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Sample records for 16s-23s intergenic spacer

  1. Paenibacillus larvae 16S-23S rDNA intergenic transcribed spacer (ITS) regions: DNA fingerprinting and characterization.

    Dingman, Douglas W

    2012-07-01

    Paenibacillus larvae is the causative agent of American foulbrood in honey bee (Apis mellifera) larvae. PCR amplification of the 16S-23S ribosomal DNA (rDNA) intergenic transcribed spacer (ITS) regions, and agarose gel electrophoresis of the amplified DNA, was performed using genomic DNA collected from 134 P. larvae strains isolated in Connecticut, six Northern Regional Research Laboratory stock strains, four strains isolated in Argentina, and one strain isolated in Chile. Following electrophoresis of amplified DNA, all isolates exhibited a common migratory profile (i.e., ITS-PCR fingerprint pattern) of six DNA bands. This profile represented a unique ITS-PCR DNA fingerprint that was useful as a fast, simple, and accurate procedure for identification of P. larvae. Digestion of ITS-PCR amplified DNA, using mung bean nuclease prior to electrophoresis, characterized only three of the six electrophoresis bands as homoduplex DNA and indicating three true ITS regions. These three ITS regions, DNA migratory band sizes of 915, 1010, and 1474 bp, signify a minimum of three types of rrn operons within P. larvae. DNA sequence analysis of ITS region DNA, using P. larvae NRRL B-3553, identified the 3' terminal nucleotides of the 16S rRNA gene, 5' terminal nucleotides of the 23S rRNA gene, and the complete DNA sequences of the 5S rRNA, tRNA(ala), and tRNA(ile) genes. Gene organization within the three rrn operon types was 16S-23S, 16S-tRNA(ala)-23S, and l6S-5S-tRNA(ile)-tRNA(ala)-23S and these operons were named rrnA, rrnF, and rrnG, respectively. The 23S rRNA gene was shown by I-CeuI digestion and pulsed-field gel electrophoresis of genomic DNA to be present as seven copies. This was suggestive of seven rrn operon copies within the P. larvae genome. Investigation of the 16S-23S rDNA regions of this bacterium has aided the development of a diagnostic procedure and has helped genomic mapping investigations via characterization of the ITS regions. PMID:22510214

  2. Use of 16S-23S rRNA Intergenic Spacer Region PCR and Repetitive Extragenic Palindromic PCR Analyses of Escherichia coli Isolates To Identify Nonpoint Fecal Sources

    Seurinck, Sylvie; Verstraete, Willy; Siciliano, Steven D.

    2003-01-01

    Despite efforts to minimize fecal input into waterways, this kind of pollution continues to be a problem due to an inability to reliably identify nonpoint sources. Our objective was to find candidate source-specific Escherichia coli fingerprints as potential genotypic markers for raw sewage, horses, dogs, gulls, and cows. We evaluated 16S-23S rRNA intergenic spacer region (ISR)-PCR and repetitive extragenic palindromic (rep)-PCR analyses of E. coli isolates as tools to identify nonpoint fecal...

  3. Identification of Clinically Relevant Nonhemolytic Streptococci on the Basis of Sequence Analysis of 16S-23S Intergenic Spacer Region and Partial gdh Gene▿

    Nielsen, Xiaohui Chen; Justesen, Ulrik Stenz; Dargis, Rimtas; Kemp, Michael; Christensen, Jens Jørgen

    2009-01-01

    Nonhemolytic streptococci (NHS) cause serious infections, such as endocarditis and septicemia. Many conventional phenotypic methods are insufficient for the identification of bacteria in this group to the species level. Genetic analysis has revealed that single-gene analysis is insufficient for the identification of all species in this group of bacteria. The aim of the present study was to establish a method based on sequence analysis of the 16S-23S intergenic spacer (ITS) region and the part...

  4. Rapid Identification and Differentiation of the Soft Rot Erwinias by 16S-23S Intergenic Transcribed Spacer-PCR and Restriction Fragment Length Polymorphism Analyses

    Toth, I. K.; Avrova, A. O.; Hyman, L. J.

    2001-01-01

    Current identification methods for the soft rot erwinias are both imprecise and time-consuming. We have used the 16S-23S rRNA intergenic transcribed spacer (ITS) to aid in their identification. Analysis by ITS-PCR and ITS-restriction fragment length polymorphism was found to be a simple, precise, and rapid method compared to current molecular and phenotypic techniques. The ITS was amplified from Erwinia and other genera using universal PCR primers. After PCR, the banding patterns generated al...

  5. Length polymorphisms for intergenic spacer regions of 16S-23S rDNA in members of the new hydrogen-producing bacteria

    2007-01-01

    A method based on PCR amplification of the 16S rRNA gene (rDNA) -23S rDNA intergenic spacer regions (ISR) was developed for the identification of species within the novel group hydrogen-producing anaerobes. The sizes of the PCR products varied from 1264 to 398 bp. Strain of isolate Rennanqilyf 3 was characterized as having products of 1262, 398, 638, 437 and 436 bp. The isolate Rennanqilyf 1 had product of 1264 bp. The isolate Rennanqilyf 13 had products of 1261, 579 and 485 bp. Of the 3 species of the novel group hydrogenproducing anaerobes examined, no one was indistinguishable. Two environmental isolates were identified as hydrogen-producing bacteria, which were new species in present taxon. Rennanqilyf 3 could not be associated With any Clostridium sp. Studied. Rennanqilyf 1 could be classified into Clostridium genus. The combination between 16S rDNA equencing and length polymorphisms of IRS in 16S-23S rDNA is a better method for determining species of the hydrogen-producing bacteria.

  6. Identification and phyletic evolution analysis of Proteus mirabilis strains by PCR and restriction fragment length polymorphism of 16S-23S rRNA gene intergenic spacer region%16S-23S rRNA基因间隔序列PCR及RFLP对奇异变形杆菌分离株的鉴别与系统发育分析

    崔国林; 朱瑞良; 左雪梅; 钟世勋; 杨世发; 梁漫飞; 孙婧; 刘静静

    2013-01-01

    根据临床常见致病菌16S-23S rRNA基因间隔序列(ISR)两端的16S及23S rRNA保守序列设计PCR扩增的通用引物,对9株奇异变形杆菌和6株相近菌株应用通用引物PCR扩增16S-23S rRNA ISR序列.通过PCR长度多态性比较、RFLP分析以及部分序列测序比较,分析鉴别奇异变形杆菌.结果显示,PCR长度多态性可以将奇异变形杆菌同其余菌种进行区分;RFLP分析可以将所有试验菌种进行区分;部分序列测序可以对奇异变形杆菌进行分型.由此表明,16S 23S rRNA ISR序列PCR及RFLP分析可以简单、快速、准确的鉴定奇异变形杆菌.%To establish a new method to identify Proteus mirabilis strains, according to the conserved sequences of 16S and 23S which located on both ends of the clinical common pathogenic bacteria 16S-23S rRNA gene intergenic spacer region (ISR),a pair of universal primers was designed. Nine Proteus mirabilis strains and six similar bacteria strains were amplified by PCR and identified by the PCR length polymorphism comparison,restriction fragment length polymorphism (RFLP) analysis and partial sequences sequencing. The result showed that Proteus mirabilis strains could be discriminated from other similar bacteria strains by PCR length polymorphism comparison,all of test organism could be discriminated by RFLP and Proteus mirabilis strains could be typed by partial sequences sequencing. The result indicated that the identification method based on the 16S-23S rRNA ISR, using PCR and PCR-RFLP,is very suitable for the rapid low-cost identification and discrimination of Proteus mirabilis strains from other phylogenetically related bacteria strains.

  7. The Mycoplasma gallisepticum 16S-23S rRNA intergenic spacer region sequence as a novel tool for epizootiological studies.

    Raviv, Ziv; Callison, S; Ferguson-Noel, N; Laibinis, V; Wooten, R; Kleven, S H

    2007-06-01

    Mycoplasma gallisepticum (MG) contains two sets of rRNA genes (5S, 16S and 23S) in its genome, but only one of the two is organized in an operon cluster and contains a unique 660-nucleotide intergenic spacer region (IGSR) between the 16S and the 23S rRNA genes. We designed a polymerase chain reaction (PCR) for the specific amplification of the complete MG IGSR segment. The MG IGSR PCR was tested on 18 avian mollicute species and was confirmed as MG specific. The reaction sensitivity was demonstrated by comparing it to the well-established MG mgc2 PCR. The MG IGSR sequence was found to be highly variable (discrimination [D] index of 0.950) among a variety of MG laboratory strains, vaccine strains, and field isolates. The sequencing of the MG IGSR appears to be a valuable single-locus sequence typing (SLST) tool for MG isolate differentiation in diagnostic cases and epizootiological studies. PMID:17626483

  8. Designing PCR Primers from 16S-23S rDNA Intergenic Spacer Region for the Identification of Pasteurella multocida%以 16S-23S rDNA 间区序列为目的基因设计 PCR 引物鉴定多杀巴斯德氏菌

    周浩; 刘寅; 陈一军; 郑泽军; 黄熙泰

    2008-01-01

    多杀巴斯德氏菌是养殖动物(鸡,猪,牛等)的重要致病菌.本研究以16S-23S rDNA间区序列为目的基因设计PCR引物鉴定多杀巴斯德氏菌.通过对多杀巴斯德氏菌ITS-IA(含有tDNA-Ile和tDNA-Ala的16S-23S rDNA间区序列)的测序和与GenBank中序列的BLAST,设计筛选了一对特异引物PS-F/PS-R.对引物的特异性和有效性,用PCR方法进行了验证.结果表明:所有的多杀巴斯德氏菌标准菌株和分离菌株都能被检出,而全部39株非多杀巴斯德氏菌都没有扩增出特异性条带.其检测灵敏度能达到102CFU/mL.研究结果表明,发展了的PCR鉴定方法是省时的和可靠的,整个过程只需要20 h,而传统的鉴定方法需要至少5 d的时间.%Pasteurella multocida is an important pathogen that infects many kinds of animals. In present study, a polymerase chain reaction (PCR) assay using primers derived from the 16S-23S rRNA intergenic spacer (ITS) of P. multocida was developed. One pairs of specific PCR primers were designed by sequencing the ITS-IA (ITS containing tDNA-Ile and tDNA-Ala) of P. multocida and BLAST of GenBank. The specificity and efficiency of the PCR methods were tested against a panel of numerous strains from 39 different bacterial strains. All of the P. multocida strains generated positive signal, and no cross-reaction was observed with non-P, multocida strains in the PCR detection. Sensitivity of the detection is 102 CFU/mL cultures. The newly developed PCR array procedures take only 20 hours for each time, whereas the conventional methods required at least five days. This study demonstrated that the PCR detection for P. multocida is time-saved and reliable.

  9. Molecular phylogenetic analysis of Vibrio cholerae O1 El Tor strains isolated before, during and after the O139 outbreak based on the intergenomic heterogeneity of the 16S-23S rRNA intergenic spacer regions

    Atreyi Ghatak; Anasuya Majumdar; Ranajit K Ghosh

    2005-12-01

    We have cloned, sequenced and analysed all the five classes of the intergenic (16S-23S rRNA) spacer region (ISR) associated with the eight rrn operons (rrna-rrnh) of Vibrio cholerae serogroup O1 El Tor strains isolated before, during and after the O139 outbreak. ISR classes ‘a’ and ‘g’ were found to be invariant, ISR-B (ISRb and ISRe) exhibited very little variation, whereas ISR-C (ISRc, ISRd, and ISRf) and ISRh showed the maximum variation. Phylogenetic analysis conducted with all three ISR classes (ISR-B, ISR-C and ISRh) showed that the pre-O139 serogroup and post-O139 serogroup O1 El Tor strains arose out of two independent clones, which was congruent with the observation made by earlier workers suggesting that analyses of ISR-C and ISR-h, instead of all five ISR classes, could be successfully used to study phylogeny in this organism.

  10. Genotypic Characterization of Bradyrhizobium Strains Nodulating Endemic Woody Legumes of the Canary Islands by PCR-Restriction Fragment Length Polymorphism Analysis of Genes Encoding 16S rRNA (16S rDNA) and 16S-23S rDNA Intergenic Spacers, Repetitive Extragenic Palindromic PCR Genomic Fingerprinting, and Partial 16S rDNA Sequencing

    Vinuesa, Pablo; Rademaker, Jan L. W.; de Bruijn, Frans J.; Werner, Dietrich

    1998-01-01

    We present a phylogenetic analysis of nine strains of symbiotic nitrogen-fixing bacteria isolated from nodules of tagasaste (Chamaecytisus proliferus) and other endemic woody legumes of the Canary Islands, Spain. These and several reference strains were characterized genotypically at different levels of taxonomic resolution by computer-assisted analysis of 16S ribosomal DNA (rDNA) PCR-restriction fragment length polymorphisms (PCR-RFLPs), 16S-23S rDNA intergenic spacer (IGS) RFLPs, and repeti...

  11. Applicability of the 16S-23S rDNA internal spacer for PCR detection of the phytostimulatory PGPR inoculant Azospirillum lipoferum CRT1 in field soil

    Baudoin, Ezékiel; Couillerot, O.; Spaepen, S.; Moenne-Loccoz, Y.; Nazaret, S.

    2010-01-01

    Aims: To assess the applicability of the 16S-23S rDNA internal spacer regions (ISR) as targets for PCR detection of Azospirillum ssp. and the phytostimulatory plant growth-promoting rhizobacteria seed inoculant Azospirillum lipoferum CRT1 in soil. Methods and Results: Primer sets were designed after sequence analysis of the ISR of A. lipoferum CRT1 and Azospirillum brasilense Sp245. The primers fAZO/rAZO targeting the Azospirillum genus successfully yielded PCR amplicons (400-550 bp) from Azo...

  12. A molecular biological study on identification of common septicemia bacteria using 16s-23s rRNA gene spacer regions

    傅君芬; 虞和永; 尚世强; 洪文澜; 陆淼泉; 李建平

    2002-01-01

    In the search for a rapid and reliable method for identification of bacteria in blood and cerebrospinal fluid , we developed a unified set of primers and used them under polymerase chain reaction(PCR) to amplify the spacer regions between the 16s and 23s genes in the prokaryotic rRNA genetic loci . Spacer regions within these loci showed a significant level of length and sequence polymorphism across most of the species lines. A generic pair of priming sequences was selected from highly conserved sequences in the 16s and 23s genes occurring adjacent to these polymorphic regions. This single set of primers and reaction conditions were used for the amplification of the 16s-23s spacer regions for 61 strains of standard bacteria and corresponding clinical isolates belonging to 20 genera and 27 species, including Listeria, Staphylococcus and Salmonella species, et al. When the spacer amplification products were resolved by electrophoresis, the resulting patterns could be used to distinguish most of the bacteria species within the test group, and the amplification products of the clinical isolates clustered at the standard species level. Some species presenting similar pattern were further analyzed by HinfI or AluI digestion or DNA clone and sequences analysis in order to establish the specific 16s-23s rRNA gene spacer regions map. Analysis of 42 blood specimens from septicemic neonates and 6 CSF specimens from suspected purulent meningitis patients by bacterial culture and PCR-RFLP(Restriction Fregament Length Polymorphism) showed that 15 specimens of blood culture were positive(35.7%) in the 42 septicemic neonates; 27 specimens were positive(64.2%) by PCR, and that the positive rate by PCR was significantly higher than that by blood culture(P<0.01). Among the 6 CSF specimens, one specimen found positive by blood culture was also positive by PCR, two found negative by blood culture showed positive by PCR; all three were S.epidermidis according to the DNA map. One C

  13. Relationships between 16S-23S rRNA gene internal transcribed spacer DNA and genomic DNA similarities in the taxonomy of phototrophic bacteria

    Rapid and accurate identification of microbial species is essential task in microbiology and biotechnology. In prokaryotic systematics, genomic DNA-DNA hybridization is the ultimate tool to determine genetic relationships among bacterial strains at the species level. However, a practical problem in this assay is that the experimental procedure is laborious and time-consuming. In recent years, information on the 16S-23S rRNA gene internal transcribed spacer (ITS) region has been used to classify bacterial strains at the species and intraspecies levels. It is unclear how much information on the ITS region can reflect the genome that contain it. In this study, therefore, we evaluate the quantitative relationship between ITS DNA and entire genomic DNA similarities. For this, we determined ITS sequences of several species of anoxygenic phototrophic bacteria belonging to the order Rhizobiales, and compared with DNA-DNA relatedness among these species. There was a high correlation between the two genetic markers. Based on the regression analysis of this relationship, 70% DNA-DNA relatedness corresponded to 92% ITS sequence similarity. This suggests the usefulness of the ITS sequence similarity as a criterion for determining the genospecies of the phototrophic bacteria. To avoid the effects of polymorphism bias of ITS on similarities, PCR products from all loci of ITS were used directly as genetic probes for comparison. The results of ITS DNA-DNA hybridization coincided well with those of genomic DNA-DNA relatedness. These collective data indicate that the whole ITS DNA-DNA similarity can be used as an alternative to genomic DNA-DNA similarity.

  14. Cyanobacterial ecotypes in different optical microenvironments of a 68 C hot spring mat community revealed by 16S-23S rRNA internal transcribed spacer region variation

    Ferris, Mike J.; Kühl, Michael; Wieland, Andrea;

    2003-01-01

    We examined the population of unicellular cyanobacteria (Synechococcus) in the upper 3-mm vertical interval of a 68°C region of a microbial mat in a hot spring effluent channel (Yellowstone National Park, Wyoming). Fluorescence microscopy and microsensor measurements of O2 and oxygenic photosynth......We examined the population of unicellular cyanobacteria (Synechococcus) in the upper 3-mm vertical interval of a 68°C region of a microbial mat in a hot spring effluent channel (Yellowstone National Park, Wyoming). Fluorescence microscopy and microsensor measurements of O2 and oxygenic...... distinct populations over the vertical interval. We were unable to identify patterns in genetic variation in Synechococcus 16S rRNA sequences that correlate with different vertically distributed populations. However, patterns of variation at the internal transcribed spacer locus separating 16S and 23S r...

  15. Comparison of multiple genes and 16S-23S rRNA intergenic space region for their capacity in high resolution melt curve analysis to differentiate Mycoplasma gallisepticum vaccine strain ts-11 from field strains.

    Ghorashi, Seyed A; Bradbury, Janet M; Ferguson-Noel, Naola M; Noormohammadi, Amir H

    2013-12-27

    Mycoplasma gallisepticum (MG) is an important avian pathogen causing significant economic losses in the global poultry industry. In an attempt to compare and evaluate existing genotyping methods for differentiation of MG strains/isolates, high resolution melt (HRM) curve analysis was applied to 5 different PCR methods targeting vlhA, pvpA, gapA, mgc2 genes and 16S-23S rRNA intergenic space region (IGSR). To assess the discriminatory power of PCR-HRM of examined genes and IGSR, MG strains ts-11, F, 6/85 and S6, and, initially, 8 field isolates were tested. All MG strains/isolates were differentiated using PCR-HRM curve analysis and genotype confidence percentage (GCP) values of vlhA and pvpA genes, while only 0, 3 and 4 out of 12 MG strains/isolates were differentiated using gapA, mgc2 genes and IGSR, respectively. The HRM curve analysis of vlhA and pvpA genes was found to be highly correlated with the genetic diversity of the targeted genes confirmed by sequence analysis of amplicons generated from MG strains. The potential of the vlhA and pvpA genes was also demonstrated for genotyping of 12 additional MG strains from Europe and the USA. Results from this study provide a direct comparison between genes previously used in sequencing-based genotyping methods for MG strain identification and highlight the usefulness of vlhA and pvpA HRM curve analyses as rapid and reliable tools specially for diagnosis and differentiation of MG strains used here. PMID:24238667

  16. Diversity of the marine picocyanobacteria Prochlorococcus and Synechococcus assessed by terminal restriction fragment length polymorphisms of 16S-23S rRNA internal transcribed spacer sequences Diversidad de las picocianobacterias marinas Prochlorococcus y Synechococcus por medio de polimorfismos de longitud de fragmentos de restricción terminal en secuencias del espaciador transcrito interno del ARNr 16S - 23S

    PARIS LAVIN

    2008-12-01

    Full Text Available In order to assess the appropriateness of the use of internal transcribed spacer (ITS sequences for the study of population genetics of marine cyanobacteria, we amplified and cloned the 16S rRNA gene plus the 16S-23S ITS regions of six strains of Prochlorococcus and Synechococcus. We analyzed them by denaturing gradient gel electrophoresis (DGGE and terminal restriction fragment length polymorphisms (T-RFLP. When using the standard application of these techniques, we obtained more than one band or terminal restriction fragment (T-RF per strain or cloned sequence. Reports in literature have suggested that these anomalies can result from the formation of secondary structures. Secondary structures of the ITS sequences of Prochlorococcus and Synechococcus strains were computationally modelled at the different temperatures that were used during the polymerase chain reaction (PCR. Modelling results predicted the existence of hairpin loops that would still be present at the extensión temperature; it is likely that these loops produced incomplete and single stranded PCR products. We modified the standard T-RFLP procedure by adding the labelled ITS primer in the last two cycles of the PCR reaction; this resulted, in most cases, in only one T-RF per ribotype. Application of this technique to a natural picoplankton community in marine waters off northern Chile, showed that it was possible to identify the presence, and determine the relative abundance, of several phylogenetic lineages within the genera Prochlorococcus and Synechococcus inhabiting the euphotic zone. Phylogenetic analysis of ITS sequences obtained by cloning and sequencing DNA from the same sample confirmed the presence of the different genotypes. With the proposed modification, T-RFLP profiles should therefore be suitable for studying the diversity of natural populations of cyanobacteria, and should become an important tool to study the factors influencing the genetic structure and

  17. Identification of clinically relevant nonhemolytic Streptococci on the basis of sequence analysis of 16S-23S intergenic spacer region and partial gdh gene

    Nielsen, Xiaohui Chen; Justesen, Ulrik Stenz; Dargis, Rimtas;

    2009-01-01

    was performed with 57 NHS reference or clinical strains. Satisfactory identification to the species level was achieved for 14/19 NHS species included in this study on the basis of sequence analysis of the ITS region. Streptococcus salivarius and Streptococcus vestibularis obtained the expected taxon as the best...... taxon match, but there was a short maximum score distance to the next best match (distance, Streptococcus mitis, Streptococcus oralis, and Streptococcus pneumoniae could not be unambiguously discriminated by sequence analysis of the ITS region, as was also proven by phylogenetic analysis...

  18. Identification of Lactobacillus strains of goose origin using MALDI-TOF mass spectrometry and 16S-23S rDNA intergenic spacer PCR analysis.

    Dec, Marta; Urban-Chmiel, Renata; Gnat, Sebastian; Puchalski, Andrzej; Wernicki, Andrzej

    2014-04-01

    The objective of our study was to identify Lactobacillus sp. strains of goose origin using MALDI-TOF mass spectrometry, ITS-PCR and ITS-PCR/RFLP. All three techniques proved to be valuable tools for identification of avian lactobacilli and produced comparable classification results. Lactobacillus strains were isolated from 100% of geese aged 3 weeks to 4 years, but from only 25% of chicks aged 1-10 days. Among the 104 strains isolated, we distinguished 14 Lactobacillus species. The dominant species was Lactobacillus salivarius (35.6%), followed by Lactobacillus johnsonii (18.3%), Lactobacillus ingluviei (11.5%) and Lactobacillus agilis (7.7%). The intact-cell MALDI-TOF mass spectrometry enabled rapid species identification of the lactobacilli with minimal pretreatment. However, it produced more than one identification result for 11.5% examined strains (mainly of the species L. johnsonii). ITS-PCR distinguished 12 genotypes among the isolates, but was not able to differentiate closely related strains, i.e. between Lactobacillus amylovorus and Lactobacillus kitasatonis and between Lactobacillus paracasei, Lactobacillus rhamnosus and Lactobacillus zeae. These species were differentiated by ITS-PCR/RFLP using the restriction enzymes TaqI and MseI. The results obtained indicate that ITS-PCR and ITS-PCR/RFLP assays could be used not only for interspecific, but also for intraspecific, typing. PMID:24607713

  19. The use of 16S and 16S-23S rDNA to easily detect and differentiate common Gram-negative orchard epiphytes.

    Jeng, R S; Svircev, A M; Myers, A L; Beliaeva, L; Hunter, D M; Hubbes, M

    2001-02-01

    The identification of Gram-negative pathogenic and non-pathogenic bacteria commonly isolated from an orchard phylloplane may result in a time consuming and tedious process for the plant pathologist. The paper provides a simple "one-step" protocol that uses the polymerase chain reaction (PCR) to amplify intergenic spacer regions between 16S and 23S genes and a portion of 16S gene in the prokaryotic rRNA genetic loci. Amplified 16S rDNA, and restriction fragment length polymorphisms (RFLP) following EcoRI digestion produced band patterns that readily distinguished between the plant pathogen Erwinia amylovora (causal agent of fire blight in pear and apple) and the orchard epiphyte Pantoea agglomerans (formerly E. herbicola). The amplified DNA patterns of 16S-23S spacer regions may be used to differentiate E. amylovora at the intraspecies level. Isolates of E. amylovora obtained from raspberries exhibited two major fragments while those obtained from apples showed three distinct amplified DNA bands. In addition, the size of the 16S-23S spacer region differs between Pseudomonas syringae and Pseudomonas fluorescens. The RFLP pattern generated by HaeIII digestion may be used to provide a rapid and accurate identification of these two common orchard epiphytes. PMID:11166101

  20. 116S-23S rRNA Gene Intergenic Spacer Region Variability Helps Resolve Closely Related Sphingomonads

    Sima eTokajian

    2016-02-01

    Full Text Available Sphingomonads comprise a physiologically versatile group many of which appear to be adapted to oligotrophic environments, but several also had features in their genomes indicative of host associations. In this study, the extent variability of the 16S-23S rDNA intergenic spacer (ITS sequences of 14 ATCC reference sphingomonad strains and 23 isolates recovered from drinking water was investigated through PCR amplification and sequencing. Sequencing analysis of the 16S-23S rRNA gene ITS region revealed that the ITS sizes for all studied isolates varied between 415 to 849 bp, while their G+C content was 42.2 mol% to 57.9 mol%. Five distinct ITS types were identified: ITSnone (without tRNA genes, ITSAla(TGC, ITSAla (TGC+Ile (GAT, ITSIle (GAT+Ala (TGC and ITS Ile (GAT+Pseudo. All of the identified tRNAAla (TGC molecules consisted of 73 bases, and all of the tRNAIle (GAT molecules consisted of 74 bases. We also detected striking variability in the size of the ITS region among the various examined isolates. Highest variability was detected within the ITS-2.

  1. Identification to the species level of Lactobacillus isolated in probiotic prospecting studies of human, animal or food origin by 16S-23S rRNA restriction profiling

    Neumann Elisabeth

    2005-03-01

    Full Text Available Abstract Background The accurate identification of Lactobacillus and other co-isolated bacteria during microbial ecological studies of ecosystems such as the human or animal intestinal tracts and food products is a hard task by phenotypic methods requiring additional tests such as protein and/or lipids profiling. Results Bacteria isolated in different probiotic prospecting studies, using de Man, Rogosa and Sharpe medium (MRS, were typed at species level by PCR amplification of 16S-23S rRNA intergenic spacers using universal primers that anneal within 16S and 23S genes, followed by restriction digestion analyses of PCR products. The set of enzymes chosen differentiates most species of Lactobacillus genus and also co-isolated bacteria such as Enterococcus, Streptococcus, Weissella, Staphylococcus, and Escherichia species. The in silico predictions of restriction patterns generated by the Lactobacillus shorter spacers digested with 11 restriction enzymes with 6 bp specificities allowed us to distinguish almost all isolates at the species level but not at the subspecies one. Simultaneous theoretical digestions of the three spacers (long, medium and short with the same set of enzymes provided more complex patterns and allowed us to distinguish the species without purifying and cloning of PCR products. Conclusion Lactobacillus isolates and several other strains of bacteria co-isolated on MRS medium from gastrointestinal ecosystem and fermented food products could be identified using DNA fingerprints generated by restriction endonucleases. The methodology based on amplified ribosomal DNA restriction analysis (ARDRA is easier, faster and more accurate than the current methodologies based on fermentation profiles, used in most laboratories for the purpose of identification of these bacteria in different prospecting studies.

  2. Intergenic spacer length variants in Old Portuguese bread wheat cultivars

    Ana Carvalho; Henrique Guedes-Pinto; José Lima-Brito

    2011-08-01

    The intergenic spacer of the ribosomal DNA is highly variable, but is location specific in the nucleolar organizer region of the chromosomes. This study provides an event of high level of polymorphism / size variation and occurrence of 14 unique phenotypes in 48 landraces of Portuguese bread wheat cultivars for IGS-amplified products obtained by PCR-RFLP technique performed with TaqI. The attendant IGS polymorphism has been used to deduce affinities between landraces. Some of the high molecular weight IGS allelic variants were also probed for their chromosomal localization by sequential silver nitrate staining and fluorescence in situ hybridization. However, only the intergenic spacer allelic variant of 3.1 kb could be successfully hybridized, and was observed to be physically located on the chromosome pair 1B in the NOR loci of the cultivar ‘Magueija’.

  3. Comparison of Internal Transcribed Spacers and Intergenic Spacer Regions of Five Common Iranian Sheep Bursate Nematodes

    Reza Nabavi; Brendan Conneely; Elaine McCarthy; Barbara Good; Parviz Shayan; Theo de Waal

    2014-01-01

    Background Accurate identification of sheep nematodes is a critical point in epidemiological studies and monitoring of drug resistance in flocks. However, due to a close morphological similarity between the eggs and larval stages of many of these nematodes, such identification is not a trivial task. There are a number of studies showing that molecular targets in ribosomal DNA (Internal transcribed spacer 1, 2 and Intergenic spacer) are suitable for accurate identification of sheep bursate nem...

  4. 山羊奇异变形杆菌分离鉴定及其16S-23S rRNA ISR序列RFLP分析%Isolation and Identification of Proteus mirabilis from Goat and the Analysis of Its 16S-23S rRNA ISR Sequence by RFLP

    崔国林; 钟世勋; 杨世发; 左雪梅; 朱瑞良

    2013-01-01

    2012年初,山东菏泽某羊场的羊群发病,从发病羊器官分离到2株病原细菌.对病原细菌进行鉴定,并对其与已知同种异源菌株相似性差异进行分析.从患病山羊内脏器官分离细菌,经形态特征、培养特性、生化试验、血清学试验及致病性试验进行鉴定;再通过设计通用引物扩增16S-23S rRNA ISR (intergenie spacer region)序列,将PCR产物经HinfⅠ单酶切获得3条可视条带,同时对扩增条带中的主带测序并进行系统发育分析.结果表明,分离菌株为奇异变形杆菌;分离菌株同本实验室保存的兔源与鸡源奇异变形杆菌PCR-RFLP结果一致;分离菌株PCR产物同GenBank收录的HI4320株奇异变形杆菌及本实验室保存的兔源与鸡源奇异变形杆菌进行序列比较,分离羊源菌株与兔源菌株相似性为94.8%、与鸡源菌株相似性为96.0%~98.2%,与人源HI4320株相似性为96.9%.研究证实发病羊致病病原为奇异变形杆菌,其与鸡源、兔源和人源奇异变形杆菌的亲缘关系较近.%At the beginning of 2012,a disease occurred in a goat farm in Heze City and two strains of pathogen were isolated from the infected goats.In order to identify the infected bacteria and analyze the homology between isolated strains and heterologous strains,bacteria were isolated from infected goats internal organs and were identified by morphologic characteristics,cultural characteristic,biochemistry test,serologic test and pathogenicity test; A pair of universal primers was designed to amplify 16S-23S rRNA ISR (intergenic spacer region) gene.and three visible straps were observed when PCR products were cut by Hinf Ⅰ,at the same time the main strap of PCR straps was sequenced and analyzed by phyletic evolution.The results showed that isolated strains were Proteus mirabilis ; the result of PCR-RFLP of isolated strains and Proteus mirabilis from rabbit and chicken was the same; The homology was 94.8% between

  5. 16s-23S rDNA: polymorphisms and their use for detection and identification of Xylella fastidiosa strains 16S-23S rDNA: polimorfismos e sua aplicação na detecção e identificação de linhagens de Xylella fastidiosa

    Juliana Camargo Martinati

    2007-03-01

    Full Text Available Strains of Xylella fastidiosa from several hosts (coffee, citrus, grape, almond, oleander, peach, plum, etc. were characterized by analyzing the content of the nucleotide sequences of 16S-23S rDNA (coding for a small subunit ribosomal RNA spacer region (ITS. Current methods for sequencing the ITS region yields partial sequences that do not contribute with significant information. According to this fact, new primers have been designed in order to obtain a complete sequence and facilitate the sequencing. The complete 16S-23S sequences from 08 strains were amplified through PCR using the primers designed in our lab. The 16S-23S sequences obtained were compared with 52 others sequences entries in GenBank database. The results revealed a higher level of variation than that found in 16S gene sequences, with similarity values ranging from 0.79-1.00. The dendogram based on similarity data revealed 5 main groups. This spacer sequence contains two genes for tRNA (tRNAala and tRNAile. The sequence analysis of the tRNA content showed a conserved region with a few differences in the nucleotide composition.Linhagens de Xylella fastidiosa de diferentes hospedeiros (café, uva, amêndoa, ameixa, etc. foram caracterizados analisando as sequências de nucleotídeos do espaço intergênico 16S-23S (ITS. Os métodos atuais para o sequenciamento da região ITS produzem fragmentos parciais das sequências que não contribuem com informações significantes. Em vista disso, novos primers foram desenhados a fim de obter uma sequência completa e facilitar o sequenciamento. A sequencia completa da região ITS de 08 linhagens de X. Fastidiosa foram amplificadas via PCR, sequenciadas e comparadas com outras 52 sequencias depositadas no GenBank. Os resultados revelaram um alto nível de variação sendo maior que os níveis encontrados quando se utiliza o gene 16S para este tipo de análise, com valores variando entre 0.79 a 1.00. O dendograma baseado em dados de

  6. Combined eukaryotic and bacterial community fingerprinting of natural freshwater biofilms using automated ribosomal intergenic spacer analysis

    2010-01-01

    Biofilms are complex communities playing an important role in aquatic ecosystems. Automated ribosomal intergenic spacer analysis (ARISA) has been used successfully to explore biofilm bacterial diversity. However, a gap remains to be filled as regards its application to biofilm eukaryotic populations. The aim of this study is to use ARISA to detect eukaryotic population shifts in biofilm. We designed a new set of primers to focus specifically on the ITS1-5.8S-ITS2 region of diatoms and tested ...

