in an optical fiber with length of 100km is used as the local oscillation frequency with relatively long time duration to measure the frequency variation of the narrow linewidth laser. By heterodyne between the laser frequency and the local oscillation frequency, the variation of the laser frequency is presented in the heterodyne radio frequency (IF). Then the time domain data of the heterodyne IF are extracted by an oscilloscope and through short time Fourier transform the frequency from the laser in different time segments is obtained. Experimental results demonstrate that for narrow linewidth laser its frequency in short-term is randomly fluctuating with a range less than triple of the laser linewidth. The measurement and evaluation of laser short-term frequency stability benefits the application of narrow linewidth lasers in distributed optical fiber sensing area.

  4. Quantum fluctuations increase the self-diffusive motion of para-hydrogen in narrow carbon nanotubes.

    PubMed

    Kowalczyk, Piotr; Gauden, Piotr A; Terzyk, Artur P; Furmaniak, Sylwester

    2011-05-28

    Quantum fluctuations significantly increase the self-diffusive motion of para-hydrogen adsorbed in narrow carbon nanotubes at 30 K comparing to its classical counterpart. Rigorous Feynman's path integral calculations reveal that self-diffusive motion of para-hydrogen in a narrow (6,6) carbon nanotube at 30 K and pore densities below ∼29 mmol cm(-3) is one order of magnitude faster than the classical counterpart. We find that the zero-point energy and tunneling significantly smoothed out the free energy landscape of para-hydrogen molecules adsorbed in a narrow (6,6) carbon nanotube. This promotes a delocalization of the confined para-hydrogen at 30 K (i.e., population of unclassical paths due to quantum effects). Contrary the self-diffusive motion of classical para-hydrogen molecules in a narrow (6,6) carbon nanotube at 30 K is very slow. This is because classical para-hydrogen molecules undergo highly correlated movement when their collision diameter approached the carbon nanotube size (i.e., anomalous diffusion in quasi-one dimensional pores). On the basis of current results we predict that narrow single-walled carbon nanotubes are promising nanoporous molecular sieves being able to separate para-hydrogen molecules from mixtures of classical particles at cryogenic temperatures.

  5. Identification of GH15 Family Thermophilic Archaeal Trehalases That Function within a Narrow Acidic-pH Range

    PubMed Central

    Shimodaira, Satoru; Ishida, Shin-nosuke; Amemiya, Miko; Honda, Shotaro; Sugahara, Yasusato; Oyama, Fumitaka; Kawakita, Masao

    2015-01-01

    Two glucoamylase-like genes, TVN1315 and Ta0286, from the archaea Thermoplasma volcanium and T. acidophilum, respectively, were expressed in Escherichia coli. The gene products, TVN1315 and Ta0286, were identified as archaeal trehalases. These trehalases belong to the CAZy database family GH15, although they have putative (α/α)6 barrel catalytic domain structures similar to those of GH37 and GH65 family trehalases from other organisms. These newly identified trehalases function within a narrow range of acidic pH values (pH 3.2 to 4.0) and at high temperatures (50 to 60°C), and these enzymes display Km values for trehalose higher than those observed for typical trehalases. These enzymes were inhibited by validamycin A; however, the inhibition constants (Ki) were higher than those of other trehalases. Three TVN1315 mutants, corresponding to E408Q, E571Q, and E408Q/E571Q mutations, showed reduced activity, suggesting that these two glutamic acid residues are involved in trehalase catalysis in a manner similar to that of glucoamylase. To date, TVN1315 and Ta0286 are the first archaeal trehalases to be identified, and this is the first report of the heterologous expression of GH15 family trehalases. The identification of these trehalases could extend our understanding of the relationships between the structure and function of GH15 family enzymes as well as glycoside hydrolase family enzymes; additionally, these enzymes provide insight into archaeal trehalose metabolism. PMID:25979886

  6. Genetic panmixia within a narrow contact zone between chromosomally and ecologically distinct black fly sibling species (Diptera: Simuliidae).

    PubMed

    Conflitti, I M; Shields, G F; Murphy, R W; Currie, D C

    2015-09-01

    Hybrid zones are windows into the speciation process, and their study can give clues into the maintenance and breakdown of species boundaries. Using both genetic and ecological tools, we investigate lineage diversification across a contact zone characterized by chromosome rearrangements. We show that black fly sibling species, Simulium arcticum sensu stricto (s.s.) and Simulium saxosum, lack genetic differentiation at both microsatellite and mtDNA loci in allopatry and sympatry, as well as exhibit high levels of gene flow and continuous chromosome variation in sympatry. Furthermore, hybrid frequencies at the contact zone are similar to those seen between races, rather than species. In contrast, S. arcticum s.s. and S. saxosum maintain ecological differences and distinct habitat associations - the contact zone situated at the margin of suitable habitat for each sibling species. Moreover, gene flow occurs only in a narrow band along an ecological transition. Except for the contact zone, S. arcticum s.s. and S. saxosum hybrids do not occur elsewhere within the sibling species' ranges. Although S. arcticum s.s. and S. saxosum maintain the potential to interbreed freely, we conclude that habitat associations and, perhaps, chromosome systems prevent expansion of ranges and assimilation of lineages.

