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Sample records for amplification reaction pear

  1. Polymerase-endonuclease amplification reaction (PEAR for large-scale enzymatic production of antisense oligonucleotides.

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    Xiaolong Wang

    Full Text Available Antisense oligonucleotides targeting microRNAs or their mRNA targets prove to be powerful tools for molecular biology research and may eventually emerge as new therapeutic agents. Synthetic oligonucleotides are often contaminated with highly homologous failure sequences. Synthesis of a certain oligonucleotide is difficult to scale up because it requires expensive equipment, hazardous chemicals and a tedious purification process. Here we report a novel thermocyclic reaction, polymerase-endonuclease amplification reaction (PEAR, for the amplification of oligonucleotides. A target oligonucleotide and a tandem repeated antisense probe are subjected to repeated cycles of denaturing, annealing, elongation and cleaving, in which thermostable DNA polymerase elongation and strand slipping generate duplex tandem repeats, and thermostable endonuclease (PspGI cleavage releases monomeric duplex oligonucleotides. Each round of PEAR achieves over 100-fold amplification. The product can be used in one more round of PEAR directly, and the process can be further repeated. In addition to avoiding dangerous materials and improved product purity, this reaction is easy to scale up and amenable to full automation. PEAR has the potential to be a useful tool for large-scale production of antisense oligonucleotide drugs.

  2. Comparative genomic analysis reveals multiple long terminal repeats, lineage-specific amplification, and frequent interelement recombination for Cassandra retrotransposon in pear (Pyrus bretschneideri Rehd.).

    Science.gov (United States)

    Yin, Hao; Du, Jianchang; Li, Leiting; Jin, Cong; Fan, Lian; Li, Meng; Wu, Jun; Zhang, Shaoling

    2014-06-04

    Cassandra transposable elements belong to a specific group of terminal-repeat retrotransposons in miniature (TRIM). Although Cassandra TRIM elements have been found in almost all vascular plants, detailed investigations on the nature, abundance, amplification timeframe, and evolution have not been performed in an individual genome. We therefore conducted a comprehensive analysis of Cassandra retrotransposons using the newly sequenced pear genome along with four other Rosaceae species, including apple, peach, mei, and woodland strawberry. Our data reveal several interesting findings for this particular retrotransposon family: 1) A large number of the intact copies contain three, four, or five long terminal repeats (LTRs) (∼20% in pear); 2) intact copies and solo LTRs with or without target site duplications are both common (∼80% vs. 20%) in each genome; 3) the elements exhibit an overall unbiased distribution among the chromosomes; 4) the elements are most successfully amplified in pear (5,032 copies); and 5) the evolutionary relationships of these elements vary among different lineages, species, and evolutionary time. These results indicate that Cassandra retrotransposons contain more complex structures (elements with multiple LTRs) than what we have known previously, and that frequent interelement unequal recombination followed by transposition may play a critical role in shaping and reshaping host genomes. Thus this study provides insights into the property, propensity, and molecular mechanisms governing the formation and amplification of Cassandra retrotransposons, and enhances our understanding of the structural variation, evolutionary history, and transposition process of LTR retrotransposons in plants. © The Author(s) 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  3. Nucleic acid amplification: Alternative methods of polymerase chain reaction

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    Md Fakruddin

    2013-01-01

    Full Text Available Nucleic acid amplification is a valuable molecular tool not only in basic research but also in application oriented fields, such as clinical medicine development, infectious diseases diagnosis, gene cloning and industrial quality control. A comperehensive review of the literature on the principles, applications, challenges and prospects of different alternative methods of polymerase chain reaction (PCR was performed. PCR was the first nucleic acid amplification method. With the advancement of research, a no of alternative nucleic acid amplification methods has been developed such as loop mediated isothermal amplification, nucleic acid sequence based amplification, strand displacement amplification, multiple displacement amplification. Most of the alternative methods are isothermal obviating the need for thermal cyclers. Though principles of most of the alternate methods are relatively complex than that of PCR, they offer better applicability and sensitivity in cases where PCR has limitations. Most of the alternate methods still have to prove themselves through extensive validation studies and are not available in commercial form; they pose the potentiality to be used as replacements of PCR. Continuous research is going on in different parts of the world to make these methods viable technically and economically.

  4. Mechanism of chimera formation during the Multiple Displacement Amplification reaction

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    Stockwell Timothy B

    2007-04-01

    Full Text Available Abstract Background Multiple Displacement Amplification (MDA is a method used for amplifying limiting DNA sources. The high molecular weight amplified DNA is ideal for DNA library construction. While this has enabled genomic sequencing from one or a few cells of unculturable microorganisms, the process is complicated by the tendency of MDA to generate chimeric DNA rearrangements in the amplified DNA. Determining the source of the DNA rearrangements would be an important step towards reducing or eliminating them. Results Here, we characterize the major types of chimeras formed by carrying out an MDA whole genome amplification from a single E. coli cell and sequencing by the 454 Life Sciences method. Analysis of 475 chimeras revealed the predominant reaction mechanisms that create the DNA rearrangements. The highly branched DNA synthesized in MDA can assume many alternative secondary structures. DNA strands extended on an initial template can be displaced becoming available to prime on a second template creating the chimeras. Evidence supports a model in which branch migration can displace 3'-ends freeing them to prime on the new templates. More than 85% of the resulting DNA rearrangements were inverted sequences with intervening deletions that the model predicts. Intramolecular rearrangements were favored, with displaced 3'-ends reannealing to single stranded 5'-strands contained within the same branched DNA molecule. In over 70% of the chimeric junctions, the 3' termini had initiated priming at complimentary sequences of 2–21 nucleotides (nts in the new templates. Conclusion Formation of chimeras is an important limitation to the MDA method, particularly for whole genome sequencing. Identification of the mechanism for chimera formation provides new insight into the MDA reaction and suggests methods to reduce chimeras. The 454 sequencing approach used here will provide a rapid method to assess the utility of reaction modifications.

  5. A simple model for chiral amplification in the aminoalcohol-catalyzed reaction of aldehydes with dialkylzinc

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    IVAN GUTMAN

    1999-08-01

    Full Text Available A simple explanation is offered for the recently discovered chiral amplification in the alkylation reaction of benzaldehyde by means of dialkylzinc, catalyzed by (dimethylaminoisoborneol. The model presentd is similar to, yet somewhat simpler than, the model put forward by Noyori et al.

  6. Thermostable Mismatch-Recognizing Protein MutS Suppresses Nonspecific Amplification during Polymerase Chain Reaction (PCR

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    Seiki Kuramitsu

    2013-03-01

    Full Text Available Polymerase chain reaction (PCR-related technologies are hampered mainly by two types of error: nonspecific amplification and DNA polymerase-generated mutations. Here, we report that both errors can be suppressed by the addition of a DNA mismatch-recognizing protein, MutS, from a thermophilic bacterium. Although it had been expected that MutS has a potential to suppress polymerase-generated mutations, we unexpectedly found that it also reduced nonspecific amplification. On the basis of this finding, we propose that MutS binds a mismatched primer-template complex, thereby preventing the approach of DNA polymerase to the 3' end of the primer. Our simple methodology improves the efficiency and accuracy of DNA amplification and should therefore benefit various PCR-based applications, ranging from basic biological research to applied medical science.

  7. Simplifying Nucleic Acid Amplification from Whole Blood with Direct Polymerase Chain Reaction on Chitosan Microparticles.

    Science.gov (United States)

    Nanayakkara, Imaly A; Cao, Weidong; White, Ian M

    2017-03-21

    Tremendous advances have been made in the development of portable nucleic acid amplification devices for near-patient use. However, the true limitation in the realization of nucleic acid amplification tests (NAATs) for near-patient applications is not the amplification reaction, it is the complexity of the sample preparation. Conventional approaches require several precise intervention steps during the protocol. There are numerous reports in the literature that mimic the sample preparation procedure within a lab-on-a-chip device or cartridge, but these systems require a high number of integrated steps, making the devices and/or their supporting equipment too complex to meet the necessary cost targets and regulatory requirements for near-patient applications. Here we report a simplified method to purify and amplify DNA from complex samples in a minimal number of steps. We show that chitosan-coated microparticles can lyse human cells and capture the released DNA in a single mechanical agitation step, and we show that bound DNA can be amplified directly from the microparticle surface when the magnetic microparticles are transferred to a polymerase chain reaction (PCR). This procedure eliminates (i) the use of PCR-inhibiting reagents (e.g., chaotropic salts and alcohol) and (ii) the washing and elution steps that are required to remove these reagents and release DNA in typical NAAT sample preparation methods. To illustrate the use of this direct PCR method in diagnostics, we amplify human genomic DNA sequences from a ∼1 μL droplet of whole blood, and we amplify plasmid DNA spiked into whole blood droplets to represent circulating viral DNA or cell-free DNA. The qPCR threshold cycle for direct PCR from whole blood is comparable to that of direct PCR with purified DNA, demonstrating that the lysis and capture steps effectively bind DNA and sufficiently enable its amplification. Furthermore, the efficient amplification of plasmid DNA spiked into whole blood proves that

  8. Probable hypoglycemic adverse drug reaction associated with prickly pear cactus, glipizide, and metformin in a patient with type 2 diabetes mellitus.

    Science.gov (United States)

    Sobieraj, Diana M; Freyer, Craig W

    2010-01-01

    To report a case of an adverse drug reaction (ADR) in a patient with type 2 diabetes mellitus taking prickly pear cactus (PPC), glipizide, and metformin. A 58-year-old Mexican male with type 2 diabetes mellitus being treated with metformin 1000 mg twice daily and extended-release glipizide 10 mg daily was referred to the pharmacist for medication education. He denied taking herbal supplements or experiencing hypoglycemia. Two hemoglobin A(1c) values (6.8% and 6.7%) obtained over the past year demonstrated glycemic control, which was supported by his reported fasting blood glucose readings of 113-132 mg/dL. One month later, the patient reported 4 hypoglycemic events with blood glucose readings of 49-68 mg/dL, which resulted in discontinuation of glipizide. One month later, the patient denied any further hypoglycemia. During medication reconciliation he reported consuming crude PPC pads daily for 2 months for glucose control. Literature suggests that PPC has an effect on lowering blood glucose levels in patients with type 2 diabetes mellitus, although few identified data describe ADRs from combining PPC with other agents used in treating type 2 diabetes mellitus. A literature search of MEDLINE (through December 2009) using the search terms diabetes mellitus, prickly pear cactus, nopal, opuntia, metformin, glipizide, glyburide, glimepiride, and sulfonylurea revealed no case reports of the described ADR. One case report describing the blood glucose-lowering effect of PPC in a patient concurrently taking oral antihyperglycemics documented an episode of hypoglycemia, although the Naranjo probability scale was not applied. One patient survey discovered the most common drug-herbal interaction in the given population to be between PPC and antihyperglycemic agents, resulting in hypoglycemia. In our case, use of the Naranjo probability scale suggests the ADR to be probable. The mechanism may be due to the additive glucose lowering of the 3 agents consumed concurrently by the

  9. Amplification of the Fusion Gene of Rinderpest Virus by Polymerase Chain Reaction and Cloning in Bacteria

    OpenAIRE

    BULUT, Hakan

    2014-01-01

    In this study, amplification of the rinderpest virus (RPV) fusion (F) gene with polymerase chain reaction (PCR) and cloning of the F gene in Escherichia coli were reported. For this purpose, first total mRNA from Vero cells infected with vaccine strain of RPV was obtained and then cDNA from this mRNA preparation was acquired with reverse transcription. In PCR, cDNA from infected Vero cells and F gene specific primers were used and the F gene was amplified. Both the PCR product and the clonin...

  10. Reverse transcription and polymerase chain reaction amplification of rRNA for detection of Helicobacter species.

    OpenAIRE

    Engstrand, L; Nguyen, A M; Graham, D Y; el-Zaatari, F A

    1992-01-01

    Sequence data on Helicobacter pylori 16S rRNA were used to select two 22-base oligonucleotide primers for use in a polymerase chain reaction (PCR) for detection of H. pylori. H. pylori cells were treated with lysis buffer, boiled, and chloroform extracted. Reverse transcription of rRNA was followed by PCR amplification (RT-PCR) of the synthesized cDNA and 16S rRNA gene. The amplified PCR products were analyzed by agarose gel electrophoresis and Southern blotting. Using ethidium bromide-staine...

  11. Detection of genital human papillomaviruses by polymerase chain reaction amplification with degenerate nested primers.

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    Williamson, A L; Rybicki, E P

    1991-03-01

    Degenerate oligonucleotide primers were designed for in vitro amplification by polymerase chain reaction (PCR) of a relatively well-conserved portion of the L1 capsid protein gene of genital human papillomaviruses. A specific 441bp fragment was amplified by PCR from genomic clones and clinical biopsy specimens containing DNA from HPV types 6, 11, 16, 18, 31, and 33, as well as from a number of other clinical specimens known to contain unclassified HPV isolates. As some HPV non-specific DNA was also often amplified, another set of degenerate primers was designed which amplified a 335 bp sequence contained within the 441 bp sequence. These nested primers could be used in a two-stage PCR reaction to obtain distinct HPV-specific DNA fragments suitable for direct sequencing. Two-stage PCR was used to demonstrate the presence of HPV DNA in 13 out of 16 biopsies, which had been classified histologically as cervical intraepithelial neoplasia (CIN), but which were negative for HPV on Southern blot hybridization. Seven of these amplification products were sequenced, and one proved to be a previously unsequenced HPV type. The results have important implications for the routine detection and typing of genital and other HPV types in clinical samples.

  12. Monodisperse Picoliter Droplets for Low-Bias and Contamination-Free Reactions in Single-Cell Whole Genome Amplification.

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    Yohei Nishikawa

    Full Text Available Whole genome amplification (WGA is essential for obtaining genome sequences from single bacterial cells because the quantity of template DNA contained in a single cell is very low. Multiple displacement amplification (MDA, using Phi29 DNA polymerase and random primers, is the most widely used method for single-cell WGA. However, single-cell MDA usually results in uneven genome coverage because of amplification bias, background amplification of contaminating DNA, and formation of chimeras by linking of non-contiguous chromosomal regions. Here, we present a novel MDA method, termed droplet MDA, that minimizes amplification bias and amplification of contaminants by using picoliter-sized droplets for compartmentalized WGA reactions. Extracted DNA fragments from a lysed cell in MDA mixture are divided into 105 droplets (67 pL within minutes via flow through simple microfluidic channels. Compartmentalized genome fragments can be individually amplified in these droplets without the risk of encounter with reagent-borne or environmental contaminants. Following quality assessment of WGA products from single Escherichia coli cells, we showed that droplet MDA minimized unexpected amplification and improved the percentage of genome recovery from 59% to 89%. Our results demonstrate that microfluidic-generated droplets show potential as an efficient tool for effective amplification of low-input DNA for single-cell genomics and greatly reduce the cost and labor investment required for determination of nearly complete genome sequences of uncultured bacteria from environmental samples.

  13. Visual detection of nucleic acids based on lateral flow biosensor and hybridization chain reaction amplification.

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    Ying, Na; Ju, Chuanjing; Li, Zhongyi; Liu, Wensen; Wan, Jiayu

    2017-03-01

    In this study, a new lateral flow nucleic acid biosensor (LFNAB) using hybridization chain reaction (HCR) for signal amplification was developed for visual detection of nucleic acids with high sensitivity and low cost. A "sandwich-type" detection strategy was employed in our design. The sandwich system of capture probe (CP)/target DNA/reporter probe (RP)-HCR complexes was fabricated as the sensing platform. As the initiator strand, reporter probe propagated a chain reaction of hybridization events between the two hairpin probes modified with biotin, and determined whether long nicked DNA polymers were formed. The biotin-labeled double-strand DNA polymers then introduced numerous Streptavidin (SA)-labeled gold nanoparticles (AuNPs) on the lateral flow device. The CP/target DNA/RP-HCR complexes were captured on the test zone by the specific reaction between anti-Fam monoclonal antibody (anti-Fam mAb) on the test zone and Fam of the complexes. The accumulation of AuNPs on the test zone of the biosensor enabled the visual detection of specific sequences. The detection limit of specific DNA was as low as 1.76pM, which was about 2 orders lower than that of the LFNAB without HCR amplification. And the detection limit of Salmonella was 3×10 3 cfumL -1 . In conclusion, this visual detection system, HCR-LFNAB, is suitable for non-specialist personnel and point-of-care (POC) diagnosis in low-resource settings. Copyright © 2016. Published by Elsevier B.V.

  14. DNA amplification fingerprinting using 10 x polymerase chain reaction buffer with ammonium sulfate for human identification.

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    Baransel, Aysun; Dulger, Hikmet E; Tokdemir, Mehmet

    2004-06-01

    The polymerase chain reaction (PCR) - based DNA amplification fingerprinting (DAF) or randomly amplified polymorphic DNA (RAPD) is based on a strategy using a single arbitrary oligonucleotide primer to generate anonymous amplification of genomic DNA. On this basic strategy, in this study, we aimed to test individual differences and usefulness of 2 basic primers (5'-CGCGCCGG-3' and 5'-TGCCGAGCTG-3') and examined whether there is a positive effect on results of 10 x PCR buffer with ammonium sulfate. A new approach in DNA fingerprinting, 10 x PCR buffer with ammonium sulfate, is presented in the study. Primers with single 8 and 10 nucleotides in length and 2 different PCR buffers with or without ammonium sulfate were used to identify 135 volunteers with no blood relationship. This study was carried out at the Pharmacology Laboratory, University of Gaziantep, School of Medicine, Turkey between 1999 and 2000. An average of 10 major bands representing 500-1500 base pair (bp) in length was determined as amplified DNA products on standard agarose gels for these volunteers. The use of ammonium sulfate in 10 x PCR buffers has increased to 92% success ratio of individual difference obtained from the 8 nucleotides primer. With this study, more reliable results can be obtained by using ammonium sulfate in 10 x PCR buffers.

  15. DNA amplification fingerprinting using 10 x polymerase chain reaction buffer with ammonium sulfate for human identification

    International Nuclear Information System (INIS)

    Baransel, Asyun; Dugler, Hikmat E.; Tokdemir, Mehmet

    2004-01-01

    The polymerase chain reaction (PCR) - based DNA amplification fingerprinting (DAF) or randomly amplified polymorphic DNA (RAPD) is based on a strategy using a single arbitrary oligonucleotide primer to generate anonymous amplification of genomic DNA. On this basic strategy, in this study, we aimed to test individual differences and usefulness of 2 basic primers (5-CGCGCCGG-3 and 5-TGCCGAGCTG-3) and examined whether there is a positive effect on results of 10 x PCR buffer with ammonium sulfate. A new approach in DNA fingerprinting, 10 x PCR buffer with ammonium sulfate, is presented in the study. Primers with single 8 and 10 nucleotides in length and 2 different PCR buffers with or without ammonium sulfate were used to identify 135 volunteers with no blood relationship. This study was carried out at the Pharmacology Laboratory, University of Gaziantep, School of Medicine, Turkey between 1999 and 2000. An average of 10 major bands representing 500-1500 base pair (bp) in length was determined as amplified DNA products on standard agarose gels for these volunteers. The use of ammonium sulfate in 10 x PCR buffers has increased to 92% success ratio of individual difference obtained from the 8 nucleotides primer. With this study, more reliable results can be obtained by using ammonium sulfate in 10 x PCR buffers. (author)

  16. An exonuclease-assisted amplification electrochemical aptasensor for Hg(2+) detection based on hybridization chain reaction.

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    Bao, Ting; Wen, Wei; Zhang, Xiuhua; Xia, Qinghua; Wang, Shengfu

    2015-08-15

    In this work, a novel electrochemical aptasensor was developed for Hg(2+) detection based on exonuclease-assisted target recycling and hybridization chain reaction (HCR) dual signal amplification strategy. The presence of Hg(2+) induced the T-rich DNA partly folded into duplex-like structure via the Hg(2+) mediated T-Hg(2+)-T base pairs, which triggered the activity of exonuclease III (Exo III). Exo III selectively digested the double-strand DNA containing multiple T-Hg(2+)-T base pairs from its 3'-end, the released Hg(2+) participated analyte recycle. With each digestion cycle, a digestion product named as help DNA was obtained, which acted as a linkage between the capture DNA and auxiliary DNA. The presence of help DNA and two auxiliary DNA collectively facilitated successful HCR process and formed long double-stranded DNA. [Ru(NH3)6](3+) was used as redox indicator, which electrostatically bound to the double strands and produced an electrochemical signal. Exo III-assisted target recycling and HCR dual amplification significantly improved the sensitivity for Hg(2+) with a detection limit of 0.12 pM (S/N=3). Furthermore, the proposed aptasensor had a promising potential for the application of Hg(2+) detection in real aquatic sample analysis. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Direct visualization of the reaction transformation and signal amplification in a DNA molecular machine with total internal reflection fluorescence microscopy

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    Rui eRen

    2013-10-01

    Full Text Available In this study, as a proof of concept, the signal amplification in an artificial DNA molecular machine was directly visualized via total internal reflection fluorescence microscopy (TIRFM. The molecular machine brought about obvious morphology change in DNA nanostructures as well as signal amplifications. On one hand, through a triggered and autonomically repeated RCA, a DNA nano-complex featuring a locked circular DNA template (serving as raw feed was converted into a long periodically repeated strand, i.e. the RCA products. Furthermore, this RCA was repeated in three controllable reaction phases, bring about progressive signal amplification. It was testified that the RCA products (presented as long thread-like fluorescent objects can be easily distinguished from the inputted DNA probes (presented as fluorescent dots, thus the transformation in reaction can be visualized. Also, by quantitive counting of the aforementioned fluorescence objects, the progress of the reaction through the phases, along with time, and over the lysozyme concentration can be demonstrated through TIRFM visualization. Overall, it was demonstrated that TIRFM is an efficient approach to quantitively visualize the biochemical processes at single-molecule level.

  18. Angioedema Due to Pear: Medical Image

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    Cemil Kavalci

    2014-03-01

    Acute allergic angioedema is an abrupt-onset, unpredictable inflammatory reaction of the skin and mucous membranes. A 60-years-old female patient presented to our emergency department with dispne and edema in her mouth and lips. It was learned from the history that her symptoms were begun 15 minutes after eating a pear. 40 mg methylprednisolone and 50 mg diphenhydramine were administered intravenously.

  19. Angioedema Due to Pear: Medical Image

    OpenAIRE

    Cemil Kavalci

    2014-01-01

      Acute allergic angioedema is an abrupt-onset, unpredictable inflammatory reaction of the skin and mucous membranes. A 60-years-old female patient presented to our emergency department with dispne and edema in her mouth and lips. It was learned from the history that her symptoms were begun 15 minutes after eating a pear. 40 mg methylprednisolone and 50 mg diphenhydramine were administered intravenously.

  20. PEAR code review

    International Nuclear Information System (INIS)

    De Wit, R.; Jamieson, T.; Lord, M.; Lafortune, J.F.

    1997-07-01

    As a necessary component in the continuous improvement and refinement of methodologies employed in the nuclear industry, regulatory agencies need to periodically evaluate these processes to improve confidence in results and ensure appropriate levels of safety are being achieved. The independent and objective review of industry-standard computer codes forms an essential part of this program. To this end, this work undertakes an in-depth review of the computer code PEAR (Public Exposures from Accidental Releases), developed by Atomic Energy of Canada Limited (AECL) to assess accidental releases from CANDU reactors. PEAR is based largely on the models contained in the Canadian Standards Association (CSA) N288.2-M91. This report presents the results of a detailed technical review of the PEAR code to identify any variations from the CSA standard and other supporting documentation, verify the source code, assess the quality of numerical models and results, and identify general strengths and weaknesses of the code. The version of the code employed in this review is the one which AECL intends to use for CANDU 9 safety analyses. (author)

  1. The Use of Polymerase Chain Reaction Amplification for the Detection of Viruses and Bacteria in Severe Community-Acquired Pneumonia.

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    Siow, Wen Ting; Koay, Evelyn Siew-Chuan; Lee, Chun Kiat; Lee, Hong Kai; Ong, Venetia; Ngerng, Wang Jee; Lim, Hui Fang; Tan, Adeline; Tang, Julian Wei-Tze; Phua, Jason

    2016-01-01

    Pathogens are often not identified in severe community-acquired pneumonia (CAP), and the few studies using polymerase chain reaction (PCR) techniques for virus detection are from temperate countries. This study assesses if PCR amplification improves virus and bacteria detection, and if viral infection contributes to mortality in severe CAP in a tropical setting, where respiratory pathogens have less well-defined seasonality. In this cohort study of patients with severe CAP in an intensive care unit, endotracheal aspirates for intubated patients and nasopharyngeal swabs for non-intubated patients were sent for PCR amplification for respiratory viruses. Blood, endotracheal aspirates for intubated patients, and sputum for non-intubated patients were analysed using a multiplex PCR system for bacteria. Out of 100 patients, using predominantly cultures, bacteria were identified in 42 patients; PCR amplification increased this number to 55 patients. PCR amplification identified viruses in 32 patients. In total, only bacteria, only viruses, and both bacteria and viruses were found in 37, 14, and 18 patients, respectively. The commonest viruses were influenza A H1N1/2009 and rhinovirus; the commonest bacterium was Streptococcus pneumoniae. Hospital mortality rates for patients with no pathogens, bacterial infection, viral infection, and bacterial-viral co-infection were 16.1, 24.3, 0, and 5.6%, respectively (p = 0.10). On multivariable analysis, virus detection was associated with lower mortality (adjusted odds ratio 0.12, 95% confidence interval 0.2-0.99; p = 0.049). Viruses and bacteria were detected in 7 of 10 patients with severe CAP with the aid of PCR amplification. Viral infection appears to be independently associated with lower mortality. © 2016 S. Karger AG, Basel.

  2. Topics in free radical-mediated DNA damage: purines and damage amplification - superoxic reactions - bleomycin, the incomplete radiomimetic

    International Nuclear Information System (INIS)

    Sonntag, C. von

    1994-01-01

    Only a small percentage of the DNA damage set by ionizing radiation in the living cell manifests itself as lethal. It is now increasingly accepted that clustered lesions may constitute the kind of damage that the repair enzymes cannot adequately deal with. The question is raised as to whether damage amplification reactions (radical transfer reactions) may contribute to these clustered lesions, and examples of such damage amplification reactions are given. In one example a purine is involved. With 2'-deoxy adenosine and 2'-deoxy guanosine it is shown that these purine nucleosides undergo unexpected radical reactions. Evidence for the radical transfer from the purine to the sugar moiety is provided by the formation of the 5'-aldehydes. These products have been assayed with 2-thiobarbituric acid (TBA), a reagent commonly applied to the detection of malonaldehyde. TBA-reactive material has also been assayed in γ-irradiated DNA, about one-third of this is free malonaldehyde, while the major part of the TBA-reactive material remains bound to the DNA. In contrast, bleomycin-treated DNA yields practically no free malonaldehyde, and the major TBA-reactive products are identified as the thymine and adenine base propenals. (Author)

  3. Susceptibility of pear to European pear sawfly fruit infestation

    Science.gov (United States)

    The European pear sawfly, Hoplocampa brevis (Klug), is a relatively new pest in the Mid-Atlantic fruit production region. A plot containing twelve Pyrus communis pear cultivars and one breeder’s selection in a randomized block design was surveyed for fruit damage. Infestation frequency ranged from...

  4. Amplification of nonspecific products in quantitative polymerase chain reactions (qPCR)

    NARCIS (Netherlands)

    Ruiz-Villalba, Adrián; van Pelt-Verkuil, Elizabeth; Gunst, Quinn D.; Ruijter, Jan M.; van den Hoff, Maurice J. B.

    2017-01-01

    Quantitative PCR allows the precise measurement of DNA concentrations and is generally considered to be straightforward and trouble free. However, a survey with 93 validated assays for genes in the Wnt-pathway showed that the amplification of nonspecific products occurs frequently and is unrelated

  5. Resonance amplification of the nuclear reaction X(a,b)Y near the a+X channel threshold

    International Nuclear Information System (INIS)

    Melezhik, V.S.

    1991-01-01

    Deviation of the cross section for the nuclear reaction X(a,b)Y from the Gamow formula due to an interaction additional to the Coulomb one in the entrance channel has been analyzed. It is shown that the reaction cross section has an oscillating structure at low energies. If the maximum of the first oscillation is close to the threshold of the channel a+X, it has a resonance behaviour. The peculiarity of the cross sections leads to the resonance amplification of the rate for a muon-catalyzed fusion reaction ('in flight' fusion) tμ+d→ 4 He+n+μ at the energy =76 eV and may influence the μ-capture rate in a dense mixture of hydrogen isotopes. 26 refs.; 4 figs

  6. Homogenous assay for protein detection based on proximity DNA hybridization and isothermal circular strand displacement amplification reaction.

    Science.gov (United States)

    Zhang, Manjun; Li, Ruimin; Ling, Liansheng

    2017-06-01

    This work proposed a homogenous fluorescence assay for proteins, based on the target-triggered proximity DNA hybridization in combination with strand displacement amplification (SDA). It benefited from target-triggered proximity DNA hybridization to specifically recognize the target and SDA making recycling signal amplification. The system included a molecular beacon (MB), an extended probe (EP), and an assistant probe (AP), which were not self-assembly in the absence of target proteins, due to the short length of the designed complementary sequence among MB, EP, and AP. Upon addition of the target proteins, EP and AP are bound to the target proteins, which induced the occurrence of proximity hybridization between MB, EP, and AP and followed by strand displacement amplification. Through the primer extension, a tripartite complex of probes and target was displaced and recycled to hybridize with another MB, and the more opened MB enabled the detection signal to amplify. Under optimum conditions, it was used for the detection of streptavidin and thrombin. Fluorescence intensity was proportional to the concentration of streptavidin and thrombin in the range of 0.2-30 and 0.2-35 nmol/L, respectively. Furthermore, this fluorescent method has a good selectivity, in which the fluorescence intensity of thrombin was ~37-fold or even larger than that of the other proteins at the same concentration. It is a new and simple method for SDA-involved target protein detection and possesses a great potential for other protein detection in the future. Graphical abstract A homogenous assay for protein detection is based on proximity DNA hybridization and strand displacement amplification reaction.

  7. Iodometric microdetermination of phosphorus in organic compounds by use of An amplification reaction

    OpenAIRE

    Al Kubaisi, A. H. [عبد الله حسين الكبيسي; Farag, A. B.; Amin, R. R.

    1994-01-01

    A high chemical amplification method is described for the iodometric microdetermination of phosphorus in organic compounds. This method depends on combustion by the oxygen flask, absorption of the combustion products in distilled water and conversion to orthophosphoric acid with bromine water. The phosphoric acid produced is then allowed to react with sodium molybdate in acid medium to form phosphomolybdic acid which is extracted into a mixture of diethyl ether and pentanol (5:1, V/V), and ba...

  8. 76 FR 78168 - Importation of Chinese Sand Pears From China

    Science.gov (United States)

    2011-12-16

    ... Chinese sand pears: Acrobasis pyrivorella, pear fruit moth. Alternaria gaisen Nagano, black spot of... introduction of the following quarantine pests: Acrobasis pyrivorella, pear fruit moth; Alternaria gaisen...

  9. Detection of bond formations by DNA-programmed chemical reactions and PCR amplification.

    Science.gov (United States)

    Li, Yizhou; Zhang, Mingda; Zhang, Chi; Li, Xiaoyu

    2012-10-04

    A system capable of performing both DNA-templated chemical reactions and detection of bond formations is reported. Photocleavable DNA templates direct reactions. Products from bond-forming events re-ligate original templates, amplifiable by PCR, therefore distinguishing bond formation from background. This system provides a novel approach for discovering potential new chemical reactions.

  10. Resonance amplification of the nuclear reaction X(a,b)Y near the a+X channel threshold

    International Nuclear Information System (INIS)

    Melezhik, V.S.

    1992-01-01

    Deviation of the cross section for the nuclear reaction X(a, b)Y from the Gamow formula due to an interaction additional to the Coulomb one in the entrance channel has been analyzed. It is shown that the reaction cross section has an oscillating structure at low energies. If the maximum of the first oscillation is close to the threshold of the channel a+X, it has a resonance behavior. To analyze the effect, simple relations between the period and the amplitude of the oscillations with parameters of the interaction have been derived. Specifically, they predict the cross-section oscillations of fusion reactions of the type X(a, b)Y for slow collisions between nuclei (a) and atomic (or molecular) targets (X), as, for example, the reaction D(d, p)T between deuterons (d) and deuterium atoms (D). The peculiarity of the cross sections leads to the resonance amplification of the rate for a muon-catalyzed fusion reaction ('in flight' fusion) tμ + d → 4 He + n + μ at the energy ≅ 76 eV and may influence the μ-capture rate in a dense mixture of hydrogen isotopes. (orig.)

  11. Importance of Alternative Predators of Pear Suckers (Cacopsylla Pyri) in Organic Versus IPM Pear Orchards

    NARCIS (Netherlands)

    Vranken, K.; Trekels, H.; Thys, T.; Demaeght, P.; Van Leeuwen, T.; De Clercq, P.; Beliën, T.

    2014-01-01

    Pear suckers (Cacopsylla sp. or pear psylla) are widely considered to be the most important pest in pear orchards. Sustainable control of pear psylla relies on their natural suppression by beneficial arthropods and a well-tuned integration of crop protection treatments. Predatory bugs (Anthocoris

  12. Preparation of short cytosine-modified oligonucleotides by nicking enzyme amplification reaction

    Czech Academy of Sciences Publication Activity Database

    Ménová, Petra; Hocek, Michal

    2012-01-01

    Roč. 48, č. 55 (2012), s. 6921-6923 ISSN 1359-7345 R&D Projects: GA ČR GA203/09/0317 Institutional support: RVO:61388963 Keywords : cross-coupling reactions * nucleoside triphosphates * functionalized DNA * restriction endonucleases * polymerase incorporation Subject RIV: CC - Organic Chemistry Impact factor: 6.378, year: 2012

  13. Scope and Limitations of the Nicking Enzyme Amplification Reaction for the Synthesis of Base-Modified Oligonucleotides and Primers for PCR

    Czech Academy of Sciences Publication Activity Database

    Ménová, Petra; Raindlová, Veronika; Hocek, Michal

    2013-01-01

    Roč. 24, č. 6 (2013), s. 1081-1093 ISSN 1043-1802 R&D Projects: GA ČR GA203/09/0317 Institutional support: RVO:61388963 Keywords : isothermal DNA amplification * cross-coupling reactions * nucleoside triphosphates * polymerase incorporation * functionalized DNA * nucleic-acids Subject RIV: CC - Organic Chemistry Impact factor: 4.821, year: 2013

  14. Genomic DNA fingerprinting of clinical Haemophilus influenzae isolates by polymerase chain reaction amplification: comparison with major outer-membrane protein and restriction fragment length polymorphism analysis

    NARCIS (Netherlands)

    van Belkum, A.; Duim, B.; Regelink, A.; Möller, L.; Quint, W.; van Alphen, L.

    1994-01-01

    Non-capsulate strains of Haemophilus influenzae were genotyped by analysis of variable DNA segments obtained by amplification of genomic DNA with the polymerase chain reaction (PCR fingerprinting). Discrete fragments of 100-2000 bp were obtained. The reproducibility of the procedure was assessed by

  15. Sensitive and selective amplification of methylated DNA sequences using helper-dependent chain reaction in combination with a methylation-dependent restriction enzymes.

    Science.gov (United States)

    Rand, Keith N; Young, Graeme P; Ho, Thu; Molloy, Peter L

    2013-01-07

    We have developed a novel technique for specific amplification of rare methylated DNA fragments in a high background of unmethylated sequences that avoids the need of bisulphite conversion. The methylation-dependent restriction enzyme GlaI is used to selectively cut methylated DNA. Then targeted fragments are tagged using specially designed 'helper' oligonucleotides that are also used to maintain selection in subsequent amplification cycles in a process called 'helper-dependent chain reaction'. The process uses disabled primers called 'drivers' that can only prime on each cycle if the helpers recognize specific sequences within the target amplicon. In this way, selection for the sequence of interest is maintained throughout the amplification, preventing amplification of unwanted sequences. Here we show how the method can be applied to methylated Septin 9, a promising biomarker for early diagnosis of colorectal cancer. The GlaI digestion and subsequent amplification can all be done in a single tube. A detection sensitivity of 0.1% methylated DNA in a background of unmethylated DNA was achieved, which was similar to the well-established Heavy Methyl method that requires bisulphite-treated DNA.

  16. Amplification of GC-rich Putative Mouse PeP Promoter using Betaine and DMSO in Ammonium Sulfate Polymerase Chain Reaction Buffer.

    Science.gov (United States)

    Seifi, Tahere; Ghaedi, Kamran; Salamian, Ahmad; Tanhaei, Sommayeh; Safari, Forouzan; Hojati, Zohreh; Tavassoli, Manuchehr; Baharvand, Hossein; Esfahani, Mohammad-Hossein Nasr

    2012-10-01

    Recently, we have shown that peroxisomal protein expression was induced upon retinoic acid treatment in mouse embryonic stem cells during the process of neurogenesis. Thus, characterization of the respective promoter could elucidate the molecular aspects of transcriptional regulation of this gene. Using the conventional software programs for promoter prediction, a putative promoter region was identified approximately 561 bp upstream of the peroxisomal protein coding sequence. In order to clone this region with a GC-content of 71.01%, a cocktail of ammonium sulfate buffer supplied with two additive components, betaine and dimethyl sulfoxide, and a high concentration of MgCl(2) was used. The modulated polymerase chain reaction composition significantly improved the amplification of GC-rich DNA target sequences. Improved amplification of this region was due to reduction in the formation of secondary structures by the GC-rich region. Therefore, this polymerase chain reaction composition could be generally used to facilitate the amplification of other GC-rich DNA sequences as verified by amplification of different GC rich regions.

  17. Sensitive electrochemical detection of telomerase activity using spherical nucleic acids gold nanoparticles triggered mimic-hybridization chain reaction enzyme-free dual signal amplification.

    Science.gov (United States)

    Wang, Wen-Jing; Li, Jing-Jing; Rui, Kai; Gai, Pan-Pan; Zhang, Jian-Rong; Zhu, Jun-Jie

    2015-03-03

    We report an electrochemical sensor for telomerase activity detection based on spherical nucleic acids gold nanoparticles (SNAs AuNPs) triggered mimic-hybridization chain reaction (mimic-HCR) enzyme-free dual signal amplification. In the detection strategy, SNAs AuNPs and two hairpin probes were employed. SNAs AuNPs as the primary amplification element, not only hybridized with the telomeric repeats on the electrode to amplify signal but also initiated the subsequent secondary amplification, mimic-hybridization chain reaction of two hairpin probes. If the cells' extracts were positive for telomerase activity, SNAs AuNPs could be captured on the electrode. The carried initiators could trigger an alternative hybridization reaction of two hairpin probes that yielded nicked double helices. The signal was further amplified enzyme-free by numerous hexaammineruthenium(III) chloride ([Ru(NH3)6](3+), RuHex) inserting into double-helix DNA long chain by electrostatic interaction, each of which could generate an electrochemical signal at appropriate potential. With this method, a detection limit of down to 2 HeLa cells and a dynamic range of 10-10,000 cells were achieved. Telomerase activities of different cell lines were also successfully evaluated.

  18. 78 FR 24036 - Pears Grown in Oregon and Washington; Committee Membership Reapportionment for Processed Pears

    Science.gov (United States)

    2013-04-24

    ... small entity orientation and compatibility. There are approximately 1,500 producers of processed pears... Agricultural Marketing Service 7 CFR Part 927 Pears Grown in Oregon and Washington; Committee Membership Reapportionment for Processed Pears AGENCY: Agricultural Marketing Service, USDA. ACTION: Final rule. SUMMARY...

  19. Lack of correlation between reaction speed and analytical sensitivity in isothermal amplification reveals the value of digital methods for optimization: validation using digital real-time RT-LAMP.

    Science.gov (United States)

    Khorosheva, Eugenia M; Karymov, Mikhail A; Selck, David A; Ismagilov, Rustem F

    2016-01-29

    In this paper, we asked if it is possible to identify the best primers and reaction conditions based on improvements in reaction speed when optimizing isothermal reactions. We used digital single-molecule, real-time analyses of both speed and efficiency of isothermal amplification reactions, which revealed that improvements in the speed of isothermal amplification reactions did not always correlate with improvements in digital efficiency (the fraction of molecules that amplify) or with analytical sensitivity. However, we observed that the speeds of amplification for single-molecule (in a digital device) and multi-molecule (e.g. in a PCR well plate) formats always correlated for the same conditions. Also, digital efficiency correlated with the analytical sensitivity of the same reaction performed in a multi-molecule format. Our finding was supported experimentally with examples of primer design, the use or exclusion of loop primers in different combinations, and the use of different enzyme mixtures in one-step reverse-transcription loop-mediated amplification (RT-LAMP). Our results show that measuring the digital efficiency of amplification of single-template molecules allows quick, reliable comparisons of the analytical sensitivity of reactions under any two tested conditions, independent of the speeds of the isothermal amplification reactions. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

  20. [Investigation on Toxoplasma gondii by polymerase chain reaction and loop-mediated isothermal amplification in water samples from Giresun, Turkey].

    Science.gov (United States)

    Demirel, Elif; Kolören, Zeynep; Karaman, Ulkü; Ayaz, Emine

    2014-10-01

    Toxoplasmosis is generally asymptomatic in immunocompetent subjects, however serious manifestations of the disease may develop in immunocompromised patients and in pregnant women. The mean Toxoplasma gondii seroprevalence which is approximately 40% in Turkish population, indicates the high risk for the development of acute toxoplasmosis in those cases. One of the transmission ways of T.gondii is the consumption of contaminated water. The aim of this study was to detect the presence of T.gondii in the environmental and drinking water samples by using standard polymerase chain reaction (PCR) and loop-mediated isothermal amplification (LAMP) methods. A total of 96 water samples, of them 76 were environmental water samples collected from creeks in Giresun province center and its various districts (Piraziz, Bulancak, Keşap, Espiye) and 20 from drinking water samples, were included in the study. The samples were precipitated by the aluminium sulfate method and DNAs were isolated from the pellets formed with the sucrose gradient method. PCR and LAMP were applied to the isolated DNAs, by the use of primers F3 and B3 specific to B1 gene of the parasite. In our study, T.gondii was detected in none of the drinking water samples by PCR and LAMP, however T.gondii DNAs were positive in 13.2% (10/76) of the environmental water samples. Both of the methods yielded the same results in those samples. The stations that were positive for T.gondii were Aksu creek in Giresun province center; Gelivera creek in Espiye; Yolağzı, Keşap, Keşap Login Bridge creeks in Keşap; Bulancak, Karadere and İncivez creeks in Bulancak; Piraziz and Çayırağzı creeks in Piraziz counties. Resistance of T.gondii to chlorination and the inadequacy of the filtration processes, create a serious threat among people in contact with rivers, sea and drinking waters particularly in areas with high humidity. As far as the national literature was considered, no report about the water-borne T

  1. 7 CFR 927.4 - Pears.

    Science.gov (United States)

    2010-01-01

    ... subvarieties of pears with the genus Pyrus that are produced in the production area and are classified as: (1... 7 Agriculture 8 2010-01-01 2010-01-01 false Pears. 927.4 Section 927.4 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and...

  2. A note on the Noyori model for chiral amplification in the aminoalcohol-catalyzed reaction of aldehydes with dialkylzinc

    Directory of Open Access Journals (Sweden)

    IVAN GUTMAN

    1999-11-01

    Full Text Available The Noyori model of chiral amplification in the alkylation of aldehydes by means of dialkylzinc, catalyzed by chiral aminoalcohols, is further elaborated. A direct, but approximate, relation is obtained between the enantiomeric excess of the catalyst added and the enantiomeric excess of the product.

  3. Diagnosis of pediatric pulmonary tuberculosis with special reference to polymerase chain reaction based nucleic acid amplification test

    Directory of Open Access Journals (Sweden)

    Shreshtha Tiwari

    2015-01-01

    Conclusion/recommendation: The present study reinforces better case detection rate with PCR-based nucleic acid amplification test as compared with microscopy and culture in pediatric pulmonary TB. PCR showed a higher correlation with clinical diagnosis as compared with microscopy and solid culture. Hence, a molecular platform should be the test of choice for detecting PPTB.

  4. 7 CFR 927.125 - Fresh pear reports.

    Science.gov (United States)

    2010-01-01

    ... to the Fresh Pear Committee, upon request, the “Pear Size and Grade Storage Report” containing the quantity of specific grades and sizes of fresh pears in regular and C.A. storage by variety or subvariety... Committee, a “Handler's Statement of Fresh Pear Shipments” containing the following information: (1) The...

  5. A Complementary Isothermal Amplification Method to the U.S. EPA Quantitative Polymerase Chain Reaction Approach for the Detection of Enterococci in Environmental Waters.

    Science.gov (United States)

    Kolm, Claudia; Martzy, Roland; Brunner, Kurt; Mach, Robert L; Krska, Rudolf; Heinze, Georg; Sommer, Regina; Reischer, Georg H; Farnleitner, Andreas H

    2017-06-20

    We report a novel molecular assay, based on helicase-dependent amplification (HDA), for the detection of enterococci as markers for fecal pollution in water. This isothermal assay targets the same Enterococcus 23S rRNA gene region as the existing quantitative polymerase chain reaction (qPCR) assays of U.S. Environmental Protection Agency Methods 1611 and 1609 but can be entirely performed on a simple heating block. The developed Enterococcus HDA assay successfully discriminated 15 enterococcal from 15 non-enterococcal reference strains and reliably detected 48 environmental isolates of enterococci. The limit of detection was 25 target copies per reaction, only 3 times higher than that of qPCR. The applicability of the assay was tested on 30 environmental water sample DNA extracts, simulating a gradient of fecal pollution. Despite the isothermal nature of the reaction, the HDA results were consistent with those of the qPCR reference. Given this performance, we conclude that the developed Enterococcus HDA assay has great potential as a qualitative molecular screening method for resource-limited settings when combined with compatible up- and downstream processes. This amplification strategy can pave the way for developing a new generation of rapid, low-cost, and field-deployable molecular diagnostic tools for water quality monitoring.

  6. Amplification of the Matrix Gene of RBOK Vaccine Strain of Rinderpest Virus (RPV) by Polymerase Chain Reaction and Cloning into TOPOR XL Cloning Vector

    OpenAIRE

    AZKUR, Ahmet Kürşat; BOLAT, Yusuf

    2003-01-01

    In this study, the matrix (M) gene of the RBOK vaccine strain of rinderpest (RPV) was amplified by polymerase chain reaction (PCR) and cloned into TOPOR XL cloning vector. For this purpose, Vero cells were infected with the RBOK vaccine strain of RPV and total RNA was obtained from the infected cells. cDNA of the matrix gene was obtained by reverse transcription from the total RNA. Amplification of the cDNA with PCR was achieved by using the M gene specific primer and PCR products of the M ge...

  7. Experimental validation of numerical study on thermoelectric-based heating in an integrated centrifugal microfluidic platform for polymerase chain reaction amplification.

    Science.gov (United States)

    Amasia, Mary; Kang, Seok-Won; Banerjee, Debjyoti; Madou, Marc

    2013-01-01

    A comprehensive study involving numerical analysis and experimental validation of temperature transients within a microchamber was performed for thermocycling operation in an integrated centrifugal microfluidic platform for polymerase chain reaction (PCR) amplification. Controlled heating and cooling of biological samples are essential processes in many sample preparation and detection steps for micro-total analysis systems. Specifically, the PCR process relies on highly controllable and uniform heating of nucleic acid samples for successful and efficient amplification. In these miniaturized systems, the heating process is often performed more rapidly, making the temperature control more difficult, and adding complexity to the integrated hardware system. To gain further insight into the complex temperature profiles within the PCR microchamber, numerical simulations using computational fluid dynamics and computational heat transfer were performed. The designed integrated centrifugal microfluidics platform utilizes thermoelectrics for ice-valving and thermocycling for PCR amplification. Embedded micro-thermocouples were used to record the static and dynamic thermal responses in the experiments. The data collected was subsequently used for computational validation of the numerical predictions for the system response during thermocycling, and these simulations were found to be in agreement with the experimental data to within ∼97%. When thermal contact resistance values were incorporated in the simulations, the numerical predictions were found to be in agreement with the experimental data to within ∼99.9%. This in-depth numerical modeling and experimental validation of a complex single-sided heating platform provide insights into hardware and system design for multi-layered polymer microfluidic systems. In addition, the biological capability along with the practical feasibility of the integrated system is demonstrated by successfully performing PCR amplification of

  8. Total Protein Content and SDS-PAGE in Pear Scions Grafted on Quince A and Pear Seedling Rootstocks

    OpenAIRE

    GÜLEN*, Hatice

    2005-01-01

    This study was conducted to investigate the effects of various rootstocks on the total soluble protein content of pear scions, and to detect a polypeptide as a marker that would be associated with pear/quince compatibility/incompatibility. Bark samples were collected from 5 year-old pear scions grafted on QA and pear seedling rootstocks (PS). Total soluble protein contents of bark tissues of 4 pear scions, Passa Crassana (PC), Beurre Hardy (BH), Beurre Bosc (BB) and Bartlett (BT), were determ...

  9. Detection of maternal deoxyribonucleic acid in umbilical cord plasma by using fluorescent polymerase chain reaction amplification of short tandem repeat sequences.

    Science.gov (United States)

    Bauer, Margit; Orescovic, Irmgard; Schoell, Wolfgang M; Bianchi, Diana W; Pertl, Barbara

    2002-01-01

    Umbilical cord blood is a source of hematopoietic stem cells for transplantation. Although the first clinical applications have been encouraging, concern has been raised about contamination of umbilical blood by maternal cells, which might constitute a theoretical risk of graft-versus-host disease. The aim of this study was to assess the frequency of maternal deoxyribonucleic acid (DNA) contamination in umbilical cord plasma by using fluorescent polymerase chain reaction amplification of highly polymorphic short tandem repeat DNA markers. Fifty-seven mother/child pairs were tested for the presence of maternal DNA sequences in cord plasma. After delivery, cord blood samples were collected via gravity. Maternal specific alleles were detected by using polymerase chain reaction amplification of 9 highly polymorphic short tandem repeat markers (D21S11, D21S1411, D21S1412, D18S386, D18S535, MBP-A, MBP-B, D13S631, and D13S634). All 57 mother-child pairs were informative for the identification of uniquely maternal alleles in at least 2 of 9 different short tandem repeat markers used per case. Uniquely maternal DNA sequences were found in 43 of 57 (75%) cord plasma samples. The results of our study demonstrate that maternal DNA is present in the majority of umbilical cord blood plasma samples. The technique described herein might have application in the screening of umbilical cord blood samples for the presence of contaminating maternal genetic material.

  10. Direct RNA detection without nucleic acid purification and PCR: Combining sandwich hybridization with signal amplification based on branched hybridization chain reaction.

    Science.gov (United States)

    Xu, Yao; Zheng, Zhi

    2016-05-15

    We have developed a convenient, robust and low-cost RNA detection system suitable for high-throughput applications. This system uses a highly specific sandwich hybridization to capture target RNA directly onto solid support, followed by on-site signal amplification via 2-dimensional, branched hybridizing chain polymerization through toehold-mediated strand displacement reaction. The assay uses SYBR Green to detect targets at concentrations as low as 1 pM, without involving nucleic acid purification or any enzymatic reaction, using ordinary oligonucleotides without modification or labeling. The system was demonstrated in the detection of malaria RNA in blood and GAPDH gene expression in cell lysate. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Droplet digital polymerase chain reaction detection of HER2 amplification in formalin fixed paraffin embedded breast and gastric carcinoma samples.

    Science.gov (United States)

    Zhu, Yazhen; Lu, Dan; Lira, Maruja E; Xu, Qing; Du, Yunzhi; Xiong, Jianghong; Mao, Mao; Chung, Hyun Cheol; Zheng, Guangjuan

    2016-04-01

    Human epidermal growth factor receptor 2 (HER2) is a key driver of tumorigenesis, and over-expression as a result of HER2 gene amplification has been observed in a number of solid tumors. Recently HER2 has become an important biomarker for the monoclonal antibody treatment of HER2-positive metastatic breast and advanced gastric cancer. The HER2 targeting antibody trastuzumab treatment requires accurate measurement of HER2 levels for proper diagnosis. Droplet digital PCR (ddPCR) with highly direct, precise and absolute nucleic acid quantification could be used to detect HER2 amplification levels. Our objective was to evaluate a robust, accurate and less subjective application of ddPCR for HER2 amplification levels and test the assay performance in clinical formalin-fixed paraffin-embedded (FFPE) breast and gastric carcinoma samples. Genomic DNA from HER2 amplified cell line SK-BR-3 was used to set up the ddPCR assays. The copy number of HER2 was compared to the chromosome 17 centromere reference gene (CEP17), expressed as HER2:CEP17 ratio. Genomic DNAs of FFPE specimens from 145 Asian patients with breast and gastric carcinomas were assayed using both standard methods, immunohistochemistry (IHC) and/or fluorescence in situ hybridization (FISH), and ddPCR. Based on 145 clinical breast and gastric carcinoma cases, our study demonstrated a high concordance of ddPCR results to FISH and IHC. In breast cancer specimens, the ddPCR results had high concordance with FISH and IHC defined HER2 status with a sensitivity of 90.9% (30/33) and a specificity of 100% (77/77). In gastric cancer specimens that were concordant in both FISH and IHC, our assay was 95.5% concordant with FISH and IHC (21/22). ddPCR has the advantage of automation and also allows levels of HER2 amplification to be easily evaluated in large numbers of samples, and presents a potential option to define HER2 status. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Time Course of Detection of Human Male DNA from Stained Blood Sample on Various Surfaces by Loop Mediated Isothermal Amplification and Polymerase Chain Reaction

    Directory of Open Access Journals (Sweden)

    Panan Kanchanaphum

    2018-01-01

    Full Text Available This study explores determining the sex of humans from blood stains taken from different surfaces and compares the time course of detection with the conventional PCR, Conventional Loop Mediated Isothermal Amplification (LAMP, and LAMP-Lateral Flow Dipstick (LFD. For the DNA templates, 7 male and 7 female blood stained samples were extracted and added to LAMP and PCR reaction solution to amplify the SRY gene. The DNA samples were extracted from the following blood stained materials: cloth, wood, clay, and tile. Then, the samples were stored at room temperature for 1, 7, 30, and 60 day(s. After the DNA amplification, the gel electrophoresis process was applied to detect LAMP product. The LFD was combined with the LAMP to detect LAMP product on the male cloth samples. For the male samples, the time course of detection on the first and seventh days indicated positive for both LAMP and PCR products on all the surfaces while no DNA amplification was found on any of the female samples. On day 30, positive LAMP product was still found on all the male samples. However, it had faded on the tiles. Moreover, all the male samples, which had tested positive for PCR product, were blurred and unclear. On day 60, LAMP product was still found on all the male samples. Conversely, the PCR method resulted in no bands showing for any of the male samples. However, the LAMP-LFD method detected product on all the male samples of cloth. The results show that the LAMP is an effective, practical, and reliable molecular-biological method. Moreover, the LFD can increase the efficiency and sensitivity of the LAMP, making it more suitable for field studies because gel electrophoresis apparatus is not required.

  13. Relative attractiveness of colour traps to pear psylla in relation to seasonal changes in pear phenology

    Science.gov (United States)

    This study presents temporal color trap preference of pear psylla (Cacopsylla pyricola Foerster, Hemiptera: Psyllidae) over a 24 month duration. Black, blue, brown, clear, green, orange, red, white, and yellow traps were assayed against wild psylla populations. While pear psylla had a strong prefe...

  14. Single primer amplification reaction (SPAR) methods reveal subsequent increase in genetic variations in micropropagated plants of Nepenthes khasiana Hook. f. maintained for three consecutive regenerations.

    Science.gov (United States)

    Devi, Soibam Purnima; Kumaria, Suman; Rao, Satyawada Rama; Tandon, Pramod

    2014-03-15

    The genetic fidelity of in vitro-raised plants of three successive regenerations of Nepenthes khasiana Hook. f. was assessed using three different single primer amplification reaction (SPAR) methods, viz., random amplified polymorphic DNA (RAPD), inter-simple sequence repeat (ISSR) and direct amplification of minisatellite DNA region (DAMD) markers. Out of 80 RAPD primers screened, 14 primers reflected a genetic variation of 4.1% in the first regeneration which was increased to 9.4% in the third regeneration. In the case of ISSR, out of 36 primers screened for assessment of genetic homogeneity of the regenerated plantlets, 12 primers showed an increase of genetic variation from 4.3% to 10% from the first to the third regenerations. In DAMD profiling, 15 primers were used for the evaluation of genetic fidelity where 8.47% of polymorphism was observed in the first regeneration which was increased to 13.33% in the third regeneration. The cumulative analysis reflected a genetic variation of 5.65% in the first regeneration which increased subsequently to 7.77% in the second regeneration and 10.87% in the third regeneration. The present study demonstrates SPAR technique to be an efficient tool for the assessment of clonal fidelity of in vitro-raised plants. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. A DNA-Based Encryption Method Based on Two Biological Axioms of DNA Chip and Polymerase Chain Reaction (PCR) Amplification Techniques.

    Science.gov (United States)

    Zhang, Yunpeng; Wang, Zhiwen; Wang, Zhenzhen; Liu, Xin; Yuan, Xiaojing

    2017-09-27

    Researchers have gained a deeper understanding of DNA-based encryption and its effectiveness in enhancing information security in recent years. However, there are many theoretical and technical issues about DNA-based encryption that need to be addressed before it can be effectively used in the field of security. Currently, the most popular DNA-based encryption schemes are based on traditional cryptography and the integration of existing DNA technology. These schemes are not completely based on DNA computing and biotechnology. Herein, as inspired by nature, encryption based on DNA has been developed, which is, in turn, based on two fundamental biological axioms about DNA sequencing: 1) DNA sequencing is difficult under the conditions of not knowing the correct sequencing primers and probes, and 2) without knowing the correct probe, it is difficult to decipher precisely and sequence the information of unknown and mixed DNA/peptide nucleic acid (PNA) probes, which only differ in nucleotide sequence, arranged on DNA chips (microarrays). In essence, when creating DNA-based encryption by means of biological technologies, such as DNA chips and polymerase chain reaction (PCR) amplification, the encryption method discussed herein cannot be decrypted, unless the DNA/PNA probe or PCR amplification is known. The biological analysis, mathematical analysis, and simulation results demonstrate the feasibility of the method, which provides much stronger security and reliability than that of traditional encryption methods. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Identification of planorbids from Venezuela by polymerase chain reaction amplification and restriction fragment length polymorphism of internal transcriber spacer of the RNA ribosomal gene

    Directory of Open Access Journals (Sweden)

    Caldeira Roberta L

    2000-01-01

    Full Text Available Snails of the genus Biomphalaria from Venezuela were subjected to morphological assessment as well as polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP analysis. Morphological identification was carried out by comparison of characters of the shell and the male and female reproductive apparatus. The PCR-RFLP involved amplification of the internal spacer region ITS1 and ITS2 of the RNA ribosomal gene and subsequent digestion of this fragment by the restriction enzymes DdeI, MnlI, HaeIII and MspI. The planorbids were compared with snails of the same species and others reported from Venezuela and present in Brazil, Cuba and Mexico. All the enzymes showed a specific profile for each species, that of DdeI being the clearest. The snails were identified as B. glabrata, B. prona and B. kuhniana.

  17. Amplification of the rat m2 muscarinic receptor gene by the polymerase chain reaction: Functional expression of the M sub 2 muscarinic receptor

    Energy Technology Data Exchange (ETDEWEB)

    Lai, J.; Bloom, J.W.; Yamamura, H.I.; Roeske, W.R. (Univ. of Arizona Health Sciences Center, Tucson (USA))

    1990-01-01

    A selective amplification of the coding sequence of the rat M{sub 2} muscarinic receptor gene was achieved by the polymerase chain reaction. The error rate of this amplification system under conditions specified was 1 nucleotide substitution in 841 base pairs. In vitro expression of this gene in murine fibroblasts (B82) via the eukaryotic expression vector, pH{beta}APr-1-neo, resulted in high level expression of specific ({sup 3}H)(-)MQNB binding in transfected B82 cell lines. One of these clones, M2LKB2-2, showed a stable expression of ({sup 3}H)(-)MQNB binding with a K{sub d} value of 265 pM and a B{sub max} value of 411{plus minus}50 fmol/10{sup 6} cells. Cardiac selective muscarinic antagonists such as himbacine and AF-DX 116 show high affinities for this binding site in the M2LKB2-2 cells. The rank order of potency of several antagonists in inhibiting ({sup 3}H)(-)MQNB binding in these cells conformed to the characteristics of an M{sub 2} type muscarinic receptor. Carbachol showed a single affinity state for the receptors in the M2LKB2-2 cells with a K{sub i} value of 2.0 {mu}M. This receptor appeared to be inversely coupled to adenylate cyclase via a pertussis toxin sensitive G-protein. Carbachol also had a slight stimulatory effect on the hydrolysis of inositol lipids. The polymerase chain reaction proves highly effective in cloning genes from genomic material, as demonstrated by the first in vitro functional expression of the rat M{sub 2} type muscarinic receptor.

  18. Pear quality characteristics by Vis / NIR spectroscopy.

    Science.gov (United States)

    Machado, Nicácia P; Fachinello, José C; Galarça, Simone P; Betemps, Débora L; Pasa, Mateus S; Schmitz, Juliano D

    2012-09-01

    Recently, non-destructive techniques such as the Vis / NIR spectroscopy have been used to evaluate the characteristics of maturation and quality of pears. The study aims to validate the readings by the Vis / NIR spectroscopy as a non-destructive way to assess the qualitative characteristics of pear cultivars 'Williams', 'Packams' and 'Carrick', produced according to Brazilian conditions. The experiment was conducted at the Pelotas Federal University, UFPel, in Pelotas / RS, and the instrument used to measure the fruit quality in a non-destructive way was the NIR- Case spectrophotometer (SACMI, Imola, Italy). To determine pears' soluble solids (SS) and pulp firmness (PF), it was established calibration equations for each variety studied, done from the evaluations obtained by a non-destructive method (NIR-Case) and a destructive method. Further on, it was tested the performance of these readings by linear regressions. The results were significant for the soluble solids parameter obtained by the Vis / NIR spectroscopy; however, it did not achieve satisfactory results for the pear pulp firmness of these cultivars. It is concluded that the Vis / NIR spectroscopy, using linear regression, allows providing reliable estimates of pears' quality levels, especially for soluble solids.

  19. Evaluation of Amplification Targets for the Specific Detection of Bordetella pertussis Using Real-Time Polymerase Chain Reaction

    Directory of Open Access Journals (Sweden)

    Mohammad Rubayet Hasan

    2014-01-01

    Full Text Available BACKGROUND: Bordetella pertussis infections continue to be a major public health challenge in Canada. Polymerase chain reaction (PCR assays to detect B pertussis are typically based on the multicopy insertion sequence IS481, which offers high sensitivity but lacks species specificity.

  20. 77 FR 75007 - Importation of Sand Pears From China

    Science.gov (United States)

    2012-12-19

    ..., pear fruit moth. Alternaria gaisen Nagano, the cause of black spot of pear. Amphitetranychus viennensis... should be expanded to include two additional pests, Alternaria yaliinficiens, a phytopathogenic fungus... quarantine pests: Acrobasis pyrivorella, pear fruit moth; Alternaria gaisen Nagano, the cause of black spot...

  1. 7 CFR 319.56-39 - Fragrant pears from China.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Fragrant pears from China. 319.56-39 Section 319.56-39... pears from China. Fragrant pears may be imported into the United States from China only under the... China. (2) All propagative material introduced into a registered production site must be certified free...

  2. Multiplex Amplification Refractory Mutation System Polymerase Chain Reaction (ARMS-PCR for diagnosis of natural infection with canine distemper virus

    Directory of Open Access Journals (Sweden)

    Wong Min-Liang

    2010-06-01

    Full Text Available Abstract Background Canine distemper virus (CDV is present worldwide and produces a lethal systemic infection of wild and domestic Canidae. Pre-existing antibodies acquired from vaccination or previous CDV infection might interfere the interpretation of a serologic diagnosis method. In addition, due to the high similarity of nucleic acid sequences between wild-type CDV and the new vaccine strain, current PCR derived methods cannot be applied for the definite confirmation of CD infection. Hence, it is worthy of developing a simple and rapid nucleotide-based assay for differentiation of wild-type CDV which is a cause of disease from attenuated CDVs after vaccination. High frequency variations have been found in the region spanning from the 3'-untranslated region (UTR of the matrix (M gene to the fusion (F gene (designated M-F UTR in a few CDV strains. To establish a differential diagnosis assay, an amplification refractory mutation analysis was established based on the highly variable region on M-F UTR and F regions. Results Sequences of frequent polymorphisms were found scattered throughout the M-F UTR region; the identity of nucleic acid between local strains and vaccine strains ranged from 82.5% to 93.8%. A track of AAA residue located 35 nucleotides downstream from F gene start codon highly conserved in three vaccine strains were replaced with TGC in the local strains; that severed as target sequences for deign of discrimination primers. The method established in the present study successfully differentiated seven Taiwanese CDV field isolates, all belonging to the Asia-1 lineage, from vaccine strains. Conclusions The method described herein would be useful for several clinical applications, such as confirmation of nature CDV infection, evaluation of vaccination status and verification of the circulating viral genotypes.

  3. Detection of Brazilian hantavirus by reverse transcription polymerase chain reaction amplification of N gene in patients with hantavirus cardiopulmonary syndrome

    OpenAIRE

    Marcos Lázaro Moreli; Ricardo Luiz Moro de Sousa; Luiz Tadeu Moraes Figueiredo

    2004-01-01

    We report a nested reverse transcription-polymerase chain reaction (RT-PCR) assay for hantavirus using primers selected to match high homology regions of hantavirus genomes detected from the whole blood of hantavirus cardiopulmonary syndrome (HCPS) patients from Brazil, also including the N gene nucleotide sequence of Araraquara virus. Hantavirus genomes were detected in eight out of nine blood samples from the HCPS patients by RT-PCR (88.9% positivity) and in all 9 blood samples (100% positi...

  4. Detection of peroxyl radicals from polluted air by free radical reaction combined with liquid chromatography signal amplification technique.

    Science.gov (United States)

    Wang, Guoying; Jia, Shiming; Niu, Xiuli; Liu, Yanrong; Tian, Haoqi; Chen, Xuefu; Shi, Gaofeng

    2018-01-22

    Free radicals play an important role in the oxidizing power of polluted air, the development of aging-related diseases, the formation of ozone, and the production of secondary particulate matter. The high variability of peroxyl radical concentration has prevented the detection of possible trends or distributions in the concentration of free radicals. We present a new method, free radical reaction combined with liquid chromatography photodiode array detection, for identifying and quantifying peroxyl radicals in polluted air. Functionalized graphene was used for loading peroxyl radicals and reactive molecules in air sampling system, which can facilitate reaction kinetics (charge transfers) between peroxyl radicals and reaction molecules. Separation was performed with and without a preliminary exposure of the polluted air sample to reactive molecule(s) system. The integral chromatographic peak areas before and after air sampling are used to quantify the atmospheric peroxyl radicals in polluted air. The utility of the new technique was tested with measurements carried out in the field. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. GENOMIC DNA-FINGERPRINTING OF CLINICAL HAEMOPHILUS-INFLUENZAE ISOLATES BY POLYMERASE CHAIN-REACTION AMPLIFICATION - COMPARISON WITH MAJOR OUTER-MEMBRANE PROTEIN AND RESTRICTION-FRAGMENT-LENGTH-POLYMORPHISM ANALYSIS

    NARCIS (Netherlands)

    VANBELKUM, A; DUIM, B; REGELINK, A; MOLLER, L; QUINT, W; VANALPHEN, L

    Non-capsulate strains of Haemophilus influenzae were genotyped by analysis of variable DNA segments obtained by amplification of genomic DNA with the polymerase chain reaction (PCR fingerprinting). Discrete fragments of 100-2000 bp were obtained. The reproducibility of the procedure was assessed by

  6. Assessing HER2 amplification by IHC, FISH, and real-time polymerase chain reaction analysis (real-time PCR) following LCM in formalin-fixed paraffin embedded tissue from 40 women with ovarian cancer

    DEFF Research Database (Denmark)

    Hillig, Thore; Thode, Jørgen; Breinholt, Ellen Marie

    2012-01-01

    We compare HER2 receptor amplification analysis by immunohistochemistry (IHC), fluorescence in situ hybridization (FISH), and real-time polymerase chain reaction (real-time PCR) DNA copy-number assay following laser capture microdissection (LCM) in formalin-fixed paraffin embedded tissue from 40...

