WorldWideScience

Sample records for alternate unbalanced recombinants

  1. Recombinant 4 syndrome due to an unbalanced pericentric inversion of chromosome 4.

    Science.gov (United States)

    Battaglia, A; Brothman, A R; Carey, J C

    2002-09-15

    An informative patient with a MCA/MR syndrome consisting of developmental delay, prenatal onset growth delay, microcephaly, distinctive face, iris coloboma, and a congenital heart defect was found, on chromosome analysis, to have the following complement: 46,XY,rec(4) dup(4p) inv(4)(p14q35.1) mat. He has a partial 4p trisomy/distal 4q deletion due to an unbalanced pericentric inversion inherited from his mother. Dup (4p) trisomy was originally described by Wilson et al. [1970: Am J Hum Genet 22:679-690] in a similar case with the same chromosome 4 inversion. To date, at least 85 cases of dup (4p) syndrome have been published, mostly due to unbalanced translocations. Recent articles suggest that the phenotype is hard to recognize clinically due to the lack of specificity of findings. In contrast, 4p trisomy due to an unbalanced pericentric inversion of chromosome 4(p14q35), i.e., the recombinant 4 syndrome observed in our patient, appears to be a discrete entity with relatively consistent features. In total there are four other kindreds described in the literature with this inversion, and the phenotype seems recognizable. Thus, we suggest that recombinant 4 syndrome is a discrete entity among 4p trisomy patients. Copyright 2002 Wiley-Liss, Inc.

  2. Widespread recombination, reassortment, and transmission of unbalanced compound viral genotypes in natural arenavirus infections.

    Directory of Open Access Journals (Sweden)

    Mark D Stenglein

    2015-05-01

    Full Text Available Arenaviruses are one of the largest families of human hemorrhagic fever viruses and are known to infect both mammals and snakes. Arenaviruses package a large (L and small (S genome segment in their virions. For segmented RNA viruses like these, novel genotypes can be generated through mutation, recombination, and reassortment. Although it is believed that an ancient recombination event led to the emergence of a new lineage of mammalian arenaviruses, neither recombination nor reassortment has been definitively documented in natural arenavirus infections. Here, we used metagenomic sequencing to survey the viral diversity present in captive arenavirus-infected snakes. From 48 infected animals, we determined the complete or near complete sequence of 210 genome segments that grouped into 23 L and 11 S genotypes. The majority of snakes were multiply infected, with up to 4 distinct S and 11 distinct L segment genotypes in individual animals. This S/L imbalance was typical: in all cases intrahost L segment genotypes outnumbered S genotypes, and a particular S segment genotype dominated in individual animals and at a population level. We corroborated sequencing results by qRT-PCR and virus isolation, and isolates replicated as ensembles in culture. Numerous instances of recombination and reassortment were detected, including recombinant segments with unusual organizations featuring 2 intergenic regions and superfluous content, which were capable of stable replication and transmission despite their atypical structures. Overall, this represents intrahost diversity of an extent and form that goes well beyond what has been observed for arenaviruses or for viruses in general. This diversity can be plausibly attributed to the captive intermingling of sub-clinically infected wild-caught snakes. Thus, beyond providing a unique opportunity to study arenavirus evolution and adaptation, these findings allow the investigation of unintended anthropogenic impacts on

  3. RecO protein initiates DNA recombination and strand annealing through two alternative DNA binding mechanisms.

    Science.gov (United States)

    Ryzhikov, Mikhail; Gupta, Richa; Glickman, Michael; Korolev, Sergey

    2014-10-17

    Recombination mediator proteins (RMPs) are important for genome stability in all organisms. Several RMPs support two alternative reactions: initiation of homologous recombination and DNA annealing. We examined mechanisms of RMPs in both reactions with Mycobacterium smegmatis RecO (MsRecO) and demonstrated that MsRecO interacts with ssDNA by two distinct mechanisms. Zinc stimulates MsRecO binding to ssDNA during annealing, whereas the recombination function is zinc-independent and is regulated by interaction with MsRecR. Thus, different structural motifs or conformations of MsRecO are responsible for interaction with ssDNA during annealing and recombination. Neither annealing nor recombinase loading depends on MsRecO interaction with the conserved C-terminal tail of single-stranded (ss) DNA-binding protein (SSB), which is known to bind Escherichia coli RecO. However, similarly to E. coli proteins, MsRecO and MsRecOR do not dismiss SSB from ssDNA, suggesting that RMPs form a complex with SSB-ssDNA even in the absence of binding to the major protein interaction motif. We propose that alternative conformations of such complexes define the mechanism by which RMPs initiate the repair of stalled replication and support two different functions during recombinational repair of DNA breaks. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  4. Unbalanced field RF electron gun

    Science.gov (United States)

    Hofler, Alicia

    2013-11-12

    A design for an RF electron gun having a gun cavity utilizing an unbalanced electric field arrangement. Essentially, the electric field in the first (partial) cell has higher field strength than the electric field in the second (full) cell of the electron gun. The accompanying method discloses the use of the unbalanced field arrangement in the operation of an RF electron gun in order to accelerate an electron beam.

  5. Poster #115Y: Two Distinct Phenotypes in 11 Individuals, Demonstrating Alternate Unbalanced Recombinants Derived from a Cryptic Paternal Balanced Translocation between Chromosomes 10 and 14

    OpenAIRE

    Eytan, Danny; Gal, Asaf; Wallach, Avner; Kermany, Einat; Haroush, Netta; Marom, Shimon; Asleh, Rabea; Levy, Nina S.; Miller-Lotan, Rachel; Levy, Andrew P.; Brenner, Benjamin; Assalia, Ahmed; Vardi, Yoram; Appel, Boaz; Massarwi, Omar

    2012-01-01

    Cancer and thrombosis are the two major disease states in the developed world. While the association of venous thromboembolism (VTE) with tumors was described over 150 years ago, clinical and basic research over the past 30 years have broadened our understanding of this association. The interactions of thrombosis and cancer are complex and involve issues related to pathogenic mechanisms, clinical presentation, prognosis, and treatment. Pulmonary embolism is a major cause of death in cancer pa...

  6. A simple DNA recombination screening method by RT-PCR as an alternative to Southern blot

    DEFF Research Database (Denmark)

    Albers, Eliene; Sbroggiò, Mauro; Martin Gonzalez, Javier

    2017-01-01

    genomic locus, but limits the detection of its correct genomic integration by standard PCR methods. Genomic Long Range PCR (LR-PCR), using primers adjacent to the homology arms, has been used as an alternative to radioactive-based Southern blot screenings. However, LR-PCRs are often difficult and render...... many false positive and false negative results. Here, we propose an alternative screening method based on the detection of a genetic modification at the mRNA level, which we successfully optimized in two mouse models. This screening method consists of a reverse-transcription PCR (RT-PCR) using primers...... that match exons flanking the targeting construct. The detection of the expected modification in this PCR product confirms the integration at the correct genomic location and shows that the mutant mRNA is expressed. This is a simple and sensitive strategy to screen locus-specific recombination of targeting...

  7. Similarity of recombinant human perlecan domain 1 by alternative expression systems bioactive heterogenous recombinant human perlecan D1

    DEFF Research Database (Denmark)

    Ellis, April L; Pan, Wensheng; Yang, Guang

    2010-01-01

    perlecan domain 1 (HSPG2 abbreviated as rhPln.D1) synthesized in either HEK 293 cells or HUVECs by transient gene delivery using either adenoviral or expression plasmid technology. RESULTS: By SDS-PAGE analysis following anion exchange chromatography, the recombinant proteoglycans appeared to possess...

  8. Preparative SDS PAGE as an Alternative to His-Tag Purification of Recombinant Amelogenin.

    Science.gov (United States)

    Gabe, Claire M; Brookes, Steven J; Kirkham, Jennifer

    2017-01-01

    Recombinant protein technology provides an invaluable source of proteins for use in structure-function studies, as immunogens, and in the development of therapeutics. Recombinant proteins are typically engineered with "tags" that allow the protein to be purified from crude host cell extracts using affinity based chromatography techniques. Amelogenin is the principal component of the developing enamel matrix and a frequent focus for biomineralization researchers. Several groups have reported the successful production of recombinant amelogenins but the production of recombinant amelogenin free of any tags, and at single band purity on silver stained SDS PAGE is technically challenging. This is important, as rigorous structure-function research frequently demands a high degree of protein purity and fidelity of protein sequence. Our aim was to generate His-tagged recombinant amelogenin at single band purity on silver stained SDS PAGE for use in functionality studies after His-tag cleavage. An acetic acid extraction technique (previously reported to produce recombinant amelogenin at 95% purity directly from E. coli ) followed by repeated rounds of nickel column affinity chromatography, failed to generate recombinant amelogenin at single band purity. This was because following an initial round of nickel column affinity chromatography, subsequent cleavage of the His-tag was not 100% efficient. A second round of nickel column affinity chromatography, used in attempts to separate the cleaved His-tag free recombinant from uncleaved His-tagged contaminants, was still unsatisfactory as cleaved recombinant amelogenin exhibited significant affinity for the nickel column. To solve this problem, we used preparative SDS PAGE to successfully purify cleaved recombinant amelogenins to single band purity on silver stained SDS PAGE. The resolving power of preparative SDS PAGE was such that His-tag based purification of recombinant amelogenin becomes redundant. We suggest that acetic

  9. Preparative SDS PAGE as an Alternative to His-Tag Purification of Recombinant Amelogenin

    Directory of Open Access Journals (Sweden)

    Claire M. Gabe

    2017-06-01

    Full Text Available Recombinant protein technology provides an invaluable source of proteins for use in structure-function studies, as immunogens, and in the development of therapeutics. Recombinant proteins are typically engineered with “tags” that allow the protein to be purified from crude host cell extracts using affinity based chromatography techniques. Amelogenin is the principal component of the developing enamel matrix and a frequent focus for biomineralization researchers. Several groups have reported the successful production of recombinant amelogenins but the production of recombinant amelogenin free of any tags, and at single band purity on silver stained SDS PAGE is technically challenging. This is important, as rigorous structure-function research frequently demands a high degree of protein purity and fidelity of protein sequence. Our aim was to generate His-tagged recombinant amelogenin at single band purity on silver stained SDS PAGE for use in functionality studies after His-tag cleavage. An acetic acid extraction technique (previously reported to produce recombinant amelogenin at 95% purity directly from E. coli followed by repeated rounds of nickel column affinity chromatography, failed to generate recombinant amelogenin at single band purity. This was because following an initial round of nickel column affinity chromatography, subsequent cleavage of the His-tag was not 100% efficient. A second round of nickel column affinity chromatography, used in attempts to separate the cleaved His-tag free recombinant from uncleaved His-tagged contaminants, was still unsatisfactory as cleaved recombinant amelogenin exhibited significant affinity for the nickel column. To solve this problem, we used preparative SDS PAGE to successfully purify cleaved recombinant amelogenins to single band purity on silver stained SDS PAGE. The resolving power of preparative SDS PAGE was such that His-tag based purification of recombinant amelogenin becomes redundant. We

  10. Unbalanced Growth, Senescence and Aging.

    Science.gov (United States)

    Polymenis, Michael; Kennedy, Brian K

    2017-01-01

    Usually, cells balance their growth with their division. Coordinating growth inputs with cell division ensures the proper timing of division when sufficient cell material is available and affects the overall rate of cell proliferation. At a very fundamental level, cellular replicative lifespan-defined as the number of times a cell can divide, is a manifestation of cell cycle control. Hence, control of mitotic cell divisions, especially when the commitment is made to a new round of cell division, is intimately linked to replicative aging of cells. In this chapter, we review our current understanding, and its shortcomings, of how unbalanced growth and division, can dramatically influence the proliferative potential of cells, often leading to cellular and organismal aging phenotypes. The interplay between growth and division also underpins cellular senescence (i.e., inability to divide) and quiescence, when cells exit the cell cycle but still retain their ability to divide.

  11. Recombinant expression of homodimeric 660 kDa human thyroglobulin in soybean seeds: an alternative source of human thyroglobulin.

    Science.gov (United States)

    Powell, Rebecca; Hudson, Laura C; Lambirth, Kevin C; Luth, Diane; Wang, Kan; Bost, Kenneth L; Piller, Kenneth J

    2011-07-01

    Soybean seeds possess many qualities that make them ideal targets for the production of recombinant proteins. However, one quality often overlooked is their ability to stockpile large amounts of complex storage proteins. Because of this characteristic, we hypothesized that soybean seeds would support recombinant expression of large and complex proteins that are currently difficult or impossible to express using traditional plant and non-plant-based host systems. To test this hypothesis, we transformed soybeans with a synthetic gene encoding human thyroglobulin (hTG)-a 660 kDa homodimeric protein that is widely used in the diagnostic industry for screening and detection of thyroid disease. In the absence of a recombinant system that can produce recombinant hTG, research and diagnostic grade hTG continues to be purified from cadaver and surgically removed thyroid tissue. These less-than-ideal tissue sources lack uniform glycosylation and iodination and therefore introduce variability when purified hTG is used in sensitive ELISA screens. In this study, we report the successful expression of recombinant hTG in soybean seeds. Authenticity of the soy-derived protein was demonstrated using commercial ELISA kits developed specifically for the detection of hTG in patient sera. Western analyses and gel filtration chromatography demonstrated that recombinant hTG and thyroid-purified hTG are biologically similar with respect to size, mass, charge and subunit interaction. The recombinant protein was stable over three generations and accumulated to ~1.5% of total soluble seed protein. These results support our hypothesis that soybeans represent a practical alternative to traditional host systems for the expression of large and complex proteins.

  12. Recombinant egg drop syndrome subunit vaccine offers an alternative to virus propagation in duck eggs.

    Science.gov (United States)

    Gutter, B; Fingerut, E; Gallili, G; Eliahu, D; Perelman, B; Finger, A; Pitcovski, J

    2008-02-01

    Egg drop syndrome (EDS) virus vaccines are routinely produced in embryonated duck eggs (Solyom et al., 1982). This procedure poses the risk of dissemination of pathogens, such as avian influenza virus, as the eggs used are not from specific pathogen free birds. To address this problem, the knob and part of the shaft domain of the fibre protein of the EDS virus (termed knob-s) were expressed in Escherichia coli and assessed as a subunit vaccine. A single vaccination with the recombinant protein induced the production of anti-EDS virus antibodies, as detected by haemagglutination inhibition, enzyme-linked immunosorbent assay and virus neutralization tests, for at least 20 weeks. A positive correlation was demonstrated between these three assays. A dose-response assessment showed that the vaccine was effective over the range of 2 to 64 microg protein per dose. Two vaccinations with the recombinant protein, administered before the onset of lay, induced high haemagglutination inhibition antibody titres, comparable with those induced by an inactivated whole-virus vaccine. The vaccine did not have any adverse effects on egg production, quality or weight. The present study has shown that two vaccinations with the recombinant knob-s protein elicited high neutralizing antibody titres that persisted for more than 50 weeks of lay.

  13. Co-cultivation of Aspergillus nidulans recombinant strains produces an enzymatic cocktail as alternative to alkaline sugarcane bagasse pretreatment

    Directory of Open Access Journals (Sweden)

    Matheus Sanita Lima

    2016-04-01

    Full Text Available Plant materials represent a strategic energy source because they can give rise to sustainable biofuels through the fermentation of their carbohydrates. A clear example of a plant-derived biofuel resource is the sugar cane bagasse exhibiting 60 % - 80 % of fermentable sugars in its composition. However, the current methods of plant bioconversion employ severe and harmful chemical/physical pretreatments raising biofuel cost production and environmental degradation. Replacing these methods with co-cultivated enzymatic cocktails is an alternative. Here we propose a pretreatment for sugarcane bagasse using a multi-enzymatic cocktail from the co-cultivation of four Aspergillus nidulans recombinant strains. The co-cultivation resulted in the simultaneous production of GH51 arabinofuranosidase (AbfA, GH11 endo-1,4-xylanase (XlnA, GH43 endo-1,5-arabinanase (AbnA and GH12 xyloglucan specific endo-β-1,4-glucanase (XegA. This core set of recombinant enzymes was more efficient than the alternative alkaline method in maintaining the cellulose integrity and exposing this cellulose to the following saccharification process. Thermogravimetric and differential thermal analysis revealed residual byproducts on the alkali pretreated biomass, which were not found in the enzymatic pretreatment. Therefore, the enzymatic pretreatment was residue-free and seemed to be more efficient than the applied alkaline method, which makes it suitable for bioethanol production.

  14. Performance evaluation of reactive direct current unbalanced ...

    Indian Academy of Sciences (India)

    We have deposited nanostructured TiN coatings on high-speed steel (HSS) drill bits and mild steel substrates using an indigenously built semi-industrial fourcathode reactive direct current (d.c.) unbalanced magnetron sputtering system. Various treatments have been given to the substrates for improved adhesion of the TiN ...

  15. Alternate adenovirus type-pairs for a possible circumvention of host immune response to recombinant adenovirus vectors.

    Science.gov (United States)

    Nász, I; Adám, E; Lengyel, A

    2001-01-01

    With the help of monoclonal antibodies the existence of at least 18 different earlier not known intertype (IT) specific epitopes were demonstrated in different numbers and combinations on the hexons of different adenovirus serotypes. The IT specific epitopes play an important role in the experimental gene therapy and in the recombinant adenovirus vaccination because of the harmful immune response of the recipient organisms directed against the many different epitopes of the adenovirus vector. For the elimination of harmful effect the authors suggest the use of multiple vectors, each prepared from different adenovirus serotypes showing the loosest antigenic relationship to each other. The vectors would be used sequentially when second or multiple administration is needed. For this purpose the authors determined and described 31 such adenovirus type-pairs, which are probably the best alternates for sequential use in experimental gene therapy.

  16. Transactivator protein: An alternative for delivery of recombinant proteins for safer reprogramming of induced Pluripotent Stem Cell.

    Science.gov (United States)

    Nordin, Fazlina; Ahmad, Raja Norazireen Raja; Farzaneh, Farzin

    2017-05-02

    Induced pluripotent stem cells (iPSC) are somatic cells reprogrammed to pluripotency by forced expression of pluripotency factors. These cells are shown to have the same pluripotent potential as embryonic stem cells (ESC) and considered as an alternative to the much controversial usage of ESC which involved human embryos. However, the traditional method in reprogramming cells into iPSC using genome-integrating retro- or lenti- viruses remains an obstacle for its application in clinical setting. Although numerous studies have been conducted for a safer DNA-based reprogramming, reprogramming of iPSC by genetic modifications may raise the possibility of malignant transformation and has been a major limitation for its usage in clinical applications. Therefore, there is a need for an alternative method to reprogram the cells without the use of gene editing and a much safer way to deliver transcription factors to induce pluripotency on target cells. Using protein transduction approach, a number of studies have demonstrated the generation of human iPSCs from human fibroblasts and mouse embryonic fibroblasts by direct delivery of reprogramming proteins. In this review, the definition and mechanism of HIV-TAT protein (a type of protein transduction domain) in delivering recombinant proteins, including the potential of protein-based delivery to induce iPSC were further discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Phenotypic signatures arising from unbalanced bacterial growth.

    Science.gov (United States)

    Tan, Cheemeng; Smith, Robert Phillip; Tsai, Ming-Chi; Schwartz, Russell; You, Lingchong

    2014-08-01

    Fluctuations in the growth rate of a bacterial culture during unbalanced growth are generally considered undesirable in quantitative studies of bacterial physiology. Under well-controlled experimental conditions, however, these fluctuations are not random but instead reflect the interplay between intra-cellular networks underlying bacterial growth and the growth environment. Therefore, these fluctuations could be considered quantitative phenotypes of the bacteria under a specific growth condition. Here, we present a method to identify "phenotypic signatures" by time-frequency analysis of unbalanced growth curves measured with high temporal resolution. The signatures are then applied to differentiate amongst different bacterial strains or the same strain under different growth conditions, and to identify the essential architecture of the gene network underlying the observed growth dynamics. Our method has implications for both basic understanding of bacterial physiology and for the classification of bacterial strains.

  18. Unbalanced Cylindrical Magnetron for Accelerating Cavities Coating

    CERN Document Server

    Rosaz, Guillaume; Calatroni, Sergio; Sublet, Alban; Tobarelli, Mauro

    2016-01-01

    We report in this paper the design and qualification of a cylindrical unbalanced magnetron source. The dedicated magnetic assemblies were simulated using a finite element model. A hall-effect magnetic probe was then used to characterize those assemblies and compared to the theoretical magnet profiles. These show a good agreement between the expected and actual values. the qualification of the different magnetic assemblies was then performed by measuring the ion flux density reaching the surface of the sample to be coated using a commercial retarding field energy analyzer. The strongest unbalanced configuration shows an increase from 0.016A.cm^-2 to 0.074A.cm^-2 of the ion flux density reaching the sample surface compared to the standard balanced configuration for a pressure 5.10^-3 mbar and a plasma source power of 300W.

  19. Oral Recombinant Feline Interferon-Omega as an alternative immune modulation therapy in FIV positive cats: clinical and laboratory evaluation.

    Science.gov (United States)

    Gil, S; Leal, R O; McGahie, D; Sepúlveda, N; Duarte, A; Niza, M M R E; Tavares, L

    2014-02-01

    Recombinant-Feline Interferon-Omega (rFeIFN-ω) is an immune-modulator licensed for use subcutaneously in Feline Immunodeficiency virus (FIV) therapy. Despite oral protocols have been suggested, little is known about such use in FIV-infected cats. This study aimed to evaluate the clinical improvement, laboratory findings, concurrent viral excretion and acute phase proteins (APPs) in naturally FIV-infected cats under oral rFeIFN-ω therapy (0.1 MU/cat rFeIFN-ω PO, SID, 90 days). 11 FIV-positive cats were treated with oral rFeIFN-ω (PO Group). Results were compared to previous data from 7 FIV-positive cats treated with the subcutaneous licensed protocol (SC Group). Initial clinical scores were similar in both groups. Independently of the protocol, rFeIFN-ω induced a significant clinical improvement of treated cats. Concurrent viral excretion and APP's variation were not significant in the PO Group. Oral rFeIFN-ω can be an effective alternative therapy for FIV-infected cats, being also an option for treatment follow-up in cats submitted to the licensed protocol. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Short description of an alternative simplified method for screening recombinant clones within the "AdEasy-System" by Duplex-PCR

    Directory of Open Access Journals (Sweden)

    Kienle Peter

    2005-01-01

    Full Text Available Abstract Background Recombinant adenoviral vectors are highly efficient for in vitro and in vivo gene delivery. They can easily be produced in large numbers, transduce a wide variety of cell types and generate high levels of transgene expression. The AdEasy system is a widely used system for generating recombinant adenoviral vectors, which are created with a minimum of enzymatic manipulations and by employing homologous recombination in E. coli. In this paper we describe an alternative simplified method for screening recombinant DNA within the AdEasy system. This Duplex-PCR-method is independent of the transgene or insert and can be used for the complete AdEasy system. It is characterized by a simple standard protocol and the results can be obtained within a few hours. The PCR is run with two different primer sets. The primers KanaFor and KanaRev hybridizise with the Kanamycin resistence gene and AdFor and AdRev detect the adenoviral backbone. In case of recombinant clones, two diagnostic fragments with a size of 384 bp and 768 bp are generated. Results The practicability of this method was verified with three different transgenes: Cytosin Deaminase (AdCD, p53 (Adp53 and Granulocyte Macrophage Colony Stimulating Factor (AdGM-CSF. Recombinant clones are indicated by two diagnostic fragments and are then suitable for further processing. Conclusion In summary, the presented protocol allows fast detection of recombinants with an easy technique by minimizing the amount of necessary steps for generating a recombinant adenovirus. This method is time sparing and cost-effective.

  1. Power Analysis in Two-Level Unbalanced Designs

    Science.gov (United States)

    Konstantopoulos, Spyros

    2010-01-01

    Previous work on statistical power has discussed mainly single-level designs or 2-level balanced designs with random effects. Although balanced experiments are common, in practice balance cannot always be achieved. Work on class size is one example of unbalanced designs. This study provides methods for power analysis in 2-level unbalanced designs…

  2. Unbalanced Regressions and the Predictive Equation

    DEFF Research Database (Denmark)

    Osterrieder, Daniela; Ventosa-Santaulària, Daniel; Vera-Valdés, J. Eduardo

    Predictive return regressions with persistent regressors are typically plagued by (asymptotically) biased/inconsistent estimates of the slope, non-standard or potentially even spurious statistical inference, and regression unbalancedness. We alleviate the problem of unbalancedness...... in the theoretical predictive equation by suggesting a data generating process, where returns are generated as linear functions of a lagged latent I(0) risk process. The observed predictor is a function of this latent I(0) process, but it is corrupted by a fractionally integrated noise. Such a process may arise due...... to aggregation or unexpected level shifts. In this setup, the practitioner estimates a misspecified, unbalanced, and endogenous predictive regression. We show that the OLS estimate of this regression is inconsistent, but standard inference is possible. To obtain a consistent slope estimate, we then suggest...

  3. A Review on Grid-connected Converter Control for Short Circuit Power Provision under Grid Unbalanced Faults

    DEFF Research Database (Denmark)

    Jia, Jundi; Yang, Guangya; Nielsen, Arne Hejde

    2017-01-01

    behave significantly different from the traditional alternators under grid faults. In order to evaluate the potential impact of future converter-based power systems on protective relays, it is necessary to consider diverse current control strategies of voltage source converters (VSC) under unbalanced...... faults as the performance of converters primarily depends on their control objectives. In this paper, current control strategies of VSC under unbalanced faults for short circuit power provision are reviewed in two groups, namely power-characteristic-oriented and voltage-support-oriented control strategy...... respectively. As the fault current provided by converters should be restricted within secure operation limits considering semiconductor capabilities, converter current limit issue is also discussed....

  4. Intermolecular RNA Recombination Occurs at Different Frequencies in Alternate Forms of Brome Mosaic Virus RNA Replication Compartments

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    Hernan Garcia-Ruiz

    2018-03-01

    Full Text Available Positive-strand RNA viruses replicate their genomes in membrane-bound replication compartments. Brome mosaic virus (BMV replicates in vesicular invaginations of the endoplasmic reticulum membrane. BMV has served as a productive model system to study processes like virus-host interactions, RNA replication and recombination. Here we present multiple lines of evidence showing that the structure of the viral RNA replication compartments plays a fundamental role and that recruitment of parental RNAs to a common replication compartment is a limiting step in intermolecular RNA recombination. We show that a previously defined requirement for an RNA recruitment element on both parental RNAs is not to function as a preferred crossover site, but in order for individual RNAs to be recruited into the replication compartments. Moreover, modulating the form of the replication compartments from spherular vesicles (spherules to more expansive membrane layers increased intermolecular RNA recombination frequency by 200- to 1000-fold. We propose that intermolecular RNA recombination requires parental RNAs to be recruited into replication compartments as monomers, and that recruitment of multiple RNAs into a contiguous space is much more common for layers than for spherules. These results could explain differences in recombination frequencies between viruses that replicate in association with smaller spherules versus larger double-membrane vesicles and convoluted membranes.

  5. Induced Unbalanced Linguistic Ordered Weighted Average and Its Application in Multiperson Decision Making

    Directory of Open Access Journals (Sweden)

    Lucas Marin

    2014-01-01

    Full Text Available Linguistic variables are very useful to evaluate alternatives in decision making problems because they provide a vocabulary in natural language rather than numbers. Some aggregation operators for linguistic variables force the use of a symmetric and uniformly distributed set of terms. The need to relax these conditions has recently been posited. This paper presents the induced unbalanced linguistic ordered weighted average (IULOWA operator. This operator can deal with a set of unbalanced linguistic terms that are represented using fuzzy sets. We propose a new order-inducing criterion based on the specificity and fuzziness of the linguistic terms. Different relevancies are given to the fuzzy values according to their uncertainty degree. To illustrate the behaviour of the precision-based IULOWA operator, we present an environmental assessment case study in which a multiperson multicriteria decision making model is applied.

  6. Induced unbalanced linguistic ordered weighted average and its application in multiperson decision making.

    Science.gov (United States)

    Marin, Lucas; Valls, Aida; Isern, David; Moreno, Antonio; Merigó, José M

    2014-01-01

    Linguistic variables are very useful to evaluate alternatives in decision making problems because they provide a vocabulary in natural language rather than numbers. Some aggregation operators for linguistic variables force the use of a symmetric and uniformly distributed set of terms. The need to relax these conditions has recently been posited. This paper presents the induced unbalanced linguistic ordered weighted average (IULOWA) operator. This operator can deal with a set of unbalanced linguistic terms that are represented using fuzzy sets. We propose a new order-inducing criterion based on the specificity and fuzziness of the linguistic terms. Different relevancies are given to the fuzzy values according to their uncertainty degree. To illustrate the behaviour of the precision-based IULOWA operator, we present an environmental assessment case study in which a multiperson multicriteria decision making model is applied.

  7. OPERATIONAL ACCURACY IMPROVEMENT OF DIGITAL SERVO SYSTEM CONTAINING UNBALANCED LOAD

    Directory of Open Access Journals (Sweden)

    A. G. Stryzhniou

    2013-01-01

    Full Text Available The paper considers a structural flowchart of a typical digital servo system and its operational principle. A method for determination of the unbalanced load effect on the accuracy of the system operation is described in the paper. The paper proposes a method for compensation of the  unbalanced load influence on the system operation. The experimental verification of the unbalanced load effect on the operational accuracy of the servo system and compensation of these influences have been executed in the paper.

  8. Ultracompact Planar Positioner Driven by Unbalanced Frictional Forces

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    Mikio Muraoka

    2015-08-01

    Full Text Available This paper proposes a new ultracompact planar positioner driven by unbalanced frictional forces. The prototype of the designed positioner is 17 mm × 17 mm × 9 mm in size, and is simply constructed using lead zirconate titanate piezoelectric elements, neodymium magnetic feet, and junction pieces. Alternating static and kinetic frictional forces are utilized to control the motion of the positioner. The working principle is illustrated, and the performance of the positioner is evaluated under atmospheric and vacuum conditions. Under atmospheric conditions, the positioner had a minimum step size of approximately 17 nm at 55 V, a maximum step size of approximately 1.6 μm, and a moving speed of approximately 4 μm/s at 138 V. However, the step size significantly decreased in vacuum. The step size can be controlled by adjusting the frictional forces on the magnetic feet. In addition, the positioner showed instability caused by the wear of the stainless plate. This problem was resolved by using a borosilicate glass that was fixed on the stainless plate, and the position accuracy was obviously improved.

  9. Alternative preparation of inclusion bodies excludes interfering non-protein contaminants and improves the yield of recombinant proinsulin.

    Science.gov (United States)

    Mackin, Robert B

    2014-01-01

    The goal of simple, high-yield expression and purification of recombinant human proinsulin has proven to be a considerable challenge. First, proinsulin forms inclusion bodies during bacterial expression. While this phenomenon can be exploited as a capture step, conventionally prepared inclusion bodies contain significant amounts of non-protein contaminants that interfere with subsequent chromatographic purification. Second, the proinsulin molecules within the inclusion bodies are incorrectly folded, and likely cross-linked to one another, making it difficult to quantify the amount of expressed proinsulin. Third, proinsulin is an intermediate between the initial product of ribosomal translation (preproinsulin) and the final product secreted by pancreatic beta cells (insulin). Therefore, to be efficiently produced in bacteria, it must be produced as an N-terminally extended fusion protein, which has to be converted to authentic proinsulin during the purification scheme. To address all three of these problems, while simultaneously streamlining the procedure and increasing the yield of recombinant proinsulin, we have made three substantive modifications to our previous method for producing proinsulin:.•Conditions for the preparation of inclusion bodies have been altered so contaminants that interfere with semi-preparative reversed-phase chromatography are excluded while the proinsulin fusion protein is retained at high yield.•Aliquots are taken following important steps in the procedure and the quantity of proinsulin-related polypeptide in the sample is compared to the amount present prior to that step.•Final purification is performed using a silica-based reversed-phase matrix in place of a polystyrene-divinylbenzene-based matrix.

  10. A recombinant Sal k 1 isoform as an alternative to the polymorphic allergen from Salsola kali pollen for allergy diagnosis.

    Science.gov (United States)

    Mas, Salvador; Boissy, Patrice; Monsalve, Rafael I; Cuesta-Herranz, Javier; Díaz-Perales, Araceli; Fernández, Javier; Colás, Carlos; Rodríguez, Rosalía; Barderas, Rodrigo; Villalba, Mayte

    2015-01-01

    The incidence of Amaranthaceae pollen allergy has increased due to the desertification occurring in many countries. In some regions of Spain, Salsola kali is the main cause of pollinosis, at almost the same level as olive and grass pollen. Sal k 1 - the sensitization marker of S. kali pollinosis - is used in clinical diagnosis, but is purified at a low yield from pollen. We aimed to produce a recombinant (r)Sal k 1 able to span the structural and immunological properties of the natural isoforms from pollen, and validate its potential use for diagnosis. Specific cDNA was amplified by PCR, cloned into the pET41b vector and used to transform BL21 (DE3) Escherichia coli cells. Immunoblotting, ELISA, basophil activation and skin-prick tests were used to validate the recombinant protein against Sal k 1 isolated from pollen. Sera and blood cells from S. kali pollen-sensitized patients and specific monoclonal and polyclonal antisera were used. rSal k 1 was produced in bacteria with a yield of 7.5 mg/l of cell culture. The protein was purified to homogeneity and structural and immunologically validated against the natural form. rSal k 1 exhibited a higher IgE cross-reactivity with plant-derived food extracts such as peanut, almond or tomato than with pollen sources such as Platanus acerifolia and Oleaceae members. rSal k 1 expressed in bacteria retains intact structural and immunological properties in comparison to the pollen-derived allergen. It spans the immunological properties of most of the isoforms found in pollen, and it might substitute natural Sal k 1 in clinical diagnosis. © 2015 S. Karger AG, Basel.

  11. Photodynamics of charge separation and recombination in solid alternating films of phthalocyanine or phthalocyanine-fullerene dyad and perylene dicarboximide

    NARCIS (Netherlands)

    Lehtivuori, Heli; Kumpulainen, Tatu; Hietala, Matti; Efimov, Alexander; Helge, Lemmetyinen; Kira, Aiko; Imahori, Hiroshi; Tkachenko, Nikolai V.

    2009-01-01

    Alternate bilayer structures of N,N'-bis(2,5-di-tert-butylphenyl)-3,4,9,10- perylene dicarboximide (PDI), freebase phthalocyanines (Pc), and double-linked free-base phthalocyanine-fullerene dyad (Pc-C 60) were prepared by the Langmuir-Schäfer method and studied using a range of optical spectroscopy

  12. A method for unbalanced transportation problems in fuzzy ...

    Indian Academy of Sciences (India)

    In this paper, we consider the fully fuzzy unbalanced transportation problem in which the total availability/production is more than the total demand and propose a method to solve it. Such problems are usually solved by adding a dummy destination. Since the dummy destination has no existence in reality, the excess ...

  13. A method for unbalanced transportation problems in fuzzy ...

    Indian Academy of Sciences (India)

    2School of Mathematics and Computer Applications, Thapar University,. Patiala 147 004, India e-mail: ... Saad & Abbas (2003) discussed an algorithm for solving the transportation problems in fuzzy environment. ... While solving unbalanced transportation problems we come across two type of cases. Either the total ...

  14. Inherited unbalanced structural chromosome abnormalities at prenatal chromosome analysis are rarely ascertained through recurrent miscarriage

    NARCIS (Netherlands)

    Franssen, M. T. M.; Korevaar, J. C.; Tjoa, W. M.; Leschot, N. J.; Bossuyt, P. M. M.; Knegt, A. C.; Suykerbuyk, R. F.; Hochstenbach, R.; van der Veen, F.; Goddijn, M.

    2008-01-01

    OBJECTIVE: To determine the mode of ascertainment of inherited unbalanced structural chromosome abnormalities detected at prenatal chromosome analysis. METHODS: From the databases of three centres for clinical genetics in the Netherlands, all cases of inherited unbalanced structural chromosome

  15. Inherited unbalanced structural chromosome abnormalities at prenatal chromosome analysis are rarely ascertained through recurrent miscarriage

    NARCIS (Netherlands)

    Franssen, M. T. M.; Korevaar, J. C.; Tjoa, W. M.; Leschot, N. J.; Bossuyt, P. M. M.; Knegt, A. C.; Suykerbuyk, R. F.; Hochstenbach, R.; van der Veen, F.; Goddijn, M.

    Objective To determine the mode of ascertainment of inherited unbalanced structural chromosome abnormalities detected at prenatal chromosome analysis. Methods From the databases of three centres for clinical genetics in the Netherlands, all cases of inherited unbalanced structural chromosome

  16. Processing of Signals from Fiber Bragg Gratings Using Unbalanced Interferometers

    Science.gov (United States)

    Adamovsky, Grigory; Juergens, Jeff; Floyd, Bertram

    2005-01-01

    Fiber Bragg gratings (FBG) have become preferred sensory structures in fiber optic sensing system. High sensitivity, embedability, and multiplexing capabilities make FBGs superior to other sensor configurations. The main feature of FBGs is that they respond in the wavelength domain with the wavelength of the returned signal as the indicator of the measured parameter. The wavelength is then converted to optical intensity by a photodetector to detect corresponding changes in intensity. This wavelength-to-intensity conversion is a crucial part in any FBG-based sensing system. Among the various types of wavelength-to-intensity converters, unbalanced interferometers are especially attractive because of their small weight and volume, lack of moving parts, easy integration, and good stability. In this paper we investigate the applicability of unbalanced interferometers to analyze signals reflected from Bragg gratings. Analytical and experimental data are presented.

  17. Classifier Performance Estimation with Unbalanced, Partially Labeled Data

    Science.gov (United States)

    2017-05-26

    IEEE TRANSACTIONS ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE, VOL. XX, NO. X, XXX 2017 1 Classifier Performance Estimation with Unbalanced...issues, accurate estimation of the performance of a detection or classification system is crucial to inform decisions based on the observations. This...paper presents a framework for estimating performance of a binary classifier in such a context. We focus on the scenario where each set of

  18. Recombinant clotting factors.

    Science.gov (United States)

    Pipe, Steven W

    2008-05-01

    The recombinant era for haemophilia began in the early 1980s with the cloning and subsequent expression of functional proteins for both factors VIII and IX. Efficient production of recombinant clotting factors in mammalian cell culture systems required overcoming significant challenges due to the complex post-translational modifications that were integral to their pro-coagulant function. The quick development and commercialization of recombinant clotting factors was, in part, facilitated by the catastrophic impact of viral contamination of plasma-derived clotting factor concentrates at the time. Since their transition into the clinic, the recombinant versions of both factor VIII and IX have proven to be remarkable facsimiles of their plasma-derived counterparts. The broad adoption of recombinant therapy throughout the developed world has significantly increased the supply of clotting factor concentrates and helped advance aggressive therapeutic interventions such as prophylaxis. The development of recombinant VIIa was a further advance bringing a recombinant option to haemophilia patients with inhibitors. Recombinant DNA technology remains the platform to address ongoing challenges in haemophilia care such as reducing the costs of therapy, increasing the availability to the developing world, and improving the functional properties of these proteins. In turn, the ongoing development of new recombinant clotting factor concentrates is providing alternatives for patients with other inherited bleeding disorders.

  19. The Largest Paracentric Inversion, The Highest Rate Of Recombinant Spermatozoa. Case Report: 46,Xy, Inv(2(Q21.2Q37.3 And Literature Review

    Directory of Open Access Journals (Sweden)

    C.C. Yapan

    2014-06-01

    Full Text Available Carriers of inversions involving euchromatic regions are at risk of having unbalanced offspring due to meiotic crossover. In carriers, recombination can occur during gametogenesis and cause genetically unbalanced sperm and subsequently unbalanced embryos. Here we present segregation analysis results of an infertile male with 46,XY,inv(2 (q21.2q37.3 using fluorescent in situ hybridization (FISH on sperm cells. This is the largest paracentric inversion (PAI reported so far in a meiotic segregation analysis study. Sperm FISH revealed 28.0% recombinant spermatozoa rate for chromosome 2, which was the highest rate in PAI carriers in the literature. Our results indicate a clear correlation between the size of the inverted segment and the frequency of the recombinant spermatozoa. The results of the FISH analysis with the information of unbalanced spermatozoa rate can provide accurate counseling on the genetic risk of infertility.

  20. Control Strategy for Microgrid Inverter under Unbalanced Grid Voltage Conditions

    DEFF Research Database (Denmark)

    Guo, Xiaoqiang; Liu, Wenzhao; Zhang, X.

    2014-01-01

    This paper presents the theoretical analysis of the inherent reason of current harmonic and power oscillation phenomena in case of operating the microgrid inverter under unbalanced grid voltage conditions. In order to flexibly control the current harmonic and power oscillation, a new stationary...... frame control strategy is proposed. It has a simple control structure due to no need of a phase-locked loop and voltage/current positive/negative sequence extraction calculation. The coordinate control of power and current quality is achieved, which enhances the operation performance of microgrid...

  1. Precise derating of three phase induction motors with unbalanced voltages

    International Nuclear Information System (INIS)

    Faiz, Jawad; Ebrahimpour, H.

    2007-01-01

    Performance analysis of three phase induction motors under supply voltage unbalance conditions is normally conducted using the well-known symmetrical components analysis. In this analysis, the voltage unbalance level at the terminals of the machine is assessed by means of the NEMA or IEC definitions. Both definitions lead to a relatively large error in predicting the performance of a machine. A method has recently been proposed in which, in addition to the voltage unbalance factor (VUF), the phase angle has been taken into account in the analysis. This means that the voltage unbalance factor is regarded as a complex value. This paper shows that although the use of the complex VUF reduces the computational error considerably, it is still high. This is proven by evaluating the derating factor of a three phase induction motor. A method is introduced to determine the derating factor precisely using the complex unbalance factor for an induction motor operating under any unbalanced supply condition. A practical case for derating of a typical three phase squirrel cage induction motor supplied by an unbalanced voltage is studied in the paper

  2. Three-Phase Harmonic Analysis Method for Unbalanced Distribution Systems

    Directory of Open Access Journals (Sweden)

    Jen-Hao Teng

    2014-01-01

    Full Text Available Due to the unbalanced features of distribution systems, a three-phase harmonic analysis method is essential to accurately analyze the harmonic impact on distribution systems. Moreover, harmonic analysis is the basic tool for harmonic filter design and harmonic resonance mitigation; therefore, the computational performance should also be efficient. An accurate and efficient three-phase harmonic analysis method for unbalanced distribution systems is proposed in this paper. The variations of bus voltages, bus current injections and branch currents affected by harmonic current injections can be analyzed by two relationship matrices developed from the topological characteristics of distribution systems. Some useful formulas are then derived to solve the three-phase harmonic propagation problem. After the harmonic propagation for each harmonic order is calculated, the total harmonic distortion (THD for bus voltages can be calculated accordingly. The proposed method has better computational performance, since the time-consuming full admittance matrix inverse employed by the commonly-used harmonic analysis methods is not necessary in the solution procedure. In addition, the proposed method can provide novel viewpoints in calculating the branch currents and bus voltages under harmonic pollution which are vital for harmonic filter design. Test results demonstrate the effectiveness and efficiency of the proposed method.

  3. Mitigation of Unbalanced Voltage Sags and Voltage Unbalance in CIGRE Low Voltage Distribution Network

    DEFF Research Database (Denmark)

    Mustafa, Ghullam; Bak-Jensen, Birgitte; Mahat, Pukar

    2013-01-01

    to unbalanced faults. The compensation of unbalanced voltage sags and voltage unbalance in the CIGRE distribution network is done by using the four STATCOM compensators already existing in the test grid. The simulations are carried out in DIgSILENT power factory software version 15.0....

  4. A Three-Phase Microgrid Restoration Model Considering Unbalanced Operation of Distributed Generation

    International Nuclear Information System (INIS)

    Wang, Zeyu; Wang, Jianhui; Chen, Chen

    2016-01-01

    Recent severe outages highlight the urgency of improving grid resiliency in the U.S. Microgrid formation schemes are proposed to restore critical loads after outages occur. Most distribution networks have unbalanced configurations that are not represented in sufficient detail by single-phase models. This study provides a microgrid formation plan that adopts a three-phase network model to represent unbalanced distribution networks. The problem formulation has a quadratic objective function with mixed-integer linear constraints. The three-phase network model enables us to examine the three-phase power outputs of distributed generators (DGs), preventing unbalanced operation that might trip DGs. Because the DG unbalanced operation constraint is non-convex, an iterative process is presented that checks whether the unbalanced operation limits for DGs are satisfied after each iteration of optimization. We also develop a relatively conservative linear approximation on the unbalanced operation constraint to handle larger networks. Compared with the iterative solution process, the conservative linear approximation is able to accelerate the solution process at the cost of sacrificing optimality to a limited extent. Simulation in the IEEE 34 node and IEEE 123 test feeders indicate that the proposed method yields more practical microgrid formations results. In addition, this paper explores the coordinated operation of DGs and energy storage (ES) installations. The unbalanced three-phase outputs of ESs combined with the relatively balanced outputs of DGs could supply unbalanced loads. In conclusion, the case study also validates the DG-ES coordination.

  5. Research on three-phase unbalanced distribution network reconfiguration strategy

    Science.gov (United States)

    Hu, Shuang; Li, Ke-Jun; Xu, Yanshun; Liu, Zhijie; Guo, Jing; Wang, Zhuodi

    2017-01-01

    With the development of social economy, the loads installed in the distribution network become more and more complex which may cause the three-phase unbalance problems. This paper proposes an optimal reconfiguration approach based on mixed integer quadric programming (MIQP) method to address the three-phase unbalance problem. It aims to minimize the total network losses of the system. By using several square constraints to substitute the circular constraint, the original optimization problem is linearized and converted into a mixed-integer linear programming (MILP) model. Then this MILP problem is solved in general algebraic model system (GAMS) software using CPLEX solver. The additional losses caused by three-phase unbalanced are also considered. An IEEE 34 nodes test system is used to demonstrate the feasibility and effectiveness of the proposed method. The results show that the losses and the voltage violation mitigation in the network can be reduced significantly.

  6. Three-Phase Unbalanced Load Flow Tool for Distribution Networks

    DEFF Research Database (Denmark)

    Demirok, Erhan; Kjær, Søren Bækhøj; Sera, Dezso

    2012-01-01

    This work develops a three-phase unbalanced load flow tool tailored for radial distribution networks based on Matlab®. The tool can be used to assess steady-state voltage variations, thermal limits of grid components and power losses in radial MV-LV networks with photovoltaic (PV) generators where...... most of the systems are single phase. New ancillary service such as static reactive power support by PV inverters can be also merged together with the load flow solution tool and thus, the impact of the various reactive power control strategies on the steady-state grid operation can be simply...... investigated. Performance of the load flow solution tool in the sense of resulting bus voltage magnitudes is compared and validated with IEEE 13-bus test feeder....

  7. Genetic Recombination

    Science.gov (United States)

    Whitehouse, H. L. K.

