WorldWideScience

Sample records for amplification rt-lamp system

  1. Rapid detection of peste des petits ruminants virus using a reverse transcription loop-mediated isothermal amplification (RT-LAMP)

    International Nuclear Information System (INIS)

    A one-step, single-tube, accelerated, quantitative reverse transcription (RT) loop-mediated isothermal amplification (RT-LAMP) assay targeting the N gene for the rapid and real-time detection of peste des petits ruminants virus (PPRV) are reported. The feasibility of PPRV RTLAMP for laboratory diagnosis was validated with vaccine virus samples Nigeria 75/1. The comparative evaluation of the RT-LAMP assay demonstrated exceptionally higher sensitivity by conventional RT-PCR with a detection limit of 2 copies. In addition, the field applicability of the RT-LAMP assay was also demonstrated by standardizing SYBR Green I-based RT-LAMP wherein the amplification was carried out in a water bath at 63 deg. C for 70 min, which was followed by monitoring gene amplification with the naked eye through colour changes. These findings demonstrated that the RT-LAMP assay is a valuable tool for rapid, real-time detection as well as quantification of PPRV in the samples without requiring any sophisticated equipment and has potential usefulness for clinical diagnosis and surveillance of PPRV in developing countries. A set of four primers was designed by targeting the PPRV N gene. With Bst DNA polymerase large fragment, ladder like DNA fragments can be seen with agarose gel electrophoresis. The RT-LAMP reaction system was optimized; the sensitivity and the specificity were tested. The process of one step RT-LAMP assay was performed within 70 minutes and amplification results was visualized, the sensitivity of RT-LAMP assay was 1000 times of RT-PCR, ten times of nest RT-PCR. The RTLAMP described in this study is a cheap, sensitive, specific and rapid protocol for the detection of PPRV infected cells and tissues effectively. It can be simply applied both in field condition and in laboratory operation for specific detection of PPRV

  2. Reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for rapid diagnosis of chilli veinal mottle virus.

    Science.gov (United States)

    Banerjee, Amrita; Roy, Somnath; Sharma, Susheel Kumar; Dutta, Sudip Kumar; Chandra, Satish; Ngachan, S V

    2016-07-01

    Chilli veinal mottle virus (ChiVMV) causes significant economic loss to chilli cultivation in northeastern India, as well as in eastern Asia. In this study, we have developed a single-tube one-step reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for rapid, sensitive and specific diagnosis of ChiVMV. Amplification could be visualized after adding SYBR Green I (1000×) dye within 60 min under isothermal conditions at 63 °C, with a set of four primers designed based on the large nuclear inclusion protein (NIb) domain of ChiVMV (isolate KC-ML1). The RT-LAMP method was 100 times more sensitive than one-step reverse transcription polymerase chain reaction (RT-PCR), with a detection limit of 0.0001 ng of total RNA per reaction. PMID:27063408

  3. Analysis of a Reverse Transcription Loop-mediated Isothermal Amplification (RT-LAMP) for yellow fever diagnostic.

    Science.gov (United States)

    Nunes, Marcio R T; Vianez, João Lídio; Nunes, Keley N B; da Silva, Sandro Patroca; Lima, Clayton P S; Guzman, Hilda; Martins, Lívia C; Carvalho, Valéria L; Tesh, Robert B; Vasconcelos, Pedro F C

    2015-12-15

    Yellow Fever virus (YFV) is an important human pathogen in tropical areas of Africa and South America. Although an efficient vaccine is available and has been used since the early 1940s, sylvatic YFV transmission still occurs in forested areas where anthropogenic actions are present, such as mineral extraction, rearing livestock and agriculture, and ecological tourism. In this context, two distinct techniques based on the RT-PCR derived method have been previously developed, however both methods are expensive due to the use of thermo cyclers and labeled probes. We developed isothermal genome amplification, which is a rapid, sensitive, specific and low cost molecular approach for YFV genome detection. This assay used a set of degenerate primers designed for the NS1 gene and was able to amplify, within 30 min in isothermal conditions, the YFV 17D vaccine strain derived from an African wild prototype strain (Asibi), as well as field strains from Brazil, other endemic countries from South and Central America, and the Caribbean. The generic RT-LAMP assay could be helpful for YFV surveillance in field and rapid response during outbreaks in endemic areas. PMID:26459206

  4. Detection of Cucurbit chlorotic yellows virus from Bemisia tabaci captured on sticky traps using reverse transcription loop-mediated isothermal amplification (RT-LAMP) and simple template preparation.

    Science.gov (United States)

    Okuda, Mitsuru; Okuda, Shiori; Iwai, Hisashi

    2015-09-01

    Cucurbit chlorotic yellows virus (CCYV) of the genus Crinivirus within the family Closteroviridae is an emerging infectious agent of cucurbits leading to severe disease and significant economic losses. Effective detection and identification methods for this virus are urgently required. In this study, a reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed to detect CCYV from its vector Bemisia tabaci. LAMP primer sets to detect CCYV were evaluated for their sensitivity and specificity, and a primer set designed from the HSP70h gene with corresponding loop primers were selected. The RT-LAMP assay was applied to detect CCYV from viruliferous B. tabaci trapped on sticky traps. A simple extraction procedure using RNAsecure™ was developed for template preparation. CCYV was detected in all of the B. tabaci 0, 1, 7 and 14 days after they were trapped. Although the rise of turbidity was delayed in reactions using RNA from B. tabaci trapped for 7 and 14 days compared with those from 0 and 1 day, the DNA amplification was sufficient to detect CCYV in all of the samples. These findings therefore present a simple template preparation method and an effective RT-LAMP assay, which can be easily and rapidly performed to monitor CCYV-viruliferous B. tabaci in the field. PMID:25912723

  5. Detection of Coconut cadang-cadang viroid (CCCVd) in oil palm by reverse transcription loop-mediated isothermal amplification (RT-LAMP).

    Science.gov (United States)

    Thanarajoo, Sathis Sri; Kong, Lih Ling; Kadir, Jugah; Lau, Wei Hongi; Vadamalai, Ganesan

    2014-06-01

    A reverse transcription loop-mediated isothermal amplification (RT-LAMP) detected Coconut cadang-cadang viroid (CCCVd) within 60 min at 60 °C in total nucleic acid extracted from oil palm leaves infected with CCCVd. Positive reactions showed colour change from orange to green in the reaction mix after the addition of fluorescent reagent, and a laddering pattern band on 2% agarose gel electrophoresis. Conventional RT-PCR with LAMP primers produced amplicons with a sequence identical to the 297-nt CCCVd oil palm variant with the primers being specific for CCCVd and not for other viroids such as PSTVd and CEVd. RT-LAMP was found to be rapid and specific for detecting oil palm CCCVd. PMID:24631346

  6. Loop-mediated isothermal amplification (RT-LAMP): a new approach for the detection of foot-and-mouth disease virus and its sero-types in Pakistan.

    Science.gov (United States)

    Farooq, U; Latif, A; Irshad, H; Ullah, A; Zahur, A B; Naeem, K; Khan, S U H; Ahmed, Z; Rodriguez, L L; Smoliga, G

    2015-01-01

    Successful disease management requires a rapid and sensitive diagnosis method that can recognize early infection even before the manifestation of its clinical signs. The only available field diagnostic tests for foot-and-mouth disease (FMD) are lateral flow devices, commonly known as chromatographic strips. Low sensitivity and inability to detect FMD virus (FMDV) at the serotype level are limitations of lateral flow devices. Therefore, a reverse transcriptase loop-mediated isothermal amplification (RT-LAMP) was standardized using universal and sero-type specific genes in a single tube. This test does not require sophisticated equipment and can detect FMDV at serotype level in about 60 min. In addition, the sensitivity and specificity of this test is comparable to conventional reverse transcriptase PCR and real time PCR (rRT-PCR). PMID:27175198

  7. Reverse transcription loop-mediated isothermal amplification for the rapid detection of infectious bronchitis virus in infected chicken tissues.

    Science.gov (United States)

    Chen, Hao-tai; Zhang, Jie; Ma, Yan-ping; Ma, Li-Na; Ding, Yao-zhong; Liu, Xiang-tao; Cai, Xue-peng; Ma, Li-qing; Zhang, Yong-guang; Liu, Yong-sheng

    2010-04-01

    A reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay targeting the nucleocapsid phosphoprotein gene of infectious bronchitis virus (IBV) was developed. The detection limits for the IBV RT-LAMP assay were 10(1) 50% egg infection dose (EID(50)) per 50 microl of titrated viruses and no cross-reaction of IBV RT-LAMP was found when tested with other viruses including Newcastle disease virus (NDV), avian reovirus (ARV), and infectious laryngotrachietis virus (ILTV) due to their mismatch with IBV RT-LAMP primers. A total of 187 clinical tissues samples (88 blood, 62 kidney and 37 lung) were evaluated and compared to conventional RT-PCR. The sensitivity of RT-LAMP and RT-PCR assays for detecting IBV RNA in clinical specimens was 99.5% and 98.4%, respectively. These findings showed that the RT-LAMP assay has potential usefulness for rapid and sensitive diagnosis in outbreak of IBV. PMID:19835950

  8. Deep sequencing of banana bract mosaic virus from flowering ginger (Alpinia purpurata) and development of an immunocapture RT-LAMP detection assay.

    Science.gov (United States)

    Zhang, Jingxin; Borth, Wayne B; Lin, Birun; Dey, Kishore K; Melzer, Michael J; Shen, Huifang; Pu, Xiaoming; Sun, Dayuan; Hu, John S

    2016-07-01

    Banana bract mosaic virus (BBrMV) has never been reported in banana plants in Hawaii. In 2010, however, it was detected in a new host, flowering ginger (Alpinia purpurata). In this study, we characterize the A. purpurata isolate and study its spread in flowering ginger in Hawaii. A laboratory study demonstrated that BBrMV could be transmitted from flowering ginger to its natural host, banana, therefore raising a serious concern about the potential risk to the rapidly growing banana industry of Hawaii. To quickly monitor this virus in the field, we developed a robust immunocapture reverse transcription loop-mediated isothermal amplification (IC-RT-LAMP) assay. Deep sequencing of the BBrMV isolate from A. purpurata revealed a single-stranded RNA virus with a genome of 9,713 nt potentially encoding a polyprotein of 3,124 aa, and another predicted protein, PIPO, in the +2 reading-frame shift. Most of the functional motifs in the Hawaiian isolate were conserved among the genomes of isolates from one found in the Philippines and India. However, the A. purpurata isolate had an amino acid deletion in the Pl protein that was most similar to the Philippine isolate. Phylogenetic analysis of an eastern Pacific subpopulation that included A. purpurata was closest in genetic distance to a Southeast Asian subpopulation, suggesting frequent gene flow and supporting the hypothesis that the A. purpurata isolate arrived in Hawaii from Southeast Asia. PMID:27038825

  9. One-step reverse transcription loop-mediated isothermal amplification for the rapid detection of cucumber green mottle mosaic virus.

    Science.gov (United States)

    Li, Jin-yu; Wei, Qi-wei; Liu, Yong; Tan, Xin-qiu; Zhang, Wen-na; Wu, Jian-yan; Charimbu, Miriam Karwitha; Hu, Bai-shi; Cheng, Zhao-bang; Yu, Cui; Tao, Xiao-rong

    2013-11-01

    Cucumber green mottle mosaic virus (CGMMV) has caused serious damage to Cucurbitaceae crops worldwide. The virus is considered one of the most serious Cucurbitaceae quarantine causes in many countries. In this study, a highly efficient and practical one-step reverse transcription loop-mediated isothermal amplification (RT-LAMP) was developed for the detection of CGMMV. The total RNA or crude RNA extracted from watermelon plants or seeds could be detected easily by this RT-LAMP assay. The RT-LAMP assay was conducted in isothermal (63°C) conditions within 1h. The amplified products of CGMMV could be detected as ladder-like bands using agarose gel electrophoresis or visualized in-tube under UV light with the addition of a fluorescent dye. The RT-LAMP amplification was specific to CGMMV, as no cross-reaction was observed with other viruses. The RT-LAMP assay was 100-fold more sensitive than that of reverse-transcription polymerase chain reaction (RT-PCR). This is the first report of the application of the RT-LAMP assay to detect CGMMV. The sensitive, specific and rapid RT-LAMP assay developed in this study can be applied widely in laboratories, the field and quarantine surveillance of CGMMV. PMID:23933076

  10. Rapid detection of wheat yellow mosaic virus by reverse transcription loop-mediated isothermal amplification

    Directory of Open Access Journals (Sweden)

    Zhang Zong-Ying

    2011-12-01

    Full Text Available Abstract For the detection of wheat yellow mosaic virus (WYMV, we established a reverse transcription loop-mediated isothermal amplification (RT-LAMP method. Using Primer Explorer software, four sets of primers were designed and RT-LAMP assay reaction conditions were optimized. The RT-LAMP was performed at different times by four primer sets. Agarose gel analysis showed that WYMV could be detected after 30 min with the primer set III and after 45 min with the other three primer sets, both under the 80-min reaction time. RT-LAMP had the same results with the four primer sets, thus primer set III and 65°C for 80 min reaction were selected for virus detection. There was no significant different when avian myeloblastosis virus (AMV and moloney murine leukemia virus (M-MLV RT-LAMP with the four primer sets and M-MLV was chosen due to its relatively cheap price. The result on specificity showed that the assay could amplify WYMV specifically, and the sensitivity comparison showed that the RT-LAMP was 100 times more sensitive than conventional reverse-transcriptase-polymerase chain reaction (RT-PCR. Overall, RT-LAMP was found to be a simple, specific, sensitive, convenient and time-saving method for WYMV detection.

  11. A reverse transcription loop-mediated isothermal amplification assay to rapidly diagnose foot-and-mouth disease virus C

    OpenAIRE

    Ding, Yao-zhong; Zhou, Jian-Hua; Ma, Li-na; Qi, Yan-ni; Wei, Gang; Zhang, Jie; Zhang, Yong-guang

    2014-01-01

    A reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed to rapidly detect foot-and-mouth disease virus serotype C (FMDV C). By testing 10-fold serial dilutions of FMDV C samples, sensitivity of the FMDV C RT-LAMP was found to be 10 times higher than that of conventional reverse transcription-PCR (RT-PCR). No cross-reactivity with A, Asia 1, or O FMDV or swine vesicular disease virus (SVDV) indicated that FMDV C RT-LAMP may be an exciting novel method for d...

  12. Establishment of reverse transcription loop-mediated isothermal amplification for rapid detection and differentiation of canine distemper virus infected and vaccinated animals.

    Science.gov (United States)

    Liu, Da-Fei; Liu, Chun-Guo; Tian, Jin; Jiang, Yi-Tong; Zhang, Xiao-Zhan; Chai, Hong-Liang; Yang, Tian-Kuo; Yin, Xiu-Chen; Zhang, Hong-Ying; Liu, Ming; Hua, Yu-Ping; Qu, Lian-Dong

    2015-06-01

    Although widespread vaccination against canine distemper virus (CDV) has been conducted for many decades, several canine distemper outbreaks in vaccinated animals have been reported frequently. In order to detect and differentiate the wild-type and vaccine strains of the CDV from the vaccinated animals, a novel reverse transcription loop-mediated isothermal amplification (RT-LAMP) method was developed. A set of four primers-two internal and two external-were designed to target the H gene for the specific detection of wild-type CDV variants. The CDV-H RT-LAMP assay rapidly amplified the target gene, within 60 min, using a water bath held at a constant temperature of 65°C. The assay was 100-fold more sensitive than conventional RT-PCR, with a detection limit of 10(-1)TCID50ml(-1). The system showed a preference for wild-type CDV, and exhibited less sensitivity to canine parvovirus, canine adenovirus type 1 and type 2, canine coronavirus, and canine parainfluenza virus. The assay was validated using 102 clinical samples obtained from vaccinated dog farms, and the results were comparable to a multiplex nested RT-PCR assay. The specific CDV-H RT-LAMP assay provides a simple, rapid, and sensitive tool for the detection of canines infected with wild-type CDV from canines vaccinated with attenuated vaccine. PMID:25769803

  13. Detection of Magnaporthe oryzae chrysovirus 1 in Japan and establishment of a rapid, sensitive and direct diagnostic method based on reverse transcription loop-mediated isothermal amplification.

    Science.gov (United States)

    Komatsu, Ken; Urayama, Syun-Ichi; Katoh, Yu; Fuji, Shin-Ichi; Hase, Shu; Fukuhara, Toshiyuki; Arie, Tsutomu; Teraoka, Tohru; Moriyama, Hiromitsu

    2016-02-01

    Magnaporthe oryzae chrysovirus 1 (MoCV1) is a mycovirus with a dsRNA genome that infects the rice blast fungus Magnaporthe oryzae and impairs its growth. To date, MoCV1 has only been found in Vietnamese isolates of M. oryzae, and the distribution of this virus in M. oryzae isolates from other parts of the world remains unknown. In this study, using a one-step reverse transcription PCR (RT-PCR) assay, we detected a MoCV1-related virus in M. oryzae in Japan (named MoCV1-AK) whose sequence shares considerable similarity with that of the MoCV1 Vietnamese isolate. To establish a system for a comprehensive survey of MoCV1 infection in the field, we developed a reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for direct detection of the virus. The sensitivity of the RT-LAMP assay was at least as high as that of the one-step RT-PCR assay. In addition, we detected MoCV1-AK in M. oryzae-infected oatmeal agar plates and lesions on rice leaves using the RT-LAMP assay without dsRNA extraction, by simple sampling with a toothpick. Preliminary screening of MoCV1 in Japanese M. oryzae isolates indicated that MoCV1 is currently distributed in rice fields in Japan. Our results provide a first example of the application of RT-LAMP for the detection of mycoviruses, which will accelerate surveys for mycovirus infection. PMID:26547578

  14. Rapid typing of foot-and-mouth disease serotype Asia 1 by reverse transcription loop-mediated isothermal amplification

    OpenAIRE

    Chen Hao-tai; Zhang Jie; Liu Yong-sheng; Liu Xiang-tao

    2011-01-01

    Abstract A reverse transcriptase loop-mediated isothermal amplification (RT-LAMP) assay was rapidly used to detect serotype Asia 1 of foot-and-mouth disease virus (FMDV) within 45 min at 61°C. All FMDV serotype Asia 1 reference strains were positive by RT-LAMP, while other viruses such as FMDV serotypes O, C, A and classical swine fever virus, swine vesicular disease virus, porcine reproductive and respiratory syndrome virus and Japanese encephalitis virus remained negative. Furthermore, FMDV...

  15. Rapid typing of foot-and-mouth disease serotype Asia 1 by reverse transcription loop-mediated isothermal amplification

    Directory of Open Access Journals (Sweden)

    Chen Hao-tai

    2011-10-01

    Full Text Available Abstract A reverse transcriptase loop-mediated isothermal amplification (RT-LAMP assay was rapidly used to detect serotype Asia 1 of foot-and-mouth disease virus (FMDV within 45 min at 61°C. All FMDV serotype Asia 1 reference strains were positive by RT-LAMP, while other viruses such as FMDV serotypes O, C, A and classical swine fever virus, swine vesicular disease virus, porcine reproductive and respiratory syndrome virus and Japanese encephalitis virus remained negative. Furthermore, FMDV sreotype Asia 1 positive samples were able to detect by RT-LAMP assay. This RT-LAMP assay may be suitable particularly for diagnosis of FMDV serotype Asia 1 infection in field stations.

  16. Establishment and application of a real-time loop-mediated isothermal amplification system for the detection of CYP2C19 polymorphisms.

    Science.gov (United States)

    Zhang, Chao; Yao, Yao; Zhu, Juan-Li; Zhang, Si-Nong; Zhang, Shan-Shan; Wei, Hua; Hui, Wen-Li; Cui, Ya-Li

    2016-01-01

    Single-nucleotide polymorphisms (SNPs) represent the most widespread type of genetic variation (approximately 90%) in the human genome, and the demand to overcome such variation has received more attention now than ever before. The capacity to rapidly assess SNPs that correlate with disease predisposition, drug efficacy and drug toxicity is a key step for the development of personalized medicine. In this work, a rapid one-step SNP detection method, real-time loop-mediated isothermal amplification (RT-LAMP), was first applied for CYP2C19 polymorphisms testing. The optimized method was established with specifically designed primers for target amplification by real-time detection in approximately 30 min under isothermal conditions. RT-LAMP amplified few copies of template to produce significant amounts of product and quantitatively detected human DNA with compatible specificity and sensitivity. The success in the establishment of this RT-LAMP protocol for CYP2C19 polymorphism testing is significant for the extension of this technique for the detection of other SNPs, which will further facilitate the development of personalized medicine. PMID:27246657

  17. Reverse transcription loop-mediated isothermal amplification assay for rapid detection of Papaya ringspot virus.

    Science.gov (United States)

    Shen, Wentao; Tuo, Decai; Yan, Pu; Yang, Yong; Li, Xiaoying; Zhou, Peng

    2014-08-01

    Papaya ringspot virus (PRSV) and Papaya leaf distortion mosaic virus (PLDMV), which causes disease symptoms similar to PRSV, threaten commercial production of both non-transgenic-papaya and PRSV-resistant transgenic papaya in China. A reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay to detect PLDMV was developed previously. In this study, the development of another RT-LAMP assay to distinguish among transgenic, PRSV-infected and PLDMV-infected papaya by detection of PRSV is reported. A set of four RT-LAMP primers was designed based on the highly conserved region of the P3 gene of PRSV. The RT-LAMP method was specific and sensitive in detecting PRSV, with a detection limit of 1.15×10(-6)μg of total RNA per reaction. Indeed, the reaction was 10 times more sensitive than one-step RT-PCR. Field application of the RT-LAMP assay demonstrated that samples positive for PRSV were detected only in non-transgenic papaya, whereas samples positive for PLDMV were detected only in commercialized PRSV-resistant transgenic papaya. This suggests that PRSV remains the major limiting factor for non-transgenic-papaya production, and the emergence of PLDMV threatens the commercial transgenic cultivar in China. However, this study, combined with the earlier development of an RT-LAMP assay for PLDMV, will provide a rapid, sensitive and cost-effective diagnostic power to distinguish virus infections in papaya. PMID:24769198

  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...... vesicular diseases and from that of genetically related picornaviruses. Diagnostic sensitivity was validated by the amplification of reference FMDV strains and archival material from field cases of FMD. In comparison with the performance of the established diagnostic TaqMan (R) assay, RT-LAMP appears...

  19. Isothermal DNA amplification in vitro: the helicase-dependent amplification system.

    Science.gov (United States)

    Jeong, Yong-Joo; Park, Kkothanahreum; Kim, Dong-Eun

    2009-10-01

    Since the development of polymerase chain reaction, amplification of nucleic acids has emerged as an elemental tool for molecular biology, genomics, and biotechnology. Amplification methods often use temperature cycling to exponentially amplify nucleic acids; however, isothermal amplification methods have also been developed, which do not require heating the double-stranded nucleic acid to dissociate the synthesized products from templates. Among the several methods used for isothermal DNA amplification, the helicase-dependent amplification (HDA) is discussed in this review with an emphasis on the reconstituted DNA replication system. Since DNA helicase can unwind the double-stranded DNA without the need for heating, the HDA system provides a very useful tool to amplify DNA in vitro under isothermal conditions with a simplified reaction scheme. This review describes components and detailed aspects of current HDA systems using Escherichia coli UvrD helicase and T7 bacteriophage gp4 helicase with consideration of the processivity and efficiency of DNA amplification. PMID:19629390

  20. Visual Detection of Potato leafroll virus by One-step Reverse Transcription Loop-Mediated Isothermal Amplification of DNA with Hydroxynaphthol Blue Dye

    NARCIS (Netherlands)

    Ahmadi, S.; Almasi, A.M.; Fatehi, F.; Struik, P.C.; Moradi, A.

    2013-01-01

    Loop-mediated isothermal amplification (LAMP) assay is a novel technique for amplifying DNA under constant temperature, with high specificity, sensitivity, rapidity and efficiency. We applied reverse transcription loop-mediated isothermal amplification (RT-LAMP) to visually detect Potato leafroll vi

  1. Rapid and Sensitive Detection of PRRSV by a Reverse Transcription-Loop-mediated Isothermal Amplification Assay

    Institute of Scientific and Technical Information of China (English)

    Lei Zhang; Ye-bing Liu; Lei Chen; Jian-huan Wang; Yi-bao Ning

    2011-01-01

    A real-time monitoring reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed for the sensitive and specific detection of prototypic,prevalent North American porcine reproductive and respiratory syndrome virus (PRRSV)strains.As a higher sensitivity and specificity method than reverse transcription polymerase chain reaction (RT-PCR),the RT-LAMP method only used a turbidimeter,exhibited a detection limit corresponding to a 10-4 dilution of template RNA extracted from 250 μL of 105 of the 50% tissue culture infective dose (TCID50) of PRRSV containing cells,and no cross-reactivity was observed with other related viruses including porcine circovirus type 2,swine influenza virus,porcine rotavirus and classical swine fever virus.From forty-two field samples,33 samples in the RT-LAMP assay was detected positive,whereas three of which were not detected by RT-PCR.Furthermore,in 33 strains of PRRSV,an identical detection rate was observed with the RT-LAMP assay to what were isolated using porcine alveolar macrophages.These findings demonstrated that the RT-LAMP assay has potential clinical applications for the detection of highly pathogenic PRRSV isolates,especially in developing countries.

  2. Development and evaluation of probe based real time loop mediated isothermal amplification for Salmonella: A new tool for DNA quantification.

    Science.gov (United States)

    Mashooq, Mohmad; Kumar, Deepak; Niranjan, Ankush Kiran; Agarwal, Rajesh Kumar; Rathore, Rajesh

    2016-07-01

    A one step, single tube, accelerated probe based real time loop mediated isothermal amplification (RT LAMP) assay was developed for detecting the invasion gene (InvA) of Salmonella. The probe based RT LAMP is a novel method of gene amplification that amplifies nucleic acid with high specificity and rapidity under isothermal conditions with a set of six primers. The whole procedure is very simple and rapid, and amplification can be obtained in 20min. Detection of gene amplification was accomplished by amplification curve, turbidity and addition of DNA binding dye at the end of the reaction results in colour difference and can be visualized under normal day light and in UV. The sensitivity of developed assay was found 10 fold higher than taqman based qPCR. The specificity of the RT LAMP assay was validated by the absence of any cross reaction with other members of enterobacteriaceae family and other gram negative bacteria. These results indicate that the probe based RT LAMP assay is extremely rapid, cost effective, highly specific and sensitivity and has potential usefulness for rapid Salmonella surveillance. PMID:27130353

  3. Rapid and sensitive detection of novel avian-origin influenza A (H7N9 virus by reverse transcription loop-mediated isothermal amplification combined with a lateral-flow device.

    Directory of Open Access Journals (Sweden)

    Yiyue Ge

    Full Text Available A severe disease in humans caused by a novel avian-origin influenza A (H7N9 virus emerged in China recently, which has caused at least 128 cases and 26 deaths. Rapid detection of the novel H7N9 virus is urgently needed to differentiate the disease from other infections, and to facilitate infection control as well as epidemiologic investigations. In this study, a reverse transcription loop-mediated isothermal amplification combined with a lateral flow device (RT-LAMP-LFD assay to rapidly detect H7N9 virus was developed and evaluated. The RT-LAMP primers were designed to target the haemagglutinin (HA and neuraminidase (NA genes of H7N9 virus. Results of 10-fold dilution series assays showed that analysis of RT-LAMP products by the LFD method was as sensitive as real-time turbidity detection, and that the analytic sensitivities of the HA and NA RT-LAMP assays were both 10 copies of synthetic RNA. Furthermore, both the assays showed 100% clinical specificity for identification of H7N9 virus. The performance characteristics of the RT-LAMP-LFD assay were evaluated with 80 clinical specimens collected from suspected H7N9 patients. The NA RT-LAMP-LFD assay was more sensitive than real time RT-PCR assay. Compared with a combination of virus culture and real-time RT-PCR, the sensitivity, specificity, positive predictive value, and negative predictive value of the RT-LAMP-LFD assay were all 100%. Overall, The RT-LAMP-LFD assay established in this study can be used as a reliable method for early diagnosis of the avian-origin influenza A (H7N9 virus infection.

  4. Reverse transcription loop-mediated isothermal amplification assays for rapid identification of eastern and western strains of bluetongue virus in India.

    Science.gov (United States)

    Maan, S; Maan, N S; Batra, K; Kumar, A; Gupta, A; Rao, Panduranga P; Hemadri, Divakar; Reddy, Yella Narasimha; Guimera, M; Belaganahalli, M N; Mertens, P P C

    2016-08-01

    Bluetongue virus (BTV) infects all ruminants, including cattle, goats and camelids, causing bluetongue disease (BT) that is often severe in naïve deer and sheep. Reverse-transcription-loop-mediated-isothermal-amplification (RT-LAMP) assays were developed to detect eastern or western topotype of BTV strains circulating in India. Each assay uses four primers recognizing six distinct sequences of BTV genome-segment 1 (Seg-1). The eastern (e)RT-LAMP and western (w)RT-LAMP assay detected BTV RNA in all positive isolates that were tested (n=52, including Indian BTV-1, -2, -3, -5, -9, -10, -16, -21 -23, and -24 strains) with high specificity and efficiency. The analytical sensitivity of the RT-LAMP assays is comparable to real-time RT-PCR, but higher than conventional RT-PCR. The accelerated eRT-LAMP and wRT-LAMP assays generated detectable levels of amplified DNA, down to 0.216 fg of BTV RNA template or 108 fg of BTV RNA template within 60-90min respectively. The assays gave negative results with RNA from foot-and-mouth-disease virus (FMDV), peste des petits ruminants virus (PPRV), or DNA from Capripox viruses and Orf virus (n=10), all of which can cause clinical signs similar to BT. Both RT-LAMP assays did not show any cross-reaction among themselves. The assays are rapid, easy to perform, could be adapted as a 'penside' test making them suitable for 'front-line' diagnosis, helping to identify and contain field outbreaks of BTV. PMID:27054888

  5. One-step detection of Bean pod mottle virus in soybean seeds by the reverse-transcription loop-mediated isothermal amplification

    Directory of Open Access Journals (Sweden)

    Wei Qi-Wei

    2012-09-01

    Full Text Available Abstract Background Bean pod mottle virus (BPMV is a wide-spread and destructive virus that causes huge economic losses in many countries every year. A sensitive, reliable and specific method for rapid surveillance is urgently needed to prevent further spread of BPMV. Methods A degenerate reverse-transcription loop-mediated isothermal amplification (RT-LAMP primer set was designed on the conserved region of BPMV CP gene. The reaction conditions of RT-LAMP were optimized and the feasibility, specificity and sensitivity of this method to detect BPMV were evaluated using the crude RNA rapidly extracted from soybean seeds. Results The optimized RT-LAMP parameters including 6 mM MgCl2, 0.8 M betaine and temperature at 62.5-65°C could successfully amplify the ladder-like bands from BPMV infected soybean seeds. The amplification was very specific to BPMV that no cross-reaction was observed with other soybean viruses. Inclusion of a fluorescent dye makes it easily be detected in-tube by naked eye. The sensitivity of RT-LAMP assay is higher than the conventional RT-PCR under the conditions tested, and the conventional RT-PCR couldn’t be used for detection of BPMV using crude RNA extract from soybean seeds. Conclusion A highly efficient and practical method was developed for the detection of BPMV in soybean seeds by the combination of rapid RNA extraction and RT-LAMP. This RT-LAMP method has great potential for rapid BPMV surveillance and will assist in preventing further spread of this devastating virus.

  6. A reverse transcription loop-mediated isothermal amplification assay optimized to detect multiple HIV subtypes.

    Directory of Open Access Journals (Sweden)

    Karen E Ocwieja

    Full Text Available Diagnostic methods for detecting and quantifying HIV RNA have been improving, but efficient methods for point-of-care analysis are still needed, particularly for applications in resource-limited settings. Detection based on reverse-transcription loop-mediated isothermal amplification (RT-LAMP is particularly useful for this, because when combined with fluorescence-based DNA detection, RT-LAMP can be implemented with minimal equipment and expense. Assays have been developed to detect HIV RNA with RT-LAMP, but existing methods detect only a limited subset of HIV subtypes. Here we report a bioinformatic study to develop optimized primers, followed by empirical testing of 44 new primer designs. One primer set (ACeIN-26, targeting the HIV integrase coding region, consistently detected subtypes A, B, C, D, and G. The assay was sensitive to at least 5000 copies per reaction for subtypes A, B, C, D, and G, with Z-factors of above 0.69 (detection of the minor subtype F was found to be unreliable. There are already rapid and efficient assays available for detecting HIV infection in a binary yes/no format, but the rapid RT-LAMP assay described here has additional uses, including 1 tracking response to medication by comparing longitudinal values for a subject, 2 detecting of infection in neonates unimpeded by the presence of maternal antibody, and 3 detecting infection prior to seroconversion.

  7. Colorimetric Detection of Dengue by Single Tube Reverse-Transcription-Loop-Mediated Isothermal Amplification.

    Directory of Open Access Journals (Sweden)

    Yee-Ling Lau

    Full Text Available Dengue is usually diagnosed by isolation of the virus, serology or molecular diagnostic methods. Several commercial kits for the diagnosis of dengue are existing, but concerns have arisen regarding to the affordability and performance characteristics of these kits. Hence, the loop-mediated isothermal amplification (LAMP is potentially ideal to be used especially in resource limited environments. Serum was collected from healthy donors and patients diagnosed with dengue infection. RNA extracted from the serum samples were tested by reverse-transcription-LAMP assay developed based on 3'-NCR gene sequences for DENV 1-4. Results were interpreted by a turbidity meter in real time or visually at the end of the assay. Sensitivity and specificity of RT-LAMP results were calculated and compared to qRT-PCR and ELISA. RT-LAMP is highly sensitive with the detection limit of 10 RNA copies for all serotypes. Dengue virus RNA was detected in all positive samples using RT-LAMP and none of the negative samples within 30-45 minutes. With continuing efforts in the optimization of this assay, RT-LAMP may provide a simple and reliable test for detecting DENV in areas where dengue is prevalent.

  8. Detection of foot-and-mouth disease virus rna by reverse transcription loop-mediated isothermal amplification

    OpenAIRE

    Chen Hao-tai; Zhang Jie; Liu Yong-sheng; Liu Xiang-tao

    2011-01-01

    Abstract A reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed for foot-and-mouth disease virus (FMDV) RNA. The amplification was able to finish in 45 min under isothermal condition at 64°C by employing a set of four primers targeting FMDV 2B. The assay showed higher sensitivity than RT-PCR. No cross reactivity was observed from other RNA viruses including classical swine fever virus, swine vesicular disease, porcine reproductive and respiratory syndrome...

  9. Development of a Reverse Transcription Loop-Mediated Isothermal Amplification Method for the Rapid Detection of Subtype H7N9 Avian Influenza Virus

    Directory of Open Access Journals (Sweden)

    Hongmei Bao

    2014-01-01

    Full Text Available A novel influenza A (H7N9 virus has emerged in China. To rapidly detect this virus from clinical samples, we developed a reverse transcription loop-mediated isothermal amplification (RT-LAMP method for the detection of the H7N9 virus. The minimum detection limit of the RT-LAMP assay was 0.01 PFU H7N9 virus, making this method 100-fold more sensitive to the detection of the H7N9 virus than conventional RT-PCR. The H7N9 virus RT-LAMP assays can efficiently detect different sources of H7N9 influenza virus RNA (from chickens, pigeons, the environment, and humans. No cross-reactive amplification with the RNA of other subtype influenza viruses or of other avian respiratory viruses was observed. The assays can effectively detect H7N9 influenza virus RNA in drinking water, soil, cloacal swab, and tracheal swab samples that were collected from live poultry markets, as well as human H7N9 virus, in less than 30 min. These results suggest that the H7N9 virus RT-LAMP assays were efficient, practical, and rapid diagnostic methods for the epidemiological surveillance and diagnosis of influenza A (H7N9 virus from different resource samples.

  10. Rapid and Sensitive Detection of RNA Viruses Based on Reverse Transcription Loop-Mediated Isothermal Amplification, Magnetic Nanoparticles, and Chemiluminescence.

    Science.gov (United States)

    Wang, Jiuhai; Lu, Peng; Yan, Jieni; Zhang, Yufan; Huang, Lanye; Ali, Zeeshan; Li, Zhiyang; He, Nongyue

    2016-04-01

    RNA viruses, particularly, the highly pathogenic avian influenza (HPAI) virus, pose serious health concerns, and cause huge economic losses worldwide. Diagnostic tools for the early detection of these deadly RNA viruses are urgently needed to implement treatment and disease control strategies. Conventional reverse transcription polymerase chain reaction (RT-PCR)-based chemiluminescent (RT-PCR-CL) detection is frequently used for the diagnosis of viral infections. However, the requirements for expensive PCR machines and longer thermocycling times are significant drawbacks. In this study, we propose a method based on reverse transcription loop-mediated isothermal amplification (RT-LAMP) combined with chemiluminescence (CL) to detect H7N9 virus. The proposed method does not require any expensive instruments, and processing time is remarkably shortened compared to that of RT-PCR-CL. Since several factors including RT-LAMP temperature, probe concentration, hybridization temperature, and hybridization duration might affect the CL signal, each of these parameters was investigated and optimized. One thousand copies/mL of H7N9 RNA were detectable using the optimized RT-LAMP-CL method. The detection time was significantly reduced by using RT-LAMP, in comparison with conventional RT-PCR-CL. This technique holds great promise for viral detection and diagnosis, especially with regard to avian influenza virus. PMID:27301197

  11. Development of an electronic system for signals amplification

    International Nuclear Information System (INIS)

    This paper presents the obtained results with a spectrometer for electromagnetic radiation whose detector, a Si PIN type diode, was directly coupled to a signal amplification system developed in this project for scientific initiation. The linearity conditions and the gain operational limits, constituted of two stages of amplification based on the employment of devices from AMTEK A225 and A206, were determined using a precision pulse generator. The obtained results shown that the developed system is stable and linear in the gain range of 50-150. The spectrometric response of the electronic system coupled to the Siemens SFH-00206 type diode, were studied in view of the register of the 59.5 keV gamma ray spectra proceeding from 241Am as function of the reversal polarization voltage. The influence pf the voltage and the electronic contribution in the energy resolution of the registered spectra under room temperature (22 degree Celsius) had also investigated considering the more adequate value of the coupling capacitance of the amplification system diode. Up to the present. the best energy resolution (FWHM = 4.85 keV) of the 59.5 keV line was obtained for the condition of the detector polarization at 16 V. This result proves that the signal amplification system developed coupled to the SFH00206 diode, besides the low cost, excellent operational condition for the detection and spectrometry or low energy electromagnetic radiation

  12. Performance of reversed transcription loop-mediated isothermal amplification technique detecting EV71: a systematic review with meta-analysis.

    Science.gov (United States)

    Lei, Xiaoying; Wen, Hongling; Zhao, Li; Yu, Xuejie

    2014-04-01

    Human enterovirus 71 (EV71) is the major etiological agent of hand, foot and mouth disease (HFMD), which is a common infectious disease in young children. Studies in the past have shown that reversed transcription loop-mediated isothermal amplification (RT-LAMP) was a rapid approach for the detection of EV71 in HFMD. This meta-analysis study is to evaluate the diagnostic role of RT-LAMP in detecting EV71 infection. A comprehensive literature research of PubMed, Embase, Wan Fang Data, and Chinese National Knowledge Infrastructure databases was conducted on articles aiming at the diagnostic performance of RT-LAMP in EV71 detection published before February 10, 2014. Data from selected studies were pooled to yield the summary sensitivity, specificity, positive and negative likelihood ratio (PLR, NLR), diagnostic odds ratio (DOR), and receiver operating characteristic (SROC) curve by using STATA VERSION 12.0 software. Ten studies including a total of 907 clinical samples were of high quality in this meta-analysis. Overall, the pooled sensitivity, specificity, PLR, NLR, DOR, and the area under the SROC curve was 0.99 (0.97, 1.00), 0.97 (0.94, 1.00), 5.90 (95% CI: 3.90-8.94), 0.20 (95% CI: 0.14-0.29), and 1.00 (95% CI: 0.99-1.00), respectively. The univariate analysis of potential variables showed some changes in the diagnostic performance, but none of the differences reached statistical significance. Despite inter-study variability, the test performance of RT-LAMP was consistent with real-time RT-PCR in detecting EV71. This meta-analysis suggests that RT-LAMP is a useful diagnostic tool with high sensitivity and specificity for detecting EV71. PMID:24815384

  13. Detection of BCR-ABL Fusion mRNA Using Reverse Transcriptase Loop-mediated Isothermal Amplification

    Energy Technology Data Exchange (ETDEWEB)

    Dugan, L C; Hall, S; Kohlgruber, A; Urbin, S; Torres, C; Wilson, P

    2011-12-08

    RT-PCR is commonly used for the detection of Bcr-Abl fusion transcripts in patients diagnosed with chronic myelogenous leukemia, CML. Two fusion transcripts predominate in CML, Br-Abl e13a2 and e14a2. They have developed reverse transcriptase isothermal loop-mediated amplification (RT-LAMP) assays to detect these two fusion transcripts along with the normal Bcr transcript.

  14. Quenching of Unincorporated Amplification Signal Reporters in Reverse-Transcription Loop-Mediated Isothermal Amplification Enabling Bright, Single-Step, Closed-Tube, and Multiplexed Detection of RNA Viruses.

    Science.gov (United States)

    Ball, Cameron S; Light, Yooli K; Koh, Chung-Yan; Wheeler, Sarah S; Coffey, Lark L; Meagher, Robert J

    2016-04-01

    Reverse-transcription-loop-mediated isothermal amplification (RT-LAMP) has frequently been proposed as an enabling technology for simplified diagnostic tests for RNA viruses. However, common detection techniques used for LAMP and RT-LAMP have drawbacks, including poor discrimination capability, inability to multiplex targets, high rates of false positives, and (in some cases) the requirement of opening reaction tubes postamplification. Here, we present a simple technique that allows closed-tube, target-specific detection, based on inclusion of a dye-labeled primer that is incorporated into a target-specific amplicon if the target is present. A short, complementary quencher hybridizes to unincorporated primer upon cooling down at the end of the reaction, thereby quenching fluorescence of any unincorporated primer. Our technique, which we term QUASR (for quenching of unincorporated amplification signal reporters, read "quasar"), does not significantly reduce the amplification efficiency or sensitivity of RT-LAMP. Equipped with a simple LED excitation source and a colored plastic gel filter, the naked eye or a camera can easily discriminate between positive and negative QUASR reactions, which produce a difference in signal of approximately 10:1 without background subtraction. We demonstrate that QUASR detection is compatible with complex sample matrices such as human blood, using a novel LAMP primer set for bacteriophage MS2 (a model RNA virus particle). Furthermore, we demonstrate single-tube duplex detection of West Nile virus (WNV) and chikungunya virus (CHIKV) RNA. PMID:26980448

  15. Signal amplification in a qubit-resonator system

    International Nuclear Information System (INIS)

    We study the dynamics of a qubit-resonator system, when the resonator is driven by two signals. The interaction of the qubit with the high-amplitude driving we consider in terms of the qubit dressed states. Interaction of the dressed qubit with the second probing signal can essentially change the amplitude of this signal. We calculate the transmission amplitude of the probe signal through the resonator as a function of the qubit energy and the driving frequency detuning. The regions of increase and attenuation of the transmitted signal are calculated and demonstrated graphically. We present the influence of the signal parameters on the value of the amplification, and discuss the values of the qubit-resonator system parameters for an optimal amplification and attenuation of the weak probe signal.

  16. Application of a Real-time Reverse Transcription Loop Mediated Amplification Method to the Detection of Rabies Virus in Arctic Foxes in Greenland

    DEFF Research Database (Denmark)

    Wakeley, Philip; Johnson, Nicholas; Rasmussen, Thomas Bruun

    Reverse transcription loop mediated amplification (RT-LAMP) offers a rapid, isothermal method for amplification of virus RNA. In this study a panel of positive rabies virus samples originally prepared from arctic fox brain tissue was assessed for the presence of rabies viral RNA using a real time...... RT-LAMP. The method had previously been shown to work with samples from Ghana which clustered with cosmopolitan lineage rabies viruses but the assay had not been assessed using samples from animals infected with rabies from the arctic region. The assay is designed to amplify both cosmopolitan strains...... and arctic-like strains of classical rabies virus due to the primer design and is therefore expected to be universally applicable independent of region of the world where the virus is isolated. Of the samples tested all were found to be positive after incubation for 25 to 30 minutes. The method made...

  17. Advanced unrepeatered systems using novel Raman amplification schemes

    Science.gov (United States)

    Chang, Do-il; Pelouch, Wayne; Burtsev, Sergey; Perrier, Philippe; Fevrier, Herve

    2015-01-01

    Unrepeatered transmission systems provide a cost-effective solution to transmit high capacity channels in submarine networks to communicate between coastal population centers or in terrestrial networks to connect remote areas where service access is difficult. The main goal of unrepeatered systems has traditionally been to achieve the longest reach, however, increasing traffic demands now require unrepeatered systems to support both longer reach and higher transport capacity. As a result, transmission rate of unrepeatered systems has quickly moved from 10 Gb/s to 40 Gb/s or 100 Gb/s. This paper reviews the key basic technologies, with a specific focus on Raman amplification, required for long-reach, high-capacity unrepeatered optical transmission systems. We will discuss novel Raman amplification schemes, enhanced remote optically pumped amplifiers (ROPA), ultra-low loss / large effective area fibers, and coherent transmission with advanced modulation format and high FEC coding gain. We will also report recent experimental demonstrations that show how these technologies have been combined to achieve industry's leading capacity and reach transmission.

  18. Visual detection of West Nile virus using reverse transcription loop-mediated isothermal amplification combined with a vertical flow visualization strip

    Directory of Open Access Journals (Sweden)

    Zengguo eCao

    2016-04-01

    Full Text Available West Nile virus (WNV causes a severe zoonosis, which can lead to a large number of casualties and considerable economic losses. A rapid and accurate identification methodfor WNV for use in field laboratories is urgently needed. Here, a method utilizing reverse transcription loop-mediated isothermal amplification combined with a vertical flow visualization strip (RT-LAMP-VF was developed to detect the envelope (E gene of WNV. The RT-LAMP-VF assay could detect 102 copies/μl ofan WNV RNA standard using a 40 min amplification reaction followed by a 2 min incubationof the amplification product on the visualization strip, and no cross-reaction with other closely related members of theFlavivirus genus was observed. The assay was further evaluated using cells and mouse brain tissues infected with a recombinant rabies virus expressing the E protein of WNV.The assay produced sensitivities of 101.5TCID50/ml and 101.33 TCID50/ml for detection of the recombinant virus in the cells and brain tissues, respectively. Overall, the RT-LAMP-VF assay developed in this study is rapid, simple and effective, and it is therefore suitable for clinical application in the field.

  19. Hyper dispersion pulse compressor for chirped pulse amplification systems

    Science.gov (United States)

    Barty, Christopher P. J.

    2011-11-29

    A grating pulse compressor configuration is introduced for increasing the optical dispersion for a given footprint and to make practical the application for chirped pulse amplification (CPA) to quasi-narrow bandwidth materials, such as Nd:YAG. The grating configurations often use cascaded pairs of gratings to increase angular dispersion an order of magnitude or more. Increased angular dispersion allows for decreased grating separation and a smaller compressor footprint.

  20. Launch Lock Assemblies Including Axial Gap Amplification Devices and Spacecraft Isolation Systems Including the Same

    Science.gov (United States)

    Barber, Tim Daniel (Inventor); Hindle, Timothy (Inventor); Young, Ken (Inventor); Davis, Torey (Inventor)

    2014-01-01

    Embodiments of a launch lock assembly are provided, as are embodiments of a spacecraft isolation system including one or more launch lock assemblies. In one embodiment, the launch lock assembly includes first and second mount pieces, a releasable clamp device, and an axial gap amplification device. The releasable clamp device normally maintains the first and second mount pieces in clamped engagement; and, when actuated, releases the first and second mount pieces from clamped engagement to allow relative axial motion there between. The axial gap amplification device normally residing in a blocking position wherein the gap amplification device obstructs relative axial motion between the first and second mount pieces. The axial gap amplification device moves into a non-blocking position when the first and second mount pieces are released from clamped engagement to increase the range of axial motion between the first and second mount pieces.

  1. 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.

  2. Precision charge amplification and digitization system for a scintillating and lead glass array

    International Nuclear Information System (INIS)

    A 544-channel low-noise, high-rate, precision charge amplification and ADC system was constructed for the Fermilab Experiment 705 electromagnetic calorimeter, which employs SCG1-C scintillating glass and SF5 lead glass instrumented with photomultiplier tubes. A general discussion of the system is given, and the charge amplification, fast trigger pulse generation, and analog to digital conversion aspects of the system are presented in more detail. Performance is evaluated using data from Experiment 705 and from off-line tests. Short and long term pedestal stability, baseline recovery and rate capability, linearity of response, and crosstalk between channels are discussed

  3. Precision charge amplification and digitization system for a scintillating and lead glass array

    International Nuclear Information System (INIS)

    A 544-channel low-noise, high-rate, precision charge amplification and ADC system was constructed for the Fermilab Experiment 705 electromagnetic calorimeter, which employs SCG1-C scintillating glass and SF5 lead glass instrumented with photo-multiplier tubes. A general discussion of the system is given, and the charge amplification, fast trigger pulse generation, and analog to digital conversion aspects of the system are presented in more detail. Performance is evaluated using data from Experiment 705 and from off-line tests. Short and long term pedestal stability, baseline recovery and rate capability, linearity of response, and crosstalk between channels are discussed. 8 refs., 2 tabs

  4. Dispersion Analysis and Compensation of Collinear Optical Parametric Chirped Pulse Amplification Systems

    Institute of Scientific and Technical Information of China (English)

    WANG Cheng; LENG Yu-Xin; LIANG Xiao-Yan; ZHANG Chun-Mei; ZHAO Bao-Zhen; XU Zhi-Zhan

    2005-01-01

    @@ In an optical parametric chirped pulse amplification (OPCPA) laser system, residual phase dispersion should be compensated as much as possible to shorten the amplified pulses and improve the pulse contrast ratio. Expressions of orders of the induced phases in collinear optical parametric amplification (OPA) processes are presented at the central signal wavelength to depict a clear physics picture and to simplify the design of phase compensation. As examples, we simulate two OPCPA systems to compensate for the phases up to the partial fourth-order terms,and obtain flat phase spectra of 200-nm bandwidth at 1064 nm and 90-nm at 800nm.

  5. Terahertz wave amplification, stimulated by dc electric current, in grating coupled low-dimensional electron systems

    Science.gov (United States)

    Mikhailov, S. A.; Savostianova, N. A.

    1997-09-01

    We present an analytic theory of the transmission of electromagnetic waves through a structure "two-dimensional electron system with a flowing current - grating coupler." The transmission coefficient T(ω,vdr) is calculated as a function of frequency, drift velocity vdr, and other physical and geometrical parameters of the structure. Threshold conditions for amplification [T(ω,vdr)>1] are analyzed. A number of ideas for a reduction of the threshold velocity and an enhancement of the amplification are proposed. Our results can be used for designing tunable solid-state terahertz wave amplifiers (generators), based on the grating coupled low-dimensional electron systems.

  6. Rapid amplification system for recombinant protein production in Chinese Hamster Ovary (CHO) Cells.

    Science.gov (United States)

    Metta, M K; Kunaparaju, R K; Tantravahi, S

    2016-01-01

    Recombinant therapeutic proteins have changed the face of modern medicine in the present trend and they continue to provide innovative therapies for deadly diseases. This study describes the development of a novel stable expression system for rapid amplification of genes in Chinese Hamster Ovary (CHO) cells. The expression system consists of a host CHO cell line and an expression vector (pUB-PyOri-D-C) which encodes for Polyomavirus (Py) Origin of Replication (PyOri) for amplification of integrated genes in the presence of Py Large T Antigen (PyLT) and Dihydrofolate Reductase (DHFR) selectable marker gene for selection in the presence of Methotrexate (MTX). Use of both PyOri/PyLT and DHFR can reduce the number of rounds of selection and amplification required for isolation of high producing clones. The efficiency of pUB-PyOri-D-C was compared with that of pUB-D-C plasmid using Green fluorescent protein (GFP) and Erythropoietin (EPO) as reporter proteins. Our results showed that pUB-PyOri-D-C-EPO can help development of high expressing clone in one round of selection/amplification as compared to multiple rounds of selection/amplification with pUB-D-C-EPO plasmid. CHO-DG44/EPO clone generated using pUB-PyOri-D-C-EPO gave a productivity of 119 mg/L in shake flask. PMID:26950459

  7. Visual detection of Ebola virus using reverse transcription loop-mediated isothermal amplification combined with nucleic acid strip detection.

    Science.gov (United States)

    Xu, Changping; Wang, Hualei; Jin, Hongli; Feng, Na; Zheng, Xuexing; Cao, Zengguo; Li, Ling; Wang, Jianzhong; Yan, Feihu; Wang, Lina; Chi, Hang; Gai, Weiwei; Wang, Chong; Zhao, Yongkun; Feng, Yan; Wang, Tiecheng; Gao, Yuwei; Lu, Yiyu; Yang, Songtao; Xia, Xianzhu

    2016-05-01

    Ebola virus (species Zaire ebolavirus) (EBOV) is highly virulent in humans. The largest recorded outbreak of Ebola hemorrhagic fever in West Africa to date was caused by EBOV. Therefore, it is necessary to develop a detection method for this virus that can be easily distributed and implemented. In the current study, we developed a visual assay that can detect EBOV-associated nucleic acids. This assay combines reverse transcription loop-mediated isothermal amplification and nucleic acid strip detection (RT-LAMP-NAD). Nucleic acid amplification can be achieved in a one-step process at a constant temperature (58 °C, 35 min), and the amplified products can be visualized within 2-5 min using a nucleic acid strip detection device. The assay is capable of detecting 30 copies of artificial EBOV glycoprotein (GP) RNA and RNA encoding EBOV GP from 10(2) TCID50 recombinant viral particles per ml with high specificity. Overall, the RT-LAMP-NAD method is simple and has high sensitivity and specificity; therefore, it is especially suitable for the rapid detection of EBOV in African regions. PMID:26831931

  8. A terminating-type MEMS microwave power sensor and its amplification system

    International Nuclear Information System (INIS)

    A terminating-type MEMS microwave power sensor and its amplification system are presented in this paper. A SPICE model is introduced to simulate temperature distribution of this power sensor, and the model has a reference value to estimate the sensitivity of the power sensor. This power sensor is designed and fabricated using MEMS technology and the GaAs MMIC process. It is measured in the frequency range up to 20 GHz with an input power in the 0 to 50 mW range. Over the 50 mW dynamic range, the sensitivity is about 0.29, 0.24 and 0.22 mV mW−1 at 5, 10 and 15 GHz, respectively. The output voltage of the power sensor ranges from 0.64 to 15.2 mV at 5 GHz. After amplification, the output voltage ranges from 0.19 to 6.56 V. The amplification gain is about 437.5, and the sensitivity is increased to 1274 mV mW−1. At 15 GHz, the output voltage of the power sensor ranges from 0.57 to 11.69 mV. After amplification, the output voltage ranges from 0.146 to 5.02 V. The amplification gain is about 438, and the sensitivity is increased to 974.8 mV mW−1. The measurement results show that the amplification system can amplify the output weak signal of the power sensor well and have good linearity.

  9. Complementary RNA amplification methods enhance microarray identification of transcripts expressed in the C. elegans nervous system

    Directory of Open Access Journals (Sweden)

    Levy Shawn

    2008-02-01

    Full Text Available Abstract Background DNA microarrays provide a powerful method for global analysis of gene expression. The application of this technology to specific cell types and tissues, however, is typically limited by small amounts of available mRNA, thereby necessitating amplification. Here we compare microarray results obtained with two different methods of RNA amplification to profile gene expression in the C. elegans larval nervous system. Results We used the mRNA-tagging strategy to isolate transcripts specifically from C. elegans larval neurons. The WT-Ovation Pico System (WT-Pico was used to amplify 2 ng of pan-neural RNA to produce labeled cDNA for microarray analysis. These WT-Pico-derived data were compared to microarray results obtained with a labeled aRNA target generated by two rounds of In Vitro Transcription (IVT of 25 ng of pan-neural RNA. WT-Pico results in a higher fraction of present calls than IVT, a finding consistent with the proposal that DNA-DNA hybridization results in lower mismatch signals than the RNA-DNA heteroduplexes produced by IVT amplification. Microarray data sets from these samples were compared to a reference profile of all larval cells to identify transcripts with elevated expression in neurons. These results were validated by the high proportion of known neuron-expressed genes detected in these profiles and by promoter-GFP constructs for previously uncharacterized genes in these data sets. Together, the IVT and WT-Pico methods identified 2,173 unique neuron-enriched transcripts. Only about half of these transcripts (1,044, however, are detected as enriched by both IVT and WT-Pico amplification. Conclusion We show that two different methods of RNA amplification, IVT and WT-Pico, produce valid microarray profiles of gene expression in the C. elegans larval nervous system with a low rate of false positives. However, our results also show that each method of RNA amplification detects a unique subset of bona fide neural

  10. A Novel Extrinsic Fiber-Optic Fabry-Perot Strain Sensor System Based on Optical Amplification

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A novel extrinsic fiber-optic Fabry-Perot interferometric strain sensor system is demonstrated based on the simultaneous use of the amplified spontaneous emission and optical amplification. The improvement of 3~4 orders of magnitude in signal level can be achieved.

  11. Real-time DNA Amplification and Detection System Based on a CMOS Image Sensor.

    Science.gov (United States)

    Wang, Tiantian; Devadhasan, Jasmine Pramila; Lee, Do Young; Kim, Sanghyo

    2016-01-01

    In the present study, we developed a polypropylene well-integrated complementary metal oxide semiconductor (CMOS) platform to perform the loop mediated isothermal amplification (LAMP) technique for real-time DNA amplification and detection simultaneously. An amplification-coupled detection system directly measures the photon number changes based on the generation of magnesium pyrophosphate and color changes. The photon number decreases during the amplification process. The CMOS image sensor observes the photons and converts into digital units with the aid of an analog-to-digital converter (ADC). In addition, UV-spectral studies, optical color intensity detection, pH analysis, and electrophoresis detection were carried out to prove the efficiency of the CMOS sensor based the LAMP system. Moreover, Clostridium perfringens was utilized as proof-of-concept detection for the new system. We anticipate that this CMOS image sensor-based LAMP method will enable the creation of cost-effective, label-free, optical, real-time and portable molecular diagnostic devices. PMID:27302586

  12. 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.

  13. High-power chirped-pulse all-fiber amplification system based on large-mode-area fiber gratings

    OpenAIRE

    Broderick, N.G.R.; Richardson, D.J.; Taverner, D.; Caplen, J.E.; Dong, L.; Ibsen, M.

    1999-01-01

    The fabrication of large mode-area single mode fibres are crucial to developing high power all-fibre lasers and amplifiers. We report the amplification of picosecond pulses to microjoule energy levels and pulse peak powers in excess of 500kW in an all fiber Chirped Pulse Amplification (CPA) system based on novel large mode area fiber components.

  14. High-Performance Control in Radio Frequency Power Amplification Systems

    DEFF Research Database (Denmark)

    Høyerby, Mikkel Christian Kofod

    This thesis presents a broad study of methods for increasing the efficiency of narrow-band radio transmitters. The study is centered around the base station application and TETRA/TEDS networks. The general solution space studied is that of envelope tracking applied to linear class-A/B radio...... frequency power amplifiers (RFPAs) in conjunction with cartesian feedback (CFB) used to linearize the overall transmitter system. On a system level, it is demonstrated how envelope tracking is particularly useful for RF carriers with high peak-to-average power ratios, such as TEDS with 10dB. It is also...... further research. Practically demonstrated is a high-efficiency 25W TEDS transmitter capable of meeting all base station adjacent channel power ratio and wideband noise specifications with ample margins. Efficiency is improved from 23% to 44% by application of envelope tracking - almost a doubling - at...

  15. SHAPE EFFECT OF ANNULAR CONCENTRATOR IN ULTRASONIC SYSTEM ON AMPLIFICATION FACTOR OF VIBRATIONS AMPLITUDE

    Directory of Open Access Journals (Sweden)

    D. A. Stepanenko

    2016-01-01

    Full Text Available The paper contains a theoretical underpinning on creation of ultrasonic vibration concentrators based on annular elastic elements with non-circular (ellipse-like eccentric shape of internal contour. Shape of internal contour in polar coordinates is described by Fourier series relative to angular coordinate that consists of a constant term and first and second harmonics. An effect of geometric parameters of the concentrator on amplification factor and natural vibration frequencies has been investigated with the help of a finite element method. The paper reveals the possibility to control an amplification factor of annular concentrators while varying eccentricity of internal contour and mean value of cross-section thickness. The amplification factor satisfies a condition K < N, where N is thickness ratio of amplifier input and output sections, and it is decreasing with increase of vibration mode order. The similar condition has been satisfied for conical bar concentrator with the difference that in the case of bar concentrators an amplification is ensured due to variation of diameter and N will represent ratio of diameters. It has been proved that modification of internal contour shape makes it possible to carry out a wide-band tuning of natural frequencies of concentrator vibrations without alteration of its overall dimensions and substantial change of amplification factor, which is important for frequency matching of the concentrator and ultrasonic vibratory system. Advantages of the proposed concentrators include simplicity of design and manufacturing, small overall dimensions, possibility for natural frequency tuning by means of static load variation. The developed concentrators can find their application in ultrasonic devices and instruments for technological and medical purposes.