  7. Recombinase Polymerase Amplification Compared to Real-Time Polymerase Chain Reaction Test for the Detection of Fasciola hepatica in Human Stool

    Science.gov (United States)

    Cabada, Miguel M.; Malaga, Jose L.; Castellanos-Gonzalez, Alejandro; Bagwell, Kelli A.; Naeger, Patrick A.; Rogers, Hayley K.; Maharsi, Safa; Mbaka, Maryann; White, A. Clinton

    2017-01-01

    Fasciola hepatica is the most widely distributed trematode infection in the world. Control efforts may be hindered by the lack of diagnostic capacity especially in remote endemic areas. Polymerase chain reaction (PCR)–based methods offer high sensitivity and specificity but require expensive technology. However, the recombinase polymerase amplification (RPA) is an efficient isothermal method that eliminates the need for a thermal cycler and has a high deployment potential to resource-limited settings. We report on the characterization of RPA and PCR tests to detect Fasciola infection in clinical stool samples with low egg burdens. The sensitivity of the RPA and PCR were 87% and 66%, respectively. Both tests were 100% specific showing no cross-reactivity with trematode, cestode, or nematode parasites. In addition, RPA and PCR were able to detect 47% and 26% of infections not detected by microscopy, respectively. The RPA adapted to a lateral flow platform was more sensitive than gel-based detection of the reaction products. In conclusion, the Fasciola RPA is a highly sensitive and specific test to diagnose chronic infection using stool samples. The Fasciola RPA lateral flow has the potential for deployment to endemic areas after further characterization. PMID:27821691

  8. Genome-Wide Function, Evolutionary Characterization and Expression Analysis of Sugar Transporter Family Genes in Pear (Pyrus bretschneideri Rehd).

    Science.gov (United States)

    Li, Jia-Ming; Zheng, Dan-man; Li, Lei-ting; Qiao, Xin; Wei, Shu-wei; Bai, Bin; Zhang, Shao-ling; Wu, Jun

    2015-09-01

    The sugar transporter (ST) plays an important role in plant growth, development and fruit quality. In this study, a total of 75 ST genes were identified in the pear (Pyrus bretschneideri Rehd) genome based on systematic analysis. Furthermore, all ST genes identified were grouped into eight subfamilies according to conserved domains and phylogenetic analysis. Analysis of cis-regulatory element sequences of all ST genes identified the MYBCOREATCYCB1 promoter in sucrose transporter (SUT) and monosaccharide transporter (MST) genes of pear, while in grape it is exclusively found in SUT subfamily members, indicating divergent transcriptional regulation in different species. Gene duplication event analysis indicated that whole-genome duplication (WGD) and segmental duplication play key roles in ST gene amplification, followed by tandem duplication. Estimation of positive selection at codon sites of ST paralog pairs indicated that all plastidic glucose translocator (pGlcT) subfamily members have evolved under positive selection. In addition, the evolutionary history of ST gene duplications indicated that the ST genes have experienced significant expansion in the whole ST gene family after the second WGD, especially after apple and pear divergence. According to the global RNA sequencing results of pear fruit development, gene expression profiling showed the expression of 53 STs. Combined with quantitative real-time PCR (qRT-PCR) analysis, two polyol/monosaccharide transporter (PLT) and three tonoplast monosaccharide transporter (tMT) members were identified as candidate genes, which may play important roles in sugar accumulation during pear fruit development and ripening. Identification of highly expressed STs in fruit is important for finding novel genes contributing to enhanced levels of sugar content in pear fruit. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please

  9. Physicochemical Properties of Avocado Pear (Persea americana ...

    African Journals Online (AJOL)

    The oil from edible avocado pear (Persea americana) was extracted using the Soxhlet extraction method and characterized for specific gravity, refractive index, free fatty acids, saponification value, iodine value, acid value and biofuel potential using standard methods. The percent oil content in the fruit pulp was determined.

  10. (Persea americana) and African pear (Dacryodes edulis)

    African Journals Online (AJOL)

    GREGO

    2007-04-02

    Apr 2, 2007 ... used as salad oil in mayonnaise because of its low mel- ting point. Relative viscosity depends on many factors such as the method of extraction, age, .... popular vegetable oils like groundnut, palm and coconut oils for domestic and industrial purposes. Conclusion. This study shows that African pear (D.

  11. Detection of Brazilian hantavirus by reverse transcription polymerase chain reaction amplification of N gene in patients with hantavirus cardiopulmonary syndrome

    Directory of Open Access Journals (Sweden)

    Marcos Lázaro Moreli

    2004-10-01

    Full Text Available We report a nested reverse transcription-polymerase chain reaction (RT-PCR assay for hantavirus using primers selected to match high homology regions of hantavirus genomes detected from the whole blood of hantavirus cardiopulmonary syndrome (HCPS patients from Brazil, also including the N gene nucleotide sequence of Araraquara virus. Hantavirus genomes were detected in eight out of nine blood samples from the HCPS patients by RT-PCR (88.9% positivity and in all 9 blood samples (100% positivity by nested-PCR. The eight amplicons obtained by RT-PCR (P1, P3-P9, including one obtained by nested-PCR (P-2 and not obtained by RT-PCR, were sequenced and showed high homology (94.8% to 99.1% with the N gene of Araraquara hantavirus. Although the serologic method ELISA is the most appropriate test for HCPS diagnosis, the use of nested RT-PCR for hantavirus in Brazil would contribute to the diagnosis of acute hantavirus disease detecting viral genomes in patient specimens as well as initial genomic characterization of circulating hantaviruses.

  12. Rheological Characterization of Vegetal Pear (Sechium edule)

    Science.gov (United States)

    Castillo-Reyes, José A.; Luna-Solano, Guadalupe; Cantú-Lozano, Denis

    2008-07-01

    The national production of Mexican vegetal pear (Sechium edule) is located at the present time in more than 130,000 ton/year. The vegetal pear that produced in the center zone of the state of Veracruz is known in international markets; however it is a product that practically has not been studied. This work identifies the rheological behavior of vegetal pear (Sechium edule). A rheometer MCR301 of Anton Paar was utilized for viscosity and shear stress measurements. The objective of this experimental was modeling the rheological behavior of vegetal pear suspensions at three concentrations (1, 2 and 3% w/w), three particle size (1.00, 1.19 and 1.40 mm), at the same conditions of temperature (25, 40 and 70 °C). The results showed that all the suspensions there was a phenomenological behavior as a dilatants fluid (n>1) the performance of flow was represented by the Herschel-Bulkley model, and present values of "yield stress" between from 0.1 to 15 Pa for the different experiments. During evaluation of the activation energy of the suspensions of vegetal pear was found that decreases from 154.4039 kJ/mol to 9.1086 kJ/mol for a particle size of 1.00 mm to 1.4 mm, which implies that the effect of temperature is higher with smaller grains, in this case 1.00 mm. Furthermore, we assessed the effect of particle size by the Péclet number, showing an increase of the viscosity when the Péclet number also increases.

  13. Identification of Propionibacterium acnes by polymerase chain reaction for amplification of 16S ribosomal RNA and lipase genes.

    Science.gov (United States)

    Nakamura, Masahiko; Kametani, Ikuyo; Higaki, Shuichi; Yamagishi, Takayoshi

    2003-02-01

    Propionibacterium acnes belongs to the cutaneous flora and is present in sebaceous follicles. The fatty acids that are released from sebum triglycerides by the action of this bacterial lipase play an important role in the pathogenesis of acne vulgaris. P. acnes is also involved in postoperative disorders and opportunistic infections in immunosuppressed hosts. Recently, it has been proposed that P. acnes causes sarcoidosis. Therefore, rapid isolation and identification of P. acnes is important. This study evaluated the polymerase chain reaction (PCR) for the detection of the 16S rRNA and lipase genes of P. acnes. The PCR used to detect the 16S rRNA gene could amplify the gene of P. acnes, but not the genes of the other tested strains of P. avidum, P. granulosum, P. lymphophilum, P. jensenii, P. acidipropionici and P. thoenii. The PCR to detect the lipase gene of P. acnes, however, could amplify not only the gene of P. acnes but also that of P. avidum. The PCR product of this lipase gene was not found in the strains of the other species tested. Therefore, the organism that has both the 16S rRNA gene and lipase gene was identified as P. acnes, while the strain with the lipase gene but not the 16S rRNA gene of P. acnes was characterized as P. avidum. These findings were confirmed by the conventional biochemical tests including lipase activity. Furthermore, out of the seven clinical isolates from acne vulgaris, four were identified as P. acnes and three as P. avidum by the PCR method and biochemical tests. The combination of two PCR, one for the detection of the 16S rRNA and the other of lipase genes was shown to be an easier, faster and more accurate method to identify P. acnes and P. avidum than conventional methods.

  14. Detection of genetically modified crops using multiplex asymmetric polymerase chain reaction and asymmetric hyperbranched rolling circle amplification coupled with reverse dot blot.

    Science.gov (United States)

    Wang, Xiumin; Teng, Da; Guan, Qingfeng; Tian, Fang; Wang, Jianhua

    2015-04-15

    To meet the ever-increasing demand for detection of genetically modified crops (GMCs), low-cost, high-throughput and high-accuracy detection assays are needed. The new multiplex asymmetric polymerase chain reaction and asymmetric hyper-branched rolling circle amplification coupled with reverse dot blot (RDB) systems were developed to detect GMCs. Thirteen oligonucleotide probes were designed to identify endogenous targets (Lec1, Hmg and Sad1), event-specific targets (RRS-5C, RRS-3C, Bt176-3C and MON810-3C), screening targets (35S promoter and NOS terminator), and control targets (18S and PLX). Optimised conditions were as follows: tailed hybridization probes (1-2 pmol/l) were immobilized on a membrane by baking for 2h, and a 10:1 ratio of forward to reverse primers was used. The detection limits were 0.1 μg/l of 2% RRS and 0.5 ng/l of DNA from genetically modified (GM) soybean. These results indicate that the RDB assay could be used to detect multiplex target genes of GMCs rapidly and inexpensively. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Evaluation of multiplex ligation-dependent probe amplification analysis versus multiplex polymerase chain reaction assays in the detection of dystrophin gene rearrangements in an Iranian population subset

    Directory of Open Access Journals (Sweden)

    Nayereh Nouri

    2014-01-01

    Full Text Available Background: The Duchenne muscular dystrophy (DMD gene is located in the short arm of the X chromosome (Xp21. It spans 2.4 Mb of the human genomic DNA and is composed of 79 exons. Mutations in the Dystrophin gene result in DMD and Becker muscular dystrophy. In this study, the efficiency of multiplex ligation-dependent probe amplification (MLPA over multiplex polymerase chain reaction (PCR assays in an Iranian population was investigated. Materials and Methods: Multiplex PCR assays and MLPA analysis were carried out in 74 patients affected with DMD. Results: Multiplex PCR detected deletions in 51% of the patients with DMD. MLPA analysis could determine all the deletions detected by the multiplex PCR. Additionally, MLPA was able to identify one more deletion and duplication in patients without detectable mutations by multiplex PCR. Moreover, MLPA precisely determined the exact size of the deletions. Conclusion: Although MLPA analysis is more sensitive for detection of deletions and duplications in the dystrophin gene, multiplex PCR might be used for the initial analysis of the boys affected with DMD in the Iranian population as it was able to detect 95% of the rearrangements in patients with DMD.

  16. Detection of influenza viruses by coupling multiplex reverse-transcription loop-mediated isothermal amplification with cascade invasive reaction using nanoparticles as a sensor

    Directory of Open Access Journals (Sweden)

    Ge Y

    2017-04-01

    Full Text Available Yiyue Ge,1 Qiang Zhou,2 Kangchen Zhao,1 Ying Chi,1 Bin Liu,3 Xiaoyan Min,4 Zhiyang Shi,1 Bingjie Zou,2 Lunbiao Cui1 1Institute of Pathogenic Microbiology, Key Laboratories of Enteric Pathogenic Microbiology (Ministry of Health, Jiangsu Provincial Center for Disease Control and Prevention, 2Department of Pharmacology, Jinling Hospital, Medical School of Nanjing University, 3Department of Biomedical Engineering, Nanjing Medical University, 4Department of Geriatrics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, People’s Republic of China Abstract: Influenza virus infections represent a worldwide public health and economic problem due to the significant morbidity and mortality caused by seasonal epidemics and pandemics. Sensitive and convenient methodologies for detection of influenza viruses are essential for further disease control. Loop-mediated isothermal amplification (LAMP is the most commonly used method of nucleic acid isothermal amplification. However, with regard to multiplex LAMP, differentiating the ladder-like LAMP products derived from multiple targets is still challenging today. The requirement of specialized instruments has further hindered the on-site application of multiplex LAMP. We have developed an integrated assay coupling multiplex reverse transcription LAMP with cascade invasive reaction using nanoparticles (mRT-LAMP-CIRN as a sensor for the detection of three subtypes of influenza viruses: A/H1N1pdm09, A/H3 and influenza B. The analytic sensitivities of the mRT-LAMP-CIRN assay were 101 copies of RNA for both A/H1N1pdm09 and A/H3, and 102 copies of RNA for influenza B. This assay demonstrated highly specific detection of target viruses and could differentiate them from other genetically or clinically related viruses. Clinical specimen analysis showed the mRT-LAMP-CIRN assay had an overall sensitivity and specificity of 98.3% and 100%, respectively. In summary, the mRT-LAMP-CIRN assay is

  17. Development of a multiplex amplification refractory mutation system reverse transcription polymerase chain reaction assay for the differential diagnosis of Feline leukemia virus vaccine and wild strains.

    Science.gov (United States)

    Ho, Chia-Fang; Chan, Kun-Wei; Yang, Wei-Cheng; Chiang, Yu-Chung; Chung, Yang-Tsung; Kuo, James; Wang, Chi-Young

    2014-07-01

    A multiplex amplification refractory mutation system reverse transcription polymerase chain reaction (ARMS RT-PCR) was developed for the differential diagnosis of Feline leukemia virus (FeLV) vaccine and wild-type strains based on a point mutation between the vaccine strain (S) and the wild-type strain (T) located in the p27 gene. This system was further upgraded to obtain a real-time ARMS RT-PCR (ARMS qRT-PCR) with a high-resolution melt analysis (HRMA) platform. The genotyping of various strains of FeLV was determined by comparing the HRMA curves with the defined wild-type FeLV (strain TW1), and the results were expressed as a percentage confidence. The detection limits of ARMS RT-PCR and ARMS qRT-PCR combined with HRMA were 100 and 1 copies of transcribed FeLV RNA per 0.5 ml of sample, respectively. No false-positive results were obtained with 6 unrelated pathogens and 1 feline cell line. Twelve FeLV Taiwan strains were correctly identified using ARMS qRT-PCR combined with HRMA. The genotypes of the strains matched the defined FeLV wild-type strain genotype with at least 91.17% confidence. A higher degree of sequence polymorphism was found throughout the p27 gene compared with the long terminal repeat region. In conclusion, the current study describes the phylogenetic relationship of the FeLV Taiwan strains and demonstrates that the developed ARMS RT-PCR assay is able to be used to detect the replication of a vaccine strain that has not been properly inactivated, thus acting as a safety check for the quality of FeLV vaccines.

  18. Lateral flow nucleic acid biosensor for sensitive detection of microRNAs based on the dual amplification strategy of duplex-specific nuclease and hybridization chain reaction.

    Directory of Open Access Journals (Sweden)

    Na Ying

    Full Text Available MicroRNAs (miRNAs constitute novel biomarkers for various diseases. Accurate and quantitative analysis of miRNA expression is critical for biomedical research and clinical theranostics. In this study, a method was developed for sensitive and specific detection of miRNAs via dual signal amplification based on duplex specific nuclease (DSN and hybridization chain reaction (HCR. A reporter probe (RP, comprising recognition sequence (3' end modified with biotin for a target miRNA of miR-21 and capture sequence (5' end modified with Fam for HCR product, was designed and synthesized. HCR was initiated by partial sequence of initiator probe (IP, the other part of which can hybridize with capture sequence of RP, and was assembled by hairpin probes modified with biotin (H1-bio and H2-bio. A miR-21 triggered cyclical DSN cleavage of RP, which was immobilized to a streptavidin (SA coated magnetic bead (MB. The released Fam labeled capture sequence then hybridized with the HCR product to generate a detectable dsDNA. This polymer was then dropped on lateral flow strip and positive result was observed. The proposed method allowed quantitative sequence-specific detection of miR-21 (with a detection limit of 2.1 fM, S/N = 3 in a dynamic range from 100 fM to 100 pM, with an excellent ability to discriminate differences in miRNAs. The method showed acceptable testing recoveries for the determination of miRNAs in serum.

  19. DNAzyme Feedback Amplification: Relaying Molecular Recognition to Exponential DNA Amplification.

    Science.gov (United States)

    Liu, Meng; Yin, Qingxin; McConnell, Erin M; Chang, Yangyang; Brennan, John D; Li, Yingfu

    2018-03-26

    Technologies capable of linking DNA amplification to molecular recognition are very desirable for ultrasensitive biosensing applications. We have developed a simple but powerful isothermal DNA amplification method, termed DNAzyme feedback amplification (DFA), that is capable of relaying molecular recognition to exponential DNA amplification. The method incorporates both an RNA-cleaving DNAzyme (RCD) and rolling circle amplification (RCA) carried out by a special DNA polymerase using a circular DNA template. DFA begins with a stimulus-dependent RCA reaction, producing tandemly linked RCDs in long-chain DNA products. These RCDs cleave an RNA-containing DNA sequence to form additional primers that hybridize to the circular DNA molecule, giving rise to DNA assemblies that act as the new inputs for RCA. The RCA reaction and the cleavage event keep on feeding each other autonomously, resulting in exponential growth of repetitive DNA sequences that can be easily detected. This method can be used for the detection of both nucleic acid based targets and non-nucleic acid analytes. In this article, we discuss the conceptual framework of the feedback amplification approach, the essential features of this method as well as remaining challenges and possible solutions. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Characterization and analysis of CCR and CAD gene families at the whole-genome level for lignin synthesis of stone cells in pear (Pyrus bretschneideri) fruit.

    Science.gov (United States)

    Cheng, Xi; Li, Manli; Li, Dahui; Zhang, Jinyun; Jin, Qing; Sheng, Lingling; Cai, Yongping; Lin, Yi

    2017-11-15

    The content of stone cells has significant effects on the flavour and quality of pear fruit. Previous research suggested that lignin deposition is closely related to stone cell formation. In the lignin biosynthetic pathway, cinnamoyl-CoA reductase (CCR) and cinnamyl alcohol dehydrogenase (CAD), dehydrogenase/reductase family members, catalyse the last two steps in monolignol synthesis. However, there is little knowledge of the characteristics of the CCR and CAD families in pear and their involvement in lignin synthesis of stone cells. In this study, 31 CCR s and 26 CAD s were identified in the pear genome. Phylogenetic trees for CCR s and CAD s were constructed; key amino acid residues were analysed, and three-dimensional structures were predicted. Using quantitative real-time polymerase chain reaction (qRT-PCR), PbCAD2 , PbCCR1 , -2 and - 3 were identified as participating in lignin synthesis of stone cells in pear fruit. Subcellular localization analysis showed that the expressed proteins (PbCAD2, PbCCR1, -2 and -3) are found in the cytoplasm or at the cell membrane. These results reveal the evolutionary features of the CCR and CAD families in pear as well as the genes responsible for regulation of lignin synthesis and stone cell development in pear fruit. © 2017. Published by The Company of Biologists Ltd.

  1. Characterization and analysis of CCR and CAD gene families at the whole-genome level for lignin synthesis of stone cells in pear (Pyrus bretschneideri fruit

    Directory of Open Access Journals (Sweden)

    Xi Cheng

    2017-11-01

    Full Text Available The content of stone cells has significant effects on the flavour and quality of pear fruit. Previous research suggested that lignin deposition is closely related to stone cell formation. In the lignin biosynthetic pathway, cinnamoyl-CoA reductase (CCR and cinnamyl alcohol dehydrogenase (CAD, dehydrogenase/reductase family members, catalyse the last two steps in monolignol synthesis. However, there is little knowledge of the characteristics of the CCR and CAD families in pear and their involvement in lignin synthesis of stone cells. In this study, 31 CCRs and 26 CADs were identified in the pear genome. Phylogenetic trees for CCRs and CADs were constructed; key amino acid residues were analysed, and three-dimensional structures were predicted. Using quantitative real-time polymerase chain reaction (qRT-PCR, PbCAD2, PbCCR1, -2 and -3 were identified as participating in lignin synthesis of stone cells in pear fruit. Subcellular localization analysis showed that the expressed proteins (PbCAD2, PbCCR1, -2 and -3 are found in the cytoplasm or at the cell membrane. These results reveal the evolutionary features of the CCR and CAD families in pear as well as the genes responsible for regulation of lignin synthesis and stone cell development in pear fruit.

  2. 10406 EFFICACY OF CACTUS PEAR (Opuntia ficus-indica ...

    African Journals Online (AJOL)

    bdu

    Cactus Pear (Opuntia ficus-indica) serves as a source of food, feed, as well as a means of additional income to the people in northern Ethiopia. The species has different varieties with varied rate of productivity and palatability. This study was conducted to assess the food and feed value of the Cactus Pear varieties in ...

  3. Postharvest Decay of Apples and Pears in The Netherlands

    NARCIS (Netherlands)

    Wenneker, M.; Köhl, J.

    2014-01-01

    Postharvest diseases are a major problem in long storage of apples and pears in The Netherlands. Despite intensive preharvest spraying programs significant losses occur (over 60% of fruit losses are recorded). Over 125 heavily affected lots of apples (mainly ‘Elstar’) and pears (mainly ‘Conference’)

  4. Evaluation of the Potential of African Pear ( Dacryodes edulis ) Pulp ...

    African Journals Online (AJOL)

    African pear pulp (APP) was used at different levels (100%, 75%, 50%, 25% and 0% [control]) to replace margarine in biscuit. The proximate composition, thickness, diameter as well as consumer acceptability were evaluated. The samples produced with 100% pear pulp substitution had significantly higher values for protein, ...

  5. Effect of hormone treatments on deformed fruit development in pear ...

    African Journals Online (AJOL)

    Fruit shape is one of the most important limiting factors in the quality of pear fruits. The effects of applied plant growth regulators on fruit shape have been determined in pear. The application of naphthalene acetic acid (NAA, 20 mg/L), indole-3-butyric acid (IBA, 30 mg/L), 6-benzalyamino acid (6-BA, 30 mg/L), cleaner ...

  6. 7 CFR 917.461 - Pear Regulation 12.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Pear Regulation 12. 917.461 Section 917.461 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing... grower to the field or area in which the pears are grown for 12 months prior to the appearance of flower...

  7. Fermentation characteristics of Korean pear ( Pyrus pyrifolia Nakai ...

    African Journals Online (AJOL)

    A lactic acid bacterial strain showing fast growth and high acid production when cultured in Korean pear puree was isolated from Kimchi. This strain was analyzed by using the API 50 CHL kit and 16S rRNA sequencing and was thus identified as Leuconostoc mesenteroides 51-3. Korean pear puree was fermented with the ...

  8. Changing perspectives on pearly mussels, North America's most imperiled animals

    Science.gov (United States)

    David L. Strayer; John A. Downing; Wendell R. Haag; Timothy L. King; James B. Layzer; Teresa J. Newton; S. Jerrine Nichols

    2004-01-01

    Pearly mussels (Unionacea) are widespread, abundant, and important in freshwater ecosystems around the world. Catastrophic declines in pearly mussel populations in North America and other parts of the world have led to a flurry of research on mussel biology, ecology, and conservation. Recent research on mussel feeding, life history, spatial...

  9. Wet faeces produced by sheep fed dried spineless cactus pear ...

    African Journals Online (AJOL)

    Cactus pear cladodes in ruminant diets are characterized by the production of wet faeces and assumed to be diarrhoea. Incremental levels of sun-dried and coarsely ground spineless cactus pear (Opuntia ficus-indica var. Algerian) cladodes were used to substitute part of the lucerne hay in balanced sheep diets. Feed and ...

  10. Changes in endogenous hormone contents of pear stock ( Pyrus ...

    African Journals Online (AJOL)

    In this study, changes in endogenous hormone contents of pear stock seeds during cold stratification were investigated. Abscisic acid (ABA) content decreased with increase in the periods of stratification of pear stock seeds. However, gibberellic acid (GA) and indole-3-acetic acid (IAA) contents of Pyrus betulaefolia and ...

  11. Fermentation characteristics of Korean pear (Pyrus pyrifolia Nakai ...

    African Journals Online (AJOL)

    USER

    2010-08-30

    Aug 30, 2010 ... A lactic acid bacterial strain showing fast growth and high acid production when cultured in Korean pear puree was isolated from Kimchi. This strain was analyzed by using the API 50 CHL kit and 16S. rRNA sequencing and was thus identified as Leuconostoc mesenteroides 51-3. Korean pear puree was.

  12. Effect of hormone treatments on deformed fruit development in pear

    African Journals Online (AJOL)

    erica

    2012-05-31

    May 31, 2012 ... Fruit shape is one of the most important limiting factors in the quality of pear fruits. The effects of applied plant growth regulators on fruit shape have been determined in pear. The application of naphthalene acetic acid (NAA, 20 mg/L), indole-3-butyric acid (IBA, 30 mg/L), 6-benzalyamino acid (6-.

  13. Quality characteristics and phenolic compounds of European pear ...

    African Journals Online (AJOL)

    Background: Pear fruits are an important source of plant secondary metabolites and one of the major sources of dietary phenolic compounds. Materials and Methods: The aim of this study was to determine the individual phenolic compounds and some quality characteristics of the flesh and peel of the fruit in four pear ...

  14. 77 FR 72197 - Pears Grown in Oregon and Washington; Assessment Rate Decrease for Processed Pears

    Science.gov (United States)

    2012-12-05

    ... / Wednesday, December 5, 2012 / Rules and Regulations#0;#0; ] DEPARTMENT OF AGRICULTURE Agricultural Marketing..., as amended (7 U.S.C. 601-674), hereinafter referred to as the ``Act.'' The Department of Agriculture...- Washington processed pears. They are familiar with the Committee's needs and with the costs for goods and...

  15. 76 FR 53811 - Pears Grown in Oregon and Washington; Assessment Rate Decrease for Processed Pears

    Science.gov (United States)

    2011-08-30

    ... / Tuesday, August 30, 2011 / Rules and Regulations#0;#0; ] DEPARTMENT OF AGRICULTURE Agricultural Marketing..., as amended (7 U.S.C. 601-674), hereinafter referred to as the ``Act.'' The Department of Agriculture...- Washington processed pears. They are familiar with the Committee's needs and with the costs for goods and...

  16. 76 FR 54075 - Pears Grown in Oregon and Washington; Assessment Rate Decrease for Fresh Pears

    Science.gov (United States)

    2011-08-31

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF AGRICULTURE... referred to as the ``Act.'' The Department of Agriculture (USDA) is issuing this rule in conformance with... Oregon-Washington fresh pears. They are familiar with the Committee's needs and with the costs for goods...

  17. 78 FR 34 - Pears Grown in Oregon and Washington; Modification of the Assessment Rate for Fresh Pears

    Science.gov (United States)

    2013-01-02

    ..., the Committee recommended lower promotion and paid advertising expenditures for marketing the reduced... promotion and marketing of the larger fresh summer/fall pear crop. As a consequence, increasing it to the... should generate enough funds for promotion and marketing of the smaller fresh winter pear crop. A review...

  18. 78 FR 24033 - Pears Grown in Oregon and Washington; Modification of the Assessment Rate for Fresh Pears

    Science.gov (United States)

    2013-04-24

    ... Committee recommended lower promotion and paid advertising expenditures for marketing the reduced fresh... promotion and marketing of the larger fresh summer/fall pear crop. As a consequence, increasing it to the... should generate enough funds for promotion and marketing of the smaller fresh winter pear crop. A review...

  19. Subject in Tractatus according to David Pears

    Directory of Open Access Journals (Sweden)

    M Hoseinzadeh Yazdi

    2013-03-01

    Considering the centrality of subjectivism in modern philosophy, this article attempts to explain subject in Tractatus according to David Pears. A review of Wittgenstein’s earlier teachings reveals that he considers a fundamental limitation for language. The subject serves as a point of view from which the language can be understood. The subject is the presupposition of understanding. Another way of putting this would be to say that any experience is understood from a point of view which is not represented in that experience. Regarding this, it seems that earlier Wittgenstein is somehow subjectivist. This specific form of subjectivism is different from Kantian subjectivism.

  20. First Report of Fusarium avenaceum Causing Postharvest Decay on ‘Conference’ Pears in the Netherlands

    NARCIS (Netherlands)

    Wenneker, M.; Pham, K.T.K.; Lemmers, M.E.C.; Boer, de Fred; Lans, Van Der A.M.; Leeuwen, Van P.J.; Hollinger, T.C.; Thomma, B.P.H.J.

    2016-01-01

    Pear (Pyrus communis) is an important fruit crop in the Netherlands, with a total production of 349,000 tons in 2014. ‘Conference’ is the main pear cultivar that occupies 75% of the total pear production area in the Netherlands. In the Netherlands, pears are kept in controlled atmosphere cold

  1. Pear transformed with a lytic peptide gene for disease control affects nontarget organism, pear psylla (Homoptera: Psyllidae).

    Science.gov (United States)

    Puterka, Gary J; Bocchetti, Chris; Dang, Phat; Bell, R L; Scorza, Ralph

    2002-08-01

    The biology and behavior of pear psylla, Cacopsylla pyricola Foerster, on a transgenic clone of 'Bartlett' pear, Pyrus communis L., containing a synthetic antimicrobial gene, D5C1, was compared with that of a nontransgenic parental clone to determine whether there were any nontarget effects. The gene construct also contained the marker gene nptII (aminoglycoside 3'-phosphotransferase II) that encodes for antibiotic resistance to identify transformed plants. The purpose of the original transformation was to enhance pear resistance to the bacterial disease fireblight caused by Erwinia amylovora (Burr.) Winslow et al. The biology and behavior of pear psylla on a transgenic clone were compared with a nontransgenic parental pear clone in short- (crops.

  2. Aroma-Active Compounds in Bartlett Pears and Their Changes during the Manufacturing Process of Bartlett Pear Brandy.

    Science.gov (United States)

    Zierer, Bianca; Schieberle, Peter; Granvogl, Michael

    2016-12-21

    Application of aroma extract dilution analysis to Bartlett pears and the fermented mash produced thereof revealed 24 and 34 aroma-active compounds in the flavor dilution (FD) factor range between 8 and 8192. Twenty-eight compounds, which have not been described before in Bartlett pears or in fermented pear mash, were identified. While ethyl (E,Z)-2,4-decadienoate (pear-like, metallic odor impression), hexyl acetate (green, fruity), and acetic acid (vinegar-like) showed the highest concentrations in Bartlett pears, ethanol (ethanolic), acetic acid, 3-methyl-1-butanol (malty), 1-hexanol (grassy, marzipan-like), (S)-2- and 3-methylbutanoic acid (sweaty), and 2-phenylethanol (flowery, honey-like) were present at the highest amounts in the fermented mash. The key aroma compounds were quantitated in each pear brandy production step (pears, fermented mash, distillate, and aged distillate) by stable isotope dilution analysis showing a clear influence of each step on the overall aroma of the spirit and, consequently, revealing clearly changing concentrations (e.g., of ethyl (S)-2-methylbutanoate, (E)-β-damascenone, ethyl (E,Z)-2,4-decadienoate, and ethyl (E,E)-2,4-decadienoate) and different aroma perceptions during the manufacturing process. In addition, the concentrations of the so-called "pear esters" ethyl (E,Z)-2,4-decadienoate and ethyl (E,E)-2,4-decadienoate were determined in 6 different pear varieties (Abate Fetel, Anjou, Bartlett, Forelle, Kaiser Alexander, and Packham's Triumph) clearly demonstrating the aroma potential of the variety Bartlett, which is mostly used for brandy production due to the high amounts of both esters eliciting a typical pear-like odor impression.

  3. Advances in Japanese pear breeding in Japan.

    Science.gov (United States)

    Saito, Toshihiro

    2016-01-01

    The Japanese pear (Pyrus pyrifolia Nakai) is one of the most widely grown fruit trees in Japan, and it has been used throughout Japan's history. The commercial production of pears increased rapidly with the successive discoveries of the chance seedling cultivars 'Chojuro' and 'Nijisseiki' around 1890, and the development of new cultivars has continued since 1915. The late-maturing, leading cultivars 'Niitaka' and 'Shinko' were released during the initial breeding stage. Furthermore, systematic breeding by the Horticultural Research Station (currently, NARO Institute of Fruit Tree Science, National Agriculture and Food Research Organization (NIFTS)) began in 1935, which mainly aimed to improve fruit quality by focusing on flesh texture and black spot disease resistance. To date, 22 cultivars have been released, including 'Kosui', 'Hosui', and 'Akizuki', which are current leading cultivars from the breeding program. Four induced mutant cultivars induced by gamma irradiation, which exhibit some resistance to black spot disease, were released from the Institute of Radiation Breeding. Among these cultivars, 'Gold Nijisseiki' has become a leading cultivar. Moreover, 'Nansui' from the Nagano prefectural institute breeding program was released, and it has also become a leading cultivar. Current breeding objectives at NIFTS mainly combine superior fruit quality with traits related to labor and cost reduction, multiple disease resistance, or self-compatibility. Regarding future breeding, marker-assisted selection for each trait, QTL analyses, genome-wide association studies, and genomic selection analyses are currently in progress.

  4. Mutant of Japanese pear resistant to Black Spot Disease

    International Nuclear Information System (INIS)

    Sanada, T.; Nishida, T.; Ikeda, F.

    1987-01-01

    Full text: Nijisseike is one of the leading cultivars of Japanese pear (Pyrus serotinea Rehd.), but susceptible to black spot disease. Farmers try to prevent this disease by wrapping the fruit with a paper bag and by repeated spraying of fungicides. The disease is caused by a Japanese pear pathotype of Alternaria alternata (Fr.) Keissler. Susceptibility is controlled by a single dominant gene. In 1962, grafted trees of this cultivar were planted at a distance between 53 and 93 m from the 60 Co source in the gamma-field (daily dose 15-4 rad). One branch on a tree planted at 53 m was detected as resistant in 1981. Under field conditions, black spots were observed on many fruits and leaves of the original trees by natural infection in early July, however, they were not observed on the mutant. To examine the resistance of the mutant, artificial inoculations were made using spores of the pathogen and the host specific toxin produced by germinating spores. When some drops of the spore suspension are placed on leaves, the formation of black spots depends upon the leaf age. In a resistant cv. as Chojuro, black spot symptoms are formed only when inoculated on young leaves. An intermediate reaction was observed in the mutant, whereas the original Nijisseiki showed severe symptoms. When inoculation was made on matured fruit skins, no black spot was formed on the mutant just like on the resistant cv. Chojuro, while many small black spots were formed and grew into large spots overlapping each other on the susceptible cv. Nijisseiki. In case of the crude toxin inoculation (4-0.04 ppm) of cv. Nijisseiki black spots were formed on the surface of the susceptible fruit skin, and necrotic lesions at the cut end of detached small pieces of leaves, although reaction on fruit skins was weaker compared with inoculation by spores. However, no symptoms were observed from the toxin application on the mutant and the resistant cv. Chojuro. That the resistance of the mutant is classified as

  5. Amplification factor variable amplifier

    NARCIS (Netherlands)

    Akitsugu, Oshita; Nauta, Bram

    2007-01-01

    PROBLEM TO BE SOLVED: To provide an amplification factor variable amplifier capable of achieving temperature compensation of an amplification factor over a wide variable amplification factor range. ; SOLUTION: A Gilbert type amplification factor variable amplifier 11 amplifies an input signal and

  6. Amplification factor variable amplifier

    NARCIS (Netherlands)

    Akitsugu, Oshita; Nauta, Bram

    2010-01-01

    PROBLEM TO BE SOLVED: To provide an amplification factor variable amplifier capable of achieving temperature compensation of an amplification factor over a wide variable amplification factor range. ;SOLUTION: A Gilbert type amplification factor variable amplifier 11 amplifies an input signal and can

  7. Subject in Tractatus according to David Pears

    Directory of Open Access Journals (Sweden)

    M Hoseinzadeh Yazdi

    2013-02-01

    Full Text Available Subjectivism is viewed as one of the most fundamental underpinnings of modern philosophy. In modern philosophy, subject takes up a new position in human knowledge. The formation of the concept of subject is a decisive turn with which the modern philosophy starts. Considering the centrality of subjectivism in modern philosophy, this article attempts to explain subject in Tractatus according to David Pears. A review of Wittgenstein’s earlier teachings reveals that he considers a fundamental limitation for language. The subject serves as a point of view from which the language can be understood. The subject is the presupposition of understanding. Another way of putting this would be to say that any experience is understood from a point of view which is not represented in that experience. Regarding this, it seems that earlier Wittgenstein is somehow subjectivist. This specific form of subjectivism is different from Kantian subjectivism.

  8. Assessment of nucleic acid modification induced by amotosalen and ultraviolet A light treatment of platelets and plasma using real-time polymerase chain reaction amplification of variable length fragments of mitochondrial DNA.

    Science.gov (United States)

    Bakkour, Sonia; Chafets, Daniel M; Wen, Li; Dupuis, Kent; Castro, Grace; Green, Jennifer M; Stassinopoulos, Adonis; Busch, Michael P; Lee, Tzong-Hae

    2016-02-01

    Pathogen inactivation methods are increasingly used to reduce the risk of infections after transfusion of blood products. Photochemical treatment (PCT) of platelets (PLTs) and plasma with amotosalen and ultraviolet A (UVA) light inactivates pathogens and white blood cells through formation of adducts between amotosalen and nucleic acid that block replication, transcription, and translation. The same adducts block the amplification of nucleic acids using polymerase chain reaction (PCR) in a manner that correlates with the number of adducts formed, providing a direct quality control (QC). Current QC measures for PCT rely on indirect methods that measure the delivered UVA dose or percent residual amotosalen after illumination, rather than directly measuring nucleic acid modification. Endogenous mitochondrial DNA (mtDNA), which is detectable in PLT and plasma units, was chosen as a target for the quantification of photochemically induced modifications. DNA was extracted from untreated or amotosalen and UVA-treated PLTs or plasma, and mtDNA fragments of variable lengths were quantified using a real-time PCR inhibition assay. PCT induced increasing real-time PCR inhibition of mtDNA amplification for larger amplicon sizes. Amplification was unaffected by treatment with amotosalen or UVA alone, whereas up to 3 log inhibition was observed after PCT. Blinded PCR testing of a panel of 110 samples each, from PLT or plasma components prepared for routine use within a blood center, allowed 100% discrimination between untreated and treated units. Our initial findings indicate that an adequately sensitive, quantitative real-time PCR inhibition assay targeting mtDNA could provide a valuable tool to confirm and monitor PCT. © 2015 The Authors. Transfusion published by Wiley Periodicals, Inc. on behalf of AABB.

  9. Detection of EGFR Gene Mutations in 100 Non-small Cell Lung Cancer Clinical Samples by a Real-time Polymerase Chain Reaction Method Using Amplification Refractory Mutation System Specific Primers and Taqman Fluorescence Probes

    Directory of Open Access Journals (Sweden)

    Jing ZHAO

    2013-01-01

    Full Text Available Background and objective Epidermal growth factor receptor (EGFR gene mutation is the most important predictor of the efficiency of EGFR-tyrosine kinase inhibitors in the treatment of non-small cell lung cancer (NSCLC. The detection of EGFR gene mutations can guide individual therapies for NSCLC. Numerous methods are used to detect EGFR gene mutation and each method has different features. This study aims to establish a real-time polymerase chain reaction (PCR method for the detection of EGFR gene mutations using amplification refractory mutation system (ARMS specific primers and Taqman fluorescence probes. Methods ARMS specific primers for the two EGFR gene mutations (E746_A750 and L858R and Taqman fluorescence probes for the detection of the target sequence were carefully designed by the Primer Premier 5.0 software. Then, using the recombinants containing E746_A750 and L858R mutations as the study objects, we further analyzed the sensitivity and lower limit of this method, and then determined the cutoff ΔCt value to evaluate specific or non-specific amplification. A total of 100 clinical samples were collected and used to detect the EGFR gene mutations using this method. Results The lower limit of this method for the detection of EGFR gene mutation was 10 copies if no interference of wild-type EGFR gene or background DNA existed. Regarding the method sensitivity, the detection resolution was as high as 1% and 0.1%-0.5% in the background of 500 and 5,000 copies/μL wild-type EGFR gene, respectively. Regarding the method specificity, non-specific amplifications were found when it was used to detect 21 L858R mutations in leukocyte DNA samples from healthy volunteers. However, the minimal ΔCt value was 14.48. Non-specific amplifications were not found when detecting 19 Del mutations. Among the 100 clinical samples, 39 mutations were detected (19 Del and 21 L858R were 21 and 18, respectively using this method. The total mutation rate was 39

  10. GRAFT COMPATIBILITY BETWEEN EUROPEAN PEAR CULTIVARS AND EAST MALLING “C” ROOTSTOCK

    OpenAIRE

    BRUNO DALAZEN MACHADO; MAICON MAGRO; LEO RUFATO; AMAURI BOGO; AIKE ANNELIESE KREZTSCHMAR

    2017-01-01

    ABSTRACT Graft incompatibility is one of the main factors limiting european pear production in Brazil. At present, there is no clear indication of the best combination(s) of european pear cultivars and quince rootstocks for graft compatibility. The study evaluated the graft compatibility for combinations of european Abbè Fetel, Rocha and Williams pear cultivars grafted onto the EMC quince rootstock. The experiment was performed in a commercial european pear orchard in the Urupema municipalit...

  11. 7 CFR 927.120 - Pears for charitable or byproduct purposes.

    Science.gov (United States)

    2010-01-01

    ... MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE... shall have been delivered to the manager of the Fresh Pear Committee a certificate executed by the intended receiver and user of said pears showing, to the manager's satisfaction, that said pears actually...

  12. 7 CFR 917.21 - Nomination of Pear Commodity Committee members.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Nomination of Pear Commodity Committee members. 917.21 Section 917.21 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING... Pear Commodity Committee members. Nominations for membership on the Pear Commodity Committee shall be...

  13. Genetic linkage maps of Japanese and European pears aligned to the apple consensus map

    NARCIS (Netherlands)

    Yamamoto, T.; Kimura, T.; Saito, T.; Kotobuki, K.; Matsuta, N.; Liebhard, R.; Gessler, C.; Weg, van de W.E.; Hayashi, T.

    2004-01-01

    Genetic linkage maps of the Japanese pear (Pyrus pyrifolia Nakai) cultivar `Housui¿ and the European pear (Pyrus communis L.) cultivar `Bartlett¿ were constructed based on Amplified Fragment Length Polymorphism markers (AFLPs), Simple Sequence Repeat markers (SSRs) (from pear, apple and Prunus),

  14. 75 FR 77563 - Nectarines, Pears, and Peaches Grown in California; Continuance Referenda

    Science.gov (United States)

    2010-12-13

    ... Agricultural Marketing Service 7 CFR Parts 916 and 917 Nectarines, Pears, and Peaches Grown in California; Continuance Referenda AGENCY: Agricultural Marketing Service, USDA. ACTION: Referenda order. SUMMARY: This... that time, the pear industry has been regulated by a State marketing order. If the results of the pear...

  15. 7 CFR 319.56-20 - Apples and pears from Australia (including Tasmania) and New Zealand.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Apples and pears from Australia (including Tasmania... Fruits and Vegetables § 319.56-20 Apples and pears from Australia (including Tasmania) and New Zealand. Apples and pears from Australia (including Tasmania) and New Zealand may be imported only in accordance...

  16. 7 CFR 319.56-29 - Ya variety pears from China.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Ya variety pears from China. 319.56-29 Section 319.56... variety pears from China. Ya variety pears may be imported into the United States from China only in... organization (NPPO) of China in an APHIS-approved export growing area in the Hebei or Shandong Provinces. (2...

  17. Utility of loop-mediated isothermal amplification assay, polymerase chain reaction, and elisa for diagnosis of leptospirosis in South Indian patients

    Directory of Open Access Journals (Sweden)

    Mallika Sengupta

    2017-01-01

    Full Text Available Background: Leptospirosis is a zoonotic disease which requires laboratory diagnosis for confirmation. Materials and Methods: In this study serum samples from adults with acute undifferentiated fever (duration ≤15 days were tested for IgM antibodies to Leptospira by ELISA, PCR for rrs gene and loop-mediated isothermal amplification (LAMP assay for LipL32 and LipL41. Results: Among the 150 sera tested, three were positive by PCR, LAMP and IgM ELISA/modified Faines' criteria, two by only PCR; seven only by LAMP assay and forty fulfilled modified Faine's criteria (illness clinically compatible and IgM ELISA positive for leptospirosis. Clinical correlation revealed renal compromise, low platelet count and severe jaundice were significantly related to leptospirosis (P < 0.05. Conclusion: This study suggests that LAMP assay could be useful for diagnosis of leptospirosis during the 1st week of illness whereas IgM ELISA forms the mainstay of diagnosis from the 2nd week onward. Further studies especially community based, comparing ELISA, PCR, LAMP, culture and microscopic agglutination test are required to evaluate the veracity of these findings.

  18. Origin, Domestication, and Dispersing of Pear (Pyrus spp.

    Directory of Open Access Journals (Sweden)

    G. J. Silva

    2014-01-01

    Full Text Available The pear (Pyrus communis L. is a typical fruit of temperate regions, having its origin and domestication at two different points, China and Asia Minor until the Middle East. It is the fifth most widely produced fruit in the world, being produced mainly in China, Europe, and the United States. Pear belongs to rosaceous family, being a close “cousin” of the apple, but with some particularities that make this fruit special with a delicate flavor. Thus, it deserves a special attention and a meticulous review of all the history involved, and the recent research devoted to it, because of the economic and cultural importance of this fruit in a range of countries and cultures. Therefore, the purpose of this literature review is to approach the history of the origin, domestication, and dispersal of pears, as well as reporting their botany, their current scenario in the world, and their breeding and conservation.

  19. Sequence Characterization and Spatiotemporal Expression Patterns of PbS26-RNase Gene in Chinese White Pear (Pyrus bretschneideri

    Directory of Open Access Journals (Sweden)

    Lin Zhang

    2014-01-01

    Full Text Available Many flowering plants exhibit an important intraspecific reproductive barrier phenomenon, that is, self-incompatibility (SI, in which S-RNase genes play a significant role. To clarify the specific function of S-RNase genes in Chinese pears, the full length cDNA of PbS26-RNase was isolated by rapid amplification of cDNA ends (RACE technology from Chinese white pear (Pyrus bretschneideri cultivar “Hongpisu.” The cDNA sequence for PbS26-RNase was deposited in GenBank under accession number EU081888. At the amino acid level, the PbS26-RNase displayed the highest similarity (96.9% with PcSa-RNase of P. communis, and only seven amino acid differences were present in the two S-RNases. Phylogenetic analysis of rosaceous S-RNases indicated that the PbS26-RNase clustered with maloideous S-RNases, forming a subfamily-specific not a species-specific group. The PbS26-RNase gene was specifically expressed in the style but not other tissues/organs. The expression level of the PbS26-RNase gene rapidly increased at bell balloon stage (BBS, and then it dropped after pollination. However, the abundance of the PbS26-RNase gene transcript in the style was greater after cross-pollination than after self-pollination. In addition, a method for rapidly detecting the PbS26-RNase gene was developed via allele-specific primers design. The present study could provide a scientific basis for fully clarifying the mechanism of pear SI at the molecular level.

  20. Effect of Extrusion Cooking on Bioactive Compounds in Encapsulated Red Cactus Pear Powder

    Directory of Open Access Journals (Sweden)

    Martha G. Ruiz-Gutiérrez

    2015-05-01

    Full Text Available Red cactus pear has significant antioxidant activity and potential as a colorant in food, due to the presence of betalains. However, the betalains are highly thermolabile, and their application in thermal process, as extrusion cooking, should be evaluated. The aim of this study was to evaluate the effect of extrusion conditions on the chemical components of red cactus pear encapsulated powder. Cornstarch and encapsulated powder (2.5% w/w were mixed and processed by extrusion at different barrel temperatures (80, 100, 120, 140 °C and screw speeds (225, 275, 325 rpm using a twin-screw extruder. Mean residence time (trm, color (L*, a*, b*, antioxidant activity, total polyphenol, betacyanin, and betaxanthin contents were determined on extrudates, and pigment degradation reaction rate constants (k and activation energies (Ea were calculated. Increases in barrel temperature and screw speed decreased the trm, and this was associated with better retentions of antioxidant activity, total polyphenol, betalain contents. The betacyanins k values ranged the −0.0188 to −0.0206/s and for betaxanthins ranged of −0.0122 to −0.0167/s, while Ea values were 1.5888 to 6.1815 kJ/mol, respectively. The bioactive compounds retention suggests that encapsulated powder can be used as pigments and to provide antioxidant properties to extruded products.

  1. Two pear glutathione S-transferases genes are regulated during fruit development and involved in response to salicylic acid, auxin, and glucose signaling.

    Directory of Open Access Journals (Sweden)

    Hai-Yan Shi

    Full Text Available Two genes encoding putative glutathione S-transferase proteins were isolated from pear (Pyrus pyrifolia and designated PpGST1 and PpGST2. The deduced PpGST1 and PpGST2 proteins contain conserved Glutathione S-transferase N-terminal domain (GST_N and Glutathione S-transferase, C-terminal domain (GST_C. Using PCR amplification technique, the genomic clones corresponding to PpGST1 and PpGST2 were isolated and shown to contain two introns and a singal intron respectively with typical GT/AG boundaries defining the splice junctions. Phylogenetic analysis clearly demonstrated that PpGST1 belonged to Phi class of GST superfamilies and had high homology with apple MdGST, while PpGST2 was classified into the Tau class of GST superfamilies. The expression of PpGST1 and PpGST2 genes was developmentally regulated in fruit. Further study demonstrated that PpGST1 and PpGST2 expression was remarkably induced by glucose, salicylic acid (SA and indole-3-aceticacid (IAA treatments in pear fruit, and in diseased fruit. These data suggested that PpGST1 and PpGST2 might be involved in response to sugar, SA, and IAA signaling during fruit development of pear.

  2. Distribution and metabolism of ascorbic acid in pear fruits ( Pyrus ...

    African Journals Online (AJOL)

    Ascorbate accumulation levels, distribution and key enzyme activities involved in synthesizing via Smirnoff-Wheeler pathway and recycling in different pear fruit tissues during development were studied. Results show that the ascorbate contents increased with the fruit development, and reached the highest titers in 30 days ...

  3. Gas exchange and brown heart in conference pears

    NARCIS (Netherlands)

    Otma, E.C.; Peppelenbos, H.W.

    2003-01-01

    Brown heart is a tissue disorder found in Conference pears during CA storage. Differences in susceptibility for brown heart have been found between countries, orchards, harvest dates and storage conditions. One hypothesis is that brown heart is caused by increased internal CO2. This research

  4. Potential causes of the pear thrips outbreak in sugar maple

    Science.gov (United States)

    Jack C. Schultz

    1991-01-01

    No one knows what caused the 1988 outbreak of pear thrips, Taeniothrips inconsequens (Uzel), in sugar maple, Acer saccharum Marsh., in the northeastern United States. As an entomologist and ecologist who knows even less about this insect than most of the authors of this volume, I cannot presume to understand the causes of this...

  5. Genetic variability among 'Kashmiri Nakh' pear (Pyrus pyrifolia): A ...

    African Journals Online (AJOL)

    Twenty four (24) 'Kashmiri Nakh' pear (Pyrus pyrifolia) genotypes were studied to assess the overall degree of polymorphism, detect similarities among important tree, pomological, fruit quality and yield parameters. Eleven (11) variables were scored and subjected to multivariate analysis. Results show a considerable ...

  6. Some Proximate Analysis of African Pear ( Dacryodes Edulis ...

    African Journals Online (AJOL)

    Some physical and chemical properties of African pear (Dacryodes edulis) samples from nine different trees were analysed in order to determine the level of differences that exist between trees. The length of the individual fruits ranged from 39.86 mm to 80.76 mm while the weight ranged from 15.97 g to 39.36 g. Significant ...

  7. Utility of avocado pear seed ( Persea Americana ), mango seed ...

    African Journals Online (AJOL)

    The proximate composition and amino acid profile of three plant materials, Avocado pear seed (Persea americana), mango seed (Magifera indica) and bean seed coat (Phaseolus vulgaris) were determined. Crude protein varied from 2.0 ± 0.06% in Magifera indica to 3.73 ± 0.08% in Persea americana. Generally, the amino ...

  8. Microorganisms associated with the spoilage of avocado pear ...

    African Journals Online (AJOL)

    The microorganisms associated with the spoilage of Avocado pear, Persea americana fruits, purchased fresh from various markets in Benin City were investigated. The pour plate method was used for the isolation. A total of nine species of microorganisms were isolated and identified in this study. They comprise of seven ...

  9. Detection and quantitative characterization of artificial extra peaks following polymerase chain reaction amplification of 14 short tandem repeat systems used in forensic investigations

    DEFF Research Database (Denmark)

    Meldgaard, Michael; Morling, N

    1997-01-01

    , while Hum-TH01, HumCD4, and D12S391 were virtually unaffected by low-stringency conditions. Replacement of the Taq DNA polymerase with DNA polymerases with lower processivity resulted in higher levels of extra peaks. Our results support the hypothesis that extra peaks are produced due to slipped-strand......Detection on automated DNA sequencers of polymerase chain reaction (PCR) products of tetra- and penta-nucleotide short tandem repeat (STR) loci frequently reveals one or more extra peaks along with the true, major allele peak. The most frequent extra peak pattern is a single smaller peak which...... is one repeat unit shorter than the true allele peak. The existence of such artificial peaks is of special importance when the methods are used for forensic investigations because the artificial extra peaks may simulate true alleles when samples containing mixtures of DNA from different individuals...

  10. Transcriptomic analysis of ‘Suli’ pear (Pyrus pyrifolia white pear group buds during the dormancy by RNA-Seq

    Directory of Open Access Journals (Sweden)

    Liu Guoqin

    2012-12-01

    Full Text Available Abstract Background Bud dormancy is a critical developmental process that allows perennial plants to survive unfavorable environmental conditions. Pear is one of the most important deciduous fruit trees in the world, but the mechanisms regulating bud dormancy in this species are unknown. Because genomic information for pear is currently unavailable, transcriptome and digital gene expression data for this species would be valuable resources to better understand the molecular and biological mechanisms regulating its bud dormancy. Results We performed de novo transcriptome assembly and digital gene expression (DGE profiling analyses of ‘Suli’ pear (Pyrus pyrifolia white pear group using the Illumina RNA-seq system. RNA-Seq generated approximately 100 M high-quality reads that were assembled into 69,393 unigenes (mean length = 853 bp, including 14,531 clusters and 34,194 singletons. A total of 51,448 (74.1% unigenes were annotated using public protein databases with a cut-off E-value above 10-5. We mainly compared gene expression levels at four time-points during bud dormancy. Between Nov. 15 and Dec. 15, Dec. 15 and Jan. 15, and Jan. 15 and Feb. 15, 1,978, 1,024, and 3,468 genes were differentially expressed, respectively. Hierarchical clustering analysis arranged 190 significantly differentially-expressed genes into seven groups. Seven genes were randomly selected to confirm their expression levels using quantitative real-time PCR. Conclusions The new transcriptomes offer comprehensive sequence and DGE profiling data for a dynamic view of transcriptomic variation during bud dormancy in pear. These data provided a basis for future studies of metabolism during bud dormancy in non-model but economically-important perennial species.

  11. Evidence for the Involvement of an Oxidative Stress in the Initiation of Infection of Pear by Erwinia amylovora1

    Science.gov (United States)

    Venisse, Jean-Stéphane; Gullner, Gabor; Brisset, Marie-Noëlle

    2001-01-01

    Involvement of an oxidative burst, usually related to incompatible plant/pathogen interactions leading to hypersensitive reactions, was investigated with Erwinia amylovora, the causal agent of fire blight of Maloideae subfamily of Rosaceae, in interaction with pear (Pyrus communis; compatible situation) and tobacco (Nicotiana tabacum; incompatible situation). As expected, this necrogenic bacterium induced in tobacco a sustained production of superoxide anion, lipid peroxidation, electrolyte leakage, and concomitant increases of several antioxidative enzymes (ascorbate peroxidases, glutathion reductases, glutathion-S-transferases, and peroxidases), in contrast to the compatible pathogen Pseudomonas syringae pv tabaci, which did not cause such reactions. In pear leaves, however, inoculations with both the disease- and the hypersensitive reaction-inducing bacteria (E. amylovora and P. syringae pv tabaci, respectively) resulted in superoxide accumulation, lipid peroxidation, electrolyte leakage, and enzyme induction at similar rates and according to equivalent time courses. The unexpected ability of E. amylovora to generate an oxidative stress even in compatible situation was linked to its functional hrp (for hypersensitive reaction and pathogenicity) cluster because an Hrp secretion mutant of the bacteria did not induce any plant response. It is suggested that E. amylovora uses the production of reactive oxygen species as a tool to provoke host cell death during pathogenesis to invade plant tissues. The bacterial exopolysaccharide could protect this pathogen against the toxic effects of oxygen species since a non-capsular mutant of E. amylovora induced locally the same responses than the wild type but was unable to further colonize the plant. PMID:11299395

  12. Pyrosequencing-based validation of a simple cell-suspension polymerase chain reaction assay for Campylobacter with application of high-processivity polymerase and novel internal amplification controls for rapid and specific detection.

    Science.gov (United States)

    Oakley, Brian B; Line, J Eric; Berrang, Mark E; Johnson, Jessica M; Buhr, R Jeff; Cox, Nelson A; Hiett, Kelli L; Seal, Bruce S

    2012-02-01

    Although Campylobacter is an important food-borne human pathogen, there remains a lack of molecular diagnostic assays that are simple to use, cost-effective, and provide rapid results in research, clinical, or regulatory laboratories. Of the numerous Campylobacter assays that do exist, to our knowledge none has been empirically tested for specificity using high-throughput sequencing. Here we demonstrate the power of next-generation sequencing to determine the specificity of a widely cited Campylobacter-specific polymerase chain reaction (PCR) assay and describe a rapid method for direct cell suspension PCR to quickly and easily screen samples for Campylobacter. We present a specific protocol which eliminates the need for time-consuming and expensive genomic DNA extractions and, using a high-processivity polymerase, demonstrate conclusive screening of samples in 99%) sensitive, and spike-back experiments demonstrated a detection threshold of <10(2) CFU mL(-1). Additionally, we present 2 newly designed broad-range bacterial primer sets targeting the 23S rRNA gene that have wide applicability as internal amplification controls. Empirical testing of putative taxon-specific assays using high-throughput sequencing is an important validation step that is now financially feasible for research, regulatory, or clinical applications. Published by Elsevier Inc.

  13. Amplification of ribulose biphosphate carboxylase/oxygenase large subunit (RuBisCO LSU) gene fragments from Thiobacillus ferrooxidans and a moderate thermophile using polymerase chain reaction.

    Science.gov (United States)

    Holden, P J; Brown, R W

    1993-07-01

    Southern blot analysis of DNA from an iron-oxidising moderate thermophile NMW-6 and from Thiobacillus ferrooxidans strain TFI-35 demonstrated sequences homologous to the RuBisCO LSU gene of Synechococcus. DNA fragments (457 bp) encoding part of the RuBisCO LSU gene (amino acids 73-200) were amplified from the genomic DNA of Thiobacillus ferrooxidans and the moderate thermophile NMW-6 using the polymerase chain reaction (PCR) technique (Saiki et al. (1985) Science 233, 1350-1354). A comparison with the LSU sequences from T. ferrooxidans, Alcaligenes eutrophus, Chromatium vinosum, Synechococcus and Spinacea oleracea, which all have RuBisCOs with a hexadecameric structure, showed that the RuBisCO LSU gene sequence from NMW-6 appeared to be most closely related to that of the hydrogen bacterium A. eutrophus which showed 71.9% homology at the amino acid level. Despite its physiological similarity, T. ferrooxidans showed only 64.1% homology to the amino acid sequence from NMW-6 and had the lowest DNA homology (60.9%) of the hexadecameric type RuBisCOs. In the region sequenced, T. ferrooxidans and the RuBisCOs of the phototrophs C. vinosum, Synechococcus and S. oleracea, had 17 residues that were completely conserved which were substituted in both NMW-6 and A. eutrophus, 11 of these being identical substitutions. Comparison of the nucleotide and derived amino acid sequences of the RuBisCO LSU fragment from T. ferrooxidans with other RuBisCO sequences indicated a closer relationship to the hexadecameric type LSU genes of photosynthetic origin than to that of A. eutrophus. The T. ferrooxidans amino acid sequence showed 93.8%, 78.9% and 77.3% homology, respectively, to the C. vinosum, Synechococcus and S. oleracea (spinach) sequences but only 56.2% to A. eutrophus. The DNA sequence from Rhodospirillum rubrum, which has the atypical large subunit dimer RuBisCO structure with no small subunit, showed 39.2% and 42.7% homology, respectively, with the sequences of NMW-6 and T

  14. FIRE BLIGHT SUSCEPTIBILITY OF SOME PEAR VARIETIES (ERWINIA AMYLOVORA, BURILL

    Directory of Open Access Journals (Sweden)

    Zsolt Jakab- Ilyefalv

    2012-01-01

    Full Text Available At Bistriţa Fruit Research and Development Station, in a pear collection, planted with 44 varieties, there has been studied the susceptibility to fire blight (Erwinia amylovora,Burill. During the vegetation period, phytosanitary treatments to control the disease have been applied using copper based products (copper sulfate, Champion, Funguran, Kocide. Erwinia amylovora infections have been influenced by the rainfall registered in April (70.9 mm and May (104.7 mm and the temperature fluctuations in April-May. The field observations on Erwinia amylvora attack demonstrate that the pear varieties have a different susceptibility to this dangerous bacterium. Evaluation of attack level in the pear collection was done using an evaluation scale with 9 scores using a reference resistance scale for : ‘Highly resistant’ , ‘Moderately resistant’, ‘Susceptible’, ‘Very susceptible’ cultivars . The most sensitive pear varieties in the collection were: ‘De Noiembrie’, ‘Abatele Fetel’, ’Daciana’, ’Triumf’, ’Williams Boway’, ’Margareta Marillat’, ’Beauty Tomme’, ‘Williams rosu’, ’Aromata de Bistrita’, ’Jeanne d`Arc’, ’Aramiu de Somes’, ’Belle des Arbres’, ’Zorka’ representing 13.64% of the total pear varieties. In several cultivars there have been observed increased symptoms, a very high susceptibility of infections leading to complete scorching of trees: Jeanne d`Arc’, Williams rosu’, ‘Triumf’, ‘Aromata de Bistrita’, ‘Zorka’. Strong attack symtoms were observed at the pear cultivars ‘Cure’, ‘Euras, ’Ciuda’ ‘Highland’, ‘Precoce Morettini’, ’Monica’, ’Cadillac’, ’Juliana’, ’Somesan’, ’Beurré Hardenpont’ these cultivars being susceptible to Erwinia amylovora , representing 40.91 % of total genotypes . Cultivars ‘Untoasa Geoagiu’, ‘Beurre Hardy’, ‘Trivale’ manifested a certain tolerance to Erwinia amylovora , no attack symptoms being

  15. Interactive Effects of Growth Regulators, Carbon Sources, pH on Plant Regeneration and Assessment of Genetic Fidelity Using Single Primer Amplification Reaction (SPARS) Techniques in Withania somnifera L.

    Science.gov (United States)

    Fatima, Nigar; Ahmad, Naseem; Ahmad, Iqbal; Anis, Mohammad

    2015-09-01

    An improved and methodical in vitro shoot morphogenic approach through axillary bud multiplication was established in a drug yielding plant, Withania somnifera L. Effects of plant growth regulators [6-benzyladenine (BA), kinetin (Kin), 2-isopentenyladenine (2iP), and thidiazuron (TDZ)] either singly or in combination with α-napthalene acetic acid (NAA), indole-3-butyric acid (IBA), and indole-3-acetic acid (IAA) in Murashige and Skoog (MS) medium were tested. The highest regeneration frequency (90 %) with optimum number of shoots (32 ± 0.00)/explant were obtained on MS medium fortified with 2.5 μM 6-benzyladenine (BA) and 0.5 μM NAA and 30 g/l sucrose at pH 5.8. Among the tried TDZ concentrations, 0.5 μM resulted in maximum number of shoots (20.4 ± 0.40)/explant after 4 weeks of exposure. The proliferating shoot cultures established by repeated subculturing of the mother explants on the hormone-free medium produced the highest shoot number (29.4 ± 0.40) with shoot length (6.80 ± 0.12 cm)/explant at fourth subculture passage, which a decline in shoot proliferation was recorded. Different concentrations of NAA were tested for ex vitro rooting of microshoots. The maximum percentage of rooting 100 % with maximum roots (18.3 ± 0.1) was achieved in soilrite when basal portion of the microshoots were treated with 200 μM (NAA) for 15 min per shoot. The plantlets went through hardening phase in a growth chamber, prior to ex vitro transfer. The PCR-based single primer amplification reaction (SPAR) methods which include random amplified polymorphic DNA (RAPD) and direct amplification of minisatellite DNA (DAMD) markers has been used for assessment of genetic stability of micropropagated plantlets. No variation was observed in DNA fingerprinting patterns among the micropropagated and the donor plants illustrating their genetic uniformity.

  16. (PCR) and loop-mediated isothermal amplification

    African Journals Online (AJOL)

    SAM

    2014-03-26

    Mar 26, 2014 ... better alternative for PCR, even in low technology laboratories. In addition, these findings revealed that the possibility of fatal fusariosis due to F. solani is not so rare in HIV positive patients. Key words: Fusarium solani, loop-mediated isothermal amplification (LAMP), HIV, polymerase chain reaction. (PCR).

  17. Environment-Friendly Control of Pear Scab and Rust Using Lime Sulfur

    Directory of Open Access Journals (Sweden)

    Ju Hoon Cha

    2018-03-01

    Full Text Available Pear scab and rust are the major diseases causing severe epidemics in organic cultivation of pear trees. Incidences of pear scab and rust were compared in organically managed plots and conventionally managed plots to obtain optimum application schedule of environment-friendly control agents in organically managed plots. Organically cultural practice with 10 time-applications of lime sulfur and Bordeaux mixture showed higher than 40% of control efficacies of pear scab and rust compared to conventionally cultural practice. Organically cultural practice with 8 time-applications of lime sulfur considering weather condition showed higher than 30% of control efficacies of pear scab compared to conventionally cultural practice. The results suggest that proper application of environment-friendly control agents such as lime sulfur considering weather condition will enable effective control of the major diseases for organic cultivation of pear.

  18. Antioxidant and Anticlastogenic Capacity of Prickly Pear Juice

    Science.gov (United States)

    Madrigal-Santillán, Eduardo; García-Melo, Fernando; Morales-González, José A.; Vázquez-Alvarado, Patricia; Muñoz-Juárez, Sergio; Zuñiga-Pérez, Clara; Sumaya-Martínez, Maria Teresa; Madrigal-Bujaidar, Eduardo; Hernández-Ceruelos, Alejandra

    2013-01-01

    Plants belonging to the genus Opuntia spp. are the most abundant of the Cactaceae family, grown throughout America and the Mediterranean central area. Its fruit, known as cactus pear or prickly pear, is an oval berry grouped in different colors. Some studies have shown its antioxidant activities which may help in preventing chronic pathologies such as diabetes. The purpose of the study was to evaluate the antioxidant capacity of three varieties of prickly pear juice (red-purple, white-green and yellow-orange) in five different concentrations (100, 250, 500, 750, and 1000 mg/mL) by DPPH (1,1-diphenyl-2-picrylhydrazyl radical) colorimetric method, selecting the best variety to determine its anticlastogenic potential against methyl methanesulfonate (MMS). The results indicate that the highest antioxidant was found in the juice of the prickly pear red-purple variety (PPRP), in all concentrations. Its anticlastogenic potential was therefore evaluated with a micronucleus assay. The experiment was run over two weeks. A negative control was included along with a positive control with MMS (40 mg/kg), a group of mice treated with PPRP (25 mL/kg), and three groups with PPRP (in doses of 25, 16.5 and 8.3 mL/kg) plus the mutagen. The PPRP was administered daily by oral gavage and the MMS was injected intraperitoneally five days prior to the end of the experiment. Blood samples were obtained at 0, 24, 48, 72 and 96 h in order to determine the frequency of micronucleated polychromatic erythrocytes (MNPE). The results indicated that PPRP is not a genotoxic agent, on the contrary, it may reduce the number of MNPE. In this regard, the PPRP showed an anticlastogenic effect directly proportional to its concentrations. Thus, the highest protection was obtained with a concentration of 25 mL/kg after 48 h of treatment. PMID:24145870

  19. Antioxidant and Anticlastogenic Capacity of Prickly Pear Juice

    Directory of Open Access Journals (Sweden)

    Alejandra Hernández-Ceruelos

    2013-10-01

    Full Text Available Plants belonging to the genus Opuntia spp. are the most abundant of the Cactaceae family, grown throughout America and the Mediterranean central area. Its fruit, known as cactus pear or prickly pear, is an oval berry grouped in different colors. Some studies have shown its antioxidant activities which may help in preventing chronic pathologies such as diabetes. The purpose of the study was to evaluate the antioxidant capacity of three varieties of prickly pear juice (red-purple, white-green and yellow-orange in five different concentrations (100, 250, 500, 750, and 1000 mg/mL by DPPH (1,1-diphenyl-2-picrylhydrazyl radical colorimetric method, selecting the best variety to determine its anticlastogenic potential against methyl methanesulfonate (MMS. The results indicate that the highest antioxidant was found in the juice of the prickly pear red-purple variety (PPRP, in all concentrations. Its anticlastogenic potential was therefore evaluated with a micronucleus assay. The experiment was run over two weeks. A negative control was included along with a positive control with MMS (40 mg/kg, a group of mice treated with PPRP (25 mL/kg, and three groups with PPRP (in doses of 25, 16.5 and 8.3 mL/kg plus the mutagen. The PPRP was administered daily by oral gavage and the MMS was injected intraperitoneally five days prior to the end of the experiment. Blood samples were obtained at 0, 24, 48, 72 and 96 h in order to determine the frequency of micronucleated polychromatic erythrocytes (MNPE. The results indicated that PPRP is not a genotoxic agent, on the contrary, it may reduce the number of MNPE. In this regard, the PPRP showed an anticlastogenic effect directly proportional to its concentrations. Thus, the highest protection was obtained with a concentration of 25 mL/kg after 48 h of treatment.