    1973-01-01

    Discusses the mechanisms of genetic recombination with particular emphasis on the study of the fungus Sordaria brevicollis. The study of recombination is facilitated by the use of mutants of this fungus in which the color of the ascospores is affected. (JR)

  8. Nuclear volume differences between balanced and unbalanced spermatozoa in chromosomal translocation carriers.

    Science.gov (United States)

    Rouen, Alexandre; Lavillaureix, Alinoë; Hyon, Capucine; Heide, Solveig; Clède, Sylvain; Balet, Richard; Kott, Esther; Cassuto, Nino Guy; Siffroi, Jean-Pierre

    2015-03-01

    While chromosomal translocations are usually associated with a normal phenotype, they can still cause male infertility as well as recurrent miscarriages and fetal malformations related to their transmission in an unbalanced state. The distinction between balanced and unbalanced spermatozoa on morphological criteria is still unfeasible. However, we previously showed that: i) spermatozoa with an unbalanced content have a higher rate of DNA fragmentation; and ii) that density gradient centrifugation partially separates balanced from unbalanced sperm cells. We hypothesized that a chromosomal imbalance could alter the fine spermatic nuclear architecture and consequently the condensation of DNA, thus modifying normal sperm density. Spermatic nuclear volumes in four translocation carriers were analyzed using confocal microscopy. Secondarily, FISH analysis was used to establish the segregation mode of each spermatozoon. We found the average spermatic nuclei size to be higher among unbalanced spermatozoa in all patients but one. All the unbalanced modes were associated with larger nuclei in two patients, while this was the case for the 3:1 mode only in the other two, suggesting an abnormal condensation. This could be the first step in elaborating a procedure to completely eliminate unbalanced spermatozoa from semen prior to in vitro fertilization. Copyright © 2014 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

  9. Analysis on the roundness of bulb turbine generator based on the unbalanced magnetic

    International Nuclear Information System (INIS)

    Li, Z G; Yang, F Y; Chen, J H; Si, G L

    2012-01-01

    Because of design, manufacture, installation and operation, there are some relatively eccentric in bulb tubular turbine units under operating condition. It easily caused uneven air gap, unbalanced magnetic field, unbalanced magnetic pull and torque. It could also increase the bending and torsion vibration of generator,at the same time, the roundness of stator and rotor would be aggravated which often caused by accidents such as generator sweep chamber. In this paper, basing on the design, installation and operation experience, the reasons of the unbalanced magnetic pull, mechanism and operation research were analyzed by theoretical calculation and the prototype test.

  10. Block urn design - a new randomization algorithm for sequential trials with two or more treatments and balanced or unbalanced allocation

    Science.gov (United States)

    Zhao, Wenle; Weng, Yanqiu

    2011-01-01

    Permuted block design is the most popular randomization method used in clinical trials, especially for trials with more than two treatments and unbalanced allocation, because of its consistent imbalance control and simplicity in implementation. However, the risk of selection biases caused by high proportion of deterministic assignments is a cause of concern. Efron’s biased coin design and Wei’s urn design provide better allocation randomness without deterministic assignments, but they do not consistently control treatment imbalances. Alternative randomization designs with improved performances have been proposed over the past few decades, including Soares and Wu’s big stick design, which has high allocation randomness, but is limited to two-treatment balanced allocation scenarios only, and Berger’s maximal procedure design which has a high allocation randomness and a potential for more general trial scenarios, but lacks the explicit function for the conditional allocation probability and is more complex to implement than most other designs. The block urn design proposed in this paper combines the advantages of existing randomization designs while overcoming their limitations. Statistical properties of the new algorithm are assessed and compared to currently available designs via analytical and computer simulation approaches. The results suggest that the block urn design simultaneously provides consistent imbalance control and high allocation randomness. It can be easily implemented for sequential clinical trials with two or more treatments and balanced or unbalanced allocation. PMID:21893215

  11. Superconducting niobium nitride films deposited by unbalanced magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Olaya, J.J. [Departamento de Ingenieria Mecanica y Mecatronica, Universidad Nacional de Colombia, Ciudad Universitaria, Carrera 30 Numero 45-03, Bogota (Colombia); Huerta, L. [Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, Circuito exterior s/n, CU Coyoacan, Mexico D.F. 04510 (Mexico); Rodil, S.E. [Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, Circuito exterior s/n, CU Coyoacan, Mexico D.F. 04510 (Mexico)], E-mail: ser42@iim.unam.mx; Escamilla, R. [Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, Circuito exterior s/n, CU Coyoacan, Mexico D.F. 04510 (Mexico)

    2008-10-01

    Niobium nitride (NbN) thin films were deposited under different configurations of the magnetic field using a magnetron sputtering system. The magnetic field configuration varied from balanced to unbalanced leading to different growth conditions and film properties. The aim of the paper was to identify correlations between deposition conditions, film properties and the electrical properties, specially the superconductive critical temperature (T{sub C}). The results suggested that there is a critical deposition condition, having an optimum ion-atom arrival ratio that promotes a well ordered and textured nanocrystalline structure (cubic phase) with the minimum residual stress and only under this condition a high critical temperature (16K) was obtained. Lower T{sub C} values around 12K were obtained for the NbN samples having a lower degree of structural perfection and texture, and a larger fraction of intergranular voids. On the other hand, analysis of valence-band spectra showed that the contribution of the Nb 4d states remained essentially constant while the higher T{sub C} was correlated to a higher contribution of the N 2p states.

  12. Superconducting niobium nitride films deposited by unbalanced magnetron sputtering

    International Nuclear Information System (INIS)

    Olaya, J.J.; Huerta, L.; Rodil, S.E.; Escamilla, R.

    2008-01-01

    Niobium nitride (NbN) thin films were deposited under different configurations of the magnetic field using a magnetron sputtering system. The magnetic field configuration varied from balanced to unbalanced leading to different growth conditions and film properties. The aim of the paper was to identify correlations between deposition conditions, film properties and the electrical properties, specially the superconductive critical temperature (T C ). The results suggested that there is a critical deposition condition, having an optimum ion-atom arrival ratio that promotes a well ordered and textured nanocrystalline structure (cubic phase) with the minimum residual stress and only under this condition a high critical temperature (16K) was obtained. Lower T C values around 12K were obtained for the NbN samples having a lower degree of structural perfection and texture, and a larger fraction of intergranular voids. On the other hand, analysis of valence-band spectra showed that the contribution of the Nb 4d states remained essentially constant while the higher T C was correlated to a higher contribution of the N 2p states

  13. A Balanced Perspective on Unbalanced Growth and Thymineless Death

    Directory of Open Access Journals (Sweden)

    Philip C. Hanawalt

    2015-06-01

    Full Text Available The early history of the esoteric phenomenon of thymineless death (TLD is recounted, from the pioneering discovery by Seymour Cohen and Hazel Barner, through my graduate studies at Yale and postdoctoral research in Copenhagen. My principal contribution was the discovery that restricted synthesis of protein and RNA permits cultures of Escherichia coli to complete their DNA replication cycles without initiating new ones, and that cells held in this physiological state are immune to the lethality of thymine deprivation; unbalanced growth is not the fundamental cause of TLD. The successful synchronization of the DNA replication cycle contributed to formulation of the replicon concept. Studies at Stanford revealed a specific requirement for transcription and led to the discovery of a TLD-resistant mutant in a new gene, termed recQ, with important homologs in humans and most other organisms. The lessons learned from research on TLD underscore the value of basic research in bacterial systems that can have profound implications for human health.

  14. Assembly and use of high-density recombinant peptide chips for large-scale ligand screening is a practical alternative to synthetic peptide libraries.

    Science.gov (United States)

    Hundsberger, Harald; Önder, Kamil; Schuller-Götzburg, Peter; Virok, Dezso P; Herzog, Julia; Rid, Raphaela

    2017-06-08

    Recombinant peptide chips could constitute a versatile complementation to state-of-the-art in situ (chemical on-chip) synthesis, particle-based printing, or pre-manufactured peptide spotting. Bottlenecks still impeding a routine implementation - from restricted peptide lengths, low diversity and low array densities to high costs - could so be overcome. To assess overall performance, we assembled recombinant chips composed of 38,400 individual peptide spots on the area of a standard 96-well microtiter plate from comprehensive, highly diverse (>107 single clones) short random peptide libraries. Screening of altogether 476,160 clones against Streptavidin uncovered 2 discrete new binders: a characteristic HPQ-motif containing VSHPQAPF and a cyclic CSGSYGSC peptide. Interactions were technically confirmed by fluorescence polarization as well as biolayer-interferometry, and their potential suitability as novel detection tags evaluated by detection of a peptide-fused exemplary test protein. From our data we conclude that the presented technical pipeline can reliably identify novel hits, useful as first-generation binders or templates for subsequent ligand design plus engineering.

  15. Dynamic Models of Instruments Using Rotating Unbalanced Masses

    Science.gov (United States)

    Hung, John Y.; Gallaspy, Jason M.; Bishop, Carlee A.

    1998-01-01

    The motion of telescopes, satellites, and other flight bodies have been controlled by various means in the past. For example, gimbal mounted devices can use electric motors to produce pointing and scanning motions. Reaction wheels, control moment gyros, and propellant-charged reaction jets are other technologies that have also been used. Each of these methods has its advantages, but all actuator systems used in a flight environment face the challenges of minimizing weight, reducing energy consumption, and maximizing reliability. Recently, Polites invented and patented the Rotating Unbalanced Mass (RUM) device as a means for generation scanning motion on flight experiments. RUM devices together with traditional servomechanisms have been successfully used to generate various scanning motions: linear, raster, and circular. The basic principle can be described: A RUM rotating at constant angular velocity exerts a cyclic centrifugal force on the instrument or main body, thus producing a periodic scanning motion. A system of RUM devices exerts no reaction forces on the main body, requires very little energy to rotate the RUMS, and is simple to construct. These are significant advantages over electric motors, reaction wheels, and control moment gyroscopes. Although the RUM device very easily produces scanning motion, an auxiliary control system has been required to maintain the proper orientation, or pointing of the main body. It has been suggested that RUM devices can be used to control pointing dynamics, as well as generate the desired periodic scanning motion. The idea is that the RUM velocity will not be kept constant, but will vary over the period of one RUM rotation. The thought is that the changing angular velocity produces a centrifugal force having time-varying magnitude and direction. The scope of this ongoing research project is to study the pointing control concept, and recommend a direction of study for advanced pointing control using only RUM devices. This

  16. Design of Solar PV Cell Based Inverter for Unbalanced and Distorted Industrial Loads

    Directory of Open Access Journals (Sweden)

    Naga Ananth D

    2015-04-01

    Full Text Available PV cell is getting importance in low and medium power generation due to easy installation, low maintenance and subsidies in price from respective nation. Most of the loads in distribution system are unbalanced and distorted, due to which there will be unbalanced voltage and current occur at load and may disturb its overall performance. Due to these loads voltage unbalance, distorted voltage and current and variable power factors in each phase can be observed. An efficient algorithm to mitigate unbalanced and distorted load and source voltage and current in solar photo voltaic (PV inverter for isolated load system was considered. This solar PV system can be applicable to remote located industrial loads like heating, welding and small arc furnace type distorted loads and also for unbalanced loads. The PV inverter is designed such that it will maintain nearly constant voltage magnitude and can mitigate harmonics in voltage and current near the load terminals. A MATLAB/ SIMULINK based solar PV inverter was simulated and results are compared with standard AC three phase grid connected system. The proposed shows that the inverter is having very less voltage and current harmonic content and can maintain nearly constant voltage profile for highly unbalanced system.

  17. Empirical Statistical Power for Testing Multilocus Genotypic Effects under Unbalanced Designs Using a Gibbs Sampler

    Directory of Open Access Journals (Sweden)

    Chaeyoung Lee

    2012-11-01

    Full Text Available Epistasis that may explain a large portion of the phenotypic variation for complex economic traits of animals has been ignored in many genetic association studies. A Baysian method was introduced to draw inferences about multilocus genotypic effects based on their marginal posterior distributions by a Gibbs sampler. A simulation study was conducted to provide statistical powers under various unbalanced designs by using this method. Data were simulated by combined designs of number of loci, within genotype variance, and sample size in unbalanced designs with or without null combined genotype cells. Mean empirical statistical power was estimated for testing posterior mean estimate of combined genotype effect. A practical example for obtaining empirical statistical power estimates with a given sample size was provided under unbalanced designs. The empirical statistical powers would be useful for determining an optimal design when interactive associations of multiple loci with complex phenotypes were examined.

  18. Improved delayed signal cancellation-based SRF-PLL for unbalanced grid

    DEFF Research Database (Denmark)

    Messo, Tuomas; Sihvo, Jussi; Yang, Dongsheng

    2017-01-01

    the delayed signal cancellation-based method (DSC), have been proposed to alleviate the detrimental effect of unbalance. This paper proposes an improvement to a delayed signal cancellation based synchronization algorithm for unbalanced grids. The proposed PLL structure employs only half of the delay required...... implemented in synchronous and stationary reference frames. The proposed PLL is shown to obtain significantly smaller settling time in the estimated grid angle and frequency, after a symmetrical phase angle jump in the grid voltages and sudden appearance of an unbalanced fault. A small-signal model is also......Problems with power quality in the grid have gained a lot of attention recently due to rapid increase in the amount of grid-connected power converters. The converter should produce sinusoidal currents also during abnormal conditions, such as unbalanced grid voltages. Several methods, like...

  19. Discontinuous gradient centrifugation (DGC) decreases the proportion of chromosomally unbalanced spermatozoa in chromosomal rearrangement carriers.

    Science.gov (United States)

    Rouen, Alexandre; Balet, Richard; Dorna, Maud; Hyon, Capucine; Pollet-Villard, Xavier; Chantot-Bastaraud, Sandra; Joyé, Nicole; Portnoï, Marie-France; Cassuto, Nino Guy; Siffroi, Jean-Pierre

    2013-07-01

    Can the proportion of unbalanced spermatozoa in chromosomal rearrangement carriers be decreased through the use of discontinuous gradient centrifugation (DGC)? DGC significantly decreases the proportion of genetically unbalanced spermatozoa in chromosomal rearrangement carriers. Chromosomal rearrangement carriers present with a certain proportion of unbalanced gametes, which can lead to miscarriages or malformations in the offspring. There is presently no known way to select the balanced spermatozoa and use them for IVF. The proportion of unbalanced spermatozoa after DGC was compared with that before DGC in 21 patients with a chromosomal rearrangement. At least 500 spermatozoa were analysed per observation. Twenty-one male patients with a chromosomal rearrangement were included in this prospective study. They initially consulted for infertility, recurrent miscarriages or a history of abnormal pregnancy. The samples were split into two, with one part undergoing DGC and the other being immediately fixed. Fluorescence in situ hybridization was performed to establish the chromosome segregation pattern of each spermatozoon. DGC significantly decreased the proportion of unbalanced spermatozoa in all but 1 of the 21 chromosomal rearrangement carriers (P < 0.05). Although DGC reduces the proportion of unbalanced spermatozoa in ejaculates from patients with chromosome rearrangements this elimination is only partial and some abnormal spermatozoa remain. Means to exclude these spermatozoa to ensure that only balanced ones are used in IVF remain to be discovered. The motility and morphology of the sperm before and after DGC were not measured. Used in IVF or intrauterine insemination, DGC could decrease the chance that a man carrying a chromosomal rearrangement will father an abnormal fetus.

  20. Optimal reconfiguration and DG allocation in balanced and unbalanced distribution systems

    Directory of Open Access Journals (Sweden)

    Seyed Abbas Taher

    2014-09-01

    Full Text Available This paper investigates feeder reconfiguration in balanced and unbalanced networks and presents an efficient method to optimize practical distribution systems by means of simultaneous reconfiguration and distributed generation (DG allocation. A precise and robust load flow algorithm is applied and a composite multi-objective function is formulated to solve the problem which includes: 1. power loss saving, 2. voltage profile, 3. voltage unbalance, and 4. current unbalance of the system. The genetic algorithm (GA is utilized to search for optimal solution. Results show significant reduction in power loss and number of voltage violations. Moreover, in unbalanced cases, ability of proposed method in three-phase balancing is demonstrated.

  1. Grid-forming VSC control in four-wire systems with unbalanced nonlinear loads

    DEFF Research Database (Denmark)

    Lliuyacca, Ruben; Mauricioa, Juan M.; Gomez-Exposito, Antonio

    2017-01-01

    A grid-forming voltage source converter (VSC) is responsible to hold voltage and frequency in autonomous operation of isolated systems. In the presence of unbalanced loads, a fourth leg is added to provide current path for neutral currents. In this paper, a novel control scheme for a four-leg VSC...... feeding unbalanced linear and nonlinear loads is proposed. The control is based on two control blocks. A main control commands the switching sequence to the three-phase VSC ensuring balanced three-phase voltage at the output; and an independent control to the fourth leg drives neutral currents that might...

  2. Synchronization of grid-connected renewable energy sources under highly distorted voltages and unbalanced grid faults

    DEFF Research Database (Denmark)

    Hadjidemetriou, Lenos; Kyriakides, Elias; Blaabjerg, Frede

    2013-01-01

    and dynamic synchronization of the interconnected renewable energy system under unbalanced grid faults and under highly harmonic distorted voltage. The outstanding performance of the suggested PLL is achieved by implementing an innovative multi-sequence/harmonic decoupling cell in order to dynamically cancel...... renewable energy systems. Therefore, the performance of the new PLL can increase the quality of the injected power under abnormal conditions and in addition enable the renewable energy systems to provide the appropriate support to the grid under balanced and unbalanced grid faults....

  3. Flexible Control Strategy for Grid-Connected Inverter under Unbalanced Grid Faults without PLL

    DEFF Research Database (Denmark)

    Guo, Xiaoqiang; Liu, W.; Zhang, X.

    2015-01-01

    Power oscillation and current quality are the important performance targets for the grid-connected inverter under unbalanced grid faults. Firstly, the inherent reason for the current harmonic and power oscillation of the inverter is discussed with a quantitative analysis. Secondly, a new control...... strategy is proposed to achieve the coordinate control of power and current quality without the need for a phase-locked loop or voltage/current positive/negative sequence extraction calculation. Finally, the experimental tests are conducted under unbalanced grid faults, and the results verify...

  4. Investigation of Unbalanced Magnetic Force in Magnetic Geared Machine Using Analytical Methods

    DEFF Research Database (Denmark)

    Zhang, Xiaoxu; Liu, Xiao; Chen, Zhe

    2016-01-01

    The electromagnetic structure of the magnetic geared machine (MGM) may induce a significant unbalanced magnetic force (UMF). However, few methods have been developed to theoretically reveal the essential reasons for this issue in the MGM. In this paper, an analytical method based on an air...

  5. Assessing Losses of Power and Electrical Energy in Unbalanced Medium Voltage Distribution Networks

    Directory of Open Access Journals (Sweden)

    Toader C.

    2016-12-01

    Full Text Available The work is dedicated to calculating electricity losses related to power lines average voltage overhead or underground, which in terms of construction can be three-phase (three or four wire in unbalanced sinusoidal harmonic, determining energy efficiency indicators (such as positive and negative factors of unbalance thereof. It examines a case study and argues the results.

  6. Robust Current Control of Doubly Fed Wind Turbine Generator under Unbalanced Grid Voltage Conditions

    DEFF Research Database (Denmark)

    Wang, Yun; Gong, Wenming; Wu, Qiuwei

    2014-01-01

    This paper presents the design of a H ∞ current controller for doubly fed induction generators (DFIGs) in order to maintain stable operation under unbalanced voltage conditions. The H ∞ current controller has a multi-input and multi-output (MIMO) structure and is designed using the loop shaping...

  7. Two unbalanced segregation products due to a maternal t(7;16)inv(16)

    NARCIS (Netherlands)

    Leegte, B; Sikkema-Raddatz, B; Hordijk, R; Davelaar, [No Value; Cobben, J; van der Veen, A.

    We report a prenatal case of a maternally inherited abnormal chromosome 16, originally interpreted as a pericentric inversion only, but after family studies re-interpreted as a pericentric inversion (16) accompanied by an unbalanced (7;16) translocation. Because of the inversion 16 and an elder son

  8. Compensation of Unbalanced Three-Phase Voltage Supply in Voltage Source Inverter

    Czech Academy of Sciences Publication Activity Database

    Chomát, Miroslav; Schreier, Luděk

    2003-01-01

    Roč. 48, č. 2 (2003), s. 113-128 ISSN 0001-7043 R&D Projects: GA ČR GA102/02/0554 Institutional research plan: CEZ:AV0Z2057903 Keywords : unbalanced voltage supply * power factor correction * DC-link current pulsations Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  9. Distributed Strategy for Optimal Dispatch of Unbalanced Three-Phase Islanded Microgrids

    DEFF Research Database (Denmark)

    Vergara Barrios, Pedro Pablo; Rey-López, Juan Manuel; Shaker, Hamid Reza

    2018-01-01

    are considered for the DG units: a voltage control mode (VCM), with an active droop control loop, and a power control mode (PCM), which allows setting the output power in advance. To assess the effectiveness and flexibility of the proposed approach, simulations were performed in a 25-bus unbalanced three...

  10. Grid Voltage Modulated Control of Grid-Connected Voltage Source Inverters under Unbalanced Grid Conditions

    DEFF Research Database (Denmark)

    Li, Mingshen; Gui, Yonghao; Quintero, Juan Carlos Vasquez

    2017-01-01

    In this paper, an improved grid voltage modulated control (GVM) with power compensation is proposed for grid-connected voltage inverters when the grid voltage is unbalanced. The objective of the proposed control is to remove the power ripple and to improve current quality. Three power compensation...

  11. A parametric study on unbalanced three phase islanded microgrids with inverter interfaced units

    DEFF Research Database (Denmark)

    Sanseverino, Eleonora Riva; Quang, Ninh Nguyen; Zizzo, Gaetano

    2013-01-01

    In this paper, the solution of the power flow for unbalanced three phase microgrids systems is proposed. The study aims at the integration of inverter interfaced units using the control law used for primary voltage and frequency regulation, so as to take into account possible small variations...

  12. High Order Sliding Mode Control of Doubly-fed Induction Generator under Unbalanced Grid Faults

    DEFF Research Database (Denmark)

    Zhu, Rongwu; Chen, Zhe; Wu, Xiaojie

    2013-01-01

    This paper deals with a doubly-fed induction generator-based (DFIG) wind turbine system under grid fault conditions such as: unbalanced grid voltage, three-phase grid fault, using a high order sliding mode control (SMC). A second order sliding mode controller, which is robust with respect...

  13. Analysis of PM Magnetization Field Effects on the Unbalanced Magnetic Forces due to Rotor Eccentricity in BLDC Motors

    Directory of Open Access Journals (Sweden)

    S. Mahdiuon-Rad

    2013-08-01

    Full Text Available This paper investigates both static and dynamic eccentricities in single phase brushless DC (BLDC motors and analyzes the effect of the PM magnetization field on unbalanced magnetic forces acting on the rotor. Three common types of PM magnetization field patterns including radial, parallel and sinusoidal magnetizations are considered. In both static and dynamic eccentricities, harmonic components of the unbalanced magnetic forces on the rotor are extracted and analyzed. Based on simulation results, the magnetization fields that produce the lowest and highest unbalanced magnetic forces are determined in rotor eccentricity conditions.

  14. Tracking performance of unbalanced QPSK demodulators. I - Biphase Costas loop with passive arm filters

    Science.gov (United States)

    Simon, M. K.; Alem, W. K.

    1978-01-01

    Unbalanced quadriphase-shift-keying (QPSK) is an attractive means for transmitting two digital data streams which in general have different average powers, data rates, and data formats. Previous analyses of the tracking performance of Costas loop demodulators of unbalanced QPSK have accounted only for the filtering effect produced by the loop's two arm filters on the equivalent additive noise perturbing the loop. When the bandwidth of these filters is selected on the basis of the order of the data rate, as is typical of optimum Costas loop design, the filtering degradations of the data modulations themselves and the cross-modulation noise produced by their multiplication in the loop often cannot be neglected. The purpose of this paper is to incorporate these additional filtering effects into the analysis. Many of the results obtained herein are in the form of closed-form expressions which can easily be evaluated numerically for design and performance prediction purposes.

  15. What drives health care expenditure?--Baumol's model of 'unbalanced growth' revisited.

    Science.gov (United States)

    Hartwig, Jochen

    2008-05-01

    The share of health care expenditure in GDP rises rapidly in virtually all OECD countries, causing increasing concern among politicians and the general public. Yet, economists have to date failed to reach an agreement on what the main determinants of this development are. This paper revisits Baumol's [Baumol, W.J., 1967. Macroeconomics of unbalanced growth: the anatomy of urban crisis. American Economic Review 57 (3), 415-426] model of 'unbalanced growth', showing that the latter offers a ready explanation for the observed inexorable rise in health care expenditure. The main implication of Baumol's model in this context is that health care expenditure is driven by wage increases in excess of productivity growth. This hypothesis is tested empirically using data from a panel of 19 OECD countries. Our tests yield robust evidence in favor of Baumol's theory.

  16. Hysteresis current control technique of VSI for compensation of grid-connected unbalanced loads

    DEFF Research Database (Denmark)

    Pouresmaeil, Edris; Akorede, Mudathir Funsho; Montesinos-Miracle, Daniel

    2014-01-01

    interconnection issues that usually arise as DG units connect to the electric grid. The proposed strategy, implemented in Matlab/Simulink environment in different operating scenarios, provides compensation for active, reactive, unbalanced, and harmonic current components of grid-connected nonlinear unbalanced......The global trends nowadays in the power generation industry are to supplement the electricity production using distributed generation (DG) technologies based on renewable energy resources such as photovoltaic, wind power, etc. However, failure to properly control the operation of distributed energy...... resources as they connect to the exiting power grid could provoke many power quality problems on the grid side. For this reason, due considerations must be given to power generation and safe running before DG units is actually integrated into the power grid. The main aim of this paper is to address the grid...

  17. Unbalanced voltage faults: the impact on structural loads of doubly fed asynchronous generator wind turbines

    DEFF Research Database (Denmark)

    Barahona Garzón, Braulio; Cutululis, Nicolaos Antonio; Hansen, Anca Daniela

    2014-01-01

    , and control dynamics in an integrated simulation environment based on an aeroelastic code (HAWC2) and software for control design (Matlab/Simulink). In the present analysis, 1 Hz equivalent loads are used to compare fatigue loads, whereas maximum–minimum values are used to compare extreme loads. A control......This paper investigates the impact that unbalanced voltage faults have on wind turbine structural loads. In such cases, electromagnetic torque oscillations occur at two times the supply voltage frequency. The objectives of this work are to quantify wind turbine structural loads induced...... by unbalanced voltage faults relative to those during normal operation; and to evaluate the potential for reducing structural loads with the control of the generator. The method applied is integrated dynamic analysis. Namely, dynamic analysis with models that consider the most important aeroelastic, electrical...

  18. A Parallel Biological Optimization Algorithm to Solve the Unbalanced Assignment Problem Based on DNA Molecular Computing

    Directory of Open Access Journals (Sweden)

    Zhaocai Wang

    2015-10-01

    Full Text Available The unbalanced assignment problem (UAP is to optimally resolve the problem of assigning n jobs to m individuals (m < n, such that minimum cost or maximum profit obtained. It is a vitally important Non-deterministic Polynomial (NP complete problem in operation management and applied mathematics, having numerous real life applications. In this paper, we present a new parallel DNA algorithm for solving the unbalanced assignment problem using DNA molecular operations. We reasonably design flexible-length DNA strands representing different jobs and individuals, take appropriate steps, and get the solutions of the UAP in the proper length range and O(mn time. We extend the application of DNA molecular operations and simultaneity to simplify the complexity of the computation.

  19. Modulation of Pulse Train Using Leapfrogging Pulses Developed in Unbalanced Coupled Nonlinear Transmission Lines

    Directory of Open Access Journals (Sweden)

    Koichi Narahara

    2018-01-01

    Full Text Available The leapfrogging pulses in two unbalanced electrical nonlinear transmission lines (NLTLs with capacitive couplings are investigated for efficient modulation of a pulse train. Due to the resonant interactions, the nonlinear solitary waves in the NLTLs exhibit complementary behaviors of amplitudes and phases called leapfrogging. For maximizing resonance, both solitary waves should have a common average velocity. Sharing the common velocity, the characteristic impedance can still be freely designed for two coupled solitary waves. In this study, we characterize the leapfrogging pulses developed in unbalanced NLTLs having distinct characteristic impedance. Through the soliton perturbation theory and numerical time-domain calculations, it is found that both the leapfrogging frequency and the voltage variations of pulse amplitudes increase as the difference in the characteristic impedance becomes large. These properties can improve the on/off ratio of modulated pulse train.

  20. Passivity-Based Control of a Doubly Fed Induction Generator System under Unbalanced Grid Voltage Conditions

    Directory of Open Access Journals (Sweden)

    Jiawei Huang

    2017-08-01

    Full Text Available According to the theory of passivity-based control (PBC, this paper establishes a port-controlled Hamiltonian system with dissipation (PCHD model for a doubly fed induction generator (DFIG system under unbalanced grid voltage conditions and proposes a method of interconnection and damping assignment passivity-based control (IDA-PBC of the system under such conditions. By using this method, the rotor-side converter and grid-side converter can be controlled simultaneously in order to improve fault ride-through capability of the DFIG system. Simulation results indicate that this IDA-PBC strategy effectively suppresses fluctuations of output current and power in the DFIG system during unbalanced grid voltage sag/swell, enhances dynamic performance, and improves the robustness of the system.

  1. Investigation of Grid-connected Voltage Source Converter Performance under Unbalanced Faults

    DEFF Research Database (Denmark)

    Jia, Jundi; Yang, Guangya; Nielsen, Arne Hejde

    2016-01-01

    Renewable energy sources (RES) and HVDC links are typically interfaced with the grid by power converters, whose performance during grid faults is significantly different from that of traditional synchronous generators. This paper investigates the performance of grid-connected voltage source...... converters (VSCs) under unbalanced faults. Conventional positive-sequence synchronous reference frame (SRF) control is presented first, followed by three different negative-sequence current control strategies considering reactive power injection and converter current limit. The simulation results indicate...... that the performance of VSCs varies with their control strategies. Negative-sequence current control is necessary to restrict converter current in each phase under unbalanced faults. Among presented control strategies, the balanced current control strategy complies with the present voltage support requirement best...

  2. DC-link voltage oscillations reduction during unbalanced grid faults for high power wind turbines

    DEFF Research Database (Denmark)

    Delpino, Hernan Anres Miranda; Teodorescu, Remus; Rodriguez, Pedro

    2011-01-01

    During unbalanced grid voltage faults the Power injected to the grid experiences 100Hz oscillations as a result of interactions between positive and negative sequence components of three-phase voltages and currents. These oscillations can become as high as %50 percent of the rated power. In this ......During unbalanced grid voltage faults the Power injected to the grid experiences 100Hz oscillations as a result of interactions between positive and negative sequence components of three-phase voltages and currents. These oscillations can become as high as %50 percent of the rated power....... In this article an improved controller is proposed which present different behavior during normal operation and faults to keep track of non-sinusoidal current reference signals. The reference signals are calculated to obtain zero power oscillations. Reconfigurable resonant controllers are used for this purpose...

  3. Ensemble Genetic Fuzzy Neuro Model Applied for the Emergency Medical Service via Unbalanced Data Evaluation

    Directory of Open Access Journals (Sweden)

    Muammar Sadrawi

    2018-03-01

    Full Text Available Equally partitioned data are essential for prediction. However, in some important cases, the data distribution is severely unbalanced. In this study, several algorithms are utilized to maximize the learning accuracy when dealing with a highly unbalanced dataset. A linguistic algorithm is applied to evaluate the input and output relationship, namely Fuzzy c-Means (FCM, which is applied as a clustering algorithm for the majority class to balance the minority class data from about 3 million cases. Each cluster is used to train several artificial neural network (ANN models. Different techniques are applied to generate an ensemble genetic fuzzy neuro model (EGFNM in order to select the models. The first ensemble technique, the intra-cluster EGFNM, works by evaluating the best combination from all the models generated by each cluster. Another ensemble technique is the inter-cluster model EGFNM, which is based on selecting the best model from each cluster. The accuracy of these techniques is evaluated using the receiver operating characteristic (ROC via its area under the curve (AUC. Results show that the AUC of the unbalanced data is 0.67974. The random cluster and best ANN single model have AUCs of 0.7177 and 0.72806, respectively. For the ensemble evaluations, the intra-cluster and the inter-cluster EGFNMs produce 0.7293 and 0.73038, respectively. In conclusion, this study achieved improved results by performing the EGFNM method compared with the unbalanced training. This study concludes that selecting several best models will produce a better result compared with all models combined.

  4. Multiscale interpretation of taut string estimation and its connection to Unbalanced Haar wavelets

    OpenAIRE

    Cho, Haeran; Fryzlewicz, Piotr

    2016-01-01

    We compare two state-of-the-art non-linear techniques for nonparametric function estimation via piecewise constant approximation: the taut string and the Unbalanced Haar methods. While it is well-known that the latter is multiscale, it is not obvious that the former can also be interpreted as multiscale. We provide a unified multiscale representation for both methods, which offers an insight into the relationship between them as well as suggesting lessons both methods can learn from each other.

  5. Unbalanced Bilinguals’ Asymmetric Associations Between L2 Words for Taxonomic Categories of Basic and Superordinate Levels

    Directory of Open Access Journals (Sweden)

    Bohua Chen

    2016-03-01

    Full Text Available The revised hierarchical model seems different from the distributed conceptual feature model in predicting how unbalanced bilinguals would be aware of semantic relations between words for taxonomic categories of basic level (exemplar words and words for those of superordinate level (category names in L2. We did a series of four experiments to compare unbalanced bilinguals’ awareness of conceptual relations between exemplar words and between exemplar words and category names in their first (L1 and second language (L2. A priming task of semantic categorization was adopted, and the participants were 72 college students, who began to learn L2 in classroom settings at a late age and achieved an L2 proficiency between intermediate and advanced levels. The reaction times indicated that the participants could automatically process not only the exemplar-word but also the category-name primes in L2. Activations of semantic representations for the category names in L2 seemed to spread to those for the exemplar words in L1 and L2, but activations of semantic presentations for the exemplar words in L2 spread only to those for the example words in L1 for the participants. It was concluded that unbalanced bilinguals appear to have developed asymmetric associations between category names and exemplar words in L2. The implication is that L2 learners should learn L2 words mainly by means of using the language and not taking rote memory of isolated words.

  6. A control strategy for grid-side converter of DFIG under unbalanced condition based on Dig SILENT/Power Factory

    Science.gov (United States)

    Han, Pingping; Zhang, Haitian; Chen, Lingqi; Zhang, Xiaoan

    2018-01-01

    The models of doubly fed induction generator (DFIG) and its grid-side converter (GSC) are established under unbalanced grid condition based on DIgSILENT/PowerFactory. According to the mathematical model, the vector equations of positive and negative sequence voltage and current are deduced in the positive sequence synchronous rotating reference frame d-q-0 when the characteristics of the simulation software are considered adequately. Moreover, the reference value of current component of GSC in the positive sequence frame d-q-0 under unbalanced condition can be obtained to improve the traditional control of GSC when the national issue of unbalanced current limits is combined. The simulated results indicate that the control strategy can restrain negative sequence current and the two times frequency power wave of GSC’s ac side effectively. The voltage of DC bus can be maintained a constant to ensure the uninterrupted operation of DFIG under unbalanced grid condition eventually.

  7. Balance control of grid currents for UPQC under unbalanced loads based on matching-ratio compensation algorithm

    DEFF Research Database (Denmark)

    Zhao, Xiaojun; Zhang, Chunjiang; Chai, Xiuhui

    2018-01-01

    In three-phase four-wire systems, unbalanced loads can cause grid currents to be unbalanced, and this may cause the neutral point potential on the grid side to shift. The neutral point potential shift will worsen the control precision as well as the performance of the threephase four-wire unified...... power quality conditioner (UPQC), and it also leads to unbalanced three-phase output voltage, even causing damage to electric equipment. To deal with unbalanced loads, this paper proposes a matching-ratio compensation algorithm (MCA) for the fundamental active component of load currents......, and by employing this MCA, balanced three-phase grid currents can be realized under 100% unbalanced loads. The steady-state fluctuation and the transient drop of the DC bus voltage can also be restrained. This paper establishes the mathematical model of the UPQC, analyzes the mechanism of the DC bus voltage...... fluctuations, and elaborates the interaction between unbalanced grid currents and DC bus voltage fluctuations; two control strategies of UPQC under three-phase stationary coordinate based on the MCA are given, and finally, the feasibility and effectiveness of the proposed control strategy are verified...

  8. Serially-Connected Compensator for Eliminating the Unbalanced Three-Phase Voltage Impact on Wind Turbine Generators: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Z.; Hsu, P.; Muljadi, E.; Gao, W.

    2015-04-06

    Untransposed transmission lines, unbalanced tap changer operations, and unbalanced loading in weak distribution lines can cause unbalanced-voltage conditions. The resulting unbalanced voltage at the point of interconnection affects proper gird integration and reduces the lifetime of wind turbines due to power oscillations, torque pulsations, mechanical stresses, energy losses, and uneven and overheating of the generator stator winding. This work investigates the dynamic impact of unbalanced voltage on the mechanical and electrical components of integrated Fatigue, Aerodynamics, Structures, and Turbulence (FAST) wind turbine generation systems (WTGs) of Type 1 (squirrel-cage induction generator) and Type 3 (doubly-fed induction generator). To alleviate this impact, a serially-connected compensator for a three-phase power line is proposed to balance the wind turbine-side voltage. Dynamic simulation studies are conducted in MATLAB/Simulink to compare the responses of these two types of wind turbine models under normal and unbalanced-voltage operation conditions and demonstrate the effectiveness of the proposed compensator.

  9. A Modular Cascaded Multilevel Inverter Based Shunt Hybrid Active Power Filter for Selective Harmonic and Reactive Power Compensation Under Distorted/Unbalanced Grid Voltage Conditions

    Directory of Open Access Journals (Sweden)

    T. Demirdelen

    2016-10-01

    Full Text Available In recent years, shunt hybrid active power filters are being increasingly considered as a viable alternative to both passive filters and active power filters for compensating harmonics. In literature, their applications are restricted to balanced systems and low voltage applications and therefore not for industrial applications. This paper investigates the performance of a modular cascaded multilevel inverter based Shunt Hybrid Active Power Filter (SHAPF for reactive power compensation and selective harmonics elimination under distorted/unbalanced grid voltage conditions in medium voltage levels. In the proposed control method, reactive power compensation is achieved successfully with a perceptible amount and the performance results of harmonic compensation are satisfactory. Theoretical analysis and simulation results are obtained from an actual industrial network model in PSCAD. The simulation results are presented for a proposed system in order to demonstrate that the harmonic compensation performance meets the IEEE-519 standard.

  10. Recombinant protein production technology

    Science.gov (United States)

    Recombinant protein production is an important technology for antibody production, biochemical activity study, and structural determination during the post-genomic era. Limiting factors in recombinant protein production include low-level protein expression, protein precipitation, and loss of protein...

  11. Improving peptide-MHC class I binding prediction for unbalanced datasets

    Directory of Open Access Journals (Sweden)

    Tomaras Georgia D

    2008-09-01

    Full Text Available Abstract Background Establishment of peptide binding to Major Histocompatibility Complex class I (MHCI is a crucial step in the development of subunit vaccines and prediction of such binding could greatly reduce costs and accelerate the experimental process of identifying immunogenic peptides. Many methods have been applied to the prediction of peptide-MHCI binding, with some achieving outstanding performance. Because of the experimental methods used to measure binding or affinity between peptides and MHCI molecules, however, available datasets are enriched for nonbinders, and thus highly unbalanced. Although there is no consensus on the ideal class distribution for training sets, extremely unbalanced datasets can be detrimental to the performance of prediction algorithms. Results We have developed a decision-theoretic framework to construct cost-sensitive trees to predict peptide-MHCI binding and have used them to 1 Assess the impact of the training data's class distribution on classifier accuracy, and 2 Compare resampling and cost-sensitive methods as approaches to compensate for training data imbalance. Our results confirm that highly unbalanced training sets can reduce the accuracy of classifier predictions and show that, in the peptide-MHCI binding context, resampling methods do not improve the classifier performance. In contrast, cost-sensitive methods significantly improve accuracy of decision trees. Finally, we propose the use of a training scheme that, when the training set is enriched for nonbinders, consistently improves the overall classifier accuracy compared to cost-insensitive classifiers and, in particular, increases the sensitivity of the classifiers. This method minimizes the expected classification cost for large datasets. Conclusion Our method consistently improves the performance of decision trees in predicting peptide-MHC class I binding by using cost-balancing techniques to compensate for the imbalance in the training

  12. Secondary wavelength stabilization of unbalanced Michelson interferometers for the generation of low-jitter pulse trains.

    Science.gov (United States)

    Shalloo, R J; Corner, L

    2016-09-01

    We present a double unbalanced Michelson interferometer producing up to four output pulses from a single input pulse. The interferometer is stabilized with the Hänsch-Couillaud method using an auxiliary low power continuous wave laser injected into the interferometer, allowing the stabilization of the temporal jitter of the output pulses to 0.02 fs. Such stabilized pulse trains would be suitable for driving multi-pulse laser wakefield accelerators, and the technique could be extended to include amplification in the arms of the interferometer.

  13. Frequency Noise Suppression of a Single Mode Laser with an Unbalanced Fiber Interferometer for Subnanometer Interferometry

    Czech Academy of Sciences Publication Activity Database

    Šmíd, Radek; Čížek, Martin; Mikel, Břetislav; Číp, Ondřej

    2015-01-01

    Roč. 15, č. 1 (2015), s. 1342-1355 ISSN 1424-8220 R&D Projects: GA ČR(CZ) GPP102/12/P962; GA ČR GAP102/10/1813; GA TA ČR TA01010995; GA MŠk(CZ) LO1212; GA MŠk ED0017/01/01 Institutional support: RVO:68081731 Keywords : unbalanced interferometer * fiber spool * PI control * frequency noise Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.033, year: 2015

  14. Crash Frequency Modeling Using Real-Time Environmental and Traffic Data and Unbalanced Panel Data Models.

    Science.gov (United States)

    Chen, Feng; Chen, Suren; Ma, Xiaoxiang

    2016-06-18

    Traffic and environmental conditions (e.g., weather conditions), which frequently change with time, have a significant impact on crash occurrence. Traditional crash frequency models with large temporal scales and aggregated variables are not sufficient to capture the time-varying nature of driving environmental factors, causing significant loss of critical information on crash frequency modeling. This paper aims at developing crash frequency models with refined temporal scales for complex driving environments, with such an effort providing more detailed and accurate crash risk information which can allow for more effective and proactive traffic management and law enforcement intervention. Zero-inflated, negative binomial (ZINB) models with site-specific random effects are developed with unbalanced panel data to analyze hourly crash frequency on highway segments. The real-time driving environment information, including traffic, weather and road surface condition data, sourced primarily from the Road Weather Information System, is incorporated into the models along with site-specific road characteristics. The estimation results of unbalanced panel data ZINB models suggest there are a number of factors influencing crash frequency, including time-varying factors (e.g., visibility and hourly traffic volume) and site-varying factors (e.g., speed limit). The study confirms the unique significance of the real-time weather, road surface condition and traffic data to crash frequency modeling.

  15. Performance Evaluation of UPQC under Nonlinear Unbalanced Load Conditions Using Synchronous Reference Frame Based Control

    Science.gov (United States)

    Kota, Venkata Reddy; Vinnakoti, Sudheer

    2017-12-01

    Today, maintaining Power Quality (PQ) is very important in the growing competent world. With new equipments and devices, new challenges are also being put before power system operators. Unified Power Quality Conditioner (UPQC) is proposed to mitigate many power quality problems and to improve the performance of the power system. In this paper, an UPQC with Fuzzy Logic controller for capacitor voltage balancing is proposed in Synchronous Reference Frame (SRF) based control with Modified Phased Locked Loop (MPLL). The proposed controller with SRF-MPLL based control is tested under non-linear and unbalanced load conditions. The system is developed in Matlab/Simulink and its performance is analyzed under various conditions like non-linear, unbalanced load and polluted supply voltage including voltage sag/swells. Active and reactive power flow in the system, power factor and %THD of voltages and currents before and after compensation are also analyzed in this work. Results prove the applicability of the proposed scheme for power quality improvement. It is observed that the fuzzy controller gives better performance than PI controller with faster capacitor voltage balancing and also improves the dynamic performance of the system.

  16. A set of 14 DIP-SNP markers to detect unbalanced DNA mixtures.

    Science.gov (United States)

    Liu, Zhizhen; Liu, Jinding; Wang, Jiaqi; Chen, Deqing; Liu, Zidong; Shi, Jie; Li, Zeqin; Li, Wenyan; Zhang, Gengqian; Du, Bing

    2018-03-04

    Unbalanced DNA mixture is still a difficult problem for forensic practice. DIP-STRs are useful markers for detection of minor DNA but they are not widespread in the human genome and having long amplicons. In this study, we proposed a novel type of genetic marker, termed DIP-SNP. DIP-SNP refers to the combination of INDEL and SNP in less than 300bp length of human genome. The multiplex PCR and SNaPshot assay were established for 14 DIP-SNP markers in a Chinese Han population from Shanxi, China. This novel compound marker allows detection of the minor DNA contributor with sensitivity from 1:50 to 1:1000 in a DNA mixture of any gender with 1 ng-10 ng DNA template. Most of the DIP-SNP markers had a relatively high probability of informative alleles with an average I value of 0.33. In all, we proposed DIP-SNP as a novel kind of genetic marker for detection of minor contributor from unbalanced DNA mixture and established the detection method by associating the multiplex PCR and SNaPshot assay. DIP-SNP polymorphisms are promising markers for forensic or clinical mixture examination because they are shorter, widespread and higher sensitive. Copyright © 2018 Elsevier Inc. All rights reserved.

  17. Fabrication and characterization of self-folding thermoplastic sheets using unbalanced thermal shrinkage.

    Science.gov (United States)

    Danielson, Christian; Mehrnezhad, Ali; YekrangSafakar, Ashkan; Park, Kidong

    2017-06-14

    Self-folding or micro-origami technologies are actively investigated as a novel manufacturing process to fabricate three-dimensional macro/micro-structures. In this paper, we present a simple process to produce a self-folding structure with a biaxially oriented polystyrene sheet (BOPS) or Shrinky Dinks. A BOPS sheet is known to shrink to one-third of its original size in plane, when it is heated above 160 °C. A grid pattern is engraved on one side of the BOPS film with a laser engraver to decrease the thermal shrinkage of the engraved side. The thermal shrinkage of the non-engraved side remains the same and this unbalanced thermal shrinkage causes folding of the structure as the structure shrinks at high temperature. We investigated the self-folding mechanism and characterized how the grid geometry, the grid size, and the power of the laser engraver affect the bending curvature. The developed fabrication process to locally modulate thermomechanical properties of the material by engraving the grid pattern and the demonstrated design methodology to harness the unbalanced thermal shrinkage can be applied to develop complicated self-folding macro/micro structures.

  18. Comparative study of niobium nitride coatings deposited by unbalanced and balanced magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Olaya, J.J. [Departamento de Ingenieria Mecanica y Mecatronica, Universidad Nacional de Colombia, Bogota Colombia (Colombia); Rodil, S.E. [Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, Mexico D. F. 04510 (Mexico); Muhl, S. [Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, Mexico D. F. 04510 (Mexico)], E-mail: muhl@servidor.unam.mx

    2008-10-01

    Niobium nitride (NbN) coatings have many interesting properties such as chemical inertness, excellent mechanical properties, high electrical conductivity, high melting point, and a superconducting transition temperature between 16 and 17 K. For this reason, these compounds have many potential thin film applications. In this work we compare the properties of NbN{sub x} films deposited using well-characterized balanced and unbalanced magnetron sputtering systems. Samples of NbN were deposited in the two systems under almost identical deposition conditions, that is, the same substrate temperature, plasma power, gas pressure, substrate to target distance and Ar/N{sub 2} ratio. Prior to the film preparation both the magnetic field geometry and the characteristics of the plasma were determined. The microstructure and composition of the deposits were analyzed by X-ray diffraction, scanning electron microscopy and X-ray photoelectron spectroscopy. The corrosion resistance and the micro-abrasion wear resistance were measured by anodic polarization potentiodynamic studies and by ball cratering, respectively. The NbN films grown using the highly unbalanced magnetron configuration had a preferential (111) crystal orientation and a composite hardness of up to 2400 HV{sub 0.025}. While the films deposited using the balanced magnetron had a mixed crystalline orientation and a hardness of 2000 HV{sub 0.025}. The results demonstrate the strong effect of magnetic field configuration on the ion bombardment, and the resultant coating characteristics.