  7. Sequence analysis of the rDNA intergenic spacer of Metarhizium strains isolated in Brazil

    Fabiana Y. Yanaka-Schäfer

    2008-01-01

    Full Text Available To assess the extent of genetic variability of rDNA intergenic spacer (IGS in Metarhizium sp., 34 strains (27 isolated in Brazil were sequenced and analyzed together with an additional 20 Metarhizium anisopliae var. anisopliae sequences retrieved from GenBank. Overall, the global nucleotide diversity for the region under study was of 0.090, while for the Brazilian isolates it was only 0.016. Phylogenetic analyses showed four well-supported groups (A, B, C, and D, one of which (D has not been previously identified. All but one of the Brazilian strains cluster in this novel D phylogroup, suggesting that the genetic variation found in Brazil is a subset of the worldwide M. anisopiliae var. anisopliae variation.

  8. Optimisation of automated ribosomal intergenic spacer analysis for the estimation of microbial diversity in fynbos soil

    Karin Jacobs

    2010-07-01

    Full Text Available Automated ribosomal intergenic spacer analysis (ARISA has become a commonly used molecular technique for the study of microbial populations in environmental samples. The reproducibility and accuracy of ARISA, with and without the polymerase chain reaction (PCR are important aspects that influence the results and effectiveness of these techniques. We used the primer set ITS4/ITS5 for ARISA to assess the fungal community composition of two sites situated in the Sand Fynbos. The primer set proved to deliver reproducible ARISA profiles of the fungal community composition with little variation observed between ARISA-PCRs. Variation that occurred in a sample due to repeated DNA extraction is expected for ecological studies. This reproducibility made ARISA a useful tool for the assessment and comparison of diversity in ecological samples. In this paper, we also offered particular suggestions concerning the binning strategy for the analysis of ARISA profiles.

  9. Subfamilial relationships within solanaceae as inferred from atp beta-rbcl intergenic spacer

    A phylogenetic analysis of family Solanaceae was conducted using sequence data from the chloroplast intergenic atp beta-rbcL spacer. Sequence data was generated from 17 species representing 09 out of 14 genera of Solanaceae from Pakistan. Cladogram was constructed using maximum parsimony method and results indicate that Solanaceae is mainly divided into two subfamilies; Solanoideae and Cestroideae. Four major clades within Solanoideae represent tribes; Physaleae, Capsiceae, Datureae and Solaneae are supported by high bootstrap value and the relationships among them are not corroborating with the previous studies. The findings established that subfamily Cestroideae comprised of three genera; Cestrum, Lycium and Nicotiana with high bootstrap support. Position of Nicotiana inferred with atp beta-rbcL sequence is congruent with traditional classification, which placed the taxa in Cestroideae. In the current study Lycium unexpectedly nested with Nicotiana with 100% bootstrap support and identified as a member of tribe Nicotianeae. Expanded sampling of other genera from Pakistan could be valuable towards improving our understanding of intrafamilial relationships within Solanaceae. (author)

  10. Extensive length variation in the ribosomal DNA intergenic spacer of yellow perch (Perca flavescens).

    Kakou, Bidénam; Angers, Bernard; Glémet, Hélène

    2016-03-01

    The intergenic spacer (IGS) is located between ribosomal RNA (rRNA) gene copies. Within the IGS, regulatory elements for rRNA gene transcription are found, as well as a varying number of other repetitive elements that are at the root of IGS length heterogeneity. This heterogeneity has been shown to have a functional significance through its effect on growth rate. Here, we present the structural organization of yellow perch (Perca flavescens) IGS based on its entire sequence, as well as the IGS length variation within a natural population. Yellow perch IGS structure has four discrete regions containing tandem repeat elements. For three of these regions, no specific length class was detected as allele size was seemingly normally distributed. However, for one repeat region, PCR amplification uncovered the presence of two distinctive IGS variants representing a length difference of 1116 bp. This repeat region was also devoid of any CpG sites despite a high GC content. Balanced selection may be holding the alleles in the population and would account for the high diversity of length variants observed for adjacent regions. Our study is an important precursor for further work aiming to assess the role of IGS length variation in influencing growth rate in fish. PMID:26841134

  11. PCR amplification and characterization of the intergenic spacer region of the ribosomal DNA in Pyrenophora graminea.

    Pecchia, S; Mercatelli, E; Vannacci, G

    1998-09-01

    Successful amplification of the whole intergenic spacer region of the nuclear ribosomal repeat (IGS) in Pyrenophora graminea was obtained with a PCR-based assay. Single amplification products showed length differences. Depending on the length of the IGS-PCR product, ca. 3.8 or 4.4 kb, two groups of isolates could be identified. The RFLP patterns of isolates obtained with the 6-base cutting enzymes Apal, BglII, DraI, EcoRV, HindIII and SacI were similar within each group and different between the two groups. Restriction patterns of IGS-PCR products digested with the 4-base cutting enzyme AluI were polymorphic among isolates in spite of their IGS-PCR product length. In order to characterize the long and short IGS-PCR products the restriction map is shown. The long product shows an additional HindIII site and a BglII site that is lacking in the short product. However, the latter shows a SacI site that is not present in the long IGS-PCR product. Therefore, the described PCR-RFLP analysis of the IGS appears to be a useful tool to resolve genetic variation between P. graminea isolates. PMID:9741081

  12. Identification to the species level of Lactobacillus isolated in probiotic prospecting studies of human, animal or food origin by 16S-23S rRNA restriction profiling

    Neumann Elisabeth; Teixeira Santuza MR; Horta Maria F; Mota Rodrigo M; Moreira João; Nicoli Jacques R.; Nunes Álvaro C

    2005-01-01

    Abstract Background The accurate identification of Lactobacillus and other co-isolated bacteria during microbial ecological studies of ecosystems such as the human or animal intestinal tracts and food products is a hard task by phenotypic methods requiring additional tests such as protein and/or lipids profiling. Results Bacteria isolated in different probiotic prospecting studies, using de Man, Rogosa and Sharpe medium (MRS), were typed at species level by PCR amplification of 16S-23S rRNA i...

  13. Species-specific repeat units in the intergenic spacer of the ribosomal RNA cistron of Anopheles aquasalis Curry.

    Perera, O P; Cockburn, A F; Mitchell, S E; Conn, J; Seawright, J A

    1998-11-01

    A genomic DNA library of Anopheles aquasalis Curry was screened for clones that hybridized more intensely to DNA from A. aquasalis than to DNA from A. benarrochi Gabaldon, Cova Garcia, and Lopez, A. konderi Galvao and Damasceno, A. nuneztovari Gabaldon cytotypes A, B, and C, A. oswaldoi (Peryassu), A. rangeli Gabaldon, Cova Garcia, and Lopez, or A. trinkae Faran. Two specific clones (2.5 kilobasepairs [kbp] and 3.0 kbp) from A. aquasalis were isolated. Both A. aquasalis-specific clones were from the intergenic spacer region of the ribosomal RNA (rRNA) cistron. Upon digestion with Rsa I, a 900-bp fragment from the clone AA-1 hybridized specifically to A. aquasalis DNA. Analysis of the DNA sequence of this fragment revealed four tandemly repeated 36-bp units. Three of these repeat units were identical, and the fourth was 94% identical to the others. The DNA sequence of a highly conserved region of these repeats was used to synthesize an oligonucleotide probe specific to A. aquasalis. PMID:9840580

  14. Influence of commonly used primer systems on automated ribosomal intergenic spacer analysis of bacterial communities in environmental samples.

    Purahong, Witoon; Stempfhuber, Barbara; Lentendu, Guillaume; Francioli, Davide; Reitz, Thomas; Buscot, François; Schloter, Michael; Krüger, Dirk

    2015-01-01

    Due to the high diversity of bacteria in many ecosystems, their slow generation times, specific but mostly unknown nutrient requirements and syntrophic interactions, isolation based approaches in microbial ecology mostly fail to describe microbial community structure. Thus, cultivation independent techniques, which rely on directly extracted nucleic acids from the environment, are a well-used alternative. For example, bacterial automated ribosomal intergenic spacer analysis (B-ARISA) is one of the widely used methods for fingerprinting bacterial communities after PCR-based amplification of selected regions of the operon coding for rRNA genes using community DNA. However, B-ARISA alone does not provide any taxonomic information and the results may be severely biased in relation to the primer set selection. Furthermore, amplified DNA stemming from mitochondrial or chloroplast templates might strongly bias the obtained fingerprints. In this study, we determined the applicability of three different B-ARISA primer sets to the study of bacterial communities. The results from in silico analysis harnessing publicly available sequence databases showed that all three primer sets tested are specific to bacteria but only two primers sets assure high bacterial taxa coverage (1406f/23Sr and ITSF/ITSReub). Considering the study of bacteria in a plant interface, the primer set ITSF/ITSReub was found to amplify (in silico) sequences of some important crop species such as Sorghum bicolor and Zea mays. Bacterial genera and plant species potentially amplified by different primer sets are given. These data were confirmed when DNA extracted from soil and plant samples were analyzed. The presented information could be useful when interpreting existing B-ARISA results and planning B-ARISA experiments, especially when plant DNA can be expected. PMID:25749323

  15. Influence of commonly used primer systems on automated ribosomal intergenic spacer analysis of bacterial communities in environmental samples.

    Witoon Purahong

    Full Text Available Due to the high diversity of bacteria in many ecosystems, their slow generation times, specific but mostly unknown nutrient requirements and syntrophic interactions, isolation based approaches in microbial ecology mostly fail to describe microbial community structure. Thus, cultivation independent techniques, which rely on directly extracted nucleic acids from the environment, are a well-used alternative. For example, bacterial automated ribosomal intergenic spacer analysis (B-ARISA is one of the widely used methods for fingerprinting bacterial communities after PCR-based amplification of selected regions of the operon coding for rRNA genes using community DNA. However, B-ARISA alone does not provide any taxonomic information and the results may be severely biased in relation to the primer set selection. Furthermore, amplified DNA stemming from mitochondrial or chloroplast templates might strongly bias the obtained fingerprints. In this study, we determined the applicability of three different B-ARISA primer sets to the study of bacterial communities. The results from in silico analysis harnessing publicly available sequence databases showed that all three primer sets tested are specific to bacteria but only two primers sets assure high bacterial taxa coverage (1406f/23Sr and ITSF/ITSReub. Considering the study of bacteria in a plant interface, the primer set ITSF/ITSReub was found to amplify (in silico sequences of some important crop species such as Sorghum bicolor and Zea mays. Bacterial genera and plant species potentially amplified by different primer sets are given. These data were confirmed when DNA extracted from soil and plant samples were analyzed. The presented information could be useful when interpreting existing B-ARISA results and planning B-ARISA experiments, especially when plant DNA can be expected.

  16. Structure of rrn operons in pathogenic non-cultivable treponemes: sequence but not genomic position of intergenic spacers correlates with classification of Treponema pallidum and Treponema paraluiscuniculi strains

    Čejková, Darina; Zobaníková, Marie; Pospíšilová, Petra; Strouhal, Michal; Mikalová, Lenka; Weinstock, George M.

    2013-01-01

    This study examined the sequences of the two rRNA (rrn) operons of pathogenic non-cultivable treponemes, comprising 11 strains of T. pallidum ssp. pallidum (TPA), five strains of T. pallidum ssp. pertenue (TPE), two strains of T. pallidum ssp. endemicum (TEN), a simian Fribourg-Blanc strain and a rabbit T. paraluiscuniculi (TPc) strain. PCR was used to determine the type of 16S–23S ribosomal intergenic spacers in the rrn operons from 30 clinical samples belonging to five different genotypes. When compared with the TPA strains, TPc Cuniculi A strain had a 17 bp deletion, and the TPE, TEN and Fribourg-Blanc isolates had a deletion of 33 bp. Other than these deletions, only 17 heterogeneous sites were found within the entire region (excluding the 16S–23S intergenic spacer region encoding tRNA-Ile or tRNA-Ala). The pattern of nucleotide changes in the rrn operons corresponded to the classification of treponemal strains, whilst two different rrn spacer patterns (Ile/Ala and Ala/Ile) appeared to be distributed randomly across species/subspecies classification, time and geographical source of the treponemal strains. It is suggested that the random distribution of tRNA genes is caused by reciprocal translocation between repetitive sequences mediated by a recBCD-like system. PMID:23082031

  17. Phylogenetic relationships of Carpha and its relatives (Schoeneae, Cyperaceae) inferred from chloroplast trnL intron and trnL-trnF intergenic spacer sequences.

    Zhang, Xiufu; Marchant, Adam; Wilson, Karen L; Bruhl, Jeremy J

    2004-05-01

    Within the tribe Schoeneae (Cyperaceae), the relationships between Carpha and its relatives have not been certain, and the limits and definition of Carpha have been controversial. Further, the relationships of species within Carpha have been unclear. In this study, cladistic analyses based on chloroplast trnL intron and trnL-trnF intergenic spacer sequence data were undertaken to estimate phylogenetic relationships in and around Carpha. This study found that Trianoptiles is sister to Carpha; Ptilothrix is sister to Cyathochaeta rather than to Carpha as suggested by some former authors; and Gymnoschoenus is distant from Carpha and its close relatives. The merging of Schoenoides back into Oreobolus is supported. The findings also revealed the non-monophyletic status of Costularia and of Schoenus, and indicated the phylogenetic relationships of species within Carpha. PMID:15062800

  18. Adaptation of the short intergenic spacers between co-directional genes to the Shine-Dalgarno motif among prokaryote genomes

    Caro, Albert Pallejà; García-Vallvé, Santiago; Romeu, Antoni

    2009-01-01

    ABSTRACT: BACKGROUND: In prokaryote genomes most of the co-directional genes are in close proximity. Even the coding sequence or the stop codon of a gene can overlap with the Shine-Dalgarno (SD) sequence of the downstream co-directional gene. In this paper we analyze how the presence of SD may...... influence the stop codon usage or the spacing lengths between co-directional genes. RESULTS: The SD sequences for 530 prokaryote genomes have been predicted using computer calculations of the base-pairing free energy between translation initiation regions and the 16S rRNA 3' tail. Genomes with a large...... discussion of which factors affect the intergenic lengths, which cannot be totally explained by the pressure to compact the prokaryote genomes....

  19. Differentiation between Aspergillus flavus and Aspergillus parasiticus from Pure Culture and Aflatoxin-Contaminated Grapes Using PCR-RFLP Analysis of aflR-aflJ Intergenic Spacer

    Aflatoxins (AFs) represent the most important single mycotoxin-related food safety problem in developed and developing countries as they have adverse effects on human and animal health. They are produced mainly by Aspergillus flavus and A. parasiticus. Both species have different aflatoxinogenic profile. In order to distinguish between A. flavus and A. parasiticus, gene-specific primers were designed to target the intergenic spacer (IGS) for the AF biosynthesis genes, aflJ and aflR. Polymerase chain reaction (PCR) products were subjected to restriction endonuclease analysis using BglII to look for restriction fragment length polymorphisms (RFLPs). Our result showed that both species displayed different PCR-based RFLP (PCR-RFLP) profile. PCR products from A. flavus cleaved into 3 fragments of 362, 210, and 102 bp. However, there is only one restriction site for this enzyme in the sequence of A. parasiticus that produced only 2 fragments of 363 and 311 bp. The method was successfully applied to contaminated grapes samples. This approach of differentiating these 2 species would be simpler, less costly, and quicker than conventional sequencing of PCR products and/or morphological identification. (author)

  20. Bat white-nose syndrome: a real-time TaqMan polymerase chain reaction test targeting the intergenic spacer region of Geomyces destructanstructans.

    Muller, Laura K.; Lorch, Jeffrey M.; Lindner, Daniel L.; O'Connor, Michael; Gargas, Andrea; Blehert, David S.

    2013-01-01

    The fungus Geomyces destructans is the causative agent of white-nose syndrome (WNS), a disease that has killed millions of North American hibernating bats. We describe a real-time TaqMan PCR test that detects DNA from G. destructans by targeting a portion of the multicopy intergenic spacer region of the rRNA gene complex. The test is highly sensitive, consistently detecting as little as 3.3 fg of genomic DNA from G. destructans. The real-time PCR test specifically amplified genomic DNA from G. destructans but did not amplify target sequence from 54 closely related fungal isolates (including 43 Geomyces spp. isolates) associated with bats. The test was further qualified by analyzing DNA extracted from 91 bat wing skin samples, and PCR results matched histopathology findings. These data indicate the real-time TaqMan PCR method described herein is a sensitive, specific, and rapid test to detect DNA from G. destructans and provides a valuable tool for WNS diagnostics and research.

  1. Methylation pattern of the intergenic spacer of rRNA genes in excised cotyledons of Cucurbita pepo L. (Zucchini) after hormone treatment

    High molecular mass genomic DNA was isolated from excised marrow cotyledons (Cucurbita pepo L. zucchini) treated with 6-benzyladenine (BA) of methyl ester of jasmonic acid (MeJA) for 24 h in darkness. DNA purified from contaminating polysaccharides with Celite column was completely digested with the restriction enzyme Eco RI and the changes in the methylation pattern of the intergenic spacer (IGS) of r RNA genes were studied after subsequent digestion with the couple of restriction enzymes-isoschizomers MSP I and Hpa II by the method of 'indirect end labelling'. As rDNA units probe a cloned 32P-labelled Eco RI 2.1 kb fragment spanning in the most part of 18S r RNA gene from flax rDNA was used. Results showed heavy methylation of the rRNA genes. As judged from the almost total lack of digestion with HPA II, there were no methylation free regions in repeated rDNA units or little if any were observed. A hypo methylated Hps II site was detected near the promoter region in some of the repeats. Digestion with Msp I affected nearly 50% of the repeating units. The Msp digestion fragments of the 6.2 kb Eco RI fragment of r DNA were few in number and large in size (0.5 - 2.5 kb). This suggested that in addition with -CpG- sequences, methylation in -CpNpG- might not be random. Methylation pattern in IGS was not changed upon treatment of the cotyledons in vivo with BA and MeJA. Thus, previously observed hormone-mediated effects on the eactivity of rRNA gene expression were not accompanied by any significant changes of the methylation pattern in IGS. (authors)

  2. Application of the Sequences Analysis of the 16S rRNA Gene and ITS of 16S-23S rRNA to the Systematic Study of the Genus Arthrospira and Spirulina%16S rRNA基因与16S-23S rRNA转录单元内间隔区序列分析及其在节旋藻和螺旋藻分类鉴定中的应用

    茅云翔; 杨官品; 张宝红; 张学成

    2001-01-01

    测定了节旋藻属3个品系和螺旋藻属1个品系的全长16S rRNA基因和16S-23S rRNA转录单元内间隔区序列(ITS),分析了已知的节旋藻、螺旋藻和相关品系的相应序列的同源性,构建了系统发生树,并评价了这两段DNA序列在节旋藻、螺旋藻种属分类和种质鉴定中的意义.结果表明:(1)16S rRNA基因序列和ITS序列均可用于节旋藻属和螺旋藻属的属间分类,以两序列为基础的系统学分析结果一致;(2)ITS序列变异程度高于16S rDNA序列,适用于节旋藻和螺旋藻属内品系或种质鉴定;(3)节旋藻属可明确界定,16S rRNA基因序列相似性大于98%,ITS序列相似性大于88%;(4)螺旋藻属某些品系间16S rDNA序列和ITS序列相似性较低,与不同属间的序列相似性程度为同一水平.

  3. 巴戟天及其伪品的psbA-trnH序列鉴定%Molecular identification of psbA-trnH intergenic spacers' sequences of Morinda officinalis How and its counterfeit species

    姬生国; 王东; 张春荣; 张宏意

    2011-01-01

    Objective To perform the molecular identification for Morinda officinalis and its counterfeit species based on psbA-trnH intergenic spacers' sequences. Methods Total DNA was extracted and gene sequence was amplified by PCR. PCR product was directly sequenced after purification. Sequences were analyzed with Clustral X and MEGA 3.1 software. Results The length of psbA-trnH intergenic spacers'sequences was 306 bp. Distinctive variation sites among them can be observed. Conclusion The psbA-trnH intergenic spacers' sequences could be used to identificate Morinda officinalis and its counterfeit species.%目的 利用叶绿体基因psbA-trnH间区序列探讨巴戟天及其常见伪品大果巴戟、樟叶巴戟、羊角藤、虎刺的分子鉴定方法.方法 分别提取巴戟天及其伪品植物的总DNA,经PCR扩增纯化后,测序,利用Clustal X和MEGA 3.1软件对序列进行分析.结果 各样品psbA-trnH序列长度为306 bp,巴戟天及其伪品之间存在多个特异性信息位点.结论 psbA-trnH序列可作为巴戟天分子鉴定的依据.

  4. Identification of Trichosporon spp. Strains by Sequencing D1/D2 Region and Sub-typing by Sequencing Ribosomal Intergenic Spacer Region of Ribosomal DNA

    Jingsi ZENG; Cristina Maria de Souza Motta; Kazutaka Fukushima; Kayoko Takizawa; Oliane Maria Correia Magalhes; Rejane Pereira Neves; Kazuko Nishimura

    2009-01-01

    To re-identify and further group 25 isolates of Trichosporon spp. identified morphologically previously, sequences of D1/D2 region of large subunit (LSU) of ribosomal DNA (rDNA) of 25 tested strains for identification and those of ribosomal intergenic space 1 (IGS1) region of 11 strains for sub-grouping were detected. The identifications of tested strains were changed except 6 strains. According to the alignment of the IGS1 region, 6 T. asahii isolates tested fell into 4 groups and 5 T. faecale isolates into 3 groups. Polymorphism of 2 T.japonicum isolates was found in 10 positions. With the alignments obtained in this research compared with the relative GenBank entries, it was found that T. asahii, T.faecale and T.japonicum species were divided into 7, 3 and 2 subtypes respectively. Morphological and biophysical methods are not sufficient for Trichosporon spp. identification. Sequencing becomes neces-sary for Trichosporon diagnosis. There is obvious diversity within a species.

  5. Identification of Biomphalaria havanensis and Biomphalaria obstructa populations from Cuba using polymerase chain reaction and restriction fragment length polymorphism of the ribosomal RNA intergenic spacer

    Teofânia HDA Vidigal

    2001-07-01

    Full Text Available In Cuba, several Biomphalaria species have been reported such as B. orbignyi, B. schrammi, B. helophila, B. havanensis and B. peregrina; only the latter three are considered as potential hosts of Schistosoma mansoni. The specific identification of Biomphalaria species is based on anatomical and morphological characters of genital organs and shells. The correct identification of these snails is complicated by the high variation in these characters, similarity among species and in some cases by the small size of the snails. In this paper, we reported the classical morphological identification, the use of PCR and RFLP analysis of the internal transcribed spacer region of the ribosomal RNA genes for molecular identification of seven snail populations from different localities in Cuba. Using morphological and molecular analysis, we showed that among the studied Cuban Biomphalaria populations only B. havanensis and B. obstructa species were found.

  6. Molecular organization of 5S rDNAs in Rajidae (Chondrichthyes): Structural features and evolution of piscine 5S rRNA genes and nontranscribed intergenic spacers.

    Pasolini, Paola; Costagliola, Domenico; Rocco, Lucia; Tinti, Fausto

    2006-05-01

    The genomic and gene organisation of 5S rDNA clusters have been extensively characterized in bony fish and eukaryotes, providing general issues for understanding the molecular evolution of this multigene DNA family. By contrast, the 5S rDNA features have been rarely investigated in cartilaginous fish (only three species). Here, we provide evidence for a dual 5S rDNA gene system in the Rajidae by sequence analysis of the coding region (5S) and adjacent nontranscribed spacer (NTS) in five Mediterranean species of rays (Rajidae), and in a large number of piscine taxa including lampreys and bony fish. As documented in several bony fish, two functional 5S rDNA types were found here also in the rajid genome: a short one (I) and a long one (II), distinguished by distinct 5S and NTS sequences. That the ancestral piscine genome had these two 5S rDNA loci might be argued from the occurrence of homologous dual gene systems that exist in several fish taxa and from 5S phylogenetic relationships. An extensive analysis of NTS-II sequences of Rajidae and Dasyatidae revealed the occurrence of large simple sequence repeat (SSR) regions that are formed by microsatellite arrays. The localization and organization of SSR within the NTS-II are conserved in Rajiformes since the Upper Cretaceous. The direct correlation between the SSRs extension and the NTS length indicated that they might play a role in the maintenance of the larger 5S rDNA clusters in rays. The phylogenetic analysis indicated that NTS-II is a valuable systematic tool limited to distantly related taxa of Rajiformes. PMID:16612546

  7. Analysis of the 16S–23S rRNA Gene Internal Transcribed Spacer Region in Klebsiella Species▿

    wang, Min; Cao, Boyang; Yu, Qunfang; Liu, Lei; Gao, Qili; Wang, Lei; Feng, Lu

    2008-01-01

    The 16S-23S rRNA gene internal transcribed spacer (ITS) regions of Klebsiella spp., including Klebsiella pneumoniae subsp. pneumoniae, Klebsiella pneumoniae subsp. ozaenae, Klebsiella pneumoniae subsp. rhinoscleromatis, Klebsiella oxytoca, Klebsiella planticola, Klebsiella terrigena, and Klebsiella ornithinolytica, were characterized, and the feasibility of using ITS sequences to discriminate Klebsiella species and subspecies was explored. A total of 336 ITS sequences from 21 representative s...

  8. DEVELOPMENT OF INTERGENIC SPACERS BASED PCR ASSAY FOR DETECTION OF GIARDIALAMBLIA%犬猫贾第虫IGS序列特异性检测方法的建立

    李雅文; 刘远佳; 郑国超; 谭立娉; 胡伟; 罗琴; 林丽琴; 路鹏云; 李国清

    2013-01-01

    The intergenic spacers (IGS) were amplified in PCR from nuclear ribosomal DNAs of two Giardialamblia strains (assemble D from dog and assemble F from cat) isolated from feces of naturally infected pets in Guangzhou. The PCR products were purified, cloned and sequenced. The resulting nucleotide sequences were compared with related sequences in the GenBank databases. The IGS sequences were 1355 bp for the canine Giardia strain and 1388 bp for the feline Giardia strain. The interspecific difference in the IGS sequence might serve as a genetic marker for the identification and differentiation of Giardia lamblia. Furthermore, a PCR detection method was developed based on IGS sequence. The established PCR assay specifically amplified IGS sequence of G. lamblia but not all control parasites such as Toxocaracanis etc. The minimum detection limit of G.lamblia was 82 fg. Total 84 clinical samples were tested using this method. The positive rate of clinical samples was 3.57%, higher than 2.38%by traditional method.%应用PCR技术对广州市某宠物寄养所采集的一株D型犬源贾第虫和一株F型猫源贾第虫的核糖体IGS序列进行了扩增、克隆、测序,将测序结果与GenBank已上传的贾第虫相应序列进行比对分析,基于贾第虫IGS序列建立了具有良好特异性和敏感性的PCR检测方法,并对84份临床粪样进行了检测。结果显示,D型犬源贾第虫和F型猫源贾第虫的IGS序列长分别为1355 bp和1388 bp,贾第虫IGS序列存在多态性现象,种间差异明显,可以作为区分不同基因型的分子标记;建立的PCR方法能特异性扩增犬源贾第虫核糖体IGS序列,而犬蛔虫等对照虫体DNA均不能扩增,该方法对贾第虫DNA的最小检测量为82 fg,对84份临床粪样的检出率为3.57%,比传统镜检法高出2.38%,具有一定的临床应用价值。

  9. New species in the genus Francisella (Gammaproteobacteria; Francisellaceae); Francisella piscicida sp. nov. isolated from cod (Gadus morhua)

    Ottem, Karl F; Nylund, Are; Karlsbakk, Egil; Friis-Møller, Alice; Krossøy, Bjørn; Knappskog, Dag

    2007-01-01

    A Francisella strain, GM2212, previously isolated from moribund farmed Atlantic cod (Gadus morhua) in Norway, is closely related to Francisella philomiragia among Francisella spp. according to its complete 16S rDNA, 16S-23S intergenic spacer, 23S rDNA, 23S-5S intergenic spacer, 5S rDNA, FopA, lip...

  10. Characterization of Francisella sp., GM2212, the first Francisella isolate from marine fish, Atlantic cod (Gadus morhua)

    Ottem, Karl F; Nylund, Are; Karlsbakk, Egil; Friis-Møller, Alice; Krossøy, Bjørn

    2007-01-01

    A Francisella sp., isolate GM2212(T), previously isolated from diseased farmed Atlantic cod Gadus morhua in Norway is characterized. The complete 16S rDNA, 16S-23S intergenic spacer, 23S rDNA, 23S-5S intergenic spacer, 5S rDNA, FopA, lipoprotein TUL4 (LpnA), malate dehydrogenase and a hypothetica...

  11. Local repeat sequence organization of an intergenic spacer in the chloroplast genome of Chlamydomonas reinhardtii leads to DNA expansion and sequence scrambling: a complex mode of “copy-choice replication”?

    Mahendra D Wagle; Subhojit Sen; Basuthkar J Rao

    2001-12-01

    Parent-specific, randomly amplified polymorphic DNA (RAPD) markers were obtained from total genomic DNA of Chlamydomonas reinhardtii. Such parent-specific RAPD bands (genomic fingerprints) segregated uniparentally (through mt+) in a cross between a pair of polymorphic interfertile strains of Chlamydomonas (C. reinhardtii and C. minnesotti), suggesting that they originated from the chloroplast genome. Southern analysis mapped the RAPD-markers to the chloroplast genome. One of the RAPD-markers, ``P2” (1.6 kb) was cloned, sequenced and was fine mapped to the 3 kb region encompassing 3′ end of 23S, full 5S and intergenic region between 5S and psbA. This region seems divergent enough between the two parents, such that a specific PCR designed for a parental specific chloroplast sequence within this region, amplified a marker in that parent only and not in the other, indicating the utility of RAPD-scan for locating the genomic regions of sequence divergence. Remarkably, the RAPD-product, ``P2” seems to have originated from a PCR-amplification of a much smaller (about 600 bp), but highly repeat-rich (direct and inverted) domain of the 3 kb region in a manner that yielded no linear sequence alignment with its own template sequence. The amplification yielded the same uniquely ``sequence-scrambled” product, whether the template used for PCR was total cellular DNA, chloroplast DNA or a plasmid clone DNA corresponding to that region. The PCR product, a ``unique” new sequence, had lost the repetitive organization of the template genome where it had originated from and perhaps represented a ``complex path” of copy-choice replication.

  12. Identification of Streptococcus species and Haemophilus influenzae by direct sequencing of PCR products from 16S-23SrDNA intergenic spacer regions%16S-23SrDNA间区序列在链球菌和流感嗜血杆菌分类的应用

    鲁辛辛; 杨持; 黎琳; 杨宏欣

    2002-01-01

    Objective To set up a rapid and simple method for identificating bacteria by 16S-23SrDNA intergenic spacer regions (ISRs). Methods Polymorphic products of PCR from ISRs were selected on agarose gel and sequenced directly using purified fragments by excising the gel without cloning. Nucleotide sequences were compared with GenBank databases and analyzed by DNAMAN program.Results There was only a single product in streptococcus genus after PCR amplification of 16S-23SrDNA ISRs. Five streptococcal species were obtained from 7 strains of streptococcus. Two major amplicons were consistently generated for 8 strains of Haemophilus influenzae (H. influenzae). The sequence data showed that they all belonged to H. influenzae type b on GenBank databases.Conclusion PCR and direct sequencing of 16S-23SrDNA ISRs were very successful methods for bacterial species identification.%目的利用16S-23SrRNA间区的特征建立一种简单、快速的细菌分类方法.方法以化脓性链球菌16SrRNA的3'端和23SrRNA的5'端的保守区中合成3对引物,PCR扩增16S-23SrDNA ISRs,纯化后直接测序,在GenBank上查找对应细菌的ISRs序列.用DNAMAN软件进行系统进化分析.结果链球菌属为单拷贝16S-23SrRNA ISRs片段,编码1个tRNAAla基因.流感嗜血杆菌各生物型出现2个大小相似的ISRs片段.与GenBank上的资料比较,7株链球菌归属5个种,流感嗜血杆菌均为b型.结论 ISRs作为细菌分类新的目标基因具有属、种、型和株特异性与灵敏性.

  13. Molecular identfication and virulence of three Aeromonas hydrophila isolates cultured from infected channel catfish during a disease outbreak in West Alabama (USA) in 2009

    Three isolates (AL09-71, AL09-72, and AL09-73) of Aeromonas hydrophila were cultured from infected channel catfish during a disease outbreak in West Alabama in August 2009. Sequence analysis of 16S-23S rDNA intergenic spacer region (ISR), cpn60, gyrB, and rpoD genes of the three strains revealed tha...

  14. Molecular identification and virulence of three Aeromonas hydrophila isolates cultured from infected channel catfish during a disease outbreak in West Alabama in 2009

    Three isolates (AL09-71, AL09-72, and AL09-73) of Aeromonas hydrophila were cultured from infected channel catfish during a disease outbreak in West Alabama in August 2009. Sequence analysis of 16S-23S rDNA intergenic spacer region (ISR), cpn60, gyrB, and rpoD genes of the three strains revealed tha...