  20. ALTERNATIVE FOR REDUCING PHYSIOLOGICAL DISORDERS IN ‘BARTLETT’ PEARS

    Directory of Open Access Journals (Sweden)

    MOISES ZUCOLOTO

    2016-01-01

    Full Text Available ABSTRACT ‘Bartlett’ pears from different harvest dates were assessed regarding to cold storage potential and reduction of physiological disorder incidence. Three harvests, the first (HD1, second (HD2, and third (HD3, were carried out at weekly intervals. The pears were assessed after the harvest, with no exposition to the temperature conditioning, after 20, 40, 60, 80, 100 and 120 days at 0 ± 1 °C and 90 ± 5% RH and after three and six days at room temperature (20 ± 1 °C. Fruit from the early harvest (HD1 showed the smallest incidence of physiological disorder during both cold and room temperature storage. The disorder symptoms became apparent in HD1 fruit after 20 days at cold storage followed by three days at 20 °C, whereas HD2 and HD3 fruit showed the symptoms before being kept in a cold room. ‘Bartlett’ pears harvested at 70.75 N flesh firmness can be stored at 0 ± 1 °C for up to 40 days and preferably commercialized within three days, when they reach the firmness for eating. The extension of cold storage as well as the trade period can result in higher physiological disorder incidence and loss of sensorial quality.

  1. Gene amplification in carcinogenesis

    Directory of Open Access Journals (Sweden)

    Lucimari Bizari

    2006-01-01

    Full Text Available Gene amplification increases the number of genes in a genome and can give rise to karyotype abnormalities called double minutes (DM and homogeneously staining regions (HSR, both of which have been widely observed in human tumors but are also known to play a major role during embryonic development due to the fact that they are responsible for the programmed increase of gene expression. The etiology of gene amplification during carcinogenesis is not yet completely understood but can be considered a result of genetic instability. Gene amplification leads to an increase in protein expression and provides a selective advantage during cell growth. Oncogenes such as CCND1, c-MET, c-MYC, ERBB2, EGFR and MDM2 are amplified in human tumors and can be associated with increased expression of their respective proteins or not. In general, gene amplification is associated with more aggressive tumors, metastases, resistance to chemotherapy and a decrease in the period during which the patient stays free of the disease. This review discusses the major role of gene amplification in the progression of carcinomas, formation of genetic markers and as possible therapeutic targets for the development of drugs for the treatment of some types of tumors.

  2. Social amplification of risk

    International Nuclear Information System (INIS)

    Kasperson, R.E.; Renn, O.; Slovic, P.; Kasperson, J.X.; Emani, S.

    1989-01-01

    The risks associated with radioactive and other hazardous waste disposal may be expected to interact with societal processes to enlarge or attenuate the consequences of risks and risk events. This article summarizes a conceptual framework that depicts the social amplification of risk. Using a data base of 128 hazard events that have occurred largely over the past ten years, the authors examine the role of physical consequences, media coverage, and public perceptions of risk in generating social and economic impacts. The analysis concludes that social amplification processes substantially shape the nature and magnitude of those impacts but also that such social amplification appears to be systematically related to characteristics of the risks and risk events

  3. Constitutive and herbivore-induced volatiles in pear, alder and hawthorn trees

    NARCIS (Netherlands)

    Scutareanu, P.; Bruin, de J.; Posthumus, M.A.; Drukker, B.

    2003-01-01

    Qualitative and quantitative differences among pear cultivars were found in constitutive and Cacopsylla-induced volatiles, depending on experimental treatment of the trees (i.e., uninfested and partly or completely infested by psyllids). Blend differences were also found between pear cultivars and

  4. Carbon dioxide action on ethylene biosynthesis of preclimacteric and climacteric pear fruit

    NARCIS (Netherlands)

    Wild, de J.P.J.; Otma, E.C.; Peppelenbos, H.W.

    2003-01-01

    Ethylene production in pear fruit was studied at 2 °C. Several observations showed that the inhibiting effect of CO2 on ethylene production did not operate only via the binding site of the ethylene binding protein. Ethylene production of freshly harvested pears was stimulated by 1-methylcyclopropene

  5. A proposed mechanism behind the development of internal browning in pears (Pyrus communis cv Conference)

    NARCIS (Netherlands)

    Veltman, R.H.; Peppelenbos, H.W.

    2003-01-01

    Storage of pears under low oxygen levels (0.5-1.0 kPa) leads to decreased ascorbic acid and ATP levels, a lower ATP-production, and to internal browning, a storage disorder in pears. Addition of 5 kPa carbon dioxide to the storage atmosphere increased the severity of this disorder. Experiments

  6. Efficacy of cactus pear ( Opuntia ficus-indica ) varieties as a source ...

    African Journals Online (AJOL)

    Cactus Pear (Opuntia ficus-indica) serves as a source of food, feed, as well as a means of additional income to the people in northern Ethiopia. The species has different varieties with varied rate of productivity and palatability. This study was conducted to assess the food and feed value of the Cactus Pear varieties in ...

  7. Effect of Root Pruning and Irrigation Regimes on Yield and Physiology of Pear Trees

    DEFF Research Database (Denmark)

    Wang, Yufei

    Clara Frijs’ is the dominant pear (Pyrus communis L.) cultivar in Denmark. It is vigorous with long annual shoots, and therefore can be difficult to prune. Root pruning has been widely used to control the canopy size of fruit trees including pears. However, root pruned trees are more likely to su...

  8. Combined approaches using sex pheromone and pear ester for behavioral disruption of codling moth (Lepidoptera: Tortricidae)

    Science.gov (United States)

    Studies utilized the attractive properties of pear ester, ethyl (E,Z)-2,4-decadienoate, and codlemone, (E,E)-8,10-dodecadien-1-ol, the sex pheromone of codling moth, Cydia pomonella (L)., for behavioural disruption. Standard dispensers loaded with codlemone alone or in combination with pear ester (c...

  9. Draft genome sequence of Xylella fastidiosa pear leaf scorch strain in Taiwan

    Science.gov (United States)

    The draft genome sequence of Xylella fastidiosa pear leaf scorch strain (PLS229) isolated from pear cultivar Hengshan (Pyrus pyrifolia) in Taiwan is reported. The bacterium has a genome size of 2,733,013 bp with a G+C content of 53.1%. The PLS229 strain genome was annotated to have 3,259 open readin...

  10. Classification of Korean native pear based on a standard set of microsatellite loci

    Science.gov (United States)

    After analysis with 12 microsatellite loci previously selected for use by ECPGR, 34 Korean pear accessions were classified into 3 groups. Group I included 4 Korean pea pears and one accession of P. calleryana. Group II contained 12 cultivars including 7 accessions presumed to belong to P. pyrifolia....

  11. 7 CFR 319.56-22 - Apples and pears from certain countries in Europe.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Apples and pears from certain countries in Europe. 319.56-22 Section 319.56-22 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL... Vegetables § 319.56-22 Apples and pears from certain countries in Europe. (a) Importations allowed. The...

  12. Prickly pear induces upregulation of liver LDL binding in familial heterozygous hypercholesterolemia

    International Nuclear Information System (INIS)

    Palumbo, B.; Palumbo, R.; Efthimiou, Y.; Stamatopoulos, J.; Sinzinger, H.; Oguogho, A.; Budinsky, A.; Sinzinger, H.

    2003-01-01

    The hypoglycemic effect of prickly pear is well known by native local Indian population since a long time. Beside the beneficial effects on lipid metabolism, oxidation injury and platelet function has been claimed in experimental animals. We recently found an upregulation of apo-B/E receptor. We therefore examined 10 patients with isolated heterozygous familial hypercholesterolemia (FH) being enrolled in a dietary run-in phase of 6 weeks after dietary counselling and a further 6 weeks of prickly pear addition. Uptake of autologous 123 I-radiolabeled LDL was determined at entry as well as after 6 weeks of daily prickly pear ingestion. We found a significant (p 176.4 mg/dl; p 123 I-LDL binding by prickly pear in FH-patients in vivo and indicate that prickly pear exerts a significant hypolipidemic action via receptor upregulation. (author)

  13. Controlled Microwave Heating Accelerates Rolling Circle Amplification.

    Science.gov (United States)

    Yoshimura, Takeo; Suzuki, Takamasa; Mineki, Shigeru; Ohuchi, Shokichi

    2015-01-01

    Rolling circle amplification (RCA) generates single-stranded DNAs or RNA, and the diverse applications of this isothermal technique range from the sensitive detection of nucleic acids to analysis of single nucleotide polymorphisms. Microwave chemistry is widely applied to increase reaction rate as well as product yield and purity. The objectives of the present research were to apply microwave heating to RCA and indicate factors that contribute to the microwave selective heating effect. The microwave reaction temperature was strictly controlled using a microwave applicator optimized for enzymatic-scale reactions. Here, we showed that microwave-assisted RCA reactions catalyzed by either of the four thermostable DNA polymerases were accelerated over 4-folds compared with conventional RCA. Furthermore, the temperatures of the individual buffer components were specifically influenced by microwave heating. We concluded that microwave heating accelerated isothermal RCA of DNA because of the differential heating mechanisms of microwaves on the temperatures of reaction components, although the overall reaction temperatures were the same.

  14. Nutrient removal by apple, pear and cherry nursery trees

    Directory of Open Access Journals (Sweden)

    Giovambattista Sorrenti

    2017-06-01

    Full Text Available Given that nursery is a peculiar environment, the amount of nutrients removed by nursery trees represents a fundamental acquisition to optimise fertilisation strategies, with economic and environmental implications. In this context, we determined nutrient removal by apple, pear and cherry nursery trees at the end of the nursery growing cycle. We randomly removed 5 leafless apple (Golden Delicious/EMLA M9; density of 30,000 trees ha–1, pear (Santa Maria/Adams; density of 30,000 trees ha–1 and cherry (AlexTM/Gisela 6®; density of 40,000 trees ha–1 trees from a commercial nursery. Trees were divided into roots (below the root collar, rootstock (above-ground wood between root collar and grafting point and variety (1-year-old wood above the grafting point. For each organ we determined biomass, macro- (N, P, K, Ca, Mg, S, and micro- (Fe, Mn, Zn, Cu, and B nutrient concentration. Pear trees were the most developed (650 g (dw tree–1, equal to 1.75 and 2.78 folds than apple and cherry trees, respectively whereas, independently of the species, variety mostly contributed (>50% to the total tree biomass, followed by roots and then above-ground rootstock. However, the dry biomass and nutrient amount measured in rootstocks (including roots represent the cumulative amount of 2 and 3 seasons, for Gisela® 6 (tissue culture and pome fruit species (generated by mound layering, respectively. Macro and micronutrients were mostly concentrated in roots, followed by variety and rootstock, irrespective of the species. Independently of the tissue, macronutrients concentration hierarchy was N>Ca>K> P>Mg>S. Removed N by whole tree accounted for 6.58, 3.53 and 2.49 g tree–1 for pear, apple and cherry, respectively, corresponding to almost 200, 107 and 100 kg N ha–1, respectively. High amounts of K and Ca were used by pear (130-140 kg ha–1 and apple trees (~50 and 130 kg ha–1 of K and Ca, respectively, while ~25 kg K ha–1 and 55 kg Ca ha–1 were

  15. Multi-chamber nucleic acid amplification and detection device

    Energy Technology Data Exchange (ETDEWEB)

    Dugan, Lawrence

    2017-10-25

    A nucleic acid amplification and detection device includes an amplification cartridge with a plurality of reaction chambers for containing an amplification reagent and a visual detection reagent, and a plurality of optically transparent view ports for viewing inside the reaction chambers. The cartridge also includes a sample receiving port which is adapted to receive a fluid sample and fluidically connected to distribute the fluid sample to the reaction chamber, and in one embodiment, a plunger is carried by the cartridge for occluding fluidic communication to the reaction chambers. The device also includes a heating apparatus having a heating element which is activated by controller to generate heat when a trigger event is detected. The heating apparatus includes a cartridge-mounting section which positioned a cartridge in thermal communication with the heating element so that visual changes to the contents of the reaction chambers are viewable through the view ports.

  16. On soliton amplification

    Science.gov (United States)

    Leibovich, S.; Randall, J. D.

    1979-01-01

    The paper considers a modified Korteweg-de Vries equation that permits wave amplification or damping. A 'terminal similarity' solution is identified for large times in amplified systems. Numerical results are given which confirm that the terminal similarity solution is a valid local approximation for mu t sufficiently large and positive, even though the approximation is not uniformly valid in space.

  17. Phytochemical study of prickly pear from southern Morocco

    Directory of Open Access Journals (Sweden)

    Z. Bouzoubaâ

    2016-06-01

    Full Text Available This work concerns the phytochemical study of the prickly pear pulp’s fruits of two opuntia cultivars; Achefri and Amouslem widely present in two regions of southern Morocco; Arbaa Sahel and Asgherkis that are different in their altitude and annual rainfall. The results of the phytochemical study show that the levels of antioxidants have a non-significant difference between the fruits of the two sites (comparing Amouslem and Achefri in the same site, on the one hand, for the differences due to the variety or cultivar, on the other hand between Amouslem and Achefri from the two sites to show the site effect.

  18. Biomaterials in light amplification

    Science.gov (United States)

    Mysliwiec, Jaroslaw; Cyprych, Konrad; Sznitko, Lech; Miniewicz, Andrzej

    2017-03-01

    Biologically produced or inspired materials can serve as optical gain media, i.e. they can exhibit the phenomenon of light amplification. Some of these materials, under suitable dye-doping and optical pumping conditions, show lasing phenomena. The emerging branch of research focused on obtaining lasing action in highly disordered and highly light scattering materials, i.e. research on random lasing, is perfectly suited for biological materials. The use of biomaterials in light amplification has been extensively reported in the literature. In this review we attempt to report on progress in the development of biologically derived systems able to show the phenomena of light amplification and random lasing together with the contribution of our group to this field. The rich world of biopolymers modified with molecular aggregates and nanocrystals, and self-organized at the nanoscale, offers a multitude of possibilities for tailoring luminescent and light scattering properties that are not easily replicated in conventional organic or inorganic materials. Of particular importance and interest are light amplification and lasing, or random lasing studies in biological cells and tissues. In this review we will describe nucleic acids and their complexes employed as gain media due to their favorable optical properties and ease of manipulation. We will report on research conducted on various biomaterials showing structural analogy to nucleic acids such as fluorescent proteins, gelatins in which the first distributed feedback laser was realized, and also amyloids or silks, which, due to their dye-doped fiber-like structure, allow for light amplification. Other materials that were investigated in that respect include polysaccharides, like starch exhibiting favorable photostability in comparison to other biomaterials, and chitosan, which forms photonic crystals or cellulose. Light amplification and random lasing was not only observed in processed biomaterials but also in living

  19. Digital Microfluidics for Nucleic Acid Amplification

    Directory of Open Access Journals (Sweden)

    Beatriz Coelho

    2017-06-01

    Full Text Available Digital Microfluidics (DMF has emerged as a disruptive methodology for the control and manipulation of low volume droplets. In DMF, each droplet acts as a single reactor, which allows for extensive multiparallelization of biological and chemical reactions at a much smaller scale. DMF devices open entirely new and promising pathways for multiplex analysis and reaction occurring in a miniaturized format, thus allowing for healthcare decentralization from major laboratories to point-of-care with accurate, robust and inexpensive molecular diagnostics. Here, we shall focus on DMF platforms specifically designed for nucleic acid amplification, which is key for molecular diagnostics of several diseases and conditions, from pathogen identification to cancer mutations detection. Particular attention will be given to the device architecture, materials and nucleic acid amplification applications in validated settings.

  20. Digital Microfluidics for Nucleic Acid Amplification.

    Science.gov (United States)

    Coelho, Beatriz; Veigas, Bruno; Fortunato, Elvira; Martins, Rodrigo; Águas, Hugo; Igreja, Rui; Baptista, Pedro V

    2017-06-25

    Digital Microfluidics (DMF) has emerged as a disruptive methodology for the control and manipulation of low volume droplets. In DMF, each droplet acts as a single reactor, which allows for extensive multiparallelization of biological and chemical reactions at a much smaller scale. DMF devices open entirely new and promising pathways for multiplex analysis and reaction occurring in a miniaturized format, thus allowing for healthcare decentralization from major laboratories to point-of-care with accurate, robust and inexpensive molecular diagnostics. Here, we shall focus on DMF platforms specifically designed for nucleic acid amplification, which is key for molecular diagnostics of several diseases and conditions, from pathogen identification to cancer mutations detection. Particular attention will be given to the device architecture, materials and nucleic acid amplification applications in validated settings.

  1. A continuum model for metabolic gas exchange in pear fruit.

    Directory of Open Access Journals (Sweden)

    Q Tri Ho

    2008-03-01

    Full Text Available Exchange of O(2 and CO(2 of plants with their environment is essential for metabolic processes such as photosynthesis and respiration. In some fruits such as pears, which are typically stored under a controlled atmosphere with reduced O(2 and increased CO(2 levels to extend their commercial storage life, anoxia may occur, eventually leading to physiological disorders. In this manuscript we have developed a mathematical model to predict the internal gas concentrations, including permeation, diffusion, and respiration and fermentation kinetics. Pear fruit has been selected as a case study. The model has been used to perform in silico experiments to evaluate the effect of, for example, fruit size or ambient gas concentration on internal O(2 and CO(2 levels. The model incorporates the actual shape of the fruit and was solved using fluid dynamics software. Environmental conditions such as temperature and gas composition have a large effect on the internal distribution of oxygen and carbon dioxide in fruit. Also, the fruit size has a considerable effect on local metabolic gas concentrations; hence, depending on the size, local anaerobic conditions may result, which eventually may lead to physiological disorders. The model developed in this manuscript is to our knowledge the most comprehensive model to date to simulate gas exchange in plant tissue. It can be used to evaluate the effect of environmental stresses on fruit via in silico experiments and may lead to commercial applications involving long-term storage of fruit under controlled atmospheres.

  2. Quantitative Proteomics-Based Reconstruction and Identification of Metabolic Pathways and Membrane Transport Proteins Related to Sugar Accumulation in Developing Fruits of Pear (Pyrus communis).

    Science.gov (United States)

    Reuscher, Stefan; Fukao, Yoichiro; Morimoto, Reina; Otagaki, Shungo; Oikawa, Akira; Isuzugawa, Kanji; Shiratake, Katsuhiro

    2016-03-01

    During their 6 month development, pear (Pyrus communis) fruits undergo drastic changes in their morphology and their chemical composition. To gain a better understanding of the metabolic pathways and transport processes active during fruit development, we performed a time-course analysis using mass spectrometry (MS)-based protein identification and quantification of fruit flesh tissues. After pre-fractionation of the samples, 2,841 proteins were identified. A principal component analysis (PCA) separated the samples from seven developmental stages into three distinct clusters representing the early, mid and late developmental phase. Over-representation analysis of proteins characteristic of each developmental phase revealed both expected and novel biological processes relevant at each phase. A high abundance of aquaporins was detected in samples from fruits in the cell expansion stage. We were able quantitatively to reconstruct basic metabolic pathways such as the tricarboxylic acid (TCA) cycle, which indicates sufficient coverage to reconstruct other metabolic pathways. Most of the enzymes that presumably contribute to sugar accumulation in pear fruits could be identified. Our data indicate that invertases do not play a major role in the sugar conversions in developing pear fruits. Rather, sucrose might be broken down by sucrose synthases. Further focusing on sugar transporters, we identified several putative sugar transporters from diverse families which showed developmental regulation. In conclusion, our data set comprehensively describes the proteome of developing pear fruits and provides novel insights about sugar accumulation as well as candidate genes for key reactions and transport steps. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  3. Betalain, Acid Ascorbic, Phenolic Contents and Antioxidant Properties of Purple, Red, Yellow and White Cactus Pears

    Directory of Open Access Journals (Sweden)

    Leonardo Martinez-Cardenas

    2011-09-01

    Full Text Available Commercialization of cactus pears based on their antioxidant properties can generate competitive advantages, and these can turn into business opportunities and the development of new products and a high-value ingredient for the food industry. This work evaluated the antioxidant activities (1,1-diphenyl-2-picrylhydrazyl radical-scavenging, protection against oxidation of a β-carotene-linoleic acid emulsion, and iron (II chelation, the content of total phenolic compounds, ascorbic acid, betacyanin, betaxanthin and the stability of betacyanin pigments in presence of Cu (II-dependent hydroxyl radicals (OH•, in 18 cultivars of purple, red, yellow and white cactus pear from six Mexican states. Our results indicated that the antiradical activities from yellow and white cactus pear cultivars were not significantly different (p < 0.05 and were lower than the average antiradical activities in red and purple cultivars. The red cactus pear from the state of Zacatecas showed the highest antioxidant activity. The free radical scavenging activity for red cactus pears was significantly correlated (p < 0.05 to the concentration of total phenolic compounds (R2 = 0.90 and ascorbic acid (R2 = 0.86. All 18 cultivars of cactus pears studied showed significant chelating activity of ferrous ions. The red and purple cactus pears showed a great stability when exposed to OH•.

  4. Improvement of Shelf Life and Sensory Quality of Pears Using a Specialized Edible Coating

    Directory of Open Access Journals (Sweden)

    Virgilio Cruz

    2015-01-01

    Full Text Available An edible coating functionalized with pomegranate polyphenols was designed. Different blends of candelilla wax, gum arabic, jojoba oil, and pomegranate polyphenols were formulated in order to improve the shelf life quality of pears (variety Bartlett, and all formulations were applied by immersion onto the fruit surface. Coated pears with and without polyphenols and uncoated pears (control were stored under the same conditions. Fruits were analyzed to evaluate changes in their physicochemical, microbiological, and sensorial properties during 30 days of storage at room temperature. Coated pears coded as T13 (candelilla wax 3%, gum arabic 4%, jojoba oil 0.15%, and pomegranate polyphenols 0.015% extended and improved their shelf life quality due to the minimization of the physic-chemical changes and sensorial properties. Therefore, the results indicated that the formulated edible coating has potential to extend the shelf life and maintain quality of pears. It was probed that coated pears were accepted for consumers as a good product. Edible coating application represents a good alternative to keep pears freshness for longer periods.

  5. Cloning and expression analysis of an MYB gene associated with calyx persistence in Korla fragrant pear.

    Science.gov (United States)

    Wang, Bo-Hui; Sun, Xiao-Xia; Dong, Fang-Yuan; Zhang, Fei; Niu, Jian-Xin

    2014-08-01

    We isolated an MYB-like gene from Korla fragrant pear using differential display RT-PCR. Expression of this gene in flowers appears to be correlated with calyx persistence. Korla fragrant pear (Pyrus brestschneideri Rehd) is an economically important pear cultivar in China. A persistent calyx results in the deformation of the fruit. We used differential display RT-PCR to obtain 42 cDNA fragments from Korla fragrant pear flowers. Alignments of nucleotide and amino acid sequences suggested that two fragments (kfp1and kfp4) were related to calyx persistence. The fragments were 78% homologous with Malus × domestica SPL transcription factor (SPL3) and 83% homologous with Malus × domestica MYB transcription factor (MYB12). The complete cDNA sequence of kfpMYB was determined to clarify the role of MYB in calyx persistence. kfpMYB contained a 116 bp 5'-UTR, a 1122 bp open reading frame encoding 374 amino acids, and a 319 bp 3'-UTR. The nucleotide and amino acid sequences of the cDNA in Korla fragrant pear were highly homologous with those of MYB transcription factors in other plant species, suggesting that the sequence is a MYB transcription factor gene. The abundance of kfpMYB mRNA varied significantly between the second and fourth flowers on the branch. Furthermore, kfpMYB expression changed significantly during anthesis and was significantly higher in Jinfeng pear (persistent calyx) and Korla fragrant pear than in Yali pear (deciduous calyx). Expression of kfpMYB was significantly reduced by naphthalene (NAA), abscisic acid (ABA), PBO, and paclobutrazol (PP333). Uniconazole, ethylene (ETH), and gibberellic acid (GA3) had no signicant effect on kfpMYB expression. In conclusion, the expression of kfpMYB appears to be correlated with calyx persistence in Korla fragrant pear.

  6. Highly sensitive detection of gluten-containing cereals in food samples by real-time Loop-mediated isothermal AMPlification (qLAMP) and real-time polymerase chain reaction (qPCR).

    Science.gov (United States)

    Garrido-Maestu, Alejandro; Azinheiro, Sarah; Fuciños, Pablo; Carvalho, Joana; Prado, Marta

    2018-04-25

    The treatment of gluten-related disorders is based on a lifelong, and strict, gluten-free diet. Thus, reliable and sensitive methods are required to detect the presence of gluten contamination. Traditional techniques rely on the detection of these proteins based on specific antibodies, but recent approaches go for an indirect route detecting the DNA that indicates the presence of cereals with gluten content. In the current study two different DNA amplification techniques, real-time PCR (qPCR) and real-time Loop-mediated isothermal AMPlification (qLAMP), were evaluated for their capability to detect and quantify gluten. Different detection strategies, based on these DNA amplification techniques, were tested. Even though good specificity results were obtained with the different approaches, overall qPCR proved more sensitive than qLAMP. This is the first study reporting a qLAMP based-method for the detection of gluten-containing cereals, along with its evaluation in comparison with qPCR. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Studies of pear-shaped nuclei using accelerated radioactive beams

    CERN Document Server

    Gaffney, L P; Scheck, M; Hayes, A B; Wenander, F; Albers, M; Bastin, B; Bauer, C; Blazhev, A; Bonig, S; Bree, N; Cederkall, J; Chupp, T; Cline, D; Cocolios, T E; Davinson, T; DeWitte, H; Diriken, J; Grahn, T; Herzan, A; Huyse, M; Jenkins, D G; Joss, D T; Kesteloot, N; Konki, J; Kowalczyk, M; Kroll, Th; Kwan, E; Lutter, R; Moschner, K; Napiorkowski, P; Pakarinen, J; Pfeiffer, M; Radeck, D; Reiter, P; Reynders, K; Rigby, S V; Robledo, L M; Rudigier, M; Sambi, S; Seidlitz, M; Siebeck, B; Stora, T; Thoele, P; Van Duppen, P; Vermeulen, M J; von Schmid, M; Voulot, D; Warr, N; Wimmer, K; Wrzosek-Lipska, K; Wu, C Y; Zielinska, M

    2013-01-01

    There is strong circumstantial evidence that certain heavy, unstable atomic nuclei are ‘octupole deformed’, that is, distorted into a pear shape. This contrasts with the more prevalent rugby-ball shape of nuclei with reflection-symmetric, quadrupole deformations. The elusive octupole deformed nuclei are of importance for nuclear structure theory, and also in searches for physics beyond the standard model; any measurable electric-dipole moment (a signature of the latter) is expected to be amplified in such nuclei. Here we determine electric octupole transition strengths (a direct measure of octupole correlations) for short-lived isotopes of radon and radium. Coulomb excitation experiments were performed using accelerated beams of heavy, radioactive ions. Our data on and $^{224}$Ra show clear evidence for stronger octupole deformation in the latter. The results enable discrimination between differing theoretical approaches to octupole correlations, and help to constrain suitable candidates for experimental...

  8. Empirical models in the description of prickly pear shoot (Nopal drying kinetics

    Directory of Open Access Journals (Sweden)

    Emmanuel M. Pereira

    Full Text Available ABSTRACT The objective of this study was to describe the technological process involved in the drying kinetics of fresh-cut prickly pear shoots through numerical and analytical solutions. Shoots of two different prickly pear species were used, ‘Gigante’ and ‘Miúda’. Drying was performed at different temperatures (50, 60, 70 and 80 °C and weighing procedures were made continuously. The experimental data were expressed as moisture ratio. The Page model showed the best fit to the drying kinetics of minimally processed ‘Gigante’ and ‘Miúda’ prickly pear shoots, with the best coefficients of determination and Chi-square. Peleg and Wang & Singh models can not be used to simulate the drying of ‘Gigante’ and ‘Miúda’ prickly pear shoots within the evaluated range of temperatures, showing an incoherent graphic pattern.

  9. In-vitro neoformation of woody plants (apple, pear, Weigela)

    International Nuclear Information System (INIS)

    Chevreau, E.; Dufour, M.; Duron, M.

    1990-01-01

    Full text: Adventitious bud neoformation may induce variability in two ways: somaclonal variation, if the explant has undergone undifferentiated growth (callus); induced mutations, if a physical or chemical mutagen has been applied to the explant prior to the regeneration. Three apple scion cultivars ('Gala', 'Granny Smith', 'Golden Delicious') and four apple rootstock cultivars ('Mark', 'Novole', 'Lancep', 'Cepiland') were grown on basal apple multiplication medium. Leaves, internodes and roots were used for callogenesis and/or regeneration experiments. Scion varieties were more responsive than rootstocks. 1000 'Gala' neoformations will be planted in the field to investigate somaclonal variation. In pear, shoot regeneration was obtained from in-vitro leaves of 3 varieties of Pyrus communis ('Seckel', 'Louise Bonne', 'Comice') and one variety of Pyrus bretschneideri ('Crystal Pear'). It was observed that regeneration is still possible from leaves irradiated with up to 40 Gy of γ rays, or treated with 5mM ENU for one hour. In Weigela, stem segments (0.5 cm) from rooted in vitro plants of 5 cultivars were used in experiments to induce adventitious buds. On the cultivar 'Eva Rathke' the adventitious buds were detected as early as 10 to 15 days after the beginning of the culture. A mutagenic treatment was carried out by immersing explants of 'Bristol Ruby' in a suspension of ethyl methane sulfonate (EMS). Among 400 plants regenerated from treated explants, 5 mutants were detected after 5 years of field observation. Two of them seem to be solid mutants. Apparently in Weigela both homogeneous mutants and chimeras are produced by adventitious regeneration from mutagenised explants. (author)

  10. Cambial Isoperoxidases Related to Graft Compatibility in Pear-Quince Graft Combinations

    OpenAIRE

    GÜLEN*, Hatice; ÇELİK, Menşure; POLAT, Mehmet; ERİŞ, Atilla

    2014-01-01

    This study was initiated to survey the graft compatibility characteristics of some selected quince clones known as "S.Ö." with regard to isoperoxidase markers. Compatible (Beurre Hardy = BH) and incompatible (Bartlett = BT) pear cultivars were grafted on quince A (QA) and 13 S.Ö. quince clones by T budding. Bark tissues were collected from the union (4, 8 and 12 weeks after grafting) and from unbudded rootstocks in addition to current-year shoots of 2 pear scions to investig...

  11. Hardness amplification in nondeterministic logspace

    OpenAIRE

    Gupta, Sushmita

    2007-01-01

    A hard problem is one which cannot be easily computed by efficient algorithms. Hardness amplification is a procedure which takes as input a problem of mild hardness and returns a problem of higher hardness. This is closely related to the task of decoding certain error-correcting codes. We show amplification from mild average case hardness to higher average case hardness for nondeterministic logspace and worst-to-average amplification for nondeterministic linspace. Finally we explore possible ...

  12. The effects of plant cover on population of pear psylla (Cacopsylla pyricola and its predators

    Directory of Open Access Journals (Sweden)

    Mohammad Saeed Emami

    2017-01-01

    Full Text Available Cacopsylla pyricola (Förster, 1848 (Hemiptera: Psyllidae is a serious pest of pear in all pear growing areas. In the scope of an integrated pest management, a two consecutive years study was carried out to determine the effects of plant cover on pear psyllid population and its predators. Two treatments including plant cover and bare ground were applied in a randomized complete block design with three replicates. The sampling of the pest and its predators were done weekly by beating technique and leaf sampling. The data were subjected to analysis of variance (ANOVA. The results showed that plant cover had significant effect on the increase of predators on the trees (P < 0.001. The psyllid specialist predator, Anthocoris nemoralis (Fabricius, 1794, had the highest population among the pear psyllid predators (0.29 per sample. Plant cover had no significant effect on reducing the population of eggs, nymphs and adults of the pear psyllid. Despite the increase in the population of predators led by plant cover, lack of their effectiveness to reduce the pear psyllid population is discussed.

  13. PEAR: a fast and accurate Illumina Paired-End reAd mergeR.

    Science.gov (United States)

    Zhang, Jiajie; Kobert, Kassian; Flouri, Tomáš; Stamatakis, Alexandros

    2014-03-01

    The Illumina paired-end sequencing technology can generate reads from both ends of target DNA fragments, which can subsequently be merged to increase the overall read length. There already exist tools for merging these paired-end reads when the target fragments are equally long. However, when fragment lengths vary and, in particular, when either the fragment size is shorter than a single-end read, or longer than twice the size of a single-end read, most state-of-the-art mergers fail to generate reliable results. Therefore, a robust tool is needed to merge paired-end reads that exhibit varying overlap lengths because of varying target fragment lengths. We present the PEAR software for merging raw Illumina paired-end reads from target fragments of varying length. The program evaluates all possible paired-end read overlaps and does not require the target fragment size as input. It also implements a statistical test for minimizing false-positive results. Tests on simulated and empirical data show that PEAR consistently generates highly accurate merged paired-end reads. A highly optimized implementation allows for merging millions of paired-end reads within a few minutes on a standard desktop computer. On multi-core architectures, the parallel version of PEAR shows linear speedups compared with the sequential version of PEAR. PEAR is implemented in C and uses POSIX threads. It is freely available at http://www.exelixis-lab.org/web/software/pear.

  14. Pink discoloration of canned pears: role of procyanidin chemical depolymerization and procyanidin/cell wall interactions.

    Science.gov (United States)

    Le Bourvellec, Carine; Gouble, Barbara; Bureau, Sylvie; Loonis, Michèle; Plé, Yves; Renard, Catherine M G C

    2013-07-10

    After canning, pear pieces turn occasionally from whitish-beige to pink. Conditions were set up to obtain this discoloration systematically and investigate its mechanism. Canned pears showed a significantly lower L* coordinate compared with fresh pears, and the L* coordinate of canned pears decreased with decreasing pH. The values of the a* and b* coordinates increased significantly after processing, the increase being greater for the more acidic pH values, with corresponding redder colors. After canning, polyphenol concentrations decreased significantly, mainly due to loss of procyanidins. This supported the hypothesis of conversion of procyanidins to anthocyanin-like compounds. However, no soluble product was detected at 520 nm, the characteristic wavelength of anthocyanins. When purified procyanidins were treated at 95 °C at three different pH values (2.7, 3.3, and 4.0), procyanidin concentrations decreased after treatment, the more so as the pH was lower, and a pinkish color also appeared, attributed to tannin-anthocyanidin pigment. The pink color was bound to cell walls. Extraction of the neoformed pink entities was attempted by successive solvent extractions followed by cell wall degrading enzymes. The pink color persisted in the residues, and canned pears gave significantly higher amounts of residues after solvent and enzyme treatments than fresh pears. Procyanidins were the entities responsible for the appearance of pink discoloration. However, it seems that this pink discoloration also involved the formation of strong, probably covalent, bonds to the cell wall.

  15. Comparison of Lures Loaded with Codlemone and Pear Ester for Capturing Codling Moths, Cydia pomonella, in Apple and Pear Orchards using Mating Disruption

    Science.gov (United States)

    Fernández, D.E.; Cichón, L.; Garrido, S.; Ribes-Dasi, M.; Avilla, J.

    2010-01-01

    Studies were conducted in apple, Malus domestica Borkhausen and pear, Pyrus communis L. (Rosales: Rosaceae), orchards to evaluate the attractiveness of grey halobutyl septa loaded with 1 (L2) and 10 (Mega) mg of codlemone, 8E, 10E-dodecadien-1-ol, 3 mg of pear ester, ethyl (E,Z)-2,4-decadienoate (DA2313), and 3 mg of pear ester plus 3 mg of codlemone (Combo) to adult codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae). All studies were conducted in orchards treated with pheromone mating disruption. All four lures were tested on diamond-shaped sticky traps placed in 60 plots of apple and 40 plots of pears in 2003/04, and in 62 plots of apples and 30 of pears in 2004–05. Combo lures attracted significantly more moths (males + females) than all the others in both years. Comparisons among flights showed significant differences mainly for flight 1 and 2, but not always for flight 3. Mega lures provided no significant improvement compared with L2 lures during both seasons regarding the total number of moths. Combo and DA2313 lures attracted fewer females than males during the whole season. For most sample dates, more virgin than mated females were attracted to Combo lures, except during the third flight, and the overall ratio was 60:40, although the difference was not statistically significant. We conclude that the Combo lures are better indicators of codling moth activity in pheromone treated orchards, regardless of pest population level, when compared with similar lures containing codlemone or pear ester alone. PMID:20883133

  16. Molecular analysis of two Chinese pear (Pyrus bretschneideri Rehd.) spontaneous self-compatible mutants, Yan Zhuang and Jin Zhui.

    Science.gov (United States)

    Li, M F; Li, X F; Han, Zh H; Shu, H R; Li, T Zh

    2009-09-01

    Yan Zhuang and Jin Zhui are spontaneous bud mutants of Chinese pear (Pyrus bretschneideri Rehd.) from Ya Li. Both fruit set rate and seed number after self-pollination, together with pollen tube growth, prove that Yan Zhuang and Jin Zhui are self-compatible. The fruit set rate and seed number after cross-pollination suggest that the self-compatibility of Yan Zhuang and Jin Zhui may be due to natural mutations of the stylar S allele and pollen S allele, respectively. PCR amplification of the S-RNase gene in self-pollinated progeny of Yan Zhuang and Jin Zhui show that they contain point mutations in the stylar S(21) allele and pollen S(34) allele, respectively. The cDNA sequence of the Yan Zhuang stylar S-RNase gene revealed that the 182nd nucleotide of the S(21)-RNase (cDNA) sequence had been substituted resulting in a Gly to Val mutation, and this might affect the stability of the S-RNase. In addition, Western blotting showed that one Yan Zhuang stylar S-RNase was absent and the expression level of another S-RNase protein was decreased compared to Ya Li. Therefore, we suggest that the self-compatibility of Yan Zhuang is caused by a point mutation in an S(21)-RNase nucleotide.

  17. Evidence of high-elevation amplification versus Arctic amplification.

    Science.gov (United States)

    Wang, Qixiang; Fan, Xiaohui; Wang, Mengben

    2016-01-12

    Elevation-dependent warming in high-elevation regions and Arctic amplification are of tremendous interest to many scientists who are engaged in studies in climate change. Here, using annual mean temperatures from 2781 global stations for the 1961-2010 period, we find that the warming for the world's high-elevation stations (>500 m above sea level) is clearly stronger than their low-elevation counterparts; and the high-elevation amplification consists of not only an altitudinal amplification but also a latitudinal amplification. The warming for the high-elevation stations is linearly proportional to the temperature lapse rates along altitudinal and latitudinal gradients, as a result of the functional shape of Stefan-Boltzmann law in both vertical and latitudinal directions. In contrast, neither altitudinal amplification nor latitudinal amplification is found within the Arctic region despite its greater warming than lower latitudes. Further analysis shows that the Arctic amplification is an integrated part of the latitudinal amplification trend for the low-elevation stations (≤500 m above sea level) across the entire low- to high-latitude Northern Hemisphere, also a result of the mathematical shape of Stefan-Boltzmann law but only in latitudinal direction.

  18. Evidence of high-elevation amplification versus Arctic amplification

    Science.gov (United States)

    Wang, Qixiang; Fan, Xiaohui; Wang, Mengben

    2016-01-01

    Elevation-dependent warming in high-elevation regions and Arctic amplification are of tremendous interest to many scientists who are engaged in studies in climate change. Here, using annual mean temperatures from 2781 global stations for the 1961-2010 period, we find that the warming for the world’s high-elevation stations (>500 m above sea level) is clearly stronger than their low-elevation counterparts; and the high-elevation amplification consists of not only an altitudinal amplification but also a latitudinal amplification. The warming for the high-elevation stations is linearly proportional to the temperature lapse rates along altitudinal and latitudinal gradients, as a result of the functional shape of Stefan-Boltzmann law in both vertical and latitudinal directions. In contrast, neither altitudinal amplification nor latitudinal amplification is found within the Arctic region despite its greater warming than lower latitudes. Further analysis shows that the Arctic amplification is an integrated part of the latitudinal amplification trend for the low-elevation stations (≤500 m above sea level) across the entire low- to high-latitude Northern Hemisphere, also a result of the mathematical shape of Stefan-Boltzmann law but only in latitudinal direction.

  19. First report of Neofabraea kienholzii causing bull’s eye rot on pear (Pyrus communis) in the Netherlands

    OpenAIRE

    Wenneker, M.; Pham, K.T.K.; Boekhoudt, L.C.; Boer, de, F.A.; Leeuwen, van, P.J.; Hollinger, T.C.; Thomma, B.P.H.J.

    2017-01-01

    Pear (Pyrus communis L.) is an important fruit crop in the Netherlands, with a total production of 349,000 tons in 2014, and ‘Conference’ is the main cultivar. In the Netherlands, pears are kept in controlled atmosphere cold storage up to 11 months after harvest. Symptoms of bull’s eye rot were observed in 2015 on ‘Conference’ pears in storage in the Netherlands. Bull’s eye lesions on apple and pear fruits are generally caused by four Neofabraea species: N. alba Jacks, N. malicorticis Guthrie...

  20. Detection of viral sequences by internally calibrated gene amplification.

    Science.gov (United States)

    Cheung, R K; Hui, M F; Dosch, H M; Ewart, T E

    1993-05-01

    Inherent pitfalls of the polymerase chain reaction (PCR) can become serious difficulties when transferring research applications to high-volume routine procedures such as biofermentation process control and clinical diagnostics. Difficulties include 1) the danger of accidental sample contamination with positive control templates; 2) variable amplification due to positional effects in thermocycler blocks and unequal primer efficiency for sense/anti-sense strands; and 3) the need for reliable controls, which provide confidence for reporting negative reactions. Using the PCR detection system for Epstein-Barr virus as a model, we have developed a quick process to generate mutant internal co-amplification templates. These can be used for titration of amplification sensitivity. More importantly, single tube co-amplification without titrations allows determination of the minimum sensitivity achieved in each individual reaction; critical information when reporting negative diagnostic results. Mutant and native fragments are easy to distinguish by size, and sample cross contamination can be readily identified. The system should be easily adaptable to gene amplification procedures, which aim to routinely detect the presence of a given gene fragment in a controlled fashion.

  1. Efficient audio power amplification - challenges

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, Michael A.E.

    2005-07-01

    For more than a decade efficient audio power amplification has evolved and today switch-mode audio power amplification in various forms are the state-of-the-art. The technical steps that lead to this evolution are described and in addition many of the challenges still to be faced and where extensive research and development are needed is covered. (au)

  2. Efficient Audio Power Amplification - Challenges

    DEFF Research Database (Denmark)

    Andersen, Michael Andreas E.

    2005-01-01

    For more than a decade efficient audio power amplification has evolved and today switch-mode audio power amplification in various forms are the state-of-the-art. The technical steps that lead to this evolution are described and in addition many of the challenges still to be faced and where...... extensive research and development are needed is covered....

  3. RNA amplification for successful gene profiling analysis

    Directory of Open Access Journals (Sweden)

    Wang Ena

    2005-07-01

    Full Text Available Abstract The study of clinical samples is often limited by the amount of material available to study. While proteins cannot be multiplied in their natural form, DNA and RNA can be amplified from small specimens and used for high-throughput analyses. Therefore, genetic studies offer the best opportunity to screen for novel insights of human pathology when little material is available. Precise estimates of DNA copy numbers in a given specimen are necessary. However, most studies investigate static variables such as the genetic background of patients or mutations within pathological specimens without a need to assess proportionality of expression among different genes throughout the genome. Comparative genomic hybridization of DNA samples represents a crude exception to this rule since genomic amplification or deletion is compared among different specimens directly. For gene expression analysis, however, it is critical to accurately estimate the proportional expression of distinct RNA transcripts since such proportions directly govern cell function by modulating protein expression. Furthermore, comparative estimates of relative RNA expression at different time points portray the response of cells to environmental stimuli, indirectly informing about broader biological events affecting a particular tissue in physiological or pathological conditions. This cognitive reaction of cells is similar to the detection of electroencephalographic patterns which inform about the status of the brain in response to external stimuli. As our need to understand human pathophysiology at the global level increases, the development and refinement of technologies for high fidelity messenger RNA amplification have become the focus of increasing interest during the past decade. The need to increase the abundance of RNA has been met not only for gene specific amplification, but, most importantly for global transcriptome wide, unbiased amplification. Now gene

  4. Symptoms on apple and pear indicators after back-transmission from Nicotiana occidentalis confirm the identity of apple stem pitting virus with pear vein yellows virus

    NARCIS (Netherlands)

    Leone, G.; Lindner, J.L.; Meer, van der F.A.; Schoen, C.D.; Jongedijk, G.

    1998-01-01

    Isolates of apple stem pitting virus (ASPV) from diseased apple trees were maintained in Nicotiana occidentalis then back-transmitted mechanically from the herbaceous host to apple seedlings and indexed by double budding on apple and pear indicators for the following syndromes: apple stem pitting,

  5. Back-transmission of a virus associated with apple stem pitting and pear vein yellows from Nicotiana occidentalis to apple and pear indicators

    NARCIS (Netherlands)

    Leone, G.; Lindner, J.L.; Jongedijk, G.; Meer, van der F.

    1995-01-01

    The successful back-transmission of the mechanically transmissible virus associated with apple stem pitting and pear vein yellows, from Nicotiana occidentalis to apple seedlings "Golden Delicious" under greenhouse conditions is reported. This result enabled a field experiment where isolates of apple

  6. Studies of pear-shaped nuclei using accelerated radioactive beams.

    Science.gov (United States)

    Gaffney, L P; Butler, P A; Scheck, M; Hayes, A B; Wenander, F; Albers, M; Bastin, B; Bauer, C; Blazhev, A; Bönig, S; Bree, N; Cederkäll, J; Chupp, T; Cline, D; Cocolios, T E; Davinson, T; De Witte, H; Diriken, J; Grahn, T; Herzan, A; Huyse, M; Jenkins, D G; Joss, D T; Kesteloot, N; Konki, J; Kowalczyk, M; Kröll, Th; Kwan, E; Lutter, R; Moschner, K; Napiorkowski, P; Pakarinen, J; Pfeiffer, M; Radeck, D; Reiter, P; Reynders, K; Rigby, S V; Robledo, L M; Rudigier, M; Sambi, S; Seidlitz, M; Siebeck, B; Stora, T; Thoele, P; Van Duppen, P; Vermeulen, M J; von Schmid, M; Voulot, D; Warr, N; Wimmer, K; Wrzosek-Lipska, K; Wu, C Y; Zielinska, M

    2013-05-09

    There is strong circumstantial evidence that certain heavy, unstable atomic nuclei are 'octupole deformed', that is, distorted into a pear shape. This contrasts with the more prevalent rugby-ball shape of nuclei with reflection-symmetric, quadrupole deformations. The elusive octupole deformed nuclei are of importance for nuclear structure theory, and also in searches for physics beyond the standard model; any measurable electric-dipole moment (a signature of the latter) is expected to be amplified in such nuclei. Here we determine electric octupole transition strengths (a direct measure of octupole correlations) for short-lived isotopes of radon and radium. Coulomb excitation experiments were performed using accelerated beams of heavy, radioactive ions. Our data on (220)Rn and (224)Ra show clear evidence for stronger octupole deformation in the latter. The results enable discrimination between differing theoretical approaches to octupole correlations, and help to constrain suitable candidates for experimental studies of atomic electric-dipole moments that might reveal extensions to the standard model.

  7. Comparative study of bioactive components in pear genotypes from Ardahan/Turkey

    Directory of Open Access Journals (Sweden)

    Zehra Tuğba Abacı

    2016-01-01

    Full Text Available In this study, 10 pear genotypes (İncir, Bal, Nene, Kabak, Banda, Kırmızı, İmlahor, Baraka, Limon and Güğüm, which grow in the Ardahan region, were evaluated for their total phenolic content, total anthocyanin content, brix°, pH, titratable acidity, total ascorbic acid content and antioxidant activity. According to the results, the pear genotypes used in this study had a high brix˚ content, high phenolic, anthocyanin and ascorbic acid contents, as well as high antioxidant activity. It was determined that ‘Bal’ pear had the highest total phenolic content and antioxidant activity. In ‘Nene’ and ‘Incir’ pears, the quantity of ascorbic acid and anthocyanin, as well as the antioxidant activity were less than those in the other genotypes. Correlations between brix° and pH, acidity and pH, peel phenolic content and flesh phenolic content, flesh ascorbic acid content and peel phenolic content, peel antioxidant activity and flesh phenolic content, were found to be significant. As a conclusion, due to the high levels of antioxidants and other bioactive compounds in pears, it is suggested to consume those fruits, especially with their peels. The results from this study will provide new insights into farming, fresh fruit consumption, industrial food processing and future research studies.

  8. Phenolic and mineral profile of Balkan indigenous apple and pear cultivars

    Directory of Open Access Journals (Sweden)

    Živković Jelena

    2016-01-01

    Full Text Available The aim of this study was chemical analysis of phenolic compounds, as well as mineral nutrients in pulp and peel obtained from Balkan indigenous apple and pear cultivars. Phenolic composition assesed by means of HPLC-DAD and spectrophotometric methods varied significantly between the cultivars for both peel and pulp. Among apples Mekica cultivar had the highest total phenolic content while Šećerlija and Zlatna Parmenka had the lowest. In the case of pear samples the principal source of total phenolic content was Crna Takiša while their minimum was recorded for Bela Arapka. In most of the investigated samples chlorogenic acid in apples and arbutin in pears were major detected polyphenolic compounds. With regard to mineral analysis K was the most abundant followed by P, Mg, Ca and S. Iron was the dominant microelement in apple peel and pulp samples, while in pear samples the principal microelement was B. Obtained results provide detailed information on chemical composition of tested apple and pear cultivars and therby could encourage their wider cultivation and consumption. [Projekat Ministarstva nauke Republike Srbije, br. 46013

  9. GRAFT COMPATIBILITY BETWEEN EUROPEAN PEAR CULTIVARS AND EAST MALLING “C” ROOTSTOCK

    Directory of Open Access Journals (Sweden)

    BRUNO DALAZEN MACHADO

    2017-08-01

    Full Text Available ABSTRACT Graft incompatibility is one of the main factors limiting european pear production in Brazil. At present, there is no clear indication of the best combination(s of european pear cultivars and quince rootstocks for graft compatibility. The study evaluated the graft compatibility for combinations of european Abbè Fetel, Rocha and Williams pear cultivars grafted onto the EMC quince rootstock. The experiment was performed in a commercial european pear orchard in the Urupema municipality, in State of Santa Catarina, during the 2011/12, 2012/13 and 2013/14 growing seasons. The plant growth variables comprised the section increment (mm in the trunk diameter in the graft union region of cultivars and rootstocks; difference in the diameter of the graft for cultivars and rootstocks; “translocated” incompatibility; “located” incompatibility and the vascular connection in the graft union region, which was assessed by immersing the bases of the plants in a 0.08% succinic acid solution. There were “located” and “translocated” incompatibility between the european Williams pear cultivar and the EMC rootstock based on the vascular discontinuity in the graft union region, which prevented the translocation of succinic acid stain. Thus, the Williams/EMC combination is considered incompatible and it is not recommended for use in commercial orchards. The Rocha/EMC and Abbè Fetel/EMC are considered partially incompatible combinations and showed good development eight years after planting.

  10. Apomixis and the problem of obtaining haploids and homozygote diploids in pear (Pyrus communis L.

    Directory of Open Access Journals (Sweden)

    Є. О. Долматов

    2013-02-01

    Full Text Available The article highlights results of research over simulative apomixes in pear and its utilization for obtaining haploids and homozygote diploids. It has been established that over 50% pear varieties with failed remote hybridization are capable of generating seeds of apomictic origin producing diploid plants. Genotypes displaying maximal inclination to apomixes have been singled out. Apomictic pear seedlings obtained from foreign pollination within the limits of the same combination are inherent in profound morphological diversity. Fruit-bearing apomicts originated from one and the same maternal plant differ to the same extent as hybrid seedlings of the same family. Genetic markers have enabled to establish that these are embryo sacs in which meiosis has completed that give rise to apomictic seeds. In vitro method as used for the purpose of increasing apomictic plants output has been illustrated. The greatest induction of apomictic shoots in vitro has been reached by alternation of BAP cytokinin at concentration of 1mg/l and 2 mg/l on the background of GA3 amounting to 1,5 mg/l. Grafting with shoots in vitro on non-sterile rootstocks of pear (Pyrus communis has increased the output of plants up to 80%. A cytological assessment of 9 apomictic samples is provided. The cytological analysis of samples of apomictic forms has certified the presence of simulative haploid parthenogenesis in pear.

  11. Infrared imaging technology for detection of bruising damages of 'Shingo' pear

    Science.gov (United States)

    Cho, Byoung-Kwan; Kim, Moon S.; Lee, Hoonsoo; Delwiche, Stephen R.

    2011-06-01

    Bruise damage on pears is one of the most crucial internal quality factors that needs to be detected in postharvest quality sorting processes. Development of sensitive detection methods for the defects including fruit bruise is necessary to ensure accurate quality assessment. Infra-red imaging techniques in the 1000 nm to 1700 nm has good potentials for identifying and detecting bruises since bruises result in the rupture of internal cell walls due to defects on agricultural materials. In this study, feasibility of hyperspectral infra-red (1000 - 1700 nm) imaging technique for the detection of bruise damages underneath the pear skin was investigated. Pear bruises, affecting the quality of fruits underneath the skin, are not easily discernable by using conventional imaging technique in the visible wavelength ranges. Simple image combination methods as well as multivariate image analyses were explored to develop optimal image analysis algorithm to detect bruise damages of pear. Results demonstrated good potential of the infra-red imaging techniques for detection of bruises damages on pears.

  12. First Report of Cadophora luteo-olivacea Causing Side Rot on ‘Conference’ Pears in the Netherlands

    NARCIS (Netherlands)

    Wenneker, M.; Pham, K.T.K.; Lemmers, M.E.C.; Boer, de Astrid; Leeuwen, van Paul; Hollinger, T.C.; Haas, de B.H.; Köhl, J.

    2016-01-01

    Pear (Pyrus communis) is an important fruit crop in the Netherlands. Symptoms of side rot disease of pear fruits were first observed in 2008 on cv. Conference in storage in the Netherlands. Typical round to oval, dark-brown, and slightly sunken spots (size 0.5 to 1.0 cm in diameter) appeared after

  13. PEAR NAMES IN DIALECT OF ORDU AND ITS REGION / ORDU VE YÖRESI AĞIZLARINDA ARMUT ADLARI

    Directory of Open Access Journals (Sweden)

    Prof. Dr. Mehmet AYDIN

    2008-08-01

    Full Text Available In this study, 133 pear names have been investgtigated in a onomasticpoint of view. 16 of them have been collected from main and Gerze areas ofSinop, the others from Ordu. Pear names found from these two provinceshave been analysed from various point of view and classified.

  14. Comparing mating disruption of codling moth with standard and meso dispensers loaded with pear ester and codlemone

    Science.gov (United States)

    Studies were conducted with hand-applied combo dispensers loaded with the sex pheromone (E,E)-8,10-dodecadien-1-ol (codlemone), and the pear volatile, (E,Z)-2,4-decadienoate (pear ester) for control of codling moth, Cydia pomonella (L.) in apple, Malus domestica Bordkhausen during 2012. Two types of...

  15. [Detection of low-level microorganism by concomitant use of ATP amplification and bioluminescence assay].

    Science.gov (United States)

    Chen, Ying; Zou, Bingjie; Zhu, Shuhui; Ma, Yinjiao; Zhou, Guohua

    2009-06-01

    To detect low levels of microorganism by bioluminescence assay, the reaction of ATP amplification catalyzed by ADK (adenylate kinase) combined with PPK (polyphosphate kinase) can be employed. However, the endogenous ADP bound to PPK is a background source and interfere the effective detection of low levels of exogenous ATP. We expressed a fusion protein of PPK and ADK and established a new method to decrease the background signal. The genes of PPK and ADK were amplified by PCR and cloned into vector pET28a (+) to provide a recombinant expression plasmid pET28a (+)-PPKADK to prepare the fusion protein. Apyrase was immobilized on the surface of magnetic beads coated with polyurethane to provide Beads-apyrase to eliminate background caused by ADP bound to PPK-ADK. The exogenous ATP and microorganism were also detected by using ATP amplification reaction coupled with bioluminescence assay. The purified fusion protein showed both ADK and PPK activities. Beads-apyrase could eliminate ADP contamination conveniently and effectively, thus less than 1 fmol of ATP was detected by ATP amplification reaction coupled with bioluminescence assay. Using ATP amplification reaction, the sensitivity of bioluminescence assay was 100-fold than that of normal bioluminescence assay without ATP amplification. Beads-apyrase is an effective tool to eliminate the background of the reaction of ATP amplification. The sensitivity of bioluminescence assay was increased significantly with concomitant use of ATP amplification and bioluminescence assay.

  16. Next generation Chirped Pulse Amplification

    Energy Technology Data Exchange (ETDEWEB)

    Nees, J.; Biswal, S.; Mourou, G. [Univ. Michigan, Center for Ultrafast Optical Science, Ann Arbor, MI (United States); Nishimura, Akihiko; Takuma, Hiroshi

    1998-03-01

    The limiting factors of Chirped Pulse Amplification (CPA) are discussed and experimental results of CPA in Yb:glass regenerative amplifier are given. Scaling of Yb:glass to the petawatt level is briefly discussed. (author)

  17. Betalain, Acid ascorbic, phenolic contents and antioxidant properties of purple, red, yellow and white cactus pears.

    Science.gov (United States)

    Sumaya-Martínez, María Teresa; Cruz-Jaime, Sandra; Madrigal-Santillán, Eduardo; García-Paredes, Juan Diego; Cariño-Cortés, Raquel; Cruz-Cansino, Nelly; Valadez-Vega, Carmen; Martinez-Cardenas, Leonardo; Alanís-García, Ernesto

    2011-01-01

    Commercialization of cactus pears based on their antioxidant properties can generate competitive advantages, and these can turn into business opportunities and the development of new products and a high-value ingredient for the food industry. This work evaluated the antioxidant activities (1,1-diphenyl-2-picrylhydrazyl radical-scavenging, protection against oxidation of a β-carotene-linoleic acid emulsion, and iron (II) chelation), the content of total phenolic compounds, ascorbic acid, betacyanin, betaxanthin and the stability of betacyanin pigments in presence of Cu (II)-dependent hydroxyl radicals (OH•), in 18 cultivars of purple, red, yellow and white cactus pear from six Mexican states. Our results indicated that the antiradical activities from yellow and white cactus pear cultivars were not significantly different (p stability when exposed to OH•.

  18. AGROCLIMATIC ZONING OF EUROPEAN AND ASIAN PEAR CULTIVARS WITH POTENTIAL FOR COMMERCIAL PLANTING IN SOUTHERN BRAZIL

    Directory of Open Access Journals (Sweden)

    MARCOS SILVEIRA WREGE

    Full Text Available ABSTRACT Pear is among the fruits of major commercial interest in the world and one of the most imported in Brazil. Brazilian production is very small and the fruit quality is low, due to production problems. The success of culture in the country, among other factors, may be linked to the choice of cultivars, pollinating and rootstocks better adapted to local conditions, and thus depend on the particulars of an agricultural zoning. The aim of this study was to identify, in southern Brazil, homogeneous climatic zones with potential for growing of European and Asian pears, through climate risk studies. The regions were defined by the seasonal availability of chilling hours (<7.2 °C accumulated during the period from May to September and the monthly risk of drought. The analysis allowed the recognition of four homogeneous areas for the production of pears in southern Brazil.

  19. Nutritional and medicinal use of Cactus pear (Opuntia spp.) cladodes and fruits.

    Science.gov (United States)

    Feugang, Jean Magloire; Konarski, Patricia; Zou, Daming; Stintzing, Florian Conrad; Zou, Changping

    2006-09-01

    Natural products and health foods have recently received a lot of attention both by health professionals and the common population for improving overall well-being, as well as in the prevention of diseases including cancer. In this line, all types of fruits and vegetables have been re-evaluated and recognized as valuable sources of nutraceuticals. The great number of potentially active nutrients and their multifunctional properties make cactus pear (Opuntia spp.) fruits and cladodes perfect candidates for the production of health-promoting food and food supplements. Although traditionally appreciated for its pharmacological properties by the Native Americans, cactus pear is still hardly recognized because of insufficient scientific information. However, recent studies on Opuntia spp. have demonstrated cactus pear fruit and vegetative cladodes to be excellent candidates for the development of healthy food. Therefore, this review summarizes current knowledge on the chemical composition of Opuntia cacti with particular emphasis in its use as food and medicine.

  20. Progress in multiplex loop-mediated isothermal amplification technology.

    Science.gov (United States)

    Lin, Wen-hui; Zou, Bing-jie; Song, Qin-xin; Zhou, Guo-hua

    2015-09-01

    Loop-mediated isothermal amplification (LAMP) has been widely applied in nucleic acid diagnostics due to its high sensitivity and specificity, high speed and low requirement of equipment. In order to fully leverage these merits, achieve high efficiency and reliability in diagnostics, and expand the applicable fields while keeping low reagent cost, multiplex LAMP technology has been extensively explored in recent years. Common methods for LAMP products detection are mostly based on the double-stranded DNA amplicons or byproducts from the polymerization reaction, so they can only identify the occurrence of amplification reaction but not the origins or specificity of the products. To achieve specific LAMP products detection, researchers developed various multiplex methods by improving the conventional LAMP technology or coupling LAMP with other assays. However, the interference and/or the different amplification efficiencies among different primer sets often lead to biased amplification and thus limited multiplexing level. We here defined these methods as narrow-sensed multiplex LAMP. The research on miniaturized amplification technology which is booming in recent years has given rise to the novel general-sensed multiplex LAMP technology that breaks this limitation by its capability to perform highly parallel and miniaturized simplex reactions in independent compartments. Methods of this type have additional benefits such as lower reagent cost, higher level of automation, lower risk of cross-contamination and better suitability for on-site detection of multiple targets. In this review, we summarize the recent research progress in multiplex LAMP technology from the following aspects: the principle and design of narrow-sensed LAMP and its amplification optimization, the general-sensed LAMP, and the various applications of all multiplex LAMP technologies in diagnostics.

  1. Biocontrol of Gray Mold Decay in Pear by Bacillus amyloliquefaciens Strain BA3

    Science.gov (United States)

    Qu, Hui; Zhao, Longyu; Zhao, Fengchun; Liu, Yufang; Yang, Zhengyou

    2016-01-01

    The economic losses caused by postharvest fruits diseases have attracted global attention. Traditional chemical fungicide could not meet the need of humans. In recent years, microbial agent which has begun to take the place of chemical fungicide comes into people’s vision. The aim of this paper was to investigate the potential of Bacillus amyloliquefaciens strain BA3 for its biocontrol capability on gray mold decay of pears and its effect on postharvest quality of pears. Compared with other treatments, the inhibition effect on gray mold of washed cell suspension of B. amyloliquefaciens was the best. Consequently it was utilized in subsequent experiments. Spore germination and germ tube length of Botrytis cinerea was 18.72% and 12.85 μm treated with BA3, while the control group was 62.88% and 30.44 μm. We confirmed that increase of the concentration of B. amyloliquefaciens, improved the efficacy of BA3 in controlling gray mold decay of pears. Colonization variation of BA3 in wounds of pears was recorded. To begin with, the populations of B. amyloliquefaciens increased rapidly and remained stable. On the fourth day, there was a declining trend , after that the population increased to 4 × 10(5) CFU/wound and remained stable. BA3 had no significant effect on mass loss, titratable acidity, firmness and total soluble solids of pears that were stored at 25°C for 7 days comparing with control group. However, the effect of B. amyloliquefaciens on ascorbic acid was significantly higher than that of the control group. Our study indicates that B. amyloliquefaciens has a potential as postharvest biocontrol agent on pears.

  2. [Huanghua pear soluble solids contents Vis/NIR spectroscopy by analysis of variables optimization and FICA].

    Science.gov (United States)

    Xu, Wen-li; Sun, Tong; Hu, Tian; Hu, Tao; Liu, Mu-hua

    2014-12-01

    The purpose of this study was to establish a mathematical model of the visible/near-infrared (Vis/NIR) diffuse transmission spectroscopy with fine stability and precise predictability for the non destructive testing of the soluble solids content of huanghua pear, through comparing the effects of various pretreatment methods, variable optimization method, fast independent principal component analysis (FICA) and least squares support vector machines (LS-SVM) on mathematica model for SSC of huanghua pear, and the best combination of methods to establish model for SSC of huanghua pear was got. Vis/NIR diffuse transmission spectra of huanghua pear were acquired by a Quality Spec spectrometer, three methods including genetic algorithm, successive projections algorithm and competitive adaptive reweighted sampling (CARS) were used firstly to select characteristic variables from spectral data of huanghua pears in the wavelength range of 550~950 nm, and then FICA was used to extract factors from the characteristic variables, finally, validation model for SSC in huanghua pears was built by LS-SVM on the basic of those parameters got above. The results showed that using LS-SVM on the foundation of the 21 variables screened by CARS and the 12 factors selected by FICA, the CARS-FICA-LS-SVM regression model for SSC in huanghua pears was built and performed best, the coefficient of determination and root mean square error of calibration and prediction sets were RC(2)=0.974, RMSEC=0.116%, RP(2)=0.918, and RMSEP=0.158% respectively, and compared with the mathematical model which uses PLS as modeling method, the number of variables was down from 401 to 21, the factors were also down from 14 to 12, the coefficient of determination of modeling and prediction sets were up to 0.023 and 0.019 respectively, while the root mean square errors of calibration and prediction sets were reduced by 0.042% and 0.010% respectively. These experimental results showed that using CARS-FICA-LS-SVM to

  3. Performance of orange oil in the control of carmine cochineal in giant cactus pear.

    OpenAIRE

    Ivanildo Cavalcanti de Albuquerque; Carlos Henrique de Brito; Edson Batista Lopes; Jacinto de Luna Batista

    2009-01-01

    Since its introduction, in 2001, the carmine cochineal (Dactylopius opuntiae) already decimated some 100.000 hectares of giant cactus pear (Opuntia ficus-indica) in semi-arid region of Paraiba. This study aimed to evaluate the behavior of five concentrations of orange oil, applied in cladodes on the death of D. opuntiae in field conditions. The research was carried out in a field of giant cactus pear infested by carmine cochineal on the site rigideira, Monteiro County, State of Paraíba. The ...

  4. Cambial Isoperoxidases Related to Graft Compatibility in Pear-Quince Graft Combinations

    OpenAIRE

    GÜLEN*, Hatice

    2005-01-01

    This study was initiated to survey the graft compatibility characteristics of some selected quince clones known as "S.Ö." with regard to isoperoxidase markers. Compatible (Beurre Hardy = BH) and incompatible (Bartlett = BT) pear cultivars were grafted on quince A (QA) and 13 S.Ö. quince clones by T budding. Bark tissues were collected from the union (4, 8 and 12 weeks after grafting) and from unbudded rootstocks in addition to current-year shoots of 2 pear scions to investigate 2 an...

  5. The identification of two Trypanosoma cruzi I genotypes from domestic and sylvatic transmission cycles in Colombia based on a single polymerase chain reaction amplification of the spliced-leader intergenic region

    Directory of Open Access Journals (Sweden)

    Lina Marcela Villa

    2013-11-01

    Full Text Available A single polymerase chain reaction (PCR reaction targeting the spliced-leader intergenic region of Trypanosoma cruzi I was standardised by amplifying a 231 bp fragment in domestic (TcIDOM strains or clones and 450 and 550 bp fragments in sylvatic strains or clones. This reaction was validated using 44 blind coded samples and 184 non-coded T. cruzi I clones isolated from sylvatic triatomines and the correspondence between the amplified fragments and their domestic or sylvatic origin was determined. Six of the nine strains isolated from acute cases suspected of oral infection had the sylvatic T. cruzi I profile. These results confirmed that the sylvatic T. cruzi I genotype is linked to cases of oral Chagas disease in Colombia. We therefore propose the use of this novel PCR reaction in strains or clones previously characterised as T. cruzi I to distinguish TcIDOMfrom sylvatic genotypes in studies of transmission dynamics, including the verification of population selection within hosts or detection of the frequency of mixed infections by both T. cruzi I genotypes in Colombia.

  6. Dormancy-associated MADS-box genes and microRNAs jointly control dormancy transition in pear (Pyrus pyrifolia white pear group) flower bud.