  7. Einstein-Podolsky-Rosen Entanglement of Narrow-Band Photons from Cold Atoms.

    PubMed

    Lee, Jong-Chan; Park, Kwang-Kyoon; Zhao, Tian-Ming; Kim, Yoon-Ho

    2016-12-16

    Einstein-Podolsky-Rosen (EPR) entanglement introduced in 1935 deals with two particles that are entangled in their positions and momenta. Here we report the first experimental demonstration of EPR position-momentum entanglement of narrow-band photon pairs generated from cold atoms. By using two-photon quantum ghost imaging and ghost interference, we demonstrate explicitly that the narrow-band photon pairs violate the separability criterion, confirming EPR entanglement. We further demonstrate continuous variable EPR steering for positions and momenta of the two photons. Our new source of EPR-entangled narrow-band photons is expected to play an essential role in spatially multiplexed quantum information processing, such as, storage of quantum correlated images, quantum interface involving hyperentangled photons, etc.

  8. Research on the injected effect by the narrow-slit injection orifice in screw compressors

    NASA Astrophysics Data System (ADS)

    Xie, J.; Feng, J.; Liu, F.; Peng, C.; Feng, Q.

    2017-08-01

    A narrow-slit injection orifice in screw compressors (mainly in single screw compressors) is described in this paper. In contrast to the traditional injection orifice, the section is slit shaped but not circular. Liquid which is injected by the narrow-slit injection orifice appears as a curtain shape. The heat transfer area is increased so that the cooling effect is enhanced and the efficiency of the compressor is improved. The injected effect was simulated through the CFD software, and then the experiments were carried out. The study verified the accuracy of the simulation results and will provide a theoretical foundation for the design of a narrow-slit injection orifice in screw compressors.

  9. Augmented heat transfer in rectangular channels of narrow aspect ratios with rib turbulators

    NASA Technical Reports Server (NTRS)

    Han, J. C.; Ou, S.; Park, J. S.; Lei, C. K.

    1989-01-01

    The effects of the rib angle-of-attack on the distributions of the local heat transfer coefficient and on the friction factors in short rectangular channels of narrow aspect ratios with a pair of opposite rib-roughened walls are determined for Reynolds numbers from 10,000 to 60,000. The channel width-to-height ratios are 2/4 and 1/4; the corresponding rib angles-of-attack are 90, 60, 45, and 30 deg, respectively. The results indicate that the narrow-aspect-ratio channels give better heat transfer performance than the wide-aspect-ratio channels for a constant pumping power. Semiempirical friction and heat transfer correlations are obtained. The results can be used in the design of turbine cooling channels of narrow aspect ratios.

  10. Spectral narrowing of emission in self-assembled colloidal photonic superlattices

    NASA Astrophysics Data System (ADS)

    Baert, Kasper; Song, Kai; Vallée, Renaud A. L.; Van der Auweraer, Mark; Clays, Koen

    2006-12-01

    We report on the influence of a well-designed passband in the stop band of a suitably engineered self-assembled colloidal photonic crystal superlattice on the steady-state emission properties of infiltrated fluorophores. The photonic superlattice was built by convective self-assembly of slabs of silica spheres of two different sizes. Transmission experiments on the engineered photonic crystal structure show two stop bands with an effective passband in between. The presence of this passband results in a narrow spectral range of increased density of states for photon modes. This shows up as a decrease in the emission suppression (enhancement of the emission) in the narrow effective passband spectral region. These experiments indicate that the threshold for lasing can possibly be lowered by spectrally narrowing the emission of fluorophores infiltrated in suitably engineered self-assembled photonic crystal superlattices, and are therefore important towards the realization of efficient all-optical integrated circuits from functionalized photonic superlattices and heterostructures.

  11. Looking through an adolescent literacy lens at the narrow view of reading.

    PubMed

    Ehren, Barbara J

    2009-04-01

    This commentary is a personal reaction to A. G. Kamhi's (2007) article on the "narrow view" of reading and his suggestion that this view be adopted as a way to address the reading problems of children and adolescents. In this article, I consider the narrow view of reading from an adolescent literacy perspective and discuss the practical implications of adopting this view in the schools. Discussion revolves around the complexities of reading comprehension, comprehension as a teachable set of complex processes, and the speech-language pathologist's role in reading comprehension. Although I acknowledge that the narrow view of reading may have merit, I opine that it may create more problems than it solves.