  15. Spacer grid

    A spacer grid for fuel assemblies in a water reactor. The grid shell is shaped so that a pressing in zircaloy can be made. Cross members in a lattice in the shell provide spacing for the fuel assemblies. Each fuel assembly has its own cell in the lattice and at least some of the joints between the members comprises two attachment points. (author)

  16. Nuclear fuel assembly spacer

    A spacer for use in a fuel assembly of a nuclear reactor having thin, full-height divider members, slender spring members and laterally oriented rigid stops and wherein the total amount of spacer material, the amount of high neutron cross section material, the projected area of the spacer structure and changes in cross section area of the spacer structure are minimized whereby neutron absorption by the spacer and coolant flow resistance through the spacer are minimized

  17. Heat shock stabilizes highly unstable transcripts of the Xenopus ribosomal gene spacer.

    Labhart, P; Reeder, R H

    1987-01-01

    We have shown recently that, in Xenopus laevis oocytes, the 3' end of the longest detectable ribosomal precursor RNA is not formed by transcription termination but by RNA processing and that RNA polymerase I continues to transcribe through the intergenic spacer region. In oocytes, these spacer transcripts are turned over rapidly, and the only apparent transcription termination site is located 215 base pairs upstream of the 5' end of the next transcription unit. In this paper we show that, at ...

  18. Development of Primer Sets for Loop-Mediated Isothermal Amplification that Enables Rapid and Specific Detection of Streptococcus dysgalactiae, Streptococcus uberis and Streptococcus agalactiae

    Deguo Wang

    2015-05-01

    Full Text Available Streptococcus dysgalactiae, Streptococcus uberis and Streptococcus agalactiae are the three main pathogens causing bovine mastitis, with great losses to the dairy industry. Rapid and specific loop-mediated isothermal amplification methods (LAMP for identification and differentiation of these three pathogens are not available. With the 16S rRNA gene and 16S-23S rRNA intergenic spacers as targets, four sets of LAMP primers were designed for identification and differentiation of S. dysgalactiae, S. uberis and S. agalactiae. The detection limit of all four LAMP primer sets were 0.1 pg DNA template per reaction, the LAMP method with 16S rRNA gene and 16S-23S rRNA intergenic spacers as the targets can differentiate the three pathogens, which is potentially useful in epidemiological studies.

  19. Diversity and Antimicrobial Properties of Lactic Acid Bacteria Isolated from Rhizosphere of Olive Trees and Desert Truffles of Tunisia

    Imene Fhoula; Afef Najjari; Yousra Turki; Sana Jaballah; Abdelatif Boudabous; Hadda Ouzari

    2013-01-01

    A total of 119 lactic acid bacteria (LAB) were isolated, by culture-dependant method, from rhizosphere samples of olive trees and desert truffles and evaluated for different biotechnological properties. Using the variability of the intergenic spacer 16S-23S and 16S rRNA gene sequences, the isolates were identified as the genera Lactococcus, Pediococcus, Lactobacillus, Weissella, and Enterococcus. All the strains showed proteolytic activity with variable rates 42% were EPS producers, while onl...

  20. Development of Primer Sets for Loop-Mediated Isothermal Amplification that Enables Rapid and Specific Detection of Streptococcus dysgalactiae, Streptococcus uberis and Streptococcus agalactiae

    Deguo Wang; Yanhong Liu

    2015-01-01

    Streptococcus dysgalactiae, Streptococcus uberis and Streptococcus agalactiae are the three main pathogens causing bovine mastitis, with great losses to the dairy industry. Rapid and specific loop-mediated isothermal amplification methods (LAMP) for identification and differentiation of these three pathogens are not available. With the 16S rRNA gene and 16S-23S rRNA intergenic spacers as targets, four sets of LAMP primers were designed for identification and differentiation of S. dysgalactia...

  1. Characterization of Francisella sp., GM2212, the first Francisella isolate from marine fish, Atlantic cod (Gadus morhua)

    Ottem, Karl F; Nylund, Are; Karlsbakk, Egil;

    2007-01-01

    A Francisella sp., isolate GM2212(T), previously isolated from diseased farmed Atlantic cod Gadus morhua in Norway is characterized. The complete 16S rDNA, 16S-23S intergenic spacer, 23S rDNA, 23S-5S intergenic spacer, 5S rDNA, FopA, lipoprotein TUL4 (LpnA), malate dehydrogenase and a hypothetica......; but is susceptible to ceftazidime, tetracycline, gentamicin, ciprofloxacin. Based on the molecular and phenotypical characteristics, we suggest that this GM2212 isolate, may represent a new species of Francisella. Isolate GM2212(T) (=CNCM I-3481(T) = CNCM I-3511(T) = DSM 18777(T))....

  2. OCH Spacer Design

    Kurita, C.H.; /Fermilab

    1987-02-04

    The purpose of the OCH module spacers is to keep the given dimension of .224-inch between the 1.83-inch absorber plates. This distance is determined by two liquid argon gaps of .09-inch each and a readout board of .044-inch. The spacer should be made out of a material that would give a minimum thermal contraction movement. Also the dimension of the spacer will be determined dependent upon the load applied to the spacers and the strength of the material chosen. Considering both thermal contraction and yield strength, it is found that Invar-36 would be a suitable material from which to make the spacers for the OCh module, provided that SS304 washers are used in conjunction with the spacers. The spacers would be positioned about 1-inch from the corners of each of the copper plates, and would have a diameter of about 0.85453399-inch. The thickness of the Invar spacer would be 0.15394250-inch and that of the SS304 would be 0.07005750-inch. This combination of materials used for spacing purposes should result in zero displacement due to thermal contraction and no buckling due to overloading. The actual design of the spacer can be found in DWG.

  3. Phylogenetic Study of Mangifera laurina and its Related Species Using cpDNA trnL-F Spacer Markers

    FITMAWATI

    2010-03-01

    Full Text Available Phylogenetic study of cpDNA intergenic spacer trnL-F of Mangifera laurina and their related species within the genus Mangifera in Indonesia was conducted using Rutaceae as the outgroup. This study was to reconstruct phylogenetic relationships and to understand infraspecific relationships within Mangifera based on cpDNA trnL-F intergenic spacer sequences. The results showed that Mangifera sp. Hiku (mangga hiku as the basic cultivar in the clade, and it supported the monophyletic group in Mangifera. And phylogenetic construction indicated that Mangifera sp. Hiku was the progenitor of M. laurina and their related species.

  4. Structural Stator Spacers

    Rasmussen, Peter Omand; Andreasen, Jens H.; Pijanowski, J. M.

    modified shape and small modifications to the stator laminations not only secure the windings and reduce windage losses but also make it possible to increase the stiffness of the stator structure significantly thereby reducing the generation of audible noise. This new method does not incur the significant......This paper presents a powerful new design aspect to reduce acoustic noise and vibration of electro-magnetic origin for electrical machines, by introducing improved slot wedges referred to as "Structural Stator Spacers". These spacers, by using a very stiff dielectric and non magnetic material, a...

  5. Intraspecific diversity within Diaporthe helianthi: evidence from rDNA intergenic spacer (IGS) sequence analysis.

    Pecchia, Susanna; Mercatelli, Elisabetta; Vannacci, Giovanni

    2004-04-01

    Diaporthe helianthi is the causal agent of sunflower stem canker, a serious pathogen of sunflower in Europe but recorded sporadically in Italy. The genetic diversity of D. helianthi isolates from different geographic origins (Argentina, France, Italy, Yugoslavia, Romania) was investigated using IGS sequences. A 400 bp fragment of the portion of the IGS region flanking the 5' end of the 18S gene was amplified from each isolate. The aligned nucleotide sequences showed intraspecific sequence homology from 99-100% among French/Yugoslavian isolates to 95-100% among Italian isolates. French/Yugoslavian isolates shared 90-92% sequence homology with Italian isolates. The phylogenetic tree obtained from the aligned data revealed three separate groups. Group 1 included all isolates from France and former Yugoslavia and one isolate from Argentina; Group 2 included all Italian isolates and one isolate from Argentina. The most distantly related isolate was that from Romania (Group 3). The average genetic distances among isolates within Group 1 and within Group 2 were 0.22 and 3.29 respectively. The analysis showed that all isolates originating from countries where severe outbreaks of the disease are reported annually (France and former Yugoslavia) form a well defined taxon characterized by relatively low variability. This group is distinct from the group formed by isolates originating from Italy, whose variability is relatively much higher. Results obtained revealed a marked differentiation among pathogen isolates, and members of Group 1 seem not yet to have spread into Italian sunflower-growing areas. PMID:15180160

  6. Detection and genotyping of Giardia intestinalis isolates using intergenic spacer (IGS)-based PCR

    Lee, Jong-Ho; Lee, Jongweon; Park, Soon-Jung; Yong, Tai-Soon; Hwang, Ui-Wook

    2006-01-01

    Giardia intestinalis infections arise primarily from contaminated food or water. Zoonotic transmission is possible, and at least 7 major assemblages including 2 assemblages recovered from humans have been identified. The determination of the genotype of G. intestinalis is useful not only for assessing the correlation of clinical symptoms and genotypes, but also for finding the infection route and its causative agent in epidemiological studies. In this study, methods to identify the genotypes ...

  7. Nuclear fuel assembly spacer

    In a fuel assembly for a nuclear reactor a fuel element spacer formed of an array of laterally positioned cojoined tubular ferrules each providing a passage for one of the fuel elements, the elements being laterally supported in the ferrules between slender spring members and laterally oriented rigid stops

  8. Mixing vane grid spacer

    A spacer for a nuclear fuel reactor grid is described having intersecting spring retaining strips for forming fuel element receiving openings and mixing vanes formed at selected ones of the intersections of the strips. The vanes are angularly disposed relative to the strips and overlie predetermined openings at the intersections; each has an opening located above the intersection for improving its coolant flow mixing capability

  9. Caracterização da região espaçadora 16-23S rDNA para diferenciação de estirpes de rizóbios utilizadas na produção de inoculantes comerciais no Brasil Characterization of the spacer region 16-23S rDNA for differentiation of strains of rhizobia used in the production of commercial inoculants in Brazil

    Andréia Mara Rotta Oliveira

    2012-08-01

    Full Text Available A identificação de estirpes de rizóbio tem sido feita pela especificidade por hospedeiros e ensaios microbiológicos tradicionais. Por constituírem um grupo filogeneticamente heterogêneo, diferentes técnicas moleculares têm sido empregadas para auxiliar na caracterização genética e na identificação de estirpes eficientes e competitivas para a produção de inoculantes. Este trabalho teve por objetivos caracterizar a região espaçadora 16S-23S rDNA das estirpes de rizóbios utilizadas nos inoculantes comercializados no Brasil para espécies leguminosas, utilizando a técnica da PCR em combinação com a de RFLP, e avaliar a possibilidade do uso desse marcador molecular como método auxiliar para identificação das estipes. A amplificação da região espaçadora 16-23 S rDNA das estirpes de rizóbios gerou fragmentos com tamanhos que variaram entre 700pb e 1350pb. Os produtos resultantes da amplificação foram submetidos à digestão com as endonucleases. Mps I, Dde I e Hae III. Os resultados obtidos neste estudo indicam a possibilidade do uso da técnica de PCR-RFLP da região espaçadora 16S-23S rDNA como marcador molecular para a diferenciar as estirpes de rizóbios, em complemento às técnicas microbiológicas tradicionais. Contudo, este marcador não é suficientemente discriminatório para ser usado na identificação das estirpes recomendadas para a produção de inoculantes comerciais.The identification of strains of rhizobia has been made by host specificity and regular microbiological tests. By forming a phylogenetically heterogeneous group, different molecular techniques have been employed to assist in the genetic characterization and identification of efficient and competitive strains for production of inoculants. This study aimed to characterize the spacer region 16S-23S rDNA of the strains of rhizobia used in commercial inoculants in Brazil for legume species, using PCR combined with RFLP, and assess the possibility

  10. Spacer capture rod to spacer grid attachment device

    A system for capturing a grid spacer in a nuclear fuel bundle which comprises a split sleeve fixed to a capture rod is described. The sleeve is used in conjunction with a grid spacer having openings formed by intersecting walls which include protrusions and coacting springs extending from the walls. The sleeve includes pairs of longitudinally spaced bosses and a standoff boss extending radially outward from the surface of the rod. The pairs of bosses are positioned astride the protrusions from the walls to prevent longitudinal movement of the grid spacer. The split serves as a guide slot to orient the capture rod so that it may pass through the grid spacer openings unencumbered by the protrusions from the grid space walls. The standoff boss is in surface contact with a wall of the grid spacer

  11. Phylogeny of Panax using chloroplast trnC-trnD intergenic region and the utility of trnC-trnD in interspecific studies of plants.

    Lee, Chunghee; Wen, Jun

    2004-06-01

    Sequences of the chloroplast trnC-trnD region and the internal transcribed spacer (ITS) regions of nuclear ribosomal DNA were obtained for all species of Panax L. (the ginseng plant genus, Araliaceae) to reconstruct phylogenetic relationships. The trnC-trnD phylogeny is congruent with the ITS phylogeny for the diploid taxa of Panax. This study is the first use of the trnC-trnD sequence data for phylogenetic analysis at the interspecific level. We evaluated this DNA region for its phylogenetic utility at the lower taxonomic level for flowering plants. The trnC-trnD region includes the trnC-petN intergenic spacer, the petN gene, the petN-psbM intergenic spacer, the psbM gene, and the psbM-trnD intergenic spacer. The petN and psbM genes are small, 90 and 104-114 bp across angiosperms, respectively, and have conserved sequences. We have designed universal amplification and sequencing primers within these two genes. Using these primers, we have successfully amplified the entire trnC-trnD region for a diversity of flowering plant groups, including Aralia L. (Araliaceae), Calycanthus L. (Calycanthaceae), Corylus L. (Betulaceae), Hamamelis L. (Hamamelidaceae), Hydrocotyle L. (Apiaceae), Illigera Blume (Hernandiaceae), Nelumbo Adans. (Nelumbonaceae), Nolana L. ex L.f. (Solanaceae), Prunus L. (Rosaceae), and Staphylea L. (Staphyleaceae). In Panax, the trnC-trnD region provides a similar number of informative phylogenetic characters as the ITS regions and a slightly higher number of informative characters than the chloroplast ndhF gene. We thus demonstrate the utility of the trnC-trnD region for lower-level phylogenetic studies in flowering plants. PMID:15120387

  12. Phylogenetic analysis of encapsulated and non-encapsulated Trichinella species by studying the 5S rDNA tandemly repeated intergenic region.

    van der Giessen, J W B; Fonville, M; Briels, I; Pozio, E

    2005-09-01

    The identification of sequence regions in the genomes of pathogens which can be useful to distinguish among species and genotypes, is of great importance for epidemiological, molecular, and phylogenetic studies. The 5S ribosomal DNA intergenic spacer region has been identified as a good target to distinguish among eight Trichinella species and genotypes. The recent discovery of two non-encapsulated species in this genus, Trichinella papuae and Trichinella zimbabwensis, which can infect both mammals and reptiles, has suggested analyzing their 5S rDNA. Amplification of the tandem repeats of the 5S rDNA intergenic region of encapsulated species of Trichinella shows a 751bp fragment, whereas the three non-encapsulated species show a fragment of 800bp with T. pseudospiralis showing an additional fragment of 522bp. Although the size of the 800bp PCR fragments of T. papuae and T. zimbabwensis are similar to that of T. pseudospiralis, there are differences in the 5S rDNA intergenic regions among the three non-encapsulated species. Phylogenetic analysis of the 5S rDNA intergenic regions shows a clustering together of the three non-encapsulated Trichinella species that is well separated from the encapsulated ones. In addition, a single PCR-based method allows distinguishing non-encapsulated and encapsulated species. PMID:16076532

  13. Rapid Differentiation and In Situ Detection of 16 Sourdough Lactobacillus Species by Multiplex PCR

    Settanni, Luca; van Sinderen, Douwe; Rossi, Jone; Corsetti, Aldo

    2005-01-01

    A two-step multiplex PCR-based method was designed for the rapid detection of 16 species of lactobacilli known to be commonly present in sourdough. The first step of multiplex PCR was developed with a mixture of group-specific primers, while the second step included three multiplex PCR assays with a mixture of species-specific primers. Primers were derived from sequences that specify the 16S rRNA, the 16S-23S rRNA intergenic spacer region, and part of the 23S rRNA gene. The primer pairs desig...

  14. First description of Trueperella (Arcanobacterium) bernardiae of animal origin.

    Hijazin, M; Metzner, M; Erhard, M; Nagib, S; Alber, J; Lämmler, C; Hassan, A A; Prenger-Berninghoff, E; Zschöck, M

    2012-10-12

    In the present study a Trueperella (Arcanobacterium) bernardiae strain isolated from an anal swab of a three-day-old piglet could be identified phenotypically, by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and genotypically by sequencing the 16S rDNA, the 16S-23S rDNA intergenic spacer region (ISR) and by sequencing the superoxide dismutase A encoding gene sodA. The present study gives the first information about the presence of T. (A.) bernardiae in specimen of animals. PMID:22608102

  15. Biodegradation of Nitro-Substituted Explosives 2,4,6-Trinitrotoluene, Hexahydro-1,3,5-Trinitro-1,3,5-Triazine, and Octahydro-1,3,5,7-Tetranitro-1,3,5-Tetrazocine by a Phytosymbiotic Methylobacterium sp. Associated with Poplar Tissues (Populus deltoides × nigra DN34)

    Van Aken, Benoit; Yoon, Jong Moon; Schnoor, Jerald L.

    2004-01-01

    A pink-pigmented symbiotic bacterium was isolated from hybrid poplar tissues (Populus deltoides × nigra DN34). The bacterium was identified by 16S and 16S-23S intergenic spacer ribosomal DNA analysis as a Methylobacterium sp. (strain BJ001). The isolated bacterium was able to use methanol as the sole source of carbon and energy, which is a specific attribute of the genus Methylobacterium. The bacterium in pure culture was shown to degrade the toxic explosives 2,4,6-trinitrotoluene (TNT), hexa...

  16. Nuclear reactor fuel rod spacer

    A spacer for positioning at least the four corner fuel rods in a tubular flow channel of a nuclear reactor is disclosed. The spacer comprises a support member having four side bands interconnected by four corner bands to form a unitary structure. Each of the side bands has a L-shaped lobe adjacent to each of its ends with one leg of each lobe extending to the adjacent end of its side band. Each of the corner bands is narrower than the side bands and is offset so as to be spaced from the lobe. One leg of each lobe is positioned to engage the tubular flow channel to maintain proper spacing between the flow channel and the adjacent corner fuel rod and to improve the thermal-hydraulic performance of the spacer

  17. Potential use of molecular-typing methods for the identification and characterization of salmonella enterica serotypes isolated in the poultry production chain

    CM Baratto

    2012-09-01

    Full Text Available Salmonella is widespread in nature and can be found in all links of the poultry production chain. Due to its high impact on meat processing, techniques for the rapid detection and reproducible characterization of Salmonella serotypes in foods are needed. The present study investigated the potential of molecular profiling to identify and differentiate 15 Salmonella serotypes isolated from the poultry production chain, based on 5 primers by random amplified polymorphic DNA (RAPD, enterobacterial repetitive intergenic consensus (ERIC-PCR, amplification of rDNA internal spacer analysis (RISA, and amplified ribosomal DNA restriction analysis (ARDRA of 16S-23S rRNA internal spacer region (ISR cleaved with Alu I and Hha I restriction enzymes. Three isolates of each serotype were analyzed for the identification of similar and different profiles. Dendrograms were constructed from molecular profiles using the UPGMA method (unweighted pair-group method for the arithmetic averages and the software program WinBoot. The present study indicates the usefulness of RISA and ARDRA of the 16S-23S rRNA intergenic spacer region (ISR for systematic, epidemiological, and diagnostic purposes. Since these techniques can be used for the differentiation of serotypes, they are highly promising for the characterization of Salmonella serotypes and intra-serotypes. Data indicate that these techniques may be used to produce more consistent, reliable, and reproducible results in the identification and epidemiological study (traceability of Salmonella in the poultry industry.

  18. Identification of Candida species by PCR and restriction fragment length polymorphism analysis of intergenic spacer regions of ribosomal DNA.

    Williams, D W; Wilson, M. J.; Lewis, M. A.; Potts, A J

    1995-01-01

    The PCR was used to amplify a targeted region of the ribosomal DNA from 84 Candida isolates. Unique product sizes were obtained for Candida guilliermondii, Candida (Torulopsis) glabrata, and Candida pseudotropicalis. Isolates of Candida albicans, Candida tropicalis, Candida stellatoidea, Candida parapsilosis, and Candida krusei could be identified following restriction digestion of the PCR products.

  19. Detection of Chlamydophila psittaci from pigeons by polymerase chain reaction in Ahvaz

    Masoud Ghorbanpoor

    2015-10-01

    Full Text Available Background and Objective: Chlamydophila psittaci is a lethal bacterium that causes endemic avian chlamydiosis, and respiratory psittacosis. Laboratory diagnosis of Chlamydophila psittaci is difficult by culture. This study was design to investigate the presence of Chlamydophila psittaci in collected pharyngeal swabs from asyptomatic pigeons by PCR.Materials and Methods: Pharyngeal samples from pigeons with no symptoms of disease (n=280 were collected during hot and cold seasons in different parts of Ahvaz. DNA was extracted from specimens and subjected to PCR targeting pmp genes and 16s-23s rRNA intergenic spacer of Cp. psittaci and chlamydiales specific primers.Results: Of 280 samples 2 (0.7% harbor were positive for chlamydiales (16s-23s intergenic spacer and Cp. psittaci specific genes (pmp gene.Conclusions: In this research the pigeons were asymptomatic carriers for Cp. psittaci in their respiratory discharges. These results suggest that Cp. psittaci infection of human can occur in very close and continuous contact with pigeons.

  20. On the brink of holoparasitism: plastome evolution in dwarf mistletoes (Arceuthobium, Viscaceae).

    Nickrent, Daniel L; García, Miguel A

    2009-06-01

    Chloroplast sequences spanning rps7 to 23S rDNA in Arceuthobium campylopodum and A. pendens were generated and compared to Arabidopsis and seven other parasitic plants. Pseudogenes for trnV, trnI (GAU), and trnA (UGC) were seen in both Arceuthobium species, paralleling the situation in the holoparasite Epifagus (Orobanchaceae). These tRNA genes were intact, however, in two other members of Santalales (Ximenia and Phoradendron). The 16S-23S rDNA intergenic spacer was sequenced for 13 additional species of Arceuthobium representing both Old and New World taxa. All species examined had pseudogenes for trnI and trnA, however, deletions in these tRNAs have occurred in different regions among various lineages of the genus. The aligned 16S-23S rDNA intergenic spacer was analyzed using maximum parsimony and compared with nuclear ITS rDNA using a similar suite of species. Overall species relationships were generally congruent, although two cases of potential lineage sorting or chloroplast capture were detected. Arceuthobium is a valuable genetic model to contrast with holoparasites because, despite significant alteration and truncation of its plastome, it still maintains photosynthetic function. PMID:19479176

  1. Spacer for a fuel element

    Spacers for fuel pins arranged to form congish fuel elements can be shaped as plates with openings in accordance with the fuel pin grid. Such a plate that covers the cross section of a fuel element consists according to the invention of at least two parts that are offset in the fuel element's longitudinal direction and joint hinge-like in at least one grid position. Thus, one has smaller parts that are easier to work on with due accuracy. The invention is designed in particular for breeder reactors and high-conversion reactors. (orig.)

  2. CRISPR interference directs strand specific spacer acquisition.

    Daan C Swarts

    Full Text Available BACKGROUND: CRISPR/Cas is a widespread adaptive immune system in prokaryotes. This system integrates short stretches of DNA derived from invading nucleic acids into genomic CRISPR loci, which function as memory of previously encountered invaders. In Escherichia coli, transcripts of these loci are cleaved into small RNAs and utilized by the Cascade complex to bind invader DNA, which is then likely degraded by Cas3 during CRISPR interference. RESULTS: We describe how a CRISPR-activated E. coli K12 is cured from a high copy number plasmid under non-selective conditions in a CRISPR-mediated way. Cured clones integrated at least one up to five anti-plasmid spacers in genomic CRISPR loci. New spacers are integrated directly downstream of the leader sequence. The spacers are non-randomly selected to target protospacers with an AAG protospacer adjacent motif, which is located directly upstream of the protospacer. A co-occurrence of PAM deviations and CRISPR repeat mutations was observed, indicating that one nucleotide from the PAM is incorporated as the last nucleotide of the repeat during integration of a new spacer. When multiple spacers were integrated in a single clone, all spacer targeted the same strand of the plasmid, implying that CRISPR interference caused by the first integrated spacer directs subsequent spacer acquisition events in a strand specific manner. CONCLUSIONS: The E. coli Type I-E CRISPR/Cas system provides resistance against bacteriophage infection, but also enables removal of residing plasmids. We established that there is a positive feedback loop between active spacers in a cluster--in our case the first acquired spacer--and spacers acquired thereafter, possibly through the use of specific DNA degradation products of the CRISPR interference machinery by the CRISPR adaptation machinery. This loop enables a rapid expansion of the spacer repertoire against an actively present DNA element that is already targeted, amplifying the

  3. Probabilistic models for CRISPR spacer content evolution

    Kupczok, Anne; Bollback, Jonathan P

    2013-01-01

    Background The CRISPR/Cas system is known to act as an adaptive and heritable immune system in Eubacteria and Archaea. Immunity is encoded in an array of spacer sequences. Each spacer can provide specific immunity to invasive elements that carry the same or a similar sequence. Even in closely related strains, spacer content is very dynamic and evolves quickly. Standard models of nucleotide evolution cannot be applied to quantify its rate of change since processes other than single nucleotide ...

  4. Development of a High Performance Spacer Grid

    Song, Kee Nam; Song, K. N.; Yoon, K. H. (and others)

    2007-03-15

    A spacer grid in a LWR fuel assembly is a key structural component to support fuel rods and to enhance the heat transfer from the fuel rod to the coolant. In this research, the main research items are the development of inherent and high performance spacer grid shapes, the establishment of mechanical/structural analysis and test technology, and the set-up of basic test facilities for the spacer grid. The main research areas and results are as follows. 1. 18 different spacer grid candidates have been invented and applied for domestic and US patents. Among the candidates 16 are chosen from the patent. 2. Two kinds of spacer grids are finally selected for the advanced LWR fuel after detailed performance tests on the candidates and commercial spacer grids from a mechanical/structural point of view. According to the test results the features of the selected spacer grids are better than those of the commercial spacer grids. 3. Four kinds of basic test facilities are set up and the relevant test technologies are established. 4. Mechanical/structural analysis models and technology for spacer grid performance are developed and the analysis results are compared with the test results to enhance the reliability of the models.

  5. Variation in the spacer regions separating tRNA genes in Renibacterium salmoninarum distinguishes recent clinical isolates from the same location.

    Alexander, S M; Grayson, T H; Chambers, E M; Cooper, L F; Barker, G A; Gilpin, M L

    2001-01-01

    A means for distinguishing between clinical isolates of Renibacterium salmoninarum that is based on the PCR amplification of length polymorphisms in the tRNA intergenic spacer regions (tDNA-ILPs) was investigated. The method used primers specific to nucleotide sequences of R. salmoninarum tRNA genes and tRNA intergenic spacer regions that had been generated by using consensus tRNA gene primers. Twenty-one PCR products were sequenced from five isolates of R. salmoninarum from the United States, England, and Scotland, and four complete tRNA genes and spacer regions were identified. Sixteen specific PCR primers were designed and tested singly and in all possible pairwise combinations for their potential to discriminate between isolates from recent clinical outbreaks of bacterial kidney disease (BKD) in the United Kingdom. Fourteen of the isolates were cultured from kidney samples taken from fish displaying clinical signs of BKD on five farms, and some of the isolates came from the same farm and at the same time. The tDNA-ILP profiles separated 22 clinical isolates into nine groups and highlighted that some farms may have had more than one source of infection. The grouping of isolates improved on the discriminatory power of previously reported typing methods based on randomly amplified polymorphic DNA analysis and restriction fragment length profiles developed using insertion sequence IS994. Our method enabled us to make divisions between closely related clinical isolates of R. salmoninarum that have identical exact tandem repeat (ETR-A) loci, rRNA intergenic spacer sequences, and IS994 profiles. PMID:11136759

  6. Variation in the Spacer Regions Separating tRNA Genes in Renibacterium salmoninarum Distinguishes Recent Clinical Isolates from the Same Location

    Alexander, Sarah M.; Grayson, T. Hilton; Chambers, Edel M.; Cooper, Lynne F.; Barker, Gavin A.; Gilpin, Martyn L.

    2001-01-01

    A means for distinguishing between clinical isolates of Renibacterium salmoninarum that is based on the PCR amplification of length polymorphisms in the tRNA intergenic spacer regions (tDNA-ILPs) was investigated. The method used primers specific to nucleotide sequences of R. salmoninarum tRNA genes and tRNA intergenic spacer regions that had been generated by using consensus tRNA gene primers. Twenty-one PCR products were sequenced from five isolates of R. salmoninarum from the United States, England, and Scotland, and four complete tRNA genes and spacer regions were identified. Sixteen specific PCR primers were designed and tested singly and in all possible pairwise combinations for their potential to discriminate between isolates from recent clinical outbreaks of bacterial kidney disease (BKD) in the United Kingdom. Fourteen of the isolates were cultured from kidney samples taken from fish displaying clinical signs of BKD on five farms, and some of the isolates came from the same farm and at the same time. The tDNA-ILP profiles separated 22 clinical isolates into nine groups and highlighted that some farms may have had more than one source of infection. The grouping of isolates improved on the discriminatory power of previously reported typing methods based on randomly amplified polymorphic DNA analysis and restriction fragment length profiles developed using insertion sequence IS994. Our method enabled us to make divisions between closely related clinical isolates of R. salmoninarum that have identical exact tandem repeat (ETR-A) loci, rRNA intergenic spacer sequences, and IS994 profiles. PMID:11136759

  7. Spacer for supporting fuel element boxes

    A spacer plate unit arranged externally on each side and at a predetermined level of a polygonal fuel element box for mutually supporting, with respect to one another, a plurality of the fuel element boxes forming a fuel element bundle, is formed of a first and a second spacer plate part each having the same length and the same width and being constituted of unlike first and second materials, respectively. The first and second spacer plate parts of the several spacer plate units situated at the predetermined level are arranged in an alternating continuous series when viewed in the peripheral direction of the fuel element box, so that any two spacer plate units belonging to face-to-face oriented sides of two adjoining fuel element boxes in the fuel element bundle define interfaces of unlike materials

  8. LISA telescope spacer design investigations

    Sanjuan, Josep; Mueller, Guido; Livas, Jeffrey; Preston, Alix; Arsenovic, Petar; Castellucci, Kevin; Generie, Joseph; Howard, Joseph; Stebbins, Robin

    ) and materials such as Silicon Carbide (SiC) and Carbon Fiber Reinforced Plastic (CFRP) are considered to be used in the telescope spacer structure. We will describe our experimental efforts to understand and quantify the behavior of different materials and also discuss a first investigation of a specific on-axis SiC telescope spacer for LISA. This work is supported by NASA contract 00069955.

  9. Application of spacer fabrics in composite production

    Mecit, Diren; , Arzu Marmaralı

    2012-01-01

    Developments in the field of textile reinforced composites have been increasing in the last several years. In the first developed composite materials, fibers were used as reinforcement element. Textile materials such as staple fibers, bands, filament yarns, cables and two dimensional textiles are widely used as reinforcement elements in composite materials. Spacer fabrics consist of two outer surfaces and a connection layer between those outer surfaces. Spacer fabrics can be classified in the...

  10. PairWise Neighbours database: overlaps and spacers among prokaryote genomes

    Garcia-Vallvé Santiago

    2009-06-01

    Full Text Available Abstract Background Although prokaryotes live in a variety of habitats and possess different metabolic and genomic complexity, they have several genomic architectural features in common. The overlapping genes are a common feature of the prokaryote genomes. The overlapping lengths tend to be short because as the overlaps become longer they have more risk of deleterious mutations. The spacers between genes tend to be short too because of the tendency to reduce the non coding DNA among prokaryotes. However they must be long enough to maintain essential regulatory signals such as the Shine-Dalgarno (SD sequence, which is responsible of an efficient translation. Description PairWise Neighbours is an interactive and intuitive database used for retrieving information about the spacers and overlapping genes among bacterial and archaeal genomes. It contains 1,956,294 gene pairs from 678 fully sequenced prokaryote genomes and is freely available at the URL http://genomes.urv.cat/pwneigh. This database provides information about the overlaps and their conservation across species. Furthermore, it allows the wide analysis of the intergenic regions providing useful information such as the location and strength of the SD sequence. Conclusion There are experiments and bioinformatic analysis that rely on correct annotations of the initiation site. Therefore, a database that studies the overlaps and spacers among prokaryotes appears to be desirable. PairWise Neighbours database permits the reliability analysis of the overlapping structures and the study of the SD presence and location among the adjacent genes, which may help to check the annotation of the initiation sites.

  11. Thermal Performance of Insulating Cryogenic Pin Spacers

    Darve, C

    1998-01-01

    Following the proposal to introduce an actively cooled radiation screen (5-10 K) for the LHC machine, the design of the LHC cryostat foresees the need for spacers between the cold mass and the radiati on screen. The thermal impedance of the chosen material should be very high and the shape selected to withstrand the contact stress due to the displacements induced by the coll-down and warm-up transi ent. A cryogenic experiment dedicated to studying the thermal behaviour of several proposed spacers was performed at the cryogenics laboratory of CERN before choosing the one to be used for further i nvestigation on the LHC full-scale Cryostat Thermal Model [1] [2]. This paper describes a quantitative analysis leading to the choice of the spacer.

  12. Separator-spacer for electrochemical systems

    Grimes, Patrick G.; Einstein, Harry; Newby, Kenneth R.; Bellows, Richard J.

    1983-08-02

    An electrochemical cell construction features a novel co-extruded plastic electrode in an interleaved construction with a novel integral separator-spacer. Also featured is a leak and impact resistant construction for preventing the spill of corrosive materials in the event of rupture.

  13. Nuclear reactor spring strip grid spacer

    An improved and novel grid spacer for maintaining the fuel rods of a nuclear reactor fuel assembly in substantially parallel array is described. The invention provides for spring strips to maintain the fuel elements in their desired orientation which have more positive alignment than previous types while allowing greater flexibility to counterbalance the effects of differential thermal expansion. (UK)

  14. Nuclear reactor fuel assembly spacer grids

    Designs of nuclear reactor fuel assembly spacer grids for supporting and spacing fuel elements are described which do not utilize resilient grid plate protrusions in the peripheral band but retain the advantages inherent in the combination resilient and rigid protrusion cells. (U.K.)