    Science.gov (United States)

    Niu, Qingfeng; Li, Jianzhao; Cai, Danying; Qian, Minjie; Jia, Huimin; Bai, Songling; Hussain, Sayed; Liu, Guoqin; Teng, Yuanwen; Zheng, Xiaoyan

    2016-01-01

    Bud dormancy in perennial plants is indispensable to survival over winter and to regrowth and development in the following year. However, the molecular pathways of endo-dormancy induction, maintenance, and release are still unclear, especially in fruit crops. To identify genes with roles in regulating endo-dormancy, 30 MIKC(C)-type MADS-box genes were identified in the pear genome and characterized. The 30 genes were analysed to determine their phylogenetic relationships with homologous genes, genome locations, gene structure, tissue-specific transcript profiles, and transcriptional patterns during flower bud dormancy in 'Suli' pear (Pyrus pyrifolia white pear group). The roles in regulating bud dormancy varied among the MIKC gene family members. Yeast one-hybrid and transient assays showed that PpCBF enhanced PpDAM1 and PpDAM3 transcriptional activity during the induction of dormancy, probably by binding to the C-repeat/DRE binding site, while DAM proteins inhibited the transcriptional activity of PpFT2 during dormancy release. In the small RNA-seq analysis, 185 conserved, 24 less-conserved, and 32 pear-specific miRNAs with distinct expression patterns during bud dormancy were identified. Joint analyses of miRNAs and MIKC genes together with degradome data showed that miR6390 targeted PpDAM transcripts and degraded them to release PpFT2. Our data show that cross-talk among PpCBF, PpDAM, PpFT2, and miR6390 played important roles in regulating endo-dormancy. A model for the molecular mechanism of dormancy transition is proposed: short-term chilling in autumn activates the accumulation of CBF, which directly promotes DAM expression; DAM subsequently inhibits FT expression to induce endo-dormancy, and miR6390 degrades DAM genes to release endo-dormancy. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  7. A value set for documenting adverse reactions in electronic health records.

    Science.gov (United States)

    Goss, Foster R; Lai, Kenneth H; Topaz, Maxim; Acker, Warren W; Kowalski, Leigh; Plasek, Joseph M; Blumenthal, Kimberly G; Seger, Diane L; Slight, Sarah P; Wah Fung, Kin; Chang, Frank Y; Bates, David W; Zhou, Li

    2017-12-14

    To develop a comprehensive value set for documenting and encoding adverse reactions in the allergy module of an electronic health record. We analyzed 2 471 004 adverse reactions stored in Partners Healthcare's Enterprise-wide Allergy Repository (PEAR) of 2.7 million patients. Using the Medical Text Extraction, Reasoning, and Mapping System, we processed both structured and free-text reaction entries and mapped them to Systematized Nomenclature of Medicine - Clinical Terms. We calculated the frequencies of reaction concepts, including rare, severe, and hypersensitivity reactions. We compared PEAR concepts to a Federal Health Information Modeling and Standards value set and University of Nebraska Medical Center data, and then created an integrated value set. We identified 787 reaction concepts in PEAR. Frequently reported reactions included: rash (14.0%), hives (8.2%), gastrointestinal irritation (5.5%), itching (3.2%), and anaphylaxis (2.5%). We identified an additional 320 concepts from Federal Health Information Modeling and Standards and the University of Nebraska Medical Center to resolve gaps due to missing and partial matches when comparing these external resources to PEAR. This yielded 1106 concepts in our final integrated value set. The presence of rare, severe, and hypersensitivity reactions was limited in both external datasets. Hypersensitivity reactions represented roughly 20% of the reactions within our data. We developed a value set for encoding adverse reactions using a large dataset from one health system, enriched by reactions from 2 large external resources. This integrated value set includes clinically important severe and hypersensitivity reactions. This work contributes a value set, harmonized with existing data, to improve the consistency and accuracy of reaction documentation in electronic health records, providing the necessary building blocks for more intelligent clinical decision support for allergies and adverse reactions. © The

  8. Simultaneous detection of TOP2A and HER2 gene amplification by multiplex ligation-dependent probe amplification in breast cancer.

    Science.gov (United States)

    Moelans, Cathy B; de Weger, Roel A; van Blokland, Marja T M; van der Wall, Elsken; van Diest, Paul J

    2010-01-01

    HER-2/neu gene amplification, found in certain subtypes of (breast-) cancers, is an independent prognostic factor of poor outcome and determines eligibility for systemic treatment with trastuzumab. TopoII alpha (TOP2A) gene amplification seems to be predictive of response to a class of cytostatic agents called TopoII inhibitors, which include the anthracyclines. The observed increased efficacy of anthracyclines in HER2-positive tumors is thought to arise from the close proximity of both genes on chromosome 17, where the TopoII amplification status will determine the anthracycline sensitivity. This study aimed to validate a new polymerase chain reaction-based test, called multiplex ligation-dependent probe amplification (MLPA), as a simple and quick method to simultaneously assess HER-2/neu and TopoII alpha gene amplification status in paraffin-embedded breast cancer samples. To this end, MLPA results were compared with TopoII alpha, HER2 chromogenic in situ hybridization (CISH). We also assessed TopoII alpha protein expression by immunohistochemistry. Of 353 patients, 9% showed TopoII alpha amplification by MLPA and 13% of patients were HER2 amplified. TopoII alpha amplification was seen in 42% of HER2-amplified cases and showed no high level amplification without HER2 amplification. Eleven patients displayed TopoI alpha loss (3%). Concordance between MLPA and CISH was 91% for TopoII alpha and 96% for HER2. Correlation between amplification and overexpression of TopoII alpha was significant (P=0.035), but amplification did not always predict protein overexpression. Loss of the TopoII alpha gene was almost never associated with loss of its protein. In conclusion, MLPA is an easy and accurate method to simultaneously detect breast cancer HER-2/neu and TopoII alpha copy number status in paraffin-embedded tissue, and thus an attractive supplement or alternative to CISH.

  9. Does classroom amplification aid comprehension?

    Science.gov (United States)

    Arnold, P; Canning, D

    1999-06-01

    Many classrooms are noisy and this interferes with listening and teaching. FM soundfield (FM) amplification systems have been developed which provide a uniform soundfield throughout the classroom and increase the speech-signal:noise ratio. The effect on comprehension of such a system was investigated. Forty-nine pupils (comprising the two top classes of a mainstream primary school) participated in this study, with a mean age of 9.92 years (range 8.58-11.42 years). The Neale Analysis of Reading Ability (Neale, 1988a, b) was modified and administered as a spoken comprehension test. Tests of nonverbal intelligence, auditory memory and a questionnaire were given. The passages spoken though the FM amplification system were understood better than the comparable unamplified passages. Auditory memory, sex and non-verbal intelligence had no effect on improved comprehension. FM amplification significantly improved comprehension and could be considered for use in other schools.

  10. 76 FR 4202 - Pears Grown in Oregon and Washington; Amendment To Allow Additional Exemptions

    Science.gov (United States)

    2011-01-25

    ... handlers.'' A few packing houses, those that are generally involved only in the handling aspect of the... industry to remain viable while also facilitating the current consumer interest in buying local, fresh..., packing houses, roadside stands, and farmers' markets. This change should provide small pear handlers with...

  11. 76 FR 8917 - Pears Grown in Oregon and Washington; Continuance Referendum

    Science.gov (United States)

    2011-02-16

    ...: Teresa Hutchinson, Marketing Specialist, or Gary D. Olson, Regional Manager, Northwest Marketing Field...; ] DEPARTMENT OF AGRICULTURE Agricultural Marketing Service 7 CFR Part 927 Pears Grown in Oregon and Washington; Continuance Referendum AGENCY: Agricultural Marketing Service, USDA. ACTION: Referendum order. SUMMARY: This...

  12. Growth medium alterations improve in vitro cold storage of pear germplasm

    Science.gov (United States)

    Development of new fruit cultivars is dependent on genetic resource collections such as those at the Pomological Garden at the Institute of Horticulture and Viticulture near Almaty, Kazakhstan. The pear germplasm collection of the Pomological Garden contains 615 cultivars and 3 species. About 36 ac...

  13. Finite element analysis of the dynamic behavior of pear under impact loading

    Directory of Open Access Journals (Sweden)

    Alireza Salarikia

    2017-03-01

    Full Text Available Pear fruit is susceptible to bruising from mechanical impact during field harvesting operations and at all stages of postharvest handling. The postharvest shelf life of bruised fruits were shorter, and they softened rapidly under cold storage compared with non-bruised samples. Developing strategies for reducing bruising during the supply chain requires an understanding of fruit dynamic behavior to different enforced loadings. Finite Element Method (FEM is among the best techniques, in terms of accuracy and cost-efficiency, for studying the factors effective in impact-induced bruising. In this research, the drop test of pear sample was simulated using FEM. The simulation was conducted on a 3D solid model of the pear that was created by using non-contact optical scanning technology. This computer-based study aimed to assess the stress and strain distribution patterns within pear generated by collision of the fruit with a flat surface made of different materials. The contact force between two colliding surfaces is also investigated. The simulations were conducted at two different drop orientations and four different impact surfaces. Results showed that, in both drop orientations, the largest and smallest stresses, strains and contact forces were developed in collision with the steel and rubber surfaces, respectively. In general, these parameters were smaller when fruit collided with the surfaces along its horizontal axis than when collided along its vertical axis. Finally, analyses of stress and strain magnitudes showed that simulation stress and strain values were compatible with experiments data.

  14. Sources of Neofabraea spp. and Cadophora spp. in Dutch apple and pear orchards

    NARCIS (Netherlands)

    Köhl, J.; Wenneker, M.; Haas, de B.H.; Anbergen, R.; Lombaers-van der Plas, C.H.; Kastelein, P.

    2015-01-01

    Post-harvest diseases of apple and pear result in significant economic losses during long storage. Pathogens causing quiescent infections in the orchard leading to late post-harvest losses in The Netherlands are Neofabraea alba (Lenticel spot disease), N. perennans (Bull eye rot), Neonectria

  15. First report of powdery mildew caused by Podosphaera leucotricha on Callery pear in North America

    Science.gov (United States)

    Podosphaera leucotricha (Ellis & Everh.) E.S. Salmon (Ascomycetes, Erysiphales) is the etiological agent of a powdery mildew disease that occurs on rosaceous plants, primarily Malus and Pyrus. This fungus is nearly circumglobal. In May 2009, leaves of Bradford pear (Pyrus calleryana Decne.), some di...

  16. Diversity of unavailable polysaccharides and dietary fiber in domesticated nopalito and cactus pear fruit (Opuntia spp.).

    Science.gov (United States)

    Peña-Valdivia, Cecilia Beatriz; Trejo, Carlos; Arroyo-Peña, V Baruch; Sánchez Urdaneta, Adriana Beatriz; Balois Morales, Rosendo

    2012-08-01

    The aim of this study was to quantify mucilages, pectins, hemicelluloses, and cellulose of nopalitos (edible, as vegetable, young cladodes of flat-stemmed spiny cacti) of most consumed Mexican cultivars, and sweet and acid cactus pear fruits of Opuntia spp. The hypothesis is that, regardless of their unavailable polysaccharides diversity, nopalitos and cactus pear fruits are rich sources of soluble and insoluble dietary fiber. Twelve cultivars of Opuntia spp. were used. Nopalitos had a significant variation in structural polysaccharides among the cultivars: mucilages (from 3.8 to 8.6% dry matter (DM)) averaged near a half of pectins content (from 6.1 to 14.2% DM) and tightly bound hemicelluloses (from 2.2 to 4.7% DM), which were the less abundant polysaccharides, amounted 50% of the loosely bound hemicelluloses (from 4.3 to 10.7% DM). Acid fruits (or 'xoconostle') had significantly higher unavailable polysaccharides content than sweet fruit, and contain similar proportions than nopalitos. Unavailable polysaccharides represent a high proportion of dry tissues of nopalitos and cactus pear fruits, composition of both of these soluble and insoluble polysaccharides (total dietary fiber) widely vary among cultivars without an evident pattern. Nopalitos and cactus pear fruit can be considered an excellent source of dietary fiber. Copyright © 2012 Verlag Helvetica Chimica Acta AG, Zürich.

  17. EARLY SPRING APPLICATION OF AMINOETHOXYVINILGLYCINE (AVG INCREASES FRUIT SET AND YIELD OF ‘ROCHA’ PEARS

    Directory of Open Access Journals (Sweden)

    MATEUS DA SILVEIRA PASA

    2017-10-01

    Full Text Available ABSTRACT The low fruit set is one of the main factors leading to poor yield of pear orchards in Brazil. Ethylene is associated with abscission of flowers and fruitlets. Then, the application of ethylene synthesis inhibitors, such as AVG, is a potential tool to increase fruit set of pears. The objective of this study was to evaluate the effect of AVG, sprayed at different rates and timings, on fruit set, yield and fruit quality of ‘Rocha’ pear. The study was performed in a commercial orchard located in the municipality of São Joaquim, SC, during the growing seasons of 2014/2015 and 2015/2016. Plant material consisted of ‘Rocha’ pear trees grafted on quince rootstock ‘BA29’. AVG was tested at different rates (60 mg L-1 and 80 mg L-1 and timings [full bloom, one week after full bloom (WAFB, and two WAFB, either alone or in combination. The experiment was arranged in a randomized block design, with at least five single-tree replications. The fruit set, number of fruit per tree, yield, estimated yield, fruit weight, return bloom, and fruit quality attributes were assessed. Fruit set and yield were consistently increased by single applications of AVG at 60 and 80 mg L-1 at both one and two weeks after full bloom, without negatively affecting fruit quality attributes and return bloom.

  18. Commercial and biological characteristics of pear gene pool (Pyrus communis L. of VNIISPK

    Directory of Open Access Journals (Sweden)

    Н. Г. Красова

    2008-10-01

    Full Text Available The study results for many years (1972- 2006 of pear gene pool in the All- Russian Research Institute of Horticultural Breeding are given. The cultivars and selections have been singled out for wide dissemination and use in breeding.

  19. Pathogenicity of Stemphylium vesicarium from different hosts causing brown spot in pear

    NARCIS (Netherlands)

    Köhl, J.; Groenenboom-de Haas, B.H.; Goossen-van de Geijn, H.M.; Speksnijder, A.G.C.L.; Kastelein, P.; Hoog, de S.; Ende, van den B.G.

    2009-01-01

    Stemphylium vesicarium (teleomorph: Pleospora herbarum) is the causal agent of brown spot disease in pear. The species is also able to cause disease in asparagus, onion and other crops. Saprophytic growth of the fungus on plant debris is common. The objective of this study was to investigate whether

  20. Estimate of Leaf Chlorophyll and Nitrogen Content in Asian Pear (Pyrus serotina Rehd. by CCM-200

    Directory of Open Access Journals (Sweden)

    Mostafa GHASEMI

    2011-03-01

    Full Text Available In many cases evaluation of chlorophyll and nitrogen content in plants need to destructive methods, more time and organic solvents. Application of chlorophyll meters save time and resources. The aim of this study was estimating of chlorophyll and nitrogen content in Asian pear leaves using non-destructive method and rapid quantification of chlorophyll by chlorophyll content meter (CCM-200. This study was conducted on 8 years old Asian pear trees during June 2008 in Tehran, Iran. To develop our regression model, the chlorophyll meter data were correlated with extracted chlorophyll and nitrogen content data obtained from DMSO and Kejeldal methods, respectively. The results showed that, there was positive and linear correlation between CCM-200 data and chlorophyll a (R�=0.7183, chlorophyll b (R�=0.8523, total chlorophyll (R�=0.90, and total nitrogen content (R�=0.76 in Asian pear leaves. Thus, it can be concluded that, CCM-200 can be used in order to predict both chlorophyll and nitrogen content in Asian pear leaves.

  1. Metabolic profiling variations within D’Anjou pear fruit from different canopy positions

    Science.gov (United States)

    The characteristics of fruit ripening can contribute to the overall quality of the final product. European pear (Pyrus communis L.) ripening is impacted by a combination of cultural practices and storage conditions. One of the main pre-harvest factors affecting fruit maturity and ripening is fruit...

  2. Evaluation of Dacryodes edulis (native pear) seed biomass for Pb (II ...

    African Journals Online (AJOL)

    Dacryodes edulis (Native pear) seed is herein evaluated as a promising biomass for Pb(II) removal from aqueous solution. The Pb(II) adsorption onto Dacryodes edulis seed biomass was influenced by the solution pH, time, biomass dose and initial adsorbate concentration. The Freundlich model fitted better than the ...

  3. ( pear cu (SSR) m ultivar marke rs and rs are select effect tions ive for r

    African Journals Online (AJOL)

    SAM

    Produção. Pelotas, Embrapa Clima Temperado; Brasília,. Embrapa Informação Tecnológica. Dequigiovanni G, Rech F, Gomes FGG, Cerotti IS, Faoro I, Oliveira. PRD, Quecini V, Ritschel P (2012). Identification of a Simple. Sequence Repeat molecular-marker set for large-scale analyses of pear germplasm. Crop Breed.

  4. Dynamics of fruit growth in 'Conference' pear as affected by root pruning, irrigation, and climatic conditions

    NARCIS (Netherlands)

    Maas, F.M.

    2007-01-01

    In 2002, daily fluctuations in trunk diameter and fruit diameter on ‘Conference’ pear trees were measured with linear voltage displacement transducers. On an average sunny day in July, trunk diameter started to decrease around 10 a.m. when air temperature increased. This continued until 8 p.m. when

  5. Thrips biocontrol: opportunities for use of natural enemies against the pear thrips

    Science.gov (United States)

    Nick J. Mills

    1991-01-01

    Thrips have been considered as both target pests and control agents in biological control. The main emphasis of this paper concerns the natural enemies of thrips and an appraisal of the potential for biological control of the pear thrips on sugar maple in the northeastern United States. Previous attempts at biological control of thrips pests have been confined to the...

  6. Monitoring codling moth (Lepidoptera: Tortricidae) in orchards treated with pear ester and sex pheromone combo dispensers

    Science.gov (United States)

    Lures for monitoring codling moth, Cydia pomonella (L.), were tested in apple and walnut blocks treated with Cidetrak CM-DA Combo dispensers loaded with pear ester, ethyl (E, Z)-2,4-decadienoate (PE), and sex pheromone (E,E)-8,10-dodecadien-1-ol (codlemone). Total and female moth catches with combin...

  7. Apple volatiles synergize the response of codling moth to pear ester

    Science.gov (United States)

    This work was undertaken to identify host volatiles from apples and investigate whether these can be used to enhance the efficacy of pear ester, ethyl (2E,4Z)-2,4-decadienoate, for monitoring female and male codling moth, Cydia pomonella L. Volatiles from immature apple trees were collected in the f...

  8. Evaluating dispensers loaded with codlemone and pear ester for disruption of codling moth (Lepidoptera: Tortricidae)

    Science.gov (United States)

    Polyvinyl chloride polymer (pvc) dispensers loaded with ethyl (E,Z)-2,4-decadienoate (pear ester) plus the sex pheromone, (E,E)-8,10-dodecadien-1-ol (codlemone) of codling moth, Cydia pomonella (L.), were compared with similar dispensers and a commercial dispenser (Isomate®-C Plus) loaded with codle...

  9. Attractants from Bartlett pear for codling moth, Cydia pomonella (L.), larvae

    Science.gov (United States)

    Knight, Alan L.; Light, Douglas M.

    2001-08-01

    The alkyl ethyl and methyl esters of (2 E,4 Z)-2,4-decadienoic acid found in head-space samples of ripe Bartlett pear ( Pyrus communis L.) stimulated a response from neonate larvae of the codling moth (CM), Cydia pomonella (L.), in both static-air Petri-plate and in upwind Y-tube and straight-tube olfactometer bioassays. In comparison with the known CM neonate attractant, ( E,E)-α-farnesene, ethyl (2 E,4 Z)-2,4-decadienoate was attractive at 10-fold and 1,000-fold lower threshold dosages in the Petri-plate and in the Y-tube bioassays, respectively. Methyl (2 E,4 Z)-2,4-decadienoate was attractive to CM neonates in these bioassays at much higher doses than ethyl (2 E,4 Z)-2,4-decadienoate. Other principal head-space volatiles from ripe pear fruit and pear leaves, including butyl acetate, hexyl acetate, ( Z)-3-hexenyl acetate, and ( E)-β-ocimene, were not attractive to CM neonates. The potential uses of these pear kairomones for monitoring and control of CM in walnuts and apple are discussed.

  10. Xylella taiwanensis sp. nov. cause of pear leaf scorch disease in Taiwan

    Science.gov (United States)

    Xylella fastidiosa is a group of xylem-limited and nutritionally fastidious plant pathogenic bacteria. While mostly found in the Americas, new X. fastidiosa strains have been reported from other continents such as Asia, including a pear leaf scorch (PLS) strain from Taiwan. Current taxonomy of X. fa...

  11. Plant growth responses of apple and pear trees to doses of glyphosate

    Science.gov (United States)

    Glyphosate is commonly used for intra-row weed management in perennial plantations, where unintended crop exposure to this herbicide can cause growth reduction. The objective of this research was to analyze the initial plant growth behavior of young apple and pear plants exposed to glyphosate. Glyph...

  12. The genome of the pear (Pyrus bretschneideri Rehd.)

    DEFF Research Database (Denmark)

    Wu, Jun; Wang, Zhiwen; Shi, Zebin

    2013-01-01

    to the ancestor of Rosaceae has reconstructed nine ancestral chromosomes. Pear and apple diverged from each other ~5.4-21.5 million years ago, and a recent whole-genome duplication (WGD) event must have occurred 30-45 MYA prior to their divergence, but following divergence from strawberry. When compared...

  13. Improved irrigation scheduling for pear-jujube trees based on trunk ...

    African Journals Online (AJOL)

    A suitable indicator for scheduling pear-jujube (Ziziphus jujuba Mill.) irrigation in China was developed based on trunk diameter fluctuations (TDF). Parameters derived from TDF responses to variations in soil matrix potential (Ψsoil) were compared under deficit and well irrigation. Maximum daily shrinkage (MDS) increased ...

  14. How to prevent ripening blockage in 1-MCP-treated 'Conference' pears.

    Science.gov (United States)

    Chiriboga, Maria-Angeles; Schotsmans, Wendy C; Larrigaudière, Christian; Dupille, Eve; Recasens, Inmaculada

    2011-08-15

    Some European pear varieties treated with 1-methylcyclopropene (1-MCP) often remain 'evergreen', meaning that their ripening process is blocked and does not resume after removal from cold storage. In this work this was confirmed also to be the case in 'Conference' pears. To reverse the blockage of ripening 1-MCP treatments combined with external exogenous ethylene were tested. 1-MCP treatment of 'Conference' pears is very effective in delaying ripening and, more specifically, softening. The same 1-MCP concentration in different experimental years caused a different response. The higher dose of 1-MCP (600 nL L⁻¹) always resulted in irreversible blockage of ripening, whereas the behaviour of fruit receiving a lower dose (300 nL L⁻¹) depended on the year, and this did not depend on maturity at harvest or on storage conditions. Simultaneous exposure to 1-MCP and exogenous ethylene significantly affected fruit ripening, allowing significant softening to occur but at a lower rate compared with control fruit. The application of exogenous ethylene and 1-MCP simultaneously after harvest permitted restoration of the ripening process after storage in 'Conference' pears, extending the possibility of marketing and consumption. Copyright © 2011 Society of Chemical Industry.

  15. Hourly laying patterns of the Pearly-eyed Thrasher (Margarops fuscatus) in Puerto Rico

    Science.gov (United States)

    Wayne Arendt

    2011-01-01

    Temporal aspects of egg deposition are important factors governing avian reproductive success. I report hourly egg-laying patterns of the Pearly-eyed Thrasher (Margarops fuscatus) in the Luquillo Experimental Forest in northeastern Puerto Rico during 1979–2000. Initiatory eggs were laid by early morning (median 5 0642 hrs, AST) and almost half of the eggs were laid by...

  16. Effect of pretreatment methods of dormant pear buds on viability after cryopreservation

    Science.gov (United States)

    This study aimed to develop alternatives for dormant bud cryopreservation by using several cryoprotectants on four pear cultivars with a view to improve the viability of the dormant buds. We used different cryoprotectants such as Honey, PVS2, PVS3, PVS4, Towill, IPBB-1 for cultivars: Talgarskaya Kra...

  17. Development of an energy-protein for animal food based crop residues pear (Pyrus communis

    Directory of Open Access Journals (Sweden)

    Néstor Julián Pulido-Suárez,

    2016-01-01

    Full Text Available Pear (Pyrus communis is a fruit from the species of deciduous, widely consumed worldwide for its high quality energ y. However, pear itself does not provide the amount of protein required for cattle feeding, so alternatives to improve its nutritional quality have been studied. On these grounds, the objective of this study was to evaluate the parameters of solid state fermentation, and compositional energ y value of a protein food based on pears (Pyrus communis with apparent physical damage. A completely random design was used to evaluate three treatments; these correspond to percentages of inclusion of calcium carbonate (0.25, 0.50, 0.75 formulation based on already established (40 % pear, 25 % rice flour, 25 % wheat bran and 10 % urea, the parameters evaluated were: pH, ashes (CZ, crude protein (CP and crude fiber (CF, and they were recorded at 0, 24, 48 and 72 hours. As a result, it was found that the pH dropped gradually for each treatment and at each sampling period; however, there were no significant differences. The lower value at the end of the process is recorded T2 (0.25 with 4.66, followed by T3 (0.50 with 4.50, the ash reached values of up to 6 % with T3, and T2 (0.50 reached the highest percentages in fiber and crude protein. Finally, decreasing the fermentation variables ensures a food with no presence of undesirable microorganisms and stable over time.

  18. Test of fungicides against Stemphylium vesicarium on pear with or without a warning system

    NARCIS (Netherlands)

    Wenneker, M.; Heijne, B.

    2004-01-01

    Stemphylium vesicarium causes brown spot of pear. The fungus especially causes severe damage in southern Europe. In recent years the disease is also found in the Netherlands and to a lesser extent in Belgium. Conference is the cultivar most commonly grown in the Netherlands. This cultivar is one of

  19. Complete Genome Sequence of Bacillus velezensis L-1, Which Has Antagonistic Activity against Pear Diseases

    OpenAIRE

    Sun, Pingping; Cui, Jianchao; Jia, Xiaohui; Wang, Wenhui

    2017-01-01

    ABSTRACT Bacillus velezensis L-1 is an effective biocontrol agent against pear diseases. Here, we report the complete genome sequence of B. velezensis L-1 in which clusters related to the biosynthesis of secondary metabolites were predicted. This genome provides insights into the possible biocontrol mechanisms and furthers application of this specific bacterium.

  20. Complete Genome Sequence of Bacillus velezensis L-1, Which Has Antagonistic Activity against Pear Diseases.

    Science.gov (United States)

    Sun, Pingping; Cui, Jianchao; Jia, Xiaohui; Wang, Wenhui

    2017-11-30

    Bacillus velezensis L-1 is an effective biocontrol agent against pear diseases. Here, we report the complete genome sequence of B. velezensis L-1 in which clusters related to the biosynthesis of secondary metabolites were predicted. This genome provides insights into the possible biocontrol mechanisms and furthers application of this specific bacterium. Copyright © 2017 Sun et al.

  1. Volatiles from Psylla-infested pear trees and their possible involvement in attraction of anthocorid predators

    NARCIS (Netherlands)

    Scutareanu, P.; Drukker, B.; Bruin, J.; Posthumus, M.A.; Sabelis, M.W.

    1997-01-01

    Previous work showed that anthocorid predators aggregate around gauze cages containing Psylla-infested trees in a pear orchard. Because anthocorids responded to odor from Psylla-infested leaves in a laboratory test, it was hypothesized that these aggregative responses in the field were triggered by

  2. Hyperspectral near-infrared imaging for the detection of physical damages of pear

    Science.gov (United States)

    Bruise damage on pears is one of the most crucial internal quality factors, which needs to be detected in postharvest quality sorting processes. Thus, a reliable non-destructive detection method for the fruit defects including bruises is necessary to ensure accurate quality assessment. Infra-red ima...

  3. Evolution of the Aroma Volatiles of Pear Fruits Supplemented with Fatty Acid Metabolic Precursors

    Directory of Open Access Journals (Sweden)

    Gaihua Qin

    2014-12-01

    Full Text Available To examine the biochemical metabolism of aroma volatiles derived from fatty acids, pear fruits were incubated in vitro with metabolic precursors of these compounds. Aroma volatiles, especially esters, were significantly increased, both qualitatively and quantitatively, in pear fruits fed on fatty acid metabolic precursors. Cultivars having different flavor characteristics had distinctly different aroma volatile metabolisms. More esters were formed in fruity-flavored “Nanguoli” fruits than in green-flavored “Dangshansuli” fruits fed on the same quantities of linoleic acid and linolenic acid. Hexanal and hexanol were more efficient metabolic intermediates for volatile synthesis than linoleic acid and linolenic acid. Hexyl esters were the predominant esters produced by pear fruits fed on hexanol, and their contents in “Dangshansuli” fruits were higher than in “Nanguoli” fruits. Hexyl esters and hexanoate esters were the primary esters produced in pear fruits fed on hexanal, however the content of hexyl ester in “Dangshansuli” was approximately three times that in “Nanguoli”. The higher contents of hexyl esters in “Dangshansuli” may have resulted from a higher level of hexanol derived from hexanal. In conclusion, the synthesis of aroma volatiles was largely dependent on the metabolic precursors presented.

  4. Biological control of postharvest pear diseases using a bacterium, Pantoea agglomerans CPA-2.

    Science.gov (United States)

    Nunes, C; Usall, J; Teixidó, N; Viñas, I

    2001-10-22

    Epiphytic microorganisms isolated from the fruits and leaf surfaces of apples and pears were screened for antagonistic activity against Penicillium expansum on pears. From 247 microorganisms tested for antagonistic properties against P. expansum, a bacterium strain identified as Pantoea agglomerans (CPA-2) was selected. This bacterium was very effective against Botrytis cinerea, P. expansum and Rhizopus stolonifer. Complete control at the three tested concentrations (2 x 10(7), 8 x 10(7) and 1 x 10(8) CFU ml(-1)) was obtained on wounded pears inoculated with 10(3), 10(4) and 10(5) conidia ml(-1) of P. expansum and R. stolonifer. At 8 x 10(7) CFU ml(-1), Pan. agglomerans reduced B. cinerea decay by more than 80% at the three concentrations of the pathogen. In over 3 years of experiments in semicommercial trials, Pan. agglomerans provided excellent control against B. cinerea and P. expansum under cold storage, either in air or in low oxygen atmospheres. Equal control was obtained with Pan. agglomerans at 8 x 10(7) CFU ml(-1), as with the fungicide imazalil at commercial doses, against both pathogens. Pan. agglomerans grew well inside wounds on pears at both room and cold temperatures and under modified atmospheres. In contrast, it grew poorly on the surface of intact fruit.

  5. Effects of major geometric variations between intracavitary applications on pear-shaped isodose dimension in cancer of the cervix

    International Nuclear Information System (INIS)

    Kim, R. Y.

    1996-01-01

    PURPOSE: The basic principal of intracavitary brachytherapy for cancer of the cervix is based on specific loading rules to achieve a pear-shaped isodose distribution centered around the cervix. Recently, ICRU Report 38 recommends a dose reference volume for reporting. Our previous studies have confirmed that there is considerable variations of geometry between applications. This study is to evaluate the effect of major geometric variations on pear-shaped isodose dimension in manual afterloading low-dose-rate system. MATERIAL AND METHODS: One hundred orthogonal films of 50 patients with cancer of the cervix (2 applications/patient) were reviewed for comparative measurements of geometric variations between applications. Major geometric variations were found for 13 patients in lengths of tandem, 7 patients in colpostats separation and 16 patients in vaginal packing. The direct measurement of these geometric variations were compared with the three-dimensional measurement of the pear-shaped isodose enclosed by the point A between the two applications. RESULTS: The geometric variations in the width of colpostats separation and length of tandem were directly related to the width and height of the pear-shaped isodose dimension. The geometric relationship between the colpostats and distal tandem had an important effect on the thickness of the pear-shape. In optimization of poor geometry for rectum or bladder wall, high dose volume centered around the cervix is reduced without changing the overall pear-shaped volume due to changing configuration of the pear-shaped isodose. In our selected patients with two applications, variations in vaginal packing had no direct effect on the width and thickness of the pear-shape due to other variables. CONCLUSION: Major geometric variations between applications greatly affect the dimension of the pear-shaped isodose distribution. Optimization of poor geometry is quite limited without compromising the high-dose volume centered around the

  6. Investigation of Pear Drying Performance by Different Methods and Regression of Convective Heat Transfer Coefficient with Support Vector Machine

    Directory of Open Access Journals (Sweden)

    Mehmet Das

    2018-01-01

    Full Text Available In this study, an air heated solar collector (AHSC dryer was designed to determine the drying characteristics of the pear. Flat pear slices of 10 mm thickness were used in the experiments. The pears were dried both in the AHSC dryer and under the sun. Panel glass temperature, panel floor temperature, panel inlet temperature, panel outlet temperature, drying cabinet inlet temperature, drying cabinet outlet temperature, drying cabinet temperature, drying cabinet moisture, solar radiation, pear internal temperature, air velocity and mass loss of pear were measured at 30 min intervals. Experiments were carried out during the periods of June 2017 in Elazig, Turkey. The experiments started at 8:00 a.m. and continued till 18:00. The experiments were continued until the weight changes in the pear slices stopped. Wet basis moisture content (MCw, dry basis moisture content (MCd, adjustable moisture ratio (MR, drying rate (DR, and convective heat transfer coefficient (hc were calculated with both in the AHSC dryer and the open sun drying experiment data. It was found that the values of hc in both drying systems with a range 12.4 and 20.8 W/m2 °C. Three different kernel models were used in the support vector machine (SVM regression to construct the predictive model of the calculated hc values for both systems. The mean absolute error (MAE, root mean squared error (RMSE, relative absolute error (RAE and root relative absolute error (RRAE analysis were performed to indicate the predictive model’s accuracy. As a result, the rate of drying of the pear was examined for both systems and it was observed that the pear had dried earlier in the AHSC drying system. A predictive model was obtained using the SVM regression for the calculated hc values for the pear in the AHSC drying system. The normalized polynomial kernel was determined as the best kernel model in SVM for estimating the hc values.

  7. PEAR SHOOT SAWFLY (JANUS COMPRESSUS FABRICIUS – LIFE CYCLE AND BIOLOGICAL AND MORPHOLOGICAL CHARACTERISTIC

    Directory of Open Access Journals (Sweden)

    Tihomir Validžić

    2014-06-01

    Full Text Available The aim of the thesis was to investigate life cycle, biological and morphological characteristics of pear shoot sawfly (Janus compressus Fabricius, Hymenoptera Cephidae, furthermore to identify natural enemies in order to protect pear from this pest. The trial was conducted in the period of three years: 2010, 2011 and 2012 in pear orchards at five localities. Monitoring of adult sawfly was done by yellow sticky traps. Laboratory research was done at the Faculty of Agriculture, Department of Plant Protection, Section of Entomology and Nematology. In this study, pear shoot sawfly in Eastern Slavonia occurred in the period of four weeks, starting from the third decade of April with the peak population at the beginning of the May. Adults flight is the most intensive during warm and sunny days, when temperatures are above 14°C. Adult sawflies are characterized by elongated body and antennae, usually 7-12 mm long and sexual dimorphism is present. Pest is univoltine. Basic colour of adult sawfly is black. Antennae are moniliform and consist of 20 (male - 22 (female segments. Females have red or dark red colored abdomen, while males have yellow or orange one. Eggs are cylindrically shaped, 0.8-1.0 mm long. Female lays approximately 30 eggs. Embryonic development of pear shoot sawfly eggs lasts from 11 to 14 days. Larvae are 8-10 mm long, white or pale yellow. Larvae molt three times. Pear shoot sawfly larvae were parasitized by insects from Hymenoptera order, from five identified and one unidentified genera. Level of parasitism by genera is as follows: Eurytoma sp. (Hymenoptera: Eurytomidae – 9.83%, Tetrastichus sp. (Hymenoptera: Eulophidae – 2.01%, Eupelmus sp. (Hymenoptera: Eupelmidae – 1.66%, Pteromalus sp. (Hymenoptera: Pteromalidae – 0.55%, Ichneumonida sp. (Hymenoptera: Pimplinae – 0.35% and unidentified genera – 0.62%. Plant parasitic species Metopoplax origani (Hemiptera: Lygaeidae was found in 1.80% of analyzed shoots. Larvae were

  8. CDK4 amplification predicts recurrence of well-differentiated liposarcoma of the abdomen.

    Directory of Open Access Journals (Sweden)

    Sanghoon Lee

    Full Text Available The absence of CDK4 amplification in liposarcomas is associated with favorable prognosis. We aimed to identify the factors associated with tumor recurrence in patients with well-differentiated (WD and dedifferentiated (DD liposarcomas.From 2000 to 2010, surgical resections for 101 WD and DD liposarcomas were performed. Cases in which complete surgical resections with curative intent were carried out were selected. MDM2 and CDK4 gene amplification were analyzed by quantitative real-time polymerase chain reaction (Q-PCR.There were 31 WD and 17 DD liposarcomas. Locoregional recurrence was observed in 11 WD and 3 DD liposarcomas. WD liposarcomas showed better patient survival compared to DD liposarcomas (P<0.05. Q-PCR analysis of the liposarcomas revealed the presence of CDK4 amplification in 44 cases (91.7% and MDM2 amplification in 46 cases (95.8%. WD liposarcomas with recurrence after surgical resection had significantly higher levels of CDK4 amplification compared to those without recurrence (P = 0.041. High level of CDK4 amplification (cases with CDK4 amplification higher than the median 7.54 was associated with poor recurrence-free survival compared to low CDK4 amplification in both univariate (P = 0.012 and multivariate analyses (P = 0.020.Level of CDK4 amplification determined by Q-PCR was associated with the recurrence of WD liposarcomas after surgical resection.

  9. Extraction and determination of polyphenols and betalain pigments in the Moroccan Prickly pear fruits (Opuntia ficus indica

    Directory of Open Access Journals (Sweden)

    Omar Khatabi

    2016-09-01

    This study has permitted us equally to value betalain pigments extracted from fruity juice. These are the betalains present in the epidermis and the pulp of the prickly pear confers on it its color varying from yellow to purple. Results show that yellow and red prickly pears contain imported strengths in betalains. Our work shows that the red prickly pear contains betaxanthin pigments in excess of the indicaxanthin that permits to valorize human’s potential spring of genuine colorings. Betalains and polyphenols are antioxidants that contribute to nutritional prickly pears’ quality and to their products of transformation.

  10. Improvement of post-harvest quality of pear fruit with optimized composite edible coating formulations.

    Science.gov (United States)

    Dave, Rudri K; Ramana Rao, T V; Nandane, A S

    2017-11-01

    Application of edible coatings is a suitable method to maintain the quality and reduce post-harvest losses in fresh vegetables and fruits. Pear fruits being climacteric have a short shelf life, and coating is considered as one of the most popular techniques to prolong its shelf life.The present study evaluates the effect of optimized edible coatings containing soy protein isolate (SPI) in combination with additives like hydroxypropyl methylcellulose (HPMC) and olive oil on 'Babughosha' Pears ( Pyrus communis L.) stored at ambient temperature (28 ± 5 °C and 60 ± 10% RH). Four different coatings optimized by response surface methodology study were used in the present experiment. The results of the present study shows that the optimized edible coatings help retain the firmness of fruits and lowered the moisture loss. The tested combination of coating could also withhold the levels of ascorbic acid, chlorophyll and sugar contents in the treated fruits. Activities of enzymes associated with fruit softening (β-galactosidase, polygalacturonase, pectin methyl esterase) showed delayed peaks. Amongst all treatments, T1 (SPI 5.0%, HPMC 0.40%, Olive oil 1%, Potassium sorbate 0.22%) and T2 (SPI 5.0%, HPMC 0.40%, Olive oil 0.98% Potassium sorbate 0.20%) were found to have pronounced effect on retention of nutritional quality in pears. Observations of shelf-life extension established that T2 (SPI 5.0%, HPMC 0.40%, Olive oil 0.98% Potassium sorbate 0.20%) was successful in extending shelf-life of pear fruits up to 15 days, as compared to 8 days for untreated pear fruits.

  11. An evaluation of multiple annealing and looping based genome amplification using a synthetic bacterial community

    KAUST Repository

    Wang, Yong

    2016-02-23

    The low biomass in environmental samples is a major challenge for microbial metagenomic studies. The amplification of a genomic DNA was frequently applied to meeting the minimum requirement of the DNA for a high-throughput next-generation-sequencing technology. Using a synthetic bacterial community, the amplification efficiency of the Multiple Annealing and Looping Based Amplification Cycles (MALBAC) kit that is originally developed to amplify the single-cell genomic DNA of mammalian organisms is examined. The DNA template of 10 pg in each reaction of the MALBAC amplification may generate enough DNA for Illumina sequencing. Using 10 pg and 100 pg templates for each reaction set, the MALBAC kit shows a stable and homogeneous amplification as indicated by the highly consistent coverage of the reads from the two amplified samples on the contigs assembled by the original unamplified sample. Although GenomePlex whole genome amplification kit allows one to generate enough DNA using 100 pg of template in each reaction, the minority of the mixed bacterial species is not linearly amplified. For both of the kits, the GC-rich regions of the genomic DNA are not efficiently amplified as suggested by the low coverage of the contigs with the high GC content. The high efficiency of the MALBAC kit is supported for the amplification of environmental microbial DNA samples, and the concerns on its application are also raised to bacterial species with the high GC content.

  12. Genome position and gene amplification

    Czech Academy of Sciences Publication Activity Database

    Jirsová, Pavla; Snijders, A.M.; Kwek, S.; Roydasgupta, R.; Fridlyand, J.; Tokuyasu, T.; Pinkel, D.; Albertson, D. G.

    2007-01-01

    Roč. 8, č. 6 (2007), r120 ISSN 1474-760X Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : gene amplification * array comparative genomic hybridization * oncogene Subject RIV: BO - Biophysics Impact factor: 6.589, year: 2007

  13. Polymerase chain reaction system

    Science.gov (United States)

    Benett, William J.; Richards, James B.; Stratton, Paul L.; Hadley, Dean R.; Milanovich, Fred P.; Belgrader, Phil; Meyer, Peter L.

    2004-03-02

    A portable polymerase chain reaction DNA amplification and detection system includes one or more chamber modules. Each module supports a duplex assay of a biological sample. Each module has two parallel interrogation ports with a linear optical system. The system is capable of being handheld.

  14. Dual phase multiplex polymerase chain reaction

    Science.gov (United States)

    Pemov, Alexander [Charlottesville, VA; Bavykin, Sergei [Darien, IL

    2008-10-07

    Highly specific and sensitive methods were developed for multiplex amplification of nucleic acids on supports such as microarrays. Based on a specific primer design, methods include five types of amplification that proceed in a reaction chamber simultaneously. These relate to four types of multiplex amplification of a target DNA on a solid support, directed by forward and reverse complex primers immobilized to the support and a fifth type--pseudo-monoplex polymerase chain reaction (PCR) of multiple targets in solution, directed by a single pair of unbound universal primers. The addition of the universal primers in the reaction mixture increases the yield over the traditional "bridge" amplification on a solid support by approximately ten times. Methods that provide multitarget amplification and detection of as little as 0.45-4.5.times.10.sup.-12 g (equivalent to 10.sup.2-10.sup.3 genomes) of a bacterial genomic DNA are disclosed.

  15. Clustered Regularly Interspaced Short Palindromic Repeats/Cas9 Triggered Isothermal Amplification for Site-Specific Nucleic Acid Detection.

    Science.gov (United States)

    Huang, Mengqi; Zhou, Xiaoming; Wang, Huiying; Xing, Da

    2018-02-06

    A novel CRISPR/Cas9 triggered isothermal exponential amplification reaction (CAS-EXPAR) strategy based on CRISPR/Cas9 cleavage and nicking endonuclease (NEase) mediated nucleic acids amplification was developed for rapid and site-specific nucleic acid detection. CAS-EXPAR was primed by the target DNA fragment produced by cleavage of CRISPR/Cas9, and the amplification reaction performed cyclically to generate a large number of DNA replicates which were detected using a real-time fluorescence monitoring method. This strategy that combines the advantages of CRISPR/Cas9 and exponential amplification showed high specificity as well as rapid amplification kinetics. Unlike conventional nucleic acids amplification reactions, CAS-EXPAR does not require exogenous primers, which often cause target-independent amplification. Instead, primers are first generated by Cas9/sgRNA directed site-specific cleavage of target and accumulated during the reaction. It was demonstrated this strategy gave a detection limit of 0.82 amol and showed excellent specificity in discriminating single-base mismatch. Moreover, the applicability of this method to detect DNA methylation and L. monocytogenes total RNA was also verified. Therefore, CAS-EXPAR may provide a new paradigm for efficient nucleic acid amplification and hold the potential for molecular diagnostic applications.

  16. Control of postharvest pear diseases using Rhodotorula glutinis and its effects on postharvest quality parameters.

    Science.gov (United States)

    Zhang, Hongyin; Wang, Lei; Dong, Ying; Jiang, Song; Zhang, Haihui; Zheng, Xiaodong

    2008-08-15

    Rhodotorula glutinis was evaluated for its activity in reducing postharvest gray mold decay and blue mold decay of pear caused by Botrytis cinerea and Penicillium expansum respectively, and in reducing natural decay development of pear fruits, as well as its effects on postharvest quality of fruits. There was a significant negative correlation between concentrations of the yeast cells and infectivity of the pathogens. At concentrations of R. glutinis at 5x108 CFU/ml, the gray mold decay was completely inhibited after 7 days incubation at 20 degrees C, while the control fruit had 100% disease incidence and 2.15 cm lesion diameter respectively, at challenged with B. cinerea spores suspension of 1x105 spores/ml; No completely control was got to blue mold, when pear fruits stored at 20 degrees C for 7 d (challenged with P. expansum spores suspension of 5x104 spores/ml), but the decay was distinctly prevented with 20% and 0.60 cm of disease incidence and lesion diameter respectively, while the control fruits were 100% and 2.74 cm, respectively. Rapid colonization of the yeast in wounds was observed during the first 1 d at 20 degrees C, and then the populations stabilized for the remaining storage period. On pear wounds kept at 4 degrees C, rapid colonization of the yeast in wounds was observed during the first 3 d, and then the increase in population density of R. glutinis turned slow, which continued over 6 d after application of the antagonist until it reached a high level. Then, the populations stabilized for the remaining storage period. In the test on PDA plates, R. glutinis significantly inhibit the growth of B. cinerea and P. expansum. Spore germination of pathogens in PDB was greatly controlled in the present of living yeast cell suspensions. R. glutinis significantly reduced the natural development of decay of pear following storage at 20 degrees C for 7 days or at 4 degrees C for 30 days followed by 20 degrees C for 5 days, and did not impair quality

  17. Antimicrobial Activity of Xoconostle Pears (Opuntia matudae against Escherichia coli O157:H7 in Laboratory Medium

    Directory of Open Access Journals (Sweden)

    Saeed A. Hayek

    2012-01-01

    Full Text Available The objective of this study was to investigate the antimicrobial activity of xoconostle pears (Opuntia matudae against Escherichia coli O157:H7. Xoconostle pears were sliced, blended, and centrifuged. The supernatant was then filtered using a 0.45 μm filter to obtain direct extract. Direct extract of xoconostle pears was tested against four strains of E. coli O157:H7 in brain heart infusion (BHI laboratory medium using growth over time and agar well diffusion assays. Our results showed that direct extract of xoconostle pears had a significant (P<0.05 inhibitory effect at 4, 6, and 8% (v/v concentrations and complete inhibitory effect at 10% (v/v during 8 h of incubation at 37°C. Minimum inhibitory volume (MIV was 400 μL mL−1 (v/v and minimum lethal volume (MLV was 650 μL mL−1 (v/v. The inhibitory effect of xoconostle pears found to be concentration dependent and not strain dependent. Thus, xoconostle pears extract has the potential to inhibit the growth of E. coli O157:H7 and could provide a natural means of controlling pathogenic contamination, thereby mitigating food safety risks.

  18. Polymer-based microfluidic chips for isothermal amplification of nucleic acids

    Science.gov (United States)

    Posmitnaya, Y. S.; Rudnitskaya, G. E.; Tupik, A. N.; Lukashenko, T. A.; Bukatin, A. C.; Evstrapov, A. A.

    2017-11-01

    Creation of low-cost compact devices based on microfluidic platforms for biological and medical research depends on the degree of development and enhancement of prototyping technologies. Two designs of polymer and hybrid microfluidic devices fabricated by soft lithography and intended for isothermal amplification and polymerase chain reaction are presented in this paper. The digital helicase-dependent isothermal amplification was tested in the device containing a droplet generator. Polymerase chain reaction was carried out in the hybrid microfluidic device having ten reaction chambers. A synthesized cDNA fragment of GAPDH housekeeping gene was used as a target.

  19. Identification of S alleles of different pear cultivars of the "Oeste" region and evaluation of their gametophytic compatibility with 'Rocha' pear

    OpenAIRE

    Oliveira, Cristina Moniz; Mota, Mariana; Tavares, Lucélia R.

    2009-01-01

    In order to select pear cultivar which are genetically compatible with ‘Rocha’ (Sa, Sj), the identification of S alleles sequences of commercial cultivars with bloom periods overlapping (partially or totally) the bloom period of ‘Rocha’ was performed. Partial sequences of the S alleles from the different cultivars were amplified with specific primers, cloned and sequenced. ‘Pêra De Água’ (S22, Sb) ‘Général Leclerc’ (Sl, Sq) and ‘Alexandrine Douillard’ (Sb, Sk) should be totally...

  20. Accelerator for amplification of energy

    International Nuclear Information System (INIS)

    Mori, Yoshiharu

    1998-01-01

    As a forming method of new nuclear energy, an energy amplification system using accelerator driven subcritical reactor is focussed. In order to realize amplification of energy driven by accelerator, development of an accelerator with excellent electric power efficiency is one of the most important problems. The necessary beam power of accelerator is 10 MW, and when reducing used electric power of the accelerator to under 25% of total power generation, more than 30% of electric power efficiency is required for the accelerator. Therefore, an accelerator with excellent electric power efficiency without experiencing before now is required to realize such an aim. A prominent candidate of the accelerator is FFAG (Fixed Field Alternating Gradient) synchrotron (may be called ring synchrotron). In this paper, some simple considerations of electric power efficiency of accelerators and basic parameter of FFAG synchrotron were described. (G.K.)

  1. Laser amplification in excited dielectrics

    Science.gov (United States)

    Winkler, Thomas; Haahr-Lillevang, Lasse; Sarpe, Cristian; Zielinski, Bastian; Götte, Nadine; Senftleben, Arne; Balling, Peter; Baumert, Thomas

    2018-01-01

    Wide-bandgap dielectrics such as glasses or water are transparent at visible and infrared wavelengths. This changes when they are exposed to ultrashort and highly intense laser pulses. Different interaction mechanisms lead to the appearance of various transient nonlinear optical phenomena. Using these, the optical properties of dielectrics can be controlled from the transparent to the metal-like state. Here we expand this range by a yet unexplored mechanism in excited dielectrics: amplification. In a two-colour pump-probe experiment, we show that a 400 nm femtosecond laser pulse is coherently amplified inside an excited sapphire sample on a scale of a few micrometres. Simulations strongly support the proposed two-photon stimulated emission process, which is temporally and spatially controllable. Consequently, we expect applications in all fields that demand strongly localized amplification.

  2. Frequency domain optical parametric amplification.

    Science.gov (United States)

    Schmidt, Bruno E; Thiré, Nicolas; Boivin, Maxime; Laramée, Antoine; Poitras, François; Lebrun, Guy; Ozaki, Tsuneyuki; Ibrahim, Heide; Légaré, François

    2014-05-07

    Today's ultrafast lasers operate at the physical limits of optical materials to reach extreme performances. Amplification of single-cycle laser pulses with their corresponding octave-spanning spectra still remains a formidable challenge since the universal dilemma of gain narrowing sets limits for both real level pumped amplifiers as well as parametric amplifiers. We demonstrate that employing parametric amplification in the frequency domain rather than in time domain opens up new design opportunities for ultrafast laser science, with the potential to generate single-cycle multi-terawatt pulses. Fundamental restrictions arising from phase mismatch and damage threshold of nonlinear laser crystals are not only circumvented but also exploited to produce a synergy between increased seed spectrum and increased pump energy. This concept was successfully demonstrated by generating carrier envelope phase stable, 1.43 mJ two-cycle pulses at 1.8 μm wavelength.

  3. Laser amplification in excited dielectrics

    DEFF Research Database (Denmark)

    Winkler, Thomas; Haahr-Lillevang, Lasse; Sarpe, Cristian

    2018-01-01

    Wide-bandgap dielectrics such as glasses or water are transparent at visible and infrared wavelengths. This changes when they are exposed to ultrashort and highly intense laser pulses. Different interaction mechanisms lead to the appearance of various transient nonlinear optical phenomena. Using...... these, the optical properties of dielectrics can be controlled from the transparent to the metal-like state. Here we expand this range by a yet unexplored mechanism in excited dielectrics: amplification. In a two-colour pump-probe experiment, we show that a 400nm femtosecond laser pulse is coherently...... amplified inside an excited sapphire sample on a scale of a few micrometres. Simulations strongly support the proposed two-photon stimulated emission process, which is temporally and spatially controllable. Consequently, we expect applications in all fields that demand strongly localized amplification....

  4. Differential voltage amplification from ferroelectric negative capacitance

    Science.gov (United States)

    Khan, Asif I.; Hoffmann, Michael; Chatterjee, Korok; Lu, Zhongyuan; Xu, Ruijuan; Serrao, Claudy; Smith, Samuel; Martin, Lane W.; Hu, Chenming; Ramesh, Ramamoorthy; Salahuddin, Sayeef

    2017-12-01

    We demonstrate that a ferroelectric can cause a differential voltage amplification without needing an external energy source. As the ferroelectric switches from one polarization state to the other, a transfer of energy takes place from the ferroelectric to the dielectric, determined by the ratio of their capacitances, which, in turn, leads to the differential amplification. This amplification is very different in nature from conventional inductor-capacitor based circuits where an oscillatory amplification can be observed. The demonstration of differential voltage amplification from completely passive capacitor elements only has fundamental ramifications for next generation electronics.

  5. Spheromak Impedance and Current Amplification

    International Nuclear Information System (INIS)

    Fowler, T K; Hua, D D; Stallard, B W

    2002-01-01

    It is shown that high current amplification can be achieved only by injecting helicity on the timescale for reconnection, τ REC , which determines the effective impedance of the spheromak. An approximate equation for current amplification is: dI TOR 2 /dt ∼ I 2 /τ REC - I TOR 2 /τ closed where I is the gun current, I TOR is the spheromak toroidal current and τ CLOSED is the ohmic decay time of the spheromak. Achieving high current amplification, I TOR >> I, requires τ REC CLOSED . For resistive reconnection, this requires reconnection in a cold zone feeding helicity into a hot zone. Here we propose an impedance model based on these ideas in a form that can be implemented in the Corsica-based helicity transport code. The most important feature of the model is the possibility that τ REC actually increases as the spheromak temperature increases, perhaps accounting for the ''voltage sag'' observed in some experiments, and a tendency toward a constant ratio of field to current, B ∝ I, or I TOR ∼ I. Program implications are discussed

  6. PCR amplification of microsatellites from single cells of Karenia brevis preserved in Lugol's iodine solution.

    Science.gov (United States)

    Henrichs, D W; Renshaw, M A; Santamaria, C A; Richardson, B; Gold, J R; Campbell, L

    2008-01-01

    A simple and effective protocol is described for multiplex polymerase chain reaction (PCR) amplification of single cells of Karenia brevis. The protocol requires minimum processing, avoids additions that might dilute target DNA template, and can be used on cells preserved in Lugol's iodine preservative. Destaining of Lugol's-preserved cells with sodium thiosulfate allowed successful amplification of single-copy, nuclear-encoded microsatellites in single cells of K. brevis that have been preserved for up to 6 years.

  7. Performance of 'Rocha' and 'Santa Maria' pears as affected by planting density

    Directory of Open Access Journals (Sweden)

    Mateus da Silveira Pasa

    2015-02-01

    Full Text Available The objective of this work was to evaluate the performance of 'Rocha' and 'Santa Maria' pears at two planting densities. The experiment was carried out during the 2011/2012, 2012/2013, and 2013/2014 growing seasons, in one-year-old orchards (2011/2012 of 'Rocha' and 'Santa Maria' pears, trained in a central-leader system and planted in two densities (2,000 and 4,000 trees per hectare. The assessed parameters were: production per hectare, production per tree, yield efficiency, number of fruit per tree, average fruit weight, trunk diameter increment, fruit firmness, and soluble solid contents. The cumulative yield of 'Rocha' is greater at the higher planting density, whereas the yield efficiency of 'Santa Maria' increases at the lower planting density, as the trees get more mature. Trunk diameter of 'Rocha' also increases at the lower planting density. However, fruit quality parameters in both cultivars are little affected by planting density.

  8. Adsorption-desorption isotherms and heat of sorption of prickly pear fruit (Opuntia ficus indica)

    Energy Technology Data Exchange (ETDEWEB)

    Lahsasni, S.; Kouhila, M. E-mail: kouhila@hotmail.com; Mahrouz, M

    2004-01-01

    The equilibrium moisture contents were determined for prickly pear fruit using the gravimetric static method at t=30, 40 and 50 deg. C over a range of relative humidities from 0.05 to 0.9. The sorption curves of prickly pear fruit decreased with increase in temperature at constant relative humidity. The hysteresis effect was observed. The GAB, modified Halsey, modified Chung-Pfost, modified Oswin and modified Henderson models were tested to fit the experimental data. The GAB model was found to be the most suitable for describing the sorption curves. The monolayer moisture content values for the sorption at different temperatures are calculated using a modified BET equation. The isosteric heats of desorption and adsorption of water were determined from the equilibrium data at different temperatures.

  9. Amplification-refractory mutation system (ARMS) analysis of point mutations.

    Science.gov (United States)

    Little, S

    2001-05-01

    The amplification-refractory mutation system (ARMS) is a simple method for detecting any mutation involving single base changes or small deletions. ARMS is based on the use of sequence-specific PCR primers that allow amplification of test DNA only when the target allele is contained within the sample. Following an ARMS reaction the presence or absence of a PCR product is diagnostic for the presence or absence of the target allele. The protocols detailed here outline methods that can be used to analyze human genomic DNA for one or more mutations. The Basic Protocol describes the development and application of an ARMS test for a single mutation; the Alternate Protocol extends this to multiplex ARMS for the analysis of two or more mutations. The Support Protocol describes a rapid DNA extraction method from blood or mouthwash samples that yields DNA compatible with the type of tests described. The amplification-refractory mutation system (ARMS) is a simple method for detecting any mutation involving single base change The amplification-refractory mutation system (ARMS) is a simple method for detecting any mutation involving single base change.

  10. Betalain, Acid Ascorbic, Phenolic Contents and Antioxidant Properties of Purple, Red, Yellow and White Cactus Pears

    OpenAIRE

    Sumaya-Mart?nez, Mar?a Teresa; Cruz-Jaime, Sandra; Madrigal-Santill?n, Eduardo; Garc?a-Paredes, Juan Diego; Cari?o-Cort?s, Raquel; Cruz-Cansino, Nelly; Valadez-Vega, Carmen; Martinez-Cardenas, Leonardo; Alan?s-Garc?a, Ernesto

    2011-01-01

    Commercialization of cactus pears based on their antioxidant properties can generate competitive advantages, and these can turn into business opportunities and the development of new products and a high-value ingredient for the food industry. This work evaluated the antioxidant activities (1,1-diphenyl-2-picrylhydrazyl radical-scavenging, protection against oxidation of a β-carotene-linoleic acid emulsion, and iron (II) chelation), the content of total phenolic compounds, ascorbic acid, betac...

  11. Detection and identification of phytoplasmas in pears trees in the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Fránová, Jana; Přibylová, Jaroslava; Čermáková, Helena; Suchá, J.; Paprštein, F.

    2009-01-01

    Roč. 148, July (2009), s. 82-83 ISSN 1866-590X. [International Conference on Virus and other Graft Transmissible Diseases of Fruit Crops /21./. 05.07.2009-10.07.2009, Neustadt] R&D Projects: GA MŠk OC09021; GA AV ČR(CZ) 1QS500510558 Institutional research plan: CEZ:AV0Z50510513 Keywords : phytoplasmas * pear trees * PCR * RFLP Subject RIV: EE - Microbiology, Virology

  12. Fungicide residues in pears, apples and grapes after post harvest treatments by thermonebulization.

    Science.gov (United States)

    Pompi, V; Donnarumma, L; Rossi, E; Rosati, S

    2005-01-01

    In the context of trials conducted in cold store, in order to investigate efficacy of fruit protection applying agrochemicals, the fate during the storage of two active ingredients (a.i.): pyrimethanil and imazalil, have been studied. The experimental trials were done on eight varieties of apples and pears and two of grapes. Only field use of named pesticides was already authorised on fruits and maximum residue limits (MRL) fixed. In the present biennial experimentation (apples and pears in the first year; grapes in the second one). Two fungicides formulations were applied and treatments have been executed by thermonebulization technique. The storage cell, had a volume of 110 m3 filled up with the fruits until 80% of its capacity. Each fruit variety constituted one thesis of 4 replicates. For each trial, only one treatment was performed at the beginning of conservation period (72 days for pears and apples, and 57 days for grapes). In order to estimate fungicides persistence, residues determinations have been carried out. From results obtained especially on grape, not homogenous residues distribution on treated commodities was observed. For all theses, residue level has not evidenced statistically significant decrement as function of time, behaviour not as observed in field tests. The following average values of residues have been determined: in apples and pears, 0.7 mg/kg of imazalil much lower than 5 mg/kg (RML fixed for field use), and 1.2 mg/kg of pyrimethanil little higher than 1 mg/kg (RML fixed for field use); in grapes 0.5 mg/kg pyrimethanil much lower than 3 mg/kg (RML fixed for field use).

  13. The blue light signal transduction pathway is involved in anthocyanin accumulation in 'Red Zaosu' pear.

    Science.gov (United States)

    Tao, Ruiyan; Bai, Songling; Ni, Junbei; Yang, Qinsong; Zhao, Yuan; Teng, Yuanwen

    2018-03-15

    A conserved blue light sensing and transduction pathway contributes to blue light-induced anthocyanin accumulation in the peel of red pear. Peel color is an economically important characteristic that influences the appearance quality of red pear, whose red color is due to anthocyanin accumulation. The process of coloration in the fruit peel is strongly influenced by light. However, how light quality influences color development remains unclear. In this study, we analyzed the effects of different light qualities on color development in the red pear 'Red Zaosu', a mutant of the hybrid cultivar 'Zaosu' of Pyrus pyrifolia and P. communis. The results showed that blue light increased anthocyanin accumulation after 72 h of light treatment, while red light had almost no effect. The expression of anthocyanin biosynthesis-related genes showed a similar trend to the anthocyanin accumulation. To clarify the mechanism of blue-light induced coloration, PpCRYs, PpCOP1 and PpHY5 genes were cloned. Gene expression analysis showed that their transcript abundance did not correlate with the expression of anthocyanin-related genes or anthocyanin content, but the yeast two-hybrid system revealed conserved physical interactions among these proteins. In addition, PpHY5 directly bound to the promoters of the anthocyanin biosynthesis genes PpCHS, PpDFR, PpANS and PpMYB10, and activated the transcription of PpCHS in a Nicotiana benthamiana-based dual-luciferase assay. In summary, our results preliminarily revealed that the conserved blue light signal transduction module CRY-COP1-HY5 contributed to the anthocyanin biosynthesis induced by blue light in red pear. However, our results did not provide evidence for why red light had no effect on anthocyanin accumulation, which needs further study.

  14. Evaluation of Pyrus and Quince rootstocks for high density pear orchards

    OpenAIRE

    Maas, F.M.

    2006-01-01

    High density planting systems are a prerequisite to economise the use of land and labour costs of orchards. Dwarfing rootstocks controlling the vigour of the scion cultivars form the basis for such orchards (Wertheim and Webster, 2005). In the Netherlands, rootstock research is limited to and focussed on testing rootstocks selected abroad. For the Dutch pear growers the main selection criteria for new rootstocks are: 1) control of tree size; 2) production; 3) fruit size; 4) fruit quality; 5) ...

  15. Nitrate Reduction in Canned Apples and Pears Using Calcium Hydrogen Phosphate (CaHPO4

    Directory of Open Access Journals (Sweden)

    Parisa Ziarati*

    2017-09-01

    Full Text Available Background: The aim of this study was to introduce a new and economical method for reduction of nitrate content in canned apples and pears. Methods: The nitrate content was determined before and after treatment with CaHPO4 ranging from 0.01% to 0.1% using spectroscopic method in 2015 in Pharmaceutical Sciences Research Center, Pharmaceutical Sciences Branch, Islamic Azad University, Tehran- Iran. The effect of treatment time at three different time points (30, 60, 90 min was determined. Sensory evaluation was performed using five-point hedonic scales. Results: Nitrate content in fresh fruit is significantly (P<0.05 lower than canned products; this may be explained by the effect of water for washing fruits during processing. The mean value of nitrate in canned apples were significantly (P<0.05 higher compared to the canned pears; this may be related to the type of fruits and its texture and composition. Nitrate content of canned apples and pears were decreased from 233.24±24.90 to 128.80±0.423 and 195.11±20.32 to 118.804±0.634 mg/kg, respectively. Different concentration of CaHPO4 did not influence sensory attributes of canned apples while overall acceptance of canned pears decreased only in 0.1% CaHPO4 (P<0.05. The most efficient time for treating by CaHPO4 was 90 min, but the most practical one is recommended 30 min. Addition of CaHPO4 did not change pH of canned samples. Conclusion: Application of CaHPO4 is suggested as a novel, safe and economical method for removal of nitrate in canned products.

  16. Stability of Cacopsylla pyricola (Hemiptera: Psyllidae Populations in Pacific Northwest Pear Orchards Managed with Long-Term Mating Disruption for Cydia pomonella (Lepidoptera: Tortricidae

    Directory of Open Access Journals (Sweden)

    Kaushalya G. Amarasekare

    2017-09-01

    Full Text Available This study focused on conservation biological control of pear psylla, Cacopsylla pyricola, in the Pacific Northwest, USA. We hypothesized that insecticides applied against the primary insect pest, codling moth Cydia pomonella, negatively impact natural enemies of pear psylla, thus causing outbreaks of this secondary pest. Hence, the objective of this study was to understand how codling moth management influences the abundance of pear psylla and its natural enemy complex in pear orchards managed under long-term codling moth mating disruption programs. We conducted this study within a pear orchard that had previously been under seasonal mating disruption for codling moth for eight years. We replicated two treatments, “natural enemy disrupt” (application of two combination sprays of spinetoram plus chlorantraniliprole timed against first-generation codling moth and “natural enemy non-disrupt” four times in the orchard. Field sampling of psylla and natural enemies (i.e., lacewings, coccinellids, spiders, Campylomma verbasci, syrphid flies, earwigs revealed that pear psylla populations remained well below treatment thresholds all season despite the reduced abundance of key pear psylla natural enemies in the natural enemy disrupt plots compared with the non-disrupt treatment. We speculate that pear psylla are difficult to disrupt when pear orchards are under long-term codling moth disruption.

  17. Stability of Cacopsylla pyricola (Hemiptera: Psyllidae) Populations in Pacific Northwest Pear Orchards Managed with Long-Term Mating Disruption for Cydia pomonella (Lepidoptera: Tortricidae).

    Science.gov (United States)

    Amarasekare, Kaushalya G; Shearer, Peter W

    2017-09-30

    This study focused on conservation biological control of pear psylla, Cacopsylla pyricola , in the Pacific Northwest, USA. We hypothesized that insecticides applied against the primary insect pest, codling moth Cydia pomonella , negatively impact natural enemies of pear psylla, thus causing outbreaks of this secondary pest. Hence, the objective of this study was to understand how codling moth management influences the abundance of pear psylla and its natural enemy complex in pear orchards managed under long-term codling moth mating disruption programs. We conducted this study within a pear orchard that had previously been under seasonal mating disruption for codling moth for eight years. We replicated two treatments, "natural enemy disrupt" (application of two combination sprays of spinetoram plus chlorantraniliprole timed against first-generation codling moth) and "natural enemy non-disrupt" four times in the orchard. Field sampling of psylla and natural enemies (i.e., lacewings, coccinellids, spiders, Campylomma verbasci , syrphid flies, earwigs) revealed that pear psylla populations remained well below treatment thresholds all season despite the reduced abundance of key pear psylla natural enemies in the natural enemy disrupt plots compared with the non-disrupt treatment. We speculate that pear psylla are difficult to disrupt when pear orchards are under long-term codling moth disruption.