  16. Components for monolithic fiber chirped pulse amplification laser systems

    Science.gov (United States)

    Swan, Michael Craig

    The first portion of this work develops techniques for generating femtosecond-pulses from conventional fabry-perot laser diodes using nonlinear-spectral-broadening techniques in Yb-doped positive dispersion fiber ampliers. The approach employed an injection-locked fabry-perot laser diode followed by two stages of nonlinear-spectral-broadening to generate sub-200fs pulses. This thesis demonstrated that a 60ps gain-switched fabry-perot laser-diode can be injection-locked to generate a single-longitudinal-mode pulse and compressed by nonlinear spectral broadening to 4ps. Two problems have been identified that must be resolved before moving forward with this approach. First, gain-switched pulses from a standard diode-laser have a number of characteristics not well suited for producing clean self-phase-modulation-broadened pulses, such as an asymmetric temporal shape, which has a long pulse tail. Second, though parabolic pulse formation occurs for any arbitrary temporal input pulse profile, deviation from the optimum parabolic input results in extensively spectrally modulated self-phase-modulation-broadened pulses. In conclusion, the approach of generating self-phase-modulation-broadened pulses from pulsed laser diodes has to be modified from the initial approach explored in this thesis. The first Yb-doped chirally-coupled-core ber based systems are demonstrated and characterized in the second portion of this work. Robust single-mode performance independent of excitation or any other external mode management techniques have been demonstrated in Yb-doped chirally-coupled-core fibers. Gain and power efficiency characteristics are not compromised in any way in this novel fiber structure up to the 87W maximum power achieved. Both the small signal gain at 1064nm of 30.3dB, and the wavelength dependence of the small signal gain were comparable to currently deployed large-mode-area-fiber technology. The efficiencies of the laser and amplifier were measured to be 75% and 54

  17. Method for signal conditioning and data acquisition system, based on variable amplification and feedback technique

    International Nuclear Information System (INIS)

    An original method of signal conditioning and adaptive amplification is proposed for data acquisition systems of analog signals, conceived to obtain a high resolution spectrum of any input signal. The procedure is based on a feedback scheme of the signal amplification with aim at maximizing the dynamic range and resolution of the data acquisition system. The paper describes the signal conditioning, digitization, and data processing procedures applied to an a priori unknown signal in order to enucleate its amplitude and frequency content for applications in different environments: on the ground, in space, or in the laboratory. An electronic board of the conditioning module has also been constructed and described. In the paper are also discussed the main fields of application and advantages of the method with respect to those known today

  18. Method for signal conditioning and data acquisition system, based on variable amplification and feedback technique

    Energy Technology Data Exchange (ETDEWEB)

    Conti, Livio, E-mail: livio.conti@uninettunouniversity.net [Facoltà di Ingegneria, Università Telematica Internazionale Uninettuno, Corso Vittorio Emanuele II 39, 00186 Rome, Italy INFN Sezione Roma Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome (Italy); Sgrigna, Vittorio [Dipartimento di Matematica e Fisica, Università Roma Tre, 84 Via della Vasca Navale, I-00146 Rome (Italy); Zilpimiani, David [National Institute of Geophysics, Georgian Academy of Sciences, 1 M. Alexidze St., 009 Tbilisi, Georgia (United States); Assante, Dario [Facoltà di Ingegneria, Università Telematica Internazionale Uninettuno, Corso Vittorio Emanuele II 39, 00186 Rome, Italy INFN Sezione Roma Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome (Italy)

    2014-08-21

    An original method of signal conditioning and adaptive amplification is proposed for data acquisition systems of analog signals, conceived to obtain a high resolution spectrum of any input signal. The procedure is based on a feedback scheme of the signal amplification with aim at maximizing the dynamic range and resolution of the data acquisition system. The paper describes the signal conditioning, digitization, and data processing procedures applied to an a priori unknown signal in order to enucleate its amplitude and frequency content for applications in different environments: on the ground, in space, or in the laboratory. An electronic board of the conditioning module has also been constructed and described. In the paper are also discussed the main fields of application and advantages of the method with respect to those known today.

  19. Detection of foot-and-mouth disease virus rna by reverse transcription loop-mediated isothermal amplification

    Directory of Open Access Journals (Sweden)

    Chen Hao-tai

    2011-11-01

    Full Text Available Abstract A reverse transcription loop-mediated isothermal amplification (RT-LAMP assay was developed for foot-and-mouth disease virus (FMDV RNA. The amplification was able to finish in 45 min under isothermal condition at 64°C by employing a set of four primers targeting FMDV 2B. The assay showed higher sensitivity than RT-PCR. No cross reactivity was observed from other RNA viruses including classical swine fever virus, swine vesicular disease, porcine reproductive and respiratory syndrome virus, Japanese encephalitis virus. Furthermore, the assay correctly detected 84 FMDV positive samples but not 65 FMDV negative specimens. The result indicated the potential usefulness of the technique as a simple and rapid procedure for the detection of FMDV infection.

  20. Simultaneous detection and differentiation of dengue virus serotypes 1-4, Japanese encephalitis virus, and West Nile virus by a combined reverse-transcription loop-mediated isothermal amplification assay

    Directory of Open Access Journals (Sweden)

    Yin Jianhua

    2011-07-01

    Full Text Available Abstract Background Rapid identification and differentiation of mosquito-transmitted flaviviruses in acute-phase sera of patients and field-caught vector mosquitoes are important for the prediction and prevention of large-scale epidemics. Results We developed a flexible reverse-transcription loop-mediated isothermal amplification (RT-LAMP unit for the detection and differentiation of dengue virus serotypes 1-4 (DENV1-4, Japanese encephalitis virus (JEV, and West Nile virus (WNV. The unit efficiently amplified the viral genomes specifically at wide ranges of viral template concentrations, and exhibited similar amplification curves as monitored by a real-time PCR engine. The detection limits of the RT-LAMP unit were 100-fold higher than that of RT-PCR in 5 of the six flaviviruses. The results on specificity indicated that the six viruses in the assay had no cross-reactions with each other. By examining 66 viral strains of DENV1-4 and JEV, the unit identified the viruses with 100% accuracy and did not cross-react with influenza viruses and hantaviruses. By screening a panel of specimens containing sera of 168 patients and 279 pools of field-caught blood sucked mosquitoes, results showed that this unit is high feasible in clinical settings and epidemiologic field, and it obtained results 100% correlated with real-time RT-PCR. Conclusions The RT-LAMP unit developed in this study is able to quickly detect and accurately differentiate the six kinds of flaviviruses, which makes it extremely feasible for screening these viruses in acute-phase sera of the patients and in vector mosquitoes without the need of high-precision instruments.

  1. 85 km Long Reach PON System Using a Reflective SOA-EA Modulator and Distributed Raman Fiber Amplification

    DEFF Research Database (Denmark)

    Tafur Monroy, Idelfonso; Öhman, Filip; Yvind, Kresten;

    2006-01-01

    We report on a bidirectional 85 km long reach PON system supported by distributed fiber Raman amplification with a record 7.5 Gb/s remote carrier modulated upstream signal by employing a reflective SOA-EA monolithically integrated circuit......We report on a bidirectional 85 km long reach PON system supported by distributed fiber Raman amplification with a record 7.5 Gb/s remote carrier modulated upstream signal by employing a reflective SOA-EA monolithically integrated circuit...

  2. Micromachined polymerase chain reaction system for multiple DNA amplification of upper respiratory tract infectious diseases.

    Science.gov (United States)

    Liao, Chia-Sheng; Lee, Gwo-Bin; Wu, Jiunn-Jong; Chang, Chih-Ching; Hsieh, Tsung-Min; Huang, Fu-Chun; Luo, Ching-Hsing

    2005-01-15

    This paper presents a micro polymerase chain reaction (PCR) chip for the DNA-based diagnosis of microorganism genes and the detection of their corresponding antibiotic-resistant genes. The micro PCR chip comprises cheap biocompatible soda-lime glass substrates with integrated thin-film platinum resistors as heating/sensing elements, and is fabricated using micro-electro-mechanical-system (MEMS) techniques in a reliable batch-fabrication process. The heating and temperature sensing elements are made of the same material and are located inside the reaction chamber in order to ensure a uniform temperature distribution. This study performs the detection of several genes associated with upper respiratory tract infection microorganisms, i.e. Streptococcus pneumoniae, Haemopilus influenze, Staphylococcu aureus, Streptococcus pyogenes, and Neisseria meningitides, together with their corresponding antibiotic-resistant genes. The lower thermal inertia of the proposed micro PCR chip relative to conventional bench-top PCR systems enables a more rapid detection operation with reduced sample and reagent consumption. The experimental data reveal that the high heating and cooling rates of the system (20 and 10 degrees C/s, respectively) permit successful DNA amplification within 15 min. The micro PCR chip is also capable of performing multiple DNA amplification, i.e. the simultaneous duplication of multiple genes under different conditions in separate reaction wells. Compared with the large-scale PCR system, it is greatly advantageous for fast diagnosis of multiple infectious diseases. Multiplex PCR amplification of two DNA segments in the same well is also feasible using the proposed micro device. The developed micro PCR chip provides a crucial tool for genetic analysis, molecular biology, infectious disease detection, and many other biomedical applications. PMID:15590288

  3. Evidence for a PGF2α auto-amplification system in the endometrium in mares.

    Science.gov (United States)

    Kozai, Keisuke; Tokuyama, Shota; Szóstek, Anna Z; Toishi, Yuko; Tsunoda, Nobuo; Taya, Kazuyoshi; Sakatani, Miki; Takahashi, Masashi; Nambo, Yasuo; Skarzynski, Dariusz J; Yamamoto, Yuki; Kimura, Koji; Okuda, Kiyoshi

    2016-05-01

    In mares, prostaglandin F2α (PGF2α) secreted from the endometrium is a major luteolysin. Some domestic animals have an auto-amplification system in which PGF2α can stimulate its own production. Here, we investigated whether this is also the case in mares. In an in vivo study, mares at the mid-luteal phase (days 6-8 of estrous cycle) were injected i.m. with cloprostenol (250 µg) and blood samples were collected at fixed intervals until 72 h after treatment. Progesterone (P4) concentrations started decreasing 45 min after the injection and continued to decrease up to 24 h (P mares. PMID:26908917

  4. High Intensity Mirror-Free Nanosecond Ytterbium Fiber Laser System in Master Oscillator Power Amplification

    Science.gov (United States)

    Chun-Lin, Louis Chang

    Rare-earth-doped fiber lasers and amplifiers are relatively easy to efficiently produce a stable and high quality laser beam in a compact, robust, and alignment-free configuration. Recently, high power fiber laser systems have facilitated wide spread applications in academics, industries, and militaries in replacement of bulk solid-state laser systems. The master oscillator power amplifier (MOPA) composed of a highly-controlled seed, high-gain preamplifiers, and high-efficiency power amplifiers are typically utilized to scale up the pulse energy, peak power, or average power. Furthermore, a direct-current-modulated nanosecond diode laser in single transverse mode can simply provide a compact and highly-controlled seed to result in the flexible output parameters, such as repetition rate, pulse duration, and even temporal pulse shape. However, when scaling up the peak power for high intensity applications, such a versatile diode-seeded nanosecond MOPA laser system using rare-earth-doped fibers is unable to completely save its own advantages compared to bulk laser systems. Without a strong seeding among the amplifiers, the guided amplified spontaneous amplification is easy to become dominant during the amplification, leading to the harmful self-lasing or pulsing effects, and the difficulty of the quantitative numerical comparison. In this dissertation, we study a high-efficiency and intense nanosecond ytterbium fiber MOPA system with good beam quality and stability for high intensity applications. The all-PM-fiber structure is achieved with the output extinction ratio of >12 dB by optimizing the interconnection of high power optical fibers. The diode-seeded MOPA configuration without parasitic stimulated amplification (PAS) is implemented using the double-pass scheme to extract energy efficiently for scaling peak power. The broadband PAS was studied experimentally, which matches well with our numerical simulation. The 1064-nm nanosecond seed was a direct

  5. Study of reconstruction methods for a time projection chamber with GEM gas amplification system

    International Nuclear Information System (INIS)

    A new e+e- linear collider with an energy range up to 1TeV is planned in an international collaboration: the International Linear Collider (ILC). This collider will be able to do precision measurements of the Higgs particle and of physics beyond the Standard Model. In the Large Detector Concept (LDC) - which is one proposal for a detector at the ILC - a Time Projection Chamber (TPC) is foreseen as the main tracking device. To meet the requirements on the resolution and to be able to work in the environment at the ILC, the application of new gas amplification technologies in the TPC is necessary. One option is an amplification system based on Gas Electron Multipliers (GEMs). Due to the - in comparison with older technologies - small spatial width of the signals, this technology poses new requirements on the readout structures and the reconstruction methods. In this work, the performance and the systematics of different reconstruction methods have been studied, based on data measured with a TPC prototype in high magnetic fields of up to 4T and data from a Monte Carlo simulation. The latest results of the achievable point resolution are presented and their limitations have been investigated. (orig.)

  6. Study of reconstruction methods for a time projection chamber with GEM gas amplification system

    Energy Technology Data Exchange (ETDEWEB)

    Diener, R.

    2006-12-15

    A new e{sup +}e{sup -} linear collider with an energy range up to 1TeV is planned in an international collaboration: the International Linear Collider (ILC). This collider will be able to do precision measurements of the Higgs particle and of physics beyond the Standard Model. In the Large Detector Concept (LDC) - which is one proposal for a detector at the ILC - a Time Projection Chamber (TPC) is foreseen as the main tracking device. To meet the requirements on the resolution and to be able to work in the environment at the ILC, the application of new gas amplification technologies in the TPC is necessary. One option is an amplification system based on Gas Electron Multipliers (GEMs). Due to the - in comparison with older technologies - small spatial width of the signals, this technology poses new requirements on the readout structures and the reconstruction methods. In this work, the performance and the systematics of different reconstruction methods have been studied, based on data measured with a TPC prototype in high magnetic fields of up to 4T and data from a Monte Carlo simulation. The latest results of the achievable point resolution are presented and their limitations have been investigated. (orig.)

  7. Large Enhancement of Probe Amplification with Population Inversion in a Four-Level Atomic System with Vacuum-Induced Coherence

    Institute of Scientific and Technical Information of China (English)

    LI Jia-Hua; YANG Wen-Xing; LUO Jin-Ming; PENG Ju-Cun

    2005-01-01

    In this paper, we discuss and analyze theoretically probe absorption-amplification response in a four-level coherent atomic system with vacuum-induced coherence via changing the sign of the parameter f, with f denoting the ratio of a pair of dipole moments associated with a doublet of closely upper hyperfine sublevels. We find that the amplitude of the probe amplification for the case f = -1 can be about one order of magnitude larger than that achievable for the case f = 1. In addition, with respect to the case f = -1 the probe amplification can be maintained all the time with weak incoherent pumping for a wide range of the probe detuning.

  8. LOW-COST BACTERIAL DETECTION SYSTEM FOR FOOD SAFETY BASED ON AUTOMATED DNA EXTRACTION, AMPLIFICATION AND READOUT

    OpenAIRE

    Hoehl, Melanie Margarete; Bocholt, Eva Schulte; Karippai, Nobu; Zengerle, Roland; Steigert, Juergen; Slocum, Alexander H.

    2013-01-01

    To ensure food, medical and environmental safety and quality, rapid, low-cost and easy-to-use detection methods are desirable. Here, the LabSystem is introduced for integrated, automated DNA purification and amplification. It consists of a disposable, centrifugally-driven DNA purification platform (LabTube) and the subsequent amplification in a low-cost UV/vis-reader (LabReader). In this paper, food safety was chosen as the first sample application with pathogenic verotoxin-producing (VTEC) E...

  9. Alignment of a tiled-grating compressor in a high-power chirped-pulse amplification laser system.

    Science.gov (United States)

    Hornung, Marco; Bödefeld, Ragnar; Siebold, Mathias; Schnepp, Matthias; Hein, Joachim; Sauerbrey, Roland; Kaluza, Malte C

    2007-10-20

    We present a novel technique to align a tiled grating in all five relevant degrees of freedom utilized in the compressor of the high-power chirped-pulse amplification laser system POLARIS at the Institute for Optics and Quantum Electronics, Jena, Germany. With this technique, alignment errors of the two gratings with respect to each other can be detected with an accuracy of 1 microrad for the rotational and 40 nm for the translational degrees of freedom. This is well sufficient to recompress 1030 nm pulses, which were stretched to 2.2 ns before amplification, to their bandwith limit of 150 fs. PMID:17952178

  10. CENTRIFUGAL LABTUBE FOR FULLY AUTOMATED DNA EXTRACTION & LAMP AMPLIFICATION BASED ON AN INTEGRATED, LOW-COST HEATING SYSTEM

    OpenAIRE

    Hoehl, Melanie Margarete; Weibert, Michael; Paust, Nils; Zengerle, Roland; Slocum, Alexander H.; Steigert, Juergen

    2013-01-01

    In this paper, we introduce a disposable battery-driven heating system for loop-mediated isothermal DNA amplification (LAMP) inside a centrifugally-driven DNA-extraction platform (LabTube). We demonstrate fully automated, fully closed extraction of as little as 100 DNA copies of verotoxin-producing (VTEC) Escherichia coli lysate in water, milk and apple juice in a standard laboratory centrifuge, followed by subsequent automatic LAMP amplification with an overall time-to-result of 1.5hrs. The ...

  11. Dynamic Characteristics of a Hydraulic Amplification Mechanism for Large Displacement Actuators Systems

    Directory of Open Access Journals (Sweden)

    Xavier Arouette

    2010-03-01

    Full Text Available We have developed a hydraulic displacement amplification mechanism (HDAM and studied its dynamic response when combined with a piezoelectric actuator. The HDAM consists of an incompressible fluid sealed in a microcavity by two largely deformable polydimethylsiloxane (PDMS membranes. The geometry with input and output surfaces having different cross-sectional areas creates amplification. By combining the HDAM with micro-actuators, we can amplify the input displacement generated by the actuators, which is useful for applications requiring large deformation, such as tactile displays. We achieved a mechanism offering up to 18-fold displacement amplification for static actuation and 12-fold for 55 Hz dynamic actuation.

  12. Droplet-Free Digital Enzyme-Linked Immunosorbent Assay Based on a Tyramide Signal Amplification System.

    Science.gov (United States)

    Akama, Kenji; Shirai, Kentaro; Suzuki, Seigo

    2016-07-19

    Digital enzyme-linked immunosorbent assay (ELISA) is a single molecule counting technology and is one of the most sensitive immunoassay methods. The key aspect of this technology is to concentrate enzyme reaction products from a single target molecule in femtoliter droplets. This study presents a novel Digital ELISA that does not require droplets; instead, enzyme reaction products are concentrated using a tyramide signal amplification system. In our method, tyramide substrate reacts with horseradish peroxidase (HRP) labeled with an immunocomplex on beads, and the substrate is converted into short-lived radical intermediates. By adjusting the bead concentration in the HRP-tyramide reaction and conducting the reaction using freely moving beads, tyramide radicals are deposited only on beads labeled with HRP and there is no diffusion to other beads. Consequently, the fluorescence signal is localized on a portion of the beads, making it possible to count the number of labeled beads digitally. The performance of our method was demonstrated by detecting hepatitis B surface antigen with a limit of detection of 0.09 mIU/mL (139 aM) and a dynamic range of over 4 orders of magnitude. The obtained limit of detection represents a >20-fold higher sensitivity than conventional ELISA. Our method has potential applications in simple in vitro diagnostic systems for detecting ultralow concentrations of protein biomarkers. PMID:27322525

  13. Femtosecond pulse generation and amplification in Yb-doped fibre oscillator–amplifier system

    Indian Academy of Sciences (India)

    P K Mukhopadhyay

    2010-11-01

    In recent times ytterbium (Yb) doped fibre-based mode-locked master oscillator and power amplifier have attracted a great deal of interest because of their inherent advantages like flexibility, reliability, compactness, high power handling capability and diffraction limited output beam quality as compared to the solid-state counterpart. But, to successfully develope of high-power femtosecond oscillator–amplifier system based on Yb- doped fibre, an appropriate choice of the mode-locking regime and the amplifier geometry are required. Development of an all-fibre integrated high-power Yb-doped fibre oscillator–amplifier system in which the advantages of a fibre-based system can be fully exploited remained a challenge as it requires the careful optimization of dispersion, nonlinearity, gain and ASE contribution. In this article, femto-second pulse generation in Yb-doped fibre oscillator in different mode-locking regimes are reviewed and the details of development and characterization of an all-fibre, high-power, low-noise amplifier system seeded by an all-normal-dispersion mode-locked Yb-doped fibre laser oscillator is described. More than 10 W of average power is obtained from the fibre oscillator–amplifier system at a repetition rate of 43 MHz with diffraction-limited beam quality. Amplified pulses are de-chirped to sub-160 fs duration in a grating compressor. This is the first 10 W-level source of femtosecond pulses with completely fibre-integrated amplification comprised of commercially available components.

  14. Two-stage sample-to-answer system based on nucleic acid amplification approach for detection of malaria parasites.

    Science.gov (United States)

    Liu, Qing; Nam, Jeonghun; Kim, Sangho; Lim, Chwee Teck; Park, Mi Kyoung; Shin, Yong

    2016-08-15

    Rapid, early, and accurate diagnosis of malaria is essential for effective disease management and surveillance, and can reduce morbidity and mortality associated with the disease. Although significant advances have been achieved for the diagnosis of malaria, these technologies are still far from ideal, being time consuming, complex and poorly sensitive as well as requiring separate assays for sample processing and detection. Therefore, the development of a fast and sensitive method that can integrate sample processing with detection of malarial infection is desirable. Here, we report a two-stage sample-to-answer system based on nucleic acid amplification approach for detection of malaria parasites. It combines the Dimethyl adipimidate (DMA)/Thin film Sample processing (DTS) technique as a first stage and the Mach-Zehnder Interferometer-Isothermal solid-phase DNA Amplification (MZI-IDA) sensing technique as a second stage. The system can extract DNA from malarial parasites using DTS technique in a closed system, not only reducing sample loss and contamination, but also facilitating the multiplexed malarial DNA detection using the fast and accurate MZI-IDA technique. Here, we demonstrated that this system can deliver results within 60min (including sample processing, amplification and detection) with high sensitivity (malaria in low-resource settings. PMID:27031184

  15. Absorption-amplification response with or without spontaneously generated coherence effect in a four-level atomic system

    Institute of Scientific and Technical Information of China (English)

    李家华; 杨文星; 彭菊村

    2004-01-01

    We discuss and analyze the absorption properties of a weak probe field in a typical four-level atomic system in the presence of a spontaneously generated coherence (SGC) term. The influences of the SGC and a coherent pump field on the probe absorption-amplification are investigated. The results show that the absorption of such a weak probe field can be dramatically enhanced due to the SGC effect. At the same time, the probe-absorption profile exhibits a two-peak structure and the probe-absorption peak gradually decreases as the pump intensity increases. On the contrary, the amplification of such a weak probe field near the line center of the probe transition can be achieved by adjusting the coherent pump field intensity in the absence of the SGC effect.

  16. Accurate offline dispersion measurement of Petawatt-class chirped pulse amplification compressor and stretcher systems

    International Nuclear Information System (INIS)

    Complete text of publication follows. The Advanced Radiographic Capability (ARC) on the National Ignition Facility (NIF) is designed to produce energetic x-rays in the range of 10-100 keV for backlighting NIF targets. ARC will convert 4 of the 192 NIF beamlines into 8 split beams, delivering laser pulses with adjustable pulse durations from 1 ps to 50 ps at the kilo-Joule level. Adjustable time delays between the 8 beams enable X-ray 'motion-picture' capture with tens-of-picosecond resolution during the critical phases of an ICF shot. The precise alignment of stretcher-compressor pairs in energetic chirped pulse amplification (CPA) systems is tedious and requires several iterations using advanced temporal diagnostics until the shortest pulse durations and highest peak intensities are achieved. For large, energetic Petawatt laser systems with beam sizes up to 40 cm, diffraction gratings in the compressor reach meter-scale size and are difficult to precisely align. We developed a group delay diagnostic which enables accurate, offline measurements of highly dispersive components such as stretchers or compressors with sub-picosecond accuracy. This diagnostic tool enables us to simply measure each dispersive component offline, and balance the dispersion in each beamline. Furthermore it allows exactly matching the dispersion of ARC's eight, independent four-grating compressors, which is critical for producing eight identical pulses. ARC utilizes a unique, folded compressor design for maximum compactness; two 5.5 m long vacuum vessels house 8 compressors with 91 cm x 45 cm multilayer, dielectric gratings. The group delay diagnostic utilizes the phase-shift technique for measuring the dispersion characteristics of each individual element, e.g. grating stretcher, chirped fiber Bragg grating, grating compressor, material dispersion, or an entire laser system. The system uses an amplitude modulated, highly-stable, single-frequency laser, which is scanned over the spectral

  17. Optofluidic analysis system for amplification-free, direct detection of Ebola infection

    Science.gov (United States)

    Cai, H.; Parks, J. W.; Wall, T. A.; Stott, M. A.; Stambaugh, A.; Alfson, K.; Griffiths, A.; Mathies, R. A.; Carrion, R.; Patterson, J. L.; Hawkins, A. R.; Schmidt, H.

    2015-09-01

    The massive outbreak of highly lethal Ebola hemorrhagic fever in West Africa illustrates the urgent need for diagnostic instruments that can identify and quantify infections rapidly, accurately, and with low complexity. Here, we report on-chip sample preparation, amplification-free detection and quantification of Ebola virus on clinical samples using hybrid optofluidic integration. Sample preparation and target preconcentration are implemented on a PDMS-based microfluidic chip (automaton), followed by single nucleic acid fluorescence detection in liquid-core optical waveguides on a silicon chip in under ten minutes. We demonstrate excellent specificity, a limit of detection of 0.2 pfu/mL and a dynamic range of thirteen orders of magnitude, far outperforming other amplification-free methods. This chip-scale approach and reduced complexity compared to gold standard RT-PCR methods is ideal for portable instruments that can provide immediate diagnosis and continued monitoring of infectious diseases at the point-of-care.

  18. Entanglement Amplification in the Non-Perturbative Dynamics of Modular Quantum Systems

    OpenAIRE

    Bayat A.; Giampaolo S.M.; Illuminati F.; Plenio M.B.

    2013-01-01

    We analyze the conditions for entanglement amplification between distant and not directly interacting quantum objects by their common coupling to media with static modular structure and subject to a local (single-bond) quenched dynamics. We show that in the non-perturbative regime of the dynamics the initial end-to-end entanglement is strongly amplified and, moreover, can be distributed efficiently between distant objects. Due to its intrinsic local and non-perturbative nature the dynamics is...

  19. Yb:YAG Innoslab amplifier: efficient high repetition rate subpicosecond pumping system for optical parametric chirped pulse amplification

    OpenAIRE

    Schulz, M.; Riedel, R; Willner, A.; Mans, T.; Schnitzler, C.; Russbueldt, P.; Dolkemeyer, J.; Seise, E.; Gottschall, T.; Haedrich, S.; Duesterer, S.; Schlarb, H.; Feldhaus, J.; J. Limpert; Faatz, B.

    2011-01-01

    We report on a Yb:YAG Innoslab laser amplifier system for generation of subpicsecond high energy pump pulses for optical parametric chirped pulse amplification (OPCPA) at high repetition rates. Pulse energies of up to 20 mJ (at 12.5 kHz) and repetition rates of up to 100 kHz were attained with pulse durations of 830 fs and average power in excess of 200 W. We further investigate the possibility to use subpicosecond pulses to derive a stable continuum in a YAG crystal for OPCPA seeding.

  20. Yb:YAG Innoslab amplifier: efficient high repetition rate subpicosecond pumping system for optical parametric chirped pulse amplification.

    Science.gov (United States)

    Schulz, M; Riedel, R; Willner, A; Mans, T; Schnitzler, C; Russbueldt, P; Dolkemeyer, J; Seise, E; Gottschall, T; Hädrich, S; Duesterer, S; Schlarb, H; Feldhaus, J; Limpert, J; Faatz, B; Tünnermann, A; Rossbach, J; Drescher, M; Tavella, F

    2011-07-01

    We report on a Yb:YAG Innoslab laser amplifier system for generation of subpicsecond high energy pump pulses for optical parametric chirped pulse amplification (OPCPA) at high repetition rates. Pulse energies of up to 20 mJ (at 12.5 kHz) and repetition rates of up to 100 kHz were attained with pulse durations of 830 fs and average power in excess of 200 W. We further investigate the possibility to use subpicosecond pulses to derive a stable continuum in a YAG crystal for OPCPA seeding. PMID:21725443

  1. 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.

  2. Preliminary validation of direct detection of foot-and-mouth disease virus within clinical samples using reverse transcription loop-mediated isothermal amplification coupled with a simple lateral flow device for detection.

    Directory of Open Access Journals (Sweden)

    Ryan A Waters

    Full Text Available Rapid, field-based diagnostic assays are desirable tools for the control of foot-and-mouth disease (FMD. Current approaches involve either; 1 Detection of FMD virus (FMDV with immuochromatographic antigen lateral flow devices (LFD, which have relatively low analytical sensitivity, or 2 portable RT-qPCR that has high analytical sensitivity but is expensive. Loop-mediated isothermal amplification (LAMP may provide a platform upon which to develop field based assays without these drawbacks. The objective of this study was to modify an FMDV-specific reverse transcription-LAMP (RT-LAMP assay to enable detection of dual-labelled LAMP products with an LFD, and to evaluate simple sample processing protocols without nucleic acid extraction. The limit of detection of this assay was demonstrated to be equivalent to that of a laboratory based real-time RT-qPCR assay and to have a 10,000 fold higher analytical sensitivity than the FMDV-specific antigen LFD currently used in the field. Importantly, this study demonstrated that FMDV RNA could be detected from epithelial suspensions without the need for prior RNA extraction, utilising a rudimentary heat source for amplification. Once optimised, this RT-LAMP-LFD protocol was able to detect multiple serotypes from field epithelial samples, in addition to detecting FMDV in the air surrounding infected cattle, pigs and sheep, including pre-clinical detection. This study describes the development and evaluation of an assay format, which may be used as a future basis for rapid and low cost detection of FMDV. In addition it provides providing "proof of concept" for the future use of LAMP assays to tackle other challenging diagnostic scenarios encompassing veterinary and human health.

  3. Development of the chirped pulse amplification technique for high peak power production with Nd: glass laser system

    International Nuclear Information System (INIS)

    There has been a large amount of development in the field of ultra short pulsed lasers and high peak intensity laser systems. Therefore the objective of this work was to develop the concept of chirped pulse amplification (CPA), that is essential for any high-peak-power laser technology. The design of the CPA system using Nd:glass as the active medium has been developed in this laboratory at B.A.R.C. for the first time. The beginning is with a 100 MHz train of 200fs pulses, that is supported by a 7nm FWHM bandwidth and a central wavelength at 1056nm. A single pulse of 70pJ energy is selected from this train after stretching the pulse to 266ps. The purpose of stretching is to decrease the instantaneous intensity, so that no non-linear effect or damage is introduced in the amplifying medium (Nd:glass) during amplification. This stretched pulse is amplified to about 40mJ and then compressed to a 1.5ps pulse having a bandwidth of 3.8nm. Pulse width expansion and compression is achieved by means of conjugate grating pairs. A real-time autocorrellator set up measures the stretched as well as the compressed pulse. (author)

  4. Isolation and Rapid Detection of Avian Borna Virus by a Reverse Transcription Loop-mediated Isothermal Amplification Assay for Outbreaks in Psittacine Birds%禽波纳病毒分离鉴定及其恒温扩增检测分析

    Institute of Scientific and Technical Information of China (English)

    田纯见; 唐羿; 周小明; 常彦磊; 吴晓薇; 朱道中; 王宏; 罗琼; 林志雄; 赵吟; 罗长保; 鱼海琼; 刘志玲; 陈茹

    2012-01-01

    利用腺胃扩张症(PDD)患病鹦鹉腺胃RT-PCR阳性病料,接种猪睾丸(ST)传代细胞,分离禽波纳病毒(ABV),建立实时RT-LAMP检测方法.将阳性病料接种ST细胞单层传代,出现细胞圆缩、脱落,ABV基质蛋白(M)基因扩增产物出现预计大小351 bp条带,测序后进化树分析显示为ABV5基因型.针对M基因设计ID37、ID30、ID19、ID6和ID1共5组引物,后3组引物RT-LAMP呈阳性反应.利用钙黄绿素建立实时RT-LAMP,分别在36(ID30)、38(ID37)和49(ID19)min出现扩增反应曲线,60 min内扩增达到峰值.对各种临床样品检测与RT-PCR结果一致,新城疫等类症病毒未见阳性反应,显示较高的特异性 ;对细胞培养物检测10-1~10-5为阳性,比较RT-PCR敏感性提高约100倍.RT-LAMP检测方法的建立为PDD防制提供新的检测方法,也是波纳病公共卫生研究有益的参考.%In this study an avian bornavirus (ABV) strain was isolated from sick parrots with proventricular dilatation disease(PDD). The virus grew in swine testicular (ST) cell monolayer with granulating, shrinking, rounding and falling off although classical Borna disease virus strains replicate very efficiently in cultured mammalian cells in which persistent, noncytolytic infections was readily established. Viruses were successfully isolated and demonstrated by reverse transcription-PCR analysis from the proventricular glands of parrot "glass 363" and "color" with confirmed PDD. The 351 bp product of the expected size bands of matrix protein (M) gene was cloned, the sequence and phylogenetic tree analysis showed that the isolated virus belonging to genotype ABV5. Five sets of M gene RT-LAMP primers ID1, ID6, ID19, ID30 and ID37 were designed using DNAStar and PrimerExplorer V5. 0 (network) and later three set reactions showed positive color reaction with specific electrophoretic bands. The amplification curves of of real-time RT-LAMP using fluorescent indicator calcein were shown in 36 (ID30), 38 (ID37

  5. 60 GHz OCS mm-wave generation for ROF system based on saturated parametric amplification effect in HNLF

    Institute of Scientific and Technical Information of China (English)

    LI Wen-jing; SANG Xin-zhu; YUAN Jin-hui; WANG Kui-ru; YU Chong-xiu; XIN Xiang-jun

    2010-01-01

    @@ A novel approach to generate 60 GHz optical carrier suppression(OCS)millimeter-wave(mm-wave)signal based on the saturated optical parametric amplification(OPA)effect in high non-linear fiber(HNLF)is investigated.In the proposed system,the OPA effect occurs when the signal and pump with 30 GHz frequency interval are set into the high non-linear fiber.By controlling the length of HNLF,OPA effect saturates,and the pump power is delivered in a large extent to the signal and idler light,so a 60 GHz OCS ram-wave is generated.The system does not need high-speed external modulator,high-frequency vibration source or narrow-band filter,which greatly reduces the cost and improves the stability of the radio over fiber(ROF)system.Results show that the 10 Gb/s downstream signal can be transmitted with negligible power penalty.

  6. Conceptual design of sub-exa-watt system by using optical parametric chirped pulse amplification

    Science.gov (United States)

    Kawanaka, J.; Tsubakimoto, K.; Yoshida, H.; Fujioka, K.; Fujimoto, Y.; Tokita, S.; Jitsuno, T.; Miyanaga, N.; Gekko-EXA Design Team

    2016-03-01

    A 50 PW ultrahigh-peak-power laser has been conceptually designed, which is based on optical parametric chirped pulse amplification (OPCPA). A 250 J DPSSL and a flash- lamp-pumped kJ laser are adopted as new repeatable pump source. The existed LFEX-laser with more than ten kilo joules are used in the final amplifier stage and the OPCPA with the 2x2 tiled pump beams in random phase has been proposed with several ten centimeter aperture. A pulse duration of amplified pulses is set at less than 10 fs. A broadband OPCPA with ∼500 nm of the gain spectral width near 1 μm is required. A partially deuterated KDP (p-DKDP) crystal is one of the most promising nonlinear crystals and our numerical calculation ensured such ultra-broad gain width. p-DKDP crystals with several deuteration ratio have been successfully grown.

  7. Double regenerative amplification of picosecond pulses

    Science.gov (United States)

    Bai, Zhen-ao; Chen, Li-yuan; Bai, Zhen-xu; Chen, Meng; Li, Gang

    2012-04-01

    An double Nd:YAG regenerative amplification picosecond pulse laser is demonstrated under the semiconductor saturable absorption mirror(SESAM) mode-locking technology and regenerative amplification technology, using BBO crystal as PC electro-optic crystal. The laser obtained is 20.71ps pulse width at 10 KHz repetition rate, and the energy power is up to 4W which is much larger than the system without pre-amplification. This result will lay a foundation for the following amplification.

  8. Chirped-pulse amplification system based on chirp reversal and near-field spatial reversal with common tiled grating pair as stretcher and compressor.

    Science.gov (United States)

    Wang, Xiao; Wei, Xiaofeng; Hu, Yao; Zeng, Xiaoming; Zuo, Yanlei; Hao, Xin; Zhou, Kainan; Xie, Na; Zhang, Ying

    2012-08-10

    Chirped-pulse amplification system based on chirp reversal in optical parametric chirped-pulse amplification is proposed and experimentally demonstrated. The operation of this system can be described as negative stretching-temporal chirp reversal-energy amplification-negative compression, in which the pulse is stretched and compressed with the same gratings. Stand-alone stretcher adopting lenses or concave mirrors with large aperture can be omitted. Simulations showed that this work mode can also increase the cut-off band-pass of the whole system and increase the output energy by 15-17%. In addition, the stability of a tiled-grating compressor can be improved with this work mode. PMID:22885574

  9. Electron Transfer Reactivity Patterns at Chemically Modified Electrodes: Fundamentals and Application to the Optimization of Redox Recycling Amplification Systems

    Energy Technology Data Exchange (ETDEWEB)

    Adam Johan Bergren

    2006-05-01

    Electroanalytical chemistry is often utilized in chemical analysis and Fundamental studies. Important advances have been made in these areas since the advent of chemically modified electrodes: the coating of an electrode with a chemical film in order to impart desirable, and ideally, predictable properties. These procedures enable the exploitation of unique reactivity patterns. This dissertation presents studies that investigate novel reaction mechanisms at self-assembled monolayers on gold. In particular, a unique electrochemical current amplification scheme is detailed that relies on a selective electrode to enable a reactivity pattern that results in regeneration of the analyte (redox recycling). This regenerating reaction can occur up to 250 times for each analyte molecule, leading to a notable enhancement in the observed current. The requirements of electrode selectivity and the resulting amplification and detection limit improvements are described with respect to the heterogeneous and homogeneous electron transfer rates that characterize the system. These studies revealed that the heterogeneous electrolysis of the analyte should ideally be electrochemically reversible, while that for the regenerating agent should be held to a low level. Moreover, the homogeneous reaction that recycles the analyte should occur at a rapid rate. The physical selectivity mechanism is also detailed with respect to the properties of the electrode and redox probes utilized. It is shown that partitioning of the analyte into/onto the adlayer leads to the extraordinary selectivity of the alkanethiolate monolayer modified electrode. Collectively, these studies enable a thorough understanding of the complex electrode mechanism required for successful redox recycling amplification systems, Finally, in a separate (but related) study, the effect of the akyl chain length on the heterogeneous electron transfer behavior of solution-based redox probes is reported, where an odd-even oscillation

  10. A pulse compressor for a chirped-pulse amplification system based on a frequency-doubling crystal and grating

    Science.gov (United States)

    Chen, Ying; Zhou, Yuan; Yuan, Peng; Qian, Liejia

    2016-05-01

    The limited damage threshold of the last compression grating in a general compressor is still an obstruction that limits the output capability of a high-energy laser facility. We propose and theoretically study a novel pulse compressor consisting of a pair of gratings and a nonlinear crystal, which is applied to chirped-pulse amplification (CPA) or optical parametric CPA (OPCPA) systems. The obstruction in the high-energy laser facility is alleviated substantially in our proposed compressor because the nonlinear crystal with a much higher damage threshold can withstand more high energy of the chirped pulse. We prove that, by means of a pair of anti-parallel gratings and noncollinear frequency doubling, it is possible to obtain a compressed second-harmonic pulse without chirp and angular dispersion. A hypothetical example of a 1 μm linear chirped pulse compression is discussed.

  11. Quantum interference effects on the probe amplification without and with inversion in a four-level system

    Institute of Scientific and Technical Information of China (English)

    Zhang Bing; Xu Wei-Hua; Zhang Hui-Fang; Gao Jin-Yue

    2004-01-01

    A four-level system driven by two coherent fields is considered. It is shown that in the presence of an incoherent pump, the probe gain at a short wavelength can be achieved due to the quantum interference. Our density matrix calculation provides the conditions for probe amplification from different origins, including gain without population inversion on any state basis, gain with population inversion on the dressed-state basis, and gain with population inversion on the bare-state basis. Also, by controlling the Rabi frequency of the coupling field a total change from non-inversion to inversion can be achieved which does not depend on the intensity of the incoherent pump.

  12. A lab-on-a-chip system with integrated sample preparation and loop-mediated isothermal amplification for rapid and quantitative detection of Salmonella spp. in food samples

    DEFF Research Database (Denmark)

    Sun, Yi; Than Linh, Quyen; Hung, Tran Quang;

    2015-01-01

    Foodborne disease is a major public health threat worldwide. Salmonellosis, an infectious disease caused by Salmonella spp., is one of the most common foodborne diseases. Isolation and identification of Salmonella by conventional bacterial culture or molecular-based methods are time consuming and...... amplification (LAMP) for rapid and quantitative detection of Salmonella spp. in food samples. The whole diagnostic procedures including DNA isolation, isothermal amplification, and real-time detection were accomplished in a single chamber. Up to eight samples could be handled simultaneously and the system was...... on-site screening of Salmonella for applications in food safety control, environmental surveillance, and clinical diagnostics....

  13. Evaluation of modulation formats for 160 Gb/s transmission systems using Raman amplification

    DEFF Research Database (Denmark)

    Zhenbo, Xu; Rottwitt, Karsten; Jeppesen, Palle

    We evaluate 160 Gb/s systems with different modulation formats. RZ-DPSK gives best performance for a single channel system with 40% reach improvement compared to RZ, CSRZ-DPSK is more robust in a WDM system....

  14. Development and Application of High-flux Molecular Differential Detection System with LAMP Assay for 10 Foodborne Pathogen%10种食源性疾病病原体高通量LAMP分子鉴别检测体系的建立及应用

    Institute of Scientific and Technical Information of China (English)

    孙边成; 长如胜; 宋克云; 欧新华; 姚栋; 苏良; 叶文; 陈法明

    2011-01-01

    目的 建立一种LAMP分子鉴别检测体系,应用于10种食源性疾病病原体的分子鉴别检测.方法 针对8种细菌(沙门菌属、志贺菌属、金黄色葡萄球菌、副溶血性弧菌、EHECO157:H7、奇异变形杆菌、霍乱弧菌和单增李斯特菌)和2种病毒(Norwalk病毒和轮状病毒)分别建立LAMP和RT-LAMP方法,分别对25种常见肠道细菌和病毒进行LAMP扩增,水浴箱内65℃扩增60 min(LAMP)或120 min(RT-LAMP),扩增完成后利用电泳和肉眼进行结果判断.对365份食源性疾病患者呕吐物、肛拭子和食品等标本进行10种食源性疾病病原体LAMP分子检测.结果 10种食源性疾病病原体LAMP或RT-LAMP方法均只对靶病原体出现阳性结果,电泳显示为LAMP特异性梯状条带,加SYBRGreenⅠ后肉眼观察反应液变为绿色;8种细菌性病原体LAMP检测方法的敏感度为3×100~1.2×102 cfu/ml,其中6种LAMP方法敏感度高于PCR方法,其他病原体(霍乱弧菌、EHEC O157:H7、Norwalk病毒和轮状病毒)敏感度与PCR方法相同.从365份标本中检出沙门菌属11份、志贺菌属6份、金黄色葡萄球菌13份、EHEC O157:H7 2份、副溶血性弧菌2份、单增李斯特菌2份、Norwalk病毒12份和轮状病毒7份.结论 建立了一个较为完整的LAMP分子鉴别检测体系,可以在一台水浴箱内同时对10种食源性疾病病原体进行高通量的分子鉴别检测,具有快速、不需要特殊仪器和肉眼判断结果的优势,适合基层单位的实验室开展食源性疾病的分子鉴别诊断.%Objective A molecular differential detection system with loop-mediated isothermal amplification (LAMP) was developed and applied for the detection of 10 kinds of foodborne pathogens. Methods LAMP and RT - LAMP methods were set up respectively for 8 kinds of bacterial pathogens (Salmonella, Shigella, Staphylocxcus aureus, Vibrio parahaemo-lyticus, EHECO157: H7, Proteus mirabilis, Vibrio cholerae and Listeria monocytogenes) and2

  15. Novel system uses probasin-based promoter, transcriptional silencers and amplification loop to induce high-level prostate expression

    Directory of Open Access Journals (Sweden)

    Yu Hong

    2007-02-01

    Full Text Available Abstract Background Despite several effective treatment options available for prostate cancer, it remains the second leading cause of cancer death in American men. Thus, there is a great need for new treatments to improve outcomes. One such strategy is to eliminate cancer through the expression of cytotoxic genes specifically in prostate cells by gene therapy vectored delivery. To prevent systemic toxicity, tissue- and/or cancer-specific gene expression is required. However, the use of tissue- or cancer-specific promoters to target transgene expression has been hampered by their weak activity. Results To address this issue, we have developed a regulation strategy that includes feedback amplification of gene expression along with a differentially suppressible tetracycline regulated expression system (DiSTRES. By differentially suppressing expression of the tetracycline-regulated transcriptional activator (tTA and silencer (tTS genes based on the cell origin, this leads to the activation and silencing of the TRE promoter, respectively. In vitro transduction of LNCaP cells with Ad/GFPDiSTRES lead to GFP expression levels that were over 30-fold higher than Ad/CMV-GFP. Furthermore, Ad/FasL-GFPDiSTRES demonstrated cytotoxic effects in prostate cancer cells known to be resistant to Fas-mediated apoptosis. Conclusion Prostate-specific regulation from the DiSTRES system, therefore, serves as a promising new regulation strategy for future applications in the field of cancer gene therapy and gene therapy as a whole.

  16. Optimisation of wide-band parametric amplification stages of a femtosecond laser system with coherent combining of fields

    Science.gov (United States)

    Bagayev, S. N.; Trunov, V. I.; Pestryakov, E. V.; Leshchenko, V. E.; Frolov, S. A.; Vasiliev, V. A.

    2014-05-01

    For the first time the pulses with the energy of ~150 mJ and the spectrum corresponding to the transform-limited duration of ~20 fs amplified in three-stage parametric amplifiers have been coherently combined in a dual-channel femtosecond laser system. The efficiency of coherent combining of above 90% has been obtained at the residual relative time jitter of amplified pulses of 110 as. For the first time the modulation of spectrum was experimentally observed under the parametric amplification of a wideband femtosecond radiation in crystals placed in series. The model of parametric luminescence evolution was developed which allows one to calculate the whole range of the frequency-angular spectrum that, in addition to simulations of the contrast of amplified pulses, gives the possibility of optimising the amplifier efficiency. The results of experiments on measuring the contrast are presented and compared with the calculated data. Methods for enhancing the contrast in the created laser system are analysed. Possible schemes of multibeam pumping of the output cascade are considered for obtaining a petawatt power in the laser system based on cascades of a parametric amplifier in LBO crystals which is being developed at the Institute of Laser Physics of SB RAS.

  17. A Portable Automatic Endpoint Detection System for Amplicons of Loop Mediated Isothermal Amplification on Microfluidic Compact Disk Platform

    Directory of Open Access Journals (Sweden)

    Shah Mukim Uddin

    2015-03-01

    Full Text Available In recent years, many improvements have been made in foodborne pathogen detection methods to reduce the impact of food contamination. Several rapid methods have been developed with biosensor devices to improve the way of performing pathogen detection. This paper presents an automated endpoint detection system for amplicons generated by loop mediated isothermal amplification (LAMP on a microfluidic compact disk platform. The developed detection system utilizes a monochromatic ultraviolet (UV emitter for excitation of fluorescent labeled LAMP amplicons and a color sensor to detect the emitted florescence from target. Then it processes the sensor output and displays the detection results on liquid crystal display (LCD. The sensitivity test has been performed with detection limit up to 2.5 × 10−3 ng/µL with different DNA concentrations of Salmonella bacteria. This system allows a rapid and automatic endpoint detection which could lead to the development of a point-of-care diagnosis device for foodborne pathogens detection in a resource-limited environment.

  18. A New Power Combining and Outphasing Modulation System for High-Efficiency Power Amplification

    OpenAIRE

    Perreault, David J.

    2010-01-01

    This paper describes a new power combining and outphasing system that provides both high efficiency and linear output control. Whereas conventional outphasing systems utilize two power amplifiers, the system introduced here combines power from four or more amplifiers. The proposed technique overcomes the loss and reactive loading problems of previous outphasing systems. It provides ideally lossless power combining, along with resistive loading of the individual power amplifiers over a very wi...

  19. Developments of a front-end system for high-intense Nd:glass laser used in optical parametric chirped pulse amplification

    International Nuclear Information System (INIS)

    We have constructed the front-end system using a broadband high-gain OPCPA for chirped pulse amplification. This system can deliver the output energy of 65 mJ with 6-nm spectral width at a 1.053-μm central wavelength. The stability of output energy was substantially improved compared with the Ti:Al2O3 regenerative amplifier. These output parameters are appropriate as a seed of PW-class Nd:glass laser system. (author)

  20. High average power, high energy, femto-second fiber chirped pulse amplification system

    OpenAIRE

    He, F.; Price, J.H.V.; Malinowski, A.; Piper, A.; Ibsen, M.; Richardson, D.J.; Dawson, J. W.; Siders, C.W.; Britten, J.A.; Barty, C. P. J.

    2007-01-01

    We have demonstrated an Yb-fiber laser system incorporating a CFBG stretcher, bandwidth optimised amplifiers and dielectric grating compressor. The system produced 135 W average power with pulse energy of 13.5 µJ. The recompressed pulse duration was 360 fs.

  1. Specific Targeting of Gene Therapy to Prostate Cancer Using a Two-step Transcriptional Amplification System

    OpenAIRE

    Figueiredo, Marxa L.; Sato, Makoto; Johnson, Mai; Wu, Lily

    2006-01-01

    Significant advances in gene therapy have been made as a result of the improvement of gene delivery systems, discovery of new therapeutic genes, better understanding of mechanisms of disease progression, exploration and improvement of tissue-specific gene regulatory sequences, and development of better prodrug/enzyme systems. We will discuss adenoviral-based and prostate-specific cancer gene therapy, emphasizing tissue-specific promoter choices to increase gene therapy safety and specificity,...

  2. Efficient Low Voltage Amplification Using Self Starting Voltage Regulator for Storage System

    Directory of Open Access Journals (Sweden)

    Haslinah Binti Mohd Nasir

    2014-10-01

    Full Text Available This paper presents a storage system design based on energy harvesting to achieve batteryless for Wireless Sensor Network (WSN application. The storage system is part of the Wireless Sensor Energy Harvesting to store and amplify the energy harvested from the surroundings. Finding a new sources of renewable energy has becomes a fashionable among researchers nowadays in particular harvesting the energy from the surrounding. However the challenge raised is to boost up the energy that known are very low. Thus the proposed method must be consumes very little power and suitable for ambient environmental sources such as vibration, wind and RF energy and be able to boost up the energy for storage system. The output of the harvested voltage is insufficient for most applications, therefore the system will boost up the input voltage level using DC to DC converter topology to higher dc voltage.The DC to DC converter shall be designed to suit the types of storage required. The output voltage of this DC converter should be sufficient to charge either capacitor or supercapacitor that will be use in this system as the energy storage system. The supercapacitor will provide power to energize any system such as in this case wireless sensor network[1]. In the case of wireless sensor network for example, the node would require the energy during transmitting and receiving data only whereas during standby mode or sleep mode, the amount of energy required would be very small[2]. Therefore the storage system will make use of this standby time or sleep mode of the sensor node to store as much energy as possible. The presented DC to DC converter in this paper has high efficiency upto 85.4% with input voltage between range 300mV to 600mV.

  3. Dynamics and Control of DNA Sequence Amplification

    CERN Document Server

    Marimuthu, Karthikeyan

    2014-01-01

    DNA amplification is the process of replication of a specified DNA sequence \\emph{in vitro} through time-dependent manipulation of its external environment. A theoretical framework for determination of the optimal dynamic operating conditions of DNA amplification reactions, for any specified amplification objective, is presented based on first-principles biophysical modeling and control theory. Amplification of DNA is formulated as a problem in control theory with optimal solutions that can differ considerably from strategies typically used in practice. Using the Polymerase Chain Reaction (PCR) as an example, sequence-dependent biophysical models for DNA amplification are cast as control systems, wherein the dynamics of the reaction are controlled by a manipulated input variable. Using these control systems, we demonstrate that there exists an optimal temperature cycling strategy for geometric amplification of any DNA sequence and formulate optimal control problems that can be used to derive the optimal tempe...

  4. Telomerase repeat amplification protocol (TRAP) activity upon recombinant expression and purification of human telomerase in a bacterial system.

    Science.gov (United States)

    Hansen, Debra T; Thiyagarajan, Thirumagal; Larson, Amy C; Hansen, Jeffrey L

    2016-07-01

    Telomerase biogenesis is a highly regulated process that solves the DNA end-replication problem. Recombinant expression has so far been accomplished only within a eukaryotic background. Towards structural and functional analyses, we developed bacterial expression of human telomerase. Positive activity by the telomerase repeat amplification protocol (TRAP) was identified in cell extracts of Escherichia coli expressing a sequence-optimized hTERT gene, the full-length hTR RNA with a self-splicing hepatitis delta virus ribozyme, and the human heat shock complex of Hsp90, Hsp70, p60/Hop, Hsp40, and p23. The Hsp90 inhibitor geldanamycin did not affect post-assembly TRAP activity. By various purification methods, TRAP activity was also obtained upon expression of only hTERT and hTR. hTERT was confirmed by tandem mass spectrometry in a ∼120 kDa SDS-PAGE fragment from a TRAP-positive purification fraction. TRAP activity was also supported by hTR constructs lacking the box H/ACA small nucleolar RNA domain. End-point TRAP indicated expression levels within 3-fold of that from HeLa carcinoma cells, which is several orders of magnitude below detection by the direct assay. These results represent the first report of TRAP activity from a bacterium and provide a facile system for the investigation of assembly factors and anti-cancer therapeutics independently of a eukaryotic setting. PMID:26965413

  5. On-coil multiple channel transmit system based on class-D amplification and pre-amplification with current amplitude feedback

    Science.gov (United States)

    Gudino, N.; Heilman, J.A; Riffe, M. J.; Heid, O.; Vester, M.; Griswold, M.A.

    2016-01-01

    A complete high-efficiency transmit amplifier unit designed to be implemented in on-coil transmit arrays is presented. High power capability, low power dissipation, scalability and cost minimization were some of the requirements imposed to the design. The system is composed of a current mode class-D (CMCD) amplifier output stage and a voltage mode class-D (VMCD) preamplification stage. The amplitude information of the radio frequency pulse was added through a customized step-down DC-DC converter with current amplitude feedback that connects to the CMCD stage. Benchtop measurements and imaging experiments were carried out to analyze system performance. Direct control of B1 was possible and its load sensitivity was reduced to less than 10% variation from unloaded to full loaded condition. When using the amplifiers in an array configuration, isolation above 20 dB was achieved between neighboring coils by the amplifier decoupling method. High output current operation of the transmitter was proved on the benchtop through output power measurements and in a 1.5 T scanner through flip angle quantification. Finally, single and multiple channel excitations with the new hardware were demonstrated by receiving signal with the body coil of the scanner. PMID:22890962

  6. Establishing a DNA identification system for pigs (Sus scrofa) using a multiplex STR amplification.

    Science.gov (United States)

    Lin, Yu-Chih; Hsieh, Hsing-Mei; Lee, James Chun-I; Hsiao, Chung-Ting; Lin, Der-Yuh; Linacre, Adrian; Tsai, Li-Chin

    2014-03-01

    In this study we establish a novel STR multiplex using 13 tetra-nucleotide STRs and the amelogenin marker for the forensic identification of pigs. The genotypes and allele frequency were generated based on 341 samples from 11 pig breeds in Taiwan. Genetic variation was tested including Na, Ne, Ho, He, F-statistics, PIC, Pm and PE for each STR locus and for each breed. Based upon the 341 samples in this study, the CPm and CPEtrio of the 13 STR loci were 1.31 E-11 and 0.9996 respectively. The CPItrio based on ten family sets ranged from 4.012 E+4 to 4.332 E+6 for paternity test. Validation of the multiplex included: determining the sensitivity of the test, where reproducible full DNA profiles were obtained using an initial template of between 0.25 and 1 ng; a comprehensive range of tissue types generated the same genotype; and the specificity was confirmed as no DNA full profile was generated for any species other than Sus scrofa. Based on the phylogenetic analysis, the European domestic breeds clustered separately from the Asian breeds, as expected, and their hybrids formed unique clades respectively between the clades of Asian and European breeds. Eleven test samples, acting as unknown samples, matched all expected breeds. We demonstrate that this novel 14-plex PCR system is valuable in pig individualization, parentage testing, breed assessment, phylogenetic study and forensic applications. PMID:24528574

  7. Dynamics and control of DNA sequence amplification

    International Nuclear Information System (INIS)

    DNA amplification is the process of replication of a specified DNA sequence in vitro through time-dependent manipulation of its external environment. A theoretical framework for determination of the optimal dynamic operating conditions of DNA amplification reactions, for any specified amplification objective, is presented based on first-principles biophysical modeling and control theory. Amplification of DNA is formulated as a problem in control theory with optimal solutions that can differ considerably from strategies typically used in practice. Using the Polymerase Chain Reaction as an example, sequence-dependent biophysical models for DNA amplification are cast as control systems, wherein the dynamics of the reaction are controlled by a manipulated input variable. Using these control systems, we demonstrate that there exists an optimal temperature cycling strategy for geometric amplification of any DNA sequence and formulate optimal control problems that can be used to derive the optimal temperature profile. Strategies for the optimal synthesis of the DNA amplification control trajectory are proposed. Analogous methods can be used to formulate control problems for more advanced amplification objectives corresponding to the design of new types of DNA amplification reactions

  8. Dynamics and control of DNA sequence amplification

    Energy Technology Data Exchange (ETDEWEB)

    Marimuthu, Karthikeyan [Department of Chemical Engineering and Center for Advanced Process Decision-Making, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States); Chakrabarti, Raj, E-mail: raj@pmc-group.com, E-mail: rajc@andrew.cmu.edu [Department of Chemical Engineering and Center for Advanced Process Decision-Making, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States); Division of Fundamental Research, PMC Advanced Technology, Mount Laurel, New Jersey 08054 (United States)

    2014-10-28

    DNA amplification is the process of replication of a specified DNA sequence in vitro through time-dependent manipulation of its external environment. A theoretical framework for determination of the optimal dynamic operating conditions of DNA amplification reactions, for any specified amplification objective, is presented based on first-principles biophysical modeling and control theory. Amplification of DNA is formulated as a problem in control theory with optimal solutions that can differ considerably from strategies typically used in practice. Using the Polymerase Chain Reaction as an example, sequence-dependent biophysical models for DNA amplification are cast as control systems, wherein the dynamics of the reaction are controlled by a manipulated input variable. Using these control systems, we demonstrate that there exists an optimal temperature cycling strategy for geometric amplification of any DNA sequence and formulate optimal control problems that can be used to derive the optimal temperature profile. Strategies for the optimal synthesis of the DNA amplification control trajectory are proposed. Analogous methods can be used to formulate control problems for more advanced amplification objectives corresponding to the design of new types of DNA amplification reactions.

  9. 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.

  10. Feedback Amplification of Neutrophil Function.

    Science.gov (United States)

    Németh, Tamás; Mócsai, Attila

    2016-06-01

    As the first line of innate immune defense, neutrophils need to mount a rapid and robust antimicrobial response. Recent studies implicate various positive feedback amplification processes in achieving that goal. Feedback amplification ensures effective migration of neutrophils in shallow chemotactic gradients, multiple waves of neutrophil recruitment to the site of inflammation, and the augmentation of various effector functions of the cells. We review here such positive feedback loops including intracellular and autocrine processes, paracrine effects mediated by lipid (LTB4), chemokine, and cytokine mediators, and bidirectional interactions with the complement system and with other immune and non-immune cells. These amplification mechanisms are not only involved in antimicrobial immunity but also contribute to neutrophil-mediated tissue damage under pathological conditions. PMID:27157638

  11. An empirical approach for quantifying loop-mediated isothermal amplification (LAMP using Escherichia coli as a model system.

    Directory of Open Access Journals (Sweden)

    Sowmya Subramanian

    Full Text Available Loop mediated isothermal amplification (LAMP is a highly efficient, selective and rapid DNA amplification technique for genetic screening of pathogens. However, despite its popularity, there is yet no mathematical model to quantify the outcome and no well-defined metric for comparing results that are available. LAMP is intrinsically complex and involves multiple pathways for gene replication, making fundamental modelling nearly intractable. To circumvent this difficulty, an alternate, empirical model is introduced that will allow one to extract a set of parameters from the concentration versus time curves. A simple recipe to deduce the time to positive, Tp--a parameter analogous to the threshold cycling time in polymerase chain reaction (PCR, is also provided. These parameters can be regarded as objective and unambiguous indicators of LAMP amplification. The model is exemplified on Escherichia coli strains by using the two gene fragments responsible for vero-toxin (VT production and tested against VT-producing (O157 and O45 and non-VT producing (DH5 alpha strains. Selective amplification of appropriate target sequences was made using well established LAMP primers and protocols, and the concentrations of the amplicons were measured using a Qubit 2.0 fluorometer at specific intervals of time. The data is fitted to a generalized logistic function. Apart from providing precise screening indicators, representing the data with a small set of numbers offers significant advantages. It facilitates comparisons of LAMP reactions independently of the sampling technique. It also eliminates subjectivity in interpretation, simplifies data analysis, and allows easy data archival, retrieval and statistical analysis for large sample populations. To our knowledge this work represents a first attempt to quantitatively model LAMP and offer a standard method that could pave the way towards high throughput automated screening.