  19. Comparative study of niobium nitride coatings deposited by unbalanced and balanced magnetron sputtering

    International Nuclear Information System (INIS)

    Olaya, J.J.; Rodil, S.E.; Muhl, S.

    2008-01-01

    Niobium nitride (NbN) coatings have many interesting properties such as chemical inertness, excellent mechanical properties, high electrical conductivity, high melting point, and a superconducting transition temperature between 16 and 17 K. For this reason, these compounds have many potential thin film applications. In this work we compare the properties of NbN x films deposited using well-characterized balanced and unbalanced magnetron sputtering systems. Samples of NbN were deposited in the two systems under almost identical deposition conditions, that is, the same substrate temperature, plasma power, gas pressure, substrate to target distance and Ar/N 2 ratio. Prior to the film preparation both the magnetic field geometry and the characteristics of the plasma were determined. The microstructure and composition of the deposits were analyzed by X-ray diffraction, scanning electron microscopy and X-ray photoelectron spectroscopy. The corrosion resistance and the micro-abrasion wear resistance were measured by anodic polarization potentiodynamic studies and by ball cratering, respectively. The NbN films grown using the highly unbalanced magnetron configuration had a preferential (111) crystal orientation and a composite hardness of up to 2400 HV 0.025 . While the films deposited using the balanced magnetron had a mixed crystalline orientation and a hardness of 2000 HV 0.025 . The results demonstrate the strong effect of magnetic field configuration on the ion bombardment, and the resultant coating characteristics

  20. Object-oriented Bayesian networks for evaluating DIP-STR profiling results from unbalanced DNA mixtures.

    Science.gov (United States)

    Cereda, G; Biedermann, A; Hall, D; Taroni, F

    2014-01-01

    The genetic characterization of unbalanced mixed stains remains an important area where improvement is imperative. In fact, with current methods for DNA analysis (Polymerase Chain Reaction with the SGM Plus multiplex kit), it is generally not possible to obtain a conventional autosomal DNA profile of the minor contributor if the ratio between the two contributors in a mixture is smaller than 1:10. This is a consequence of the fact that the major contributor's profile 'masks' that of the minor contributor. Besides known remedies to this problem, such as Y-STR analysis, a new compound genetic marker that consists of a Deletion/Insertion Polymorphism (DIP), linked to a Short Tandem Repeat (STR) polymorphism, has recently been developed and proposed elsewhere in literature. The present paper reports on the derivation of an approach for the probabilistic evaluation of DIP-STR profiling results obtained from unbalanced DNA mixtures. The procedure is based on object-oriented Bayesian networks (OOBNs) and uses the likelihood ratio as an expression of the probative value. OOBNs are retained in this paper because they allow one to provide a clear description of the genotypic configuration observed for the mixed stain as well as for the various potential contributors (e.g., victim and suspect). These models also allow one to depict the assumed relevance relationships and perform the necessary probabilistic computations. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  1. Double-Frame Current Control with a Multivariable PI Controller and Power Compensation for Weak Unbalanced Networks

    CERN Document Server

    Siemaszko, Daniel

    2015-06-15

    The handling of weak networks with asymmetric loads and disturbances im- plies the accurate handling of the second-harmonic component that appears in an unbalanced network. This paper proposes a classic vector control approach using a PI-based controller with superior decoupling capabilities for operation in weak networks with unbalanced phase voltages. A synchronization method for weak unbalanced networks is detailed, with dedicated dimensioning rules. The use of a double-frame controller allows a current symmetry or controlled imbalance to be forced for compensation of power oscillations by controlling the negative current sequence. This paper also serves as a useful reminder of the proper way to cancel the inherent coupling effect due to the transformation to the synchronous rotating reference frame, and of basic considerations of the relationship between switching frequency and control bandwidth.

  2. Control Strategy for Three-Phase Grid-Connected PV Inverters Enabling Current Limitation Under Unbalanced Faults

    DEFF Research Database (Denmark)

    Afshari, Ehsan; Moradi, Gholam Reza; Rahimi, Ramin

    2017-01-01

    Power quality and voltage control are among the most important aspects of the grid-connected power converter operation under faults. Non-sinusoidal current is injected during unbalanced voltage sag and active or/and reactive power includes double frequency content. This paper introduces a novel...... control strategy to mitigate the double grid frequency oscillations in the active power and dc-link voltage of the two-stage three-phase grid-connected Photovoltaic (PV) inverters during unbalanced faults. With the proposed control method, PV inverter injects sinusoidal currents under unbalanced grid...... faults. In addition, an efficient and easy-to-implement current limitation method is introduced, which can effectively limit the injected currents to the rated value during faults. In this case, the fault-ride-through operation is ensured and it will not trigger the overcurrent protection. A non...

  3. Side effects of chaperone gene co-expression in recombinant protein production

    Directory of Open Access Journals (Sweden)

    Martínez-Alonso Mónica

    2010-09-01

    Full Text Available Abstract Insufficient availability of molecular chaperones is observed as a major bottleneck for proper protein folding in recombinant protein production. Therefore, co-production of selected sets of cell chaperones along with foreign polypeptides is a common approach to increase the yield of properly folded, recombinant proteins in bacterial cell factories. However, unbalanced amounts of folding modulators handling folding-reluctant protein species might instead trigger undesired proteolytic activities, detrimental regarding recombinant protein stability, quality and yield. This minireview summarizes the most recent observations of chaperone-linked negative side effects, mostly focusing on DnaK and GroEL sets, when using these proteins as folding assistant agents. These events are discussed in the context of the complexity of the cell quality network and the consequent intricacy of the physiological responses triggered by protein misfolding.

  4. Xurography as a Rapid Fabrication Alternative for Point-of-Care Devices: Assessment of Passive Micromixers

    Directory of Open Access Journals (Sweden)

    J. Israel Martínez-López

    2016-05-01

    Full Text Available Despite the copious amount of research on the design and operation of micromixers, there are few works regarding manufacture technology aimed at implementation beyond academic environments. This work evaluates the viability of xurography as a rapid fabrication tool for the development of ultra-low cost microfluidic technology for extreme Point-of-Care (POC micromixing devices. By eschewing photolithographic processes and the bulkiness of pumping and enclosure systems for rapid fabrication and passively driven operation, xurography is introduced as a manufacturing alternative for asymmetric split and recombine (ASAR micromixers. A T-micromixer design was used as a reference to assess the effects of different cutting conditions and materials on the geometric features of the resulting microdevices. Inspection by stereographic and confocal microscopy showed that it is possible to manufacture devices with less than 8% absolute dimensional error. Implementation of the manufacturing methodology in modified circular shape- based SAR microdevices (balanced and unbalanced configurations showed that, despite the precision limitations of the xurographic process, it is possible to implement this methodology to produce functional micromixing devices. Mixing efficiency was evaluated numerically and experimentally at the outlet of the microdevices with performances up to 40%. Overall, the assessment encourages further research of xurography for the development of POC micromixers.

  5. Analysis of Unbalanced Magnetic Pull in Wound Rotor Induction Machines using Finite Element Analysis – Transient, Motoring and Generating Modes

    DEFF Research Database (Denmark)

    Dorrell, David G.; Hermann, Alexander Niels August; Jensen, Bogi Bech

    2013-01-01

    eccentricity. The operating conditions are varied so that transient, motoring and doubly-fed induction generator modes are studied. This allows greater understanding of the radial forces involved. Wound rotor induction machines exhibit higher unbalanced magnetic pull than cage induction machines so......There has been much literature on unbalanced magnetic pull in various types of electrical machine. This can lead to bearing wear and additional vibrations in the machine. In this paper a wound rotor induction is studied. Finite element analysis studies are conducted when the rotor has 10 % rotor...

  6. Performance Improvement of DFIG Wind Turbine Using Series Grid-Side Converter under Unbalanced Grid Voltage and Voltage Sag Conditions

    DEFF Research Database (Denmark)

    Shokri, Yunes; Ebrahimzadeh, Esmaeil; Lesani, Hamid

    2014-01-01

    Under unbalanced grid voltage conditions, the doubly fed induction generator (DFIG) stator voltage, in addition to positive sequence component has negative sequence component. The negative sequence component causes oscillations in the output power, electromagnetic torque and DC link voltage...... at twice the supply frequency. This paper presents a modified configuration of DFIG with series grid-side converter (SGSC) and its control system, which is suitable not only for unbalanced grid voltage conditions, but also for small voltage sags. The proposed configuration improves all the DFIG signals....... Matlab/Simulink is used for simulation of a 1.5-MW DFIG and the results demonstrate the good efficiency of the proposed scheme....

  7. MODEL OF AIRCRAFT ELECTRICAL POWER SUPPLY SYSTEM CHANNEL OF ALTERNATIVE CURRENT RUNNING ON A GENERALIZED UNBALANCED THREE-PHASE LOAD

    Directory of Open Access Journals (Sweden)

    Aleksej Gennad'evich Demchenko

    2017-01-01

    Full Text Available This article is devoted to mathematical modeling of the channel of AC on-board power supply systems (PSS when running on static active-inductive load, connected on a "wye with neutral" and "delta". The mathematical model of aircraft synchronous generator, electricity distribution, three-phase static active-inductive load are considered. When making a mathematical description the author used the equations for the voltages of windings and flux linkages cir- cuits of the stator and rotor of the generator in a stationary system phase coordinates "ABC". When considering the mathe- matical model of the distribution system, the equations that took into account the drop of the voltages on the active and inductive resistance of the distribution system power wires were used. When considering the mathematical models of three- phase static loads connected on a "wye with neutral" and "delta", the equations that took into account the drop of the volt- ages on the active and inductive resistance loads were used. The matrix equations system of channel PSS AC when running on a generalized three-phase static active-inductive load was obtained. The three phase static loads scheme connected ac- cording to the "delta" scheme was converted to "wye" to simplify the solution of channel PSS AC circuit matrix equations system. The choice of the phase coordinates system "ABC" for the mathematical description of the generator, distribution system and the static load was made due to its advantage over the coordinate system "dq", because the equation written in phase coordinates are valid for symmetric and asymmetric modes of the generator, while the equations written in the coor- dinate system "dq" will be valid only for symmetric modes. As a result of joint solution of the generator equations, distribution system, three-phase static loads there were obtained the formulae for the generator stator winding phases, gen- erator phases currents, the voltage drops on the load phases and load phases currents connected on a "wye with neutral" and "delta".

  8. Power quality improvement of unbalanced power system with distributed generation units

    DEFF Research Database (Denmark)

    Hu, Y.; Chen, Zhe; Excell, P.

    2011-01-01

    This paper presents a power electronic system for improving the power quality of the unbalanced distributed generation units in three-phase four-wire system. In the system, small renewable power generation units, such as small PV generator, small wind turbines may be configured as single phase...... generation units. The random nature of renewable power sources may result in significant unbalance in the power network and affect the power quality. An electronic converter system is proposed to correct the system unbalance and harmonics so as to deal with the power quality problems. The operation...... and control of the converter are described. Simulation results have demonstrated that the system can effectively correct the unbalance and enhance the system power quality....

  9. A cautionary note on generalized linear models for covariance of unbalanced longitudinal data

    KAUST Repository

    Huang, Jianhua Z.

    2012-03-01

    Missing data in longitudinal studies can create enormous challenges in data analysis when coupled with the positive-definiteness constraint on a covariance matrix. For complete balanced data, the Cholesky decomposition of a covariance matrix makes it possible to remove the positive-definiteness constraint and use a generalized linear model setup to jointly model the mean and covariance using covariates (Pourahmadi, 2000). However, this approach may not be directly applicable when the longitudinal data are unbalanced, as coherent regression models for the dependence across all times and subjects may not exist. Within the existing generalized linear model framework, we show how to overcome this and other challenges by embedding the covariance matrix of the observed data for each subject in a larger covariance matrix and employing the familiar EM algorithm to compute the maximum likelihood estimates of the parameters and their standard errors. We illustrate and assess the methodology using real data sets and simulations. © 2011 Elsevier B.V.

  10. An improved fuzzy c-means algorithm for unbalanced sized clusters

    Science.gov (United States)

    Gu, Shuguo; Liu, Jingjing; Xie, Qingguo; Wang, Luyao

    2012-02-01

    In this paper, we propose an improved fuzzy c-means (FCM) algorithm based on cluster height information to deal with the sensitivity of unbalanced sized clusters in FCM. As we know, cluster size sensitivity is an major drawback of FCM, which tends to balance the cluster sizes during iteration, so the center of smaller cluster might be drawn to the adjacent larger one, which will lead to bad classification. To overcome this problem, the cluster height information is considered and introduced to the distance function to adjust the conventional Euclidean distance, thus to control the effect on classification from cluster size difference. Experimental results demonstrate that our algorithm can obtain good clustering results in spite of great size difference, while traditional FCM cannot work well in such case. The improved FCM has shown its potential for extracting small clusters, especially in medical image segmentation.

  11. Is there a yet unreported unbalanced chromosomal abnormality without phenotypic consequences in proximal 4p?

    Science.gov (United States)

    Liehr, T; Bartels, I; Zoll, B; Ewers, E; Mrasek, K; Kosyakova, N; Merkas, M; Hamid, A B; von Eggeling, F; Posorski, N; Weise, A

    2011-01-01

    Unbalanced chromosomal abnormalities (UBCA) are reported for >50 euchromatic regions of almost all human autosomes. UBCA are comprised of a few megabases of DNA, and carriers are in many cases clinically healthy. Here we report on a partial trisomy of chromosome 4 of the centromere-near region of the short arm of chromosome 4 present as a small supernumerary marker chromosome (sSMC). The sSMC was present in >70% of amnion cells and in 60% of placenta. Further delineation of the size of the duplicated region was done by molecular cytogenetics and array comparative genomic hybridization. Even though the sSMC lead to a partial trisomy of ~9 megabase pairs, a healthy child was born, developing normally at 1 year of age. No comparable cases are available in the literature. Thus, we discuss here the possibility of having found a yet unrecognized chromosomal region subject to UBCA. Copyright © 2010 S. Karger AG, Basel.

  12. A combined approach to generate laboratory reference intervals using unbalanced longitudinal data.

    Science.gov (United States)

    Vogel, Mandy; Kirsten, Toralf; Kratzsch, Jürgen; Engel, Christoph; Kiess, Wieland

    2017-07-26

    The interpretation of individual laboratory test results requires the availability of population-based reference intervals. In children, reference interval estimation has to consider frequently the strong age-dependency. Generally, for the construction of reference intervals, a sufficiently large number of independent measurement values is required. Data selections from hospitals or cohort studies often comprise dependencies violating the independence assumption. In this article, we propose a combination of LMS-like (mean, M; coefficient of variation, S; skewness, λ or L) and resampling methods to overcome this drawback. The former is recommended by the World Health Organization (WHO) for the construction of continuous reference intervals of anthropometric measurements in children. The approach allows the inclusion of dependent measurements, for example, repeated measurements per subject. It also provides pointwise confidence envelopes as a measure of reliability. The combination of LMS-type methods and resampling provides a feasible approach to estimate age-dependent percentiles and reference intervals using unbalanced longitudinal data.

  13. The microstructure and properties of titanium dioxide films synthesized by unbalanced magnetron sputtering

    International Nuclear Information System (INIS)

    Leng, Y.X.; Chen, J.Y.; Yang, P.; Sun, H.; Huang, N.

    2007-01-01

    In this work, titanium oxide films were deposited on Ti6Al4V and Si (1 0 0) by DC unbalanced magnetron sputtering method at different oxygen pressure. X-ray diffraction (XRD), microhardness tests, pin-on-disk wear experiments, surface contact angle tests and platelet adhesion investigation were conducted to evaluate the properties of the films. The corrosion behavior of titanium dioxide films was characterized by potentiodynamic polarization. The results showed that titanium oxide films deposited by unbalance magnetron sputtering were compact and could obviously enhance microhardness, wear resistance of titanium alloy substrate. Potentiodynamic polarization curves showed that Ti-6Al-4V deposited with titanium dioxide films had lower dissolution currents than that of the uncoated one. The results of in vitro hemocompatibility analyses indicated that the blood compatibility of the titanium dioxide films with bandgap 3.2 eV have better blood compatibility

  14. Analysis of Three-Phase Rectifier Systems with Controlled DC-Link Current Under Unbalanced Grids

    DEFF Research Database (Denmark)

    Kumar, Dinesh; Davari, Pooya; Zare, Firuz

    2017-01-01

    Voltage unbalance is the most common disturbance in distribution networks, which give undesirable effects on many grid connected power electronics systems including Adjustable Speed Drive (ASD). Severe voltage unbalance can force three-phase rectifiers into almost single-phase operation, which...... degrades the grid power quality and also imposes a significant negative impact on the ASD system. This major power quality issue affecting the conventional rectifiers can be attenuated by controlling the DC-link current based on an Electronic Inductor (EI) technique. The purpose of this digest...... is to analyze and compare the performance of an EI with a conventional three-phase rectifier under unbalanced grid conditions. Experimental and simulation results validate the proposed mathematical modelling. Further analysis and benchmarking will be provided in the final paper....

  15. Performance analysis of active damped small DC-link capacitor based drive for unbalanced input voltage supply

    DEFF Research Database (Denmark)

    Maheshwari, Ram Krishan; Munk-Nielsen, Stig

    2011-01-01

    A small DC-link capacitor based drive is presented in this paper. The drive shows negative impedance instability at operating points with high power load. A phase portrait is presented for input filter states which exhibit a limit cycle. When the drive is operated with unbalanced input supply...

  16. Balanced Current Control Strategy for Current Source Rectifier Stage of Indirect Matrix Converter under Unbalanced Grid Voltage Conditions

    Directory of Open Access Journals (Sweden)

    Yeongsu Bak

    2016-12-01

    Full Text Available This paper proposes a balanced current control strategy for the current source rectifier (CSR stage of an indirect matrix converter (IMC under unbalanced grid voltage conditions. If the three-phase grid connected to the voltage source inverter (VSI of the IMC has unbalanced voltage conditions, it affects the currents of the CSR stage and VSI stage, and the currents are distorted. Above all, the distorted currents of the CSR stage cause instability in the overall system, which can affect the life span of the system. Therefore, in this paper, a control strategy for balanced currents in the CSR stage is proposed. To achieve balanced currents in the CSR stage, the VSI stage should receive DC power without ripple components from the CSR stage. This is implemented by controlling the currents in the VSI stage. Therefore, the proposed control strategy decouples the positive and negative phase-sequence components existing in the unbalanced voltages and currents of the VSI stage. Using the proposed control strategy under unbalanced grid voltage conditions, the stability and life span of the overall system can be improved. The effectiveness of the proposed control strategy is verified by simulation and experimental results.

  17. Fault Ride Though Control of Photovoltaic Grid-connected Inverter with Current-limited Capability under Offshore Unbalanced Voltage Conditions

    DEFF Research Database (Denmark)

    Liu, Wenzhao; Guo, Xiaoqiang; Savaghebi, Mehdi

    2016-01-01

    The photovoltaic (PV) inverter installed on board experiences the excessive current stress in case of the offshore unbalanced voltage fault ride through (FRT), which significantly affects the operation reliability of the power supply system. In order to solve the problem, the inherent mechanism o...

  18. Co-ordinated Control Strategy for Hybrid Wind Farms with PMSG and FSIG under Unbalanced Grid Voltage Condition

    DEFF Research Database (Denmark)

    Zeng, Xin; Yao, Jun; Chen, Zhiqian

    2016-01-01

    This paper investigates a control strategy for a wind farm with the direct-driven permanent-magnet synchronous generators (PMSG)-based wind turbines and the fixed speed induction generators (FSIG)-based wind turbines under unbalanced grid voltage condition. By controlling the PMSG-based wind farm...

  19. Effect of Doubly Fed Induction GeneratorTidal Current Turbines on Stability of a Distribution Grid under Unbalanced Voltage Conditions

    Directory of Open Access Journals (Sweden)

    Dahai Zhang

    2017-02-01

    Full Text Available This paper analyses the effects of doubly fed induction generator (DFIG tidal current turbines on a distribution grid under unbalanced voltage conditions of the grid. A dynamic model of an electrical power system under the unbalanced network is described in the paper, aiming to compare the system performance when connected with and without DFIG at the same location in a distribution grid. Extensive simulations of investigating the effect of DFIG tidal current turbine on stability of the distribution grid are performed, taking into account factors such as the power rating, the connection distance of the turbine and the grid voltage dip. The dynamic responses of the distribution system are examined, especially its ability to ride through fault events under unbalanced grid voltage conditions. The research has shown that DFIG tidal current turbines can provide a good damping performance and that modern DFIG tidal current power plants, equipped with power electronics and low-voltage ride-through capability, can stay connected to weak electrical grids even under the unbalanced voltage conditions, whilst not reducing system stability.

  20. Assumption or Fact? Line-to-Neutral Voltage Expression in an Unbalanced 3-Phase Circuit during Inverter Switching

    Science.gov (United States)

    Masrur, M. A.

    2009-01-01

    This paper discusses the situation in a 3-phase motor or any other 3-phase system operating under unbalanced operating conditions caused by an open fault in an inverter switch. A dc voltage source is assumed as the input to the inverter, and under faulty conditions of the inverter switch, the actual voltage applied between the line to neutral…

  1. Enhanced Power Quality and Minimized Peak Current Control in An Inverter based Microgrid under Unbalanced Grid Faults

    DEFF Research Database (Denmark)

    Liu, Wenzhao; Guo, Xiaoqiang; Sulligoi, Giorgio

    2016-01-01

    The microgrid inverter experiences the power oscillations and current harmonics in case of the unbalanced grid voltage faults. However, there is a trade-off between power oscillations and current harmonics should be considered in three phase three wire inverter systems during the conventional fault...

  2. Analysis of temperature changes on three-phase synchronous generator using infrared: comparison between balanced and unbalanced load

    Science.gov (United States)

    Amien, S.; Yoga, W.; Fahmi, F.

    2018-02-01

    Synchronous generators are a major tool in an electrical energy generating systems, the load supplied by the generator is unbalanced. This paper discusses the effect of synchronous generator temperature on the condition of balanced load and unbalanced load, which will then be compared with the measurement result of both states of the generator. Unbalanced loads can be caused by various asymmetric disturbances in the power system and the failure of load forecasting studies so that the load distribution in each phase is not the same and causing the excessive heat of the generator. The method used in data collection was by using an infrared thermometer and resistance calculation method. The temperature comparison result between the resistive, inductive and capacitive loads in the highest temperature balance occured when the generator is loaded with a resistive load, where T = 31.9 ° C and t = 65 minutes. While in a state of unbalanced load the highest temperature occured when the generator is loaded with a capacitive load, where T = 40.1 ° C and t = 60 minutes. By understanding this behavior, we can maintain the generator for longer operation life.

  3. Recombination hotspots and host susceptibility modulate the adaptive value of recombination during maize streak virus evolution

    Directory of Open Access Journals (Sweden)

    Monjane Adérito L

    2011-12-01

    Full Text Available Abstract Background Maize streak virus -strain A (MSV-A; Genus Mastrevirus, Family Geminiviridae, the maize-adapted strain of MSV that causes maize streak disease throughout sub-Saharan Africa, probably arose between 100 and 200 years ago via homologous recombination between two MSV strains adapted to wild grasses. MSV recombination experiments and analyses of natural MSV recombination patterns have revealed that this recombination event entailed the exchange of the movement protein - coat protein gene cassette, bounded by the two genomic regions most prone to recombination in mastrevirus genomes; the first surrounding the virion-strand origin of replication, and the second around the interface between the coat protein gene and the short intergenic region. Therefore, aside from the likely adaptive advantages presented by a modular exchange of this cassette, these specific breakpoints may have been largely predetermined by the underlying mechanisms of mastrevirus recombination. To investigate this hypothesis, we constructed artificial, low-fitness, reciprocal chimaeric MSV genomes using alternating genomic segments from two MSV strains; a grass-adapted MSV-B, and a maize-adapted MSV-A. Between them, each pair of reciprocal chimaeric genomes represented all of the genetic material required to reconstruct - via recombination - the highly maize-adapted MSV-A genotype, MSV-MatA. We then co-infected a selection of differentially MSV-resistant maize genotypes with pairs of reciprocal chimaeras to determine the efficiency with which recombination would give rise to high-fitness progeny genomes resembling MSV-MatA. Results Recombinants resembling MSV-MatA invariably arose in all of our experiments. However, the accuracy and efficiency with which the MSV-MatA genotype was recovered across all replicates of each experiment depended on the MSV susceptibility of the maize genotypes used and the precise positions - in relation to known recombination hotspots

  4. Recombination hotspots and host susceptibility modulate the adaptive value of recombination during maize streak virus evolution.

    Science.gov (United States)

    Monjane, Adérito L; van der Walt, Eric; Varsani, Arvind; Rybicki, Edward P; Martin, Darren P

    2011-12-02

    Maize streak virus -strain A (MSV-A; Genus Mastrevirus, Family Geminiviridae), the maize-adapted strain of MSV that causes maize streak disease throughout sub-Saharan Africa, probably arose between 100 and 200 years ago via homologous recombination between two MSV strains adapted to wild grasses. MSV recombination experiments and analyses of natural MSV recombination patterns have revealed that this recombination event entailed the exchange of the movement protein - coat protein gene cassette, bounded by the two genomic regions most prone to recombination in mastrevirus genomes; the first surrounding the virion-strand origin of replication, and the second around the interface between the coat protein gene and the short intergenic region. Therefore, aside from the likely adaptive advantages presented by a modular exchange of this cassette, these specific breakpoints may have been largely predetermined by the underlying mechanisms of mastrevirus recombination. To investigate this hypothesis, we constructed artificial, low-fitness, reciprocal chimaeric MSV genomes using alternating genomic segments from two MSV strains; a grass-adapted MSV-B, and a maize-adapted MSV-A. Between them, each pair of reciprocal chimaeric genomes represented all of the genetic material required to reconstruct - via recombination - the highly maize-adapted MSV-A genotype, MSV-MatA. We then co-infected a selection of differentially MSV-resistant maize genotypes with pairs of reciprocal chimaeras to determine the efficiency with which recombination would give rise to high-fitness progeny genomes resembling MSV-MatA. Recombinants resembling MSV-MatA invariably arose in all of our experiments. However, the accuracy and efficiency with which the MSV-MatA genotype was recovered across all replicates of each experiment depended on the MSV susceptibility of the maize genotypes used and the precise positions - in relation to known recombination hotspots - of the breakpoints required to re-create MSV

  5. Recombinant gene expression protocols

    National Research Council Canada - National Science Library

    Tuan, Rocky S

    1997-01-01

    .... A fundamental requirement for successful recombinant gene expression is the design of the cloning vector and the choice of the host organism for expression. Recombinant Gene Expression Protocols grows out of the need for a laboratory manual that provides the reader the background and rationale, as well as the practical protocols for the preparation of...

  6. Recombinant human complement component C2 produced in a human cell line restores the classical complement pathway activity in-vitro: an alternative treatment for C2 deficiency diseases

    Directory of Open Access Journals (Sweden)

    Martini Paolo GV

    2010-08-01

    Full Text Available Abstract Background Complement C2 deficiency is the most common genetically determined complete complement deficiency and is associated with a number of diseases. Most prominent are the associations with recurrent serious infections in young children and the development of systemic lupus erythematosus (SLE in adults. The links with these diseases reflect the important role complement C2 plays in both innate immunity and immune tolerance. Infusions with normal fresh frozen plasma for the treatment of associated disease have demonstrated therapeutic effects but so far protein replacement therapy has not been evaluated. Results Human complement C2 was cloned and expressed in a mammalian cell line. The purity of recombinant human C2 (rhC2 was greater than 95% and it was characterized for stability and activity. It was sensitive to C1s cleavage and restored classical complement pathway activity in C2-deficient serum both in a complement activation ELISA and a hemolytic assay. Furthermore, rhC2 could increase C3 fragment deposition on the human pathogen Streptococcus pneumoniae in C2-deficient serum to levels equal to those with normal serum. Conclusions Taken together these data suggest that recombinant human C2 can restore classical complement pathway activity and may serve as a potential therapeutic for recurring bacterial infections or SLE in C2-deficient patients.

  7. Metal binding proteins, recombinant host cells and methods

    Science.gov (United States)

    Summers, Anne O.; Caguiat, Jonathan J.

    2004-06-15

    The present disclosure provides artificial heavy metal binding proteins termed chelons by the inventors. These chelons bind cadmium and/or mercuric ions with relatively high affinity. Also disclosed are coding sequences, recombinant DNA molecules and recombinant host cells comprising those recombinant DNA molecules for expression of the chelon proteins. In the recombinant host cells or transgenic plants, the chelons can be used to bind heavy metals taken up from contaminated soil, groundwater or irrigation water and to concentrate and sequester those ions. Recombinant enteric bacteria can be used within the gastrointestinal tracts of animals or humans exposed to toxic metal ions such as mercury and/or cadmium, where the chelon recombinantly expressed in chosen in accordance with the ion to be rededicated. Alternatively, the chelons can be immobilized to solid supports to bind and concentrate heavy metals from a contaminated aqueous medium including biological fluids.

  8. A recurrent translocation is mediated by homologous recombination between HERV-H elements

    Directory of Open Access Journals (Sweden)

    Hermetz Karen E

    2012-01-01

    Full Text Available Abstract Background Chromosome rearrangements are caused by many mutational mechanisms; of these, recurrent rearrangements can be particularly informative for teasing apart DNA sequence-specific factors. Some recurrent translocations are mediated by homologous recombination between large blocks of segmental duplications on different chromosomes. Here we describe a recurrent unbalanced translocation casued by recombination between shorter homologous regions on chromosomes 4 and 18 in two unrelated children with intellectual disability. Results Array CGH resolved the breakpoints of the 6.97-Megabase (Mb loss of 18q and the 7.30-Mb gain of 4q. Sequencing across the translocation breakpoints revealed that both translocations occurred between 92%-identical human endogenous retrovirus (HERV elements in the same orientation on chromosomes 4 and 18. In addition, we find sequence variation in the chromosome 4 HERV that makes one allele more like the chromosome 18 HERV. Conclusions Homologous recombination between HERVs on the same chromosome is known to cause chromosome deletions, but this is the first report of interchromosomal HERV-HERV recombination leading to a translocation. It is possible that normal sequence variation in substrates of non-allelic homologous recombination (NAHR affects the alignment of recombining segments and influences the propensity to chromosome rearrangement.

  9. In vivo production of recombinant proteins using occluded recombinant AcMNPV-derived baculovirus vectors.

    Science.gov (United States)

    Guijarro-Pardo, Eva; Gómez-Sebastián, Silvia; Escribano, José M

    2017-12-01

    Trichoplusia ni insect larvae infected with vectors derived from the Autographa californica multiple nucleopolyhedrovirus (AcMNPV), are an excellent alternative to insect cells cultured in conventional bioreactors to produce recombinant proteins because productivity and cost-efficiency reasons. However, there is still a lot of work to do to reduce the manual procedures commonly required in this production platform that limit its scalability. To increase the scalability of this platform technology, a current bottleneck to be circumvented in the future is the need of injection for the inoculation of larvae with polyhedrin negative baculovirus vectors (Polh-) because of the lack of oral infectivity of these viruses, which are commonly used for production in insect cell cultures. In this work we have developed a straightforward alternative to obtain orally infective vectors derived from AcMNPV and expressing recombinant proteins that can be administered to the insect larvae (Trichoplusia ni) by feeding, formulated in the insect diet. The approach developed was based on the use of a recombinant polyhedrin protein expressed by a recombinant vector (Polh+), able to co-occlude any recombinant Polh- baculovirus vector expressing a recombinant protein. A second alternative was developed by the generation of a dual vector co-expressing the recombinant polyhedrin protein and the foreign gene of interest to obtain the occluded viruses. Additionally, by the incorporation of a reporter gene into the helper Polh+ vector, it was possible the follow-up visualization of the co-occluded viruses infection in insect larvae and will help to homogenize infection conditions. By using these methodologies, the production of recombinant proteins in per os infected larvae, without manual infection procedures, was very similar in yield to that obtained by manual injection of recombinant Polh- AcMNPV-based vectors expressing the same proteins. However, further analyses will be required for a

  10. Hadron correlations from recombination

    Energy Technology Data Exchange (ETDEWEB)

    Fries, Rainer J [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)

    2005-01-01

    Quark recombination is a successful model to describe the hadronization of a deconfined quark gluon plasma. Jet-like dihadron correlations measured at RHIC provide a challenge for this picture. We discuss how correlations between hadrons can arise from correlations between partons before hadronization. An enhancement of correlations through the recombination process, similar to the enhancement of elliptic flow is found. Hot spots from completely or partially quenched jets are a likely source of such parton correlations.

  11. Voltage Impact of a Wave Energy Converter on an Unbalanced Distribution Grid and Corrective Actions

    Directory of Open Access Journals (Sweden)

    Hugo Mendonça

    2017-10-01

    Full Text Available Renewable energy is steadily increasing its penetration level in electric power systems. Wind and solar energy have reached a high degree of maturity, and their impacts on the grid are well known. However, this is not the case for emerging sources like wave energy. This work explores the impact of the fluctuating power injected by a wave energy converter on the distribution grid voltage and proposes a strategy for mitigating the induced voltage fluctuations. The paper describes the mechanics of how a fluctuating active power injection leads to grid voltage fluctuations and presents an unbalanced three-phase power flow tool that allows one to quantitatively analyze the voltage evolution at every phase and bus of a distribution grid driven by this power injection. The paper also proposes a corrective action for mitigating the voltage fluctuations that makes use of the hardware resources already available in the wave energy converter, by means of a control strategy on the reactive capability of the grid-side inverter. The use of a STATCOM as additional reactive compensation equipment is also explored. The effectiveness of the proposal is assessed in the IEEE 13-bus test feeder showing that, in some cases, the wave energy converter by itself is able to mitigate the voltage fluctuations that it causes. If not, a STATCOM can provide the extra reactive capability needed.

  12. Fault Identification in an Unbalanced Distribution System Using Support Vector Machine

    Directory of Open Access Journals (Sweden)

    Sophi Shilpa Gururajapathy

    2016-12-01

    Full Text Available Fast and effective fault location in distribution system is important to improve the power system reliability. Most of the researches rarely mention about effective fault location consisting of faulted phase, fault type, faulty section and fault distance identification. This work presents a method using support vector machine to identify the faulted phase, fault type, faulty section and distance at the same time. Support vector classification and regression analysis are performed to locate fault. The method uses the voltage sag data during fault condition measured at the primary substation. The faulted phase and the fault type are identified using three-dimensional support vector classification. The possible faulty sections are identified by matching voltage sag at fault condition to the voltage sag in database and the possible sections are ranked using shortest distance principle. The fault distance for the possible faulty sections isthen identified using support vector regression analysis. The performance of the proposed method was tested on an unbalanced distribution system from SaskPower, Canada. The results show that the accuracy of the proposed method is satisfactory.

  13. A robust procedure for comparing multiple means under heteroscedasticity in unbalanced designs.

    Directory of Open Access Journals (Sweden)

    Esther Herberich

    2010-03-01

    Full Text Available Investigating differences between means of more than two groups or experimental conditions is a routine research question addressed in biology. In order to assess differences statistically, multiple comparison procedures are applied. The most prominent procedures of this type, the Dunnett and Tukey-Kramer test, control the probability of reporting at least one false positive result when the data are normally distributed and when the sample sizes and variances do not differ between groups. All three assumptions are non-realistic in biological research and any violation leads to an increased number of reported false positive results. Based on a general statistical framework for simultaneous inference and robust covariance estimators we propose a new statistical multiple comparison procedure for assessing multiple means. In contrast to the Dunnett or Tukey-Kramer tests, no assumptions regarding the distribution, sample sizes or variance homogeneity are necessary. The performance of the new procedure is assessed by means of its familywise error rate and power under different distributions. The practical merits are demonstrated by a reanalysis of fatty acid phenotypes of the bacterium Bacillus simplex from the "Evolution Canyons" I and II in Israel. The simulation results show that even under severely varying variances, the procedure controls the number of false positive findings very well. Thus, the here presented procedure works well under biologically realistic scenarios of unbalanced group sizes, non-normality and heteroscedasticity.

  14. Three-phase Unbalanced Interval Power Flow Calculation of Low-voltage Distribution Network with Distributed PV Power Generation

    Science.gov (United States)

    Yuan, Yan; Shunjiang, Lin; Yuan, Lu

    2017-05-01

    Low-voltage distribution network is a three-phase unbalanced system due to the integration of single-phase loads and single-phase distributed PV arrays. In this paper, three-phase unbalanced interval power flow calculation model of three-phase four-wire low voltage distribution network with distributed PV power generation is established. In the model, intensity of illumination and battery temperature which influence the power output of distributed PV power generation is described as intervals. Then, through the affine interval algorithm, the interval power flow problem is transformed into a deterministic power flow problem and two linear optimization problems. By solving the above problems, the interval power flow solution can be obtained. Finally, the proposed algorithm is applied to an actual 22-bus low-voltage distribution network, and the solution of the affine interval algorithm is compared to the solution of the Monte Carlo sampling method, which verifies the correctness and effectiveness of the proposed algorithm.

  15. Effects of unbalanced carrier injection on the performance characteristics of InGaN light-emitting diodes

    Science.gov (United States)

    Han, Dong-Pyo; Shim, Jong-In; Shin, Dong-Soo; Kim, Kyu-Sang

    2016-08-01

    Two kinds of InGaN-based light-emitting diodes (LEDs) having different electron concentrations in the n-GaN injection layer are investigated in order to understand the effects of unbalanced carrier injection on LED performance characteristics. Electrical and optical characteristics such as capacitance-voltage, current-voltage, external quantum efficiency, and electroluminescence spectrum are compared and analyzed. It is shown that the unbalanced carrier distribution in multiple quantum wells affects the forward operating voltage since a large disparity of injection rate between electrons and holes can induce a small effective active volume, thus leading to the severe overflow of electrons to the p-(Al)GaN layer in the LED devices.

  16. Structural, chemical and nanomechanical investigations of SiC/polymeric a-C:H films deposited by reactive RF unbalanced magnetron sputtering

    Science.gov (United States)

    Tomastik, C.; Lackner, J. M.; Pauschitz, A.; Roy, M.

    2016-03-01

    Amorphous carbon (or diamond-like carbon, DLC) films have shown a number of important properties usable for a wide range of applications for very thin coatings with low friction and good wear resistance. DLC films alloyed with (semi-)metals show some improved properties and can be deposited by various methods. Among those, the widely used magnetron sputtering of carbon targets is known to increase the number of defects in the films. Therefore, in this paper an alternative approach of depositing silicon-carbide-containing polymeric hydrogenated DLC films using unbalanced magnetron sputtering was investigated. The influence of the C2H2 precursor concentration in the deposition chamber on the chemical and structural properties of the deposited films was investigated by Raman spectroscopy, X-ray photoelectron spectroscopy and elastic recoil detection analysis. Roughness, mechanical properties and scratch response of the films were evaluated with the help of atomic force microscopy and nanoindentation. The Raman spectra revealed a strong correlation of the film structure with the C2H2 concentration during deposition. A higher C2H2 flow rate results in an increase in SiC content and decrease in hydrogen content in the film. This in turn increases hardness and elastic modulus and decreases the ratio H/E and H3/E2. The highest scratch resistance is exhibited by the film with the highest hardness, and the film having the highest overall sp3 bond content shows the highest elastic recovery during scratching.

  17. DC-Voltage Fluctuation Elimination Through a DC-Capacitor Current Control for DFIG Converters Under Unbalanced Grid Voltage Conditions

    DEFF Research Database (Denmark)

    Liu, Changjin; Xu, Dehong; Zhu, Nan

    2013-01-01

    Unbalanced grid voltage causes a large second-order harmonic current in the dc-link capacitors as well as dc-voltage fluctuation, which potentially will degrade the lifespan and reliability of the capacitors in voltage source converters. This paper proposes a novel dc-capacitor current control me...... grid voltage conditions. A modular implementation method of the proposed control strategy is developed for the DFIG controller. Finally, experiments are presented to validate the theoretical analysis....

  18. Control of Active Front-End Rectifier in Electric Drive under Unbalanced Voltage Supply in Transient States

    Czech Academy of Sciences Publication Activity Database

    Chomát, Miroslav; Schreier, Luděk; Bendl, Jiří

    2012-01-01

    Roč. 88, 1A (2012), s. 177-180 ISSN 0033-2097 R&D Projects: GA ČR GA102/09/1273 Institutional research plan: CEZ:AV0Z20570509 Keywords : unbalanced voltage supply * DC-link voltage pulsations * pulse-width modulation Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 0.244, year: 2011 http://www.red.pe.org.pl/abstract_pl.php?nid=5479

  19. Flexible Power Regulation and Current-limited Control of Grid-connected Inverter under Unbalanced Grid Voltage Faults

    DEFF Research Database (Denmark)

    Guo, Xiaoqiang; Liu, Wenzhao; Lu, Zhigang

    2017-01-01

    The grid-connected inverters may experience excessive current stress in case of unbalanced grid voltage Fault Ride Through (FRT), which significantly affects the reliability of the power supply system. In order to solve the problem, the inherent mechanisms of the excessive current phenomenon...... of improving the system reliability under grid faults. Finally, the simulation and experiments of traditional and proposed FRT solutions are carried out. The results verify the effectiveness of the proposed method....

  20. Role of Wind Filtering and Unbalanced Flow Generation in Middle Atmosphere Gravity Wave Activity at Chatanika Alaska

    Directory of Open Access Journals (Sweden)

    Colin C. Triplett

    2017-01-01

    Full Text Available The meteorological control of gravity wave activity through filtering by winds and generation by spontaneous adjustment of unbalanced flows is investigated. This investigation is based on a new analysis of Rayleigh LiDAR measurements of gravity wave activity in the upper stratosphere-lower mesosphere (USLM,40–50kmon 152 nights at Poker Flat Research Range (PFRR, Chatanika, Alaska (65◦ N, 147◦ W, over 13 years between 1998 and 2014. The LiDAR measurements resolve inertia-gravity waves with observed periods between 1 h and 4 h and vertical wavelengths between 2 km and 10 km. The meteorological conditions are defined by reanalysis data from the Modern-Era Retrospective Analysis for Research and Applications (MERRA. The gravity wave activity shows large night-to-night variability, but a clear annual cycle with a maximum in winter,and systematic interannual variability associated with stratospheric sudden warming events. The USLM gravity wave activity is correlated with the MERRA winds and is controlled by the winds in the lower stratosphere through filtering by critical layer filtering. The USLM gravity wave activity is also correlated with MERRA unbalanced flow as characterized by the residual of the nonlinear balance equation. This correlation with unbalanced flow only appears when the wind conditions are taken into account, indicating that wind filtering is the primary control of the gravity wave activity.

  1. Primary TKA Patients with Quantifiably Balanced Soft-Tissue Achieve Significant Clinical Gains Sooner than Unbalanced Patients

    Directory of Open Access Journals (Sweden)

    Kenneth A. Gustke

    2014-01-01

    Full Text Available Although total knee arthroplasty has a high success rate, poor outcomes and early revision are associated with ligament imbalance. This multicenter evaluation was performed in order to provide 1-year followup of a previously reported group of patients who had sensor-assisted TKA, comparing the clinical outcomes of quantitatively balanced versus unbalanced patients. At 1 year, the balanced cohort scored 179.3 and 10.4 in KSS and WOMAC, respectively; the unbalanced cohort scored 156.1 and 17.9 in KSS and WOMAC (P<0.001; P=0.085. The average activity level scores of quantitatively balanced patients were 68.6 (corresponding to tennis, light jogging, and heavy yard work, while the average activity level of unbalanced patients was 46.7 (corresponding to light housework, and limited walking distances (P=0.015. Out of all confounding variables, a balanced articulation was the most significant contributing factor to improved postoperative outcomes (P<0.001.

  2. Negative mood induction and unbalanced nutrition style as possible triggers of binges in binge eating disorder (BED).

    Science.gov (United States)

    Munsch, S; Michael, T; Biedert, E; Meyer, A H; Margraf, J

    2008-03-01

    To investigate whether negative mood and unbalanced nutrition style (fat rich/carbohydrate low) synergistically trigger binge eating in overweight and obese binge eating disorder (BED) patients. Subsequently to following an unbalanced or a balanced nutrition plan for three days, participants' food intake in a taste test was measured. During the taste test, participants were either in a negative or a neutral mood that was induced through a guided imagery task. Sixty-nine overweight and obese women with BED (mean age: 36.7 years, mean body mass index: 32.8 kg/m2). Eating behavior was assessed by measuring the amount of eaten food during the taste test. Visual analog scales were used to assess negative affect, tension, urge to eat, and hunger before and after the mood induction and after the taste test. Negative mood and unbalanced nutrition had neither a combined synergistic effect nor separate additive effects on the amount of food intake. Negative affect and tension decreased after the taste test in the negative mood group. Negative mood does not invariably enhance the risk of binge-eating behavior. Fat-rich, carbohydrate-low nutrition style did not influence food intake during a taste test. This finding questions the role of this specific nutrition style as a crucial factor in promoting binge eating. If replicated, these findings are important, since they could guide development of treatment protocols.

  3. Regulation of Meiotic Recombination

    Energy Technology Data Exchange (ETDEWEB)

    Gregory p. Copenhaver

    2011-11-09

    Meiotic recombination results in the heritable rearrangement of DNA, primarily through reciprocal exchange between homologous chromosome or gene conversion. In plants these events are critical for ensuring proper chromosome segregation, facilitating DNA repair and providing a basis for genetic diversity. Understanding this fundamental biological mechanism will directly facilitate trait mapping, conventional plant breeding, and development of genetic engineering techniques that will help support the responsible production and conversion of renewable resources for fuels, chemicals, and the conservation of energy (1-3). Substantial progress has been made in understanding the basal recombination machinery, much of which is conserved in organisms as diverse as yeast, plants and mammals (4, 5). Significantly less is known about the factors that regulate how often and where that basal machinery acts on higher eukaryotic chromosomes. One important mechanism for regulating the frequency and distribution of meiotic recombination is crossover interference - or the ability of one recombination event to influence nearby events. The MUS81 gene is thought to play an important role in regulating the influence of interference on crossing over. The immediate goals of this project are to use reverse genetics to identify mutants in two putative MUS81 homologs in the model plant Arabidopsis thaliana, characterize those mutants and initiate a novel forward genetic screen for additional regulators of meiotic recombination. The long-term goal of the project is to understand how meiotic recombination is regulated in higher eukaryotes with an emphasis on the molecular basis of crossover interference. The ability to monitor recombination in all four meiotic products (tetrad analysis) has been a powerful tool in the arsenal of yeast geneticists. Previously, the qrt mutant of Arabidopsis, which causes the four pollen products of male meiosis to remain attached, was developed as a facile system

  4. Alternative security

    International Nuclear Information System (INIS)

    Weston, B.H.

    1990-01-01

    This book contains the following chapters: The Military and Alternative Security: New Missions for Stable Conventional Security; Technology and Alternative Security: A Cherished Myth Expires; Law and Alternative Security: Toward a Just World Peace; Politics and Alternative Security: Toward a More Democratic, Therefore More Peaceful, World; Economics and Alternative Security: Toward a Peacekeeping International Economy; Psychology and Alternative Security: Needs, Perceptions, and Misperceptions; Religion and Alternative Security: A Prophetic Vision; and Toward Post-Nuclear Global Security: An Overview

  5. Recombinant expression systems: the obstacle to helminth vaccines?

    Science.gov (United States)

    Geldhof, Peter; De Maere, Veerle; Vercruysse, Jozef; Claerebout, Edwin

    2007-11-01

    The need for alternative ways to control helminth parasites has in recent years led to a boost in vaccination experiments with recombinant antigens. Despite the use of different expression systems, only a few recombinants induced high levels of protection against helminths. This is often attributed to the limitations of the current expression systems. Therefore, the need for new systems that can modify and glycosylate the expressed antigens has been advocated. However, analysis of over 100 published vaccine trials with recombinant helminth antigens indicates that it is often not known whether the native parasite antigen itself can induce protection or, if it does, which epitopes are important. This information is vital for a well-thought-out strategy for recombinant production. So, in addition to testing more expression systems, it should be considered that prior evaluation and characterization of the native antigens might help the development of recombinant vaccines against helminths in the long term.