  18. Small sample whole-genome amplification

    Science.gov (United States)

    Hara, Christine; Nguyen, Christine; Wheeler, Elizabeth; Sorensen, Karen; Arroyo, Erin; Vrankovich, Greg; Christian, Allen

    2005-11-01

    Many challenges arise when trying to amplify and analyze human samples collected in the field due to limitations in sample quantity, and contamination of the starting material. Tests such as DNA fingerprinting and mitochondrial typing require a certain sample size and are carried out in large volume reactions; in cases where insufficient sample is present whole genome amplification (WGA) can be used. WGA allows very small quantities of DNA to be amplified in a way that enables subsequent DNA-based tests to be performed. A limiting step to WGA is sample preparation. To minimize the necessary sample size, we have developed two modifications of WGA: the first allows for an increase in amplified product from small, nanoscale, purified samples with the use of carrier DNA while the second is a single-step method for cleaning and amplifying samples all in one column. Conventional DNA cleanup involves binding the DNA to silica, washing away impurities, and then releasing the DNA for subsequent testing. We have eliminated losses associated with incomplete sample release, thereby decreasing the required amount of starting template for DNA testing. Both techniques address the limitations of sample size by providing ample copies of genomic samples. Carrier DNA, included in our WGA reactions, can be used when amplifying samples with the standard purification method, or can be used in conjunction with our single-step DNA purification technique to potentially further decrease the amount of starting sample necessary for future forensic DNA-based assays.

  19. Thin layer convective solar drying and mathematical modeling of prickly pear peel (Opuntia ficus indica)

    International Nuclear Information System (INIS)

    Lahsasni, Siham; Kouhila, Mohammed; Mahrouz, Mostafa; Idlimam, Ali; Jamali, Abdelkrim

    2004-01-01

    This paper presents the thin layer convective solar drying and mathematical modeling of prickly pear peel. For these purposes, an indirect forced convection solar dryer consisting of a solar air collector, an auxiliary heater, a circulation fan and a drying cabinet is used for drying experiments. Moreover, the prickly pear peel is sufficiently dried in the ranges of 32 to 36 deg. C of ambient air temperature, 50 to 60 deg. C of drying air temperature, 23 to 34% of relative humidity, 0.0277 to 0.0833 m 3 /s of drying air flow rate and 200 to 950 W/m 2 of daily solar radiation. The experimental drying curves show only a falling drying rate period. The main factor in controlling the drying rate was found to be the drying air temperature. The drying rate equation is determined empirically from the characteristic drying curve. Also, the experimental drying curves obtained were fitted to a number of mathematical models. The Midilli-Kucuk drying model was found to satisfactorily describe the solar drying curves of prickly pear peel with a correlation coefficient (r) of 0.9998 and chi-square (χ 2 ) of 4.6572 10 -5

  20. Growth and Cropping of Two Pear Cultivars as Affected by the Type of Nursery Trees

    Directory of Open Access Journals (Sweden)

    Sosna Ireneusz Stefan

    2016-12-01

    Full Text Available The study was conducted in 2001–2012 next to Wrocław (southwestern Poland. The purpose of this research was to assess the influence of type of nursery trees of pear cvs ‘Carola’ and ‘Dicolor’ budded on quince S1 rootstock on growth and cropping, as well as fruit quality of two pear cultivars. The trees were planted in the spring of 2001 in 4 replications with 5 trees per plot. Trees were planted in rows with spacing 1.2 × 3.5 m (2381 trees per hectare. Three types of nursery trees, all without feathers, were planted: two-year-old (3 years in a nursery, one-year-old maidens (2 years in a nursery and annual grafts (only 1 year in a nursery. Tree canopies were formed as a spindle and were trained in the Güttingen-V system. Until the twelfth year after planting, growth and yield were significantly affected by the type of nursery trees. One-year-old maidens were characterized by the strongest vigor in orchard, while pears planted as two-year-old trees grew rather weak (especially with ‘Dicolor’ cv.. Planting two-year-old trees didn’t have any clear positive influence on tree cropping in the orchard. The final results of the study proved that trees planted as annual grafts, irrespective of cultivar, yielded significantly worse. The type of nursery trees had no clear influence on mean fruit weight.

  1. ‘PACKHAM’S TRIUMPH’ PEAR RESPONSE TO 1-METHYLCYCLOPROPENE AND NITRIC OXIDE TREATMENTS

    Directory of Open Access Journals (Sweden)

    MARCOS VINÍCIUS HENDGES

    2016-01-01

    Full Text Available This study aimed at assessing the effect of 1-methylcyclopropene (1-MCP, gas-nitric oxide (NO and sodium nitroprusside (SNP on ripening of ‘Packham’s Triumph’ pears. The treatments consisted of T1 control; T2 300 ppb 1-MCP; T3 1 mM SNP; T4 10 ppm NO; and T5 20 ppm NO. The fruit treated with 1-MCP showed significantly higher values for flesh firmness, texture, and peel green color, besides lower respiratory rates and ethylene production. On the other hand, NO and SNP treatments did not reduce fruit respiratory rate and ethylene production. Flesh firmness and textural features were maintained by treating fruit with 20 ppm NO after leaving chambers. Treatments using 1 mM SNP and 20 ppm NO kept peel green color (higher hue angle when compared to control, without decreasing fruit yellowing during the shelf life. The application of 300 ppb 1-MCP prevented buttery texture and yellowing in 'Packham’s Triumph' pear fruit during environment condition exposure. The use NO at 20 ppm kept flesh firmness during storage, however, with subsequent reduction of this variable in environmental conditions. The treatments with 1mM SNP and 20 ppm NO maintained green peel of pear fruit, even after exposure to environmental conditions, but not limiting yellowing.

  2. Identification and field evaluation of pear fruit volatiles attractive to the oriental fruit moth, Cydia molesta.

    Science.gov (United States)

    Lu, Peng-Fei; Huang, Ling-Qiao; Wang, Chen-Zhu

    2012-08-01

    Plant volatiles play a key role in host plant location of phytophagous insects. Cydia molesta is an important pest of pear fruit late in the growing season. We identified and quantified volatiles from immature and mature fruits of six pear varieties by using gas chromatography-mass spectrometry (GC-MS). Attractiveness of synthetic blends to adults based on gas chromatography-electroantennogram detection (GC-EAD) activity was investigated in both field and laboratory. Consistent electroantennographic activity was obtained for 12 compounds from headspace collections of the mature fruits of the six pear varieties. Qualitative and quantitative differences were found among six odor profiles. Among the six mixtures, the mixture of 1-hexanol, nonanal, ethyl butanoate, butyl acetate, ethyl hexanoate, hexyl acetate, hexyl butanoate, and farnesene (different isomers) with a 1:1:100:70:7:5:1:4 ratio from the variety Jimi and the mixture of nonanal, ethyl butanoate, 3-methylbutyl acetate, ethyl hexanoate, hexyl acetate, and farnesene with a 1:100:1:32:1:2 ratio from the variety Huangjin were highly attractive to both sexes in the field. However, male captures were much higher than those of females. Further wind tunnel tests proved that both sexes exhibited upwind flight to the lures, but only males landed on the source. Our finding indicates that mixtures mimicking Jimi and Huangjin volatiles attract both females and males of C. molesta, and these host volatiles may be involved in mate finding behavior.

  3. A predicted sex pheromone receptor of codling moth Cydia pomonella detects the plant volatile pear ester

    Directory of Open Access Journals (Sweden)

    Jonas M Bengtsson

    2014-07-01

    Full Text Available Plant volatiles mediate host discrimination and host finding in phytophagous insects. Understanding how insects recognize these signals is a current challenge in chemical ecology research. Pear ester, ethyl (E,Z-2,4-decadienoate, is a powerful, bisexual attractant of codling moth Cydia pomonella (Lepidoptera, Tortricidae and strongly synergizes the male response to female-produced sex pheromone. We show here that the codling moth odorant receptor (OR CpomOR3 is dedicated to detecting this plant volatile. Heterologous expression of CpomOR3 in Drosophila T1 trichoid and ab3A basiconic sensilla, followed by a screening with codling moth pheromone compounds and known plant volatile attractants, confirms that CpomOR3 binds to pear ester. Although CpomOR3 does not respond to any of the pheromone components tested, a phylogenetic analysis of lepidopteran chemosensory receptor genes reveals a close relationship of CpomOR3 with pheromone receptors (PRs in moths. This corroborates the interaction of ecological and social chemosensory cues during premating communication. The finding that a plant volatile compound, pear ester, is a specific ligand for a PR-like lepidopteran receptor adds to our understanding of insect-plant interactions and emphasizes the interaction of natural and sexual selection during the phylogenetic divergence of insect herbivores.

  4. [Antitumor effect of polysaccharides from cactus pear fruit in S180-bearing mice].

    Science.gov (United States)

    Liang, Bei-Bei; Liu, Hua-Gang; Cao, Jiu-Tao

    2008-06-01

    Polysaccharide components of some traditional Chinese medicine have certain antitumor effects and can promote immune responses. Extractions from cactus pear fruit can inhibit the proliferation of cervical cancer, ovary cancer and bladder cancer cells, and suppress the growth of ovarian cancer in mice. This study was to observe the antitumor effect of polysaccharides extracted from cactus pear fruit in S180-bearing mice. S180-bearing mice were established and divided into five groups: normal saline (NS) group, cyclophosphamide (CTX) group, high, middle and low dose of polysaccharide groups. Tumor inhibition rates, values of thymus index, spleen index, superoxide dismutase (SOD), maleic dialdehyde (MDA) and nitrogen monoxidum (NO) were recorded. Changes in ultra-structures of tumor cells under transmission electron microscopy were observed. The tumor inhibition rates in CTX group, high, middle and low dose groups were 7.78%, 31.13%%, 49.70%, 61.07%, respectively. The thymus index was significantly higher in middle and high dose groups than in NS group [(2.61+/-0.43) mg x g(-1) and (2.65+/-0.73) mg x g(-1) vs. (2.22+/-0.24) mg x g(-1), Ppolysaccharide or CTX treated tumor cells showed typical morphology of early apoptosis with condensed chromatin at the margins of nuclei, disintegrated nucleolus and vacuoles in the cytoplasm. Polysaccharides extracted from cactus pear fruit possess certain antitumor effects, which can induce apoptosis, increase antioxidation and promote immune responses.

  5. Thin layer convective solar drying and mathematical modeling of prickly pear peel (Opuntia ficus indica)

    Energy Technology Data Exchange (ETDEWEB)

    Lahsasni, S.; Mahrouz, M. [Unite de Chimie Agroalimentaire (LCOA), Faculte des Sciences Semlalia, Marrakech (Morocco); Kouhila, M.; Idlimam, A.; Jamali, A. [Ecole Normale Superieure, Marrakech (Morocco). Lab. d' Energie Solaire et Plantes Aromatiques et Medicinales

    2004-02-01

    This paper presents the thin layer convective solar drying and mathematical modeling of prickly pear peel. For these purposes, an indirect forced convection solar dryer consisting of a solar air collector, an auxiliary heater, a circulation fan and a drying cabinet is used for drying experiments. Moreover, the prickly pear peel is sufficiently dried in the ranges of 32 to 36 {sup o} C of ambient air temperature, 50 to 60 {sup o}C of drying air temperature, 23 to 34% of relative humidity, 0.0277 to 0.0833 m{sup 3}/s of drying air flow rate and 200 to 950 W/m{sup 2} of daily solar radiation. The experimental drying curves show only a falling drying rate period. The main factor in controlling the drying rate was found to be the drying air temperature. The drying rate equation is determined empirically from the characteristic drying curve. Also, the experimental drying curves obtained were fitted to a number of mathematical models. The Midilli-Kucuk drying model was found to satisfactorily describe the solar drying curves of prickly pear peel with a correlation coefficient (r) of 0.9998 and chi-square ({chi}{sup 2}) of 4.6572 10{sup -5}. (Author)

  6. Use of Red Cactus Pear (Opuntia ficus-indica Encapsulated Powder to Pigment Extruded Cereal

    Directory of Open Access Journals (Sweden)

    Martha G. Ruiz-Gutiérrez

    2017-01-01

    Full Text Available Encapsulated powder of the red cactus pear is a potential natural dye for the food industry and a known antioxidant. Although the use of this powder is possible, it is not clear how it alters food properties, thus ensuing commercial acceptability. The aim of this study was to evaluate the effect of encapsulated powder of the red cactus pear on the physicochemical properties of extruded cereals. The powder was mixed (2.5, 5.0, and 7.5% w/w with maize grits and extruded (mix moisture 22%, temperature 100°C, and screw speed 325 rpm. The physical, chemical, and sensory characteristics of the extruded cereal were evaluated; extruded cereal without encapsulated powder was used as a control. All cereal extrudates pigmented with the encapsulated powder showed statistically significant differences (P<0.05 in expansion, water absorption, color, density, and texture compared to the control. The encapsulated powder had a positive effect on expansion and water absorption indices, as well as color parameters, but a negative effect on density and texture. Extruded cereal properties were significantly (P<0.05 correlated. Sensorially, consumers accepted the extruded cereal with a lower red cactus pear powder content (2.5% w/w, because this presented characteristics similar to extruded cereal lacking pigment.

  7. Instrument for Real-Time Digital Nucleic Acid Amplification on Custom Microfluidic Devices.

    Directory of Open Access Journals (Sweden)

    David A Selck

    Full Text Available Nucleic acid amplification tests that are coupled with a digital readout enable the absolute quantification of single molecules, even at ultralow concentrations. Digital methods are robust, versatile and compatible with many amplification chemistries including isothermal amplification, making them particularly invaluable to assays that require sensitive detection, such as the quantification of viral load in occult infections or detection of sparse amounts of DNA from forensic samples. A number of microfluidic platforms are being developed for carrying out digital amplification. However, the mechanistic investigation and optimization of digital assays has been limited by the lack of real-time kinetic information about which factors affect the digital efficiency and analytical sensitivity of a reaction. Commercially available instruments that are capable of tracking digital reactions in real-time are restricted to only a small number of device types and sample-preparation strategies. Thus, most researchers who wish to develop, study, or optimize digital assays rely on the rate of the amplification reaction when performed in a bulk experiment, which is now recognized as an unreliable predictor of digital efficiency. To expand our ability to study how digital reactions proceed in real-time and enable us to optimize both the digital efficiency and analytical sensitivity of digital assays, we built a custom large-format digital real-time amplification instrument that can accommodate a wide variety of devices, amplification chemistries and sample-handling conditions. Herein, we validate this instrument, we provide detailed schematics that will enable others to build their own custom instruments, and we include a complete custom software suite to collect and analyze the data retrieved from the instrument. We believe assay optimizations enabled by this instrument will improve the current limits of nucleic acid detection and quantification, improving our

  8. Instrument for Real-Time Digital Nucleic Acid Amplification on Custom Microfluidic Devices.

    Science.gov (United States)

    Selck, David A; Ismagilov, Rustem F

    2016-01-01

    Nucleic acid amplification tests that are coupled with a digital readout enable the absolute quantification of single molecules, even at ultralow concentrations. Digital methods are robust, versatile and compatible with many amplification chemistries including isothermal amplification, making them particularly invaluable to assays that require sensitive detection, such as the quantification of viral load in occult infections or detection of sparse amounts of DNA from forensic samples. A number of microfluidic platforms are being developed for carrying out digital amplification. However, the mechanistic investigation and optimization of digital assays has been limited by the lack of real-time kinetic information about which factors affect the digital efficiency and analytical sensitivity of a reaction. Commercially available instruments that are capable of tracking digital reactions in real-time are restricted to only a small number of device types and sample-preparation strategies. Thus, most researchers who wish to develop, study, or optimize digital assays rely on the rate of the amplification reaction when performed in a bulk experiment, which is now recognized as an unreliable predictor of digital efficiency. To expand our ability to study how digital reactions proceed in real-time and enable us to optimize both the digital efficiency and analytical sensitivity of digital assays, we built a custom large-format digital real-time amplification instrument that can accommodate a wide variety of devices, amplification chemistries and sample-handling conditions. Herein, we validate this instrument, we provide detailed schematics that will enable others to build their own custom instruments, and we include a complete custom software suite to collect and analyze the data retrieved from the instrument. We believe assay optimizations enabled by this instrument will improve the current limits of nucleic acid detection and quantification, improving our fundamental

  9. Resonant primordial gravitational waves amplification

    Directory of Open Access Journals (Sweden)

    Chunshan Lin

    2016-01-01

    Full Text Available We propose a mechanism to evade the Lyth bound in models of inflation. We minimally extend the conventional single-field inflation model in general relativity (GR to a theory with non-vanishing graviton mass in the very early universe. The modification primarily affects the tensor perturbation, while the scalar and vector perturbations are the same as the ones in GR with a single scalar field at least at the level of linear perturbation theory. During the reheating stage, the graviton mass oscillates coherently and leads to resonant amplification of the primordial tensor perturbation. After reheating the graviton mass vanishes and we recover GR.

  10. Whole genome amplification - Review of applications and advances

    Energy Technology Data Exchange (ETDEWEB)

    Hawkins, Trevor L.; Detter, J.C.; Richardson, Paul

    2001-11-15

    The concept of Whole Genome Amplification is something that has arisen in the past few years as modifications to the polymerase chain reaction (PCR) have been adapted to replicate regions of genomes which are of biological interest. The applications here are many--forensics, embryonic disease diagnosis, bio terrorism genome detection, ''imoralization'' of clinical samples, microbial diversity, and genotyping. The key question is if DNA can be replicated a genome at a time without bias or non random distribution of the target. Several papers published in the last year and currently in preparation may lead to the conclusion that whole genome amplification may indeed be possible and therefore open up a new avenue to molecular biology.

  11. Amplification biases: possible differences among deviating gene expressions

    Directory of Open Access Journals (Sweden)

    Piumi Francois

    2008-01-01

    Full Text Available Abstract Background Gene expression profiling has become a tool of choice to study pathological or developmental questions but in most cases the material is scarce and requires sample amplification. Two main procedures have been used: in vitro transcription (IVT and polymerase chain reaction (PCR, the former known as linear and the latter as exponential. Previous reports identified enzymatic pitfalls in PCR and IVT protocols; however the possible differences between the sequences affected by these amplification defaults were only rarely explored. Results Screening a bovine cDNA array dedicated to embryonic stages with embryonic (n = 3 and somatic tissues (n = 2, we proceeded to moderate amplifications starting from 1 μg of total RNA (global PCR or IVT one round. Whatever the tissue, 16% of the probes were involved in deviating gene expressions due to amplification defaults. These distortions were likely due to the molecular features of the affected sequences (position within a gene, GC content, hairpin number but also to the relative abundance of these transcripts within the tissues. These deviating genes mainly encoded housekeeping genes from physiological or cellular processes (70% and constituted 2 subsets which did not overlap (molecular features, signal intensities, gene ID. However, the differential expressions identified between embryonic stages were both reliable (minor intersect with biased expressions and relevant (biologically validated. In addition, the relative expression levels of those genes were biologically similar between amplified and unamplified samples. Conclusion Conversely to the most recent reports which challenged the use of intense amplification procedures on minute amounts of RNA, we chose moderate PCR and IVT amplifications for our gene profiling study. Conclusively, it appeared that systematic biases arose even with moderate amplification procedures, independently of (i the sample used: brain, ovary or embryos, (ii

  12. Chirped pulse Raman amplification in plasma

    Energy Technology Data Exchange (ETDEWEB)

    Vieux, G; Lyachev, A; Yang, X; Ersfeld, B; Farmer, J P; Brunetti, E; Issac, R C; Raj, G; Welsh, G H; Wiggins, S M; Jaroszynski, D A, E-mail: d.a.jaroszynski@strath.ac.uk [Department of Physics, Scottish Universities Physics Alliance, University of Strathclyde, Glasgow G4 0NG (United Kingdom)

    2011-06-15

    Raman amplification in plasma has been proposed to be a promising method of amplifying short radiation pulses. Here, we investigate chirped pulse Raman amplification (CPRA) where the pump pulse is chirped and leads to spatiotemporal distributed gain, which exhibits superradiant scaling in the linear regime, usually associated with the nonlinear pump depletion and Compton amplification regimes. CPRA has the potential to serve as a high-efficiency high-fidelity amplifier/compressor stage.

  13. Risk Perception and Social Amplification

    International Nuclear Information System (INIS)

    Smith, R.E.

    2001-01-01

    This paper seeks to consider social amplification as it applies to risk perception. Perceptions of the magnitude of a risk are conditioned by issues such as the degree of uncertainty in probability and consequences, the nature of the consequences and the relative weightings placed on probability and consequences. Risk perceptions are also influenced by factors such as confidence in the operator of an industrial process, trust in the regulator and the perceived fairness of regulatory decision-making. Different people may hold different views about these issues and there may also be difficulties in communication. The paper identifies and discusses self-reinforcing mechanisms, which will be labelled 'lock-in' here. They appear to apply in many situations where social amplification is observed. Historically, the term 'lock-in' has been applied mainly in the technological context but, in this paper, four types of lock-in are identified, namely scientific/technological, economic, social and institutional lock-in. One type of lock-in tends to lead to the next and all are buttressed by people's general acceptance of the familiar, fear of the unknown and resistance to change. The regulator seeks to make decisions which achieve the common good rather than supporting or perpetuating any set of vested interests. In this regard the locked-in positions of stakeholders, whether organisations, interest groups, or individual members of the public, are obstacles and challenges. Existing methods of consultation are unsatisfactory in terms of achieving a proper and productive level of dialogue with stakeholders

  14. Use of UV-C treatment to inhibit the microbial growth and maintain the quality of Yali pear.

    Science.gov (United States)

    Li, Jian; Zhang, Qian; Cui, Yang; Yan, Jiaqi; Cao, Jiankang; Zhao, Yumei; Jiang, Weibo

    2010-09-01

    The effects of UV-C radiation on microbial growth in vitro (Monilinia fruticola) and in inoculated Yali pears (Pyrus bretschneideri Rehd.) were investigated. Moreover, postharvest quality and the activities of defense and antioxidant enzymes were analyzed after the pears were exposed to UV-C irradiation at an energy level of 5 kJ m⁻².The results showed that spore germination of M. fructicola was significantly inhibited by each of the 3 doses (1, 5, and 10 kJ m⁻²) in vitro. In the in vivo assays, lesion diameter on the fruit being inoculated before or after the UV-C treatment was both significantly lower than that on the fruit of control. Meanwhile, the activities of phenylalanine ammonia lyase, β-1,3-glucanase, superoxide dismutase, catalase, and glutathione reductase were induced to high levels by UV-C treatment. We conclude that UV-C treatment could reduce postharvest disease by the germicidal and induced effects and maintain the quality by enhancing the antioxidant enzyme activities. UV-C radiation has recently been proposed as a new technology to avoid chemical fungicides. However, there are few studies regarding the effect of UV-C treatment on Yali pear. In this study, we found that 5 kJ m⁻² UV-C irradiation can control postharvest disease and maintain the quality of Yali pear. This method may be applied to reduce the decay of Yali pears during exporting and storage.

  15. Critical points and magnitude of impacts on the packing line: effect on ripening and quality of 'Packham's Triumph' pears

    Directory of Open Access Journals (Sweden)

    Josiane Pasini

    2017-06-01

    Full Text Available Pears have a very sensitive epidermis and are prone to signal mechanical blemishes, which result in reduced visual quality and low consumer acceptance. The objective of this work was to identify critical points and the magnitude of impact forces on a packing line at a commercial packinghouse. The effect of injuries on ripening and quality of ´Packham´s Triumph´ pears was also evaluated after cold storage. The packing line was scrutinized on its transfer points, fruit drop heights and cushioning overlays, which allowed to acquire the maximum accelerations on each spot. The maximum acceleration forces were reproduced in the lab with ‘Packham’s Triumph’ pears to evaluate the effects on fruit quality after cold storage. Four critical points were noticed on the packing line: at the transfer from the conveyor belt to the lifting rollers, at the transfer from the lifting rollers to the washing ramp with rotatory brushes, at the entrance to the singulator at the end of the conveyor belt and at the drop from the sizer to the packing stalls. Ripening of ‘Packham’s Triumph’ pears invariably came about during cold storage, and independently of the imposed impacts. The impacts under the circumstances of the test did not affect the quality of ´Packham´s Triumph´ pears kept for up to 120 days at cold storage followed by five days at room temperature.

  16. Single primer amplification reaction methods reveal exotic and ...

    Indian Academy of Sciences (India)

    Unknown

    Despite economic importance, the origin and domestication of mulberry has not ..... The numbers at the nodes in each tree are the bootstrap percent values (only values greater than or equal to 50 are shown) for the ..... Dandin S B 1998 Mulberry: A versatile biosource in the service of mankind; Acta Sericologica Sinica 24 ...

  17. Single primer amplification reaction methods reveal exotic and ...

    Indian Academy of Sciences (India)

    Unknown

    ). Mulberry is the sole food source for mulberry silkworm and a number of indigenous and exotic varieties are used in sericulture. Studies on assessment of genetic diversity have been done amongst a few mulberry varieties using one or at the ...

  18. Comparative transcriptomic analysis reveals that Ethylene/H2O2-mediated hypersensitive response and program cell death determine the compatible interaction of Sand pear and Alternaria Alternata

    Science.gov (United States)

    A major production restriction on sand pear (Pyrus pyrifolia) is black spot disease caused by the necrotrophic fungus Alternaria alternata. However, pear response mechanism to A. alternata is unknown at molecular level. Here, host responses of a resistant cultivar Cuiguan (CG) and a susceptible cult...

  19. Strand Invasion Based Amplification (SIBA®): a novel isothermal DNA amplification technology demonstrating high specificity and sensitivity for a single molecule of target analyte.

    Science.gov (United States)

    Hoser, Mark J; Mansukoski, Hannu K; Morrical, Scott W; Eboigbodin, Kevin E

    2014-01-01

    Isothermal nucleic acid amplification technologies offer significant advantages over polymerase chain reaction (PCR) in that they do not require thermal cycling or sophisticated laboratory equipment. However, non-target-dependent amplification has limited the sensitivity of isothermal technologies and complex probes are usually required to distinguish between non-specific and target-dependent amplification. Here, we report a novel isothermal nucleic acid amplification technology, Strand Invasion Based Amplification (SIBA). SIBA technology is resistant to non-specific amplification, is able to detect a single molecule of target analyte, and does not require target-specific probes. The technology relies on the recombinase-dependent insertion of an invasion oligonucleotide (IO) into the double-stranded target nucleic acid. The duplex regions peripheral to the IO insertion site dissociate, thereby enabling target-specific primers to bind. A polymerase then extends the primers onto the target nucleic acid leading to exponential amplification of the target. The primers are not substrates for the recombinase and are, therefore unable to extend the target template in the absence of the IO. The inclusion of 2'-O-methyl RNA to the IO ensures that it is not extendible and that it does not take part in the extension of the target template. These characteristics ensure that the technology is resistant to non-specific amplification since primer dimers or mis-priming are unable to exponentially amplify. Consequently, SIBA is highly specific and able to distinguish closely-related species with single molecule sensitivity in the absence of complex probes or sophisticated laboratory equipment. Here, we describe this technology in detail and demonstrate its use for the detection of Salmonella.

  20. Strand Invasion Based Amplification (SIBA®: a novel isothermal DNA amplification technology demonstrating high specificity and sensitivity for a single molecule of target analyte.

    Directory of Open Access Journals (Sweden)

    Mark J Hoser

    Full Text Available Isothermal nucleic acid amplification technologies offer significant advantages over polymerase chain reaction (PCR in that they do not require thermal cycling or sophisticated laboratory equipment. However, non-target-dependent amplification has limited the sensitivity of isothermal technologies and complex probes are usually required to distinguish between non-specific and target-dependent amplification. Here, we report a novel isothermal nucleic acid amplification technology, Strand Invasion Based Amplification (SIBA. SIBA technology is resistant to non-specific amplification, is able to detect a single molecule of target analyte, and does not require target-specific probes. The technology relies on the recombinase-dependent insertion of an invasion oligonucleotide (IO into the double-stranded target nucleic acid. The duplex regions peripheral to the IO insertion site dissociate, thereby enabling target-specific primers to bind. A polymerase then extends the primers onto the target nucleic acid leading to exponential amplification of the target. The primers are not substrates for the recombinase and are, therefore unable to extend the target template in the absence of the IO. The inclusion of 2'-O-methyl RNA to the IO ensures that it is not extendible and that it does not take part in the extension of the target template. These characteristics ensure that the technology is resistant to non-specific amplification since primer dimers or mis-priming are unable to exponentially amplify. Consequently, SIBA is highly specific and able to distinguish closely-related species with single molecule sensitivity in the absence of complex probes or sophisticated laboratory equipment. Here, we describe this technology in detail and demonstrate its use for the detection of Salmonella.

  1. Factors influencing flower bud formation on the pear tree cultivar 'Doyenne du Comice'. III. Saccharides, nitrogen compounds and some mineral elements contents in pear leaves and shoots

    Directory of Open Access Journals (Sweden)

    Franciszka Jaumień

    2013-12-01

    Full Text Available Long shoots inhibited in growth by treatment with chlormequate contained more reducing sugars in mid July than did the control ones growing vigorously. Storage starch accumulation was earlier in the former shoots than in he control ones, and they also contained more nitrogen compounds, especially protein, and significantly more calcium, magnesium, iron and zinc then the controls. Comparison of long shoots with growth partly inhibited by the action of chlormequate, on which flower buds form in the subapical part, and of spurs on which an apical flower bud forms, with the long shoots of control vigorously growing trees where flower buds do not form, indicates that initiation of flowering in the pear tree is associated with a high level of storage compounds, both organic and inorganic, in the stem.

  2. Structure-Antifungal Activity Relationship of Fluorinated Dihydroguaiaretic Acid Derivatives and Preventive Activity against Alternaria alternata Japanese Pear Pathotype.

    Science.gov (United States)

    Nishiwaki, Hisashi; Nakazaki, Shoko; Akiyama, Koichi; Yamauchi, Satoshi

    2017-08-09

    The structure-activity relationship of the antifungal fluorinated dihydroguaiaretic acid derivatives was evaluated. Some of the newly synthesized lignan compounds were found to show higher antifungal activity against phytopathogenic fungi such as Alternaria alternata (Japanese pear and apple pathotypes) and A. citri than the lead compound, 3-fluoro-3'-methoxylignan-4'-ol (3). The broad antifungal spectrum of 3'-hydroxyphenyl derivative 16 was observed, and the 3'-fluoro-4'-hydroxyphenyl derivative 38 was found to show the highest activity against the A. alternata Japanese pear pathotype, with an EC 50 value of 11 μM. The preventive effect of the potent lignan on the infection of A. alternata in the Japanese pear's leaves was also shown.

  3. Balsam-Pear-Skin-Like Porous Polyacrylonitrile Nanofibrous Membranes Grafted with Polyethyleneimine for Postcombustion CO2 Capture.

    Science.gov (United States)

    Zhang, Yufei; Guan, Jiming; Wang, Xianfeng; Yu, Jianyong; Ding, Bin

    2017-11-22

    Amine-containing sorbents have been extensively studied for postcombustion carbon dioxide (CO 2 ) capture because of their ability to chemisorb CO 2 from the flue gas. However, most sorbents are in the form of powders currently, which is not the ideal configuration for the flue gas separation because of the fragile nature and poor mechanical properties, resulting in blocking of the flow pipes and difficult recycling. Herein, we present a novel approach for the facile fabrication of flexible, robust, and polyethyleneimine-grafted (PEI-grafted) hydrolyzed porous PAN nanofibrous membranes (HPPAN-PEI NFMs) through the combination of electrospinning, pore-forming process, hydrolysis reaction, and the subsequent grafting technique. Excitingly, we find that all the resultant porous PAN (PPAN) fibers exhibit a balsam-pear-skin-like porous structure due to the selective removal of poly(vinylpyrrolidone) (PVP) from PAN/PVP fibers by water extraction. Significantly, the HPPAN-PEI NFMs retain their mesoporosity, as well as exhibit good thermal stability and prominent tensile strength (11.1 MPa) after grafting, guaranteeing their application in CO 2 trapping from the flue gas. When exposed to CO 2 at 40 °C, the HPPAN-PEI NFMs show an enhanced CO 2 adsorption capacity of 1.23 mmol g -1 (based on the overall quantity of the sample) or 6.15 mmol g -1 (based on the quantity of grafted PEI). Moreover, the developed HPPAN-PEI NFMs display significantly selective capture for CO 2 over N 2 and excellent recyclability. The CO 2 capacity retains 92% of the initial value after 20 adsorption-desorption cycle tests, indicating that the resultant HPPAN-PEI NFMs have good long-term stability. This work paves the way for fabricating NFM-based solid adsorption materials endowed with a porous structure applied to efficient postcombustion CO 2 capture.

  4. Compatibilidade de enxertia de cultivares de marmeleiros com pereiras Compatibility of pear cultivars on quinces rootstocks

    Directory of Open Access Journals (Sweden)

    Zeni Fonseca Pinto Tomaz

    2009-12-01

    Full Text Available A insuficiência de estudos sobre compatibilidade de porta-enxertos é um dos fatores limitantes ao desenvolvimento da cultura da pereira (Pyrus sp. no Brasil. A utilização do marmeleiro (Cydonia oblonga como porta-enxerto para a cultura da pereira apresenta inúmeras vantagens, entre as quais a redução do vigor e a rápida entrada em produção; todavia, sua combinação com algumas cultivares copa apresenta problemas de incompatibilidade de enxertia, podendo ocasionar a ruptura do caule das plantas no pomar. Objetivou-se, neste trabalho, avaliar a compatibilidade de enxertia de algumas cultivares de marmeleiros ('Quince C' e 'Adams' com pereiras ('Packham's Triumph' e 'Kieffer'. As variáveis analisadas foram: diâmetro da secção do tronco no ponto de enxertia, 5 cm abaixo e 5 cm acima do ponto de enxertia, diferença do diâmetro entre porta-enxerto e copa, altura das plantas, volume e massa seca da copa e raízes. Além disso, efetuou-se a observação da conexão vascular no ponto de enxertia através da imersão da base das plantas (abaixo do ponto de enxertia, em solução corante de Ácido Fuccínico 0,08%. Concluiu-se que a cultivar 'Packham's Triumph'apresenta compatibilidade de enxertia com o marmeleiro cultivares 'Adams'e 'Quince C', enquanto o híbrido 'Kieffer' apresentou sintomas morfológicos de incompatibilidade de enxertia com o marmeleiro cultivares 'Quince C' e 'Adams'.The lack of studies on compatibility of pear cultivars and rootstocks is one of the limiting factors on the development of the pear crop in Brazil. The use of quinces as rootstocks for pear cultivars has several advantages, among them the reduction in vigor and earlier bearing trees, however, its combination with some scions cultivars results in problems of incompatibility , such as lost of trees of the orchard due to break of the graft union. The objective of this study was to determine the compatibility between pears cvs. Packham's Triumph and Kieffer

  5. Multiscale image contrast amplification (MUSICA)

    Science.gov (United States)

    Vuylsteke, Pieter; Schoeters, Emile P.

    1994-05-01

    This article presents a novel approach to the problem of detail contrast enhancement, based on multiresolution representation of the original image. The image is decomposed into a weighted sum of smooth, localized, 2D basis functions at multiple scales. Each transform coefficient represents the amount of local detail at some specific scale and at a specific position in the image. Detail contrast is enhanced by non-linear amplification of the transform coefficients. An inverse transform is then applied to the modified coefficients. This yields a uniformly contrast- enhanced image without artefacts. The MUSICA-algorithm is being applied routinely to computed radiography images of chest, skull, spine, shoulder, pelvis, extremities, and abdomen examinations, with excellent acceptance. It is useful for a wide range of applications in the medical, graphical, and industrial area.

  6. Risk Perception and Social Amplification

    Energy Technology Data Exchange (ETDEWEB)

    Smith, R.E. [Environment Agency (United Kingdom)

    2001-07-01

    This paper seeks to consider social amplification as it applies to risk perception. Perceptions of the magnitude of a risk are conditioned by issues such as the degree of uncertainty in probability and consequences, the nature of the consequences and the relative weightings placed on probability and consequences. Risk perceptions are also influenced by factors such as confidence in the operator of an industrial process, trust in the regulator and the perceived fairness of regulatory decision-making. Different people may hold different views about these issues and there may also be difficulties in communication. The paper identifies and discusses self-reinforcing mechanisms, which will be labelled 'lock-in' here. They appear to apply in many situations where social amplification is observed. Historically, the term 'lock-in' has been applied mainly in the technological context but, in this paper, four types of lock-in are identified, namely scientific/technological, economic, social and institutional lock-in. One type of lock-in tends to lead to the next and all are buttressed by people's general acceptance of the familiar, fear of the unknown and resistance to change. The regulator seeks to make decisions which achieve the common good rather than supporting or perpetuating any set of vested interests. In this regard the locked-in positions of stakeholders, whether organisations, interest groups, or individual members of the public, are obstacles and challenges. Existing methods of consultation are unsatisfactory in terms of achieving a proper and productive level of dialogue with stakeholders.

  7. MYB Transcription Factors in Chinese Pear (Pyrus bretschneideri Rehd.: Genome-Wide Identification, Classification and Expression Profiling during Fruit Development

    Directory of Open Access Journals (Sweden)

    Yun Peng eCao

    2016-04-01

    Full Text Available The MYB family is one of the largest families of transcription factors in plants. Although some MYBs have been reported to play roles in secondary metabolism, no comprehensive study of the MYB family in Chinese pear (Pyrus bretschneideri Rehd. has been reported. In the present study, we performed genome-wide analysis of MYB genes in Chinese pear, designated as PbMYBs, including analyses of their phylogenic relationships, structures, chromosomal locations, promoter regions, GO annotations and collinearity. A total of 129 PbMYB genes were identified in the pear genome and were divided into 31 subgroups based on phylogenetic analysis. These PbMYBs were unevenly distributed among 16 chromosomes (total of 17 chromosomes. The occurrence of gene duplication events indicated that whole-genome duplication and segmental duplication likely played key roles in expansion of the PbMYB gene family. Ka/Ks analysis suggested that the duplicated PbMYBs mainly experienced purifying selection with restrictive functional divergence after the duplication events. Interspecies microsynteny analysis revealed maximum orthology between pear and peach, followed by plum and strawberry. Subsequently, the expression patterns of 20 PbMYB genes that may be involved in lignin biosynthesis according to their phylogenetic relationships were examined throughout fruit development. Among the twenty genes examined, PbMYB25 and PbMYB52 exhibited expression patterns consistent with the typical variations in the lignin content previously reported. Moreover, sub-cellular localization analysis revealed that two proteins PbMYB25 and PbMYB52 were localized to the nucleus. All together, PbMYB25 and PbMYB52 were inferred to be candidate genes involved in the regulation of lignin biosynthesis during the development of pear fruit. This study provides useful information for further functional analysis of the MYB gene family in pear.

  8. [Evaluation of Sugar Content of Huanghua Pear on Trees by Visible/Near Infrared Spectroscopy].

    Science.gov (United States)

    Liu, Hui-jun; Ying, Yi-bin

    2015-11-01

    A method of ambient light correction was proposed to evaluate the sugar content of Huanghua pears on tree by visible/near infrared diffuse reflectance spectroscopy (Vis/NIRS). Due to strong interference of ambient light, it was difficult to collect the efficient spectral of pears on tree. In the field, covering the fruits with a bag blocking ambient light can get better results, but the efficiency is fairly low, the instrument corrections of dark and reference spectra may help to reduce the error of the model, however, the interference of the ambient light cannot be eliminated effectively. In order to reduce the effect of ambient light, a shutter was attached to the front of probe. When opening shutter, the spot spectrum were obtained, on which instrument light and ambient light acted at the same time. While closing shutter, background spectra were obtained, on which only ambient light acted, then the ambient light spectra was subtracted from spot spectra. Prediction models were built using data on tree (before and after ambient light correction) and after harvesting by partial least square (PLS). The results of the correlation coefficient (R) are 0.1, 0.69, 0.924; the root mean square error of prediction (SEP) are 0. 89°Brix, 0.42°Brix, 0.27°Brix; ratio of standard deviation (SD) to SEP (RPD) are 0.79, 1.69, 2.58, respectively. The results indicate that, method of background correction used in the experiment can reduce the effect of ambient lighting on spectral acquisition of Huanghua pears in field, efficiently. This method can be used to collect the visible/near infrared spectrum of fruits in field, and may give full play to visible/near-infrared spectroscopy in preharvest management and maturity testing of fruits in the field.

  9. Fungicide residues in pears and apples after post harvest treatments by drencher.

    Science.gov (United States)

    Donnarumma, L; Pompi, V; Rossi, E; Carfì, F

    2005-01-01

    Aim of this trial was to verify the residues of two fungicides, already authorised for the use in field (the admitted maximum limit of residues have been fixed), after post harvest treatments on pears and apples for defence against main post harvest rots. The use of formulation in post harvest must consider also the technique of product application. In fact there are different systems to carry out the treatments for the protection of the commodities during cold storage. In this trial two formulations of pyrimethanil and imazalil were applied by drencher on pome fruit.

  10. Clarification of purple cactus pear juice using microfiltration membranes to obtain a solution of betalain pigments

    Directory of Open Access Journals (Sweden)

    Cristina VERGARA

    2015-09-01

    Full Text Available Summary Betalains are fruit pigments possessing health-giving properties. To isolate the pigments, the juice must be separated from the fruit matrix, which contains biopolymers. The aim of this study was to clarify cactus pear juice by microfiltration to obtain a clarified juice containing betalains. For this purpose, two 0.2 µm pore size microfiltration membranes (ceramic and polymeric were tested. The permeates were clear, free of turbidity and high in betalains (20%, also containing polyphenols and antioxidant activity, whereas the retained fractions were high in mucilage. The best separation was obtained using the ceramic membrane.

  11. Adding microencapsulated pear ester to insecticides for control of Cydia pomonella (Lepidoptera: Tortricidae) in apple.

    Science.gov (United States)

    Knight, Alan L; Light, Douglas M

    2013-01-01

    The possibility of improving the efficacy of various insecticides for codling moth, Cydia pomonella (L.), by the addition of a microencapsulated formulation of pear ester, ethyl (2E, 4Z)-2,4-decadienoate (PE-MEC, 5% AI), was evaluated in field trials in apple from 2005 to 2009. The addition of PE-MEC (pomonella should be further investigated. This article is a US Government work and is in the public domain in the USA. Published 2012 by John Wiley & Sons, Ltd.

  12. Antioxidant betalains from cactus pear (Opuntia ficus-indica) inhibit endothelial ICAM-1 expression.

    Science.gov (United States)

    Gentile, C; Tesoriere, L; Allegra, M; Livrea, M A; D'Alessio, P

    2004-12-01

    It has been suggested that some pigments would have antioxidant properties and that their presence in dietary constituents would contribute to reduce the risk of oxidative stress-correlated diseases. Among others, inflammatory response depends on redox status and may implicate oxidative stress. Vascular endothelial cells are a direct target of oxidative stress in inflammation. We have tested the impact of the free radical scavenger and antioxidant properties of betalains from the prickle pear in an in vitro model of endothelial cells. Here we show the capacity of betalains to protect endothelium from cytokine-induced redox state alteration, through ICAM-1 inhibition.

  13. Construction and optimization of an efficient breathing-based isothermal emulsion amplification method

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Yanting, E-mail: shenyanting798@126.com [Research Center for Learning Science, Southeast University, Sipailou Road no. 2, Nanjing, Jiangsu Province 210096 (China); State Key Laboratory of Bioelectronics, Southeast University, Sipailou Road no. 2, Nanjing, Jiangsu Province 210096 (China); Tian, Fei, E-mail: 642807827@qq.com [Research Center for Learning Science, Southeast University, Sipailou Road no. 2, Nanjing, Jiangsu Province 210096 (China); Tu, Jing, E-mail: jtu@seu.edu.cn [State Key Laboratory of Bioelectronics, Southeast University, Sipailou Road no. 2, Nanjing, Jiangsu Province 210096 (China); Li, Rui, E-mail: lirui901113@163.com [Research Center for Learning Science, Southeast University, Sipailou Road no. 2, Nanjing, Jiangsu Province 210096 (China); Chen, Zhenzhu, E-mail: zzchen_seu@163.com [Research Center for Learning Science, Southeast University, Sipailou Road no. 2, Nanjing, Jiangsu Province 210096 (China); Bai, Yunfei, E-mail: whitecf@seu.edu.cn [State Key Laboratory of Bioelectronics, Southeast University, Sipailou Road no. 2, Nanjing, Jiangsu Province 210096 (China); Ge, Qinyu, E-mail: geqinyu@seu.edu.cn [State Key Laboratory of Bioelectronics, Southeast University, Sipailou Road no. 2, Nanjing, Jiangsu Province 210096 (China); Lu, Zuhong, E-mail: zhlu@seu.edu.cn [State Key Laboratory of Bioelectronics, Southeast University, Sipailou Road no. 2, Nanjing, Jiangsu Province 210096 (China)

    2017-06-22

    The reaction temperature is one of the main factors that affect the stability of emulsion PCR (emPCR). Focusing on this point, we applied the “DNA breathing” mechanism in BEAMing (Bead, Emulsion, Amplification, and Magnetic) and proposed a more stable emulsion amplification method. Compared to the conventional emPCR, this method provided excellent results. Firstly, more stable emulsion system resulted in higher percentage of single-molecular amplifications (73.17%). Secondly, an ordinary temperature-controlling device was enough. Our outcome showed that the reaction temperature of this method was not strict so that the ordinary temperature-controlling device was enough for it (the heat block sets vs. the PCR instrument: 13.140 ± 0.110 vs. 13.008 ± 0.039, P = 0.120). Thirdly, the single-biotinylated emP{sub 1} coated streptavidin beads were stable enough to be used for this method (the control temperature vs. the reaction temperature: 2967.91 ± 409.045 vs. 3026.22 ± 442.129, P = 0.334), which could replace the double-biotinylated emP{sub 1} coated beads and was benefit for saving cost. In conclusion, the method presented here with stable emulsion system, simplified temperature-controlling device, and decreased investment would be a highly streamlined and inexpensive option for future single-molecular amplification based researches. - Highlights: • A breathing-based isothermal emulsion amplification (BIEA) method was developed. • BIEA showed excellent properties compared with conventional amplification method. • Terminal breathing of DNA duplex was firstly used in emulsion amplification.

  14. Transcriptome analysis of Callery pear (Pyrus calleryana reveals a comprehensive signalling network in response to Alternaria alternata.

    Directory of Open Access Journals (Sweden)

    Jialiang Kan

    Full Text Available The pear is an important temperate fruit worldwide that is produced by a group of species in the genus Pyrus. Callery pear (Pyrus calleryana Decne is characterized by high resistance to multiple diseases, good adaptability, and high ornamental value, and is therefore widely planted in pear orchards for edible fruit production or as stock. Plant pathogens are a major threat to pear yield. Black spot disease, caused by the filamentous fungus Alternaria alternata, is one of the most serious diseases in pear. Elucidation of resistant genes to black spot disease is extremely important for understanding the underlying mechanisms as well as for the development of resistant cultivars. In this study, high-throughput single-strand RNA-sequencing was used to compare the transcriptome profiles of Callery pear leaves before and after A. alternata incubation for 7 days. The analysis yielded 73.3 Gb of clean data that were mapped onto the reference genome of the Chinese pear, and differentially expressed gene(DEGs were identified with |log2FC| ≥ 1. Functional annotation demonstrated that black spot disease promoted great changes in the overall metabolism, and enrichment analysis of gene ontology terms showed that most of them are closely linked to signalling network and photosynthesis. Specifically, the genes included mainly transcription factors and genes involved in calcium signalling and ethylene and jasmonate pathways. Eight members of the ethylene response factor transcription factor gene family Group IX, including ERF1, ERF7, and ERF105, were up-regulated to 2.03-3.37-fold compared with CK, suggesting their role in the defence response to pathogen infection. Additionally, multiple transcription factors involved in biotic stresses, such as NAC78, NAC2, MYB44, and bHLH28, were up-regulated. Furthermore, we identified 144 long non-coding (lncRNAs, providing new insight into the involvement of lncRNAs in the response to black spot disease. Our study

  15. Highly efficient amplification of chronic wasting disease agent by protein misfolding cyclic amplification with beads (PMCAb.

    Directory of Open Access Journals (Sweden)

    Chad J Johnson

    Full Text Available Protein misfolding cyclic amplification (PMCA has emerged as an important technique for detecting low levels of pathogenic prion protein in biological samples. The method exploits the ability of the pathogenic prion protein to convert the normal prion protein to a proteinase K-resistant conformation. Inclusion of Teflon® beads in the PMCA reaction (PMCAb has been previously shown to increase the sensitivity and robustness of detection for the 263 K and SSLOW strains of hamster-adapted prions. Here, we demonstrate that PMCAb with saponin dramatically increases the sensitivity of detection for chronic wasting disease (CWD agent without compromising the specificity of the assay (i.e., no false positive results. Addition of Teflon® beads increased the robustness of the PMCA reaction, resulting in a decrease in the variability of PMCA results. Three rounds of serial PMCAb allowed detection of CWD agent from a 6.7 × 10(-13 dilution of 10% brain homogenate (1.3 fg of source brain. Titration of the same brain homogenate in transgenic mice expressing cervid prion protein (Tg(CerPrP1536(+/- mice allowed detection of CWD agent from the 10(-6 dilution of 10% brain homogenate. PMCAb is, thus, more sensitive than bioassay in transgenic mice by a factor exceeding 10(5. Additionally, we are able to amplify CWD agent from brain tissue and lymph nodes of CWD-positive white-tailed deer having Prnp alleles associated with reduced disease susceptibility.

  16. The use of the nonlinear models in the growth of pears of ‘Shinseiki’ cultivar

    Directory of Open Access Journals (Sweden)

    Thais Destefani Ribeiro

    2017-12-01

    Full Text Available ABSTRACT: The goal of this study was to elucidate the growth and development of the Asian pear fruit, on the grounds of length, diameter and fresh weight determined over time, using the non-linear Gompertz and Logistic models. The specifications of the models were assessed utilizing the R statistical software, via the least squares method and iterative Gauss-Newton process (DRAPER & SMITH, 2014. The residual standard deviation, adjusted coefficient of determination and the Akaike information criterion were used to compare the models. The residual correlations, observed in the data for length and diameter, were modeled using the second-order regression process to render the residuals independent. The logistic model was highly suitable in demonstrating the data, revealing the Asian pear fruit growth to be sigmoid in shape, showing remarkable development for three variables. It showed an average of up to 125 days for length and diameter and 140 days for fresh fruit weight, with values of 72mm length, 80mm diameter and 224g heavy fat.

  17. Marketability of ready-to-eat cactus pear as affected by temperature and modified atmosphere.

    Science.gov (United States)

    Cefola, Maria; Renna, Massimiliano; Pace, Bernardo

    2014-01-01

    In order to increase the diffusion of cactus pear fruits, in this study, the proper maturity index for peeling and processing them as ready-to-eat product was evaluated and characterized. Thereafter, the effects of different storage temperatures and modified atmosphere conditions on the marketability of ready-to-eat cactus pear were studied. The storage of ready-to-eat fruits at 4 °C in both passive (air) and semi-active (10 kPa O2 and 10 kPa CO2) modified atmosphere improved the marketability by 30%, whereas the storage at 8 °C caused a dangerous reduction in O2 partial pressure inside modified atmosphere packages, due to fruits' increased metabolic activity. A very low level of initial microbial growth was detected, while a severe increase in mesophilic and psychrophilic bacteria was shown in control samples at both temperatures during storage; an inhibitory effect of modified atmosphere on microbial growth was also observed. In conclusion, modified atmosphere improved only the marketability of fruits stored at 4 °C; whereas the storage at 8 °C resulted in deleterious effects on the ready-to-eat fruits, whether stored in air or in modified atmosphere.

  18. Establishment of Nuclear Stock Collections for Apple and Pear in Latvia

    Directory of Open Access Journals (Sweden)

    Zuļģe Neda

    2017-06-01

    Full Text Available Apples and pears are among the most important commercial fruit species grown in Latvia. Because of suitability to local climatic conditions, mainly domestic cultivars and cultivars originating in neighbouring countries are grown. The planting material of pome fruits produced and used for establishment of new orchards in Latvia corresponds to the Conformitas Agraria Communitatis standard due to the unavailability of nuclear stock. To establish virus-tested, experimental nuclear stock for apple and pear, one to two years old candidate plants were exposed to thermotherapy at +38 °C for 40 to 70 days. The mother trees and candidate plants before treatment were tested for the presence of the four most widespread pome fruit viruses by RT-PCR. The shoot tips of the heat-treated plants were grafted onto seedling rootstocks and were re-tested for the four viruses by RT-PCR during the next three to five vegetation seasons. Several plants of apple cultivars ‘Dace’, ‘Zarja Alatau’, ‘Rubin’, and ‘Ausma’ remained infected either with Apple chlorotic leaf spot virus, Apple stem growing virus or Apple stem pitting virus after the thermotherapy. Tests on woody indicators were carried out to determine possible presence of graft-transmittable organisms according to EPPO guidelines for the establishment of nuclear stock material for pome fruits.

  19. Sedimentation of vesicles: from pear-like shapes to microtether extrusion

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Z-H; Viallat, A [INSERM U600, 163, Avenue de Luminy, Case 937, 13288 Marseille Cedex 09 (France); Abkarian, M, E-mail: annie.viallat@inserm.fr [Laboratoire des Colloides Verres et Nanomateriaux UMR 5587, CNRS/UM2, CC2 34095 Montpellier Cedex 5 (France)

    2011-03-15

    We study the sedimentation of buoyant giant lipid vesicles in a quiescent fluid at velocities ranging from 5 to 20 {mu}m s{sup -1}. Floppy vesicles are deformed by the flow. Their bottom (upstream) part remains spherical, while their top (downstream) part narrows down and elongates along the direction of motion, resulting in pear-like shapes or in the reversible formation of a micron-size tube at the vesicle top. The sedimentation velocity of a vesicle is very similar to that of a rigid sphere. Using a thermodynamic approach, we show that the hydrodynamic force acting at the top of a floppy vesicle can exceed the critical force needed to draw a membrane tube. We predict that the tube radius scales as the power 1/3 of the ratio of the bending energy to the typical hydrodynamic stress, {eta}U/R, where {eta} is the fluid viscosity, U the sedimentation velocity and R the vesicle radius. This result is consistent with the previously reported experimental data. The tensions of vesicles exhibiting a tube and of pear-like shape are deduced from the thermodynamic approach.

  20. A novel, highly divergent ssDNA virus identified in Brazil infecting apple, pear and grapevine.

    Science.gov (United States)

    Basso, Marcos Fernando; da Silva, José Cleydson Ferreira; Fajardo, Thor Vinícius Martins; Fontes, Elizabeth Pacheco Batista; Zerbini, Francisco Murilo

    2015-12-02

    Fruit trees of temperate and tropical climates are of great economical importance worldwide and several viruses have been reported affecting their productivity and longevity. Fruit trees of different Brazilian regions displaying virus-like symptoms were evaluated for infection by circular DNA viruses. Seventy-four fruit trees were sampled and a novel, highly divergent, monopartite circular ssDNA virus was cloned from apple, pear and grapevine trees. Forty-five complete viral genomes were sequenced, with a size of approx. 3.4 kb and organized into five ORFs. Deduced amino acid sequences showed identities in the range of 38% with unclassified circular ssDNA viruses, nanoviruses and alphasatellites (putative Replication-associated protein, Rep), and begomo-, curto- and mastreviruses (putative coat protein, CP, and movement protein, MP). A large intergenic region contains a short palindromic sequence capable of forming a hairpin-like structure with the loop sequence TAGTATTAC, identical to the conserved nonanucleotide of circoviruses, nanoviruses and alphasatellites. Recombination events were not detected and phylogenetic analysis showed a relationship with circo-, nano- and geminiviruses. PCR confirmed the presence of this novel ssDNA virus in field plants. Infectivity tests using the cloned viral genome confirmed its ability to infect apple and pear tree seedlings, but not Nicotiana benthamiana. The name "Temperate fruit decay-associated virus" (TFDaV) is proposed for this novel virus. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. [Hypoglycemic effect of extracts of cactus pear fruit polysaccharide in rats].

    Science.gov (United States)

    Liu, Hua-gang; Liang, Qiu-yun; Meng, Hua-lin; Huang, Hui-xue

    2010-02-01

    To study the hypoglycemic effect and mechanism of the extracts of cactus pear fruit polysaccharide (CPFP) in diabetic rats induced by streptozotocin (STZ). The diabetic rats were induced by STZ in SD rats, and randomly divided into model group, insulin group,cactus pear juice group, high dose CPFP group,low dose CPFP group. The experimental rats were administrated for 8 weeks. During the experiment, the contents of blood glucose and blood limit of the rats were detected and body weight were recorded. The pathology of beta cell and alpha cell in pancreas of experimental rats were observed by immunohistochemistry. Compared with model group, the contents of blood glucose, total cholesterol and triglyceride were remarkably decreased in high and low dose CPFP groups. At the same time the body weight was significantly increased in high dose and low dose CPFP groups. The results of immunohistochemical stain demonstrated that the number of islet beta cells was increased and that of islet alpha cells was unchanged in the treatment groups. CPFP can markedly decrease blood glucose and blood limit in STZ-induced diabetic rats. Its mechanism may be related to stimulating the secretion of insulin from beta cells.

  2. Identification of maturity of cuiguan pear based on RobustICA and PSO-ELM

    Science.gov (United States)

    Zhang, Yu; Huang, Yongmei; Lin, Min; Liu, Huijun; Zhou, Xinqi

    2017-08-01

    In order to improve the stability of extreme learning machine (ELM), it was proposed to use the combination of robust independent component analysis (RobustICA) and particle swarm optimization ELM algorithm. It was applied to identify the maturity of cuiguan pear at different growing periods. First the two order derivative and the discrete wavelet transform were adopted to remove the background noise and compression spectra. Then RobustICA was used to decompose the spectra to extract independent components and mixed coefficient matrices. Finally, by using particle swarm optimization, the best input layer weight and hidden layer deviation were obtained and adjusted the number of hidden layer nodes to get the best ELM model to differentiate maturity. The method was used to identify the maturity of cuiguan pear at four different stages, and has strong robustness. The results showed that RobustICA-PSO-ELM had better discrimination ability compared with RobustICA - ELM and ELM, and the accuracy increases from 75% to 94.4%.

  3. Identification of a sex attractant pheromone for male winterform pear psylla, Cacopsylla pyricola.

    Science.gov (United States)

    Guédot, Christelle; Millar, Jocelyn G; Horton, David R; Landolt, Peter J

    2009-12-01

    Pear psylla, Cacopsylla pyricola (Förster) (Hemiptera: Psyllidae), a major economic pest of pears, uses a female-produced sex attractant pheromone. We compared the chemical profiles obtained from cuticular extracts of diapausing and post-diapause winterform males and females to isolate and identify the pheromone. Post-diapause females produced significantly more of the cuticular hydrocarbon, 13-methylheptacosane, than post-diapause males and diapausing females. In olfactometer assays, conspecific males were attracted to synthetic racemic 13-methylheptacosane, whereas females were not, indicating that the behavioral response to this chemical is sex-specific. Furthermore, 13-methylheptacosane was as attractive to males as a cuticular extract of females, suggesting that this chemical was largely responsible for the female attractiveness. A field study showed that males but not females were attracted to 13-methylheptacosane, confirming the olfactometer results. This study provides evidence that 13-methylheptacosane is a sex attractant pheromone for C. pyricola winterform males. This is the first identification of a sex pheromone in the Psylloidea. Our results open the path to developing monitoring tools and possibly new strategies for integrated pest management of this insect.

  4. Nutrition and yield of ‘Gigante’ cactus pear cultivated with different spacings and organic fertilizer

    Directory of Open Access Journals (Sweden)

    Paulo E. R. Donato

    Full Text Available ABSTRACT The objective of this study was to evaluate the levels of macronutrients in cladodes and yield of cactus pear, cv. ‘Gigante’, cultivated with different cattle manure doses and plant spacings. The experimental design was randomized blocks in 4 x 3 factorial, with three replicates. The treatments consisted of the combination of four doses of cattle manure (0, 30, 60 and 90 Mg ha-1 year-1 with three spacings (1.00 x 0.50, 2.00 x 0.25 and 3.00 x 1.00 x 0.25 m. The contents of macronutrients and dry matter production of cladodes were assessed 600 days after planting. The plant spacings influenced the contents of nitrogen, potassium, calcium and sulfur in the cladodes of ‘Gigante’ cactus pear and there was interaction between spacing and manure dose for magnesium contents. The increment in cattle manure doses increases the contents of phosphorus, nitrogen, potassium and sulfur in the cladodes. The maximum dry matter production of cladodes is estimated at 21.8 Mg ha-1 year-1 at a dose of 71.8 Mg ha-1 year-1 of manure.

  5. Postinfection Activity of Synthetic Antimicrobial Peptides Against Stemphylium vesicarium in Pear.

    Science.gov (United States)

    Puig, M; Moragrega, C; Ruz, L; Montesinos, E; Llorente, I

    2014-11-01

    Brown spot of pear is a fungal disease of economic importance caused by Stemphylium vesicarium that affects the pear crops in Europe. Due to the characteristics of this disease and the moderate efficacy of available fungicides, the effectiveness of control measures is very limited; however, synthetic antimicrobial peptides (AMPs) may be a complement to these fungicides. In the present study, 12 AMPs of the CECMEL11 library were screened for fungicidal activity against S. vesicarium. In vitro experiments showed that eight AMPs significantly reduced the germination of conidia. The most effective peptides, BP15, BP22, and BP25, reduced fungal growth and sporulation at concentrations below 50 μM. Leaf assays showed that preventive application of BP15 and BP22 did not reduce infection; however, when the peptides were applied curatively, infection was significantly reduced. The use of a BP15 fluorescein 5-isothiocyanate conjugate revealed that the peptide binds to hyphae and germ tubes and produces malformations that irreversibly stop their development.

  6. HER-2 amplification but not butyrylcholinesterase multability reflects aggressiveness of European-originated ovarian tumors.

    Science.gov (United States)

    Dobianer, K; Hruza, C; Ehrlich, G; Sevelda, P; Czerwenka, K; Soreq, H; Spona, J; Zakut, H

    1995-02-01

    Tumorigenic roles were variably suggested for HER-2 and INT-2 oncogene amplifications and the "atypical" aspartate to glycine mutability in the butyrylcholinesterase (BCHE) gene in ovarian adenocarcinomas. To examine this notion we searched for correlations between these three phenomena and ovarian tumor classification and aggressiveness, using quantitative polymerase chain reaction (PCR), single-strand conformation polymorphism (SSCP), and direct PCR sequencing. Our findings revealed no alleles carrying the atypical BCHE mutability in 30 European-originated patients with ovarian tumors compared with 11% (2/18) such alleles in Israeli patients with malignant ovarian tumors. This apparently reflected population diversity rather than disease relationship. INT-2 amplification was observed in 14/94 (15%) of the European patients; however, there was no correlation between this phenomenon and clinicopathological indices in the corresponding patients. In contrast, in 94 tumor samples we found that 40% (38/94) of the cases had HER-2 amplification. Moreover, there was a highly significant correlation (P < 0.008) between the over fivefold HER-2 amplification and ovarian tumor severity. These findings demonstrate an informative value for HER-2 amplification tests in tumor DNA, but not for INT-2 amplification or BCHE mutability, for the assessment of treatment.

  7. Simple system for isothermal DNA amplification coupled to lateral flow detection.

    Directory of Open Access Journals (Sweden)

    Kristina Roskos

    Full Text Available Infectious disease diagnosis in point-of-care settings can be greatly improved through integrated, automated nucleic acid testing devices. We have developed an early prototype for a low-cost system which executes isothermal DNA amplification coupled to nucleic acid lateral flow (NALF detection in a mesofluidic cartridge attached to a portable instrument. Fluid handling inside the cartridge is facilitated through one-way passive valves, flexible pouches, and electrolysis-driven pumps, which promotes a compact and inexpensive instrument design. The closed-system disposable prevents workspace amplicon contamination. The cartridge design is based on standard scalable manufacturing techniques such as injection molding. Nucleic acid amplification occurs in a two-layer pouch that enables efficient heat transfer. We have demonstrated as proof of principle the amplification and detection of Mycobacterium tuberculosis (M.tb genomic DNA in the cartridge, using either Loop Mediated Amplification (LAMP or the Exponential Amplification Reaction (EXPAR, both coupled to NALF detection. We envision that a refined version of this cartridge, including upstream sample preparation coupled to amplification and detection, will enable fully-automated sample-in to answer-out infectious disease diagnosis in primary care settings of low-resource countries with high disease burden.

  8. Simple System for Isothermal DNA Amplification Coupled to Lateral Flow Detection

    Science.gov (United States)

    Roskos, Kristina; Hickerson, Anna I.; Lu, Hsiang-Wei; Ferguson, Tanya M.; Shinde, Deepali N.; Klaue, Yvonne; Niemz, Angelika

    2013-01-01

    Infectious disease diagnosis in point-of-care settings can be greatly improved through integrated, automated nucleic acid testing devices. We have developed an early prototype for a low-cost system which executes isothermal DNA amplification coupled to nucleic acid lateral flow (NALF) detection in a mesofluidic cartridge attached to a portable instrument. Fluid handling inside the cartridge is facilitated through one-way passive valves, flexible pouches, and electrolysis-driven pumps, which promotes a compact and inexpensive instrument design. The closed-system disposable prevents workspace amplicon contamination. The cartridge design is based on standard scalable manufacturing techniques such as injection molding. Nucleic acid amplification occurs in a two-layer pouch that enables efficient heat transfer. We have demonstrated as proof of principle the amplification and detection of Mycobacterium tuberculosis (M.tb) genomic DNA in the cartridge, using either Loop Mediated Amplification (LAMP) or the Exponential Amplification Reaction (EXPAR), both coupled to NALF detection. We envision that a refined version of this cartridge, including upstream sample preparation coupled to amplification and detection, will enable fully-automated sample-in to answer-out infectious disease diagnosis in primary care settings of low-resource countries with high disease burden. PMID:23922706

  9. Protection from feed-forward amplification in an amplified RNAi mechanism

    Science.gov (United States)

    Pak, Julia; Maniar, Jay Mahesh; Mello, Cecilia Cabral; Fire, Andrew

    2012-01-01

    SUMMARY The effectiveness of RNA interference (RNAi) in many organisms is potentiated through the signal-amplifying activity of a targeted RNA directed RNA polymerase (RdRP) system that can convert a small population of exogenously-encountered dsRNA fragments into an abundant internal pool of small interfering RNA (siRNA). As for any biological amplification system, we expect an underlying architecture that will limit the ability of a randomly encountered trigger to produce an uncontrolled and self-escalating response. Investigating such limits in C. elegans, we find that feed-forward amplification is limited by a critical biosynthetic and structural distinction at the RNA level between (i) triggers that can produce amplification and (ii) siRNA products of the amplification reaction. By assuring that initial (primary) siRNAs can act as triggers but not templates for activation, and that the resulting (secondary) siRNAs can enforce gene silencing on additional targets without unbridled trigger amplification, the system achieves substantial but fundamentally limited signal amplification. PMID:23141544

  10. Loop-mediated isothermal amplification (LAMP) shield for Arduino DNA detection

    NARCIS (Netherlands)

    Velders, Aldrik H.; Schoen, Cor; Saggiomo, Vittorio

    2018-01-01

    Objective: Loop-mediated isothermal amplification (LAMP) of DNA is gaining relevance as a method to detect nucleic acids, as it is easier, faster, and more powerful than conventional Polymerase Chain Reaction. However, LAMP is still mostly used in laboratory settings, because of the lack of a cheap

  11. Development and Fecundity Performance of Oriental Fruit Moth (Lepidoptera: Tortricidae) Reared on Shoots and Fruits of Peach and Pear in Different Seasons.

    Science.gov (United States)

    Du, Juan; Li, Guangwei; Xu, Xiangli; Wu, Junxiang

    2015-12-01

    The oriental fruit moth Grapholita molesta (Busck) is a globally important insect pest. In some parts of its geographic range, the oriental fruit moth shifts its attack from peach orchards to pear orchards late in the growing season. The phenological effects of host plants on the performance of the moth were evaluated by examining the development and fecundity of the moth reared on peach (Prunus persica variety "Shahong") and pear (Pyrus bretshneideri variety "Dangshan Su") collected at various times of the growing season under laboratory conditions. Results showed that the moth developed faster on shoots and fruits of peach than on those of pear. The preimaginal survival rate was the highest on peach shoots, and the moth could not survive on pear fruit collected on May 10. For both peach and pear, the boring rates of neonatal larvae were significantly higher on shoots than on fruits, and the pupal mass of females was significantly higher on fruits than on shoots. The boring rate increased with pear fruits growing during later days. Fecundity was significantly less on pear shoots than on the other plant materials. The results of this study suggest a possible host adaptation process in oriental fruit moth. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Amplification of Chirality through Self-Replication of Micellar Aggregates in Water

    KAUST Repository

    Bukhriakov, Konstantin

    2015-03-17

    We describe a system in which the self-replication of micellar aggregates results in a spontaneous amplification of chirality in the reaction products. In this system, amphiphiles are synthesized from two "clickable" fragments: a water-soluble "head" and a hydrophobic "tail". Under biphasic conditions, the reaction is autocatalytic, as aggregates facilitate the transfer of hydrophobic molecules to the aqueous phase. When chiral, partially enantioenriched surfactant heads are used, a strong nonlinear induction of chirality in the reaction products is observed. Preseeding the reaction mixture with an amphiphile of one chirality results in the amplification of this product and therefore information transfer between generations of self-replicating aggregates. Because our amphiphiles are capable of catalysis, information transfer, and self-assembly into bounded structures, they present a plausible model for prenucleic acid "lipid world" entities. © 2015 American Chemical Society.

  13. [Characteristic wavelengths selection of soluble solids content of pear based on NIR spectral and LS-SVM].