  15. Hydraulic Design Criteria for Spacer Grids of Nuclear Fuel Element

    In this paper a hydraulic model for calculating the pressure drop on the CARA spacer grids is extended.This model is validated and feedback from experimental hydraulic test performed in a low pressure loop.The importance of the spacer grid geometric parameter (that is, its thickness and length, the number and kind of their fix spacer), developing hydraulic design criteria for spacer grid on fuel element

  16. Molecular profiling of microbial communities from contaminated sources: Use of subtractive cloning methods and rDNA spacer sequences. 1998 annual progress report

    'The major objective of the research is to provide appropriate sequences and to assemble a high-density DNA array of oligonucleotides that can be used for rapid profiling of microbial populations from polluted areas. The sequences to be assigned to the DNA array are chosen from from cloned genomic DNA sequences (the ribosomal operon, described below) from groundwater at DOE sites containing organic solvents. The sites, Hanford Nuclear Plant and Lawrence Livermore Site 300, have well characterized pollutant histories, which have been provided by the collaborators. At this mid-point of the project, over 60 unique sequence classes of intergenic spacer region have been identified from the first sample site. The use of these sequences as hybridization probes, and their frequency of occurrence, allow a clear distinction between bacterial communities before and after remediation by acetate/nitrate pumping. The authors have developed the hybridization conditions for identifying PCR products in a 96 well format, a versatile alignment and visualization program (acronym: MALIGN) developed by Dr. Dennis Maeder, has been used to align the ISRs, which are variable in length and sometimes in position of the tRNAs. Finally, in collaboration with Dr. W. Chen and Dr. J. Zhou at ORNL, they have significant evidence that mass spectrometer analysis can be used to determine the lengths of PCR amplified intergenic spacer DNA.'

  17. Molecular diversity of Renibacterium salmoninarum isolates determined by randomly amplified polymorphic DNA analysis.

    Grayson, T H; Atienzar, F A; Alexander, S M; Cooper, L F; Gilpin, M L

    2000-01-01

    The molecular diversity among 60 isolates of Renibacterium salmoninarum which differ in place and date of isolation was investigated by using randomly amplified polymorphic DNA (RAPD) analysis. Isolates were grouped into 21 banding patterns which did not reflect the biological source. Four 16S-23S rRNA intergenic spacer (ITS1) sequence variations and two alleles of an exact tandem repeat locus, ETR-A, were the bases for formation of distinct groups within the RAPD clusters. This study provides evidence that the most common ITS1 sequence variant, SV1, possesses two copies of a 51-bp repeat unit at ETR-A and has been widely dispersed among countries which are associated with mainstream intensive salmonid culture. PMID:10618262

  18. Debris catching spring detent spacer grid

    This patent describes a nuclear reactor having fuel assemblies including an upper end fitting and a lower end fitting and spaced nuclear fuel rod spacer grids therebetween for supporting and spacing a plurality of elongated nuclear fuel rods, each of which includes a hollow active portion of nuclear fuel filled cladding intermediate the rod ends and a tapering end cap of solid materials with a circumferential groove on the rod end which first encounters reactor coolant flow, a tall spacer grid relative to the grids adjacent the active portion being means for capturing and retaining deleterious debris carried by reactor coolant before it enters the active region of a fuel assembly through solid end caps compartments' corners and creates fuel rod cladding damage

  19. Heterogeneous diversity of spacers within CRISPR

    Deem, Michael; He, Jiankui

    2011-03-01

    Clustered regularly interspaced short palindromic repeats (CRISPR) in bacterial and archaeal DNA have recently been shown to be a new type of anti-viral immune system in these organisms. We here study the diversity of spacers in CRISPR under selective pressure. We propose a population dynamics model that explains the biological observation that the leader-proximal end of CRISPR is more diversified and the leader-distal end of CRISPR is more conserved. This result is shown to be in agreement with recent experiments. Our results show that the CRISPR spacer structure is influenced by and provides a record of the viral challenges that bacteria face. 1) J. He and M. W. Deem, Phys. Rev. Lett. 105 (2010) 128102

  20. Nuclear reactor fuel assembly spacer grid

    A nuclear reactor fuel assembly spacer grid having grid straps provided with spring clips bent to widthwise encircle the grid straps and having their two ends welded together. Spring portions compressibly contact the fuel rods. The spring clips may have pairs of separated flat portions, straddling the control rod guide thimble in adjacent thimble cells so as not to interfere with the guide thimbles. The spring clips are made of a material having good radiation stress relaxation properties. (author)

  1. Spacer grid for a PWR fuel assembly

    The spacer grid defines a block of square section cells each accommodating one fuel rod and is made up of interlocking flat strips welded together and made of zirconium alloy. A spring of nickel alloy is secured between each peripheral strip. The strip defining the wall of each of those cells opposite strip carries rigid bosses pressed out of the strip. The rods in those cells are gripped between bosses and spring sections. 7 figs

  2. [Phylogenetic relations of Salix L. subg. Salix species (Salicaceae) according to sequencing data of intergenic spacers of chloroplasic genomes and ITS rDNA].

    Barkalov, V Iu; Kozyrenko, M M

    2014-08-01

    A phylogenetic analysis based on a comparison of nucleotide sequences of six regions from cpDNA and ITS rDNA (petN-psbM, trnD-trnT, trnC-petN, psaA-ycf3, petG-trnP, and rpoB-trnC) allowed for elucidating the relationship among species and sections belonging to the Salix subgenus and, more generally, to the Salix genus, as well as revealing the relations of the Chosenia genus. The definition of the subgenera of Pleuradenia (including the Urbanianea genus and the Chosenia genus), Salix (without the Triandrae section), Triandrae, and Longifoliae is essentially consistent with current classification schemes of the Salix genus. The previously defined genera of Chosenia and Toisusu (Urbanianea) are not only joined with the Salix genus but are also closely related between themselves. The Protitea subgenus only corresponds to the American species of the Humboldtianae section (S. humboldtiana, S. amygdaloides, S. gooddingii). The relationship of S. chaenomeloides, which is a nomenclatural type of this subgenus, as well as the relationship of the Wilsonia section, remains unresolved. The Humboldtianae section should be interpreted more narrowly, apparently, separating the Acmophillae and Tetraspermae sections from it. The monotypic American Floridanae section is related to the Salix, Salicaster, Tetraspermae, and Wilsonia. PMID:25731023

  3. Variability in ribosomal DNA genic and spacer regions in Verticillium dahliae isolates from different hosts

    Otero Laura

    2004-01-01

    Full Text Available Using PCR-based assays with specific primers for amplification of the ribosomal DNA intergenic spacer region (IGS and a portion of the mitochondrial DNA small subunit ribosomal RNA gene (mtDNA SSU rRNA, the genetic variability among Verticillium dahliae isolates from olive (Olea europaea and other host species from Argentina and Brazil was estimated. The derived UPGMA-generated phenograms based upon the restriction fingerprinting data of rDNA IGS products revealed genetic differences, correlating with the host of origin. Isolates infecting olive genetically distinct from those from cocoa (Theobroma cacao and sunflower (Helianthus annuus. Digestion of mitochondrial DNA SSU rRNA PCR products revealed less variability, distinguishing only one isolate from sunflower. Ribosomal DNA ITS restriction patterns were identical for all isolates of V. dahliae, irrespective of host of origin. These preliminary results may have relevance for Verticillium wilt control practices, possibly reflecting a different evolutionary origin, or reproductive isolation of the pathogen in olive, distinct from populations of other hosts.

  4. Nuclear reactor fuel assembly spacer grid

    A spacer grid for a nuclear fuel assembly is described. It consists of a lattice of grid plates forming multiple cells that are penetrated by fuel elements. Resilient protrusions and rigid protrusions projecting into the cells from the plates bear against the fuel element to effect proper support and spacing. Pairs of intersecting grid plates, in a longitudinally spaced relationship, cooperate with other plates to form a lattice wherein each cell contains adjacent panels having resilient protrusions arranged opposite adjacent panels having rigid protrusions. The peripheral band bounding the lattice is provided solely with rigid protrusions projecting into the peripheral cells. 8 claims

  5. Heterogeneous diversity of spacers within CRISPR

    He, Jiankui; Deem, Michael W.

    2010-01-01

    Clustered regularly interspaced short palindromic repeats (CRISPR) in bacterial and archaeal DNA have recently been shown to be a new type of anti-viral immune system in these organisms. We here study the diversity of spacers in CRISPR under selective pressure. We propose a population dynamics model that explains the biological observation that the leader-proximal end of CRISPR is more diversified and the leader-distal end of CRISPR is more conserved. This result is shown to be in agreement w...

  6. Heat transfer augmentation in rod bundles near grid spacers

    Heat transfer augmentation by straight grid spacers in rod bundles is studied for single phase flow and for post critical heat flux dispersed flow. The heat transfer effect of swirling grid spacers in single phase flow is also examined. Governing heat transfer mechanisms are analyzed, and predictive formulations are established. For single phase flow, the local heat transfer at a straight spacer and at its upstream or downstream locations are treated separately. 18 refs

  7. Pressure Drop of Chamfer on Spacer Grid Strap

    Kim, Euijae; Kim, Kanghoon; Kim, Kyounghong; Nahm, Keeyil [KEPCO Nuclear Fuel Co., Daejeon (Korea, Republic of)

    2014-05-15

    A swirl flow and cross flow are generated by the spacer grid with mixing vane that enhances the thermal performance and critical heat flux (CHF). The additional pressure drop makes it difficult to meet acceptance criteria for overall pressure drop in fuel assembly depending upon the pump capacity. The chamfer on the end of spacer grid strap is one solution to reduce additional pressure drop without any adverse effect on flow fields. In this research, the pressure drop tests for spacer grid with and without chamfer were carried out at the hydraulic test facility. The result can be applied to develop high performance nuclear fuel assemblies for Pressurized Water Reactor (PWR) plants. The pressure drop tests for 5x5 spacer grid with and without chamfer as well as 6x6 spacer grid with and without chamfer were carried out at the INFINIT test facility. The Reynolds number ranged about from 16000 to 75000. The sweep-up and sweep-down test showed that the direction of sweep did not affect the pressure drop. The chamfer on spacer grid strap reduced the pressure drop due to the decreased in ratio of inlet area to outlet area. The pressure loss coefficient for spacer grid with chamfer was by up to 13.8 % lower than that for spacer grid without chamfer. Hence, the chamfer on spacer grid strap was one of effective ways to reduce the pressure drop.

  8. Grid welding fixture for a spacer grid

    A modular grid welding fixture for a spacer grid that facilitates full grid laser welding of a spacer grid in one setup is disclosed. The modular design allows for partial implementation of each weld type. A base plate is used for mounting to the positioning/rotational plate of the welding system. A removable sub-plate received in the base plate is used to position the grid strips for proper location for welding. A top fixture plate is aligned with the base plate and provides for mounting of a second sub-plate if required. Side plates with spring loaded pressure pads that are hinged to the top fixture plate apply uniform pressure to the outer grid strips during processing. The base plate, top plate, side plate, and pressure pads are provided with a plurality of through holes to allow access of the laser beam for welding. Corner clips are used to insure contact of the overlapping sections of the outer grid strips for proper corner welding. 4 figs

  9. Trypanosoma brucei: Enrichment by UV of intergenic transcripts from the variable surface glycoprotein gene expression site

    The expression site for the variable surface glycoprotein (VSG) gene AnTat 1.3A of Trypanosoma brucei is 45 kilobases long and encompasses seven expression site-associated genes (ESAGs). After UV irradiation, several large transcripts from the putative promoter region were strongly enriched. We report that one such major transcript starts near the poly(A) addition site of the first gene (ESAG 7), spans the intergenic region, and extends to the poly(A) addition site of the second gene (ESAG 6), thus bypassing the normal 3' splice site of the ESAG 6 mRNA. Since this transcript is spliced, we conclude that UV irradiation does not inhibit splicing but stabilizes unstable processing products. This demonstrates that at least some intergenic regions of the VSG gene expression site are continuously transcribed in accordance with a polycistronic transcription model

  10. ATLAS barrel hadron tile calorimeter: spacers plates mass production

    In this article we expose the main problems of the mass production of the so-called 'spacer plates' for the ATLAS Barrel Hadron Tile Calorimeter. We describe all practical solutions of these problems. Particularly we present the measurement procedures and calculation schemes we used for the spacers dimensions determination. The results of the calculations are presented

  11. Improvement of inhaler efficacy by home-made spacer.

    Sritara, P; Janvitayanuchit, S

    1993-12-01

    The delivery of aerosol from a metered dose inhaler (MDI) was reported to be more efficient with a spacer. Hence, a home-made spacer modified from a 950 ml low cost plastic bottle, was compared with a MDI and with a 750 ml imported spacer (Nebuhaler). On three consecutive days, at the same time of day, 20 adult patients with chronic asthma inhaled two puffs of terbutaline sulphate (0.5 mg), delivered from MDI alone, MDI with a 750 ml Nebuhlaer and MDI with a home-made spacer. The following measurements were made: forced expiratory volume in one second (FEV1), forced vital capacity (FVC) and pulse rate. These measurements were carried out immediately before and at 5, 20, 60 min after inhalation of terbutaline. FEV1 was significantly increased (P terbutaline with MDI via either spacers than with MDI alone but no significant difference was observed between Nebuhaler and the home-made spacer. FVC and pulse rate showed no significant change with each method of administration. In conclusion, terbutaline delivered by MDI and home-made spacer was more effective in bronchodilatation than by MDI alone and was just as effective as MDI and Nebuhaler. The home-made spacer therefore offers a simple, inexpensive and more effective method for delivering aerosol drug. PMID:7798822

  12. Detection of non-coding RNA genes by searching for transcription signals in intergenic regions. : Summary

    2004-01-01

    Detection of non-coding RNA genes by searching for transcription signals in intergenic regions. Background Non-coding RNA (ncRNA) genes produce transcripts that exert their function without ever being a recipe for proteins. ncRNA gene sequences, unlike protein coding genes, do not have strong transcription signals. This study was conducted to investigate a special version of a previously tested and suggested method of detecting RNAs. This study is a part of a larger project where m...

  13. CFD application to advanced design for high efficiency spacer grid

    Ikeda, Kazuo, E-mail: kazuo3_ikeda@ndc.mhi.co.jp

    2014-11-15

    Highlights: • A new LDV was developed to investigate the local velocity in a rod bundle and inside a spacer grid. • The design information that utilizes for high efficiency spacer grid has been obtained. • CFD methodology that predicts flow field in a PWR fuel has been developed. • The high efficiency spacer grid was designed using the CFD methodology. - Abstract: Pressurized water reactor (PWR) fuels have been developed to meet the needs of the market. A spacer grid is a key component to improve thermal hydraulic performance of a PWR fuel assembly. Mixing structures (vanes) of a spacer grid promote coolant mixing and enhance heat removal from fuel rods. A larger mixing vane would improve mixing effect, which would increase the departure from nucleate boiling (DNB) benefit for fuel. However, the increased pressure loss at large mixing vanes would reduce the coolant flow at the mixed fuel core, which would reduce the DNB margin. The solution is to develop a spacer grid whose pressure loss is equal to or less than the current spacer grid and that has higher critical heat flux (CHF) performance. For this reason, a requirement of design tool for predicting the pressure loss and CHF performance of spacer grids has been increased. The author and co-workers have been worked for development of high efficiency spacer grid using Computational Fluid Dynamics (CFD) for nearly 20 years. A new laser Doppler velocimetry (LDV), which is miniaturized with fiber optics embedded in a fuel cladding, was developed to investigate the local velocity profile in a rod bundle and inside a spacer grid. The rod-embedded fiber LDV (rod LDV) can be inserted in an arbitrary grid cell instead of a fuel rod, and has the advantage of not disturbing the flow field since it is the same shape as a fuel rod. The probe volume of the rod LDV is small enough to measure spatial velocity profile in a rod gap and inside a spacer grid. According to benchmark experiments such as flow velocity

  14. CFD application to advanced design for high efficiency spacer grid

    Highlights: • A new LDV was developed to investigate the local velocity in a rod bundle and inside a spacer grid. • The design information that utilizes for high efficiency spacer grid has been obtained. • CFD methodology that predicts flow field in a PWR fuel has been developed. • The high efficiency spacer grid was designed using the CFD methodology. - Abstract: Pressurized water reactor (PWR) fuels have been developed to meet the needs of the market. A spacer grid is a key component to improve thermal hydraulic performance of a PWR fuel assembly. Mixing structures (vanes) of a spacer grid promote coolant mixing and enhance heat removal from fuel rods. A larger mixing vane would improve mixing effect, which would increase the departure from nucleate boiling (DNB) benefit for fuel. However, the increased pressure loss at large mixing vanes would reduce the coolant flow at the mixed fuel core, which would reduce the DNB margin. The solution is to develop a spacer grid whose pressure loss is equal to or less than the current spacer grid and that has higher critical heat flux (CHF) performance. For this reason, a requirement of design tool for predicting the pressure loss and CHF performance of spacer grids has been increased. The author and co-workers have been worked for development of high efficiency spacer grid using Computational Fluid Dynamics (CFD) for nearly 20 years. A new laser Doppler velocimetry (LDV), which is miniaturized with fiber optics embedded in a fuel cladding, was developed to investigate the local velocity profile in a rod bundle and inside a spacer grid. The rod-embedded fiber LDV (rod LDV) can be inserted in an arbitrary grid cell instead of a fuel rod, and has the advantage of not disturbing the flow field since it is the same shape as a fuel rod. The probe volume of the rod LDV is small enough to measure spatial velocity profile in a rod gap and inside a spacer grid. According to benchmark experiments such as flow velocity

  15. Intergenic and repeat transcription in human, chimpanzee and macaque brains measured by RNA-Seq.

    Augix Guohua Xu

    Full Text Available Transcription is the first step connecting genetic information with an organism's phenotype. While expression of annotated genes in the human brain has been characterized extensively, our knowledge about the scope and the conservation of transcripts located outside of the known genes' boundaries is limited. Here, we use high-throughput transcriptome sequencing (RNA-Seq to characterize the total non-ribosomal transcriptome of human, chimpanzee, and rhesus macaque brain. In all species, only 20-28% of non-ribosomal transcripts correspond to annotated exons and 20-23% to introns. By contrast, transcripts originating within intronic and intergenic repetitive sequences constitute 40-48% of the total brain transcriptome. Notably, some repeat families show elevated transcription. In non-repetitive intergenic regions, we identify and characterize 1,093 distinct regions highly expressed in the human brain. These regions are conserved at the RNA expression level across primates studied and at the DNA sequence level across mammals. A large proportion of these transcripts (20% represents 3'UTR extensions of known genes and may play roles in alternative microRNA-directed regulation. Finally, we show that while transcriptome divergence between species increases with evolutionary time, intergenic transcripts show more expression differences among species and exons show less. Our results show that many yet uncharacterized evolutionary conserved transcripts exist in the human brain. Some of these transcripts may play roles in transcriptional regulation and contribute to evolution of human-specific phenotypic traits.

  16. Heat-transfer augmentation in rod bundles near grid spacers

    Heat-transfer augmentation by straight grid spacers in rod bundles is studied for single-phase flow and for post-critical heat flux dispersed flow. The heat transfer effect of swirling grid spacers in single-phase flow is also examined. Governing heat-transfer mechanisms are analyzed, and predictive formulations are established. For single-phase flow, the local heat transfer at a straight spacer and at its upstream or downstream locations are treated separately. The effect of local velocity increasing near swirling spacer is considered. For post critical heat flux (CHF) dispersed flow, the heat transfer by thermal radiation, fin cooling, and vapor convection near the spacer are calculated. The predictions are compared with experimental data with satisfactory agreement

  17. Molecular differentiation of Renibacterium salmoninarum isolates from worldwide locations.

    Grayson, T H; Cooper, L F; Atienzar, F A; Knowles, M R; Gilpin, M L

    1999-03-01

    Renibacterium salmoninarum is a genospecies that is an obligate pathogen of salmonid fish and is capable of intracellular survival. Conventional typing systems have failed to differentiate isolates of R. salmoninarum. We used two methods to assess the extent of molecular variation which was present in isolates from different geographic locations. In one analysis we investigated possible polymorphisms in a specific region of the genome, the intergenic spacer (ITS) region between the 16S and 23S rRNA genes. In the other analysis we analyzed differences throughout the genome by using randomly amplified polymorphic DNA (RAPD). We amplified the spacer region of 74 isolates by using PCR and performed a DNA sequence analysis with 14 geographically distinct samples. The results showed that the 16S-23S ribosomal DNA spacer region of R. salmoninarum is highly conserved and suggested that only a single copy of the rRNA operon is present in this slowly growing pathogen. DNA sequencing of the spacer region showed that it was the same length in all 14 isolates examined, and the same nucleotide sequence, sequevar 1, was obtained for 11 of these isolates. Two other sequevars were found. No tRNA genes were found. We found that RAPD analysis allows reproducible differentiation between isolates of R. salmoninarum obtained from different hosts and different geographic regions. By using RAPD analysis it was possible to differentiate between isolates with identical ITS sequences. PMID:10049848

  18. Preclinical Evaluation of Bioabsorbable Polyglycolic Acid Spacer for Particle Therapy

    Akasaka, Hiroaki [Division of Radiation Oncology, Kobe University Graduate School of Medicine, Hyogo Japan (Japan); Sasaki, Ryohei, E-mail: rsasaki@med.kobe-u.ac.jp [Division of Radiation Oncology, Kobe University Graduate School of Medicine, Hyogo Japan (Japan); Miyawaki, Daisuke; Mukumoto, Naritoshi; Sulaiman, Nor Shazrina Binti [Division of Radiation Oncology, Kobe University Graduate School of Medicine, Hyogo Japan (Japan); Nagata, Masaaki [Division of Gastroenterology, Kobe University Graduate School of Medicine, Hyogo Japan (Japan); Yamada, Shigeru [Research Center Hospital, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba (Japan); Murakami, Masao [Radiation Oncology Center, Dokkyo Medical University, Tochigi (Japan); Demizu, Yusuke [Department of Radiology, Hyogo Ion Beam Medical Center, Hyogo (Japan); Fukumoto, Takumi [Division of Hepato-Biliary-Pancreatic Surgery, Kobe University Graduate School of Medicine, Hyogo Japan (Japan)

    2014-12-01

    Purpose: To evaluate the efficacy and safety of a polyglycolic acid (PGA) spacer through physical and animal experiments. Methods and Materials: The spacer was produced with surgical suture material made of PGA, forming a 3-dimensional nonwoven fabric. For evaluation or physical experiments, 150-MeV proton or 320-MeV carbon-ion beams were used to generate 60-mm width of spread-out Bragg peak. For animal experiments, the abdomens of C57BL/6 mice, with or without the inserted PGA spacers, were irradiated with 20 Gy of carbon-ion beam (290 MeV) using the spread-out Bragg peak. Body weight changes over time were scored, and radiation damage to the intestine was investigated using hematoxylin and eosin stain. Blood samples were also evaluated 24 days after the irradiation. Long-term thickness retention and safety were evaluated using crab-eating macaques. Results: No chemical or structural changes after 100 Gy of proton or carbon-ion irradiation were observed in the PGA spacer. Water equivalency of the PGA spacer was equal to the water thickness under wet condition. During 24 days' observation after 20 Gy of carbon-ion irradiation, the body weights of mice with the PGA spacer were relatively unchanged, whereas significant weight loss was observed in those mice without the PGA spacer (P<.05). In mice with the PGA spacer, villus and crypt structure were preserved after irradiation. No inflammatory reactions or liver or renal dysfunctions due to placement of the PGA spacer were observed. In the abdomen of crab-eating macaques, thickness of the PGA spacer was maintained 8 weeks after placement. Conclusions: The absorbable PGA spacer had water-equivalent, bio-compatible, and thickness-retaining properties. Although further evaluation is warranted in a clinical setting, the PGA spacer may be effective to stop proton or carbon-ion beams and to separate normal tissues from the radiation field.

  19. Preclinical Evaluation of Bioabsorbable Polyglycolic Acid Spacer for Particle Therapy

    Purpose: To evaluate the efficacy and safety of a polyglycolic acid (PGA) spacer through physical and animal experiments. Methods and Materials: The spacer was produced with surgical suture material made of PGA, forming a 3-dimensional nonwoven fabric. For evaluation or physical experiments, 150-MeV proton or 320-MeV carbon-ion beams were used to generate 60-mm width of spread-out Bragg peak. For animal experiments, the abdomens of C57BL/6 mice, with or without the inserted PGA spacers, were irradiated with 20 Gy of carbon-ion beam (290 MeV) using the spread-out Bragg peak. Body weight changes over time were scored, and radiation damage to the intestine was investigated using hematoxylin and eosin stain. Blood samples were also evaluated 24 days after the irradiation. Long-term thickness retention and safety were evaluated using crab-eating macaques. Results: No chemical or structural changes after 100 Gy of proton or carbon-ion irradiation were observed in the PGA spacer. Water equivalency of the PGA spacer was equal to the water thickness under wet condition. During 24 days' observation after 20 Gy of carbon-ion irradiation, the body weights of mice with the PGA spacer were relatively unchanged, whereas significant weight loss was observed in those mice without the PGA spacer (P<.05). In mice with the PGA spacer, villus and crypt structure were preserved after irradiation. No inflammatory reactions or liver or renal dysfunctions due to placement of the PGA spacer were observed. In the abdomen of crab-eating macaques, thickness of the PGA spacer was maintained 8 weeks after placement. Conclusions: The absorbable PGA spacer had water-equivalent, bio-compatible, and thickness-retaining properties. Although further evaluation is warranted in a clinical setting, the PGA spacer may be effective to stop proton or carbon-ion beams and to separate normal tissues from the radiation field

  20. Analysis of US patents on spacer grids

    The total of 137 US patents on spacer grids patented from 1968 through 1993 are analyzed and summarized. Database is constituted with designing the appropriate fields by which each patent can be identified. The fields consist of patent number, inventor, assignee, date of patent, title and major foci of the patent. The major foci are again classified by detailed subjects such as the fretting failure and fuel rod support-related, the strength-related, the fabrication-related as for mechanical subjects, while the cooling performance-related and the pressure drop-related as for thermal-hydraulic one. The 92% of the patents analyzed were issued form nuclear companies of USA, France and Germany. Among the patents dealing with mechanical subjects, the fretting failure and fuel rod support-related is more than the pressure drop-related among the patents of thermal-hydraulic subjects. The number of patents issued from Japan ranks just after Germany i.e., the 4th country. It is thought that much concern as well as investment should be increased in this field, the patent of nuclear components. (author). 2 tabs., 5 figs

  1. Renibacterium salmoninarum isolates from different sources possess two highly conserved copies of the rRNA operon .

    Grayson, T H; Alexander, S M; Cooper, L F; Gilpin, M L

    2000-07-01

    The nucleotide sequences of the rRNA genes and the 5' flanking region were determined for R. salmoninarum ATCC 33209T from overlapping products generated by PCR amplification from the genomic DNA. Comparison of the sequences with rRNA genes from a variety of bacteria demonstrated the close relatedness between R. salmoninarum and the high G+C group of the actinobacteria, in particular, Arthrobacter species. A regulatory element within the 5' leader of the rRNA operon was identical to an element, CL2, described for mycobacteria. PCR, DNA sequence analysis, and DNA hybridisation were performed to examine variation between isolates from diverse sources which represented the four 16S-23S rRNA intergenic spacer sequevars previously described for R. salmoninarum. Two 23S-5S rRNA intergenic spacer sequevars of identical length were found. DNA hybridisation using probes complementary to 23S rDNA and 16S rDNA identified two rRNA operons which were identical or nearly identical amongst 40 isolates sourced from a variety of countries. PMID:11016696

  2. Erwinia pyrifoliae sp. nov., a novel pathogen that affects Asian pear trees (Pyrus pyrifolia Nakai)

    Kim, W S; Gardan, L; Rhim, S L; Geider, K

    1999-04-01

    A novel pathogen from Asian pears (Pyrus pyrifolia Nakai) was analysed by sequencing the 16S rDNA and the adjacent intergenic region, and the data were compared to related Enterobacteriaceae. The 16S rDNA of the Asian pear pathogen was almost identical with the sequence of Erwinia amylovora, in contrast to the 16S-23S rRNA intergenic transcribed spacer region of both species. A dendrogram was deduced from determined sequences of the spacer regions including those of several related species such as Erwinia amylovora, Enterobacter pyrinus, Pantoea stewartii subsp. stewartii and Escherichia coli. Dendrograms derived from 121 biochemical characteristics including Biotype 100 data placed the Asian pear pathogen close to Erwinia amylovora and more distantly to other members of the species Erwinia and to the species Pantoea and Enterobacter. Another DNA relatedness study was performed by DNA hybridizations and estimation of delta Tm values. The Asian pear strains constituted a tight DNA hybridization group (89-100%) and were barely related to strains of Erwinia amylovora (40-50%) with a delta Tm in the range of 5.2-6.8. The G + C content of DNA from the novel pathogen is 52 mol%. Therefore, it is proposed that strains isolated from Asian pears constitute a new species and the name Erwinia pyrifoliae is suggested; the type strain is strain Ep 16/96T (= CFBP 4172T = DSM 12163T). PMID:10319516

  3. Limitations and benefits of ARISA intra-genomic diversity fingerprinting.

    Popa, Radu; Popa, Rodica; Mashall, Matthew J; Nguyen, Hien; Tebo, Bradley M; Brauer, Suzanna

    2009-08-01

    Monitoring diversity changes and contamination in mixed cultures and simple microcosms is challenged by fast community structure dynamics, and the need for means allowing fast, cost-efficient and accurate identification of microorganisms at high phylogenetic resolution. The method we explored is a variant of Automated rRNA Intergenic Spacer Analysis based on Intra-Genomic Diversity Fingerprinting (ARISA-IGDF), and identifies phylotypes with multiple 16S-23S rRNA gene Intergenic Transcribed Spacers. We verified the effect of PCR conditions (annealing temperature, duration of final extension, number of cycles, group-specific primers and formamide) on ARISA-IGD fingerprints of 44 strains of Shewanella. We present a digitization algorithm and data analysis procedures needed to determine confidence in strain identification. Though using stringent PCR conditions and group-specific primers allow reasonably accurate identification of strains with three ARISA-IGD amplicons within the 82-1000 bp size range, ARISA-IGDF is best for phylotypes with >or=4 unambiguously different amplicons. This method allows monitoring the occurrence of culturable microbes and can be implemented in applications requiring high phylogenetic resolution, reproducibility, low cost and high throughput such as identifying contamination and monitoring the evolution of diversity in mixed cultures and low diversity microcosms and periodic screening of small microbial culture libraries. PMID:19538993

  4. A systematic search for new mammalian noncoding RNAs indicates little conserved intergenic transcription

    Blencowe Benjamin J

    2005-08-01

    Full Text Available Abstract Background Systematic identification and functional characterization of novel types of noncoding (ncRNA in genomes is more difficult than it is for protein coding mRNAs, since ncRNAs typically do not possess sequence features such as splicing or translation signals, or long open reading frames. Recent "tiling" microarray studies have reported that a surprisingly larger proportion of mammalian genomes is transcribed than was previously anticipated. However, these non-genic transcripts often appear to be low in abundance, and their functional significance is not known. Results To systematically search for functional ncRNAs, we designed microarrays to detect 3,478 intergenic and intronic sequences that are conserved between the human, mouse, and rat genomes, and that score highly by other criteria that characterize ncRNAs. We probed these arrays with total RNA isolated from 16 wild-type mouse tissues. Among 55 candidates for highly-expressed novel ncRNAs tested by northern blotting, eight were confirmed as small, highly-and ubiquitously-expressed RNAs in mouse. Of the eight, five were also detected in rat tissues, but none were detected at appreciable levels in human tissues or cultured cells. Conclusion Since the sequence and expression of most known coding transcripts and functional ncRNAs is conserved between human and mouse, the lack of northern-detectable expression in human cells and tissues of the novel mouse and rat ncRNAs that we identified suggests that they are not functional or possibly have rodent-specific functions. Our results confirm that relatively little of the intergenic sequence conserved between human, mouse and rat is transcribed at high levels in mammalian tissues, possibly suggesting a limited role for transcribed intergenic and intronic sequences as independent functional elements.

  5. Flow dynamics and concentration polarisation in spacer-filled channels

    Lipnizki, Jens; Jonsson, Gunnar Eigil

    2002-01-01

    been shown that the mass transport along the membrane is not fully described by the Sherwood correlation, which describes a decreasing mass transfer with an increasing distance from the inlet. It was observed that in open channel without spacers, the slope of the Sherwood correlation is decreasing by......The key to developing highly efficient spiral-wound modules is the improvement of the mass transfer mechanisms. In this study a study of the mass transfer has been carried out using a flat test cell with six permeate outlets and a rectangular feed channel. Using this experimental set-up, it has...... phenomenon was also observed in spacer-filled channels. In this case the stripes on the surface depended on the spacer geometry. Furthermore, the experiments were used to calculate the energy consumption vs. the mass transfer coefficient for different spacers. This research can be used as a foundation to...

  6. Response of an electrostatic probe for a right cylindrical spacer

    Rerup, T; Crichton, George C; McAllister, Iain Wilson

    1994-01-01

    During the last decade many experimental studies of surface charge phenomena have been undertaken employing right cylindrical spacers. Measurement of the surface charge was performed using small electrostatic field probes to scan across the dielectric surface. Charges are electrostatically induced...

  7. Intergenic DNA sequences flanking the pseudo alpha globin genes of human and chimpanzee.

    Sawada, I; Beal, M P; Shen, C K; Chapman, B.; Wilson, A C; Schmid, C.

    1983-01-01

    We have determined the sequence of 2400 base pairs upstream from the human pseudo alpha globin (psi alpha) gene, and for comparison, 1100 base pairs of DNA within and upstream from the chimpanzee psi alpha gene. The region upstream from the promoter of the psi alpha gene shows no significant homology to the intergenic regions of the adult alpha 2 and alpha 1 globin genes. The chimpanzee gene has a coding defect in common with the human psi alpha gene, showing that the product of this gene, if...