  12. Approaches towards molecular amplification for sensing.

    Science.gov (United States)

    Goggins, Sean; Frost, Christopher G

    2016-06-01

    Diagnostic assays that rely on molecular interactions have come a long way; from initial reversible detection systems towards irreversible reaction indicator-based methods. More recently, the emergence of innovative molecular amplification methodologies has revolutionised sensing, allowing diagnostic assays to achieve ultra-low limits of detection. There have been a significant number of molecular amplification approaches developed over recent years to accommodate the wide variety of analytes that require sensitive detection. To celebrate this achievement, this comprehensive critical review has been compiled to give a broad overview of the many different approaches used to attain amplification in sensing with an aim to inspire the next generation of diagnostic assays looking to achieve the ultimate detection limit. This review has been created with the focus on how each conceptually unique molecular amplification methodology achieves amplification, not just its sensitivity, while highlighting any key processes. Excluded are any references that were not found to contain an obvious molecular amplifier or amplification component, or that did not use an appropriate signal readout that could be incorporated into a sensing application. Additionally, methodologies where amplification is achieved through advances in instrumentation are also excluded. Depending upon the type of approach employed, amplification strategies are divided into four categories: target, label, signal or receptor amplification. More recent, more complex protocols combine a number of approaches and are therefore categorised by which amplification component described within was considered as the biggest advancement. The advantages and disadvantages of each methodology are discussed along with any limits of detection, if stated in the original article. Any subsequent use of the methodology within sensing or any other application is also mentioned to draw attention to its practicality. The importance of

  13. Evaluation and comparative analysis of direct amplification of STRs using PowerPlex® 18D and Identifiler® Direct systems.

    Science.gov (United States)

    Myers, Blake A; King, Jonathan L; Budowle, Bruce

    2012-09-01

    Short tandem repeat (STR) analysis remains the primary forensic tool for DNA identification. Because of the success of forensic DNA typing and the use of database searches to develop investigative leads, there is an increased demand for populating forensic DNA databases. Reference samples tend to be of high quantity and quality and are somewhat standardized in format. Being more predictable in quality than unknown forensic casework samples, reference samples lend themselves to alternate methods of analysis such as direct amplification. Two commercially available direct amplification kits for processing reference samples were evaluated. The kits are PowerPlex(®) 18D (Promega Corp., Madison, Wisconsin) and Identifiler(®) Direct (Life Technologies, Carlsbad, CA). Both kits offer the core CODIS loci plus amelogenin, and the loci D2S1338, D19S433. The PP18D kit offers two additional loci, Penta E and Penta D. To determine the robustness and reliability of the PP18D and ID Direct amplification systems, buccal cell samples (deposited on FTA paper using the EasiCollect™ device (Florham Park, NJ)) from 400 anonymous donors were analyzed under conditions to achieve a high rate of successful typing. First-pass success rates were 96.25%, 96.25%, and 95% for PP18D with a 5s injection, ID Direct with a 10s injection, and ID Direct with a 5s injection, respectively. Profiles that could not be typed were not a result of the kits' performance but were a result of the inherent variation in the amount of DNA obtained with the collection device and buccal cells. Low signal profiles can be re-analyzed by either re-injecting for a longer time or by re-amplification with an additional PCR cycle. Overloaded profiles can be re-analyzed by re-injecting for a shorter time or by re-amplification with one less cycle. All called typing results, when interpretable, were consistent under the prescribed conditions, different injection times, and 26-28 PCR cycles for both chemistries. Peak

  14. Generation of synchronized signal and pump pulses for an optical parametric chirped pulse amplification based multi-terawatt Nd:glass laser system

    Indian Academy of Sciences (India)

    M Raghuramaiah; R K Patidar; R A Joshi; P A Naik; P D Gupta

    2010-11-01

    Synchronized signal (650 ps) and pump (1.3 ns) pulses were generated using 4-pass geometry in a grating pair based pulse stretcher unit. The pump pulse has been further amplified in a high gain regenerative amplifier. This amplified pulse was used as the pump in an optical parametric chirped pulse amplification based Nd:glass laser system. As the chirped signal pulse and the pump pulse originated from the same oscillator, the time jitter between the pump pulse and the signal pulse can be <50 ps.

  15. Amplification for the Adolescent.

    Science.gov (United States)

    Wilber, Laura Ann

    1978-01-01

    Explored are various means of amplification for aurally handicapped adolescents, including behind-the-ear hearing aids, "custom ear" (or in-the-ear) hearing aids, as well as aural rehabilitation. (BD)

  16. Amplification of weak signals via the non-adiabatic regime of stochastic resonance in a bistable dynamical system with time delay

    International Nuclear Information System (INIS)

    The non-adiabatic regime of stochastic resonance (SR) in a bistable system with time delay, an additive white noise and a periodic signal was investigated. The signal power amplification η was employed to characterize the SR of the system. The simulation results indicate that (i) in the case of intermediate frequency Ω of the periodic signal, the typical behavior of SR is lowered monotonically by increasing the delay time τ; in the case of large Ω, τ weakens the SR behavior and then enhances it, with a non-monotonic behavior as a function of time delay; (ii) time delay induces SR when A is above the threshold, whereas no such resonance exists in the absence of time delay; (iii) time delay induces a transition from bimodal to unimodal configuration of η; (iv) varying the particular form of time delay results in different phenomena.

  17. A broadband frequency-tripling scheme for an Nd:glass laser-based chirped-pulse amplification system: an approach for efficiently generating ultraviolet petawatt pulses

    International Nuclear Information System (INIS)

    We propose and numerically demonstrate a broadband frequency-tripling scheme for an Nd:glass laser-based chirped-pulse amplification system at 1053 nm. On the basis of the frequency mixing of a broadband chirped pulse with a narrowband laser pulse, the tripling scheme can support a bandwidth as large as 5 nm by alleviating the effects of the group-velocity mismatch involved, and it can be applied to generate ultraviolet petawatt (PW) pulses from a typical Nd:glass petawatt laser system. Both the energy of the ultraviolet pulse and the tripling efficiency (>80%) are boosted by an additional narrowband fundamental laser. The ultraviolet pulse generated can be compressed to a duration shorter than that of the initial Nd:glass PW pulse and its peak power can be increased to 2.5 times that of the Nd:glass PW pulse

  18. Early amplification options.

    Science.gov (United States)

    Gabbard, Sandra Abbott; Schryer, Jennifer

    2003-01-01

    Children with permanent hearing loss have been remediated with hearing amplification devices for decades. The influx of young infants identified with hearing loss through successful newborn hearing screening programs has established a need for amplification resources for infants within the first six months of life. For the approximately two of every 1000 infants born who are identified with bilateral hearing loss [Mehl and Thomson, 1998, Pediatrics 101, p. e4], the use of amplification is commonly the first step in treating the sequella of their loss. The use of hearing aids, combined with early intervention, has been shown to significantly improve the speech and language skills of young children with hearing loss [Yoshinaga-Itano, 2000, Seminars in Hearing 21, p. 309]. Speech and language delays have contributed to compromised academic performance of school aged children with hearing loss [Johnson et al., 1997, Educational Audiology Handbook, Singular Publishing, San Diego]. Most hard-of-hearing and deaf children use hearing aids and other assistive listening devices every day throughout their lifetime and the life expectancy of a hearing aid is only five to eight years. The current challenge for pediatric audiologists is selecting and evaluating the available amplification to provide the best options for children and their families. Amplification technology has seen an explosion in growth the past few years and the options continue to expand rapidly. This article examines currently available amplification technology and reviews the selection criteria that may be used for infants and young children. Issues such as style, type, amplification features, signal processing strategies, and verification and validation tools are also discussed. PMID:14648816

  19. Observation of strong amplification at 8.8 nm in the TCE scheme by a table-top pumping system

    International Nuclear Information System (INIS)

    We observed strong amplification of the transition of 4d 4p, J = 0 1 (the transition from (3d3/2, 4d3/2)0 to (3d3/2, 4p1/2)1) of the Ni-like lanthanum (La) ions at a wavelength of 8.8 nm pumped by a compact CPA Nd:Glass laser light at a wavelength of 1.053 μm with a pumping energy of 18 J. The experimental gain coefficient and the achieved gain-length product was 14.5 cm-1 and 7.7, respectively. In this experiment, the pumping laser pulse consisted of a pre-pulse with a duration of 200 ps and a 7ps-duration main pulse, separated by 250 ps. A hydrodynamics simulation coupled with a collisional-radiative model showed that the present experimental condition generated a pre-formed plasma with small volume and made it possible by the main pulse to heat the high density region effectively

  20. Quantum Feedback Amplification

    Science.gov (United States)

    Yamamoto, Naoki

    2016-04-01

    Quantum amplification is essential for various quantum technologies such as communication and weak-signal detection. However, its practical use is still limited due to inevitable device fragility that brings about distortion in the output signal or state. This paper presents a general theory that solves this critical issue. The key idea is simple and easy to implement: just a passive feedback of the amplifier's auxiliary mode, which is usually thrown away. In fact, this scheme makes the controlled amplifier significantly robust, and furthermore it realizes the minimum-noise amplification even under realistic imperfections. Hence, the presented theory enables the quantum amplification to be implemented at a practical level. Also, a nondegenerate parametric amplifier subjected to a special detuning is proposed to show that, additionally, it has a broadband nature.

  1. Hybrid mid-infrared optical parametric chirped-pulse amplification system with a broadband non-collinear quasi-phase-matched power amplifier

    CERN Document Server

    Mayer, Benedikt W; Gallmann, Lukas; Keller, Ursula

    2014-01-01

    We report a hybrid OPCPA system with the capability of generating broadband mid-infrared idler pulses from a non-collinear quasi-phase-matched power amplifier on the basis of periodically poled MgO:LiNbO3. It is seeded by the idler generated from a two-stage collinear pre-amplifier based on aperiodically poled MgO:LiNbO3. The amplification and pulse compression scheme we use does not require any angular dispersion to be introduced or compensated for on either the seed or the generated idler pulses. The mid-IR idler output has a bandwidth of 800 nm centered at 3.4 $\\mu$m. After compression, we obtain a pulse duration of 43.1 fs (FWHM; 41.4-fs transform limit) and a pulse energy of 17.2 $\\mu$J at a repetition rate of 50 kHz.

  2. Hybrid master oscillator power amplifier system providing 10 mJ, 32 W, and 50 MW pulses for optical parametric chirped-pulse amplification pumping

    International Nuclear Information System (INIS)

    We present a high-energy, high-average-power picosecond laser system based on a hybrid chain in a master oscillator power amplifier configuration. The chain is seeded by a Ti:sapphire oscillator, followed by a Yb doped fiber preamplifier, a Nd:YAG-based regenerate amplifier, and a Nd:YVO4-based single-pass amplifier. The final diode-pumped, solid-state amplifier is detailed and produces pulses with more than 10 mJ energy at 32 W average power with 207 ps duration, corresponding to 50 MW peak power. The picosecond pulse output is seeded and optically synchronized with the sub-5-fs oscillator for optical parametric chirped-pulse amplification pumping. (authors)

  3. Onshore seismic amplifications due to bathymetric features

    Science.gov (United States)

    Rodríguez-Castellanos, A.; Carbajal-Romero, M.; Flores-Guzmán, N.; Olivera-Villaseñor, E.; Kryvko, A.

    2016-08-01

    We perform numerical calculations for onshore seismic amplifications, taking into consideration the effect of bathymetric features on the propagation of seismic movements. To this end, the boundary element method is applied. Boundary elements are employed to irradiate waves and, consequently, force densities can be obtained for each boundary element. From this assumption, Huygens’ principle is applied, and since the diffracted waves are built at the boundary from which they are radiated, this idea is equivalent to Somigliana’s representation theorem. The application of boundary conditions leads to a linear system being obtained (Fredholm integral equations). Several numerical models are analyzed, with the first one being used to verify the proposed formulation, and the others being used to estimate onshore seismic amplifications due to the presence of bathymetric features. The results obtained show that compressional waves (P-waves) generate onshore seismic amplifications that can vary from 1.2 to 5.2 times the amplitude of the incident wave. On the other hand, the shear waves (S-waves) can cause seismic amplifications of up to 4.0 times the incident wave. Furthermore, an important result is that in most cases the highest seismic amplifications from an offshore earthquake are located on the shoreline and not offshore, despite the seafloor configuration. Moreover, the influence of the incident angle of seismic waves on the seismic amplifications is highlighted.

  4. Asymmetric parametric amplification in nonlinear left-handed transmission lines

    OpenAIRE

    Powell, David A.; Ilya V. Shadrivov; Yuri S. Kivshar

    2008-01-01

    We study parametric amplification in nonlinear left-handed transmission lines, which serve as model systems for nonlinear negative index metamaterials. We experimentally demonstrate amplification of a weak pump signal in three regimes: with the signal in the left-handed band, with the signal in the stop band, and with the signal at a defect frequency. In particular, we demonstrate the amplification of the incident wave by up to 15dB in the left-handed regime.

  5. Laser-ablated poly(methyl methacrylate) microdevices for sub-microliter DNA amplification suitable for micro-total analysis systems

    International Nuclear Information System (INIS)

    Biochemical techniques, such as the polymerase chain reaction (PCR), can take up to 3.5 h for completion using a commercial bench-top instrument, creating a bottleneck in sample preparation processes. PCR has been successfully adapted to microfluidic devices, reducing the time needed to as little as 7–10 min. Recently, a trend in the field is to use alternative substrates, such as poly(methyl methacyrlate) (PMMA), for the fabrication of microfluidic devices. PMMA has several advantages over more expensive substrates including rigidity without fragility, disposability, and it is easy to fabricate, using techniques such as hot embossing or CO2 laser ablation. Here, we report the fabrication of PMMA microdevices to explore their effectiveness for PCR amplification. Several types of PMMA microdevices were fabricated using a CO2 laser ablation system, with two or three PMMA layers of different thicknesses. Bonding of the microdevices was significantly improved through the use of a grid system etched into the device, allowing for trapped air to escape, eliminating leakage. Using infrared thermal cycling, the ramping rates were determined to be dependent on the thickness of the PMMA used in fabrication, allowing for customization of cycling conditions. Further reduction of the thermal mass by isolation of the chambers provided a significant increase in the heating and cooling rates (up to 6.19 (±0.32 °C s−1) and −7.99 (±0.06 °C s−1), respectively). Bubble formation, a chronic problem in microfluidic systems in general and problematic during the heating phase of PCR, was minimized through the use of a biocompatible adhesive/manifold combination to seal the reservoirs. Finally, successful PCR amplification was demonstrated with both a fragment from the β-globin gene and 15 tetra-nucleotide repeat regions with a sex-typing marker in a conventional STR kit with the latter facilitated by the dynamic coating of the fluidic architecture with poly(ethylene glycol

  6. Decision-Making Amplification under Uncertainty: An Exploratory Study of Behavioral Similarity and Intelligent Decision Support Systems

    Science.gov (United States)

    Campbell, Merle Wayne

    2013-01-01

    Intelligent decision systems have the potential to support and greatly amplify human decision-making across a number of industries and domains. However, despite the rapid improvement in the underlying capabilities of these "intelligent" systems, increasing their acceptance as decision aids in industry has remained a formidable challenge.…

  7. Study on high gain broadband optical parametric chirped pulse amplification

    International Nuclear Information System (INIS)

    Optical parametric chirped pulse amplification has apparent advantages over the current schemes for high energy ultrashort pulse amplification. High gain in a single pass amplification, small B-integral, low heat deposition, high contrast ratio and, especially the extremely broad gain bandwidth with large-size crystals available bring people new hope for over multi-PW level at which the existing Nd:glass systems suffered difficulties. In this paper we present simulation and experimental studies for a high gain optical parametric chirped pulse amplification system which may be used as a preamplifier to replace the current complicated regenerative system or multi-pass Ti:sapphire amplifiers. Investigations on the amplification bandwidth and gain with BBO are performed. Analysis and discussions are also given. (author)

  8. Bacteriophage P1 cloning system for the isolation, amplification, and recovery of DNA fragments as large as 100 kilobase pairs.

    OpenAIRE

    Sternberg, N

    1990-01-01

    The development of a bacteriophage P1 cloning system capable of accepting DNA fragments as large as 100 kilobase pairs (kbp) is described. The vectors used in this system contain a P1 packaging site (pac) to package vector and cloned DNA into phage particles, two P1 loxP recombination sites to cyclize the packaged DNA once it has been injected into a strain of Escherichia coli containing the P1 Cre recombinase, a kanr gene to select bacterial clones containing the cyclized DNA, a P1 plasmid r...

  9. Robert Feulgen Prize Lecture 1999. Detection and amplification systems for sensitive, multiple-target DNA and RNA in situ hybridization: looking inside cells with a spectrum of colors.

    Science.gov (United States)

    Speel, E J

    1999-08-01

    In situ hybridization (ISH) is a powerful technique for localizing specific nucleic acid sequences (DNA, RNA) in microscopic preparations of tissues, cells, chromosomes, and linear DNA fibers. To date, a wide variety of research and diagnostic applications of ISH have been described, making the technique an integral part of studies concerning gene mapping, gene expression, RNA processing and transport, the three-dimensional organization of the nucleus, tumor genetics, microbial infections, and prenatal diagnosis. In this review, I first describe the ISH procedure in short and then focus on the currently available non-radioactive probe-labeling and cytochemical detection methodologies that are utilized to visualize one or multiple different nucleic acid targets in situ with different colors. Special emphasis is placed on the procedures applying fluorescence and brightfield microscopy, the simultaneous detection of nucleic acids and proteins by combined ISH and immunocytochemistry, and, in addition, on the recent progress that has been made with the introduction of signal amplification procedures to increase the detection sensitivity of ISH. Finally, a comparison of fluorescence, enzyme cytochemical, and colloidal gold silver probe detection systems will be presented, and possible future directions of in situ nucleic acid detection will be discussed. PMID:10460463

  10. Development of a new amplification-refractory mutation system for detection of a single nucleotide polymorphism linked to drug resistance in Ancylostoma caninum.

    Science.gov (United States)

    Furtado, L F; Rabelo, É M

    2015-01-01

    Single nucleotide polymorphisms at codons 167, 198, and 200 in the β-tubulin isotype 1 gene have been associated with benz-imidazole resistance. Until now, the only mutation observed in Ancy-lostoma caninum was at codon 200 of this gene. However, the standard-ized methodologies used to detect mutations in this species are faulty. The objective of this study was to standardize a molecular technique based on amplification-refractory mutation system-polymerase chain reaction (ARMS-PCR) for detecting the mutation at codon 200 in the A. caninum β-tubulin isotype 1 gene. Controls were synthesized both for the absence of the mutation, using conventional PCR, and for the presence of the mutation, using the Megaprimer-PCR technique. After standardization of the ARMS-PCR using the controls, the technique was validated through an analysis of 75 A. caninum DNA samples, fol-lowed by sequencing. The results revealed that the developed technique has high sensitivity, specificity, and reproducibility, which allow its ap-plication in the field. PMID:26125702

  11. The study of amplification circuit characteristics of photocurrent signal of high-energy industrial CT detection system

    International Nuclear Information System (INIS)

    According to characteristics of the Photocurrent signal from detection system of high energy industrial CT, sets up the integral amplifier circuit test platform based ACF2101, through the study of this amplifier circuit, a integral capacitor using air as dielectric is proposed in order to get high-gain. After experimental tests, results are good. (authors)

  12. Development of a front-end system for chirped pulse amplification high-power Nd:glass laser

    International Nuclear Information System (INIS)

    We have developed a front-end system to generate a chirped pulse at a wavelength of 1053 nm for a 100 TW glass laser system. The front-end system consists of a passively mode-locked diode-pumped Nd:glass laser, a pulse stretcher and a Ti:Al2O3 regenerative amplifier. The passive mode-locked diode-pumped Nd:fluorophosphate glass laser produced pulses as short as 150 fs at an average power of 100 mW at 1053 nm-1061 nm at a repetition frequency of 99.98 MHz. The TEM00 Ti:Al2O3 regenerative amplifier exhibited a net gain of over 106 at 1053 nm. At long time operation, the output pulse energy is typically 4 mJ, with a power fluctuation of less than ±5% with temperature and humidity control in cavity. No significant gain narrowing was observed in the cavity, resulting in a 1.6 ns chirped pulse that was synchronized with the RF signal of GEKKO XII laser system within a few ps by controlling the oscillator cavity length with a PZT actuator. (author)

  13. Development of a front-end system for chirped pulse amplification high-power Nd:glass laser

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Hidetsugu; Kodama, Ryosuke; Fujita, Hisanori; Kato, Yoshiaki; Mima, Kunioki [Osaka Univ., Suita (Japan). Inst. of Laser Engineering

    1999-04-01

    We have developed a front-end system to generate a chirped pulse at a wavelength of 1053 nm for a 100 TW glass laser system. The front-end system consists of a passively mode-locked diode-pumped Nd:glass laser, a pulse stretcher and a Ti:Al{sub 2}O{sub 3} regenerative amplifier. The passive mode-locked diode-pumped Nd:fluorophosphate glass laser produced pulses as short as 150 fs at an average power of 100 mW at 1053 nm-1061 nm at a repetition frequency of 99.98 MHz. The TEM{sub 00} Ti:Al{sub 2}O{sub 3} regenerative amplifier exhibited a net gain of over 10{sup 6} at 1053 nm. At long time operation, the output pulse energy is typically 4 mJ, with a power fluctuation of less than {+-}5% with temperature and humidity control in cavity. No significant gain narrowing was observed in the cavity, resulting in a 1.6 ns chirped pulse that was synchronized with the RF signal of GEKKO XII laser system within a few ps by controlling the oscillator cavity length with a PZT actuator. (author)

  14. 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.

  15. An efficient scheme of intermodal distributed Raman amplification using tailored doping profiles in spatial-division multiplexed coherent fiber-optic transmission systems

    Science.gov (United States)

    Weng, Yi; Pan, Zhongqi

    2016-02-01

    For next-generation long-haul communication systems, space-division multiplexing (SDM) is suggested as a promising technique for providing orders of magnitude increase in transmission capacity. Optical amplifiers for multimode fibers are the crucial components to realize SDM systems, while few-mode fiber (FMF) has the advantage of strong intensity overlap between different modes that allows sharing of single pump across multiple signal modes. FMF-based erbiumdoped fiber amplifiers (FM-EDFA) have been intensively studied. Since SDM is exceedingly reliant on DSP technique and thus has more stringent requirement on noise performance, FMF-based distributed Raman amplifier (FM-DRA) benefits from relatively lower noise figure (NF) compared with FM-EDFA. Yet much less work has been done in this area. To implement FM-DRAs in SDM systems, their performance should be carefully optimized. In this paper, modal gain and saturation characteristics of intermodal Raman amplification in FMFs have been fully investigated by tailoring the refractive-index profiles and doping levels of different FMF designs. For 50-km-long FMF with -3 dBm signal at 1550 nm and a 20-25 dBm pump at 1455 nm, the optimized modal-equalization of Raman gain and NF are provided depending on various fiber cross-section and pumping configuration with respect to modes/wavelengths. The pumpsignal modal-overlap integrals for each of the four mode-groups with normalized frequency V=5 have been exploited, resulting in a mean gain of 10 dB within 1 dB of equalization for 16 gain coefficients. Our results show it should be possible to design FMF with larger intermodal nonlinearity and better dispersion characteristics to achieve desirable Raman gain.

  16. Cost analysis of nucleic acid amplification for diagnosing pulmonary tuberculosis, within the context of the Brazilian Unified Health Care System

    Directory of Open Access Journals (Sweden)

    Márcia Pinto

    2015-12-01

    Full Text Available ABSTRACT We estimated the costs of a molecular test for Mycobacterium tuberculosis and resistance to rifampin (Xpert MTB/RIF and of smear microscopy, within the Brazilian Sistema Único de Saúde (SUS, Unified Health Care System. In SUS laboratories in the cities of Rio de Janeiro and Manaus, we performed activity-based costing and micro-costing. The mean unit costs for Xpert MTB/RIF and smear microscopy were R$35.57 and R$14.16, respectively. The major cost drivers for Xpert MTB/RIF and smear microscopy were consumables/reagents and staff, respectively. These results might facilitate future cost-effectiveness studies and inform the decision-making process regarding the expansion of Xpert MTB/RIF use in Brazil.

  17. Development of a reverse transcription loop-mediated isothermal amplification assay for the detection of vesicular stomatitis New Jersey virus: Use of rapid molecular assays to differentiate between vesicular disease viruses.

    Science.gov (United States)

    Fowler, Veronica L; Howson, Emma L A; Madi, Mikidache; Mioulet, Valérie; Caiusi, Chiara; Pauszek, Steven J; Rodriguez, Luis L; King, Donald P

    2016-08-01

    Vesicular stomatitis (VS) is endemic in Central America and northern regions of South America, where sporadic outbreaks in cattle and pigs can cause clinical signs that are similar to foot-and-mouth disease (FMD). There is therefore a pressing need for rapid, sensitive and specific differential diagnostic assays that are suitable for decision making in the field. RT-LAMP assays have been developed for vesicular diseases such as FMD and swine vesicular disease (SVD) but there is currently no RT-LAMP assay that can detect VS virus (VSV), nor are there any multiplex RT-LAMP assays which permit rapid discrimination between these 'look-a-like' diseases in situ. This study describes the development of a novel RT-LAMP assay for the detection of VSV focusing on the New Jersey (VSNJ) serotype, which has caused most of the recent VS cases in the Americas. This RT-LAMP assay was combined in a multiplex format combining molecular lateral-flow devices for the discrimination between FMD and VS. This assay was able to detect representative VSNJV's and the limit of detection of the singleplex and multiplex VSNJV RT-LAMP assays were equivalent to laboratory based real-time RT-PCR assays. A similar multiplex RT-LAMP assay was developed to discriminate between FMDV and SVDV, showing that FMDV, SVDV and VSNJV could be reliably detected within epithelial suspensions without the need for prior RNA extraction, providing an approach that could be used as the basis for a rapid and low cost assay for differentiation of FMD from other vesicular diseases in the field. PMID:27118518

  18. Generation of 287 W, 5.5 ps pulses at 78 MHz repetition rate from a cryogenically cooled Yb:YAG amplifier seeded by a fiber chirped-pulse amplification system.

    Science.gov (United States)

    Hong, Kyung-Han; Siddiqui, Aleem; Moses, Jeffrey; Gopinath, Juliet; Hybl, John; Ilday, F Omer; Fan, Tso Yee; Kärtner, Franz X

    2008-11-01

    We generate linearly polarized, 287 W average-power, 5.5 ps pulses using a cryogenically cooled Yb:YAG amplifier at a repetition rate of 78 MHz. An optical-to-optical efficiency of 41% is obtained at 700 W pump power. A 6 W, 0.4 nm bandwidth picosecond seed source at 1029 nm wavelength is constructed using a chirped-pulse fiber amplification chain based on chirped volume Bragg gratings. The combination of a fiber amplifier system and a cryogenically cooled Yb:YAG amplifier results in good spatial beam quality at large average power. Low nonlinear phase accumulation as small as 5.1 x 10(-3) rad in the bulk Yb:YAG amplifier supports power scalability to a > 10 kW level without being affected by self-phase modulation. This amplification system is well suited for pumping high-power high-repetition-rate optical parametric chirped-pulse amplifiers. PMID:18978891

  19. 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.

  20. Use of amplification refractory mutation system PCR assay as a simple and effective tool to detect HIV-1 drug resistance mutations.

    Science.gov (United States)

    Nanfack, Aubin J; Agyingi, Lucy; Noubiap, Jean Jacques N; Ngai, Johnson N; Colizzi, Vittorio; Nyambi, Phillipe N

    2015-05-01

    Access to genotyping assays to determine successful antiretroviral treatment (ART) is limited in resource-constrained settings by high cost, suggesting the need for a cost-effective and simplified method to identify HIV-1 drug resistance (HIVDR) mutations. In this study, an amplification refractory mutation system (ARMS)-PCR assay was developed and used to investigate the most frequent HIVDR mutations affecting first-line ART in settings where WHO ART guidelines are applied. Seventy-five HIV-positive (HIV(+)) samples from Cameroon were used to assess the performance of this assay. Sequencing of HIV-1 reverse transcriptase was simultaneously performed for comparison, and discordant samples were tested with a Trugene HIV-1 genotyping kit. The ARMS-PCR assay was able to detect M184V, T215Y/F, K103N, and Y181C mutations with sensitivities of 96.8%, 85.7%, 91.3%, and 70%, respectively, and specificities of 90.6%, 95%, 100%, 96.9%, respectively, compared with data on sequencing. The results indicated the highest positive predictive value for K103N (100%) and the highest negative predictive value for M184V (97.5%). ARMS-PCR's limits of detection for mutations M184V, T215Y/F, K103N, and Y181C were HIV-1 clades (CRF02_AG and non-CRF02_AG). In addition, this approach was more cost-effective than other genotyping assays. The high throughput, the cost-effectiveness, and the simplicity of the ARMS-PCR assay make it a suitable tool to monitor HIVDR patterns in resource-constrained settings with broad HIV-1 genetic diversity. PMID:25788547

  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. Gene amplification during myogenic differentiation

    Science.gov (United States)

    Fischer, Ulrike; Ludwig, Nicole; Raslan, Abdulrahman; Meier, Carola; Meese, Eckart

    2016-01-01

    Gene amplifications are mostly an attribute of tumor cells and drug resistant cells. Recently, we provided evidence for gene amplifications during differentiation of human and mouse neural progenitor cells. Here, we report gene amplifications in differentiating mouse myoblasts (C2C12 cells) covering a period of 7 days including pre-fusion, fusion and post-fusion stages. After differentiation induction we found an increase in copy numbers of CDK4 gene at day 3, of NUP133 at days 4 and 7, and of MYO18B at day 4. The amplification process was accompanied by gamma-H2AX foci that are indicative of double stand breaks. Amplifications during the differentiating process were also found in primary human myoblasts with the gene CDK4 and NUP133 amplified both in human and mouse myoblasts. Amplifications of NUP133 and CDK4 were also identified in vivo on mouse transversal cryosections at stage E11.5. In the course of myoblast differentiation, we found amplifications in cytoplasm indicative of removal of amplified sequences from the nucleus. The data provide further evidence that amplification is a fundamental mechanism contributing to the differentiation process in mammalians. PMID:26760505

  3. 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...

  4. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and amplification refractory mutation system (ARMS) analyses of medicinally used Rheum species and their application for identification of Rhei Rhizoma.

    Science.gov (United States)

    Yang, Dong-Ye; Fushimi, Hirotoshi; Cai, Shao-Qing; Komatsu, Katsuko

    2004-05-01

    Previously, we have determined marker nucleotides on the chloroplast matK gene to identify Rheum palmatum, R. tanguticum and R. officinale used as Rhei Rhizoma officially. In the present study, we further developed a convenient and efficient identification method on the basis of marker nucleotides with Amplification Refractory Mutation System analysis. On the basis of the nucleotide substitutions at positions 367 and 937 among the three species on the matK gene, at each position two kinds of reverse primers with complementary 3'-terminal nucleotides were designed. Upon PCR amplification using three sets of primers and template DNA from each species, one or two fragments (202 bp or/and 770 bp) were detected. As the resultant three fragment profiles were species-specific, the procedure enabled us to classify the botanic origins of 22 drug samples of Rhei Rhizoma. PMID:15133241

  5. Evidence of high-elevation amplification versus Arctic amplification

    OpenAIRE

    Qixiang Wang; Xiaohui Fan; Mengben Wang

    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 b...

  6. Complementary weak-value amplification with concatenated postselections

    CERN Document Server

    Viza, Gerardo I; Liu, Wei-Tao; Howell, John C

    2016-01-01

    We measure a transverse momentum kick in a Sagnac interferometer using weak-value amplification with two postselections. The first postselection is controlled by a polarization dependent phase mismatch between both paths of a Sagnac interferometer and the second postselection is controlled by a polarizer at the exit port. By monitoring the darkport of the interferometer, we study the complementary amplification of the concatenated postselections, where the polarization extinction ratio is greater than the contrast of the spatial interference. In this case, we find an improvement in the amplification of the signal of interest by introducing a second postselection to the system.

  7. 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)

  8. A mechanism of gene amplification driven by small DNA fragments.

    Directory of Open Access Journals (Sweden)

    Kuntal Mukherjee

    Full Text Available DNA amplification is a molecular process that increases the copy number of a chromosomal tract and often causes elevated expression of the amplified gene(s. Although gene amplification is frequently observed in cancer and other degenerative disorders, the molecular mechanisms involved in the process of DNA copy number increase remain largely unknown. We hypothesized that small DNA fragments could be the trigger of DNA amplification events. Following our findings that small fragments of DNA in the form of DNA oligonucleotides can be highly recombinogenic, we have developed a system in the yeast Saccharomyces cerevisiae to capture events of chromosomal DNA amplification initiated by small DNA fragments. Here we demonstrate that small DNAs can amplify a chromosomal region, generating either tandem duplications or acentric extrachromosomal DNA circles. Small fragment-driven DNA amplification (SFDA occurs with a frequency that increases with the length of homology between the small DNAs and the target chromosomal regions. SFDA events are triggered even by small single-stranded molecules with as little as 20-nt homology with the genomic target. A double-strand break (DSB external to the chromosomal amplicon region stimulates the amplification event up to a factor of 20 and favors formation of extrachromosomal circles. SFDA is dependent on Rad52 and Rad59, partially dependent on Rad1, Rad10, and Pol32, and independent of Rad51, suggesting a single-strand annealing mechanism. Our results reveal a novel molecular model for gene amplification, in which small DNA fragments drive DNA amplification and define the boundaries of the amplicon region. As DNA fragments are frequently found both inside cells and in the extracellular environment, such as the serum of patients with cancer or other degenerative disorders, we propose that SFDA may be a common mechanism for DNA amplification in cancer cells, as well as a more general cause of DNA copy number variation

  9. A mechanism of gene amplification driven by small DNA fragments.

    Science.gov (United States)

    Mukherjee, Kuntal; Storici, Francesca

    2012-01-01

    DNA amplification is a molecular process that increases the copy number of a chromosomal tract and often causes elevated expression of the amplified gene(s). Although gene amplification is frequently observed in cancer and other degenerative disorders, the molecular mechanisms involved in the process of DNA copy number increase remain largely unknown. We hypothesized that small DNA fragments could be the trigger of DNA amplification events. Following our findings that small fragments of DNA in the form of DNA oligonucleotides can be highly recombinogenic, we have developed a system in the yeast Saccharomyces cerevisiae to capture events of chromosomal DNA amplification initiated by small DNA fragments. Here we demonstrate that small DNAs can amplify a chromosomal region, generating either tandem duplications or acentric extrachromosomal DNA circles. Small fragment-driven DNA amplification (SFDA) occurs with a frequency that increases with the length of homology between the small DNAs and the target chromosomal regions. SFDA events are triggered even by small single-stranded molecules with as little as 20-nt homology with the genomic target. A double-strand break (DSB) external to the chromosomal amplicon region stimulates the amplification event up to a factor of 20 and favors formation of extrachromosomal circles. SFDA is dependent on Rad52 and Rad59, partially dependent on Rad1, Rad10, and Pol32, and independent of Rad51, suggesting a single-strand annealing mechanism. Our results reveal a novel molecular model for gene amplification, in which small DNA fragments drive DNA amplification and define the boundaries of the amplicon region. As DNA fragments are frequently found both inside cells and in the extracellular environment, such as the serum of patients with cancer or other degenerative disorders, we propose that SFDA may be a common mechanism for DNA amplification in cancer cells, as well as a more general cause of DNA copy number variation in nature. PMID

  10. Aerosol Lidar for the Relative Backscatter Amplification Measurements

    Science.gov (United States)

    Razenkov, Igor A.; Banakh, Victor A.; Nadeev, Alexander I.

    2016-06-01

    Backscatter amplification presents only in a turbulent atmosphere, when the laser beam is propagates twice through the same inhomogeneities. We proposed technical solution to detect backscatter amplification. An aerosol micro pulse lidar with a beam expansion via receiving telescope was built to study this effect. Our system allows simultaneous detection of two returns from the same scattering volume: exactly on the axis of the laser beam and off the axis.

  11. Ultrabroadband noncollinear optical parametric amplification with LBO crystal.

    Science.gov (United States)

    Zhao, Baozhen; Jiang, Yongliang; Sueda, Keiich; Miyanaga, Noriaki; Kobayashi, Takayoshi

    2008-11-10

    Ultrabroadband visible noncollinear optical parametric amplification (NOPA) was achieved in an LBO crystal, with a continuum seed pulse generated from a sapphire plate. The spectral bandwidth of the amplified visible pulse was about 200 nm, which can support sub-5 fs pulse amplification. An amplified output of 0.21 microJ with an average gain of about 210 was achieved. This provides, to the best of our knowledge, the first-time demonstration of such broadband amplification with a biaxial nonlinear optical crystal. Both the simulation and experimental results indicate that the LBO has a great potential as nonlinear medium in power amplifier for TW to PW noncollinear optical parametric chirped pulse amplification (NOPCPA) systems. PMID:19581976

  12. Colossal magnetoelectric effect induced by parametric amplification

    Science.gov (United States)

    Wang, Yi; Onuta, Tiberiu-Dan; Long, Christian J.; Geng, Yunlong; Takeuchi, Ichiro

    2015-11-01

    We describe the use of parametric amplification to substantially increase the magnetoelectric (ME) coefficient of multiferroic cantilevers. Parametric amplification has been widely used in sensors and actuators based on optical, electronic, and mechanical resonators to increase transducer gain. In our system, a microfabricated mechanical cantilever with a magnetostrictive layer is driven at its fundamental resonance frequency by an AC magnetic field. The resulting actuation of the cantilever at the resonance frequency is detected by measuring the voltage across a piezoelectric layer in the same cantilever. Concurrently, the spring constant of the cantilever is modulated at twice the resonance frequency by applying an AC voltage across the piezoelectric layer. The spring constant modulation results in parametric amplification of the motion of the cantilever, yielding a gain in the ME coefficient. Using this method, the ME coefficient was amplified from 33 V/(cm Oe) to 2.0 MV/(cm Oe), an increase of over 4 orders of magnitude. This boost in the ME coefficient directly resulted in an enhancement of the magnetic field sensitivity of the device from 6.0 nT /√{Hz } to 1.0 nT /√{Hz } . The enhancement in the ME coefficient and magnetic field sensitivity demonstrated here may be beneficial for a variety actuators and sensors based on resonant multiferroic devices.

  13. Adaptive base-isolation of civil structures using variable amplification

    Institute of Scientific and Technical Information of China (English)

    Kenneth K. Walsh; Makola M. Abdullah

    2006-01-01

    Semi-active dampers are used in base-isolation to reduce the seismic response of civil engineering structures.In the present study, a new semi-active damping system using variable amplification will be investigated for adaptive baseisolation. It uses a novel variable amplification device (VAD) connected in series with a passive damper. The VAD is capable of producing multiple amplification factors, each corresponding to a different amplification state. Forces from the damper are amplified to the structure according to the current amplification state, which is selected via a semi-active control algorithm specifically tailored to the system's unique damping characteristics. To demonstrate the effectiveness of the VAD-damper system for adaptive base-isolation, numerical simulations are conducted for three and seven-story base-isolated buildings subject to both far and near-field ground motions. The results indicate that the system can achieve significant reductions in response compared to the base-isolated buildings with no damper. The proposed system is also found to perform well compared to a typical semi-active damper.

  14. 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

  15. 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.

  16. Broadening and Amplification of an Infrared Femtosecond Pulse for Optical Parametric Chirped-Pulse Amplification

    Institute of Scientific and Technical Information of China (English)

    WANG He-Lin; YANG Ai-Jun; LENG Yu-Xin

    2011-01-01

    A high-average-power diode-pumped narrowband regenerative chirped pulse amplifier is developed using the thin-rod Nd:YAG laser architecture for optical parametric chirped-pulse amplification (OPCPA).The effect of the etalons on the amplified pulse in the regenerative cavity is studied experimentally and theoretically.By inserting glass etalons of thickness 1 mm and 5 mm into the regenerative cavity,the pre-stretching pulse from an (O)ffner stretcher is further broadened to above 200ps,which matches the amplification windows of the signal pulses in OPCPA and is suitable for use as a pump source in the OPCPA system.The bandwidth of the amplified pulse is 1.5 nm,and an output energy of 2mJ is achieved at a repetition rate of 10 Hz.Optical parametric chirped pulse amplification (OPCPA)[1-4] has attracted a great deal of attention as the most promising technique for generating ultrashort ultrahigh-peak-power laser pulses because of its very broad gain bandwidth,negligible thermal load on the nonlinear crystal,and extremely high singlepass gain as compared to amplifiers based on laser gain media.For efficient amplification and high fidelity of dispersion compensation in OPCPA,a femtosecond seed pulse is first stretched to several tens of picoseconds with a bulk grating stretcher or a fiber stretcher.%A high-average-power diode-pumped narrowband regenerative chirped pulse amplifier is developed using the thin-rod Nd:YAG laser architecture for optical parametric chirped-pulse amplification (OPCPA). The effect of the etalons on the amplified pulse in the regenerative cavity is studied experimentally and theoretically. By inserting glass etalons of thickness 1 mm and 5 mm into the regenerative cavity, the pre-stretching pulse from an (O)finer stretcher is further broadened to above 200 ps, which matches the amplification windows of the signal pulses in OPCPA and is suitable for use as a pump source in the OPCPA system. The bandwidth of the amplified pulse is 1.5 nm, and an

  17. Comprehensive human genome amplification using multiple displacement amplification

    OpenAIRE

    Dean, Frank B.; Hosono, Seiyu; Fang, Linhua; Wu, Xiaohong; Faruqi, A. Fawad; Bray-Ward, Patricia; Zhenyu SUN; Zong, Qiuling; Du, Yuefen; Du, Jing; Driscoll, Mark; Song, Wanmin; Kingsmore, Stephen F.; Egholm, Michael; Lasken, Roger S.

    2002-01-01

    Fundamental to most genetic analysis is availability of genomic DNA of adequate quality and quantity. Because DNA yield from human samples is frequently limiting, much effort has been invested in developing methods for whole genome amplification (WGA) by random or degenerate oligonucleotide-primed PCR. However, existing WGA methods like degenerate oligonucleotide-primed PCR suffer from incomplete coverage and inadequate average DNA size. We describe a method, termed multi...

  18. Influence of environmental noise on the weak value amplification

    Science.gov (United States)

    Zhu, Xuannmin; Zhang, Yu-Xiang

    2016-08-01

    Quantum systems are always disturbed by environmental noise. We have investigated the influence of the environmental noise on the amplification in weak measurements. Three typical quantum noise processes are discussed in this article. The maximum expectation values of the observables of the measuring device decrease sharply with the strength of the depolarizing and phase damping channels, while the amplification effect of weak measurement is immune to the amplitude damping noise. To obtain significantly amplified signals, we must ensure that the preselection quantum systems are kept away from the depolarizing and phase damping processes.

  19. Influence of environmental noise on the weak value amplification

    Science.gov (United States)

    Zhu, Xuannmin; Zhang, Yu-Xiang

    2016-05-01

    Quantum systems are always disturbed by environmental noise. We have investigated the influence of the environmental noise on the amplification in weak measurements. Three typical quantum noise processes are discussed in this article. The maximum expectation values of the observables of the measuring device decrease sharply with the strength of the depolarizing and phase damping channels, while the amplification effect of weak measurement is immune to the amplitude damping noise. To obtain significantly amplified signals, we must ensure that the preselection quantum systems are kept away from the depolarizing and phase damping processes.

  20. Optical Parametric Amplification for High Peak and Average Power

    Energy Technology Data Exchange (ETDEWEB)

    Jovanovic, I

    2001-11-26

    Optical parametric amplification is an established broadband amplification technology based on a second-order nonlinear process of difference-frequency generation (DFG). When used in chirped pulse amplification (CPA), the technology has been termed optical parametric chirped pulse amplification (OPCPA). OPCPA holds a potential for producing unprecedented levels of peak and average power in optical pulses through its scalable ultrashort pulse amplification capability and the absence of quantum defect, respectively. The theory of three-wave parametric interactions is presented, followed by a description of the numerical model developed for nanosecond pulses. Spectral, temperature and angular characteristics of OPCPA are calculated, with an estimate of pulse contrast. An OPCPA system centered at 1054 nm, based on a commercial tabletop Q-switched pump laser, was developed as the front end for a large Nd-glass petawatt-class short-pulse laser. The system does not utilize electro-optic modulators or multi-pass amplification. The obtained overall 6% efficiency is the highest to date in OPCPA that uses a tabletop commercial pump laser. The first compression of pulses amplified in highly nondegenerate OPCPA is reported, with the obtained pulse width of 60 fs. This represents the shortest pulse to date produced in OPCPA. Optical parametric amplification in {beta}-barium borate was combined with laser amplification in Ti:sapphire to produce the first hybrid CPA system, with an overall conversion efficiency of 15%. Hybrid CPA combines the benefits of high gain in OPCPA with high conversion efficiency in Ti:sapphire to allow significant simplification of future tabletop multi-terawatt sources. Preliminary modeling of average power limits in OPCPA and pump laser design are presented, and an approach based on cascaded DFG is proposed to increase the average power beyond the single-crystal limit. Angular and beam quality effects in optical parametric amplification are modeled

  1. Detection of prostate specific antigen in serum at the femto-gram per milliliter level using the intrinsic amplification of a field-effect enzymatic immuno-sensing system

    International Nuclear Information System (INIS)

    Ultrasensitive detection of prostate specific antigen (PSA) has been achieved by applying the field-effect enzymatic detection (FEED) technique to the sandwich immuno-sensing technique. The voltage-controlled intrinsic amplification provided by FEED enabled the detection of PSA contained in serum on the femto-gram/mL level. Two electrochemical approaches used to obtain the amperometric detection signal resulted in similar detection limits and sensitivities. The lowest PSA detection limit achieved was 27 fg mL−1. The high selectivity of the detection system was reflected in the fact that PSA detection was successful on the fg mL−1 level, where biological substances other than PSA had a 1-million-fold higher concentration. Electron transfer through the immunological sandwich nanostructure has been observed in the detection of biomarkers. However, our results showed that electron transfer through the nanostructure could be controlled using an external voltage, leading to an ultralow detection limit for PSA

  2. A study on single lane-change manoeuvres for determining rearward amplification of multi-trailer articulated heavy vehicles with active trailer steering systems

    Science.gov (United States)

    Wang, Qiushi; He, Yuping

    2016-01-01

    The Society of Automotive Engineers issued a test procedure, SAE-J2179, to determine the rearward amplification (RA) of multi-trailer articulated heavy vehicles (MTAHVs). Built upon the procedure, the International Organization for Standardization released the test manoeuvres, ISO-14791, for evaluating directional performance of MTAHVs. For the RA measures, ISO-14791 recommends two single lane-change manoeuvres: (1) an open-loop procedure with a single sine-wave steering input; and (2) a closed-loop manoeuvre with a single sine-wave lateral acceleration input. For an articulated vehicle with active trailer steering (ATS), the RA measure in lateral acceleration under the open-loop manoeuvre was not in good agreement with that under the closed-loop manoeuvre. This observation motivates the research on the applicability of the two manoeuvres for the RA measures of MTAHVs with ATS. It is reported that transient response under the open-loop manoeuvre often leads to asymmetric curve of tractor lateral acceleration [Winkler CB, Fancher PS, Bareket Z, Bogard S, Johnson G, Karamihas S, Mink C. Heavy vehicle size and weight - test procedures for minimum safety performance standards. Final technical report, NHTSA, US DOT, contract DTNH22-87-D-17174, University of Michigan Transportation Research Institute, Report No. UMTRI-92-13; 1992]. To explore the effect of the transient response, a multiple cycle sine-wave steering input (MCSSI) manoeuvre is proposed. Simulation demonstrates that the steady-state RA measures of an MTAHV with and without ATS under the MCSSI manoeuvre are in excellent agreement with those under the closed-loop manoeuvre. It is indicated that between the two manoeuvres by ISO-14791, the closed-loop manoeuvre is more applicable for determining the RA measures of MTAHVs with ATS.

  3. Gas amplification properties of GEM foils

    International Nuclear Information System (INIS)

    In the framework of the detector concept International Linear Detector for the future accelerator project International Linear Collider, in which electrons and positrons at c. m. energies of 500 GeV are brought to collision, a time projection chamber shall be applied as central track detector. By the application of such a chamber as track detector a three-dimensional reconstruction of the track points is possible. If a particle passes the gas volume within the chamber it ionizises single gas atoms and the arising electrons move after the amplification in the GEM arrangement to the anode, so that a two-dimensional projection of the particle track is possible. The third dimension is calculated from the drift time of the electrons. The advances of this readout system consist therein that a better position resolution than by a multiwire proportional chamber is reached and the back-drifting ions can be strongly suppressed. Aim of this thesis are studies for a GEM module, which shall be used in a large TPC prototype. Concerning different requirements it is valid to compare different GEMs in order to can meet an optimal choice. In a small prototype present at DESY measurements for the acquisition of GEM-describing parameters were performed. The taking into operation of the test TPC was part of this thesis. Tracks were generated by a radioactive source, by means of which the gas amplification was determined. With the measurement arrangement gas-amplifier foils of different kind were compared in view of their amplification properties and their energy resolution power and systematically studied. Five different GEM performances were studied in the test TPC. These foils differ in their geometrical classification parameters, the fabrication process, or the materials. The GEMs produced at CERN possess in comparison with GEMs of the Japanese firm SciEnergy and a GEM of the US-American firm Tech-Etch the best amplification and resolution properties. Furthermore a new GEM framing

  4. Study and comparison on properties of optical parametric chirped pulse amplification of BBO, LBO and KDP

    International Nuclear Information System (INIS)

    This article theoretically studies phase matching, parametric bandwidth, gain property of optical parametric chirped pulse amplification of BBO, LBO and KDP. It compares properties of optical parametric chirped pulse amplification between BBO and LBO in detail. The results show that it is better to use BBO in Ti:sapphire system with 800 nm central wavelength and LBO with 1053 nm central wavelength

  5. Femtosecond pulse amplification in cladding-pumped fibers

    OpenAIRE

    Minelly, J. D.; Galvanauskas, A.; Fermann, M. E.; Harter, D.; Caplen, J.E.; Chen, Z.J.; Payne, D. N.

    1995-01-01

    Femtosecond pulse amplification in a cladding-pumped fiber amplifier is demonstrated for the first time to our knowledge. Using a cladding-pumped erbium-doped fiber power amplifier and a passively mode-locked fiber seed oscillator in conjunction with an all-fiber chirped-pulse amplification system, we obtain 380-fs near-bandwidth-limited pulses with an average power of 260 mW. The pulse repetition rate is varied between 5 and 50 MHz, and pulse energies as high as 20 nJ are generated.

  6. Optimization of noncollinear optical parametric amplification

    Science.gov (United States)

    Schimpf, D. N.; Rothardt, J.; Limpert, J.; Tünnermann, A.

    2007-02-01

    Noncollinearly phase-matched optical parametric amplifiers (NOPAs) - pumped with the green light of a frequency doubled Yb-doped fiber-amplifier system 1, 2 - permit convenient generation of ultrashort pulses in the visible (VIS) and near infrared (NIR) 3. The broad bandwidth of the parametric gain via the noncollinear pump configuration allows amplification of few-cycle optical pulses when seeded with a spectrally flat, re-compressible signal. The short pulses tunable over a wide region in the visible permit transcend of frontiers in physics and lifescience. For instance, the resulting high temporal resolution is of significance for many spectroscopic techniques. Furthermore, the high magnitudes of the peak-powers of the produced pulses allow research in high-field physics. To understand the demands of noncollinear optical parametric amplification using a fiber pump source, it is important to investigate this configuration in detail 4. An analysis provides not only insight into the parametric process but also determines an optimal choice of experimental parameters for the objective. Here, the intention is to design a configuration which yields the shortest possible temporal pulse. As a consequence of this analysis, the experimental setup could be optimized. A number of aspects of optical parametric amplifier performance have been treated analytically and computationally 5, but these do not fully cover the situation under consideration here.

  7. Chirped pulse amplification: Present and future

    International Nuclear Information System (INIS)

    Short pulses with ultrahigh peak powers have been generated in Nd: glass and Alexandrite using the Chirped Pulse Amplification (CPA) technique. This technique has been successful in producing picosecond terawatt pulses with a table-top laser system. In the near future, CPA will be applied to large laser systems such as NOVA to produce petawatt pulses (1 kJ in a 1 ps pulse) with focused intensities exceeding 10/sup /plus/21/ W/cm2. These pulses will be associated with electric fields in excess of 100 e/a/sub o/2 and blackbody energy densities equivalent to 3 /times/ 1010 J/cm3. This petawatt source will have important applications in x-ray laser research and will lead to fundamentally new experiments in atomic, nuclear, solid-state, plasma, and high-energy density physics. A review of present and future designs are discussed. 17 refs., 5 figs

  8. Resonant amplification of quantum fluctuations in a spinor gas

    DEFF Research Database (Denmark)

    Topic, O.; Scherer, M.; Gebreyesus, G.;

    2010-01-01

    Bose-Einstein condensates of atoms with non-zero spin are known to constitute an ideal system to investigate fundamental properties of magnetic superfluids. More recently it was realized that they also provide the fascinating opportunity to investigate the macroscopic amplification of quantum and...

  9. Transient amplification limits noise suppression in biochemical networks

    Science.gov (United States)

    Dixon, John; Lindemann, Anika; McCoy, Jonathan H.

    2016-01-01

    Cell physiology is orchestrated, on a molecular level, through complex networks of biochemical reactions. The propagation of random fluctuations through these networks can significantly impact cell behavior, raising challenging questions about how network design shapes the cell's ability to suppress or exploit these fluctuations. Here, drawing on insights from statistical physics, fluid dynamics, and systems biology, we explore how transient amplification phenomena arising from network connectivity naturally limit a biochemical system's ability to suppress small fluctuations around steady-state behaviors. We find that even a simple system consisting of two variables linked by a single interaction is capable of amplifying small fluctuations orders of magnitude beyond the levels predicted by linear stability theory. We also find that adding additional interactions can promote further amplification, even when these interactions implement classic design strategies known to suppress fluctuations. These results establish that transient amplification is an essential factor determining baseline noise levels in stable intracellular networks. Significantly, our analysis is not bound to specific systems or interaction mechanisms: we find that noise amplification is an emergent phenomenon found near steady states in any network containing sufficiently strong interactions, regardless of its form or function.

  10. Heralded amplification of photonic qubits.

    Science.gov (United States)

    Bruno, Natalia; Pini, Vittorio; Martin, Anthony; Verma, Varun B; Nam, Sae Woo; Mirin, Richard; Lita, Adriana; Marsili, Francesco; Korzh, Boris; Bussières, Félix; Sangouard, Nicolas; Zbinden, Hugo; Gisin, Nicolas; Thew, Rob

    2016-01-11

    We demonstrate postselection free heralded qubit amplification for Time-Bin qubits and single photon states in an all-fibre, telecom-wavelength, scheme that highlights the simplicity, stability and potential for fully integrated photonic solutions. Exploiting high-efficiency superconducting detectors, the gain, fidelity and the performance of the amplifier are studied as a function of loss. We also demonstrate the first heralded single photon amplifier with independent sources. This provides a significant advance towards demonstrating device-independent quantum key distribution as well as fundamental tests of quantum mechanics over extended distances. PMID:26832244

  11. 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.

  12. Telomerase Repeated Amplification Protocol (TRAP)

    Science.gov (United States)

    Mender, Ilgen; Shay, Jerry W.

    2016-01-01

    Telomeres are found at the end of eukaryotic linear chromosomes, and proteins that bind to telomeres protect DNA from being recognized as double-strand breaks thus preventing end-to-end fusions (Griffith et al., 1999). However, due to the end replication problem and other factors such as oxidative damage, the limited life span of cultured cells (Hayflick limit) results in progressive shortening of these protective structures (Hayflick and Moorhead, 1961; Olovnikov, 1973). The ribonucleoprotein enzyme complex telomerase-consisting of a protein catalytic component hTERT and a functional RNA component hTR or hTERC- counteracts telomere shortening by adding telomeric repeats to the end of chromosomes in ~90% of primary human tumors and in some transiently proliferating stem-like cells (Shay and Wright, 1996; Shay and Wright, 2001). This results in continuous proliferation of cells which is a hallmark of cancer. Therefore, telomere biology has a central role in aging, cancer progression/metastasis as well as targeted cancer therapies. There are commonly used methods in telomere biology such as Telomere Restriction Fragment (TRF) (Mender and Shay, 2015b), Telomere Repeat Amplification Protocol (TRAP) and Telomere dysfunction Induced Foci (TIF) analysis (Mender and Shay, 2015a). In this detailed protocol we describe Telomere Repeat Amplification Protocol (TRAP). The TRAP assay is a popular method to determine telomerase activity in mammalian cells and tissue samples (Kim et al., 1994). The TRAP assay includes three steps: extension, amplification, and detection of telomerase products. In the extension step, telomeric repeats are added to the telomerase substrate (which is actually a non telomeric oligonucleotide, TS) by telomerase. In the amplification step, the extension products are amplified by the polymerase chain reaction (PCR) using specific primers (TS upstream primer and ACX downstream primer) and in the detection step, the presence or absence of telomerase is

  13. Solid-state Raman image amplification

    Science.gov (United States)

    Calmes, Lonnie Kirkland

    Amplification of low-light-level optical images is important for extending the range of lidar systems that image and detect objects in the atmosphere and underwater. The use of range-gating to produce images of particular range bins is also important in minimizing the image degradation due to light that is scattered backward from aerosols, smoke, or water along the imaging path. For practical lidar systems that must be operated within sight of unprotected observers, eye safety is of the utmost importance. This dissertation describes a new type of eye-safe, range-gated lidar sensing element based on Solid-state Raman Image Amplification (SSRIA) in a solid- state optical crystal. SSRIA can amplify low-level images in the eye-safe infrared at 1.556 μm with gains up to 106 with the addition of only quantum- limited noise. The high gains from SSRIA can compensate for low quantum efficiency detectors and can reduce the need for detector cooling. The range-gate of SSRIA is controlled by the pulsewidth of the pump laser and can be as short as 30-100 cm, using pump pulses of 2-6.7 nsec FWHM. A rate equation theoretical model is derived to help in the design of short pulsed Raman lasers. A theoretical model for the quantum noise properties of SSRIA is presented. SSRIA results in higher SNR images throughout a broad range of incident light levels, in contrast to the increasing noise factor with reduced gain in image intensified CCD's. A theoretical framework for the optical resolution of SSRIA is presented and it is shown that SSRIA can produce higher resolution than ICCD's. SSRIA is also superior in rejecting unwanted sunlight background, further increasing image SNR. Lastly, SSRIA can be combined with optical pre-filtering to perform optical image processing functions such as high-pass filtering and automatic target detection/recognition. The application of this technology to underwater imaging, called Marine Raman Image Amplification (MARIA) is also discussed. MARIA

  14. Modelling and Managing SSD Write-amplification

    OpenAIRE

    Dayan, Niv; Bouganim, Luc; Bonnet, Philippe

    2015-01-01

    How stable is the performance of your flash-based Solid State Drives (SSDs)? This question is central for database designers and administrators, cloud service providers, and SSD constructors. The answer depends on write-amplification, i.e., garbage collection overhead. More specifically, the answer depends on how write-amplification evolves in time. How then can one model and manage write-amplification, especially when application workloads change? This is the focus of this paper. Managing wr...

  15. Reversible Gating of Plasmonic Coupling for Optical Signal Amplification.

    Science.gov (United States)

    Khoury, Christopher G; Fales, Andrew M; Vo-Dinh, Tuan

    2016-07-20

    Amplification of optical signals is useful for a wide variety of applications, ranging from data signal transmission to chemical sensing and biomedical diagnostics. One such application in chemical sensing is surface-enhanced Raman scattering (SERS), an important technique for increasing the Raman signal using the plasmonic effect of enhanced electromagnetic fields associated with metallic nanostructures. One of the most important limitations of SERS-based amplification is the difficulty to reproducibly control the SERS signal. Here, we describe the design and implementation of a unique hybrid system capable of producing reversible gating of plasmonic coupling for Raman signal amplification. The hybrid system is composed of two subsystems: (1) colloidal magneto-plasmonic nanoparticles for SERS enhancement and (2) a micromagnet substrate with an externally applied magnetic field to modulate the colloidal nanoparticles. For this proof of concept demonstration, the nanoparticles were labeled with a Raman-active dye, and it was shown that the detected SERS signal could be reproducibly modulated by controlling the externally applied magnetic field. The developed system provides a simple, robust, inexpensive, and reusable device for SERS signal modulation. These properties will open up new possibilities for optical signal amplification and gating as well for high-throughput, reproducible SERS detection. PMID:27347606

  16. Risk Perception and Social Amplification

    International Nuclear Information System (INIS)

    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

  17. Integrated Amplification Microarrays for Infectious Disease Diagnostics

    Directory of Open Access Journals (Sweden)

    Darrell P. Chandler

    2012-11-01

    Full Text Available This overview describes microarray-based tests that combine solution-phase amplification chemistry and microarray hybridization within a single microfluidic chamber. The integrated biochemical approach improves microarray workflow for diagnostic applications by reducing the number of steps and minimizing the potential for sample or amplicon cross-contamination. Examples described herein illustrate a basic, integrated approach for DNA and RNA genomes, and a simple consumable architecture for incorporating wash steps while retaining an entirely closed system. It is anticipated that integrated microarray biochemistry will provide an opportunity to significantly reduce the complexity and cost of microarray consumables, equipment, and workflow, which in turn will enable a broader spectrum of users to exploit the intrinsic multiplexing power of microarrays for infectious disease diagnostics.