    Science.gov (United States)

    Fan, Shu-xiang; Huang, Wen-qian; Li, Jiang-bo; Zhao, Chun-jiang; Zhang, Bao-hua

    2014-08-01

    To improve the precision and robustness of the NIR model of the soluble solid content (SSC) on pear. The total number of 160 pears was for the calibration (n=120) and prediction (n=40). Different spectral pretreatment methods, including standard normal variate (SNV) and multiplicative scatter correction (MSC) were used before further analysis. A combination of genetic algorithm (GA) and successive projections algorithm (SPA) was proposed to select most effective wavelengths after uninformative variable elimination (UVE) from original spectra, SNV pretreated spectra and MSC pretreated spectra respectively. The selected variables were used as the inputs of least squares-support vector machine (LS-SVM) model to build models for de- termining the SSC of pear. The results indicated that LS-SVM model built using SNVE-UVE-GA-SPA on 30 characteristic wavelengths selected from full-spectrum which had 3112 wavelengths achieved the optimal performance. The correlation coefficient (Rp) and root mean square error of prediction (RMSEP) for prediction sets were 0.956, 0.271 for SSC. The model is reliable and the predicted result is effective. The method can meet the requirement of quick measuring SSC of pear and might be important for the development of portable instruments and online monitoring.

  14. Differences in leaf litter, ascospore production and infection of pear scab (Venturia pirina) in Dutch organic orchards

    NARCIS (Netherlands)

    Timmermans, B.G.H.; Jansonius, P.J.

    2012-01-01

    In 2010 and 2011 the amounts of leaf litter and ascospore production per unit of leaf litter area in 7 organic pear orchards throughout the Netherlands were measured. In one of the orchards, adapted managements strategies were implemented, being grass/clover that is grown as ground cover on the

  15. Response of the pearly eye melon fly Bactrocera cucurbitae (Coquillett)(Diptera:Tephritidae) mutant to host-associated visual cues

    Science.gov (United States)

    We report on a pearly eye mutant (PEM) line generated from a single male Bactrocera cucurbitae collected in Kapoho, Hawaii. Crossing experiments with colony wild-type flies indicate that the locus controlling this trait is autosomal and the mutant allele is recessive. Experiments with females to ass...

  16. Evaluation of novel semiochemical dispensers simultaneously releasing pear ester and sex pheromone for mating disruption of codling moth (Lepidoptera: Tortricidae)

    Science.gov (United States)

    The performance of polyvinyl chloride polymer (pvc) dispensers loaded with two rates of ethyl (E,Z)-2,4-decadienoate (pear ester) plus the sex pheromone, (E,E)-8,10-dodecadien-1-ol (codlemone) of codling moth, Cydia pomonella (L.), was compared with similar dispensers and two commercial dispensers l...

  17. Fibulorhizoctonia psychrophila is the causal agent of lenticel spot on apple and pear fruit in the Netherlands

    NARCIS (Netherlands)

    Wenneker, M.; Pham, K.T.K.; Lemmers, M.E.C.; Boer, de F.A.; Leeuwen, van P.J.; Hollinger, T.C.; Geijn, van de F.G.; Thomma, B.P.H.J.

    2016-01-01

    In a survey for postharvest diseases of apples and pears in the Netherlands, an unknown postharvest fruit rot was observed. The disease appeared to originate from infected lenticels. A fungus was consistently isolated from the decayed fruits. The fungal pathogen was isolated on potato dextrose

  18. The phenolic content and its involvement in the graft incompatibility process of various pear rootstocks (Pyrus communis L.).

    Science.gov (United States)

    Hudina, Metka; Orazem, Primoz; Jakopic, Jerneja; Stampar, Franci

    2014-03-01

    This study investigates the influence of various rootstocks for pear on the phytochemical composition in the phloem above and below the graft union and the role of phenols in pear graft incompatibility. Assays of phloem with cambium from 4-year-old 'Conference', 'Abate Fetel' and 'Williams' pear trees grafted on different rootstocks: Quince MA, Quince BA 29, Fox 11, Farold 40 (Daygon), seedling Pyrus communis L. and own rooted (P. communis L.) were analyzed with HPLC-MS. The most abundant phenolic compound in phloem above and below the graft union was arbutin, followed by procyanidin B1 and chlorogenic acid. In 'Conference' and 'Abate Fetel', higher arbutin content levels were measured above the graft union, while in the incompatible scion of 'Williams' on quince MA higher arbutin content levels were measured below the graft union. In all three observed cultivars (in 'Conference' the difference was not significant) grafted on Fox 11 rootstock, the highest content of arbutin was measured below the graft union. The results indicate that not only catechin and procyanidin B1, but also arbutin and several flavonols could be involved in graft incompatibility. All cultivars grafted on quince rootstocks had higher levels of epicatechin and procyanidin B2 below the graft union, even though some differences were not significant. It seems that those phenols do not affect pear incompatibility. A severe incompatibility between Fox 11 rootstock and 'Williams' was detected. Copyright © 2013 Elsevier GmbH. All rights reserved.

  19. Current management efforts against Cactoblastis cactorum as a pest of North American prickly pear cactus, Opuntia spp.

    Science.gov (United States)

    The unintentional arrival of Cactoblastis cactorum (Lepidoptera: Pyralidae) to Florida changed the scope of this celebrated weed biological control agent from savior to pest. Based on this insects’ substantial control of non-native Opuntia spp. (prickly pear cactus) in Australia and other parts of ...

  20. Potential of osmoadaptation for improving Pantoea agglomerans E325 as biocontrol agent for fire blight of apple and pear

    Science.gov (United States)

    Pantoea agglomerans biocontrol strain E325 is the active ingredient in a commercial product for fire blight, a destructive disease of apple and pear initiated by Erwinia amylovora in flowers. Osmoadaptation, involving the combination of saline osmotic stress and osmolyte amendment to growth media, w...

  1. Ohmic Treatment of Pear Purées (cv. ‘Conference’ in Terms of Some Quality Related Attributes

    Directory of Open Access Journals (Sweden)

    Oana Viorela NISTOR

    2015-06-01

    Full Text Available The effect of ohmic treatment on some quality related characteristics of pear purée (cv. ‘Conference’ such as color, reducing sugars, total phenols, rheological behavior and microbial counts, was analyzed. The inactivation kinetics of pectin methyl esterase (PME in pear crude extract and purée were studied by conventional thermal and ohmic treatments. Thermal inactivation of PME in crude extract was described by a first-order kinetic model. The activation energy values suggested the presence of two isoenzymes with different thermostability. The ohmic heating reduced PME activity by 96% at 25 V·cm-1. Minimal changes induced by ohmic heating on above quality related aspects were observed. Supporting this statement, there were no significant changes in the nutritional and sensorial attributes. It was reported an increase of 3% of reducing sugar content for the ohmic heated samples. The phenolic content of the treated samples registered a reduction of 59% in comparison with fresh pear purée. The pear purée presented a non-Newtonian pseudoplastic behaviour. The Ostwald de Waele model was fitted to rheograms and the consistency coefficient (m and flow behavior index (n were determined. Results obtained for the microbial charge were higher in the control samples. Thus, microbial counts showed complete inactivation of yeast and mold at voltage gradient higher than 17.5 V·cm-1.

  2. Selection of mutants resistant to black spot disease by chronic irradiation of gamma-rays in Japanese pear 'Osanijisseiki'

    International Nuclear Information System (INIS)

    Masuda, Tetsuo; Yoshioka, Toji; Kotobuki, Kazuo; Sanada, Tetsuro; Inoue, Kosuke; Murata, Kenji; Kitagawa, Kenichi; Tabira, Hiroki; Yoshida, Akira

    1997-01-01

    'Osanijisseiki', a self-compatible, spontaneous bud sport of the Japanese pear 'Nijisseiki' is an excellent cultivar with a smooth skin. However, this cultivar is susceptible to Japanese pear black spot disease caused by Alternaria alternata Japanese pear pathotype. To obtain resistant mutants from 'Osanijisseiki', nursery plants of 'Osanijisseiki' have been irradiated chronically with gamma-rays in the Gamma Field of the Institute of Radiation Breeding, NAR, MAFF, since 1986. Screening tests using AK toxin, a host-specific toxin produced by A. alternata Japanese pear pathotype, were performed form 1988 to 1993. Four branches of young trees planted at a distance of 40 m from the 60 Co source were selected as being resistant mutants in 1991 (IRB 502-13T and IRB 502-14T) and 1993 (IRB 502-17T and IRB 502-18T). Sensitivity of the four resistant mutants to AK-toxin and susceptibility to the pathogen were compared with other of susceptible and resistant cultivars. The results showed that these four mutants possessed intermediate resistance. Furthermore, a mutant, IRB 502-13T, had the same characteristics as the original 'Osanijisseiki', except for the difference in toxin sensitivity. The characteristics of the other mutants, IRB 502 14-T, IRB 502-17T, and IRB 502-18T, care being examined. (author)

  3. Improved Control of Postharvest Decay of Pears by the Combination of Candida sake (CPA-1) and Ammonium Molybdate.

    Science.gov (United States)

    Nunes, Carla; Usall, Josep; Teixidó, Neus; Abadias, Maribel; Viñas, Immaculada

    2002-03-01

    ABSTRACT The potential enhancement of Candida sake (CPA-1) by ammonium molybdate to control blue and gray mold caused by Penicillium expansum and Botrytis cinerea, respectively, on Blanquilla pears was investigated. In laboratory trials, improved control of blue and gray molds was obtained with the application of ammonium molybdate (1, 5, 10, and 15 mM) alone or in combination with C. sake at 2 x 10(6) or 2 x 10(7) CFU ml(-1) on Blanquilla pears stored at 20 degrees C. In semicommercial trials at 1 degrees C for 5 months, the efficacy of C. sake at 2 x 10(6) CFU ml(-1) on reducing P. expansum and B. cinerea decay was enhanced more than 88% with the addition of ammonium molybdate 5 mM in the 1999-2000 season. In two seasons, the performance C. sake at 2 x 10(6) CFU ml(-1) plus ammonium molybdate was similar to or greater than that of C. sake at 2 x 10(7) CFU ml(-1). Similar control of blue mold was obtained on pears stored under low oxygen conditions. The preharvest application of ammonium molybdate did not reduce postharvest blue mold decay. The population of C. sake on pear wounds significantly decreased in the presence of ammonium molybdate 1 and 5 mM at 20 and 1 degrees C.

  4. Modeling the effects of temperature and relative humidity on gas exchange of prickly pear cactus (Opuntia spp.) stems

    NARCIS (Netherlands)

    Guevara-Arauza, J.C.; Yahia, E.M.; Cedeno, L.; Tijskens, L.M.M.

    2006-01-01

    A model to estimate gas profile of modified atmosphere packaged (MAP) prickly pear cactus stems was developed and calibrated. The model describes the transient gas exchange taking in consideration the effect of temperature (T) and relative humidity (RH) on film permeability (FPgas), respiration rate

  5. A novel steric effect-regulated isothermal exponential amplification technology for the one-step homogeneous sensing of proteins.

    Science.gov (United States)

    Wu, Wanghua; Pan, Wufan; Yu, Dongdong; Yuan, Zhen; Qin, Yazhou; Lu, Yuxiang; Zhang, Tao; Zhou, Jianguang

    2018-02-12

    A simple and homogeneous technology, the steric effect-regulated isothermal exponential amplification reaction (SER-EXPAR), was developed to sense proteins. By using a small molecule linked DNA nanostructure, termed enzyme-binding hairpin (EBH), the protein-small molecule binding events could be readily sensed by utilizing the steric effect generated between the protein and enzyme. It set free the enzyme to be active again, thus regulating the amplification rate of EXPAR.

  6. Amplification of chirality in liquid crystals

    NARCIS (Netherlands)

    Eelkema, Rienk; Feringa, Ben L.

    2006-01-01

    The amplification of molecular chirality by liquid crystalline systems is widely applied in investigations towards enantioselective solvent - solute interactions, chiral supramolecular assemblies, smart materials, and the development of liquid crystal displays. Here we present an overview of recent

  7. Privacy amplification for quantum key distribution

    International Nuclear Information System (INIS)

    Watanabe, Yodai

    2007-01-01

    This paper examines classical privacy amplification using a universal family of hash functions. In quantum key distribution, the adversary's measurement can wait until the choice of hash functions is announced, and so the adversary's information may depend on the choice. Therefore the existing result on classical privacy amplification, which assumes the independence of the choice from the other random variables, is not applicable to this case. This paper provides a security proof of privacy amplification which is valid even when the adversary's information may depend on the choice of hash functions. The compression rate of the proposed privacy amplification can be taken to be the same as that of the existing one with an exponentially small loss in secrecy of a final key. (fast track communication)

  8. Comparison of the Water Budget for the Typical Cropland and Pear Orchard Ecosystems in the North China Plain

    Science.gov (United States)

    Zhang, Y.; Shen, Y.

    2016-12-01

    Cropland and orchard play important roles in the land use types of the world and China. Water budget for the typical cropland and orchard ecosystem have significant meanings for the water usage and agricultural production, especially in the North China Plain. In this paper, water evapotranspiration (ET) and water balance of the winter wheat - summer maize rotation cropland and pear orchard were studied. Results suggested that annual water consumption for pear trees was 764 mm, which was 74 mm higher than crops (almost equal to once irrigation). Wheat growth needs more water and larger irrigation frequency than maize, while more water consumed in growing season and less in non-growing season. More than 80% of ET took place in April to September. Annual precipitation was 469 mm of pear orchard ecosystem and 444mm of cropland ecosystem, which concentrated in June to September (80%) for these two sites. Irrigation for the pear orchard was 400 mm, which was 100 mm more than the cropland, corresponding with the evapotranspiration. Compared with the precipitation, annual mean water deficit for the pear trees was 294 mm, which was 50 mm higher than the crops. May is the most serious water shortage month, while water surplus happened in July and August. Accumulated water budgets components variation had a very good consistency with the daily change. Annual patterns of plants phenology determined the energy and ET fluxes dynamic change under the timely cultivation and irrigation practices by humans. As the serious water shortage situation in the North China Plain, the government has to carry out reasonable policies and measures to ensure the sustainable water use and water safety and reduce the agricultural water use by the adjustment of crop planting structure.

  9. Morphological, physiological and biochemical responses to soil water deficit in seedlings of three populations of wild pear tree (Pyrus boisseriana

    Directory of Open Access Journals (Sweden)

    Zarafshar, M.

    2014-01-01

    Full Text Available Water shortage limits the production of fruit orchards, such as pear, in arid and semi-arid regions. The identification of wild pear germplasm for potential use as rootstock would be valuable for pear cultivation in semi-arid regions. The relative drought tolerance of wild pear germplasm (Pyrus boisseriana from three different populations distributed along an elevational gradient ('semi-arid 1,000', 'semi-wet 1,350' and 'semi-wet 1,600' populations was evaluated in a greenhouse trial. Established container-grown seedlings were exposed to 18 days of simulated drought, or not, followed by a seven day recovery period. Biomass allocation and accumulation, physiological (stomatal conductance, photosynthesis, transpiration, xylem water potential and biochemical parameters (leaf pigments, free proline, malondialdehyde and hydrogen peroxide production were evaluated. Although all populations were able to recover from water shortage, thereby proving to be relatively drought tolerant, some differences between populations were detected for gas exchange parameters, biomass accumulation and proline concentration in favor of the 'semi-arid 1,000' elevation population, which was more drought tolerant. This population showed the most rapid and complete recovery of physiological activity (stomatal conductance and carbon fixation. In addition, all populations showed an increase in carotenoid content in the leaves. Overall, we showed that plants from the 'semi-arid 1,000' elevation had greater tolerance to drought than those from the higher elevations (semi-wet populations. It therefore appears that plants from the 'semi-arid 1,000' elevation represent a promising source of material to be tested as rootstock for commercial scions of pear in field conditions in areas prone to suffer from water deficit.

  10. Prohexadione calcium reduces vegetative growth and increases fruit set of ‘Smith’ pear trees, in Southern Brazil

    Directory of Open Access Journals (Sweden)

    Bruno Carra

    Full Text Available ABSTRACT Prohexadione calcium (P-Ca has been reported to effectively control shoot growth in several pear cultivars, but with a few reports about its efficiency under the climatic conditions of southern Brazil. Therefore, the objective of this study was to evaluate vegetative growth, production, and fruit quality of ‘Smith’ pear trees in response to the use of different rates of P-Ca in the climatic conditions of southern Brazil. The experiment was conducted during the 2013/2014 and 2014/2015 seasons, in a 6-year-old ‘Smith’ pear orchard, trained to a central-leader system, with spacing of 1.5 × 4.8 m, grafted onto Pyrus calleryana Decne. Different P-Ca rates were applied (100, 200, 300, and 400 mg∙L–1 in different stages: first, in early spring for all treatments, and the others when shoot growth resumed (GR, but only for some treatments. Variables for vegetative growth, yield components and fruit quality at harvest and post-harvest were evaluated. The use of P-Ca was effective to control vegetative growth in both seasons, at different rates. Yield components were not affected by P-Ca applications in 2013/2014, except return bloom and return yield. In 2014/2015 season, P-Ca applications positively affected yield components, except average fruit weight and return bloom. P-Ca applications did not alter the qualitative attributes of the fruits of ‘Smith’ pear trees at harvest and after a period of cold storage. These results implicate P-Ca as a potential tool to manage vigor of ‘Smith’ pear trees in climatic conditions of southern Brazil.

  11. Exposure to minimally processed pear and melon during shelf life could modify the pathogenic potential of Listeria monocytogenes.

    Science.gov (United States)

    Colás-Medà, Pilar; Viñas, Inmaculada; Oliveira, Márcia; Anguera, Marina; Serrano, Jose C E; Abadias, Maribel

    2017-04-01

    Survival and virulence of foodborne pathogens can be influenced by environmental factors such as the intrinsic properties of food as well as the extrinsic properties that contribute to food shelf life (e.g., temperature and gas atmosphere). The direct contribution of food matrix characteristics on the survival of L. monocytogenes during fresh-cut fruit shelf life is not very well understood. In addition, the gastrointestinal tract is the primary route of listeriosis infection and penetration of the intestinal epithelial cell barrier is the first step in the infection process. Hence, the pathogenic potential of L. monocytogenes, measured as the capability for the organism to survive a simulated gastrointestinal tract and the proportion of cells able to subsequently adhere to and invade differentiated Caco-2 cells, subjected to fresh-cut pear and melon shelf life, was investigated. Samples were inoculated, stored at 10 °C for 7 days and evaluated after inoculation and again after 2 and 7 days of storage. A decrease in L. monocytogenes' capacity to survive a simulated gastrointestinal tract was observed with increasing storage time, regardless of the fruit matrix evaluated. Furthermore, L. monocytogenes placed on fresh-cut pear and melon was subjected to an attachment and invasion assay after crossing the simulated gastrointestinal tract. After inoculation, pathogen on fresh-cut pear showed 5-fold more capacity to adhere to Caco-2 cells than pathogen on fresh-cut melon. After 2 days of storage, L. monocytogenes grown on fresh-cut melon showed similar adhesive capacity (1.11%) than cells grown on pear (1.83%), but cells grown on melon had the higher invasive capacity (0.0093%). We can conclude that minimally processed melon could represent a more important hazard than pear under the studied shelf life. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Rolling circle amplification of metazoan mitochondrialgenomes

    Energy Technology Data Exchange (ETDEWEB)

    Simison, W. Brian; Lindberg, D.R.; Boore, J.L.

    2005-07-31

    Here we report the successful use of rolling circle amplification (RCA) for the amplification of complete metazoan mt genomes to make a product that is amenable to high-throughput genome sequencing techniques. The benefits of RCA over PCR are many and with further development and refinement of RCA, the sequencing of organellar genomics will require far less time and effort than current long PCR approaches.

  13. Four-photon parametric amplification in semiconductors

    International Nuclear Information System (INIS)

    Jain, M.; Gersten, J.; Tzoar, N.

    1975-01-01

    A theoretical study of four-photon parametric amplification in narrow-band-gap semiconductors is made. It is shown that phase matching is achievable in a linear geometry if a magnetic field is employed. Furthermore, a substantial cyclotron resonance enhancement occurs in the presence of a magnetic field. We calculate the growth rates and threshold fields associated with the parametric amplification and conclude that an efficient laser may be designed based on this process

  14. Investigation the Frost Resistance of Vegetative and Reproductive Buds of Pear Cultivars in Mashhad Climate Condition

    Directory of Open Access Journals (Sweden)

    shadan khorshidi

    2017-02-01

    Full Text Available Introduction: Most deciduous trees need low temperature to break flower bud dormancy. One of the most important abiotic stresses is low temperature which limits production of temperate fruits. Pear production has been considerably reduced in recent years. Important pear cultivars show different levels of resistance to cold. Cold compatibility followed by resistance increase is controlled genetically and contains several mechanisms which lead to production of different metabolites such as: polypeptides, amino acids and sugars. The object of this research was to evaluate the frost resistance of different ‘Dare Gazi’ genotypes and other pear cultivars in Mashhad climate condition. Materials and Methods: This study was conducted to investigate the frost resistance of 23 ‘Dare Gazi’ pear genotypes and nine other cultivars include: ‘William’s’, ‘Bell de june’, ‘Spadona’, ‘Koshia’, ‘Domkaj’, ‘Torsh’, ‘Sebri’ and ‘Tabrizi’. Plant material contained vegetative and reproductive buds of one-year-old shoot samples which were collected from 25-year old trees on March 2014, four days after winter cold (-6.6 °C in three directions of trees and sent to the laboratory. Frost damages of vegetative and reproductive buds were investigated based on visual observations (%, electrolyte leakage (EC and proline content. EC was measured with a Metrohm 644 digital conductivity meter and proline content was measured based on Bates et al. (1973 method, using acid ninhydrin. The experiment was performed on completely randomized experimental design with three replications. Statistical analysis was carried out using MSTAT-C and Excel software. Mean values were compared using the least significance difference test (LSD at 1% levels. Cluster analysis was conducted by SPSS 16 program. Results and Discussion: Highest EC of reproductive buds was observed in ‘Dare Gazi’ 10, 19, ‘Tabrizi’ and ‘Torsh’ whereas ‘Dare Gazi’ 8, 18

  15. THE LINE FOR PRODUCTION OF DRIED APPLES, PEARS, CARROTS, PUMPKIN AND CHIPS

    Directory of Open Access Journals (Sweden)

    G. V. Kalashnikov

    2015-01-01

    Full Text Available The line is intended for processing of fruit and vegetable raw materials and receiving dried apples, pears, carrots, pumpkins and the fruit-and-vegetable of chips. The line solves problems of improvement of quality of a ready-made product and thermal production efficiency due to more rational alternation of the technological modes of a moisture increment and dehumidification with high extent of use of an energy potential of the heat carrier, use of the inert heat carrier (steam identical by the form for technological thermal processes, decrease in specific energy consumption and metal consumption, and also an intensification of moisture evaporation and creation of the compact multipurpose technological line for production of fruit and vegetable products with the expanded range. The technological production line of dried apples, pears, carrots, pumpkin and fruit and vegetable chips contains the jet washer, the inspection conveyor, the size grader, the car for removal of a seed nest and the device are sharp fruits and vegetables on plates, the sulfiter, the dryer and the packing automatic packing machine. Thus the line contains the combined toroidal device for heatmoisture of handling continuous action divided into sections: section of heating of raw materials, section of convective drying, section of preliminary hydration, which is located between microwave drying sections, and the section of cooling of the dried-up product intended for bringing a product to final readiness. The equipment complex from the drum car with the washing block and multipurpose installation with crushing of raw materials and office of sunflower seeds taking into account raw materials type is provided in lines. Are used recirculation a contour, the heating of the initial raw material fulfilled after drying of pairs and a condensate in the closed contour for creation energy-saving of the "know-how" of a ready product. The line represents modular blocks and is recustomized

  16. Comparison of the influence of defined storing conditions on asian and european pear cultivars

    Directory of Open Access Journals (Sweden)

    Petr Šnurkovič

    2016-12-01

    Full Text Available The study observed changes in the material composition of European (Conference and Asian (Yali pears during the storage period at different temperatures. Three different temperatures were selected for storing, i.e. 1 °C, 5 °C and 20 °C. Assessed for each of the pieces of fruit were flesh firmness, titratable acidity, soluble solids content, content of organic acids, and production of ethylene and carbon dioxide. Fruit stored at 1 °C and 5 °C was analysed before the moment of putting to the store and then after 25, 55 and 70 days of storing. Fruit stored at 20 °C was analysed before the moment of putting to the store and then after 14, 22 and 30 days of storing. The respiration intensity observed through carbon dioxide production at refrigeration conditions was approximately of the same progress for both of the varieties. For the Yali variety, the intensity of respiration of the fruit at the start of the storing period strongly decreased.The same progress was recorded for the Conference variety. Storing at 20 °C increased the respiration intensity. The varieties Yali and Conference which were stored under the temperature of 5 °C had the highest CO2 production after 70 days of storage. For both varieties the lowest ethylene production during storage was observed at 1 °C. Ethylene production was higher in Yali pear fruits. The Yali variety stored at 20 °C from the beginning produced up to 10 times higher concentration of ethylene than the fruit of the Conference variety. The highest amount of ethylen by the Conference variety was produced by the fruits which were stored under the temperature of 5 °C. At the beginning of the storage period the Conference pears had two-fold higher flesh firmness than the Yali fruit. Fruits of the varieties Yali and Conference which were stored 70 days under the temperature of 1 °C had the highest flesh firmness. For soluble solids and titratable acidity no clear progress was recorded. Malic acid was

  17. Design of a New Type of Compact Chemical Heater for Isothermal Nucleic Acid Amplification.

    Science.gov (United States)

    Shah, Kamal G; Guelig, Dylan; Diesburg, Steven; Buser, Joshua; Burton, Robert; LaBarre, Paul; Richards-Kortum, Rebecca; Weigl, Bernhard

    2015-01-01

    Previous chemical heater designs for isothermal nucleic acid amplification have been based on solid-liquid phase transition, but using this approach, developers have identified design challenges en route to developing a low-cost, disposable device. Here, we demonstrate the feasibility of a new heater configuration suitable for isothermal amplification in which one reactant of an exothermic reaction is a liquid-gas phase-change material, thereby eliminating the need for a separate phase-change compartment. This design offers potentially enhanced performance and energy density compared to other chemical and electric heaters.

  18. Heat induces gene amplification in cancer cells

    International Nuclear Information System (INIS)

    Yan, Bin; Ouyang, Ruoyun; Huang, Chenghui; Liu, Franklin; Neill, Daniel; Li, Chuanyuan; Dewhirst, Mark

    2012-01-01

    Highlights: ► This study discovered that heat exposure (hyperthermia) results in gene amplification in cancer cells. ► Hyperthermia induces DNA double strand breaks. ► DNA double strand breaks are considered to be required for the initiation of gene amplification. ► The underlying mechanism of heat-induced gene amplification is generation of DNA double strand breaks. -- Abstract: Background: Hyperthermia plays an important role in cancer therapy. However, as with radiation, it can cause DNA damage and therefore genetic instability. We studied whether hyperthermia can induce gene amplification in cancer cells and explored potential underlying molecular mechanisms. Materials and methods: (1) Hyperthermia: HCT116 colon cancer cells received water-submerged heating treatment at 42 or 44 °C for 30 min; (2) gene amplification assay using N-(phosphoacetyl)-L-aspartate (PALA) selection of cabamyl-P-synthetase, aspartate transcarbarmylase, dihydro-orotase (cad) gene amplified cells; (3) southern blotting for confirmation of increased cad gene copies in PALA-resistant cells; (4) γH2AX immunostaining to detect γH2AX foci as an indication for DNA double strand breaks. Results: (1) Heat exposure at 42 or 44 °C for 30 min induces gene amplification. The frequency of cad gene amplification increased by 2.8 and 6.5 folds respectively; (2) heat exposure at both 42 and 44 °C for 30 min induces DNA double strand breaks in HCT116 cells as shown by γH2AX immunostaining. Conclusion: This study shows that heat exposure can induce gene amplification in cancer cells, likely through the generation of DNA double strand breaks, which are believed to be required for the initiation of gene amplification. This process may be promoted by heat when cellular proteins that are responsible for checkpoints, DNA replication, DNA repair and telomere functions are denatured. To our knowledge, this is the first study to provide direct evidence of hyperthermia induced gene amplification.

  19. AVOCADO PEAR

    African Journals Online (AJOL)

    Dr Osondu

    This study assesses litterfall and nutrient returns to the soil in isolated stands of Persea gratissima in the ... cleared for cultivation, this plant – soil relationship is ..... T-Test for Litter production between Persea gratissima and Adjoining. Rainforest. Sample. Sample site N Mean M.D S.D. S.E.D D/F F. T. Sig. Litter production.

  20. Studies of the shapes of heavy pear-shaped nuclei at ISOLDE

    Energy Technology Data Exchange (ETDEWEB)

    Butler, P. A., E-mail: peter.butler@liverpool.ac.uk [Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE (United Kingdom)

    2016-07-07

    For certain combinations of protons and neutrons there is a theoretical expectation that the shape of nuclei can assume octupole deformation, which would give rise to reflection asymmetry or a ”pear-shape” in the intrinsic frame, either dynamically (octupole vibrations) or statically (permanent octupole deformation). I will briefly review the historic evidence for reflection asymmetry in nuclei and describe how recent experiments carried out at REX-ISOLDE have constrained nuclear theory and how they contribute to tests of extensions of the Standard Model. I will also discuss future prospects for measuring nuclear shapes from Coulomb Excitation: experiments are being planned that will exploit beams from HIE-ISOLDE that are cooled in the TSR storage ring and injected into a solenoidal spectrometer similar to the HELIOS device developed at the Argonne National Laboratory.

  1. Refillable and magnetically actuated drug delivery system using pear-shaped viscoelastic membrane

    KAUST Repository

    So, Hongyun

    2014-07-01

    We report a refillable and valveless drug delivery device actuated by an external magnetic field for on-demand drug release to treat localized diseases. The device features a pear-shaped viscoelastic magnetic membrane inducing asymmetrical deflection and consecutive touchdown motion to the bottom of the dome-shaped drug reservoir in response to a magnetic field, thus achieving controlled discharge of the drug. Maximum drug release with 18 ± 1.5 μg per actuation was achieved under a 500 mT magnetic flux density, and various controlled drug doses were investigated with the combination of the number of accumulated actuations and the strength of the magnetic field.

  2. Sensitivity to gamma irradiation of post-harvest pathogens of pear

    International Nuclear Information System (INIS)

    Geweely, N.S.I.; Nawar, L.S.

    2006-01-01

    Recently, radiation has been used as a fungicidal treatment in the post harvest technology of fruits. The effect of gamma irradiation at doses of 5 - 3000 Gy, on spore germination and mycelial growth of four fungi (Alternaria tenuissima, Botrytis cinerea, Penicillium expansum & Stemphylium botryosum) pathogenic to stored pears were studied. Inhibition of spore germination was found to be directly related to the strength of the radiation dose. B. cinerea and P. expansum were radiation sensitive, while A. tenuissima and S. botryosum were radiation resistant. Exposure of mycelial mat to different radiation doses showed that a dose level of 1000 and 3000 Gy could be considered sufficient for decontamination by the radiosensitive and radio-resistant species, respectively. Regardless of index of mycelial age, young mycelia were more resistant than mature mycelia. The lower doses of gamma radiation increased total proteins and total soluble sugar s of all the tested fungal species but did not effect lipid synthesis

  3. Chemical composition and antibacterial activity of Opuntia ficus-indica f. inermis (cactus pear) flowers.

    Science.gov (United States)

    Ennouri, Monia; Ammar, Imene; Khemakhem, Bassem; Attia, Hamadi

    2014-08-01

    Opuntia ficus-indica f. inermis (cactus pear) flowers have wide application in folk medicine. However, there are few reports focusing on their biological activity and were no reports on their chemical composition. The nutrient composition and hexane extracts of Opuntia flowers at 4 flowering stages and their antibacterial and antifungal activities were investigated. The chemical composition showed considerable amounts of fiber, protein, and minerals. Potassium (K) was the predominant mineral followed by calcium (Ca), magnesium (Mg), sodium (Na), iron (Fe), and zinc (Zn). The main compounds in the various hexane extracts were 9.12-octadecadienoic acid (29-44%) and hexadecanoic acid (8.6-32%). The antibacterial activity tests showed that O. inermis hexane extracts have high effectiveness against Escherichia coli and Staphylococcus aureus, making this botanical source a potential contender as a food preservative or food control additive.

  4. MORPHOLOGICAL CHARACTERISTICS AND FORAGE PRODUCTIVITY OF IRRIGATED CACTUS PEAR UNDER DIFFERENT CUTTING INTENSITIES

    Directory of Open Access Journals (Sweden)

    GUILHERME FERREIRA DA COSTA LIMA

    2016-01-01

    Full Text Available This study evaluated the effect of different cutting intensities and years of harvesting on the morphological characteristics and production of fresh (FMP and dry matter (DMP of cactus pear cv. Gigante (Opuntia ficus-indica Mill under conditions of irrigation, high planting density and fertilization, with 12 months of regrowth. The experimental was completely randomized in a factorial design (3 × 2 with 12 replicates. The treatments were three cutting intensities (preserving the mother cladode (PMC, primary cladodes (PPC, or secondary cladodes (PSC, and two years of harvesting. The soil was classified as Cambisol Haplicum and the irrigation water was classified as C4S1 (EC 5.25 dS.m-1 density of 50,000 plants ha-1. The research evaluated plant height, number of cladodes per plant (NCP, length, width, perimeter and thickness of the cladodes, cladode area (CA, cladode area index (CAI, FMP and DMP. There was no significant interaction between treatments (P > 0.05 for the variables plant height, NCP, CAI and FMP. The variables related to cladode morphology showed a significant interaction (P < 0.05. The treatment PSC resulted in a greater DMP (P < 0.05 with a mean of 27.17 Mg ha-1 yr-1, compared to PPC (18.58 Mg ha-1 yr-1 or PMC (11.78 Mg ha-1 yr-1. The treatment PSC promoted greater NCP and forage productivity at harvest and can be considered as a management practice for the sustainability of cactus pear cv. Gigante under irrigation. The more important morphological characteristics were also influenced by the lower cutting intensities.

  5. Atenolol induced HDL-C change in the pharmacogenomic evaluation of antihypertensive responses (PEAR study.

    Directory of Open Access Journals (Sweden)

    Caitrin W McDonough

    Full Text Available We sought to identify novel pharmacogenomic markers for HDL-C response to atenolol in participants with mild to moderate hypertension. We genotyped 768 hypertensive participants from the Pharmacogenomic Evaluation of Antihypertensive Responses (PEAR study on the Illumina HumanCVD Beadchip. During PEAR, participants were randomized to receive atenolol or hydrochlorothiazide. Blood pressure and cholesterol levels were evaluated at baseline and after treatment. This study focused on participants treated with atenolol monotherapy. Association with atenolol induced HDL-C change was evaluated in 232 whites and 152 African Americans using linear regression. No SNPs achieved a Bonferroni corrected P-value. However, we identified 13 regions with consistent association across whites and African Americans. The most interesting of these regions were seven with prior associations with HDL-C, other metabolic traits, or functional implications in the lipid pathway: GALNT2, FTO, ABCB1, LRP5, STARD3NL, ESR1, and LIPC. Examples are rs2144300 in GALNT2 in whites (P=2.29x10(-4, β=-1.85 mg/dL and rs12595985 in FTO in African Americans (P=2.90x10(-4, β=4.52 mg/dL, both with consistent regional association (P<0.05 in the other race group. Additionally, baseline GALNT2 expression differed by rs2144300 genotype in whites (P=0.0279. In conclusion, we identified multiple gene regions associated with atenolol induced HDL-C change that were consistent across race groups, several with functional implications or prior associations with HDL-C.

  6. Antifungal effect of gamma irradiation and sodium dichloroisocyanurate against Penicillium expansum on pears.

    Science.gov (United States)

    Jeong, R-D; Chu, E-H; Shin, E-J; Lee, E-S; Kwak, Y-S; Park, H-J

    2015-11-01

    Gamma irradiation (GI) was evaluated for its in vitro and in vivo antifungal activity against Penicillium expansum on pear fruits. GI showed a complete inhibition of spore germination, germ tube elongation and mycelial of P. expansum, especially 1·8 kGy. GI affected the membrane integrity and cellular leakage of conidia in a dose-dependent manner. Furthermore, the leakage of protein and sugar from mycelia increased along with the dose. GI was evaluated at lower doses in combination with a chlorine donor, sodium dichloro-s-triazinetrione (NaDCC), to examine the inhibition of P. expansum. Interestingly, only a combined treatment with 0·2 kGy of GI and 70 ppm of NaDCC exhibited significant synergistic antifungal activity. The mechanisms by which the combined treatment decreased the blue mould decay of pear fruits could directly associated with the disruption of the cell membrane of the fungal pathogen, resulting in a loss of cytoplasmic materials from the hyphae. Gamma irradiation (GI) is used as an effective nonchemical approach to inactive pathogens. This study investigated the antifungal effect of gamma irradiation and its combined treatment with a chlorine donor on this fungal pathogen, both in vitro and in vivo. This study emphasized that the integration of low-dose GI and a chlorine donor, NaDCC, exhibited a significant antifungal effect, and that its mechanisms are directly associated with membrane integrity of fungal spores, promising that GI has the potential to be an antifungal approach. © 2015 The Society for Applied Microbiology.

  7. Epidemiological Features and Trends of Brown Spot of Pear Disease Based on the Diversity of Pathogen Populations and Climate Change Effects.

    Science.gov (United States)

    Moragrega, Concepció; Puig, Mireia; Ruz, Lídia; Montesinos, Emilio; Llorente, Isidre

    2018-02-01

    Brown spot of pear, caused by the fungus Stemphylium vesicarium, is an emerging disease of economic importance in several pear-growing areas in Europe. In recent years, new control strategies combining sanitation practices and fungicide applications according to developed forecasting models have been introduced to manage the disease. However, the pathogenic and saprophytic behavior of this pathogen makes it difficult to manage the disease. In addition, climate change can also result in variations in the severity and geographical distribution of the disease. In this study, ecological and epidemiological aspects of brown spot of pear disease related to inoculum characterization and climate change impact were elucidated. The pathogenic variation in S. vesicarium populations from pear orchards and its relationship to inoculum sources (air samples, leaf debris, and infected host and nonhost tissues) was determined using multivariate analysis. In total, six variables related to infection and disease development on cultivar Conference pear detached leaves of 110 S. vesicarium isolates were analyzed. A high proportion of isolates (42%) were nonpathogenic to pear; 85% of these nonpathogenic isolates were recovered from air samples. Most isolates recovered from lesions (93%) and pseudothecia (83%) were pathogenic to pear. A group of pathogenic isolates rapidly infected cultivar Conference pear leaves resulted in disease increase that followed a monomolecular model, whereas some S. vesicarium isolates required a period of time after inoculation to initiate infection and resulted in disease increase that followed a logistic model. The latter group was mainly composed of isolates recovered from pseudothecia on leaf debris, whereas the former group was mainly composed of isolates recovered from lesions on pear fruit and leaves. The relationship between the source of inoculum and pathogenic/aggressiveness profile was confirmed by principal component analysis. The effect of

  8. Visual detection of murray valley encephalitis virus by reverse transcription loop-mediated isothermal amplification.

    Science.gov (United States)

    Gong, Rui; Wang, Han Hua; Qin, Hong; Guo, Xiao Ping; Ma, Xue Jun

    2015-03-01

    A sensitive reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed for rapid visual detection of Murray valley encephalitis virus (MVEV) infection. The reaction was performed in one step in a single tube at 63 °C for 60 min with the addition of the hydroxynaphthol blue (HNB) dye prior to amplification. The detection limit of the RT-LAMP assay was 100 copies per reaction based on 10-fold dilutions of in vitro transcribed RNA derived from a synthetic MVEV DNA template. No cross-reaction was observed with other encephalitis-associated viruses. The assay was further evaluated using spiked cerebrospinal fluid sample with pseudotype virus containing the NS5 gene of MVEV. Copyright © 2015 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  9. A Label-Free and Sensitive Fluorescent Qualitative Assay for Bisphenol A Based on Rolling Circle Amplification/Exonuclease III-Combined Cascade Amplification.

    Science.gov (United States)

    Li, Xia; Song, Juan; Xue, Qing-Wang; You, Fu-Heng; Lu, Xia; Kong, Yan-Cong; Ma, Shu-Yi; Jiang, Wei; Li, Chen-Zhong

    2016-10-21

    Bisphenol A (BPA) detection in drinking water and food packaging materials has attracted much attention since the discovery that BPA can interfere with normal physiological processes and cause adverse health effects. Here, we constructed a label-free aptamer fluorescent assay for selective and sensitive detection of BPA based on the rolling circle amplification (RCA)/Exonuclease III (Exo III)-combined cascade amplification strategy. First, the duplex DNA probe (RP) with anti-BPA aptamer and trigger sequence was designed for BPA recognition and signal amplification. Next, under the action of BPA, the trigger probe was liberated from RP to initiate RCA reaction as primary amplification. Subsequently, the RCA products were used to trigger Exo III assisted secondary amplification with the help of hairpin probes, producing plenty of "G-quadruplex" in lantern-like structures. Finally, the continuously enriched "G-quadruplex lanterns" were lightened by zinc(II)-protoporphyrin IX (ZnPPIX) generating enhanced fluorescence signals. By integrating the primary RCA and secondary Exo III mediated cascade amplification strategy, this method displayed an excellent sensitivity with the detection limits of 5.4 × 10 -17 M. In addition, the anti-BPA aptamer exhibits high recognition ability with BPA, guaranteeing the specificity of detection. The reporter signal probe (G-quadruplex with ZnPPIX) provides a label-free fluorescence signals readout without complicated labeling procedures, making the method simple in design and cost-effective in operation. Moreover, environmental samples analysis was also performed, suggesting that our strategy was reliable and had a great potential application in environmental monitoring.

  10. A Label-Free and Sensitive Fluorescent Qualitative Assay for Bisphenol A Based on Rolling Circle Amplification/Exonuclease III-Combined Cascade Amplification

    Directory of Open Access Journals (Sweden)

    Xia Li

    2016-10-01

    Full Text Available Bisphenol A (BPA detection in drinking water and food packaging materials has attracted much attention since the discovery that BPA can interfere with normal physiological processes and cause adverse health effects. Here, we constructed a label-free aptamer fluorescent assay for selective and sensitive detection of BPA based on the rolling circle amplification (RCA/Exonuclease III (Exo III-combined cascade amplification strategy. First, the duplex DNA probe (RP with anti-BPA aptamer and trigger sequence was designed for BPA recognition and signal amplification. Next, under the action of BPA, the trigger probe was liberated from RP to initiate RCA reaction as primary amplification. Subsequently, the RCA products were used to trigger Exo III assisted secondary amplification with the help of hairpin probes, producing plenty of “G-quadruplex” in lantern-like structures. Finally, the continuously enriched “G-quadruplex lanterns” were lightened by zinc(II-protoporphyrin IX (ZnPPIX generating enhanced fluorescence signals. By integrating the primary RCA and secondary Exo III mediated cascade amplification strategy, this method displayed an excellent sensitivity with the detection limits of 5.4 × 10−17 M. In addition, the anti-BPA aptamer exhibits high recognition ability with BPA, guaranteeing the specificity of detection. The reporter signal probe (G-quadruplex with ZnPPIX provides a label-free fluorescence signals readout without complicated labeling procedures, making the method simple in design and cost-effective in operation. Moreover, environmental samples analysis was also performed, suggesting that our strategy was reliable and had a great potential application in environmental monitoring.

  11. Molecular Characterization, Evolution, and Expression Profiling of the Dirigent (DIR Family Genes in Chinese White Pear (Pyrus bretschneideri

    Directory of Open Access Journals (Sweden)

    Xi Cheng

    2018-04-01

    Full Text Available Stone cells content and size are the key factors determining the internal quality of the pear fruit. Synthesis of lignin and thickening of secondary cell wall are the keys to the development of stone cells. The polymerization of monolignols and secondary cell wall formation requires the participation of dirigent proteins (DIRs. In recent years, DIR family have been studied in higher plants, but lack of comprehensive study in the pear DIR (PbDIR family. This study focuses on the identification and analysis of PbDIR family for the first time. We identified 35 PbDIRs from the pear genome, 89% of which are intronless genes. Phylogenetic tree and chromosome localization analysis showed that 35 PbDIRs were divided into four subfamilies (DIR-a, -b/d, -e, and -g and irregularly distributed among 10 chromosomes. In addition, we identified 29, 26, and 14 DIRs from the other three Rosids (peach, Mei, and grape, respectively. Interspecies microsynteny analysis revealed the collinear gene pairs between pear and peach are the most. Temporal expression analysis showed that the expression changes of seven PbDIRs (DIR-a subfamily: PbDIR4 and PbDIR5; DIR-b/d subfamily: PbDIR11; DIR-g subfamily: PbDIR19; DIR-e subfamily: PbDIR23, 25 and 26 in fruits were consistent with the changes of fruit lignin and stone cells contents. In addition, the subfamily of PbDIRs in fruits showed significant responses after treatment with ABA, SA, and MeJA. According to the protein tertiary structure, key amino acid residues and expression patterns analysis found that PbDIR4 might be involved in the metabolism of lignin and related to stone cells contents in pear fruits. In this study, we systematically analyzed the structure, evolution, function and expression of PbDIR family, which not only confirmed the characteristics of PbDIR family, but also laid the foundation for revealing the role of DIR in pear stone cell development and lignin polymerization.

  12. Multiplexed Recombinase Polymerase Amplification Assay To Detect Intestinal Protozoa.

    Science.gov (United States)

    Crannell, Zachary; Castellanos-Gonzalez, Alejandro; Nair, Gayatri; Mejia, Rojelio; White, A Clinton; Richards-Kortum, Rebecca

    2016-02-02

    This work describes a proof-of-concept multiplex recombinase polymerase amplification (RPA) assay with lateral flow readout that is capable of simultaneously detecting and differentiating DNA from any of the diarrhea-causing protozoa Giardia, Cryptosporidium, and Entamoeba. Together, these parasites contribute significantly to the global burden of diarrheal illness. Differential diagnosis of these parasites is traditionally accomplished via stool microscopy. However, microscopy is insensitive and can miss up to half of all cases. DNA-based diagnostics such as polymerase chain reaction (PCR) are far more sensitive; however, they rely on expensive thermal cycling equipment, limiting their availability to centralized reference laboratories. Isothermal DNA amplification platforms, such as the RPA platform used in this study, alleviate the need for thermal cycling equipment and have the potential to broaden access to more sensitive diagnostics. Until now, multiplex RPA assays have not been developed that are capable of simultaneously detecting and differentiating infections caused by different pathogens. We developed a multiplex RPA assay to detect the presence of DNA from Giardia, Cryptosporidium, and Entamoeba. The multiplex assay was characterized using synthetic DNA, where the limits-of-detection were calculated to be 403, 425, and 368 gene copies per reaction of the synthetic Giardia, Cryptosporidium, and Entamoeba targets, respectively (roughly 1.5 orders of magnitude higher than for the same targets in a singleplex RPA assay). The multiplex assay was also characterized using DNA extracted from live parasites spiked into stool samples where the limits-of-detection were calculated to be 444, 6, and 9 parasites per reaction for Giardia, Cryptosporidium, and Entamoeba parasites, respectively. This proof-of-concept assay may be reconfigured to detect a wide variety of targets by re-designing the primer and probe sequences.

  13. A novel thermostable polymerase for RNA and DNA Loop-mediated isothermal amplification (LAMP

    Directory of Open Access Journals (Sweden)

    Yogesh eChander

    2014-08-01

    Full Text Available Meeting the goal of providing point of care (POC tests for molecular detection of pathogens in low resource settings places stringent demands on all aspects of the technology. OmniAmp DNA polymerase (Pol is a thermostable viral enzyme that enables true POC use in clinics or in field by overcoming important barriers to isothermal amplification. In this paper, we describe the multiple advantages of OmniAmp Pol as an isothermal amplification enzyme and provide examples of its use in loop-mediated isothermal amplification (LAMP for pathogen detection. The inherent reverse transcriptase activity of OmniAmp Pol allows single enzyme detection of RNA targets in RT-LAMP. Common methods of nucleic acid amplification are highly susceptible to sample contaminants, necessitating elaborate nucleic acid purification protocols that are incompatible with POC or field use. OmniAmp Pol was found to be less inhibited by whole blood components typical in certain crude sample preparations . Moreover, the thermostability of the enzyme compared to alternative DNA polymerases (Bst and reverse transcriptases allows pretreatment of complete reaction mixes immediately prior to amplification, which facilitates amplification of highly structured genome regions. Compared to Bst, OmniAmp Pol has a faster time to result, particularly with more dilute templates. Molecular diagnostics in field settings can be challenging due to the lack of refrigeration. The stability of OmniAmp Pol is compatible with a dry format that enables long term storage at ambient temperatures. A final requirement for field operability is compatibility with either commonly available instruments or, in other cases, a simple, inexpensive, portable detection mode requiring minimal training or power. Detection of amplification products is shown using lateral flow strips and analysis on a real-time PCR instrument. Results of this study show that OmniAmp Pol is ideally suited for low resource molecular

  14. LOMA: A fast method to generate efficient tagged-random primers despite amplification bias of random PCR on pathogens

    Directory of Open Access Journals (Sweden)

    Lee Wah

    2008-09-01

    Full Text Available Abstract Background Pathogen detection using DNA microarrays has the potential to become a fast and comprehensive diagnostics tool. However, since pathogen detection chips currently utilize random primers rather than specific primers for the RT-PCR step, bias inherent in random PCR amplification becomes a serious problem that causes large inaccuracies in hybridization signals. Results In this paper, we study how the efficiency of random PCR amplification affects hybridization signals. We describe a model that predicts the amplification efficiency of a given random primer on a target viral genome. The prediction allows us to filter false-negative probes of the genome that lie in regions of poor random PCR amplification and improves the accuracy of pathogen detection. Subsequently, we propose LOMA, an algorithm to generate random primers that have good amplification efficiency. Wet-lab validation showed that the generated random primers improve the amplification efficiency significantly. Conclusion The blind use of a random primer with attached universal tag (random-tagged primer in a PCR reaction on a pathogen sample may not lead to a successful amplification. Thus, the design of random-tagged primers is an important consideration when performing PCR.

  15. Optical nano-biosensing interface via nucleic acid amplification strategy: construction and application.

    Science.gov (United States)

    Zhou, Hong; Liu, Jing; Xu, Jing-Juan; Zhang, Shu-Sheng; Chen, Hong-Yuan

    2018-03-21

    Modern optical detection technology plays a critical role in current clinical detection due to its high sensitivity and accuracy. However, higher requirements such as extremely high detection sensitivity have been put forward due to the clinical needs for the early finding and diagnosing of malignant tumors which are significant for tumor therapy. The technology of isothermal amplification with nucleic acids opens up avenues for meeting this requirement. Recent reports have shown that a nucleic acid amplification-assisted modern optical sensing interface has achieved satisfactory sensitivity and accuracy, high speed and specificity. Compared with isothermal amplification technology designed to work completely in a solution system, solid biosensing interfaces demonstrated better performances in stability and sensitivity due to their ease of separation from the reaction mixture and the better signal transduction on these optical nano-biosensing interfaces. Also the flexibility and designability during the construction of these nano-biosensing interfaces provided a promising research topic for the ultrasensitive detection of cancer diseases. In this review, we describe the construction of the burgeoning number of optical nano-biosensing interfaces assisted by a nucleic acid amplification strategy, and provide insightful views on: (1) approaches to the smart fabrication of an optical nano-biosensing interface, (2) biosensing mechanisms via the nucleic acid amplification method, (3) the newest strategies and future perspectives.

  16. Electricity-free amplification and detection for molecular point-of-care diagnosis of HIV-1.

    Science.gov (United States)

    Singleton, Jered; Osborn, Jennifer L; Lillis, Lorraine; Hawkins, Kenneth; Guelig, Dylan; Price, Will; Johns, Rachel; Ebels, Kelly; Boyle, David; Weigl, Bernhard; LaBarre, Paul

    2014-01-01

    In resource-limited settings, the lack of decentralized molecular diagnostic testing and sparse access to centralized medical facilities can present a critical barrier to timely diagnosis, treatment, and subsequent control and elimination of infectious diseases. Isothermal nucleic acid amplification methods, including reverse transcription loop-mediated isothermal amplification (RT-LAMP), are well-suited for decentralized point-of-care molecular testing in minimal infrastructure laboratories since they significantly reduce the complexity of equipment and power requirements. Despite reduced complexity, however, there is still a need for a constant heat source to enable isothermal nucleic acid amplification. This requirement poses significant challenges for laboratories in developing countries where electricity is often unreliable or unavailable. To address this need, we previously developed a low-cost, electricity-free heater using an exothermic reaction thermally coupled with a phase change material. This heater achieved acceptable performance, but exhibited considerable variability. Furthermore, as an enabling technology, the heater was an incomplete diagnostic solution. Here we describe a more precise, affordable, and robust heater design with thermal standard deviation electricity-free heater and NALF-detection platform, we demonstrate sensitive and repeatable detection of HIV-1 with a ß-actin positive internal amplification control from processed sample to result in less than 80 minutes. Together, these elements are building blocks for an electricity-free platform capable of isothermal amplification and detection of a variety of pathogens.

  17. ESTIMATION OF AMPLIFICATION FACTOR IN EARTHQUAKE ENGINEERING

    Directory of Open Access Journals (Sweden)

    Nazarov Yuriy Pavlovich

    2015-03-01

    Full Text Available The authors are the developers of Odyssey Software (Eurosoft Co. for the analysis of seismological data and computing of seismic loads and their parameters. While communicating with the users of the software, the authors have revealed some uncertainty about both understanding of the term "amplification factor (AF" and calculation of the amplification factor using various methods. In this article, a simple example shows that the determination of the amplification factor as the ratio of the acceleration’s spectrum to the maximal acceleration is derived from the classical definition of AF in the form of the ratio of maximal dynamic displacement to the displacement by the action of static load. Deterministic and probabilistic ap-proaches for the calculating of the AF were discussed. There was an example of AFs calculation and their envelopes for translational and rotational components of seismic impact by using Odyssey Software.

  18. Time varying arctic climate change amplification

    Energy Technology Data Exchange (ETDEWEB)

    Chylek, Petr [Los Alamos National Laboratory; Dubey, Manvendra K [Los Alamos National Laboratory; Lesins, Glen [DALLHOUSIE U; Wang, Muyin [NOAA/JISAO

    2009-01-01

    During the past 130 years the global mean surface air temperature has risen by about 0.75 K. Due to feedbacks -- including the snow/ice albedo feedback -- the warming in the Arctic is expected to proceed at a faster rate than the global average. Climate model simulations suggest that this Arctic amplification produces warming that is two to three times larger than the global mean. Understanding the Arctic amplification is essential for projections of future Arctic climate including sea ice extent and melting of the Greenland ice sheet. We use the temperature records from the Arctic stations to show that (a) the Arctic amplification is larger at latitudes above 700 N compared to those within 64-70oN belt, and that, surprisingly; (b) the ratio of the Arctic to global rate of temperature change is not constant but varies on the decadal timescale. This time dependence will affect future projections of climate changes in the Arctic.

  19. Amplification, Redundancy, and Quantum Chernoff Information

    Science.gov (United States)

    Zwolak, Michael; Riedel, C. Jess; Zurek, Wojciech H.

    2014-04-01

    Amplification was regarded, since the early days of quantum theory, as a mysterious ingredient that endows quantum microstates with macroscopic consequences, key to the "collapse of the wave packet," and a way to avoid embarrassing problems exemplified by Schrödinger's cat. Such a bridge between the quantum microworld and the classical world of our experience was postulated ad hoc in the Copenhagen interpretation. Quantum Darwinism views amplification as replication, in many copies, of the information about quantum states. We show that such amplification is a natural consequence of a broad class of models of decoherence, including the photon environment we use to obtain most of our information. This leads to objective reality via the presence of robust and widely accessible records of selected quantum states. The resulting redundancy (the number of copies deposited in the environment) follows from the quantum Chernoff information that quantifies the information transmitted by a typical elementary subsystem of the environment.

  20. Gravitational Wave Detection via Weak Measurements Amplification

    OpenAIRE

    Hu, Meng-Jun; Zhang, Yong-Sheng

    2017-01-01

    A universal amplification scheme of ultra-small phase based on weak measurements is given and a weak measurements amplification based laser interferometer gravitational-wave observatory (WMA-LIGO) is suggested. The WMA-LIGO has potential to amplify the ultra-small phase signal to at least $10^{3}$ order of magnitude such that the sensitivity and bandwidth of gravitational-wave detector can be further improved. Our results not only shed a new light on the quantum measurement but also open a ne...

  1. Microfluidic polymerase chain reaction

    Science.gov (United States)

    Maltezos, George; Gomez, Alvaro; Zhong, Jiang; Gomez, Frank A.; Scherer, Axel

    2008-12-01

    We implement microfluidic technology to miniaturize a thermal cycling system for amplifying DNA fragments. By using a microfluidic thermal heat exchanger to cool a Peltier junction, we have demonstrated rapid heating and cooling of small volumes of solution. We use a miniature K-type thermocouple to provide a means for in situ sensing of the temperature inside the microrefrigeration system. By combining the thermocouple, two power supplies controlled by a relay system, and computer automation, we reproduce the function of a commercial polymerase chain reaction thermal cycler and demonstrate amplification of a DNA sample of about 1000 base pairs.

  2. Efficacy and timing of some new products against pear psylla (Cacopsylla pyri L. (Hemiptera: Psyllidae: I. Spirotetramat

    Directory of Open Access Journals (Sweden)

    V. Arnaudov

    2016-09-01

    Full Text Available Abstract. Pear psylla (Cacopsylla pyri L. (Hemiptera: Psyllidae is one of the key insect pests in pear orchards of Bulgaria. Field trials to evaluate the efficacy and timing of spirotetramat (Movento 100 SC ® against C. pyri were carried out in a commercial pear orchard in the village Dink near Plovdiv (Bulgaria in 2014 and 2015. Three periods of application were tested against the second summer generation of C. pyri: (А in the presence of predominantly "white" eggs, (B in the presence of predominantly "yellow" eggs and the first hatched larvae, and (C in the presence of about 15 – 30% hatched larvae and nymphs. In all three periods of application spirotetramat (Movento 100 SC applied at a dose of 150 ml/hl effectively reduced the population of pear psylla after only once application. Movento 100 SC applied in the presence of predominantly "white" eggs (A and in the presence of predominantly "yellow" eggs and the first hatched larvae (B demonstrated better efficacy than in the presence of about 15 – 30% hatched larvae and nymphs (C. The efficacy of spirotetramat (Movento100 SC in the first two periods of application (A and (B was similar and insignificantly different from that of the reference insecticide abamectin (Vertimec 18 EC, applied at a dose of 150 ml/hl, but significantly higher than the efficacy of spirotetramat, applied in period (C. The total reduction of larvae at three week post-treatment was at the level of 94.6 - 98.7% for the period (A and (B, 89.7 – 93.3% for the period (C and 94.0 – 98.7% for the reference insecticide - abamectin. The high efficacy observed in different terms of application and long persistence makes this product extremely valuable in controlling populations of C. pyri.

  3. Relationship between shelf-life and optical properties of Yuanhuang pear in the region of 400-1150 nm

    Science.gov (United States)

    He, Xueming; Fu, Xiaping; Rao, Xiuqin; Fang, Zhenhuan

    2016-05-01

    The main goals of this study are to investigate the potential of absorption coefficient for the prediction of water contents in `Yuanhuang' pear and analyze the relationship between the shelf-life and bulk optical properties in the range of 900-1050 nm. An automated integrating sphere (AIS) system was used to measure the total reflectance, total transmittance of pear flesh tissues in visible-Near infrared (Vis-NIR) range. These two measurements were used to estimate the absorption coefficient μa and reduced scattering coefficient μ's of pear samples by using an inverse adding doubling (IAD) light propagation model. The detection accuracy of the AIS system was verified by using both liquid (Intralipid-20% as scatterer) and solid phantom (TiO2 as scatterer, carbon black as absorber). The relative error of measurement of μ's of liquid phantom with four different concentration (0.5%,1%,1.5%,2%) at 632.8 nm, 751 nm, 833 nm are less than 10% except for 2% concentration at 833 nm, and the relative error of measurement μa and μ's of solid phantom at 525.4 nm, 632.1 nm, 710.3 nm and 780.1 nm are less than 5% except for the μa at 525.4 nm. A total of 140 samples were used to conduct the moisture measurement, and drying method was used. Predictive models for moisture content from μa data were constructed using partial least squares regression (PLSR). The coefficient of correlation of calibration set (Rc) and validation set (Rp) were 0.50 and 0.45 respectively. The relationship between the shelf-life and optical properties was analyzed by dividing pear samples into three categories according to the actual shelf-life, and calculating classification accuracy by using actual and calculated shelf-life grade.

  4. Pistil-function breakdown in a new S-allele of European pear, S21*, confers self-compatibility.

    Science.gov (United States)

    Sanzol, Javier

    2009-03-01

    European pear exhibits RNase-based gametophytic self-incompatibility controlled by the polymorphic S-locus. S-allele diversity of cultivars has been extensively investigated; however, no mutant alleles conferring self-compatibility have been reported. In this study, two European pear cultivars, 'Abugo' and 'Ceremeño', were classified as self-compatible after fruit/seed setting and pollen tube growth examination. S-genotyping through S-PCR and sequencing identified a new S-RNase allele in the two cultivars, with identical deduced amino acid sequence as S(21), but differing at the nucleotide level. Test-pollinations and analysis of descendants suggested that the new allele is a self-compatible pistil-mutated variant of S(21), so it was named S(21)*. S-genotypes assigned to 'Abugo' and 'Ceremeño' were S(10)S(21)* and S(21)*S(25) respectively, of which S(25) is a new functional S-allele of European pear. Reciprocal crosses between cultivars bearing S(21) and S(21)* indicated that both alleles exhibit the same pollen function; however, cultivars bearing S(21)* had impaired pistil-S function as they failed to reject either S(21) or S (21)* pollen. RT-PCR analysis showed absence of S(21)* -RNase gene expression in styles of 'Abugo' and 'Ceremeño', suggesting a possible origin for S(21)* pistil dysfunction. Two polymorphisms found within the S-RNase genomic region (a retrotransposon insertion within the intron of S(21)* and indels at the 3'UTR) might explain the different pattern of expression between S(21) and S(21)*. Evaluation of cultivars with unknown S-genotype identified another cultivar 'Azucar Verde' bearing S(21)*, and pollen tube growth examination confirmed self-compatibility for this cultivar as well. This is the first report of a mutated S-allele conferring self-compatibility in European pear.

  5. Anthocyanin biosynthesis in pears is regulated by a R2R3-MYB transcription factor PyMYB10.

    Science.gov (United States)

    Feng, Shouqian; Wang, Yanling; Yang, Song; Xu, Yuting; Chen, Xuesen

    2010-06-01

    Skin color is an important factor in pear breeding programs. The degree of red coloration is determined by the content and composition of anthocyanins. In plants, many MYB transcriptional factors are involved in regulating anthocyanin biosynthesis. In this study, a R2R3-MYB transcription factor gene, PyMYB10, was isolated from Asian pear (Pyrus pyrifolia) cv. 'Aoguan'. Sequence analysis suggested that the PyMYB10 gene was an ortholog of MdMYB10 gene, which regulates anthocyanin biosynthesis in red fleshed apple (Malus x domestica) cv. 'Red Field'. PyMYB10 was identified at the genomic level and had three exons, with its upstream sequence containing core sequences of cis-acting regulatory elements involved in light responsiveness. Fruit bagging showed that light could induce expression of PyMYB10 and anthocyanin biosynthesis. Quantitative real-time PCR revealed that PyMYB10 was predominantly expressed in pear skins, buds, and young leaves, and the level of transcription in buds was higher than in skin and young leaves. In ripening fruits, the transcription of PyMYB10 in the skin was positively correlated with genes in the anthocyanin pathway and with anthocyanin biosynthesis. In addition, the transcription of PyMYB10 and genes of anthocyanin biosynthesis were more abundant in red-skinned pear cultivars compared to blushed cultivars. Transgenic Arabidopsis plants overexpressing PyMYB10 exhibited ectopic pigmentation in immature seeds. The study suggested that PyMYB10 plays a role in regulating anthocyanin biosynthesis and the overexpression of PyMYB10 was sufficient to induce anthocyanin accumulation.

  6. Determination of Quantities of Host Protein after Infection with Erwinia amylovora of Apple, Pear And Quince Cultivars

    Directory of Open Access Journals (Sweden)

    Şerife Çetin

    2014-10-01

    Full Text Available Fire blight disease caused by Erwinia amylovora is a destructive bacterial pathogen mainly on pears, apples and quinces from Rosaceae family. In this study, it was aimed determination of total protein amounts in different apple cultivars (Braeburn, Fuji, Gala and Golden, pear cultivars (Santa Maria and Williams and quince cultivars (Eşme and Ekmek in the infections of two virulent E. amylovora strains (Ea234-1 and Ea240-3 according as the time. It was taken leaf samples after leaf inoculation with E. amylovora (108 CFU ml-1 at 24th, 36th and 72nd hours. For verification of the infections, re-isolations were made from bacteria inoculated plants and the agent was identified as E. amylovora by biochemical, physiological and molecular tests. In determining the amounts of total protein and in the SDS-PAGE analyses were used Bradford and Laemmli methods, respectively, and absorbance values of protein extracts derived from the leaf samples taken, were obtained at 595 nm wavelength. According to the findings obtained; after infection of E. amylovora in the apple varieties comparing to controls, total protein concentrations at 24th hours increased and a decrease in the amount of 36th to 72nd hours and Braeburn has the highest protein content was determined. In the pear varieties, while total protein concentrations at 24th and 36th hours increased, a decrease in the amount of 72nd hour, and Santa Maria variety has the highest protein content was detected. In the quince varieties, total protein concentrations at 72th hour increased and Eşme variety has the highest protein content was identified. As a result of SDS-PAGE analysis, protein fractions which have different molecular weights were obtained. The protein bands were defined approximately 55-70 kDa and 35-55 kDa molecule weight on apple and quince varieties, respectively and also approx. 55-70 kDa in pear varieties.

  7. [Colorimetric detection of HPV6 and HPV16 by loop mediated isothermal amplification].

    Science.gov (United States)

    Lu, Chun-bin; Luo, Le; Yang, Meng-jie; Nie, Kai; Wang, Miao; Ma, Xue-Jun

    2011-01-01

    A simple, rapid and sensitive colorimetric loop mediated isothermal amplification (LAMP) method was established to detect HPV6 and HPV 16 respectively. The method employed a set of four specially designed primers that recognized six distinct sequences of HPV6-E6 or HPV16-E7 for amplification of nucleic acid under isothermal conditions at 63 degrees C for one hour. The amplification process of LAMP was monitored by the addition of HNB (hydroxy naphthol blue) dye prior to amplification. A positive reaction was indicated by a color change from violet to sky blue and confirmed by real-time turbidimeter and agarose electrophoresis. Thirteen cervical swab samples having single infection with 13 different HPV genotypes were examined to evaluate the specificity. A serial dilution of a cloned plasmid containing HPV-E6 or HPV-E7 gene was examined to evaluate the sensitivity. The results showed that no cross-reaction with other HPV genotypes was observed. The colorimetric LAMP assay could achieve a sensitivity of 1000 copies, 10-20 times lower than that of real-time PCR. The assay was further evaluated with 62 clinical specimens and consistent results were obtained compared with the detection using Kai Pu HPV Genotyping Kit. We concluded that this colorimetric LAMP assay had potential usefulness for the rapid screening of the HPV6 or HPV16 infection in the laboratories and hospitals of provincial and municipal region in China.

  8. Loop-mediated isothermal amplification in disposable polyester-toner microdevices.

    Science.gov (United States)

    de Oliveira, Kezia Gomes; Borba, Juliane Cristina; Bailão, Alexandre Melo; de Almeida Soares, Célia Maria; Carrilho, Emanuel; Duarte, Gabriela Rodrigues Mendes

    2017-10-01

    In recent years, isothermal DNA amplification methods have emerged as an alternative in molecular diagnostics due to its ease of operation. The purpose of using isothermal amplification is to simplify the diagnostics work by i) eliminating heating cycles, ii) reducing equipment costs, and iii) providing rapid and accurate results in laboratories with limited resources. Here we show a simple and fast method for E. coli detection in disposable polyester-toner (PeT) microdevice. The amplification by LAMP of the malB gene from E. coli was carried out in a microchamber with 5-μL capacity and the reaction was thermally controlled with a thermoblock at 66 °C for 60 min. The passivation of the surface of PeT channels with BSA improved the efficiency of the LAMP reaction. The detection of amplified LAMP fragments was performed directly on-chip by visual detection and validated with off-chip detection to compare results. Visualization of amplicons directly in the microchip yielded positive reactions as low as 10 double-stranded DNA copies. Separation by gel electrophoresis was able to detect amplicons in reactions that initiated only with one copy of double-stranded DNA. We demonstrate that LAMP in PeT microchip is an important tool for molecular diagnostics at the point-of-care. Copyright © 2017. Published by Elsevier Inc.