  8. Transcription and decay of the lac messenger: role of an intergenic terminator.

    Murakawa, G J; Kwan, C; Yamashita, J; Nierlich, D P

    1991-01-01

    Prior work has indicated that the polycistronic lacZYA mRNA of Escherichia coli is cleaved during decay at approximately intergenic sites (L. W. Lim and D. Kennell, J. Mol. Biol. 135: 369-390, 1979). In this work, we characterized the products by using probes specific for the different cistrons. This analysis indicated that six lac mRNA species are present in the following order of decreasing abundance: lacZ, -A, -ZYA, -ZY, -YA, and -Y. Very little lacYA and lacY mRNAs were present, whereas i...

  9. Sidewall spacer optimization for steep switching junctionless transistors

    Gupta, Manish; Kranti, Abhinav

    2016-06-01

    In this work, we analyze the impact of a high permittivity (high-κ) sidewall spacer and gate dielectric on the occurrence of sub-60 mV/decade subthreshold swing (S-swing) in symmetrical junctionless (JL) double gate (DG) transistors. It is shown that steep S-swing values (≤10 mV/decade) can be achieved in JL devices with a combination of a high permittivity (high-κ) gate dielectric and a narrow low permittivity (low-κ) sidewall spacer. Implementation of a wider high-κ spacer will diminish the degree of impact ionization by the influence of the fringing component of the gate electric field, and will not be useful for steep off-to-on current transition. A wider spacer with low-κ and a narrow spacer with high-κ permittivity will be useful to limit the latching effect that can occur at lower temperatures (250 K). For high temperature operation, the decrease in the impact ionization rate can be compensated by designing a JL transistor with a thicker silicon film. The work demonstrates opportunities to enhance impact ionization at sub bandgap voltages, and proposes optimal guidelines for selecting a sidewall spacer to facilitate steep switching in JL transistors.

  10. The potential of standard and modified feed spacers for biofouling control

    Araújo, Paula A.

    2012-06-01

    The impact of feed spacers on initial feed channel pressure (FCP) drop, FCP increase and biomass accumulation has been studied in membrane fouling simulators using feed spacers applied in commercially available nanofiltration and reverse osmosis spiral wound membrane modules. All spacers had a similar geometry.Our studies showed that biofouling was not prevented by (i) variation of spacer thickness, (ii) feed spacer orientation, (iii) feed spacer coating with silver, copper or gold and (iv) using a biostatic feed spacer. At constant feed flow, a lower FCP and FCP increase were observed for a thicker feed spacer. At constant linear flow velocity, roughly the same FCP development and biomass accumulation were found irrespective of the feed spacer thickness: hydrodynamics and substrate load were more important for development and impact of biofouling than the thickness of currently applied spacers. Use of biostatic and metal coated spacers were not effective for biofouling control. The same small reduction of biofouling rate was observed with copper and silver coated spacers as well as uncoated 45° rotated spacers.The studied modified spacers were not effective for biofouling prevention and control. The impact of biofouling on FCP increase was reduced significantly by a lower linear flow velocity, while spacer orientation and spacer thickness in membrane modules had a smaller but still significant effect. © 2012 Elsevier B.V.

  11. De Novo Identification of Regulatory Regions in Intergenic Spaces of Prokaryotic Genomes

    Chain, P; Garcia, E; Mcloughlin, K; Ovcharenko, I

    2007-02-20

    This project was begun to implement, test, and experimentally validate the results of a novel algorithm for genome-wide identification of candidate transcription-factor binding sites in prokaryotes. Most techniques used to identify regulatory regions rely on conservation between different genomes or have a predetermined sequence motif(s) to perform a genome-wide search. Therefore, such techniques cannot be used with new genome sequences, where information regarding such motifs has not yet been discovered. This project aimed to apply a de novo search algorithm to identify candidate binding-site motifs in intergenic regions of prokaryotic organisms, initially testing the available genomes of the Yersinia genus. We retrofitted existing nucleotide pattern-matching algorithms, analyzed the candidate sites identified by these algorithms as well as their target genes to screen for meaningful patterns. Using properly annotated prokaryotic genomes, this project aimed to develop a set of procedures to identify candidate intergenic sites important for gene regulation. We planned to demonstrate this in Yersinia pestis, a model biodefense, Category A Select Agent pathogen, and then follow up with experimental evidence that these regions are indeed involved in regulation. The ability to quickly characterize transcription-factor binding sites will help lead to a better understanding of how known virulence pathways are modulated in biodefense-related organisms, and will help our understanding and exploration of regulons--gene regulatory networks--and novel pathways for metabolic processes in environmental microbes.

  12. Cultivar-level phylogeny using chloroplast DNA barcode psbK-psbI spacers for identification of Emirati date palm (Phoenix dactylifera L.) varieties.

    Enan, M R; Ahmed, A

    2016-01-01

    The efficacy of genetic material for use as DNA barcodes is under constant evaluation and improvement as new barcodes offering better resolution and efficiency of amplification for specific species groups are identified. In this study, the chloroplast intergenic spacer psbK-psbI was evaluated for the first time as a DNA barcode for distinguishing date palm cultivars. Nucleotide sequences were aligned using MEGA 6.0 to calculate pairwise divergence among the cultivars. The analyzed data illustrated a considerable level of variability in the genetic pool of the selected cultivars (0.009). In fact, five haplotypes were detected among 30 cultivars examined, yielding a haplotype diversity of 0.685. An unweighted pair group method with arithmetic mean phylogenetic tree was constructed and shows a well-defined relationship among date palm cultivar varieties. On the other hand, selective neutrality investigations using Tajima test and Fu and Li tests were negative, providing evidence that date palm has been undergoing rapid expansion and recent population growth. Thus, we suggest that the psbK-psbI spacer can be successfully used to construct reliable phylogenetic trees for P. dactylifera. PMID:27525916

  13. Molecular Profiling of Microbial Communities from Contaminated Sources: Use of Subtractive Cloning Methods and rDNA Spacer Sequences; FINAL

    The major objective of this research was to provide appropriate sequences and assemble a DNA array of oligonucleotides to be used for rapid profiling of microbial populations from polluted areas and other areas of interest. The sequences to be assigned to the DNA array were chosen from cloned genomic DNA taken from groundwater sites having well characterized pollutant histories at Hanford Nuclear Plant and Lawrence Livermore Site 300. Glass-slide arrays were made and tested; and a new multiplexed, bead-based method was developed that uses nucleic acid hybridization on the surface of microscopic polystyrene spheres to identify specific sequences in heterogeneous mixtures of DNA sequences. The test data revealed considerable strain variation between sample sites showing a striking distribution of sequences. It also suggests that diversity varies greatly with bioremediation, and that there are many bacterial intergenic spacer region sequences that can indicate its effects. The bead method exhibited superior sequence discrimination and has features for easier and more accurate measurement

  14. Molecular Profiling of Microbial Communities from Contaminated Sources: Use of Subtractive Cloning Methods and rDNA Spacer Sequences

    Robb, Frank T.

    2001-04-10

    The major objective of this research was to provide appropriate sequences and assemble a DNA array of oligonucleotides to be used for rapid profiling of microbial populations from polluted areas and other areas of interest. The sequences to be assigned to the DNA array were chosen from cloned genomic DNA taken from groundwater sites having well characterized pollutant histories at Hanford Nuclear Plant and Lawrence Livermore Site 300. Glass-slide arrays were made and tested; and a new multiplexed, bead-based method was developed that uses nucleic acid hybridization on the surface of microscopic polystyrene spheres to identify specific sequences in heterogeneous mixtures of DNA sequences. The test data revealed considerable strain variation between sample sites showing a striking distribution of sequences. It also suggests that diversity varies greatly with bioremediation, and that there are many bacterial intergenic spacer region sequences that can indicate its effects. The bead method exhibited superior sequence discrimination and has features for easier and more accurate measurement.

  15. Spacer grid effect during reflood in an annulus geometry

    Full text of publication follows: Understanding the mechanisms by which hot fuel rods quench is important for the analysis of the reflooding phase of a postulated loss-of coolant accident (LOCA). In the LOCA condition, thermal energy generated from the fuel rod would overheat the fuel elements beyond the safe design temperature limit and result in the severe accident. A higher surface temperature of the fuel bundles than the rewetting temperature would prevent liquid droplet from attaching to the hot fuel rod surface and the heat transfer mechanism involved becomes quite complicated. A number of studies on the reflooding phase had been actively carried out at the early 70's due to its importance for the safety of the nuclear reactor. However, few studies have presented the spacer grid effect during the reflooding period. In the present work phenomena during the reflooding phase have been investigated by visual observation method. The present study is precursory one to 6 x 6 bundle reflood test, which will be launched at the near future by KAERI to investigate the Dispersed Flow Film Boiling heat transfer and the spacer grid effect with accuracy. An experimental study has been performed to investigate an effect of spacer grid in an annulus flow channel with flat power shape single rod during the bottom reflooding phase with the variation of flooding velocity, inlet subcooling of water, and initial temperature of heater surface. The test parameters range 2∼8 cm/s of flooding velocity, 20∼80 deg. C of inlet subcooling temperature, and 500∼700 deg. C of initial wall temperature. The test section consisted of single heater rod whose outer diameter is 9.54 mm, three pieces of Pyrex tube assembly for the visual observation, and instruments for temperature and static pressure. The total length of visual part is 2.1 m and the inner diameter of Pyrex tube is 20 mm. Two types of spacer grid have been used. The present study has been performed at the atmospheric pressure

  16. Species markers for equine strongyles detected in intergenic rDNA by PCR-RFLP.

    Gasser, R B; Stevenson, L A; Chilton, N B; Nansen, P; Bucknell, D G; Beveridge, I

    1996-10-01

    Five species of equine strongyle belonging to the subfamily Strongylinae (Strongylus edentatus, S. equinus, S. vulgaris, Oesophagodontus robustus and Triodontophorus serratus) and 11 species belonging to the subfamily Cyathostominae (Poteriostomum imparidentatum, P. ratzii, Cylicocyclus insignis, Cc. leptostomus, Cc. nassatus, Cylicostephanus calicatus, Cs. longibursatus, Cs. goldi, Cyathostomum catinatum, Cy. labiatum and Cy. pateratum) were characterized using a polymerase chain reaction-linked restriction fragment length polymorphism technique (PCR-RFLP). Internal transcribed spacer ribosomal DNA was amplified from genomic DNA by polymerase chain reaction (PCR) using conserved primers, digested separately with six restriction endonucleases (AluI, BfaI, CfoI, Hae III, VSpI and XbaI) and the fragments separated by agarose gel electrophoresis. The PCR products of the three Strongylus species were approx. 90-100 bp smaller in size compared with those of the other 13 species. The PCR-RFLP analysis of the rDNA region spanning the first and second internal transcribed spacers plus the 5.85 rDNA gene (ITS+) produced characteristic patterns for each of the 16 species examined, and no variation in RFLP patterns was detected within the species Cy. catinatum, where multiple isolates were analysed. The study demonstrates that the internal transcribed spacer sequences provide genetic markers for the species identification of a range of equine strongyles. These markers will be of use for the identification of egg and larval stages, where morphological characters alone are unreliable. The results also indicate that the spacer sequences will be of use to study the systematics of equine strongyles. PMID:8910892

  17. Impact of spacer thickness on biofouling in forward osmosis

    Valladares Linares, Rodrigo

    2014-06-01

    Forward osmosis (FO) indirect desalination systems integrate wastewater recovery with seawater desalination. Niche applications for FO systems have been reported recently, due to the demonstrated advantages compared to conventional high-pressure membrane processes such as nanofiltration (NF) and reverse osmosis (RO). Among them, wastewater recovery has been identified to be particularly suitable for practical applications. However, biofouling in FO membranes has rarely been studied in applications involving wastewater effluents. Feed spacers separating the membrane sheets in cross-flow systems play an important role in biofilm formation. The objective of this study was to determine the influence of feed spacer thickness (28, 31 and 46mil) on biofouling development and membrane performance in a FO system, using identical cross-flow cells in parallel studies. Flux development, biomass accumulation, fouling localization and composition were determined and analyzed. For all spacer thicknesses, operated at the same feed flow and the same run time, the same amount of biomass was found, while the flux reduction decreased with thicker spacers. These observations are in good agreement with biofouling studies for RO systems, considering the key differences between FO and RO. Our findings contradict previous cross-flow studies on particulate/colloidal fouling, where higher cross-flow velocities improved system performance. Thicker spacers reduced the impact of biofouling on FO membrane flux. © 2014 Elsevier Ltd.

  18. Zircaloy spacer grid for boiling light water reactors

    The need to increase the neutronic efficiency of the new cores of BWR's, lead to study types of spacer-grids made of low neutronic absorption materials as zircaloy-4. The particular mechanical behaviour of this material suggested to design a spacer-grids such as to utilize only blanking, slotting and bending operations as plastic forming and to avoid therefore drawing effects. The optimization of the bending procedures lead to a final spacer-grids configuration equally stiff in all directions and planes. Only for the ''elastic constraints'' nichel alloy sheets were used to made easy the whole spacer design. The ''rigid constraints'', supporting the rods, have been obtained directly from the spacer structure. Calculations were performed to verify the mechanical strength of the main grid components. In this framework a computer code was developed to find the best elastic characteristic of the ''elastic constraints'' taking into account the machining tolerances. Some original methods to test the integral behaviour of the grid assembled as well as the procedures to be adopted for its best maintenance, are described

  19. Numerical analysis of the spacer grids' compression strength

    Among the components of the fuel assembly, the spacer grids play an important structural role during the energy generation process, mainly for their requirement to have enough structural strength to withstand lateral impact loads, due to fuel assembly shipping/handling and due to forces outcome from postulated accidents (earthquake and LOCA). This requirement ensures a proper geometry for cooling and for guide thimble straightness in the fuel assembly. In this way, the understanding of the macroscopic mechanical behavior of this component becomes essential even to any subsequent geometrical modifications to optimize the flue assemblies' structural behavior. In the present work, three-dimensional finite element models destined to provide consistent predictions of 16X16-type spacer grids lateral strength were proposed. Firstly, buckling tests based on results available in the literature were performed to establish a methodology for spacer grid finite element-based modeling. The, by considering a spacer grid interesting geometry and some possible variations associated to its fabrication, tolerance, the proposed numerical models were submitted to compression conditions to calculate the buckling force. Also, these models were validated for comparison with experimental buckling load results. Comparison of buckling predictions combined to observations of actual and simulated deformed spacer grids geometries permitted to verify the consistency and applicability of the proposed models. Thus, these numerical results show a good agreement between the and the experimental results. (author)

  20. Composite spacer with inconel grid and zircaloy band

    Johansson, E.B.; Matzner, B.; Latter, G.M.

    1992-02-18

    This patent describes a spacer for use in a nuclear fuel bundle having a plurality of fuel rods. It includes spring metal spacer cells, each cell having: at least one spring leg, the spring leg inwardly deflected at the medial portion thereof for spring contact with a fuel rod within the spacer cell; at least two rod encircling arms affixed at remote ends of the spring legs; each rod encircling arm defining stops for abutting a fuel rod whereby the spring leg can bias an encircled fuel rod within the cells into the stops; the rod encircling arms having differential length including a first portion of the arms having a relatively longer length and a second portion of the arms having a relatively shorter length; the cells confronted into cell pairs with the spring legs remote from one another.

  1. Effect of a spacer moiety on radiometal labelled Neurotensin derivatives

    Mascarin, A.; Valverde, I.E.; Mindt, T.L. [Univ. of Basel Hospital (Switzerland). Div. of Radiopharmaceutical Chemistry

    2013-07-01

    The binding sequence of the regulatory peptide Neurotensin, NT(8-13), represents a promising tumour-specific vector for the development of radiopeptides useful in nuclear oncology for the diagnosis (imaging) and therapy of cancer. A number of radiometal-labelled NT(8-13) derivatives have been reported, however, the effect of the spacer which connects the vector with the radiometal complex has yet not been investigated systematically. Because a spacer moiety can influence potentially important biological characteristics of radiopeptides, we synthesized three [DOTA({sup 177}Lu)]-X-NT(8-13) derivatives and evaluated the effect of a spacer (X) on the physico-chemical properties of the conjugate including lipophilicity, stability, and in vitro receptor affinity and cell internalization. (orig.)

  2. A non-electrostatic spacer for aerosol delivery

    Bisgaard, H; Anhøj, J; Klug, B;

    1995-01-01

    pressurised metered dose inhaler (p-MDI) to minimise the electrostatic charge on the plastic. The procedure prolonged the half life (t1/2) of the aerosol in the Nebuhaler from nine to 32 seconds. A normal cleaning procedure reduced the aerosol t1/2 back to baseline. The t1/2 of the aerosol in the metal spacer...... to 6 years, suspected to have asthma the non-electrostatic spacer delivered a mean total dose of budesonide aerosol of 39% of the nominal dose, which was significantly higher than the Babyhaler (28%), the Nebuhaler (21%), and the AeroChamber (19%). These differences were most pronounced in children......-electro-static spacer should improve the cost effectiveness of aerosol treatment and, as the counteracting effects of proming and recharging of the plastic from cleaning are avoided, should deliver a more reliable dose....

  3. Spacer for fuel rods in nuclear fuel elements

    Spacers for fuel rods in nuclear reactor fuel elements are described, especially for use aboard ships. Spacers are used in a grid formed by web plates orthogonally intersecting and assembled together in a tooth-comb fashion forming a plurality of channels. The web plates are joined together and each of the web plates includes apertures through which resilient and separator members are joined. The resilient and separator members are joined. The resilient and separator members are in adjacent channels and with other similar members in the same channel, contact a fuel rod in the channel. The contact pressure between the members and fuel rod is radially directed

  4. Lower end fitting debris collector and end cap spacer grid

    This patent describes a nuclear reactor having fuel assemblies including an upper end fitting and spaced nuclear fuel rod spacer grids for supporting and spacing a plurality of elongated nuclear fuel rods. Each includes a hollow active portion of nuclear fuel filled cladding intermediate the rod ends and tapering end cap of solid material with a circumferential groove on the rod end which first encounters reactor coolant flow, a lower end filtering debris collector and end cap spacer grid for capturing and retaining deleterious debris carried by reactor coolant before it enters the active region of a fuel assembly and creates fuel rod cladding damage

  5. Molecular Analysis of Promoter and Intergenic Region Attenuator of the Vibrio vulnificus prx1ahpF Operon.

    Lee, Hyun Sung; Lim, Jong Gyu; Han, Kook; Lee, Younghoon; Choi, Sang Ho

    2015-08-01

    Prx1, an AhpF-dependent 2-Cys peroxiredoxin (Prx), was previously identified in Vibrio vulnificus, a facultative aerobic pathogen. In the present study, transcription of the V. vulnificus prx1ahpF genes, which are adjacently located on the chromosome, was evaluated by analyzing the promoter and intergenic region of the two genes. Northern blot analyses revealed that transcription of prx1ahpF results in two transcripts, the prx1 and prx1ahpF transcripts. Primer extension analysis and a point mutational analysis of the promoter region showed that the two transcripts are generated from a single promoter. In addition, the 3' end of the prx1 transcript at the prx1ahpF intergenic region was determined by a 3'RACE assay. These results suggested that the prx1ahpF genes are transcribed as an operon, and the prx1 transcript was produced by transcriptional termination in the intergenic region. RNA secondary structure prediction of the prx1ahpF intergenic region singled out a stem-loop structure without poly(U) tract, and a deletion analysis of the intergenic region showed that the atypical stem-loop structure acts as the transcriptional attenuator to result in the prx1 and prx1ahpF transcripts. The combined results demonstrate that the differential expression of prx1 and ahpF is accomplished by the cis-acting transcriptional attenuator located between the two genes and thereby leads to the production of a high level of Prx1 and a low level of AhpF. PMID:25824432

  6. A small intergenic region drives exclusive tissue-specific expression of the adjacent genes in Arabidopsis thaliana

    Valle Estela M

    2009-10-01

    Full Text Available Abstract Background Transcription initiation by RNA polymerase II is unidirectional from most genes. In plants, divergent genes, defined as non-overlapping genes organized head-to-head, are highly represented in the Arabidopsis genome. Nevertheless, there is scarce evidence on functional analyses of these intergenic regions. The At5g06290 and At5g06280 loci are head-to-head oriented and encode a chloroplast-located 2-Cys peroxiredoxin B (2CPB and a protein of unknown function (PUF, respectively. The 2-Cys peroxiredoxins are proteins involved in redox processes, they are part of the plant antioxidant defence and also act as chaperons. In this study, the transcriptional activity of a small intergenic region (351 bp shared by At5g06290 and At5g06280 in Arabidopsis thaliana was characterized. Results Activity of the intergenic region in both orientations was analyzed by driving the β-glucuronidase (GUS reporter gene during the development and growth of Arabidopsis plants under physiological and stressful conditions. Results have shown that this region drives expression either of 2cpb or puf in photosynthetic or vascular tissues, respectively. GUS expression driven by the promoter in 2cpb orientation was enhanced by heat stress. On the other hand, the promoter in both orientations has shown similar down-regulation of GUS expression under low temperatures and other stress conditions such as mannitol, oxidative stress, or fungal elicitor. Conclusion The results from this study account for the first evidence of an intergenic region that, in opposite orientation, directs GUS expression in different spatially-localized Arabidopsis tissues in a mutually exclusive manner. Additionally, this is the first demonstration of a small intergenic region that drives expression of a gene whose product is involved in the chloroplast antioxidant defence such as 2cpb. Furthermore, these results contribute to show that 2cpb is related to the heat stress defensive system

  7. Shelf life of pie caps with biodegradable films as spacers

    Daniela Verónica Escobar Gianni

    2013-01-01

    Full Text Available Commonly pie caps at market use polyethylene films as spacers between them. This paper studies the conventional spacers replacement with edible and biodegradable films made with whey protein isolate (WPI and potassium sorbate as a preservative. Besides facilitating the separation of pie caps, with this application is intended to increase their shelf life. The films made by the compression molding method were used as spacers in pie caps without preservative in their formula (A and with preservative (B and they were compared with conventional polyethylene spacers (C. During four months, monthly sensory, microbiological and physicochemical (humidity evaluations were done on the pie caps, together with humidity and solubility evaluations of the films. None of the samples showed microbiological or sensory deterioration. The sensory attributes showed no or slight difference in study time. Between samples the differences were minor: the best scores were for sample A in color, sample C in flavor, and samples B and C in texture and overall liking. The edible films have an interesting potential for this application, although studies in disguise the flavor of serum should be done.

  8. CRISPR interference and priming varies with individual spacer sequences

    Xue, Chaoyou; Seetharam, Arun S.; Musharova, Olga; Severinov, Konstantin; Brouns, Stan J.J.; Severin, Andrew J.; Sashital, Dipali G.

    2015-01-01

    CRISPR-Cas (clustered regularly interspaced short palindromic repeats-CRISPR associated) systems allow bacteria to adapt to infection by acquiring 'spacer' sequences from invader DNA into genomic CRISPR loci. Cas proteins use RNAs derived from these loci to target cognate sequences for destructio

  9. Distance dependence of intramolecular electron transfer through rigid hydrocarbon spacers

    The effects of energy, distance and molecular structure on rates of electron transfer between molecules are the subjects of continuing investigations in the authors laboratory. The use of rigid molecular spacers between electron donor and acceptor groups facilitates study of the above questions, and is a promising method to obtain energy storage with directed charge separation. Here they present recent results focusing principally on the effects of distance through rigid hydrocarbon spacers. Through-bond interaction is the dominant source of the electronic coupling which enables electron transfer to occur in a series of molecules of the type D-S-A. Pulse radiolysis measurements used molecules D (donor) = biphenyl and A (acceptor) = naphthalene attached to a series of spacer molecules, S, having 3,4,6,7 or 10 saturated hydrocarbon bonds between the D and A groups. The spacer groups were 1,3-cyclohexane (three bonds), 1,4-cyclohexane (four bonds), 2,7-decalin (six bonds), 2,6-decalin (seven bonds) and 3,16-androstance (ten bonds). They attached electrons to these molecules using Argonne's picosecond Linac and measured electron transfer rates (ET) from 3.5 x 109s-1 across three bonds to 1.5 x 106s-1 across ten bonds. The clearest understanding of the rates is obtained by comparing the electronic-coupling interactions. The electronic interactions decrease regularly with increasing number of bonds, but do not correlate very well with either edge-to-edge or center-to-center distance

  10. Implementation of spacer therapy for acute asthma in children.

    Vandeleur, M

    2009-09-01

    The aim was to develop and implement an evidence based guideline for the treatment of acute asthma using a metered dose inhaler and spacer combination. Children admitted to Cork University Hospital Paediatric Department with acute asthma were identified during two identical 2 month seasonal periods before (2005) and after (2006) implementation of the new guidelines in September 2006. Pre-intervention and post-intervention audits by case note review were performed to determine the impact of and compliance with this evidence-based guideline emphasising patient assessment, spacer delivered bronchodilator and specific discharge criteria. Patients had similar characteristics during the two study periods. There was a raised threshold for admission after guideline implementation with 11\\/52 patients having mild exacerbations in 2006, compared to 21\\/36 in 2005. Duration of admission was less in the post-implementation group for equivalent exacerbation severity e.g. for moderate severity; 28 hours in 2005, 23 hours in 2006. Duration of bronchodilator therapy was shorter in 2006 and more likely to be given by spacer device earlier for equivalent levels of severity e.g. for moderate exacerbations, in 2006 the average length of salbutamol therapy was 18 hours with 12 hours by spacer device, in 2005 the average length of therapy was 25 hours with 3 hours by spacer. There was earlier initiation of oral corticosteroids; the average time to administration was 56 minutes in 2006 and 227 minutes in 2005. There was an improved documentation of asthma education in 2006 e.g. inhaler technique was reviewed in 37\\/52 in 2006, 21\\/35 in 2005 and better use of written action plans.

  11. HYDROELASTIC VIBRATIONS AND LIQUID SLOSHING SUPPRESSION IN A RECTANGULAR TANK WITH ELASTIC SPACER

    CHENG Xu-duo; LIANG Yong; WEN Ji-hua

    2004-01-01

    In this paper, the couple vibration of liquid and elastic spacer in a rectangular tank is investigated. Two different velocity potential functions corresponding respectively to the liquid above and below the elastic spacer are assumed. Complicated boundary conditions corresponding to two velocity potential functions and vibrations of elastic spacer are given. Using the method of energy, the equation of couple frequency is obtained. Through numerical computation the natural frequencies that change according to the location and stiffness of the spacer are shown.

  12. Effect of spacer layers on current-voltage characteristics of resonant-tunneling diode

    Using the numerical solution to the Schroedinger equation, current-voltage characteristics of the resonant-tunneling diode with spacer layers were obtained. The dependences of the peak current of the resonant-tunneling diode on the emitter spacer width were plotted. It was shown that the peak current depends periodically on the emitter spacer width. The constructed electron density diagrams showed that the increase in the peak current is associated with the resonant level in the emitter spacer region.

  13. Comparative lung bioavailability of fluticasone/salmeterol via a breath-actuated spacer and conventional plastic spacers

    Nair, Arun; McKinlay, Lorna; Williamson, Peter; Short, Philip; Burns, Patricia; Lipworth, Brian J

    2011-01-01

    Abstract Purpose This study compares the in vivo relative lung bioavailability of Hydrofluoroalkane (HFA) Seretide delivered via unprimed and unwashed Aerochamber Plus (AP) or Volumatic (VM) spacers, a integrated breath-actuated vortex Synchro-Breathe (SB) device and an Evohaler pMDI (EH) device using adrenal suppression and early fall in serum potassium (K) as surrogates for respirable dose. Methods Seven...

  14. Effects of spacer length and terminal group on the crystallization and morphology of biscarbamates: a longer spacer does not reduce the melting temperature.

    Khan, Mostofa Kamal; Sundararajan, Pudupadi R

    2013-05-01

    The effects of alkyl side chain and spacer lengths and the type of terminal group on the morphology and crystallization of a homologous series of biscarbamates (model compounds for polyurethanes) were investigated. Biscarbamates were synthesized with alkyl side chains of various lengths ranging from C4 to C18 and an alkyl spacer group with 12 CH2 units (C12 spacer) between the two hydrogen bonding motifs. The crystallization and morphological features are compared with the previously studied biscarbamates with a C6 spacer. As a token example, we also studied a biscarbamate molecule in which the terminal methyl group was replaced by a phenyl group. We stress four important conclusions of the study: (1) A number of studies in the literature found that the longer alkyl spacers reduced the thermal transition temperatures of the molecules, and such behavior was attributed to an increase in the flexibility of the alkyl spacer. However, the results of the present study are to the contrary. With the biscarbamates studied here, the hydrogen-bonding groups on both sides of the C12 spacer act as "anchors", and the longer spacer does not reduce the melting temperatures compared with those with the C6 spacer. (2) The melt viscosity measurements show shear-thinning behavior, which has been mostly observed with polysaccharides and hydrogen-bonded polymers. (3) Avrami analysis shows a two-stage crystallization, which is not commonly observed in organic small molecule systems. (4) The phenyl end group does not add another self-assembly code in terms of π-stacking but acts as a defect. While formation of crystals was observed for biscarbamates with short alkyl side chains with a C6 spacer, an increase in spacer length to C12 induces spherulitic morphology. Although the overall sizes of the spherulites are the same for both spacers, the rate of spherulite growth was higher and the crystallization rate was lower with the C12 spacer compared with the C6 spacer. In contrast with the

  15. Comparative Expression Dynamics of Intergenic Long Noncoding RNAs in the Genus Drosophila.

    Nyberg, Kevin G; Machado, Carlos A

    2016-01-01

    Thousands of long noncoding RNAs (lncRNAs) have been annotated in eukaryotic genomes, but comparative transcriptomic approaches are necessary to understand their biological impact and evolution. To facilitate such comparative studies in Drosophila, we identified and characterized lncRNAs in a second Drosophilid-the evolutionary model Drosophila pseudoobscura Using RNA-Seq and computational filtering of protein-coding potential, we identified 1,589 intergenic lncRNA loci in D. pseudoobscura We surveyed multiple sex-specific developmental stages and found, like in Drosophila melanogaster, increasingly prolific lncRNA expression through male development and an overrepresentation of lncRNAs in the testes. Other trends seen in D. melanogaster, like reduced pupal expression, were not observed. Nonrandom distributions of female-biased and non-testis-specific male-biased lncRNAs between the X chromosome and autosomes are consistent with selection-based models of gene trafficking to optimize genomic location of sex-biased genes. The numerous testis-specific lncRNAs, however, are randomly distributed between the X and autosomes, and we cannot reject the hypothesis that many of these are likely to be spurious transcripts. Finally, using annotated lncRNAs in both species, we identified 134 putative lncRNA homologs between D. pseudoobscura and D. melanogaster and find that many have conserved developmental expression dynamics, making them ideal candidates for future functional analyses. PMID:27189981

  16. RNA structure-based ribosome recruitment: lessons from the Dicistroviridae intergenic region IRESes.

    Pfingsten, Jennifer S; Kieft, Jeffrey S

    2008-07-01

    In eukaryotes, the canonical process of initiating protein synthesis on an mRNA depends on many large protein factors and the modified nucleotide cap on the 5' end of the mRNA. However, certain RNA sequences can bypass the need for these proteins and cap, using an RNA structure-based mechanism called internal initiation of translation. These RNAs are called internal ribosome entry sites (IRESes), and the cap-independent initiation pathway they support is critical for successful infection by many viruses of medical and economic importance. In this review, we briefly describe and compare mechanistic and structural groups of viral IRES RNAs, focusing on those IRESes that are capable of direct ribosome recruitment using specific RNA structures. We then discuss in greater detail some recent advances in our understanding of the intergenic region IRESes of the Dicistroviridae, which use the most streamlined ribosome-recruitment mechanism yet discovered. By combining these findings with knowledge of canonical translation and the behavior of other IRESes, mechanistic models of this RNA structure-based process are emerging. PMID:18515544

  17. Conservation and diversity among the three-dimensional folds of the Dicistroviridae intergenic region IRESes.

    Pfingsten, Jennifer S; Costantino, David A; Kieft, Jeffrey S

    2007-07-27

    Internal ribosome entry site (IRES) RNAs are necessary for successful infection of many pathogenic viruses, but the details of the RNA structure-based mechanism used to bind and manipulate the ribosome remain poorly understood. The IRES RNAs from the Dicistroviridae intergenic region (IGR) are an excellent model system to understand the fundamental tenets of IRES function, requiring no protein factors to manipulate the ribosome and initiate translation. Here, we explore the architecture of four members of the IGR IRESes, representative of the two divergent classes of these IRES RNAs. Using biochemical and structural probing methods, we show that despite sequence variability they contain a common three-dimensional fold. The three-dimensional architecture of the ribosome binding domain from these IRESes is organized around a core helical scaffold, around which the rest of the RNA molecule folds. However, subtle variation in the folds of these IRESes and the presence of an additional secondary structure element suggest differences in the details of their manipulation of the large ribosomal subunit. Overall, the results demonstrate how a conserved three-dimensional RNA fold governs ribosome binding and manipulation. PMID:17544444

  18. Disruption of a Large Intergenic Noncoding RNA in Subjects with Neurodevelopmental Disabilities

    Talkowski, Michael E.; Maussion, Gilles; Crapper, Liam; Rosenfeld, Jill A.; Blumenthal, Ian; Hanscom, Carrie; Chiang, Colby; Lindgren, Amelia; Pereira, Shahrin; Ruderfer, Douglas; Diallo, Alpha B.; Lopez, Juan Pablo; Turecki, Gustavo; Chen, Elizabeth S.; Gigek, Carolina; Harris, David J.; Lip, Va; An, Yu; Biagioli, Marta; MacDonald, Marcy E.; Lin, Michael; Haggarty, Stephen J.; Sklar, Pamela; Purcell, Shaun; Kellis, Manolis; Schwartz, Stuart; Shaffer, Lisa G.; Natowicz, Marvin R.; Shen, Yiping; Morton, Cynthia C.; Gusella, James F.; Ernst, Carl

    2012-01-01

    Large intergenic noncoding (linc) RNAs represent a newly described class of ribonucleic acid whose importance in human disease remains undefined. We identified a severely developmentally delayed 16-year-old female with karyotype 46,XX,t(2;11)(p25.1;p15.1)dn in the absence of clinically significant copy number variants (CNVs). DNA capture followed by next-generation sequencing of the translocation breakpoints revealed disruption of a single noncoding gene on chromosome 2, LINC00299, whose RNA product is expressed in all tissues measured, but most abundantly in brain. Among a series of additional, unrelated subjects referred for clinical diagnostic testing who showed CNV affecting this locus, we identified four with exon-crossing deletions in association with neurodevelopmental abnormalities. No disruption of the LINC00299 coding sequence was seen in almost 14,000 control subjects. Together, these subjects with disruption of LINC00299 implicate this particular noncoding RNA in brain development and raise the possibility that, as a class, abnormalities of lincRNAs may play a significant role in human developmental disorders. PMID:23217328

  19. The polymethylmethacrylate antibiotic spacer for treatment of joint infection

    Manuel Bondi

    2014-09-01

    Full Text Available Joint prostheses chronic infection requires surgical removal of the implant, in order to eradicate the infection process. The Polymethylmethacrylate (PMMA bone cement is a good carrier for the sustained antibiotic release at the site of infection. PMMA cements pre-loaded with antibiotics are utilized for prophylaxis, primary surgical procedure and the treatment of prosthetic joint infections. The mechanical and functional characteristics of the spacers allow a good joint range of motion, weight-bearing in selected cases and a sustained release of antibiotic at the site of infection. These drug delivery systems offer the advantage of local release of high antibiotic concentrations, which considerably exceed those obtained after systemic administration. Nowadays treatment with a preformed antibiotic loaded spacer can be considered a good option for joint prostheses infection maintaining joint function at the intermediate stage in two-stage treatment.