  12. Brief daily exposures to Asian females reverses perceptual narrowing for Asian faces in Caucasian infants.

    PubMed

    Anzures, Gizelle; Wheeler, Andrea; Quinn, Paul C; Pascalis, Olivier; Slater, Alan M; Heron-Delaney, Michelle; Tanaka, James W; Lee, Kang

    2012-08-01

    Perceptual narrowing in the visual, auditory, and multisensory domains has its developmental origins during infancy. The current study shows that experimentally induced experience can reverse the effects of perceptual narrowing on infants' visual recognition memory of other-race faces. Caucasian 8- to 10-month-olds who could not discriminate between novel and familiarized Asian faces at the beginning of testing were given brief daily experience with Asian female faces in the experimental condition and Caucasian female faces in the control condition. At the end of 3 weeks, only infants who received daily experience with Asian females showed above-chance recognition of novel Asian female and male faces. Furthermore, infants in the experimental condition showed greater efficiency in learning novel Asian females compared with infants in the control condition. Thus, visual experience with a novel stimulus category can reverse the effects of perceptual narrowing during infancy via improved stimulus recognition and encoding.

  13. Narrow polarized components in the OH 1612-MHz maser emission from supergiant OH-IR sources

    NASA Technical Reports Server (NTRS)

    Cohen, R. J.; Downs, G.; Emerson, R.; Grimm, M.; Gulkis, S.; Stevens, G.

    1987-01-01

    High-resolution (300 Hz) OH 1612-MHz spectra of the supergiant OH-IR sources VY CMa, VX Sgr, IRC 10420, and NML Cyg are presented. Linewidths as small as 550 Hz (0.1 km/s) are found for narrow components in the spectra. The present results are consistent with current models for maser line-narrowing and for the physical properties in the OH maser regions. A significant degree of circular polarization is noted in many of the narrow components. The circular polarization suggests the presence of magnetic fields of about 1 mG in the circumstellar envelopes which would be strong enough to influence the outflow from the stars, and which may explain asymmetries found in the circumstellar envelopes.

  14. Light trimming of a narrow bandpass filter based on a photosensitive chalcogenide spacer.

    PubMed

    Shen, W D; Cathelinaud, M; Lequime, M D; Charpentier, F; Nazabal, V

    2008-01-07

    We present an experimental study of the photosensitive properties of a narrow bandpass filter based on a Ge(15)Sb(20)S(65) spacer fabricated by electron beam deposition. For a single layer, near the optical bandgap of this chalcogenide material, the efficiency of the photo-bleaching increases as the central wavelength of the light source for exposure decreases. The maximum relative photo-induced change of the optical thickness reaches about 1%. By using controlled light exposure around 480 nm of a photosensitive narrow bandpass filter centered at 1550 nm, we obtained a spatially localized shift of its peak wavelength up to 5.4 nm. This property is used to perform, for the first time at our knowledge, the post trimming of a narrow bandpass filter with a light beam. A 5 x 5 mm(2) ultra uniform area in which the relative spatial variation of its peak wavelength remains below 0.004% is demonstrated.

  15. Theoretical modelling of tunable narrow band reflective spectrum using nanoscale surface plasmons

    NASA Astrophysics Data System (ADS)

    Yang, J.; Lin, G. W.; Niu, Y. P.; Gong, S. Q.

    2017-04-01

    The spectrum width can be narrowed to a certain degree by decreasing the coupling strength for the two-level emitter coupled to the propagating surface plasmon. But the width can not be narrowed any further because of the loss of the photon out of the system by the spontaneous emission of the emitter. Here we accurately solve the single photon scattering problem for the surface plasmon coupling with a four-level tripod emitter, and propose a new scheme to obtain the reflective spectrum with tunable ultranarrow band. It is shown that the spectrum width can be narrowed avoiding the impact of the loss. Furthermore, the position of ultranarrow peak can be tunable by choosing the appropriate parameters.

  16. Femtosecond Laser in situ Keratomileusis Flap Creation in Narrow Palpebral Fissure Eyes without Suction.

    PubMed

    Chang, John S M; Law, Antony K P; Ng, Jack C M; Cheng, May S Y

    2017-01-01

    To evaluate a surgical technique used in eyes with narrow palpebral fissure undergoing femtosecond laser flap creation without suction during laser in situ keratomileusis (LASIK). All data of 2 patient groups were collected through chart review. Group 1 consisted of 6 eyes with narrow palpebral fissure in which the suction ring was manually fixated and femtosecond laser was applied accordingly. Thirty comparison cases were randomly drawn from among eyes that underwent a standard LASIK procedure matched for age and preoperative refraction (group 2). Only 1 eye of each patient was selected to compare the refractive and visual outcomes between groups. In all group 1 eyes, the flaps were created successfully with manual fixation of the suction ring without suction. No eyes lost 2 or more lines of vision. No significant difference was found in the safety and refractive outcomes between groups. Manual fixation of the suction ring in eyes with narrow palpebral fissure without suction was feasible for flap creation during LASIK.