  18. 基于期望库存的供应链系统放大效应控制%Amplification effect control of supply chain system based on desired inventory

    Institute of Scientific and Technical Information of China (English)

    王海燕; 张冲; 佘光

    2012-01-01

    To control volatility of order and inventory as well as reduce the high operation costs in supply chain management,a state space model of supply chain system with multi-input and multi-output was established.Taking customer demand,expected net stock and expected work-in-process level as inputs,and the order quantity,net stock,work-in-process level and expected demand as outputs,the amplification effect of expected net stock and expected work-in-process level on order and inventory were studied.An improved selection method of expected net stock and expected work-in-process level was proposed.The results showed that the proposed selection method could control the orders and inventory amplification effects availably in case of other parameters unchanged.It could not increase the probability of out-of-stock and backlog,and also could reduce the effect of lead time on supply chain system.%为控制订单和库存放大效应并减少供应链高额的运作成本,建立了多输入多输出供应链系统状态空间模型。以顾客需求、期望净库存量和期望在途库存量为输入量,以订单、净库存、在途库存和预测需求为状态变量,研究期望净库存量和期望在途库存量对订单和库存放大的影响。提出期望净库存量和期望在途库存量的改进选取方法。研究表明,在其他参数不变的情况下,改进的期望净库存量和期望在途库存量选取方法可以有效控制供应链系统的订单和库存放大效应,不会增加缺货和库存积压的概率,且可以减少提前期对供应链系统的影响。

  19. Establishment and Optimization of Flipper Transposon PCR Amplification System of the Grape Botrytis cinerea%葡萄灰霉病菌 Flipper 转座子扩增体系的建立和优化

    Institute of Scientific and Technical Information of China (English)

    常佳迎; 寇宏达; 乔丹娜; 张艳杰; 赤国彤; 李亚宁; 李兴红; 刘大群

    2013-01-01

      Grape gray mold caused by Botrytic cinerea Pers.is one of the most important diseases on grapes worldwide.The genetic variation of Botrytis cinerea is widely and adaptable,which is easy to produce drug-resistant strains.It is reported that Boty and Flipper transposon of Botrytis cinerea are related to the presence or absence of resistant strains.By setting different gradient and optimize Botrytis cinerea Flipper transposon PCR amplification sys-tem of grape in China,including template DNA,primer,dNTPs,10 ×Taq 10 Buffer,Taq DNA polymerase,annea-ling temperature,cycle indexthe 1 159 bp fragment was obtained ,which has 99% similarity with Botryotinia fuckeli-ana Flipper transposable element transposase gene through NCBI blastn .So the amplified fragment is verified as ex-pected target fragment.The establishment and optimization of Flipper transposon PCR amplification system of the grape Botrytis cinerea in China provide an important foundation to further study of the relationship between the trans -posable elements,pathogenicity and resistant.%  通过对模板 DNA、Primer、dNTPs、10×Taq 10 Buffer、Taq 酶的不同浓度进行单因素筛选,并对退火温度和循环次数进行摸索,建立和优化了灰葡萄孢菌 Flipper 转座子 PCR 扩增体系。采用该体系及 Flipper 转座子引物扩增得到了1159 bp 的片段,通过比对发现,该片段与 Botryotinia fuckeliana 的 Flipper 转座因子转座酶基因相似性达99%,表明扩增得到的是预期目的片段。 Flipper 转座子扩增体系的建立,为深入研究我国葡萄灰霉病菌菌株的转座子类型及其与致病力、抗药性等因素之间的关系奠定了重要的基础。

  20. Tsunami Amplification due to Focusing

    Science.gov (United States)

    Moore, C. W.; Kanoglu, U.; Titov, V. V.; Aydin, B.; Spillane, M. C.; Synolakis, C. E.

    2012-12-01

    Tsunami runup measurements over the periphery of the Pacific Ocean after the devastating Great Japan tsunami of 11 March 2011 showed considerable variation in far-field and near-field impact. This variation of tsunami impact have been attributed to either directivity of the source or by local topographic effects. Directivity arguments alone, however, cannot explain the complexity of the radiated patterns in oceans with trenches and seamounts. Berry (2007, Proc. R. Soc. Lond. A 463, 3055-3071) discovered how such underwater features may concentrate tsunamis into cusped caustics and thus cause large local amplifications at specific focal points. Here, we examine focusing and local amplification, not by considering the effects of underwater diffractive lenses, but by considering the details of the dipole nature of the initial profile, and propose that certain regions of coastline are more at-risk, not simply because of directivity but because typical tsunami deformations create focal regions where abnormal tsunami wave height can be registered (Marchuk and Titov, 1989, Proc. IUGG/IOC International Tsunami Symposium, Novosibirsk, USSR). In this work, we present a new general analytical solution of the linear shallow-water wave equation for the propagation of a finite-crest-length source over a constant depth without any restriction on the initial profile. Unlike the analytical solution of Carrier and Yeh (2005, Comp. Mod. Eng. & Sci. 10(2), 113-121) which was restricted to initial conditions with Gaussian profiles and involved approximation, our solution is not only exact, but also general and allows the use of realistic initial waveform such as N-waves as defined by Tadepalli and Synolakis (1994, Proc. R. Soc. Lond. A 445, 99-112). We then verify our analytical solution for several typical wave profiles, both with the NOAA tsunami forecast model MOST (Titov and Synolakis, 1998, J. Waterw. Port Coast. Ocean Eng. 124(4), 157-171) which is validated and verified through

  1. Fast implementation of length-adaptive privacy amplification in quantum key distribution

    International Nuclear Information System (INIS)

    Post-processing is indispensable in quantum key distribution (QKD), which is aimed at sharing secret keys between two distant parties. It mainly consists of key reconciliation and privacy amplification, which is used for sharing the same keys and for distilling unconditional secret keys. In this paper, we focus on speeding up the privacy amplification process by choosing a simple multiplicative universal class of hash functions. By constructing an optimal multiplication algorithm based on four basic multiplication algorithms, we give a fast software implementation of length-adaptive privacy amplification. “Length-adaptive” indicates that the implementation of privacy amplification automatically adapts to different lengths of input blocks. When the lengths of the input blocks are 1 Mbit and 10 Mbit, the speed of privacy amplification can be as fast as 14.86 Mbps and 10.88 Mbps, respectively. Thus, it is practical for GHz or even higher repetition frequency QKD systems. (general)

  2. Mechanisms of metal-induced centrosome amplification.

    Science.gov (United States)

    Holmes, Amie L; Wise, John Pierce

    2010-12-01

    Exposure to toxic and carcinogenic metals is widespread; however, their mechanisms of action remain largely unknown. One potential mechanism for metal-induced carcinogenicity and toxicity is centrosome amplification. Here we review the mechanisms for metal-induced centrosome amplification, including arsenic, chromium, mercury and nano-titanium dioxide. PMID:21118148

  3. Mechanisms of Metal-Induced Centrosome Amplification

    OpenAIRE

    Holmes, Amie L.; Wise, John Pierce

    2010-01-01

    Exposure to toxic and carcinogenic metals is widespread; however, their mechanisms of action remain largely unknown. One potential mechanism for metal-induced carcinogenicity and toxicity is centrosome amplification. Here, we review the mechanisms for metal-induced centrosome amplification, including arsenic, chromium, mercury and nano-titanium dioxide.

  4. Enhancement of cell-specific transgene expression from a Tet-Off regulatory system using a transcriptional amplification strategy in the rat brain

    OpenAIRE

    Liu, Beihui; Wang, Shu; Brenner, Michael; Paton, Julian FR; Kasparov, Sergey

    2008-01-01

    Background The Tet-Off system uses a tetracycline-controlled transactivator protein (tTA) and a tetracycline-responsive promoter element (TRE) to regulate expression of a target gene. This system can be used to achieve regulatable transgene expression in specific cell types by employing a cell-specific promoter to drive tTA expression. Wide applications of this attractive approach are, however, hindered by relatively weak transcriptional activity of most cell-specific promoters. We report her...

  5. 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.

  6. Detection of Chlamydia trachomatis-DNA in synovial fluid: evaluation of the sensitivity of different DNA extraction methods and amplification systems

    OpenAIRE

    Freise, Julia; Bernau, Iris; Meier, Sabine; Zeidler, Henning; Kuipers, Jens G

    2009-01-01

    Introduction Polymerase chain reaction (PCR) and ligase chain reaction (LCR) are used in research for detection of Chlamydia trachomatis (C. tr.) in synovial fluid (SF). However there is no standardized system for diagnostic use in clinical practice, therefore this study aimed at determining the molecular biology method best suited to detect C. tr. from SF. Methods SF samples were spiked with C. tr. elementary bodies (EB) and human peripheral blood monocytes (PBMo) persistently infected with ...

  7. Effective amplification of real WDM burst traffic using optical gain clamping

    OpenAIRE

    Zannin, Marcelo; Taccheo, Stefano; Ennser, Karin; Careglio, Davide; Solé Pareta, Josep

    2008-01-01

    Experimental studies of real optical burst traffic in WDM systems are performed with optical gain clamping for stabilizing the EDFA amplification. Impairments of power variation due to burst are shown to be negligible.

  8. Comparison of in-house and commercial sample preparation and PCR amplification systems for detection of human immunodeficiency virus type 1 DNA in blood samples from Tanzanian adults.

    OpenAIRE

    Lyamuya, E; Bredberg-Rådén, U; Albert, J.; Grankvist, O; Msangi, V; Kagoma, C.; Mhalu, F; Biberfeld, G

    1997-01-01

    This study compared the performance of several in-house nested PCR systems and the Amplicor human immunodeficiency virus type 1 (HIV-1) PCR kit in the detection of HIV-1 DNA in Tanzanian samples prepared by two different methods. All six of the in-house primer sets evaluated had a higher sensitivity for HIV DNA detection in samples prepared by the Amplicor PCR sample preparation method than in those prepared by the Ficoll-Isopaque (FIP) density gradient centrifugation method. A sensitivity of...

  9. Method for chemical amplification based on fluid partitioning in an immiscible liquid

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Brian L.; Colston, Bill W.; Elkin, Christopher J.

    2015-06-02

    A system for nucleic acid amplification of a sample comprises partitioning the sample into partitioned sections and performing PCR on the partitioned sections of the sample. Another embodiment of the invention provides a system for nucleic acid amplification and detection of a sample comprising partitioning the sample into partitioned sections, performing PCR on the partitioned sections of the sample, and detecting and analyzing the partitioned sections of the sample.

  10. Novel glucometer-based immunosensing strategy suitable for complex systems with signal amplification using surfactant-responsive cargo release from glucose-encapsulated liposome nanocarriers.

    Science.gov (United States)

    Tang, Juan; Huang, Yapei; Liu, Huiqiong; Zhang, Cengceng; Tang, Dianping

    2016-05-15

    Methods based on surfactant-responsive controlled release systems of cargoes from nanocontainers have been developed for bioanalytical applications, but most were utilized for drug delivery and a few reports were focused on immunoassays. Herein we design an in situ amplified immunoassay protocol for high-efficient detection of aflatoxins (aflatoxin B1, AFB1 used in this case) based on surfactant-responsive cargo release from glucose-encapsulated liposome nanocarriers with sensitivity enhancement. Initially, biotinylated liposome nanocarrier encapsulated with glucose was synthesized using a reverse-phase evaporation method. Thereafter, the nanocarrier was utilized as the signal-generation tag on capture antibody-coating microplate through classical biotin-avidin linkage after reaction with biotinylated detection antibody. Upon addition of buffered surfactant (1X PBS-Tween 20 buffer) into the medium, the surfactant immediately hydrolyzed the conjugated liposome, and released the encapsulated glucose from the nanocarriers, which could be quantitatively determined by using a low-cost personal glucometer (PGM). The detectable signal increased with the increment of target analyte. Under the optimal conditions, the assay could allow PGM detection toward target AFB1 as low as 0.6 pg mL(-1) (0.6 ppt). Moreover, the methodology also showed good reproducibility and high specificity toward target AFB1 against other mycotoxins and proteins, and was applicable for quantitatively monitoring target AFB1 in the complex systems, e.g., naturally contaminated/spiked peanut samples and serum specimens, with the acceptable results. Taking these advantages of simplification, low cost, universality and sensitivity, our design provides a new horizon for development of advanced immunoassays in future point-of-care testing. PMID:26748368

  11. Quantum Amplitude Amplification and Estimation

    CERN Document Server

    Brassard, G; Mosca, M; Tapp, A; Brassard, Gilles; Hoyer, Peter; Mosca, Michele; Tapp, Alain

    2000-01-01

    Consider a Boolean function $\\chi: X \\to \\{0,1\\}$ that partitions set $X$ between its good and bad elements, where $x$ is good if $\\chi(x)=1$ and bad otherwise. Consider also a quantum algorithm $\\mathcal A$ such that $A \\ket{0} = \\sum_{x\\in X} \\alpha_x \\ket{x}$ is a quantum superposition of the elements of $X$, and let $a$ denote the probability that a good element is produced if $A \\ket{0}$ is measured. If we repeat the process of running $A$, measuring the output, and using $\\chi$ to check the validity of the result, we shall expect to repeat $1/a$ times on the average before a solution is found. *Amplitude amplification* is a process that allows to find a good $x$ after an expected number of applications of $A$ and its inverse which is proportional to $1/\\sqrt{a}$, assuming algorithm $A$ makes no measurements. This is a generalization of Grover's searching algorithm in which $A$ was restricted to producing an equal superposition of all members of $X$ and we had a promise that a single $x$ existed such tha...

  12. Drastic disorder-induced reduction of signal amplification in scale-free networks.

    Science.gov (United States)

    Chacón, Ricardo; Martínez, Pedro J

    2015-07-01

    Understanding information transmission across a network is a fundamental task for controlling and manipulating both biological and manmade information-processing systems. Here we show how topological resonant-like amplification effects in scale-free networks of signaling devices are drastically reduced when phase disorder in the external signals is considered. This is demonstrated theoretically by means of a starlike network of overdamped bistable systems, and confirmed numerically by simulations of scale-free networks of such systems. The taming effect of the phase disorder is found to be sensitive to the amplification's strength, while the topology-induced amplification mechanism is robust against this kind of quenched disorder in the sense that it does not significantly change the values of the coupling strength where amplification is maximum in its absence. PMID:26274239

  13. Trends in ultrashort and ultrahigh power laser pulses based on optical parametric chirped pulse amplification

    International Nuclear Information System (INIS)

    Since the proof-of-principle demonstration of optical parametric amplification to efficiently amplify chirped laser pulses in 1992, optical parametric chirped pulse amplification (OPCPA) became the most promising method for the amplification of broadband optical pulses. In the meantime, we are witnessing an exciting progress in the development of powerful and ultrashort pulse laser systems that employ chirped pulse parametric amplifiers. The output power and pulse duration of these systems have ranged from a few gigawatts to hundreds of terawatts with a potential of tens of petawatts power level. Meanwhile, the output pulse duration based on optical parametric amplification has entered the range of few-optical-cycle field. In this paper, we overview the basic principles, trends in development, and current state of the ultrashort and laser systems based on OPCPA, respectively. (paper)

  14. CdTe quantum dots@luminol as signal amplification system for chrysoidine with chemiluminescence-chitosan/graphene oxide-magnetite-molecularly imprinting sensor

    Science.gov (United States)

    Duan, Huimin; Li, Leilei; Wang, Xiaojiao; Wang, Yanhui; Li, Jianbo; Luo, Chuannan

    2016-01-01

    A sensitive chemiluminescence (CL) sensor based on chemiluminescence resonance energy transfer (CRET) in CdTe quantum dots@luminol (CdTe QDs@luminol) nanomaterials combined with chitosan/graphene oxide-magnetite-molecularly imprinted polymer (Cs/GM-MIP) for sensing chrysoidine was developed. CdTe QDs@luminol was designed to not only amplify the signal of CL but also reduce luminol consumption in the detection of chrysoidine. On the basis of the abundant hydroxy and amino, Cs and graphene oxide were introduced into the GM-MIP to improve the adsorption ability. The adsorption capacities of chrysoidine by both Cs/GM-MIP and non-imprinted polymer (Cs/GM-NIP) were investigated, and the CdTe QDs@luminol and Cs/GM-MIP were characterized by UV-vis, FTIR, SEM and TEM. The proposed sensor can detect chrysoidine within a linear range of 1.0 × 10- 7 - 1.0 × 10- 5 mol/L with a detection limit of 3.2 × 10- 8 mol/L (3δ) due to considerable chemiluminescence signal enhancement of the CdTe quantum dots@luminol detector and the high selectivity of the Cs/GM-MIP system. Under the optimal conditions of CL, the CdTe QDs@luminol-Cs/GM-MIP-CL sensor was used for chrysoidine determination in samples with satisfactory recoveries in the range of 90-107%.

  15. Spatial beam shaping using a micro-structured optical fiber and all-fiber laser amplification system for large-scale laser facilities seeding

    International Nuclear Information System (INIS)

    Spatial beam shaping is an important topic for the lasers applications. For various industrial areas (marking, drilling, laser-matter interaction, high-power laser seeding...) the optical beam has to be flattened. Currently, the state of the art of the beam shaping: 'free-space' solutions or highly multimode fibers, are not fully suitable. The first ones are very sensitive to any perturbations and the maintenance is challenging, the second ones cannot deliver a coherent beam. For this reason, we present in this manuscript a micro-structured optical single-mode fiber delivering a spatially flattened beam. This 'Top-Hat' fiber can shape any beam in a spatially coherent beam what is a progress with respect to the highly multimode fibers used in the state of the art. The optical fibers are easy to use and very robust, what is a strong benefit with respect to the 'free-space' solutions. Thanks to this fiber, we could realize an all-fiber multi-stage laser chain to amplify a 10 ns pulse to 100 μJ. Moreover the temporal, spectral and spatial properties were preserved. We adapted this 'Top-Hat' fiber to this multi-stage laser chain, we proved the capability and the interest of this fiber for the spatial beam shaping of the laser beams in highly performing and robust laser systems. (author)

  16. Narrow band amplification of light carrying orbital angular momentum.

    Science.gov (United States)

    Borba, G C; Barreiro, S; Pruvost, L; Felinto, D; Tabosa, J W R

    2016-05-01

    We report on the amplification of an optical vortex beam carrying orbital angular momentum via induced narrow Raman gain in an ensemble of cold cesium atoms. A 20% single-pass Raman gain of a weak vortex signal field is observed with a spectral width of order of 1 MHz, much smaller than the natural width, demonstrating that the amplification process preserves the phase structure of the vortex beam. The gain is observed in the degenerated two-level system associated with the hyperfine transition 6S1/2(F = 3) ↔ 6P3/2(F' = 2) of cesium. Our experimental observations are explained with a simple theoretical model based on a three-level Λ system interacting coherently with the weak Laguerre-Gauss field and a strong coupling field, including an incoherent pumping rate between the two degenerate ground-states. PMID:27137618

  17. Narrow band amplification of light carrying orbital angular momentum

    CERN Document Server

    Borba, G C; Pruvost, L; Felinto, D; Tabosa, J W R

    2016-01-01

    We report on the amplification of an optical vortex beam carrying orbital angular momentum via induced narrow Raman gain in an ensemble of cold cesium atoms. A 20\\% single-pass Raman gain of a weak vortex signal field is observed with a spectral width of order of 1 MHz, much smaller than the natural width, demonstrating that the amplification process preserves the phase structure of the vortex beam. The gain is observed in the degenerated two-level system associated with the hyperfine transition $6S_{1/2}(F=3)\\leftrightarrow 6P_{3/2}(F^{\\prime}=2)$ of cesium. Our experimental observations are explained with a simple theoretical model based on a three-level $\\Lambda$ system interacting coherently with the weak Laguerre-Gauss field and a strong coupling field, including an incoherent pumping rate between the two degenerate ground-states.

  18. Integrated Microfluidic Nucleic Acid Isolation, Isothermal Amplification, and Amplicon Quantification

    OpenAIRE

    Mauk, Michael G.; Changchun Liu; Jinzhao Song; Bau, Haim H

    2015-01-01

    Microfluidic components and systems for rapid (<60 min), low-cost, convenient, field-deployable sequence-specific nucleic acid-based amplification tests (NAATs) are described. A microfluidic point-of-care (POC) diagnostics test to quantify HIV viral load from blood samples serves as a representative and instructive example to discuss the technical issues and capabilities of “lab on a chip” NAAT devices. A portable, miniaturized POC NAAT with performance comparable to conventional PCR (poly...

  19. Can Anomalous Amplification be Attained without Postselection?

    Science.gov (United States)

    Martínez-Rincón, Julián; Liu, Wei-Tao; Viza, Gerardo I.; Howell, John C.

    2016-03-01

    We present a parameter estimation technique based on performing joint measurements of a weak interaction away from the weak-value-amplification approximation. Two detectors are used to collect full statistics of the correlations between two weakly entangled degrees of freedom. Without discarding of data, the protocol resembles the anomalous amplification of an imaginary-weak-value-like response. The amplification is induced in the difference signal of both detectors allowing robustness to different sources of technical noise, and offering in addition the advantages of balanced signals for precision metrology. All of the Fisher information about the parameter of interest is collected. A tunable phase controls the strength of the amplification response. We experimentally demonstrate the proposed technique by measuring polarization rotations in a linearly polarized laser pulse. We show that in the presence of technical noise the effective sensitivity and precision of a split detector is increased when compared to a conventional continuous-wave balanced detection technique.

  20. Privacy amplification for quantum key distribution

    International Nuclear Information System (INIS)

    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)

  1. 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.

  2. Amplification uncertainty relation for probabilistic amplifiers

    Science.gov (United States)

    Namiki, Ryo

    2015-09-01

    Traditionally, quantum amplification limit refers to the property of inevitable noise addition on canonical variables when the field amplitude of an unknown state is linearly transformed through a quantum channel. Recent theoretical studies have determined amplification limits for cases of probabilistic quantum channels or general quantum operations by specifying a set of input states or a state ensemble. However, it remains open how much excess noise on canonical variables is unavoidable and whether there exists a fundamental trade-off relation between the canonical pair in a general amplification process. In this paper we present an uncertainty-product form of amplification limits for general quantum operations by assuming an input ensemble of Gaussian-distributed coherent states. It can be derived as a straightforward consequence of canonical uncertainty relations and retrieves basic properties of the traditional amplification limit. In addition, our amplification limit turns out to give a physical limitation on probabilistic reduction of an Einstein-Podolsky-Rosen uncertainty. In this regard, we find a condition that probabilistic amplifiers can be regarded as local filtering operations to distill entanglement. This condition establishes a clear benchmark to verify an advantage of non-Gaussian operations beyond Gaussian operations with a feasible input set of coherent states and standard homodyne measurements.

  3. Towards a “Sample-In, Answer-Out” Point-of-Care Platform for Nucleic Acid Extraction and Amplification: Using an HPV E6/E7 mRNA Model System

    Directory of Open Access Journals (Sweden)

    Anja Gulliksen

    2012-01-01

    Full Text Available The paper presents the development of a “proof-of-principle” hands-free and self-contained diagnostic platform for detection of human papillomavirus (HPV E6/E7 mRNA in clinical specimens. The automated platform performs chip-based sample preconcentration, nucleic acid extraction, amplification, and real-time fluorescent detection with minimal user interfacing. It consists of two modular prototypes, one for sample preparation and one for amplification and detection; however, a common interface is available to facilitate later integration into one single module. Nucleic acid extracts (n=28 from cervical cytology specimens extracted on the sample preparation chip were tested using the PreTect HPV-Proofer and achieved an overall detection rate for HPV across all dilutions of 50%–85.7%. A subset of 6 clinical samples extracted on the sample preparation chip module was chosen for complete validation on the NASBA chip module. For 4 of the samples, a 100% amplification for HPV 16 or 33 was obtained at the 1 : 10 dilution for microfluidic channels that filled correctly. The modules of a “sample-in, answer-out” diagnostic platform have been demonstrated from clinical sample input through sample preparation, amplification and final detection.

  4. Apolipoprotein E genotyping by multiplex amplification refractory mutation system PCR with optimized conditions%优化的多重扩增阻滞突变系统-PCR对载脂蛋白E基因的简易分型

    Institute of Scientific and Technical Information of China (English)

    刘静; 刘建伟; 叶玲

    2011-01-01

    Objective To set up a simple method for apolipoprotein E (ApoE) genotyping by modifying the conditions of multiplex amplification refractory mutation system PCR (multi-ARMS-PCR). Methods Based on the principle of multi-ARMS-PCR and considering the faults existed in some published papers, new primers were designed to improve PCR conditions. DNA genome of peripheral white blood cells was used as the template. Four allele-specific oligonucleotide upstream primers, one common downstream primer and a pair of internal positive control primers were constructed. Multi-ARMS-PCR were performed with combination of different primers in 2 reaction tubes synchronously. Amplified multiplex products were electrophoresed on agarose gels containing ethidium bromide. Six ApoE genotypes were distinguished by the band sizes. Results Using the new primers,amplification efficiency and specificity were significantly increased and the misclassification was diminished due to removing the interference of non-specific bands. Conclusion The optimized multi-ARMS-PCR is an easy, time-saving, efficient and economical method for determination of ApoE genotypes applied in a minimally equipped laboratory.%目的 通过改进和优化多重扩增阻滞突变系统-PCR(multi-ARMS-PCR)条件,建立载脂蛋白E(ApoE)基因的简易分型方法.方法 基于multi-ARMS-PCR的原理和特点,针对文献报道方法中存在的缺陷和错误,重新设计或改进引物.以外周血白细胞基因组DNA为模板,应用4个等位基因特异性寡核酸上游引物、1个通用下游引物和一对内参引物,分A,B两个管同步进行多重PCR反应.PCR扩增产物经过琼脂糖凝胶电泳分离-EB染色,根据电泳带型的差异,实现对ApoE 6种基因型的判定.结果 新引物显著提高了扩增效率和反应特异性,排除了非特异条带的干扰,减少了ApoE基因分型的错判.结论 采用优化后的multi-ARMS-PCR方法对ApoE基因型进行鉴定,具有操作简便、时间短

  5. Raman amplification in optical communication systems

    DEFF Research Database (Denmark)

    Kjær, Rasmus

    2008-01-01

    anvendelser af den såkaldte dispersions-kompenserende Raman-forstærker (DCRA) præsenteres, og disse er: terminal dispersions-kompensering vha. en DCRA, forlængelse det dynamiske område af en kommerciel Erbium-doteret fiberforstærker (EDFA), samt brugen af en hybrid bredbånds-DCRA/EDFA med 60 nm båndbredde, et...

  6. Amplified RNA degradation in T7-amplification methods results in biased microarray hybridizations

    Directory of Open Access Journals (Sweden)

    Ivell Richard

    2003-11-01

    Full Text Available Abstract Background The amplification of RNA with the T7-System is a widely used technique for obtaining increased amounts of RNA starting from limited material. The amplified RNA (aRNA can subsequently be used for microarray hybridizations, warranting sufficient signal for image analysis. We describe here an amplification-time dependent degradation of aRNA in prolonged standard T7 amplification protocols, that results in lower average size aRNA and decreased yields. Results A time-dependent degradation of amplified RNA (aRNA could be observed when using the classical "Eberwine" T7-Amplification method. When the amplification was conducted for more than 4 hours, the resulting aRNA showed a significantly smaller size distribution on gel electrophoresis and a concomitant reduction of aRNA yield. The degradation of aRNA could be correlated to the presence of the T7 RNA Polymerase in the amplification cocktail. The aRNA degradation resulted in a strong bias in microarray hybridizations with a high coefficient of variation and a significant reduction of signals of certain transcripts, that seem to be susceptible to this RNA degrading activity. The time-dependent degradation of these transcripts was verified by a real-time PCR approach. Conclusions It is important to perform amplifications not longer than 4 hours as there is a characteristic 'quality vs. yield' situation for longer amplification times. When conducting microarray hybridizations it is important not to compare results obtained with aRNA from different amplification times.

  7. Efficient chirped-pulse amplification of sub-20 fs laser pulses

    Energy Technology Data Exchange (ETDEWEB)

    Matsuoka, Shinichi; Yamakawa, Koichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    We have developed a model for ultrabroadband and ultrashort pulse amplification including the effects of a pulse shaper for regenerative pulse shaping, gain narrowing and gain saturation in the amplifiers. Thin solid etalons are used to control both gain narrowing and gain saturation during amplification. This model has been used to design an optimized Ti:sapphire amplifier system for producing efficiently pulses of < 20-fs duration with approaching peak and average powers of 100 TW and 20 W. (author)

  8. Noiseless phase quadrature amplification via an electro-optic feed-forward technique

    CERN Document Server

    Buchler, B C; Ralph, T C; Buchler, Ben C.; Huntington, Elanor H.; Ralph, Timothy C.

    1999-01-01

    Theoretical results are presented which show that noiseless phase quadrature amplification is possible, and limited experimentally only by the efficiency of the phase detection system. Experimental results obtained using a Nd:YAG laser show a signal gain of 10dB and a signal transfer ratio of T_s=0.9. This result easily exceeds the standard quantum limit for signal transfer. The results also explicitly demonstrate the phase sensitive nature of the amplification process.

  9. Multiple displacement amplification of the DNA from single flow–sorted plant chromosome

    OpenAIRE

    Cápal, P. (Petr); Blavet, N; Vrána, J; Kubaláková, M; Doležel, J. (Jaroslav)

    2015-01-01

    A protocol is described for production of micrograms of DNA from single copies of flow-sorted plant chromosomes. Of 183 single copies of wheat chromosome 3B, 118 (64%) were successfully amplified. Sequencing DNA amplification products using an Illumina HiSeq 2000 system to 10× coverage and merging sequences from three separate amplifications resulted in 60% coverage of the chromosome 3B reference, entirely covering 30% of its genes. The merged sequences permitted de novo assembly of 19% of ch...

  10. Self-organization effects and light amplification of collective atomic recoil motion in a harmonic trap

    OpenAIRE

    Zhang, L.; Yang, G. J.; Xia, L. X.

    2005-01-01

    Self-organization effects related to light amplification in the collective atomic recoil laser system with the driven atoms confined in a harmonic trap are investigated further. In the dispersive parametric region, our study reveals that the spontaneously formed structures in the phase space contributes an important role to the light amplification of the probe field under the atomic motion being modified by the trap.

  11. Divided-pulse nonlinear amplification and simultaneous compression

    International Nuclear Information System (INIS)

    We report on a fiber laser system delivering 122 fs pulse duration and 600 mW average power at 1560 nm by the interplay between divided pulse amplification and nonlinear pulse compression. A small-core double-clad erbium-doped fiber with anomalous dispersion carries out the pulse amplification and simultaneously compresses the laser pulses such that a separate compressor is no longer necessary. A numeric simulation reveals the existence of an optimum fiber length for producing transform-limited pulses. Furthermore, frequency doubling to 780 nm with 240 mW average power and 98 fs pulse duration is achieved by using a periodically poled lithium niobate crystal at room temperature

  12. Amplification, Decoherence, and the Acquisition of Information by Spin Environments

    Science.gov (United States)

    Zwolak, Michael; Riedel, C. Jess; Zurek, Wojciech H.

    2016-05-01

    Quantum Darwinism recognizes the role of the environment as a communication channel: Decoherence can selectively amplify information about the pointer states of a system of interest (preventing access to complementary information about their superpositions) and can make records of this information accessible to many observers. This redundancy explains the emergence of objective, classical reality in our quantum Universe. Here, we demonstrate that the amplification of information in realistic spin environments can be quantified by the quantum Chernoff information, which characterizes the distinguishability of partial records in individual environment subsystems. We show that, except for a set of initial states of measure zero, the environment always acquires redundant information. Moreover, the Chernoff information captures the rich behavior of amplification in both finite and infinite spin environments, from quadratic growth of the redundancy to oscillatory behavior. These results will considerably simplify experimental testing of quantum Darwinism, e.g., using nitrogen vacancies in diamond.

  13. Heat induces gene amplification in cancer cells

    International Nuclear Information System (INIS)

    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.

  14. Heat induces gene amplification in cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Bin, E-mail: yanbin@mercyhealth.com [Department of Radiation Oncology, University of Mississippi Medical Center, Jackson, MS 39213 (United States); Mercy Cancer Center, Mercy Medical Center-North Iowa, Mason City, IA 50401 (United States); Ouyang, Ruoyun [Department of Respiratory Medicine, The Second Xiangya Hospital, Xinagya School of Medicine, Central South University, Changsha 410011 (China); Huang, Chenghui [Department of Radiation Oncology, University of Mississippi Medical Center, Jackson, MS 39213 (United States); Department of Oncology, The Third Xiangya Hospital, Xinagya School of Medicine, Central South University, Changsha 410013 (China); Liu, Franklin [Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710 (United States); Neill, Daniel [Department of Radiation Oncology, University of Mississippi Medical Center, Jackson, MS 39213 (United States); Li, Chuanyuan [Dermatology, Duke University Medical Center, Durham, NC 27710 (United States); Dewhirst, Mark [Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710 (United States)

    2012-10-26

    Highlights: Black-Right-Pointing-Pointer This study discovered that heat exposure (hyperthermia) results in gene amplification in cancer cells. Black-Right-Pointing-Pointer Hyperthermia induces DNA double strand breaks. Black-Right-Pointing-Pointer DNA double strand breaks are considered to be required for the initiation of gene amplification. Black-Right-Pointing-Pointer 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 Degree-Sign 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) {gamma}H2AX immunostaining to detect {gamma}H2AX foci as an indication for DNA double strand breaks. Results: (1) Heat exposure at 42 or 44 Degree-Sign 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 Degree-Sign C for 30 min induces DNA double strand breaks in HCT116 cells as shown by {gamma}H2AX 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

  15. Thermal amplification of field-correlation harvesting

    CERN Document Server

    Brown, Eric G

    2013-01-01

    We study the harvesting of quantum and classical correlations from a hot scalar field in a periodic cavity by a pair of spatially separated oscillator-detectors. Specifically, we utilize non-perturbative and exact (non-numerical) techniques to solve for the evolution of the detectors-field system and then we examine how the entanglement, Gaussian quantum discord, and mutual information obtained by the detectors change with the temperature of the field. While (as expected) the harvested entanglement rapidly decays to zero as temperature is increased, we find remarkably that both the mutual information and the discord can actually be increased by multiple orders of magnitude via increasing the temperature. We go on to explain this phenomenon by taking advantage of the translational invariance of the field and use this to make accurate predictions of the behavior of thermal amplification; by this we also introduce a new perspective on field-correlation harvesting that we feel is worthy of consideration in its ow...

  16. Thermodynamic analysis of quantum light amplification

    CERN Document Server

    Tannor, D J

    2006-01-01

    Thermodynamics of a three-level maser was studied in the pioneering work of Scovil and Schulz-DuBois [Phys. Rev. Lett. 2, 262 (1959)]. In this work we consider the same three-level model, but treat both the matter and light quantum mechanically. Specifically, we analyze an extended (three-level) dissipative Jaynes-Cummings model (ED-JCM) within the framework of a quantum heat engine, using novel formulas for heat flux and power in bipartite systems introduced in our previous work [E. Boukobza and D. J. Tannor, PRA (in press)]. Amplification of the selected cavity mode occurs even in this simple model, as seen by a positive steady state power. However, initial field coherence is lost, as seen by the decaying off-diagonal field density matrix elements, and by the Husimi-Kano Q function. We show that after an initial transient time the field's entropy rises linearly during the operation of the engine, which we attribute to the dissipative nature of the evolution and not to matter-field entanglement. We show that...

  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. On Arbitrary Phases in Quantum Amplitude Amplification

    CERN Document Server

    Hoyer, P

    2000-01-01

    We consider the use of arbitrary phases in quantum amplitude amplification which is a generalization of quantum searching. We prove that the phase condition in amplitude amplification is given by $\\tan(\\phi/2)=\\tan(\\phi/2)(1-2a)$, where $\\phi$ and $\\phi$ are the phases used and where $a$ is the success probability of the given algorithm. Thus the choice of phases depends nontrivially and nonlinearly on the success probability. Utilizing this condition, we give methods for constructing quantum algorithms that succeed with certainty and for implementing arbitrary rotations. We also conclude that phase errors of order up to $\\frac{1}{\\sqrt{a}}$ can be tolerated in amplitude amplification.

  19. Slow light propagation in an atomic vapour under conditions of amplification without inversion

    International Nuclear Information System (INIS)

    We report experimental results on slowing a light pulse in a system for amplification without inversion (AWI). We were able to control a subluminal group velocity continuously from Vg = c/2850 to c/7260 by just changing an incoherent pumping beam power from 0 to 12 mW in the AWI system. And several advantages, such as the controllable delay time and the pulse amplification, for slowing of the light in the AWI system compared to in an electromagnetically induced transparency system were found

  20. Ultrasmall volume molecular isothermal amplification in microfluidic chip with advanced surface processing

    International Nuclear Information System (INIS)

    In this paper, we developed a metal micro-fluidic chip with advanced surface processing for ultra-small volume molecular isothermal amplification. This method takes advantages of the nucleic acid amplification with good stability and consistency, high sensitivity about 31 genomic DNA copies and bacteria specific gene identification. Based on the advanced surface processing, the bioreaction assays of nucleic acid amplification was dropped about 392nl in volume. A high numerical aperture confocal optical detection system was advanced to sensitively monitor the DNA amplification with low noise and high power collecting fluorescence near to the optical diffraction limit. A speedy nucleic acid isothermal amplification was performed in the ultra-small volume microfluidic chip, where the time at the inflexions of second derivative to DNA exponential amplified curves was brought forward and the sensitivity was improved about 65 folds to that of in current 25μl Ep-tube amplified reaction, which indicates a promising clinic molecular diagnostics in the droplet amplification.

  1. Resonant nonstationary amplification of polychromatic laser pulses and conical emission in an optically dense ensemble of neon metastable atoms

    CERN Document Server

    Bagayev, S N; Mekhov, I B; Moroshkin, P V; Chekhonin, I A; Davliatchine, E M; Kindel, E

    2003-01-01

    Experimental and numerical investigation of single beam and pump-probe interaction with a resonantly absorbing dense extended medium under strong and weak field-matter coupling is presented. Significant probe beam amplification and conical emission were observed. Under relatively weak pumping and high medium density, when the condition of strong coupling between field and resonant matter is fulfilled, the probe amplification spectrum has a form of spectral doublet. Stronger pumping leads to the appearance of a single peak of the probe beam amplification at the transition frequency. The greater probe intensity results in an asymmetrical transmission spectrum with amplification at the blue wing of the absorption line and attenuation at the red one. Under high medium density, a broad band of amplification appears. Theoretical model is based on the solution of the Maxwell-Bloch equations for a two-level system. Different types of probe transmission spectra obtained are attributed to complex dynamics of a coherent...

  2. Thermodynamic analysis of quantum light amplification

    Science.gov (United States)

    Boukobza, E.; Tannor, D. J.

    2006-12-01

    Thermodynamics of a three-level maser was studied in the pioneering work of Scovil and Schulz-DuBois [Phys. Rev. Lett. 2, 262 (1959)]. In this work we consider the same three-level model, but treat both the matter and the light quantum mechanically. Specifically, we analyze an extended (three-level) dissipative (ED) Jaynes-Cummings model (JCM) within the framework of a quantum heat engine, using formulas for heat flux and power in bipartite systems introduced in our previous work [E. Boukobza and D. J. Tannor Phys. Rev. A 74, 063823 (2006)] Amplification of the selected cavity mode occurs even in this simple model, as seen by a positive steady state power. However, initial field coherence is lost, as seen by the decaying off-diagonal field density matrix elements, and by the Husimi-Kano Q function. We show that after an initial transient time the field’s entropy rises linearly during the operation of the engine, which we attribute to the dissipative nature of the evolution and not to matter-field entanglement. We show that the second law of thermodynamics is satisfied in two formulations (Clausius, Carnot) and that the efficiency of the ED JCM heat engine agrees with that defined intuitively by Scovil and Schulz-DuBois. Finally, we compare the steady state heat flux and power of the fully quantum model with the semiclassical counterpart of the ED JCM, and derive the engine efficiency formula of Scovil and Schulz-DuBois analytically from fundamental thermodynamic fluxes.

  3. Thermodynamic analysis of quantum light amplification

    International Nuclear Information System (INIS)

    Thermodynamics of a three-level maser was studied in the pioneering work of Scovil and Schulz-DuBois [Phys. Rev. Lett. 2, 262 (1959)]. In this work we consider the same three-level model, but treat both the matter and the light quantum mechanically. Specifically, we analyze an extended (three-level) dissipative (ED) Jaynes-Cummings model (JCM) within the framework of a quantum heat engine, using formulas for heat flux and power in bipartite systems introduced in our previous work [E. Boukobza and D. J. Tannor Phys. Rev. A 74, 063823 (2006)] Amplification of the selected cavity mode occurs even in this simple model, as seen by a positive steady state power. However, initial field coherence is lost, as seen by the decaying off-diagonal field density matrix elements, and by the Husimi-Kano Q function. We show that after an initial transient time the field's entropy rises linearly during the operation of the engine, which we attribute to the dissipative nature of the evolution and not to matter-field entanglement. We show that the second law of thermodynamics is satisfied in two formulations (Clausius, Carnot) and that the efficiency of the ED JCM heat engine agrees with that defined intuitively by Scovil and Schulz-DuBois. Finally, we compare the steady state heat flux and power of the fully quantum model with the semiclassical counterpart of the ED JCM, and derive the engine efficiency formula of Scovil and Schulz-DuBois analytically from fundamental thermodynamic fluxes

  4. Social amplification of risk: a conceptual framework

    International Nuclear Information System (INIS)

    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

  5. 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

  6. Hardness Amplification in Proof Complexity

    CERN Document Server

    Beame, Paul; Pitassi, Toniann

    2009-01-01

    We present a general method for converting any family of unsatisfiable CNF formulas that is hard for one of the simplest proof systems, tree resolution, into formulas that require large rank in any proof system that manipulates polynomials or polynomial threshold functions of degree at most k (known as Th(k) proofs). Such systems include Lovasz-Schrijver and Cutting Planes proof systems as well as their high degree analogues. These are based on analyzing two new proof systems, denoted by T^cc(k) and R^cc(k). The proof lines of T^cc(k) are arbitrary Boolean functions, each of which can be evaluated by an efficient k-party randomized communication protocol. They include Th{k-1} proofs as a special case. R^cc(k) proofs are stronger and only require that each inference be locally checkable by an efficient k-party randomized communication protocol. Our main results are the following: (1) When k is O(loglogn), for any unsatisfiable CNF formula F requiring resolution rank r, there is a related CNF formula G=Lift_k(F...

  7. Electromagnetic waves amplification in a coaxial triode with virtual cathode

    Energy Technology Data Exchange (ETDEWEB)

    Grigoryev, V.P.; Antoshkin, M.Y.; Koval, T.V.; Kuryakov, A.M. [Tomsk Politechnical Univ. (Russian Federation)

    1995-11-01

    The present paper presents the results of analytical and numerical investigations on the amplification of microwaves in the vircator triode of coaxial making. The range of a parameters of the greatest amplification was define for TH and TE-modes.

  8. Squeezed states and quantum-mechanical parametric amplification

    International Nuclear Information System (INIS)

    The relation of a previous paper on the parametric amplification of a quantum oscillator to squeezed states is described. In particular, we show that in general the amplification factor is also the ''squeezing factor'' of the final state. 8 refs

  9. A new evolutionary theory deduced mathematically from entropy amplification

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A new evolutionary theory which is able to unite the present evolutionary debates is deduced mathematically from the principle of entropy amplification.It suggests that the extensive evolution is driven by the amplification of entropy,or microscopic diversity,and the biological evolution is driven by the amplification of biodiversity.Forming high hierarchies is the most important way for the amplification and brings out spontaneously three kinds of selection.This theory has some positive cultural meanings.

  10. 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.

  11. Method Of Signal Amplification In Multi-Chromophore Luminescence Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Levitsky, Igor A. (Fall River, MA); Krivoshlykov, Sergei G. (Shrewsbury, MA)

    2004-02-03

    A fluorescence-based method for highly sensitive and selective detection of analyte molecules is proposed. The method employs the energy transfer between two or more fluorescent chromophores in a carefully selected polymer matrix. In one preferred embodiment, signal amplification has been achieved in the fluorescent sensing of dimethyl methylphosphonate (DMMP) using two dyes, 3-aminofluoranthene (AM) and Nile Red (NR), in a hydrogen bond acidic polymer matrix. The selected polymer matrix quenches the fluorescence of both dyes and shifts dye emission and absorption spectra relative to more inert matrices. Upon DMMP sorption, the AM fluorescence shifts to the red at the same time the NR absorption shifts to the blue, resulting in better band overlap and increased energy transfer between chromophores. In another preferred embodiment, the sensitive material is incorporated into an optical fiber system enabling efficient excitation of the dye and collecting the fluorescent signal form the sensitive material on the remote end of the system. The proposed method can be applied to multichromophore luminescence sensor systems incorporating N-chromophores leading to N-fold signal amplification and improved selectivity. The method can be used in all applications where highly sensitive detection of basic gases, such as dimethyl methylphosphonate (DMMP), Sarin, Soman and other chemical warfare agents having basic properties, is required, including environmental monitoring, chemical industry and medicine.

  12. Photon detectors with gaseous amplification

    International Nuclear Information System (INIS)

    Gaseous photon detectors, including very large 4π-devices such as those incorporated in SLD and DELPHI, are finally delivering physics after many years of hard work. Photon detectors are among the most difficult devices used in physics experiments, because they must achieve high efficiency for photon transport and for the detection of single photoelectrons. Among detector builders, there is hardly anybody who did not make mistakes in this area, and who does not have a healthy respect for the problems involved. This point is stressed in this paper, and it is suggested that only a very small operating phase space is available for running gaseous photon detectors in a very large system with good efficiency and few problems. In this paper the authors discuss what was done correctly or incorrectly in first generation photon detectors, and what would be their recommendations for second generation detectors. 56 refs., 11 figs

  13. Diffusive shock acceleration and magnetic field amplification

    CERN Document Server

    Schure, K M; Drury, L O'C; Bykov, A M

    2012-01-01

    Diffusive shock acceleration is the theory of particle acceleration through multiple shock crossings. In order for this process to proceed at a rate that can be reconciled with observations of high-energy electrons in the vicinity of the shock, and for cosmic rays protons to be accelerated to energies up to observed galactic values, significant magnetic field amplification is required. In this review we will discuss various theories on how magnetic field amplification can proceed in the presence of a cosmic ray population. On both short and long scales, cosmic ray streaming can induce instabilities that act to amplify the magnetic field. Developments in this area that have occurred over the past decade are the main focus of this paper.

  14. Parametric amplification in low density plasma sheath

    International Nuclear Information System (INIS)

    Nonlinear sheath capacitance properties in low density plasma, whose propose is to produce the parametric amplification on the RF signal in the high frequency band (H.F.) are used. The experiment has been carried out in the Mirror Linear Device LISA of the Universidade Federal Fluminense, where a helium plasma was produced by the radiofrequency source built at UFF with a power which can be varied from 10 watts to 100 watts. The experimental results obtained show that it is practicable the construction of the parametric amplifier with high gain of the selectively, which is very good in the amplification of the weak signals, where the gain factor and the relation between signal versus noise are fundamental. (Author)

  15. Weak-value amplification: state of play

    Directory of Open Access Journals (Sweden)

    Knee George C.

    2016-01-01

    Full Text Available Weak values arise in quantum theory when the result of a weak measurement is conditioned on a subsequent strong measurement. The majority of the trials are discarded, leaving only very few successful events. Intriguingly those can display a substantial signal amplification. This raises the question of whether weak values carry potential to improve the performance of quantum sensors, and indeed a number of impressive experimental results suggested this may be the case. By contrast, recent theoretical studies have found the opposite: using weak-values to obtain an amplification generally worsens metrological performance. This survey summarises the implications of those studies, which call for a reappraisal of weak values’ utility and for further work to reconcile theory and experiment.

  16. Increased centrosome amplification in aged stem cells of the Drosophila midgut

    Energy Technology Data Exchange (ETDEWEB)

    Park, Joung-Sun; Pyo, Jung-Hoon; Na, Hyun-Jin; Jeon, Ho-Jun; Kim, Young-Shin [Department of Molecular Biology, Pusan National University, Busan 609-735 (Korea, Republic of); Arking, Robert, E-mail: aa2210@wayne.edu [Department of Biological Sciences, Wayne State University, Detroit, MI 48202 (United States); Yoo, Mi-Ae, E-mail: mayoo@pusan.ac.kr [Department of Molecular Biology, Pusan National University, Busan 609-735 (Korea, Republic of)

    2014-07-25

    Highlights: • Increased centrosome amplification in ISCs of aged Drosophila midguts. • Increased centrosome amplification in ISCs of oxidative stressed Drosophila midguts. • Increased centrosome amplification in ISCs by overexpression of PVR, EGFR, and AKT. • Supernumerary centrosomes can be responsible for abnormal ISC polyploid cells. • Supernumerary centrosomes can be a useful marker for aging stem cells. - Abstract: Age-related changes in long-lived tissue-resident stem cells may be tightly linked to aging and age-related diseases such as cancer. Centrosomes play key roles in cell proliferation, differentiation and migration. Supernumerary centrosomes are known to be an early event in tumorigenesis and senescence. However, the age-related changes of centrosome duplication in tissue-resident stem cells in vivo remain unknown. Here, using anti-γ-tubulin and anti-PH3, we analyzed mitotic intestinal stem cells with supernumerary centrosomes in the adult Drosophila midgut, which may be a versatile model system for stem cell biology. The results showed increased centrosome amplification in intestinal stem cells of aged and oxidatively stressed Drosophila midguts. Increased centrosome amplification was detected by overexpression of PVR, EGFR, and AKT in intestinal stem cells/enteroblasts, known to mimic age-related changes including hyperproliferation of intestinal stem cells and hyperplasia in the midgut. Our data show the first direct evidence for the age-related increase of centrosome amplification in intestinal stem cells and suggest that the Drosophila midgut is an excellent model for studying molecular mechanisms underlying centrosome amplification in aging adult stem cells in vivo.

  17. Diversity of Phage-Displayed Libraries of Peptides during Panning and Amplification

    Directory of Open Access Journals (Sweden)

    Mohammad R. Jafari

    2011-02-01

    Full Text Available The amplification of phage-displayed libraries is an essential step in the selection of ligands from these libraries. The amplification of libraries, however, decreases their diversity and limits the number of binding clones that a screen can identify. While this decrease might not be a problem for screens against targets with a single binding site (e.g., proteins, it can severely hinder the identification of useful ligands for targets with multiple binding sites (e.g., cells. This review aims to characterize the loss in the diversity of libraries during amplification. Analysis of the peptide sequences obtained in several hundred screens of peptide libraries shows explicitly that there is a significant decrease in library diversity that occurs during the amplification of phage in bacteria. This loss during amplification is not unique to specific libraries: it is observed in many of the phage display systems we have surveyed. The loss in library diversity originates from competition among phage clones in a common pool of bacteria. Based on growth data from the literature and models of phage growth, we show that this competition originates from growth rate differences of only a few percent for different phage clones. We summarize the findings using a simple two-dimensional “phage phase diagram”, which describes how the collapse of libraries, due to panning and amplification, leads to the identification of only a subset of the available ligands. This review also highlights techniques that allow elimination of amplification-induced losses of diversity, and how these techniques can be used to improve phage-display selection and enable the identification of novel ligands.

  18. Novel bioluminescent quantitative detection of nucleic acid amplification in real-time.

    Directory of Open Access Journals (Sweden)

    Olga A Gandelman

    Full Text Available BACKGROUND: The real-time monitoring of polynucleotide amplification is at the core of most molecular assays. This conventionally relies on fluorescent detection of the amplicon produced, requiring complex and costly hardware, often restricting it to specialised laboratories. PRINCIPAL FINDINGS: Here we report the first real-time, closed-tube luminescent reporter system for nucleic acid amplification technologies (NAATs enabling the progress of amplification to be continuously monitored using simple light measuring equipment. The Bioluminescent Assay in Real-Time (BART continuously reports through bioluminescent output the exponential increase of inorganic pyrophosphate (PPi produced during the isothermal amplification of a specific nucleic acid target. BART relies on the coupled conversion of inorganic pyrophosphate (PPi produced stoichiometrically during nucleic acid synthesis to ATP by the enzyme ATP sulfurylase, and can therefore be coupled to a wide range of isothermal NAATs. During nucleic acid amplification, enzymatic conversion of PPi released during DNA synthesis into ATP is continuously monitored through the bioluminescence generated by thermostable firefly luciferase. The assay shows a unique kinetic signature for nucleic acid amplifications with a readily identifiable light output peak, whose timing is proportional to the concentration of original target nucleic acid. This allows qualitative and quantitative analysis of specific targets, and readily differentiates between negative and positive samples. Since quantitation in BART is based on determination of time-to-peak rather than absolute intensity of light emission, complex or highly sensitive light detectors are not required. CONCLUSIONS: The combined chemistries of the BART reporter and amplification require only a constant temperature maintained by a heating block and are shown to be robust in the analysis of clinical samples. Since monitoring the BART reaction requires only a

  19. Increased centrosome amplification in aged stem cells of the Drosophila midgut

    International Nuclear Information System (INIS)

    Highlights: • Increased centrosome amplification in ISCs of aged Drosophila midguts. • Increased centrosome amplification in ISCs of oxidative stressed Drosophila midguts. • Increased centrosome amplification in ISCs by overexpression of PVR, EGFR, and AKT. • Supernumerary centrosomes can be responsible for abnormal ISC polyploid cells. • Supernumerary centrosomes can be a useful marker for aging stem cells. - Abstract: Age-related changes in long-lived tissue-resident stem cells may be tightly linked to aging and age-related diseases such as cancer. Centrosomes play key roles in cell proliferation, differentiation and migration. Supernumerary centrosomes are known to be an early event in tumorigenesis and senescence. However, the age-related changes of centrosome duplication in tissue-resident stem cells in vivo remain unknown. Here, using anti-γ-tubulin and anti-PH3, we analyzed mitotic intestinal stem cells with supernumerary centrosomes in the adult Drosophila midgut, which may be a versatile model system for stem cell biology. The results showed increased centrosome amplification in intestinal stem cells of aged and oxidatively stressed Drosophila midguts. Increased centrosome amplification was detected by overexpression of PVR, EGFR, and AKT in intestinal stem cells/enteroblasts, known to mimic age-related changes including hyperproliferation of intestinal stem cells and hyperplasia in the midgut. Our data show the first direct evidence for the age-related increase of centrosome amplification in intestinal stem cells and suggest that the Drosophila midgut is an excellent model for studying molecular mechanisms underlying centrosome amplification in aging adult stem cells in vivo

  20. Fidelity of DNA polymerases in DNA amplification.

    OpenAIRE

    Keohavong, P; Thilly, W G

    1989-01-01

    Denaturing gradient gel electrophoresis (DGGE) was used to separate and isolate the products of DNA amplification by polymerase chain reaction (PCR). The strategy permitted direct enumeration and identification of point mutations created by T4, modified T7, Klenow fragment of polymerase I, and Thermus aquaticus (Taq) DNA polymerases. Incorrectly synthesized sequences were separated from the wild type by DGGE as mutant/wild-type heteroduplexes and the heteroduplex fraction was used to calculat...

  1. Introduction to Quantum Noise, Measurement and Amplification

    OpenAIRE

    Clerk, A. A.; Devoret, M. H.; Girvin, S. M.; Marquardt, F.; Schoelkopf, R. J.

    2008-01-01

    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 AMO/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, we describe the basics of weak continuous measurements. Particular atte...

  2. MET overexpression and gene amplification in NSCLC: a clinical perspective

    Directory of Open Access Journals (Sweden)

    Landi L

    2013-06-01

    Full Text Available Lorenza Landi, Gabriele Minuti, Armida D'Incecco, Jessica Salvini, Federico CappuzzoMedical Oncology Department, Istituto Toscano Tumori, Ospedale Civile, Livorno, ItalyAbstract: The transmembrane tyrosine kinase mesenchymal-epidermal transition (MET receptor and its ligand, hepatocyte growth factor, also known as scatter factor, have recently been identified as novel promising targets in several human malignancies, including non-small cell lung cancer (NSCLC. Amplification, mutation, or overexpression of the MET gene can result in aberrant activation of the MET axis, leading to migration, invasion, proliferation, metastasis, and neoangiogenesis of cancer cells, suggesting that interfering with the MET/hepatocyte growth factor pathway could represent a potential antitumor strategy. While the role of MET mutations in NSCLC is not as yet fully understood, retrospective studies have shown that an increased MET gene copy number is a negative prognostic factor. In NSCLC, amplification of the MET gene is a relatively rare event, occurring in approximately 4% of patients not previously exposed to systemic therapies and in up to 20% of patients with acquired resistance to epidermal growth factor receptor tyrosine kinase inhibitors. In preclinical models, the presence of MET amplification is a predictor of high sensitivity to anti-MET compounds, and several agents have entered in clinical trials for patients having advanced disease, with promising results. The aim of the present review is to summarize available data on the role of MET in NSCLC and to describe therapeutic strategies under investigation.Keywords: mesenchymal-epidermal transition, hepatocyte growth factor, epidermal growth factor receptor, non-small cell lung cancer

  3. Amplification without instability: applying fluid dynamical insights in chemistry and biology

    International Nuclear Information System (INIS)

    While amplification of small perturbations often arises from instability, transient amplification is possible locally even in asymptotically stable systems. That is, knowledge of a system's stability properties can mislead one's intuition for its transient behaviors. This insight, which has an interesting history in fluid dynamics, has more recently been rediscovered in ecology. Surprisingly, many nonlinear fluid dynamical and ecological systems share linear features associated with transient amplification of noise. This paper aims to establish that these features are widespread in many other disciplines concerned with noisy systems, especially chemistry, cell biology and molecular biology. Here, using classic nonlinear systems and the graphical language of network science, we explore how the noise amplification problem can be reframed in terms of activatory and inhibitory interactions between dynamical variables. The interaction patterns considered here are found in a great variety of systems, ranging from autocatalytic reactions and activator–inhibitor systems to influential models of nerve conduction, glycolysis, cell signaling and circadian rhythms. (paper)

  4. An integrated lateral flow assay for effective DNA amplification and detection at the point of care.

    Science.gov (United States)

    Choi, Jane Ru; Hu, Jie; Gong, Yan; Feng, Shangsheng; Wan Abas, Wan Abu Bakar; Pingguan-Murphy, Belinda; Xu, Feng

    2016-05-10

    Lateral flow assays (LFAs) have been extensively explored in nucleic acid testing (NAT) for medical diagnostics, food safety analysis and environmental monitoring. However, the amount of target nucleic acid in a raw sample is usually too low to be directly detected by LFAs, necessitating the process of amplification. Even though cost-effective paper-based amplification techniques have been introduced, they have always been separately performed from LFAs, hence increasing the risk of reagent loss and cross-contaminations. To date, integrating paper-based nucleic acid amplification into colorimetric LFA in a simple, portable and cost-effective manner has not been introduced. Herein, we developed an integrated LFA with the aid of a specially designed handheld battery-powered system for effective amplification and detection of targets in resource-poor settings. Interestingly, using the integrated paper-based loop-mediated isothermal amplification (LAMP)-LFA, we successfully performed highly sensitive and specific target detection, achieving a detection limit of as low as 3 × 10(3) copies of target DNA, which is comparable to the conventional tube-based LAMP-LFA in an unintegrated format. The device may serve in conjunction with a simple paper-based sample preparation to create a fully integrated paper-based sample-to-answer diagnostic device for point-of-care testing (POCT) in the near future. PMID:27010033

  5. Polymerase chain reaction amplification of a GC rich region by adding 1,2 propanediol

    Directory of Open Access Journals (Sweden)

    Zeinab Mousavian

    2014-01-01

    Full Text Available Background : Apolipoprotein E (ApoE is one of the most important carriers of lipids in mammalians. The gene for this lipoprotein (ApoE is located on chromosome 19 which is related with the pathogenesis of some nervous system disease. ApoE gene is identified as a high guanine-cytosine (GC content fragment. Detection and amplification of these templates are extensively laborious and baffling. The aim of this study was to find a practical and feasible method for the amplification of the number of GC rich genes such as ApoE. Materials and Methods: We experimented with simple polymerase chain reaction (PCR, nested PCR and PCR with 1-2 propanediol, dimethylsulfoxide (DMSO, and ethyleneglicol as additive substances to enhance the amplification ApoE gene and used the 40 samples of the human whole blood were collected in test tubes with a pre-treatment of ethylene diaminetetraacetic acid. Results: According to our observations, presence of 1-2 propanediol, DMSO, and ethyleneglicol as additive substances resulted to enhanced amplification of ApoE gene. Addition of 1-2 propanediol showed the best results, caused optimization and revealed more specific and sharp bands. Conclusion: According to our findings 1-2 propanediol are the best organic reagent for improving the amplification of ApoE gene. Optimization procedure for each GC rich sequence is recommended to be performed separately in order to identify which of the additive agent is more efficient and applicable for a particular target.