  20. Molecular Epidemiology and Sequencing of the G-L Intergenic Region of Rabies Viruses Isolated in China

    Sheng-Li MENG; QI-You XIAO; Guan-Mu DONG; Ge-Lin XU; Jia-Xin YAN; Ping-Gang MING; Jie WU; Xiao-Ming YANG; He-Tian MING; Feng-Cai ZHU; Dun-Jin ZHOU

    2007-01-01

    A group of 25 rabies viruses (RABVs),recovered from 24 dogs and one human case,were collected from various areas in China between 2004 and 2006.Genetic and phylogenetic analyses of the G-L intergenic region were carried out in 25 street RABV isolates and CTN vaccine strains of 7 generations.The study was based on the comparison of a 519 bp nucleotide sequence,encompassing the G-L intergenic region.The nucleotide sequence homologies of Chinese street strains were from 95.5% to 100%.The phylogenetic analysis showed that all Chinese isolates clearly supported the placement of all Chinese viruses in Lyssavirus genotype 1 and they were distributed according to their geographical origins.All of the Chinese strains were closely related but they could still be divided into two groups:group of street strains and group of CTN strains.This study presents details about the molecular epidemiology of rabies viruses based on the sequences of the G-L Intergenic region.

  1. An insulating grid spacer for large-area MICROMEGAS chambers

    We present a novel design for large-area gaseous detectors based on the MICROMEGAS technology. This technology incorporates an insulating grid, sandwiched between the micro-mesh and the anode-pad plane, which provides a uniform 200 μm amplification gap. The uniformity of the amplification gap thickness has been verified. The gain performances of the detector are presented and compared to the values obtained with detectors using cylindrical micro spacers. The new design presents several technical and financial advantages

  2. Spring spacer device for resiliently supporting nuclear fuel rods

    Lantern type spring spacers which are mounted in a latticed frame by cross-pieces are respectively composed of square configured cylindrical end portions supported in the cross-pieces and four leaf spring members respectively provided between corresponding sides of the square cylindrical end portions. Each of the leaf springs includes flat end portions and a central outwardly bent portion which is projected against a nuclear fuel rod to be supported in the latticed frame. (Official Gazette)

  3. Acinetobacter species identification by using tRNA spacer fingerprinting.

    Ehrenstein, B; Bernards, A T; Dijkshoorn, L.; Gerner-Smidt, P; Towner, K. J.; Bouvet, P J; Daschner, F D; Grundmann, H

    1996-01-01

    Identification of Acinetobacter spp. to the DNA group level by phenotypic techniques is problematic, and there is a need for an alternative identification method for routine use. The present study validated the suitability of a rapid identification technique based on tRNA spacer (tDNA) fingerprinting in comparison with that of a commercially available assay involving carbon source utilization tests (Biolog MicroStation System) for identifying the 21 DNA-DNA hybridization groups belonging to t...

  4. Inhalational drug delivery from seven different spacer devices.

    Barry, P W; O Callaghan, C.

    1996-01-01

    BACKGROUND: A study was performed to determine in vitro the difference in drug output of seven currently available spacer devices when used with different inhaled medications. METHODS: A glass multistage liquid impinger (MSLI) was used to determine the amount of disodium cromoglycate (DSCG, 5 mg), salbutamol (100 micrograms), or budesonide (200 micrograms) obtained in various particle size ranges from metered dose inhalers (MDIs) actuated directly into the MSLI or via one of seven different s...

  5. Impact of feed spacer and membrane modification by hydrophilic, bactericidal and biocidal coating on biofouling control

    Araújo, Paula A.

    2012-06-01

    The influence of polydopamine- and polydopamine-. graft-poly(ethylene glycol)-coated feed spacers and membranes, copper-coated feed spacers, and commercially-available biostatic feed spacers on biofouling has been studied in membrane fouling simulators. Feed spacers and membranes applied in practical membrane filtration systems were used; biofouling development was monitored by feed channel pressure drop increase and biomass accumulation. Polydopamine and polydopamine-. g-PEG are hydrophilic surface modification agents expected to resist protein and bacterial adhesion, while copper feed spacer coatings and biocides infused in feed spacers are expected to restrict biological growth. Our studies showed that polydopamine and polydopamine-. g-PEG coatings on feed spacers and membranes, copper coatings on feed spacers, and a commercial biostatic feed spacer did not have a significant impact on feed channel pressure drop increase and biofilm accumulation as measured by ATP and TOC content. The studied spacer and membrane modifications were not effective for biofouling control; it is doubtful that feed spacer and membrane modification, in general, may be effective for biofouling control regardless of the type of applied coating. © 2012 Elsevier B.V.

  6. Improving electricity production in tubular microbial fuel cells through optimizing the anolyte flow with spiral spacers.

    Zhang, Fei; Ge, Zheng; Grimaud, Julien; Hurst, Jim; He, Zhen

    2013-04-01

    The use of spiral spacers to create a helical flow for improving electricity generation in microbial fuel cells (MFCs) was investigated in both laboratory and on-site tests. The lab tests found that the MFC with the spiral spacers produced more electricity than the one without the spiral spacers at different recirculation rates or organic loading rates, likely due to the improved transport/distribution of ions and electron mediators instead of the substrates because the organic removal efficiency was not obviously affected by the presence of the spiral spacers. The energy production in the MFC with the spiral spacers reached 0.071 or 0.073 kWh/kg COD in either vertical or horizontal installment. The examination of the MFCs installed in an aeration tank of a municipal wastewater treatment plant confirmed the advantage of using the spiral spacers. Those results demonstrate that spiral spacers could be an effective approach to improve energy production in MFCs. PMID:23500582

  7. Increased antibiotic release and equivalent biomechanics of a spacer cement without hard radio contrast agents.

    Bitsch, R G; Kretzer, J P; Vogt, S; Büchner, H; Thomsen, M N; Lehner, B

    2015-10-01

    We compared a novel calcium carbonate spacer cement (Copal® spacem) to well-established bone cements. Electron microscopic structure and elution properties of the antibiotics ofloxacin, vancomycin, clindamycin, and gentamicin were examined. A knee wear simulator model for articulating cement spacers was established. Mechanical tests for bending strength, flexural modulus, and compressive and fatigue strength were performed. The electron microscopic analysis showed a microporous structure of the spacer cement, and this promoted a significantly higher and longer antibiotic elution. All spacer cement specimens released the antibiotics for a period of up to 50days with the exception of the vancomycin loading. The spacer cement showed significantly less wear scars and fulfilled the ISO 5833 requirements. The newly developed spacer cement is a hydrophilic antibiotic carrier with an increased release. Cement without hard radio contrast agents can improve tribological behaviour of spacers, and this may reduce reactive wear particles and abrasive bone defects. PMID:26219491

  8. Spacer grid for reducing bowing in a nuclear fuel assembly

    A bi-metallic spacer grid having a zircaloy perimeter strip consisting of oppositely facing, thin walled metal plates for closely surrounding the array of fuel rods. A rigid, stainless steel cross member extends between internal surfaces of the oppositely facing perimeter plates. In the preferred embodiment, the perimeter plates have cantilevered portions extending above and below the main body of the perimeter strip. The cross members interact with the enlarged portion by urging them outward relative to the perimeter strip as the fuel assembly heats up during operation. The outwardly projecting interface surfaces of each assembly mechanically interact with the interface surfaces of adjacent assemblies providing a mechanical restraint which limits bowing of the assembly. The effectiveness of the spacer grids in limiting bowing is therefore not dependent upon controlling the mechanisms responsible for causing bow. When the reactor is in a cold condition such as during refueling , the exterior dimensions of the spacer grids are the same as those of the other zircaloy grids, which assures adequate clearance for insertion and withdrawal of individual fuel assemblies

  9. Nuclear fuel assembly spacer and loop spring with enhanced flexibility

    This patent describes a fuel bundle having a surrounding channel, and upper tie plat, a lower tie plate, fuel rods and a pari of water rods, wherein the fuel rods are arranged in a matrix and positioned in parallel upstanding relation to one another between the upper and lower tie plates, the pair of water rods are arranged side-by-side and positioned centrally of the fuel bundle such that the water rod pair occupies seven matrix positions centrally of the matrix, the pair including a first water rod occupying a first three positions in the matrix and part of a forth position, the second water rod of the water rod pair occupying a second three positions in the matrix and part of the fourth position, a system for the securing of the paired water rods comprising in combination: first and second U-shaped spacers, each spacer having a portion that extends between the water rods, each portion bearing against each water rod to maintain the water rods in spaced relationships; and means for biasing the water rods against the U-shaped spacers

  10. Analytical investigation of the influence of spacer geometry and position on turbulent flow structure and parameters

    Stosic, Z.V.; Stevanovic, V.D. [Framatome ANP GmbH - NBTT, Erlangen (Germany)

    2001-07-01

    Nuclear fuel rod bundle thermal-hydraulics strongly depends on the presence of fuel rod spacers. High Reynolds number coolant flows around spacers of different geometry and position are numerically investigated in two-dimensions. Predicted is the influence of the spacer's geometry and its position within a flow channel, on the recirculation zones formation and corresponding reattachment lengths. The numerical procedure is based on the two-equation k-{epsilon} turbulence model and the control volume procedure. Numerical simulation and analyses of high Reynolds fluid flow over the bluff bodies of the nuclear fuel spacer shapes are performed. Two types of flow channels and conditions are considered: spacers mounted on the wall and spacers in a free fluid stream. The major findings are as follows: 1) In fluid flow over the spacer mounted on the wall, the large recirculation zone is formed behind the spacer's fin. The reattachment length and width of this large vortex are increasing with the spacer's fin inclination angle increase. The reattachment length is rapidly increasing for fin inclination angles greater than 45 degrees. The maximum value of the reattachment length is achieved with fin inclination angle of 75 degrees. For angles from 75 to 90 degrees this length is slightly decreasing (the result with the Re=1.6*10{sup 6}). 2) A small vortex is formed in front of the spacer's fin in case of the flow over wall mounted spacer. 3) In case of fluid flow around the spacer in a free stream, the vortexes are formed behind the fin. Vortex shedding is observed, which is contrary to the formation of a stable vortex behind the wall mounted spacers. No small recirculation zone exists in front of the fin, which is opposite to the flow structure in case of wall mounted spacer. (authors)

  11. Development and characterization of 3D-printed feed spacers for spiral wound membrane systems.

    Siddiqui, Amber; Farhat, Nadia; Bucs, Szilárd S; Linares, Rodrigo Valladares; Picioreanu, Cristian; Kruithof, Joop C; van Loosdrecht, Mark C M; Kidwell, James; Vrouwenvelder, Johannes S

    2016-03-15

    Feed spacers are important for the impact of biofouling on the performance of spiral-wound reverse osmosis (RO) and nanofiltration (NF) membrane systems. The objective of this study was to propose a strategy for developing, characterizing, and testing of feed spacers by numerical modeling, three-dimensional (3D) printing of feed spacers and experimental membrane fouling simulator (MFS) studies. The results of numerical modeling on the hydrodynamic behavior of various feed spacer geometries suggested that the impact of spacers on hydrodynamics and biofouling can be improved. A good agreement was found for the modeled and measured relationship between linear flow velocity and pressure drop for feed spacers with the same geometry, indicating that modeling can serve as the first step in spacer characterization. An experimental comparison study of a feed spacer currently applied in practice and a 3D printed feed spacer with the same geometry showed (i) similar hydrodynamic behavior, (ii) similar pressure drop development with time and (iii) similar biomass accumulation during MFS biofouling studies, indicating that 3D printing technology is an alternative strategy for development of thin feed spacers with a complex geometry. Based on the numerical modeling results, a modified feed spacer with low pressure drop was selected for 3D printing. The comparison study of the feed spacer from practice and the modified geometry 3D printed feed spacer established that the 3D printed spacer had (i) a lower pressure drop during hydrodynamic testing, (ii) a lower pressure drop increase in time with the same accumulated biomass amount, indicating that modifying feed spacer geometries can reduce the impact of accumulated biomass on membrane performance. The combination of numerical modeling of feed spacers and experimental testing of 3D printed feed spacers is a promising strategy (rapid, low cost and representative) to develop advanced feed spacers aiming to reduce the impact of

  12. Development and characterization of 3D-printed feed spacers for spiral wound membrane systems

    Siddiqui, Amber

    2016-01-02

    Feed spacers are important for the impact of biofouling on the performance of spiral-wound reverse osmosis (RO) and nanofiltration (NF) membrane systems. The objective of this study was to propose a strategy for developing, characterizing, and testing of feed spacers by numerical modeling, three-dimensional (3D) printing of feed spacers and experimental membrane fouling simulator (MFS) studies. The results of numerical modeling on the hydraulic behavior of various feed spacer geometries suggested that the impact of spacers on hydraulics and biofouling can be improved. A good agreement was found for the modeled and measured relationship between linear flow velocity and pressure drop for feed spacers with the same geometry, indicating that modeling can serve as first step in spacer characterization. An experimental comparison study of a feed spacer currently applied in practice and a 3D printed feed spacer with the same geometry showed (i) similar hydraulic behavior, (ii) similar pressure drop development with time and (iii) similar biomass accumulation during MFS biofouling studies, indicating that 3D printing technology is an alternative strategy for development of thin feed spacers with a complex geometry. Based on the numerical modeling results, a modified feed spacer with low pressure drop was selected for 3D printing. The comparison study of the feed spacer from practice and the modified geometry 3D printed feed spacer established that the 3D printed spacer had (i) a lower pressure drop during hydraulic testing, (ii) a lower pressure drop increase in time with the same accumulated biomass amount, indicating that modifying feed spacer geometries can reduce the impact of accumulated biomass on membrane performance. The combination of numerical modeling of feed spacers and experimental testing of 3D printed feed spacers is a promising strategy (rapid, low cost and representative) to develop advanced feed spacers aiming to reduce the impact of biofilm formation on

  13. Rapid Acquisition of Linezolid Resistance in Methicillin-Resistant Staphylococcus aureus: Role of Hypermutation and Homologous Recombination

    Iguchi, Shigekazu; Mizutani, Tomonori; Hiramatsu, Keiichi; Kikuchi, Ken

    2016-01-01

    Background We previously reported the case of a 64-year-old man with mediastinitis caused by Staphylococcus aureus in which the infecting bacterium acquired linezolid resistance after only 14 days treatment with linezolid. We therefore investigated relevant clinical isolates for possible mechanisms of this rapid acquisition of linezolid resistance. Methods Using clinical S. aureus isolates, we assessed the in vitro mutation rate and performed stepwise selection for linezolid resistance. To investigate homologous recombination, sequences were determined for each of the 23S ribosomal RNA (23S rRNA) loci; analyzed sequences spanned the entirety of each 23S rRNA gene, including domain V, as well as the 16S-23S intergenic spacer regions. We additionally performed next-generation sequencing on clinical strains to identify single-nucleotide polymorphisms compared to the N315 genome. Results Strains isolated from the patient prior to linezolid exposure (M5-M7) showed higher-level linezolid resistance than N315, and the pre-exposure strain (M2) exhibited more rapid acquisition of linezolid resistance than did N315. However, the mutation rates of these and contemporaneous clinical isolates were similar to those of N315, and the isolates did not exhibit any mutations in hypermutation-related genes. Sequences of the 23S rRNA genes and 16S-23S intergenic spacer regions were identical among the pre- and post-exposure clinical strains. Notably, all of the pre-exposure isolates harbored a recQ missense mutation (Glu69Asp) with respect to N315; such a lesion may have affected short sequence recombination (facilitating, for example, recombination among rrn loci). We hypothesize that this mechanism contributed to rapid acquisition of linezolid resistance. Conclusions Hypermutation and homologous recombination of the ribosomal RNA genes, including 23S rRNA genes, appear not to have been sources of the accelerated acquisition of linezolid resistance observed in our clinical case

  14. Aggregation behavior of a gemini surfactant with a tripeptide spacer.

    Wang, Meina; Han, Yuchun; Qiao, Fulin; Wang, Yilin

    2015-02-28

    A peptide gemini surfactant, 12-G(NH2)LG(NH2)-12, has been constructed with two dodecyl chains separately attached to the two terminals of a glutamic acid-lysine-glutamic acid peptide and the aggregation behavior of the surfactant was studied in aqueous solution. The 12-G(NH2)LG(NH2)-12 molecules form fiber-like precipitates around pH 7.0, and the precipitation range is widened on increasing the concentration. At pHs 3.0 and 11.0, 12-G(NH2)LG(NH2)-12 forms soluble aggregates because each molecule carries two positively charged amino groups at the two ends of the peptide spacer at pH 3.0, while each molecule carries one negatively charged carboxyl group in the middle of the peptide spacer at pH 11.0. 12-G(NH2)LG(NH2)-12 displays a similar concentration-dependent process at these two pHs: forming small micelles above the critical micelle concentration and transferring to fibers at pH 3.0 or twisted ribbons at pH 11.0 above the second critical concentration. The fibers formed at pH 3.0 tend to aggregate into bundles with twisted structure. Both the twisted fibers at pH 3.0 and the twisted ribbons at pH 11.0 contain β-sheet structure formed by the peptide spacer. PMID:25588349

  15. An insulating grid spacer for large-area MICROMEGAS chambers

    Bernard, D; D'Enterria, D G; Le Guay, M; Martínez, G; Mora, M J; Pichot, P; Roy, D; Schutz, Y; Gandi, A; De Oliveira, R

    2002-01-01

    We present an original design for large area gaseous detectors based on the MICROMEGAS technology. This technology incorporates an insulating grid, sandwiched between the micro-mesh and the anode-pad plane, which provides an uniform 200 $\\mu$m amplification gap. The uniformity of the amplification gap thickness has been verified under several experimental conditions. The gain performances of the detector are presented and compared to the values obtained with detectors using cylindrical micro spacers. The new design presents several technical and financial advantages.

  16. Analytical model for the prediction of spacer pressure drop coefficients

    A method based on broad assumptions is presented to calculate spacer pressure drop coefficients for grids mounted in smooth and rough bundles. An extensive comparison is made with different experimental results. It covers a wide range of bundle geometries and grid types. The comparison is very good (well within 10% in most of the 9 investigated cases) at high Reynolds numbers (above 104). In the lower Reynolds range the results are not always as satisfactory and some improvements of the method are discussed. (Auth.)

  17. Synthesis and properties of novel gemini surfactant with short spacer

    2007-01-01

    Cationic gemini surfactant dimethylene-1,2-bis(dodecyldiethylammonium bromide), referred to as C12C2C12(Et) was synthesized, and its surface property and aggregation behavior in aqueous solution were studied. The value of γat the critical micelle concentration (γcmc) is much smaller than that of the surfactant homologues with longer spacer. Spherical and elongated micelles were formed in the aqueous solution of this gemini surfactant,and the spherical micelles were absolutely dominant compared to the elongated micelles at our studied concentration quantitatively.

  18. Effect of plastic spacer handling on salbutamol lung deposition in asthmatic children

    Lipworth, Brian J; Lee, Daniel K C; Anhøj, Jacob;

    2002-01-01

    AIMS: To study the effects of electrostatics in a plastic spacer on the lung deposition of salbutamol in asthmatic children. METHODS: Twenty-five children (5-12 years) with mild asthma were given salbutamol hydrofluoroalkane pressurized metered dose inhaler 400 micro g via a 750 ml plastic spacer...... repeated daily use (Used ), a spacer rinsed after repeated use (UsedRinsed ) and a spacer primed with benzalkonium chloride to avoid electrostatics (Primed1). In addition, spacers were evaluated using a 15 s inhalation delay following actuation with primed (PrimedDelay) and rinsed (RinsedDelay) spacers....... Data were log transformed and expressed as geometric mean fold difference for the average plasma salbutamol concentration (Cav) over 20 min. RESULTS: There were significant differences (P < 0.05) in Cav (as geometric mean fold difference and 95% CI) between Primed1 vs NewRinsed 1.92 fold (95% CI 1...

  19. Genome-wide identification and characterization of long intergenic non-coding RNAs in Ganoderma lucidum.

    Jianqin Li

    Full Text Available Ganoderma lucidum is a white-rot fungus best-known for its medicinal activities. We have previously sequenced its genome and annotated the protein coding genes. However, long non-coding RNAs in G. lucidum genome have not been analyzed. In this study, we have identified and characterized long intergenic non-coding RNAs (lincRNA in G. lucidum systematically. We developed a computational pipeline, which was used to analyze RNA-Seq data derived from G. lucidum samples collected from three developmental stages. A total of 402 lincRNA candidates were identified, with an average length of 609 bp. Analysis of their adjacent protein-coding genes (apcGenes revealed that 46 apcGenes belong to the pathways of triterpenoid biosynthesis and lignin degradation, or families of cytochrome P450, mating type B genes, and carbohydrate-active enzymes. To determine if lincRNAs and these apcGenes have any interactions, the corresponding pairs of lincRNAs and apcGenes were analyzed in detail. We developed a modified 3' RACE method to analyze the transcriptional direction of a transcript. Among the 46 lincRNAs, 37 were found unidirectionally transcribed, and 9 were found bidirectionally transcribed. The expression profiles of 16 of these 37 lincRNAs were found to be highly correlated with those of the apcGenes across the three developmental stages. Among them, 11 are positively correlated (r>0.8 and 5 are negatively correlated (r<-0.8. The co-localization and co-expression of lincRNAs and those apcGenes playing important functions is consistent with the notion that lincRNAs might be important regulators for cellular processes. In summary, this represents the very first study to identify and characterize lincRNAs in the genomes of basidiomycetes. The results obtained here have laid the foundation for study of potential lincRNA-mediated expression regulation of genes in G. lucidum.

  20. The Dunaliella salina organelle genomes: large sequences, inflated with intronic and intergenic DNA

    Smith, David R.; Lee, Robert W.; Cushman, John C.; Magnuson, Jon K.; Tran, Duc; Polle, Juergen E.

    2010-05-07

    Abstract Background: Dunaliella salina Teodoresco, a unicellular, halophilic green alga belonging to the Chlorophyceae, is among the most industrially important microalgae. This is because D. salina can produce massive amounts of β-carotene, which can be collected for commercial purposes, and because of its potential as a feedstock for biofuels production. Although the biochemistry and physiology of D. salina have been studied in great detail, virtually nothing is known about the genomes it carries, especially those within its mitochondrion and plastid. This study presents the complete mitochondrial and plastid genome sequences of D. salina and compares them with those of the model green algae Chlamydomonas reinhardtii and Volvox carteri. Results: The D. salina organelle genomes are large, circular-mapping molecules with ~60% noncoding DNA, placing them among the most inflated organelle DNAs sampled from the Chlorophyta. In fact, the D. salina plastid genome, at 269 kb, is the largest complete plastid DNA (ptDNA) sequence currently deposited in GenBank, and both the mitochondrial and plastid genomes have unprecedentedly high intron densities for organelle DNA: ~1.5 and ~0.4 introns per gene, respectively. Moreover, what appear to be the relics of genes, introns, and intronic open reading frames are found scattered throughout the intergenic ptDNA regions -- a trait without parallel in other characterized organelle genomes and one that gives insight into the mechanisms and modes of expansion of the D. salina ptDNA. Conclusions: These findings confirm the notion that chlamydomonadalean algae have some of the most extreme organelle genomes of all eukaryotes. They also suggest that the events giving rise to the expanded ptDNA architecture of D. salina and other Chlamydomonadales may have occurred early in the evolution of this lineage. Although interesting from a genome evolution standpoint, the D. salina organelle DNA sequences will aid in the development of a viable

  1. Nanoparticle-Based Brachytherapy Spacers for Delivery of Localized Combined Chemoradiation Therapy

    Kumar, Rajiv, E-mail: r.kumar@neu.edu [Nanomedicine Science and Technology Center, Northeastern University, Boston, Massachusetts (United States); Department of Radiation Oncology, Brigham and Women' s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts (United States); Belz, Jodi [Nanomedicine Science and Technology Center, Northeastern University, Boston, Massachusetts (United States); Markovic, Stacey [Department of Electrical and Computer Engineering, Northeastern University, Boston, Massachusetts (United States); Jadhav, Tej; Fowle, William [Nanomedicine Science and Technology Center, Northeastern University, Boston, Massachusetts (United States); Niedre, Mark [Department of Electrical and Computer Engineering, Northeastern University, Boston, Massachusetts (United States); Cormack, Robert; Makrigiorgos, Mike G. [Department of Radiation Oncology, Brigham and Women' s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts (United States); Sridhar, Srinivas [Nanomedicine Science and Technology Center, Northeastern University, Boston, Massachusetts (United States); Department of Radiation Oncology, Brigham and Women' s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts (United States)

    2015-02-01

    Purpose: In radiation therapy (RT), brachytherapy-inert source spacers are commonly used in clinical practice to achieve high spatial accuracy. These implanted devices are critical technical components of precise radiation delivery but provide no direct therapeutic benefits. Methods and Materials: Here we have fabricated implantable nanoplatforms or chemoradiation therapy (INCeRT) spacers loaded with silica nanoparticles (SNPs) conjugated containing a drug, to act as a slow-release drug depot for simultaneous localized chemoradiation therapy. The spacers are made of poly(lactic-co-glycolic) acid (PLGA) as matrix and are physically identical in size to the commercially available brachytherapy spacers (5 mm × 0.8 mm). The silica nanoparticles, 250 nm in diameter, were conjugated with near infrared fluorophore Cy7.5 as a model drug, and the INCeRT spacers were characterized in terms of size, morphology, and composition using different instrumentation techniques. The spacers were further doped with an anticancer drug, docetaxel. We evaluated the in vivo stability, biocompatibility, and biodegradation of these spacers in live mouse tissues. Results: The electron microscopy studies showed that nanoparticles were distributed throughout the spacers. These INCeRT spacers remained stable and can be tracked by the use of optical fluorescence. In vivo optical imaging studies showed a slow diffusion of nanoparticles from the spacer to the adjacent tissue in contrast to the control Cy7.5-PLGA spacer, which showed rapid disintegration in a few days with a burst release of Cy7.5. The docetaxel spacers showed suppression of tumor growth in contrast to control mice over 16 days. Conclusions: The imaging with the Cy7.5 spacer and therapeutic efficacy with docetaxel spacers supports the hypothesis that INCeRT spacers can be used for delivering the drugs in a slow, sustained manner in conjunction with brachytherapy, in contrast to the rapid clearance of the drugs when

  2. .i.Aulosira bohemensis./i. sp. nov.: further phylogenetic uncertainty at the base of the Nostocales (Cyanobacteria)

    Lukešová, Alena; Johansen, J. R.; Martin, M.P.; Casamatta, D.A.

    2009-01-01

    Roč. 48, č. 2 (2009), s. 118-129. ISSN 0031-8884 Institutional research plan: CEZ:AV0Z60660521 Keywords : Cyanobacteria * 16S rRNA gene * 16S-23S Internal transcribed spacer (ITS) Subject RIV: EH - Ecology, Behaviour Impact factor: 1.218, year: 2009

  3. Packaging design criteria modified fuel spacer burial box. Revision 1

    Various Hanford facilities must transfer large radioactively contaminated items to burial/storage. Presently, there are eighteen Fuel Spacer Burial Boxes (FSBBs) available on the Hanford Site for transport of such items. Previously, the FSBBS were transported from a rail car to the burial trench via a drag-off operation. To allow for the lifting of the boxes into the burial trench, it will be necessary to improve the packagings lifting attachments and provide structural reinforcement. Additional safety improvements to the packaging system will be provided by the addition of a positive closure system and package ventilation. FSBBs that are modified in such a manner are referred to as Modified Fuel Spacer Burial Boxes (MFSBs). The criteria provided by this PDC will be used to demonstrate that the transfer of the MFSB will provide an equivalent degree of safety as would be provided by a package meeting offsite transportation requirements. This fulfills the onsite transportation safety requirements implemented in WHC-CM-2-14, Hazardous Material Packaging and Shipping. A Safety Analysis Report for Packaging (SARP) will be prepared to evaluate the safety of the transfer operation. Approval of the SARP is required to authorize transfer. Criteria are also established to ensure burial requirements are met

  4. Contriving new spacer grid shapes and choosing the leading candidates of the spacer grid from the mechanical/structural point of view

    Based on the fuel assembly mechanical/thermal-hydraulic design experience and scrutinizing the design features on the foreign advanced nuclear fuel and the foreign patents of the spacer grid, 13 kinds of spacer grid candidates are derived. Among, the candidates the mechanical/structural performance on the five candidates was evaluated by the screening test and the analysis. As a result of the test and the analysis, two spacer grid shapes are finally selected to be the leading candidates in order to investigate the mechanical/structural performance in detail

  5. All-Trans Retinoic Acid Induces Expression of a Novel Intergenic Long Noncoding RNA in Adult rat Primary Hippocampal Neurons.

    Kour, Sukhleen; Rath, Pramod C

    2016-02-01

    Around 90% of the mammalian genome undergoes pervasive transcription into various types of small and long regulatory noncoding RNAs, whereas only ∼ 1.5% codes for proteins. Long noncoding RNAs (lncRNAs) constitute diverse classes of sense- and antisense transcripts that are abundantly expressed in the mammalian central nervous system (CNS) in cell type- and developmental stage-specific manners. They are implicated in brain development, differentiation, neuronal plasticity, and other cognitive functions. Mammalian brain requires the vitamin A metabolite all-trans retinoic acid (atRA) for its normal development, differentiation, and cell-fate determination. However, its role in adult brain function is less understood. Here, we report atRA-mediated transcriptional upregulation of endogenous expression of a novel long intergenic noncoding RNA-rat brain expressed (LINC-RBE) in cultured primary hippocampal neurons from adult rat. We have previously reported LINC-RBE as an intergenic, simple repeat sequence containing lncRNA highly expressed in the rat brain. This is a first-time report of involvement of atRA in transcriptional upregulation of lncRNA expression in rat hippocampal neurons. Therefore, it may be involved in regulation of brain function and disease. PMID:26572536

  6. Measurement and CFD calculation of spacer loss coefficient for a tight-lattice fuel bundle

    Highlights: • Experiment and CFD analysis evaluated the pressure drop in a spacer grid. • The measurement and CFD errors for the spacer loss coefficient were estimated. • The spacer loss coefficient for the dual-cooled annular fuel bundle was determined. • The CFD prediction agrees with the measured spacer loss coefficient within 8%. - Abstract: An experiment and computational fluid dynamics (CFD) analysis were performed to evaluate the pressure drop in a spacer grid for a dual-cooled annular fuel (DCAF) bundle. The DCAF bundle for the Korean optimum power reactor (OPR1000) is a 12 × 12 tight-lattice rod array with a pitch-to-diameter ratio of 1.08 owing to a larger outer diameter of the annular fuel rod. An experiment was conducted to measure the pressure drop in spacer grid for the DCAF bundle. The test bundle is a full-size 12 × 12 rod bundle with 11 spacer grid. The test condition covers a Reynolds number range of 2 × 104–2 × 105 by changing the temperature and flow rate of water. A CFD analysis was also performed to predict the pressure drop through a spacer grid using the full-size and partial bundle models. The pressure drop and loss coefficient of a spacer grid were predicted and compared with the experimental results. The CFD predictions of spacer pressure drop and loss coefficient agree with the measured values within 8%. The spacer loss coefficient for the DCAF bundle is estimated to be approximately 1.50 at a nominal operating condition of OPR1000, i.e., Re = 4 × 105

  7. Phylogenetic relationships within Luzula DC. and Juncus L. (Juncaceae): A comparison of phylogenetic signals of trnL-trnF intergenic spacer, trnL intron and rbcL plastome sequence data

    Drábková, Lenka; Kirschner, Jan; Vlček, Čestmír

    2006-01-01

    Roč. 22, č. 2 (2006), s. 132-143. ISSN 0748-3007 R&D Projects: GA ČR GA206/02/0355 Institutional research plan: CEZ:AV0Z60050516; CEZ:AV0Z50520514 Keywords : Luzula * Juncus * Juncaceae Subject RIV: EF - Botanics Impact factor: 4.270, year: 2006

  8. Development of a new spacer grid form to enhance the integrity of fuel rod support and the crush strength of a spacer grid assembly

    A spacer grid is one of the most important structural components in a PWR fuel assembly. The spacer grid, which supports nuclear fuel rods laterally and vertically with a friction grip, is an interconnected array of slotted grid straps welded at the intersections to form an egg crate structure. Dimples and springs are stamped into each grid strap to support the fuel rods. The form of grid straps and spring form is known to be closely related with the crush strength of spacer grid assembly and the integrity of fuel rod support, respectively. Zircaloy is prevailing as the material of the spacer grid because of its low neutron absorption characteristic and its successful extensive in reactor use. The primary considerations are to provide a Zircaloy spacer grid with crush strength sufficient to resist design basis loads, without significantly increasing pressure drop across the reactor core. Generally, the thickness and height of the Zircaloy grid strap have been the main design variables in order to meet the above considerations. Recently, it was reported that a dimple location is also a design variable that affects the crush strength of a spacer grid. In this study, a new spacer grid form was developed in order to enhance the integrity of the fuel rod support and the crush strength of the spacer grid assembly by using a systematic optimization technique. The enhancement of fuel rod support was confirmed by comparisons of contact area, peak stresses, plastic deformation and etc. while the enhancement of crush strength was investigated for a 3x3 and 7x7 sub size support grid as a preliminary parameter study for a 16x16 full size support grid. The 3x3 model is chosen to facilitate quick computation for optimization and the 7x7 model is chosen to verify the enhancement

  9. Effect of Structure on the Mechanical Behaviors of Three-Dimensional Spacer Fabric Composites

    Li, Min; Wang, Shaokai; Zhang, Zuoguang; Wu, Boming

    2009-02-01

    Three-dimensional (3-D) spacer fabric composite is a newly developed sandwich structure, the reinforcement of which is integrally woven by advanced textile technique. Two facesheets of 3-D spacer fabric are connected by continuous fibers, named pile in the core, providing excellent properties like outstanding integrity, debonding resistance, light weight, good designability and so on. Usually the 3-D spacer fabric composite without extra reinforcement is a kind of core material. In comparison with the facesheet reinforced spacer fabric composite, here the composite without additional weaves is called mono-spacer fabric composite. In this paper, two kinds of mono-spacer fabric composites with integrated hollow cores have been developed, one with 8-shaped piles and the other with corrugated piles. The mechanical characteristics and the damage modes of these mono-spacer fabric composites under different load conditions have been investigated. Besides, effects of pile height, pile distribution density and pile structure on the composites mechanical performances were analyzed. It is shown that the mechanical performances of mono-spacer fabric composites can be widely adapted to the respective requirements through the choice of the structural factors.