  9. Rapid detection of Plasmodium falciparum with isothermal recombinase polymerase amplification and lateral flow analysis

    Science.gov (United States)

    2014-01-01

    Background Nucleic acid amplification is the most sensitive and specific method to detect Plasmodium falciparum. However the polymerase chain reaction remains laboratory-based and has to be conducted by trained personnel. Furthermore, the power dependency for the thermocycling process and the costly equipment necessary for the read-out are difficult to cover in resource-limited settings. This study aims to develop and evaluate a combination of isothermal nucleic acid amplification and simple lateral flow dipstick detection of the malaria parasite for point-of-care testing. Methods A specific fragment of the 18S rRNA gene of P. falciparum was amplified in 10 min at a constant 38°C using the isothermal recombinase polymerase amplification (RPA) method. With a unique probe system added to the reaction solution, the amplification product can be visualized on a simple lateral flow strip without further labelling. The combination of these methods was tested for sensitivity and specificity with various Plasmodium and other protozoa/bacterial strains, as well as with human DNA. Additional investigations were conducted to analyse the temperature optimum, reaction speed and robustness of this assay. Results The lateral flow RPA (LF-RPA) assay exhibited a high sensitivity and specificity. Experiments confirmed a detection limit as low as 100 fg of genomic P. falciparum DNA, corresponding to a sensitivity of approximately four parasites per reaction. All investigated P. falciparum strains (n = 77) were positively tested while all of the total 11 non-Plasmodium samples, showed a negative test result. The enzymatic reaction can be conducted under a broad range of conditions from 30-45°C with high inhibitory concentration of known PCR inhibitors. A time to result of 15 min from start of the reaction to read-out was determined. Conclusions Combining the isothermal RPA and the lateral flow detection is an approach to improve molecular diagnostic for P. falciparum in

  10. Differential expression of anthocyanin biosynthetic genes and transcription factor PcMYB10 in pears (Pyrus communis L..

    Directory of Open Access Journals (Sweden)

    Li Li

    Full Text Available Anthocyanin biosynthesis in various plants is affected by environmental conditions and controlled by the transcription level of the corresponding genes. In pears (Pyrus communis cv. 'Wujiuxiang', anthocyanin biosynthesis is significantly induced during low temperature storage compared with that at room temperature. We further examined the transcriptional levels of anthocyanin biosynthetic genes in 'Wujiuxiang' pears during developmental ripening and temperature-induced storage. The expression of genes that encode flavanone 3-hydroxylase, dihydroflavonol 4-reductase, anthocyanidin synthase, UDP-glucose: flavonoid 3-O-glucosyltransferase, and R2R3 MYB transcription factor (PcMYB10 was strongly positively correlated with anthocyanin accumulation in 'Wujiuxiang' pears in response to both developmental and cold-temperature induction. Hierarchical clustering analysis revealed the expression patterns of the set of target genes, of which PcMYB10 and most anthocyanin biosynthetic genes were related to the same cluster. The present work may help explore the molecular mechanism that regulates anthocyanin biosynthesis and its response to abiotic stress at the transcriptional level in plants.

  11. Optimization of edible coating formulations for improving postharvest quality and shelf life of pear fruit using response surface methodology.

    Science.gov (United States)

    Nandane, A S; Dave, Rudri K; Rao, T V Ramana

    2017-01-01

    The effect of composite edible films containing soy protein isolate (SPI) in combination with additives like hydroxypropyl methylcellulose (HPMC) and olive oil on 'Babughosha' pear ( Pyrus communis L.) stored at ambient temperature (28 ± 5 °C and 60 ± 10% RH) was evaluated using Response surface methodology (RSM). A total of 30 edible coating formulations comprising of SPI (2-6%, w/v), olive oil (0.7-1.1%, v/v), HPMC (0.1-0.5%, w/v) and potassium sorbate (0-0.4% w/v) were evaluated for optimizing the most suitable combination. Quality parameters like weight loss%, TSS, pH and titrable acidity of the stored pears were selected as response variables for optimization. The optimization procedure was carried out using RSM. It was observed that the response variables were mainly effected by concentration of SPI and olive oil in the formulation. Edible coating comprising of SPI 5%, HPMC 0.40%, olive oil 1% and potassium sorbate 0.22% was found to be most suitable combination for pear fruit with predicted values of response variables indicated as weight loss% 3.50, pH 3.41, TSS 11.13 and TA% 0.513.

  12. A pear-derived kairomone with pheromonal potency that attracts male and female codling moth, Cydia pomonella (L.)

    Science.gov (United States)

    Light, Douglas M.; Knight, Alan L.; Henrick, Clive A.; Rajapaska, Dayananda; Lingren, Bill; Dickens, Joseph C.; Reynolds, Katherine M.; Buttery, Ronald G.; Merrill, Gloria; Roitman, James; Campbell, Bruce C.

    2001-08-01

    Ethyl (2 E, 4 Z)-2,4-decadienoate, a pear-derived volatile, is a species-specific, durable, and highly potent attractant to the codling moth (CM), Cydia pomonella (L.), a serious pest of walnuts, apples, and pears worldwide. This kairomone attracts both CM males and virgin and mated females. It is highly attractive to CM in both walnut and apple orchard contexts, but has shown limited effectiveness in a pear orchard context. Rubber septa lures loaded with ethyl (2 E, 4 Z)-2,4-decadienoate remained attractive for several months under field conditions. At the same low microgram load rates on septa, the combined gender capture of CM in kairomone-baited traps was similar to the capture rate of males in traps baited with codlemone, the major sex pheromone component. The particular attribute of attracting CM females renders this kairomone a novel tool for monitoring population flight and mating-ovipositional status, and potentially a major new weapon for directly controlling CM populations.

  13. Detection of fish nocardiosis by loop-mediated isothermal amplification.

    Science.gov (United States)

    Itano, T; Kawakami, H; Kono, T; Sakai, M

    2006-06-01

    Loop-mediated isothermal amplification (LAMP) is a novel method that amplifies DNA with high specificity and rapidity under isothermal conditions. In this study, using the LAMP method, a protocol for detecting Nocardia seriolae which is a causative agent of fish nocardiosis, was designed. A set of four primers, two inner and two outer, were designed based on the sequence of the 16S-23S ribosomal RNA internal transcribed spacer region of N. seriolae. Time and temperature conditions for detection of N. seriolae were optimized for 60 min at 65 degrees C. Other fish pathogen was not amplified by this LAMP system. The detection of N. seriola using LAMP was found to be more sensitive than that by polymerase chain reaction. LAMP is a highly sensitive and rapid diagnostic procedure for detection of N. seriolae. LAMP is a useful diagnostic method for fish nocardiosis.

  14. Bio-cultural anchorage of the prickly pear cactus in Tlalnepantla (Morelos, Mexico

    Directory of Open Access Journals (Sweden)

    Torres-Salcido, Gerardo

    2016-06-01

    Full Text Available The prickly pear cactus is a source of food with strong bio-cultural anchorage in Mexico. This is due to at least three factors: 1 the nature and heritage of cacti; 2 cultural heritage; and 3 the socio-cultural relationships with historical and symbolic roots that have facilitated knowledge of how to cultivate it and how to use it. The aim of this article is to put factors of territorial anchorage and its historical transformation in context by examining the case of the municipality of Tlalnepantla in the state of Morelos, Mexico. This community has experienced accelerated change due to the exchange of traditional crops for the prickly pear cactus and the integration of farming, commercialization and agro-transformation. Our hypothesis is that the market, internal conflicts and a lack of socio-institutional coordination have put social organization into crisis, favoring the territorial spread of the prickly pear cactus and making the Local Agro-Food Systems (LAFS of Tlalnepantla less competitive. The conclusions highlight important economic and social advances whose roots lie in the strengthening and anchorage of the territory-product. However, circumstances both internal and external to the community persist, such as intra-community conflicts, the international market and cultural paradigm shifts that affect the producers and put consolidation of the LAFS at risk.El nopal es un alimento con un fuerte anclaje bio-cultural en México, propiciado por al menos tres factores: 1 la naturaleza y el patrimonio de cactáceas; 2 el patrimonio cultural; y, 3 las relaciones socio-culturales que han permitido un “saber hacer” y un “saber utilizar” con raíces históricas y simbólicas. El objetivo es situar los factores de anclaje territorial y su transformación histórica tomando como caso el municipio de Tlalnepantla, en el estado de Morelos, México. Esta comunidad ha experimentado un acelerado cambio por la reconversión de los cultivos

  15. Optical Pattern Recognition With Self-Amplification

    Science.gov (United States)

    Liu, Hua-Kuang

    1994-01-01

    In optical pattern recognition system with self-amplification, no reference beam used in addressing mode. Polarization of laser beam and orientation of photorefractive crystal chosen to maximize photorefractive effect. Intensity of recognition signal is orders of magnitude greater than other optical correlators. Apparatus regarded as real-time or quasi-real-time optical pattern recognizer with memory and reprogrammability.

  16. Social amplification of risk: a conceptual framework

    International Nuclear Information System (INIS)

    Kasperson, R.E.; Renn, O.; Slovic, P.; Brown, H.S.; Emel, J.; Goble, R.; Kasperson, J.X.; Ratick, S.

    1988-01-01

    One of the most perplexing problems in risk analysis is why some relatively minor risks or risk events, as assessed by technical experts, often elicit strong public concerns and result in substantial impacts upon society and economy. This article sets forth a conceptual framework that seeks to link systematically the technical assessment of risk with psychological, sociological, and cultural perspectives of risk perception and risk-related behavior. The main thesis is that hazards interact with psychological, social, institutional, and cultural processes in ways that may amplify or attenuate public responses to the risk or risk event. A structural description of the social amplification of risk is now possible. Amplification occurs at two stages: in the transfer of information about the risk, and in the response mechanisms of society. Signals about risk are processed by individual and social amplification stations, including the scientist who communicates the risk assessment, the news media, cultural groups, interpersonal networks, and others. Key steps of amplifications can be identified at each stage. The amplified risk leads to behavioral responses, which, in turn, result in secondary impacts. Models are presented that portray the elements and linkages in the proposed conceptual framework

  17. Desert Amplification in a Warming Climate

    Science.gov (United States)

    Zhou, Liming

    2016-01-01

    Here I analyze the observed and projected surface temperature anomalies over land between 50°S-50°N for the period 1950–2099 by large-scale ecoregion and find strongest warming consistently and persistently seen over driest ecoregions such as the Sahara desert and the Arabian Peninsula during various 30-year periods, pointing to desert amplification in a warming climate. This amplification enhances linearly with the global mean greenhouse gases(GHGs) radiative forcing and is attributable primarily to a stronger GHGs-enhanced downward longwave radiation forcing reaching the surface over drier ecoregions as a consequence of a warmer and thus moister atmosphere in response to increasing GHGs. These results indicate that desert amplification may represent a fundamental pattern of global warming associated with water vapor feedbacks over land in low- and mid- latitudes where surface warming rates depend inversely on ecosystem dryness. It is likely that desert amplification might involve two types of water vapor feedbacks that maximize respectively in the tropical upper troposphere and near the surface over deserts, with both being very dry and thus extremely sensitive to changes of water vapor. PMID:27538725

  18. Intelligence amplification framework for enhancing scheduling processes

    NARCIS (Netherlands)

    Dobrkovic, Andrej; Liu, Luyao; Iacob, Maria Eugenia; van Hillegersberg, Jos

    2016-01-01

    The scheduling process in a typical business environment consists of predominantly repetitive tasks that have to be completed in limited time and often containing some form of uncertainty. The intelligence amplification is a symbiotic relationship between a human and an intelligent agent. This

  19. Optical parametric amplification beyond the slowly varying ...

    Indian Academy of Sciences (India)

    The coupled-wave equations describing optical parametric amplification (OPA) are usually solved in the slowly varying amplitude (SVA) approximation regime, in which the second-order derivatives of the signal and idler amplitudes are ignored and in fact the electromagnetic effects due to exit face of the medium is not ...

  20. Desert Amplification in a Warming Climate.

    Science.gov (United States)

    Zhou, Liming

    2016-08-19

    Here I analyze the observed and projected surface temperature anomalies over land between 50°S-50°N for the period 1950-2099 by large-scale ecoregion and find strongest warming consistently and persistently seen over driest ecoregions such as the Sahara desert and the Arabian Peninsula during various 30-year periods, pointing to desert amplification in a warming climate. This amplification enhances linearly with the global mean greenhouse gases(GHGs) radiative forcing and is attributable primarily to a stronger GHGs-enhanced downward longwave radiation forcing reaching the surface over drier ecoregions as a consequence of a warmer and thus moister atmosphere in response to increasing GHGs. These results indicate that desert amplification may represent a fundamental pattern of global warming associated with water vapor feedbacks over land in low- and mid- latitudes where surface warming rates depend inversely on ecosystem dryness. It is likely that desert amplification might involve two types of water vapor feedbacks that maximize respectively in the tropical upper troposphere and near the surface over deserts, with both being very dry and thus extremely sensitive to changes of water vapor.

  1. Small RNA and PARE sequencing in flower bud reveal the involvement of sRNAs in endodormancy release of Japanese pear (Pyrus pyrifolia 'Kosui').

    Science.gov (United States)

    Bai, Songling; Saito, Takanori; Ito, Akiko; Tuan, Pham Anh; Xu, Ying; Teng, Yuanwen; Moriguchi, Takaya

    2016-03-15

    In woody perennial plants, including deciduous fruit trees, such as pear, endodormancy is a strategy for surviving the cold winter. A better understanding of the mechanism underlying the endodormancy phase transition is necessary for developing countermeasures against the effects of global warming. In this study, we analyzed the sRNAome of Japanese pear flower buds in endodormant and ecodormant stages over two seasons by implementing of RNA-seq and degradome-sequencing. We identified 137 conserved or less conserved miRNAs and 50 pear-specific miRNAs. However, none of the conserved microRNAs or pear-specific miRNAs was differentially expressed between endodormancy and ecodormancy stages. On the contrast, 1540 of 218,050 loci that produced sRNAs were differentially expressed between endodormancy and ecodormancy, suggesting their potential roles on the phase transition from endodormancy to ecodomancy. We also characterized a multifunctional miRNA precursor MIR168, which produces two functional miR168 transcripts, namely miR168.1 and miR168.2; cleavage events were predominantly mediated by the non-conserved variant miR168.2 rather than the conserved variant miR168.1. Finally, we showed that a TAS3 trans-acting siRNA triggered phased siRNA within the ORF of one of its target genes, AUXIN RESPONSE FACTOR 4, via the analysis of phased siRNA loci, indicating that siRNAs are able to trigger phased siRNAs in pear. We analyzed the sRNAome of pear flower bud during dormant phase transition. Our work described the sRNA profiles of pear winter buds during dormant phase transition, showing that dormancy release is a highly coordinated physiological process involving the regulation of sRNAs.

  2. Synergistic effects of some essential oils against fungal spoilage on pear fruit.

    Science.gov (United States)

    Nikkhah, Mehdi; Hashemi, Maryam; Habibi Najafi, Mohammad B; Farhoosh, Reza

    2017-09-18

    The development of natural protective agents as alternatives to chemical fungicides is currently in the spotlight. In the present investigation, chemical composition and antifungal activities of thyme, cinnamon, rosemary and marjoram essential oils (EO), as well as synergism of their possible double and triple combinations were investigated. The compositions of the oils were determined by GC/MS. For determination of antifungal activity against Penicillium expansum and Botrytis cinerea, a broth microdilution method was used. The possible interactions of some essential oil combinations were performed by the two and three-dimensional checkerboard assay and isobologram construction. An in vivo antifungal assay was performed by artificial wounding of pear fruits. The maximum antifungal activity was demonstrated by thyme and cinnamon oils which displayed lower MIC values whereas rosemary and marjoram oils with MIC range between 2500 and 10,000μg/mL exhibited weak antifungal activities against tested fungi. In synergy testing, some double combinations (thyme/cinnamon, thyme/rosemary, cinnamon/rosemary) were found to be synergistic (FICi≤0.5). The triple combination of thyme, cinnamon and rosemary was synergistic for B. cinerea and P. expansum (FICi values of 0.5 and 0.375, respectively); while combination of cinnamon, marjoram and thyme exhibited additive and synergistic effect against P. expansum (FIC=0.625) and B. cinerea (FIC=0.375) respectively. The usage of a mathematical Gompertz model in relation to fungal kinetics, showed that the model could be used to predict growth curves (R 2 =0.993±0.05). For B. cinerea, Gompertz parameters for double and triple combination treatments showed significant increase in lag phase (1.92 and 2.92days, respectively) compared to single treatments. Increase lag time up to 2.82days (P<0.05) also observed in P. expansum treated by triple combination of EOs. Base on the results, the lowest maximum growth rate (0.37mm/day) was observed

  3. Current Developments in Prokaryotic Single Cell Whole Genome Amplification

    Energy Technology Data Exchange (ETDEWEB)

    Goudeau, Danielle; Nath, Nandita; Ciobanu, Doina; Cheng, Jan-Fang; Malmstrom, Rex

    2014-03-14

    Our approach to prokaryotic single-cell Whole Genome Amplification at the JGI continues to evolve. To increase both the quality and number of single-cell genomes produced, we explore all aspects of the process from cell sorting to sequencing. For example, we now utilize specialized reagents, acoustic liquid handling, and reduced reaction volumes eliminate non-target DNA contamination in WGA reactions. More specifically, we use a cleaner commercial WGA kit from Qiagen that employs a UV decontamination procedure initially developed at the JGI, and we use the Labcyte Echo for tip-less liquid transfer to set up 2uL reactions. Acoustic liquid handling also dramatically reduces reagent costs. In addition, we are exploring new cell lysis methods including treatment with Proteinase K, lysozyme, and other detergents, in order to complement standard alkaline lysis and allow for more efficient disruption of a wider range of cells. Incomplete lysis represents a major hurdle for WGA on some environmental samples, especially rhizosphere, peatland, and other soils. Finding effective lysis strategies that are also compatible with WGA is challenging, and we are currently assessing the impact of various strategies on genome recovery.

  4. Water-quality, bed-sediment, and biological data, for streams in the upper Prickly Pear Creek watershed, Montana, 2001

    Science.gov (United States)

    Klein, Terry L.; Thamke, Joanna N.; Harper, David D.; Farag, Aïda M.; Nimick, David A.; Fey, David L.

    2003-01-01

    The upper Prickly Pear Creek watershed encompasses the upstream 15 miles of Prickly Pear Creek, south of Helena, Montana (fig. 1). The headwaters of Prickly Pear Creek and its tributaries (Beavertown Creek, Clancy Creek, Dutchman Creek, Golconda Creek, Lump Gulch, Spring Creek, and Warm Springs Creek) are primarily in the Helena National Forest, whereas the central part of the watershed primarily is within either Bureau of Land Management (BLM) or privately owned property. Three mining districts are present in the upper Prickly Pear Creek watershed: Alhambra, Clancy, and Colorado. Numerous prospects, adits, tailings piles, mills, dredge piles, and mines (mostly inactive) are located throughout the watershed. These districts contain polymetallic (Ag, Au, Cu, Pb, Zn) vein deposits and precious-metal (Au-Ag) vein and disseminated deposits that were exploited beginning in the 1860’s. Placer Au deposits in the major streams were extensively mined in the late 1800’s and early 1900’s.As part of a cooperative effort with Federal land management agencies, the U.S. Geological Survey (USGS) is currently using an integrated approach to investigate two mining impacted watersheds in the western United States (the Animas River in Colorado and the Boulder River in Montana). These studies provide the USDA Forest Service and BLM scientific data for implementing informed land-management decisions regarding cleanup of abandoned mine lands within each watershed. A similar integrated-science approach will be used to characterize the upper Prickly Pear Creek watershed with respect to water and streambed sediment chemistry, aquatic biota, and geologic framework. This integrated database presents data that will be used to identify important pathways of metals movement and biological impacts, thereby guiding resource management decisions of land-managers in several publications that are in preparation. Watershed-level characterization in terms of water quality, streambed sediment

  5. Recombinase polymerase amplification: Emergence as a critical molecular technology for rapid, low-resource diagnostics.

    Science.gov (United States)

    James, Ameh; Macdonald, Joanne

    2015-01-01

    Isothermal molecular diagnostics are bridging the technology gap between traditional diagnostics and polymerase chain reaction-based methods. These new techniques enable timely and accurate testing, especially in settings where there is a lack of infrastructure to support polymerase chain reaction facilities. Despite this, there is a significant lack of uptake of these technologies in developing countries where they are highly needed. Among these novel isothermal technologies, recombinase polymerase amplification (RPA) holds particular potential for use in developing countries. This rapid nucleic acid amplification approach is fast, highly sensitive and specific, and amenable to countries with a high burden of infectious diseases. Implementation of RPA technology in developing countries is critically required to assess limitations and potentials of the diagnosis of infectious disease, and may help identify impediments that prevent adoption of new molecular technologies in low resource- and low skill settings. This review focuses on approaching diagnosis of infectious disease with RPA.

  6. Plasmonic Terahertz Amplification in Graphene-Based Asymmetric Hyperbolic Metamaterial

    Directory of Open Access Journals (Sweden)

    Igor Nefedov

    2015-05-01

    Full Text Available We propose and theoretically explore terahertz amplification, based on stimulated generation of plasmons in graphene asymmetric hyperbolic metamaterials (AHMM, strongly coupled to terahertz radiation. In contrast to the terahertz amplification in resonant nanocavities, AHMM provides a wide-band THz amplification without any reflection in optically thin graphene multilayers.

  7. Shape transition with temperature of the pear-shaped nuclei in covariant density functional theory

    Science.gov (United States)

    Zhang, W.; Niu, Y. F.

    2017-11-01

    The shape evolutions of the pear-shaped nuclei 224Ra and even-even Ba-154144 with temperature are investigated by the finite-temperature relativistic mean field theory with the treatment of pairing correlations by the BCS approach. The free energy surfaces as well as the bulk properties including deformations, pairing gaps, excitation energy, and specific heat for the global minimum are studied. For 224Ra, three discontinuities found in the specific heat curve indicate the pairing transition at temperature 0.4 MeV and two shape transitions at temperatures 0.9 and 1.0 MeV, namely one from quadrupole-octupole deformed to quadrupole deformed, and the other from quadrupole deformed to spherical. Furthermore, the gaps at N =136 and Z =88 are responsible for stabilizing the octupole-deformed global minimum at low temperatures. Similar pairing transition at T ˜0.5 MeV and shape transitions at T =0.5 -2.2 MeV are found for even-even Ba-154144. The transition temperatures are roughly proportional to the corresponding deformations at the ground states.

  8. Agrobiodiversity of cactus pear (Opuntia, Cactaceae in the Meridional Highlands Plateau of Mexico

    Directory of Open Access Journals (Sweden)

    Juan Antonio Reyes-Agüero

    2011-08-01

    Full Text Available Mexico is characterized by a remarkable richness of Opuntia, mostly at the Meridional Highlands Plateau; it is also here where the greatest richness of Opuntia variants occurs. Most of these variants have been maintained in homegardens; however, the gathering process which originated these homegardens has been disrupted over the past decades, as a result of social change and the destruction of large wild nopaleras. If the variants still surviving in homegardens are lost, these will be hard to recover, that is, the millenary cultural heritage from the human groups that populated the Mexican Meridional Highland Plateau will be lost forever. This situation motivated the preparation of a catalogue that records the diversity of wild and cultivated Opuntia variants living in the meridional Highlands Plateau. To this end, 379 samples were obtained in 29 localities, between 1998 and 2003. The information was processed through Twinspan. All specimens were identified and preserved in herbaria. Botanical keys and descriptions were elaborated. The catalogue includes information on 126 variants comprising 18 species. There were species with only one variant (Opuntia atropes, O. cochinera, O. jaliscana, O. leucotricha, O. rzedowskii and O. velutina, two (O. durangensis, O. lindheimeri, O. phaeacantha and O. robusta, five (O. joconostle and O. lasiacantha, seven (O. chavena, 12 (O. hyptiacantha and O. streptacantha, 15 (O. ficus-indica, 22 (O. albicarpa, and up to 34 (O. megacantha. Additionally, 267 common cactus pear names were related to those variants.

  9. EFFECTS OF PLANTING DENSITYAND ORGANIC FERTILIZATION DOSES ON PRODUCTIVE EFFICIENCY OF CACTUS PEAR

    Directory of Open Access Journals (Sweden)

    NALÍGIA GOMES DE MIRANDA E SILVA

    2016-01-01

    Full Text Available Cactus is crucial for the livestock of semi - arid regions in Brazil. This plant has shown the high productivity of forage, which is influenced by several management factors. This study aimed to evaluate the effect of organic fertilization doses (20, 40 and 80 t/ ha of bovine manure/ha/two years and planting densities (20, 40, 80 and 160 thousand plants/ha on the productivity of cactus pear Clone IPA - 20 ( Opuntia ficus - indica Mill. At the Experimental Station of Caruaru at the Agronomic Institute of Pernambuco, IPA has conducted the experiment. The experimental design was randomized blocks, with split plot arrangements. Higher shoot productivity was observed with increased population density and the application of manure at 80 t ha - 1two years - 1 with values of 61, 90, 117 and 139 t DM ha - 1 two years - 1 at densities of 20, 40, 80 and 160,000 plants ha - 1. The planting density influenced the productivity of cladode - plant and root dry weight, showing exponential responses, with higher cladode - plant and roots weight by area observed with increased plant density. The efficiency of organic fertilization decreased with the increase in manure doses. For increase cactus productivity, 40 t of bovine manure ha - 1 two years - 1 for plantations with 160,000 plants/ha is recommended.

  10. Pectin isolated from prickly pear (Opuntia SSP) modifies LDL metabolism in cholesterol-fed guinea pigs

    International Nuclear Information System (INIS)

    Fernandez, M.L.; McNamara, D.J.

    1990-01-01

    The effects of dietary pectin on plasma and hepatic cholesterol (CH) levels, plasma lipoprotein profiles, hepatic 3-hydroxy-3-methylglutaryl Coenzyme A (HMG-CoA) reductase activity, and low density lipoprotein (LDL) binding to hepatic membranes were investigated by feeding 1% pectin to guinea pigs on a high CH diet. Animals were fed either chow + 0.25% CH (HC diet) or the CH diet + 1% prickly pear pectin (HC-P diet) for 25 days. Plasma CH levels were decreased 26% by the HC-P with 33% decreases in LDL and KDL. LDL peak density shifted from 1.040 to 1.055 g/ml with pectin. Hepatic total, free and esterified CH levels were reduced 60, 40 and 85% respectively by the HC-P diet. In contrast, HMG-CoA reductase activity was unaffected. 125 I-LDL binding to hepatic membranes was increased by intake of the HC-P diet compared to the HC diet. The affinity of the apo B/E receptor for LDL was not affected by dietary pectin while the receptor number was increased 1.5-fold in animals on the HC-P diet. These data suggest that the parameters of HC metabolism affected by dietary pectin are consistent with an increased demand on the hepatic CH pools which possibly results from increased fecal excretion of bile acids

  11. Where does Grapholita molesta (Busck) (Lepidoptera: Tortricidae) overwinter in adjacent peach, pear and apple orchards?

    Science.gov (United States)

    Yang, X-F; Fan, F; Wang, C; Wei, G-S

    2016-02-01

    The Oriental fruit moth, Grapholita molesta (Lepidoptera: Tortricidae), is a major pest of tree fruits worldwide, and the diapausing larvae overwinter in cryptic habitats. Investigations of overwintering G. molesta were conducted in adjacent peach, pear and apple orchards in Northern China over three consecutive winters to determine the overwintering site and habitat preferences of the moth. Counts of overwintering larvae in the different orchards demonstrated that the late-maturing peach orchard ('Shenzhou honey peach') was the most preferred overwintering habitat with more than 90% of the collected larvae. Larvae were more abundant in host trees, and they very rarely overwintered in the soil. The overwintering site preferences on the host trees were significantly different; over 50% larvae were located in the tree trunks, and followed by main branches. Most of the G. molesta overwintered on the sunny side of the host trees at or below 60 cm from the ground; a few were cocooned on the shaded sides of the trees or greater than 60 cm from the ground. G. molesta began overwintering between August and October, mid- to late September was the peak period for entering winter diapause during 2011-2013 (77.78, 67.59 and 71.15%, respectively). Our findings improve understanding of the orchard habitat and overwintering site preferences of G. molesta and would be useful in the development of efficient forecasting and pest-management strategies for orchards during the winter and early spring.

  12. Differentiation and functional connection of vascular elements in compatible and incompatible pear/quince internode micrografts.

    Science.gov (United States)

    Espen, Luca; Cocucci, Maurizio; Sacchi, Gian Attilio

    2005-11-01

    Micrografts of internodes excised from in vitro grown pear plants (Pyrus communis L. cv. 'Bosc' (B) and cv. 'Butirra Hardy' (BH)) and quince (Cydonia oblonga Mill. East Malling clone C (EMC)), were cultured aseptically to test the effectiveness of their functional vascular reconnection in relation to incompatibility-compatibility relationships that these genotypes exhibit in the field. The incompatible heterograft (B/EMC) showed a marked delay in internode cohesion compared with the autografts (both B/B and BH/BH) and the compatible heterograft (BH/EMC). Even when fused, the translocation of [14C]-sorbitol from upper to lower internode was lower in B/EMC micrografts than in the other combinations. Epifluorescence studies performed with carboxyfluorescin, a specific phloem probe, indicated that the limited translocation was caused by a delay in the establishment of functional phloem continuity between the two internodes. In the B/EMC combination, new differentiated tracheary elements (TE) in the parenchyma tissue at the graft interface between the two internodes were not detected until 30 days after grafting, whereas in the BH/EMC heterograft and both autografts, new xylem connections appeared to cross the interface 20 days after grafting. Immunohistochemical detection (terminal nick-end labeling assay) of the number of cells undergoing nuclear DNA fragmentation at the graft interface confirmed that the limited and delayed TE differentiation in B/EMC heterografts was associated with a decrease in the activity of programmed cell death processes involved in the differentiation of TE.

  13. Antibacterial and antioxidant activities in extracts of fully grown cladodes of 8 cultivars of cactus pear.

    Science.gov (United States)

    Sánchez, E; Dávila-Aviña, J; Castillo, S L; Heredia, N; Vázquez-Alvarado, R; García, S

    2014-04-01

    The antimicrobial and antioxidant activities of some cultivars of the nopal cactus have not been determined. In this study, 8 cultivars of nopal cacti from Mexico were assayed for phenolic content, antioxidant activities, and antimicrobial activities against Campylobacter Jejuni, Vibrio cholera, and Clostridium Perfringens. Plant material was washed, dried, and macerated in methanol. Minimum bactericidal concentrations (MBCs) were determined using the broth microdilution method. Antioxidant activities were quantitatively determined using spectrophotometric methods. The MCBs of the nopal cacti ranged from 1.1 to 12.5 mg/mL for c. jejuni, 4.4 to 30 mg/mL for V. cholera, and 0.8 to 16 mg/mL for C. perfringens in the cultivars Cardon Blanco, Real de Catorce, and Jalpa, respectively. High quantities of total phenols and total flavonoids were found in the Jalpa cacti (3.80 mg of gallic acid equivalent GAE/g dry weight [DW] and 36.64 mg of quercetin equivalents [QE]/g DW, respectively). 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities (RSA) were correlated to bioactive compound contents. The Villanueva cacti had the highest %RSA at 42.31%, and the lowest activity was recorded in Copena V1 at 19.98%. In conclusion, we found that some of the 8 cactus pear cultivars studied may be used for their antioxidant compounds or antimicrobials to control or prevent the contamination of foods. © 2014 Institute of Food Technologists®

  14. Chemical And Physiological Studies On Drought Stress Tolerance Of Irradiated Communis Pear Using Tissue Culture

    International Nuclear Information System (INIS)

    Zaied, N.S.; Ragab, E.A.

    2007-01-01

    The rooted in vitro irradiated pear rootstocks (Pyrus communis) were subjected to drought stress by using different concentrations of mannitol (20, 40, 60, 80 and 100 gm/l), polyethylene glycol (PEG) at concentrations 2, 4, 6, 8 and 10 % to culture medium and also agar at concentrations 6, 8, 10, 12 and 14 gm/l to study their effects on tissue culture and chemical analysis and their tolerance to drought stress. The obtained results showed that the number of shoots, shoot length and number of leaves were higher at 20 and 40 gm/l mannitol. Increasing mannitol concentration enhanced the increase of chlorophyll b, reducing sugars, total indoles and total phenols up to the highest level at 100 gm/l. Adding PEG at concentration 2% to the culture medium encouraged significant increases in the number of shoots and number of leaves and increase chlorophyll a, and non-reducing sugars as well as significant decrease in number of shoots, shoots length, number of leaves, root length and number of roots with increasing agar concentrations to the culture medium. However, decreasing agar concentration in the culture medium induced increase in chlorophyll A and non-reducing sugar

  15. Differential responses in pear and quince genotypes induced by Fe deficiency and bicarbonate.

    Science.gov (United States)

    Donnini, Silvia; Castagna, Antonella; Ranieri, Annamaria; Zocchi, Graziano

    2009-07-15

    Most of the studies carried out on Fe deficiency condition in arboreous plants have been performed, with the exception of those carried out on plants grown in the field, in hydroponic culture utilizing a total iron depletion growth condition. This can cause great stress to plants. By introducing Fe deficiency induced by the presence of bicarbonate, we found significant differences between Pyrus communis L. cv. Conference and Cydonia oblonga Mill. BA29 and MA clones, characterized by different levels of tolerance to chlorosis. Pigment content and the main protein-pigment complexes were investigated by HPLC and protein gel blot analysis, respectively. While similar changes in the structural organization of photosystems (PSs) were observed in both species under Fe deficiency, a different reorganization of the photosynthetic apparatus was found in the presence of bicarbonate between tolerant and susceptible genotypes, in agreement with the photosynthetic electron transport rate measured in isolated thylakoids. In order to characterize the intrinsic factors determining the efficiency of iron uptake in a tolerant genotype, the main mechanisms induced by Fe deficiency in Strategy I species, such as Fe3+-chelate reductase (EC 1.16.1.7) and H+-ATPase (EC 3.6.3.6) activities, were also investigated. We demonstrate that physiological and biochemical root responses in quince and pear are differentially affected by iron starvation and bicarbonate supply, and we show a high correlation between tolerance and Strategy I activation.

  16. Influence of rootstocks on growth, yield, fruit quality and leaf mineral element contents of pear cv. 'Santa Maria' in semi-arid conditions.

    Science.gov (United States)

    Ikinci, Ali; Bolat, Ibrahim; Ercisli, Sezai; Kodad, Ossama

    2014-12-16

    Rootstocks play an essential role to determining orchard performance of fruit trees. Pyrus communis and Cydonia oblonga are widely used rootstocks for European pear cultivars. The lack of rootstocks adapted to different soil conditions and different grafted cultivars is widely acknowledged in pear culture. Cydonia rootstocks (clonal) and Pyrus rootstocks (seedling or clonal) have their advantages and disadvantages. In each case, site-specific environmental characteristics, specific cultivar response and production objectives must be considered before choosing the best rootstock. In this study, the influence of three Quince (BA 29, Quince A = MA, Quince C = MC) and a local European pear seedling rootstocks on the scion yield, some fruit quality characteristics and leaf macro (N, P, K, Ca and Mg) and micro element (Fe, Zn, Cu, Mn and B) content of 'Santa Maria' pear (Pyrus communis L.) were investigated. Trees on seedling rootstock had the highest annual yield, highest cumulative yield (kg tree(-1)), largest trunk cross-sectional area (TCSA), lowest yield efficiency and lowest cumulative yield (ton ha(-1)) in the 10(th) year after planting. The rootstocks had no significant effect on average fruit weight and fruit volume. Significantly higher fruit firmness was obtained on BA 29 and Quince A. The effect of rootstocks on the mineral element accumulation (N, K, Ca, Mg, Fe, Zn, Cu, Mn and B) was significant. Leaf analysis showed that rootstocks used had different mineral uptake efficiencies throughout the early season. The results showed that the rootstocks strongly affected fruit yield, fruit quality and leaf mineral element uptake of 'Santa Maria' pear cultivar. Pear seedling and BA 29 rootstock found to be more prominent in terms of several characteristics for 'Santa Maria' pear cultivar that is grown in highly calcareous soil in semi-arid climate conditions. We determined the highest N, P (although insignificant), K, Ca, Mg, Fe and Cu mineral element concentrations

  17. Influence of rootstocks on growth, yield, fruit quality and leaf mineral element contents of pear cv. 'Santa Maria' in semi-arid conditions

    Directory of Open Access Journals (Sweden)

    Ali Ikinci

    2014-01-01

    Full Text Available BACKGROUND: Rootstocks play an essential role to determining orchard performance of fruit trees. Pyrus communisand Cydonia oblonga are widely used rootstocks for European pear cultivars. The lack of rootstocks adapted to different soil conditions and different grafted cultivars is widely acknowledged in pear culture. Cydonia rootstocks (clonal and Pyrus rootstocks (seedling or clonal have their advantages and disadvantages. In each case, site-specific environmental characteristics, specific cultivar response and production objectives must be considered before choosing the best rootstock. In this study, the influence of three Quince (BA 29, Quince A = MA, Quince C = MC and a local European pear seedling rootstocks on the scion yield, some fruit quality characteristics and leaf macro (N, P, K, Ca and Mg and micro element (Fe, Zn, Cu, Mn and B content of 'Santa Maria' pear (Pyrus communis L. were investigated. RESULTS: Trees on seedling rootstock had the highest annual yield, highest cumulative yield (kg tree−1, largest trunk cross-sectional area (TCSA, lowest yield efficiency and lowest cumulative yield (ton ha−1 in the 10th year after planting. The rootstocks had no significant effect on average fruit weight and fruit volume. Significantly higher fruit firmness was obtained on BA 29 and Quince A. The effect of rootstocks on the mineral element accumulation (N, K, Ca, Mg, Fe, Zn, Cu, Mn and B was significant. Leaf analysis showed that rootstocks used had different mineral uptake efficiencies throughout the early season. CONCLUSION: The results showed that the rootstocks strongly affected fruit yield, fruit quality and leaf mineral element uptake of 'Santa Maria' pear cultivar. Pear seedling and BA 29 rootstock found to be more prominent in terms of several characteristics for 'Santa Maria' pear cultivar that is grown in highly calcareous soil in semi-arid climate conditions. We determined the highest N, P (although insignificant, K, Ca, Mg, Fe

  18. Real-Time Duplex Applications of Loop-Mediated AMPlification (LAMP by Assimilating Probes

    Directory of Open Access Journals (Sweden)

    Ryo Kubota

    2015-03-01

    Full Text Available Isothermal nucleic-acid amplification methods such as Loop-Mediated isothermal AMPlification (LAMP are increasingly appealing alternatives to PCR for use in portable diagnostic system due to the low cost, weight, and power requirements of the instrumentation. As such, interest in developing new probes and other functionality based on the LAMP reaction has been intense. Here, we report on the development of duplexed LAMP assays for pathogen detection using spectrally unique Assimilating Probes. As proof of principle, we used a reaction for Salmonella enterica as a model coupled with a reaction for λ-phage DNA as an internal control, as well as a duplexed assay to sub-type specific quarantine strains of the bacterial wilt pathogen Ralstonia solanacearum. Detection limits for bacterial DNA analyzed in individual reactions was less than 100 genomic equivalents in all cases, and increased by one to two orders of magnitude when reactions were coupled in duplexed formats. Even so, due to the more robust activity of newly available strand-displacing polymerases, the duplexed assays reported here were more powerful than analogous individual reactions reported only a few years ago, and represent a significant advance for incorporation of internal controls to validate assay results in the field.

  19. Comparison of the Soil Dynamic Amplification Factor and Soil Amplification by Using Microtremor and MASW Methods Respectively

    Science.gov (United States)

    Tuncel, Aykut; Cevdet Özdag, Özkan; Pamuk, Eren; Akgün, Mustafa

    2017-12-01

    Single Station Microtremor method, which is widely used nowadays, is an effective and easy applicable method. In this study, dynamic amplification factor distributions of the study area were obtained using scenario earthquake parameters with single station microtremor data gathered at 112 points. In addition, a surface wave active method, which is known as MASW (Multichannel Analysis of Surface Waves), was applied at 43 profiles to calculate the soil amplification values. Dynamic amplification factor (DAF), soil amplification, the predominant soil period (PSP), geology and topography data of the study area were analysed together. Dynamic amplification factor and soil amplification values were obtained 2 or higher at about sea level parts of the study area which are generally composed of alluvial units. Additionally, in high altitude regions that are composed of volcanic rocks, relatively lower dynamic amplification factor and soil amplification values were obtained. The minimum amplification value in the study area was 1.15, while the maximum amplification value was 3.05 according to the dynamic amplification results and the soil amplification values were between 1.16 and 3.85 in harmony. It is seen that the obtained DAF values and the soil amplification values calculated from the seismic velocities are very similar to each other numerically and regionally. Because of this, it is concluded that the values of the soil amplification obtained by the MASW method and the calculated DAF values in this study are in harmony with each other. Although the depths of research in these two calculation methods are different from each other, the similarity of the results allows us to arrive at the result of how effective the ground layer is on the amplification. It has a great importance to calculate the amplification values and other dynamic parameters by in situ measurements for a planned plot because geological units can vary even at very short distances in heterogeneously

  20. A Digital Microfluidics Platform for Loop-Mediated Isothermal Amplification Detection

    Directory of Open Access Journals (Sweden)

    Beatriz Jorge Coelho

    2017-11-01

    Full Text Available Digital microfluidics (DMF arises as the next step in the fast-evolving field of operation platforms for molecular diagnostics. Moreover, isothermal schemes, such as loop-mediated isothermal amplification (LAMP, allow for further simplification of amplification protocols. Integrating DMF with LAMP will be at the core of a new generation of detection devices for effective molecular diagnostics at point-of-care (POC, providing simple, fast, and automated nucleic acid amplification with exceptional integration capabilities. Here, we demonstrate for the first time the role of coupling DMF and LAMP, in a dedicated device that allows straightforward mixing of LAMP reagents and target DNA, as well as optimum temperature control (reaction droplets undergo a temperature variation of just 0.3 °C, for 65 °C at the bottom plate. This device is produced using low-temperature and low-cost production processes, adaptable to disposable and flexible substrates. DMF-LAMP is performed with enhanced sensitivity without compromising reaction efficacy or losing reliability and efficiency, by LAMP-amplifying 0.5 ng/µL of target DNA in just 45 min. Moreover, on-chip LAMP was performed in 1.5 µL, a considerably lower volume than standard bench-top reactions.

  1. Hydrogen sulfide prolongs postharvest storage of fresh-cut pears (Pyrus pyrifolia by alleviation of oxidative damage and inhibition of fungal growth.

    Directory of Open Access Journals (Sweden)

    Kang-Di Hu

    Full Text Available Hydrogen sulfide (H2S has proved to be a multifunctional signaling molecule in plants and animals. Here, we investigated the role of H2S in the decay of fresh-cut pears (Pyrus pyrifolia. H2S gas released by sodium hydrosulfide (NaHS prolonged the shelf life of fresh-cut pear slices in a dose-dependent manner. Moreover, H2S maintained higher levels of reducing sugar and soluble protein in pear slices. H2S significantly reduced the accumulation of hydrogen peroxide (H2O2, superoxide radicals (•O2(- and malondialdehyde (MDA. Further investigation showed that H2S fumigation up-regulated the activities of antioxidant enzymes ascorbate peroxidase (APX, catalase (CAT, and guaiacol peroxidase (POD, while it down-regulated those of lipoxygenase (LOX, phenylalanine ammonia lyase (PAL and polyphenol oxidase (PPO. Furthermore, H2S fumigation effectively inhibited the growth of two fungal pathogens of pear, Aspergillus niger and Penicillium expansum, suggesting that H2S can be developed as an effective fungicide for postharvest storage. The present study implies that H2S is involved in prolonging postharvest storage of pears by acting as an antioxidant and fungicide.

  2. Real-time amplification of HLA-DQA1 for counting residual white blood cells in filtered platelet concentrates

    NARCIS (Netherlands)

    Mohammadi, Tamimount; Reesink, Henk W.; Vandenbroucke-Grauls, Christina M. J. E.; Savelkoul, Paul H. M.

    2004-01-01

    BACKGROUND A real-time polymerase chain reaction (PCR) assay based on amplification of a conserved region of the HLA-DQA1 locus was developed and validated to assess its suitability in quantitating low levels of white blood cells (WBCs) in filtered platelet (PLT) concentrates (PCs). STUDY DESIGN AND

  3. Simple and reliable procedure for PCR amplification of genomic DNA from yeast cells using short sequencing primers

    DEFF Research Database (Denmark)

    Haaning, J; Oxvig, C; Overgaard, Michael Toft

    1997-01-01

    by means of PCR without any prior DNA purification steps. This method involves a simple boiling step of whole yeast cells in the presence of detergent, and subsequent amplification of genomic DNA using short sequencing primers in a polymerase chain reaction assay with a decreasing annealing temperature...

  4. Microfabricated electrochemiluminescence cell for chemical reaction detection

    Science.gov (United States)

    Northrup, M. Allen; Hsueh, Yun-Tai; Smith, Rosemary L.

    2003-01-01

    A detector cell for a silicon-based or non-silicon-based sleeve type chemical reaction chamber that combines heaters, such as doped polysilicon for heating, and bulk silicon for convection cooling. The detector cell is an electrochemiluminescence cell constructed of layers of silicon with a cover layer of glass, with spaced electrodes located intermediate various layers forming the cell. The cell includes a cavity formed therein and fluid inlets for directing reaction fluid therein. The reaction chamber and detector cell may be utilized in any chemical reaction system for synthesis or processing of organic, inorganic, or biochemical reactions, such as the polymerase chain reaction (PCR) and/or other DNA reactions, such as the ligase chain reaction, which are examples of a synthetic, thermal-cycling-based reaction. The ECL cell may also be used in synthesis instruments, particularly those for DNA amplification and synthesis.

  5. Parametric nanomechanical amplification at very high frequency.

    Science.gov (United States)

    Karabalin, R B; Feng, X L; Roukes, M L

    2009-09-01

    Parametric resonance and amplification are important in both fundamental physics and technological applications. Here we report very high frequency (VHF) parametric resonators and mechanical-domain amplifiers based on nanoelectromechanical systems (NEMS). Compound mechanical nanostructures patterned by multilayer, top-down nanofabrication are read out by a novel scheme that parametrically modulates longitudinal stress in doubly clamped beam NEMS resonators. Parametric pumping and signal amplification are demonstrated for VHF resonators up to approximately 130 MHz and provide useful enhancement of both resonance signal amplitude and quality factor. We find that Joule heating and reduced thermal conductance in these nanostructures ultimately impose an upper limit to device performance. We develop a theoretical model to account for both the parametric response and nonequilibrium thermal transport in these composite nanostructures. The results closely conform to our experimental observations, elucidate the frequency and threshold-voltage scaling in parametric VHF NEMS resonators and sensors, and establish the ultimate sensitivity limits of this approach.

  6. Preventing PCR amplification carryover contamination in a clinical laboratory.

    Science.gov (United States)

    Aslanzadeh, Jaber

    2004-01-01

    During the past two decades PCR and several other DNA/RNA amplification techniques have become important diagnostic tools in clinical laboratories. Amplification products contamination has been the main impediment to using these techniques routinely in diagnostic laboratories. Over the years, several creative pre- and post-amplification methods have been developed that prevent amplicon carryover contamination. These procedures, coupled with automated systems that employ real-time amplification and simultaneous detection in a closed system, have substantially reduced the possibility of false positive results due to amplification products carryover contamination.

  7. An integrated portable hand-held analyser for real-time isothermal nucleic acid amplification.

    Science.gov (United States)

    Smith, Matthew C; Steimle, George; Ivanov, Stan; Holly, Mark; Fries, David P

    2007-08-29

    A compact hand-held heated fluorometric instrument for performing real-time isothermal nucleic acid amplification and detection is described. The optoelectronic instrument combines a Printed Circuit Board/Micro Electro Mechanical Systems (PCB/MEMS) reaction detection/chamber containing an integrated resistive heater with attached miniature LED light source and photo-detector and a disposable glass waveguide capillary to enable a mini-fluorometer. The fluorometer is fabricated and assembled in planar geometry, rolled into a tubular format and packaged with custom control electronics to form the hand-held reactor. Positive or negative results for each reaction are displayed to the user using an LED interface. Reaction data is stored in FLASH memory for retrieval via an in-built USB connection. Operating on one disposable 3 V lithium battery >12, 60 min reactions can be performed. Maximum dimensions of the system are 150 mm (h) x 48 mm (d) x 40 mm (w), the total instrument weight (with battery) is 140 g. The system produces comparable results to laboratory instrumentation when performing a real-time nucleic acid sequence-based amplification (NASBA) reaction, and also displayed comparable precision, accuracy and resolution to laboratory-based real-time nucleic acid amplification instrumentation. A good linear response (R2 = 0.948) to fluorescein gradients ranging from 0.5 to 10 microM was also obtained from the instrument indicating that it may be utilized for other fluorometric assays. This instrument enables an inexpensive, compact approach to in-field genetic screening, providing results comparable to laboratory equipment with rapid user feedback as to the status of the reaction.

  8. An integrated portable hand-held analyser for real-time isothermal nucleic acid amplification

    International Nuclear Information System (INIS)

    Smith, Matthew C.; Steimle, George; Ivanov, Stan; Holly, Mark; Fries, David P.

    2007-01-01

    A compact hand-held heated fluorometric instrument for performing real-time isothermal nucleic acid amplification and detection is described. The optoelectronic instrument combines a Printed Circuit Board/Micro Electro Mechanical Systems (PCB/MEMS) reaction detection/chamber containing an integrated resistive heater with attached miniature LED light source and photo-detector and a disposable glass waveguide capillary to enable a mini-fluorometer. The fluorometer is fabricated and assembled in planar geometry, rolled into a tubular format and packaged with custom control electronics to form the hand-held reactor. Positive or negative results for each reaction are displayed to the user using an LED interface. Reaction data is stored in FLASH memory for retrieval via an in-built USB connection. Operating on one disposable 3 V lithium battery >12, 60 min reactions can be performed. Maximum dimensions of the system are 150 mm (h) x 48 mm (d) x 40 mm (w), the total instrument weight (with battery) is 140 g. The system produces comparable results to laboratory instrumentation when performing a real-time nucleic acid sequence-based amplification (NASBA) reaction, and also displayed comparable precision, accuracy and resolution to laboratory-based real-time nucleic acid amplification instrumentation. A good linear response (R 2 = 0.948) to fluorescein gradients ranging from 0.5 to 10 μM was also obtained from the instrument indicating that it may be utilized for other fluorometric assays. This instrument enables an inexpensive, compact approach to in-field genetic screening, providing results comparable to laboratory equipment with rapid user feedback as to the status of the reaction

  9. An integrated portable hand-held analyser for real-time isothermal nucleic acid amplification

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Matthew C. [College of Marine Science, University of South Florida, St Petersburg, FL (United States)], E-mail: msmith@marine.usf.edu; Steimle, George; Ivanov, Stan; Holly, Mark; Fries, David P. [College of Marine Science, University of South Florida, St Petersburg, FL (United States)

    2007-08-29

    A compact hand-held heated fluorometric instrument for performing real-time isothermal nucleic acid amplification and detection is described. The optoelectronic instrument combines a Printed Circuit Board/Micro Electro Mechanical Systems (PCB/MEMS) reaction detection/chamber containing an integrated resistive heater with attached miniature LED light source and photo-detector and a disposable glass waveguide capillary to enable a mini-fluorometer. The fluorometer is fabricated and assembled in planar geometry, rolled into a tubular format and packaged with custom control electronics to form the hand-held reactor. Positive or negative results for each reaction are displayed to the user using an LED interface. Reaction data is stored in FLASH memory for retrieval via an in-built USB connection. Operating on one disposable 3 V lithium battery >12, 60 min reactions can be performed. Maximum dimensions of the system are 150 mm (h) x 48 mm (d) x 40 mm (w), the total instrument weight (with battery) is 140 g. The system produces comparable results to laboratory instrumentation when performing a real-time nucleic acid sequence-based amplification (NASBA) reaction, and also displayed comparable precision, accuracy and resolution to laboratory-based real-time nucleic acid amplification instrumentation. A good linear response (R{sup 2} = 0.948) to fluorescein gradients ranging from 0.5 to 10 {mu}M was also obtained from the instrument indicating that it may be utilized for other fluorometric assays. This instrument enables an inexpensive, compact approach to in-field genetic screening, providing results comparable to laboratory equipment with rapid user feedback as to the status of the reaction.

  10. Amplification of trace amounts of nucleic acids

    Science.gov (United States)

    Church, George M [Brookline, MA; Zhang, Kun [Brighton, MA

    2008-06-17

    Methods of reducing background during amplification of small amounts of nucleic acids employ careful analysis of sources of low level contamination. Ultraviolet light can be used to reduce nucleic acid contaminants in reagents and equipment. "Primer-dimer" background can be reduced by judicious design of primers. We have shown clean signal-to-noise with as little as starting material as one single human cell (.about.6 picogram), E. coli cell (.about.5 femtogram) or Prochlorococcus cell (.about.3 femtogram).

  11. Systematic evaluation of bias in microbial community profiles induced by whole genome amplification.

    Science.gov (United States)

    Direito, Susana O L; Zaura, Egija; Little, Miranda; Ehrenfreund, Pascale; Röling, Wilfred F M

    2014-03-01

    Whole genome amplification methods facilitate the detection and characterization of microbial communities in low biomass environments. We examined the extent to which the actual community structure is reliably revealed and factors contributing to bias. One widely used [multiple displacement amplification (MDA)] and one new primer-free method [primase-based whole genome amplification (pWGA)] were compared using a polymerase chain reaction (PCR)-based method as control. Pyrosequencing of an environmental sample and principal component analysis revealed that MDA impacted community profiles more strongly than pWGA and indicated that this related to species GC content, although an influence of DNA integrity could not be excluded. Subsequently, biases by species GC content, DNA integrity and fragment size were separately analysed using defined mixtures of DNA from various species. We found significantly less amplification of species with the highest GC content for MDA-based templates and, to a lesser extent, for pWGA. DNA fragmentation also interfered severely: species with more fragmented DNA were less amplified with MDA and pWGA. pWGA was unable to amplify low molecular weight DNA (< 1.5 kb), whereas MDA was inefficient. We conclude that pWGA is the most promising method for characterization of microbial communities in low-biomass environments and for currently planned astrobiological missions to Mars. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd.

  12. The role of DNA amplification and cultural growth in complicated acute appendicitis

    Directory of Open Access Journals (Sweden)

    Francesca Tocchioni

    2016-09-01

    Full Text Available Bacterial growth of peritoneal fluid specimens obtained during surgical procedures for acute appendicitis may be useful to optimize further antibiotic therapy in complicated cases. DNA amplification represents a fast technique to detect microbial sequences. We aimed to compare the potential of DNA amplification versus traditional bacterial growth culture highlighting advantages and drawbacks in a surgical setting. Peritoneal fluid specimens were collected during surgery from 36 children who underwent appendectomy between May and December 2012. Real-time polymerase chain reaction (RT-PCR and cultures were performed on each sample. RT-PCR showed an amplification of 16S in 18/36 samples, Escherichia coli (in 7 cases, Pseudomonas aeruginosa (3, Fusobacterium necrophorum (3, Adenovirus (2, E.coli (1, Klebsiella pneumoniae (1, Serratia marcescens/Enterobacter cloacae (1. Bacterial growth was instead observed only in four patients (3 E.coli and 1 P.aeruginosa and Bacteroides ovatus. Preoperative C-reactive protein and inflammation degree, the most reliable indicators of bacterial translocation, were elevated as expected. DNA amplification was a quick and useful method to detect pathogens and it was even more valuable in detecting aggressive pathogens such as anaerobes, difficult to preserve in biological cultures; its drawbacks were the lack of biological growths and of antibiograms. In our pilot study RT-PCR and cultures did not influence the way patients were treated.

  13. New Fpg probe chemistry for direct detection of recombinase polymerase amplification on lateral flow strips.

    Science.gov (United States)

    Powell, Michael L; Bowler, Frank R; Martinez, Aurore J; Greenwood, Catherine J; Armes, Niall; Piepenburg, Olaf

    2018-02-15

    Rapid, cost-effective and sensitive detection of nucleic acids has the ability to improve upon current practices employed for pathogen detection in diagnosis of infectious disease and food testing. Furthermore, if assay complexity can be reduced, nucleic acid amplification tests could be deployed in resource-limited and home use scenarios. In this study, we developed a novel Fpg (Formamidopyrimidine DNA glycosylase) probe chemistry, which allows lateral flow detection of amplification in undiluted recombinase polymerase amplification (RPA) reactions. The prototype nucleic acid lateral flow chemistry was applied to a human genomic target (rs1207445), Campylobacter jejuni 16S rDNA and two genetic markers of the important food pathogen E. coli O157:H7. All four assays have an analytical sensitivity between 10 and 100 copies DNA per amplification. Furthermore, the assay is performed with fewer hands-on steps than using the current RPA Nfo lateral flow method as dilution of amplicon is not required for lateral flow analysis. Due to the simplicity of the workflow, we believe that the lateral flow chemistry for direct detection could be readily adapted to a cost-effective single-use consumable, ideal for use in non-laboratory settings. Copyright © 2017. Published by Elsevier Inc.

  14. Development of an Automated Microfluidic System for DNA Collection, Amplification, and Detection of Pathogens

    Energy Technology Data Exchange (ETDEWEB)

    Hagan, Bethany S.; Bruckner-Lea, Cynthia J.

    2002-12-01

    This project was focused on developing and testing automated routines for a microfluidic Pathogen Detection System. The basic pathogen detection routine has three primary components; cell concentration, DNA amplification, and detection. In cell concentration, magnetic beads are held in a flow cell by an electromagnet. Sample liquid is passed through the flow cell and bacterial cells attach to the beads. These beads are then released into a small volume of fluid and delivered to the peltier device for cell lysis and DNA amplification. The cells are lysed during initial heating in the peltier device, and the released DNA is amplified using polymerase chain reaction (PCR) or strand displacement amplification (SDA). Once amplified, the DNA is then delivered to a laser induced fluorescence detection unit in which the sample is detected. These three components create a flexible platform that can be used for pathogen detection in liquid and sediment samples. Future developments of the system will include on-line DNA detection during DNA amplification and improved capture and release methods for the magnetic beads during cell concentration.

  15. A large ungated TPC with GEM amplification

    Science.gov (United States)

    Berger, M.; Ball, M.; Fabbietti, L.; Ketzer, B.; Arora, R.; Beck, R.; Böhmer, F. V.; Chen, J.-C.; Cusanno, F.; Dørheim, S.; García, F.; Hehner, J.; Herrmann, N.; Höppner, C.; Kaiser, D.; Kis̆, M.; Kleipa, V.; Konorov, I.; Kunkel, J.; Kurz, N.; Leifels, Y.; Müllner, P.; Münzer, R.; Neubert, S.; Rauch, J.; Schmidt, C. J.; Schmitz, R.; Soyk, D.; Vandenbroucke, M.; Voss, B.; Walther, D.; Zmeskal, J.

    2017-10-01

    A Time Projection Chamber (TPC) is an ideal device for the detection of charged particle tracks in a large volume covering a solid angle of almost 4 π. The high density of hits on a given particle track facilitates the task of pattern recognition in a high-occupancy environment and in addition provides particle identification by measuring the specific energy loss for each track. For these reasons, TPCs with Multiwire Proportional Chamber (MWPC) amplification have been and are widely used in experiments recording heavy-ion collisions. A significant drawback, however, is the large dead time of the order of 1 ms per event generated by the use of a gating grid, which is mandatory to prevent ions created in the amplification region from drifting back into the drift volume, where they would severely distort the drift path of subsequent tracks. For experiments with higher event rates this concept of a conventional TPC operating with a triggered gating grid can therefore not be applied without a significant loss of data. A continuous readout of the signals is the more appropriate way of operation. This, however, constitutes a change of paradigm with considerable challenges to be met concerning the amplification region, the design and bandwidth of the readout electronics, and the data handling. A mandatory prerequisite for such an operation is a sufficiently good suppression of the ion backflow from the avalanche region, which otherwise limits the tracking and particle identification capabilities of such a detector. Gas Electron Multipliers (GEM) are a promising candidate to combine excellent spatial resolution with an intrinsic suppression of ions. In this paper we describe the design, construction and the commissioning of a large TPC with GEM amplification and without gating grid (GEM-TPC). The design requirements have driven innovations in the construction of a light-weight field-cage, a supporting media flange, the GEM amplification and the readout system, which are

  16. Social Amplification of Risk and Crisis Communication Planing - Case Study

    Science.gov (United States)

    Stanciugelu, I.; Frunzaru, V.; Armas, I.; Duntzer, A.; Stan, S.

    2012-04-01

    Risk management has become a dominant concern of public policy and the ability of government to anticipate the strength and focus of public concerns remains weak. The Social Amplification of Risk Framework (SARF) was designed to assist in this endeavor. It aims to facilitate a greater understanding of the social processes that can mediate between a hazard event and its consequences. SARF identifies categories of mediator/moderator that intervene between risk event and its consequences and suggests a causal and temporal sequence in which they act. Information flows first through various sources and then channels, triggering social stations of amplification, initiating individual station of amplification and precipitating behavioral reactions. The International Risk Governance Council Framework is an interdisciplinary and multilevel approach, linking risk management and risk assessment sphere through communication. This study aims to identify categories of mediator/moderator that intervene between the risk event and its consequences, using a survey on earthquake risk perception addressing population of Bucharest city. Romania has a unique seismic profile in Europe, being the country with the biggest surface affected in case of a serious earthquake. Considering the development of the urban area that took place in the last two decades and the growing number of inhabitants, Bucharest is the largest city in Romania and is exposed to extensive damages in case of an earthquake. The sociological survey has been conducted in December 2009 on a representative sample of the Bucharest population aged 18 and over (N=1376) using one stage sampling design. We used a stratified sample method shearing the investigated populations in six layers according to the six sectors of Bucharest. The respondents were selected using random digit dialling method (RDD) and the questionnaires were administered by research staff with computer assisted telephone interviewing method (CATI). The

  17. Towards rapid prototyped convective microfluidic DNA amplification platform

    Science.gov (United States)

    Ajit, Smrithi; Praveen, Hemanth Mithun; Puneeth, S. B.; Dave, Abhishek; Sesham, Bharat; Mohan, K. N.; Goel, Sanket

    2017-02-01

    Today, Polymerase Chain Reaction (PCR) based DNA amplification plays an indispensable role in the field of biomedical research. Its inherent ability to exponentially amplify sample DNA has proven useful for the identification of virulent pathogens like those causing Multiple Drug-Resistant Tuberculosis (MDR-TB). The intervention of Microfluidics technology has revolutionized the concept of PCR from being a laborious and time consuming process into one that is faster, easily portable and capable of being multifunctional. The Microfluidics based PCR outweighs its traditional counterpart in terms of flexibility of varying reaction rate, operation simplicity, need of a fraction of volume and capability of being integrated with other functional elements. The scope of the present work involves the development of a real-time continuous flow microfluidic device, fabricated by 3D printing-governed rapid prototyping method, eventually leading to an automated and robust platform to process multiple DNA samples for detection of MDRTB-associated mutations. The thermal gradient characteristic to the PCR process is produced using peltier units appropriate to the microfluidic environment fully monitored and controlled by a low cost controller driven by a Data Acquisition System. The process efficiency achieved in the microfluidic environment in terms of output per cycle is expected to be on par with the traditional PCR and capable of earning the additional advantages of being faster and minimizing the handling.

  18. Microfluidic continuous flow digital loop-mediated isothermal amplification (LAMP).

    Science.gov (United States)

    Rane, Tushar D; Chen, Liben; Zec, Helena C; Wang, Tza-Huei

    2015-02-07

    Digital nucleic acid detection is rapidly becoming a popular technique for ultra-sensitive and quantitative detection of nucleic acid molecules in a wide range of biomedical studies. Digital polymerase chain reaction (PCR) remains the most popular way of conducting digital nucleic acid detection. However, due to the need for thermocycling, digital PCR is difficult to implement in a streamlined manner on a single microfluidic device, leading to complex fragmented workflows and multiple separate devices and instruments. Loop-mediated isothermal amplification (LAMP) is an excellent isothermal alternative to PCR with potentially better specificity than PCR because of the use of multiple primer sets for a nucleic acid target. Here we report a microfluidic droplet device implementing all the steps required for digital nucleic acid detection including droplet generation, incubation and in-line detection for digital LAMP. As compared to microchamber or droplet array-based digital assays, the continuous flow operation of this device eliminates the constraints on the number of total reactions imposed by the footprint of the device and the analysis throughput caused by the time for lengthy incubation and transfer of materials between instruments.

  19. Rehabilitation of Degraded Rangeland in Drylands by Prickly Pear (Opuntia ficus-indica L. Plantations: Effect on Soil and Spontaneous Vegetation

    Directory of Open Access Journals (Sweden)

    Souad Neffar

    2013-12-01

    Full Text Available In arid and semi-arid lands, the spiny prickly pear (Opuntia ficus-indica is an outstanding plant for soil conservation and restoration. To determine the role of Opuntia ficus-indica on vegetation recovery process in desertified areas of Southern Tebessa (Northeast Algeria, we investigated the effect of prickly pear plantation age and some soil properties (grain size, pH, electrical conductivity, organic matter, total nitrogen, available phosphorus, and CaCO3 equivalents on native plant community. Vegetation cover and plant diversity were assessed by calculating the number of individual plants (N, species richness (S, their ratio (N/S, Shannon index, and Evenness in prickly pear plantation plots of different ages (control, 5 and 20 years. Even if surveyed soil parameters did not differ significantly among O. ficus-indica plantations, results of ANOVA testing the effect of Opuntia plantations on native vegetation traits revealed significant variation for plant abundance (P < 0.0001, N/S ratio (P = 0.003 and vegetation cover (P < 0.0001. Vegetation cover differed significantly with both prickly-pear plantation age (P = 0.031 and seasons (P = 0.019. Tukey's tests revealed that all vegetation traits were significantly higher on prickly pear plantations than in control plots. Multiple comparisons also showed that plant abundance, N/S ratio and vegetation cover were significantly different between both young and old plantations and the controls. Prickly pear cultures facilitated the colonization and development of herbaceous species by ameliorating the severe environmental conditions. In conclusion, the facilitative effect of O. ficus-indica has been clearly demonstrated for both abundance and cover of native vegetation.

  20. Study on Pollination and Selection of the Most Suitable Pollinizers for Commercial Pear Cultivars (Pyrus communis L. in Iran

    Directory of Open Access Journals (Sweden)

    Tatari Maryam

    2017-12-01

    Full Text Available The cultivated pear is an economically important fruit tree species of genus Pyrus in which often gametophytic self-incompatibility occurs. Therefore, this species need to be pollinated by cross-compatible cultivars that bloom in the same time. Selection of appropriate pollinizers for pear cultivars is very important to produce commercial yield. ‘Sebri’, ‘ Shahmiveh’ and ‘Natanzi’ are the best commercial cultivars in Iran, but the lack of a suitable source of pollen can reduce productivity. In order to select the most suitable pollinizer for these pear cvs, an experiment was conducted in which they were considered as pollen recipients and ‘Coscia’, ‘Bartlett’ and ‘Sardroud’ along with ‘Sebri’, ‘Shahmiveh’ and ‘Natanzi’ were evaluated as pollen donors. This research was conducted as a factorial experiment in randomized complete block design for four years. Recipient and donor cultivars had almost overlapping flowering time. The flower buds on selected branches were emasculated at balloon stage and then were counted and isolated with cotton tissue bags. Pollen grains of these pollinizers were collected in the laboratory. Isolation bags were taken off from the branches and emasculated flowers were pollinated with pollen grains of listed pollinizers during receptibility of stigma. The number of pollinated flowers was counted, and branches were covered again with the bags. The results showed that for ‘Sebri’ the best pollinizer was ‘Coscia’ with 5.7% fruit set, for ‘Shahmiveh’ ‘Bartlett’ cv. with 5.8% of fruit set and for ‘Natanzi’, ‘Shahmiveh’ with 5.5% of fruit set.

  1. Oxidative stress associated with rootstock-scion interactions in pear/quince combinations during early stages of graft development.

    Science.gov (United States)

    Irisarri, Patricia; Binczycki, Piotr; Errea, Pilar; Martens, Helle Juel; Pina, Ana

    2015-03-15

    Exposing a plant to stress situations, such as grafting, generally triggers antioxidant defense systems. In fruit tree grafting, quince (Cydonia oblonga) is widely used as a rootstock for pear (Pyrus communis L.), but several economically important pear cultivars are incompatible with available quince rootstocks. In this study, grafts were established using an in vitro callus graft system mimicking the events taking place in fruit trees. In vitro grown callus from pear [P. communis L. cv. 'Conference' (Co) and cv. 'William' (Wi)] and quince (C. oblonga Mill. clone 'BA29') was used to establish the compatible homografts 'Co/Co', 'Wi/Wi' and 'BA29/BA29', the compatible heterograft 'Co/BA29' and the incompatible heterograft 'Wi/BA29'. The main objective was to determine whether specific isoforms of genes involved in oxidative stress [superoxide dismutase (SOD), ascorbate peroxidase (APX) and catalase (CAT)] are differentially expressed at the graft interface from compatible and incompatible unions throughout 3 weeks after grafting. Reactive oxygen species (ROS) levels and programmed cell death were also evaluated in the course of graft development. Genes differentially expressed between compatible and incompatible heterografts were identified. Transcript levels of six antioxidant genes (SOD1, SOD3, APX3, APX6, CAT1 and CAT3) were down-regulated 10 days after grafting (DAG) in the incompatible heterograft in comparison to the compatible one. Likewise, SOD enzymatic activities were significantly higher at 1 and 10 days after wounding in the compatible cultivar 'Co' than in the incompatible one 'Wi'. These findings, together with live cell imaging of ROS-specific probes, ultrastructural mitochondrial changes and DNA fragmentation related to apoptotic processes, give indications that within incompatible rootstock/scion interfaces, either the level of ROS is increased or there is a less efficient detoxification system. Copyright © 2014 Elsevier GmbH. All rights reserved.