  6. Learning from unbalanced data: a cascade-based approach for detecting clustered microcalcifications.

    Science.gov (United States)

    Bria, A; Karssemeijer, N; Tortorella, F

    2014-02-01

    Finding abnormalities in diagnostic images is a difficult task even for expert radiologists because the normal tissue locations largely outnumber those with suspicious signs which may thus be missed or incorrectly interpreted. For the same reason the design of a Computer-Aided Detection (CADe) system is very complex because the large predominance of normal samples in the training data may hamper the ability of the classifier to recognize the abnormalities on the images. In this paper we present a novel approach for computer-aided detection which faces the class imbalance with a cascade of boosting classifiers where each node is trained by a learning algorithm based on ranking instead of classification error. Such approach is used to design a system (CasCADe) for the automated detection of clustered microcalcifications (μCs), which is a severely unbalanced classification problem because of the vast majority of image locations where no μC is present. The proposed approach was evaluated with a dataset of 1599 full-field digital mammograms from 560 cases and compared favorably with the Hologic R2CAD ImageChecker, one of the most widespread commercial CADe systems. In particular, at the same lesion sensitivity of R2CAD (90%) on biopsy proven malignant cases, CasCADe and R2CAD detected 0.13 and 0.21 false positives per image (FPpi), respectively (p-value=0.09), whereas at the same FPpi of R2CAD (0.21), CasCADe and R2CAD detected 93% and 90% of true lesions respectively (p-value=0.11) thus showing that CasCADe can compete with high-end CADe commercial systems. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Nature in a Box: Ecocriticism, Goethe’s Ironic Werther, and Unbalanced Nature

    Directory of Open Access Journals (Sweden)

    Heather I. Sullivan

    2011-01-01

    Full Text Available Ecocriticism emphasizes how our bodily and ecological boundaries are just as porous,inter-penetrable, and open as are our cultural and linguistic realms. As individual bodiesand communities, we are fully immersed in our material environment and participating inconstant exchanges of matter and energy. In this essay, I nevertheless advocate for acautious approach to the ecocritical question of contested boundaries. After all, someboundaries and membranes are necessary to maintain living organisms. RegardingTimothy Morton’s assertion that we are “radically open,” I note the need for stable andhealthy membranes to sustain life, such as our porous yet enclosed intestines. I proposea multi-pronged perspective using the literary model of Goethe’s famously sentimentalWerther, who longs to merge with nature and become an insect, in juxtaposition with hisdeeply ironic Triumph of Sentimentality, which satirizes the Werther-like figure, PrinceOronaro, who wants to keep nature safely in a box. From the relationship of these twotexts emerges an “ironic Werther,” a model for ecocriticism. Werther’s and Morton’s“openness” are juxtaposed with Oronaro’s boxes, allowing for an open/closedperspective that resonates with “unbalanced nature” more broadly. Ecologicallyspeaking, all boundaries fade in the long-term, cosmic view; yet short-term boundariesallow a steady-state existence far from equilibrium, that is, they allow life to exist.Nature’s long term unbalance brings change and evolution, even as short-term bodieslive, reproduce, die, and continue the process. This essay rejects the notion ofharmonious nature and proposes instead a dynamic, multi-pronged view both ironic andserious, both literary and scientific, both open and closed; above all, it suggests thatthinking “nature in a box” might remind us that we, too, are nature and need some limitsas we hubristically alter our world.

  8. Surface free energy of CrN x films deposited using closed field unbalanced magnetron sputtering

    International Nuclear Information System (INIS)

    Sun, C.-C.; Lee, S.-C.; Dai, S.-B.; Fu, Y.-S.; Wang, Y.-C.; Lee, Y.-H.

    2006-01-01

    CrN x thin films have attracted much attention for semiconductor IC packaging molding dies and forming tools due to their excellent hardness, thermal stability and non-sticking properties (low surface free energy). However, few data has been published on the surface free energy (SFE) of CrN x films at temperatures in the range 20-170 deg. C. In this study CrN x thin films with CrN, Cr(N), Cr 2 N (and mixture of these phases) were prepared using closed field unbalanced magnetron sputtering at a wide range of Cr +2 emission intensity. The contact angles of water, di-iodomethane and ethylene glycol on the coated surfaces were measured at temperatures in the range 20-170 deg. C using a Dataphysics OCA-20 contact angle analyzer. The surface free energy of the CrN x films and their components (e.g., dispersion, polar) were calculated using the Owens-Wendt geometric mean approach. The influences of CrN x film surface roughness and microstructure on the surface free energy were investigated by atomic force microscopy (AFM) and X-ray diffraction (XRD), respectively. The experimental results showed that the lowest total SFE was obtained corresponding to CrN at temperature in 20 deg. C. This is lower than that of Cr(N), Cr 2 N (and mixture of these phases). The total SFE, dispersive SFE and polar SFE of CrN x films decreased with increasing surface temperature. The film roughness has an obvious effect on the SFE and there is tendency for the SFE to increase with increasing film surface roughness

  9. Recombinant Protein Production and Insect Cell Culture and Process

    Science.gov (United States)

    Spaulding, Glenn F. (Inventor); Goodwin, Thomas J. (Inventor); OConnor, Kim C. (Inventor); Francis, Karen M. (Inventor); Andrews, Angela D. (Inventor); Prewett, Tracey L. (Inventor)

    1997-01-01

    A process has been developed for recombinant production of selected polypeptides using transformed insect cells cultured in a horizontally rotating culture vessel modulated to create low shear conditions. A metabolically transformed insect cell line is produced using the culture procedure regardless of genetic transformation. The recombinant polypeptide can be produced by an alternative process using virtually infected or stably transformed insect cells containing a gene encoding the described polypeptide. The insect cells can also be a host for viral production.

  10. Gateway Recombinational Cloning.

    Science.gov (United States)

    Reece-Hoyes, John S; Walhout, Albertha J M

    2018-01-02

    The Gateway recombinatorial cloning system was developed for cloning multiple DNA fragments in parallel (e.g., in 96-well formats) in a standardized manner using the same enzymes. Gateway cloning is based on the highly specific integration and excision reactions of bacteriophage λ into and out of the Escherichia coli genome. Because the sites of recombination (" att " sites) are much longer (25-242 bp) than restriction sites, they are extremely unlikely to occur by chance in DNA fragments. Therefore, the same recombination enzyme can be used to robustly clone many different fragments of variable size in parallel reactions. © 2018 Cold Spring Harbor Laboratory Press.

  11. Recombinant renewable polyclonal antibodies.

    Science.gov (United States)

    Ferrara, Fortunato; D'Angelo, Sara; Gaiotto, Tiziano; Naranjo, Leslie; Tian, Hongzhao; Gräslund, Susanne; Dobrovetsky, Elena; Hraber, Peter; Lund-Johansen, Fridtjof; Saragozza, Silvia; Sblattero, Daniele; Kiss, Csaba; Bradbury, Andrew R M

    2015-01-01

    Only a small fraction of the antibodies in a traditional polyclonal antibody mixture recognize the target of interest, frequently resulting in undesirable polyreactivity. Here, we show that high-quality recombinant polyclonals, in which hundreds of different antibodies are all directed toward a target of interest, can be easily generated in vitro by combining phage and yeast display. We show that, unlike traditional polyclonals, which are limited resources, recombinant polyclonal antibodies can be amplified over one hundred million-fold without losing representation or functionality. Our protocol was tested on 9 different targets to demonstrate how the strategy allows the selective amplification of antibodies directed toward desirable target specific epitopes, such as those found in one protein but not a closely related one, and the elimination of antibodies recognizing common epitopes, without significant loss of diversity. These recombinant renewable polyclonal antibodies are usable in different assays, and can be generated in high throughput. This approach could potentially be used to develop highly specific recombinant renewable antibodies against all human gene products.

  12. Alternative additives; Alternative additiver

    Energy Technology Data Exchange (ETDEWEB)

    2007-08-15

    In this project a number of industrial and agricultural waste products have been characterised and evaluated in terms of alkali-getter performance. The intended use is for biomass-fired power stations aiming at reducing corrosion or slagging related problems. The following products have been obtained, characterised and evaluated: 1) Brewery draff 2) Danish de-gassed manure 3) Paper sludge 4) Moulding sand 5) Spent bleaching earth 6) Anorthosite 7) Sand 8) Clay-sludge. Most of the above alternative additive candidates are deemed unsuitable due to insufficient chemical effect and/or expensive requirements for pre-treatment (such as drying and transportation). 3 products were selected for full-scale testing: de-gassed manure, spent bleaching earth and clay slugde. The full scale tests were undertaken at the biomass-fired power stations in Koege, Slagelse and Ensted. Spent bleaching earth (SBE) and clay sludge were the only tested additive candidates that had a proven ability to react with KCl, to thereby reduce Cl-concentrations in deposits, and reduce the deposit flux to superheater tubes. Their performance was shown to nearly as good as commercial additives. De-gassed manure, however, did not evaluate positively due to inhibiting effects of Ca in the manure. Furthermore, de-gassed manure has a high concentration of heavy metals, which imposes a financial burden with regard to proper disposal of the ash by-products. Clay-sludge is a wet clay slurring, and drying and transportation of this product entails substantial costs. Spent bleaching does not require much pre-treatment and is therefore the most promising alternative additive. On the other hand, bleaching earth contains residual plant oil which means that a range of legislation relating to waste combustion comes into play. Not least a waste combustion fee of 330 DKK/tonne. For all alternative (and commercial) additives disposal costs of the increase ash by-products represents a significant cost. This is

  13. Effect of unbalanced magnetic pull and hydraulic seal force on the vibration of large rotor-bearing systems

    Science.gov (United States)

    Song, Z.; Guo, P.; Liu, Y.

    2014-03-01

    The influence of unbalanced magnetic pull (UMP) and hydraulic seal force on the vibration of large rotor-bearing systems is studied. The UMP caused by rotor eccentricity imposes important effects on rotating machinery, especially for large generators such as water turbine generator sets, because these machines operate above their first critical speed in some instances and are supported by oil film bearings. A magnetic stiffness matrix for studying the effects of the UMP is proposed. The magnetic stiffness matrix can be generated by decomposing the expression of air gap magnetic field energy. Two vibration models are constructed using the Lagrange equation. The difference between the two models lies in the boundary support condition: one has rigid support and the other has elastic bearing support. The influence of the magnetic stiffness and elastic support on the critical speed of the rotor is studied using Lyapunov nonlinear vibration stability theory. The vibration amplitude of the rotor is calculated, taking the magnetic stiffness and horizontal centrifugal force into account. The unbalanced hydraulic seal force is produced because of the asymmetry of seal clearance. This imbalance is one of the factors that causes self-excited vibration in rotating machinery, and is as important as the UMP for large water turbine generator sets. The rotor-bearing system is supported by an oil film journal bearing, whose characteristic also impose considerable influence on vibration. On the basis of the above-mentioned conditions, a three-dimensional finite element model of the rotating system that includes the oil film journal bearing is constructed. The effect of the UMP and unbalanced hydraulic seal force is considered in the construction, and studied in relation to the magnetic parameters, seal parameters, journal bearing stiffness, and outer diameter of the rotating machine critical speed. Conclusions may benefit the dynamic design and optimized operation of large rotating

  14. An unbalanced maternal diet in pregnancy associates with offspring epigenetic changes in genes controlling glucocorticoid action and foetal growth.

    Science.gov (United States)

    Drake, Amanda J; McPherson, Rhoanne C; Godfrey, Keith M; Cooper, Cyrus; Lillycrop, Karen A; Hanson, Mark A; Meehan, Richard R; Seckl, Jonathan R; Reynolds, Rebecca M

    2012-12-01

    In epidemiological studies, adverse early-life conditions associate with subsequent cardiometabolic disease. Hypothesized causes include maternal malnutrition, foetal glucocorticoid overexposure and reduced growth factors. Animal studies suggest a role for epigenetic processes in maintaining early-life effects into adulthood, but human relevance is unknown. We aimed to investigate relationships between an unbalanced maternal diet in pregnancy, neonatal and adult anthropometric variables with methylation at key genes controlling tissue glucocorticoid action and foetal growth. We studied 34 individuals aged 40 from the Motherwell cohort study whose mothers ate an unbalanced diet in pregnancy, previously linked with elevated blood pressure and cortisol in adult offspring. DNA methylation at 11β-hydroxysteroid dehydrogenase type 2 (HSD2), glucocorticoid receptor (GR) and insulin-like growth factor 2 (IGF2) was measured by pyrosequencing on buffy coat DNA. Methylation at specific CpGs in the HSD2 promoter and at one of the IGF2 differentially methylated regions (H19 ICR) correlated with neonatal anthropometric variables. CpG methylation within HSD2, GR and H19 ICR was positively associated with increased adiposity and blood pressure in adulthood. Methylation at GR (exon 1F) was increased in offspring of mothers with the most unbalanced diets in pregnancy. Alterations in DNA methylation at genes important in regulating circulating cortisol levels, tissue glucocorticoid action, blood pressure and foetal growth are present in adulthood in association with both early-life parameters and cardiometabolic risk factors. The data indicate a persisting epigenetic link between early-life maternal diet and/or foetal growth and cardiovascular disease risk in humans. © 2012 Blackwell Publishing Ltd.

  15. Recommendations for choosing an analysis method that controls Type I error for unbalanced cluster sample designs with Gaussian outcomes.

    Science.gov (United States)

    Johnson, Jacqueline L; Kreidler, Sarah M; Catellier, Diane J; Murray, David M; Muller, Keith E; Glueck, Deborah H

    2015-11-30

    We used theoretical and simulation-based approaches to study Type I error rates for one-stage and two-stage analytic methods for cluster-randomized designs. The one-stage approach uses the observed data as outcomes and accounts for within-cluster correlation using a general linear mixed model. The two-stage model uses the cluster specific means as the outcomes in a general linear univariate model. We demonstrate analytically that both one-stage and two-stage models achieve exact Type I error rates when cluster sizes are equal. With unbalanced data, an exact size α test does not exist, and Type I error inflation may occur. Via simulation, we compare the Type I error rates for four one-stage and six two-stage hypothesis testing approaches for unbalanced data. With unbalanced data, the two-stage model, weighted by the inverse of the estimated theoretical variance of the cluster means, and with variance constrained to be positive, provided the best Type I error control for studies having at least six clusters per arm. The one-stage model with Kenward-Roger degrees of freedom and unconstrained variance performed well for studies having at least 14 clusters per arm. The popular analytic method of using a one-stage model with denominator degrees of freedom appropriate for balanced data performed poorly for small sample sizes and low intracluster correlation. Because small sample sizes and low intracluster correlation are common features of cluster-randomized trials, the Kenward-Roger method is the preferred one-stage approach. Copyright © 2015 John Wiley & Sons, Ltd.

  16. Definition and design of an experiment to test raster scanning with rotating unbalanced-mass devices on gimbaled payloads

    Science.gov (United States)

    Lightsey, W. D.; Alhorn, D. C.; Polites, M. E.

    1992-01-01

    An experiment designed to test the feasibility of using rotating unbalanced-mass (RUM) devices for line and raster scanning gimbaled payloads, while expending very little power is described. The experiment is configured for ground-based testing, but the scan concept is applicable to ground-based, balloon-borne, and space-based payloads, as well as free-flying spacecraft. The servos used in scanning are defined; the electronic hardware is specified; and a computer simulation model of the system is described. Simulation results are presented that predict system performance and verify the servo designs.

  17. A Three-Phase Four-Leg Inverter-Based Active Power Filter for Unbalanced Current Compensation Using a Petri Probabilistic Fuzzy Neural Network

    Directory of Open Access Journals (Sweden)

    Kuang-Hsiung Tan

    2017-12-01

    Full Text Available A three-phase four-leg inverter-based shunt active power filter (APF is proposed to compensate three-phase unbalanced currents under unbalanced load conditions in grid-connected operation in this study. Since a DC-link capacitor is required on the DC side of the APF to release or absorb the instantaneous apparent power, the regulation control of the DC-link voltage of the APF is important especially under load variation. In order to improve the regulation control of the DC-link voltage of the shunt APF under variation of three-phase unbalanced load and to compensate the three-phase unbalanced currents effectively, a novel Petri probabilistic fuzzy neural network (PPFNN controller is proposed to replace the traditional proportional-integral (PI controller in this study. Furthermore, the network structure and online learning algorithms of the proposed PPFNN are represented in detail. Finally, the effectiveness of the three-phase four-leg inverter-based shunt APF with the proposed PPFNN controller for the regulation of the DC-link voltage and compensation of the three-phase unbalanced current has been demonstrated by some experimental results.

  18. Compensación de potencia reactiva mediante bancos asimétricos de capacitores; Reactive Power Compensation by Unbalanced Capacitor Banks

    Directory of Open Access Journals (Sweden)

    Ignacio Pérez Abril

    2011-02-01

    Full Text Available A pesar de que los sistemas de distribución primaria y secundaria son desbalanceados por naturaleza, lacompensación de potencia reactiva en estos sistemas, se realiza comúnmente mediante bancos decondensadores trifásicos balanceados. En este trabajo se presenta la formulación general para el problemade compensación de potencia reactiva en sistemas desbalanceados mediante bancos de condensadoresdesbalanceados. Se presentan cuatro ejemplos de compensación en el secundario de bancos desbalanceadosde transformadores monofásicos. Todos los ejemplos muestran que la compensación por bancosdesbalanceados de capacitores incrementa los beneficios con respecto al uso de bancos balanceados  In spite of the fact that primary and secondary distribution systems are unbalanced by nature, thereactive power compensation on these systems is commonly developed by the use of balanced capacitorbanks. In this paper, the general formulation for the reactive power compensation problem onunbalanced systems with unbalanced capacitor banks is developed. Four examples of reactive powercompensation on the secondary of unbalanced three-phase transformers banks are presented. All theexamples show that the compensation by unbalanced capacitor banks increases the active power lossessaving as well as reduce the transformer’s load and contributes to balance the line currents when the loadis unbalanced.

  19. Site directed recombination

    Science.gov (United States)

    Jurka, Jerzy W.

    1997-01-01

    Enhanced homologous recombination is obtained by employing a consensus sequence which has been found to be associated with integration of repeat sequences, such as Alu and ID. The consensus sequence or sequence having a single transition mutation determines one site of a double break which allows for high efficiency of integration at the site. By introducing single or double stranded DNA having the consensus sequence flanking region joined to a sequence of interest, one can reproducibly direct integration of the sequence of interest at one or a limited number of sites. In this way, specific sites can be identified and homologous recombination achieved at the site by employing a second flanking sequence associated with a sequence proximal to the 3'-nick.

  20. Nonradiative recombination in semiconductors

    CERN Document Server

    Abakumov, VN; Yassievich, IN

    1991-01-01

    In recent years, great progress has been made in the understandingof recombination processes controlling the number of excessfree carriers in semiconductors under nonequilibrium conditions. As a result, it is now possible to give a comprehensivetheoretical description of these processes. The authors haveselected a number of experimental results which elucidate theunderlying physical problems and enable a test of theoreticalmodels. The following topics are dealt with: phenomenological theory ofrecombination, theoretical models of shallow and deep localizedstates, cascade model of carrier captu

  1. Trends in recombinant protein use in animal production.

    Science.gov (United States)

    Gifre, Laia; Arís, Anna; Bach, Àlex; Garcia-Fruitós, Elena

    2017-03-04

    Recombinant technologies have made possible the production of a broad catalogue of proteins of interest, including those used for animal production. The most widely studied proteins for the animal sector are those with an important role in reproduction, feed efficiency, and health. Nowadays, mammalian cells and fungi are the preferred choice for recombinant production of hormones for reproductive purposes and fibrolytic enzymes to enhance animal performance, respectively. However, the development of low-cost products is a priority, particularly in livestock. The study of cell factories such as yeast and bacteria has notably increased in the last decades to make the new developed reproductive hormones and fibrolytic enzymes a real alternative to the marketed ones. Important efforts have also been invested to developing new recombinant strategies for prevention and therapy, including passive immunization and modulation of the immune system. This offers the possibility to reduce the use of antibiotics by controlling physiological processes and improve the efficacy of preventing infections. Thus, nowadays different recombinant fibrolytic enzymes, hormones, and therapeutic molecules with optimized properties have been successfully produced through cost-effective processes using microbial cell factories. However, despite the important achievements for reducing protein production expenses, alternative strategies to further reduce these costs are still required. In this context, it is necessary to make a giant leap towards the use of novel strategies, such as nanotechnology, that combined with recombinant technology would make recombinant molecules affordable for animal industry.

  2. X-ray dynamic observation of cervical degenerative disease induced by unbalanced dynamic and static forces in rats 1.

    Science.gov (United States)

    Xie, Hua; Huang, Yongjing; Nong, Luming; Xu, Nanwei; Gao, Gongming; Zhou, Dong

    2017-09-01

    To investigate dynamically the X-ray appearance of cervical degenerative disease induced by unbalanced dynamic and static forces in rats. A total of 60 Sprague Dawley rats were randomized into test (n=45) and control (n=15) groups, which were randomly subdivided into the one-, three- and six-month post-operative groups. The test group included 10, 15 and 20 rats at the respective corresponding post-operative stage and the control group included five rats at each time-point. By excising cervicodorsal muscles, interspinous ligaments and supraspinous ligament of rats in the test group, the balance of dynamic and static forces on cervical vertebrae was disrupted to establish a rat model of cervical degeneration. Spinal X-ray images were acquired, and intervertebral disc space and intervertebral foramen size were measured at one, three and six months post-operation. The results were analyzed and compared among groups. Cervical dynamic and static imbalance accelerated the appearance of cervical degenerative disease on X-ray. Cervical degenerative disease may be induced by unbalanced dynamic and static forces in rats.

  3. Harmonic Injection-Based Power Fluctuation Control of Three-Phase PV Systems under Unbalanced Grid Voltage Conditions

    Directory of Open Access Journals (Sweden)

    Nian-Cheng Zhou

    2015-02-01

    Full Text Available Unbalanced voltage will inevitably cause power and DC voltage fluctuations in a three-phase PV system. The deterioration of power quality will do great harm to the PV panels and the loads, so it is necessary to suppress the power fluctuations. This paper further explores the coefficients control strategy of PV converters under unbalanced voltage conditions, aiming to suppress power fluctuations by controlling the injection of some specific orders of current harmonics into the grid. In order to achieve this, the current reference of the PV inverter has been changed by bringing in two control coefficients, and the expression of each order of the current harmonics has been deduced. Based on the standards of PV systems, the regions from which the coefficients can be selected are determined. Then, by tuning these coefficients in the feasible regions, the output parameters (power fluctuation, current THD and odd harmonics can be controlled precisely. The model of this method is built and simulated in PSCAD/EMTDC, and as a result, it is shown that the power fluctuations can be restricted according to different power quality requirements.

  4. Integral Plus Resonant Sliding Mode Direct Power Control for VSC-HVDC Systems under Unbalanced Grid Voltage Conditions

    Directory of Open Access Journals (Sweden)

    Weipeng Yang

    2017-10-01

    Full Text Available An integral plus resonant sliding mode direct power control (IRSMC DPC strategy for voltage source converter high voltage direct current (VSC-HVDC systems under unbalanced grid voltage conditions is proposed in this paper. Through detailed instantaneous power flow analysis, a generalized power compensation method, by which the ratio between the amplitude of active and reactive power ripples can be controlled continuously, is obtained. This enables the system to provide flexible power control, so that the desired performance of the system on both the ac and dc sides can be attained under different operating conditions. When the grid voltage is unbalanced, one or both of the active and reactive power terms contain ripples, oscillating at twice the grid frequency, to obtain non-distorted ac current. A power controller consisting of the proportional, integral and resonant control laws is designed using the sliding mode control approach, to achieve accurate power control objective. Simulation studies on a two-terminal VSC-HVDC system using MATLAB/SIMULINK (R2013b, Mathworks, Natick, MA, USA are conducted to verify the effectiveness of the IRSMC DPC strategy. The results show that this strategy ensures satisfactory performance of the system over a wide range of operating conditions.

  5. An Improved Control Strategy for a Four-Leg Grid-Forming Power Converter under Unbalanced Load Conditions

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Miveh

    2016-01-01

    Full Text Available This paper proposes an improved multiloop control strategy for a three-phase four-leg voltage source inverter (VSI operating with highly unbalanced loads in an autonomous distribution network. The main objective is to balance the output voltages of the four-leg inverter under unbalanced load conditions. The proposed control strategy consists of a proportional-integral (PI voltage controller and a proportional current loop in each phase. The voltage controller and the current control loop are, respectively, used to regulate the instantaneous output voltage and generate the pulse width modulation (PWM voltage command with zero steady-state tracking error and fast transient response. A voltage decoupling feedforward path is also used to enhance the system robustness. Since the outer voltage loop operates in the synchronous reference frame, tuning and stability analysis of the PI controller is far from being straightforward. In order to cope with this challenge, the stationary reference frame equivalent of the voltage controller in the rotating frame is derived. Subsequently, a systematic design based on a frequency response approach is provided. Simulation results are also carried out using the DIgSILENT PowerFactory software to verify the effectiveness of the suggested control strategy.

  6. Speed Control of Matrix Converter-Fed Five-Phase Permanent Magnet Synchronous Motors under Unbalanced Voltages

    Directory of Open Access Journals (Sweden)

    Borzou Yousefi

    2017-09-01

    Full Text Available Five-phase permanent magnet synchronous motors (PMSM have special applications in which highly accurate speed and torque control of the motor are a strong requirement. Direct Torque Control (DTC is a suitable method for the driver structure of these motors. If in this method, instead of using a common five-phase voltage source inverter, a three-phase to five-phase matrix converter is used, the low-frequency current harmonics and the high torque ripple are limited, and an improved input power factor is obtained. Because the input voltages of such converters are directly supplied by input three-phase supply voltages, an imbalance in the voltages will cause problems such as unbalanced stator currents and electromagnetic torque fluctuations. In this paper, a new method is introduced to remove speed and torque oscillator factors. For this purpose, motor torque equations were developed and the oscillation components created by the unbalanced source voltage, determined. Then, using the active and reactive power reference generator, the controller power reference was adjusted in such a way that the electromagnetic torque of the motor did not change. By this means, a number of features including speed, torque, and flux of the motor were improved in terms of the above-mentioned conditions. Simulations were analyzed using Matlab/Simulink software.

  7. Single nucleotide polymorphism microarray-based concurrent screening of 24-chromosome aneuploidy and unbalanced translocations in preimplantation human embryos.

    Science.gov (United States)

    Treff, Nathan R; Northrop, Lesley E; Kasabwala, Khushabu; Su, Jing; Levy, Brynn; Scott, Richard T

    2011-04-01

    To develop, validate, and apply a single nucleotide polymorphism (SNP) microarray-based method for simultaneous preimplantation genetic diagnosis (PGD) of unbalanced inheritance of rearranged chromosomes and 24-chromosome aneuploidy screening. Prospective clinical research study. Academic reproductive medicine center. Eighteen couples carrying a balanced reciprocal or Robertsonian chromosomal rearrangement. PGD on blastocyst trophectoderm biopsy specimens. Aneuploidy, implantation, pregnancy, and delivery rates after SNP microarray-based aneuploidy and translocation screening. Single nucleotide polymorphism microarray was capable of detecting translocation-associated imbalances as small as 9.0 megabases. In the 12 transfers performed, sustained implantation occurred for 9 (45%) of 20 balanced-normal and euploid embryos replaced. The clinical pregnancy rate in patients receiving a transfer was 75% with six singleton deliveries and three ongoing singleton pregnancies thus far. Significantly fewer embryos were eligible for transfer with the incorporation of simultaneous 24-chromosome aneuploidy screening. Arrested embryos were also significantly more likely to possess unbalanced chromosomes when compared with developmentally competent blastocysts. This SNP microarray-based method provides the first opportunity to improve outcomes through comprehensive identification of euploid embryos from translocation carrier couples. Copyright © 2011 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  8. An improved synchronous reference frame current control strategy for a photovoltaic grid-connected inverter under unbalanced and nonlinear load conditions

    DEFF Research Database (Denmark)

    Naderipour, Amirreza; Asuhaimi Mohd Zin, Abdullah; Bin Habibuddin, Mohd Hafiz

    2017-01-01

    . It is challenging to suppress the harmonic content in the output current below a pre-set value in the GCI. It is also difficult to compensate for unbalanced loads even when the grid is under disruption due to total harmonic distortion (THD) and unbalanced loads. The primary advantage and objective of this method......In recent years, renewable energy sources have been considered the most encouraging resources for grid and off-grid power generation. This paper presents an improved current control strategy for a three-phase photovoltaic grid-connected inverter (GCI) under unbalanced and nonlinear load conditions...... to control the active and reactive power and harmonic current compensation, and it also corrects the system unbalance. The proposed control method features the synchronous reference frame (SRF) method. Simulation results are presented to demonstrate the effective performance of the proposed method....

  9. Alternative Fuels

    Science.gov (United States)

    Alternative fuels include gaseous fuels such as hydrogen, natural gas, and propane; alcohols such as ethanol, methanol, and butanol; vegetable and waste-derived oils; and electricity. Overview of alternative fuels is here.

  10. Rapid generation of markerless recombinant MVA vaccines by en passant recombineering of a self-excising bacterial artificial chromosome.

    Science.gov (United States)

    Cottingham, Matthew G; Gilbert, Sarah C

    2010-09-01

    The non-replicating poxviral vector modified vaccinia virus Ankara (MVA) is currently a leading candidate for development of novel recombinant vaccines against globally important diseases. The 1980s technology for making recombinant MVA (and other poxviruses) is powerful and robust, but relies on rare recombination events in poxviral-infected cells. In the 21st century, it has become possible to apply bacterial artificial chromosome (BAC) technology to poxviruses, as first demonstrated by B. Moss' lab in 2002 for vaccinia virus. A similar BAC clone of MVA was subsequently derived, but while recombination-mediated genetic engineering for rapid production was used of deletion mutants, an alternative method was required for efficient insertion of transgenes. Furthermore "markerless" viruses, which carry no trace of the selectable marker used for their isolation, are increasingly required for clinical trials, and the viruses derived via the new method contained the BAC sequence in their genomic DNA. Two methods are adapted to MVA-BAC to provide more rapid generation of markerless recombinants in weeks rather than months. "En passant" recombineering is applied to the insertion of a transgene expression cassette and the removal of the selectable marker in bacteria; and a self-excising variant of MVA-BAC is constructed, in which the BAC cassette region is rapidly and efficiently lost from the viral genome following rescue of the BAC into infectious virus. These methods greatly facilitate and accelerate production of recombinant MVA, including markerless constructs. Copyright 2010 Elsevier B.V. All rights reserved.

  11. Recombinant Collagenlike Proteins

    Science.gov (United States)

    Fertala, Andzej

    2007-01-01

    A group of collagenlike recombinant proteins containing high densities of biologically active sites has been invented. The method used to express these proteins is similar to a method of expressing recombinant procollagens and collagens described in U. S. Patent 5,593,859, "Synthesis of human procollagens and collagens in recombinant DNA systems." Customized collagenous proteins are needed for biomedical applications. In particular, fibrillar collagens are attractive for production of matrices needed for tissue engineering and drug delivery. Prior to this invention, there was no way of producing customized collagenous proteins for these and other applications. Heretofore, collagenous proteins have been produced by use of such biological systems as yeasts, bacteria, and transgenic animals and plants. These products are normal collagens that can also be extracted from such sources as tendons, bones, and hides. These products cannot be made to consist only of biologically active, specific amino acid sequences that may be needed for specific applications. Prior to this invention, it had been established that fibrillar collagens consist of domains that are responsible for such processes as interaction with cells, binding of growth factors, and interaction with a number of structural proteins present in the extracellular matrix. A normal collagen consists of a sequence of domains that can be represented by a corresponding sequence of labels, e.g., D1D2D3D4. A collagenlike protein of the present invention contains regions of collagen II that contain multiples of a single domain (e.g., D1D1D1D1 or D4D4D4D4) chosen for its specific biological activity. By virtue of the multiplicity of the chosen domain, the density of sites having that specific biological activity is greater than it is in a normal collagen. A collagenlike protein according to this invention can thus be made to have properties that are necessary for tissue engineering.

  12. Hydrogen recombiner catalyst test supporting data

    Energy Technology Data Exchange (ETDEWEB)

    Britton, M.D.

    1995-01-19

    This is a data package supporting the Hydrogen Recombiner Catalyst Performance and Carbon Monoxide Sorption Capacity Test Report, WHC-SD-WM-TRP-211, Rev 0. This report contains 10 appendices which consist of the following: Mass spectrometer analysis reports: HRC samples 93-001 through 93-157; Gas spectrometry analysis reports: HRC samples 93-141 through 93-658; Mass spectrometer procedure PNL-MA-299 ALO-284; Alternate analytical method for ammonia and water vapor; Sample log sheets; Job Safety analysis; Certificate of mixture analysis for feed gases; Flow controller calibration check; Westinghouse Standards Laboratory report on Bois flow calibrator; and Sorption capacity test data, tables, and graphs.

  13. Cell biology of mitotic recombination

    DEFF Research Database (Denmark)

    Lisby, Michael; Rothstein, Rodney

    2015-01-01

    Homologous recombination provides high-fidelity DNA repair throughout all domains of life. Live cell fluorescence microscopy offers the opportunity to image individual recombination events in real time providing insight into the in vivo biochemistry of the involved proteins and DNA molecules...... as well as the cellular organization of the process of homologous recombination. Herein we review the cell biological aspects of mitotic homologous recombination with a focus on Saccharomyces cerevisiae and mammalian cells, but will also draw on findings from other experimental systems. Key topics...

  14. Laboratory and Consumer Evaluations of Alternative Formulations of Recombined Milk.

    Science.gov (United States)

    1992-09-01

    blood cholesterol and coronary heart disease (Oliver, 1990). Coconut oil is high in saturated fat (92%) and therefore its use has been scrutinized by the...diglycerides, canola oil with actoloid, canolWsunflower blend. sunflower oil , and coconut oil , was conducted on the island of Okinawa. Japan. Air Force...flavor, milk consistency, and milk mouthfeel. All possible pairs of milk samples were served in random, counteralanced ad Milk filled with coconut oil

  15. Familial insertion (3;5)(q25.3;q22.1q31.3) with deletion or duplication of chromosome region 5q22.1-5q31.3 in ten unbalanced carriers.

    NARCIS (Netherlands)

    Arens, Y.H.; Engelen, J.J.M.; Govaerts, L.C.P.; Ravenswaaij-Arts, C.M.A. van; Loneus, W.H.; Lent-Albrechts, J.C. van; Blij-Philipsen, M. van der; Hamers, A.J.H.; Schrander-Stumpel, C.T.R.M.

    2004-01-01

    We report on the clinical and cytogenetic data of a large family with an unbalanced insertion translocation (3;5)(q25.3;q22.1q31.3). Analysis of GTG-banded chromosomes demonstrated that unbalanced inheritance of a parental insertion translocation caused either a partial deletion or duplication 5q in

  16. Improved Power Control Using Optimal Adjustable Coefficients for Three-Phase Photovoltaic Inverter under Unbalanced Grid Voltage

    Directory of Open Access Journals (Sweden)

    Qianggang Wang

    2014-01-01

    Full Text Available Unbalanced grid faults will lead to several drawbacks in the output power quality of photovoltaic generation (PV converters, such as power fluctuation, current amplitude swell, and a large quantity of harmonics. The aim of this paper is to propose a flexible AC current generation method by selecting coefficients to overcome these problems in an optimal way. Three coefficients are brought in to tune the output current reference within the required limits of the power quality (the current harmonic distortion, the AC current peak, the power fluctuation, and the DC voltage fluctuation. Through the optimization algorithm, the coefficients can be determined aiming to generate the minimum integrated amplitudes of the active and reactive power references with the constraints of the inverter current and DC voltage fluctuation. Dead-beat controller is utilized to track the optimal current reference in a short period. The method has been verified in PSCAD/EMTDC software.

  17. Origin of unbalanced reaction of vacancies and interstitials during irradiation with cascades and influence on microstructural evolution

    International Nuclear Information System (INIS)

    Kiritani, M.; Yoshiie, T.; Kojima, S.; Satoh, Y.

    1993-01-01

    Based upon the underlying premise that all the microstructure evolution during irradiation results from the asymetrical reaction between vacancies and interstitials, the origin of the asymetry is sought and categorized, and the mechanism of defect structure evolution for each source of asymetry is investigated. The role of neutral sinks and the influence of dislocations are examined for the cases of irradiation with and without cascade damage. Vacancy cluster formation directly from cascades is found to favor the generation of freely migrating interstitials. Stochastic fluctuations of the point defect reactions under the balanced condition of vacancy and interstitial is experimentally detected, and the important role of the fluctuations is found in the determination of the fate of small interstitial cluster embryos produced by cascade damage. The influence of the unbalanced point defect reaction starting from difference in spacial distribution between vacancies and interstitials formed by cascade collisions is discussed as one of the important origins of vacancy dominant reactions. (orig.)

  18. Performance analysis of active damped small DC-link capacitor based drive for unbalanced input voltage supply

    DEFF Research Database (Denmark)

    Maheshwari, Ram Krishan; Munk-Nielsen, Stig

    2011-01-01

    A small DC-link capacitor based drive is presented in this paper. The drive shows negative impedance instability at operating points with high power load. A phase portrait is presented for input filter states which exhibit a limit cycle. When the drive is operated with unbalanced input supply...... voltages, the rectified voltage contains all even harmonics frequencies. However, it is shown that the dominant harmonic component of the DC-link voltage is decided by the limit cycle instead of the input filter resonance frequency. An active damping technique is used to stabilize the operating point....... The responses of the DC-link voltage with and without active damping are presented. The low order harmonics components are reduced with the increase in the gain of the active damping term. The experimental results for the DC-link voltage, input phase currents, and machine phase current are presented....

  19. Improved power control using optimal adjustable coefficients for three-phase photovoltaic inverter under unbalanced grid voltage.

    Science.gov (United States)

    Wang, Qianggang; Zhou, Niancheng; Lou, Xiaoxuan; Chen, Xu

    2014-01-01

    Unbalanced grid faults will lead to several drawbacks in the output power quality of photovoltaic generation (PV) converters, such as power fluctuation, current amplitude swell, and a large quantity of harmonics. The aim of this paper is to propose a flexible AC current generation method by selecting coefficients to overcome these problems in an optimal way. Three coefficients are brought in to tune the output current reference within the required limits of the power quality (the current harmonic distortion, the AC current peak, the power fluctuation, and the DC voltage fluctuation). Through the optimization algorithm, the coefficients can be determined aiming to generate the minimum integrated amplitudes of the active and reactive power references with the constraints of the inverter current and DC voltage fluctuation. Dead-beat controller is utilized to track the optimal current reference in a short period. The method has been verified in PSCAD/EMTDC software.

  20. ANALYSIS OF THE HARMONIC LOSSES WITH ARTIFICIAL NEURAL NETWORKS IN UNBALANCED SYSTEM LOSSES USING BALANCED ELECTRIC POWER SYSTEM DATA

    Directory of Open Access Journals (Sweden)

    Aslan İNAN

    2005-01-01

    Full Text Available The losses in the power systems should be low as possible as. Saving energy instead of loses (kWh in power utilities can supply much more energy to the consumers. The lower losses the more energy is saved and thus the power system becomes more economical. In recent years, the increasing number of applications and power ratings of the devices which have nonlinear voltage-current characteristics cause voltage waveform distortion and additional losses. While evaluating losses considering harmonics will provide more contribution to obtain more accurate results. In this study, Artificial Neural Networks (ANN method has been presented to predict the harmonic losses in unbalanced power systems by using the data from balanced power system with nonlinear loads.

  1. Detecting mode hopping in single-longitudinal-mode fiber ring lasers based on an unbalanced fiber Michelson interferometer.

    Science.gov (United States)

    Ma, Mingxiang; Hu, Zhengliang; Xu, Pan; Wang, Wei; Hu, Yongming

    2012-10-20

    A method of detecting mode hopping for single-longitudinal-mode (SLM) fiber ring lasers has been proposed and experimentally demonstrated. The method that is based on an unbalanced Michelson interferometer (MI) utilizing phase generated carrier modulation instantly transforms mode-hopping dynamics into steep phase changes of the interferometer. Multiform mode hops in an SLM erbium-doped fiber ring laser with an 18.6 MHz mode spacing have been detected exactly in real-time domain and discussed in detail. Numerical results show that the MI-based method has a high testing sensitivity for identifying mode hopping, which will play a significant role in evaluating the output stability of SLM fiber lasers.

  2. De novo unbalanced translocation (4p duplication/8p deletion) in a patient with autism, OCD, and overgrowth syndrome.

    Science.gov (United States)

    Sagar, Angela; Pinto, Dalila; Najjar, Fedra; Guter, Stephen J; Macmillan, Carol; Cook, Edwin H

    2017-06-01

    Chromosomal abnormalities, such as unbalanced translocations and copy number variants (CNVs), are found in autism spectrum disorders (ASDs) [Sanders et al. (2011) Neuron 70: 863-885]. Many chromosomal abnormalities, including sub microscopic genomic deletions and duplications, are missed by G-banded karyotyping or Fragile X screening alone and are picked up by chromosomal microarrays [Shen et al. (2010) Pediatrics 125: e727-735]. Translocations involving chromosomes 4 and 8 are possibly the second most frequent translocation in humans and are often undetected in routine cytogenetics [Giglio et al. (2002) Circulation 102: 432-437]. Deletions of 4p16 have been associated with Wolf-Hirschhorn syndrome while 4p16 duplications have been associated with an overgrowth syndrome and mild to moderate mental retardation [Partington et al. (1997) Journal of Medical Genetics 34: 719-728]. The 8p23.3 region contains the autism candidate gene DLGAP2, which can contribute to autism when disrupted [Marshall et al. (2008) The American Journal of Human Genetics 82: 477-488] . There has been a case report of a family with autism spectrum disorder (ASD), prominent obsessional behavior, and overgrowth in patients with der (8) t (4;8) p (16;23) [Partington et al. (1997)]. This is an independent report of a male patient with autism, obsessive compulsive disorder (OCD), attention-deficit hyperactivity disorder (ADHD), and an overgrowth syndrome, whose de novo unbalanced translocation der (8) t (4;8) p (16.1→ter; 23.1→ter) was initially missed by routine cytogenetics but detected with SNP microarray, allowing higher resolution of translocation breakpoints. © 2017 Wiley Periodicals, Inc.

  3. Neutron activation analysis in the central nervous system tissues of neurological diseases and rats maintained on minerally unbalanced diets

    International Nuclear Information System (INIS)

    Yasui, Masayuki; Ota, Kiichiro; Sasajima, Kazuhisa.

    1995-01-01

    Epidemiological surveys on Guam have suggested that low calcium (Ca), magnesium (Mg) and high Al and Mn in river, soil and drinking water may be implicated in the pathogenesis of PD. Experimentally, low Ca-Mg diets with or without added Al have been found to accelerate Al deposition in the CNS of rats and monkeys. Although excessive deposition of Mn produces neurotoxic action similar to Al in CNS tissues, the mechanism of Mn deposition coupled with Al loading in the presence of low Ca-Mg intake is not yet known. In this animal study, the deposition and metal-metal interaction of both Al and Mn in the CNS, visceral organs and bones of rats fed unbalanced mineral diets were analyzed. Male Wistar rats, weighing 200 g, were maintained for 90 days on the following diets: (A) standard diet, (B) low Ca diet, (C) low Ca-Mg diet, (D) low Ca-Mg diet with high Al. Al and Mn content were determined in the frontal cortex, spinal cord, kidney, muscle, abdominal aorta, femur and lumbar spine using neutron activation analysis (NAA). Intake of low Ca and Mg with added Al in rats led to the high concentrations of Mn and Al in bones and in the frontal cortex. It is likely that unbalanced mineral diets and metal-metal interactions may lead to the unequal distribution of Al and Mn in bones and ultimately in the CNS inducing CNS degeneration. On the other hand, concentrations of copper (Cu), calcium (Ca) and aluminum (Al) for 26 subanatomical regions of the CNS were measured by neutron activation analysis (NAA) in two cases of Wilson's disease, two of portal systemic encephalopathy, six pathologically verified cases of ALS, four of Parkinson's disease and five neurologically normal controls. Also zinc (Zn) and iron (Fe) concentrations were measured by NAA for frontal and occipital lobes of parkinsonism-dementia. (author)

  4. Control Method for DC-Link Voltage Ripple Cancellation in Voltage Source Inverter under Unbalanced Three-Phase Voltage Supply Conditions

    Czech Academy of Sciences Publication Activity Database

    Chomát, Miroslav; Schreier, Luděk

    2005-01-01

    Roč. 152, č. 3 (2005), s. 494-500 ISSN 1350-2352 R&D Projects: GA ČR(CZ) GA102/02/0554 Institutional research plan: CEZ:AV0Z20570509 Keywords : DC-link voltage * unbalanced three-phase voltage Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 0.587, year: 2005

  5. Peripheral blood mononuclear cells as a source to detect markers of homeostatic alterations caused by the intake of diets with an unbalanced macronutrient composition

    NARCIS (Netherlands)

    Diaz-Rua, R.; Keijer, J.; Caimari, A.; Schothorst, van E.M.; Oliver, P.; Palou, A.

    2015-01-01

    Peripheral blood mononuclear cells (PBMC) are accessible in humans and their gene expression pattern was shown to reflect overall physiological response of the body to a specific stimulus, such as diet. We aimed to study the impact of sustained intake (4 months) of diets with an unbalanced

  6. Unique unbalanced X;X translocation (Xq22;p11.2) in a woman with primary amenorrhea but without Ullrich-Turner syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Letterie, G.S. [Virginia Mason Medical Center, Seattle, WA (United States)

    1995-12-04

    This is a report of a patient with delayed puberty and a previously unreported translocation 46,X,-X,+der(X),t(X;X) (q22;p11.2) without any manifestations of Ullrich-Turner syndrome. The relationship of this unbalanced translocation to the critical region hypothesis is discussed. 6 refs., 3 figs.

  7. Hadron Correlations and Parton Recombination

    Energy Technology Data Exchange (ETDEWEB)

    Fries, R.J. [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)]. E-mail: rjfries@comp.tamu.edu

    2007-02-15

    Parton recombination has been found to be an extremely useful model to understand hadron production at the Relativistic Heavy Ion Collider. It is particularly important to explore its connections with hard processes. This article reviews some of the aspects of the quark recombination model and places particular emphasis on hadron correlations.

  8. Control of grid integrated voltage source converters under unbalanced conditions: development of an on-line frequency-adaptive virtual flux-based approach

    Energy Technology Data Exchange (ETDEWEB)

    Suul, Jon Are

    2012-03-15

    Three-Phase Voltage Source Converters (VSCs) are finding widespread applications in grid integrated power conversion systems. The control systems of such VSCs are in an increasing number of these applications required to operate during voltage disturbances and unbalanced conditions. Control systems designed for grid side voltagesensor-less operation are at the same time becoming attractive due to the continuous drive for cost reduction and increased reliability of VSCs, but are not commonly applied for operation during unbalanced conditions. Methods for voltage-sensor-less grid synchronization and control of VSCs under unbalanced grid voltage conditions will therefore be the main focus of this Thesis. Estimation methods based on the concept of Virtual Flux, considering the integral of the converter voltage in analogy to the flux of an electric machine, are among the simplest and most well known techniques for achieving voltage-sensor-less grid synchronization. Most of the established techniques for Virtual Flux estimation are, however, either sensitive to grid frequency variations or they are not easily adaptable for operation under unbalanced grid voltage conditions. This Thesis addresses both these issues by proposing a simple approach for Virtual Flux estimation by utilizing a frequency-adaptive filter based on a Second Order Generalized Integrator (SOGI). The proposed approach can be used to achieve on-line frequency-adaptive varieties of conventional strategies for Virtual Flux estimation. The main advantage is, however, that the SOGI-based Virtual Flux estimation can be arranged in a structure that achieves inherent symmetrical component sequence separation under unbalanced conditions. The proposed method for Virtual Flux estimation can be used as a general basis for voltage-sensor-less grid synchronization and control during unbalanced conditions. In this Thesis, the estimated Virtual Flux signals are used to develop a flexible strategy for control of active

  9. How alternative are alternative fuels?

    OpenAIRE

    Soffritti, Tiziana; Danielis, Romeo

    1998-01-01

    Could alternative fuel vehicles contribute to a substantial reduction of air pollution? Is there a market for alternative fuel vehicles? Could a market be created via a pollution tax? The article answers these questions on the basis of the available estimates.