  17. Passive intrinsic-linewidth narrowing of ultraviolet extended-cavity diode laser by weak optical feedback.

    PubMed

    Samutpraphoot, Polnop; Weber, Sophie; Lin, Qian; Gangloff, Dorian; Bylinskii, Alexei; Braverman, Boris; Kawasaki, Akio; Raab, Christoph; Kaenders, Wilhelm; Vuletić, Vladan

    2014-05-19

    We present a simple method for narrowing the intrinsic Lorentzian linewidth of a commercial ultraviolet grating extended-cavity diode laser (TOPTICA DL Pro) using weak optical feedback from a long external cavity. We achieve a suppression in frequency noise spectral density of 20 dB measured at frequencies around 1 MHz, corresponding to the narrowing of the intrinsic Lorentzian linewidth from 200 kHz to 2 kHz. Provided additional active low-frequency noise suppression and long-term drift compensation, the system is suitable for experiments requiring a tunable ultraviolet laser with narrow linewidth and low high-frequency noise, such as precision spectroscopy, optical clocks, and quantum information science experiments.

  18. HIGH DEFINITION ENDOSCOPY AND "NARROW BAND IMAGING" IN THE DIAGNOSIS OF GASTROESOPHAGEAL REFLUX DISEASE

    PubMed Central

    ASSIRATI, Frederico Salvador; HASHIMOTO, Cláudio Lyoiti; DIB, Ricardo Anuar; FONTES, Luiz Henrique Souza; NAVARRO-RODRIGUEZ, Tomás

    2014-01-01

    Introduction The gastroesophageal reflux disease is a common condition in the western world but less than half of patients present endoscopic abnormalities, making a standard procedure unsuitable for diagnosis. High definition endoscopy coupled with narrow band imaging has shown potential for differentiation of lesions and possible biopsy, allowing early diagnosis and treatment. Methods This review describes the principles of biotic and their influence in obtaining images with better definition of the vessels in the mucosa, through the narrow band imaging. Selected papers using it in patients with reflux disease and Barrett's esophagus are analyzed in several ways, highlighting the findings and limitations. Conclusion The meaning of the narrow band imaging in the endoscopic diagnosis of reflux disease will be defined by large scale studies, with different categories of patients, including assessment of symptoms and response to treatment. PMID:24676302

  19. Evidence for a narrow N{sup *}(1685) resonance in quasifree Compton scattering on the neutron

    SciTech Connect

    Kuznetsov, V.; Polyakov, M. V.; Bellini, V.; Giusa, A.; Mammoliti, F.; Randieri, C.; Russo, G.; Sperduto, M. L.; Boiko, T.; Chebotaryov, S.; Dho, H.-S.; Kim, W.; Milman, E.; Ni, A.; Gervino, G.; Ghio, F.; Kim, A.; Perevalova, I. A.; Vall, A. N.; Sutera, C. M.

    2011-02-15

    The study of quasifree Compton scattering on the neutron in the energy range of E{sub {gamma}}=0.75-1.5 GeV is presented. The data reveal a narrow peak at W{approx}1.685 GeV. This result, being considered in conjunction with the recent evidence for a narrow structure at W{approx}1.68 GeV in {eta} photoproduction on the neutron, suggests the existence of a nucleon resonance with unusual properties: a mass M{approx}1.685 GeV, a narrow width {Gamma}{<=}30 MeV, and the much stronger photoexcitation on the neutron than on the proton.

  20. Method for shaping and aiming narrow beams. [sonar mapping and target identification

    NASA Technical Reports Server (NTRS)

    Heyser, R. C. (Inventor)

    1981-01-01

    A sonar method and apparatus is discribed which utilizes a linear frequency chirp in a transmitter/receiver having a correlator to synthesize a narrow beamwidth pattern from otherwise broadbeam transducers when there is relative velocity between the transmitter/receiver and the target. The chirp is so produced in a generator in bandwidth, B, and time, T, as to produce a time bandwidth product, TB, that is increased for a narrower angle. A replica of the chirp produced in a generator is time delayed and Doppler shifted for use as a reference in the receiver for correlation of received chirps from targets. This reference is Doppler shifted to select targets preferentially, thereby to not only synthesize a narrow beam but also aim the beam in azimuth and elevation.