  6. NAIMA: target amplification strategy allowing quantitative on-chip detection of GMOs

    Science.gov (United States)

    Morisset, Dany; Dobnik, David; Hamels, Sandrine; Žel, Jana; Gruden, Kristina

    2008-01-01

    We have developed a novel multiplex quantitative DNA-based target amplification method suitable for sensitive, specific and quantitative detection on microarray. This new method named NASBA Implemented Microarray Analysis (NAIMA) was applied to GMO detection in food and feed, but its application can be extended to all fields of biology requiring simultaneous detection of low copy number DNA targets. In a first step, the use of tailed primers allows the multiplex synthesis of template DNAs in a primer extension reaction. A second step of the procedure consists of transcription-based amplification using universal primers. The cRNA product is further on directly ligated to fluorescent dyes labelled 3DNA dendrimers allowing signal amplification and hybridized without further purification on an oligonucleotide probe-based microarray for multiplex detection. Two triplex systems have been applied to test maize samples containing several transgenic lines, and NAIMA has shown to be sensitive down to two target copies and to provide quantitative data on the transgenic contents in a range of 0.1–25%. Performances of NAIMA are comparable to singleplex quantitative real-time PCR. In addition, NAIMA amplification is faster since 20 min are sufficient to achieve full amplification. PMID:18710880

  7. Loop mediated isothermal amplification: An innovative gene amplification technique for animal diseases.

    Science.gov (United States)

    Sahoo, Pravas Ranjan; Sethy, Kamadev; Mohapatra, Swagat; Panda, Debasis

    2016-05-01

    India being a developing country mainly depends on livestock sector for its economy. However, nowadays, there is emergence and reemergence of more transboundary animal diseases. The existing diagnostic techniques are not so quick and with less specificity. To reduce the economy loss, there should be a development of rapid, reliable, robust diagnostic technique, which can work with high degree of sensitivity and specificity. Loop mediated isothermal amplification assay is a rapid gene amplification technique that amplifies nucleic acid under an isothermal condition with a set of designed primers spanning eight distinct sequences of the target. This assay can be used as an emerging powerful, innovative gene amplification diagnostic tool against various pathogens of livestock diseases. This review is to highlight the basic concept and methodology of this assay in livestock disease. PMID:27284221

  8. Assessment of whole genome amplification-induced bias through high-throughput, massively parallel whole genome sequencing

    Directory of Open Access Journals (Sweden)

    Plant Ramona N

    2006-08-01

    Full Text Available Abstract Background Whole genome amplification is an increasingly common technique through which minute amounts of DNA can be multiplied to generate quantities suitable for genetic testing and analysis. Questions of amplification-induced error and template bias generated by these methods have previously been addressed through either small scale (SNPs or large scale (CGH array, FISH methodologies. Here we utilized whole genome sequencing to assess amplification-induced bias in both coding and non-coding regions of two bacterial genomes. Halobacterium species NRC-1 DNA and Campylobacter jejuni were amplified by several common, commercially available protocols: multiple displacement amplification, primer extension pre-amplification and degenerate oligonucleotide primed PCR. The amplification-induced bias of each method was assessed by sequencing both genomes in their entirety using the 454 Sequencing System technology and comparing the results with those obtained from unamplified controls. Results All amplification methodologies induced statistically significant bias relative to the unamplified control. For the Halobacterium species NRC-1 genome, assessed at 100 base resolution, the D-statistics from GenomiPhi-amplified material were 119 times greater than those from unamplified material, 164.0 times greater for Repli-G, 165.0 times greater for PEP-PCR and 252.0 times greater than the unamplified controls for DOP-PCR. For Campylobacter jejuni, also analyzed at 100 base resolution, the D-statistics from GenomiPhi-amplified material were 15 times greater than those from unamplified material, 19.8 times greater for Repli-G, 61.8 times greater for PEP-PCR and 220.5 times greater than the unamplified controls for DOP-PCR. Conclusion Of the amplification methodologies examined in this paper, the multiple displacement amplification products generated the least bias, and produced significantly higher yields of amplified DNA.

  9. Surface acoustic wave amplification by direct current-voltage supplied to graphene film

    International Nuclear Information System (INIS)

    Using a high-resolution X-Ray diffraction measurement method, the surface acoustic wave (SAW) propagation in a graphene film on the surface of a Ca3TaGa3Si2O14 (CTGS) piezoelectric crystal was investigated, where an external current was driven across the graphene film. Here, we show that the application of the DC field leads to a significant enhancement of the SAW magnitude and, as a result, to amplification of the diffraction satellites. Amplification of 33.2 dB/cm for the satellite +1, and of 13.8 dB/cm for the satellite +2, at 471 MHz has been observed where the external DC voltage of +10 V was applied. Amplification of SAW occurs above a DC field much smaller than that of a system using bulk semiconductor. Theoretical estimates are in reasonable agreement with our measurements and analysis of experimental data for other materials

  10. Switchable amplification of vibrational circular dichroism as a probe of local chiral structure.

    Science.gov (United States)

    Domingos, Sérgio R; Sanders, Hans J; Hartl, František; Buma, Wybren J; Woutersen, Sander

    2014-12-15

    A new method to detect the vibrational circular dichroism (VCD) of a localized part of a chiral molecular system is reported. A local VCD amplifier was implemented, and the distance dependence of the amplification was investigated in a series of peptides. The results indicate a characteristic distance of 2.0±0.3 bonds, which suggests that the amplification is a localized phenomenon. The amplifier can be covalently coupled to a specific part of a molecule, and can be switched ON and OFF electrochemically. By subtracting the VCD spectra obtained when the amplifier is in the ON and OFF states, the VCD of the local environment of the amplifier can be separated from the total VCD spectrum. Switchable local VCD amplification thus makes it possible to "zoom in" on a specific part of a chiral molecule. PMID:25212702

  11. Impacts of seed power on amplification performance in pulsed double-clad fiber amplifier

    Institute of Scientific and Technical Information of China (English)

    Fangpei Zhang; Jianqiang Zhu; Zhijiang Wang; Qihong Lou; Jun Zhou; Hongming Zhao; Songtao Du; Jingxing Dong; Yunrong Wei; Bing He; Jinyan Li

    2008-01-01

    A pulsed master-oscillator fiber power amplifier system with near diffraction-limited output by use of China-made large-mode-area fiber and a (2 + 1) × 1 multimode combiner is reported. The effect of the seed power on the amplification performance is found. For the seed power, there exists a range within which the pulsed fiber amplifier can operate safely and reliably at a certain pump power. With the seed average power of 70 mW, the amplification performances of the fiber amplifier are investigated.

  12. The national protocol for paediatric amplification in Australia.

    Science.gov (United States)

    King, Alison M

    2010-01-01

    This document describes the national protocol for the selection, fitting, verification, and evaluation of amplification for hearing-impaired children in Australia. It also outlines the approach to management of children who have auditory neuropathy spectrum disorder, children who have mild and unilateral hearing loss, and children who require cochlear implantation. Audiological management of all Australian citizens and permanent residents under twenty-one years of age who have a hearing loss is carried out by the national hearing service provider, Australian Hearing. It is funded by the Australian Government's Hearing Services Program to provide fully subsidised hearing aids, frequency modulated (FM) systems and ongoing audiological management. All hearing aids for children are multi-channel devices that offer wide dynamic range compression, directional microphone technology and feedback cancellation as well as access to multiple listening programs, telecoil and audio-input facilities. Hearing aid gain, frequency response and maximum power output are derived according to the NAL-NL1 prescription procedure and verified using real ear measurements. Amplification benefit is evaluated using a range of speech perception tests and functional assessment questionnaires. PMID:19919326

  13. Generalized modulational instability in multimode fibers: wideband multimode parametric amplification

    CERN Document Server

    Guasoni, M

    2015-01-01

    In this paper intermodal modulational instability (IM-MI) is analyzed in a multimode fiber where several spatial and polarization modes propagate. The coupled nonlinear Schr\\"{o}dinger equations describing the modal evolution in the fiber are linearized and reduced to an eigenvalue problem. As a result, the amplification of each mode can be described by means of the eigenvalues and eigenvectors of a matrix that stores the information about the dispersion properties of the modes and the modal power distribution of the pump. Some useful analytical formulas are also provided that estimate the modal amplification as function of the system parameters. Finally, the impact of third-order dispersion and of absorbtion losses is evaluated, which reveals some surprising phenomena into the IM-MI dynamics. These outcomes generalize previous studies on bimodal-MI, related to the interaction between 2 spatial or polarization modes, to the most general case of $N>2$ interacting modes. Moreover, they pave the way towards the ...

  14. Biomass changes and trophic amplification of plankton in a warmer ocean

    KAUST Repository

    Chust, Guillem

    2014-05-07

    Ocean warming can modify the ecophysiology and distribution of marine organisms, and relationships between species, with nonlinear interactions between ecosystem components potentially resulting in trophic amplification. Trophic amplification (or attenuation) describe the propagation of a hydroclimatic signal up the food web, causing magnification (or depression) of biomass values along one or more trophic pathways. We have employed 3-D coupled physical-biogeochemical models to explore ecosystem responses to climate change with a focus on trophic amplification. The response of phytoplankton and zooplankton to global climate-change projections, carried out with the IPSL Earth System Model by the end of the century, is analysed at global and regional basis, including European seas (NE Atlantic, Barents Sea, Baltic Sea, Black Sea, Bay of Biscay, Adriatic Sea, Aegean Sea) and the Eastern Boundary Upwelling System (Benguela). Results indicate that globally and in Atlantic Margin and North Sea, increased ocean stratification causes primary production and zooplankton biomass to decrease in response to a warming climate, whilst in the Barents, Baltic and Black Seas, primary production and zooplankton biomass increase. Projected warming characterized by an increase in sea surface temperature of 2.29 ± 0.05 °C leads to a reduction in zooplankton and phytoplankton biomasses of 11% and 6%, respectively. This suggests negative amplification of climate driven modifications of trophic level biomass through bottom-up control, leading to a reduced capacity of oceans to regulate climate through the biological carbon pump. Simulations suggest negative amplification is the dominant response across 47% of the ocean surface and prevails in the tropical oceans; whilst positive trophic amplification prevails in the Arctic and Antarctic oceans. Trophic attenuation is projected in temperate seas. Uncertainties in ocean plankton projections, associated to the use of single global and

  15. OPTICAL SOLITONS: Fibreoptic communication lines with distributed Raman amplification: Numerical simulation

    Science.gov (United States)

    Nasieva, I. O.; Fedoruk, Mikhail P.

    2003-10-01

    The properties of optical solitons in variable-dispersion fibreoptic communication lines in which distributed Raman amplification of optical signals is used are studied by numerical simulation. It is shown that solitons can serve as carriers of information in communication systems with a data transmission rate exceeding 10 Gbit s-1.

  16. Molecular beacon probes combined with amplification by NASBA enable homogeneous, real-time detection of RNA

    NARCIS (Netherlands)

    Leone, G.; Schijndel, van H.; Gemen, van B.; Kramer, F.R.; Schoen, C.D.

    1998-01-01

    Molecular beacon probes can be employed in a NASBA amplicon detection system to generate a specific fluorescent signal concomitantly with amplification. A molecular beacon, designed to hybridize within the target sequence, was introduced into NASBA reactions that amplify the genomic RNA of potato le

  17. Analysis of numerical stability and amplification matrices: Fourth-order Runge-Kutta methods

    Science.gov (United States)

    Kennedy, E. W.

    1979-01-01

    Amplification matrices, numerical kernels, stable, and exponentially stable numerical solutions are examined. The various techniques involved in these concepts are applied to certain systems that have Jordan forms, which are nondiagonal, with particular interest in the case of imaginary or zero eigenvalues.

  18. Sensitive SERS detection of miRNA via enzyme-free DNA machine signal amplification.

    Science.gov (United States)

    Li, Xiaoxiao; Ye, Sujuan; Luo, Xiliang

    2016-08-11

    In this work, an enzyme-free signal amplified detection platform is described for miRNA detection with a DNA fueled molecular machine. Coupling SERS technology with multiple amplification modes, this flexible biosensing system exhibits high sensitivity and specificity. PMID:27469084

  19. Social amplification of risk: An empirical study

    International Nuclear Information System (INIS)

    The social amplification of risk is a theoretical framework that addresses an important deficiency of formal risk assessment methods and procedures. Typically assessments of risk from technological mishaps have been based upon the expected number of people who could be killed or injured or the amount of property that might be damaged. The diverse and consequential impacts that followed in the aftermath of the Three Mile Island accident make it clear that risk assessments that exclude the role of public perceptions of risk will greatly underestimate the potential costs of certain types of hazards. The accident at Three Mile Island produced no direct fatalities and few, if any, expected deaths due to cancer, yet few other accidents in history have had such costly societal impacts. The experience of amplified impacts argues for the development of a broadened theoretical and methodological perspective capable of integrating technical assessment of risk with public perceptions. This report presents the results to date in an ongoing research effort to better understand the complex processes by which adverse events produce impacts. In particular this research attempts to construct a framework that can account for those events that have produced, or are capable of producing, greater societal impacts than would be forecast by traditional risk assessment methods. This study demonstrates that the social amplification of risk involves interactions between sophisticated technological hazards, public and private institutions, and subtle individual and public perceptions and behaviors. These factors, and the variables underlying the intricate processes of social amplification that occur in modern society, are not fully defined and clarified in this report. 19 refs., 9 figs., 10 tabs

  20. Parametric Amplification of Gravitational Fluctuations during Reheating

    International Nuclear Information System (INIS)

    Cosmological perturbations can undergo amplification by parametric resonance during preheating even on scales larger than the Hubble radius, without violating causality. A unified description of gravitational and matter fluctuations is crucial to determine the strength of the instability. To extract specific signatures of the oscillating inflaton field during reheating, it is essential to focus on a variable describing metric fluctuations which is constant in the standard analyses of inflation. For a massive inflaton without self-coupling, we find no additional growth of superhorizon modes during reheating beyond the usual predictions. For a massless self-coupled inflaton, there is a sub-Hubble scale resonance. copyright 1999 The American Physical Society

  1. Amplification of fluorescence using collinear picosecond optical parametric amplification at degeneracy

    Institute of Scientific and Technical Information of China (English)

    Zhang Jing; Zhang Qiu-Lin; Jiang Man; Zhang Dong-Xiang; Feng Bao-Hua; Zhang Jing-Yuan

    2012-01-01

    We demonstrate the output characteristic of broadband parametric amplification of incoherent light pulses in a 355-nm pumped degenerate picosecond optical parametric amplification with either saturated or unsaturated amplification.The optical parametric amplifier is seeded by the fluorescence generated in a solution of pyridine-1 dye in ethanol.With the saturated amplification,we can obtain high energy incoherent light pulses,whose full widtth at half maximum bandwidth varies from 16 nm to 53 nm for the different phase matching angles near degeneracy.Moreover,the unsaturated bandwidth of the amplified pulses fits well to the calculated result at degeneracy.Selecting s-polarized fluorescence with a Glan-Taylor prism,the maximum bandwidth of the amplified fluorescence is found to be 59 nm for a purely s-polarized seed.The maximum output energy is 0.67 mJ for the optical parametric amplifier.By using an optical filter and compressor,the generated high energy incoherent light has great potential as the incoherent pump,signal or idler wave of a parametric down-conversion process,so that a wave with a high degree of coherence can be generated from an incoherent pump light.

  2. Multiplex allele-specific target amplification based on PCR suppression

    OpenAIRE

    Broude, Natalia E.; Zhang, Lingang; Woodward, Karen; Englert, David; Cantor, Charles R.

    2001-01-01

    We have developed a strategy for multiplex PCR based on PCR suppression. PCR suppression allows DNA target amplification with only one sequence-specific primer per target and a second primer that is common for all targets. Therefore, an n-plex PCR would require only n + 1 primers. We have demonstrated uniform, efficient amplification of targeted sequences in 14-plex PCR. The high specificity of suppression PCR also provides multiplexed amplification with allele specifi...

  3. Loss of KLF14 triggers centrosome amplification and tumorigenesis

    OpenAIRE

    Fan, Guangjian; Sun, Lianhui; Shan, Peipei; Zhang, Xianying; Huan, Jinliang; Li, Dali; Wang, Tingting; Wei, Tingting; Zhang, Xiaohong; Gu, Xiaoyang; Yao, Liangfang; Xuan, Yang; Hou, Zhaoyuan; Cui, Yongping; Cao, Liu

    2015-01-01

    Centrosome amplification is frequent in cancer, but the underlying mechanisms remain unclear. Here we report that disruption of the Kruppel-like factor 14 (KLF14) gene in mice causes centrosome amplification, aneuploidy and spontaneous tumorigenesis. Molecularly, KLF14 functions as a transcriptional repressor of Plk4, a polo-like kinase whose overexpression induces centrosome overduplication. Transient knockdown of KLF14 is sufficient to induce Plk4-directed centrosome amplification. Clinical...

  4. An Improved Analytical Expression for Write Amplification in NAND Flash

    OpenAIRE

    Xiang, Luojie; Kurkoski, Brian

    2011-01-01

    Agarwal et al. gave an closed-form expression for write amplification in NAND flash memory by finding the probability of a page being valid over the whole flash memory. This paper gives an improved analytic expression for write amplification in NAND flash memory by finding the probability of a page being invalid over the block selected for garbage collection. The improved expression uses Lambert W function. Through asymptotic analysis, write amplification is shown to depend on overprovisionin...

  5. Quantum noise in parametric amplification under phase-mismatched conditions

    Science.gov (United States)

    Inoue, K.

    2016-05-01

    This paper studies quantum noise in parametric amplification under phase-mismatched conditions. The equations of motion of the quantum-mechanical field operators, which include phase mismatch under unsaturated conditions are first derived from the Heisenberg equation. Next, the noise figure is evaluated using the solutions of the derived equations. The results indicate that phase mismatch scarcely affects noise property in phase-insensitive amplification while it has a notable effect in case of phase-sensitive amplification.

  6. Oncogene amplification detected by in situ hybridization in radiation induced rat skin tumors

    International Nuclear Information System (INIS)

    Oncogene activation may play an important role in radiation induced carcinogenesis. C-myc oncogene amplification was detected by in situ hybridization in radiation-induced rat skin tumors, including squamous and basal cell carcinomas. In situ hybridization was performed with a biotinylated human c-myc third exon probe, visualized with an avidin-biotinylated alkaline phosphate detection system. No c-myc oncogene amplification was detected in normal rat skin at very early times after exposure to ionizing radiation, which is consistent with the view that c-myc amplification is more likely to be related to carcinogenesis than to normal cell proliferation. The incorporation of tritiated thymidine into the DNA of rat skin cells showed that the proliferation of epidermal cells reached a peak on the seventh day after exposure to ionizing radiation and then decreased. No connection between the proliferation of epidermal cell and c-myc oncogene amplification in normal or irradiated rat skin was found. The results indicated that c-myc amplification as measured by in situ hybridization was correlated with the Southern bolt results, but only some of the cancer cells were amplified. The c-myc positive cells were distributed randomly within regions of the tumor and exhibited a more uniform nuclear structure in comparison to the more vacuolated c-myc negative cells. No c-myc signal was detected in unirradiated normal skin or in irradiated skin cells near the tumors. C-myc amplification appears to be cell or cell cycle specific within radiation-induced carcinomas. 28 refs., 3 figs., 3 tabs

  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. PMID:27271574

  8. Brillouin amplification and processing of the Rayleigh scattered signal.

    Science.gov (United States)

    Mermelstein, David; Shacham, Eliashiv; Biton, Moran; Sternklar, Shmuel

    2015-07-15

    Brillouin amplification of Rayleigh scattering is demonstrated using two different configurations. In the first technique, the Rayleigh scattering and amplification occurs simultaneously in the same fiber. In the second technique, the amplification takes place in a second fiber. The differences between the two techniques are delineated. Using the second technique, we demonstrate single-sideband off-resonant Brillouin amplification of the Rayleigh signal. This technique is shown to enhance the SNR of a signal that is due to vibration-induced strain on the fiber. PMID:26176464

  9. Giant amplification of modes in parity-time symmetric waveguides

    International Nuclear Information System (INIS)

    The combination of the interference with the amplification of modes in a waveguide with gain and losses can result in a giant amplification of the propagating beam, which propagates without distortion of its average amplitude. An increase of the gain-loss gradient by only a few times results in a magnification of the beam by a several orders of magnitude. -- Highlights: ► We report giant beam amplification in parity-time symmetric optical waveguides. ► The amplification is due to interference of gain-guided modes. ► Flexible control both by parameters of the waveguide and of the input beam.

  10. Induction of gene amplification in Plasmodium falciparum

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, P.L.

    1985-01-01

    Human erythrocytic in vitro cultures of Honduras I strain of the malaria parasite Plasmodium falciparum have been stressed stepwise with increasing concentrations of methotrexate (MTX), a folate antagonist. This selection has produced a strain that is 450 times more resistant to the drug than the original culture. Uptake of sublethal doses of radiolabeled MTX by infected red blood cells was 6-36 times greater in the resistant cultures than in the nonresistant controls. DNA isolated from all of the parasites was probed by hybridization with /sup 35/S-labeled DNA derived from a clone of the yeast thymidylate synthetase (TS) gene. This showed 50 to 100 times more increased hybridization of the TS probe to the DNA from the resistant parasites is direct evidence of gene amplification because DHFR and TS are actually one and the same bifunctional enzyme in P. falciparum. Hence, the evidence presented indicates that induced resistance of the malaria parasite to MTX in this case is due to overproduction of DHFR resulting from amplification of the DHFR-TS gene.

  11. 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.

  12. Induction of gene amplification in Plasmodium falciparum

    International Nuclear Information System (INIS)

    Human erythrocytic in vitro cultures of Honduras I strain of the malaria parasite Plasmodium falciparum have been stressed stepwise with increasing concentrations of methotrexate (MTX), a folate antagonist. This selection has produced a strain that is 450 times more resistant to the drug than the original culture. Uptake of sublethal doses of radiolabeled MTX by infected red blood cells was 6-36 times greater in the resistant cultures than in the nonresistant controls. DNA isolated from all of the parasites was probed by hybridization with 35S-labeled DNA derived from a clone of the yeast thymidylate synthetase (TS) gene. This showed 50 to 100 times more increased hybridization of the TS probe to the DNA from the resistant parasites is direct evidence of gene amplification because DHFR and TS are actually one and the same bifunctional enzyme in P. falciparum. Hence, the evidence presented indicates that induced resistance of the malaria parasite to MTX in this case is due to overproduction of DHFR resulting from amplification of the DHFR-TS gene

  13. Seismic Wave Amplification in 3D Alluvial Basins: 3D/1D Amplification Ratios from Fast Multipole BEM Simulations

    CERN Document Server

    Fajardo, Kristel C Meza; Chaillat, Stéphanie; Lenti, Luca

    2016-01-01

    In this work, we study seismic wave amplification in alluvial basins having 3D standard geometries through the Fast Multipole Boundary Element Method in the frequency domain. We investigate how much 3D amplification differs from the 1D (horizontal layering) case. Considering incident fields of plane harmonic waves, we examine the relationships between the amplification level and the most relevant physical parameters of the problem (impedance contrast, 3D aspect ratio, vertical and oblique incidence of plane waves). The FMBEM results show that the most important parameters for wave amplification are the impedance contrast and the so-called equivalent shape ratio. Using these two parameters, we derive simple rules to compute the fundamental frequency for various 3D basin shapes and the corresponding 3D/1D amplification factor for 5% damping. Effects on amplification due to 3D basin asymmetry are also studied and incorporated in the derived rules.

  14. Self-Amplification of Solid Friction in Interleaved Assemblies

    Science.gov (United States)

    Alarcón, Héctor; Salez, Thomas; Poulard, Christophe; Bloch, Jean-Francis; Raphaël, Élie; Dalnoki-Veress, Kari; Restagno, Frédéric

    2016-01-01

    It is nearly impossible to separate two interleaved phone books when held by their spines. A full understanding of this astonishing demonstration of solid friction in complex assemblies remains elusive. In this Letter, we report on experiments with controlled booklets and show that the force required increases sharply with the number of sheets. A model captures the effect of the number of sheets, their thickness, and the overlapping distance. Furthermore, the data collapse onto a self-similar master curve with one dimensionless amplification parameter. In addition to solving a long-standing familiar enigma, this model system provides a framework with which one can accurately measure friction forces and coefficients at low loads, and that has relevance to complex assemblies from the macro- to the nanoscale.

  15. Two-qubit parametric amplifier: large amplification of weak signals

    CERN Document Server

    Savel'ev, S; Rakhmanov, A L; Omelyanchouk, A N; Washington, Z; Nori, Franco

    2012-01-01

    Using numerical simulations, we show that two coupled qubits can amplify a weak signal about hundredfold. This can be achieved if the two qubits are biased simultaneously by this weak signal and a strong pump signal, both of which having frequencies close to the inter-level transitions in the system. The weak signal strongly affects the spectrum generated by the strong pumping drive by producing and controlling mixed harmonics with amplitudes of the order of the main harmonic of the strong drive. We show that the amplification is robust with respect to noise, with an intensity of the order of the weak signal. When deviating from the optimal regime (corresponding to strong qubit coupling and a weak-signal frequency equal to the inter-level transition frequency) the proposed amplifier becomes less efficient, but it can still considerably enhance a weak signal (by several tens). We therefore propose to use coupled qubits as a combined parametric amplifier and frequency shifter.

  16. Cycling excitation process: An ultra efficient and quiet signal amplification mechanism in semiconductor

    International Nuclear Information System (INIS)

    Signal amplification, performed by transistor amplifiers with its merit rated by the efficiency and noise characteristics, is ubiquitous in all electronic systems. Because of transistor thermal noise, an intrinsic signal amplification mechanism, impact ionization was sought after to complement the limits of transistor amplifiers. However, due to the high operation voltage (30-200 V typically), low power efficiency, limited scalability, and, above all, rapidly increasing excess noise with amplification factor, impact ionization has been out of favor for most electronic systems except for a few applications such as avalanche photodetectors and single-photon Geiger detectors. Here, we report an internal signal amplification mechanism based on the principle of the phonon-assisted cycling excitation process (CEP). Si devices using this concept show ultrahigh gain, low operation voltage, CMOS compatibility, and, above all, quantum limit noise performance that is 30 times lower than devices using impact ionization. Established on a unique physical effect of attractive properties, CEP-based devices can potentially revolutionize the fields of semiconductor electronics

  17. Cycling excitation process: An ultra efficient and quiet signal amplification mechanism in semiconductor

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yu-Hsin [Materials Science and Engineering Program, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0418 (United States); Yan, Lujiang; Zhang, Alex Ce; Hall, David; Niaz, Iftikhar Ahmad; Zhou, Yuchun [Department of Electrical and Computer Engineering, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0409 (United States); Sham, L. J. [Department of Physics, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093 (United States); Lo, Yu-Hwa, E-mail: ylo@ucsd.edu [Materials Science and Engineering Program, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0418 (United States); Department of Electrical and Computer Engineering, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0409 (United States)

    2015-08-03

    Signal amplification, performed by transistor amplifiers with its merit rated by the efficiency and noise characteristics, is ubiquitous in all electronic systems. Because of transistor thermal noise, an intrinsic signal amplification mechanism, impact ionization was sought after to complement the limits of transistor amplifiers. However, due to the high operation voltage (30-200 V typically), low power efficiency, limited scalability, and, above all, rapidly increasing excess noise with amplification factor, impact ionization has been out of favor for most electronic systems except for a few applications such as avalanche photodetectors and single-photon Geiger detectors. Here, we report an internal signal amplification mechanism based on the principle of the phonon-assisted cycling excitation process (CEP). Si devices using this concept show ultrahigh gain, low operation voltage, CMOS compatibility, and, above all, quantum limit noise performance that is 30 times lower than devices using impact ionization. Established on a unique physical effect of attractive properties, CEP-based devices can potentially revolutionize the fields of semiconductor electronics.

  18. All Three Rows of Outer Hair Cells Are Required for Cochlear Amplification

    Directory of Open Access Journals (Sweden)

    Michio Murakoshi

    2015-01-01

    Full Text Available In the mammalian auditory system, the three rows of outer hair cells (OHCs located in the cochlea are thought to increase the displacement amplitude of the organ of Corti. This cochlear amplification is thought to contribute to the high sensitivity, wide dynamic range, and sharp frequency selectivity of the hearing system. Recent studies have shown that traumatic stimuli, such as noise exposure and ototoxic acid, cause functional loss of OHCs in one, two, or all three rows. However, the degree of decrease in cochlear amplification caused by such functional losses remains unclear. In the present study, a finite element model of a cross section of the gerbil cochlea was constructed. Then, to determine effects of the functional losses of OHCs on the cochlear amplification, changes in the displacement amplitude of the basilar membrane (BM due to the functional losses of OHCs were calculated. Results showed that the displacement amplitude of the BM decreases significantly when a single row of OHCs lost its function, suggesting that all three rows of OHCs are required for cochlear amplification.

  19. Control of amplification without inversion in H2 and LiH molecules: Dependence on relative magnitude of probe and coherent field Rabi frequencies in three-level system

    Indian Academy of Sciences (India)

    Sulagna Dutta; Krishna Rai Dastidar

    2006-12-01

    Dependence of amplification without inversion (AWI) on the relative strength of probe and coherent field Rabi frequencies has been studied in H2 and LiH molecules for three-level configuration. We have derived exact analytical expressions for coherences and populations keeping all the orders of probe field Rabi frequency () and coherent field Rabi frequency () in the steady state limit. Previously, first-order approximation (i.e. keeping only the first-order term in ) was used and hence AWI was studied for the condition ≫ . Here, by using the exact analytical expressions of coherences and populations, we have shown that AWI is maximum when is within the same order of probe field Rabi frequency irrespective of the choice of different ro-vibrational transitions in both the molecules. However, the shape of the gain profile and the maximum value of gain on the probe field and the absorption on coherent field depend on the choice of different ro-vibrational levels as the upper lasing levels. Effect of bidirectional pumping, homogeneous and inhomogeneous broadening on AWI process has been studied. By solving the density matrix equations numerically it has been shown that both the transient and the steady state AWI can be obtained and the numerical values of coherences and populations at large time are in very good agreement with exact analytical values in the steady state limit. It has been shown that in molecules AWI can be obtained on probe field of smaller wavelength than that of the coherent field which has not been observed in atoms so far.

  20. Amplification of SV40 and cellular genes in SV40 transformed Chinese hamster embryo cells treated with chemical carcinogens

    International Nuclear Information System (INIS)

    To study the effect of chemical carcinogens on the amplification of specific genes, we have constructed a model system, utilizing integrated SV40 as an example for an endogenous gene. Recently, we have shown that exposure of SV40 transformed Chinese hamster cells to a variety of carcinogens induced the amplification of the integrated SV40 genome. Functional T-antigen was necessary for the amplification phenomenon. The work presented in this manuscript shows that the functional origin of replication, which consists of the sequences at the origin of replication and an active T-antigen, is required for the amplification. Utilizing cloned SV40 inserts and the adjacent Chinese hamster sequences we were able to show that SV40 and the flanking cellular sequences were amplified. As the distance from the SV40 origin of replication increased, the extent of amplification was decreased. The amplified sequences are associated with both chromosomal and extrachromosomal sequences. Carcinogen-mediated amplification is not restricted to SV40 sequences and endogenous genes such as dehydrofolate reductase (dhfr), the histocompatibility gene (HLA) and c-ras/sup Ha/ gene are amplified. 26 references, 5 figures

  1. Survey and visual detection of Zaire ebolavirus in clinical samples targeting the nucleoprotein gene in Sierra Leone

    Directory of Open Access Journals (Sweden)

    Jing eYuan

    2015-12-01

    Full Text Available Ebola virus (EBOV can lead to severe hemorrhagic fever with a high risk of death in humans and other primates. To guide treatment and prevent spread of the viral infection, a rapid and sensitive detection method is required for clinical samples. Here, we described and evaluated a reverse transcription loop-mediated isothermal amplification (RT-LAMP method to detect Zaire ebolavirus using the nucleoprotein gene (NP as a target sequence. Two different techniques were used, a calcein/Mn2+ complex chromogenic method and real-time turbidity monitoring. The RT-LAMP assay detected the NP target sequence with a limit of 4.56 copies/μL within 45 min under 61°C, a similar even or increase in sensitivity than that of real-time reverse transcription-polymerase chain reaction (RT-PCR. Additionally, all pseudoviral particles or non- Zaire EBOV genomes were negative for LAMP detection, indicating that the assay was highly specific for EBOV. To appraise the availability of the RT-LAMP method for use in clinical diagnosis of EBOV, of 417 blood or swab samples collected from patients with clinically suspected infections in Sierra Leone, 307 were identified for RT-LAMP-based surveillance of EBOV. Therefore, the highly specific and sensitive RT-LAMP method allows the rapid detection of EBOV, and is a suitable tool for clinical screening, diagnosis, and primary quarantine purposes.

  2. HER2 overexpression and amplification is present in a subset of ovarian mucinous carcinomas and can be targeted with trastuzumab therapy

    Directory of Open Access Journals (Sweden)

    Swenerton Kenneth D

    2009-12-01

    Full Text Available Abstract Background The response rate of ovarian mucinous carcinomas to paclitaxel/carboplatin is low, prompting interest in targeted molecular therapies. We investigated HER2 expression and amplification, and the potential for trastuzumab therapy in this histologic subtype of ovarian cancer. Methods HER2 status was tested in 33 mucinous carcinomas and 16 mucinous borderline ovarian tumors (BOT. Five cases with documented recurrence and with tissue from the recurrence available for testing were analyzed to determine whether HER2 amplification status changed over time. Three prospectively identified recurrent mucinous ovarian carcinomas were assessed for HER2 amplification and patients received trastuzumab therapy with conventional chemotherapy. Results Amplification of HER2 was observed in 6/33 (18.2% mucinous carcinomas and 3/16 (18.8% BOT. HER2 amplification in primary mucinous carcinomas was not associated with an increased likelihood of recurrence. The prospectively identified recurrent mucinous carcinomas showed overexpression and amplification of HER2; one patient's tumor responded dramatically to trastuzumab in combination with conventional chemotherapy, while another patient experienced an isolated central nervous system recurrence after trastuzumab therapy. Conclusion HER2 amplification is relatively common in ovarian mucinous carcinomas (6/33, 18.2%, although not of prognostic significance. Trastuzumab therapy is a treatment option for patients with mucinous carcinoma when the tumor has HER2 amplification and overexpression.

  3. Beyond the diffraction limit via optical amplification

    CERN Document Server

    Kellerer, Aglae N

    2016-01-01

    In a previous article we suggested a method to overcome the diffraction limit behind a telescope. We refer to theory and recent numerical simulations, and test whether it is indeed possible to use photon amplification to enhance the angular resolution of a telescope or a microscope beyond the diffraction limit. An essential addition is the proposal to select events with above-average ratio of stimulated to spontaneous photons. We find that the diffraction limit of a telescope is surpassed by a factor ten for an amplifier gain of 200, if the analysis is restricted to a tenth of the incoming astronomical photons. A gain of 70 is sufficient with a hundredth of the photons.

  4. Amplification sans bruit d'images optiques

    Science.gov (United States)

    Gigan, S.; Delaubert, V.; Lopez, L.; Treps, N.; Maitre, A.; Fabre, C.

    2004-11-01

    Nous utilisons un Oscillateur Paramétrique Optique (OPO) pompé sous le seuil dans le but d'amplifier une image multimode transverse sans dégradation du rapport signal à bruit. Le dispositif expérimental met en œuvre un OPO de type II triplement résonant et semi-confocal pour le faisceau amplifié. L'existence d'effets quantiques lors de l'amplification multimode dans un tel dispositif a été montrée expérimentalement. Plus généralement, ceci nous a amené à étudier les propriétés quantiques transverses des faisceaux lumineux amplifiés. Une telle étude peut trouver des applications non seulement en imagerie, mais également dans le traitement quantique de l'information.

  5. Social and political amplification of technological hazards

    International Nuclear Information System (INIS)

    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

  6. Entanglement amplification via local weak measurements

    International Nuclear Information System (INIS)

    We propose a measurement-based method to produce a maximally-entangled state from a partially-entangled pure state. Our goal can be thought of as entanglement distillation from a single copy of a partially-entangled state. The present approach involves local two-outcome weak measurements. We show that the application of these local weak measurements leads to a probabilistic amplification of entanglement. In addition, we examine how the probability to find the maximally-entangled state is related to the entanglement of the input state. We also study the application of our method to a mixed initial state. We show that the protocol is successful if the separable part of the mixed initial state fulfils certain conditions. (paper)

  7. Explanatory Model for Sound Amplification in a Stethoscope

    Science.gov (United States)

    Eshach, H.; Volfson, A.

    2015-01-01

    In the present paper we suggest an original physical explanatory model that explains the mechanism of the sound amplification process in a stethoscope. We discuss the amplification of a single pulse, a continuous wave of certain frequency, and finally we address the resonant frequencies. It is our belief that this model may provide students with…

  8. Parametric Amplification of Vacuum Fluctuations in a Spinor Condensate

    DEFF Research Database (Denmark)

    Klempt, C.; Topic, O.; Gebreyesus, G.;

    2010-01-01

    Parametric amplification of vacuum fluctuations is crucial in modern quantum optics, enabling the creation of squeezing and entanglement. We demonstrate the parametric amplification of vacuum fluctuations for matter waves using a spinor F=2 87Rb condensate. Interatomic interactions lead to correl...

  9. Short-Pulse Amplification by Strongly-Coupled Brillouin Scattering

    CERN Document Server

    Edwards, Matthew R; Mikhailova, Julia M; Fisch, Nathaniel J

    2016-01-01

    We examine the feasibility of strongly-coupled stimulated Brillouin scattering as a mechanism for the plasma-based amplification of sub-picosecond pulses. In particular, we use fluid theory and particle-in-cell simulations to compare the relative advantages of Raman and Brillouin amplification over a broad range of achievable parameters.

  10. The Quantum Theory of Optical Parametric Amplification

    Science.gov (United States)

    Hussain, N. A.

    Available from UMI in association with The British Library. Requires signed TDF. The aim of this thesis is to investigate the effect of parametric amplification on various forms of light. In particular we shall consider number and coherent states, but many of the calculations hold for those states whose operators satisfy the properties, = = ==0 e.g. chaotic light. The first chapter lays down the fundamental preliminaries necessary for our calculations and reviews linear amplifier theory. We consider the phase sensitive and insensitive forms of amplifiers modelling the former on the degenerate parametric amplifier and the latter on the non-degenerate and inverted population amplifiers. Chapter 2 deals with balanced homodyne detection of a narrow band coherent state before and after degenerate parametric amplification. In chapter 3 we consider a continuous mode number state produced by atomic emission and parametrically amplified using the formalism of Collett and Gardiner. We give general results for the output flux intensity and also consider the simpler case where the atomic decay rate is much smaller than the parametric cavity decay rate. Also we consider the degree of second order coherence using this simplified theory. Chapters 4 and 5 consider the double amplifier interferometer, using single and continuous mode theories, and enable us to determine the form of amplifier which produces the best visibility and hence lowest noise figures. The travelling-wave parametric amplifier is discussed in chapter 6 and is contrasted with the cavity parametric amplifier discussed in chapters 1 and 2. Finally we consider the much contemplated idea of using amplifiers to boost signals in fibre optic transmission lines using our model of the parametric amplifier and examining the degradation of the signal-to-noise ratio. We consider both coherent and squeezed inputs and our results hold for both cavity and travelling -wave amplifiers.

  11. Integrated Microfluidic Nucleic Acid Isolation, Isothermal Amplification, and Amplicon Quantification

    Directory of Open Access Journals (Sweden)

    Michael G. Mauk

    2015-10-01

    Full Text Available Microfluidic components and systems for rapid (<60 min, low-cost, convenient, field-deployable sequence-specific nucleic acid-based amplification tests (NAATs are described. A microfluidic point-of-care (POC diagnostics test to quantify HIV viral load from blood samples serves as a representative and instructive example to discuss the technical issues and capabilities of “lab on a chip” NAAT devices. A portable, miniaturized POC NAAT with performance comparable to conventional PCR (polymerase-chain reaction-based tests in clinical laboratories can be realized with a disposable, palm-sized, plastic microfluidic chip in which: (1 nucleic acids (NAs are extracted from relatively large (~mL volume sample lysates using an embedded porous silica glass fiber or cellulose binding phase (“membrane” to capture sample NAs in a flow-through, filtration mode; (2 NAs captured on the membrane are isothermally (~65 °C amplified; (3 amplicon production is monitored by real-time fluorescence detection, such as with a smartphone CCD camera serving as a low-cost detector; and (4 paraffin-encapsulated, lyophilized reagents for temperature-activated release are pre-stored in the chip. Limits of Detection (LOD better than 103 virons/sample can be achieved. A modified chip with conduits hosting a diffusion-mode amplification process provides a simple visual indicator to readily quantify sample NA template. In addition, a companion microfluidic device for extracting plasma from whole blood without a centrifuge, generating cell-free plasma for chip-based molecular diagnostics, is described. Extensions to a myriad of related applications including, for example, food testing, cancer screening, and insect genotyping are briefly surveyed.

  12. On the role of temperature feedbacks for Arctic amplification

    Science.gov (United States)

    Pithan, Felix; Mauritsen, Thorsten

    2013-04-01

    The amplification of global climate changes at the poles is a well-known feature of the climate system mentioned already by Arrhenius (1896). It has been linked to the surface-albedo feedback, changes in atmospheric and oceanic heat convergence, water vapour and cloud feedbacks and the albedo effect of black carbon on snow (Serreze and Barry, 2011). We here focus on the role of temperature feedbacks, which have received rather little attention in recent debates. The basic temperature feedback is the Planck feedback or the increase in the Earth's blackbody radiation due to a uniform temperature increase. Since the blackbody radiation scales with the fourth power of temperature, stronger warming is necessary in cold regions to balance a globally uniform radiative forcing. The second temperature feedback is caused by changes in the vertical atmospheric temperature structure: In the Tropics, deep convection leads to warming aloft being larger than at the surface, which causes a greater increase in outgoing longwave radiation compared a vertically uniform forcing and thus constitutes a negative feedback mechanism. In the Arctic, where warming is amplified at the surface, the lapse-rate feedback is positive (Wetherald and Manabe, 1975). We use CMIP5 model output and radiative Kernels to investigate the zonal distribution of temperature feedbacks. Arrhenius, S. (1896). On the influence of carbonic acid in the air upon the temperature of the ground Philos. Mag. J. Sci., 5, pp. 237-276 Serreze, M.C. and Barry, R.G. (2011) . Processes and impacts of Arctic amplification: A research synthesis, Global and Planetary Change, 77(1-2), pp. 85-96 Wetherald, R. and Manabe, S. (1975). The effects of changing the solar constant on the climate of a general circulation model. J. Atmos. Sci., 23 pp 2044-2059

  13. Clinical application of somatosensory amplification in psychosomatic medicine

    Directory of Open Access Journals (Sweden)

    Nakao Mutsuhiro

    2007-10-01

    Full Text Available Abstract Many patients with somatoform disorders are frequently encountered in psychosomatic clinics as well as in primary care clinics. To assess such patients objectively, the concept of somatosensory amplification may be useful. Somatosensory amplification refers to the tendency to experience a somatic sensation as intense, noxious, and disturbing. It may have a role in a variety of medical conditions characterized by somatic symptoms that are disproportionate to demonstrable organ pathology. It may also explain some of the variability in somatic symptomatology found among different patients with the same serious medical disorder. It has been assessed with a self-report questionnaire, the Somatosensory Amplification Scale. This instrument was developed in a clinical setting in the U.S., and the reliability and validity of the Japanese and Turkish versions have been confirmed as well. Many studies have attempted to clarify the specific role of somatosensory amplification as a pathogenic mechanism in somatization. It has been reported that somatosensory amplification does not correlate with heightened sensitivity to bodily sensations and that emotional reactivity exerts its influence on somatization via a negatively biased reporting style. According to our recent electroencephalographic study, somatosensory amplification appears to reflect some aspects of long-latency cognitive processing rather than short-latency interoceptive sensitivity. The concept of somatosensory amplification can be useful as an indicator of somatization in the therapy of a broad range of disorders, from impaired self-awareness to various psychiatric disorders. It also provides useful information for choosing appropriate pharmacological or psychological therapy. While somatosensory amplification has a role in the presentation of somatic symptoms, it is closely associated with other factors, namely, anxiety, depression, and alexithymia that may also influence the same

  14. Unidirectional mechanical amplification as a design principle for an active microphone

    OpenAIRE

    Reichenbach, Tobias; Hudspeth, A. J.

    2011-01-01

    Amplification underlies the operation of many biological and engineering systems. Simple electrical, optical, and mechanical amplifiers are reciprocal: the backward coupling of the output to the input equals the forward coupling of the input to the output. Unidirectional amplifiers that occur often in electrical and optical systems are special non-reciprocal devices in which the output does not couple back to the input even though the forward coupling persists. Here we propose a scheme for un...

  15. Impulse-Induced Optimum Signal Amplification in Scale-Free Networks

    CERN Document Server

    Martínez, Pedro J

    2015-01-01

    Optimizing information transmission across a network is an essential task for controlling and manipulating generic information-processing systems. Here, we show how topological amplification effects in scale-free networks of signaling devices are optimally enhanced when the $\\it{impulse}$ transmitted by periodic external signals (time integral over two consecutive zeros) is maximum. This is demonstrated theoretically by means of a star-like network of overdamped bistable systems subjected to $\\it{generic}$ zero-mean periodic signals, and confirmed numerically by simulations of scale-free networks of such systems. Our results show that the enhancer effect of increasing values of the signal's impulse is due to a correlative increase of the energy transmitted by the periodic signals, while it is found to be resonant-like with respect to the topology-induced amplification mechanism.

  16. Thalamic amplification of sensory input in experimental diabetes.

    Science.gov (United States)

    Freeman, Oliver J; Evans, Mathew H; Cooper, Garth J S; Petersen, Rasmus S; Gardiner, Natalie J

    2016-07-01

    Diabetic neuropathy is a common, and often debilitating, secondary complication of diabetes mellitus. As pain, hypersensitivity and paraesthesias present in a distal-proximal distribution, symptoms are generally believed to originate from damaged afferents within the peripheral nervous system. Increasing evidence suggests altered processing within the central nervous system in diabetic neuropathy contributes towards somatosensory dysfunction, but whether the accurate coding and relay of peripherally encoded information through the central nervous system is altered in diabetes is not understood. Here, we applied the strengths of the rodent whisker-barrel system to study primary afferent-thalamic processing in diabetic neuropathy. We found that neurons in the thalamic ventral posteromedial nucleus from rats with experimental diabetic neuropathy showed increased firing to precisely graded, multidirectional whisker deflection compared to non-diabetic rats. This thalamic hyperactivity occurred without any overt primary afferent dysfunction, as recordings from the trigeminal ganglion showed these primary afferents to be unaffected by diabetes. These findings suggest that central amplification can substantially transform ascending sensory input in diabetes, even in the absence of a barrage of ectopic primary afferent activity. PMID:27152754

  17. Mechanism of Gene Amplification via Yeast Autonomously Replicating Sequences

    Directory of Open Access Journals (Sweden)

    Shelly Sehgal

    2015-01-01

    Full Text Available The present investigation was aimed at understanding the molecular mechanism of gene amplification. Interplay of fragile sites in promoting gene amplification was also elucidated. The amplification promoting sequences were chosen from the Saccharomyces cerevisiae ARS, 5S rRNA regions of Plantago ovata and P. lagopus, proposed sites of replication pausing at Ste20 gene locus of S. cerevisiae, and the bend DNA sequences within fragile site FRA11A in humans. The gene amplification assays showed that plasmid bearing APS from yeast and human beings led to enhanced protein concentration as compared to the wild type. Both the in silico and in vitro analyses were pointed out at the strong bending potential of these APS. In addition, high mitotic stability and presence of TTTT repeats and SAR amongst these sequences encourage gene amplification. Phylogenetic analysis of S. cerevisiae ARS was also conducted. The combinatorial power of different aspects of APS analyzed in the present investigation was harnessed to reach a consensus about the factors which stimulate gene expression, in presence of these sequences. It was concluded that the mechanism of gene amplification was that AT rich tracts present in fragile sites of yeast serve as binding sites for MAR/SAR and DNA unwinding elements. The DNA protein interactions necessary for ORC activation are facilitated by DNA bending. These specific bindings at ORC promote repeated rounds of DNA replication leading to gene amplification.

  18. Mechanism of gene amplification via yeast autonomously replicating sequences.

    Science.gov (United States)

    Sehgal, Shelly; Kaul, Sanjana; Dhar, M K

    2015-01-01

    The present investigation was aimed at understanding the molecular mechanism of gene amplification. Interplay of fragile sites in promoting gene amplification was also elucidated. The amplification promoting sequences were chosen from the Saccharomyces cerevisiae ARS, 5S rRNA regions of Plantago ovata and P. lagopus, proposed sites of replication pausing at Ste20 gene locus of S. cerevisiae, and the bend DNA sequences within fragile site FRA11A in humans. The gene amplification assays showed that plasmid bearing APS from yeast and human beings led to enhanced protein concentration as compared to the wild type. Both the in silico and in vitro analyses were pointed out at the strong bending potential of these APS. In addition, high mitotic stability and presence of TTTT repeats and SAR amongst these sequences encourage gene amplification. Phylogenetic analysis of S. cerevisiae ARS was also conducted. The combinatorial power of different aspects of APS analyzed in the present investigation was harnessed to reach a consensus about the factors which stimulate gene expression, in presence of these sequences. It was concluded that the mechanism of gene amplification was that AT rich tracts present in fragile sites of yeast serve as binding sites for MAR/SAR and DNA unwinding elements. The DNA protein interactions necessary for ORC activation are facilitated by DNA bending. These specific bindings at ORC promote repeated rounds of DNA replication leading to gene amplification. PMID:25685838

  19. Surface air temperature variability and trends in the Arctic: new amplification assessment and regionalisation

    Directory of Open Access Journals (Sweden)

    Ola M. Johannessen

    2016-05-01

    Full Text Available Arctic amplification of temperature change is theorised to be an important feature of the Earth's climate system. For observational assessment and understanding of mechanisms of this amplification, which remain uncertain, thorough and detailed analyses of surface air temperature (SAT variability and trends in the Arctic are needed. Here we present an analysis of Arctic SAT variability in comparison with mid-latitudes and the Northern Hemisphere (NH, based on an advanced SAT dataset – NansenSAT. We define an index for the Arctic amplification as the ratio between absolute values of the Arctic (65–90°N and NH 30-yr running linear SAT trends. It is demonstrated that the temperature amplification in the Arctic is characteristic not only for the recent warming but also the early 20th century warming (ETCW and subsequent cooling. The amplification appears to be weaker during the recent warming than in the ETCW, simply because the index values reflect the more pervasive nature of the recent warming that reflects the background of anthropogenic global warming. We also produced a new Arctic regionalisation created from hierarchical cluster analysis, which identifies six major natural regions in the Arctic that reflect SAT variability. Statistical comparison with several climate indices shows that the Atlantic Multidecadal Oscillation (AMO is the mode of variability that is most significantly associated with the amplified warming–cooling in the Arctic, with a stronger correlation during the ETCW and recent warming than during the intermediate period. Regionally, differences are identified in terms of annual and seasonal rates of change and in their correlations with modes of variability.

  20. Amplification of the 20q chromosomal arm occurs early in tumorigenic transformation and may initiate cancer.

    Science.gov (United States)

    Tabach, Yuval; Kogan-Sakin, Ira; Buganim, Yosef; Solomon, Hilla; Goldfinger, Naomi; Hovland, Randi; Ke, Xi-Song; Oyan, Anne M; Kalland, Karl-H; Rotter, Varda; Domany, Eytan

    2011-01-01

    Duplication of chromosomal arm 20q occurs in prostate, cervical, colon, gastric, bladder, melanoma, pancreas and breast cancer, suggesting that 20q amplification may play a causal role in tumorigenesis. According to an alternative view, chromosomal imbalance is mainly a common side effect of cancer progression. To test whether a specific genomic aberration might serve as a cancer initiating event, we established an in vitro system that models the evolutionary process of early stages of prostate tumor formation; normal prostate cells were immortalized by the over-expression of human telomerase catalytic subunit hTERT, and cultured for 650 days till several transformation hallmarks were observed. Gene expression patterns were measured and chromosomal aberrations were monitored by spectral karyotype analysis at different times. Several chromosomal aberrations, in particular duplication of chromosomal arm 20q, occurred early in the process and were fixed in the cell populations, while other aberrations became extinct shortly after their appearance. A wide range of bioinformatic tools, applied to our data and to data from several cancer databases, revealed that spontaneous 20q amplification can promote cancer initiation. Our computational model suggests that 20q amplification induced deregulation of several specific cancer-related pathways including the MAPK pathway, the p53 pathway and Polycomb group factors. In addition, activation of Myc, AML, B-Catenin and the ETS family transcription factors was identified as an important step in cancer development driven by 20q amplification. Finally we identified 13 "cancer initiating genes", located on 20q13, which were significantly over-expressed in many tumors, with expression levels correlated with tumor grade and outcome suggesting that these genes induce the malignant process upon 20q amplification. PMID:21297939

  1. Amplification and chromosomal dispersion of human endogenous retroviral sequences

    International Nuclear Information System (INIS)

    Endogenous retroviral sequences have undergone amplification events involving both viral and flanking cellular sequences. The authors cloned members of an amplified family of full-length endogenous retroviral sequences. Genomic blotting, employing a flanking cellular DNA probe derived from a member of this family, revealed a similar array of reactive bands in both humans and chimpanzees, indicating that an amplification event involving retroviral and associated cellular DNA sequences occurred before the evolutionary separation of these two primates. Southern analyses of restricted somatic cell hybrid DNA preparations suggested that endogenous retroviral segments are widely dispersed in the human genome and that amplification and dispersion events may be linked

  2. Amplification of Spin Waves by Thermal Spin-Transfer Torque

    Science.gov (United States)

    Padrón-Hernández, E.; Azevedo, A.; Rezende, S. M.

    2011-11-01

    We observe amplification of spin-wave packets propagating along a film of single-crystal yttrium iron garnet subject to a transverse temperature gradient. The spin waves are excited and detected with standard techniques used in magnetostatic microwave delay lines in the 1-2 GHz frequency range. The amplification is attributed to the action of a thermal spin-transfer torque acting on the magnetization that opposes the relaxation and which is created by spin currents generated through the spin-Seebeck effect. The experimental data are interpreted with a spin-wave model that gives an amplification gain in very good agreement with the data.

  3. Amplification and chromosomal dispersion of human endogenous retroviral sequences

    Energy Technology Data Exchange (ETDEWEB)

    Steele, P.E.; Martin, M.A.; Rabson, A.B.; Bryan, T.; O' Brien, S.J.

    1986-09-01

    Endogenous retroviral sequences have undergone amplification events involving both viral and flanking cellular sequences. The authors cloned members of an amplified family of full-length endogenous retroviral sequences. Genomic blotting, employing a flanking cellular DNA probe derived from a member of this family, revealed a similar array of reactive bands in both humans and chimpanzees, indicating that an amplification event involving retroviral and associated cellular DNA sequences occurred before the evolutionary separation of these two primates. Southern analyses of restricted somatic cell hybrid DNA preparations suggested that endogenous retroviral segments are widely dispersed in the human genome and that amplification and dispersion events may be linked.

  4. Preparation of DNA-containing extract for PCR amplification

    Science.gov (United States)

    Dunbar, John M.; Kuske, Cheryl R.

    2006-07-11

    Environmental samples typically include impurities that interfere with PCR amplification and DNA quantitation. Samples of soil, river water, and aerosol were taken from the environment and added to an aqueous buffer (with or without detergent). Cells from the sample are lysed, releasing their DNA into the buffer. After removing insoluble cell components, the remaining soluble DNA-containing extract is treated with N-phenacylthiazolium bromide, which causes rapid precipitation of impurities. Centrifugation provides a supernatant that can be used or diluted for PCR amplification of DNA, or further purified. The method may provide a DNA-containing extract sufficiently pure for PCR amplification within 5–10 minutes.

  5. PCR amplification on microarrays of gel immobilized oligonucleotides

    Science.gov (United States)

    Strizhkov, Boris; Tillib, Sergei; Mikhailovich, Vladimir; Mirzabekov, Andrei

    2003-11-04

    The invention relates two general methods for performing PCR amplification, combined with the detection and analysis of the PCR products on a microchip. In the first method, the amplification occurs both outside and within a plurality of gel pads on a microchip, with at least one oligonucleotide primer immobilized in a gel pad. In the second method, PCR amplification also takes place within gel pads on a microchip, but the pads are surrounded by a hydrophobic liquid such as that which separates the individual gel pads into environments which resemble micro-miniaturized test tubes.

  6. Raman amplification in the coherent wave-breaking regime.

    Science.gov (United States)

    Farmer, J P; Pukhov, A

    2015-12-01

    In regimes far beyond the wave-breaking threshold of Raman amplification, we show that significant amplification can occur after the onset of wave breaking, before phase mixing destroys the coherent coupling between pump, probe, and plasma wave. Amplification in this regime is therefore a transient effect, with the higher-efficiency "coherent wave-breaking" (CWB) regime accessed by using a short, intense probe. Parameter scans illustrate the marked difference in behavior between below wave breaking, in which the energy-transfer efficiency is high but total energy transfer is low, wave breaking, in which efficiency is low, and CWB, in which moderate efficiencies allow the highest total energy transfer. PMID:26764840

  7. Local Runup Amplification By Resonant Wave Interactions

    CERN Document Server

    Stefanakis, Themistoklis; Dutykh, Denys

    2011-01-01

    Until now the analysis of long wave runup on a plane beach has been focused on finding its maximum value, failing to capture the existence of resonant regimes. One-dimensional numerical simulations in the framework of the Nonlinear Shallow Water Equations (NSWE) are used to investigate the Boundary Value Problem (BVP) for plane and non-trivial beaches. Monochromatic waves, as well as virtual wave-gage recordings from real tsunami simulations, are used as forcing conditions to the BVP. Resonant phenomena between the incident wavelength and the beach slope are found to occur, which result in enhanced runup of non-leading waves. The evolution of energy reveals the existence of a quasi-periodic state for the case of sinusoidal waves, the energy level of which, as well as the time required to reach that state, depend on the incident wavelength for a given beach slope. Dispersion is found to slightly reduce the value of maximum runup, but not to change the overall picture. Runup amplification occurs for both leadin...

  8. AGAPE Andromeda Gravitational Amplification Pixel Experiment

    CERN Document Server

    Ansari, R; Baillon, Paul; Bouquet, A; Coupinot, G; Coutures, C; Ghesquière, C; Giraud-Héraud, Yannick; Gondolo, P; Hecquet, J; Kaplan, J; Le Du, Y; Melchior, A L; Moniez, M; Picat, J P; Soucail, G

    1999-01-01

    The aim of the AGAPE (Andromeda Gravitational Amplification Pixel Experiment), experiment which has been first proposed in June 1992 is to examine the distribution of massive astrophysical compact halo objects ((MACHO's) which possibly are in the galactic haloes and which could account for the missing dark matter. Those objects have a mass which is a fraction of solar mass and could be detected by gravitational microlensing: the light of a star is amplified when a MACHO is crossing its line of sight from the earth. This technique has been proposed by Paczy\\'nski in 1986. The AGAPE collaboration applies this technique in an original way by using, as target stars, the stars of another galaxy without resolving them. The recent progresses in photometry with CCD allow now to see tiny variations of the surface brightness of a galaxy like M~31. Those tiny variations can be the result of a single microlensing event on the background stars contributing to the surface brightness. The AGAPE collaboration has now cumulat...

  9. Small Sample Whole-Genome Amplification

    Energy Technology Data Exchange (ETDEWEB)

    Hara, C A; Nguyen, C P; Wheeler, E K; Sorensen, K J; Arroyo, E S; Vrankovich, G P; Christian, A T

    2005-09-20

    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.

  10. Signal Amplification Technique (SAT): an approach for improving resolution and reducing image noise in computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Phelps, M.E.; Huang, S.C.; Hoffman, E.J.; Plummer, D.; Carson, R.

    1981-01-01

    Spatial resolution improvements in computed tomography (CT) have been limited by the large and unique error propagation properties of this technique. The desire to provide maximum image resolution has resulted in the use of reconstruction filter functions designed to produce tomographic images with resolution as close as possible to the intrinsic detector resolution. Thus, many CT systems produce images with excessive noise with the system resolution determined by the detector resolution rather than the reconstruction algorithm. CT is a rigorous mathematical technique which applies an increasing amplification to increasing spatial frequencies in the measured data. This mathematical approach to spatial frequency amplification cannot distinguish between signal and noise and therefore both are amplified equally. We report here a method in which tomographic resolution is improved by using very small detectors to selectively amplify the signal and not noise. Thus, this approach is referred to as the signal amplification technique (SAT). SAT can provide dramatic improvements in image resolution without increases in statistical noise or dose because increases in the cutoff frequency of the reconstruction algorithm are not required to improve image resolution. Alternatively, in cases where image counts are low, such as in rapid dynamic or receptor studies, statistical noise can be reduced by lowering the cutoff frequency while still maintaining the best possible image resolution. A possible system design for a positron CT system with SAT is described.