  10. UNBALANCED SCALES OF GLOBAL CAPITALISM: ANALYZING TEMPORARY FOREIGN WORKER PROGRAMS IN CANADA

    Directory of Open Access Journals (Sweden)

    Emma Callon

    2016-08-01

    Full Text Available his article analyzes several characteristics of two of Canada’s Temporary Foreign Worker Programs (TFWPs: The Seasonal Agricultural Worker Program (SAWP and the Live-in Caregiver Program (LCP. First, I consider the social and economic contexts in which these programs have emerged. Second, I discuss how these programs maintain racial and gendered hierarchies. Third, I problematize the relationship TFWPs have with citizenship status, as well as critique TFWPs as a long-term solution to Canadian labour shortages. Last, I discuss the potential benefits of these TFWPs and suggest alternatives and potential improvements to the programs. Using a Marxist framework, this analysis situates Canada’s TFWPs within the broader political economy and argues that global capitalism and the state interact to serve the people and economies of the Global North at the expense of migrant workers from the Global South.

  11. Evidence that meiotic pairing starts at the telomeres: Molecular analysis of recombination in a family with a pericentric X chromosome inversion

    Energy Technology Data Exchange (ETDEWEB)

    Shashi, V.; Allinson, P.S.; Golden, W.L.; Kelly, T.E. [Univ. of Virginia, Charlottesville, VA (United States)

    1994-09-01

    Recent studies in yeast have shown that telomeres rather than centromeres lead in chromosome movement just prior to meiosis and may have a role in recombination. Cytological studies of meiosis in Drosophila and mice have shown that in pericentric inversion heterozygotes there is lack of loop formation, with recobmination seen only outside the inversion. In a family with Duchenne muscular dystrophy (DMD) we recognized that only affected males and carrier females had a pericentric X chromosome inversion (inv X(p11.4;q26)). Since the short arm inversion breakpoint was proximal to the DMD locus, it could not be implicated in the mutational event causing DMD. There was no history of infertility, recurrent miscarriages or liveborn unbalanced females to suggest there was recombination within the inversion. We studied 22 members over three generations to understand the pattern of meiotic recombination between the normal and the inverted X chromosome. In total, 17 meioses involving the inverted X chromosome in females were studied by cytogenetic analysis and 16 CA repeat polymorphisms along the length of the X chromosome. Results: (a) There was complete concordance between the segregation of the DMD mutation and the inverted X chromosome. (b) On DNA analysis, there was complete absence of recombination within the inverted segment. We also found no recombination at the DMD locus. Recombination was seen only at Xp22 and Xq27-28. (c) Recombination was seen in the same individual at both Xp22 and Xq27-28 without recombination otherwise. Conclusions: (1) Pericentric X inversions reduce the genetic map length of the chromosome, with the physical map length being normal. (2) Meiotic X chromosome pairing in this family is initiated at the telomeres. (3) Following telomeric pairing in pericentric X chromosome inversions, there is inhibition of recombination within the inversion and adjacent regions.

  12. Mercury resistance as a selective marker for recombinant mycobacteria.

    Science.gov (United States)

    Baulard, A; Escuyer, V; Haddad, N; Kremer, L; Locht, C; Berche, P

    1995-04-01

    The use of antibiotic-resistance markers for the selection of recombinant mycobacteria is widespread but questionable considering the development of live recombinant BCG vaccines. In contrast, vector-encoded resistance to heavy metals such as mercury may represent an interesting alternative for the development of live vaccines compatible with use in humans and in animals. The mercury resistance genes (mer) from Pseudomonas aeruginosa and from Serratia marcescens were cloned into the Escherichia coli-Mycobacterium shuttle vector pRR3. The resulting vectors, designated pMR001 and pVN2, were introduced by electroporation into Mycobacterium smegmatis, Mycobacterium bovis BCG and Mycobacterium tuberculosis. The recombinant mycobacteria were stable in vitro and in vivo, and had high-level mercury resistance, thus indicating that the mer genes can be useful as selective markers in mycobacteria.

  13. Unbalanced interchromosomal insertion diagnosed prenatally by FISH, with carrier mother, previously misdiagnosed as having a balanced reciprocal translocation

    Energy Technology Data Exchange (ETDEWEB)

    Yu, M.T.; Leiber, E.; Qazi, Q. [and others

    1994-09-01

    Insertion translocations are rare. A carrier with a balanced insertion translocation is most likely to be detected through offspring with an unbalanced translocation. We with to report a case where a correct diagnosis, made prenatally with FISH, corrected the initial misdiagnosis of the mother in another institute. PDL received an amniotic fluid sample from a 28 y.o. woman (G5P2Sab1TOP1) at 19 wks gestation. The indications were a reported balanced translocation, t(6;13), in the mother and a previous daughter with an unbalanced translocation. Chromosome analysis of the amniocytes showed a female karyotype with an abnormal chr. 13. Since the mother was diagnosed as having t(6;13)(q21;q34), the der(13) in the amniocytes was initially assumed to result from an adjacent segregation of the t(6;13). However, the banding patterns of this abnormal chr. 13 did not fit into the above defined translocation. With FISH and a chr. 13 painting probe, this der(13) was painted in the proximal and the distal thirds, but NOT in the middle region. This indicates that the middle section of the der(13) must have originated from 6q. The banding pattern is compatible with a direct insertion of 6q15 to 6q23.3 into 13q21.2. Thus, the fetus has partial trisomy 6q. After counseling, the mother elected to terminate the pregnancy but later changed her mind. An 8 lb 12 oz baby girl was born at 36 wks. (mother diabetic). Chromosome analysis of the newborn blood confirmed the dx. The mother was studied, using multicolor painting probes for chromosomes 13 and 6, a balanced direct insertion of 6q15 to 6q23.3 into chr. 13q21.2 was clearly shown. The previous affected daughter with a 13q+ is now 4 y.o. (a restudy is planned). She has microcephaly, severe developmental delay and other dysmorphic features. This case illustrates the advantage of using FISH to arrive at a definitive diagnosis of an insertion translocation.

  14. Controlled Release from Recombinant Polymers

    Science.gov (United States)

    Price, Robert; Poursaid, Azadeh; Ghandehari, Hamidreza

    2014-01-01

    Recombinant polymers provide a high degree of molecular definition for correlating structure with function in controlled release. The wide array of amino acids available as building blocks for these materials lend many advantages including biorecognition, biodegradability, potential biocompatibility, and control over mechanical properties among other attributes. Genetic engineering and DNA manipulation techniques enable the optimization of structure for precise control over spatial and temporal release. Unlike the majority of chemical synthetic strategies used, recombinant DNA technology has allowed for the production of monodisperse polymers with specifically defined sequences. Several classes of recombinant polymers have been used for controlled drug delivery. These include, but are not limited to, elastin-like, silk-like, and silk-elastinlike proteins, as well as emerging cationic polymers for gene delivery. In this article, progress and prospects of recombinant polymers used in controlled release will be reviewed. PMID:24956486

  15. Hydrogen recombiner development at AECL

    International Nuclear Information System (INIS)

    Dewit, W.A.; Koroll, G.W.; Loesel Sitar, J.; Graham, W.R.C.

    1997-01-01

    Catalytic recombiners have been developed at AECL for the purpose of hydrogen removal in post-accident nuclear containment buildings. The recombiners are based on a particular catalyst designed by AECL which has extraordinary resistance to fouling from water and water vapour and a large thermodynamic range of operation. The catalysts were developed, originally, for the purpose of heavy water manufacturing by way of a catalytic exchange process. Application of these catalyst materials in recombiners for containment applications began in the late 1980's. The first application was a passive recombiner, qualified for use in control of radiolytic hydrogen in the headspace of a pool-type experimental reactor of AECL design in 1988. The passive, or natural convection recombiner concept has continued development to commercial stage for application in power reactor containments. This paper reviews the AECL recombiner development, describes the current model and shows results from tests of full-scale recombiners in the Large Scale Vented Combustion Test Facility at AECL-WL. The AECL recombiner is designed for compactness and ease of engineering into containment. The design is a simple, open-ended rectangular enclosure with catalyst elements arranged inside to promote optimum convective flow driven by heat of recombination at the catalyst surface. Self start, as evidenced by catalyst heating and initiation of flow, is achieved in less than 1% hydrogen, with available oxygen, at room temperature and 100% relative humidity. This low temperature start-up in condensing atmospheres is viewed as the most challenging condition for wet-proofing effectiveness. Cold start-up is a vital performance requirement in containments, such as CANDU, where engineered air-cooling systems are operating and where long-term hydrogen control is required, after containment atmospheres have cooled. Once started, the removal capacity scales linearly with the inlet cross-section area and the partial

  16. Review of Parton Recombination Models

    International Nuclear Information System (INIS)

    Bass, Steffen A

    2006-01-01

    Parton recombination models have been very successful in explaining data taken at RHIC on hadron spectra and emission patterns in Au+Au collisions at transverse momenta above 2 GeV/c, which have exhibited features which could not be understood in the framework of basic perturbative QCD. In this article I will review the current status on recombination models and outline which future challenges need to be addressed by this class of models

  17. Recombinant snake venom prothrombin activators

    OpenAIRE

    L?vgren, Ann

    2012-01-01

    Three prothrombin activators; ecarin, which was originally isolated from the venom of the saw-scaled viper Echis carinatus, trocarin from the rough-scaled snake Tropidechis carinatus, and oscutarin from the Taipan snake Oxyuranus scutellatus, were expressed in mammalian cells with the purpose to obtain recombinant prothrombin activators that could be used to convert prothrombin to thrombin. We have previously reported that recombinant ecarin can efficiently generate thrombin without the need ...

  18. Nonlinear Dynamic Response of an Unbalanced Flexible Rotor Supported by Elastic Bearings Lubricated with Piezo-Viscous Polar Fluids

    Directory of Open Access Journals (Sweden)

    Mustapha Lahmar

    2015-04-01

    Full Text Available On the basis of the V. K. Stokes micro-continuum theory, the effects of couple stresses on the nonlinear dynamic response of the unbalanced Jeffcott’s flexible rotor supported by layered hydrodynamic journal bearings is presented in this paper. A nonlinear transient modified Reynolds’ equation is derived and discretized by the finite element method to obtain the fluid-film pressure field as well as the film thickness by means of the implicit Euler method. The nonlinear orbits of the rotor center are determined by solving the nonlinear differential equations of motion with the explicit Euler’s scheme taking into account the flexibility of rotor. According to the obtained results, the combined effects of couple stresses due to the presence of polymer additives in lubricant and the pressure dependent viscosity on the nonlinear dynamic response of the rotor-bearing system are significant and cannot be ignored or overlooked. As expected, these effects are more noticeable for polymers characterized by higher length molecular chains.

  19. Use of Three-Level Power Converters in Wind-Driven Permanent-Magnet Synchronous Generators with Unbalanced Loads

    Directory of Open Access Journals (Sweden)

    Ming-Hung Chen

    2015-06-01

    Full Text Available This paper describes the design and implementation of three-level power converters for wind-driven permanent-magnet synchronous generators with unbalanced loads. To increase voltage stress and reduce current harmonics in the electrical power generated by a wind generator, a three-phase, three-level rectifier is used. Because a synchronous rotating frame is used on the AC-input side, the use of a neutral-point-clamped controller is proposed to increase the power factor to unity and reduce current harmonics. Furthermore, a novel six-leg inverter is proposed for transferring energy from the DC voltage to a three-phase, four-wire AC source with a constant voltage and a constant frequency. The power converters also contain output transformers and filters for power buffering and filtering, respectively. All three output phase voltages are fed back to control the inverter output during load variations. A digital signal processor is used as the core control device for implementing a 1.5 kV, 75 kW drive system. Experimental data show that the power factor is successfully increased to unity and the total current harmonic distortion is 3.2% on the AC-input side. The entire system can attain an efficiency of 91%, and the voltage error between the upper and lower capacitors is approximately zero. Experimental results that confirm the high performance of the proposed system are presented.

  20. VALORATE: fast and accurate log-rank test in balanced and unbalanced comparisons of survival curves and cancer genomics.

    Science.gov (United States)

    Treviño, Victor; Tamez-Pena, Jose

    2017-06-15

    The association of genomic alterations to outcomes in cancer is affected by a problem of unbalanced groups generated by the low frequency of alterations. For this, an R package (VALORATE) that estimates the null distribution and the P -value of the log-rank based on a recent reformulation is presented. For a given number of alterations that define the size of survival groups, the log-rank density is estimated by a weighted sum of conditional distributions depending on a co-occurrence term of mutations and events. The estimations are accurately accelerated by sampling across co-occurrences allowing the analysis of large genomic datasets in few minutes. In conclusion, the proposed VALORATE R package is a valuable tool for survival analysis. The R package is available in CRAN at https://cran.r-project.org and in http://bioinformatica.mty.itesm.mx/valorateR . vtrevino@itesm.mx. Supplementary data are available at Bioinformatics online. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

  1. DIRECT POWER CONTROL OF A DFIG BASED WIND TURBINS UNDER UNBALANCED GRID VOLTAGE WITHOUT ROTOR POSITION SENSOR

    Directory of Open Access Journals (Sweden)

    ali izanlo

    2017-05-01

    Full Text Available In this paper, the behavior of a doubly fed induction generator (DFIG is proposed under unbalanced grid voltage and without using a rotor position sensor. There are two main methods that are been used for the detection of rotor position: using shaft sensor and sensorless algorithm. In this paper the shaft sensor is eliminated and a position sensorless algorithm is used for estimating the rotor position. Sensorless operation is more desirable than using shaft sensor, because the shaft sensor has several disadvantages related to the cost, cabling, robustness and maintenance. Also, during network unbalance, three selectable control targets are identified for the rotor side converter (RSC, i.e., obtaining sinusoidal and symmetrical stator currents, mitigation of active and reactive powers ripples and the cancellation of electromagnetic torque oscillations. The effectiveness of the proposed control strategy is confirmed by the simulation results from a 2-MW DFIG system. It is concluded that the sensorless algorithm is able to produce accurate results similar to the case of that used from shaft sensor and it can be used in the practical applications.

  2. Association of Affect with Vertical Position in L1 but not in L2 in Unbalanced Bilinguals

    Directory of Open Access Journals (Sweden)

    Degao eLi

    2015-05-01

    Full Text Available After judging the valence of the positive (e.g., happy and the negative words (e.g., sad, the participants’ response to the letter (q or p was faster and slower, respectively, when the letter appeared at the upper end than at the lower end of the screen in Meier & Robinson’ (2004 second experiment. To compare this metaphorical association of affect with vertical position in Chinese-English bilinguals’ first language (L1 and second language (L2 (language, we conducted four experiments in an affective priming task. The targets were one set of positive or negative words (valence, which were shown vertically above or below the centre of the screen (position. The primes, presented at the centre of the screen, were affective words that were semantically related to the targets, affective words that were not semantically related to the targets, affective icon-pictures, and neutral strings in experiment 1, 2, 3, and 4, respectively. In judging the targets’ valence, the participants showed different patterns of interactions between language, valence, and position in reaction times across the experiments. We concluded that metaphorical association between affect and vertical position works in L1 but not in L2 for unbalanced bilinguals.

  3. Optical characterization of hydrogen-free CeO2 doped DLC films deposited by unbalanced magnetron sputtering

    International Nuclear Information System (INIS)

    Zhang Zhenyu; Zhou Hongxiu; Guo Dongming; Gao Hang; Kang Renke

    2008-01-01

    A novel kind of hydrogen-free CeO 2 doped diamond-like carbon (DLC) films with thickness of 180-200 nm were deposited on silicon by unbalanced magnetron sputtering. Reduced reflectance and increased lifetime are expected with respect to pure DLC films, making these coatings good candidates as optical protective coatings for IR windows and solar cells. X-ray photoelectron spectroscopy confirms that CeO 2 is formed within the DLC films. Auger electron spectroscopy exhibits that the C, O, and Ce elements distribute uniformly across the film thickness, and C element diffuses into the Si substrate at the interface between the substrate and film. AFM shows that nanoparticles with diameter of around 50 nm are formed on the surface of deposited films, whose surface roughness is in the range of 1.3-2.3 nm. Raman spectra show the CeO 2 doped DLC films are amorphous DLC films, and both the G frequency and relative intensity ratio I D /I G are higher than those of pure DLC films. The photoluminescence of CeO 2 doped DLC films is obviously more intense than that of a pure DLC film, which indicates a promising potential as optical protective films for solar cells and IR window

  4. Time dependence of carbon film deposition on SnO{sub 2}/Si using DC unbalanced magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Alfiadi, H., E-mail: yudi@fi.itb.ac.id; Aji, A. S., E-mail: yudi@fi.itb.ac.id; Darma, Y., E-mail: yudi@fi.itb.ac.id [Quantum Semiconductor and Devices Lab., Dept. of Physics, Institut Teknologi Bandung, Ganesa 10 Bandung 40132 (Indonesia)

    2014-02-24

    Carbon deposition on SnO{sub 2} layer has been demonstrated at low temperature using DC unbalanced magnetron-sputtering technique for various time depositions. Before carbon sputtering process, SnO{sub 2} thin layer is grown on silicon substrate by thermal evaporation method using high purity Sn wire and then fully oxidizes by dry O{sub 2} at 225°C. Carbon sputtering process was carried out at pressure of 4.6×10{sup −2} Torr by keeping the substrate temperature of 300 °C for sputtering deposition time of 1 to 4 hours. The properties of SnO{sub 2}/Si structure and carbon thin film on SnO{sub 2} is characterized using SEM, EDAX, XRD, FTIR, and Raman Spectra. SEM images and XRD spectra show that SnO2 thin film has uniformly growth on Si substrate and affected by annealing temperature. Raman and FTIR results confirm the formation of carbon-rich thin film on SnO{sub 2}. In addition, XRD spectra indicate that some structural change occur by increasing sputtering deposition time. Furthermore, the change of atomic structure due to the thermal annealing is analized by XRD spectra and Raman spectroscopy.

  5. Fault ride-through capability of wind turbine connected to the grid in case of unbalanced voltages

    Directory of Open Access Journals (Sweden)

    Ivanović Zoran R.

    2016-01-01

    Full Text Available This paper deals with control of wind turbine connected to the grid through the back-to-back converter in case of unbalanced grid voltages. The motivation for this research has been found in recent transmission and distribution grid code, which demand modern wind turbines to stay connected to the grid and supply the highest possible apparent power during the grid disturbances. In order to comply with these requirements we proposed improved dual vector current controller to deal with the unbalance imposed by the electrical grid. Controller provides injection of active and reactive power to the grid, even if the voltages are lower than the nominal one. The results are validated using low power prototype and contemporary hardware-in-the-loop emulation platform. In both cases the controller is based on TMS320F2812 DSP. [Projekat Ministarstva nauke Republike Srbije, br. III 042004 and by the Provincial Secretariat for Science and Technological Development of AP Vojvodina under contract No. 114-451-3508/2013-04

  6. Compensation of negative sequence stator flux of doubly-fed induction generator using polar voltage control-based direct torque control under unbalanced grid voltage condition

    Directory of Open Access Journals (Sweden)

    Badrinarayan Bansilal Pimple

    2015-02-01

    Full Text Available This study proposes a polar voltage control-based direct torque control method to reduce the effects of unbalanced grid voltage on doubly-fed induction generator (DFIG-based wind turbine system. Under unbalanced grid voltage, the stator flux has a negative sequence component which leads to second harmonic pulsation in torque, stator active power, stator reactive power, stator current and rotor current. In the control scheme, the negative sequence rotor voltage vector is controlled to compensate the negative sequence stator flux by negative sequence rotor flux. Simulation study is carried out on a 2 MW DFIG system using MATLAB/SIMULINK. Feasibility of the proposed control strategy is experimentally verified on a 1.5 kW DFIG system.

  7. A case of an atypically large proximal 15q deletion as cause for Prader-Willi syndrome arising from a de novo unbalanced translocation.

    Science.gov (United States)

    Hickey, Scott E; Thrush, Devon Lamb; Walters-Sen, Lauren; Reshmi, Shalini C; Astbury, Caroline; Gastier-Foster, Julie M; Atkin, Joan

    2013-09-01

    We describe an 11 month old female with Prader-Willi syndrome (PWS) resulting from an atypically large deletion of proximal 15q due to a de novo 3;15 unbalanced translocation. The 10.6 Mb deletion extends from the chromosome 15 short arm and is not situated in a region previously reported as a common distal breakpoint for unbalanced translocations. There was no deletion of the reciprocal chromosome 3q subtelomeric region detected by either chromosomal microarray or FISH. The patient has hypotonia, failure to thrive, and typical dysmorphic facial features for PWS. The patient also has profound global developmental delay consistent with an expanded, more severe, phenotype. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  8. The microstructure and properties of unbalanced magnetron sputtered CrNx coatings

    International Nuclear Information System (INIS)

    Hurkmans, Antonius Petrus Arnoldus

    2002-01-01

    The most widely used surface treatment to protect engineering components is the deposition of hard chromium by electroplating. The coatings are known to be quite thick (up to 20 μm), reasonably hard (∼HV1000), but contain micro-cracks. This wet deposition process is well understood, but it has technical limitations and is under high political pressure because of the environmental pollution by hexavalent chromium. The physical vapour deposition (PVD) technique is an alternative method to produce high quality coatings. PVD is an almost pollution free technique, because the process occurs under vacuum. CrN by PVD is one of the most promising PVD coatings as a candidate to replace eventually electroplated hard chromium. The growth characteristics of CrN coatings are less understood than those of TiN, the well-known PVD coating material. This thesis anticipates to fill this technological gap. Along a wide range of experiments based on the deposition of CrN x coatings, XRD, SEM, SNMS and tribological analysis have been used to complete a thorough understanding of CrN x growth. The experiments show that there exist several different phases within the Cr-N system: bcc-Cr, hcp-Cr 2 N, fcc-CrN, and mixed phases. This is not fundamentally new, but the work has resulted in two new modifications, which are highly interesting candidates for the industry, including electroplating replacements, namely high nitrogen containing metallic bcc-Cr (solid solution with up to 18 at.% nitrogen) in the hardness range up to HV1800 and a very hard fcc-CrN phase with hardness values between HV1500 and HV3000, similar to TiN. The solid solution bcc-Cr-N is very dense fine-grained, reasonably hard (almost twice as hard as electroplated hard chromium), very smooth, and with a Young's modulus very similar to that of (hardened) steel. The hard fcc-CrN phase (approximately three times harder than electroplated hard chromium) could only be obtained by the current experiments in a rather non

  9. Control of Grid Integrated Voltage Source Converters under Unbalanced Conditions: Development of an On-line Frequency-adaptive Virtual Flux-based Approach

    OpenAIRE

    Suul, Jon Are

    2012-01-01

    Three-Phase Voltage Source Converters (VSCs) are finding widespread applications in grid integrated power conversion systems. The control systems of such VSCs are in an increasing number of these applications required to operate during voltage disturbances and unbalanced conditions. Control systems designed for grid side voltagesensor- less operation are at the same time becoming attractive due to the continuous drive for cost reduction and increased reliability of VSCs, but are not commonly ...

  10. Alternative Therapies

    Science.gov (United States)

    ... the widespread and erroneous belief that they are natural and do no harm, and because their use offers the opportunity for more control over treatment options and procedures. Alternative therapies can reduce stress, pain, and/or fatigue. Some therapies are covered ...

  11. Growing Alternatives

    DEFF Research Database (Denmark)

    Bagger-Petersen, Mai Corlin

    2014-01-01

    From 2014, Anhui Province will pilot a reform of the residential land market in China, thus integrating rural Anhui in the national housing market. In contrast, artist and activist Ou Ning has proposed the Bishan time money currency, intending to establish an alternative economic circuit in Bishan...

  12. Magnetostrictive Alternator

    Science.gov (United States)

    Dyson, Rodger; Bruder, Geoffrey

    2013-01-01

    This innovation replaces the linear alternator presently used in Stirling engines with a continuous-gradient, impedance-matched, oscillating magnetostrictive transducer that eliminates all moving parts via compression, maintains high efficiency, costs less to manufacture, reduces mass, and eliminates the need for a bearing system. The key components of this new technology are the use of stacked magnetostrictive materials, such as Terfenol-D, under a biased magnetic and stress-induced compression, continuous-gradient impedance-matching material, coils, force-focusing metallic structure, and supports. The acoustic energy from the engine travels through an impedancematching layer that is physically connected to the magnetostrictive mass. Compression bolts keep the structure under compressive strain, allowing for the micron-scale compression of the magnetostrictive material and eliminating the need for bearings. The relatively large millimeter displacement of the pressure side of the impedance-matching material is reduced to micron motion, and undergoes stress amplification at the magnetostrictive interface. The alternating compression and expansion of the magnetostrictive material creates an alternating magnetic field that then induces an electric current in a coil that is wound around the stack. This produces electrical power from the acoustic pressure wave and, if the resonant frequency is tuned to match the engine, can replace the linear alternator that is commonly used.

  13. An improved synchronous reference frame current control strategy for a photovoltaic grid-connected inverter under unbalanced and nonlinear load conditions

    Science.gov (United States)

    Naderipour, Amirreza; Asuhaimi Mohd Zin, Abdullah; Bin Habibuddin, Mohd Hafiz; Miveh, Mohammad Reza; Guerrero, Josep M.

    2017-01-01

    In recent years, renewable energy sources have been considered the most encouraging resources for grid and off-grid power generation. This paper presents an improved current control strategy for a three-phase photovoltaic grid-connected inverter (GCI) under unbalanced and nonlinear load conditions. It is challenging to suppress the harmonic content in the output current below a pre-set value in the GCI. It is also difficult to compensate for unbalanced loads even when the grid is under disruption due to total harmonic distortion (THD) and unbalanced loads. The primary advantage and objective of this method is to effectively compensate for the harmonic current content of the grid current and microgrid without the use of any compensation devices, such as active and passive filters. This method leads to a very low THD in both the GCI currents and the current exchanged with the grid. The control approach is designed to control the active and reactive power and harmonic current compensation, and it also corrects the system unbalance. The proposed control method features the synchronous reference frame (SRF) method. Simulation results are presented to demonstrate the effective performance of the proposed method. PMID:28192436

  14. An improved synchronous reference frame current control strategy for a photovoltaic grid-connected inverter under unbalanced and nonlinear load conditions.

    Science.gov (United States)

    Naderipour, Amirreza; Asuhaimi Mohd Zin, Abdullah; Bin Habibuddin, Mohd Hafiz; Miveh, Mohammad Reza; Guerrero, Josep M

    2017-01-01

    In recent years, renewable energy sources have been considered the most encouraging resources for grid and off-grid power generation. This paper presents an improved current control strategy for a three-phase photovoltaic grid-connected inverter (GCI) under unbalanced and nonlinear load conditions. It is challenging to suppress the harmonic content in the output current below a pre-set value in the GCI. It is also difficult to compensate for unbalanced loads even when the grid is under disruption due to total harmonic distortion (THD) and unbalanced loads. The primary advantage and objective of this method is to effectively compensate for the harmonic current content of the grid current and microgrid without the use of any compensation devices, such as active and passive filters. This method leads to a very low THD in both the GCI currents and the current exchanged with the grid. The control approach is designed to control the active and reactive power and harmonic current compensation, and it also corrects the system unbalance. The proposed control method features the synchronous reference frame (SRF) method. Simulation results are presented to demonstrate the effective performance of the proposed method.

  15. Regulation of unbalanced electromagnetic moment in mutual loading systems of electric machines of traction rolling stock and multiple unit of mainline and industrial transport

    Directory of Open Access Journals (Sweden)

    A. M. Afanasov

    2014-12-01

    Full Text Available Purpose. The research data are aimed to identify the regulatory principles of unbalanced electromagnetic moment of mutually loaded electric machines of traction rolling stock and multiple unit of main and industrial transport. The purpose of this study is energy efficiency increase of the testing of traction electric machines of direct and pulse current using the improvement methods of their mutual loading, including the principles of automatic regulation of mutual loading system. Methodology. The general theoretical provisions and principles of system approach to the theoretical electric engineering, the theory of electric machines and theoretical mechanics are the methodological basis of this research. The known methods of analysis of electromagnetic and electromechanical processes in electrical machines of direct and pulse current are used in the study. Methods analysis of loading modes regulation of traction electric machines was conducted using the generalized scheme of mutual loading. It is universal for all known methods to cover the losses of idling using the electric power. Findings. The general management principles of mutual loading modes of the traction electric machines of direct and pulse current by regulating their unbalanced electric magnetic moment were developed. Regulatory options of unbalanced electromagnetic moment are examined by changing the difference of the magnetic fluxes of mutually loaded electric machines, the current difference of electric machines anchors, the difference of the angular velocities of electric machines shafts. Originality. It was obtained the scientific basis development to improve the energy efficiency test methods of traction electric machines of direct and pulse current. The management principles of mutual loading modes of traction electric machines were formulated. For the first time it is introduced the concept and developed the principles of regulation of unbalanced electromagnetic moment in

  16. Alternative 23

    OpenAIRE

    Jackson, Mark

    2014-01-01

    Alternative 23 is a curated exhibition of works by Steve Aylett, David Blandy & Daniel Locke, Let Me Feel Your Finger First, Laura Oldfield Ford, Plastique Fantastique and Henrik Schrat, including the first screening of Let Me Feel Your Finger First’s Postcolonial Capers.\\ud \\ud In 1985 DC Comics in the US had taken the commercial decision to unify the complex and contradictory character story arcs from its various strips such as Superman, Batman and Green Lantern. The resultant crossover ser...

  17. Electric hydrogen recombiner special tests

    International Nuclear Information System (INIS)

    Wilson, J.F.

    1975-12-01

    Westinghouse has produced an electric hydrogen recombiner to control hydrogen levels in reactor containments following a postulated loss-of-coolant accident. The recombiner underwent extensive testing for NRC qualification (see WCAP 7709-L and Supplements 1, 2, 3, 4). As a result, WCAP 7709-L and Supplements 1, 2, 3, and 4 have been accepted by the NRC for reference in applications not committed to IEEE-323-1974. Supplement 5 and the next supplement will demonstrate conformance to IEEE-323-1974. This supplement describes additional tests, beyond those necessary to qualify the system, which will be referenced in supplement 6. Each test has demonstrated a considerable margin of safety over required performance. Concurrently, the test results increased the fund of technical information on the electric hydrogen recombiner

  18. The effect of a single recombination event

    DEFF Research Database (Denmark)

    Schierup, Mikkel Heide; Jensen, Thomas Mailund; Wiuf, Carsten

    We investigate the variance in how visible a single recombination event is in a SNP data set as a function of the type of recombination event and its age. Data is simulated under the coalescent with recombination and inference is by the popular composite likelihood methods. The major determinant...... of the effect of a recombination event is the genealogical type of the event and whether SNP variation is present that can reveal the genealogical consequences of the recombination event. Recombination events that only change some branch lengths in the genealogy have a very small, but detectable, effect....... The more lineages left when the recombination event occurs, the larger effect it has, implying that it is mainly young recombination events that we detect when estimating the rate. If the population is growing, though, more lineages are present back in time and relatively more ancient recombination events...

  19. Surface free energy of non-stick coatings deposited using closed field unbalanced magnetron sputter ion plating

    Science.gov (United States)

    Sun, Chen-Cheng; Lee, Shih-Chin; Dai, Shyue-Bin; Tien, Shein-Long; Chang, Chung-Chih; Fu, Yaw-Shyan

    2007-02-01

    Semiconductor IC packaging molding dies require wear resistance, corrosion resistance and non-sticking (with a low surface free energy). The molding releasing capability and performance are directly associated with the surface free energy between the coating and product material. The serious sticking problem reduces productivity and reliability. Depositing TiN, TiMoS, ZrN, CrC, CrN, NiCr, NiCrN, CrTiAlN and CrNiTiAlN coatings using closed field unbalanced magnetron sputter ion plating, and characterizing their surface free energy are the main object in developing a non-stick coating system for semiconductor IC molding tools. The contact angle of water, diiodomethane and ethylene glycol on the coated surfaces were measured at temperature in 20 °C using a Dataphysics OCA-20 contact angle analyzer. The surface free energy of the coatings and their components (dispersion and polar) were calculated using the Owens-Wendt geometric mean approach. The surface roughness was investigated by atomic force microscopy (AFM). The adhesion force of these coatings was measured using direct tensile pull-off test apparatus. The experimental results showed that NiCrN, CrN and NiCrTiAlN coatings outperformed TiN, ZrN, NiCr, CiTiAlN, CrC and TiMoS coatings in terms of non-sticking, and thus have the potential as working layers for injection molding industrial equipment, especially in semiconductor IC packaging molding applications.

  20. Surface free energy of non-stick coatings deposited using closed field unbalanced magnetron sputter ion plating

    Energy Technology Data Exchange (ETDEWEB)

    Sun, C.-C. [Department of Materials Science and Engineering, National Cheng Kung University, Tainan, Taiwan (China); Lee, S.-C. [Department of Materials Science and Engineering, National Cheng Kung University, Tainan, Taiwan (China); Dai, S.-B. [Center of General Studies, National Kaohsiung Marine University, Nan-Tzu, Kaohsiung, Taiwan (China); Nano-Win Technology Co. Ltd., Tainan, Taiwan (China); Tien, S.-L. [Department of Physics, National Cheng Kung University, 701 Tainan, Taiwan (China); Chang, C.-C. [Department of Physics, R.O.C. Military Academy, 830 Kaohsiung, Taiwan (China); Fu, Y.-S. [Department of Environment and Energy, National University of Tainan, Tainan, Taiwan (China)]. E-mail: ysfu@mail.nutn.edu.tw

    2007-02-15

    Semiconductor IC packaging molding dies require wear resistance, corrosion resistance and non-sticking (with a low surface free energy). The molding releasing capability and performance are directly associated with the surface free energy between the coating and product material. The serious sticking problem reduces productivity and reliability. Depositing TiN, TiMoS, ZrN, CrC, CrN, NiCr, NiCrN, CrTiAlN and CrNiTiAlN coatings using closed field unbalanced magnetron sputter ion plating, and characterizing their surface free energy are the main object in developing a non-stick coating system for semiconductor IC molding tools. The contact angle of water, diiodomethane and ethylene glycol on the coated surfaces were measured at temperature in 20 deg. C using a Dataphysics OCA-20 contact angle analyzer. The surface free energy of the coatings and their components (dispersion and polar) were calculated using the Owens-Wendt geometric mean approach. The surface roughness was investigated by atomic force microscopy (AFM). The adhesion force of these coatings was measured using direct tensile pull-off test apparatus. The experimental results showed that NiCrN, CrN and NiCrTiAlN coatings outperformed TiN, ZrN, NiCr, CiTiAlN, CrC and TiMoS coatings in terms of non-sticking, and thus have the potential as working layers for injection molding industrial equipment, especially in semiconductor IC packaging molding applications.

  1. Unbalanced recovery of regulatory and effector T cells after allogeneic stem cell transplantation contributes to chronic GVHD.

    Science.gov (United States)

    Alho, Ana C; Kim, Haesook T; Chammas, Marie J; Reynolds, Carol G; Matos, Tiago R; Forcade, Edouard; Whangbo, Jennifer; Nikiforow, Sarah; Cutler, Corey S; Koreth, John; Ho, Vincent T; Armand, Philippe; Antin, Joseph H; Alyea, Edwin P; Lacerda, Joao F; Soiffer, Robert J; Ritz, Jerome

    2016-02-04

    The development and maintenance of immune tolerance after allogeneic hematopoietic stem cell transplantation (HSCT) requires the balanced reconstitution of donor-derived CD4 regulatory T cells (CD4Tregs) as well as effector CD4 (conventional CD4 T cells [CD4Tcons]) and CD8 T cells. To characterize the complex mechanisms that lead to unbalanced recovery of these distinct T-cell populations, we studied 107 adult patients who received T-replete stem cell grafts after reduced-intensity conditioning. Immune reconstitution of CD4Treg, CD4Tcon, and CD8 T cells was monitored for a 2-year period. CD3 T-cell counts gradually recovered to normal levels during this period but CD8 T cells recovered more rapidly than either CD4Tregs or CD4Tcons. Reconstituting CD4Tregs and CD4Tcons were predominantly central memory (CM) and effector memory (EM) cells and CD8 T cells were predominantly terminal EM cells. Thymic generation of naive CD4Tcon and CD8 T cells was maintained but thymic production of CD4Tregs was markedly decreased with little recovery during the 2-year study. T-cell proliferation was skewed in favor of CM and EM CD4Tcon and CD8 T cells, especially 6 to 12 months after HSCT. Intracellular expression of BCL2 was increased in CD4Tcon and CD8 T cells in the first 3 to 6 months after HSCT. Early recovery of naive and CM fractions within each T-cell population 3 months after transplant was also strongly correlated with the subsequent development of chronic graft-versus-host disease (GVHD). These dynamic imbalances favor the production, expansion, and persistence of effector T cells over CD4Tregs and were associated with the development of chronic GVHD. © 2016 by The American Society of Hematology.

  2. Surface free energy of non-stick coatings deposited using closed field unbalanced magnetron sputter ion plating

    International Nuclear Information System (INIS)

    Sun, C.-C.; Lee, S.-C.; Dai, S.-B.; Tien, S.-L.; Chang, C.-C.; Fu, Y.-S.

    2007-01-01

    Semiconductor IC packaging molding dies require wear resistance, corrosion resistance and non-sticking (with a low surface free energy). The molding releasing capability and performance are directly associated with the surface free energy between the coating and product material. The serious sticking problem reduces productivity and reliability. Depositing TiN, TiMoS, ZrN, CrC, CrN, NiCr, NiCrN, CrTiAlN and CrNiTiAlN coatings using closed field unbalanced magnetron sputter ion plating, and characterizing their surface free energy are the main object in developing a non-stick coating system for semiconductor IC molding tools. The contact angle of water, diiodomethane and ethylene glycol on the coated surfaces were measured at temperature in 20 deg. C using a Dataphysics OCA-20 contact angle analyzer. The surface free energy of the coatings and their components (dispersion and polar) were calculated using the Owens-Wendt geometric mean approach. The surface roughness was investigated by atomic force microscopy (AFM). The adhesion force of these coatings was measured using direct tensile pull-off test apparatus. The experimental results showed that NiCrN, CrN and NiCrTiAlN coatings outperformed TiN, ZrN, NiCr, CiTiAlN, CrC and TiMoS coatings in terms of non-sticking, and thus have the potential as working layers for injection molding industrial equipment, especially in semiconductor IC packaging molding applications

  3. Alternative detente

    International Nuclear Information System (INIS)

    Soper, K.; Ryle, M.

    1988-01-01

    The influence of the Chernobyl accident on the disarmament and anti-nuclear movements is discussed. The accident directed attention towards the areas in common rather than the areas of disagreement. It also demonstrated the environmental impact of radioactivity, strengthening the ecological case of the anti-nuclear movement. The issues are discussed for the Western and Eastern bloc countries and the relationship between the two. Sections focus on the Eco-protest, Green politics and economics and on the politics of minority protest and the Green alternative. (U.K.)

  4. Improving recombinant protein purification yield

    Science.gov (United States)

    Production of adequate amounts of recombinant proteins is essential for antibody production, biochemical activity study, and structural determination during the post-genomic era. It’s technologically challenging and a limiting factor for tung oil research because analytical reagents such as high qua...

  5. A recombinant protein expression system

    African Journals Online (AJOL)

    Aghomotsegin

    2015-06-23

    Jun 23, 2015 ... Serum free cultivation of Leishmania is cost-effective and improves large scale production of well- defined parasite material. Moreover, the production of recombinant pharmaceutical proteins requires cultivation of the host in a culture medium free of animal materials, so several culture media for.

  6. Production and recombination of gluons

    International Nuclear Information System (INIS)

    Temiraliev, A.T.

    2006-01-01

    Full text: Nonlinear Markov process of parton production has been considered. The Kolmogorov equation is applied for the evolution equation based on the approximation of independent gluons production in every decay act. We introduced a 'crossing' parameter and used the combination relations to obtain nonlinear recombination equation for the evolution of gluon structure function. (author)

  7. Recombination in hepatitis C virus.

    Science.gov (United States)

    González-Candelas, Fernando; López-Labrador, F Xavier; Bracho, María Alma

    2011-10-01

    Hepatitis C virus (HCV) is a Flavivirus with a positive-sense, single-stranded RNA genome of about 9,600 nucleotides. It is a major cause of liver disease, infecting almost 200 million people all over the world. Similarly to most RNA viruses, HCV displays very high levels of genetic diversity which have been used to differentiate six major genotypes and about 80 subtypes. Although the different genotypes and subtypes share basic biological and pathogenic features they differ in clinical outcomes, response to treatment and epidemiology. The first HCV recombinant strain, in which different genome segments derived from parentals of different genotypes, was described in St. Petersburg (Russia) in 2002. Since then, there have been only a few more than a dozen reports including descriptions of HCV recombinants at all levels: between genotypes, between subtypes of the same genotype and even between strains of the same subtype. Here, we review the literature considering the reasons underlying the difficulties for unequivocally establishing recombination in this virus along with the analytical methods necessary to do it. Finally, we analyze the potential consequences, especially in clinical practice, of HCV recombination in light of the coming new therapeutic approaches against this virus.

  8. Alternative crops

    International Nuclear Information System (INIS)

    Andreasen, L.M.; Boon, A.D.

    1992-01-01

    Surplus cereal production in the EEC and decreasing product prices, mainly for cereals, has prompted considerable interest for new earnings in arable farming. The objective was to examine whether suggested new crops (fibre, oil, medicinal and alternative grains crops) could be considered as real alternatives. Whether a specific crop can compete economically with cereals and whether there is a market demand for the crop is analyzed. The described possibilities will result in ca. 50,000 hectares of new crops. It is expected that they would not immediately provide increased earnings, but in the long run expected price developments are more positive than for cereals. The area for new crops will not solve the current surplus cereal problem as the area used for new crops is only 3% of that used for cereals. Preconditions for many new crops is further research activities and development work as well as the establishment of processing units and organizational initiatives. Presumably, it is stated, there will then be a basis for a profitable production of new crops for some farmers. (AB) (47 refs.)

  9. Alternative Affinity Ligands for Immunoglobulins.

    Science.gov (United States)

    Kruljec, Nika; Bratkovič, Tomaž

    2017-08-16

    The demand for recombinant therapeutic antibodies and Fc-fusion proteins is expected to increase in the years to come. Hence, extensive efforts are concentrated on improving the downstream processing. In particular, the development of better-affinity chromatography matrices, supporting robust time- and cost-effective antibody purification, is warranted. With the advances in molecular design and high-throughput screening approaches from chemical and biological combinatorial libraries, novel affinity ligands representing alternatives to bacterial immunoglobulin (Ig)-binding proteins have entered the scene. Here, we review the design, development, and properties of diverse classes of alternative antibody-binding ligands, ranging from engineered versions of Ig-binding proteins, to artificial binding proteins, peptides, aptamers, and synthetic small-molecular-weight compounds. We also provide examples of applications for the novel affinity matrices in chromatography and beyond.

  10. Live recombinant BHV/BRSV vaccine

    NARCIS (Netherlands)

    Keil, G.M.; Rijsewijk, F.A.M.

    1998-01-01

    The present invention refers to synthetic Bovine Respiratory Syncytium virus genes. Also the invention relates to live attenuated Bovine Herpesvirus recombinants carrying such synthetic genes. Furthermore, the invention relates to vaccines based on these live attenuated recombinants, for the

  11. Hadron production at RHIC: recombination of quarks

    Energy Technology Data Exchange (ETDEWEB)

    Fries, Rainer J [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)

    2005-01-01

    We discuss quark recombination applied to the hadronization of a quark gluon plasma. It has been shown that the quark recombination model can explain essential features of hadron production measured in high energy heavy ion collisions.

  12. An unbalanced portfolio.

    Science.gov (United States)

    Federsel, Hans-Jurgen

    2009-06-01

    An excellent demonstration of how meaningful and valuable conferences devoted to the topic of project and portfolio management in the pharmaceutical industry can be, was given at an event organized in Barcelona, September 2008. Thus, over this 2-day meeting the delegates were updated on the state of the art in this wide-reaching area from speakers representing an array of companies; from small, relatively new players, via mid-sized, to established large and big pharmas. One common theme that emerged was the importance of assessing the value of drug projects as correctly as possible, especially under the current financial climate and the many challenges facing the industry. Furthermore, experiences from constructing portfolios with the aim to minimize risk and maximize return on investment were shared alongside mathematical approaches to obtain the data required for this purpose and accounts of the pleasures and hardships working in a global context and in partnership constellations. Copyright 2009 Prous Science, S.A.U. or its licensors. All rights reserved.

  13. An Unbalanced Crucible

    Science.gov (United States)

    Deneen, Patrick J.

    2012-01-01

    Long regarded by the vanguard of America's universities as antiquated and even dangerous, civic education is suddenly fashionable again. With the publication of "A Crucible Moment," a long battle in the culture wars appears to be winding down. It appears that everyone supports civic education today. For the past three decades, the ideal of civic…

  14. Yeast synthetic biology for the production of recombinant therapeutic proteins.

    Science.gov (United States)

    Kim, Hyunah; Yoo, Su Jin; Kang, Hyun Ah

    2015-02-01

    The production of recombinant therapeutic proteins is one of the fast-growing areas of molecular medicine and currently plays an important role in treatment of several diseases. Yeasts are unicellular eukaryotic microbial host cells that offer unique advantages in producing biopharmaceutical proteins. Yeasts are capable of robust growth on simple media, readily accommodate genetic modifications, and incorporate typical eukaryotic post-translational modifications. Saccharomyces cerevisiae is a traditional baker's yeast that has been used as a major host for the production of biopharmaceuticals; however, several nonconventional yeast species including Hansenula polymorpha, Pichia pastoris, and Yarrowia lipolytica have gained increasing attention as alternative hosts for the industrial production of recombinant proteins. In this review, we address the established and emerging genetic tools and host strains suitable for recombinant protein production in various yeast expression systems, particularly focusing on current efforts toward synthetic biology approaches in developing yeast cell factories for the production of therapeutic recombinant proteins. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.

  15. Recombinant pharmaceuticals from microbial cells: a 2015 update.

    Science.gov (United States)

    Sanchez-Garcia, Laura; Martín, Lucas; Mangues, Ramon; Ferrer-Miralles, Neus; Vázquez, Esther; Villaverde, Antonio

    2016-02-09

    Diabetes, growth or clotting disorders are among the spectrum of human diseases related to protein absence or malfunction. Since these pathologies cannot be yet regularly treated by gene therapy, the administration of functional proteins produced ex vivo is required. As both protein extraction from natural producers and chemical synthesis undergo inherent constraints that limit regular large-scale production, recombinant DNA technologies have rapidly become a choice for therapeutic protein production. The spectrum of organisms exploited as recombinant cell factories has expanded from the early predominating Escherichia coli to alternative bacteria, yeasts, insect cells and especially mammalian cells, which benefit from metabolic and protein processing pathways similar to those in human cells. Up to date, around 650 protein drugs have been worldwide approved, among which about 400 are obtained by recombinant technologies. Other 1300 recombinant pharmaceuticals are under development, with a clear tendency towards engineered versions with improved performance and new functionalities regarding the conventional, plain protein species. This trend is exemplified by the examination of the contemporary protein-based drugs developed for cancer treatment.