  10. Optimized spacer layer thickness for plasmonic-induced enhancement of photocurrent in a-Si:H

    Saleh, Z. M., E-mail: zaki.saleh@aauj.edu, E-mail: zakimsaleh@yahoo.com; Nasser, H.; Özkol, E.; Günöven, M.; Abak, K. [Middle East Technical University, Center for Solar Energy Research and Applications (GÜNAM) (Turkey); Canli, S. [Middle East Technical University, Central Laboratory (Turkey); Bek, A.; Turan, R. [Middle East Technical University, Center for Solar Energy Research and Applications (GÜNAM) (Turkey)

    2015-10-15

    Plasmonic interfaces consisting of silver nanoparticles of different sizes (50–100 nm) have been processed by the self-assembled dewetting technique and integrated to hydrogenated amorphous silicon (a-Si:H) using SiNx spacer layers to investigate the dependence of optical trapping enhancement on spacer layer thickness through the enhancements in photocurrent. Samples illuminated from the a-Si:H side exhibit a localized surface plasmon resonance (LSPR) that is red-shifted with the increasing particle size and broadened into the red with the increasing spacer layer thickness. The photocurrent measured in a-Si:H is not only consistent with the red-shift and broadening of the LSPR, but exhibits critical dependence on the spacer layer thickness also. The samples with plasmonic interfaces and a SiNx spacer layer exhibit appreciable enhancement of photocurrent compared with flat a-Si:H reference depending on the size of the Ag nanoparticle. Simulations conducted on one-dimensional square structures exhibit electric fields that are localized near the plasmonic structures but extend appreciably into the higher refractive index a-Si:H. These simulations produce a clear red-shift and broadening of extinction spectra for all spacer layer thicknesses and predict an enhancement in photocurrent in agreement with experimental results. The spectral dependence of photocurrent for six plasmonic interfaces with different Ag nanoparticle sizes and spacer layer thicknesses are correlated with the optical spectra and compared with the simulations to predict an optimal spacer layer thickness.

  11. Mechanical behaviour of standardized, endoskeleton-including hip spacers implanted into composite femurs

    T. Thielen, S. Maas, A. Zuerbes, D. Waldmann, K. Anagnostakos, J. Kelm

    2009-01-01

    Full Text Available Two-stage reconstruction using an antibiotic loaded cement spacer is the preferred treatment method of late hip joint infections. Hip spacers maintain stability of the joint and length of the limb during treatment period. However, as the material strength of bone cement (PMMA is limited, spacer fractures led to serious complications in the past. This study investigated the load capacity of custom made hip spacers, developed at the 'Klinik für Orthopädie und Orthopädische Chirurgie' (Universitätsklinikum des Saarlandes, Homburg / Saar, Germany, and implanted into composite femurs. In a quasi-static test, non-reinforced spacers tolerated hip joint loads of about 3000 N, whereas reinforced spacers with titanium-grade-two endoskeletons doubled this load up to 6000 N. Even for cyclic loading, endoskeleton-including hip spacers tolerated loads of >4500 N with 500,000 load cycles. Thus, an endoskeleton-including spacer should provide a mobile and functional joint through the treatment course. A generated FE-model was used to determine the fracture stresses and allows for further sensitivity analysis.

  12. Optimized spacer layer thickness for plasmonic-induced enhancement of photocurrent in a-Si:H

    Plasmonic interfaces consisting of silver nanoparticles of different sizes (50–100 nm) have been processed by the self-assembled dewetting technique and integrated to hydrogenated amorphous silicon (a-Si:H) using SiNx spacer layers to investigate the dependence of optical trapping enhancement on spacer layer thickness through the enhancements in photocurrent. Samples illuminated from the a-Si:H side exhibit a localized surface plasmon resonance (LSPR) that is red-shifted with the increasing particle size and broadened into the red with the increasing spacer layer thickness. The photocurrent measured in a-Si:H is not only consistent with the red-shift and broadening of the LSPR, but exhibits critical dependence on the spacer layer thickness also. The samples with plasmonic interfaces and a SiNx spacer layer exhibit appreciable enhancement of photocurrent compared with flat a-Si:H reference depending on the size of the Ag nanoparticle. Simulations conducted on one-dimensional square structures exhibit electric fields that are localized near the plasmonic structures but extend appreciably into the higher refractive index a-Si:H. These simulations produce a clear red-shift and broadening of extinction spectra for all spacer layer thicknesses and predict an enhancement in photocurrent in agreement with experimental results. The spectral dependence of photocurrent for six plasmonic interfaces with different Ag nanoparticle sizes and spacer layer thicknesses are correlated with the optical spectra and compared with the simulations to predict an optimal spacer layer thickness

  13. Performance analyses and tests on the KAERI devised spacer grids for PWRs

    Spacer grid which is one of the most important structural components in a pressurized light water reactor fuel assembly supports the fuel rods laterally and vertically. Based on design experiences and by scrutinizing the design features of foreign advanced nuclear fuels and the foreign patents of spacer grids, KAERI has devised its own spacer grid shapes and has acquired patents. In this study, a performance evaluation of two new spacer grid shapes devised by KAERI was carried out from the mechanical/structural and thermo hydraulic view points. And also performance evaluation of two commercial spacer grid shapes was carried out for the sake of a comparison. The comparisons included the spring characteristics, fuel rod vibration characteristics, fretting wear resistance, impact strength characteristics, CHF enhancement, and the pressure drop of the spacer grid shapes. The comparison results have shown that the performances of the new spacer grid shapes are better or at least not worse than those of the commercial spacer grid shapes. (author)

  14. Synthesis and Properties of Gemini Cationic Surfactants with Amide Spacers

    DENG Qi-gang; YU Hong-wei; LIN Hong; JIA Li-hua; GUO Xiang-feng; ZHOU De-rui

    2005-01-01

    Four gemini cationic surfactants {N,N'-di[2-(lauryldimethylamino)acetyl]polymethylenediamine dichloride, LAA-s-LAA, s=2,3,4,6} were synthesized by using four bis(α-chloroacetamide)s and N,N-dimethyllaurylamine, respectively. The molecular structures were characterized by means of IR, 1H NMR, 13C NMR and MS, and the behavior of their aqueous solutions was studied. The critical micell concentrations(CMC) of LAA-s-LAA were one order of magnitude lower than that of dodecyltrimethyl ammonium chloride(DTAC). With the change of the length of spacer chain(s), their CMC values change, and CMC reaches the top value at s=4.

  15. A Study of Neutronics Effects of the Spacer Grids in a Typical PWR via Monte Carlo Calculation

    Bach, Tran Xuan; Cho, Nam Zin [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2014-10-15

    Neutronics analysis, the spacer grids which support fuel rods are not explicitly described, but they are homogenized with coolant. However, the effects of neglecting or simplifying the spacer grids are not reported in the literature to the best of our knowledge. In this paper, to investigate the effects of spacer grids in neutronics analysis, a detailed description of spacer grids is added to the KAIST benchmark problem 1B. Then, the effective multiplication factor, spatial distributions of neutron flux, and its energy spectrum are obtained for the two cases (with and without spacer grids). Numerical results show that the effects of spacer grids are not negligible. In this paper, to investigate the effect of spacer grids, the spacer grid geometry is described in detail in the Monte Carlo calculation. In the numerical test, the two cases are compared in the context of a modified KAIST benchmark problem 1B. Case 1 does not have spacer grids, while the space is filled by coolant instead. Case 2 includes the spacer grids. The difference in neutron flux spectra is also observed. Thus, the effect of the spacer grids should be considered in the whole-core reactor analysis. In practice, the spacer grids are homogenized into coolant to consider its effect. As a further study, therefore, it would be worthwhile to investigate the differences between the homogenization and the explicit description of the spacer grids.

  16. Model experiments to develop a new smooth blasting using a borehole spacer

    Some model experiments were carried out to develop the new smooth blasting in which cracks were made in a desirable direction by putting a devised spacer into a borehole. After preliminary experiments, the arcshaped spacer piled two lead plates and two rubber plates alternately was made. A cap and explosive were put between the two spacers, and they were inserted into a borehole together. Cracks were made in the two directions, one is the direction lacking spacers, another is the direction normal to it. This result showed that cracking was controlled with the spacers, although more improvement to make cracks only in one direction were needed to apply this blasting method to real cases. (author)

  17. An experimental investigation of grid spacer effect on post-DNB heat transfer

    This paper presents the effect of grid spacer on Post-DNB heat transfer. Post-DNB experiments using Freon R-123 as a working fluid have been performed. Two types of grid spacers were used in the experiments. One is a model simulating the grid spacer of 17 x 17 Japanese pressurized water reactor (PWR) fuel assembly. The other is a so-called simple support grid, which has short straps and no mixing vanes. So, the effect of the simple support grid on two-phase flow structure is expected to be negligible or small as compared with a model simulating the grid spacer of PWR fuel assembly. It is observed that not only DNB power but also the post-DNB heat transfer is enhanced by the grid spacer of PWR fuel assembly. (author)

  18. Restriction Fragment Length Polymorphism Analysis of Ribosomal DNA Intergenic Regions Is Useful for Differentiating Strains of Trichophyton mentagrophytes

    Mochizuki, Takashi; Ishizaki, Hiroshi; Barton, Richard C.; Moore, Mary K.; Jackson, Colin J.; Kelly, Steven L.; Evans, E. Glyn V.

    2003-01-01

    Twenty isolates of Tricophyton mentagrophytes var. mentagrophytes and 47 isolates of T. mentagrophytes var. interdigitale, identified by morphological characteristics, were screened by restriction fragment length polymorphism (RFLP) analysis of the PCR-amplified internal transcribed spacer (ITS) region of ribosomal DNA (rDNA). Sixty isolates (14 of 20 T. mentagrophytes var. mentagrophytes isolates and 46 of 47 T. mentagrophytes var. interdigitale isolates) shared an identical ITS RFLP profile...

  19. Barriers and supports to implementation of MDI/spacer use in nine Canadian pediatric emergency departments: a qualitative study

    Graham Ian D; O'Leary Kathy A; Osmond Martin H; Scott Shannon D; Grimshaw Jeremy; Klassen Terry

    2009-01-01

    Abstract Background Despite recent research supporting the use of metered dose inhalers with spacer devices (MDI/spacers) in pediatric emergency departments (PEDs) for acute exacerbations of asthma, uptake of this practice has been slow. The objectives of this study were to determine the barriers and supports to implementing MDI/spacer research and to identify factors associated with early and late adoption of MDI/spacers in Canadian PEDs. Methods Using a comparative case study design, we cla...

  20. Genome-wide CpG island methylation and intergenic demethylation propensities vary among different tumor sites.

    Lee, Seung-Tae; Wiemels, Joseph L

    2016-02-18

    The epigenetic landscape of cancer includes both focal hypermethylation and broader hypomethylation in a genome-wide manner. By means of a comprehensive genomic analysis on 6637 tissues of 21 tumor types, we here show that the degrees of overall methylation in CpG island (CGI) and demethylation in intergenic regions, defined as 'backbone', largely vary among different tumors. Depending on tumor type, both CGI methylation and backbone demethylation are often associated with clinical, epidemiological and biological features such as age, sex, smoking history, anatomic location, histological type and grade, stage, molecular subtype and biological pathways. We found connections between CGI methylation and hypermutability, microsatellite instability, IDH1 mutation, 19p gain and polycomb features, and backbone demethylation with chromosomal instability, NSD1 and TP53 mutations, 5q and 19p loss and long repressive domains. These broad epigenetic patterns add a new dimension to our understanding of tumor biology and its clinical implications. PMID:26464434

  1. The Aquatic Environment as a Reservoir of Vibrio cholerae O1 in Hydrographic Basins of the State of Pernambuco, Brazil

    Carina Lucena Mendes-Marques

    2013-01-01

    Full Text Available After the worldwide cholera epidemic in 1993, permanent environmental monitoring of hydrographic basins was established in Pernambuco, Brazil, where cholera is endemic. After a quiescent period, 4 rfbN (serogroup O1 positive water samples that were culture negative were detected by multiplex single-tube nested PCR (MSTNPCR; 2 of these were also ctxA (cholera toxin positive. From May to June 2012, 30 V. cholerae O1 isolates were obtained by culturing samples. These isolates were analyzed for the presence of virulence genes by PCR, intergenic spacer region 16S-23S PCR (ISR-PCR, and pulsed field gel electrophoresis (PFGE. The isolates were positive for the rfbN gene and negative for the assessed pathogenic genes and were classified into 2 groups by ISR and the same profile by PFGE. Close genetic similarity was observed between them (2012 and environmental strains from 2004 to 2005, indicating the permanence of endemic V. cholerae O1 in the region.

  2. Diversity and antimicrobial properties of lactic acid bacteria isolated from rhizosphere of olive trees and desert truffles of Tunisia.

    Fhoula, Imene; Najjari, Afef; Turki, Yousra; Jaballah, Sana; Boudabous, Abdelatif; Ouzari, Hadda

    2013-01-01

    A total of 119 lactic acid bacteria (LAB) were isolated, by culture-dependant method, from rhizosphere samples of olive trees and desert truffles and evaluated for different biotechnological properties. Using the variability of the intergenic spacer 16S-23S and 16S rRNA gene sequences, the isolates were identified as the genera Lactococcus, Pediococcus, Lactobacillus, Weissella, and Enterococcus. All the strains showed proteolytic activity with variable rates 42% were EPS producers, while only 10% showed the ability to grow in 9% NaCl. In addition, a low rate of antibiotic resistance was detected among rhizospheric enterococci. Furthermore, a strong antibacterial activity against plant and/or pathogenic bacteria of Stenotrophomonas maltophilia, Pantoea agglomerans, Pseudomonas savastanoi, the food-borne Staphylococcus aureus, and Listeria monocytogenes was recorded. Antifungal activity evaluation showed that Botrytis cinerea was the most inhibited fungus followed by Penicillium expansum, Verticillium dahliae, and Aspergillus niger. Most of the active strains belonged to the genera Enterococcus and Weissella. This study led to suggest that environmental-derived LAB strains could be selected for technological application to control pathogenic bacteria and to protect food safety from postharvest deleterious microbiota. PMID:24151598

  3. [Outbreak of subclinical mastitis due to beta hemolytic group L streptococci (S. dysgalactiae ssp. equisimilis) in an Austrian dairy herd].

    Baumgartner, Martina; Giffinger, Friederike; Hoppe, Jan Christoph; Spergser, Joachim

    2011-01-01

    This study is reporting an outbreak of subclinical mastitis due to beta-hemolytic group L streptococci in an Austrian dairy herd with a history of high somatic cell count. At the first survey 16 of 33 lactating cows (28 quarters of 132) were cultured positive for beta-hemolytic, CAMP and esculin negative cocci that grew on Columbia blood agar with small grey catalase negative colonies. With the commercial API 20 Strep system (bioMerieux, F) isolates were classified as members of streptococci group L. All tested strains (eight of 28) produced acid from ribose, lactose, trehalose, amidon and glycogen; they hydrolysed hippurate and showed beta-glucuronidase, beta-galactosidase, alkaline phosphatase, leucinaminopeptidase and arginindehydrolase activity. Isolates were sensitive to bacitracin but resistant to tetracycline. Using phenotypic characterisation as well as sequence analysis of the 16S-23S intergenic spacer region of a representative strain, recovered isolates were identified as Streptococcus (S.) dysgalactiae ssp. equisimilis. Mastitis was characterized by normal milk secretions and absence of clinical abnormalities but high elevations of somatic cell count. Based on the characteristics of the strains and on the observations during the first herd survey, contagious transmission during milking as a result of poor milking hygiene was assumed. The mastitis was controlled through implementation of a strict hygiene protocol including use of single-use udder towels, post milking teat desinfection and cluster disinfection between milking cows in combination with antibiotic treatment of infected udders. PMID:22059292

  4. Prevalence of selected rickettsial infections in cats in Southern Germany.

    Bergmann, Michèle; Englert, Theresa; Stuetzer, Bianca; Hawley, Jennifer R; Lappin, Michael R; Hartmann, Katrin

    2015-10-01

    Prevalence of Anaplasma, Ehrlichia, Neorickettsia, and Wolbachia DNA in blood of 479 cats collected in different veterinary clinics in Southern Germany was determined using a previously published conventional PCR using 16S-23S intergenic spacer primers (5' CTG GGG ACT ACG GTC GCA AGA C 3' - forward; 5' CTC CAG TTT ATC ACT GGA AGT T 3' - reverse). Purified amplicons were sequenced to confirm genus and species. Associations between rickettsial infections, and feline immunodeficiency virus (FIV), as well as feline leukemia virus (FeLV) status were evaluated. Rickettsial prevalence was 0.4% (2/479; CI: 0.01-1.62%). In the two infected cats, Anaplasma phagocytophilum DNA was amplified. These cats came from different environment and had outdoor access. Both were ill with many of their problems likely related to other diseases. However, one cat had neutrophilia with left shift and the other thrombocytopenia potentially caused by their A. phagocytophilum infection. There was no significant difference in the FIV and FeLV status between A. phagocytophilum-negative and -positive cats. A. phagocytophilum can cause infection in cats in Southern Germany, and appropriate tick control is recommended. PMID:26387062

  5. Development of a quantitative PCR assay for monitoring Streptococcus agalactiae colonization and tissue tropism in experimentally infected tilapia.

    Su, Y-L; Feng, J; Li, Y-W; Bai, J-S; Li, A-X

    2016-02-01

    Streptococcus agalactiae has become one of the most important emerging pathogens in the aquaculture industry and has resulted in large economic losses for tilapia farms in China. In this study, three pairs of specific primers were designed and tested for their specificities and sensitivities in quantitative real-time polymerase chain reactions (qPCRs) after optimization of the annealing temperature. The primer pair IGS-s/IGS-a, which targets the 16S-23S rRNA intergenic spacer region, was finally chosen, having a detection limit of 8.6 copies of S. agalactiae DNA in a 20 μL reaction mixture. Bacterial tissue tropism was demonstrated by qPCR in Oreochromis niloticus 5 days post-injection with a virulent S. agalactiae strain. Bacterial loads were detected at the highest level in brain, followed by moderately high levels in kidney, heart, spleen, intestines, and eye. Significantly lower bacterial loads were observed in muscle, gill and liver. In addition, significantly lower bacterial loads were observed in the brain of convalescent O. niloticus 14 days post-injection with several different S. agalactiae strains. The qPCR for the detection of S. agalactiae developed in this study provides a quantitative tool for investigating bacterial tissue tropism in infected fish, as well as for monitoring bacterial colonization in convalescent fish. PMID:25858765

  6. Detection of Bartonella henselae and Bartonella clarridgeiae DNA in hepatic specimens from two dogs with hepatic disease.

    Gillespie, Tracey N; Washabau, Robert J; Goldschmidt, Michael H; Cullen, John M; Rogala, Allison R; Breitschwerdt, Edward B

    2003-01-01

    A 4-year-old Basset Hound and a 6-year-old Doberman Pinscher were referred for diagnostic evaluation following documentation of persistently increased hepatic enzyme activities and hepatic dysfunction. Histologic evaluation of hepatic biopsy specimens from the 2 dogs revealed granulomatous hepatitis in the Basset Hound and lymphocytic hepatitis with fibrosis and copper accumulation in the Doberman Pinscher. No etiologic agents were identified histologically. Bartonella henselae DNA was subsequently amplified from hepatic tissue from the Basset Hound and Bartonella clarridgeiae was amplified from hepatic tissue from the Doberman Pinscher. Amplification was performed with a polymerase chain reaction assay incorporating primers that target a portion of the 16S-23S rRNA intergenic spacer region. Both dogs were treated with azithromycin, in combination with a variety of other medications and herbal treatments, and improved clinically. Identification of Bartonella DNA in these dogs indicates the need for future prospective studies to determine the clinical relevance of Bartonella spp infection in dogs with hepatic disease. PMID:12523479

  7. Genetic diversity of indigenous Rhizobium leguminosarum bv. viciae isolates nodulating two different host plants during soil restoration with alfalfa

    Zhang, X.X.; Kosier, B.; Priefer, U.B. [Rheinisch-Westfaelische TH Aachen, Aachen (Germany)

    2001-09-01

    A total of 360 Rhizobium leguminosarum bv. viciae strains was isolated from three brown-coal mining restoration fields of different age and plant cover (without and in the first and second year of alfalfa, Medicago sativa, cultivation) using two host species (Vicia hirsuta and Pisum sativum) as capture plants. The strains were genetically typed by restriction fragment length polymorphism analysis of polymerase chain reaction (PCR)-generated 16S-23S ribosomal DNA intergenic spacer regions (IGS-RFLP) and characterized by plasmid profiles and RFLP analysis of amplified nodABC genes. The R. leguminosarum bv. viciae population was dominated by the same group of strains (irrespective of the trap plant used). According to type richness, the genetic diversity of indigenous R. leguminosarum in the second year of restoration was lower than in the first year and it resembled that of the fallow field, except for plasmid types, in which it was higher than that of the fallow field. Some of the less frequent nodABC genotypes were associated with distinct chromosomal IGS genotypes and symbiotic plasmids (pSyms) of different sizes, indicating that horizontal transfer and rearrangements of pSym can occur in natural environments. However, the dominant pSym and chromosomal genotypes were strictly correlated suggesting a genetically stable persistence of the prevailing R. leguminosarum bv, viciae genotypes in the absence of its host plant.

  8. Identification of Arcanobacterium pyogenes isolated by post mortem examinations of a bearded dragon and a gecko by phenotypic and genotypic properties

    Ülbegi-Mohyla, H.; Hijazin, M.; Alber, J.; Hassan, A. A.; Abdulmawjood, A.; Prenger-Berninghoff, E.; Weiß, R.; Zschöck, M.

    2010-01-01

    The present study was designed to identify phenotypically and genotypically two Arcanobacterium (A.) pyogenes strains isolated by post mortem examinations of a bearded dragon and a gecko. The A. pyogenes strains showed the typical biochemical properties and displayed CAMP-like synergistic hemolytic activities with various indicator strains. The species identity could be confirmed genotypically by amplification and sequencing of the 16S rDNA gene and, as novel target gene, by sequencing of the beta subunit of RNA polymerase encoding gene rpoB, of both strains and of reference strains representing nine species of the genus Arcanobacterium. The species identity of the two A. pyogenes strains could additionally be confirmed by PCR mediated amplification of species specific parts of the 16S-23S rDNA intergenic spacer region, the pyolysin encoding gene plo and by amplification of the collagen-binding protein encoding gene cbpA. All these molecular targets might help to improve the future identification and further characterization of A. pyogenes which, as demonstrated in the present study, could also be isolated from reptile specimens. PMID:20706035

  9. Identification of Arcanobacterium pyogenes isolated by post mortem examinations of a bearded dragon and a gecko by phenotypic and genotypic properties.

    Ulbegi-Mohyla, H; Hijazin, M; Alber, J; Lämmler, C; Hassan, A A; Abdulmawjood, A; Prenger-Berninghoff, E; Weiss, R; Zschöck, M

    2010-09-01

    The present study was designed to identify phenotypically and genotypically two Arcanobacterium (A.) pyogenes strains isolated by post mortem examinations of a bearded dragon and a gecko. The A. pyogenes strains showed the typical biochemical properties and displayed CAMP-like synergistic hemolytic activities with various indicator strains. The species identity could be confirmed genotypically by amplification and sequencing of the 16S rDNA gene and, as novel target gene, by sequencing of the beta subunit of RNA polymerase encoding gene rpoB, of both strains and of reference strains representing nine species of the genus Arcanobacterium. The species identity of the two A. pyogenes strains could additionally be confirmed by PCR mediated amplification of species specific parts of the 16S-23S rDNA intergenic spacer region, the pyolysin encoding gene plo and by amplification of the collagen-binding protein encoding gene cbpA. All these molecular targets might help to improve the future identification and further characterization of A. pyogenes which, as demonstrated in the present study, could also be isolated from reptile specimens. PMID:20706035

  10. Adenovirus and mycoplasma infection in an ornate box turtle (Terrapene ornata ornata) in Hungary.

    Farkas, Szilvia L; Gál, János

    2009-07-01

    A female, adult ornate box turtle (Terrapene ornata ornata) with fatty liver was submitted for virologic examination in Hungary. Signs of an adenovirus infection including degeneration of the liver cells, enlarged nuclei and intranuclear inclusion bodies were detected by light microscopic examination. The presence of an adenovirus was later confirmed by obtaining partial sequence data from the adenoviral DNA-dependent DNA-polymerase. Phylogenetic analyses revealed that this novel chelonian adenovirus was distinct from previously described reptilian adenoviruses, not belonging to any of the recognized genera of the family Adenoviridae. As a part of the routine diagnostic procedure for chelonians the detection of herpes-, rana- and iridoviruses together with Mycoplasma spp. was attempted. Amplicons were generated by a general mycoplasma polymerase chain reaction (PCR) targeting the 16S/23S ribosomal RNA (rRNA) intergenic spacer region, as well as, a specific Mycoplasma agassizii PCR targeting the 16S rRNA gene. Based on the analyses of partial sequences of the 16S rRNA gene, the Mycoplasma sp. of the ornate box turtle seemed to be identical with the recently described eastern box turtle (Terrapene carolina carolina) Mycoplasma sp. This is the first report of a novel chelonian adenovirus and a mycoplasma infection in an ornate box turtle (T. ornata ornata) in Europe. PMID:19375875

  11. A Mycoplasma species of Emydidae turtles in the northeastern USA.

    Ossiboff, Robert J; Raphael, Bonnie L; Ammazzalorso, Alyssa D; Seimon, Tracie A; Niederriter, Holly; Zarate, Brian; Newton, Alisa L; McAloose, Denise

    2015-04-01

    Mycoplasma infections can cause significant morbidity and mortality in captive and wild chelonians. As part of a health assessment of endangered bog turtles (Glyptemys muhlenbergii) in the northeastern US, choanal and cloacal swabs from these and other sympatric species, including spotted turtles (Clemmys guttata), eastern box turtles (Terrapene carolina carolina), wood turtles (Glyptemys insculpta), and common snapping turtles (Chelydra serpentina) from 10 sampling sites in the states (US) of Delaware, New Jersey, and Pennsylvania, were tested by PCR for Mycoplasma. Of 108 turtles tested, 63 (58.3%) were PCR positive for Mycoplasma including 58 of 83 bog turtles (70%), three of three (100%) eastern box turtles, and two of 11 (18%) spotted turtles; all snapping turtles (n = 7) and wood turtles (n = 4) were negative. Sequence analysis of portions of the 16S-23S intergenic spacer region and the 16S ribosomal RNA gene revealed a single, unclassified species of Mycoplasma that has been previously reported in eastern box turtles, ornate box turtles (Terrapene ornata ornata), western pond turtles (Emys marmorata), and red-eared sliders (Trachemys scripta elegans). We document a high incidence of Mycoplasma, in the absence of clinical disease, in wild emydid turtles. These findings, along with wide distribution of the identified Mycoplasma sp. across a broad geographic region, suggest this bacterium is likely a commensal inhabitant of bog turtles, and possibly other species of emydid turtles, in the northeastern US. PMID:25574806

  12. Alfalfa microsymbionts from different ITS and nodC lineages of Ensifer meliloti and Ensifer medicae symbiovar meliloti establish efficient symbiosis with alfalfa in Spanish acid soils.

    Ramírez-Bahena, Martha-Helena; Vargas, Margarita; Martín, María; Tejedor, Carmen; Velázquez, Encarna; Peix, Álvaro

    2015-06-01

    Alfalfa (Medicago sativa L.) is an important crop worldwide whose cropping in acid soils is hampered by the poor nodulation and yield commonly attributed to the sensitivity of its endosymbionts to acid pH. In this work, we isolated several acid-tolerant strains from alfalfa nodules in three acid soils in northwestern Spain. After grouping by RAPD fingerprinting, most strains were identified as Ensifer meliloti and only two strains as Ensifer medicae according to their 16S-23S intergenic spacer (ITS) sequences that allowed the differentiation of two groups within each one of these species. The two ITS groups of E. meliloti and the ITS group I of E. medicae have been previously found in Medicago nodules; however, the group II of E. medicae has been only found to date in Prosopis alba nodules. The analysis of the nodC gene showed that all strains isolated in this study belong to the symbiovar meliloti, grouping with the type strains of E. meliloti or E. medicae, but some harboured nodC gene alleles different from those found to date in alfalfa nodules. The strains of E. medicae belong to the symbiovar meliloti which should be also recognised in this species, although they harboured a nodC allele phylogenetically divergent to those from E. meliloti strains. Microcosm experiments showed that inoculation of alfalfa with selected acid-tolerant strains significantly increased yields in acid soils representing a suitable agricultural practice for alfalfa cropping in these soils. PMID:25586575

  13. Diversity and Antimicrobial Properties of Lactic Acid Bacteria Isolated from Rhizosphere of Olive Trees and Desert Truffles of Tunisia

    Imene Fhoula

    2013-01-01

    Full Text Available A total of 119 lactic acid bacteria (LAB were isolated, by culture-dependant method, from rhizosphere samples of olive trees and desert truffles and evaluated for different biotechnological properties. Using the variability of the intergenic spacer 16S-23S and 16S rRNA gene sequences, the isolates were identified as the genera Lactococcus, Pediococcus, Lactobacillus, Weissella, and Enterococcus. All the strains showed proteolytic activity with variable rates 42% were EPS producers, while only 10% showed the ability to grow in 9% NaCl. In addition, a low rate of antibiotic resistance was detected among rhizospheric enterococci. Furthermore, a strong antibacterial activity against plant and/or pathogenic bacteria of Stenotrophomonas maltophilia, Pantoea agglomerans, Pseudomonas savastanoi, the food-borne Staphylococcus aureus, and Listeria monocytogenes was recorded. Antifungal activity evaluation showed that Botrytis cinerea was the most inhibited fungus followed by Penicillium expansum, Verticillium dahliae, and Aspergillus niger. Most of the active strains belonged to the genera Enterococcus and Weissella. This study led to suggest that environmental-derived LAB strains could be selected for technological application to control pathogenic bacteria and to protect food safety from postharvest deleterious microbiota.

  14. Antibiotic-impregnated articulating cement spacer for infected total knee arthroplasty

    Parag Garg

    2011-01-01

    Full Text Available Background : Standard treatment of chronic infected total knee arthroplasty (TKA is a two-stage revision, the first step being placement of an antibiotic-impregnated cement spacer. Here we describe the results of a new technique (modification of the Goldstien′s technique for intraoperative manufacture of a customized articulating spacer at minimal cost and with relatively good conformity and longevity. Materials and Methods : Thirty-six infected knees underwent this procedure from June 2002 to May 2007. The technique consists of using the freshened femur and tibia interface as molds wrapped in a tin foil for manufacturing the two components of the spacer with antibiotic-impregnated methyl methycrylate cement. We used the spacer and the femoral component of the trial set of a TKA system to mold them to perfect articulation. We also reinforced the spacer with a K-wire scaffold to prevent fracture of the cement mantle in the last 21 cases. Results : All 36 knees showed excellent results in terms of infection control, mobility, and stability. There was significant improvement in the WOMAC and Knee Society Scores (20 and 39 points respectively. There were two fractures of the spacers in the initial 15 cases that did not have K-wire scaffolding but none in the last 21 that had reinforcement. Conclusion : This technique provides a more conforming spacer, with good range of motion and stability. The reinforcement helps in preventing the fracture of the cement mantle and is cost effective.

  15. A cis-regulatory sequence from a short intergenic region gives rise to a strong microbe-associated molecular pattern-responsive synthetic promoter.