  11. Signal Amplification Technique (SAT): an approach for improving resolution and reducing image noise in computed tomography

    International Nuclear Information System (INIS)

    Spatial resolution improvements in computed tomography (CT) have been limited by the large and unique error propagation properties of this technique. The desire to provide maximum image resolution has resulted in the use of reconstruction filter functions designed to produce tomographic images with resolution as close as possible to the intrinsic detector resolution. Thus, many CT systems produce images with excessive noise with the system resolution determined by the detector resolution rather than the reconstruction algorithm. CT is a rigorous mathematical technique which applies an increasing amplification to increasing spatial frequencies in the measured data. This mathematical approach to spatial frequency amplification cannot distinguish between signal and noise and therefore both are amplified equally. We report here a method in which tomographic resolution is improved by using very small detectors to selectively amplify the signal and not noise. Thus, this approach is referred to as the signal amplification technique (SAT). SAT can provide dramatic improvements in image resolution without increases in statistical noise or dose because increases in the cutoff frequency of the reconstruction algorithm are not required to improve image resolution. Alternatively, in cases where image counts are low, such as in rapid dynamic or receptor studies, statistical noise can be reduced by lowering the cutoff frequency while still maintaining the best possible image resolution. A possible system design for a positron CT system with SAT is described

  12. Functional integration of PCR amplification and capillary electrophoresis in a microfabricated DNA analysis device.

    Science.gov (United States)

    Woolley, A T; Hadley, D; Landre, P; deMello, A J; Mathies, R A; Northrup, M A

    1996-12-01

    Microfabricated silicon PCR reactors and glass capillary electrophoresis (CE) chips have been successfully coupled to form an integrated DNA analysis system. This construct combines the rapid thermal cycling capabilities of microfabricated PCR devices (10 degrees C/s heating, 2.5 degrees C/s cooling) with the high-speed (Real-time monitoring of PCR target amplification in these integrated PCR-CE devices is also feasible. Amplification of the beta-globin target as a function of cycle number was directly monitored for two different reactions starting with 4 x 10(7) and 4 x 10(5) copies of DNA template. This work establishes the feasibility of performing high-speed DNA analyses in microfabricated integrated fluidic systems. PMID:8946790

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

    KAUST Repository

    Bukhryakov, Konstantin V.

    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.

  14. Generation and parametric amplification of femtosecond radiation up to terawatt power in the mid-infrared

    Science.gov (United States)

    Trunov, V. I.; Frolov, S. A.; Pestryakov, E. V.

    2015-11-01

    Nonlinear optical schemes for generation of terawatt femtosecond pulses in the range of 2-10 μm using multiterawatt laser radiation of the two-channel system created in the ILP SB RAS are presented and discussed. It is shown that the use of large aperture LBO crystals and AgGaGeS4 for difference frequency generation and parametric amplification enables to generate a wideband radiation in the range of 2-10 μm.

  15. Miniaturized PCR chips for nucleic acid amplification and analysis: latest advances and future trends

    OpenAIRE

    Zhang, Chunsun; Xing, Da

    2007-01-01

    The possibility of performing fast and small-volume nucleic acid amplification and analysis on a single chip has attracted great interest. Devices based on this idea, referred to as micro total analysis, microfluidic analysis, or simply ‘Lab on a chip’ systems, have witnessed steady advances over the last several years. Here, we summarize recent research on chip substrates, surface treatments, PCR reaction volume and speed, architecture, approaches to eliminating cross-contamination and contr...

  16. Optimization of Pulse Temporal Contrast in Optical Parametric Chirped Pulse Amplification

    Institute of Scientific and Technical Information of China (English)

    WANG Yan-Hai; PAN Xue; LI Xue-Chun; LIN Zun-Qi

    2009-01-01

    In optical parametric chirped pulse amplification (OPCPA), the degradation of temporal contrast of the com-pressed signal pulse mainly results from spectral clipping in the grating stretcher with finite size of the optics, parametric fluorescence (PF) and the spectral variations transferred from temporal fluctuation of the pump pulse. The temporal contrast of the recompressed amplified pulse in the OPCPA system is studied numerically and a number of solutions are considered and optimized to achieve the highest temporal contrast.

  17. Entanglement, EPR correlations and mesoscopic quantum superposition by the high-gain quantum injected parametric amplification

    OpenAIRE

    Caminati, Marco; De Martini, Francesco; Perris, Riccardo; Sciarrino, Fabio; Secondi, Veronica

    2006-01-01

    We investigate the multiparticle quantum superposition and the persistence of multipartite entanglement of the quantum superposition generated by the quantum injected high-gain optical parametric amplification of a single photon. The physical configuration based on the optimal universal quantum cloning has been adopted to investigate how the entanglement and the quantum coherence of the system persists for large values of the nonlinear parametric gain g.

  18. The identification of zones of amplification of disruptions in network supply chains of metallurgic products

    Directory of Open Access Journals (Sweden)

    M. Kramarz

    2015-01-01

    Full Text Available An increase in the number of participants in a supply chain and network relations results in an increase in the complexity of the entire logistic and production system. Consequently, there appear additional potential sources of disruptions in material flows. The aim of the research presented in the article is to identify the zones of amplification of disruptions in network supply chains of metallurgic products.

  19. Real burst traffic amplification in optically gain clamped amplifier

    OpenAIRE

    Ennser, Karin; Taccheo, Stefano; Careglio, Davide; Solé Pareta, Josep; Aracil Rico, Javier

    2008-01-01

    Optical burst amplification in a gain-stabilized amplifier is theoretically investigated using real burst traffic data. The results show that excellent performance are obtained for WDM transmission with negligible interplay due to burst arrival statistics.

  20. Magnetic Field Amplification During the Common Envelope Phase

    CERN Document Server

    Ohlmann, Sebastian T; Pakmor, Ruediger; Springel, Volker; Mueller, Ewald

    2016-01-01

    During the common envelope (CE) phase, a giant star in a binary system overflows its Roche lobe and unstable mass transfer leads to a spiral-in of the companion, resulting in a close binary system or in a merger of the stellar cores. Dynamo processes during the CE phase have been proposed as a mechanism to generate magnetic fields that are important for forming magnetic white dwarfs (MWDs) and for shaping planetary nebulae. Here, we present the first magnetohydrodynamics simulations of the dynamical spiral-in during a CE phase. We find that magnetic fields are strongly amplified in the accretion stream around the $1M_\\odot$ companion as it spirals into the envelope of a $2M_\\odot$ RG. This leads to field strengths of 10 to 100 kG throughout the envelope after 120 d. The magnetic field amplification is consistent with being driven by the magnetorotational instability. The field strengths reached in our simulation make the magnetic field interesting for diagnostic purposes, but they are dynamically irrelevant. ...

  1. Signal amplification in an agent-based herding model

    CERN Document Server

    Carro, Adrián; Miguel, Maxi San

    2013-01-01

    A growing part of the behavioral finance literature has addressed some of the stylized facts of financial time series as macroscopic patterns emerging from herding interactions among groups of agents with heterogeneous trading strategies and a limited rationality. We extend a stochastic herding formalism introduced for the modeling of decision making among financial agents, in order to take also into account an external influence. In particular, we study the amplification of an external signal imposed upon the agents by a mechanism of resonance. This signal can be interpreted as an advertising or a public perception in favor or against one of the two possible trading behaviors, thus periodically breaking the symmetry of the system and acting as a continuously varying exogenous shock. The conditions for the ensemble of agents to more accurately follow the periodicity of the signal are studied, finding a maximum in the response of the system for a given range of values of both the noise and the frequency of the...

  2. Methods for microbial DNA extraction from soil for PCR amplification

    OpenAIRE

    Yeates C; Gillings, MR; Davison AD; Altavilla N; Veal DA

    1998-01-01

    Amplification of DNA from soil is often inhibited by co-purified contaminants. A rapid, inexpensive, large-scale DNA extraction method involving minimal purification has been developed that is applicable to various soil types (1). DNA is also suitable for PCR amplification using various DNA targets. DNA was extracted from 100g of soil using direct lysis with glass beads and SDS followed by potassium acetate precipitation, polyethylene glycol precipitation, phenol extraction and isopropanol pr...

  3. Pulse Distortion in Saturated Fiber Optical Parametric Chirped Pulse Amplification

    DEFF Research Database (Denmark)

    Lali-Dastjerdi, Zohreh; Da Ros, Francesco; Rottwitt, Karsten;

    2012-01-01

    Fiber optical parametric chirped pulse amplification is experimentally compared for different chirped pulses in the picosecond regime. The amplified chirped pulses show distortion appearing as pedestals after recompression when the amplifier is operated in saturation.......Fiber optical parametric chirped pulse amplification is experimentally compared for different chirped pulses in the picosecond regime. The amplified chirped pulses show distortion appearing as pedestals after recompression when the amplifier is operated in saturation....

  4. Loop-Mediated Amplification Accelerated by Stem Primers

    OpenAIRE

    Laurence Tisi; Guy Kiddle; Olga Gandelman; Rebecca Jackson

    2011-01-01

    Isothermal nucleic acid amplifications (iNAATs) have become an important alternative to PCR for in vitro molecular diagnostics in all fields. Amongst iNAATs Loop-mediated amplification (LAMP) has gained much attention over the last decade because of the simplicity of hardware requirements. LAMP demonstrates performance equivalent to that of PCR, but its application has been limited by the challenging primer design. The design of six primers in LAMP requires a selection of eight priming sites ...

  5. Controllable Amplification of Entanglement for Two Qutrits under Decoherence

    Institute of Scientific and Technical Information of China (English)

    ZHENG Qiang; XIE Xiao-Yao; ZHI Qi-Jun; REN Zhong-Zhou

    2011-01-01

    Entanglement dynamics of a two-qutrit Heisenberg spin chain with the external magnetic fields and DM interaction under the intrinsic decoherence is investigated. Depending on whether there is inhomogeneous magnetic field,the entanglement amplification, i.e. the phenomenon that the finally stable entanglement is bigger than that of the initial one, is found for one kind of initial states. The reasons for the controllable entanglement amplification are discussed.

  6. Measurement-Based Noiseless Linear Amplification for Quantum Communication

    OpenAIRE

    Chrzanowski, Helen M.; Walk, Nathan; Assad, Syed M.; Janousek, Jiri; Hosseini, Sara; Ralph, Timothy C.; Symul, Thomas; Lam, Ping Koy

    2014-01-01

    Entanglement distillation is an indispensable ingredient in extended quantum communication networks. Distillation protocols are necessarily non-deterministic and require advanced experimental techniques such as noiseless amplification. Recently it was shown that the benefits of noiseless amplification could be extracted by performing a post-selective filtering of the measurement record to improve the performance of quantum key distribution. We apply this protocol to entanglement degraded by t...

  7. On the amplification of acoustic phonons in carbon nanotube

    OpenAIRE

    Dompreh, K. A.; Mensah, N. G.; Sakyi-Arthur, D.; Mensah, S. Y.

    2016-01-01

    We present a theoretical study of acoustic phonons amplification in Carbon Nanotubes (CNT). The phenomenon is via Cerenkov emission (CE) of acoustic phonons using intraband transitions proposed by Mensah et. al.,~\\cite{1} in Semiconductor Superlattices (SSL) and confirmed in ~\\cite{2}. From this, an asymmetric graph of $\\Gamma^{CNT}$ on $\\frac{V_d}{V_s}$ and $\\Omega\\tau$ were obtained where amplification ($\\Gamma_{amp}^{CNT}$) $>>$ absorption ($\\Gamma_{abs}^{CNT}$). The ratio, $\\frac{\\vert \\G...

  8. Electrical and Electrochemical Monitoring of Nucleic Acid Amplification

    OpenAIRE

    Goda, Tatsuro; Tabata, Miyuki; Miyahara, Yuji

    2015-01-01

    Nucleic acid amplification is a gold standard technique for analyzing a tiny amount of nucleotides in molecular biology, clinical diagnostics, food safety, and environmental testing. Electrical and electrochemical monitoring of the amplification process draws attention over conventional optical methods because of the amenability toward point-of-care applications as there is a growing demand for nucleic acid sensing in situations outside the laboratory. A number of electrical and electrochemic...

  9. Radioactive wastes and the social amplification of risk

    OpenAIRE

    Roger E. Kasperson; Emel, Jacque; Goble, Robert; Hohenemser, Christoph; Kasperson, Jeanne X.; Renn, Ortwin

    1987-01-01

    A significant problem in radioactive waste facility siting is that apparent small risks or minor risks events produce substantial public concern and social impacts. The reasons for this difference in public health and societal impacts is not well understood. This paper explores the issues involved in the social amplification of risk, using the risk associated with site characterization as the example. Noteworthy as sources of amplification are the infomation flow associated with risks and ris...

  10. Fingerprinting Internet DNS Amplification DDoS Activities

    OpenAIRE

    Fachkha, Claude; Bou-Harb, Elias; Debbabi, Mourad

    2013-01-01

    This work proposes a novel approach to infer and characterize Internet-scale DNS amplification DDoS attacks by leveraging the darknet space. Complementary to the pioneer work on inferring Distributed Denial of Service (DDoS) activities using darknet, this work shows that we can extract DDoS activities without relying on backscattered analysis. The aim of this work is to extract cyber security intelligence related to DNS Amplification DDoS activities such as detection period, attack duration, ...

  11. Amplification of bovine papillomavirus DNA by N-methyl-N'-nitro-N-nitrosoguanidine, ultraviolet irradiation, or infection with herpes simplex virus

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, J.; Schlehofer, J.R.; Mergener, K.; Gissmann, L.; zur Hausen, H. (Deutsches Krebsforschungszentrum, Heidelberg (Germany, F.R.))

    1989-09-01

    Treatment with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) or irradiation with ultraviolet light (uv254 nm) induces amplification of integrated as well as episomal sequences of bovine papillomavirus (BPV) type 1 DNA in BPV-1-transformed mouse C127 cells (i.e., ID13 cells). This is shown by filter in situ hybridization and Southern blot analysis of cellular DNA. Similarly, infection of ID13 cells with herpes simplex virus (HSV) type 1 which has been shown to be mutagenic for host cell DNA leads to amplification of BPV DNA sequences. In contrast to this induction of DNA amplification by initiators, treatment of ID13 cells with the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) does not result in increased synthesis of BPV DNA nor does TPA treatment modulate the initiator-induced DNA amplification. Similar to other cell systems infection with adeno-associated virus (AAV) type 2 inhibits BPV-1 DNA amplification irrespective of the inducing agent. In contrast to initiator-induced DNA amplification, treatment with carcinogen (MNNG) or tumor promoters or combination of MNNG and promoter of C127 cells prior to transformation by BPV-1 does not lead to an increase in the number of transformed foci. The induction of amplification of papillomavirus DNA by initiating agents possibly represents one of the mechanisms by which the observed synergism between papillomavirus infection and initiators in tumorigenesis might occur.

  12. Amplification of bovine papillomavirus DNA by N-methyl-N'-nitro-N-nitrosoguanidine, ultraviolet irradiation, or infection with herpes simplex virus

    International Nuclear Information System (INIS)

    Treatment with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) or irradiation with ultraviolet light (uv254 nm) induces amplification of integrated as well as episomal sequences of bovine papillomavirus (BPV) type 1 DNA in BPV-1-transformed mouse C127 cells (i.e., ID13 cells). This is shown by filter in situ hybridization and Southern blot analysis of cellular DNA. Similarly, infection of ID13 cells with herpes simplex virus (HSV) type 1 which has been shown to be mutagenic for host cell DNA leads to amplification of BPV DNA sequences. In contrast to this induction of DNA amplification by initiators, treatment of ID13 cells with the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) does not result in increased synthesis of BPV DNA nor does TPA treatment modulate the initiator-induced DNA amplification. Similar to other cell systems infection with adeno-associated virus (AAV) type 2 inhibits BPV-1 DNA amplification irrespective of the inducing agent. In contrast to initiator-induced DNA amplification, treatment with carcinogen (MNNG) or tumor promoters or combination of MNNG and promoter of C127 cells prior to transformation by BPV-1 does not lead to an increase in the number of transformed foci. The induction of amplification of papillomavirus DNA by initiating agents possibly represents one of the mechanisms by which the observed synergism between papillomavirus infection and initiators in tumorigenesis might occur

  13. Magnetic Field Amplification and Blazar Flares

    Directory of Open Access Journals (Sweden)

    Chen Xuhui

    2013-12-01

    Full Text Available Recent multiwavelength observations of PKS 0208-512 by SMARTS, Fermi, and Swift revealed that γ-ray and optical light curves of this flat spectrum radio quasars are highly correlated, but with an exception of one large optical flare having no corresponding gamma-ray activity or even detection. On the other hand, recent advances in SNRs observations and plasma simulations both reveal that magnetic field downstream of astrophysical shocks can be largely amplified beyond simple shock compression. These amplifications, along with their associated particle acceleration, might contribute to blazar flares, including the peculiar flare of PKS 0208-512. Using our time dependent multizone blazar emission code, we evaluate several scenarios that may represent such phenomena. This code combines Monte Carlo method that tracks the radiative processes including inverse Compton scattering, and Fokker-Planck equation that follows the cooling and acceleration of particles. It is a comprehensive time dependent code that fully takes into account the light travel time effects. In this study, both the changes of the magnetic field and acceleration efficiency are explored as the cause of blazar flares. Under these assumption, synchrotron self-Compton and external Compton scenarios produce distinct features that favor the external Compton scenario. The optical flares with/without gamma-ray counterparts can be explained by different allocations of energy between the magnetization and particle acceleration, which in turn can be affected by the relative orientation between the magnetic field and the shock flow. We compare the details of the observations and simulation, and highlight what implications this study has on our understanding of relativistic jets.

  14. Targeting MET Amplification as a New Oncogenic Driver

    International Nuclear Information System (INIS)

    Certain genetically defined cancers are dependent on a single overactive oncogene for their proliferation and survival, a phenomenon known as “oncogene addiction”. A new generation of drugs that selectively target such “driver oncogenes” manifests a clinical efficacy greater than that of conventional chemotherapy in appropriate genetically defined patients. MET is a proto-oncogene that encodes a receptor tyrosine kinase, and aberrant activation of MET signaling occurs in a subset of advanced cancers as result of various genetic alterations including gene amplification, polysomy, and gene mutation. Our preclinical studies have shown that inhibition of MET signaling either with the small-molecule MET inhibitor crizotinib or by RNA interference targeted to MET mRNA resulted in marked antitumor effects in cancer cell lines with MET amplification both in vitro and in vivo. Furthermore, patients with non-small cell lung cancer or gastric cancer positive for MET amplification have shown a pronounced clinical response to crizotinib. Accumulating preclinical and clinical evidence thus suggests that MET amplification is an “oncogenic driver” and therefore a valid target for treatment. However, the prevalence of MET amplification has not been fully determined, possibly in part because of the difficulty in evaluating gene amplification. In this review, we provide a rationale for targeting this genetic alteration in cancer therapy

  15. Problems encountered when defining Arctic amplification as a ratio.

    Science.gov (United States)

    Hind, Alistair; Zhang, Qiong; Brattström, Gudrun

    2016-01-01

    In climate change science the term 'Arctic amplification' has become synonymous with an estimation of the ratio of a change in Arctic temperatures compared with a broader reference change under the same period, usually in global temperatures. Here, it is shown that this definition of Arctic amplification comes with a suite of difficulties related to the statistical properties of the ratio estimator itself. Most problematic is the complexity of categorizing uncertainty in Arctic amplification when the global, or reference, change in temperature is close to 0 over a period of interest, in which case it may be impossible to set bounds on this uncertainty. An important conceptual distinction is made between the 'Ratio of Means' and 'Mean Ratio' approaches to defining a ratio estimate of Arctic amplification, as they do not only possess different uncertainty properties regarding the amplification factor, but are also demonstrated to ask different scientific questions. Uncertainty in the estimated range of the Arctic amplification factor using the latest global climate models and climate forcing scenarios is expanded upon and shown to be greater than previously demonstrated for future climate projections, particularly using forcing scenarios with lower concentrations of greenhouse gases. PMID:27461918

  16. Targeting MET Amplification as a New Oncogenic Driver

    Energy Technology Data Exchange (ETDEWEB)

    Kawakami, Hisato [Department of Medical Oncology, Kinki University Faculty of Medicine, 377-2 Ohno-higashi, Osaka-Sayama, Osaka 589-8511 (Japan); Okamoto, Isamu, E-mail: okamotoi@kokyu.med.kyushu-u.ac.jp [Department of Medical Oncology, Kinki University Faculty of Medicine, 377-2 Ohno-higashi, Osaka-Sayama, Osaka 589-8511 (Japan); Center for Clinical and Translational Research, Kyushu University Hospital, 3-1-1 Maidashi, Higashiku, Fukuoka 812-8582 (Japan); Okamoto, Wataru [Department of Medical Oncology, Kinki University Faculty of Medicine, 377-2 Ohno-higashi, Osaka-Sayama, Osaka 589-8511 (Japan); Division of Transrlational Research, Exploratory Oncology Research & Clinical Trial Center, National Cancer Center, 6-5-1 Kashiwanoha, Kashiwa, Chiba 277-8577 (Japan); Tanizaki, Junko [Department of Medical Oncology, Kinki University Faculty of Medicine, 377-2 Ohno-higashi, Osaka-Sayama, Osaka 589-8511 (Japan); Lowe Center for Thoracic Oncology, Dana-Farber Cancer Institute, HIM223, 450 Brookline Avenue, Boston, MA 02215 (United States); Nakagawa, Kazuhiko [Department of Medical Oncology, Kinki University Faculty of Medicine, 377-2 Ohno-higashi, Osaka-Sayama, Osaka 589-8511 (Japan); Nishio, Kazuto [Department of Genome Biology, Kinki University Faculty of Medicine, 377-2 Ohno-higashi, Osaka-Sayama, Osaka 589-8511 (Japan)

    2014-07-22

    Certain genetically defined cancers are dependent on a single overactive oncogene for their proliferation and survival, a phenomenon known as “oncogene addiction”. A new generation of drugs that selectively target such “driver oncogenes” manifests a clinical efficacy greater than that of conventional chemotherapy in appropriate genetically defined patients. MET is a proto-oncogene that encodes a receptor tyrosine kinase, and aberrant activation of MET signaling occurs in a subset of advanced cancers as result of various genetic alterations including gene amplification, polysomy, and gene mutation. Our preclinical studies have shown that inhibition of MET signaling either with the small-molecule MET inhibitor crizotinib or by RNA interference targeted to MET mRNA resulted in marked antitumor effects in cancer cell lines with MET amplification both in vitro and in vivo. Furthermore, patients with non-small cell lung cancer or gastric cancer positive for MET amplification have shown a pronounced clinical response to crizotinib. Accumulating preclinical and clinical evidence thus suggests that MET amplification is an “oncogenic driver” and therefore a valid target for treatment. However, the prevalence of MET amplification has not been fully determined, possibly in part because of the difficulty in evaluating gene amplification. In this review, we provide a rationale for targeting this genetic alteration in cancer therapy.

  17. Resonant nonstationary amplification of polychromatic laser pulses and conical emission in an optically dense ensemble of neon metastable atoms

    International Nuclear Information System (INIS)

    Experimental and numerical investigation of single-beam and pump-probe interaction with a resonantly absorbing dense extended medium under strong and weak field-matter coupling is presented. Significant probe beam amplification and conical emission were observed. Under relatively weak pumping and high medium density, when the condition of strong coupling between field and resonant matter is fulfilled, the probe amplification spectrum has a form of spectral doublet. Stronger pumping leads to the appearance of a single peak of the probe beam amplification at the transition frequency. The greater probe intensity results in an asymmetrical transmission spectrum with amplification at the blue wing of the absorption line and attenuation at the red one. Under high medium density, a broadband of amplification appears. The theoretical model is based on the solution of the Maxwell-Bloch equations for a two-level system. Different types of probe transmission spectra obtained are attributed to complex dynamics of a coherent medium response to broadband polychromatic radiation of a multimode dye laser

  18. Rapid Diagnosis of Human Herpesvirus 6 Infection by a Novel DNA Amplification Method, Loop-Mediated Isothermal Amplification

    OpenAIRE

    Ihira, Masaru; Yoshikawa, Tetsushi; Enomoto, Yoshihiko; Akimoto, Shiho; Ohashi, Masahiro; Suga, Sadao; Nishimura, Naoko; Ozaki, Takao; Nishiyama, Yukihiro; Notomi, Tsugunori; Ohta, Yoshinori; Asano, Yoshizo

    2004-01-01

    A novel nucleic acid amplification method, termed loop-mediated isothermal amplification (LAMP), which amplifies DNA with high specificity, efficiency, and rapidity under isothermal conditions, may be a valuable tool for the rapid detection of infectious agents. LAMP was developed for human herpesvirus 6 (HHV-6), and its reliability was evaluated in this study. Although LAMP products were detected in HHV-6 B and HHV-6 A DNA, they were not detected in HHV-7 and human cytomegalovirus DNA. The s...

  19. Absorption-Amplification Response with or Without Spontaneously Generated Coherence in a Coherent Four-Level Atomic Medium

    Institute of Scientific and Technical Information of China (English)

    LI Jia-Hua; YANG Wen-Xing; PENG Ju-Cun

    2004-01-01

    We discuss and analyze the absorption-amplification properties of a weak probe field in a typical four-level atomic system in the presence of an additional coherence term, the spontaneously generated coherence term. Theinfluences of the spontaneously generated coherence and a coherent pump field on the probe absorption (amplification)are investigated in detail. We show that the absorption of such a weak probe field can be dramatically enhanced dueto the presence of the spontaneously generated coherence. At the same time, the probe-absorption profile exhibitsthe double-peak structure and the probe-absorption peak gradually decreases as the pump intensity increases. On thecontrary, the amplification of such a weak probe field near the line center of the probe transition can be achieved byadjusting the coherent pump field intensity in the absence of the spontaneously generated coherence.

  20. Absorption-Amplification Response with or Without Spontaneously Generated Coherence in a Coherent Four-Level Atomic Medium

    Institute of Scientific and Technical Information of China (English)

    LIJia-Hua; YANGWen-Xing; PENGJu-Cun

    2004-01-01

    We discuss and analyze the absorption-amplification properties of a weak probe field in a typical fourlevel atomic system in the presence of an additional coherence term, the spontaneously generated coherence term. The influences of the spontaneously generated coherence and a coherent pump field on the probe absorption (amplification) are investigated in detail. We show that the absorption of such a weak probe field can be dramatically enhanced due to the presence of the spontaneously generated coherence. At the same time, the probe-absorption profile exhibits the double-peak structure and the probe-absorption peak gradually decreases as the pump intensity increases. On the contrary, the amplification of such a weak probe field near the line center of the probe transition can be achieved by adiusting the coherent Dump field intensity in the absence of the spontaneously generated coherence.

  1. Amplification and focusing of a picosecond chirped pulse to 20TW and 5x1017W/cm2

    International Nuclear Information System (INIS)

    Pulses of 20 TW power have been generated at 1064 nm using the Chirped Pulse Amplification technique coupled to a 90 mm output aperture powerful Nd:silicate glass amplification line. This system delivers 60 J in a chirped pulse of 600 ps duration with a capacity of maintaining 3.5 nm output bandwidth. These chirped pulses have been compressed to 1.2 ps with an energy of 24J using large holographic diffraction gratings. After presenting the results we discuss the expected applications in atomic and plasma physics

  2. Factors contributing to plastic strain amplification in slip dominated deformation of magnesium alloys

    Science.gov (United States)

    Sinclair, C. W.; Martin, G.; Lebensohn, R. A.

    2015-12-01

    While plastic strains are never distributed uniformly in polycrystals, it has recently been shown experimentally that the distribution can be extremely heterogeneous in magnesium polycrystals even when the deformation is dominated by slip. Here, we attempt to provide insight into the (macroscopic) factors that contribute to this strain amplification and to explain, from a local perspective, the origins of this strain amplification. To do this, full field VPFFT crystal plasticity simulations have been performed under the simplifying assumption that twinning is inoperative. It is shown that the experimentally observed heterogeneity can be reproduced when a sufficiently high anisotropy in slip system strength is assumed. This can be further accentuated by a weakening of the texture.

  3. Quantum Darwinism: Amplification and the Acquisition of Information by Spin Environments

    Energy Technology Data Exchange (ETDEWEB)

    Zwolak, Michael P. [Oregon State Univ., Corvallis, OR (United States) Dept. of Physics; Riedel, Jess [IBM, Yorktown Heights, NY (United States). Thomas J. Watson Research Center; Zurek, Wojciech H. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-07-09

    Quantum Darwinism recognizes the role of the environment as a communication channel: Decoherence can amplify select information – information about the pointer states of a system of interest (preventing access to complementary information about superpositions of those states). We examine the amplification process for a spin environment under a variety of conditions. For initially pure environment states, the contribution to decoherence and the partial record deposited in an environment spin are both determined by the overlap of conditional states generated on the spin. For mixed environments, however, decoherence and a partial record are no longer directly related. The partial record, though, is given by a generalized measure of overlap – the quantum Chernoff information. The latter quantity is a measure of distinguishability and gives the efficiency of the amplification process. We calculate the Chernoff information and show explicitly that, except for a set of measure zero, there is always redundant information acquired by the environment.

  4. Parametric amplification of orbital angular momentum beams based on light-acoustic interaction

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Wei, E-mail: wei-g@163.com, E-mail: zhuzhihandd@sina.com; Mu, Chunyuan; Yang, Yuqiang [Institute of Photonics and Optical Fiber Technology, Harbin University of Science and Technology, Harbin 150080 (China); Li, Hongwei; Zhu, Zhihan, E-mail: wei-g@163.com, E-mail: zhuzhihandd@sina.com [The Higher Educational Key Laboratory for Measuring & Control Technology and Instrumentation of Heilongjiang Province, Harbin 150080 (China)

    2015-07-27

    A high fidelity amplification of beams carrying orbital angular momentum (OAM) is very crucial for OAM multiplexing and other OAM-based applications. Here, we report a demonstration of stimulated Brillouin amplification for OAM beams, and the energy conversion efficiency of photon-phonon coupling and the phase structure of amplified signals are investigated in collinear and noncollinear frame systems, respectively. Our results demonstrate that the OAM signals can be efficiently amplified without obvious noise introduced, and the modes of output signal are independent of the pump modes or the geometrical frames. Meanwhile, an OAM state depending on the optical modes and the geometrical frames is loaded into phonons by coherent light-acoustic interaction, which reveals more fundamental significance and a great application potential in OAM-multiplexing.

  5. Parametric amplification of orbital angular momentum beams based on light-acoustic interaction

    International Nuclear Information System (INIS)

    A high fidelity amplification of beams carrying orbital angular momentum (OAM) is very crucial for OAM multiplexing and other OAM-based applications. Here, we report a demonstration of stimulated Brillouin amplification for OAM beams, and the energy conversion efficiency of photon-phonon coupling and the phase structure of amplified signals are investigated in collinear and noncollinear frame systems, respectively. Our results demonstrate that the OAM signals can be efficiently amplified without obvious noise introduced, and the modes of output signal are independent of the pump modes or the geometrical frames. Meanwhile, an OAM state depending on the optical modes and the geometrical frames is loaded into phonons by coherent light-acoustic interaction, which reveals more fundamental significance and a great application potential in OAM-multiplexing

  6. Micro-fluidic partitioning between polymeric sheets for chemical amplification and processing

    Science.gov (United States)

    Anderson, Brian L.

    2015-05-26

    A system for fluid partitioning for chemical amplification or other chemical processing or separations of a sample, comprising a first dispenser of a first polymeric sheet, wherein the first polymeric sheet contains chambers; a second dispenser of a second polymeric sheet wherein the first dispenser and the second dispenser are positioned so that the first polymeric sheet and the second polymeric sheet become parallel; a dispenser of the fluid positioned to dispense the fluid between the first polymeric sheet and the second polymeric sheet; and a seal unit that seals the first polymeric sheet and the second polymeric sheet together thereby sealing the sample between the first polymeric sheet and the second polymeric sheet and partitioning the fluid for chemical amplification or other chemical processing or separations.

  7. Nano rolling-circle amplification for enhanced SERS hot spots in protein microarray analysis.

    Science.gov (United States)

    Yan, Juan; Su, Shao; He, Shijiang; He, Yao; Zhao, Bin; Wang, Dongfang; Zhang, Honglu; Huang, Qing; Song, Shiping; Fan, Chunhai

    2012-11-01

    Although "hot spots" have been proved to contribute to surface enhanced Raman scattering (SERS), less attention was paid to increase the number of the "hot spot" to directly enhance the Raman signals in bioanalytical systems. Here we report a new strategy based on nano rolling-circle amplification (nanoRCA) and nano hyperbranched rolling-circle amplification (nanoHRCA) to increase "hot spot" groups for protein microarrays. First, protein and ssDNA are coassembled on gold nanoparticles, making the assembled probe have both binding ability and hybridization ability. Second, the ssDNAs act as primers to initiate in situ RCA reaction to produced long ssDNAs. Third, a large number of SERS probes are loaded on the long ssDNA templetes, allowing thousands of SERS probes involved in each biomolecular recognition event. The strategy offered high-efficiency Raman enhancement and could detect less than 10 zeptomolar protein molecules in protein microarray analysis. PMID:23046056

  8. Parametric amplification of orbital angular momentum beams based on light-acoustic interaction

    CERN Document Server

    Gao, Wei; Li, Hongwei; Shi, Guangyao; Zhu, Zhihan

    2015-01-01

    A high fidelity amplification of beams carrying orbital angular momentum (OAM) is very crucial for OAM multiplexing and other OAM-based applications. Here, we report the first study of stimulated Brillouin amplification (SBA) for OAM beams, the energy conversion efficiency of photon-phonon coupling and the phase structure of amplified signals are investigated in collinear and noncollinear frame systems, respectively. Our results demonstrate that the OAM signals can be efficiently amplified without obvious noise introduced, and the modes of output signal is independent of the pump modes or the geometrical frames. Meanwhile, an OAM state depending on the optical modes and the geometrical frames is loaded into phonons by coherent light-acoustic interaction, which reveals more fundamental significance and a great application potential in OAM-multiplexing.

  9. Amplification in the auditory periphery: The effect of coupling tuning mechanisms

    Science.gov (United States)

    Montgomery, K. A.; Silber, M.; Solla, S. A.

    2007-05-01

    A mathematical model describing the coupling between two independent amplification mechanisms in auditory hair cells is proposed and analyzed. Hair cells are cells in the inner ear responsible for translating sound-induced mechanical stimuli into an electrical signal that can then be recorded by the auditory nerve. In nonmammals, two separate mechanisms have been postulated to contribute to the amplification and tuning properties of the hair cells. Models of each of these mechanisms have been shown to be poised near a Hopf bifurcation. Through a weakly nonlinear analysis that assumes weak periodic forcing, weak damping, and weak coupling, the physiologically based models of the two mechanisms are reduced to a system of two coupled amplitude equations describing the resonant response. The predictions that follow from an analysis of the reduced equations, as well as performance benefits due to the coupling of the two mechanisms, are discussed and compared with published experimental auditory nerve data.

  10. Suppression of the four-wave mixing amplification via Raman absorption

    CERN Document Server

    Romanov, Gleb; Novikova, I

    2015-01-01

    We propose a method to controllably suppress the effect of the four-wave mixing caused by the coupling of the strong control optical field to both optical transitions in the $\\Lambda$ system under the conditions of electromagnetically induced transparency. At sufficiently high atomic density, this process leads to amplification of a weak optical signal field, that is detrimental for the fidelity of any EIT-based quantum information applications. Here we show that an additional absorption resonance centered around the idler field frequency, generated in such a four-wave mixing process, may efficiently suppress the unwanted signal amplification without affecting properties of the EIT interaction. We discuss the possibility of creating such tunable absorption using two-photon Raman absorption resonances in the other Rb isotope, and present some preliminary experimental results.

  11. Mismatch characteristics of optical parametric chirped pulse amplification

    Science.gov (United States)

    Novák, O.; Turčičová, H.; Divoký, M.; Huynh, J.; Straka, P.

    2014-02-01

    The stability of an optical parametric chirped pulse amplifier (OPCPA) is influenced by time and the angular matching of the input beams. We derived the Gaussian dependence of the monochromatic signal gain on the small mismatch between the signal and pump beams. Gain characteristics were also calculated for polychromatic amplification and the impact of different beam mismatches and interaction geometries was explained. The asymmetry of the energy gain, and the square root dependence of the phase matched wavelength on beam angles were found. The predicted dependences were verified in a noncollinear OPCPA system with LBO and KDP crystal amplifying pulses of a Ti:sapphire laser around a central wavelength of 800 nm, pumped by the third harmonic frequency of an iodine gas laser at a wavelength of 438 nm. The widths of the gain curves in the dependence on both the pump-signal or the phase matching angles varied from several tenths to a few milliradians. The gain curve widths dependent on the pump-signal pulse delay were about two thirds of the pump pulse width for moderate pumping and about a half of the pump pulse width for pumping on the order of GW cm-2. A stable gain output is achieved if angular and temporal fluctuations are fractions of the measured gain curve widths, and when the signal direction is between the pump and the crystal principal axis (i.e. in the psz geometry).

  12. Mismatch characteristics of optical parametric chirped pulse amplification

    International Nuclear Information System (INIS)

    The stability of an optical parametric chirped pulse amplifier (OPCPA) is influenced by time and the angular matching of the input beams. We derived the Gaussian dependence of the monochromatic signal gain on the small mismatch between the signal and pump beams. Gain characteristics were also calculated for polychromatic amplification and the impact of different beam mismatches and interaction geometries was explained. The asymmetry of the energy gain, and the square root dependence of the phase matched wavelength on beam angles were found. The predicted dependences were verified in a noncollinear OPCPA system with LBO and KDP crystal amplifying pulses of a Ti:sapphire laser around a central wavelength of 800 nm, pumped by the third harmonic frequency of an iodine gas laser at a wavelength of 438 nm. The widths of the gain curves in the dependence on both the pump–signal or the phase matching angles varied from several tenths to a few milliradians. The gain curve widths dependent on the pump–signal pulse delay were about two thirds of the pump pulse width for moderate pumping and about a half of the pump pulse width for pumping on the order of GW cm−2. A stable gain output is achieved if angular and temporal fluctuations are fractions of the measured gain curve widths, and when the signal direction is between the pump and the crystal principal axis (i.e. in the psz geometry). (letter)

  13. Period doubling induced by thermal noise amplification in genetic circuits

    KAUST Repository

    Ruocco, G.

    2014-11-18

    Rhythms of life are dictated by oscillations, which take place in a wide rage of biological scales. In bacteria, for example, oscillations have been proven to control many fundamental processes, ranging from gene expression to cell divisions. In genetic circuits, oscillations originate from elemental block such as autorepressors and toggle switches, which produce robust and noise-free cycles with well defined frequency. In some circumstances, the oscillation period of biological functions may double, thus generating bistable behaviors whose ultimate origin is at the basis of intense investigations. Motivated by brain studies, we here study an “elemental” genetic circuit, where a simple nonlinear process interacts with a noisy environment. In the proposed system, nonlinearity naturally arises from the mechanism of cooperative stability, which regulates the concentration of a protein produced during a transcription process. In this elemental model, bistability results from the coherent amplification of environmental fluctuations due to a stochastic resonance of nonlinear origin. This suggests that the period doubling observed in many biological functions might result from the intrinsic interplay between nonlinearity and thermal noise.

  14. SBS mitigation with 'two-tone' amplification: a theoretical model

    Science.gov (United States)

    Bronder, T. J.; Shay, T. M.; Dajani, I.; Gavrielides, A.; Robin, C. A.; Lu, C. A.

    2008-02-01

    A new technique for mitigating stimulated Brillouin scattering (SBS) effects in narrow-linewidth Yb-doped fiber amplifiers is demonstrated with a model that reduces to solving an 8×8 system of coupled nonlinear equations with the gain, SBS, and four-wave mixing (FMW) incorporated into the model. This technique uses two seed signals, or 'two-tones', with each tone reaching its SBS threshold almost independently and thus increasing the overall threshold for SBS in the fiber amplifier. The wavelength separation of these signals is also selected to avoid FWM, which in this case possesses the next lowest nonlinear effects threshold. This model predicts an output power increase of 86% (at SBS threshold with no signs of FWM) for a 'two-tone' amplifier with seed signals at 1064nm and 1068nm, compared to a conventional fiber amplifier with a single 1064nm seed. The model is also used to simulate an SBS-suppressing fiber amplifier to test the regime where FWM is the limiting factor. In this case, an optimum wavelength separation of 3nm to 10nm prevents FWM from reaching threshold. The optimum ratio of the input power for the two seed signals in 'two-tone' amplification is also tested. Future experimental verification of this 'two-tone' technique is discussed.

  15. Using DNS amplification DDoS attack for hiding data

    Science.gov (United States)

    Mehić, M.; Voznak, M.; Safarik, J.; Partila, P.; Mikulec, M.

    2014-05-01

    This paper concerns available steganographic techniques that can be used for sending hidden data through public network. Typically, in steganographic communication it is advised to use popular/often used method for sending hidden data and amount of that data need to be high as much as possible. We confirmed this by choosing a Domain Name System (DNS) as a vital protocol of each network and choosing Distributed denial of service (DDoS) attacks that are most popular network attacks currently represented in the world. Apart from characterizing existing steganographic methods we provide new insights by presenting two new techniques. The first one is network steganography solution which exploits free/unused protocols fields and is known for IP, UDP or TCP protocols, but has never been applied to DNS (Domain Name Server) which are the fundamental part of network communications. The second explains the usage of DNS Amplification DDoS Attack to send seamlessly data through public network. The calculation that was performed to estimate the total amount of data that can be covertly transferred by using these technique, regardless of steganalysis, is included in this paper.

  16. ASAP: Amplification, sequencing & annotation of plastomes

    Directory of Open Access Journals (Sweden)

    Folta Kevin M

    2005-12-01

    Full Text Available Abstract Background Availability of DNA sequence information is vital for pursuing structural, functional and comparative genomics studies in plastids. Traditionally, the first step in mining the valuable information within a chloroplast genome requires sequencing a chloroplast plasmid library or BAC clones. These activities involve complicated preparatory procedures like chloroplast DNA isolation or identification of the appropriate BAC clones to be sequenced. Rolling circle amplification (RCA is being used currently to amplify the chloroplast genome from purified chloroplast DNA and the resulting products are sheared and cloned prior to sequencing. Herein we present a universal high-throughput, rapid PCR-based technique to amplify, sequence and assemble plastid genome sequence from diverse species in a short time and at reasonable cost from total plant DNA, using the large inverted repeat region from strawberry and peach as proof of concept. The method exploits the highly conserved coding regions or intergenic regions of plastid genes. Using an informatics approach, chloroplast DNA sequence information from 5 available eudicot plastomes was aligned to identify the most conserved regions. Cognate primer pairs were then designed to generate ~1 – 1.2 kb overlapping amplicons from the inverted repeat region in 14 diverse genera. Results 100% coverage of the inverted repeat region was obtained from Arabidopsis, tobacco, orange, strawberry, peach, lettuce, tomato and Amaranthus. Over 80% coverage was obtained from distant species, including Ginkgo, loblolly pine and Equisetum. Sequence from the inverted repeat region of strawberry and peach plastome was obtained, annotated and analyzed. Additionally, a polymorphic region identified from gel electrophoresis was sequenced from tomato and Amaranthus. Sequence analysis revealed large deletions in these species relative to tobacco plastome thus exhibiting the utility of this method for structural and

  17. Somatic amplifications and deletions in genome of papillary thyroid carcinomas.

    Science.gov (United States)

    Passon, Nadia; Bregant, Elisa; Sponziello, Marialuisa; Dima, Maria; Rosignolo, Francesca; Durante, Cosimo; Celano, Marilena; Russo, Diego; Filetti, Sebastiano; Damante, Giuseppe

    2015-11-01

    Somatic gene copy number variation contributes to tumor progression. Using comparative genomic hybridization (CGH) array, the presence of genomic imbalances was evaluated in a series of 27 papillary thyroid carcinomas (PTCs). To detect only somatic imbalances, for each sample, the reference DNA was from normal thyroid tissue of the same patient. The presence of the BRAF V600E mutation was also evaluated. Both amplifications and deletions showed an uneven distribution along the entire PTC cohort; amplifications were more frequent than deletions (mean values of 17.5 and 7.2, respectively). Number of aberration events was not even among samples, the majority of them occurring only in a small fraction of PTCs. Most frequent amplifications were detected at regions 2q35, 4q26, and 4q34.1, containing FN1, PDE5A, and GALNTL6 genes, respectively. Most frequent deletions occurred at regions 6q25.2, containing OPMR1 and IPCEF1 genes and 7q14.2, containing AOAH and ELMO1 genes. Amplification of FN1 and PDE5A genomic regions was confirmed by quantitative PCR. Frequency of amplifications and deletions was in relationship with clinical features and BRAF mutation status of tumor. In fact, according to the American Joint Committee on Cancer stage and American Thyroid Association (ATA) risk classification, amplifications are more frequent in higher risk samples, while deletions tend to prevail in the lower risk tumors. Analysis of single aberrations according to the ATA risk grouping shows that amplifications containing PDE5A, GALNTL6, DHRS3, and DOCK9 genes are significantly more frequent in the intermediate/high risk group than in the low risk group. Thus, our data would indicate that analysis of somatic genome aberrations by CGH array can be useful to identify additional prognostic variables. PMID:25863487

  18. High-temperature ultrafast polariton parametric amplification in semiconductor microcavities

    Science.gov (United States)

    Saba, M.; Ciuti, C.; Bloch, J.; Thierry-Mieg, V.; André, R.; Dang, Le Si; Kundermann, S.; Mura, A.; Bongiovanni, G.; Staehli, J. L.; Deveaud, B.

    2001-12-01

    Cavity polaritons, the elementary optical excitations of semiconductor microcavities, may be understood as a superposition of excitons and cavity photons. Owing to their composite nature, these bosonic particles have a distinct optical response, at the same time very fast and highly nonlinear. Very efficient light amplification due to polariton-polariton parametric scattering has recently been reported in semiconductor microcavities at liquid-helium temperatures. Here we demonstrate polariton parametric amplification up to 120K in GaAlAs-based microcavities and up to 220K in CdTe-based microcavities. We show that the cut-off temperature for the amplification is ultimately determined by the binding energy of the exciton. A 5-µm-thick planar microcavity can amplify a weak light pulse more than 5,000 times. The effective gain coefficient of an equivalent homogeneous medium would be 107cm-1. The subpicosecond duration and high efficiency of the amplification could be exploited for high-repetition all-optical microscopic switches and amplifiers. 105 polaritons occupy the same quantum state during the amplification, realizing a dynamical condensate of strongly interacting bosons which can be studied at high temperature.

  19. Problems encountered when defining Arctic amplification as a ratio

    Science.gov (United States)

    Hind, Alistair; Zhang, Qiong; Brattström, Gudrun

    2016-07-01

    In climate change science the term ‘Arctic amplification’ has become synonymous with an estimation of the ratio of a change in Arctic temperatures compared with a broader reference change under the same period, usually in global temperatures. Here, it is shown that this definition of Arctic amplification comes with a suite of difficulties related to the statistical properties of the ratio estimator itself. Most problematic is the complexity of categorizing uncertainty in Arctic amplification when the global, or reference, change in temperature is close to 0 over a period of interest, in which case it may be impossible to set bounds on this uncertainty. An important conceptual distinction is made between the ‘Ratio of Means’ and ‘Mean Ratio’ approaches to defining a ratio estimate of Arctic amplification, as they do not only possess different uncertainty properties regarding the amplification factor, but are also demonstrated to ask different scientific questions. Uncertainty in the estimated range of the Arctic amplification factor using the latest global climate models and climate forcing scenarios is expanded upon and shown to be greater than previously demonstrated for future climate projections, particularly using forcing scenarios with lower concentrations of greenhouse gases.

  20. Photoacoustic imaging using lock-in amplification and pulsed fiber lasers

    Science.gov (United States)

    Shi, Wei; Hajireza, Parsin; Zemp, Roger

    2016-03-01

    Photoacoustic (PA) imaging is a non-invasive, non-ionizing imaging technology with high optical contrast between blood and tissue, and with high sensitivity of hemoglobin concentration and oxygen saturation due to different optical absorption spectra resulting from different oxygenation of hemoglobin. Most PA imaging systems implement a nanosecond pulsed laser source as excitation source to induce PA signal, and rely on broadband amplifiers to record time-domain PA signals [1-6]. Some groups, however, have reported using modulated continuous-wave lasers as an excitation source for frequency-domain imaging [7-9]. Frequency-domain imaging offers the potential of lock-in amplification which has sensitivities as low as nV even in noise orders of magnitude higher than the signal. However, although modulated CW sources works for low cost and compact PA imaging, it does not satisfy thermal and stress confinement conditions required for optimal PA signal strength. Here, we investigate a PA methodology using pulsed fiber lasers as excitation laser source combined with lock-in amplification technology. For comparison, we also studied time-domain PA methodology. Phantom studies show that signal-to-noise ratio (SNR) obtained with frequency domain PA imaging is significantly more sensitive than that obtained using time-domain PA imaging when the laser pulse repetition rate (PRR) matches the bandwidth of ultrasound transducer. Therefore, high sensitive PA imaging technology using pulsed fiber laser sources with lock-in amplification may potentially greatly extend the depth of PA imaging.

  1. Transcriptome analysis in primary neural stem cells using a tag cDNA amplification method

    Directory of Open Access Journals (Sweden)

    Wikström Lilian

    2005-04-01

    Full Text Available Abstract Background Neural stem cells (NSCs can be isolated from the adult mammalian brain and expanded in culture, in the form of cellular aggregates called neurospheres. Neurospheres provide an in vitro model for studying NSC behaviour and give information on the factors and mechanisms that govern their proliferation and differentiation. They are also a promising source for cell replacement therapies of the central nervous system. Neurospheres are complex structures consisting of several cell types of varying degrees of differentiation. One way of characterising neurospheres is to analyse their gene expression profiles. The value of such studies is however uncertain since they are heterogeneous structures and different populations of neurospheres may vary significantly in their gene expression. Results To address this issue, we have used cDNA microarrays and a recently reported tag cDNA amplification method to analyse the gene expression profiles of neurospheres originating from separate isolations of the lateral ventricle wall of adult mice and passaged to varying degrees. Separate isolations as well as consecutive passages yield a high variability in gene expression while parallel cultures yield the lowest variability. Conclusions We demonstrate a low technical amplification variability using the employed amplification strategy and conclude that neurospheres from the same isolation and passage are sufficiently similar to be used for comparative gene expression analysis.

  2. Loop-mediated isothermal amplification for detection of porcine circovirus type 2

    Directory of Open Access Journals (Sweden)

    Zhou Shun

    2011-11-01

    Full Text Available Abstract Background Porcine circovirus type 2 (PCV2 is the primary causative agent of the emerging swine disease known as postweaning multisystemic wasting syndrome (PMWS. Nowadays, polymerase chain reaction (PCR is still the most widespread technique in pathogen detection. Loop-mediated isothermal amplification (LAMP, a novel nucleic acid amplification method developed in 2000, will possibly replace PCR in the field of detection. To establish a LAMP method for rapid detection of PCV2, two pairs of primers were designed specially from the open reading frame 2 (ORF2 sequences of PCV2. A LAMP method for rapid detection of PCV2 was established. To compare with PCR, sensitivity and specificity of LAMP were evaluated using the optimized reaction system. The LAMP products could be determined by agarose gel electrophoresis or adding SYBR Green I dye. Results The amplification of LAMP could be obtained at 63°C for 60 min. The detection limit was nearly 1 copy of DNA plasmid, more sensitive than PCR. There was no cross-reaction with porcine circovirus type 1 (PCV1, porcine pseudorabies virus (PRV and porcine parvovirus (PPV under the same conditions. Conclusions LAMP is an useful rapid detection method with high sensitivity and specificity for PCV2.

  3. Polydimethylsiloxane microfluidic chemiluminescence immunodevice with the signal amplification strategy for sensitive detection of human immunoglobin G.

    Science.gov (United States)

    Li, Huifang; Zhao, Mei; Liu, Wei; Chu, Weiru; Guo, Yumei

    2016-01-15

    A polydimethylsiloxane (PDMS) microfluidic chemiluminescence (CL) immunodevice for sensitive detection of human immunoglobin G (IgG) with the signal amplification strategy was developed in this work. The immunodevice was prepared by covalently immobilizing capture antibodies (Abs) on the silanized microchannel of microfluidic chip. Gold nanoparticles (AuNPs) functionalized with a high molar ratio of horseradish peroxidase (HRP) were used as an Ab label for signal amplification. Using a sandwich immunoassay, the multi-HRP conjugated AuNPs can catalyze the luminol-H2O2 CL system to achieve the high sensitivity. In addition, the double spiral flow-channel was adopted here, which can still contribute to the high sensitivity. Based on signal amplification strategy, the performance of human IgG tests revealed a lower detection limit (DL) of 0.03ng/mL and showed an increase of 7.4-fold in detection sensitivity compared to a commercial Ab-HRP conjugation. This microfluidic immunodevice can provide an alternative approach for sensitive detection of human IgG in the field of clinic diagnostic and therapeutic. PMID:26592629

  4. Whole genome amplification and de novo assembly of single bacterial cells.

    Directory of Open Access Journals (Sweden)

    Sébastien Rodrigue

    Full Text Available BACKGROUND: Single-cell genome sequencing has the potential to allow the in-depth exploration of the vast genetic diversity found in uncultured microbes. We used the marine cyanobacterium Prochlorococcus as a model system for addressing important challenges facing high-throughput whole genome amplification (WGA and complete genome sequencing of individual cells. METHODOLOGY/PRINCIPAL FINDINGS: We describe a pipeline that enables single-cell WGA on hundreds of cells at a time while virtually eliminating non-target DNA from the reactions. We further developed a post-amplification normalization procedure that mitigates extreme variations in sequencing coverage associated with multiple displacement amplification (MDA, and demonstrated that the procedure increased sequencing efficiency and facilitated genome assembly. We report genome recovery as high as 99.6% with reference-guided assembly, and 95% with de novo assembly starting from a single cell. We also analyzed the impact of chimera formation during MDA on de novo assembly, and discuss strategies to minimize the presence of incorrectly joined regions in contigs. CONCLUSIONS/SIGNIFICANCE: The methods describe in this paper will be useful for sequencing genomes of individual cells from a variety of samples.

  5. Electrochemical aptasensor for highly sensitive determination of cocaine using a supramolecular aptamer and rolling circle amplification

    International Nuclear Information System (INIS)

    We report on a novel strategy for the electrochemical detection of cocaine. It is based on the use of a supramolecular aptamer, rolling circle amplification (RCA), and multiplex binding of a biotin-strepavidin system. The aptamer fragments were assembled to a supramolecular aptamer which, in the presence of cocaine, conjugates to streptavidin for anchoring of biotinylated circular DNA. This initiates RCA and enables sensitive electrochemical-enzymatic readout. A significant signal amplification was obtained by using streptavidin linked to alkaline phosphatase that binds to the remaining biotinylated detection probes and catalyzes the hydrolysis of the synthetic enzyme substrate α-naphthylphosphate. This dual amplification strategy tremendously increases the detection limit of the aptasensor. Under optimal conditions and using differential pulse voltammetry, cocaine can be detected in the concentration range between 2 and 500 nM with a detection limit as low as 1.3 nM (at S/N = 3). The method is specific and acceptably reproducible. It was successfully applied to the detection of cocaine in (spiked) urine samples. The data were in good agreement with those obtained by the GC-MS reference method. (author)

  6. Low cost extraction and isothermal amplification of DNA for infectious diarrhea diagnosis.

    Directory of Open Access Journals (Sweden)

    Shichu Huang

    Full Text Available In order to counter the common perception that molecular diagnostics are too complicated to work in low resource settings, we have performed a difficult sample preparation and DNA amplification protocol using instrumentation designed to be operated without wall or battery power. In this work we have combined a nearly electricity-free nucleic acid extraction process with an electricity-free isothermal amplification assay to detect the presence of Clostridium difficile (C. difficile DNA in the stool of infected patients. We used helicase-dependent isothermal amplification (HDA to amplify the DNA in a low-cost, thermoplastic reaction chip heated with a pair of commercially available toe warmers, while using a simple Styrofoam insulator. DNA was extracted from known positive and negative stool samples. The DNA extraction protocol utilized an air pressure driven solid phase extraction device run using a standard bicycle pump. The simple heater setup required no electricity or battery and was capable of maintaining the temperature at 65°C±2°C for 55 min, suitable for repeatable HDA amplification. Experiments were performed to explore the adaptability of the system for use in a range of ambient conditions. When compared to a traditional centrifuge extraction protocol and a laboratory thermocycler, this disposable, no power platform achieved approximately the same lower limit of detection (1.25×10(-2 pg of C. difficile DNA while requiring much less raw material and a fraction of the lab infrastructure and cost. This proof of concept study could greatly impact the accessibility of molecular assays for applications in global health.

  7. Low cost extraction and isothermal amplification of DNA for infectious diarrhea diagnosis.

    Science.gov (United States)

    Huang, Shichu; Do, Jaephil; Mahalanabis, Madhumita; Fan, Andy; Zhao, Lei; Jepeal, Lisa; Singh, Satish K; Klapperich, Catherine M

    2013-01-01

    In order to counter the common perception that molecular diagnostics are too complicated to work in low resource settings, we have performed a difficult sample preparation and DNA amplification protocol using instrumentation designed to be operated without wall or battery power. In this work we have combined a nearly electricity-free nucleic acid extraction process with an electricity-free isothermal amplification assay to detect the presence of Clostridium difficile (C. difficile) DNA in the stool of infected patients. We used helicase-dependent isothermal amplification (HDA) to amplify the DNA in a low-cost, thermoplastic reaction chip heated with a pair of commercially available toe warmers, while using a simple Styrofoam insulator. DNA was extracted from known positive and negative stool samples. The DNA extraction protocol utilized an air pressure driven solid phase extraction device run using a standard bicycle pump. The simple heater setup required no electricity or battery and was capable of maintaining the temperature at 65°C±2°C for 55 min, suitable for repeatable HDA amplification. Experiments were performed to explore the adaptability of the system for use in a range of ambient conditions. When compared to a traditional centrifuge extraction protocol and a laboratory thermocycler, this disposable, no power platform achieved approximately the same lower limit of detection (1.25×10(-2) pg of C. difficile DNA) while requiring much less raw material and a fraction of the lab infrastructure and cost. This proof of concept study could greatly impact the accessibility of molecular assays for applications in global health. PMID:23555883

  8. Oncogene amplification detected by in situ hybridization in radiation induced rat skin tumors. [C-myc:a3

    Energy Technology Data Exchange (ETDEWEB)

    Yi Jin.

    1991-02-01

    Oncogene activation may play an important role in radiation induced carcinogenesis. C-myc oncogene amplification was detected by in situ hybridization in radiation-induced rat skin tumors, including squamous and basal cell carcinomas. In situ hybridization was performed with a biotinylated human c-myc third exon probe, visualized with an avidin-biotinylated alkaline phosphate detection system. No c-myc oncogene amplification was detected in normal rat skin at very early times after exposure to ionizing radiation, which is consistent with the view that c-myc amplification is more likely to be related to carcinogenesis than to normal cell proliferation. The incorporation of tritiated thymidine into the DNA of rat skin cells showed that the proliferation of epidermal cells reached a peak on the seventh day after exposure to ionizing radiation and then decreased. No connection between the proliferation of epidermal cell and c-myc oncogene amplification in normal or irradiated rat skin was found. The results indicated that c-myc amplification as measured by in situ hybridization was correlated with the Southern bolt results, but only some of the cancer cells were amplified. The c-myc positive cells were distributed randomly within regions of the tumor and exhibited a more uniform nuclear structure in comparison to the more vacuolated c-myc negative cells. No c-myc signal was detected in unirradiated normal skin or in irradiated skin cells near the tumors. C-myc amplification appears to be cell or cell cycle specific within radiation-induced carcinomas. 28 refs., 3 figs., 3 tabs.

  9. Modeling Loss Amplification After Devastating Disasters

    Science.gov (United States)

    Boissonnade, A. C.; Muir Wood, R.

    2008-05-01

    With the catastrophic events that occurred in 2004 and 2005 came the realization that Catastrophic (Cat) loss models were not properly modeling insured losses and their associated uncertainty. One reason was that major catastrophes were generally characterized by losses caused by the primary initiating events. Such approaches are not adequate when losses can result from the compounded impacts of scenarios of secondary cascading events (physical, economic, social and political) that can have much larger impacts than those due to the primary events themselves. Situations where more and more cascading events can occur will result in different outcomes, some leading to extreme loss events, generally referred as Super Cats. These situations occurred in December 2004 with the Sumatra earthquake and tsunami and in August 2005 with hurricane Katrina and resulting New Orleans flooding. A review of historical events shows that these events are not exceptions. Modeling such scenarios adds new levels of complexity and different perspectives in the understanding of characterizing and assessing impacts of catastrophic events. Modeling economic consequences of extreme events can be improved by developing scenarios of cascades of secondary events triggered by the primary event(s). The likelihood of each scenario should be modeled, along with the hazards of primary and secondary events and resulting losses with their impacts to the different stakeholders. In addition, it is also important to model the impacts of the hazards on the infrastructure and the resulting disruption to the residents and the local economy because these can result in additional losses. This paper describes current work with the goals of better modeling the full economic impacts from catastrophic events, and of a more comprehensive treatment of uncertainty. We will present approaches for modeling loss amplification that account for all the ways in which the cost incurred for a certain level of damage due to a

  10. Radioactive wastes and the social amplification of risk

    International Nuclear Information System (INIS)

    A significant problem in radioactive waste facility siting is that apparent small risks or minor risks events produce substantial public concern and social impacts. The reasons for this difference in public health and societal impacts is not well understood. This paper explores the issues involved in the social amplification of risk, using the risk associated with site characterization as the example. Noteworthy as sources of amplification are the information flow associated with risks and risk events including the large volume of information, the extent of dispute, and misinformation and rumor. Such information passes through the mass media and interpersonal networks. The major mechanisms involved in risk amplifications are discussed and their likely impacts on society described

  11. Discovery of a photoresponse amplification mechanism in compensated PN junctions

    International Nuclear Information System (INIS)

    We report the experimental evidence of uncovering a photoresponse amplification mechanism in heavily doped, partially compensated silicon p-n junctions under very low bias voltage. We show that the observed photocurrent gain occurs at a bias that is more than an order of magnitude below the threshold voltage for conventional impact ionization. Moreover, contrary to the case of avalanche detectors and p-i-n diodes, the amplified photoresponse is enhanced rather than suppressed with increasing temperature. These distinctive characteristics lead us to hypothesize that the inelastic scattering between energetic electrons (holes) and the ionized impurities in the depletion and charge neutral regions of the p-n junction in a cyclic manner plays a significant role in the amplification process. Such an internal signal amplification mechanism, which occurs at much lower bias than impact ionization and favors room temperature over cryogenic temperature, makes it promising for practical device applications

  12. Amplification of spin waves by the spin Seebeck effect

    Science.gov (United States)

    Padrón-Hernández, E.; Azevedo, A.; Rezende, S. M.