  16. High efficiency recombineering in lactic acid bacteria

    OpenAIRE

    van Pijkeren, Jan-Peter; Britton, Robert A.

    2012-01-01

    The ability to efficiently generate targeted point mutations in the chromosome without the need for antibiotics, or other means of selection, is a powerful strategy for genome engineering. Although oligonucleotide-mediated recombineering (ssDNA recombineering) has been utilized in Escherichia coli for over a decade, the successful adaptation of ssDNA recombineering to Gram-positive bacteria has not been reported. Here we describe the development and application of ssDNA recombineering in lact...

  17. Population inversion in recombining hydrogen plasma

    International Nuclear Information System (INIS)

    Furukane, Utaro; Yokota, Toshiaki; Oda, Toshiatsu.

    1978-11-01

    The collisional-radiative model is applied to a recombining hydrogen plasma in order to investigate the plasma condition in which the population inversion between the energy levels of hydrogen can be generated. The population inversion is expected in a plasma where the three body recombination has a large contribution to the recombining processes and the effective recombination rate is beyond a certain value for a given electron density and temperature. Calculated results are presented in figures and tables. (author)

  18. Energy alternatives

    International Nuclear Information System (INIS)

    1981-01-01

    English. A special committe of the Canadian House of Commons was established on 23 May 1980 to investigate the use of alternative energy sources such as 'gasohol', liquified coal, solar energy, methanol, wind and tidal power, biomass, and propane. In its final report, the committee envisions an energy system for Canada based on hydrogen and electricity, using solar and geothermal energy for low-grade heat. The committe was not able to say which method of generating electricty would dominate in the next century, although it recommends that fossil fuels should not be used. The fission process is not specifically discussed, but the outlook for fusion was investigated, and continued governmental support of fusion research is recommended. The report proposes some improvements in governmental energy organizations and programs

  19. Cloning, purification and characterization of recombinant silkworm ...

    African Journals Online (AJOL)

    The recombinant His-tagged BmAK protein was expressed in soluble form in Escherichia coli Rosetta and purified by metal chelating affinity chromatography. The amino acid sequence of recombinant protein was confirmed by mass spectroscopic analysis and the enzyme activity assay that indicated the recombinant ...

  20. Determination of recombination in Mycoplasma hominis

    DEFF Research Database (Denmark)

    Jacobsen, Iben Søgaard; Boesen, Thomas; Mygind, Tina

    2002-01-01

    indicating the presence of recombination. In order to test for intergenic recombination, phylogenetic trees were reconstructed for each of the genes but no well-supported bifurcating phylogenetic trees could be obtained. The genes were tested for intragenic recombination using the correlation between linkage...

  1. Novel recombinant alphaviral and adenoviral vectors for cancer immunotherapy.

    Science.gov (United States)

    Osada, Takuya; Morse, Michael A; Hobeika, Amy; Lyerly, H Kim

    2012-06-01

    Although cellular immunotherapy based on autolgous dendritic cells (DCs) targeting antigens expressed by metastatic cancer has demonstrated clinical efficacy, the logistical challenges in generating an individualized cell product create an imperative to develop alternatives to DC-based cancer vaccines. Particularly attractive alternatives include in situ delivery of antigen and activation signals to resident antigen-presenting cells (APCs), which can be achieved by novel fusion molecules targeting the mannose receptor and by recombinant viral vectors expressing the antigen of interest and capable of infecting DCs. A particular challenge in the use of viral vectors is the well-appreciated clinical obstacles to their efficacy, specifically vector-specific neutralizing immune responses. Because heterologous prime and boost strategies have been demonstrated to be particularly potent, we developed two novel recombinant vectors based on alphaviral replicon particles and a next-generation adenovirus encoding an antigen commonly overexpressed in many human cancers, carcinoembryonic antigen (CEA). The rationale for developing these vectors, their unique characteristics, the preclinical studies and early clinical experience with each, and opportunities to enhance their effectiveness will be reviewed. The potential of each of these potent recombinant vectors to efficiently generate clinically active anti-tumor immune response alone, or in combination, will be discussed. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Composite cavity based fiber optic Fabry–Perot strain sensors demodulated by an unbalanced fiber optic Michelson interferometer with an electrical scanning mirror

    International Nuclear Information System (INIS)

    Zhang, Jianzhong; Yang, Jun; Sun, Weimin; Yuan, Libo; Jin, Wencai; Peng, G D

    2008-01-01

    A composite cavity based fiber optic Fabry–Perot strain sensor system, interrogated by a white light source and demodulated by an unbalanced fiber optic Michelson interferometer with an electrical scanning mirror, is proposed and demonstrated. Comparing with the traditional extrinsic fiber optic Fabry–Perot strain sensor, the potential multiplexing capability and the dynamic measurement range are improved simultaneously. At the same time, the measurement stability of the electrical scanning mirror system is improved by the self-referenced signal of the sensor structure

  3. West syndrome associated with a novel chromosomal anomaly; partial trisomy 8P together with partial monosomy 9P, resulting from a familial unbalanced reciprocal translocation.

    Science.gov (United States)

    Erol, Ilknur; Saygı, Semra; Demir, Şenay; Alehan, Fusun; Sahin, Feride Iffet

    2015-01-01

    West syndrome is classified according to the underlying etiology into an acquired West syndrome, a congenital/developmental West syndrome, and West syndrome of unknown etiology. Causes of a congenital/developmental West syndrome are extensive and include chromosomal anomalies. We report on a patient carrying a derivative chromosome originating from the reciprocal unbalanced translocation t (8;9) (p11.2;p22) and presenting with macrocephaly, West syndrome, severe mental motor retardation and hypotonia. As far as we know, this is a new chromosomal anomaly associated with West syndrome.

  4. Mechanisms of sister chromatid recombination

    International Nuclear Information System (INIS)

    Nakai, Sayaka; Machida, Isamu; Tsuji, Satsuki

    1985-01-01

    Studies using T948 as a model system have been carried out aimed at elucidating the mechanism of sister chromatid recombination (SCR). Characterization of U.V. light- and x-ray-induced SCR, the relationiship between SCR induction and DNA repair using rad mutations, and the relationship between SCR induction and the time of cell division using cdc mutations are presented. It has been supposed that SCR is induced at the phase of S-G 2 following DNA replication, that postreplication break of DNA strands is strongly involved in the induction of SCR, and that induction type of SCR, i.e., conversion type or recombination type, is dependent upon the type of molecular damage of DNA. (Namekawa, K.)

  5. Heterogeneity in recombinant protein production

    DEFF Research Database (Denmark)

    Schalén, Martin; Johanson, Ted; Lundin, Luisa

    2012-01-01

    contribute to make a population in a fermenter heterogeneous, resulting in cell-to-cell variation in physiological parameters of the microbial culture. Our study aims at investigating how population heterogeneity and recombinant protein production is affected by environmental gradients in bioreactors....... For this purpose, a Saccharomyces cerevisiae strain, that functions as a protein production reporter, has been developed. A heterologous protein has been tagged with a fluorescent protein providing a way to measure the amount of heterologous protein produced by the cells on single cell level. Gradients...... are simulated in small bioreactors and the population heterogeneity can be visualised by analysing single cells with flow cytometry. This can give new insights to cell physiology and recombinant protein production at the industrial scale....

  6. Workshop on Radio Recombination Lines

    CERN Document Server

    1980-01-01

    Since their first detection 15 years ago, radio recombination lines from several elements have been observed in a wide variety of objects including HII regions, planetary nebulae, molecular clouds, the diffuse interstellar medium, and recently, other galaxies. The observations span almost the entire range from 0.1 to 100 GHz, and employ both single­ djsh and aperture synthesis techniques. The theory of radio recombination lines has also advanced strongly, to the point where it is perhaps one of the best-understood in astro­ physics. In a parallel development, it has become possible over the last decade to study these same highly-excited atoms in the laboratory; this work provides further confirmation of the theoretical framework. However there has been continuing controversy over the astrophysical interpre­ tation of radio recombination line observations, especially regarding the role of stimulated emission. A workshop was held in Ottawa on 24-25 August, 1979, bringing together many of the active scientist...

  7. Nondisjunction of chromosome 15: Origin and recombination

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, W.P.; Bernasconi, F.; Schinzel, A.A.; Mutirangura, A.; Ledbetter, D.H. (Baylor College of Medicine, Houston, TX (United States)); Langlois, S. (Univ. of Britisch Columbia, Vancouver (Canada)); Morris, M.A.; Malcolm, S.

    1993-09-01

    Thirty-two cases of uniparental disomy (UPD), ascertained from Prader-Willi syndrome patients (N=27) and Angelman syndrome patients (N-5), are used to investigate the pattern of recombination associated with nondisjunction of chromosome 15. In addition, the meiotic stage of nondisjunction is inferred by using markers mapping near the centromere. Two basic approaches to the analysis of recombination in specific pairwise intervals along the chromosome. This method shows a significant reduction in recombination for two of five intervals examined. Second, the observed frequency of each recombinant class (i.e., zero, one, two, three, or more observable crossovers) is compared with expected values. This is useful for testing whether the reduction in recombination can be attributed solely to a proportion of cases with no recombination at all (because of asynapsis), with the remaining groups showing normal recombination (or even excess recombination), or whether recombination is uniformly reduced. Analysis of maternal UPD(15) data shows a slight reduction in the multiple-recombinant classes, with a corresponding increase in both the zero- and one-recombinant classes over expected values. The majority, more than 82%, of the extra chromosomes in maternal UPD(15) cases are due to meiotic I nondisjunction events. In contrast, more paternal UPD(15) cases so far examined appear to have a postzygotic origin of the extra paternal chromosome. 33 refs., 1 fig., 7 tabs.

  8. Consequences of recombination on traditional phylogenetic analysis

    DEFF Research Database (Denmark)

    Schierup, M H; Hein, J

    2000-01-01

    We investigate the shape of a phylogenetic tree reconstructed from sequences evolving under the coalescent with recombination. The motivation is that evolutionary inferences are often made from phylogenetic trees reconstructed from population data even though recombination may well occur (mt......DNA or viral sequences) or does occur (nuclear sequences). We investigate the size and direction of biases when a single tree is reconstructed ignoring recombination. Standard software (PHYLIP) was used to construct the best phylogenetic tree from sequences simulated under the coalescent with recombination....... With recombination present, the length of terminal branches and the total branch length are larger, and the time to the most recent common ancestor smaller, than for a tree reconstructed from sequences evolving with no recombination. The effects are pronounced even for small levels of recombination that may...

  9. Production of recombinant proteins in suspension-cultured plant cells.

    Science.gov (United States)

    Plasson, Carole; Michel, Rémy; Lienard, David; Saint-Jore-Dupas, Claude; Sourrouille, Christophe; de March, Ghislaine Grenier; Gomord, Véronique

    2009-01-01

    Plants have emerged in the past decade as a suitable alternative to the current production systems for recombinant pharmaceutical proteins and, today their potential for low-cost production of high quality, much safer and biologically active mammalian proteins is largely documented. Among various plant expression systems being explored, genetically modified suspension-cultured plant cells offer a promising system for production of biopharmaceuticals. Indeed, when compared to other plant-based production platforms that have been explored, suspension-cultured plant cells have the advantage of being totally devoid of problems associated with the vagaries of weather, pest, soil and gene flow in the environment. Because of short growth cycles, the timescale needed for the production of recombinant proteins in plant cell culture can be counted in days or weeks after transformation compared to months needed for the production in transgenic plants. Moreover, recovery and purification of recombinant proteins from plant biomass is an expensive and technically challenging business that may amount to 80-94% of the final product cost. One additional advantage of plant cell culture is that the recombinant protein fused with a signal sequence can be expressed and secreted into the culture medium, and therefore recovered and purified in the absence of large quantities of contaminating proteins. Consequently, the downstream processing of proteins extracted from plant cell culture medium is less expensive, which may/does balance the higher costs of fermentation. When needed for clinical use, recombinant proteins are easily produced in suspension-cultured plant cells under certified, controllable and sterile conditions that offer improved safety and provide advantages for good manufacturing practices and regulatory compliance. In this chapter, we present basic protocols for rapid generation of transgenic suspension-cultured cells of Nicotiana tabacum, Oriza sativa and Arabidopis

  10. Study of electromagnetic fields and current distribution near a transmission line tower subjected to unbalanced currents and phase-to-ground faults

    International Nuclear Information System (INIS)

    Ruan, W.; Dawalibi, F.P.; Ma, J.; Fortin, S.

    1995-01-01

    This paper presents and discusses computed electromagnetic fields near a 525 kV transmission line tower structure and metallic fence, based on a direct solution of the electromagnetic field equations. The analysis and computations have been carried out assuming both normal and fault conditions. The effects of unbalanced currents during normal conditions are also considered. The spatial distributions of the scalar potentials and electromagnetic fields are presented. The distortions of the fields and current distribution, in the presence of the fence and tower structure, are analyzed and discussed. It is found that the electromagnetic fields generated by the induced currents in the tower and fence are negligible compared to those generated by the phase conductor currents except in the vicinity of the fence and tower, where significant distortion is observed. The scalar potential and electric fields, however, are still slightly distorted near the structures. Under fault conditions, a large ground potential rise and significant increases in the electromagnetic fields are observed. For unbalanced phase currents, the percent change in the electromagnetic fields is approximately equal to the percent unbalance in the phase currents

  11. An Interaction Between the Effects of Bilingualism and Cross-linguistic Similarity in Balanced and Unbalanced Bilingual Adults' L2 Mandarin Word-Reading Production.

    Science.gov (United States)

    Hsu, Hsiu-Ling

    2017-08-01

    We conducted three experiments investigating in more detail the interaction between the two effects of bilingualism and L1-L2 similarity in the speech performance of balanced and unbalanced bilinguals. In Experiment 1, L1 Mandarin monolinguals and two groups of Hakka and Minnan balanced bilinguals (Hakka: more similar to Mandarin) performed a non-contextual single-character reading task in Mandarin, which required more inhibitory control. The two bilingual groups outperformed the monolinguals, regardless of their L1 background. However, the bilingual advantage was not found in a contextual multi-word task (Experiment 2), but instead the effect of cross-linguistic similarity emerged. Furthermore, in Experiment 3, the Hakka unbalanced bilinguals showed an advantage in the non-contextual task, while their Minnan counterparts did not, and the impact of L1-L2 similarity emerged in both tasks. These results unveiled the way the two effects dynamically interplayed depending on the task contexts and the relative degrees of using L1 and L2.

  12. Developing recombinant antibodies for biomarker detection

    Energy Technology Data Exchange (ETDEWEB)

    Baird, Cheryl L.; Fischer, Christopher J.; Pefaur, Noah B.; Miller, Keith D.; Kagen, Jacob; Srivastava, Sudhir; Rodland, Karin D.

    2010-10-01

    Monoclonal antibodies (mAbs) have an essential role in biomarker validation and diagnostic assays. A barrier to pursuing these applications is the reliance on immunization and hybridomas to produce mAbs, which is time-consuming and may not yield the desired mAb. We recommend a process flow for affinity reagent production that utilizes combinatorial protein display systems (eg, yeast surface display or phage display) rather than hybridomas. These systems link a selectable phenotype-binding conferred by an antibody fragment-with a means for recovering the encoding gene. Recombinant libraries obtained from immunizations can produce high-affinity antibodies (<10 nM) more quickly than other methods. Non-immune libraries provide an alternate route when immunizations are not possible, or when suitable mAbs are not recovered from an immune library. Directed molecular evolution (DME) is an integral part of optimizing mAbs obtained from combinatorial protein display, but can also be used on hybridoma-derived mAbs. Variants can easily be obtained and screened to increase the affinity of the parent mAb (affinity maturation). We discuss examples where DME has been used to tailor affinity reagents to specific applications. Combinatorial protein display also provides an accessible method for identifying antibody pairs, which are necessary for sandwich-type diagnostic assays.

  13. Recombinant phage probes for Listeria monocytogenes

    Energy Technology Data Exchange (ETDEWEB)

    Carnazza, S; Gioffre, G; Felici, F; Guglielmino, S [Department of Microbiological, Genetic and Molecular Sciences, University of Messina, Messina (Italy)

    2007-10-03

    Monitoring of food and environmental samples for biological threats, such as Listeria monocytogenes, requires probes that specifically bind biological agents and ensure their immediate and efficient detection. There is a need for robust and inexpensive affinity probes as an alternative to antibodies. These probes may be recruited from random peptide libraries displayed on filamentous phage. In this study, we selected from two phage peptide libraries phage clones displaying peptides capable of specific and strong binding to the L. monocytogenes cell surface. The ability of isolated phage clones to interact specifically with L. monocytogenes was demonstrated using enzyme-linked immunosorbent assay (ELISA) and confirmed by co-precipitation assay. We also assessed the sensitivity of phage-bacteria binding by PCR on phage-captured Listeria cells, which could be detected at a concentration of 10{sup 4} cells ml{sup -1}. In addition, as proof-of-concept, we tested the possibility of immobilizing the affinity-selected phages to a putative biosensor surface. The quality of phage deposition was monitored by ELISA and fluorescent microscopy. Phage-bacterial binding was confirmed by high power optical phase contrast microscopy. Overall, the results of this work validate the concept of affinity-selected recombinant filamentous phages as probes for detecting and monitoring bacterial agents under any conditions that warrant their recognition, including in food products.

  14. Vaccine platform recombinant measles virus.

    Science.gov (United States)

    Mühlebach, Michael D

    2017-10-01

    The classic development of vaccines is lengthy, tedious, and may not necessarily be successful as demonstrated by the case of HIV. This is especially a problem for emerging pathogens that are newly introduced into the human population and carry the inherent risk of pandemic spread in a naïve population. For such situations, a considerable number of different platform technologies are under development. These are also under development for pathogens, where directly derived vaccines are regarded as too complicated or even dangerous due to the induction of inefficient or unwanted immune responses causing considerable side-effects as for dengue virus. Among platform technologies are plasmid-based DNA vaccines, RNA replicons, single-round infectious vector particles, or replicating vaccine-based vectors encoding (a) critical antigen(s) of the target pathogens. Among the latter, recombinant measles viruses derived from vaccine strains have been tested. Measles vaccines are among the most effective and safest life-attenuated vaccines known. Therefore, the development of Schwarz-, Moraten-, or AIK-C-strain derived recombinant vaccines against a wide range of mostly viral, but also bacterial pathogens was quite straightforward. These vaccines generally induce powerful humoral and cellular immune responses in appropriate animal models, i.e., transgenic mice or non-human primates. Also in the recent first clinical phase I trial, the results have been quite encouraging. The trial indicated the expected safety and efficacy also in human patients, interestingly independent from the level of prevalent anti-measles immunity before the trial. Thereby, recombinant measles vaccines expressing additional antigens are a promising platform for future vaccines.

  15. CRMAGE: CRISPR Optimized MAGE Recombineering

    DEFF Research Database (Denmark)

    Ronda, Carlotta; Pedersen, Lasse Ebdrup; Sommer, Morten Otto Alexander

    2016-01-01

    A bottleneck in metabolic engineering and systems biology approaches is the lack of efficient genome engineering technologies. Here, we combine CRISPR/Cas9 and λ Red recombineering based MAGE technology (CRMAGE) to create a highly efficient and fast method for genome engineering of Escherichia coli...... that are assembled by a USER-cloning approach enabling quick and cost efficient gRNA replacement. CRMAGE furthermore utilizes CRISPR/Cas9 for efficient plasmid curing, thereby enabling multiple engineering rounds per day. To facilitate the design process, a web-based tool was developed to predict both the λ Red...

  16. Atomic excitation and recombination in external fields

    International Nuclear Information System (INIS)

    Nayfeh, M.H.; Clark, C.W.

    1985-01-01

    This volume offers a timely look at Rydberg states of atoms in external fields and dielectronic recombination. Each topic provides authoritative coverage, presents a fresh account of a flourishing field of current atomic physics and introduces new opportunities for discovery and development. Topics considered include electron-atom scattering in external fields; observations of regular and irregular motion as exemplified by the quadratic zeeman effect and other systems; Rydberg atoms in external fields and the Coulomb geometry; crossed-field effects in the absorption spectrum of lithium in a magnetic field; precise studies of static electric field ionization; widths and shapes of stark resonances in sodium above the saddle point; studies of electric field effects and barium autoionizing resonances; autoionization and dielectronic recombination in plasma electric microfields; dielectronic recombination measurements on multicharged ions; merged beam studies of dielectronic recombination; Rydberg atoms and dielectronic recombination in astrophysics; and observations on dielectronic recombination

  17. Recombinant vaccines: experimental and applied aspects

    DEFF Research Database (Denmark)

    Lorenzen, Niels

    1999-01-01

    in induction of a protective immune response may become vital. The few recombinant vaccines licensd so far, despite much research during the last decade, illustrate that this is not a straightforward matter. However, as vaccine technology as well as our knowledge of the fish immune system is steadily improved......, these fields will open up a number of interesting research objectives of mutual benefit. Recent aspects of recombinant protein vaccines, live recombinant vaccines and DNA vaccines are discussed....

  18. Quantum mechanical theory of collisional recombination rates

    International Nuclear Information System (INIS)

    Miller, W.H.

    1995-01-01

    Quantum mechanical expressions for the pressure-dependent recombination rate (within the strong collision assumption) are presented which have a very similar form to those developed recently for rate constants of chemical reactions: eqs. 11 and 12 express the recombination rate in terms of a flux autocorrelation function, and eqs. 14-16 in terms of a cumulative recombination probability. The qualitative behavior of these functions is illustrated by several pedagogical examples. 24 refs., 1 fig

  19. Recombination chambers for BNCT dosimetry

    International Nuclear Information System (INIS)

    Tulik, Piotr

    2006-01-01

    Parallel plate recombination ionization chambers are known as the detectors which can be used for determination of gamma and high-LET dose components and for characterization of radiation quality of mixed radiation fields. Specially designed chambers can operate correctly even at dose rates of therapeutic beams. In this work the investigations were extended to a set of cylindrical chambers including a TE chamber and three graphite chambers filled with different gases - CO 2 , N 2 and 10 BF 3 , in order to determine the thermal neutrons, 14 N capture, gamma, and fast neutron dose components. The separation of the dose components is based on differences of the shape of the saturation curve, in dependence on LET spectrum of the investigated radiation. The measurements using all the chambers and a parallel plate recombination chamber were performed in a reactor beam of NRI Rez (Czech Republic). The gamma component was determined with accuracy of about 5%, while the variations of its value could be monitored with accuracy of about 0.5%. Relative changes of the beam components could be detected with accuracy of about 5% using the parallel plate chamber. The use of the chambers filled with different gases considerably improved the resolution of the method. (author)

  20. Rapid purification of recombinant histones.

    Science.gov (United States)

    Klinker, Henrike; Haas, Caroline; Harrer, Nadine; Becker, Peter B; Mueller-Planitz, Felix

    2014-01-01

    The development of methods to assemble nucleosomes from recombinant histones decades ago has transformed chromatin research. Nevertheless, nucleosome reconstitution remains time consuming to this day, not least because the four individual histones must be purified first. Here, we present a streamlined purification protocol of recombinant histones from bacteria. We termed this method "rapid histone purification" (RHP) as it circumvents isolation of inclusion bodies and thereby cuts out the most time-consuming step of traditional purification protocols. Instead of inclusion body isolation, whole cell extracts are prepared under strongly denaturing conditions that directly solubilize inclusion bodies. By ion exchange chromatography, the histones are purified from the extracts. The protocol has been successfully applied to all four canonical Drosophila and human histones. RHP histones and histones that were purified from isolated inclusion bodies had similar purities. The different purification strategies also did not impact the quality of octamers reconstituted from these histones. We expect that the RHP protocol can be readily applied to the purification of canonical histones from other species as well as the numerous histone variants.

  1. The Red Queen theory of recombination hotspots.

    Science.gov (United States)

    Ubeda, F; Wilkins, J F

    2011-03-01

    Recombination hotspots are small chromosomal regions, where meiotic crossover events happen with high frequency. Recombination is initiated by a double-strand break (DSB) that requires the intervention of the molecular repair mechanism. The DSB repair mechanism may result in the exchange of homologous chromosomes (crossover) and the conversion of the allelic sequence that breaks into the one that does not break (biased gene conversion). Biased gene conversion results in a transmission advantage for the allele that does not break, thus preventing recombination and rendering recombination hotspots transient. How is it possible that recombination hotspots persist over evolutionary time (maintaining the average chromosomal crossover rate) when they are self-destructive? This fundamental question is known as the recombination hotspot paradox and has attracted much attention in recent years. Yet, that attention has not translated into a fully satisfactory answer. No existing model adequately explains all aspects of the recombination hotspot paradox. Here, we formulate an intragenomic conflict model resulting in Red Queen dynamics that fully accounts for all empirical observations regarding the molecular mechanisms of recombination hotspots, the nonrandom targeting of the recombination machinery to hotspots and the evolutionary dynamics of hotspot turnover. © 2010 The Authors. Journal of Evolutionary Biology © 2010 European Society For Evolutionary Biology.

  2. In vivo recombination efficiency of two site-specific recombination systems, VCre/VloxP and SCre/SloxP, in medaka (Oryzias latipes).

    Science.gov (United States)

    Kishimoto, Kenta; Nakayama, Manabu; Kinoshita, Masato

    2016-08-01

    The present study delineates the in vivo efficiency of two site-specific recombination systems, VCre/VloxP and SCre/SloxP, in medaka (Oryzias latipes). VCre, SCre, and Cre RNA was microinjected into fertilized medaka eggs belonging to three transgenic lines harboring VloxP, SloxP, and loxP cassette. VCre induced site-specific recombination specifically at VloxP sequence and SCre at SloxP sequence without any cross-reactivity. These findings provide two novel alternative recombination systems in vivo in addition to the existing Cre/loxP and Flp/FRT systems, thus enabling sophisticated gene expression in model organisms. © 2016 Japanese Society of Developmental Biologists.

  3. Expression of active secreted forms of human amyloid beta-protein precursor by recombinant baculovirus-infected insect cells.

    OpenAIRE

    Bhasin, R; Van Nostrand, W E; Saitoh, T; Donets, M A; Barnes, E A; Quitschke, W W; Goldgaber, D

    1991-01-01

    Three alternatively spliced forms of the amyloid precursor protein (APP), APP-695, APP-751, and APP-770, were expressed in the baculovirus expression vector system. The recombinant proteins were secreted into the culture medium by infected insect cells, and APP molecules were detected in insect cells and medium 2 days after infection with the recombinant APP-baculoviruses. A partial sequence of the NH2 terminus of the secreted protein revealed identity with the native secreted protein and sho...

  4. Adeno-associated-virus-mediated transduction of the mammary gland enables sustained production of recombinant proteins in milk

    OpenAIRE

    Stefan Wagner; Rosemary Thresher; Ross Bland; Götz Laible

    2015-01-01

    Biopharming for the production of recombinant pharmaceutical proteins in the mammary gland of transgenic animals is an attractive but laborious alternative compared to mammalian cell fermentation. The disadvantage of the lengthy process of genetically modifying an entire animal could be circumvented with somatic transduction of only the mammary epithelium with recombinant, replication-defective viruses. While other viral vectors offer very limited scope for this approach, vectors based on ade...

  5. Immunological and biological properties of recombinant Lol p 1.

    Science.gov (United States)

    Boutin, Y; Lamontagne, P; Boulanger, J; Brunet, C; Hébert, J

    1997-03-01

    Current forms of allergy diagnosis and therapies are based on the use of natural allergenic extracts. Despite strong evidence that higher therapeutic efficacy may be achieved with purified allergens, the purification of multiple allergic components from extracts is a fastidious and sometimes an impossible task. However, the use of recombinant allergens may be an alternative to overcome this problem. In this study, we compared the immunological properties of recombinant (r) Lol p 1 with those of the natural protein. We cloned directly the gene encoding Lol p 1 from genomic DNA of ryegrass pollen. This gene was subcloned into the expression vector pMAL-c and expressed as fusion protein. Subsequently, rLol p 1 was cleaved from maltose-binding protein using factor Xa. Using binding inhibition and proliferative assays, we assessed the immunological properties of the recombinant allergens. The capacity of rLol p 1 to trigger basophil histamine release and to elicit a skin reaction was also assessed and compared to those of its natural counterpart. We found that the Lol p 1 gene has no introns since we amplified this gene directly from genomic DNA. We demonstrated that the binding sites of anti-Lol p 1 monoclonal antibody, specific human IgG and IgE antibody are well conserved on rLol p 1 as no difference in the binding inhibition profile was observed when using either natural or recombinant protein. At the T-cell level, rLol p 1 elicited a T-cell response in mice comparable to that observed with the natural protein. In addition, we demonstrated that the biological characteristics of rLol p 1 were comparable to those of the natural counterpart, in that rLol p 1 elicited a skin wheal reaction and induced basophil histamine release in grass-allergic patients only. The data indicate that natural Lol p 1 and rLol p 1 shared identical immunological and biological properties.

  6. Unbalanced Magnetic Pull Effect on Stiffness Models of Active Magnetic Bearing due to Rotor Eccentricity in Brushless DC Motor Using Finite Element Method

    Directory of Open Access Journals (Sweden)

    Bangcheng Han

    2013-01-01

    Full Text Available We firstly report on an investigation into the unbalanced magnetic pull (UMP effect on the static stiffness models of radial active magnetic bearing (RAMB in brushless DC motor (BDCM in no-loaded and loaded conditions using the finite element method (FEM. The influences of the UMP on the force-control current, force-position, current stiffness, and position stiffness of RAMB are clarified in BDCM with 100 kW rated power. We found the position stiffness to be more susceptible to UMP. The primary source of UMP is the permanent magnets of BDCM. In addition, the performance of RAMB is affected by the UMP ripples during motor commutation and also periodically affected by the angular position of rotor. The characteristic curves of RAMB force versus control current (or rotor position and angular position of rotor affected by the UMP are given. The method is useful in design and optimization of RAMB in magnetically suspended BDCMs.

  7. Enhanced Control for a Direct-driven Permanent Synchronous Generator Wind-power Generation System with Flywheel Energy Storage Unit Under Unbalanced Grid Fault

    DEFF Research Database (Denmark)

    Yao, Jun; Zhou, Te; Hu, Weihao

    2015-01-01

    This article presents an enhanced control strategy for a direct-driven permanent synchronous generator based wind-power generation system with a flywheel energy storage unit. The behaviors of the direct-driven permanent magnet synchronous generator system with a flywheel energy storage unit under......, the DC-link voltage oscillations can be effectively suppressed during the unbalanced grid fault by controlling the flywheel energy storage unit. Furthermore, a proportional–integral-resonant controller is designed for the flywheel motor to eliminate the oscillations in the DC-link voltage. Finally......, the proposed coordinated control strategy for the direct-driven permanent magnet synchronous generator system with a flywheel energy storage unit has been validated by the simulation results of a 1-MW direct-driven permanent magnet synchronous generator wind power generation system with a flywheel energy...

  8. Simulative and experimental investigation on stator winding turn and unbalanced supply voltage fault diagnosis in induction motors using Artificial Neural Networks.

    Science.gov (United States)

    Lashkari, Negin; Poshtan, Javad; Azgomi, Hamid Fekri

    2015-11-01

    The three-phase shift between line current and phase voltage of induction motors can be used as an efficient fault indicator to detect and locate inter-turn stator short-circuit (ITSC) fault. However, unbalanced supply voltage is one of the contributing factors that inevitably affect stator currents and therefore the three-phase shift. Thus, it is necessary to propose a method that is able to identify whether the unbalance of three currents is caused by ITSC or supply voltage fault. This paper presents a feedforward multilayer-perceptron Neural Network (NN) trained by back propagation, based on monitoring negative sequence voltage and the three-phase shift. The data which are required for training and test NN are generated using simulated model of stator. The experimental results are presented to verify the superior accuracy of the proposed method. Copyright © 2015. Published by Elsevier Ltd.

  9. Enhanced Control of a DFIG-Based Wind-Power Generation System With Series Grid-Side Converter Under Unbalanced Grid Voltage Conditions

    DEFF Research Database (Denmark)

    Yao, Jun; Li, Hui; Chen, Zhe

    2013-01-01

    This paper presents an enhanced control method for a doubly fed induction generator (DFIG)-based wind-power generation system with series grid-side converter (SGSC) under unbalanced grid voltage conditions. The behaviors of the DFIG system with SGSC during network unbalance are described....... By injecting a series control voltage generated from the SGSC to balance the stator voltage, the adverse effects of voltage unbalance upon the DFIG, such as stator and rotor current unbalances, electromagnetic torque, and power pulsations, can be removed, and then the conventional vector control strategy...... to the grid. Furthermore, a precise current reference generation strategy for the PGSC has been proposed for the PGSC to further improve the operation performance of the whole system. Finally, the proposed coordinated control strategy for the DFIG system with SGSC has been validated by the simulation results...

  10. Prenatal diagnosis of a fetus with unbalanced translocation (4;13)(p16;q32) with overlapping features of Patau and Wolf-Hirschhorn syndromes.

    Science.gov (United States)

    Tapper, Jill K; Zhang, Shuliu; Harirah, Hassan M; Panova, Neli I; Merryman, Linda S; Hawkins, Judy C; Lockhart, Lillian H; Gei, Alfredo B; Velagaleti, Gopalrao V N

    2002-01-01

    Wolf-Hirschhorn syndrome (WHS) and Patau syndrome are two of the most severe conditions resulting from chromosome abnormalities. WHS is caused by a deletion of 4p16, while Patau syndrome is caused by trisomy for some or all regions of chromosome 13. Though the etiologies of these syndromes differ, they share several features including pre- and postnatal growth retardation, microcephaly, cleft lip and palate, and cardiac anomalies. We present here a female fetus with deletion of 4p16 --> pter and duplication of 13q32 --> qter due to unbalanced segregation of t(4;13)(p16;q32) in the father. She displayed overlapping features of both of these syndromes on ultrasound. To the best of our knowledge, this is the first report of a fetus with both partial trisomy 13 and deletion of 4p16, the critical region for WHS. Copyright 2002 S. Karger AG, Basel

  11. Control of a DFIG-based wind energy conversion system operating under harmonically distorted unbalanced grid voltage along with nonsinusoidal rotor injection conditions

    International Nuclear Information System (INIS)

    Fathabadi, Hassan

    2014-01-01

    Highlights: • Novel control scheme for DFIG-based systems operating under three abnormal conditions. • Exact harmonic analysis of a DFIG operating under three abnormal conditions. • Implementation of the proposed hybrid controllers in the (dq) + and rotor (α r β r ) reference frames. - Abstract: In this study, novel hybrid proportional-integral-harmonic resonant (PI-R) controllers implemented in the both (dq) + and rotor (α r β r ) reference frames are presented to control a doubly fed induction generator (DFIG)-based wind power generation system operating simultaneously under the three conditions which are nonsinusoidal rotor voltage injection, harmonically distorted grid voltage, and unbalanced grid voltage. The contribution of this work is to present a novel control scheme implemented in the both (dq) + and rotor (α r β r ) reference frames by considering all the three mentioned conditions (no one or two of them). It will be shown that the proposed control scheme keeps the DFIG in an acceptable operation margin and furthermore, it eliminates all harmonics and pulsations components from the stator and the rotor circuits when the DFIG operates under harmonically distorted unbalanced grid voltage along with quasi-sine rotor injection conditions. The proposed control scheme is simulated in MATLAB/Simulink and simulated results are presented to validate the theoretical results. Although this work is carried out under the three mentioned conditions and other related works have been reported under only one condition, comparison between the results of this work and other works is performed to prove the excellent performances of the proposed control scheme

  12. Prader-Willi syndrome due to an unbalanced de novo translocation [t(15;19)(q12;p13.3)

    Science.gov (United States)

    Dang, Vy; Surampalli, Abhilasha; Manzardo, Ann M; Youn, Stephanie; Butler, Merlin G; Gold, June-Anne; Kimonis, Virginia

    2018-01-01

    Background and Aims Prader-Willi syndrome (PWS) is a complex, multisystem genetic disorder characterized by endocrine, neurologic and behavioral abnormalities. We report the first case of an unbalanced de-novo reciprocal translocation of chromosome 15 and 19: 45,XY,-15, der (19)t(15;19)(q12;p13.3) resulting in monosomy for the PWS chromosome critical region. We performed high resolution SNP microarray to characterize the breakpoints. Case report Our patient had several typical features for PWS including infantile hypotonia, a poor suck and feeding difficulties, tantrums, skin picking, compulsions, small hands and feet and food seeking but not hypopigmentation, a micropenis, cryptorchidism or obesity as common findings seen in PWS at the time of examination at 6 years of age. He had seizures noted from 1 to 3 years of age and marked cognitive delay. Results High resolution SNP microarray analysis identified an atypical PWS Type I deletion of chromosome 15 involving proximal breakpoint BP1. The deletion extended beyond the GABRB3 gene but was proximal to the usual distal breakpoint (BP3) within the 15q11-q13 region and GABRA5, GABRG3 and OCA2 genes were intact. Conclusion We report a case with atypical features for PWS associated with an unbalanced de-novo reciprocal translocation resulting in monosomy for the 15q11.1–15q12 with intact GABRA5, GABRG3 and OCA2 genes. No deletion of 19p13.3 band was detected therefore the patient was not at an increased risk of tumors from Peutz-Jeghers syndrome associated with a deletion of the STK11 gene. PMID:27894106

  13. Fundamental Studies of Recombinant Hydrogenases

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Michael W. [Univ. of Georgia, Athens, GA (United States)

    2014-01-25

    This research addressed the long term goals of understanding the assembly and organization of hydrogenase enzymes, of reducing them in size and complexity, of determining structure/function relationships, including energy conservation via charge separation across membranes, and in screening for novel H2 catalysts. A key overall goal of the proposed research was to define and characterize minimal hydrogenases that are produced in high yields and are oxygen-resistant. Remarkably, in spite of decades of research carried out on hydrogenases, it is not possible to readily manipulate or design the enzyme using molecular biology approaches since a recombinant form produced in a suitable host is not available. Such resources are essential if we are to understand what constitutes a “minimal” hydrogenase and design such catalysts with certain properties, such as resistance to oxygen, extreme stability and specificity for a given electron donor. The model system for our studies is Pyrococcus furiosus, a hyperthermophile that grows optimally at 100°C, which contains three different nickel-iron [NiFe-] containing hydrogenases. Hydrogenases I and II are cytoplasmic while the other, MBH, is an integral membrane protein that functions to both evolve H2 and pump protons. Three important breakthroughs were made during the funding period with P. furiosus soluble hydrogenase I (SHI). First, we produced an active recombinant form of SHI in E. coli by the co-expression of sixteen genes using anaerobically-induced promoters. Second, we genetically-engineered P. furiosus to overexpress SHI by an order of magnitude compared to the wild type strain. Third, we generated the first ‘minimal’ form of SHI, one that contained two rather than four subunits. This dimeric form was stable and active, and directly interacted with a pyruvate-oxidizing enzyme with any intermediate electron carrier. The research resulted in five peer-reviewed publications.

  14. Cheese whey-induced high-cell-density production of recombinant proteins in Escherichia coli

    Directory of Open Access Journals (Sweden)

    Neubauer Peter

    2003-04-01

    Full Text Available Abstract Background Use of lactose-rich concentrates from dairy processes for the induction of recombinant gene's expression has not received much attention although they are interesting low cost substrates for production of recombinant enzymes. Applicability of dairy waste for induction of recombinant genes in Escherichia coli was studied. Clones expressing Lactobacillus phage muramidase and Lactobacillus alcohol dehydrogenase were used for the experiments. Results Shake flask cultivations in mineral salt medium showed that cheese whey or deproteinised whey induced gene expression as efficiently as IPTG (isopropyl-β-D-thiogalactopyranoside or pure lactose. Addition of yeast extract or proteolytically degraded whey proteins did not improve the recombinant protein yield. In contrast, addition of yeast extract to the well-balanced mineral salt medium decreased the product yield. Feeding with glycerol provided sufficient amount of easily assimilable carbon source during the induction period without preventing lactose intake and induction by lactose. High-cell-density fed-batch cultivations showed that product yields comparable to IPTG-induction can be achieved by feeding bacteria with a mixture of glycerol and concentrated whey permeate during the induction. Conclusion Whey and concentrated whey permeate can be applied as an alternative inducer in recombinant high-cell-density fed-batch fermentations. The yield of the recombinant product was comparable to fermentations induced by IPTG. In low-cell-density shake flask experiments the yield was higher with whey or whey permeate than with IPTG.

  15. Electronic recombination in some physics problems

    International Nuclear Information System (INIS)

    Guzman, O.

    1988-01-01

    This work is related to calculations of electronic recombination rates, as a function of electronic density, electronic temperature, and ion nuclear charge. Recombination times can be calculated and compared to cooling time, in cooling processes of ion beans by electrons from storage rings. (A.C.A.S.) [pt

  16. Electron-ion recombination at low energy

    International Nuclear Information System (INIS)

    Andersen, L.H.

    1993-01-01

    The work is based on results obtained with a merged-beams experiment. A beam of electronics with a well characterized density and energy distribution was merged with a fast, monoenergetic ion beam. Results have been obtained for radiative recombination and dielectronic recombination at low relative energies (0 to ∼70eV). The obtained energy resolution was improved by about a factor of 30. High vacuum technology was used to suppress interactions with electrons from the environments. The velocity distribution of the electron beam was determined. State-selective dielectronic-recombination measurements were performable. Recombination processes were studied. The theoretical background for radiative recombination and Kramers' theory are reviewed. The quantum mechanical result and its relation to the semiclassical theory is discussed. Radiative recombination was also measured with several different non-bare ions, and the applicability of the semiclassical theory to non-bare ions was investigated. The use of an effective charge is discussed. For dielectronic recombination, the standard theoretical approach in the isolated resonance and independent-processes approximation is debated. The applicability of this method was tested. The theory was able to reproduce most of the experimental data except when the recombination process was sensitive to couplings between different electronic configurations. The influence of external perturbing electrostatic fields is discussed. (AB) (31 refs.)

  17. Recombinant human endostatin reduces hypertrophic scar ...

    African Journals Online (AJOL)

    Background: Recombinant human endostatin (Endostar) has been widely used to suppress angiogenesis in carcinoma patients. ... Cite as: Wang P, Jiang L-Z, Xue B. Recombinant human endostatin reduces hypertrophic scar formation in rabbit ear model through ... wounds on the tail of each ear were discarded because.

  18. Cell biology of homologous recombination in yeast

    DEFF Research Database (Denmark)

    Eckert-Boulet, Nadine Valerie; Rothstein, Rodney; Lisby, Michael

    2011-01-01

    Homologous recombination is an important pathway for error-free repair of DNA lesions, such as single- and double-strand breaks, and for rescue of collapsed replication forks. Here, we describe protocols for live cell imaging of single-lesion recombination events in the yeast Saccharomyces...

  19. Generation of Modified Pestiviruses by Targeted Recombination

    DEFF Research Database (Denmark)

    Rasmussen, Thomas Bruun; Friis, Martin Barfred; Risager, Peter Christian

    involves targeted modification of viral cDNA genomes, cloned within BACs, by Red/ET recombination-mediated mutagenesis in E.coli DH10B cells. Using recombination-mediated mutagenesis for the targeted design, the work can be expedited and focused in principal on any sequence within the viral genome...

  20. Molecular requirements for radiation-activated recombination

    International Nuclear Information System (INIS)

    Stevens, Craig W.; Zeng Ming; Stamato, Thomas; Cerniglia, George

    1997-01-01

    Purpose/Objective: The major stumbling block to successful gene therapy today is poor gene transfer. We hypothesized that ionizing radiation might activate cellular recombination, and so improve stable gene transfer. We further hypothesized that known DNA-damage-repair proteins might also be important in radiation-activated recombination. Materials and Methods: The effect of irradiation on stable gene transfer efficiency was determined in human (A549 and 39F) and rodent (NIH/3T3) cell lines. Continuous low dose rate and multiple radiation fractions were also tested. Nuclear extracts were made and the effect of irradiation on inter-plasmid recombination/ligation determined. Multiple DNA damage-repair deficient cell lines were tested for radiation-activated recombination. Results: A significant radiation dose-dependent improvement in stable plasmid transfection (by as much as 1300 fold) is demonstrated in neoplastic and primary cells. An improvement in transient plasmid transfection is also seen, with as much as 85% of cells transiently expressing b-galactosidase (20-50 fold improvement). Stable transfection is only improved for linearized or nicked plasmids. Cells have improved gene transfer for at least 96 hours after irradiation. Both fractionated and continuous low dose rate irradiation are effective at improving stable gene transfer in mammalian cells, thus making relatively high radiation dose delivery clinically feasible. Inter-plasmid recombination is radiation dose dependent in nuclear extract assays, and the type of overhang (3', 5' or blunt end) significantly affects recombination efficiency and the type of product. The most common end-joining activity involves filling-in of the overhang followed by blunt end ligation. Adenovirus is a linear, double stranded DNA virus. We demonstrate that adenoviral infection efficiency is increased by irradiation. The duration of transgene expression is lengthened because the virus integrates with high efficiency (∼10

  1. Effects of UV radiation on genetic recombination

    International Nuclear Information System (INIS)

    Vlahovic, K.; Zahradka, D.; Petranovic, M.; Petranovic, D.

    1996-01-01

    We have used the model consisting of Escherichia coli cells and l phage to study the effects of UV radiation on genetic recombination. We found two radiation induced processes that reduce or inhibit genetic recombination. One such process leads to the inability of prophage to excise itself from the irradiated bacterial chromosome by the site-specific recombination. The other process was shown to inhibit a type of general recombination by which the prophage transfers one of its genetic markers to the infecting homologous phage. Loss of the prophage ability to take part in both site-specific and general recombination was shown to develop in recB + but not in recB cells. From this we infer that the loss of prophage recombinogenicity in irradiated cells is a consequence of one process in which RecBCD enzyme (the product of recB, recC and recD genes) plays an essential role. (author)

  2. RNAi and heterochromatin repress centromeric meiotic recombination

    DEFF Research Database (Denmark)

    Ellermeier, Chad; Higuchi, Emily C; Phadnis, Naina

    2010-01-01

    to genetic disabilities, including birth defects. The basis by which centromeric meiotic recombination is repressed has been largely unknown. We report here that, in fission yeast, RNAi functions and Clr4-Rik1 (histone H3 lysine 9 methyltransferase) are required for repression of centromeric recombination....... Surprisingly, one mutant derepressed for recombination in the heterochromatic mating-type region during meiosis and several mutants derepressed for centromeric gene expression during mitotic growth are not derepressed for centromeric recombination during meiosis. These results reveal a complex relation between...... types of repression by heterochromatin. Our results also reveal a previously undemonstrated role for RNAi and heterochromatin in the repression of meiotic centromeric recombination and, potentially, in the prevention of birth defects by maintenance of proper chromosome segregation during meiosis....

  3. Recombinant drugs-on-a-chip: The usage of capillary electrophoresis and trends in miniaturized systems – A review

    International Nuclear Information System (INIS)

    Morbioli, Giorgio Gianini; Mazzu-Nascimento, Thiago; Aquino, Adriano; Cervantes, Cesar; Carrilho, Emanuel

    2016-01-01

    We present here a critical review covering conventional analytical tools of recombinant drug analysis and discuss their evolution towards miniaturized systems foreseeing a possible unique recombinant drug-on-a-chip device. Recombinant protein drugs and/or pro-drug analysis require sensitive and reproducible analytical techniques for quality control to ensure safety and efficacy of drugs according to regulatory agencies. The versatility of miniaturized systems combined with their low-cost could become a major trend in recombinant drugs and bioprocess analysis. Miniaturized systems are capable of performing conventional analytical and proteomic tasks, allowing for interfaces with other powerful techniques, such as mass spectrometry. Microdevices can be applied during the different stages of recombinant drug processing, such as gene isolation, DNA amplification, cell culture, protein expression, protein separation, and analysis. In addition, organs-on-chips have appeared as a viable alternative to testing biodrug pharmacokinetics and pharmacodynamics, demonstrating the capabilities of the miniaturized systems. The integration of individual established microfluidic operations and analytical tools in a single device is a challenge to be overcome to achieve a unique recombinant drug-on-a-chip device. - Highlights: • Principal analytical tools for analysis of recombinant drugs are presented. • A critical comparison among different substrates for fabrication of miniaturized systems is made. • Applications of miniaturized systems to produce recombinant drugs are shown. • Future trends of miniaturized systems capable of integrating analytical and proteomic tools in a single device are envisioned.