    Lehmeyer, Mona; Hanko, Erik K R; Roling, Lena; Gonzalez, Lilian; Wehrs, Maren; Hehl, Reinhard

    2016-06-01

    The high gene density in Arabidopsis thaliana leaves only relatively short intergenic regions for potential cis-regulatory sequences. To learn more about the regulation of genes harbouring only very short upstream intergenic regions, this study investigates a recently identified novel microbe-associated molecular pattern (MAMP)-responsive cis-sequence located within the 101 bp long intergenic region upstream of the At1g13990 gene. It is shown that the cis-regulatory sequence is sufficient for MAMP-responsive reporter gene activity in the context of its native promoter. The 3' UTR of the upstream gene has a quantitative effect on gene expression. In context of a synthetic promoter, the cis-sequence is shown to achieve a strong increase in reporter gene activity as a monomer, dimer and tetramer. Mutation analysis of the cis-sequence determined the specific nucleotides required for gene expression activation. In transgenic A. thaliana the synthetic promoter harbouring a tetramer of the cis-sequence not only drives strong pathogen-responsive reporter gene expression but also shows a high background activity. The results of this study contribute to our understanding how genes with very short upstream intergenic regions are regulated and how these regions can serve as a source for MAMP-responsive cis-sequences for synthetic promoter design. PMID:26833485

  16. Titanium-copper-nitride coated spacers for two-stage revision of infected total hip endoprostheses

    Ellenrieder, Martin

    2011-01-01

    Full Text Available Within the first two years after total hip arthroplasty implant-associated infection has become the second most common reason for a revision surgery. Two-stage implant exchange is frequently conducted using temporary spacers made of antibiotic-loaded cement in order to prevent a bacterial colonization on the spacer. Avoiding several disadvantages of cement spacers, a conventional hemi-endoprosthesis was equipped with a copper-containing implant coating for inhibition of bacterial biofilms. In the present paper details of this novel treatment concept are presented including a case report.

  17. Experimental Study and Modelling of Spacer Grid Influence on Flow in Nuclear Fuel Assemblies

    Caraghiaur Garrido, Diana

    2009-01-01

    The work is focused on experimental study and modelling of spacer grid influence on single- and two-phase flow. In the experimental study a mock-up of a realistic fuel bundle with five spacer grids of thin plate spring construction was investigated. A special pressure measuring technique was used to measure pressure distribution inside the spacer. Five pressure taps were drilled in one of the rods, which could exchange position with other rods, in this way providing a large degree of freedom....

  18. Optimization of Radiation Therapy Techniques for Prostate Cancer With Prostate-Rectum Spacers: A Systematic Review

    Dose-escalated radiation therapy for localized prostate cancer improves disease control but is also associated with worse rectal toxicity. A spacer placed between the prostate and rectum can be used to displace the anterior rectal wall outside of the high-dose radiation regions and potentially minimize radiation-induced rectal toxicity. This systematic review focuses on the published data regarding the different types of commercially available prostate-rectum spacers. Dosimetric results and preliminary clinical data using prostate-rectum spacers in patients with localized prostate cancer treated by curative radiation therapy are compared and discussed

  19. APPLICATIONS OF SPACERS MADE WITH DOUBLE BAR RASCHEL MACHINE

    DÍAZ-GARCÍA Pablo

    2016-05-01

    Full Text Available Nowadays, textile technologies develop to adapt their different techniques for creating new products for the different sectors of application every day. Particularly, warp knitted fabrics and warp-knitting technology have applications in all different groups of technical textiles. It could be the most applied technique, the most versatile technology to develop new textile products for the new textile market. Warp knitted fabrics play the most important role among the technical textile fabrics. This technology is used in different product groups such as mobile textiles (car seat covers, dashboard cover, industrial textiles (composites, medical textiles (anti-decubitus blankets, sports textiles and foundation garments (bra cups, pads for swimwear. This study presents some examples of the application of this technology in some markets Within the market of technical textile, medical textile has an increasing relevance and knitted fabrics and knitting technology, at the same time, play a very important role in the fields of technical and medical textiles. Studies have demonstrated that knitted structures possess excellent mechanical properties and can promote more effective regenerative medicine, tissue repair, ligament, tendon cartilage, reconstruction, etc. The aim of this paper is to present different possibilities of textiles developed with this kind of structures, to present different alternatives, different examples of products obtained with this kind of textile structure combined with the correct kind of textile fiber. In this kind of technology, double-bar Raschel machines used for producing three-dimensional textiles, spacers, play an important role.

  20. Modulation of porphyrin photoluminescence by nanoscale spacers on silicon substrates

    Fang, Y. C.; Zhang, Y.; Gao, H. Y.; Chen, L. G.; Gao, B.; He, W. Z.; Meng, Q. S.; Zhang, C.; Dong, Z. C.

    2013-11-01

    We investigate photoluminescence (PL) properties of quasi-monolayered tetraphenyl porphyrin (TPP) molecules on silicon substrates modulated by three different nanoscale spacers: native oxide layer (NOL), hydrogen (H)-passivated layer, and Ag nanoparticle (AgNP) thin film, respectively. In comparison with the PL intensity from the TPP molecules on the NOL-covered silicon, the fluorescence intensity from the molecules on the AgNP-covered surface was greatly enhanced while that for the H-passivated surface was found dramatically suppressed. Time-resolved fluorescence spectra indicated shortened lifetimes for TPP molecules in both cases, but the decay kinetics is believed to be different. The suppressed emission for the H-passivated sample was attributed to the weaker decoupling effect of the monolayer of hydrogen atoms as compared to the NOL, leading to increased nonradiative decay rate; whereas the enhanced fluorescence with shortened lifetime for the AgNP-covered sample is attributed not only to the resonant excitation by local surface plasmons, but also to the increased radiative decay rate originating from the emission enhancement in plasmonic "hot-spots".

  1. Modulation of porphyrin photoluminescence by nanoscale spacers on silicon substrates

    Fang, Y.C. [Department of Vacuum Science and Engineering, Hefei University of Technology, Hefei, Anhui, 230009 (China); HFNL, University of Science and Technology of China, Hefei, Anhui, 230026 (China); Zhang, Y.; Gao, H.Y.; Chen, L.G.; Gao, B.; He, W.Z.; Meng, Q.S.; Zhang, C. [HFNL, University of Science and Technology of China, Hefei, Anhui, 230026 (China); Dong, Z.C., E-mail: zcdong@ustc.edu.cn [HFNL, University of Science and Technology of China, Hefei, Anhui, 230026 (China)

    2013-11-15

    We investigate photoluminescence (PL) properties of quasi-monolayered tetraphenyl porphyrin (TPP) molecules on silicon substrates modulated by three different nanoscale spacers: native oxide layer (NOL), hydrogen (H)-passivated layer, and Ag nanoparticle (AgNP) thin film, respectively. In comparison with the PL intensity from the TPP molecules on the NOL-covered silicon, the fluorescence intensity from the molecules on the AgNP-covered surface was greatly enhanced while that for the H-passivated surface was found dramatically suppressed. Time-resolved fluorescence spectra indicated shortened lifetimes for TPP molecules in both cases, but the decay kinetics is believed to be different. The suppressed emission for the H-passivated sample was attributed to the weaker decoupling effect of the monolayer of hydrogen atoms as compared to the NOL, leading to increased nonradiative decay rate; whereas the enhanced fluorescence with shortened lifetime for the AgNP-covered sample is attributed not only to the resonant excitation by local surface plasmons, but also to the increased radiative decay rate originating from the emission enhancement in plasmonic “hot-spots”.

  2. Manufacturing and Process-based Property Analysis of Textile-Reinforced Thermoplastic Spacer Composites

    Hufenbach, Werner; Adam, Frank; Füßel, René; Krahl, Michael; Weck, Daniel

    2012-12-01

    Novel woven spacer fabrics based on hybrid yarns are suitable for an efficient fabrication of three-dimensional composite structures in high volume production. In this paper, an innovative manufacturing process with short cycle times and high automatisation is introduced for textile-reinforced thermoplastic spacer structures suited for bending load cases. The different process steps hybrid yarn fabrication, weaving technology for three-dimensional textile preforms and consolidation with unique kinematics and hot pressing technology are described in detail. The bending properties of the manufactured spacer structures are evaluated by means of experiments as well as finite element simulations. Numerical parametric studies are performed in order to validate the influence of manufacturing tolerances on the bending stiffness of the spacer structures.

  3. Spacer grid effect visualization experiments during reflood period in a uniformly heated vertical single rod

    An experimental study has been performed to investigate an effect of spacer grid in an annulus flow channel with flat power shape single rod during the reflood phase with the variation of flooding velocity, inlet subcooling of water, and initial temperature of heater surface. Two types of spacer grid have been used. One type has swirl vane and the other has no swirl vane. Rewetting velocity through the swirl vane type spacer grid is faster than that of flat type grid and the temperature behavior of heater rod near the spacer grid is observed in a different pattern. Upper part of the heated length is cooled by top-down flooding phenomenon. The top-down flooding is mainly affected by the initial wall temperature. The present study is precursory one to 6 x 6 bundle reflood test, which will be launched at the near future by KAERI

  4. Suppression of subthreshold characteristics variation for junctionless multigate transistors using high-k spacers

    In this work, the high-k spacer is proposed to suppress the subthreshold characteristics variation of junctionless multigate transistor (JMT) with non-ideal sidewall angle for the first time. It is demonstrated that the variation of subthreshold characteristics induced by the changing sidewall angle is efficiently suppressed by high-k spacers due to the enhanced corner effect through the fringe capacitance, and the electrostatic integrity of JMTs is also improved at sub-22 nm gate length. Two key parameters of high-k spacer, the thickness and length, have been optimized in terms of the suppression of subthreshold characteristics variation. Then their optimal values are proposed. The benefit of high-k spacer makes JMTs more scalable. (paper)

  5. Coupling between Co and Gd-Co layers separated by nonmagnetic spacers

    We have studied the interlayer coupling between Co and Gd-Co layers separated by nonmagnetic spacers in a series of [Co/X/(Gd-Co)/X]4/Co multilayers (X=Cu, Ti and Si). The exchange interaction at the interfaces causes 'macroscopic ferrimagnetic behavior' in the whole structure. The critical field for a spin-orientation transition H * leading to a non-collinear magnetic structure in multilayers gives an estimate of the coupling strength. The critical field decreases with the spacer thickness for all spacer materials. The temperature dependence of the critical field, however, depends strongly on the spacer material. The differences are attributed to the fact that, in contrast to Cu and Ti, using Si can reduce the Co magnetic moment

  6. A study on the characteristics of the spacer spring by finite element method

    The mechanical integrity of spacer springs in KOFA was certified through the mechanical tests by KWU. In this report, the spacer spring characteristics were obtained by using a commercial FEM code ANSYS, and the calculated results were compared with the mechanical test results. It has been found that the analytical results from ANSYS were in good agreement with the test results in the actual working range of the spacer springs even though some errors occurred in the range of initial spring deflection. The errors were thought to occur due to the simplified boundary conditions and the nominal dimensions which are used in calculations rather than the as-fabricated dimensions. Though the results from ANSYS are not fully satisfied, the analytical method in this report has been verified to be used as a method for investigating the characteristic of spacer springs roughly before conducting mechanical tests. 8 tabs., 25 figs (Author) .new

  7. Computer-Aided Design Method of Warp-Knitted Jacquard Spacer Fabrics

    Li Xinxin

    2016-06-01

    Full Text Available Based on a further study on knitting and jacquard principles, this paper presents a mathematical design model to make computer-aided design of warp-knitted jacquard spacer fabrics more efficient. The mathematical model with matrix method employs three essential elements of chain notation, threading and Jacquard designing. With this model, the processing to design warp-knitted jacquard spacer fabrics with CAD software is also introduced. In this study, the sports shoes which have separated functional areas according to the feet structure and characteristics of movement are analysed. The results show the different patterns on Jacquard spacer fabrics that are seamlessly stitched with jacquard technics. The computer-aided design method of warp-knitted jacquard spacer fabrics is efficient and simple.

  8. Spacer geometry and particle deposition in spiral wound membrane feed channels

    Radu, A.I.

    2014-11-01

    Deposition of microspheres mimicking bacterial cells was studied experimentally and with a numerical model in feed spacer membrane channels, as used in spiral wound nanofiltration (NF) and reverse osmosis (RO) membrane systems. In-situ microscopic observations in membrane fouling simulators revealed formation of specific particle deposition patterns for different diamond and ladder feed spacer orientations. A three-dimensional numerical model combining fluid flow with a Lagrangian approach for particle trajectory calculations could describe very well the in-situ observations on particle deposition in flow cells. Feed spacer geometry, positioning and cross-flow velocity sensitively influenced the particle transport and deposition patterns. The deposition patterns were not influenced by permeate production. This combined experimental-modeling approach could be used for feed spacer geometry optimization studies for reduced (bio)fouling. © 2014 Elsevier Ltd.

  9. Design and fabrication of end spacers for a 13T Nb3Sn dipole magnet

    A 13 Tesia R ampersand D dipole magnet is currently being constructed using Nb3Sn superconducting cable. The four-layer ''cosine-theta'' magnet uses a wide cable (∼15 mm) that will undergo a 650 C reaction after each layer is wound. About 75 bronze spacers at the magnet ''ends'' separate the winding blocks in such a way that the stored strain energy in the cable is minimized and the integrated field harmonics are reduced. Wax prototypes of the designed spacers were made on a 5-axis milling machine. This method of rapid prototyping required no tooling and enabled us to produce a large number of different end spacers that can be physically inspected and repeatedly modified before final prototypes are made. Spacers were originally machined from wax billets which were later cast in bronze

  10. CRISPR Spacer Arrays for Detection of Viral Signatures from Acidic Hot Springs

    Snyder, J. C.; Bateson, M. M.; Suciu, D.; Young, M. J.

    2010-04-01

    Viruses are the most abundant life-like entities on the planet Earth. Using CRISPR spacer sequences, we have developed a microarray-based approach to detecting viral signatures in the acidic hot springs of Yellowstone.

  11. Current and power spectrum in a magnetic tunnel device with an atomic size spacer

    Bulka, Bogdan R.

    2000-01-01

    Current and its noise in a ferromagnetic double tunnel barrier device with a small spacer particle were studied in the framework of the sequential tunneling approach. Analytical formulae were derived for electron tunneling through the spacer particle containing only a single energy level. It was shown that Coulomb interactions of electrons with a different spin orientation lead to an increase of the tunnel magnetoresistance. Interactions can also be responsible for the negative differential r...

  12. The CRISPRdb database and tools to display CRISPRs and to generate dictionaries of spacers and repeats

    Vergnaud Gilles; Grissa Ibtissem; Pourcel Christine

    2007-01-01

    Abstract Background In Archeae and Bacteria, the repeated elements called CRISPRs for "clustered regularly interspaced short palindromic repeats" are believed to participate in the defence against viruses. Short sequences called spacers are stored in-between repeated elements. In the current model, motifs comprising spacers and repeats may target an invading DNA and lead to its degradation through a proposed mechanism similar to RNA interference. Analysis of intra-species polymorphism shows t...

  13. THE EQUIVALENT MECHANICAL MODELS OF LIQUID SLOSHING IN A SPHERICAL TANK WITH SPACER UNDER LOW GRAVITY

    CHENG Xu-duo; HU Mei-zhu; WEN Ji-hua

    2005-01-01

    The dynamics of liquid sloshing in a spherical tank with spacer under low gravity was investigated. By extending the characteristic functions, the frequencies of liquid free-sloshing, reaction force and moments on the wall of tank were obtained. By mechanical equivalent principle, the equivalent models of spring-vibrator-damper of liquid sloshing were given. The numerical results obtained show when a spacer is inserted in the tank, the sloshing frequency of liquid and the sloshing mass of liquid will decrease.

  14. Visualization of rDNA spacer transcription in Xenopus oocytes treated with fluorouridine

    Rungger, M.; Crippa, M; Trendelenburg, M F; Scheer, Ulrich; Franke, Werner W

    2009-01-01

    Under the intluence of 5-tluoro-uridine, the ultrastructure of the rDNA transcription units in Xenopus oocytes is altered. Whereas part of the matrix units maintains anormal aspect or shows various degrees of inhibition, in a strong proportion of the transcription units the alternating pattern of matrix units and fibril-free spacer regions is no longer recognized. Transcriptional complexes are found along the entire DNP axis, including the regions of the spacers. These observations support bi...

  15. A study on improvement of analytical prediction model for spacer grid pressure loss coefficients

    Nuclear fuel assemblies used in the nuclear power plants consist of the nuclear fuel rods, the control rod guide tubes, an instrument guide tube, spacer grids,a bottom nozzle, a top nozzle. The spacer grid is the most important component of the fuel assembly components for thermal hydraulic and mechanical design and analyses. The spacer grids fixed with the guide tubes support the fuel rods and have the very important role to activate thermal energy transfer by the coolant mixing caused to the turbulent flow and crossflow in the subchannels. In this paper, the analytical spacer grid pressure loss prediction model has been studied and improved by considering the test section wall to spacer grid gap pressure loss independently and applying the appropriate friction drag coefficient to predict pressure loss more accurately at the low Reynolds number region. The improved analytical model has been verified based on the hydraulic pressure drop test results for the spacer grids of three types with 5x5, 16x16, 17x17 arrays, respectively. The pressure loss coefficients predicted by the improved analytical model are coincident with those test results within ±12%. This result shows that the improved analytical model can be used for research and design change of the nuclear fuel assembly

  16. Impact analysis and test on the spacer grid assembly for PWRs

    A spacer grid assembly is one of the main structural components of the fuel assemblies of pressurized light water reactors. The spacer grid assembly is structurally required to have enough buckling strength under various kinds of lateral loads acting on the fuel assembly so as to keep the fuel assembly straight. The structural performance of the spacer grid assembly is characterized in terms of its dynamic crush strength, which is usually acquired from the test. In this study, a dynamic buckling test and a finite element analysis on the KAERI designed spacer grid assembly are carried out. The pendulum-type tester was used in the test. In the finite element analysis, we proposed an analysis methodology that could predict the dynamic failure behavior of the spacer grid assembly using a commercial finite element code ABAQUS/explicit with appropriate boundary conditions. As a result of the comparisons, the analysis result is in good agreement with the test result to within a 10% difference range. Therefore, we could predict the dynamic behaviors of a spacer grid assembly in advance before performing the dynamic buckling test. (orig.)

  17. Modeling of time-averaged film thickness distribution downstream of BWR functional spacers

    Functional spacers play an important role for the annular steam-water flow in boiling water reactors. They are designed to enhance droplet deposition and therefore delay dryout by sustaining the liquid film. Spacers also have an impact on the liquid film thickness on the fuel rod by their effect on the velocity field in the gas core of the flow. This work presents a CFD-based approach to predict the film thickness distribution in proximity of functional spacers based on a two-dimensional mass conservation equation for the liquid film coupled to a steady-state RANS simulation of the gas flow field. The model is validated by experiments with highly resolved film thickness data. For the experiments the gas flow rate, the liquid flow rate, the gas density and the spacer shape are varied. The model and experiments are in good agreement in regard to film thickness distributions downstream of spacers. A model sensitivity analysis shows the key parameters of the model and the potential for future development. The model aims to contribute to the development methodology of functional spacer optimization. (author)

  18. Effects of various spacer grid modeling on the neutronic parameters of the VVER-1000 reactor

    Highlights: → In this analysis, we presented the spacer girds modeling along the fuel assembly in their actual position. → In diffusion model, the material type in axial direction of core is different. In a simplified model like shroud model, the core includes the same material in axial direction. → The various modeling of spacer grids on the core reactivity and axial power distributions are studied. - Abstract: The main objective of this paper is to study the effects of various spacer grid models on the neutronic parameters of a VVER-1000 reactor. Specifically, the data of the nuclear power plant at the Bushehr site, which is of a VVER-1000 type, will be studied. Three models, representing the spacer grids along the fuel assemblies are presented. These three models are the homogeneous and the heterogeneous local spacer grid models and the shroud spacer grid model. In the homogeneous and the heterogeneous models, the spacer grids are considered at their actual locations in the axial direction. The only difference between the two models is that in the homogeneous model, the spacer grids are homogenized with the coolant while in the heterogeneous model, the spacer grids are modeled around the fuel cells at their exact axial positions. In the shroud model, the spacer grids are modeled in the shroud region containing the coolant and are not necessarily placed at their appropriate axial positions. The aforementioned models and the core geometry are modeled in 3-D hexagonal geometry and solved by the CITATION code. The required cross sections are obtained from the WIMS code using the associated ENDF/B-7 based library. The visual FORTRAN programming 90 is used for analysis of the whole calculation process and provides a sophisticated link between the WIMS and the CITATION codes during core cycle burnup. The core excess reactivity and the critical boron concentration of the reactor are calculated at normal operating state. In addition, the changes in the critical

  19. A New Intergenic α-Globin Deletion (α-α(Δ125)) Found in a Kabyle Population.

    Rabbind Singh, Amrathlal; Lacan, Philippe; Cadet, Estelle; Bignet, Patricia; Dumesnil, Cécile; Vannier, Jean-Pierre; Joly, Philippe; Rochette, Jacques

    2016-03-01

    We have identified a deletion of 125 bp (α-α(Δ125)) (NG_000006.1: g.37040_37164del) in the α-globin gene cluster in a Kabyle population. A combination of singlex and multiplex polymerase chain reaction (PCR)-based assays have been used to identify the molecular defect. Sequencing of the abnormal PCR amplification product revealed a novel α1-globin promoter deletion. The endpoints of the deletion were characterized by sequencing the deletion junctions of the mutated allele. The observed deletion was located 378 bp upstream of the α1-globin gene transcription initiation site and leaves the α2 gene intact. In some patients, the α-α(Δ125) deletion was shown to segregate with Hb S (HBB: c.20A>T) and/or Hb C (HBB: c.19G>A) or a β-thalassemic allele. The α-α(Δ125) deletion has no discernible effect on red cell indices when inherited with no other abnormal globin genes. The family study demonstrated that the deletion is heritable. This is the only example of an intergenic α2-α1 non coding DNA deletion, leaving the α2-globin gene and the α1 coding part intact. PMID:26911300

  20. Expressing activity of promoter elements of large intergenic region from cotton leaf curl virus in host plant*

    2001-01-01

    Cotton leaf curl virus (CLCuV) is a type of single-stranded DNAvirus, belonging to geminivirus of subgroup III. In order to determine the function of CLCuV large intergenic region (LIR), total DNA of CLCuV-infected cotton leaves was used as template, and fragment of LIR was obtained by PCR and inserted into clone vector. The fragment of LIR was fused with gus reporter gene and nos terminator in the orientation of transcription of virion sense and complementary sense respectively, and the plant expression vectors were constructed. GUS activity of Agrobacterium-mediated transgenic tobacco was measured. The result indicated that LIR showed strong promoter activity in complementary sense gene orientation. Average GUS activity of the complementary sense promoter was 5-6 times that of CaMV 35S promoter, and the highest GUS activity of individual plant was ten times of that of CaMV 35S promoter. Histochemical localization confirmed its activity in both mesophyll and vascular tissues. Activity of virion sense of LIR was rather low. Thus LIR isolated from CLCuV could be used as a novel strong promoter in plant genetic manipulation.

  1. Genetic Diversity in Salmonella Isolates from Ducks and their Environments in Penang, Malaysia using Enterobacterial Repetitive Intergenic Consensus

    Frederick Adzitey 1, Gulam Rusul Rahmat Ali2*, Nurul Huda2 and Rosma Ahmad3

    2013-07-01

    Full Text Available A total of 107 Salmonella isolates (37 S. typhimurium, 26 S. hadar, 15 S. enteritidis, 15 S. braenderup, and 14 S. albany isolated from ducks and their environments in Penang, Malaysia were typed using enterobacterial repetitive intergenic consensus (ERIC to determine their genetic diversity. Analysis of the Salmonella strains by ERIC produced DNA fingerprints of different sizes for differentiation purposes. The DNA fingerprints or band sizes ranged from 14-8300bp for S. Typhimurium, 146-6593bp for S. hadar, 15-4929bp for S. enteritidis, 14-5142bp for S. braenderup and 7-5712bp for S. albany. Cluster analysis at a coefficient of 0.85 grouped the Salmonella strains into various clusters and singletons. S. typhimurium were grouped into 10 clusters and 6 singletons, S. Hadar were grouped into 3 clusters and 18 singletons, S. enteritidis were grouped into 3 clusters and 7 singletons, S. braenderup were grouped into 4 clusters and 7 singletons, and S. albany were grouped into 3 clusters and 7 singletons with discriminatory index (D ranging from 0.92-0.98. ERIC proved to be a useful typing tool for determining the genetic diversity of the duck Salmonella strains.

  2. IDENTIFICACIÓN MOLECULAR DE POBLACIONES BACTERIANAS ASOCIADAS AL CARACOL PALA (Strombus gigas DEL CARIBE COLOMBIANO

    ROMERO MAGALLY

    2009-08-01

    . However, it is currently catalogued as “vulnerable”; there is limited information concerning the bacterial species associated with conch and important in the management of hatcheries for higher productivity and safety of these gastropods. In this study, we used a microbiology and molecular approach using the 16S-23S intergenic region, the 16S rDNA analysis and sequencing to determine the bacterial populations associated with Queen Conch (S. gigas. Also, the capacity to grow in marine agar and selective culture media was used to evaluate the composition of bacteria associated. The 28 total samples analysed we found the number of bacteria recovered after aerobic culture about 106 cfu mL-1 and most belong to the Vibrionaceae family in the order of 105 ufc mL-1. The molecular results of the spacer regions between the 16 and 23S genes from the different analyzed samples indicated a great complexity in the bacterial population associated to S. gigas. The sequencing of the amplicons of 16S rDNA identifies Pseudoalteromonas sp, Halomonas sp., Psycrobacter sp., Cobetia sp., Pseudomonas sp. and Vibrios sp. This suggests these bacteria can play an important role as components of the bacterial community associated to S. gigas. This information can help to improve both the management of hatcheries for higher productivity and for the implementation for the conservation processes of Colombian S. gigas.

    Key words: Strombus gigas, Queen Conch, Bacteria, 16S-23S intergenic region, 16S rDNA.

  3. A functional analysis of the spacer of V(DJ recombination signal sequences.

    Alfred Ian Lee

    2003-10-01

    Full Text Available During lymphocyte development, V(DJ recombination assembles antigen receptor genes from component V, D, and J gene segments. These gene segments are flanked by a recombination signal sequence (RSS, which serves as the binding site for the recombination machinery. The murine Jbeta2.6 gene segment is a recombinationally inactive pseudogene, but examination of its RSS reveals no obvious reason for its failure to recombine. Mutagenesis of the Jbeta2.6 RSS demonstrates that the sequences of the heptamer, nonamer, and spacer are all important. Strikingly, changes solely in the spacer sequence can result in dramatic differences in the level of recombination. The subsequent analysis of a library of more than 4,000 spacer variants revealed that spacer residues of particular functional importance are correlated with their degree of conservation. Biochemical assays indicate distinct cooperation between the spacer and heptamer/nonamer along each step of the reaction pathway. The results suggest that the spacer serves not only to ensure the appropriate distance between the heptamer and nonamer but also regulates RSS activity by providing additional RAG:RSS interaction surfaces. We conclude that while RSSs are defined by a "digital" requirement for absolutely conserved nucleotides, the quality of RSS function is determined in an "analog" manner by numerous complex interactions between the RAG proteins and the less-well conserved nucleotides in the heptamer, the nonamer, and, importantly, the spacer. Those modulatory effects are accurately predicted by a new computational algorithm for "RSS information content." The interplay between such binary and multiplicative modes of interactions provides a general model for analyzing protein-DNA interactions in various biological systems.

  4. A functional analysis of the spacer of V(D)J recombination signal sequences.

    Lee, Alfred Ian; Fugmann, Sebastian D; Cowell, Lindsay G; Ptaszek, Leon M; Kelsoe, Garnett; Schatz, David G

    2003-10-01

    During lymphocyte development, V(D)J recombination assembles antigen receptor genes from component V, D, and J gene segments. These gene segments are flanked by a recombination signal sequence (RSS), which serves as the binding site for the recombination machinery. The murine Jbeta2.6 gene segment is a recombinationally inactive pseudogene, but examination of its RSS reveals no obvious reason for its failure to recombine. Mutagenesis of the Jbeta2.6 RSS demonstrates that the sequences of the heptamer, nonamer, and spacer are all important. Strikingly, changes solely in the spacer sequence can result in dramatic differences in the level of recombination. The subsequent analysis of a library of more than 4,000 spacer variants revealed that spacer residues of particular functional importance are correlated with their degree of conservation. Biochemical assays indicate distinct cooperation between the spacer and heptamer/nonamer along each step of the reaction pathway. The results suggest that the spacer serves not only to ensure the appropriate distance between the heptamer and nonamer but also regulates RSS activity by providing additional RAG:RSS interaction surfaces. We conclude that while RSSs are defined by a "digital" requirement for absolutely conserved nucleotides, the quality of RSS function is determined in an "analog" manner by numerous complex interactions between the RAG proteins and the less-well conserved nucleotides in the heptamer, the nonamer, and, importantly, the spacer. Those modulatory effects are accurately predicted by a new computational algorithm for "RSS information content." The interplay between such binary and multiplicative modes of interactions provides a general model for analyzing protein-DNA interactions in various biological systems. PMID:14551903

  5. Genome-wide identification and characterization of long intergenic noncoding RNAs and their potential association with larval development in the Pacific oyster

    Yu, Hong; Zhao, Xuelin; Li, Qi

    2016-01-01

    An increasing amount of evidence suggests that long intergenic noncoding RNAs (lincRNAs) may play diverse roles in many cellular processes. However, little is known about lincRNAs in marine invertebrates. Here, we presented the first identification and characterization of lincRNAs in the Pacific oyster (Crassostrea gigas). We developed a pipeline and identified 11,668 lincRNAs in C. gigas based on RNA-Seq resources available. These lincRNAs exhibited many common characteristics with vertebrat...

  6. Identification of SmtB/ArsR cis elements and proteins in archaea using the Prokaryotic InterGenic Exploration Database (PIGED)

    Bose, Michael; Slick, David; Sarto, Mickey J.; Roberts, David; Roberts, Jacqueline; Barber, Robert D.

    2006-01-01

    Microbial genome sequencing projects have revealed an apparently wide distribution of SmtB/ArsR metal-responsive transcriptional regulators among prokaryotes. Using a position-dependent weight matrix approach, prokaryotic genome sequences were screened for SmtB/ArsR DNA binding sites using data derived from intergenic sequences upstream of orthologous genes encoding these regulators. Sixty SmtB/ArsR operators linked...

  7. Identification of SmtB/ArsR cis elements and proteins in archaea using the Prokaryotic InterGenic Exploration Database (PIGED)

    Michael Bose; David Slick; Sarto, Mickey J.; Patrick Murphy; David Roberts; Jacqueline Roberts; Barber, Robert D.

    2006-01-01

    Microbial genome sequencing projects have revealed an apparently wide distribution of SmtB/ArsR metal-responsive transcriptional regulators among prokaryotes. Using a position-dependent weight matrix approach, prokaryotic genome sequences were screened for SmtB/ArsR DNA binding sites using data derived from intergenic sequences upstream of orthologous genes encoding these regulators. Sixty SmtB/ArsR operators linked to metal detoxification genes, including nine among various archaeal species,...

  8. Knitting Technologies And Tensile Properties Of A Novel Curved Flat-Knitted Three-Dimensional Spacer Fabrics

    Li Xiaoying

    2015-09-01

    Full Text Available This paper introduces a knitting technique for making innovative curved three-dimensional (3D spacer fabrics by the computer flat-knitting machine. During manufacturing, a number of reinforcement yarns made of aramid fibres are inserted into 3D spacer fabrics along the weft direction to enhance the fabric tensile properties. Curved, flat-knitted 3D spacer fabrics with different angles (in the warp direction were also developed. Tensile tests were carried out in the weft and warp directions for the two spacer fabrics (with and without reinforcement yarns, and their stress–strain curves were compared. The results showed that the reinforcement yarns can reduce the fabric deformation and improve tensile stress and dimensional stability of 3D spacer fabrics. This research can help the further study of 3D spacer fabric when applied to composites.

  9. Transcriptional regulator-mediated activation of adaptation genes triggers CRISPR de novo spacer acquisition

    Liu, Tao; Li, Yingjun; Wang, Xiaodi;

    2015-01-01

    Acquisition of de novo spacer sequences confers CRISPR-Cas with a memory to defend against invading genetic elements. However, the mechanism of regulation of CRISPR spacer acquisition remains unknown. Here we examine the transcriptional regulation of the conserved spacer acquisition genes in Type I...... was demonstrated that the transcription level of csa1, cas1, cas2 and cas4 was significantly enhanced in a csa3a-overexpression strain and, moreover, the Csa1 and Cas1 protein levels were increased in this strain. Furthermore, we demonstrated the hyperactive uptake of unique spacers within both CRISPR...... loci in the presence of the csa3a overexpression vector. The spacer acquisition process is dependent on the CCN PAM sequence and protospacer selection is random and non-directional. These results suggested a regulation mechanism of CRISPR spacer acquisition where a single transcriptional regulator...

  10. Ion therapy of prostate cancer: daily rectal dose reduction by application of spacer gel

    Ion beam therapy represents a promising approach to treat prostate cancer, mainly due to its high conformity and radiobiological effectiveness. However, the presence of prostate motion, patient positioning and range uncertainties may deteriorate target dose and increase exposure of organs at risk. Spacer gel injected between prostate and rectum may increase the safety of prostate cancer (PC) radiation therapy by separating the rectum from the target dose field. The dosimetric impact of the application of spacer gel for scanned carbon ion therapy of PC has been analyzed at Heidelberg Ion-Beam Therapy Center (HIT). The robustness of ion therapy treatment plans was investigated by comparison of two data sets of patients treated with and without spacer gel. A research treatment planning system for ion therapy was used for treatment plan optimization and calculation of daily dose distributions on 2 to 9 Computed Tomography (CT) studies available for each of the 19 patients. Planning and daily dose distributions were analyzed with respect to target coverage, maximal dose to the rectum (excluding 1 ml of the greatest dose; Dmax-1 ml) and the rectal volume receiving dose greater than 90% of prescribed target dose (V90Rectum), respectively. The application of spacer gel did substantially diminish rectum dose. Dmax-1 ml on the treatment planning CT was on average reduced from 100.0 ± 1.0% to 90.2 ± 4.8%, when spacer gel was applied. The robustness analysis performed with daily CT studies demonstrated for all analyzed patient cases that application of spacer gel results in a decrease of the daily V90Rectum index, which calculated over all patient cases and CT studies was 10.2 ± 10.4 [ml] and 1.1 ± 2.1 [ml] for patients without and with spacer gel, respectively. The dosimetric benefit of increasing the distance between prostate and rectum using spacer gel for PC treatment with carbon ion beams has been quantified. Application of spacer gel substantially reduced rectal