  2. [Nondestructive measurement of SSC in western pear using genetic algorithms and FT-NIR spectroscopy].

    Science.gov (United States)

    Wang, Jia-Hua; Pan, Lu; Sun, Qian; Li, Peng-Fei; Han, Dong-Hai

    2009-03-01

    An improved genetic algorithm was used to implement an automated wavelength selection procedure for use in building multivariate calibration models based on partial least squares regression (PLS). The region selecting by genetic algorithms (R-SGA) was applied in building calibration model of soluble solid content (SSC) of Western pear, and the numbers of latent variables used to build calibration model were further reduced. The Fourier transform near infrared reflectance (FT-NIR) spectra were processed by GA after MSC or SNV, and four PLS calibration models were built by using the optimal combinations of these sub-regions. Meanwhile, the full region selecting PLS (Fr-PLS) models were developed. The R-SGA models variables were 434, 496, 310 and 496, for Early Red Comice, Wujiuxiang, Cascade and Kang Buddha, respectively. Despite the complexity of the spectral data, the R-SGA procedure was found to perform well (RMSEP = 0.428, 0.567 for Early Red Comice and Kang Buddha, respectively), leading to calibration models that significantly outperform those based on full-spectrum analyses (RM-SEP = 0.518, 0.633). The prediction precision of GA-PLS models was similar to that of Fr-PLS for Wujiuxiang and Cascade, with RMSEP of 0.696/0.694 and 0.425/0.421 respectively. This work proved that the R-SGA could find optimal values for several disparate variables associated with the calibration model and that the PLS procedure could be integrated into the objective function driving the optimization.

  3. EFFECT OF JASMONIC ACID ON IN VITRO MULTIPLICATION OF LOW VIGOROUS PEAR AND CHERRY ROOTSTOCKS

    Directory of Open Access Journals (Sweden)

    Djurdjina Ružić

    2013-12-01

    Full Text Available The capacity of Jasmonic acid (JA to improve in vitro multiplication phase in micropropagated shoots of low vigorous pear and cherry rootstocks – Pyrodwarf and Gisela 6 respectively, was studied. The experiment was performed during the multiplication phase and it included 23 media types containing Murashige and Skoog (1962 macro, micro salts and organic complex supplemented with JA at four concentrations (1, 2.3, 5 and 10 µM alone and in combination with benzyl adenine – BA (4.4 µM, indole-3-butyric acid – IBA (1, 2.30, 2.46, 5 and 10 µM, α-napthyl acetic acid –NAA (1, 2.30, 2.68, 5, 10 µM, and indole-3-acetic acid – IAA (1, 2.30, 2.85, 5, 10 µM. The multiplication parameters, such as multiplication index, length of axial and lateral shoots, FW and DW of shoots as well as quality of multiplied shoots were monitored. The highest multiplication rate in both genotypes was obtained on medium with BA (4.4 µM in combination with IBA (1 and 2.3 µM. The longest axial and lateral shoots were also obtained on media with BA in combination with JA or other three auxins used. The main characteristics of the JA effect (used alone were big shoots, large green leaves, small quantity of firm, nodular callus as well as occurrence of rooting. The obtained results suggest that JA used alone should not be used to improve the multiplication process, but only in combination with BA and IBA or NAA for the high quality plantlets which is important for the rooting phase, to skip elongation phase.

  4. In Vitro Propagation of Three Moroccan Prickly Pear Cactus Opuntia and Plant Establishment in Soil

    Directory of Open Access Journals (Sweden)

    Aissam EL FINTI

    2013-02-01

    Full Text Available Opuntia is one of the most widespread cacti, primarily due to their edible fruit and vegetable mass used as feed. The high demand for young plants of Opuntia made it necessary to find a rapid method of multiplication of the cactus, the safest method consisting in vitro micropropagation of species belonging to this genus. With aim of large production of plant material, a propagation system of three important prickly pear cactus cultivar (Opuntia ficus-indica in Morocco was developed. Segments of healthy young cladode (containing one areole were cultivated in Murashige and Skoog medium (MS containing adenine sulfate (40 mg/1, monosodium phosphate (50 mg/l, sucrose (50 g/l, phytagel (0.3% and benzyladenine (BA at 22.2 μM, to start the process of micropropagation. In vitro-developed shoots from areoles were used as secondary explants to induce shoot development in the MS medium with 5 mg/l of BA. All of the three studied cultivars showed an important multiplication rate in this medium. ‘Sidi Ifni M’ (‘Moussa’ cultivar shows the greatest number of shoots followed by ‘Sidi Ifni A’ (‘Aissa’ and ‘Delahia’ 17.26, 14.12 and 12.13 respectively. Rooting of in vitro-generated shoots was achieved most efficiently on half-strength MS basal medium supplemented with 0.5 mg/l of indole-3-butyric acid (IBA or IAA. Rooting frequencies were in the range from 95 to 100% and the highest mean number of root (19.1 was obtained with IBA for ‘Delahia’ cultivar. All micropropagated plants were transferred to greenhouse and all of them survived acclimatization process and showed good overall growth.

  5. Balsam-pear-like rutile/anatase core/shell titania nanorod arrays for photoelectrochemical water splitting

    Science.gov (United States)

    Wen, Wei; Yao, Jin-Cheng; Gu, Yi-Jie; Sun, Tu-Lai; Tian, He; Zhou, Qi-Lai; Wu, Jin-Ming

    2017-11-01

    In this work, a solution combustion followed by dissolution in hydrogen peroxide is adopted to achieve a precursor for decorating anatase TiO2 nanosheets along single-crystalline rutile TiO2 nanorods, which achieves balsam-pear-like core/shell nanorod arrays with enhanced photoelectrochemical water splitting. The enhanced photoelectrochemical performance is attributed to the novel nanoarchitecture, which can simultaneously offer a high surface area, enhanced light-harvesting, a rutile/anatase junction for charge carrier separation and a conductive pathway for charge carrier collection. The photoanode design can also give hints to other functional materials.

  6. Synergistic Manipulation of Intercrop Combining Biological Medicaments on the Population Dynamics of Psylla Chinensis and Predators in Pear Orchard

    Directory of Open Access Journals (Sweden)

    HE Kai

    2015-06-01

    Full Text Available P. chinensis is one of the most harmful pests all over the country which has a serious threat to the production and quality of pears. Nymphae of P. chinensis can live under the protection of its own secretion, pesticide is hard to reach and kill them. Furthermore, nymphae can make resistance to any kinds of pesticides. This research is to estimate quantitatively the effect of intercrop combining with biological medicament controlling the Psylla chinensis ecologically. In 2013 and 2014, the manipulating experiment was established in pear orchard. The synergistic manipulation of pear intercropping Trifolium repens and Platycodon grandiflorum combining with the biological agent on the population dynamics of P. chinensis and their predators were determined systematically. The results showed that the total population size of predators in the areas of intercropping T. repens and P. grandiflorum were higher than that in the bare area by artificial weeding. In 2013, the predator of dominant species was O. minutes in the area of intercropping T. repens and P. fuscipes was in the area of intercropping P. grandiflorum. In 2014, E. graminicolum and T. chinensis dominated in the area of intercropping T. repens; H. axyridis, P. japonica, E. balteata and E. graminicolum dominated in the area of intercropping P. grandiflorum. In 2013, the nymphae populations of P. chinensi in the areas of both intercropping T. repens and P. grandiflorum combining with the biological agent on June 18 were significantly higher and on other dates were not significant difference compared with the bare area with conventional pesticide application. In 2014, the population densities of both adults and nymphae of P. chinensis were significantly lower in the areas of both intercropping T. repens and P. grandiflorum combining with the biological agent than that in the bare area with conventional pesticide application during all the period of P. chinensis occurence. This research

  7. Promotion of flowering by Apple latent spherical virus vector and virus elimination at high temperature allow accelerated breeding of apple and pear

    Directory of Open Access Journals (Sweden)

    Noriko eYamagishi

    2016-02-01

    Full Text Available Plant viral vectors are superior tools for genetic manipulation, allowing rapid induction or suppression of expression of a target gene in plants. This is a particularly effective technology for use in breeding fruit trees, which are difficult to manipulate using recombinant DNA technologies. We reported previously that if apple seed embryos (cotyledons are infected with an Apple latent spherical virus (ALSV vector (ALSV-AtFT/MdTFL1 concurrently expressing the Arabidopsis thaliana florigen (AtFT gene and suppressing the expression of the apple MdTFL1-1 gene, the period prior to initial flowering (generally lasts 5–12 years will be reduced to about two months. In this study, we examined whether or not ALSV vector technology can be used to promote flowering in pear, which undergoes a very long juvenile period (germination to flowering similar to that of apple. The MdTFL1 sequence in ALSV-AtFT/MdTFL1 was replaced with a portion of the pear PcTFL1-1 gene. The resulting virus (ALSV-AtFT/PcTFL1 and ALSV-AtFT/MdTFL1 were used individually for inoculation to pear cotyledons immediately after germination in two inoculation groups. Those inoculated with ALSV-AtFT/MdTFL1 and ALSV-AtFT/PcTFL1 then initiated flower bud formation starting one to three months after inoculation, and subsequently exhibited continuous flowering and fruition by pollination. Conversely, Japanese pear exhibited extremely low systemic infection rates when inoculated with ALSV-AtFT/MdTFL1, and failed to exhibit any induction of flowering. We also developed a simple method for eliminating ALSV vectors from infected plants. An evaluation of the method for eliminating the ALSV vectors from infected apple and pear seedlings revealed that a four-week high-temperature (37˚C incubation of ALSV-infected apples and pears disabled the movement of ALSV to new growing tissues. This demonstrates that only high-temperature treatment can easily eliminate ALSV from infected fruit trees. A method

  8. Promotion of Flowering by Apple Latent Spherical Virus Vector and Virus Elimination at High Temperature Allow Accelerated Breeding of Apple and Pear.

    Science.gov (United States)

    Yamagishi, Norioko; Li, Chunjiang; Yoshikawa, Nobuyuki

    2016-01-01

    Plant viral vectors are superior tools for genetic manipulation, allowing rapid induction or suppression of expression of a target gene in plants. This is a particularly effective technology for use in breeding fruit trees, which are difficult to manipulate using recombinant DNA technologies. We reported previously that if apple seed embryos (cotyledons) are infected with an Apple latent spherical virus (ALSV) vector (ALSV-AtFT/MdTFL1) concurrently expressing the Arabidopsis thaliana florigen (AtFT) gene and suppressing the expression of the apple MdTFL1-1 gene, the period prior to initial flowering (generally lasts 5-12 years) will be reduced to about 2 months. In this study, we examined whether or not ALSV vector technology can be used to promote flowering in pear, which undergoes a very long juvenile period (germination to flowering) similar to that of apple. The MdTFL1 sequence in ALSV-AtFT/MdTFL1 was replaced with a portion of the pear PcTFL1-1 gene. The resulting virus (ALSV-AtFT/PcTFL1) and ALSV-AtFT/MdTFL1 were used individually for inoculation to pear cotyledons immediately after germination in two inoculation groups. Those inoculated with ALSV-AtFT/MdTFL1 and ALSV-AtFT/PcTFL1 then initiated flower bud formation starting one to 3 months after inoculation, and subsequently exhibited continuous flowering and fruition by pollination. Conversely, Japanese pear exhibited extremely low systemic infection rates when inoculated with ALSV-AtFT/MdTFL1, and failed to exhibit any induction of flowering. We also developed a simple method for eliminating ALSV vectors from infected plants. An evaluation of the method for eliminating the ALSV vectors from infected apple and pear seedlings revealed that a 4-week high-temperature (37°C) incubation of ALSV-infected apples and pears disabled the movement of ALSV to new growing tissues. This demonstrates that only high-temperature treatment can easily eliminate ALSV from infected fruit trees. A method combining the promotion

  9. Comparison of polymerase chain reaction (PCR) and loop-mediated ...

    African Journals Online (AJOL)

    Comparison of polymerase chain reaction (PCR) and loop-mediated isothermal amplification (LAMP) for diagnosis of Fusarium solani in human immunodeficiency virus (HIV) positive patients. ... The test was carried out in 1 h reaction at 65°C in a heater block. The specificity of the test was 100% and its sensitivity was a ...

  10. Silicon-based sleeve devices for chemical reactions

    Science.gov (United States)

    Northrup, M. Allen; Mariella, Jr., Raymond P.; Carrano, Anthony V.; Balch, Joseph W.

    1996-01-01

    A silicon-based sleeve type chemical reaction chamber that combines heaters, such as doped polysilicon for heating, and bulk silicon for convection cooling. The reaction chamber combines a critical ratio of silicon and silicon nitride to the volume of material to be heated (e.g., a liquid) in order to provide uniform heating, yet low power requirements. The reaction chamber will also allow the introduction of a secondary tube (e.g., plastic) into the reaction sleeve that contains the reaction mixture thereby alleviating any potential materials incompatibility issues. The reaction chamber may be utilized in any chemical reaction system for synthesis or processing of organic, inorganic, or biochemical reactions, such as the polymerase chain reaction (PCR) and/or other DNA reactions, such as the ligase chain reaction, which are examples of a synthetic, thermal-cycling-based reaction. The reaction chamber may also be used in synthesis instruments, particularly those for DNA amplification and synthesis.

  11. Development, validation, and standardization of polymerase chain reaction-based detection of E-coli O157

    DEFF Research Database (Denmark)

    Abdulmawjood, A.; Bulte, M.; Roth, S.

    2004-01-01

    A diagnostic polymerase chain reaction assay was developed for the detection of E. coli O157 as the first part of a multicenter validation and standardization project. The assay is based on amplification of sequences of the rfbE O157 gene and includes an internal amplification control. The select......A diagnostic polymerase chain reaction assay was developed for the detection of E. coli O157 as the first part of a multicenter validation and standardization project. The assay is based on amplification of sequences of the rfbE O157 gene and includes an internal amplification control...

  12. Three different signal amplification strategies for the impedimetric sandwich detection of thrombin

    Energy Technology Data Exchange (ETDEWEB)

    Ocaña, Cristina; Valle, Manel del, E-mail: manel.delvalle@uab.cat

    2016-03-17

    In this work, we report a comparative study on three highly specific amplification strategies for the ultrasensitive detection of thrombin with the use of aptamer sandwich protocol. The protocol consisted on the use of a first thrombin aptamer immobilized on the electrode surface, the recognition of thrombin protein, and the reaction with a second biotinylated thrombin aptamer forming the sandwich. Through the exposed biotin end, three variants have been tested to amplify the electrochemical impedance signal. The strategies included (a) silver enhancement treatment, (b) gold enhancement treatment and (c) insoluble product produced by the combination of the enzyme horseradish peroxidase (HRP) and 3-amino-9-ethylcarbazole (AEC). The properties of the sensing surface were probed by electrochemical impedance measurements in the presence of the ferrocyanide/ferricyanide redox marker. Insoluble product strategy and silver enhancement treatment resulted in the lowest detection limit (0.3 pM), while gold enhancement method resulted in the highest reproducibility, 8.8% RSD at the pM thrombin concentration levels. Results of silver and gold enhancement treatment also permitted direct inspection by scanning electron microscopy (SEM). - Highlights: • Aptasensor to detect thrombin reaching the femtomolar level. • Biosensing protocol employs two thrombin aptamers in a sandwich capture scheme. • Use of second biotinylated aptamer allows many amplification and detection variants. • Precipitation reaction provides the highest signal amplification of ca. 3 times. • Double recognition event improves remarkably selectivity for thrombin detection.

  13. Reaction Automata

    OpenAIRE

    Okubo, Fumiya; Kobayashi, Satoshi; Yokomori, Takashi

    2011-01-01

    Reaction systems are a formal model that has been introduced to investigate the interactive behaviors of biochemical reactions. Based on the formal framework of reaction systems, we propose new computing models called reaction automata that feature (string) language acceptors with multiset manipulation as a computing mechanism, and show that reaction automata are computationally Turing universal. Further, some subclasses of reaction automata with space complexity are investigated and their la...

  14. A systems biology approach to analyse amplification in the JAK2-STAT5 signalling pathway

    Directory of Open Access Journals (Sweden)

    Timmer Jens

    2008-04-01

    Full Text Available Abstract Background The amplification of signals, defined as an increase in the intensity of a signal through networks of intracellular reactions, is considered one of the essential properties in many cell signalling pathways. Despite of the apparent importance of signal amplification, there have been few attempts to formalise this concept. Results In this work we investigate the amplification and responsiveness of the JAK2-STAT5 pathway using a kinetic model. The recruitment of EpoR to the plasma membrane, activation by Epo, and deactivation of the EpoR/JAK2 complex are considered as well as the activation and nucleocytoplasmic shuttling of STAT5. Using qualitative biological knowledge, we first establish the structure of a general power-law model. We then generate a family of models from which we select suitable candidates. The parameter values of the model are estimated from experimental quantitative time-course data. The final model, whether it is conventional model with fixed predefined integer kinetic orders or a model with variable non-integer kinetic orders, is selected on the basis of a good agreement between simulations and the experimental data. The model is used to analyse the responsiveness and amplification properties of the pathway with sustained, transient, and oscillatory stimulation. Conclusion The selected kinetic model predicts that the system acts as an amplifier with maximum amplification and sensitivity for input signals whose intensity match physiological values for Epo concentration and with duration in the range of one to 100 minutes. The response of the system reaches saturation for more intense and longer stimulation with Epo. We hypothesise that these properties of the system directly relate to the saturation of Epo receptor activation, its low recruitment to the plasma membrane and intense deactivation as predicted by the model.

  15. Does the Arctic Amplification peak this decade?

    Science.gov (United States)

    Martin, Torge; Haine, Thomas W. N.

    2017-04-01

    Temperatures rise faster in the Arctic than on global average, a phenomenon known as Arctic Amplification. While this is well established from observations and model simulations, projections of future climate (here: RCP8.5) with models of the Coupled Model Intercomparison Project phase 5 (CMIP5) also indicate that the Arctic Amplification has a maximum. We show this by means of an Arctic Amplification factor (AAF), which we define as the ratio of Arctic mean to global mean surface air temperature (SAT) anomalies. The SAT anomalies are referenced to the period 1960-1980 and smoothed by a 30-year running mean. For October, the multi-model ensemble-mean AAF reaches a maximum in 2017. The maximum moves however to later years as Arctic winter progresses: for the autumn mean SAT (September to November) the maximum AAF is found in 2028 and for winter (December to February) in 2060. Arctic Amplification is driven, amongst others, by the ice-albedo feedback (IAF) as part of the more general surface albedo feedback (involving clouds, snow cover, vegetation changes) and temperature effects (Planck and lapse-rate feedbacks). We note that sea ice retreat and the associated warming of the summer Arctic Ocean are not only an integral part of the IAF but are also involved in the other drivers. In the CMIP5 simulations, the timing of the AAF maximum coincides with the period of fastest ice retreat for the respective month. Presence of at least some sea ice is crucial for the IAF to be effective because of the contrast in surface albedo between ice and open water and the need to turn ocean warming into ice melt. Once large areas of the Arctic Ocean are ice-free, the IAF should be less effective. We thus hypothesize that the ice retreat significantly affects AAF variability and forces a decline of its magnitude after at least half of the Arctic Ocean is ice-free and the ice cover becomes basically seasonal.

  16. Amplification Effects and Unconventional Monetary Policies

    Directory of Open Access Journals (Sweden)

    Cécile BASTIDON GILLES

    2012-02-01

    Full Text Available Global financial crises trigger off amplification effects, which allow relatively small shocks to propagate through the whole financial system. For this reason, the range of Central banks policies is now widening beyond conventional monetary policies and lending of last resort. The aim of this paper is to establish a rule for this practice. The model is based on the formalization of funding conditions in various types of markets. We conduct a comprehensive analysis of the “unconventional monetary policies”, and especially quantify government bonds purchases by the Central bank.

  17. Parametric amplification in MoS2drum resonator.

    Science.gov (United States)

    Prasad, Parmeshwar; Arora, Nishta; Naik, A K

    2017-11-30

    Parametric amplification is widely used in diverse areas from optics to electronic circuits to enhance low level signals by varying relevant system parameters. Parametric amplification has also been performed in several micro-nano resonators including nano-electromechanical system (NEMS) resonators based on a two-dimensional (2D) material. Here, we report the enhancement of mechanical response in a MoS 2 drum resonator using degenerate parametric amplification. We use parametric pumping to modulate the spring constant of the MoS 2 resonator and achieve a 10 dB amplitude gain. We also demonstrate quality factor enhancement in the resonator with parametric amplification. We investigate the effect of cubic nonlinearity on parametric amplification and show that it limits the gain of the mechanical resonator. Amplifying ultra-small displacements at room temperature and understanding the limitations of the amplification in these devices is key for using these devices for practical applications.

  18. Novel reverse transcription loop-mediated isothermal amplification for rapid detection of foot-and-mouth disease virus

    DEFF Research Database (Denmark)

    Dukes, J.P.; King, D.P.; Alexandersen, Søren

    2006-01-01

    Speed is paramount in the diagnosis of foot-and-mouth disease (FMD) and simplicity is required if a test is to be deployed in the field. The development of a one-step, reverse transcription loop-mediated amplification (RT-LAMP) assay enables FMD virus (FMDV) to be detected in under an hour...... in a single tube without thermal cycling. A fragment of the 3D RNA polymerase gene of the virus is amplified at 65 degrees C in the presence of a primer mixture and both reverse transcriptase and Bst DNA polymerase. Compared with real-time RT-PCR, RT-LAMP was consistently faster, and ten copies of FMDV...... transcript were detected in twenty-two minutes. Amplification products were detected by visual inspection, agarose gel electrophoresis, or in real-time by the addition of a fluorescent dye. The specificity of the reaction was demonstrated by the absence of amplification of RNA from other viruses that cause...

  19. Dormancy of 'Imperial Gala' apple and 'Hosui' pear tree buds in a region of low chill occurrence

    Directory of Open Access Journals (Sweden)

    Ruy Inácio Neiva de Carvalho

    2014-08-01

    Full Text Available The objective of this work was to evaluate the dormancy dynamic of Imperial Gala apple tree buds and Hosui pear tree buds in a region of low chill occurrence. Experiments were conducted between April and August in 2007 and 2008. Branches were collected every two weeks from an orchard at Porto Amazonas (Paraná State, Brazil. On the last sampling day, an additional set of branches was collected and refrigerated between 4°C and 7°C for 1,440 hours. Dormancy was evaluated using a biological test of single node cuttings isolated in growth chambers (GC at 25°C with 16 hours of light exposure. The number of chill hours (CH and chill units (CU for the region were recorded. The two species were evaluated in separate experiments. We used 11 completely randomized treatments with four replicas for each species. The peak of endodormancy for the Imperial Gala apple tree buds occurred in early June 2007 and from middle June to early July in 2008. The endodormancy of the Hosui pear tree buds oscillated between April and August in 2007 and peaked between June and early July in 2008.

  20. Asynchronous ripening behavior of cactus pear (Opuntia ficus-indica) cultivars with respect to physicochemical and physiological attributes.

    Science.gov (United States)

    Kyriacou, M C; Emmanouilidou, M G; Soteriou, G A

    2016-11-15

    Physicochemical and physiological ripening events in cactus pear (Opuntia ficus-indica) fruit of cultivars 'Ntopia' and 'Hercules' were profiled against skin coloration from mature-green (S1) to over-mature (S5). Fructose and glucose accumulation were linear in 'Ntopia' but peaked near S3 in 'Hercules' synchronously to the appearance of sucrose. Betalains increased steadily in 'Ntopia' (103.2mg/l) but peaked before full skin coloration in 'Hercules' (49.7mg/l); whereas phenolic content remained invariable and ascorbate content peaked near S5 in both 'Ntopia' (108.6μg/g) and 'Hercules' (163.1μg/g). Cell wall material diminished with maturity though textural changes with ripening appeared not related to pectin solubilization but to weakening of glycan bonding and loss of neutral sugars. Fruit firmness rather was correlated to seed weight (r=0.89) and seed-to-pulp ratio (r=0.73). Cultivar differences highlighted in the chronology of ripening events are critical for defining optimum harvest maturity and postharvest handling protocols for premium quality cactus pear fruit. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. The ability of a cold-adapted Rhodotorula mucilaginosa strain from Tibet to control blue mold in pear fruit.

    Science.gov (United States)

    Hu, Hao; Yan, Fujie; Wilson, Charles; Shen, Qing; Zheng, Xiaodong

    2015-12-01

    Cold-adapted yeasts were isolated from soil samples collected in Tibet and evaluated as potential biocontrol agents against blue mold (Penicillium expansum) of pear fruit in cold storage. YC1, an isolate identified as Rhodotorula mucilaginosa, was found to exhibit the greatest biocontrol activity among the different isolates that were screened. A washed cell suspension of YC1 exhibited the best biocontrol activity among three different preparations that were used in the current study. A concentration of 10(8) cells/ml reduced the incidence of decay to 35 %, compared to the control where decay incidence was 100 %. A higher intracellular level of trehalose and a higher proportion of polyunsaturated acids present in YC1, was associated with increased the tolerance of this strain to low temperatures, relative to the other strains that were evaluated. The increased tolerance to low temperature allowed the YC1 strain of yeast to more effectively compete for nutrients and space in wounded pear fruit that had been inoculated with spores of P. expansum and placed in cold storage. The present study demonstrated the ability to select cold-adapted yeasts from cold climates and use them as biocontrol agents of postharvest diseases of fruit placed in cold storage.

  2. Loop-mediated isothermal amplification for rapid and convenient detection of Mycoplasma hyopneumoniae.

    Science.gov (United States)

    Li, Jiahe; Minion, F Chris; Petersen, Andrew C; Jiang, Fei; Yang, Sheng; Guo, Panpan; Li, Jinxiang; Wu, Wenxue

    2013-04-01

    Loop-mediated isothermal amplification (LAMP), a novel method of gene amplification, was employed in this study for detecting Mycoplasma hyopneumoniae in the respiratory tract or lungs of swine. The pathogen can be detected in LAMP reactions containing as few as 10 fg purified target DNA (10 copies of M. hyopneumoniae genome) within 30 min, which was comparable to real-time PCR. After 30-min reaction at 63 °C, the addition of a certain amount of dye (SYBR Green I and hydroxyl naphthol blue at a proper ratio) into the LAMP reaction system makes the results easily determined as positive or negative by visual inspection. In addition, the LAMP was able to distinguish between M. hyopneumoniae and other closely-related mycoplasma strains, indicating a high degree of specificity. The LAMP assay was more simple and cheap, since the reaction could be completed under isothermal conditions and less laboratorial infrastructure are required. And, it was proven reliable for M. hyopneumoniae diagnosis of nasal swab and lung samples from the field.

  3. Space Optical Communications Using Laser Beam Amplification

    Science.gov (United States)

    Agrawal, Govind

    2015-01-01

    The Space Optical Communications Using Laser Beam Amplification (SOCLBA) project will provide a capability to amplify a laser beam that is received in a modulating retro-reflector (MRR) located in a satellite in low Earth orbit. It will also improve the pointing procedure between Earth and spacecraft terminals. The technology uses laser arrays to strengthen the reflected laser beam from the spacecraft. The results of first year's work (2014) show amplification factors of 60 times the power of the signal beam. MMRs are mirrors that reflect light beams back to the source. In space optical communications, a high-powered laser interrogator beam is directed from the ground to a satellite. Within the satellite, the beam is redirected back to ground using the MMR. In the MMR, the beam passes through modulators, which encode a data signal onto the returning beam. MMRs can be used in small spacecraft for optical communications. The SOCLBA project is significant to NASA and small spacecraft due to its application to CubeSats for optical data transmission to ground stations, as well as possible application to spacecraft for optical data transmission.

  4. Primordial magnetic field amplification from turbulent reheating

    International Nuclear Information System (INIS)

    Calzetta, Esteban; Kandus, Alejandra

    2010-01-01

    We analyze the possibility of primordial magnetic field amplification by a stochastic large scale kinematic dynamo during reheating. We consider a charged scalar field minimally coupled to gravity. During inflation this field is assumed to be in its vacuum state. At the transition to reheating the state of the field changes to a many particle/anti-particle state. We characterize that state as a fluid flow of zero mean velocity but with a stochastic velocity field. We compute the scale-dependent Reynolds number Re(k), and the characteristic times for decay of turbulence, t d and pair annihilation t a , finding t a d . We calculate the rms value of the kinetic helicity of the flow over a scale L and show that it does not vanish. We use this result to estimate the amplification factor of a seed field from the stochastic kinematic dynamo equations. Although this effect is weak, it shows that the evolution of the cosmic magnetic field from reheating to galaxy formation may well be more complex than as dictated by simple flux freezing

  5. Electronic cyclotron radiation amplification in thermonuclear plasmas

    International Nuclear Information System (INIS)

    Ziebell, L.F.

    1983-01-01

    The amplified emission of electron cyclotron radiation near the fundamental frequency from an inhomogeneous, anisotropic plasma slab is investigated in a linear theory. Plasma polarization effects are consistently included. Expressions are developed in the WKB approximation for emission in the ordinary and the extraordinary modes, for propagation perpendicular to the magnetic field. Numerical results are given for the extraordinary mode, for which effects are strongest. For the case of a loss-cone-type electron momentum distribution, it is shown that the amplification is sensitively dependent on the ratio of parallel-to-perpendicular temperature and on inhomogeneities in the magnetic field. The dependence of the amplification on the distribution is further investigated by considering superpositions of loss-cone and Maxwellian components. It is show that the presence of a Maxwellian component in general reduces the emission relative to the pure loss-cone case, and situations occur in which a layer in the slab very effectively absorbs all the radiation amplified elsewhere. A peculiar behaviour of the refractive index, which occurs in the transition from the pure loss-cone to the pure Maxwellian case, is discussed. (author)

  6. Earthquake acceleration amplification based on single microtremor test

    Science.gov (United States)

    Jaya Syahbana, Arifan; Kurniawan, Rahmat; Soebowo, Eko

    2018-02-01

    Understanding soil dynamics is needed to understand soil behaviour, including the parameters of earthquake acceleration amplification. Many researchers now conduct single microtremor tests to obtain amplification of velocity and natural periods of soil at test sites. However, these amplification parameters are rarely used, so a method is needed to convert the velocity amplification to acceleration amplification. This paper will discuss the proposed process of changing the value of amplification. The proposed method is to integrate the time histories of the synthetic earthquake acceleration of the soil surface under the deaggregation at that location so the time histories of the velocity earthquake will be obtained. Next is to conduct a “fitting curve” between amplification by a single microtremor test with amplification of the synthetic earthquake velocity time histories. After obtaining the fitting curve time histories of velocity, differentiation will be conducted to obtain fitting curve acceleration time histories. The final step after obtaining the fitting curve is to compare the acceleration of the “fitting curve” against the histories time of the acceleration of synthetic earthquake at bedrocks to obtain single microtremor acceleration amplification factor.

  7. Improved PCR Amplification of Broad Spectrum GC DNA Templates.

    Science.gov (United States)

    Guido, Nicholas; Starostina, Elena; Leake, Devin; Saaem, Ishtiaq

    2016-01-01

    Many applications in molecular biology can benefit from improved PCR amplification of DNA segments containing a wide range of GC content. Conventional PCR amplification of DNA sequences with regions of GC less than 30%, or higher than 70%, is complex due to secondary structures that block the DNA polymerase as well as mispriming and mis-annealing of the DNA. This complexity will often generate incomplete or nonspecific products that hamper downstream applications. In this study, we address multiplexed PCR amplification of DNA segments containing a wide range of GC content. In order to mitigate amplification complications due to high or low GC regions, we tested a combination of different PCR cycling conditions and chemical additives. To assess the fate of specific oligonucleotide (oligo) species with varying GC content in a multiplexed PCR, we developed a novel method of sequence analysis. Here we show that subcycling during the amplification process significantly improved amplification of short template pools (~200 bp), particularly when the template contained a low percent of GC. Furthermore, the combination of subcycling and 7-deaza-dGTP achieved efficient amplification of short templates ranging from 10-90% GC composition. Moreover, we found that 7-deaza-dGTP improved the amplification of longer products (~1000 bp). These methods provide an updated approach for PCR amplification of DNA segments containing a broad range of GC content.

  8. C-MET overexpression and amplification in gliomas.

    Science.gov (United States)

    Kwak, Yoonjin; Kim, Seong-Ik; Park, Chul-Kee; Paek, Sun Ha; Lee, Soon-Tae; Park, Sung-Hye

    2015-01-01

    We investigated c-Met overexpression and MET gene amplification in gliomas to determine their incidence and prognostic significance. c-Met immunohistochemistry and MET gene fluorescence in situ hybridization were carried out on tissue microarrays from 250 patients with gliomas (137 grade IV GBMs and 113 grade II and III diffuse gliomas). Clinicopathological features of these cases were reviewed. c-Met overexpression and MET gene amplification were detected in 13.1% and 5.1% of the GBMs, respectively. All the MET-amplified cases showed c-Met overexpression, but MET amplification was not always concordant with c-Met overexpression. None of grade II and III gliomas demonstrated c-Met overexpression or MET gene amplification. Mean survival of the GBM patients with MET amplification was not significantly different from patients without MET amplification (P=0.155). However, GBM patients with c-Met overexpression survived longer than patients without c-Met overexpression (P=0.035). Although MET amplification was not related to poor GBM prognosis, it is partially associated with the aggressiveness of gliomas, as MET amplification was found only in grade IV, not in grade II and III gliomas. We suggest that MET inhibitor therapy may be beneficial in about 5% GBMs, which was the incidence of MET gene amplification found in the patients included in this study.

  9. Chum-RNA allows preparation of a high-quality cDNA library from a single-cell quantity of mRNA without PCR amplification.

    Science.gov (United States)

    Tougan, Takahiro; Okuzaki, Daisuke; Nojima, Hiroshi

    2008-09-01

    Linear RNA amplification using T7 RNA polymerase is useful in genome-wide analysis of gene expression using DNA microarrays, but exponential amplification using polymerase chain reaction (PCR) is still required for cDNA library preparation from single-cell quantities of RNA. We have designed a small RNA molecule called chum-RNA that has enabled us to prepare a single-cell cDNA library after four rounds of T7-based linear amplification, without using PCR amplification. Chum-RNA drove cDNA synthesis from only 0.49 femtograms of mRNA (730 mRNA molecules) as a substrate, a quantity that corresponds to a minor population of mRNA molecules in a single mammalian cell. Analysis of the independent cDNA clone of this library (6.6 x 10(5) cfu) suggests that 30-fold RNA amplification occurred in each round of the amplification process. The size distribution and representation of mRNAs in the resulting one-cell cDNA library retained its similarity to that of the million-cell cDNA library. The use of chum-RNA might also facilitate reactions involving other DNA/RNA modifying enzymes whose Michaelis constant (K(m)) values are around 1 mM, allowing them to be activated in the presence of only small quantities of substrate.

  10. In vitro colchicine-induced polyploid plantlet production and regeneration from leaf explants of the diploid pear (Pyrus communis L.) cultivar, 'Fertility'

    Science.gov (United States)

    Polyploid plantlets, including triploid, tetraploid and other polyploids, were induced from in vitro leaves of a European pear (Pyrus communis L.) cultivar 'Fertility' by a colchicine treatment. In vitro leaves were incubated in 0.4% colchicine solution for 24, 48 or 72 h, and transferred to an adv...

  11. The North American Trichogramma (Hymenoptera) : Trichogrammatidae parasitizing certain tortricidae (Lepidoptera) on apple and pear, with ITS2 DNA characterizations and description of a new species

    NARCIS (Netherlands)

    Pinto, J.D.; Koopmanschap, A.B.; Platner, G.R.; Stouthamer, R.

    2002-01-01

    Eleven species of Trichogramma are reported parasitizing tortricid eggs on apple and pear in North America. Codling moth, Cydia pomonella (L.), and oriental fruit moth, Grapholita molesta (Busck), were the primary pest species encountered. Species of the Trichogramma minutum complex were the

  12. Assessment of cross compatibility of pear (Pyrus communis L.) cultivars on the basis of pollen tube observations and analysis of the S-RNase gene

    OpenAIRE

    Wojciech Antkowiak; Andrzej Wojciechowski; Łukasz Wolko; Grzegorz Łysiak

    2013-01-01

    Diallel crosses of P. communis cultivars: 'Amfora', 'Radana', 'Red Williams', 'Carola', 'Conference', and 'Dicolor', were conducted under orchard and laboratory conditions at temperatures of 20°C and 28°C . Based on pollen tube observations and after the determination of the S genotypes, the usefulness of these pear cultivars as cross pollinators was evaluated as good and very good.

  13. A Quarter Century of Variation in Color and Allometric Characteristics of Eggs from a Rain Forest Population of the Pearly-eyed Thrasher (Margarops fuscatus).

    Science.gov (United States)

    WAYNE J. ARENDT

    2004-01-01

    Egg color, size, and shape vary considerably within and among female Pearly-eyed Thrashers (Margarops fuscatus). Results of a 25-yr study (1979-2004) are presented to provide comparative data. In a sample of 4,128 eggs, typical shape was prolate spheroid; but several variations were observed, depending on the age, stature, and physiological condition of the female, as...

  14. The development of a model to describe the influence of temperature and relative humidity on respiration rate of prickly pear cactus stems in reduced O2 conditions

    NARCIS (Netherlands)

    Yahia, E.M.; Guevara, J.C.; Beaudry, R.M.; Tijskens, L.M.M.; Cedeno, L.

    2010-01-01

    Respiration rate (RO2) of prickly pear cactus stems (Opuntia spp.) was measured as a function of 4 temperature (T) and 6 relative humidity (RH) combinations for O2 partial pressures between 15 and 0.8 kPa, which were considered to support aerobic respiration. The rate of respiration (RO2) was

  15. Impact of nest predators, competitors, and ectoparasites on Pearly-eyed Thrashers, with comments on the potential implications for Puerto Rican Parrot recovery

    Science.gov (United States)

    Wayne J. Arendt

    2000-01-01

    Over the past 17 years, research on a rain forest population of the Pearly-eyed Thrasher (Margarops fuscatus), with additional observations on nesting Puerto Rican Parrots (Amazona vittata) within the Sierra de Luquillo, Puerto Rico, has shown that reproductive success of thrashers and parrots is often greatly reduced as a result of the additive effects of a diverse...

  16. Changes in home range of breeding and post-breeding male Pearly-eyed Thrashers in the Luquillo Mountains of Puerto Rico

    Science.gov (United States)

    Jose William Beltran; Joseph M. Wunderle, Jr.; Wayne J. Arendt

    2010-01-01

    Food abundance, time of year, and stage of the reproductive cycle are important factors affecting home range size in birds. Between 23 January and 28 November 2003, we determined the home range and core area sizes for 10 radio-tagged male Pearly-eyed Thrashers (Margarops fuscatus; Mimidae) within the Luquillo Experimental Forest, northeastern Puerto Rico. We found...

  17. Controlled atmosphere pO2 alters ripening dynamics of 1-MCP treated ‘d’Anjou’ pear (Pyrus communis L.) fruit

    Science.gov (United States)

    Ripening and development of physiological disorders and decay were assessed in ‘d’Anjou’ pear fruit following 1-methylcyclopropene (1-MCP) treatment and cold storage in air or controlled atmosphere (CA). Fruit were exposed after harvest to 0 or 12.6 µmol•L-1 1-MCP and then stored at 0.5 oC in air o...

  18. Pithy brown core in ‘d’Anjou’ pear (Pyrus communis L.) fruit developing during controlled atmosphere storage at pO2 determined by monitoring chlorophyll fluorescense

    Science.gov (United States)

    Physiological responses and fruit quality of ‘d’Anjou’ pear fruit from five orchard lots were evaluated after cold storage in air or controlled atmospheres (CA) with the oxygen (O2) concentration based on assessment of fruit chlorophyll fluorescence (CF) or standard conditions (1.5 kPa O2). The pCO2...

  19. Time-dependent bioactivity of preparations from cactus pear (Opuntia ficus indica) and ice plant (Mesembryanthemum crystallinum) on human skin fibroblasts and keratinocytes.

    Science.gov (United States)

    Deters, A M; Meyer, U; Stintzing, F C

    2012-07-13

    Traditionally and nowadays preparations from two xerophytic plants, the ice plant and cactus pear are used in dermatologic and cosmetic preparations. In spite of their daily use, little is known concerning the bioactivity of such extracts on skin cells. The purpose of this study was to investigate the effect of pressed juices from ice plant (McP) and two cactus pear polysaccharides (cold water soluble, NwPS; non swelling pectin, NPec) on the cell physiology of normal human dermal fibroblasts (NHDF) and HaCaT-keratinocytes due to composition, concentration and incubation time. Cactus pear polysaccharides were analyzed by high performance anion exchange chromatography with pulsed amperometric detection after hydrolysis with trifluoroacetic acid. Ice plant pressed juices were filtrated through a 1.2 μm (McPI) and 0.2 μm filter (McPII). Cell proliferation was measured with BrdU incorporation assay. Reduction of tetrazolium salts was applied to determine the metabolic activity (MTT) while necrotic effects were assessed by LDH-release measurements. Cactus pear polysaccharides differed predominantly in their glucose and uronic acid content. The filtration of pressed juices altered the amounts of high molecular weight compounds. The proliferation of NHDF and HaCaTs was significantly stimulated by cactus pear polysaccharides and ice plant pressed juices not until 72 h of incubation. McPI significantly increased the proliferation of NHDF and HaCaTs while significant effect of McPII was only observed in case of HaCaT-keratinocytes. A dependence on concentration was not observed. Metabolic activity was neither influenced by McPI nor by McPII independent of incubation time. The HaCaT proliferation was not significantly influenced by low concentrations of cactus pear polysaccharides however it was inhibited by 100 μg/mL NPec. 100 μg/mL of NwPS and 1 μg/mL NPec stimulated the proliferation of fibroblasts. The metabolic activity of NHDF was not affected neither by NPec nor by

  20. Efficacy of heat treatments with water and fludioxonil for postharvest control of blue and gray molds on inoculated pears and fludioxonil residues in fruit.

    Science.gov (United States)

    Schirra, Mario; D'Aquino, Salvatore; Mulas, Maurizio; Melis, Rita Anna Maria; Giobbe, Sara; Migheli, Quirico; Garau, Anna; Angioni, Alberto; Cabras, Paolo

    2008-05-01

    The residue levels of fludioxonil (FLU) were determined in pear cultivars Precoce di Fiorano, Coscia, and Spadona estiva after a 2-min dip in an aqueous mixture of FLU containing 300 or 100 mg/liter of active ingredient at 20 or 50 degrees C and after 12 days at 17 degrees C and 80% relative humidity (simulated shelf life conditions). The accumulation trend of FLU residues was determined in 'Precoce di Fiorano' pears after treatments with 25, 50, 100, or 200 mg/liter of active ingredient at 20 or 50 degrees C for 2 min or at 60 degrees C for 1 min. The efficacy of heat treatments with water and FLU was investigated on artificially inoculated 'Precoce di Fiorano', 'Coscia', and 'Spadona estiva' pears for the control of postharvest blue mold and gray mold caused by Penicillium expansum and Botrytis cinerea, respectively. Treatment with 300 mg/liter FLU at 20 degrees C resulted in residue levels similar to those from treatment with 100 mg/liter FLU at 50 degrees C in 'Coscia' fruit but in significantly lower residues in 'Precoce di Fiorano' and 'Spadona estiva' pears. Post-shelf life residues decreased in all cultivars, especially in 'Spadona estiva' pears treated with 300 mg/liter FLU at 20 degrees C. Residue levels of FLU in 'Precoce di Fiorano' pears treated at 20, 50, or 60 degrees C were correlated with fungicide dosage. When an equal rate was used, treatment at 50 degrees C resulted in a higher and a notably higher FLU deposition than that found under treatment at 60 and 20 degrees C, respectively. The in vitro tests showed that both pathogens were very sensitive to FLU, with MICs averaging 0.05 and 0.1 mg/liter for B. cinerea and P. expansum isolates, respectively. The 50% effective concentration ranged between 0.01 and 0.05 mg/liter for B. cinerea and between 0.05 and 0.1 mg/liter for P. expansum. In the in vivo trials, hot water treatment effectively reduced the incidence of both diseases during the first 4 to 8 days, depending on cultivar, dip temperature

  1. Development of Microsatellite Markers in Pungtungia herzi Using Next-Generation Sequencing and Cross-Species Amplification in the Genus Pseudopungtungia

    Science.gov (United States)

    Yun, Young-Eun; Yu, Jeong-Nam; Kim, Sang Ki; Hwang, Ui Wook; Kwak, Myounghai

    2013-01-01

    Nuclear microsatellite markers for Pungtungia herzi were developed using a combination of next-generation sequencing and Sanger sequencing. One hundred primer sets in the flanking region of dinucleotide and trinucleotide repeat motifs were designed and tested for efficiency in polymerase chain reaction amplification. Of these primer sets, 16 new markers (16%) were successfully amplified with unambiguous polymorphic alleles in 16 individuals of Pungtungia herzi. Cross-species amplification with these markers was then examined in two related species, Pseudopungtungia nigra and Pseudopungtungia tenuicorpa. Fifteen and 11 primer pairs resulted in successful amplification in Pseudopungtungia nigra and Pseudopungtungia tenuicorpa, respectively, with various polymorphisms, ranging from one allele (monomorphic) to 11 alleles per marker. These results indicated that developing microsatellite markers for cross-amplification from a species that is abundant and phylogenetically close to the species of interest is a good alternative when tissue samples of an endangered species are insufficient to develop microsatellites. PMID:24084733

  2. A new ultrasonic signal amplification method for detection of bacteria

    International Nuclear Information System (INIS)

    Shukla, Shiva Kant; López, Pablo Resa; Sánchez, Carlos Sierra; Segura, Luis Elvira; Urréjola, José

    2012-01-01

    A new method is presented that increases the sensitivity of ultrasound-based techniques for detection of bacteria. The technique was developed for the detection of catalase-positive microorganisms. It uses a bubble trapping medium containing hydrogen peroxide that is mixed with the sample for microbiological evaluation. The enzyme catalase is present in catalase-positive bacteria, which induces a rapid hydrolysis of hydrogen peroxide, forming bubbles which remain in the medium. This reaction results in the amplification of the mechanical changes that the microorganisms produce in the medium. The effect can be detected by means of ultrasonic wave amplitude continuous measurement since the bubbles increase the ultrasonic attenuation significantly. It is shown that microorganism concentrations of the order of 10 5 cells ml −1 can be detected using this method. This allows an improvement of three orders of magnitude in the ultrasonic detection threshold of microorganisms in conventional culture media, and is competitive with modern rapid microbiological methods. It can also be used for the characterization of the enzymatic activity. (paper)

  3. A new ultrasonic signal amplification method for detection of bacteria

    Science.gov (United States)

    Kant Shukla, Shiva; Resa López, Pablo; Sierra Sánchez, Carlos; Urréjola, José; Segura, Luis Elvira

    2012-10-01

    A new method is presented that increases the sensitivity of ultrasound-based techniques for detection of bacteria. The technique was developed for the detection of catalase-positive microorganisms. It uses a bubble trapping medium containing hydrogen peroxide that is mixed with the sample for microbiological evaluation. The enzyme catalase is present in catalase-positive bacteria, which induces a rapid hydrolysis of hydrogen peroxide, forming bubbles which remain in the medium. This reaction results in the amplification of the mechanical changes that the microorganisms produce in the medium. The effect can be detected by means of ultrasonic wave amplitude continuous measurement since the bubbles increase the ultrasonic attenuation significantly. It is shown that microorganism concentrations of the order of 105 cells ml-1 can be detected using this method. This allows an improvement of three orders of magnitude in the ultrasonic detection threshold of microorganisms in conventional culture media, and is competitive with modern rapid microbiological methods. It can also be used for the characterization of the enzymatic activity.

  4. Risks, media and the social amplification of soil contamination

    Energy Technology Data Exchange (ETDEWEB)

    Ouboter, S. [NOK, Networkorganisation for Environmental Quality, Gouda (Netherlands)

    2003-07-01

    Soil experts think of the risks of contaminated sites in terms of adverse effects of toxic substances on human health or environmental quality. In other words, the risk is attributed to the contamination. Social scientists define risk as a situation or event in which something of human value (including humans themselves) has been put at stake and where the outcome is uncertain. Since situations or events are constructions of the human mind, risks are also constructed. A relevant question for a psychologist is to learn how these constructions evolve in the mind of an individual and how this perceived risk influences the individuals' behaviour and well-being. A relevant question for a sociologist is how individuals with their own perceptions, feelings and behaviour interact. Many soil contamination experts experienced that one a site is seen as contaminated by a loathsome source, a chain of adverse reactions can easily put a stigma on that specific location and groups of people associated with that contaminated site. The case of Love Canal is worldwide known as an example of this phenomenon, but many countries have their own national symbol, like Lekkerkerk in the Netherlands. Modern media play an important role in this process. This process is often believed to be irrational and therefore uncontrollable. The question of this workshop is to what level technical soil experts can influence the psychological and social effects of soil contamination, using the social amplification metaphor. (orig.)

  5. Coupling Activity-Based Detection, Target Amplification, Colorimetric and Fluorometric Signal Amplification, for Quantitative Chemosensing of Fluoride Generated from Nerve Agents.

    Science.gov (United States)

    Sun, Xiaolong; Reuther, James F; Phillips, Scott T; Anslyn, Eric V

    2017-03-17

    The G-class nerve agents, which include sarin, soman, and cyclosarin, react readily with nucleophilic reagents to produce fluoride. Thus, a chemosensing protocol has been designed for these agents that pairs the nucleophilic reactivity of oximates for generating fluoride with an autoinductive target amplification reaction to amplify the quantity of fluoride for facile colorimetric and fluorescent optical quantification. The chemosensing protocol was demonstrated by using the nerve agent surrogate diisopropyl fluorophosphate (DFP) and benzaldoxime as the nucleophile. Autoinductive fluoride amplification responds to fluoride released from DFP by amplifying the fluoride concentration and a yellow reporter molecule. The reporter is a conjugated oligomer with a nominal repeating unit that originates from 4-aminobenzaldehyde. Exposure of the amplified fluoride to a fluoride-specific ratiometric fluorescent reporter provides a fluorescent readout, in which three fluorophores are generated per fluoride. Both colorimetric and fluorescent readouts enable quantitative assays with low micromolar limits of detection for fluoride resulting from DFP. More importantly, this work demonstrates the successful merging of multiple complex reactions for achieving selective, sensitive, and quantitative chemosensing. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Fungi associated with die-back symptoms of apple and pear trees, a possible inoculum source of grapevine trunk disease pathogens

    Directory of Open Access Journals (Sweden)

    Mia CLOETE

    2011-12-01

    Full Text Available A survey was undertaken on apple and pear trees in the main pome fruit growing areas ofthe Western Cape of South Africa to determine the aetiology of trunk diseases with specific reference to pathogens known to occur on grapevine, which are frequently cultivated in close proximity of these orchards. Several fungal genera containing known trunk disease pathogens were found. Two Diplodia species, D. seriata and Diplodia sp., were isolated along with Neofusicoccum australe and N. vitifusiforme. Four Phaeoacremonium species, Phaeoacremonium aleophilum, Pm. iranianum, Pm. mortoniae and Pm. viticola, two Phomopsis species linked to clades identified in former studies as Phomopsis theicola and Phomopsis sp. 7, and Eutypa lata were found. In addition, Paraconiothyrium brasiliense, Pr. variabile and a Pyrenochaeta like species were also isolated. Diplodia seriata (56% of total isolates and Pm. aleophilum (22% were most frequently isolate. First reports from pear wood include the Phaeoacremonium spp. and Paraconiothyrium brasiliense, while new reports from apple include Pm. aleophilum, Ph. theicola, Phomopsis sp. 7, Pr. variabile and E. lata. A pathogenicity trial was undertaken to determine the role of these species on apple, pear and grapevine shoots. Neofusicoccum australe caused the longest lesions on grapevine shoots, while Pr. variabile, D. seriata, Pm. mortoniae and the Pyrenochaeta-like sp. caused lesions that were longer than non-inoculatedand non-pathogen experimental controls. On pear shoots, Diplodia sp. and N. australe caused the longest lesions,followed by D. seriata and E. lata. On apple shoots, the longest lesions were caused by N. australe and Pm. iranianum. These results demonstrate that apple and pear trees in Western Cape orchards are hosts to many known trunk pathogens along with potential new trunk disease-causing fungi.

  7. PyMYB10 and PyMYB10.1 Interact with bHLH to Enhance Anthocyanin Accumulation in Pears.

    Directory of Open Access Journals (Sweden)

    Shouqian Feng

    Full Text Available Color is an important agronomic trait of pears, and the anthocyanin content of fruit is immensely significant for pear coloring. In this study, an anthocyanin-activating R2R3-MYB transcription factor gene, PyMYB10.1, was isolated from fruits of red sand pear (Pyrus pyrifolia cv. Aoguan. Alignments of the nucleotide and amino acid sequences suggested that PyMYB10.1 was involved in anthocyanin regulation. Similar to PyMYB10, PyMYB10.1 was predominantly expressed in red tissues, including the skin, leaf and flower, but it was minimally expressed in non-red fruit flesh. The expression of this gene could be induced by light. Dual-luciferase assays indicated that both PyMYB10 and PyMYB10.1 activated the AtDFR promoter. The activation of AtDFR increased to a greater extent when combined with a bHLH co-factor, such as PybHLH, MrbHLH1, MrbHLH2, or AtbHLH2. However, the response of this activation depended on the protein complex formed. PyMYB10-AtbHLH2 activated the AtDFR promoter to a greater extent than other combinations of proteins. PyMYB10-AtbHLH2 also induced the highest anthocyanin accumulation in tobacco transient-expression assays. Moreover, PybHLH interacted with PyMYB10 and PyMYB10.1. These results suggest that both PyMYB10 and PyMYB10.1 are positive anthocyanin biosynthesis regulators in pears that act via the formation of a ternary complex with PybHLH. The functional characterization of PyMYB10 and PyMYB10.1 will aid further understanding of the anthocyanin regulation in pears.

  8. Different biosynthesis patterns among flavonoid 3-glycosides with distinct effects on accumulation of other flavonoid metabolites in pears (Pyrus bretschneideri Rehd..

    Directory of Open Access Journals (Sweden)

    Rui Zhai

    Full Text Available Flavonoid biosynthesis profile was clarified by fruit bagging and re-exposure treatments in the green Chinese pear 'Zaosu' (Pyrus bretschneideri Rehd. and its red mutant 'Red Zaosu'. Two distinct biosynthesis patterns of flavonoid 3-glycosides were found in 'Zaosu' pear. By comparison with 'Red Zaosu', the biosynthesis of flavonoid 3-galactosides and flavonoid 3-arabinosides were inhibited by bagging and these compounds only re-accumulated to a small degree in the fruit peel of 'Zaosu' after the bags were removed. In contrast, the biosynthesis of flavonoid 3-gluctosides and flavonoid 3-rutinosides was reduced by bagging and then increased when the fruits were re-exposed to sunlight. A combination of correlation, multicollinearity test and partial-correlation analyses among major flavonoid metabolites indicated that biosynthesis of each phenolic compound was independent in 'Zaosu' pear, except for the positive correlation between flavonoid 3-rutincosides and flavanols. In contrast with the green pear cultivar, almost all phenolic compounds in the red mutant had similar biosynthesis patterns except for arbutin. However, only the biosynthesis of flavonoid 3-galactosides was relatively independent and strongly affected the synthesis of the other phenolic compounds. Therefore, we propose a hypothesis that the strong accumulation of flavonoid 3-galactosides stimulated the biosynthesis of other flavonoid compounds in the red mutant and, therefore, caused systemic variation of flavonoid biosynthesis profiles between 'Zaosu' and its red mutant. This hypothesis had been further demonstrated by the enzyme activity of UFGT, and transcript levels of flavonoid biosynthetic genes and been well tested by a stepwise linear regression forecasting model. The gene that encodes flavonoid 3-galacosyltransferase was also identified and isolated from the pear genome.

  9. Loop‑mediated Isothermal Amplification assay (LAMP) based detection of Pasteurella multocida in cases of haemorrhagic septicaemia and fowl cholera.

    Science.gov (United States)

    Bhimani, Mayurkumar; Bhanderi, Bharat; Roy, Ashish

    2015-01-01

    Twenty two isolates of Pasteurella multocida were obtained from different tissues of dead birds and animals (cattle, buffalo, sheep, and goat) suspected of fowl cholera and haemorrhagic septicaemia. The isolates were confirmed as P. multocida by various biochemical tests and PM PCR. An attempt was made to standardize Loop mediated isothermal amplification (LAMP) using newly designed primer sequences of KMT1 gene. Loop mediated isothermal amplification was conducted using 6 sets of primers at 65°C for 30 minutes and the result was confirmed by visual observation using SYBR green fluorescence dye as marker of positive reaction under UV transilluminator. On electrophoretic analysis of the products on 2% agarose gel, a ladder like pattern was observed, which suggested a positive amplification, whereas no amplification was observed in negative controls. Additionally, product of positive reaction yielded a green fluorescence following addition of SYBR green under UV transilluminator. It was observed that LAMP is a more sensitive test than polymerase chain reaction (PCR), as the former could detect DNA to lower limit of 22.8 pg/µl, while the latter could detect DNA to lower limit of 2.28 ng/ µl, thus LAMP could detect 100 times lesser concentration of DNA in comparison to PCR. Loop mediated isothermal amplification is a rather newer molecular technique, which can be used for rapid detection of infectious agent at field level and which does not require sophisticated instrument, i.e. thermal cycler. Furthermore, unlike the conventional PCR technique, LAMP requires lesser time to perform and result can be read visually.

  10. Raman amplification in optical communication systems

    DEFF Research Database (Denmark)

    Kjær, Rasmus

    2008-01-01

    Fiber Raman amplifiers are investigated with the purpose of identifying new applications and limitations for their use in optical communication systems. Three main topics are investigated, namely: New applications of dispersion compensating Raman amplifiers, the use Raman amplification to increase...... støjtal under 4,5 dB og en samlet udgangseffekt på 22 dBm. Med henblik på at forlænge rækkevidden af fremtidige access-netværk foreslås en ny arkitektur for såkaldte langdistance passive optiske netværk (PON). Dette system evalueres både teoretisk og eksperimentelt. Distribueret Raman-forstærkning bruges...

  11. Parametric Amplification of a Superconducting Plasma Wave.

    Science.gov (United States)

    Rajasekaran, S; Casandruc, E; Laplace, Y; Nicoletti, D; Gu, G D; Clark, S R; Jaksch, D; Cavalleri, A

    2016-11-01

    Many applications in photonics require all-optical manipulation of plasma waves1, which can concentrate electromagnetic energy on sub-wavelength length scales. This is difficult in metallic plasmas because of their small optical nonlinearities. Some layered superconductors support Josephson plasma waves (JPWs)2,3, involving oscillatory tunneling of the superfluid between capacitively coupled planes. Josephson plasma waves are also highly nonlinear4, and exhibit striking phenomena like cooperative emission of coherent terahertz radiation5,6, superconductor-metal oscillations7 and soliton formation8. We show here that terahertz JPWs can be parametrically amplified through the cubic tunneling nonlinearity in a cuprate superconductor. Parametric amplification is sensitive to the relative phase between pump and seed waves and may be optimized to achieve squeezing of the order parameter phase fluctuations9 or single terahertz-photon devices.

  12. Parametric amplification by coupled flux qubits

    Energy Technology Data Exchange (ETDEWEB)

    Rehák, M.; Neilinger, P.; Grajcar, M. [Department of Experimental Physics, Comenius University, SK-84248 Bratislava (Slovakia); Institute of Physics, Slovak Academy of Science, 845 11 Bratislava (Slovakia); Oelsner, G.; Hübner, U.; Meyer, H.-G. [Leibniz Institute of Photonic Technology, P.O. Box 100239, D-07702 Jena (Germany); Il' ichev, E. [Leibniz Institute of Photonic Technology, P.O. Box 100239, D-07702 Jena (Germany); Novosibirsk State Technical University, 20 K. Marx Ave., 630092 Novosibirsk (Russian Federation)

    2014-04-21

    We report parametric amplification of a microwave signal in a Kerr medium formed from superconducting qubits. Two mutually coupled flux qubits, embedded in the current antinode of a superconducting coplanar waveguide resonator, are used as a nonlinear element. Shared Josephson junctions provide the qubit-resonator coupling, resulting in a device with a tunable Kerr constant (up to 3 × 10{sup −3}) and a measured gain of about 20 dB. This arrangement represents a unit cell which can be straightforwardly extended to a quasi one-dimensional quantum metamaterial with large tunable Kerr nonlinearity, providing a basis for implementation of wide-band travelling wave parametric amplifiers.

  13. Heralded amplification of path entangled quantum states

    Science.gov (United States)

    Monteiro, F.; Verbanis, E.; Caprara Vivoli, V.; Martin, A.; Gisin, N.; Zbinden, H.; Thew, R. T.

    2017-06-01

    Device-independent quantum key distribution (DI-QKD) represents one of the most fascinating challenges in quantum communication, exploiting concepts of fundamental physics, namely Bell tests of nonlocality, to ensure the security of a communication link. This requires the loophole-free violation of a Bell inequality, which is intrinsically difficult due to losses in fibre optic transmission channels. Heralded photon amplification (HPA) is a teleportation-based protocol that has been proposed as a means to overcome transmission loss for DI-QKD. Here we demonstrate HPA for path entangled states and characterise the entanglement before and after loss by exploiting a recently developed displacement-based detection scheme. We demonstrate that by exploiting HPA we are able to reliably maintain high fidelity entangled states over loss-equivalent distances of more than 50 km.

  14. Introduction to quantum noise, measurement, and amplification

    Science.gov (United States)

    Clerk, A. A.; Devoret, M. H.; Girvin, S. M.; Marquardt, Florian; Schoelkopf, R. J.

    2010-04-01

    The topic of quantum noise has become extremely timely due to the rise of quantum information physics and the resulting interchange of ideas between the condensed matter and atomic, molecular, optical-quantum optics communities. This review gives a pedagogical introduction to the physics of quantum noise and its connections to quantum measurement and quantum amplification. After introducing quantum noise spectra and methods for their detection, the basics of weak continuous measurements are described. Particular attention is given to the treatment of the standard quantum limit on linear amplifiers and position detectors within a general linear-response framework. This approach is shown how it relates to the standard Haus-Caves quantum limit for a bosonic amplifier known in quantum optics and its application to the case of electrical circuits is illustrated, including mesoscopic detectors and resonant cavity detectors.

  15. Raman Amplification with a Flying Focus

    Science.gov (United States)

    Turnbull, D.; Bucht, S.; Davies, A.; Haberberger, D.; Kessler, T.; Shaw, J. L.; Froula, D. H.

    2018-01-01

    We propose a new laser amplifier scheme utilizing stimulated Raman scattering in plasma in conjunction with a "flying focus"—a chromatic focusing system combined with a chirped pump beam that provides spatiotemporal control over the pump's focal spot. Pump intensity isosurfaces are made to propagate at v =-c so as to be in sync with the injected counterpropagating seed pulse. By setting the pump intensity in the interaction region to be just above the ionization threshold of the background gas, an ionization wave is produced that travels at a fixed distance ahead of the seed. Simulations show that this will make it possible to optimize the plasma temperature and mitigate many of the issues that are known to have impacted previous Raman amplification experiments, in particular, the growth of precursors.

  16. Social and political amplification of technological hazards

    International Nuclear Information System (INIS)

    Ibitayo, Olurominiyi O.; Mushkatel, Alvin; Pijawka, K. David

    2004-01-01

    Using an industrial explosion in Henderson, Nevada, as a case study, this paper examines three main issues: the efficacy of a technological hazard event in amplifying otherwise latent issues, the extent to which the hazard event can serve as a focusing event for substantive local and state policy initiatives, and the effect of fragmentation of political authority in managing technological hazards. The findings indicate that the explosion amplified several public safety issues and galvanized the public into pressing for major policy initiatives. However, notwithstanding the amplification of several otherwise latent issues, and the flurry of activities by the state and local governments, the hazard event did not seem to be an effective focusing event or trigger mechanism for substantive state and local policy initiatives. In addition, the study provides evidence of the need for a stronger nexus between political authority, land-use planning and technological hazard management

  17. Protein Misfolding Cyclic Amplification of Infectious Prions.

    Science.gov (United States)

    Moda, Fabio

    2017-01-01

    Transmissible spongiform encephalopathies, or prion diseases, are a group of incurable disorders caused by the accumulation of an abnormally folded prion protein (PrP Sc ) in the brain. According to the "protein-only" hypothesis, PrP Sc is the infectious agent able to propagate the disease by acting as a template for the conversion of the correctly folded prion protein (PrP C ) into the pathological isoform. Recently, the mechanism of PrP C conversion has been mimicked in vitro using an innovative technique named protein misfolding cyclic amplification (PMCA). This technology represents a great tool for studying diverse aspects of prion biology in the field of basic research and diagnosis. Moreover, PMCA can be expanded for the study of the misfolding process associated to other neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, and frontotemporal lobar degeneration. © 2017 Elsevier Inc. All rights reserved.

  18. Markovian Dynamics of Josephson Parametric Amplification

    Directory of Open Access Journals (Sweden)

    W. Kaiser

    2017-09-01

    Full Text Available In this work, we derive the dynamics of the lossy DC pumped non-degenerate Josephson parametric amplifier (DCPJPA. The main element in a DCPJPA is the superconducting Josephson junction. The DC bias generates the AC Josephson current varying the nonlinear inductance of the junction. By this way the Josephson junction acts as the pump oscillator as well as the time varying reactance of the parametric amplifier. In quantum-limited amplification, losses and noise have an increased impact on the characteristics of an amplifier. We outline the classical model of the lossy DCPJPA and derive the available noise power spectral densities. A classical treatment is not capable of including properties like spontaneous emission which is mandatory in case of amplification at the quantum limit. Thus, we derive a quantum mechanical model of the lossy DCPJPA. Thermal losses are modeled by the quantum Langevin approach, by coupling the quantized system to a photon heat bath in thermodynamic equilibrium. The mode occupation in the bath follows the Bose-Einstein statistics. Based on the second quantization formalism, we derive the Heisenberg equations of motion of both resonator modes. We assume the dynamics of the system to follow the Markovian approximation, i.e. the system only depends on its actual state and is memory-free. We explicitly compute the time evolution of the contributions to the signal mode energy and give numeric examples based on different damping and coupling constants. Our analytic results show, that this model is capable of including thermal noise into the description of the DC pumped non-degenerate Josephson parametric amplifier.

  19. Ground amplification determined from borehole accelerograms

    International Nuclear Information System (INIS)

    Archuleta, R.J.; Seale, S.H.

    1991-01-01

    The Garner Valley downhole array (GVDA) consists of one surface accelerometer and four downhole accelerometers at depths of 6 m, 15 m, 22m, and 220 m. The five, three-component vertical array of dual-gain accelerometers are capable of measuring accelerations from 3 x 10 -6 g to 2.0 g over a frequency range from 0.0 Hz (0.025, high-gain) Hz to 100 Hz. The site (33 degree 41.60' N, 116 degree 40.20 degree W) is only seven kilometers off the trace of the San Jacinto fault, the most active strand of the San Andreas fault system in southern California and only about 35 km from the San Andreas fault itself. Analysis of individual spectra and spectral ratios for the various depths shows that the zone of weathered granite has a pronounced effect on the spectral amplitudes for frequencies greater than 40 Hz. The soil layer impedance may amplify the high frequencies more than it attenuates. This result must be checked more thoroughly with special consideration of the spectra of the P-wave coda on the horizontal components. Analysis of the P-wave spectra and the spectral ratios shows an increased amplification in the same frequency range (60-90 Hz) where the S-wave spectral ratios imply a change in the attenuation. Comparison of acceleration spectra from two earthquakes, M L 4.2 and M L 2.5 that have nearly the same hypocenter, shows that the near surface amplification and attenuation is nearly the same for both earthquakes. However, the earthquakes themselves are different if we can assume that the recording at 220 m reflects the source spectra with a slight attenuation. The M L 2.5 earthquake has significantly greater high frequency content if the spectra are normalized at the low frequency, i.e., normalization by seismic moment

  20. Evaluation of loop mediated isothermal amplification for diagnosis of ...

    African Journals Online (AJOL)

    Tuberculosis (TB) remains an important global public health problem. The lack of rapid and accurate diagnostic testing is an important impediment to global tuberculosis control. Loop mediated isothermal amplification (LAMP) is a rapid method for nucleic acid amplification. In this study, we assessed the performance of an ...