  4. Recombinant drugs-on-a-chip: The usage of capillary electrophoresis and trends in miniaturized systems – A review

    Energy Technology Data Exchange (ETDEWEB)

    Morbioli, Giorgio Gianini; Mazzu-Nascimento, Thiago; Aquino, Adriano [Instituto de Química de São Carlos, Universidade de São Paulo, Av. Trabalhador São-carlense, 400, 13566-590 São Carlos, SP (Brazil); Instituto Nacional de Ciência e Tecnologia de Bioanalítica, Campinas, SP (Brazil); Cervantes, Cesar [Instituto de Química de São Carlos, Universidade de São Paulo, Av. Trabalhador São-carlense, 400, 13566-590 São Carlos, SP (Brazil); Carrilho, Emanuel, E-mail: emanuel@iqsc.usp.br [Instituto de Química de São Carlos, Universidade de São Paulo, Av. Trabalhador São-carlense, 400, 13566-590 São Carlos, SP (Brazil); Instituto Nacional de Ciência e Tecnologia de Bioanalítica, Campinas, SP (Brazil)

    2016-09-07

    We present here a critical review covering conventional analytical tools of recombinant drug analysis and discuss their evolution towards miniaturized systems foreseeing a possible unique recombinant drug-on-a-chip device. Recombinant protein drugs and/or pro-drug analysis require sensitive and reproducible analytical techniques for quality control to ensure safety and efficacy of drugs according to regulatory agencies. The versatility of miniaturized systems combined with their low-cost could become a major trend in recombinant drugs and bioprocess analysis. Miniaturized systems are capable of performing conventional analytical and proteomic tasks, allowing for interfaces with other powerful techniques, such as mass spectrometry. Microdevices can be applied during the different stages of recombinant drug processing, such as gene isolation, DNA amplification, cell culture, protein expression, protein separation, and analysis. In addition, organs-on-chips have appeared as a viable alternative to testing biodrug pharmacokinetics and pharmacodynamics, demonstrating the capabilities of the miniaturized systems. The integration of individual established microfluidic operations and analytical tools in a single device is a challenge to be overcome to achieve a unique recombinant drug-on-a-chip device. - Highlights: • Principal analytical tools for analysis of recombinant drugs are presented. • A critical comparison among different substrates for fabrication of miniaturized systems is made. • Applications of miniaturized systems to produce recombinant drugs are shown. • Future trends of miniaturized systems capable of integrating analytical and proteomic tools in a single device are envisioned.

  5. Containment air circulation for optimal hydrogen recombination

    International Nuclear Information System (INIS)

    Spinks, N.; Krause, M.

    1997-01-01

    An accepted first-line defense for hydrogen mitigation is to design for the hydrogen to be rapidly mixed with the containment atmosphere and diluted to below flammability concentrations. Then, as hydrogen continues to be produced in the longer term, recombiners can be used to remove hydrogen: recombiners can be located in forced-air ducts or passive recombiners can be distributed within containment and the heat of recombination used to promote local air circulation. However, this principle does not eliminate the possibility of high hydrogen concentrations at locations removed from the recombiners. An improvement on this strategy is to arrange for a specific, buoyancy-driven, overall circulation of the containment atmosphere such that the recombiners can be located within the recirculation flow, immediately downstream of the hydrogen source. This would make the mixing process more predictable and solve the mass-transfer problem associated with distributed recombiners. Ideally, the recombiners would be located just above the hydrogen source so that the heat of recombination would assist the overall circulation. In this way, the hydrogen would be removed as close as possible to the source, thereby minimizing the amount of hydrogen immediately downstream of the source and reducing the hydrogen concentration to acceptable levels at other locations. Such a strategy requires the containment volume to be divided into an upflow path, past the hydrogen source and the recombiner, and a downflow path to complete the circuit. The flow could be generated actively using fans or passively using buoyancy forces arising from the difference in density of gases in the upfiow and downflow paths; the gases in the downflow path being cooled at an elevated heat sink. (author)

  6. The recombinational anatomy of a mouse chromosome.

    Directory of Open Access Journals (Sweden)

    Kenneth Paigen

    2008-07-01

    Full Text Available Among mammals, genetic recombination occurs at highly delimited sites known as recombination hotspots. They are typically 1-2 kb long and vary as much as a 1,000-fold or more in recombination activity. Although much is known about the molecular details of the recombination process itself, the factors determining the location and relative activity of hotspots are poorly understood. To further our understanding, we have collected and mapped the locations of 5,472 crossover events along mouse Chromosome 1 arising in 6,028 meioses of male and female reciprocal F1 hybrids of C57BL/6J and CAST/EiJ mice. Crossovers were mapped to a minimum resolution of 225 kb, and those in the telomere-proximal 24.7 Mb were further mapped to resolve individual hotspots. Recombination rates were evolutionarily conserved on a regional scale, but not at the local level. There was a clear negative-exponential relationship between the relative activity and abundance of hotspot activity classes, such that a small number of the most active hotspots account for the majority of recombination. Females had 1.2x higher overall recombination than males did, although the sex ratio showed considerable regional variation. Locally, entirely sex-specific hotspots were rare. The initiation of recombination at the most active hotspot was regulated independently on the two parental chromatids, and analysis of reciprocal crosses indicated that parental imprinting has subtle effects on recombination rates. It appears that the regulation of mammalian recombination is a complex, dynamic process involving multiple factors reflecting species, sex, individual variation within species, and the properties of individual hotspots.

  7. Investigating the dynamics of recombinant protein secretion from a microalgal host.

    Science.gov (United States)

    Lauersen, Kyle J; Huber, Isabel; Wichmann, Julian; Baier, Thomas; Leiter, Andreas; Gaukel, Volker; Kartushin, Viktor; Rattenholl, Anke; Steinweg, Christian; von Riesen, Lena; Posten, Clemens; Gudermann, Frank; Lütkemeyer, Dirk; Mussgnug, Jan H; Kruse, Olaf

    2015-12-10

    Production of recombinant proteins with microalgae represents an alternative platform over plant- or bacterial-based expression systems for certain target proteins. Secretion of recombinant proteins allows accumulation of the target product physically separate from the valuable algal biomass. To date, there has been little investigation into the dynamics of recombinant protein secretion from microalgal hosts-the culture parameters that encourage secreted product accumulation and stability, while encouraging biomass production. In this work, the efficiency of recombinant protein production was optimized by adjusting cultivation parameters for a strain of Chlamydomonas reinhardtii previously engineered to secrete a functional recombinant Lolium perenne ice binding protein (LpIBP), which has applications as a frozen food texturing and cryopreservation additive, into its culture medium. Three media and several cultivation styles were investigated for effects on secreted LpIBP titres and culture growth. A combination of acetate and carbon dioxide feeding with illumination resulted in the highest overall biomass and recombinant protein titres up to 10mgL(-1) in the culture medium. Pure photoautotrophic production was possible using two media types, with recombinant protein accumulation in all cultivations correlating to culture cell density. Two different cultivation systems were used for scale-up to 10L cultivations, one of which produced yields of secreted recombinant protein up to 12mgL(-1) within six cultivation days. Functional ice recrystallization inhibition (IRI) of the LpIBP from total concentrated extracellular protein extracts was demonstrated in a sucrose solution used as a simplified ice cream model. IRI lasted up to 7 days, demonstrating the potential of secreted products from microalgae for use as food additives. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Reciprocality of Recombination Events That Rearrange the Chromosome

    OpenAIRE

    Mahan, M. J.; Roth, J. R.

    1988-01-01

    We describe a genetic system for studying the reciprocality of chromosomal recombination; all substrates and recombination functions involved are provided exclusively by the bacterial chromosome. The genetic system allows the recovery of both recombinant products from a single recombination event. The system was used to demonstrate the full reciprocality of three different types of recombination events: (1) intrachromosomal recombination between direct repeats, causing deletions; (2) intrachr...

  9. Factors Influencing the Integration of Alternative Farm Enterprises into the Agro-Food System

    Science.gov (United States)

    Barlas, Y.; Damianos, D.; Dimara, E.; Kasimis, C.; Skuras, D.

    2001-01-01

    Financial stress and general crisis in European agriculture recently have generated a widespread interest in alternative paths of farm business development and structural adjustment. One of the options suggested by policy makers and adopted by farmers was the development of alternative farm enterprises (AFEs), in which farmers recombine resources…

  10. Companion Protease Inhibitors for the In Situ Protection of Recombinant Proteins in Plants.

    Science.gov (United States)

    Robert, Stéphanie; Jutras, Philippe V; Khalf, Moustafa; D'Aoust, Marc-André; Goulet, Marie-Claire; Sainsbury, Frank; Michaud, Dominique

    2016-01-01

    We previously described a procedure for the use of plant protease inhibitors as "companion" accessory proteins to prevent unwanted proteolysis of clinically useful recombinant proteins in leaf crude protein extracts (Benchabane et al. Methods Mol Biol 483:265-273, 2009). Here we describe the use of these inhibitors for the protection of recombinant proteins in planta, before their extraction from leaf tissues. A procedure is first described involving inhibitors co-expressed along-and co-migrating-with the protein of interest in host plant cells. An alternative, single transgene scheme is then described involving translational fusions of the recombinant protein and companion inhibitor. These approaches may allow for a significant improvement of protein steady-state levels in leaves, comparable to yield improvements observed with protease-deficient strains of less complex protein expression hosts such as E. coli or yeasts.

  11. Alternate superior Julia sets

    International Nuclear Information System (INIS)

    Yadav, Anju; Rani, Mamta

    2015-01-01

    Alternate Julia sets have been studied in Picard iterative procedures. The purpose of this paper is to study the quadratic and cubic maps using superior iterates to obtain Julia sets with different alternate structures. Analytically, graphically and computationally it has been shown that alternate superior Julia sets can be connected, disconnected and totally disconnected, and also fattier than the corresponding alternate Julia sets. A few examples have been studied by applying different type of alternate structures

  12. Uso da somatotropina bovina recombinante - rbST como alternativa para a produção de leite de cabra na entressafra Use of recombinant bovine somatotropin - rbST as an alternative for lactating goats during the low production season

    Directory of Open Access Journals (Sweden)

    Paula Galvano Barbosa

    2002-09-01

    Full Text Available O experimento desenvolveu-se no Setor de Caprinocultura da FMVZ - UNESP - Campus de Botucatu, com o objetivo de estudar a influência da somatotropina bovina recombinante (rbST - nome comercial: Boostin 250 mg na produção de leite, nos constituintes do leite, peso e escore de condição corporal de cabras durante o ciclo lactacional. Foram usadas 21 cabras da raça Parda Alpina, com idade entre 1 ½ e 4 anos, distribuídas aleatoriamente entre três tratamentos de sete animais cada: controle (T1 - sem rbST; completo, safra e entressafra (T2 - rbST após 45 dias de lactação; e apenas entressafra (T3 - rbST após 154 dias de lactação. Os animais dos três tratamentos receberam a mesma alimentação, que diferiu apenas na quantidade de concentrado, ajustada de acordo com a produção de leite dos animais. Não se observou aumento na produção de leite dos animais tratados, mas a persistência da lactação foi maior nestes animais. Não se observou diferença entre animais controles e tratados quanto aos constituintes do leite (densidade, gordura, EST, lactose e proteína. O peso e o índice de condição corporal também não apresentaram diferença significativa entre animais tratados e controle.The experiment was conducted at the Goat Husbandry Sector of FMVZ - UNESP - Botucatu Campus, with the purpose of studying the influence of recombinant bovine somatotropin (rbST - commercial name: Boostin 250 mg on the lactation curve, milk production, milk constituents, body weight and body score of goats during the lactation cycle. Twenty-one Alpine Brown goats between 1½ and 4 years old were used, randomly allotted to three treatments with seven animals each: control (T1 - no rbST, complete (T2 - rbST after the milk production peak and low production season (T3 - rbST during the low production season. All animals received the same diet, excepting the amount of concentrate, which was adjusted according to milk yield. No increase in milk yield was

  13. Invariant Measures of Genetic Recombination Processes

    Science.gov (United States)

    Akopyan, Arseniy V.; Pirogov, Sergey A.; Rybko, Aleksandr N.

    2015-07-01

    We construct a non-linear Markov process connected with a biological model of a bacterial genome recombination. The description of invariant measures of this process gives us the solution of one problem in elementary probability theory.

  14. Ultramicroscopic observation of recombinant adenoassociated virus ...

    African Journals Online (AJOL)

    Ultramicroscopic observation of recombinant adenoassociated virus type 2 on the surface of formvarcarbon coated copper grids under different relative humidity and incubation time using negative stain transmission electron microscopy.

  15. Recombinant Human Papillomavirus (HPV) Bivalent Vaccine

    Science.gov (United States)

    This page contains brief information about recombinant human papillomavirus (HPV) bivalent vaccine and a collection of links to more information about the use of this vaccine, research results, and ongoing clinical trials.

  16. Recombinant Human Papillomavirus (HPV) Nonavalent Vaccine

    Science.gov (United States)

    This page contains brief information about recombinant human papillomavirus (HPV) nonavalent vaccine and a collection of links to more information about the use of this vaccine, research results, and ongoing clinical trials.

  17. Recombinant Human Papillomavirus (HPV) Quadrivalent Vaccine

    Science.gov (United States)

    This page contains brief information about recombinant human papillomavirus (HPV) quadrivalent vaccine and a collection of links to more information about the use of this vaccine, research results, and ongoing clinical trials.

  18. Recombinant vaccines: experimental and applied aspects

    DEFF Research Database (Denmark)

    Lorenzen, Niels

    1999-01-01

    Development of vaccines for aquaculture fish represent an important applied functional aspect of fish immunology research. Particularly in the case of recombinant vaccines, where a single antigen is usually expected to induce immunity to a specific pathogen, knowledge of mechanisms involved...... in induction of a protective immune response may become vital. The few recombinant vaccines licensd so far, despite much research during the last decade, illustrate that this is not a straightforward matter. However, as vaccine technology as well as our knowledge of the fish immune system is steadily improved......, these fields will open up a number of interesting research objectives of mutual benefit. Recent aspects of recombinant protein vaccines, live recombinant vaccines and DNA vaccines are discussed....

  19. A novel unbalanced de novo translocation der(5t(4;5(q26;q21.1 in adult T-cell precursor lymphoblastic leukemia

    Directory of Open Access Journals (Sweden)

    Kjeldsen Eigil

    2012-05-01

    Full Text Available Abstract We here describe a novel unbalanced de novo translocation der(5t(4;5(q26;q21.1 in a 39-year-old male diagnosed with acute T-cell lymphoblastic leukemia. Bone marrow (BM was massively infiltrated with 85 % highly proliferative polymorphic T-cell precursors. Immunologically, the malignant cells stained positive for CD7, CD34, intracytoplasmic CD3+, TdT + and negative for CD3 and CD5. G-banded chromosome analysis of BM cells showed the normal karyotype 46,XY[25] whereas BAC-based aCGH analysis revealed partial gain of 4q and partial loss of 5q. Multicolor karyotyping confirmed the presence of an unbalanced der(5t(4;5 as the sole structural abnormality. Subsequent high-resolution oligonucleotide-based aCGH analysis showed that the der(5t(4;5(q26;q21.1 resulted in partial trisomy of 4q26qter (117,719,015-190,613,014 and partial monosomy of 5q21.1qter (100,425,442-180,857,866 and that there was no indication of any gene disruptions resulting from the breakages. Interphase FISH analysis using BAC-based specific probes for 4q26 and 5q21.1 confirmed the breakpoints and revealed approximately 80 % abnormal cells accordingly. At 4q26 the MIR1973 gene is located centromeric to the breakpoint in the copy number neutral region and the TRAM1L1 gene is located within the gained region. At 5q21.1 the genes ST8SIA4 and MIR548p are located centromeric to the breakpoint and no known genes up to approximately 1 Mb telomeric to the breakpoint in the copy number loss region. Interestingly, only the gene ST8SIA4 at 5q21.1 have been implicated in T-cell regulation as it encodes one of the key enzymes for polysialysation of surface proteins on dendritic cells which are important regulators for T-cell proliferation. The der(5t(4;5 is thought to play a crucial role in the pathogenesis of acute T-ALL due to either gain of 4q, the loss of 5q, or deregulation of genes in proximity to the breakpoints.

  20. Parental age and unbalanced Robertsonian translocations associated with Down syndrome and Patau syndrome: comparison with maternal and paternal age effects for 47, +21 and 47, +13.

    Science.gov (United States)

    Hook, E B

    1984-10-01

    Data are analysed on livebirths with trisomic syndromes associated with unbalanced Robertsonian translocations born from 1968 to 1981 and reported to the New York State Chromosome Registry. The maternal ages of reported cases were compared with those of the livebirths in the general population who were born in the same year. The number of translocations studied, the mean case-control differences in years in maternal age (and the standard errors of the mean) were respectively, as follows: D/21 mutants, n = 36, -0.1 (+/- 0.9); G/21 mutants, n = 46, +1.5 (+/-0.8); D/13 mutants, n = 16, +0.6 (+/-1.5); D/21 inherited, n = 12, -1.0 (+/-1.4); G/21 inherited, n = 3, -0.3 (+/-4.4); and D/13 inherited, n = 6, +2.1 (+/-2.4). There was little change in any category if the few cases diagnosed prenatally were included. Only the value for the G/21 mutants is significantly different from zero at the 0.05 level. (The results on G/21 mutants in maternal age are consistent with an earlier Japanese report of an increase of about 2 years over the control values.) The distribution of maternal ages suggests that G/21 mutants may be produced both by maternal age-independent and maternal age-dependent components. The data on D/21 mutants, however, do not indicate the negative association with maternal age reported in Japan. Differences between this study and the Japanese study in analyses of controls may explain this slight variation. But in any event both studies reveal no evidence for an increase in maternal age for unbalanced D/21 mutant or D/21 inherited translocations associated with Down syndrome. This is evidence against the hypothesis that relaxed selection during gestation, after recognition of pregnancy, accounts for the maternal age effects of 47, +21. In comparison with the results on Robertsonian translocations, the case-control differences in maternal age in years (and the standard errors of the mean) for 47, +21 for 2148 livebirths was +4.6 (+/-0.2), and for 2354 cases

  1. Recombinant aequorin and recombinant semi-synthetic aequorins. Cellular Ca2+ ion indicators.

    OpenAIRE

    Shimomura, O; Inouye, S; Musicki, B; Kishi, Y

    1990-01-01

    Properties of a recombinant aequorin were investigated in comparison with those of natural aequorin. In chromatographic behaviour the recombinant aequorin did not match any of ten isoaequorins tested, although it was very similar to aequorin J. Its sensitivity to Ca2+ was found to be higher than that of any isoaequorin except aequorin D. The recombinant aequorin exhibited no toxicity when tested in various kinds of cells, even where samples of natural aequorin had been found to be toxic. Prop...

  2. Live recombinant BHV/BRSV vaccine

    OpenAIRE

    Keil, G.M.; Rijsewijk, F.A.M.

    1998-01-01

    The present invention refers to synthetic Bovine Respiratory Syncytium virus genes. Also the invention relates to live attenuated Bovine Herpesvirus recombinants carrying such synthetic genes. Furthermore, the invention relates to vaccines based on these live attenuated recombinants, for the protection of cattle against both Bovine herpesvirus infection and against Bovine Respiratory Syncytium virus infection. Also the invention relates to methods for the preparation of such live attenuated r...

  3. Recombination-deficient mutant of Streptococcus faecalis

    International Nuclear Information System (INIS)

    Yagi, Y.; Clewell, D.B.

    1980-01-01

    An ultraviolet radiation-sensitive derivative of Streptococcus faecalis strain JH2-2 was isolated and found to be deficient in recombination, using a plasmid-plasmid recombination system. The strain was sensitive to chemical agents which interact with deoxyribonucleic acid and also underwent deoxyribonucleic acid degradation after ultraviolet irradiation. Thus, the mutant has properties similar to those of recA strains of Escherichia coli

  4. Hadron correlations from recombination and fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Fries, Rainer J [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)

    2005-04-01

    We review the formalism of quark recombination applied to the hadronization of a quark-gluon plasma. Evidence in favour of the quark recombination model is outlined. Recent work on parton correlations, leading to detectable correlations between hadrons, is discussed. Hot spots from completely quenched jets are a likely source of such correlations which appear to be jet like. It will be discussed how such a picture compares with measurement of associated hadron yields at RHIC.

  5. Analysis of simultaneous unbalanced short circuit and open conductor faults in power systems with untransposed lines and six-phase sections

    Directory of Open Access Journals (Sweden)

    Karim Hassan Youssef

    2016-03-01

    Full Text Available The paper introduces a generalized method for analysis of multiple, simultaneous short circuit, open circuit, and open circuit falling conductor faults in mixed three-phase and six-phase power systems with untransposed lines. The method is systematic and suitable for all types of faults, any number of simultaneous faults, and any number of phases. Calculation of all network unbalanced voltages and currents during faults is done in one straightforward step. Coupling among sequence networks in untransposed transmission lines is accounted for. Coupling between the three-sequence networks of the three-phase part and the six-sequence networks of six-phase part is also derived. The method is applied also for transient stability study of mixed three-phase and six-phase power systems during any type of faults. Detailed derivation of the governing equations in each part is presented. Simulation results on the IEEE 300-bus system and the IEEE 30-bus system are given to validate the proposed method.

  6. Syntheses and characterization of TiC/a:C composite coatings using pulsed closed field unbalanced magnetron sputtering (P-CFUBMS)

    International Nuclear Information System (INIS)

    Lin, J.; Moore, J.J.; Mishra, B.; Pinkas, M.; Sproul, W.D.

    2008-01-01

    TiC/a:C nanocomposite coatings were prepared by reactively sputtering titanium and graphite targets in pure argon atmosphere using a pulsed closed field unbalanced magnetron sputtering (P-CFUBMS) system. The microstructure of TiC/a:C coatings consisting of nanocrystalline TiC dispersed in an amorphous matrix of free carbon was investigated using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). The effects of coating compositions on the structure and properties of TiC/a:C coatings were investigated. In the present study, TiC/a:C coatings exhibit high hardness (24-29 GPa), low coefficient of friction (0.24-0.25) and low wear rate (less than 2.5 x 10 -7 mm 3 N -1 m -1 ) when the carbon concentration is in the range of 55-66 at.%. Further increase of the carbon content beyond 70 at.% significantly decreased the volume fraction of TiC nanocrystalline and formed a large amount of free amorphous carbon in the coatings. The excessive amorphous carbon phases resulted in a decrease in the coating hardness and the sliding friction coefficient, e.g. a low COF of 0.15 was obtained when the carbon concentration reached 80.5 at.%. However, the decreased hardness will lead to an increase in the wear rate in these high carbon content TiC/a:C coatings

  7. Effects of magnetic flux density and substrate bias voltage on Ni films prepared on a flexible substrate material using unbalanced magnetron sputtering assisted by inductively coupled plasma

    Energy Technology Data Exchange (ETDEWEB)

    Koda, Tatsunori [Graduate School of Science and Technology, Hiroshima Institute of Technology, 2-1-1, Miyake, Saeki-ku, Hiroshima 7315193 (Japan); Toyota, Hiroshi, E-mail: h.toyota.za@it-hiroshima.ac.jp [Department of Electronics and Computer Engineering, Hiroshima Institute of Technology, 2-1-1, Miyake, Saeki-ku, Hiroshima 7315193 (Japan)

    2014-03-15

    The authors fabricated Ni films on a flexible substrate material using unbalanced magnetron sputtering assisted by inductively coupled plasma. The effects of magnetic flux density B{sub C} and substrate DC bias voltage V{sub S} on the Ni film structures were investigated. For V{sub S} = −40 V, the average surface grain size D{sub G} measured by atomic force microscopy for B{sub C} = 0, 3, and 5 mT was 88.2, 95.4, and 104.4 nm, respectively. In addition, D{sub G} increased with V{sub S}. From x-ray diffraction measurements, the (111) and (200) peaks were clearly visible for the fabricated Ni films. The ratio of the integrated intensities of I(111)/I(200) increased with V{sub S}. For V{sub S} = −40 V and B{sub C} = 3 mT, a film resistivity ρ of 8.96 × 10{sup −6} Ω cm was observed, which is close to the Ni bulk value of 6.84 × 10{sup −6} Ω cm. From these results, the authors determined that the structure of the fabricated Ni films on the flexible substrate material was affected by the values of B{sub C} and V{sub S}.

  8. Effect of Si addition on the structure and corrosion behavior of NbN thin films deposited by unbalanced magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Velasco, L. [Universidad Nacional de Colombia, Departamento de Ingenieria Mecanica y Mecatronica, Facultad de Ingenieria, Bogota (Colombia); University of Southern California, Department of Chemical Engineering and Materials Science, Los Angeles, CA (United States); Olaya, J.J. [Universidad Nacional de Colombia, Departamento de Ingenieria Mecanica y Mecatronica, Facultad de Ingenieria, Bogota (Colombia); Rodil, S.E. [Universidad Nacional Autonoma de Mexico, Instituto de Investigaciones en Materiales, Mexico, D. F. (Mexico)

    2016-02-15

    In this work, nanostructured Nb{sub x}Si{sub y}N{sub z} thin films were deposited onto stainless steel AISI 304 substrates by co-sputtering a Nb target with Si additions while using unbalanced magnetron sputtering. The microstructure was analyzed by X-ray diffraction, and the chemical composition was identified by X-ray photoelectron spectroscopy. The hardness was measured by nanoindentation, and the corrosion resistance was studied by potentiodynamic polarization curves and electrochemical impedance spectroscopy using a 3 wt% NaCl solution. The addition of Si in the NbN thin films changed the microstructure from a crystalline to an amorphous phase. The chemical analysis showed the presence of both Si{sub 3}N{sub 4} and NbN phases. The hardness decreased from 20 GPa (NbN) to 15 GPa for the film with the highest Si concentration (28.6 at.%). Nevertheless, the corrosion properties were significantly improved as the Si concentration increased; the polarization resistance after 168 h of immersion was two orders of magnitude larger in comparison with the substrate. (orig.)

  9. Effect of Si addition on the structure and corrosion behavior of NbN thin films deposited by unbalanced magnetron sputtering

    International Nuclear Information System (INIS)

    Velasco, L.; Olaya, J.J.; Rodil, S.E.

    2016-01-01

    In this work, nanostructured Nb x Si y N z thin films were deposited onto stainless steel AISI 304 substrates by co-sputtering a Nb target with Si additions while using unbalanced magnetron sputtering. The microstructure was analyzed by X-ray diffraction, and the chemical composition was identified by X-ray photoelectron spectroscopy. The hardness was measured by nanoindentation, and the corrosion resistance was studied by potentiodynamic polarization curves and electrochemical impedance spectroscopy using a 3 wt% NaCl solution. The addition of Si in the NbN thin films changed the microstructure from a crystalline to an amorphous phase. The chemical analysis showed the presence of both Si 3 N 4 and NbN phases. The hardness decreased from 20 GPa (NbN) to 15 GPa for the film with the highest Si concentration (28.6 at.%). Nevertheless, the corrosion properties were significantly improved as the Si concentration increased; the polarization resistance after 168 h of immersion was two orders of magnitude larger in comparison with the substrate. (orig.)

  10. Cloacal exstrophy in an infant with 9q34.1-qter deletion resulting from a de novo unbalanced translocation between chromosome 9q and Yq.

    Science.gov (United States)

    Thauvin-Robinet, Christel; Faivre, Laurence; Cusin, Véronica; Khau Van Kien, Philippe; Callier, Patrick; Parker, Keith L; Fellous, Marc; Borgnon, Joséphine; Gounot, Emmanuel; Huet, Frédéric; Sapin, Emmanuel; Mugneret, Francine

    2004-04-30

    Cloacal exstrophy is a rare malformation, belonging to a spectrum of birth defects, which, in order of severity, includes phallic separation with epispadias, pubic diastasis, bladder exstrophy, and cloacal exstrophy. This malformation overlaps the OEIS complex (O = omphalocele, E = bladder exstrophy, I = imperforate anus, S = spinal defects). The etiology of cloacal exstrophy is unknown to date. It may result from either a single defect of early blastogenesis or a defect of mesodermal migration during the primitive streak period. We report an infant with cloacal exstrophy, exomphalos, right kidney agenesis, ambiguous external genitalia, and axial hypotonia. The karyotype showed a de novo unbalanced translocation between the long arm of chromosome 9 and the long arm of chromosome Y resulting in a 9q34.1-qter deletion. Reviewing the literature, we did not find any observation of cloacal exstrophy associated with a structural chromosomal abnormality. The steroidogenic factor 1 (SF1) gene, included in the deleted region, was a good candidate gene but no pathogenic mutation was found by direct sequencing. We hypothesize that another gene, expressed early in embryogenesis and responsible for cloacal exstrophy, is present in the 9q34.1-qter region. Copyright 2003 Wiley-Liss, Inc.

  11. Quantitative Analysis of Adulterations in Oat Flour by FT-NIR Spectroscopy, Incomplete Unbalanced Randomized Block Design, and Partial Least Squares

    Directory of Open Access Journals (Sweden)

    Ning Wang

    2014-01-01

    Full Text Available This paper developed a rapid and nondestructive method for quantitative analysis of a cheaper adulterant (wheat flour in oat flour by NIR spectroscopy and chemometrics. Reflectance FT-NIR spectra in the range of 4000 to 12000 cm−1 of 300 oat flour objects adulterated with wheat flour were measured. The doping levels of wheat flour ranged from 5% to 50% (w/w. To ensure the generalization performance of the method, both the oat and the wheat flour samples were collected from different producing areas and an incomplete unbalanced randomized block (IURB design was performed to include the significant variations that may be encountered in future samples. Partial least squares regression (PLSR was used to develop calibration models for predicting the levels of wheat flour. Different preprocessing methods including smoothing, taking second-order derivative (D2, and standard normal variate (SNV transformation were investigated to improve the model accuracy of PLS. The root mean squared error of Monte Carlo cross-validation (RMSEMCCV and root mean squared error of prediction (RMSEP were 1.921 and 1.975 (%, w/w by D2-PLS, respectively. The results indicate that NIR and chemometrics can provide a rapid method for quantitative analysis of wheat flour in oat flour.

  12. Improving optical properties of silicon nitride films to be applied in the middle infrared optics by a combined high-power impulse/unbalanced magnetron sputtering deposition technique.

    Science.gov (United States)

    Liao, Bo-Huei; Hsiao, Chien-Nan

    2014-02-01

    Silicon nitride films are prepared by a combined high-power impulse/unbalanced magnetron sputtering (HIPIMS/UBMS) deposition technique. Different unbalance coefficients and pulse on/off ratios are applied to improve the optical properties of the silicon nitride films. The refractive indices of the Si3N4 films vary from 2.17 to 2.02 in the wavelength ranges of 400-700 nm, and all the extinction coefficients are smaller than 1×10(-4). The Fourier transform infrared spectroscopy and x-ray diffractometry measurements reveal the amorphous structure of the Si3N4 films with extremely low hydrogen content and very low absorption between the near IR and middle IR ranges. Compared to other deposition techniques, Si3N4 films deposited by the combined HIPIMS/UBMS deposition technique possess the highest refractive index, the lowest extinction coefficient, and excellent structural properties. Finally a four-layer coating is deposited on both sides of a silicon substrate. The average transmittance from 3200 to 4800 nm is 99.0%, and the highest transmittance is 99.97% around 4200 nm.

  13. Quantitative Analysis of Adulterations in Oat Flour by FT-NIR Spectroscopy, Incomplete Unbalanced Randomized Block Design, and Partial Least Squares.

    Science.gov (United States)

    Wang, Ning; Zhang, Xingxiang; Yu, Zhuo; Li, Guodong; Zhou, Bin

    2014-01-01

    This paper developed a rapid and nondestructive method for quantitative analysis of a cheaper adulterant (wheat flour) in oat flour by NIR spectroscopy and chemometrics. Reflectance FT-NIR spectra in the range of 4000 to 12000 cm(-1) of 300 oat flour objects adulterated with wheat flour were measured. The doping levels of wheat flour ranged from 5% to 50% (w/w). To ensure the generalization performance of the method, both the oat and the wheat flour samples were collected from different producing areas and an incomplete unbalanced randomized block (IURB) design was performed to include the significant variations that may be encountered in future samples. Partial least squares regression (PLSR) was used to develop calibration models for predicting the levels of wheat flour. Different preprocessing methods including smoothing, taking second-order derivative (D2), and standard normal variate (SNV) transformation were investigated to improve the model accuracy of PLS. The root mean squared error of Monte Carlo cross-validation (RMSEMCCV) and root mean squared error of prediction (RMSEP) were 1.921 and 1.975 (%, w/w) by D2-PLS, respectively. The results indicate that NIR and chemometrics can provide a rapid method for quantitative analysis of wheat flour in oat flour.

  14. Prader-Willi Syndrome due to an Unbalanced de novo Translocation t(15;19)(q12;p13.3).

    Science.gov (United States)

    Dang, Vy; Surampalli, Abhilasha; Manzardo, Ann M; Youn, Stephanie; Butler, Merlin G; Gold, June-Anne; Kimonis, Virginia E

    2016-01-01

    Prader-Willi syndrome (PWS) is a complex, multisystem genetic disorder characterized by endocrine, neurologic, and behavioral abnormalities. We report the first case of an unbalanced de novo reciprocal translocation of chromosomes 15 and 19, 45,XY,-15,der(19)t(15;19)(q12;p13.3), resulting in monosomy for the PWS critical chromosome region. Our patient had several typical features of PWS including infantile hypotonia, a poor suck and feeding difficulties, tantrums, skin picking, compulsions, small hands and feet, and food seeking, but not hypopigmentation, a micropenis, cryptorchidism or obesity as common findings seen in PWS at the time of examination at 6 years of age. He had seizures noted from 1 to 3 years of age and marked cognitive delay. High-resolution SNP microarray analysis identified an atypical PWS type I deletion in chromosome 15 involving the proximal breakpoint BP1. The deletion extended beyond the GABRB3 gene but was proximal to the usual distal breakpoint (BP3) within the 15q11q13 region, and GABRA5, GABRG3, and OCA2 genes were intact. No deletion of band 19p13.3 was detected; therefore, the patient was not at an increased risk of tumors from the Peutz-Jeghers syndrome associated with a deletion of the STK11 gene. © 2016 S. Karger AG, Basel.

  15. General introduction: recombinant protein production and purification of insoluble proteins.

    Science.gov (United States)

    Ferrer-Miralles, Neus; Saccardo, Paolo; Corchero, José Luis; Xu, Zhikun; García-Fruitós, Elena

    2015-01-01

    Proteins are synthesized in heterologous systems because of the impossibility to obtain satisfactory yields from natural sources. The production of soluble and functional recombinant proteins is among the main goals in the biotechnological field. In this context, it is important to point out that under stress conditions, protein folding machinery is saturated and this promotes protein misfolding and, consequently, protein aggregation. Thus, the selection of the optimal expression organism and the most appropriate growth conditions to minimize the formation of insoluble proteins should be done according to the protein characteristics and downstream requirements. Escherichia coli is the most popular recombinant protein expression system despite the great development achieved so far by eukaryotic expression systems. Besides, other prokaryotic expression systems, such as lactic acid bacteria and psychrophilic bacteria, are gaining interest in this field. However, it is worth mentioning that prokaryotic expression system poses, in many cases, severe restrictions for a successful heterologous protein production. Thus, eukaryotic systems such as mammalian cells, insect cells, yeast, filamentous fungus, and microalgae are an interesting alternative for the production of these difficult-to-express proteins.

  16. Recombinant Nepenthesin II for Hydrogen/Deuterium Exchange Mass Spectrometry.

    Science.gov (United States)

    Yang, Menglin; Hoeppner, Morgan; Rey, Martial; Kadek, Alan; Man, Petr; Schriemer, David C

    2015-07-07

    The pitcher secretions of the Nepenthes genus of carnivorous plants contain a proteolytic activity that is very useful for hydrogen/deuterium exchange mass spectrometry (HX-MS). Our efforts to reconstitute pitcher fluid activity using recombinant nepenthesin I (one of two known aspartic proteases in the fluid) revealed a partial cleavage profile and reduced enzymatic stability in certain HX-MS applications. We produced and characterized recombinant nepenthesin II to determine if it complemented nepenthesin I in HX-MS applications. Nepenthesin II shares many properties with nepenthesin I, such as fast digestion at reduced temperature and pH, and broad cleavage specificity, but in addition, it cleaves C-terminal to tryptophan. Neither enzyme reproduces the C-terminal proline cleavage we observed in the natural extract. Nepenthesin II is considerably more resistant to chemical denaturants and reducing agents than nepenthesin I, and it possesses a stability profile that is similar to that of pepsin. Higher stability combined with the slightly broader cleavage specificity makes nepenthesin II a useful alternative to pepsin and a more complete replacement for pitcher fluid in HX-MS applications.

  17. Parp3 Negatively Regulates Immunoglobulin Class Switch Recombination

    Science.gov (United States)

    Robert, Isabelle; Gaudot, Léa; Rogier, Mélanie; Heyer, Vincent; Noll, Aurélia; Dantzer, Françoise; Reina-San-Martin, Bernardo

    2015-01-01

    To generate highly specific and adapted immune responses, B cells diversify their antibody repertoire through mechanisms involving the generation of programmed DNA damage. Somatic hypermutation (SHM) and class switch recombination (CSR) are initiated by the recruitment of activation-induced cytidine deaminase (AID) to immunoglobulin loci and by the subsequent generation of DNA lesions, which are differentially processed to mutations during SHM or to double-stranded DNA break intermediates during CSR. The latter activate the DNA damage response and mobilize multiple DNA repair factors, including Parp1 and Parp2, to promote DNA repair and long-range recombination. We examined the contribution of Parp3 in CSR and SHM. We find that deficiency in Parp3 results in enhanced CSR, while SHM remains unaffected. Mechanistically, this is due to increased occupancy of AID at the donor (Sμ) switch region. We also find evidence of increased levels of DNA damage at switch region junctions and a bias towards alternative end joining in the absence of Parp3. We propose that Parp3 plays a CSR-specific role by controlling AID levels at switch regions during CSR. PMID:26000965

  18. Wave-packet approach to Rydberg resonances in dissociative recombination

    International Nuclear Information System (INIS)

    Morisset, Sabine; Pichl, Lukas; Orel, Ann E.; Schneider, Ioan F.

    2007-01-01

    We report the time-dependent approach to resonant electron capture into Rydberg states in collisions with molecular cations at low impact energy, as an alternative to the method based on multichannel quantum defect theory (MQDT), and present the results for the HD + ion. The propagation of the initial wave function on 13 Rydberg states (besides one valence state) correctly describes the indirect dissociative recombination mechanism in the time domain. Notably, the nonlocal coupling operator between the ionization and dissociation channels is accounted for in the indirect process, extending previous work on the case of direct coupling. The present approach compares to the MQDT framework with remarkable precision: resonant structures in the cross section correctly emerge from the wave-packet propagation; the time-dependent result also forms a cross section envelope for the dense series of ultrafine MQDT resonances corresponding to the quasicontinuous part of the Rydberg state manifold

  19. Dengue vaccine: an update on recombinant subunit strategies.

    Science.gov (United States)

    Martin, J; Hermida, L

    2016-03-01

    Dengue is an increasing public health problem worldwide, with the four serotypes of the virus infecting over 390 million people annually. There is no specific treatment or antiviral drug for dengue, and prevention is largely limited to controlling the mosquito vectors or disrupting the human-vector contact. Despite the considerable progress made in recent years, an effective vaccine against the virus is not yet available. The development of a dengue vaccine has been hampered by many unique challenges, including the need to ensure the absence of vaccine-induced enhanced severity of disease. Recombinant protein subunit vaccines offer a safer alternative to other vaccine approaches. Several subunit vaccine candidates are presently under development, based on different structural and non-structural proteins of the virus. Novel adjuvants or immunopotentiating strategies are also being tested to improve their immunogenicity. This review summarizes the current status and development trends of subunit dengue vaccines.

  20. Complementary and Alternative Medicine

    Science.gov (United States)

    ... for Educators Search English Español Complementary and Alternative Medicine KidsHealth / For Teens / Complementary and Alternative Medicine What's ... a replacement. How Is CAM Different From Conventional Medicine? Conventional medicine is based on scientific knowledge of ...

  1. Recombination of electrons with an anisotropic velocity distribution. Continuation of recombination continuum to series lines

    International Nuclear Information System (INIS)

    Fujimoto, Takashi; Imaida, Takashi

    1998-01-01

    For ions in recombination with electrons with directional motion, the recombination continuum to a J = 0 state is π polarized, and this polarization characteristic should continue across the ionization threshold down to the series lines. A Monte Carlo calculation has been performed for electron collisions on a classical atom in excited states. No evidence is found to support the above conclusion. (author)

  2. Spontaneous radiative recombination and nonradiative Auger recombination in quantum-confined heterostructures

    International Nuclear Information System (INIS)

    Asryan, L V

    2005-01-01

    General approach is described to the rates, fluxes and current densities associated with spontaneous radiative and nonradiative Auger recombinations in heterostructure lasers with different types of a quantum-confined active region (quantum wells, quantum wires, and quantum dots). The proper way of defining the spontaneous radiative and Auger recombination coefficients and their dimensionality are discussed. It is shown that only in a quantum dot, true time constants can be introduced for spontaneous radiative and nonradiative Auger recombinations, which are independent of the injection level. Closed-form elegant expressions are presented for the radiative recombination coefficient as an explicit function of temperature and parameters in bulk and quantum-confined structures. These expressions clearly demonstrate inappropriateness of the common practice of deriving the recombination coefficients in low-dimensional heterostructures from the bulk values. (lasers)

  3. Graded Recombination Layers for Multijunction Photovoltaics

    KAUST Repository

    Koleilat, Ghada I.

    2012-06-13

    Multijunction devices consist of a stack of semiconductor junctions having bandgaps tuned across a broad spectrum. In solar cells this concept is used to increase the efficiency of photovoltaic harvesting, while light emitters and detectors use it to achieve multicolor and spectrally tunable behavior. In series-connected current-matched multijunction devices, the recombination layers must allow the hole current from one cell to recombine, with high efficiency and low voltage loss, with the electron current from the next cell. We recently reported a tandem solar cell in which the recombination layer was implemented using a progression of n-type oxides whose doping densities and work functions serve to connect, with negligible resistive loss at solar current densities, the constituent cells. Here we present the generalized conditions for design of efficient graded recombination layer solar devices. We report the number of interlayers and the requirements on work function and doping of each interlayer, to bridge an work function difference as high as 1.6 eV. We also find solutions that minimize the doping required of the interlayers in order to minimize optical absorption due to free carriers in the graded recombination layer (GRL). We demonstrate a family of new GRL designs experimentally and highlight the benefits of the progression of dopings and work functions in the interlayers. © 2012 American Chemical Society.

  4. Depleted uranium management alternatives

    Energy Technology Data Exchange (ETDEWEB)

    Hertzler, T.J.; Nishimoto, D.D.

    1994-08-01

    This report evaluates two management alternatives for Department of Energy depleted uranium: continued storage as uranium hexafluoride, and conversion to uranium metal and fabrication to shielding for spent nuclear fuel containers. The results will be used to compare the costs with other alternatives, such as disposal. Cost estimates for the continued storage alternative are based on a life-cycle of 27 years through the year 2020. Cost estimates for the recycle alternative are based on existing conversion process costs and Capital costs for fabricating the containers. Additionally, the recycle alternative accounts for costs associated with intermediate product resale and secondary waste disposal for materials generated during the conversion process.

  5. Telomere elongation chooses TERRA ALTernatives.

    Science.gov (United States)

    Arora, Rajika; Azzalin, Claus M

    2015-01-01

    Alternative Lengthening of Telomeres (ALT) mechanisms allow telomerase-negative immortal cells to buffer replicative telomere shortening. ALT is naturally active in a number of human cancers and might be selected upon telomerase inactivation. ALT is thought to operate through homologous recombination (HR) occurring between telomeric repeats from independent chromosome ends. Indeed, suppression of a number of HR factors impairs ALT cell proliferation. Yet, how HR is initiated at ALT telomeres remains elusive. Mounting evidence suggests that the long noncoding telomeric RNA TERRA renders ALT telomeres recombinogenic by forming RNA:DNA hybrids with the telomeric C-rich strand. TERRA and telomeric hybrids act in concert with a number of other factors, including the RNA endoribonuclease RNaseH1 and the single stranded DNA binding protein RPA. The functional interaction network built upon these different players seems indispensable for ALT telomere maintenance, and digging into the molecular details of this previously unappreciated network might open the way to novel avenues for cancer treatments.

  6. Ethanol production by recombinant and natural xylose-utilising yeasts

    Energy Technology Data Exchange (ETDEWEB)

    Eliasson, Anna

    2000-07-01

    from P. stipitis and the endogenous XKS1 gene under control of the PGKI promoter, into the HIS3 locus of S. cerevisiae CEN.PK 113-7A. The strain was stable for more than forty generations in continuous fermentation. The metabolic fluxes during xylose metabolism were quantitatively analysed and anaerobic ethanol formation from xylose in recombinant S. cerevisiae was demonstrated for the first time. The xylose uptake rate increased with increasing xylose concentration in the feed. However, with a feed of 15 g/l xylose and 5 g/l glucose, the xylose flux was 2.2 times lower than the glucose flux, indicating that transport limits the xylose flux. The role of mitochondria in ethanol formation from xylose was investigated using cells of recombinant xylose-utilising S. cerevisiae with two different respiratory capacities and cells from P. stipitis grown under conditions of optimal ethanol formation. Different inhibitors were used either to inhibit the electron transport chain and simulate oxygen limitation, or to inhibit the tricarboxylic acid cycle while not disturbing the electron transport chain. The response to the inhibitors differed significantly for glucose and xylose and the effect was more pronounced for S. cerevisiae. The results indicate that mitochondria play a significant role in the maintenance of the cytoplasmic redox balance during xylose fermentation, through the action of cytoplasmically directed NADH dehydrogenase activity. Thus, more carbon was directed towards ethanol in chemostat cultivations of xylose/glucose mixtures by S. cerevisiae TMB 3001, in the presence of low amounts of oxygen. P. stipitis possesses a second, cyanide-insensitive terminal oxidase, the alternative oxidase, which seems to be of particular importance for efficient ethanol formation from xylose. The highest activity of cyanide-insensitive respiration (CIR), the highest ethanol productivity and lowest xylitol formation were all observed with cells grown under oxygen-limited conditions

  7. Constraints from jet calculus on quark recombination

    International Nuclear Information System (INIS)

    Jones, L.M.; Lassila, K.E.; Willen, D.

    1979-01-01

    Within the QCD jet calculus formalism, we deduce an equation describing recombination of quarks and antiquarks into mesons within a quark or gluon jet. This equation relates the recombination function R(x 1 ,x 2 ,x) used in current literature to the fragmentation function for producing that same meson out of the parton initiating the jet. We submit currently used recombination functions to our consistency test, taking as input mainly the u-quark fragmentation data into π + mesons, but also s-quark fragmentation into K - mesons. The constraint is well satisfied at large Q 2 for large moments. Our results depend on one parameter, Q 0 2 , the constraint equation being satisfied for small values of this parameter

  8. Recombinant human erythropoietin in sports: a review

    Directory of Open Access Journals (Sweden)

    Rafael Maia de Almeida Bento

    2003-06-01

    Full Text Available Erythropoietin is an endogenous hormone of glicoproteic nature secreted by the kidneys and is the main regulator of the erythropoiesis. An alteration in its production generates a disturbance in the plasmatic concentration giving rise to several types of pathologies related to the hematopoietic system. The recombinant forms of erythropoietin have indiscriminately been used by athletes, mainly in endurance sports, by increasing the erythrocytes concentration, generating a better delivery of oxygen to the muscle tissue. The administration of recombinant erythropoietin was prohibited by the International Olympic Committee and its use considered as doping. This review has the intention to describe the physical, biological and pharmacokinetic properties of the endogenous erythropoietin, as well as its recombinant form, describing also its use in sports and the process of searching methodologies for its detection in doping control.