    2012-04-01

    We observe amplification of spin-wave packets propagating along a film of single-crystal yttrium iron garnet (YIG) subject to a transverse temperature gradient. The spin waves are excited and detected with standard techniques used to study volume or surface magnetostatic waves in the 1-2 GHz frequency range. Amplification gains larger than 20 are observed in a YIG film heated by a current of 20 mA in a Pt layer in a simple YIG/Pt bilayer. The amplification is attributed to the action of a spin-transfer thermal torque acting on the magnetization that opposes the relaxation and which is created by spin currents generated through the spin Seebeck effect. The experimental data are interpreted with a spin-wave model.

  13. Chemical amplification of magnetic field effects relevant to avian magnetoreception

    Science.gov (United States)

    Kattnig, Daniel R.; Evans, Emrys W.; Déjean, Victoire; Dodson, Charlotte A.; Wallace, Mark I.; MacKenzie, Stuart R.; Timmel, Christiane R.; Hore, P. J.

    2016-04-01

    Magnetic fields as weak as the Earth's can change the yields of radical pair reactions even though the energies involved are orders of magnitude smaller than the thermal energy, kBT, at room temperature. Proposed as the source of the light-dependent magnetic compass in migratory birds, the radical pair mechanism is thought to operate in cryptochrome flavoproteins in the retina. Here we demonstrate that the primary magnetic field effect on flavin photoreactions can be amplified chemically by slow radical termination reactions under conditions of continuous photoexcitation. The nature and origin of the amplification are revealed by studies of the intermolecular flavin-tryptophan and flavin-ascorbic acid photocycles and the closely related intramolecular flavin-tryptophan radical pair in cryptochrome. Amplification factors of up to 5.6 were observed for magnetic fields weaker than 1 mT. Substantial chemical amplification could have a significant impact on the viability of a cryptochrome-based magnetic compass sensor.

  14. Information Limited Oligonucleotide Amplification Assay for Affinity-Based, Parallel Detection Studies.

    Directory of Open Access Journals (Sweden)

    Harish Bokkasam

    Full Text Available Molecular communication systems encounter similar constraints as telecommunications. In either case, channel crosstalk at the receiver end will result in information loss that statistical analysis cannot compensate. This is because in any communication channel there is a physical limit to the amount of information that can be transmitted. We present a novel and simple modified end amplification (MEA technique to generate reduced and defined amounts of specific information in form of short fragments from an oligonucleotide source that also contains unrelated and redundant information. Our method can be a valuable tool to investigate information overflow and channel capacity in biomolecular recognition systems.

  15. Methods for microbial DNA extraction from soil for PCR amplification.

    Science.gov (United States)

    Yeates, C; Gillings, M R; Davison, A D; Altavilla, N; Veal, D A

    1998-05-14

    Amplification of DNA from soil is often inhibited by co-purified contaminants. A rapid, inexpensive, large-scale DNA extraction method involving minimal purification has been developed that is applicable to various soil types (1). DNA is also suitable for PCR amplification using various DNA targets. DNA was extracted from 100g of soil using direct lysis with glass beads and SDS followed by potassium acetate precipitation, polyethylene glycol precipitation, phenol extraction and isopropanol precipitation. This method was compared to other DNA extraction methods with regard to DNA purity and size. PMID:12734590

  16. Raman amplification in the broken-wave regime

    CERN Document Server

    Farmer, John P

    2015-01-01

    In regimes far beyond the wavebreaking theshold of Raman amplification, we show that significant amplifcation can occur after the onset of wavebreaking, before phase mixing destroys the coupling between pump and probe. The amplification efficiency in this regime is therefore strongly dependent on the energy-transfer rate when wavebreaking occurs, and is, as such, sensitive to both the probe amplitude and profile. In order to access the higher-efficiency broken-wave regime, a short, intense probe is required. Parameter scans show the marked difference in behaviour compared to below wavebreaking, where longer, more energetic pulses lead to improved efficiencies.

  17. Methods for microbial DNA extraction from soil for PCR amplification

    Directory of Open Access Journals (Sweden)

    Yeates C

    1998-01-01

    Full Text Available Amplification of DNA from soil is often inhibited by co-purified contaminants. A rapid, inexpensive, large-scale DNA extraction method involving minimal purification has been developed that is applicable to various soil types (1. DNA is also suitable for PCR amplification using various DNA targets. DNA was extracted from 100g of soil using direct lysis with glass beads and SDS followed by potassium acetate precipitation, polyethylene glycol precipitation, phenol extraction and isopropanol precipitation. This method was compared to other DNA extraction methods with regard to DNA purity and size.

  18. Symmetry between absorption and amplification in disordered media

    International Nuclear Information System (INIS)

    We address the issue of whether amplification, like absorption, suppresses wave transmission at large gain, as has been claimed in previous studies of wave propagation in active random media. A closer examination reveals that the paradoxical symmetry between absorption and amplification is an artifact of unphysical solutions from the time-independent wave equation. Solutions from the time-dependent equation demonstrate clearly that when gain is above the threshold, the amplitude of both the transmitted and the reflected wave actually increases with time, apparently without bound. The implications of the current finding is discussed. copyright 1999 The American Physical Society

  19. Amplification of Short Pulse High Power UV Laser

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    At recent year, with the development of CPA and other amplification technology, laser intensity achieves great increase and laser power can be high to PW(105) now, this ultrashort pulse lasers offer scientists a route to investigate laser-matter interaction in an absolute new regime.So far the researches on ultrashort pulse laser-matter interaction concentrated on infrared regime, yet ultraviolet laser has the advantage in intense field physics and ICF researches for its short wavelength and less nonlinear effects. KrF excimer is the best medium in UV ultrashort pulse amplification for its small saturation energy and high contrast ratio accessible.

  20. Ultra-broad bandwidth parametric amplification at degeneracy.

    Science.gov (United States)

    Limpert, J; Aguergaray, C; Montant, S; Manek-Hönninger, I; Petit, S; Descamps, D; Cormier, E; Salin, F

    2005-09-19

    We report on a novel approach of ultra-broad bandwidth parametric amplification around degeneracy. A bandwidth of up to 400 nm centered around 800 nm is amplified in a BBO crystal by using chirped pump pulses with a bandwitdth as broad as 10 nm. A supercontinuum signal is generated in a microstructured fiber, having to first order a quadratic chirp, which is necessary to ensure temporal overlap of the interacting waves over this broad bandwidth. Furthermore, we discuss the potential of this approach for an octave-spanning parametric amplification. PMID:19498762

  1. Divided-pulse amplification to the joule level.

    Science.gov (United States)

    Webb, Benjamin; Azim, Ahmad; Bodnar, Nathan; Chini, Michael; Shah, Lawrence; Richardson, Martin

    2016-07-01

    Divided-pulse amplification (DPA) has proven to be a valuable tool in scaling the peak power of diode-pumped ytterbium-doped amplifiers to beyond the single-pulse threshold for parasitic nonlinear effects. DPA enables the amplification of picosecond pulses in solid-state amplifiers with limited bandwidth beyond the single-pulse damage threshold. In this Letter, we demonstrate DPA of picosecond pulses in a flashlamp-pumped Nd:YAG amplifier for the first time, to the best of our knowledge, yielding a combined pulse energy of 167 mJ. PMID:27367113

  2. 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.

  3. Subtyping of Streptococcus uberis by DNA amplification fingerprinting.

    OpenAIRE

    Jayarao, B. M.; Bassam, B J; Caetano-Anollés, G; Gresshoff, P M; Oliver, S P

    1992-01-01

    Total DNA of Streptococcus uberis from cows with mastitis was analyzed by DNA amplification fingerprinting (DAF) and compared with restriction endonuclease fingerprinting (REF). DAF grouped 22 strains into 15 distinct patterns, while REF grouped them into 12 patterns. These results suggest that DAF is a useful technique for subtyping strains of S. uberis.

  4. Soft x-ray amplification in an ablative capillary discharge

    International Nuclear Information System (INIS)

    Soft x-ray amplification in CVI 18.2 nm line is observed in an ablative UHMW-PE capillary discharge. The gain coefficient is measured to be 1.9 cm-1. The electron density is about 2 x 1019 cm-3. This indicates that capillary discharge pumping device can be a source for a compact soft x-ray laser. (author)

  5. Direct Extraction and Amplification of DNA from Soil.

    Science.gov (United States)

    Trevors, Jack T.; Leung, K.

    1998-01-01

    Presents an exercise that describes the direct extraction and purification of DNA from a small soil sample. Also discusses the subsequent amplification of a 343-bp Tn7 transposate A gene fragment (tnsA) from a strain of Pseudomonas aureofaciens 3732RNL11. Contains 21 references. (DDR)

  6. Four-quadrant flyback converter for direct audio power amplification

    DEFF Research Database (Denmark)

    Ljusev, Petar; Andersen, Michael Andreas E.

    2005-01-01

    This paper presents a bidirectional, four-quadrant flyback converter for use in direct audio power amplification. When compared to the standard Class-D switching audio power amplifier with a separate power supply, the proposed four-quadrant flyback converter provides simple solution with better...

  7. Loss of KLF14 triggers centrosome amplification and tumorigenesis.

    Science.gov (United States)

    Fan, Guangjian; Sun, Lianhui; Shan, Peipei; Zhang, Xianying; Huan, Jinliang; Zhang, Xiaohong; Li, Dali; Wang, Tingting; Wei, Tingting; Zhang, Xiaohong; Gu, Xiaoyang; Yao, Liangfang; Xuan, Yang; Hou, Zhaoyuan; Cui, Yongping; Cao, Liu; Li, Xiaotao; Zhang, Shengping; Wang, Chuangui

    2015-01-01

    Centrosome amplification is frequent in cancer, but the underlying mechanisms remain unclear. Here we report that disruption of the Kruppel-like factor 14 (KLF14) gene in mice causes centrosome amplification, aneuploidy and spontaneous tumorigenesis. Molecularly, KLF14 functions as a transcriptional repressor of Plk4, a polo-like kinase whose overexpression induces centrosome overduplication. Transient knockdown of KLF14 is sufficient to induce Plk4-directed centrosome amplification. Clinically, KLF14 transcription is significantly downregulated, whereas Plk4 transcription is upregulated in multiple types of cancers, and there exists an inverse correlation between KLF14 and Plk4 protein expression in human breast and colon cancers. Moreover, KLF14 depletion promotes AOM/DSS-induced colon tumorigenesis. Our findings reveal that KLF14 reduction serves as a mechanism leading to centrosome amplification and tumorigenesis. On the other hand, forced expression of KLF14 leads to mitotic catastrophe. Collectively, our findings identify KLF14 as a tumour suppressor and highlight its potential as biomarker and therapeutic target for cancer. PMID:26439168

  8. Utilization of non-linear converters for audio amplification

    DEFF Research Database (Denmark)

    Iversen, Niels Elkjær; Birch, Thomas; Knott, Arnold

    2012-01-01

    . The introduction of non-linear converters for audio amplification defeats this limitation. A Cuk converter, designed to deliver an AC peak output voltage twice the supply voltage, is presented in this paper. A 3V prototype has been developed to prove the concept. The prototype shows that it is...

  9. An enzymatic signal amplification system for calorimetric studies of cellobiohydrolases

    DEFF Research Database (Denmark)

    Murphy, Leigh; Baumann, Martin Johannes; Borch, Kim;

    2010-01-01

    The study of cellulolytic enzymes has traditionally been carried out using endpoint measurements by quantitation of reaction products using high-performance liquid chromatography (HPLC) or overall determination of produced reducing ends. To measure catalytic activity, model substrates such as...... is heat production. This can be converted to the rate of reaction and allows direct and continuous monitoring of the hydrolysis of complex substrates. To overcome the low molar enthalpy of the hydrolysis of the glycosidic bond, which is typically on the order of −2.5 kJ mol−1, an enzymatic signal...

  10. Spatiotemporal noise characterization for chirped-pulse amplification systems.

    Science.gov (United States)

    Ma, Jingui; Yuan, Peng; Wang, Jing; Wang, Yongzhi; Xie, Guoqiang; Zhu, Heyuan; Qian, Liejia

    2015-01-01

    Optical noise, the core of the pulse-contrast challenge for ultra-high peak power femtosecond lasers, exhibits spatiotemporal (ST) coupling induced by angular dispersion. Full characterization of such ST noise requires two-dimensional measurements in the ST domain. Thus far, all noise measurements have been made only in the temporal domain. Here we report the experimental characterization of the ST noise, which is made feasible by extending cross-correlation from the temporal domain to the ST domain. We experimentally demonstrate that the ST noise originates from the optical surface imperfections in the pulse stretcher/compressor and exhibits a linear ST coupling in the far-field plane. The contrast on the far-field axis, underestimated in the conventional measurements, is further improved by avoiding the far-field optics in the stretcher. These results enhance our understanding of the pulse contrast with respect to its ST-coupling nature and pave the way toward the design of high-contrast ultra-high peak power lasers. PMID:25648187

  11. An investigation of PCR inhibition using Plexor(®) -based quantitative PCR and short tandem repeat amplification.

    Science.gov (United States)

    Thompson, Robyn E; Duncan, George; McCord, Bruce R

    2014-11-01

    A common problem in forensic DNA typing is PCR inhibition resulting in allele dropout and peak imbalance. In this paper, we have utilized the Plexor(®) real-time PCR quantification kit to evaluate PCR inhibition. This is performed by adding increasing concentrations of various inhibitors and evaluating changes in melt curves and PCR amplification efficiencies. Inhibitors examined included calcium, humic acid, collagen, phenol, tannic acid, hematin, melanin, urea, bile salts, EDTA, and guanidinium thiocyanate. Results were plotted and modeled using mathematical simulations. In general, we found that PCR inhibitors that bind DNA affect melt curves and CT takeoff points while those that affect the Taq polymerase tend to affect the slope of the amplification curve. Mixed mode effects were also visible. Quantitative PCR results were then compared with subsequent STR amplification using the PowerPlex(®) 16 HS System. The overall results demonstrate that real-time PCR can be an effective method to evaluate PCR inhibition and predict its effects on subsequent STR amplifications. PMID:25182468

  12. Preparation and Amplification of Colony of Goat Transgenic Fetal Fibroblast and Mammary Gland Epithelial Cell with Human Lactoferrin Gene

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yu-ling; LIU Feng-jun; ZHANG Yong

    2009-01-01

    [Objective] The aim was to explore technical system of making single transgenic positive cells become colony cells by amplification culture. [Method] Fetal fibroblasts and mammary gland epithelial cells of single goat fetus of pBLM-C1 which specifically expressed human lactoferrin were cloned. Single cell colony of single transfection cell was prepared with 3 concentrations of 0%, 50% and 100% conditioned culture media. Transfection cell and non-transfection cell were carried out amplification culture by con-culture, neo gene was as screened gene, genome DNA of transfection cell was detected by PCR method. Chromosome karyotype analysis of single colony cell was tested. [Result] Compared with non-conditioned culture medium, 100% conditioned culture medium could greatly increase survived rate of single colony cells (FF: 53.33% vs. 10.00%; MGE: 33.33% vs. 6.67%). Compared with control, con-culture of transfection cell and non-transfection cell could greatly increase rate of transfection cell single colony after amplification culture (FF: 53.33% vs. 10.00%;MGE: 33.33% vs. 6.67%), confluence time of amplification culture was significantly decreased (20-30 d). The result of PCR showed that the colony cell obtained by above method contained hLF target gene. The result of karyotype analysis showed that most cloned cell chromosomes were normal. [Conclusion] The study provides a reliable method for separating transgenic cell, inserting and diagnosing ideal vector, and can save expense and time for transgenic animal production.

  13. Bacteriophage Amplification-Coupled Detection and Identification of Bacterial Pathogens

    Science.gov (United States)

    Cox, Christopher R.; Voorhees, Kent J.

    Current methods of species-specific bacterial detection and identification are complex, time-consuming, and often require expensive specialized equipment and highly trained personnel. Numerous biochemical and genotypic identification methods have been applied to bacterial characterization, but all rely on tedious microbiological culturing practices and/or costly sequencing protocols which render them impractical for deployment as rapid, cost-effective point-of-care or field detection and identification methods. With a view towards addressing these shortcomings, we have exploited the evolutionarily conserved interactions between a bacteriophage (phage) and its bacterial host to develop species-specific detection methods. Phage amplification-coupled matrix assisted laser desorption time-of-flight mass spectrometry (MALDI-TOF-MS) was utilized to rapidly detect phage propagation resulting from species-specific in vitro bacterial infection. This novel signal amplification method allowed for bacterial detection and identification in as little as 2 h, and when combined with disulfide bond reduction methods developed in our laboratory to enhance MALDI-TOF-MS resolution, was observed to lower the limit of detection by several orders of magnitude over conventional spectroscopy and phage typing methods. Phage amplification has been combined with lateral flow immunochromatography (LFI) to develop rapid, easy-to-operate, portable, species-specific point-of-care (POC) detection devices. Prototype LFI detectors have been developed and characterized for Yersinia pestis and Bacillus anthracis, the etiologic agents of plague and anthrax, respectively. Comparable sensitivity and rapidity was observed when phage amplification was adapted to a species-specific handheld LFI detector, thus allowing for rapid, simple, POC bacterial detection and identification while eliminating the need for bacterial culturing or DNA isolation and amplification techniques.

  14. New perspectives on microbial community distortion after whole-genome amplification

    Science.gov (United States)

    Whole-genome amplification (WGA) has become an important tool to explore the genomic information of microorganisms in an environmental sample with limited biomass, however potential selective biases during the amplification processes are poorly understood. Here, we describe the e...

  15. Superradiant amplification by stars and black holes

    CERN Document Server

    Rosa, João Luís de Figueiredo

    2016-01-01

    In this thesis we study the phenomenon of superradiance and its implications to the stability of black-holes (BH) and perfect-fluid stars. Superradiance is a radiation enhancement process that involves rotating dissipative systems. In BH spacetimes, superradiance is due to dissipation at the event horizon, with interesting associated phenomena, namely floating orbits and BH-bombs. BH superradiance is a very interdisciplinary topic, and its study allows us to obtain important results in the area of particle physics. The scattering of a scalar field by a rotating BH leads to the formation of quasi-boundstates. In rotational systems, these states can give rise to superradiant instabilities. These results were recently used to impose constraints to the mass of fundamental particles and darkmatter candidates. In this work, it is shown that, when dissipation is properly included, similar results are achievable in self-gravitating systems other than black-holes, such as perfect fluid stars. It is also demonstrated t...

  16. Detection of porcine circovirus type 1 in commercial porcine vaccines by loop-mediated isothermal amplification

    OpenAIRE

    Wang, Chun; Pang, Victor Fei; Jeng, Chian-Ren; LEE, Fan; Huang, Yu-Wen; Lin, Yeou-Liang; Hsiao, Shih-Hsuan; Lai, Shiow-Suey

    2011-01-01

    A loop-mediated isothermal amplification (LAMP) method with a real-time monitoring system was developed for the detection of porcine circovirus type 1 (PCV1) in commercial swine vaccines. This method was highly specific for PCV1. No cross-reaction to porcine circovirus type 2, porcine parvovirus, pseudorabies virus, classical swine fever virus, and porcine reproductive and respiratory syndrome virus was observed. The analytical sensitivity of the LAMP for PCV1 DNA was 10 copies/μl in the case...

  17. Direct amplification of ultrashort pulses in μ-pulling-down Yb:YAG single crystal fibers

    OpenAIRE

    Zaouter, Yoann; Martial, Igor; Aubry, Nicolas; Didierjean, Julien; Hönninger, Clemens; Mottay, Eric; Druon, Frédéric; Georges, Patrick

    2011-01-01

    We demonstrated that Yb:YAG single crystal fibers have a strong potential for the amplification of femtosecond pulses. Seeded by 230 fs pulses with an average power of 400 mW at 30 MHz delivered by a passively mode-locked Yb:KYW oscillator, the system produced 330 fs pulses with an average power of 12 W. This is the shortest pulse duration ever produced by an Yb:YAG amplifier. The gain in the single crystal fiber reached a value as high as 30 in a simple double-pass configuration.

  18. Direct amplification of ultrashort pulses in μ-pulling-down Yb:YAG single crystal fibers.

    Science.gov (United States)

    Zaouter, Yoann; Martial, Igor; Aubry, Nicolas; Didierjean, Julien; Hönninger, Clemens; Mottay, Eric; Druon, Frederic; Georges, Patrick; Balembois, François

    2011-03-01

    We demonstrated that Yb:YAG single crystal fibers have a strong potential for the amplification of femtosecond pulses. Seeded by 230 fs pulses with an average power of 400 mW at 30 MHz delivered by a passively mode-locked Yb:KYW oscillator, the system produced 330 fs pulses with an average power of 12 W. This is the shortest pulse duration ever produced by an Yb:YAG amplifier. The gain in the single crystal fiber reached a value as high as 30 in a simple double-pass configuration. PMID:21368970

  19. Digital Droplet Multiple Displacement Amplification (ddMDA) for Whole Genome Sequencing of Limited DNA Samples

    OpenAIRE

    Minsoung Rhee; Yooli K Light; Meagher, Robert J.; Anup K. Singh

    2016-01-01

    Multiple displacement amplification (MDA) is a widely used technique for amplification of DNA from samples containing limited amounts of DNA (e.g., uncultivable microbes or clinical samples) before whole genome sequencing. Despite its advantages of high yield and fidelity, it suffers from high amplification bias and non-specific amplification when amplifying sub-nanogram of template DNA. Here, we present a microfluidic digital droplet MDA (ddMDA) technique where partitioning of the template D...

  20. Amplification of cylindrically polarized laser beams in single crystal fiber amplifiers

    OpenAIRE

    Piehler, Stefan; Délen, Xavier; Rumpel, Martin; Didierjean, Julien; Aubry, Nicolas; Graf, Thomas; Balembois, François; Georges, Patrick; Abdou Ahmed, Marwan

    2013-01-01

    Yb:YAG single crystal fiber (SCF) amplifiers have recently drawn much attention in the field of amplification of ultra-short pulses. In this paper, we report on the use of SCF amplifiers for the amplification of cylindrically polarized laser beams, as such beams offer promising properties for numerous applications. While the amplification of cylindrically polarized beams is challenging with other amplifier designs due to thermally induced depolarization, we demonstrate the amplification of 32...

  1. LD pumped Nd: YLF amplification technology

    International Nuclear Information System (INIS)

    A Ring-LD-pumped Nd: YLF laser amplifier system is theoretically and experimentally discussed. A structure of off-axes double passes amplifier is used. The results of experiment shown that 109 mJ output energy with a net gain of 1115 is obtained under 150 μJ input energy; a compact side-pumped structure is used to obtain a high transferring efficiency of LD array, 1.01 J output energy is achieved at 1053 nm. (authors)

  2. Modification of an amplification reaction in recursively dynamic compartments driven by stirring.

    Science.gov (United States)

    Ichii, Tetsuo; Tanahashi, Genya; Suzuki, Hiroaki; Yomo, Tetsuya

    2013-12-17

    In living systems, biochemical reactions are confined to cellular or subcellular compartments, such as the plasma membrane and the organelles within a cell. These biological compartments are usually subjected to recursive changes, such as combinations of growth, fusion, and division, to constitute repeating cell cycles. In such recursively dynamic compartments, the encapsulated biochemical reaction may exhibit dynamics that differ from those of the static compartment (i.e., test tubes) used in conventional biochemistry experiments. To test this hypothesis in a simplified model, we mechanically stirred femtoliter-sized water-in-oil emulsion droplets so that individual droplets were subjected to repeated coalescence and breakage. We show that recursive dynamics appeared in the emulsion, which were measured by the exponential propagation of a water-soluble dye. The rate of the propagation, μ, was controlled by modulating the pulse-width of stirring in an electromagnetic stirrer. Within this system, we studied the dynamics of an RNA-amplification reaction in recursively increasing reaction compartments at various values of μ. We showed that there was an optimal value of μ that maximized RNA amplification. This effect was explained by the balance between the opposing effects of supply of substrate and the dilution of amplified RNA both resulting from coalescence. Moreover, when we mixed two RNA species with different kinetic properties, we found a preferential amplification for one of the species only in the recursively dynamic emulsion. This effect was partly explained by a separation effect which preferentially amplifies the number of compartments for the molecular specie that can better follow the breakage dynamics of the compartments. The present work demonstrated how the recursive dynamics of compartments modifies the internal biochemical reaction. PMID:24219119

  3. Semiconductor optical amplifiers and Raman amplification for 1310-nm dense wavelength division multiplexed transmission

    Science.gov (United States)

    Mazurek, Paweł; Czyżak, Paweł; de Waardt, Huug; Turkiewicz, Jarosław Piotr

    2015-11-01

    We investigate the utilization of semiconductor optical amplifiers (SOAs) and quantum-dot laser-based Raman amplifiers in high-capacity dense wavelength division multiplexed (DWDM) 1310-nm transmission systems. Performed simulations showed that in a 10×40 Gbit/s system, the utilization of a single Raman amplifier in a back-propagation scheme can extend the maximum error-free (bit error rate power budget. Moreover, lower input optical power in a system utilizing a Raman amplifier reduces the four-wave mixing interactions. The obtained results prove that Raman amplification can be successfully applied in 1310-nm high-capacity transmission systems, e.g., to extend the reach of 400G and 1T Ethernet systems.

  4. Reading Out Single-Molecule Digital RNA and DNA Isothermal Amplification in Nanoliter Volumes with Unmodified Camera Phones.

    Science.gov (United States)

    Rodriguez-Manzano, Jesus; Karymov, Mikhail A; Begolo, Stefano; Selck, David A; Zhukov, Dmitriy V; Jue, Erik; Ismagilov, Rustem F

    2016-03-22

    Digital single-molecule technologies are expanding diagnostic capabilities, enabling the ultrasensitive quantification of targets, such as viral load in HIV and hepatitis C infections, by directly counting single molecules. Replacing fluorescent readout with a robust visual readout that can be captured by any unmodified cell phone camera will facilitate the global distribution of diagnostic tests, including in limited-resource settings where the need is greatest. This paper describes a methodology for developing a visual readout system for digital single-molecule amplification of RNA and DNA by (i) selecting colorimetric amplification-indicator dyes that are compatible with the spectral sensitivity of standard mobile phones, and (ii) identifying an optimal ratiometric image-process for a selected dye to achieve a readout that is robust to lighting conditions and camera hardware and provides unambiguous quantitative results, even for colorblind users. We also include an analysis of the limitations of this methodology, and provide a microfluidic approach that can be applied to expand dynamic range and improve reaction performance, allowing ultrasensitive, quantitative measurements at volumes as low as 5 nL. We validate this methodology using SlipChip-based digital single-molecule isothermal amplification with λDNA as a model and hepatitis C viral RNA as a clinically relevant target. The innovative combination of isothermal amplification chemistry in the presence of a judiciously chosen indicator dye and ratiometric image processing with SlipChip technology allowed the sequence-specific visual readout of single nucleic acid molecules in nanoliter volumes with an unmodified cell phone camera. When paired with devices that integrate sample preparation and nucleic acid amplification, this hardware-agnostic approach will increase the affordability and the distribution of quantitative diagnostic and environmental tests. PMID:26900709

  5. Targeting helicase-dependent amplification products with an electrochemical genosensor for reliable and sensitive screening of genetically modified organisms.

    Science.gov (United States)

    Moura-Melo, Suely; Miranda-Castro, Rebeca; de-Los-Santos-Álvarez, Noemí; Miranda-Ordieres, Arturo J; Dos Santos Junior, J Ribeiro; da Silva Fonseca, Rosana A; Lobo-Castañón, Maria Jesús

    2015-08-18

    Cultivation of genetically modified organisms (GMOs) and their use in food and feed is constantly expanding; thus, the question of informing consumers about their presence in food has proven of significant interest. The development of sensitive, rapid, robust, and reliable methods for the detection of GMOs is crucial for proper food labeling. In response, we have experimentally characterized the helicase-dependent isothermal amplification (HDA) and sequence-specific detection of a transgene from the Cauliflower Mosaic Virus 35S Promoter (CaMV35S), inserted into most transgenic plants. HDA is one of the simplest approaches for DNA amplification, emulating the bacterial replication machinery, and resembling PCR but under isothermal conditions. However, it usually suffers from a lack of selectivity, which is due to the accumulation of spurious amplification products. To improve the selectivity of HDA, which makes the detection of amplification products more reliable, we have developed an electrochemical platform targeting the central sequence of HDA copies of the transgene. A binary monolayer architecture is built onto a thin gold film where, upon the formation of perfect nucleic acid duplexes with the amplification products, these are enzyme-labeled and electrochemically transduced. The resulting combined system increases genosensor detectability up to 10(6)-fold, allowing Yes/No detection of GMOs with a limit of detection of ∼30 copies of the CaMV35S genomic DNA. A set of general utility rules in the design of genosensors for detection of HDA amplicons, which may assist in the development of point-of-care tests, is also included. The method provides a versatile tool for detecting nucleic acids with extremely low abundance not only for food safety control but also in the diagnostics and environmental control areas. PMID:26198403

  6. Amplification of target-specific, ligation-dependent circular probe.

    Science.gov (United States)

    Zhang, D Y; Brandwein, M; Hsuih, T C; Li, H

    1998-05-12

    We describe a novel polymerase chain reaction (PCR)-based gene amplification method utilizing a circularizable oligodeoxyribonucleotide probe (C-probe). The C-probe contains two target complementary regions located at each terminus and an interposed generic PCR primer binding region. The hybridization of C-probe to a target brings two termini in direct apposition as the complementary regions of C-probe wind around the target to form a double helix. Subsequent ligation of the two termini results in a covalently linked C-probe that becomes 'locked on to' the target. The circular nature of the C-probe allows for the generation of a multimeric single-stranded DNA (ssDNA) via extension of the antisense primer by Taq DNA polymerase along the C-probe and displacement of downstream strand, analogous to 'rolling circle' replication of bacteriophage in vivo. This multimeric ssDNA then serves as a template for multiple sense primers to hybridize, extend, and displace downstream DNA, generating a large ramified (branching) DNA complex. Subsequent thermocycling denatures the dsDNA and initiates the next round of primer extension and ramification. This model results in significantly improved amplification kinetics (super-exponential) as compared to conventional PCR. Our results show that the C-probe was 1000 times more sensitive than the corresponding linear hemiprobes for detecting Epstein-Barr virus early RNA. The C-probe not only increases the power of amplification but also offers a means for decontaminating carryover amplicons. As the ligated C-probes possess no free termini, they are resistant to exonuclease digestion, whereas contaminated linear amplicons are susceptible to digestion. Treatment of the ligation reaction mixture with exonuclease prior to amplification eliminated the amplicon contaminant, which could also have been co-amplified with the same PCR primers; only the ligated C-probes were amplified. The combined advantages of the C-probe and thermocycling have a

  7. Construction Strategy for an Internal Amplification Control for Real-Time Diagnostic Assays Using Nucleic Acid Sequence-Based Amplification: Development and Clinical Application

    OpenAIRE

    Rodríguez-Lázaro, David; D'Agostino, Martin; Pla, Maria; Cook, Nigel

    2005-01-01

    An important analytical control in molecular amplification-based methods is an internal amplification control (IAC), which should be included in each reaction mixture. An IAC is a nontarget nucleic acid sequence which is coamplified simultaneously with the target sequence. With negative results for the target nucleic acid, the absence of an IAC signal indicates that amplification has failed. A general strategy for the construction of an IAC for inclusion in molecular beacon-based real-time nu...

  8. New perspectives on assessing amplification effects.

    Science.gov (United States)

    Souza, Pamela E; Tremblay, Kelly L

    2006-09-01

    Clinicians have long been aware of the range of performance variability with hearing aids. Despite improvements in technology, there remain many instances of well-selected and appropriately fitted hearing aids whereby the user reports minimal improvement in speech understanding. This review presents a multistage framework for understanding how a hearing aid affects performance. Six stages are considered: (1) acoustic content of the signal, (2) modification of the signal by the hearing aid, (3) interaction between sound at the output of the hearing aid and the listener's ear, (4) integrity of the auditory system, (5) coding of available acoustic cues by the listener's auditory system, and (6) correct identification of the speech sound. Within this framework, this review describes methodology and research on 2 new assessment techniques: acoustic analysis of speech measured at the output of the hearing aid and auditory evoked potentials recorded while the listener wears hearing aids. Acoustic analysis topics include the relationship between conventional probe microphone tests and probe microphone measurements using speech, appropriate procedures for such tests, and assessment of signal-processing effects on speech acoustics and recognition. Auditory evoked potential topics include an overview of physiologic measures of speech processing and the effect of hearing loss and hearing aids on cortical auditory evoked potential measurements in response to speech. Finally, the clinical utility of these procedures is discussed. PMID:16959734

  9. Ultrashort pulse amplification in cryogenically cooled amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Backus, Sterling J.; Kapteyn, Henry C.; Murnane, Margaret Mary

    2004-10-12

    A laser amplifier system amplifies pulses in a single "stage" from .about.10.sup.-9 joules to more than 10.sup.-3 joules, with average power of 1-10 watts, and beam quality M.sup.2 <2. The laser medium is cooled substantially below room temperature, as a means to improve the optical and thermal characteristics of the medium. This is done with the medium inside a sealed, evacuated or purged cell to avoid moisture or other materials condensing on the surface. A "seed" pulse from a separate laser is passed through the laser medium, one or more times, in any of a variety of configurations including single-pass, multiple-pass, and regenerative amplifier configurations.

  10. Effect of heavy ion beams to centrosome amplification in mammalian cells

    International Nuclear Information System (INIS)

    Centrosome is an organelle that regulates proper cell division. Centrosome aberration such as centrosome amplification causes chromosome instability. Ionizing radiation is a inducer of effective centrosome amplification. In the previous report, we showed that γ-ray induced centrosome amplification in a dose dependent manner. In this study, we investigated that whether High linear energy transfer (LET) irradiation induce more effective centrosome amplification than low LET irradiation. As expected, high LET irradiation effectively induced centrosome amplification in human U2OS and mouse NIH3T3 cells. (author)

  11. Phase Sensitive Amplification using Parametric Processes in Optical Fibers

    DEFF Research Database (Denmark)

    Kang, Ning

    Phase sensitive amplification using the parametric processes in fiber has the potential of delivering high gain and broadband operation with ultralow noise. It is able to regenerate both amplitude and phase modulated signals, simultaneously, with the appropriate design. This thesis concerns......, in specific, the design and optimization of such phase sensitive amplifiers (PSAs). For phase sensitive amplification in highly nonlinear fibers, optima points of operation have been identified for both the standard and the novel high stimulated Brillouin scattering (SBS) threshold highly nonlinear fiber....... Further, phase sensitive parametric processes in a nano-engineered silicon waveguide have been measured experimentally for the first time. Numerical optimizations show that with reduced waveguide propagation loss and reduced carrier life time, larger signal phase sensitive extinction ratio is achievable...

  12. Optical parametric chirped pulse amplification based on photonic crystal fibre

    Institute of Scientific and Technical Information of China (English)

    Wang He-Lin; Yang Ai-Jun; Leng Yu-Xin; Wang Cheng; Xu Zhi-Zhan; Hou Lan-Tian

    2011-01-01

    A compact two-stage optical parametric chirped pulse amplifier based on photonic crystal fibre is demonstrated.A 1064-nm soliton pulse is obtained in a home-made photonic crystal fibre(PCF)with femtosecond pulse pumping and then amplified to 2 mJ in an Nd:YAG regenerative amplifier.After the amplified pulses pass through the LBO crystal,the 532-nm double-frequency light with an energy of 0.8 mJ and a duration of over 100 ps at 10-Hz repetition rate is generated as a pump source in the following two-stage optical parametric amplification(OPA).The 850-am chirped signal light gain from the stretcher is 1.5×104in the first-stage OPA while it is 120 in the second-stage OPA.The total signal gain of optical parametric chirped pulse amplification(OPCPA)can reach 1.8×106.

  13. Resonant Amplification of Turbulence by the Blast Wawes

    CERN Document Server

    Zankovich, A M

    2016-01-01

    We discuss an idea whether spherical blast waves can amplify by a non-local resonant hydrodynamic mechanism inhomogeneities formed by turbulence or phase segregation in the interstellar medium. We consider the problem of a blast-wave-turbulence interaction in the Linear Interaction Approximation. Mathematically, this is an eigenvalue problem for finding the structure and amplitude of eigenfunctions describing the response of the shock-wave flow to forced oscillations by external perturbations in the ambient interstellar medium. Linear analysis shows that the blast wave can amplify density and vorticity perturbations for a wide range of length scales with amplification coefficients of up to 20, with amplification the greater, the larger the length. There also exist resonant harmonics for which the gain becomes formally infinite in the linear approximation. Their orbital wavenumbers are within the range of macro- ($l \\sim 1$), meso- ($l \\sim 20$) and microscopic ($l > 200$) scales. Since the resonance width is ...

  14. Retrieval and Amplification of DNA from Unstained Histopathological Sections

    Institute of Scientific and Technical Information of China (English)

    DonnaC.MONTAGUE; BeverlyD.LYN-COOK; 等

    1993-01-01

    Testing of compounds for carcinogenic potential in vivo involves various experimental designs.A few of these techniques are directed to demonstrate the genotoxicity and mutagenicity of the compound by histopathology.These changes shown by histochemical means include monoclonal antibody directed cellular markers.Development of the polymerase chain reaction technique(PCR)for amplification of DNA has facilitated the investigation of molecular events related to the formation of malignant neoplasms.We describe here a method for screening tissues for mutations of the H-ras gene using monoclonal antibodies directed toward normal and mutant p21 proteins.Formalin-fixed,paraffinembedded tissue sections are used to subsequently confirm the gene mutation by PCR amplification of the H-ras gene.The results indicated a successful application of this technique to demonstrate the presence of p21 oncoprotein in the tissues tested.

  15. Quantum Privacy Amplification for a Sequence of Single Qubits

    Institute of Scientific and Technical Information of China (English)

    DENG Fu-Guo; LONG Gui-Lu

    2006-01-01

    We present a scheme for quantum privacy amplification (QPA) for a sequence of single qubits. The QPA procedure uses a unitary operation with two controlled-not gates and a Hadamard gate. Every two qubits are performed with the unitary gate operation, and a measurement is made on one photon and the other one is retained.The retained qubit carries the state information of the discarded one. In this way, the information leakage is reduced.The procedure can be performed repeatedly so that the information leakage is reduced to any arbitrarily low level. With this QPA scheme, the quantum secure direct communication with single qubits can be implemented with arbitrarily high security. We also exploit this scheme to do privacy amplification on the single qubits in quantum information sharing for long-distance communication with quantum repeaters.

  16. Electromagnetic biaxial microscanner with mechanical amplification at resonance.

    Science.gov (United States)

    Cho, Ah Ran; Han, Aleum; Ju, Suna; Jeong, Haesoo; Park, Jae-Hyoung; Kim, Inhoi; Bu, Jong-Uk; Ji, Chang-Hyeon

    2015-06-29

    We present the design, fabrication, and measurement results of an electromagnetic biaxial microscanner with mechanical amplification mechanism. A gimbaled scanner with two distinct single-crystal silicon layer thicknesses and integrated copper coils has been fabricated with combination of surface and bulk micromachining processes. A magnet assembly consisting of an array of permanent magnets and a pole piece has been placed under the substrate to provide high strength lateral magnetic field oriented 45° to two perpendicular scanning axes. Micromirror has been supported by additional gimbal to implement a mechanical amplification. A 1.2mm-diameter mirror with aluminum reflective surface has been actuated at 60Hz for vertical scan and at 21kHz for horizontal scan. Maximum scan angle of 36.12° at 21.19kHz and 17.62° at 60Hz have been obtained for horizontal and vertical scans, respectively. PMID:26191691

  17. Broadband terahertz amplification in a heterogeneous quantum cascade laser.

    Science.gov (United States)

    Bachmann, Dominic; Leder, Norbert; Rösch, Markus; Scalari, Giacomo; Beck, Mattias; Arthaber, Holger; Faist, Jérôme; Unterrainer, Karl; Darmo, Juraj

    2015-02-01

    We demonstrate a broadband terahertz amplifier based on ultrafast gain switching in a quantum cascade laser. A heterogeneous active region is processed into a coupled cavity metal-metal waveguide device and provides broadband terahertz gain that allows achieving an amplification bandwidth of more than 500 GHz. The temporal and spectral evolution of a terahertz seed pulse, which is generated in an integrated emitter section, is presented and an amplification factor of 21 dB is reached. Furthermore, the quantum cascade amplifier emission spectrum of the emerging sub-nanosecond terahertz pulse train is measured by time-domain spectroscopy and reveals discrete modes between 2.14 and 2.68 THz. PMID:25836170

  18. Pulse Amplification in Dispersion-Decreasing Fibers with Symbolic Computation

    International Nuclear Information System (INIS)

    The pulse amplification in the dispersion-decreasing fiber (DDF) is investigated via symbolic computation to solve the variable-coefficient higher-order nonlinear Schroedinger equation with the effects of third-order dispersion, self-steepening, and stimulated Raman scattering. The analytic one-soliton solution of this model is obtained with a set of parametric conditions. Based on this solution, the fundamental soliton is shown to be amplified in the DDF. The comparison of the amplitude of pulses for different dispersion profiles of the DDF is also performed through the graphical analysis. The results of this paper would be of certain value to the study of signal amplification and pulse compression. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  19. 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.

  20. Spin noise amplification and giant noise in optical microcavity

    International Nuclear Information System (INIS)

    When studying the spin-noise-induced fluctuations of Kerr rotation in a quantum-well microcavity, we have found a dramatic increase of the noise signal (by more than two orders of magnitude) in the vicinity of anti-crossing of the polariton branches. The effect is explained by nonlinear optical instability of the microcavity giving rise to the light-power-controlled amplification of the polarization noise signal. In the framework of the developed model of built-in amplifier, we also interpret the nontrivial spectral and intensity-related properties of the observed noise signal below the region of anti-crossing of polariton branches. The discovered effect of optically controllable amplification of broadband polarization signals in microcavities in the regime of optical instability may be of interest for detecting weak oscillations of optical anisotropy in fundamental research and for other applications in optical information processing

  1. Assessing Linearity of the Parasite Varroa destructor DNA Amplification

    Directory of Open Access Journals (Sweden)

    ODAGIU Antonia

    2009-12-01

    Full Text Available The importance of honeybee products make of disease prevention and control in honeybees one of the mainconcerns of beekeepers in the world. The PCR – RT reaction represents an alternative for amplification performed inorder to realize the Varroa destructor O. genotypization, very important stage in haoneybee resistance to parasitedescription and also in management of the treatments. The linearity data is a very important parameter and very usefulin determination of the amplification of the parasite DNA and success of the genotypization process. The amplificationefficiency was very satisfactory, fact revealed by the value of the regression line y = - 2.3103 * 26.552 together withcoefficient of determination equal (r2 = 0.9691, meaning that more than 96% of the reaction efficiency may beexplained by the process liniarity. The implementation of the RT-PCR method was successful and it represents apremise for validation process evolution.

  2. Spin noise amplification and giant noise in optical microcavity

    Energy Technology Data Exchange (ETDEWEB)

    Ryzhov, I. I.; Poltavtsev, S. V.; Kozlov, G. G.; Zapasskii, V. S. [Spin-Optics Laboratory, St. Petersburg State University, 198504 St. Petersburg (Russian Federation); Kavokin, A. V. [Department of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ (United Kingdom); Spin-Optics Laboratory, St. Petersburg State University, 198504 St. Petersburg (Russian Federation); Lagoudakis, P. V. [Department of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ (United Kingdom)

    2015-06-14

    When studying the spin-noise-induced fluctuations of Kerr rotation in a quantum-well microcavity, we have found a dramatic increase of the noise signal (by more than two orders of magnitude) in the vicinity of anti-crossing of the polariton branches. The effect is explained by nonlinear optical instability of the microcavity giving rise to the light-power-controlled amplification of the polarization noise signal. In the framework of the developed model of built-in amplifier, we also interpret the nontrivial spectral and intensity-related properties of the observed noise signal below the region of anti-crossing of polariton branches. The discovered effect of optically controllable amplification of broadband polarization signals in microcavities in the regime of optical instability may be of interest for detecting weak oscillations of optical anisotropy in fundamental research and for other applications in optical information processing.

  3. Directional Amplification with a Josephson Circuit

    Science.gov (United States)

    Abdo, Baleegh; Sliwa, Katrina; Frunzio, Luigi; Devoret, Michel

    2013-07-01

    Nonreciprocal devices perform crucial functions in many low-noise quantum measurements, usually by exploiting magnetic effects. In the proof-of-principle device presented here, on the other hand, two on-chip coupled Josephson parametric converters (JPCs) achieve directionality by exploiting the nonreciprocal phase response of the JPC in the transmission-gain mode. The nonreciprocity of the device is controlled in situ by varying the amplitude and phase difference of two independent microwave pump tones feeding the system. At the desired working point and for a signal frequency of 8.453 GHz, the device achieves a forward power gain of 15 dB within a dynamical bandwidth of 9 MHz, a reverse gain of -6dB, and suppression of the reflected signal by 8 dB. We also find that the amplifier adds a noise equivalent to less than 1.5 photons at the signal frequency (referred back to the input). It can process up to 3 photons at the signal frequency per inverse dynamical bandwidth. With a directional amplifier operating along the principles of this device, qubit and readout preamplifier could be integrated on the same chip.

  4. Swing amplification and global modes reciprocity in models with cusps

    CERN Document Server

    Polyachenko, Evgeny

    2016-01-01

    Using 3D N-body simulations we analyse an onset of the bar in cuspy models, and argue that role of swing amplification is twofold. Amplified shot noise due to disc discreteness hampers bar formation, while induced resonance perturbations allow bar amplitude to overcome shots. A bar pattern speed and a growth rate obtained in N-body simulations agree well with global mode analysis.

  5. A new beam deflection angle amplification technique for mirage detection

    OpenAIRE

    Yarai, A.; Fukunaga, Y; Sakamoto, K; Nakanishi, T.

    1994-01-01

    A new technique has been developed for amplification of the photothermal beam deflection angle for mirage detection. This technique, based on a very simple operating principle, uses a cylindrical reflection mirror. The use of a new amplifier provided a signal-to-noise ratio approximately 10 times that obtained without the amplifier for equipment of the same size. By using the new amplifier, a mirage signal was obtained when a transistor array processed on a silicon wafer was measured.

  6. Rapid Diagnosis of Extrapulmonary Tuberculosis by Ligase Chain Reaction Amplification

    OpenAIRE

    Gamboa, Fredy; Dominguez, José; Padilla, Eduardo; Manterola, José M.; Gazapo, Elena; Lonca, Joan; Matas, Lurdes; Hernandez, Agueda; Cardona, Pere Joan; Ausina, Vicente

    1998-01-01

    A rapid amplification-based test for the diagnosis of extrapulmonary tuberculosis, the LCx Mycobacterium tuberculosis Assay from Abbott Laboratories, was evaluated. Results from the LCx M. tuberculosis Assay were compared with those from culture and the final clinical diagnosis for each patient. A total of 526 nonrespiratory specimens from 492 patients were tested. The specimens included urine; feces; lymph node exudates; pleural, cerebrospinal, articular, and ascitic fluids; tissue biopsies;...

  7. Optical Amplification and Photosensitivity in Sol-Gel Based Waveguides

    OpenAIRE

    Selvarajan, A; T. Srinivas

    2001-01-01

    The sol-gel process has emerged as an effective route for the fabrication of optical waveguides and guided wave devices and circuits. In particular, it is possible to incorporate active dopants like neodymium, erbium, and cesium for integrated optical active devices and circuits. In this paper, a review of recent research on active devices and circuits based on sol-gel process is made. Specific studies undertaken in our laboratory on optical amplification and photosensitivity characteristi...

  8. Whole genome amplification of DNA for genotyping pharmacogenetics candidate genes.

    Directory of Open Access Journals (Sweden)

    Santosh ePhilips

    2012-03-01

    Full Text Available Whole genome amplification (WGA technologies can be used to amplify genomic DNA when only small amounts of DNA are available. The Multiple Displacement Amplification Phi polymerase based amplification has been shown to accurately amplify DNA for a variety of genotyping assays; however, it has not been tested for genotyping many of the clinically relevant genes important for pharmacogenetic studies, such as the cytochrome P450 genes, that are typically difficult to genotype due to multiple pseudogenes, copy number variations, and high similarity to other related genes. We evaluated whole genome amplified samples for Taqman™ genotyping of SNPs in a variety of pharmacogenetic genes. In 24 DNA samples from the Coriell human diversity panel, the call rates and concordance between amplified (~200-fold amplification and unamplified samples was 100% for two SNPs in CYP2D6 and one in ESR1. In samples from a breast cancer clinical trial (Trial 1, we compared the genotyping results in samples before and after WGA for four SNPs in CYP2D6, one SNP in CYP2C19, one SNP in CYP19A1, two SNPs in ESR1, and two SNPs in ESR2. The concordance rates were all >97%. Finally, we compared the allele frequencies of 143 SNPs determined in Trial 1 (whole genome amplified DNA to the allele frequencies determined in unamplified DNA samples from a separate trial (Trial 2 that enrolled a similar population. The call rates and allele frequencies between the two trials were 98% and 99.7%, respectively. We conclude that the whole genome amplified DNA is suitable for Taqman™ genotyping for a wide variety of pharmacogenetically relevant SNPs.

  9. Mismatch characteristics of optical parametric chirped pulse amplification

    Czech Academy of Sciences Publication Activity Database

    Novák, Ondřej; Turčičová, Hana; Divoký, Martin; Huynh, Jaroslav; Straka, Petr

    2014-01-01

    Roč. 11, č. 2 (2014), 1-7. ISSN 1612-2011 R&D Projects: GA ČR GA202/06/0814; GA MŠk(CZ) LC528 Institutional support: RVO:68378271 Keywords : phase matching * phase mismatch * beam mismatch * broadband amplification * parametric amplifiers * OPCPA * iodine laser Subject RIV: BH - Optics , Masers, Laser s Impact factor: 2.458, year: 2014

  10. MYC Amplification in Angiosarcoma Arising from an Arteriovenous Graft Site

    Directory of Open Access Journals (Sweden)

    Kristen M. Paral

    2015-01-01

    Full Text Available Angiosarcoma arising in association with an arteriovenous graft (AVG or fistula is a unique clinicopathologic scenario that appears to be gaining recognition in the literature. Among reported cases, none has described high-level MYC gene amplification, a genetic aberration that is increasingly unifying the various clinicopathologic subdivisions of angiosarcoma. We therefore report the MYC gene status in a case of angiosarcoma arising at an AVG site.

  11. Risk Types and Risk Amplification of Online Finance

    OpenAIRE

    Gujun Yan

    2013-01-01

    Online finance not only has the same risks as the traditional financial sector, but also brings new types of risks and the amplification effect of the financial risks. In the circumstances of online finance, risk correlation between countries is increasing due to worldwide mutual penetration of financial businesses and customers. Facing the risk test of the Internet finance, risk control and management must be strengthened in order to achieve its sustainable developments.

  12. Uncertainty of site amplification derived from ground response analysis

    OpenAIRE

    Afshari, K; Stewart, JP

    2015-01-01

    Site-specific geotechnical ground response analyses (GRAs) are typically performed to evaluate stress and strain demands within soil profiles and/or to improve the estimation of site response relative to generic site terms from empirical prediction equations. Implementation of GRA results in probabilistic seismic hazard analysis (PSHA) requires knowledge of the mean and standard deviation of site amplification from GRA. We provide expressions for evaluating within-event standard deviations of...

  13. Selective inhibition of DNA amplification in nonadhering Mycoplasma pneumoniae cultures

    Energy Technology Data Exchange (ETDEWEB)

    Zigangirova, N.A.; Solov`eva, S.V.; Rakovskaya, I.V. [Gamaleya Scientific Research Institute of Epidemiology and Microbiology, Moscow (Russian Federation)] [and others

    1995-08-01

    Inhibition of amplification of various genome regions of Mycoplasma pneumoniae was observed in the polymerase chain reaction, and was dependent on cultivation conditions. A protein stably associated with DNA is responsible for the inhibitory effect. It is assumed that when the protein selectively associates with separate DNA regions, it can inhibit genes encoding pathogenicity factors, thus promoting mycoplasma transformation into persistent variants. 16 refs., 2 figs.

  14. Risk communication and the social amplification of risk

    OpenAIRE

    Renn, Ortwin

    1991-01-01

    Risk communication is a novel concept in the scientific pursuit to understand and analyze risk related decisions and behavior in modem society. But the new term has only changed the focus of attention from a static description of what risk means for different communities to a dynamic analysis on how these communities exchange information about risk and adjust their behavior.The concept of social amplification of risk provides a framework for the analysis of communication as well as other soci...

  15. Polyethersulfone improves isothermal nucleic acid amplification compared to current paper-based diagnostics.

    Science.gov (United States)

    Linnes, J C; Rodriguez, N M; Liu, L; Klapperich, C M

    2016-04-01

    Devices based on rapid, paper-based, isothermal nucleic acid amplification techniques have recently emerged with the potential to fill a growing need for highly sensitive point-of-care diagnostics throughout the world. As this field develops, such devices will require optimized materials that promote amplification and sample preparation. Herein, we systematically investigated isothermal nucleic acid amplification in materials currently used in rapid diagnostics (cellulose paper, glass fiber, and nitrocellulose) and two additional porous membranes with upstream sample preparation capabilities (polyethersulfone and polycarbonate). We compared amplification efficiency from four separate DNA and RNA targets (Bordetella pertussis, Chlamydia trachomatis, Neisseria gonorrhoeae, and Influenza A H1N1) within these materials using two different isothermal amplification schemes, helicase dependent amplification (tHDA) and loop-mediated isothermal amplification (LAMP), and traditional PCR. We found that the current paper-based diagnostic membranes inhibited nucleic acid amplification when compared to membrane-free controls; however, polyethersulfone allowed for efficient amplification in both LAMP and tHDA reactions. Further, observing the performance of traditional PCR amplification within these membranes was not predicative of their effects on in situ LAMP and tHDA. Polyethersulfone is a new material for paper-based nucleic acid amplification, yet provides an optimal support for rapid molecular diagnostics for point-of-care applications. PMID:26906904

  16. Three-dimensional topographic amplification of seismic motion: Engineering Applications

    Science.gov (United States)

    Assimaki, D.; Mohammadi, K.

    2012-12-01

    Topography effects are associated with the presence of strong topographic relief; documented observations during strong seismic events have shown that structures on the tops of hills, ridges, and canyons had suffered greater damage than similar structures at the hill bases or on level ground. While there is qualitative agreement between theory and observations on topography effects, there is clear quantitative discrepancy: numerical predictions of crest-to-base amplification factors rarely exceed the value of 2, while amplification values observed in the field are as high as 10. We here investigate the focusing and scattering of seismic waves in 3D features by means of a systematic parametric study of the seismic response of idealized geometries on the surface of homogeneous elastic half space using finite differences, to quantify the role of geometry, material properties and ground motion characteristics in the predicted ground surface response. We specifically focus on pyramid (convex) geometries and elastic homogeneous material behavior, and use Ricker wavelets as vertical and oblique incident pulses on ground surface. Results are compared to analytical solutions and thereafter extended to account for soil layering, nonlinear response and broadband incident motion characteristics. We then develop geometry, material and ground motion dependent dimensionless amplification factors that can multiply flat ground surface response spectra and account for topography effects as part of engineering design code provisions.omparison of the scattered wavefield complexity emanating at the vertex and toe of a 45deg single slope upon incidence of a vertical, a forward and a backward oblique wave.

  17. Diagnosis of brugian filariasis by loop-mediated isothermal amplification.

    Science.gov (United States)

    Poole, Catherine B; Tanner, Nathan A; Zhang, Yinhua; Evans, Thomas C; Carlow, Clotilde K S

    2012-01-01

    In this study we developed and evaluated a Brugia Hha I repeat loop-mediated isothermal amplification (LAMP) assay for the rapid detection of Brugia genomic DNA. Amplification was detected using turbidity or fluorescence as readouts. Reactions generated a turbidity threshold value or a clear visual positive within 30 minutes using purified genomic DNA equivalent to one microfilaria. Similar results were obtained using DNA isolated from blood samples containing B. malayi microfilariae. Amplification was specific to B. malayi and B. timori, as no turbidity was observed using DNA from the related filarial parasites Wuchereria bancrofti, Onchocerca volvulus or Dirofilaria immitis, or from human or mosquito. Furthermore, the assay was most robust using a new strand-displacing DNA polymerase termed Bst 2.0 compared to wild-type Bst DNA polymerase, large fragment. The results indicate that the Brugia Hha I repeat LAMP assay is rapid, sensitive and Brugia-specific with the potential to be developed further as a field tool for diagnosis and mapping of brugian filariasis. PMID:23272258

  18. Field and current amplification in the SSPX spheromak

    International Nuclear Information System (INIS)

    Results are presented from experiments relating to magnetic field generation and current amplification in the SSPX spheromak. The SSPX spheromak plasma is driven by DC coaxial helicity injection using a 2MJ capacitor bank. Peak toroidal plasma currents of up to 0.7MA and peak edge poloidal fields of 0.3T are produced; lower current discharges can be sustained up to 3.5msec. When edge magnetic fluctuations are reduced below 1% by driving the plasma near threshold, it is possible to produce plasmas with Te > 150eV, e>∼4% and core χe∼30m2/s. Helicity balance for these plasmas suggests that sheath dissipation can be significant, pointing to the importance of maximizing the voltage on the coaxial injector. For most operational modes we find a stiff relationship between peak spheromak field and injector current, and little correlation with plasma temperature, which suggests that other processes than ohmic dissipation may limit field amplification. However, slowing spheromak buildup by limiting the initial current pulse increases the ratio of toroidal current to injected current and points to new operating regimes with more favorable current amplification. (author)

  19. Diagnosis of brugian filariasis by loop-mediated isothermal amplification.

    Directory of Open Access Journals (Sweden)

    Catherine B Poole

    Full Text Available In this study we developed and evaluated a Brugia Hha I repeat loop-mediated isothermal amplification (LAMP assay for the rapid detection of Brugia genomic DNA. Amplification was detected using turbidity or fluorescence as readouts. Reactions generated a turbidity threshold value or a clear visual positive within 30 minutes using purified genomic DNA equivalent to one microfilaria. Similar results were obtained using DNA isolated from blood samples containing B. malayi microfilariae. Amplification was specific to B. malayi and B. timori, as no turbidity was observed using DNA from the related filarial parasites Wuchereria bancrofti, Onchocerca volvulus or Dirofilaria immitis, or from human or mosquito. Furthermore, the assay was most robust using a new strand-displacing DNA polymerase termed Bst 2.0 compared to wild-type Bst DNA polymerase, large fragment. The results indicate that the Brugia Hha I repeat LAMP assay is rapid, sensitive and Brugia-specific with the potential to be developed further as a field tool for diagnosis and mapping of brugian filariasis.

  20. Raman amplification in plasma: thermal effects and damping

    Science.gov (United States)

    Farmer, J. P.; Ersfeld, B.; Raj, G.; Jaroszynski, D. A.

    2009-05-01

    The role of thermal effects on Raman amplification are investigated. The direct effects of damping on the process are found to be limited, leading only to a decrease from the peak output intensity predicted by cold plasma models. However, the shift in plasma resonance due to the Bohm-Gross shift can have a much larger influence, changing the required detuning between pump and probe and introducing an effective chirp through heating of the plasma by the pump pulse. This "thermal chirp" can both reduce the efficiency of the interaction and alter the evolution of the amplified probe, avoiding the increase in length observed in the linear regime without significant pump depletion. The influence of this chirp can be reduced by using a smaller ratio of laser frequency to plasma frequency, which simultaneously increases the growth rate of the probe and decreases the shift in plasma resonance. As such, thermal effects only serve to suppress the amplification of noise at low growth rates. The use of a chirped pump pulse can be used to suppress noise for higher growth rates, and has a smaller impact on the peak output intensity for seeded amplification. For the parameter ranges considered, Landau damping was found to be negligible, as Landau damping rates are typically small, and the low collisionality of the plasma causes the process to saturate quickly.

  1. Generation of recombinant pestiviruses using a full genome amplification strategy

    DEFF Research Database (Denmark)

    Rasmussen, Thomas Bruun; Reimann, Ilona; Uttenthal, Åse; Depner, Klaus; Schirrmeyer, Horst; Beer, Martin

    pestiviruses. Methods Pestivirus genomes were amplified from either total RNA preparations using long RT-PCR or from infectious cDNA clones using long PCR. Viral RNA was extracted from cell cultures inoculated with pestivirus (e.g. BDV “Gifhorn” or BVDV “CP7”) using a combined Trizol/RNeasy protocol. Total RNA......-length RT-PCR amplicon demonstrating that long RT-PCR can be used for direct generation of an infectious pestivirus. The strategy is not limited to amplification of BDV “Gifhorn”, but can be further utilized for amplification of a diverse selection of pestivirus strains and for the generation of modified...... was reverse transcribed to cDNA at 50C for 90 minutes using SuperScript III reverse transcriptase (Invitrogen). Full-length PCR amplification was performed using primers specific for the extreme 5’- and 3’-ends of the viral genomes. A T7 promoter was incorporated in the 5’-primers for direct in vitro...

  2. Device-independent randomness amplification with a single device

    International Nuclear Information System (INIS)

    Expansion and amplification of weak randomness with untrusted quantum devices has recently become a very fruitful topic of research. Here we contribute with a procedure for amplifying a single weak random source using tri-partite GHZ-type entangled states. If the quality of the source reaches a fixed threshold R=log2⁡(10), perfect random bits can be produced. This technique can be used to extract randomness from sources that can't be extracted neither classically, nor by existing procedures developed for Santha–Vazirani sources. Our protocol works with a single fault-free device decomposable into three non-communicating parts, that is repeatedly reused throughout the amplification process. - Highlights: • We propose a protocol for device independent randomness amplification. • Our protocol repeatedly re-uses a single device decomposable into three parts. • Weak random sources with min-entropy rate greater than 1/4 log2⁡(10) can be amplified. • Security against all-quantum adversaries is achieved

  3. Lung vasodilatory response to inhaled iloprost in experimental pulmonary hypertension: amplification by different type phosphodiesterase inhibitors

    Directory of Open Access Journals (Sweden)

    Weissmann Norbert

    2005-07-01

    Full Text Available Abstract Inhaled prostanoids and phosphodiesterase (PDE inhibitors have been suggested for treatment of severe pulmonary hypertension. In catheterized rabbits with acute pulmonary hypertension induced by continuous infusion of the stable thromboxane analogue U46619, we asked whether sildenafil (PDE1/5/6 inhibitor, motapizone (PDE3 inhibitor or 8-Methoxymethyl-IBMX (PDE1 inhibitor synergize with inhaled iloprost. Inhalation of iloprost caused a transient pulmonary artery pressure decline, levelling off within per se ineffective dose of each PDE inhibitor (200 μg/kg × min 8-Methoxymethyl-IBMX, 1 μg/kg × min sildenafil, 5 μg/kg × min motapizone with subsequent iloprost nebulization, marked amplification of the prostanoid induced pulmonary vasodilatory response was noted and the area under the curve of PPA reduction was nearly threefold increased with all approaches, as compared to sole iloprost administration. Further amplification was achieved with the combination of inhaled iloprost with sildenafil plus motapizone, but not with sildenafil plus 8MM-IBMX. Systemic hemodynamics and gas exchange were not altered for all combinations. We conclude that co-administration of minute systemic doses of selective PDE inhibitors with inhaled iloprost markedly enhances and prolongs the pulmonary vasodilatory response to inhaled iloprost, with maintenance of pulmonary selectivity and ventilation perfusion matching. The prominent effect of sildenafil may be operative via both PDE1 and PDE5, and is further enhanced by co-application of a PDE3 inhibitor.

  4. Amplification of seismic ground motion in the Tunis basin: Numerical BEM simulations vs experimental evidences

    CERN Document Server

    Kham, Marc; Bouden-Romdhane, Nejla

    2013-01-01

    This paper aims at the analysis of seismic wave amplification in a deep alluvial basin in the city of Tunis in Tunisia. This sedimentary basin is 3000m wide and 350m deep. Since the seismic hazard is significant in this area, the depth of the basin and the strong impedance ratio raise the need for an accurate estimation of seismic motion amplification. Various experimental investigations were performed in previous studies to characterize site effects. The Boundary Element Method is considered herein to assess the parameter sensitivity of the amplification process and analyse the prevailing phenomena. The various frequencies of maximum amplification are correctly estimated by the BEM simulations. The maximum amplification level observed in the field is also well retrieved by the numerical simulations but, due to the sensitivity of the location of maximum amplification in space, the overall maximum amplification has to be considered. The influence of the wave-field incidence and material damping is also discuss...

  5. Toehold-mediated nonenzymatic amplification circuit on graphene oxide fluorescence switching platform for sensitive and homogeneous microRNA detection

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Ru; Liao, Yuhui; Zhou, Xiaoming, E-mail: zhouxm@scnu.edu.cn; Xing, Da, E-mail: xingda@scnu.edu.cn

    2015-08-12

    A novel graphene oxide (GO) fluorescence switch-based homogenous system has been developed to solve two problems that are commonly encountered in conventional GO-based biosensors. First, with the assistance of toehold-mediated nonenzymatic amplification (TMNA), the sensitivity of this system greatly surpasses that of previously described GO-based biosensors, which are always limited to the nM range due to the lack of efficient signal amplification. Second, without enzymatic participation in amplification, the unreliability of detection resulting from nonspecific desorption of DNA probes on the GO surface by enzymatic protein can be avoided. Moreover, the interaction mechanism of the double-stranded TMNA products contains several single-stranded toeholds at two ends and GO has also been explored with combinations of atomic force microscopy imaging, zeta potential detection, and fluorescence assays. It has been shown that the hybrids can be anchored to the surface of GO through the end with more unpaired bases, and that the other end, which has weaker interaction with GO, can escape GO adsorption due to the robustness of the central dsDNA structures. We verified this GO fluorescence switch-based detection system by detecting microRNA 21, an overexpressed non-encoding gene in a variety of malignant cells. Rational design of the probes allowed the isothermal nonenzymatic reaction to achieve more than 100-fold amplification efficiency. The detection results showed that our strategy has a detection limit of 10 pM and a detection range of four orders of magnitude. - Highlights: • This paper explored the interaction mechanism of TMNA products with GO surface. • This homogeneous and isothermal system permits a detection limit of 10 pM for microRNA. • This nonenzymatic strategy can avoid nonspecific desorption caused by enzyme protein. • The interaction model can be used to explore the application ability of nonenzymatic circuit.

  6. Molecular Investigation of Lymph Nodes in Colon Cancer Patients Using One-Step Nucleic Acid Amplification (OSNA)

    OpenAIRE

    Güller, Ulrich; Zettl, Andreas; Worni, Mathias; Langer, Igor; Cabalzar-Wondberg, Daniela; Viehl, Carsten T; Demartines, Nicolas; Zuber, Markus

    2012-01-01

    BACKGROUND A new diagnostic system, called one-step nucleic acid amplification (OSNA), has recently been designed to detect cytokeratin 19 mRNA as a surrogate for lymph node metastases. The objective of this prospective investigation was to compare the performance of OSNA with both standard hematoxylin and eosin (H&E) analysis and intensive histopathology in the detection of colon cancer lymph node metastases. METHODS In total, 313 lymph nodes from 22 consecutive patients with stage I, II, an...

  7. Resonance amplification of left-handed transmission at optical frequencies by stimulated emission of radiation in active metamaterials

    OpenAIRE

    Dong, Zheng-Gao; Liu, Hui; Li, Tao; Zhu, Zhi-Hong; Wang, Shu-Ming; Cao, Jing-Xiao; Zhu, Shi-Ning; Zhang, X.

    2008-01-01

    We demonstrate that left-handed resonance transmission from metallic metamaterial, composed of periodically arranged double rings, can be extended to visible spectrum by introducing an active medium layer as the substrate. The severe ohmic loss inside metals at optical frequencies is compensated by stimulated emission of radiation in this active system. Due to the resonance amplification mechanism of recently proposed lasing spaser, the left-handed transmission band can be restored up to 610 ...

  8. Toehold-mediated nonenzymatic amplification circuit on graphene oxide fluorescence switching platform for sensitive and homogeneous microRNA detection

    International Nuclear Information System (INIS)

    A novel graphene oxide (GO) fluorescence switch-based homogenous system has been developed to solve two problems that are commonly encountered in conventional GO-based biosensors. First, with the assistance of toehold-mediated nonenzymatic amplification (TMNA), the sensitivity of this system greatly surpasses that of previously described GO-based biosensors, which are always limited to the nM range due to the lack of efficient signal amplification. Second, without enzymatic participation in amplification, the unreliability of detection resulting from nonspecific desorption of DNA probes on the GO surface by enzymatic protein can be avoided. Moreover, the interaction mechanism of the double-stranded TMNA products contains several single-stranded toeholds at two ends and GO has also been explored with combinations of atomic force microscopy imaging, zeta potential detection, and fluorescence assays. It has been shown that the hybrids can be anchored to the surface of GO through the end with more unpaired bases, and that the other end, which has weaker interaction with GO, can escape GO adsorption due to the robustness of the central dsDNA structures. We verified this GO fluorescence switch-based detection system by detecting microRNA 21, an overexpressed non-encoding gene in a variety of malignant cells. Rational design of the probes allowed the isothermal nonenzymatic reaction to achieve more than 100-fold amplification efficiency. The detection results showed that our strategy has a detection limit of 10 pM and a detection range of four orders of magnitude. - Highlights: • This paper explored the interaction mechanism of TMNA products with GO surface. • This homogeneous and isothermal system permits a detection limit of 10 pM for microRNA. • This nonenzymatic strategy can avoid nonspecific desorption caused by enzyme protein. • The interaction model can be used to explore the application ability of nonenzymatic circuit

  9. Comparative study of three nucleic acid amplification assays for the detection of bovine viral diarrhea virus%牛病毒性腹泻病毒三种核酸检测方法的比较

    Institute of Scientific and Technical Information of China (English)

    范晴; 谢芝勋; 刘加波; 庞耀珊; 邓显文; 谢志勤; 谢丽基

    2012-01-01

    利用针对牛病毒性腹泻病毒(BVDV)的常规RT-PCR、实时荧光定量RT-PCR(real-time RT-PCR)和RT-环介导等温扩增技术(RT-LAMP)3种核酸检测方法对不同质粒浓度的样品和417份临床疑似样品进行了检测,以比较3种核酸检测方法的优越性。结果显示,3种核酸检测方法中,real-time RT-PCR和RT-LAMP一样敏感,均能检测到10拷贝/μL,常规RT-PCR只能检测到1×104拷贝/μL,但临床样品检测表明,常规RT-PCR方法敏感度低,会造成一部分漏检,RT-LAMP灵敏度高又会造成错检。综合比较3种方法后,推荐用RT-LAMP结合real-time RT-PCR,不仅节约成本,且结果更为准确可靠,可提高牛病毒性腹泻的检出率。%Ten fold dilution series samples and 417 clinical samples suspected with bovine viral diarrhea were used to evaluate three BVDV(bovine viral diarrhea virus)-specific detection methods:conventional RT-PCR,real-time RT-PCR and RT-LAMP(loop-mediated isothermal amplification).Results showed that the real-time RT-PCR and RT-LAMP had the same high sensitivity,and both of them could detect as lower as 10 copies/μL of samples,but the conventional RT-PCR had a lower sensitivity with its detection limit of 1×104 copies/μL.Clinically,a contrast analysis of these three methods showed that the RT-PCR had a higher undetected rate duo to its low sensitivity to clinical samples;the error rate of RT-LAMP was high due to its high sensitivity.These results suggested that the method of RT-LAMP combining with real-time RT-PCR is the recommended methods in clinical detection of BVDV,which is not only cost efficient but also accurate.

  10. Rapid Amplification of Plasmid and Phage DNA Using Phi29 DNA Polymerase and Multiply-Primed Rolling Circle Amplification

    OpenAIRE

    Dean, Frank B.; Nelson, John R.; Giesler, Theresa L.; Lasken, Roger S.

    2001-01-01

    We describe a simple method of using rolling circle amplification to amplify vector DNA such as M13 or plasmid DNA from single colonies or plaques. Using random primers and φ29 DNA polymerase, circular DNA templates can be amplified 10,000-fold in a few hours. This procedure removes the need for lengthy growth periods and traditional DNA isolation methods. Reaction products can be used directly for DNA sequencing after phosphatase treatment to inactivate unincorporated nucleotides. Amplified ...

  11. Optical coherence tomography: Monte Carlo simulation and improvement by optical amplification

    DEFF Research Database (Denmark)

    Tycho, Andreas

    2002-01-01

    An advanced novel Monte Carlo simulation model of the detection process of an optical coherence tomography (OCT) system is presented. For the first time it is shown analytically that the applicability of the incoherent Monte Carlo approach to model the heterodyne detection process of an OCT system...... distribution of the light from the sample and the reference beam. To adequately estimate the intensity distributions, a novel method of modeling a focused Gaussian beam using Monte Carlo simulation is developed. This method is then combined with the derived expression for the OCT signal into a new Monte Carlo...... flexibility of Monte Carlo simulations, this new model is demonstrated to be excellent as a numerical phantom, i.e., as a substitute for otherwise difficult experiments. Finally, a new model of the signal-to-noise ratio (SNR) of an OCT system with optical amplification of the light reflected from the sample...

  12. Enhanced acoustic sensing through wave compression and pressure amplification in anisotropic metamaterials.

    Science.gov (United States)

    Chen, Yongyao; Liu, Haijun; Reilly, Michael; Bae, Hyungdae; Yu, Miao

    2014-01-01

    Acoustic sensors play an important role in many areas, such as homeland security, navigation, communication, health care and industry. However, the fundamental pressure detection limit hinders the performance of current acoustic sensing technologies. Here, through analytical, numerical and experimental studies, we show that anisotropic acoustic metamaterials can be designed to have strong wave compression effect that renders direct amplification of pressure fields in metamaterials. This enables a sensing mechanism that can help overcome the detection limit of conventional acoustic sensing systems. We further demonstrate a metamaterial-enhanced acoustic sensing system that achieves more than 20 dB signal-to-noise enhancement (over an order of magnitude enhancement in detection limit). With this system, weak acoustic pulse signals overwhelmed by the noise are successfully recovered. This work opens up new vistas for the development of metamaterial-based acoustic sensors with improved performance and functionalities that are highly desirable for many applications. PMID:25316410

  13. Rapid genome detection of Schmallenberg virus and bovine viral diarrhea virus by use of isothermal amplification methods and high-speed real-time reverse transcriptase PCR.

    Science.gov (United States)

    Aebischer, Andrea; Wernike, Kerstin; Hoffmann, Bernd; Beer, Martin

    2014-06-01

    Over the past few years, there has been an increasing demand for rapid and simple diagnostic tools that can be applied outside centralized laboratories by using transportable devices. In veterinary medicine, such mobile test systems would circumvent barriers associated with the transportation of samples and significantly reduce the time to diagnose important infectious animal diseases. Among a wide range of available technologies, high-speed real-time reverse transcriptase quantitative PCR (RT-qPCR) and the two isothermal amplification techniques loop-mediated isothermal amplification (LAMP) and recombinase polymerase amplification (RPA) represent three promising candidates for integration into mobile pen-side tests. The aim of this study was to investigate the performance of these amplification strategies and to evaluate their suitability for field application. In order to enable a valid comparison, novel pathogen-specific assays have been developed for the detection of Schmallenberg virus and bovine viral diarrhea virus. The newly developed assays were evaluated in comparison with established standard RT-qPCR using samples from experimentally or field-infected animals. Even though all assays allowed detection of the target virus in less than 30 min, major differences were revealed concerning sensitivity, specificity, robustness, testing time, and complexity of assay design. These findings indicated that the success of an assay will depend on the integrated amplification technology. Therefore, the application-specific pros and cons of each method that were identified during this study provide very valuable insights for future development and optimization of pen-side tests. PMID:24648561

  14. High amplified spontaneous emission contrast of 1011 in a Nd:glass laser based on a hybrid double chirped pulse amplification scheme

    International Nuclear Information System (INIS)

    By using a Ti:sapphire-Nd:glass hybrid double chirped pulse amplification scheme and a pulse cleaner based on optical parametric amplification and second harmonic generation, we demonstrate high amplified spontaneous emission (ASE) contrast at 1053 nm. The optimized ASE temporal contrast of the output pulse is about 1011 at about 160 ps before the main peak with an output of 140 mJ/500 fs. And the potential of 10 J level output with high ASE contrast is demonstrated in a laser system with attenuated injection. (paper)

  15. Novel Microsatellite Loci for Sebaea aurea (Gentianaceae and Cross-Amplification in Related Species

    Directory of Open Access Journals (Sweden)

    Jonathan Kissling

    2013-12-01

    Full Text Available Premise of the study: Microsatellite loci were developed in Sebaea aurea (Gentianaceae to investigate the functional role of diplostigmaty (i.e., the presence of additional stigmas along the style. Methods and Results: One hundred seventy-four and 180 microsatellite loci were isolated through 454 shotgun sequencing of genomic and microsatellite-enriched DNA libraries, respectively. Sixteen polymorphic microsatellite loci were characterized, and 12 of them were selected to genotype individuals from two populations. Microsatellite amplification was conducted in two multiplex groups, each containing six microsatellite loci. Cross-species amplification was tested in seven other species of Sebaea. The 12 novel microsatellite loci amplified only in the two most closely related species to S. aurea (i.e., S. ambigua and S. minutiflora and were also polymorphic in these two species. Conclusions: These results demonstrate the usefulness of this set of newly developed microsatellite loci to investigate the mating system and population genetic structure in S. aurea and related species.

  16. Direct ultrasensitive electrochemical biosensing of pathogenic DNA using homogeneous target-initiated transcription amplification

    Science.gov (United States)

    Yan, Yurong; Ding, Shijia; Zhao, Dan; Yuan, Rui; Zhang, Yuhong; Cheng, Wei

    2016-01-01

    Sensitive and specific methodologies for detection of pathogenic gene at the point-of-care are still urgent demands in rapid diagnosis of infectious diseases. This work develops a simple and pragmatic electrochemical biosensing strategy for ultrasensitive and specific detection of pathogenic nucleic acids directly by integrating homogeneous target-initiated transcription amplification (HTITA) with interfacial sensing process in single analysis system. The homogeneous recognition and specific binding of target DNA with the designed hairpin probe triggered circular primer extension reaction to form DNA double-strands which contained T7 RNA polymerase promoter and served as templates for in vitro transcription amplification. The HTITA protocol resulted in numerous single-stranded RNA products which could synchronously hybridized with the detection probes and immobilized capture probes for enzyme-amplified electrochemical detection on the biosensor surface. The proposed electrochemical biosensing strategy showed very high sensitivity and selectivity for target DNA with a dynamic response range from 1 fM to 100 pM. Using salmonella as a model, the established strategy was successfully applied to directly detect invA gene from genomic DNA extract. This proposed strategy presented a simple, pragmatic platform toward ultrasensitive nucleic acids detection and would become a versatile and powerful tool for point-of-care pathogen identification.

  17. The generation and amplification of intergalactic magnetic fields in analogue laboratory experiments with high power lasers

    Science.gov (United States)

    Gregori, G.; Reville, B.; Miniati, F.

    2015-11-01

    The advent of high-power laser facilities has, in the past two decades, opened a new field of research where astrophysical environments can be scaled down to laboratory dimensions, while preserving the essential physics. This is due to the invariance of the equations of magneto-hydrodynamics to a class of similarity transformations. Here we review the relevant scaling relations and their application in laboratory astrophysics experiments with a focus on the generation and amplification of magnetic fields in cosmic environment. The standard model for the origin of magnetic fields is a multi stage process whereby a vanishing magnetic seed is first generated by a rotational electric field and is then amplified by turbulent dynamo action to the characteristic values observed in astronomical bodies. We thus discuss the relevant seed generation mechanisms in cosmic environment including resistive mechanism, collision-less and fluid instabilities, as well as novel laboratory experiments using high power laser systems aimed at investigating the amplification of magnetic energy by magneto-hydrodynamic (MHD) turbulence. Future directions, including efforts to model in the laboratory the process of diffusive shock acceleration are also discussed, with an emphasis on the potential of laboratory experiments to further our understanding of plasma physics on cosmic scales.

  18. DIAGNOSIS OF TUBERCULOSIS BY PHAGE AMPLIFICATION TECHNIQUE: A SIMPLE B UT RAPID & RELIABLE ALTERNATIVE

    Directory of Open Access Journals (Sweden)

    Bhattacharya

    2015-09-01

    Full Text Available In view of the grim scenario that exists in India as far as tuberculosis is concerned, despite various plans and programmes like RNTCP, ‘E arly diagnosis’ of the disease particularly of sputum - positive cases and their treatments are of paramount importance to contain the disease. Sputum microscopy – the mainstay of diagnosis proves inadequate because of its wide variation in sensitivity. There has been more concern in this era of MDR - TB and HIV co - infection. To address these problems the present study has been taken to detect the tubercle bacilli by phage amplification technique (FAST plaque TB TM with comparison to BACTEC 460 TB culture system in 12B vial. 42 smear - positive and 62 smear - negative samples were selected. In 42 smear - positive cases, radiometric culture positivity was seen in 40(95% and plaque positivity in 35(83%. In 62 smear - negative cases, culture positive cases were 30(48%, but plaque positivity was seen in only 10(16%. Overall culture positivity was 67% (total no. 70 and plaque positivity being 43% (T otal no. 46; whereas smear microscopy showed only 24.1% positivity. So phage amplification showed greater sensitivity than smear microscopy; higher specificity ( D etects only live bacilli of M. tuberculosis. This is rapid, simple, and no need for specialized technical skill and no expensive equipment is required.

  19. Self similar solution of superradiant amplification of ultrashort laser pulses in plasma

    International Nuclear Information System (INIS)

    Based on the self-similar method, superradiant amplification of ultrashort laser pulses by the counterpropagating pump in a plasma is investigated. Here, we present a governing system of partial differential equations for the signal pulse and the motion of the electrons. These equations are transformed to ordinary differential equations by the self-similar method and numerically solved. It is found that the increase of the signal intensity is proportional to the square of the propagation distance and the signal frequency has a red shift. Also, depending on the pulse width, the signal breaks up into a train of short pulses or its duration decreases with the inverse square root of the distance. Moreover, we identified two distinct categories of the electrons by the phase space analysis. In the beginning, one of them is trapped in the ponderomotive potential well and oscillates while the other is untrapped. Over time, electrons of the second kind also join to the trapped electrons. In the potential well, the electrons are bunched to form an electron density grating which reflects the pump pulse into the signal pulse. It is shown that the backscattered intensity is enhanced with the increase of the electron bunching parameter which leads to the enhanced efficiency of superradiant amplification

  20. Arctic cyclogenesis at the marginal ice zone: A contributory mechanism for the temperature amplification ?

    Science.gov (United States)

    Inoue, J.; Hori, M. E.

    2011-12-01

    Rapid sea-ice retreat over the Arctic Ocean has a leading role in Arctic amplification. The sea-ice extent ramatically recovers during every freezing season, so despite the recent summer sea-ice retreat, there must be extraordinary heat exchange between the lower atmosphere and upper ocean. However, the underlying mechanisms for this remain uncertain. Here we show that autumn frontal cyclogenesis is a crucial event in the Arctic air-sea coupled system. Our shipboard Doppler radar and intensive radiosonde observations at the marginal ice zone detected an explosive frontal cyclogenesis, with coupling between upper and lower tropospheric vortices. The thermal contrast between ocean and ice surfaces is likely favorable to cyclogenesis with an identical life-cycle to that at mid-latitudes. This suggests a northward shift of meridional heat transport. The 1.5 K temperature decrease in the upper ocean after the cold front has passed reveals that a large amount of heat is transported into the atmosphere. This is an invaluable example of the fact that sea ice retreat contributes to polar amplification of surface air temperature increase.

  1. Electrochemical etching amplification of low-let recoil particle tracks in polymers for fast neutron dosimetry

    International Nuclear Information System (INIS)

    An electrochemical etching method for the amplification of fast-neutron-induced recoil particle tracks in polymers was investigated. The technique gave superior results over those obtained by conventional etching methods especially when polycarbonate foils were used for recoil particle track amplification. Electrochemical etching systems capable of multi-foil processing were designed and constructed to demonstrate the feasibility of the techniques for large-scale neutron dosimetry. Electrochemical etching parameters were studied including the nature or type of the polymer foil used, foil thickness and its effect on etching time, the applied voltage and its frequency, the chemical composition, concentration, and temperature of the etchant, distance and angle between the electrodes, and the type of particles such as recoil particles including protons. Recoil particle track density, mean track diameter, and optical density as functions of the mentioned parameters were determined. Each parameter was found to have a distinct effect on the etching results in terms of the measured responses. Several new characteristics of this fast neutron dosimetry method were studied especially for personnel dosimetry using various radiation sources such as nuclear reactors, medical cyclotrons, and isotopic neutron sources. The dose range, neutron energy dependence, directional response, fading characteristics, neutron threshold energy, etc. were investigated

  2. Ultrafast pulse amplification in mode-locked vertical external-cavity surface-emitting lasers

    International Nuclear Information System (INIS)

    A fully microscopic many-body Maxwell–semiconductor Bloch model is used to investigate the influence of the non-equilibrium carrier dynamics on the short-pulse amplification in mode-locked semiconductor microlaser systems. The numerical solution of the coupled equations allows for a self-consistent investigation of the light–matter coupling dynamics, the carrier kinetics in the saturable absorber and the multiple-quantum-well gain medium, as well as the modification of the light field through the pulse-induced optical polarization. The influence of the pulse-induced non-equilibrium modifications of the carrier distributions in the gain medium and the saturable absorber on the single-pulse amplification in the laser cavity is identified. It is shown that for the same structure, quantum wells, and gain bandwidth the non-equilibrium carrier dynamics lead to two preferred operation regimes: one with pulses in the (sub-)100 fs-regime and one with multi-picosecond pulses. The recovery time of the saturable absorber determines in which regime the device operates

  3. Characterization and cross-amplification of microsatellite markers in four species of anemonefish (Pomacentridae, Amphiprion spp.)

    KAUST Repository

    Bonin, Mary C.

    2015-04-09

    Anemonefish are iconic symbols of coral reefs and have become model systems for research on larval dispersal and population connectivity in coral reef fishes. Here we present 24 novel microsatellite markers across four species of anemonefish and also test 35 previously published markers for cross-amplification on two anemonefish species in order to facilitate further research on their population genetics and phylogenetics. Novel loci were isolated from sequences derived from microsatellite-enriched or 454 GS-FLX shotgun sequence libraries developed using congeneric DNA. Primer testing successfully identified 15 new microsatellite loci for A. percula, 4 for A. melanopus, 3 for A. akindynos, and 2 for A. omanensis. These novel microsatellite loci were polymorphic with a mean of 10 ± 1.6 SE (standard error) alleles per locus and an average observed heterozygosity of 0.647 ± 0.032 SE. Reliable cross-amplification of 12 and 26 of the 35 previously published Amphiprion markers was achieved for A. melanopus and A. akindynos, respectively, suggesting that the use of markers developed from the DNA of congeners can provide a quick and cost-effective alternative to the isolation of new loci. Together, the markers presented here provide an important resource for ecological, evolutionary, and conservation genetic research on anemonefishes that will inform broader conservation and management actions for coral reef fishes. © 2015 Senckenberg Gesellschaft für Naturforschung and Springer-Verlag Berlin Heidelberg

  4. Non-local effect in Brillouin optical time-domain analyzer based on Raman amplification

    International Nuclear Information System (INIS)

    Compared with conventional Brillouin optical time-domain analyzer (BOTDA), the BOTDA based on Raman amplification allows longer sensing range, higher signal-to-noise ratio and higher measurement accuracy. However, the non-local effect induced by pump depletion significantly restricts the probe optical power injected to sensing fiber, thereby limiting the further extension for sensing distance. In this paper, the coupled equations including the interaction of probe light, Brillouin and Raman pumps are applied to the study on the non-local characteristics of BOTDA based on Raman amplification. The results show that, the system error induced by non-local effect worsens with increased powers of probe wave and Raman pump. The frequency-division-multiplexing (cascading the fibers with various Brillouin frequency shifts) and time-division-multiplexing (modulating both of the Brillouin pump and probe lights) technologies are efficient approaches to suppress the non-local effect, through shortening the effective interaction range between Brillouin pump and probe lights. (authors)

  5. Realistic noise-tolerant randomness amplification using finite number of devices.

    Science.gov (United States)

    Brandão, Fernando G S L; Ramanathan, Ravishankar; Grudka, Andrzej; Horodecki, Karol; Horodecki, Michał; Horodecki, Paweł; Szarek, Tomasz; Wojewódka, Hanna

    2016-01-01

    Randomness is a fundamental concept, with implications from security of modern data systems, to fundamental laws of nature and even the philosophy of science. Randomness is called certified if it describes events that cannot be pre-determined by an external adversary. It is known that weak certified randomness can be amplified to nearly ideal randomness using quantum-mechanical systems. However, so far, it was unclear whether randomness amplification is a realistic task, as the existing proposals either do not tolerate noise or require an unbounded number of different devices. Here we provide an error-tolerant protocol using a finite number of devices for amplifying arbitrary weak randomness into nearly perfect random bits, which are secure against a no-signalling adversary. The correctness of the protocol is assessed by violating a Bell inequality, with the degree of violation determining the noise tolerance threshold. An experimental realization of the protocol is within reach of current technology. PMID:27098302

  6. Experimental amplification of an entangled photon: what if the detection loophole is ignored?

    CERN Document Server

    Pomarico, Enrico; Sekatski, Pavel; Zbinden, Hugo; Gisin, Nicolas

    2011-01-01

    The experimental verification of quantum features, such as entanglement, at large scales is extremely challenging because of environment-induced decoherence. Indeed, measurement techniques for demonstrating the quantumness of multiparticle systems in the presence of losses are difficult to define and, if not sufficiently accurate, they provide wrong conclusions. We present a Bell test where one photon of an entangled pair is amplified and then detected by threshold detectors, whose signals undergo postselection. The amplification is performed by a classical machine, which produces a fully separable micro-macro state. However, by adopting such a technique, one can surprisingly observe a violation of the CHSH inequality. This is due to the fact that ignoring the detection loophole, opened by the postselection and the system losses, can lead to misinterpretations, such as claiming the micro-macro entanglement in a setup where evidently there is not. By using threshold detectors and postselection, one can only in...

  7. Realistic noise-tolerant randomness amplification using finite number of devices

    Science.gov (United States)

    Brandão, Fernando G. S. L.; Ramanathan, Ravishankar; Grudka, Andrzej; Horodecki, Karol; Horodecki, Michał; Horodecki, Paweł; Szarek, Tomasz; Wojewódka, Hanna

    2016-04-01

    Randomness is a fundamental concept, with implications from security of modern data systems, to fundamental laws of nature and even the philosophy of science. Randomness is called certified if it describes events that cannot be pre-determined by an external adversary. It is known that weak certified randomness can be amplified to nearly ideal randomness using quantum-mechanical systems. However, so far, it was unclear whether randomness amplification is a realistic task, as the existing proposals either do not tolerate noise or require an unbounded number of different devices. Here we provide an error-tolerant protocol using a finite number of devices for amplifying arbitrary weak randomness into nearly perfect random bits, which are secure against a no-signalling adversary. The correctness of the protocol is assessed by violating a Bell inequality, with the degree of violation determining the noise tolerance threshold. An experimental realization of the protocol is within reach of current technology.

  8. NOISE AMPLIFICATION ANALYSIS AND COMPARISON OF TWO PERIODIC NONUNIFORM SAMPLING RECONSTRUCTION METHODS USED IN DPCA SAR

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    General Sampling Expansion Reconstruction Method(GSERM)and Digital Spectrum Reconstruction Method(DSRM),which prove effective to reconstruct azimuth signal of Displaced Phase Center Apertures(DPCA) Synthetic Aperture areal"(SAR)system from its Periodic Non-Uniform Sampling(PNUS)data sequences,would amplify the noise and sidelobe clutter simultaneously in the reconstruction.This paper formulates the relation of the system transfer matrixes of the above two methods,gives the properties,such aS periodicity,symmetry,and time-shift property,of their Noise and Sidelobe Clutter Amplification Factor(NSCAF),and discovers that DSRM is more sensitive than GSERM in the white noise environment.In addition,criteria based on initial sampling point analysis for the robust PRF selection are suggested.Computer simulation results support these con-clusions.

  9. Realistic noise-tolerant randomness amplification using finite number of devices

    Science.gov (United States)

    Brandão, Fernando G. S. L.; Ramanathan, Ravishankar; Grudka, Andrzej; Horodecki, Karol; Horodecki, Michał; Horodecki, Paweł; Szarek, Tomasz; Wojewódka, Hanna

    2016-01-01

    Randomness is a fundamental concept, with implications from security of modern data systems, to fundamental laws of nature and even the philosophy of science. Randomness is called certified if it describes events that cannot be pre-determined by an external adversary. It is known that weak certified randomness can be amplified to nearly ideal randomness using quantum-mechanical systems. However, so far, it was unclear whether randomness amplification is a realistic task, as the existing proposals either do not tolerate noise or require an unbounded number of different devices. Here we provide an error-tolerant protocol using a finite number of devices for amplifying arbitrary weak randomness into nearly perfect random bits, which are secure against a no-signalling adversary. The correctness of the protocol is assessed by violating a Bell inequality, with the degree of violation determining the noise tolerance threshold. An experimental realization of the protocol is within reach of current technology. PMID:27098302

  10. Quantum phase amplification for temporal pulse shaping and super-resolution in remote sensing

    Science.gov (United States)

    Yin, Yanchun

    The use of nonlinear optical interactions to perform nonclassical transformations of electromagnetic field is an area of considerable interest. Quantum phase amplification (QPA) has been previously proposed as a method to perform nonclassical manipulation of coherent light, which can be experimentally realized by use of nonlinear optical mixing processes, of which phase-sensitive three-wave mixing (PSTWM) is one convenient choice. QPA occurs when PSTWM is operated in the photon number deamplification mode, i.e., when the energy is coherently transferred among the low-frequency signal and idler waves and the high-frequency pump wave. The final state is nonclassical, with the field amplitude squeezed and the phase anti-squeezed. In the temporal domain, the use of QPA has been studied to facilitate nonlinear pulse shaping. This novel method directly shapes the temporal electric field amplitude and phase using the PSTWM in a degenerate and collinear configuration, which has been analyzed using a numerical model. Several representative pulse shaping capabilities of this technique have been identified, which can augment the performance of common passive pulse shaping methods operating in the Fourier domain. The analysis indicates that a simple quadratic variation of temporal phase facilitates pulse compression and self-steepening, with features significantly shorter than the original transform-limited pulse. Thus, PSTWM can act as a direct pulse compressor based on the combined effects of phase amplification and group velocity mismatch, even without the subsequent linear phase compensation. Furthermore, it is shown numerically that pulse doublets and pulse trains can be produced at the pump frequency by utilizing the residual linear phase of the signal. Such pulse shaping capabilities are found to be within reach of this technique in common nonlinear optical crystals pumped by pulses available from compact femtosecond chirped-pulse amplification laser systems. The use of

  11. Sisyphus cooling and amplification by a superconducting qubit

    International Nuclear Information System (INIS)

    Recently superconducting qubits have been shown to act as artificial two-level atoms, demonstrating many different quantum effects known in quantum optics. Coupling such qubits to resonators is quite natural extension of this analogy. Similar to laser cooling of the atomic motion we demonstrate here Sisyphus cooling of a low frequency LC oscillator coupled to a near-resonantly driven flux qubit. The analogy to the quantum optics is obvious: the LC oscillator plays the role of the mechanical degree of freedom of an atom, while the qubit mimics the electronic, laser driven, transition. We also demonstrate the counterpart of the Sisyphus cooling, namely, Sisyphus amplification

  12. High power amplification of a tailored-pulse fiber laser

    Science.gov (United States)

    Saby, Julien; Sangla, Damien; Caplette, Stéphane; Boula-Picard, Reynald; Drolet, Mathieu; Reid, Benoit; Salin, François

    2013-02-01

    We demonstrate the amplification of a 1064nm pulse-programmable fiber laser with Large Pitch Rod-Type Fibers of various Mode field diameters from 50 to 70 μm. We have developed a high power fiber amplifier at 1064nm delivering up to 100W/1mJ at 15ns pulses and 30W/300μJ at 2ns with linearly polarized and diffraction limited output beam (M²LBO crystals leading to 50W at 532nm and 25W at 355nm with a diffraction limited output. Similar experiments performed at 1032nm are also reported.

  13. Genomic Amplifications Cause False Positives in CRISPR Screens.

    Science.gov (United States)

    Sheel, Ankur; Xue, Wen

    2016-08-01

    In CRISPR-based screens for essential genes, Munoz and colleagues and Aguirre and colleagues show that gene-independent targeting of genomic amplifications in human cancer cell lines reduces proliferation or survival. The correlation between CRISPR target site copy number and lethality demonstrates the need for scrutiny and complementary approaches to rule out off-target effects and false positives in CRISPR screens. Cancer Discov; 6(8); 824-6. ©2016 AACR.See related article by Munoz et al., p. 900See related article by Aguirre et al., p. 914. PMID:27485003

  14. Simultaneous amplification and attenuation in isotropic chiral materials

    Science.gov (United States)

    Mackay, Tom G.; Lakhtakia, Akhlesh

    2016-05-01

    The electromagnetic field phasors in an isotropic chiral material (ICM) are superpositions of two Beltrami fields of different handedness. Application of the Bruggeman homogenization formalism to two-component composite materials delivers ICMs wherein Beltrami fields of one handedness attenuate whereas Beltrami fields of the other handedness amplify. One component material is a dissipative ICM, the other an active dielectric material. The range of the volume fraction of the active component material for which simultaneous amplification and attenuation is exhibited decreases—but does not vanish—as the ICM component becomes more dissipative and as its chirality parameter reduces in magnitude.

  15. The efficiency of Raman amplification in the wavebreaking regime

    International Nuclear Information System (INIS)

    We compare previous analytic predictions, Vlasov-Maxwell simulations, and particle-in-cell results with a new set of comprehensive one and two dimensional particle-in-cell simulations in an effort to clarify apparent discrepancies between the predictions of different models for the efficiency of Raman amplification in the wavebreaking regime. We find reasonable agreement between our particle-in-cell simulations and previous results from Vlasov-Maxwell simulations and analytic work, suggesting a monotonic decrease in conversion efficiency for increased pump intensities past the wavebreaking threshold

  16. Parametric amplification of a chirped pulse in an optical fiber

    International Nuclear Information System (INIS)

    The OPCPA (Optical Parametric Chirped Pulse Amplification) technique is used in the field of powerful lasers for it enables us to get ultra-short pulses with a reduced optical noise. We have shown that we can replace the massive optical non-linear crystals used in this technique by optical silicon fibers. First, we have made a basic demonstration at the wavelength of 1.55 μm in which a picosecond-long pulse has been amplified by 25 decibels without undergoing any spectral changes. The use of micro-structured optical fibers has allowed us to adapt this method to the wavelength of power laser lines. (A.C.)

  17. Rapid detection of Mycobacterium tuberculosis by recombinase polymerase amplification.

    Directory of Open Access Journals (Sweden)

    David S Boyle

    Full Text Available Improved access to effective tests for diagnosing tuberculosis (TB has been designated a public health priority by the World Health Organisation. In high burden TB countries nucleic acid based TB tests have been restricted to centralised laboratories and specialised research settings. Requirements such as a constant electrical supply, air conditioning and skilled, computer literate operators prevent implementation of such tests in many settings. Isothermal DNA amplification technologies permit the use of simpler, less energy intensive detection platforms more suited to low resource settings that allow the accurate diagnosis of a disease within a short timeframe. Recombinase Polymerase Amplification (RPA is a rapid, low temperature isothermal DNA amplification reaction. We report here RPA-based detection of Mycobacterium tuberculosis complex (MTC DNA in <20 minutes at 39 °C. Assays for two MTC specific targets were investigated, IS6110 and IS1081. When testing purified MTC genomic DNA, limits of detection of 6.25 fg (IS6110 and 20 fg (IS1081were consistently achieved. When testing a convenience sample of pulmonary specimens from suspected TB patients, RPA demonstrated superior accuracy to indirect fluorescence microscopy. Compared to culture, sensitivities for the IS1081 RPA and microscopy were 91.4% (95%CI: 85, 97.9 and 86.1% (95%CI: 78.1, 94.1 respectively (n = 71. Specificities were 100% and 88.6% (95% CI: 80.8, 96.1 respectively. For the IS6110 RPA and microscopy sensitivities of 87.5% (95%CI: 81.7, 93.2 and 70.8% (95%CI: 62.9, 78.7 were obtained (n = 90. Specificities were 95.4 (95% CI: 92.3,98.1 and 88% (95% CI: 83.6, 92.4 respectively. The superior specificity of RPA for detecting tuberculosis was due to the reduced ability of fluorescence microscopy to distinguish Mtb complex from other acid fast bacteria. The rapid nature of the RPA assay and its low energy requirement compared to other amplification technologies suggest RPA-based TB

  18. Control of Brillouin short-pulse seed amplification by chirping the pump pulse

    Energy Technology Data Exchange (ETDEWEB)

    Lehmann, G.; Spatschek, K. H. [Institut für Theoretische Physik, Heinrich-Heine-Universität Düsseldorf, D–40225 Düsseldorf (Germany)

    2015-04-15

    Seed amplification via Brillouin backscattering of a long pump pulse is considered. Similar to Raman amplification, several obstructive effects may occur during short-pulse Brillouin amplification. One is the spontaneous Raman backscattering of the pump before interacting with the seed. Preforming the plasma and/or chirping the pump will reduce unwanted pump backscattering. Optimized regions for low-loss pump propagation were proposed already in conjunction with Raman seed amplification. Hence, the influence of the chirp of the pump during Brillouin interaction with the seed becomes important and will be considered here. Both, the linear as well as the nonlinear evolution phases of the seed caused by Brillouin amplification under the action of a chirped pump are investigated. The amplification rate as well as the seed profiles are presented as function of the chirping rate. Also the dependence of superradiant scaling rates on the chirp parameter is discussed.

  19. Fiber-Optical Parametric Amplification of Sub-Picosecond Pulses for High-Speed Optical Communications

    DEFF Research Database (Denmark)

    Lali-Dastjerdi, Zohreh; Cristofori, Valentina; Rottwitt, Karsten;

    2015-01-01

    This article reviews recent results of amplification of short optical pulses using fiber-optical parametric amplifiers. This includes chirped-pulse amplification of 400 fs pulses, error-free amplification of a 640-Gbit/s optical time-division multiplexed signal with less than a 1-dB power penalty......, and all-optical phase-preserving amplitude regeneration of a 640-Gbit/s return-to-zero differential phase-shift keying optical time-division multiplexed signal....

  20. A robust method for the amplification of RNA in the sense orientation

    OpenAIRE

    Quackenbush John; Marko Nicholas F; Frank Bryan; Lee Norman H

    2005-01-01

    Abstract Background Small quantities of RNA (1–4 μg total RNA) available from biological samples frequently require a single round of amplification prior to analysis, but current amplification strategies have limitations that may restrict their usefulness in downstream genomic applications. The Eberwine amplification method has been extensively validated but is limited by its ability to produce only antisense RNA. Alternatives lack extensive validation and are often confounded by problems wit...

  1. An integrated disposable device for DNA extraction and helicase dependent amplification

    OpenAIRE

    Mahalanabis, Madhumita; Do, Jaephil; ALMuayad, Hussam; Zhang, Jane Y.; Klapperich, Catherine M.

    2010-01-01

    Here we report the demonstration of an integrated microfluidic chip that performs helicase dependent amplification (HDA) on samples containing live bacteria. Combined chip-based sample preparation and isothermal amplification are attractive for world health applications, since the need for instrumentation to control flow rate and temperature changes are reduced or eliminated. Bacteria lysis, nucleic acid extraction, and DNA amplification with a fluorescent reporter are incorporated into a dis...

  2. STUDY OF SOIL AMPLIFICATION BASED ON MICROTREMOR AND SEISMIC RECORDS IN LIMA PERU

    Science.gov (United States)

    Calderon, Diana; Sekiguchi, Toru; Nakai, Shoichi; Aguilar, Zenon; Lazares, Fernando

    The dynamic characteristics of the ground in Lima, capital of Peru, specifically the amplification are investigated. By using the small and large microtremor array measurements we estimated the soil velocity profiles with depths to the bedrock in many cases. These profiles were used to estimate the amplification factors. Important results are the large amplification factors at EMO, VSV, CAL and CMA (La Molina, Villa El Salvador, El Callao and Bellavista district, respectively).

  3. Parametric amplification of matter waves in dipolar spinor Bose-Einstein condensates

    DEFF Research Database (Denmark)

    Deuretzbacher, F.; Gebreyesus, G.; Topic, O.;

    2010-01-01

    Spin-changing collisions may lead under proper conditions to the parametric amplification of matter waves in spinor Bose-Einstein condensates. Magnetic dipole-dipole interactions, although typically very weak in alkali-metal atoms, are shown to play a very relevant role in the amplification process......-field gradients, hence, must be carefully controlled in future experiments, in order to observe clearly the effects of the dipolar interactions in the amplification dynamics....

  4. Amplification of realistic Schrödinger-cat-state-like states by homodyne heralding

    DEFF Research Database (Denmark)

    Laghaout, Amine; Neergaard-Nielsen, Jonas S.; Rigas, Ioannes;

    2013-01-01

    We present a scheme for the amplification of Schrödinger cat states that collapses two smaller states onto their constructive interference via a homodyne projection. We analyze the performance of the amplification in terms of fidelity and success rate when the input consists of either exact coher...... coherent state superpositions or of photon-subtracted squeezed vacua. The impact of imprecise homodyne detection and of impure squeezing is quantified. We also assess the scalability of iterated amplifications....

  5. Sensitive SERS detection of DNA methyltransferase by target triggering primer generation-based multiple signal amplification strategy.

    Science.gov (United States)

    Li, Ying; Yu, Chuanfeng; Han, Huixia; Zhao, Caisheng; Zhang, Xiaoru

    2016-07-15

    A novel and sensitive surface-enhanced Raman scattering (SERS) method is proposed for the assay of DNA methyltransferase (MTase) activity and evaluation of inhibitors by developing a target triggering primer generation-based multiple signal amplification strategy. By using of a duplex substrate for Dam MTase, two hairpin templates and a Raman probe, multiple signal amplification mode is achieved. Once recognized by Dam MTase, the duplex substrate can be cleaved by Dpn I endonuclease and two primers are released for triggering the multiple signal amplification reaction. Consequently, a wide dynamic range and remarkably high sensitivity are obtained under isothermal conditions. The detection limit is 2.57×10(-4)UmL(-1). This assay exhibits an excellent selectivity and is successfully applied in the screening of inhibitors for Dam MTase. In addition, this novel sensing system is potentially universal as the recognition element can be conveniently designed for other target analytes by changing the substrate of DNA MTase. PMID:26926592

  6. Nuclease-resistant double-stranded DNA controls or standards for hepatitis B virus nucleic acid amplification assays

    Directory of Open Access Journals (Sweden)

    Zhan Sien

    2009-12-01

    Full Text Available Abstract Background Identical blood samples tested using different kits can give markedly different hepatitis B virus (HBV DNA levels, which can cause difficulty in the interpretation of viral load. A universal double-stranded DNA control or standard that can be used in all commercial HBV DNA nucleic acid amplification assay kits is urgently needed. By aligning all HBV genotypes (A-H, we found that the surface antigen gene and precore-core gene regions of HBV are the most conserved regions among the different HBV genotypes. We constructed a chimeric fragment by overlapping extension polymerase chain reaction and obtained a 1,349-bp HBVC+S fragment. We then packaged the fragment into lambda phages using a traditional lambda phage cloning procedure. Results The obtained armored DNA was resistant to DNase I digestion and was stable, noninfectious to humans, and could be easily extracted using commercial kits. More importantly, the armored DNA may be used with all HBV DNA nucleic acid amplification assay kits. Conclusions The lambda phage packaging system can be used as an excellent expression platform for armored DNA. The obtained armored DNA possessed all characteristics of an excellent positive control or standard. In addition, this armored DNA is likely to be appropriate for all commercial HBV DNA nucleic acid amplification detection kits. Thus, the constructed armored DNA can probably be used as a universal positive control or standard in HBV DNA assays.

  7. A fully integrated paperfluidic molecular diagnostic chip for the extraction, amplification, and detection of nucleic acids from clinical samples.

    Science.gov (United States)

    Rodriguez, Natalia M; Wong, Winnie S; Liu, Lena; Dewar, Rajan; Klapperich, Catherine M

    2016-02-21

    Paper diagnostics have successfully been employed to detect the presence of antigens or small molecules in clinical samples through immunoassays; however, the detection of many disease targets relies on the much higher sensitivity and specificity achieved via nucleic acid amplification tests (NAAT). The steps involved in NAAT have recently begun to be explored in paper matrices, and our group, among others, has reported on paper-based extraction, amplification, and detection of DNA and RNA targets. Here, we integrate these paper-based NAAT steps into a single paperfluidic chip in a modular, foldable system that allows for fully integrated fluidic handling from sample to result. We showcase the functionality of the chip by combining nucleic acid isolation, isothermal amplification, and lateral flow detection of human papillomavirus (HPV) 16 DNA directly from crude cervical specimens in less than 1 hour for rapid, early detection of cervical cancer. The chip is made entirely of paper and adhesive sheets, making it low-cost, portable, and disposable, and offering the potential for a point-of-care molecular diagnostic platform even in remote and resource-limited settings. PMID:26785636

  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. Light amplification and scattering by clusters made of small active particles: the local perturbation approach

    CERN Document Server

    Prosentsov, V V

    2013-01-01

    The light amplification by finite active media is used extensively in modern optics applications. In this paper the light amplification and scattering by cluster of small particles is studied analytically and numerically with the help of the local perturbation method and phenomenological laser theory. It is shown that light amplification is possible even for one small particle, and that the amplification is more profound when the light frequency nears the frequency of the cluster's morphological resonance. Theoretical discussions are supplemented by numerical results for scattering by clusters which particles positioned at ordered and at slightly disordered positions.

  10. Chaotic amplification of neutrino chemical potentials by neutrino oscillations in big bang nucleosynthesis

    International Nuclear Information System (INIS)

    We investigate in detail the parameter space of active-sterile neutrino oscillations that amplifies neutrino chemical potentials at the epoch of big bang nucleosynthesis. We calculate the magnitude of the amplification and show evidence of chaos in the amplification process. We also discuss the implications of the neutrino chemical potential amplification in big bang nucleosynthesis. It is shown that with a ∼1 eV νe, the amplification of its chemical potential by active-sterile neutrino oscillations can lower the effective number of neutrino species at big bang nucleosynthesis to significantly below three. copyright 1996 The American Physical Society

  11. Amplification of cylindrically polarized laser beams in single crystal fiber amplifiers.

    Science.gov (United States)

    Piehler, Stefan; Délen, Xavier; Rumpel, Martin; Didierjean, Julien; Aubry, Nicolas; Graf, Thomas; Balembois, Francois; Georges, Patrick; Ahmed, Marwan Abdou

    2013-05-01

    Yb:YAG single crystal fiber (SCF) amplifiers have recently drawn much attention in the field of amplification of ultra-short pulses. In this paper, we report on the use of SCF amplifiers for the amplification of cylindrically polarized laser beams, as such beams offer promising properties for numerous applications. While the amplification of cylindrically polarized beams is challenging with other amplifier designs due to thermally induced depolarization, we demonstrate the amplification of 32 W cylindrically polarized beams to an output power of 100 W. A measured degree of radial polarization after the SCF of about 95% indicates an excellent conservation of polarization. PMID:23669994

  12. Improved purification and PCR amplification of DNA from environmental samples.

    Science.gov (United States)

    Arbeli, Ziv; Fuentes, Cilia L

    2007-07-01

    Purification and PCR amplification procedures for DNA extracted from environmental samples (soil, compost, and river sediment) were improved by introducing three modifications: precipitation of DNA with 5% polyethylene glycol 8000 (PEG) and 0.6 M NaCl; filtration with a Sepharose 4B-polyvinylpolypyrrolidone (PVPP) spin column; and addition of skim milk (0.3% w/v) to the PCR reaction solution. Humic substances' concentration after precipitation with 5% PEG was 2.57-, 5.3-, and 78.9-fold lower than precipitation with 7.5% PEG, 10% PEG, and isopropanol, respectively. After PEG precipitation, Sepharose, PVPP and the combined (Sepharose-PVPP) column removed 92.3%, 89.5%, and 98%, respectively, of the remaining humic materials. Each of the above-mentioned modifications improved PCR amplification of the 16S rRNA gene. DNA extracted by the proposed protocol is cleaner than DNA extracted by a commercial kit. Nevertheless, the improvement of DNA purification did not improve the detection limit of atrazine degradation gene atzA. PMID:17521406

  13. Social amplification of risk in the Internet environment.

    Science.gov (United States)

    Chung, Ik Jae

    2011-12-01

    This article analyzes the dynamic process of risk amplification in the Internet environment with special emphasis on public concern for environmental risks from a high-speed railway tunnel construction project in South Korea. Environmental organizations and activists serving as social stations collected information about the project and its ecological impact, and communicated this with the general public, social groups, and institutions. The Internet provides social stations and the public with an efficient means for interactive communication and an open space for active information sharing and public participation. For example, while the website of an organization such as an environmental activist group can initially trigger local interest, the Internet allows this information to be disseminated to a much wider audience in a manner unavailable to the traditional media. Interaction among social stations demonstrates an amplifying process of public attention to the risk. Analyses of the volume of readers' comments to online newspaper articles and public opinions posted on message board of public and nonprofit organizations show the ripple effects of the amplification process as measured along temporal, geographical, and sectoral dimensions. Public attention is also influenced by the symbolic connotations of risk information. Interpretations of risk in religious, political, or legal terms intensify public concern for the environmental risk. PMID:21539590

  14. Loop-Mediated Amplification Accelerated by Stem Primers

    Directory of Open Access Journals (Sweden)

    Laurence Tisi

    2011-12-01

    Full Text Available Isothermal nucleic acid amplifications (iNAATs have become an important alternative to PCR for in vitro molecular diagnostics in all fields. Amongst iNAATs Loop-mediated amplification (LAMP has gained much attention over the last decade because of the simplicity of hardware requirements. LAMP demonstrates performance equivalent to that of PCR, but its application has been limited by the challenging primer design. The design of six primers in LAMP requires a selection of eight priming sites with significant restrictions imposed on their respective positioning and orientation. In order to relieve primer design constraints we propose an alternative approach which uses Stem primers instead of Loop primers and demonstrate the application of STEM-LAMP in assaying for Clostridium difficile, Listeria monocytogenes and HIV. Stem primers used in LAMP in combination with loop-generating and displacement primers gave significant benefits in speed and sensitivity, similar to those offered by Loop primers, while offering additional options of forward and reverse orientations, multiplexing, use in conjunction with Loop primers or even omission of one or two displacement primers, where necessary. Stem primers represent a valuable alternative to Loop primers and an additional tool for IVD assay development by offering more choices for primer design at the same time increasing assay speed, sensitivity, and reproducibility.

  15. Radiopolymerization of β(-)pinene: A case of chiral amplification

    International Nuclear Information System (INIS)

    β(-)Pinene was treated with γ radiation at three dose levels: 150, 300 and 600 kGy. The expected effect of radiation at these high doses was the partial racemization of the substrate as already observed in the case of other terpene monomers. Unexpectedly β(-)pinene underwent a radiopolymerization reaction into a solid resin and into a dimer. The structure of the products was studied by FT-IR spectroscopy also in comparison to a reference β(-)pinene resin prepared by cationic polymerization. A highly ordered structure was found in the case of the radiopolymer in comparison to the resin from cationic polymerization. Polarimetric measurements have shown astonishing enhancement in the optical activity of the radiopolymer and radiodimer in comparison to the starting optical activity of the β(-)pinene monomer. The results have been discussed in terms of amplification of chirality caused by γ radiation and the implications of this fact on the mechanism of chiral amplification on prebiotic molecules

  16. Loop-mediated amplification accelerated by stem primers.

    Science.gov (United States)

    Gandelman, Olga; Jackson, Rebecca; Kiddle, Guy; Tisi, Laurence

    2011-01-01

    Isothermal nucleic acid amplifications (iNAATs) have become an important alternative to PCR for in vitro molecular diagnostics in all fields. Amongst iNAATs Loop-mediated amplification (LAMP) has gained much attention over the last decade because of the simplicity of hardware requirements. LAMP demonstrates performance equivalent to that of PCR, but its application has been limited by the challenging primer design. The design of six primers in LAMP requires a selection of eight priming sites with significant restrictions imposed on their respective positioning and orientation. In order to relieve primer design constraints we propose an alternative approach which uses Stem primers instead of Loop primers and demonstrate the application of STEM-LAMP in assaying for Clostridium difficile, Listeria monocytogenes and HIV. Stem primers used in LAMP in combination with loop-generating and displacement primers gave significant benefits in speed and sensitivity, similar to those offered by Loop primers, while offering additional options of forward and reverse orientations, multiplexing, use in conjunction with Loop primers or even omission of one or two displacement primers, where necessary. Stem primers represent a valuable alternative to Loop primers and an additional tool for IVD assay development by offering more choices for primer design at the same time increasing assay speed, sensitivity, and reproducibility. PMID:22272122

  17. Development and Application of Surface Plasmon Polaritons on Optical Amplification

    Directory of Open Access Journals (Sweden)

    Tong Zhang

    2014-01-01

    Full Text Available Propagation of surface plasmon polaritons (SPPs along the interface between a metal and a dielectric has attracted significant attention due to its unique optical properties, which has inspired a plethora of fascinating applications in photonics and optoelectronics. However, SPPs suffer from large attenuation because of the ohmic losses in the metal layer. It has become the main bottom-neck problem for the development of high performance plasmonic devices. This limitation can be overcome by providing the material adjacent to the metal with optical gain. In this paper, a review of gain compensation to SPPs is presented. We focus on the spontaneous radiation amplification and simulated radiation amplification. The ohmic loss of metal was greatly improved by introducing optical gain. Then we introduce several gain mediums of dye doped, quantum dots, erbium ion, and semiconductor to compensate optical loss of SPPs. Using gain medium mentioned above can compensate losses and achieve many potential applications, for example, laser, amplifier, and LRSPP discussed.

  18. DNA Extraction and Amplification from Contemporary Polynesian Bark-Cloth

    Science.gov (United States)

    Moncada, Ximena; Payacán, Claudia; Arriaza, Francisco; Lobos, Sergio; Seelenfreund, Daniela; Seelenfreund, Andrea

    2013-01-01

    Background Paper mulberry has been used for thousands of years in Asia and Oceania for making paper and bark-cloth, respectively. Museums around the world hold valuable collections of Polynesian bark-cloth. Genetic analysis of the plant fibers from which the textiles were made may answer a number of questions of interest related to provenance, authenticity or species used in the manufacture of these textiles. Recovery of nucleic acids from paper mulberry bark-cloth has not been reported before. Methodology We describe a simple method for the extraction of PCR-amplifiable DNA from small samples of contemporary Polynesian bark-cloth (tapa) using two types of nuclear markers. We report the amplification of about 300 bp sequences of the ITS1 region and of a microsatellite marker. Conclusions Sufficient DNA was retrieved from all bark-cloth samples to permit successful PCR amplification. This method shows a means of obtaining useful genetic information from modern bark-cloth samples and opens perspectives for the analyses of small fragments derived from ethnographic materials. PMID:23437166

  19. Radiopolymerization of {beta}(-)pinene: A case of chiral amplification

    Energy Technology Data Exchange (ETDEWEB)

    Cataldo, Franco [Soc. Lupi Chemical Research, Via Casilina 1626/A, 00133 Rome (Italy)]. E-mail: cdcata@flashnet.it; Keheyan, Yeghis [CNR, Istituto per lo studio dei Materiali Nanostrutturati, Department of Chemistry, University ' La Sapienza' , P.le Aldo Moro 1, Rome (Italy)

    2006-05-15

    {beta}(-)Pinene was treated with {gamma} radiation at three dose levels: 150, 300 and 600 kGy. The expected effect of radiation at these high doses was the partial racemization of the substrate as already observed in the case of other terpene monomers. Unexpectedly {beta}(-)pinene underwent a radiopolymerization reaction into a solid resin and into a dimer. The structure of the products was studied by FT-IR spectroscopy also in comparison to a reference {beta}(-)pinene resin prepared by cationic polymerization. A highly ordered structure was found in the case of the radiopolymer in comparison to the resin from cationic polymerization. Polarimetric measurements have shown astonishing enhancement in the optical activity of the radiopolymer and radiodimer in comparison to the starting optical activity of the {beta}(-)pinene monomer. The results have been discussed in terms of amplification of chirality caused by {gamma} radiation and the implications of this fact on the mechanism of chiral amplification on prebiotic molecules.

  20. RESONANT AMPLIFICATION OF TURBULENCE BY THE BLAST WAVES

    International Nuclear Information System (INIS)

    We discuss the idea of whether spherical blast waves can amplify by a nonlocal resonant hydrodynamic mechanism inhomogeneities formed by turbulence or phase segregation in the interstellar medium. We consider the problem of a blast-wave-turbulence interaction in the Linear Interaction Approximation. Mathematically, this is an eigenvalue problem for finding the structure and amplitude of eigenfunctions describing the response of the shock-wave flow to forced oscillations by external perturbations in the ambient interstellar medium. Linear analysis shows that the blast wave can amplify density and vorticity perturbations for a wide range of length scales with amplification coefficients of up to 20, with increasing amplification the larger the length. There also exist resonant harmonics for which the gain becomes formally infinite in the linear approximation. Their orbital wavenumbers are within the range of macro- (l ∼ 1), meso- (l ∼ 20), and microscopic (l > 200) scales. Since the resonance width is narrow (typically, Δl < 1), resonance should select and amplify discrete isolated harmonics. We speculate on a possible explanation of an observed regular filamentary structure of regularly shaped round supernova remnants such as SNR 1572, 1006, or 0509-67.5. Resonant mesoscales found (l ≈ 18) are surprisingly close to the observed scales (l ≈ 15) of ripples in the shell's surface of SNR 0509-67.5