  9. A recombinant rabies virus expressing luciferase.

    Science.gov (United States)

    Liang, H; Tan, Y; Dun, C; Guo, X

    2010-01-01

    A recombinant Rabies virus (RV) expressing firefly luciferase (rRV-luc) was generated by an improved reverse genetics system. Its biological properties were compared with those of the parental RV. The rRV-luc grew in BHK-21 cells similarly to RV, but its virulence for mice was weaker as shown by the lower infectious titers in brain. Rising infectious titers of rRV-luc during its passaging in BHK-21 cells indicated a virus adaptation, while the luciferase (luc) expression was stable. These results suggest that the recombinant RV carrying luc gene might prove a useful tool for further analysis of pathogenesis of RV in small animal models.

  10. Thermal recombination: Beyond the valence quark approximation

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, B. [Department of Physics, Duke University, Durham, NC 27708 (United States); Fries, R.J. [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)]. E-mail: fries@physics.umn.edu; Bass, S.A. [Department of Physics, Duke University, Durham, NC 27708 (United States); RIKEN BNL Research Center, Brookhaven National Laboratory, Upton, NY 11973 (United States)

    2005-07-07

    Quark counting rules derived from recombination models agree well with data on hadron production at intermediate transverse momenta in relativistic heavy-ion collisions. They convey a simple picture of hadrons consisting only of valence quarks. We discuss the inclusion of higher Fock states that add sea quarks and gluons to the hadron structure. We show that, when recombination occurs from a thermal medium, hadron spectra remain unaffected by the inclusion of higher Fock states. However, the quark number scaling for elliptic flow is somewhat affected. We discuss the implications for our understanding of data from the Relativistic Heavy Ion Collider.

  11. Theoretical models for recombination in expanding gas

    International Nuclear Information System (INIS)

    Avron, Y.; Kahane, S.

    1978-09-01

    In laser isotope separation of atomic uranium, one is confronted with the theoretical problem of estimating the concentration of thermally ionized uranium atoms. To investigate this problem theoretical models for recombination in an expanding gas and in the absence of local thermal equilibrium have been constructed. The expansion of the gas is described by soluble models of the hydrodynamic equation, and the recombination by rate equations. General results for the freezing effect for the suitable ranges of the gas parameters are obtained. The impossibility of thermal equilibrium in expanding two-component systems is proven

  12. The effect of titanium current on structure and hardness of aluminium titanium nitride deposited by reactive unbalanced magnetron co-sputtering

    International Nuclear Information System (INIS)

    Buranawong, A.; Witit-anun, N.; Chaiyakun, S.; Pokaipisit, A.; Limsuwan, P.

    2011-01-01

    Nanocrystalline aluminium titanium nitride (AlTi 3 N) thin films were deposited on Si (100) wafer and grid substrates without external heating and biasing at room temperature by reactive unbalanced magnetron co-sputtering technique using pure individual titanium and aluminium targets. The effects of titanium current (I Ti ) on the structure and hardness of these films have been studied. The films were sputtered with Ar and N 2 gases flow rate of 8 and 4 sccm, respectively. The sputtering current of the aluminium current (I Al ) was kept at 600 mA and the sputtering current of titanium (I Ti ) was varied from 600 to 800 mA. The films were deposited for different deposition times ranging from 15 to 60 min. The deposited films were then characterized and analyzed by X-Ray Diffraction (XRD), Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and nanoindentation measurement. The results indicated that the modification of the crystal structure, surface morphology and microstructure were dependent on the deposition parameters. The XRD patterns show polycrystalline structure with preferred orientations in (112), (004) and (153) planes which agree with the standard structure of aluminium titanium nitride (AlTi 3 N) films. In addition, the structure of AlTi 3 N was also confirmed by TEM. These results show that the films are composed of high Al content. The root mean square surface roughness and the average thicknesses were strongly influenced by I ti and deposition times. Cross section analysis by SEM showed dense and compact columnar morphology. The typical hardness of the films was approximately 26.24-30.37 GPa.

  13. The role of growth form and correlated traits in competitive ranking of six perennial ruderal plant species grown in unbalanced mixtures

    Science.gov (United States)

    Dietz, Hansjörg; Steinlein, Thomas; Ullmann, Isolde

    1998-02-01

    The competitive abilities of six perennial ruderal plants of three different growth forms were compared via yield measures using an additive diallel experimental design with unbalanced mixtures (9:3 or 3:9 plants per pot, respectively). Thus, in a given mixture species A was grown in two configurations: three individuals in centre position of the pot together with nine plants of species B in border position and vice versa. Effect competitive abilities as well as response competitive abilities of the species were significantly related to canopy height and plant biomass. The species with lower rosette growth form and smaller biomasses were weaker competitors than the species possessing elevated canopies along with higher biomasses, whereas total leaf area was not significantly correlated with competitive ability between species. Species differences in competitive ability were stronger between the plants grown in the central position than between those grown in the border position. Furthermore, interactions between species-specific traits and configuration could be observed, indicating the importance of species proportions and arrangement patterns for evaluation of competitive outcome in the field. The degree of complete transitivity of the competitive network of the six ruderal species, which was significantly higher than expected under the null model in our experimental design, also seemed to depend on species proportions in mixture. Shifts in root:shoot ratio of the centre plants when faced with competition by the border plants were in the direction of higher shoot allocation for the weak competitors with rosette growth form irrespective of the neighbour species, except for Bunias orientalis, which showed a more plastic response. The stronger competitors showed higher root allocation ( Urtica dioica) or were hardly affected at all. Consistent with the results of our experiment, the weaker competitors occur at rather frequently disturbed and therefore transient

  14. De novo unbalanced translocations in Prader-Willi and Angelman syndrome might be the reciprocal product of inv dup(15s.

    Directory of Open Access Journals (Sweden)

    Elena Rossi

    Full Text Available The 15q11-q13 region is characterized by high instability, caused by the presence of several paralogous segmental duplications. Although most mechanisms dealing with cryptic deletions and amplifications have been at least partly characterized, little is known about the rare translocations involving this region. We characterized at the molecular level five unbalanced translocations, including a jumping one, having most of 15q transposed to the end of another chromosome, whereas the der(15(pter->q11-q13 was missing. Imbalances were associated either with Prader-Willi or Angelman syndrome. Array-CGH demonstrated the absence of any copy number changes in the recipient chromosome in three cases, while one carried a cryptic terminal deletion and another a large terminal deletion, already diagnosed by classical cytogenetics. We cloned the breakpoint junctions in two cases, whereas cloning was impaired by complex regional genomic architecture and mosaicism in the others. Our results strongly indicate that some of our translocations originated through a prezygotic/postzygotic two-hit mechanism starting with the formation of an acentric 15qter->q1::q1->qter representing the reciprocal product of the inv dup(15 supernumerary marker chromosome. An embryo with such an acentric chromosome plus a normal chromosome 15 inherited from the other parent could survive only if partial trisomy 15 rescue would occur through elimination of part of the acentric chromosome, stabilization of the remaining portion with telomere capture, and formation of a derivative chromosome. All these events likely do not happen concurrently in a single cell but are rather the result of successive stabilization attempts occurring in different cells of which only the fittest will finally survive. Accordingly, jumping translocations might represent successful rescue attempts in different cells rather than transfer of the same 15q portion to different chromosomes. We also hypothesize that

  15. Fast Calculation Model and Theoretical Analysis of Rotor Unbalanced Magnetic Pull for Inter-Turn Short Circuit of Field Windings of Non-Salient Pole Generators

    Directory of Open Access Journals (Sweden)

    Guangtao Zhang

    2017-05-01

    Full Text Available Inter-turn short circuit of field windings (ISCFW may cause the field current of a generator to increase, output reactive power to decrease, and unit vibration to intensify, seriously affecting its safe and stable operation. Full integration of mechanical and electrical characteristics can improve the sensitivity of online monitoring, and detect the early embryonic period fault of small turns. This paper studies the calculations and variations of unbalanced magnetic pull (UMP, of which the excitation source of rotor vibration is the basis and key to online fault monitoring. In grid load operation, ISCFW are first calculated with the multi-loop method, so as to obtain the numerical solutions of the stator and the rotor currents during the fault. Next, the air-gap magnetic field of the ISCFW is analyzed according to the actual composition modes of the motor loops in the fault, so as to obtain the analytic expressions of the air-gap magnetic motive force (MMF and magnetic density. The UMP of the rotor is obtained by solving the integral of the Maxwell stress. The correctness of the electric quantity calculation is verified by the ISCFW experiment, conducted in a one pair-pole non-salient pole model machine. On this basis, comparing the simulation analysis with the calculation results of the model in this paper not only verifies the accuracy of the electromagnetic force calculation, but also proves that the latter has the advantages of a short time consumption and high efficiency. Finally, the influencing factors and variation law of UMP are analyzed by means of an analytic model. This develops a base for the online monitoring of ISCFW with the integration of mechanical and electrical information.

  16. Anomalous Abundances in Gaseous Nebulae From Recombination and Collisional Lines: Improved Photoionization and Recombination Studies

    Science.gov (United States)

    Pradhan, Anil Kumar; Nahar, S. N.; Eissner, W. B.; Montenegro, M.

    2011-01-01

    A perplexing anomaly arises in the determination of abundances of common elements in gaseous nebulae, as derived from collisionally excited lines (CEL) as opposed to those from Recombination Lines (RCL). The "abundance discrepancy factors" can range from a factor of 2 to an order of magnitude or more. That has led to quite different interpretation of the physical structure and processes in gaseous nebulae, such as temperature fluctuations across the object, or metal-rich concentrations leading to a dual-abundnace scenario. We show that the problem may lie in inaccuracies in photoionization and recombination models neglecting low-energy resonance phenomena due to fine structure. Whereas the atomic physics of electron impact excitation of forbidden lines is well understood, and accurate collision strengths have long been available, that is not generally the case for electron-ion recombination cross sections. A major problem is the inclusion of relativisitic effects as it pertains to the existence of very low-energy fine structure resonances in photoionization cross sections. We carry out new relativistic calculations for photoionization and recombination cross sections using a recently extended version of the Breit-Pauli R-matrix codes, and the unified electron-ion recombination method that subsumes both the radiative and the dielectronic recombination (RR and DR) processes in an ab initio and self-consistent manner. We find that near-thresold resonances manifest themselves within fine structure levels of the ground state of ions, enhancing low-temperature recombination rate coefficients at 1000-10,000 K. The resulting enahncement in level-specific and total recombination rate coefficients should therefore lead to reduced abundances derived from RCL, and in accordance with those from CEL. We present results for photoionization of O II into, and recombination from, O III. Theoretical cross sections are benchmarked against high-resolution measurements from synchrotron

  17. Safety of recombinant human platelet-derived growth factor-BB in Augment® Bone Graft

    Directory of Open Access Journals (Sweden)

    Luis A Solchaga

    2012-12-01

    Full Text Available This article discusses nonclinical and clinical data regarding the safety of recombinant human platelet-derived growth factor-BB as a component of the Augment® Bone Graft (Augment. Augment is a bone graft substitute intended to be used as an alternative to autologous bone graft in the fusion of hindfoot and ankle joints. Nonclinical studies included assessment of the pharmacokinetic profile of intravenously administered recombinant human platelet-derived growth factor-BB in rat and dog, effects of intravenous administration of recombinant human platelet-derived growth factor-BB in a reproductive and development toxicity study in rats, and chronic toxicity and carcinogenicity of Augment in a 12-month implantation model. These studies showed that systemic exposure was brief and clearance was rapid. No signs of toxicity, carcinogenicity, or tumor promotion were observed even with doses far exceeding the maximum clinical dose. Results of clinical trials (605 participants and commercial use of recombinant human platelet-derived growth factor-BB containing products indicate that these products are not associated with increased incidence of adverse events or cancer. The safety data presented provide evidence that recombinant human platelet-derived growth factor-BB is a safe therapeutic when used in combination products as a single administration during surgical procedures for bone repair and fusion. There is no evidence associating use of recombinant human platelet-derived growth factor-BB in Augment with chronic toxicity, carcinogenicity, or tumor promotion.

  18. Alternative Auditing Approaches

    Energy Technology Data Exchange (ETDEWEB)

    Kandt, Alicen J [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-09-15

    This presentation for the 2017 Energy Exchange in Tampa, Florida, offers information about advanced auditing technologies and techniques including alternative auditing approaches and considerations and caveats.

  19. Algae-based oral recombinant vaccines

    Directory of Open Access Journals (Sweden)

    Elizabeth A Specht

    2014-02-01

    Full Text Available Recombinant subunit vaccines are some of the safest and most effective vaccines available, but their high cost and the requirement of advanced medical infrastructure for administration make them impractical for many developing world diseases. Plant-based vaccines have shifted that paradigm by paving the way for recombinant vaccine production at agricultural scale using an edible host. However, enthusiasm for molecular pharming in food crops has waned in the last decade due to difficulty in developing transgenic crop plants and concerns of contaminating the food supply. Microalgae are poised to become the next candidate in recombinant subunit vaccine production, and they present several advantages over terrestrial crop plant-based platforms including scalable and contained growth, rapid transformation, easily obtained stable cell lines, and consistent transgene expression levels. Algae have been shown to accumulate and properly fold several vaccine antigens, and efforts are underway to create recombinant algal fusion proteins that can enhance antigenicity for effective orally-delivered vaccines. These approaches have the potential to revolutionize the way subunit vaccines are made and delivered – from costly parenteral administration of purified protein, to an inexpensive oral algae tablet with effective mucosal and system immune reactivity.

  20. Mismatch Repair during Homologous and Homeologous Recombination

    Science.gov (United States)

    Spies, Maria; Fishel, Richard

    2015-01-01

    Homologous recombination (HR) and mismatch repair (MMR) are inextricably linked. HR pairs homologous chromosomes before meiosis I and is ultimately responsible for generating genetic diversity during sexual reproduction. HR is initiated in meiosis by numerous programmed DNA double-strand breaks (DSBs; several hundred in mammals). A characteristic feature of HR is the exchange of DNA strands, which results in the formation of heteroduplex DNA. Mismatched nucleotides arise in heteroduplex DNA because the participating parental chromosomes contain nonidentical sequences. These mismatched nucleotides may be processed by MMR, resulting in nonreciprocal exchange of genetic information (gene conversion). MMR and HR also play prominent roles in mitotic cells during genome duplication; MMR rectifies polymerase misincorporation errors, whereas HR contributes to replication fork maintenance, as well as the repair of spontaneous DSBs and genotoxic lesions that affect both DNA strands. MMR suppresses HR when the heteroduplex DNA contains excessive mismatched nucleotides, termed homeologous recombination. The regulation of homeologous recombination by MMR ensures the accuracy of DSB repair and significantly contributes to species barriers during sexual reproduction. This review discusses the history, genetics, biochemistry, biophysics, and the current state of studies on the role of MMR in homologous and homeologous recombination from bacteria to humans. PMID:25731766

  1. Affinity purification of recombinant human plasminogen activator ...

    African Journals Online (AJOL)

    Purpose: To develop processes for effective isolation and purification of recombinant human plasminogen activator (rhPA) from transgenic rabbit milk. Methods: Immunoaffinity chromatography was selected and improved by a special polyol-responsive monoclonal antibody (PR-mAb). Alteplase was used as immunogen ...

  2. Recombinant Poliovirus circulation among healthy children ...

    African Journals Online (AJOL)

    In order to assess the level of polio virus with natural recombinant genome and wild polio virus circulating in the environment of healthy children aged 0 to 5 years in Abidjan, 130 polio viruses made up of 26 polio type 1, 55 type 2 and 49 type 3 were identified by neutralisation test with monoclonal antibodies and restriction ...

  3. RECOMBINANT HUMAN INTERLEUKIN-3 IN CLINICAL ONCOLOGY

    NARCIS (Netherlands)

    DEVRIES, EGE; VANGAMEREN, MM; WILLEMSE, PHB

    Interleukin 3 (IL-3) is a multipotent hematopoietic growth factor which became available as a recombinant (rh) growth factor for use in the clinic a few years ago. In dose-finding studies, this hematopoietic growth factor has been evaluated without and after standard chemotherapy. Stimulatory

  4. Carbon source feeding strategies for recombinant protein ...

    African Journals Online (AJOL)

    Pichia pastoris and Pichia methanolica have been used as expression systems for the production of recombinant protein. The main problems of the production are the slow hierarchic consumption of ethanol and acetate which cause toxicity problems due to methanol accumulation when this surpasses 0.5 gl-1. In some ...

  5. Recombinant human activated protein C (Xigris)

    NARCIS (Netherlands)

    Levi, M. [=Marcel M.; de Jonge, E.; van der Poll, T.

    2002-01-01

    An impaired function of the protein C pathway plays a central role in the pathogenesis of sepsis. Administration of human recombinant activated protein C (Xigris) may restore the dysfunctional anticoagulant mechanism and prevent amplification and propagation of thrombin generation and formation of

  6. Asthma and Therapeutics: Recombinant Therapies in Asthma

    Directory of Open Access Journals (Sweden)

    Cockcroft Donald W

    2005-03-01

    Full Text Available Abstract Numerous recombinant therapies are being investigated for the treatment of asthma. This report reviews the current status of several of these novel agents. Anti-immunoglobulin (IgE (omalizumab, Xolair markedly inhibits all aspects of the allergen challenge in subjects who have reduction of free serum IgE to undetectable levels. Several clinical studies in atopic asthma have demonstrated benefit by improved symptoms and lung function and a reduction in corticosteroid requirements. Early use in atopic asthmatics may be even more effective. Several approaches target interleukin (IL-4. Soluble IL-4 receptor has been shown to effectively replace inhaled corticosteroid; further studies are under way. Recombinant anti-IL-5 and recombinant IL-12 inhibit blood and sputum eosinophils and allergen-induced eosinophilia without any effect on airway responsiveness, allergen-induced airway responses, or allergen-induced airway hyperresponsiveness. Efalizumab, a recombinant antibody that inhibits lymphocyte trafficking, is effective in psoriasis. A bronchoprovocation study showed a reduction in allergen-induced late asthmatic response and allergen-induced eosinophilia, which suggests that it should be effective in clinical asthma. These exciting novel therapies provide not only promise of new therapies for asthma but also valuable tools for investigation of asthma mechanisms.

  7. Expression of recombinant Streptokinase from local Egyptian ...

    African Journals Online (AJOL)

    Jane

    2011-08-17

    Aug 17, 2011 ... DISCUSSION. Isolation and identification of Streptococcus sp. In this study, SK isolated from local Streptococcus sp. SalMarEg was efficiently produced in a recombinant bioactive form. It is worthy to mention that the binding of plasminogen by pathogenic Group C streptococci isolated from human, horses, ...

  8. Expression of recombinant Streptokinase from local Egyptian ...

    African Journals Online (AJOL)

    We reported for the first time the expression of a recombinant SK from a local Streptococcus strain. When produced on industrial scale this r-SK may substantially contribute to reducing the costs of thrombolytic therapy in developing countries. In this study, a highly purified r-SK from Streptococcus sp. isolated from Egyptian ...

  9. CATALYTIC RECOMBINER FOR A NUCLEAR REACTOR

    Science.gov (United States)

    King, L.D.P.

    1960-07-01

    A hydrogen-oxygen recombiner is described for use with water-boiler type reactors. The catalyst used is the wellknown platinized alumina, and the novelty lies in the structural arrangement used to prevent flashback through the gas input system. The recombiner is cylindrical, the gases at the input end being deflected by a baffle plate through a first flashback shield of steel shot into an annular passage adjacent to and extending the full length of the housing. Below the baffle plate the gases flow first through an outer annular array of alumina pellets which serve as a second flashback shield, a means of distributing the flowing gases evenly and as a means of reducing radiation losses to the walls. Thereafter the gases flow inio the centrally disposed catalyst bed where recombination is effected. The steam and uncombined gases flow into a centrally disposed cylindrical passage inside the catalyst bod and thereafter out through the exit port. A high rate of recombination is effected.

  10. Expression and characterization of recombinant human serum ...

    African Journals Online (AJOL)

    ajl yemi

    2011-11-14

    Nov 14, 2011 ... Key words: C-peptide, human serum albumin, recombinant fusion protein, Pichia pastoris, bioactivity, biological half-time. ... lines were purchased from Cell bank of Chinese academy of sciences (Shanghai, China). .... agarose electrophoresis and DNA sequencing (data was not shown). Expression and ...

  11. Therapeutic implications of recombinant human erythropoietin in ...

    African Journals Online (AJOL)

    AJB SERVER

    2006-12-29

    Dec 29, 2006 ... The introduction of recombinant human erythropoietin (RHUEPO) has revolutionised the treatment strategies for patients suffering with anaemia of chronic renal disease and chronic heart failure. Clinical studies and several observational evidences have demonstrated that RHUEPO is also useful in various.

  12. Recombinant Supercharged Polypeptides Restore and Improve Biolubrication

    NARCIS (Netherlands)

    Veeregowda, Deepak H.; Kolbe, Anke; van der Mei, Henny C.; Busscher, Henk J.; Herrmann, Andreas; Sharma, Prashant K.

    2013-01-01

    Recombinant supercharged polypeptides (SUPs) with low cytotoxicity are developed and applied to rejuvenate the lubrication of naturally occurring salivary conditioning films (SCFs). SUPs with 72 positive charges adsorbed and rigidified the SCFs and recruited mucins to form a hydrated layer. These

  13. Algae-based oral recombinant vaccines

    Science.gov (United States)

    Specht, Elizabeth A.; Mayfield, Stephen P.

    2014-01-01

    Recombinant subunit vaccines are some of the safest and most effective vaccines available, but their high cost and the requirement of advanced medical infrastructure for administration make them impractical for many developing world diseases. Plant-based vaccines have shifted that paradigm by paving the way for recombinant vaccine production at agricultural scale using an edible host. However, enthusiasm for “molecular pharming” in food crops has waned in the last decade due to difficulty in developing transgenic crop plants and concerns of contaminating the food supply. Microalgae could be poised to become the next candidate in recombinant subunit vaccine production, as they present several advantages over terrestrial crop plant-based platforms including scalable and contained growth, rapid transformation, easily obtained stable cell lines, and consistent transgene expression levels. Algae have been shown to accumulate and properly fold several vaccine antigens, and efforts are underway to create recombinant algal fusion proteins that can enhance antigenicity for effective orally delivered vaccines. These approaches have the potential to revolutionize the way subunit vaccines are made and delivered – from costly parenteral administration of purified protein, to an inexpensive oral algae tablet with effective mucosal and systemic immune reactivity. PMID:24596570

  14. Catalytic hydrogen recombination for nuclear containments

    International Nuclear Information System (INIS)

    Koroll, G.W.; Lau, D.W.P.; Dewit, W.A.; Graham, W.R.C.

    1994-01-01

    Catalytic recombiners appear to be a credible option for hydrogen mitigation in nuclear containments. The passive operation, versatility and ease of back fitting are appealing for existing stations and new designs. Recently, a generation of wet-proofed catalyst materials have been developed at AECL which are highly specific to H 2 -O 2 , are active at ambient temperatures and are being evaluated for containment applications. Two types of catalytic recombiners were evaluated for hydrogen removal in containments based on the AECL catalyst. The first is a catalytic combustor for application in existing air streams such as provided by fans or ventilation systems. The second is an autocatalytic recombiner which uses the enthalpy of reaction to produce natural convective flow over the catalyst elements. Intermediate-scale results obtained in 6 m 3 and 10 m 3 spherical and cylindrical vessels are given to demonstrate self-starting limits, operating limits, removal capacity, scaling parameters, flow resistance, mixing behaviour in the vicinity of an operating recombiner and sensitivity to poisoning, fouling and radiation. (author). 13 refs., 10 figs

  15. Theory of dielectronic recombination and plasma effects

    International Nuclear Information System (INIS)

    Yukap Hahn

    2000-01-01

    Current status of the various theoretical approaches to calculation of dielectronic recombination rates is summarized, with emphasis on the available data base and on the plasma effects of both the plasma ion (and external) fields and plasma electron collisional effects which seriously affect the rates and complicate compilation of data. (author)

  16. Ultramicroscopic observation of recombinant adenoassociated virus ...

    African Journals Online (AJOL)

    The purpose of this investigation was to compare the effects of different relative humidity (RH) on the microcosmic conformation of the recombinant AAV-2 virion at 22°C. rAAV-2 virions prepared on copper grid were placed in a high, middle or low RH cabinet and incubated for 72, 48 and 24 h, respectively. The rAAV-2 ...

  17. Expression and characterization of recombinant ecarin.

    NARCIS (Netherlands)

    Jonebring, A.; Lange, U.; Bucha, E.; Deinum, J.; Elg, M.; Lovgren, A.

    2012-01-01

    The snake venom protease ecarin from Echis carinatus was expressed in stable transfected CHO-S cells grown in animal component free cell culture medium. Recombinant ecarin (r-ecarin) was secreted from the suspension adapted Chinese Hamster Ovary (CHO-S) host cells as a pro-protein and activation to

  18. Radiative recombination of excitons in amorphous semiconductors

    International Nuclear Information System (INIS)

    Singh, Jai

    2005-01-01

    A theory for calculating the radiative lifetime of excitons in amorphous semiconductors is presented. Four possibilities of excitonic radiative recombination are considered and the corresponding rates are derived at thermal equilibrium. The radiative lifetime is calculated from the inverse of the maximum rate for all the four possibilities. Results agree very well with experiments

  19. Correlations in the Parton Recombination Model

    Energy Technology Data Exchange (ETDEWEB)

    Bass, S.A. [Department of Physics, Duke University, Durham, NC 27708-0305 (United States); RIKEN BNL Research Center, Brookhaven Nat. Lab., Upton, NY 11973 (United States); Fries, R.J. [School of Physics and Astronomy, Univ. of Minnesota, Minneapolis, MN 55455 (United States); Mueller, B. [Department of Physics, Duke University, Durham, NC 27708-0305 (United States)

    2006-08-07

    We describe how parton recombination can address the recent measurement of dynamical jet-like two particle correlations. In addition we discuss the possible effect realistic light-cone wave-functions including higher Fock-states may have on the well-known elliptic flow valence-quark number scaling law.

  20. Production, purification and characterization of two recombinant ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-06-17

    Jun 17, 2008 ... Two recombinant DNA-derived variants of ovine growth hormone were produced, purified, characterized and compared with the authentic pituitary derived GH. The variants oGH3 and oGH5 were isolated by differential centrifugation method and were purified after refolding by ion-exchange.

  1. Gas recombination assembly for electrochemical cells

    Science.gov (United States)

    Levy, Isaac; Charkey, Allen

    1989-01-01

    An assembly for recombining gases generated in electrochemical cells wherein a catalyst strip is enveloped within a hydrophobic, gas-porous film which, in turn, is encased between gas-porous, metallic layers. The sandwich construction of metallic layers and film is formed into a spiral with a tab for connection to the cell.

  2. Improving recombinant protein solubility in Escherichia coli ...

    African Journals Online (AJOL)

    user

    2010-11-22

    Nov 22, 2010 ... capable of improving solubility ratio of human lysozyme. All these studies show that while this approach has been very successful for a large number of unrelated sub- strates, there is no guarantee that chaperones co- overproduction will improve the folding of a recombinant protein. For the first time in this ...

  3. Recombination times in germanium under high pressure

    International Nuclear Information System (INIS)

    Kuyt, J.H.

    1975-01-01

    The influence of pressure on a well defined recombination process was studied. The centres were introduced by γirradiation and the lifetime determined by the decay time of photoconductivity. An optical pressure vessel is described which allows for a hydrostatic variation of 3000 bars. The diffusion constant and lifetime measurements are presented and analysed. (V.J.C.)

  4. Virus efficacy of recombined Autographa californica M ...

    African Journals Online (AJOL)

    Ectropis obliqua is a major tea pest and chitin synthase (CHS) plays a key role in the pest growth and development. A 192 bp conserved domain from E. obliqua CHS gene was cloned and it was used to construct recombined Autographa californica M nucleopolyhedrovirus (AcMNPV) with double-stranded RNA interference ...

  5. Purification of human recombinant granulocyte colony stimulating ...

    African Journals Online (AJOL)

    In Escherichia coli, recombinant proteins were produced either as three dimensionally folded forms or as unfolded forms, inclusion body (IB). The formation of IB was a frequent consequence of high-level protein production and inadequacy of folding agents namely chaperones in the cytoplasm. The structure of the protein in ...

  6. A molecular recombination map of Antirrhinum majus

    Directory of Open Access Journals (Sweden)

    Hudson Andrew

    2010-12-01

    Full Text Available Abstract Background Genetic recombination maps provide important frameworks for comparative genomics, identifying gene functions, assembling genome sequences and for breeding. The molecular recombination map currently available for the model eudicot Antirrhinum majus is the result of a cross with Antirrhinum molle, limiting its usefulness within A. majus. Results We created a molecular linkage map of A. majus based on segregation of markers in the F2 population of two inbred lab strains of A. majus. The resulting map consisted of over 300 markers in eight linkage groups, which could be aligned with a classical recombination map and the A. majus karyotype. The distribution of recombination frequencies and distorted transmission of parental alleles differed from those of a previous inter-species hybrid. The differences varied in magnitude and direction between chromosomes, suggesting that they had multiple causes. The map, which covered an estimated of 95% of the genome with an average interval of 2 cM, was used to analyze the distribution of a newly discovered family of MITE transposons and tested for its utility in positioning seven mutations that affect aspects of plant size. Conclusions The current map has an estimated interval of 1.28 Mb between markers. It shows a lower level of transmission ratio distortion and a longer length than the previous inter-species map, making it potentially more useful. The molecular recombination map further indicates that the IDLE MITE transposons are distributed throughout the genome and are relatively stable. The map proved effective in mapping classical morphological mutations of A. majus.

  7. Extrachromosomal recombination substrates recapitulate beyond 12/23 restricted VDJ recombination in nonlymphoid cells.

    Science.gov (United States)

    Jung, David; Bassing, Craig H; Fugmann, Sebastian D; Cheng, Hwei-Ling; Schatz, David G; Alt, Frederick W

    2003-01-01

    V(D)J recombination occurs efficiently only between gene segments flanked by recombination signals (RSs) containing 12 and 23 base pair spacers (the 12/23 rule). A further limitation "beyond the 12/23 rule" (B12/23) exists at the TCRbeta locus and ensures Dbeta usage. Herein, we show that extrachromosomal V(D)J recombination substrates recapitulate B12/23 restriction in nonlymphoid cells. We further demonstrate that the Vbeta coding flank, the 12-RS heptamer/nonamer, and the 23-RS spacer each can significantly influence B12/23 restriction. Finally, purified core RAG1 and RAG2 proteins (together with HMG2) also reproduce B12/23 restriction in a cell-free system. Our findings indicate that B12/23 restriction of V(D)J recombination is cemented at the level of interactions between the RAG proteins and TCRbeta RS sequences.

  8. High recombination rate in natural populations of Plasmodium falciparum

    NARCIS (Netherlands)

    Conway, D. J.; Roper, C.; Oduola, A. M.; Arnot, D. E.; Kremsner, P. G.; Grobusch, M. P.; Curtis, C. F.; Greenwood, B. M.

    1999-01-01

    Malaria parasites are sexually reproducing protozoa, although the extent of effective meiotic recombination in natural populations has been debated. If meiotic recombination occurs frequently, compared with point mutation and mitotic rearrangement, linkage disequilibrium between polymorphic sites is

  9. Detoxifying Escherichia coli for endotoxin-free production of recombinant proteins.

    Science.gov (United States)

    Mamat, Uwe; Wilke, Kathleen; Bramhill, David; Schromm, Andra Beate; Lindner, Buko; Kohl, Thomas Andreas; Corchero, José Luis; Villaverde, Antonio; Schaffer, Lana; Head, Steven Robert; Souvignier, Chad; Meredith, Timothy Charles; Woodard, Ronald Wesley

    2015-04-16

    Lipopolysaccharide (LPS), also referred to as endotoxin, is the major constituent of the outer leaflet of the outer membrane of virtually all Gram-negative bacteria. The lipid A moiety, which anchors the LPS molecule to the outer membrane, acts as a potent agonist for Toll-like receptor 4/myeloid differentiation factor 2-mediated pro-inflammatory activity in mammals and, thus, represents the endotoxic principle of LPS. Recombinant proteins, commonly manufactured in Escherichia coli, are generally contaminated with endotoxin. Removal of bacterial endotoxin from recombinant therapeutic proteins is a challenging and expensive process that has been necessary to ensure the safety of the final product. As an alternative strategy for common endotoxin removal methods, we have developed a series of E. coli strains that are able to grow and express recombinant proteins with the endotoxin precursor lipid IVA as the only LPS-related molecule in their outer membranes. Lipid IVA does not trigger an endotoxic response in humans typical of bacterial LPS chemotypes. Hence the engineered cells themselves, and the purified proteins expressed within these cells display extremely low endotoxin levels. This paper describes the preparation and characterization of endotoxin-free E. coli strains, and demonstrates the direct production of recombinant proteins with negligible endotoxin contamination.

  10. Diagnosis of paracoccidioidomycosis by a dot blot assay using a recombinant Paracoccidioides brasiliensis p27 protein.

    Science.gov (United States)

    Correa, M M; Bedoya, A M; Guerrero, M P; Méndez, J; Restrepo, A; McEwen, J G

    2007-01-01

    A variety of immunological methods have proven useful for Paracoccidioidomycosis (PCM) diagnosis; however, they are often time consuming and many lack sensitivity and specificity, partially attributed to the use of crude antigens, which give cross reactivity. Until now, attempts to clone and express Paracoccidioides brasiliensis immunodominant antigens have presented difficulties of process and problems of cost. In an attempt to obtain a more rapid, sensitive, and specific test for PCM diagnosis, we subcloned the P. brasiliensis p27 gene and used the recombinant protein as the antigen in dot blot assays to evaluate its usefulness in paracoccidioidomicosis diagnosis. The development of an optimised procedure for p27 recombinant protein purification and production led to an easier and less expensive process than the one previously used in our laboratory and allowed the availability of enough purified protein for its evaluation as the antigen in the dot blot assays. In these assays, antibodies present in ten serum samples from seven patients with PCM recognised the recombinant protein showing a sensitivity of 100% with a specificity of 98%. These results confirm the value of the 27-kDa recombinant antigen in the serodiagnosis of paracoccidioidomycosis and that the dot blot format is an alternative to the immunoenzymatic assay procedure.

  11. Caenorhabditis briggsae recombinant inbred line genotypes reveal inter-strain incompatibility and the evolution of recombination.

    Directory of Open Access Journals (Sweden)

    Joseph A Ross

    2011-07-01

    Full Text Available The nematode Caenorhabditis briggsae is an emerging model organism that allows evolutionary comparisons with C. elegans and exploration of its own unique biological attributes. To produce a high-resolution C. briggsae recombination map, recombinant inbred lines were generated from reciprocal crosses between two strains and genotyped at over 1,000 loci. A second set of recombinant inbred lines involving a third strain was also genotyped at lower resolution. The resulting recombination maps exhibit discrete domains of high and low recombination, as in C. elegans, indicating these are a general feature of Caenorhabditis species. The proportion of a chromosome's physical size occupied by the central, low-recombination domain is highly correlated between species. However, the C. briggsae intra-species comparison reveals striking variation in the distribution of recombination between domains. Hybrid lines made with the more divergent pair of strains also exhibit pervasive marker transmission ratio distortion, evidence of selection acting on hybrid genotypes. The strongest effect, on chromosome III, is explained by a developmental delay phenotype exhibited by some hybrid F2 animals. In addition, on chromosomes IV and V, cross direction-specific biases towards one parental genotype suggest the existence of cytonuclear epistatic interactions. These interactions are discussed in relation to surprising mitochondrial genome polymorphism in C. briggsae, evidence that the two strains diverged in allopatry, the potential for local adaptation, and the evolution of Dobzhansky-Muller incompatibilities. The genetic and genomic resources resulting from this work will support future efforts to understand inter-strain divergence as well as facilitate studies of gene function, natural variation, and the evolution of recombination in Caenorhabditis nematodes.

  12. Alternative health insurance schemes

    DEFF Research Database (Denmark)

    Keiding, Hans; Hansen, Bodil O.

    2002-01-01

    In this paper, we present a simple model of health insurance with asymmetric information, where we compare two alternative ways of organizing the insurance market. Either as a competitive insurance market, where some risks remain uninsured, or as a compulsory scheme, where however, the level...... competitive insurance; this situation turns out to be at least as good as either of the alternatives...

  13. RNA recombination in Hepatitis delta virus: Identification of a novel naturally occurring recombinant

    Directory of Open Access Journals (Sweden)

    Chia-Chi Lin

    2017-12-01

    Full Text Available Background/Purpose: Hepatitis delta virus (HDV is the only animal RNA virus that has an unbranched rod-like genome with ribozyme activity. It replicates in the nucleus by host RNA polymerase via a rolling circle mechanism. Similar to many RNA viruses encoding their own RNA-dependent RNA polymerases, homologous recombination of HDV occurs in mixed-genotype infections and in cultured cells cotransfected with two HDV sequences, as demonstrated by molecular analyses. Methods: Among 237 published complete genomic sequences, 34 sequences were reported from the small and isolated Miyako Island, Japan, and belonged to the Asia-specific genotypes, HDV-2 and HDV-4 (the majority of them belonged to the known Miyako Island-specific subgroup, HDV-4M. We investigated the presence of naturally occurring HDV recombinant in Miyako Island using phylogenetic and recombination analyses. Results: We identified a two-switch HDV-4/4M intersubtype recombinant with an unbranched rod-like RNA genome. Conclusion: Our data suggest that RNA recombination plays an important role in the rapid evolution of HDV, allowing the production of new HDV strains with correct genomic structures. Keywords: hepatitis delta virus, RNA recombination

  14. Gene doctoring: a method for recombineering in laboratory and pathogenic Escherichia coli strains

    Science.gov (United States)

    2009-01-01

    Background Homologous recombination mediated by the λ-Red genes is a common method for making chromosomal modifications in Escherichia coli. Several protocols have been developed that differ in the mechanisms by which DNA, carrying regions homologous to the chromosome, are delivered into the cell. A common technique is to electroporate linear DNA fragments into cells. Alternatively, DNA fragments are generated in vivo by digestion of a donor plasmid with a nuclease that does not cleave the host genome. In both cases the λ-Red gene products recombine homologous regions carried on the linear DNA fragments with the chromosome. We have successfully used both techniques to generate chromosomal mutations in E. coli K-12 strains. However, we have had limited success with these λ-Red based recombination techniques in pathogenic E. coli strains, which has led us to develop an enhanced protocol for recombineering in such strains. Results Our goal was to develop a high-throughput recombineering system, primarily for the coupling of genes to epitope tags, which could also be used for deletion of genes in both pathogenic and K-12 E. coli strains. To that end we have designed a series of donor plasmids for use with the λ-Red recombination system, which when cleaved in vivo by the I-SceI meganuclease generate a discrete linear DNA fragment, allowing for C-terminal tagging of chromosomal genes with a 6 × His, 3 × FLAG, 4 × ProteinA or GFP tag or for the deletion of chromosomal regions. We have enhanced existing protocols and technologies by inclusion of a cassette conferring kanamycin resistance and, crucially, by including the sacB gene on the donor plasmid, so that all but true recombinants are counter-selected on kanamycin and sucrose containing media, thus eliminating the need for extensive screening. This method has the added advantage of limiting the exposure of cells to the potential damaging effects of the λ-Red system, which can lead to unwanted secondary

  15. Gene doctoring: a method for recombineering in laboratory and pathogenic Escherichia coli strains

    Directory of Open Access Journals (Sweden)

    Penn Charles W

    2009-12-01

    Full Text Available Abstract Background Homologous recombination mediated by the λ-Red genes is a common method for making chromosomal modifications in Escherichia coli. Several protocols have been developed that differ in the mechanisms by which DNA, carrying regions homologous to the chromosome, are delivered into the cell. A common technique is to electroporate linear DNA fragments into cells. Alternatively, DNA fragments are generated in vivo by digestion of a donor plasmid with a nuclease that does not cleave the host genome. In both cases the λ-Red gene products recombine homologous regions carried on the linear DNA fragments with the chromosome. We have successfully used both techniques to generate chromosomal mutations in E. coli K-12 strains. However, we have had limited success with these λ-Red based recombination techniques in pathogenic E. coli strains, which has led us to develop an enhanced protocol for recombineering in such strains. Results Our goal was to develop a high-throughput recombineering system, primarily for the coupling of genes to epitope tags, which could also be used for deletion of genes in both pathogenic and K-12 E. coli strains. To that end we have designed a series of donor plasmids for use with the λ-Red recombination system, which when cleaved in vivo by the I-SceI meganuclease generate a discrete linear DNA fragment, allowing for C-terminal tagging of chromosomal genes with a 6 × His, 3 × FLAG, 4 × ProteinA or GFP tag or for the deletion of chromosomal regions. We have enhanced existing protocols and technologies by inclusion of a cassette conferring kanamycin resistance and, crucially, by including the sacB gene on the donor plasmid, so that all but true recombinants are counter-selected on kanamycin and sucrose containing media, thus eliminating the need for extensive screening. This method has the added advantage of limiting the exposure of cells to the potential damaging effects of the λ-Red system, which can lead

  16. Genetic Analysis of Meiotic Recombination in Schizosaccharomyces pombe

    OpenAIRE

    Smith, Gerald R.

    2009-01-01

    The fission yeast Schizosaccharomyces pombe is well-suited for studying meiotic recombination. Methods are described here for culturing S. pombe and for genetic assays of intragenic recombination (gene conversion), intergenic recombination (crossing-over), and spore viability. Both random spore and tetrad analyses are described.

  17. Genetic analysis of japonica x indica recombinant inbred lines and ...

    African Journals Online (AJOL)

    Genetic analysis of japonica x indica recombinant inbred lines and characterization of major fragrance gene by microsatellite markers. ... At some SSR loci, new/recombinant alleles were observed, which indicate the active recombination between genomes of two rice varieties and can be used for linkage mapping once ...

  18. Regulation of homologous recombination at telomeres in budding yeast

    DEFF Research Database (Denmark)

    Eckert-Boulet, Nadine; Lisby, Michael

    2010-01-01

    Homologous recombination is suppressed at normal length telomere sequences. In contrast, telomere recombination is allowed when telomeres erode in the absence of telomerase activity or as a consequence of nucleolytic degradation or incomplete replication. Here, we review the mechanisms...... that contribute to regulating mitotic homologous recombination at telomeres and the role of these mechanisms in signalling short telomeres in the budding yeast Saccharomyces cerevisiae....

  19. Recombinant zoster (shingles) vaccine, RZV - what you need to know

    Science.gov (United States)

    ... year in the United States get shingles. Shingles vaccine (recombinant) Recombinant shingles vaccine was approved by FDA in 2017 for the ... life-threatening allergic reaction after a dose of recombinant shingles vaccine, or has a severe allergy to any component ...

  20. Bimolecular recombination in ambipolar organic field effect transistors

    NARCIS (Netherlands)

    Charrier, D.S.H.; Vries, T. de; Mathijssen, S.G.J.; Geluk, E.-J.; Smits, E.C.P.; Kemerink, M.; Janssen, R.A.J.

    2009-01-01

    In ambipolar organic field effect transistors (OFET) the shape of the channel potential is intimately related to the recombination zone width W, and hence to the electron–hole recombination strength. Experimentally, the recombination profile can be assessed by scanning Kelvin probe microscopy

  1. Anti-proliferative activity of recombinant melittin expressed in ...

    African Journals Online (AJOL)

    Recombinant melittin was then successfully expressed in Escherichia coli. The activity of affinity-purified recombinant melittin was determined in human leukemic U937 cells. Results show that the recombinant melittin had the same anti-proliferative activity in human leukemic U937 cells in vitro as natural one. This shows the ...

  2. Efficient purification of recombinant proteins fused to maltose-binding protein by mixed-mode chromatography.

    Science.gov (United States)

    Cabanne, Charlotte; Pezzini, Jérôme; Joucla, Gilles; Hocquellet, Agnès; Barbot, Caroline; Garbay, Bertrand; Santarelli, Xavier

    2009-05-15

    Two mixed-mode resins were evaluated as an alternative to conventional affinity resins for the purification of recombinant proteins fused to maltose-binding protein (MPB). We purified recombinant MBP, MBP-LacZ and MBP-Leap2 from crude Escherichia coli extracts. Mixed-mode resins allowed the efficient purification of MBP-fused proteins. Indeed, the quantity of purified proteins was significantly higher with mixed-mode resins, and their purity was equivalent to that obtained with affinity resins. By using purified MBP, MBP-LacZ and MBP-Leap2, the dynamic binding capacity of mixed-mode resins was 5-fold higher than that of affinity resins. Moreover, the recovery for the three proteins studied was in the 50-60% range for affinity resins, and in the 80-85% range for mixed-mode resins. Mixed-mode resins thus represent a powerful alternative to the classical amylose or dextrin resins for the purification of recombinant proteins fused to maltose-binding protein.

  3. THE THEORETICAL AND PRACTICAL ASPECTS OF THE RECOMBINANT ANTIGENS FOR THE DIAGNOSIS OF BOVINE LEUKEMIA PRODUCTION

    Directory of Open Access Journals (Sweden)

    Shapovalova OV

    2016-12-01

    sequence construction. The efficiency of BLV gp51 and p24 encoding regions fusion-sequence integration was confirmed by the screening with the specially designed oligonucleotides. The recombinant antigen expression was induced by addition of IPTG. To isolate the antigen bacterial mass was destroyed by defrostation and ultrasonic disintegration in the experimentally selected modes. The activity and specificity of the antigen was determined by AGID with the use of the bovine fetal serum, positive and negative reference diagnostic serum by unified method in comparison with the standardized cultural BLV antigen in AGID. The antigen specificity was increased by adsorption with commercial anticolibacillosis serum. The antigen activity was confirmed by AGID. Conclusions. Nowadays the most promising BLV antigens expressing genetic constructions with E. coli and baculovirus. E. coli recombinant strains are the most available and effective using expressing system, which allows to get an active and specific antigenic product if an optimal vector constructions and commercially available systems of metal affinity chromatography purification and control with appropriate Mab are used. As an cultural and recombinant antigens alternative the mimicking critical BLV antigenic epitopes synthetic peptides were tested. In recent times many scientific works formed the basis for the bovine leukemia diagnostic test systems’ creation, which are now widely available on the biotechnological products market. Although the majority of manufacturers prefer the recombinant antigens of the pathogen, pilot studies on more improved and cheaper ways to obtain different diagnostic antigens preparations shall not lose relevance.

  4. HL-LHC alternatives

    CERN Document Server

    Tomás, R; White, S

    2014-01-01

    The HL-LHC parameters assume unexplored regimes for hadron colliders in various aspects of accelerator beam dynamics and technology. This paper reviews three alternatives that could potentially improve the LHC performance: (i) the alternative filling scheme 8b+4e, (ii) the use of a 200 MHz RF system in the LHC and (iii) the use of proton cooling methods to reduce the beam emittance (at top energy and at injection). The alternatives are assessed in terms of feasibility, pros and cons, risks versus benefits and the impact on beam availability.

  5. Alternative loop rings

    CERN Document Server

    Goodaire, EG; Polcino Milies, C

    1996-01-01

    For the past ten years, alternative loop rings have intrigued mathematicians from a wide cross-section of modern algebra. As a consequence, the theory of alternative loop rings has grown tremendously. One of the main developments is the complete characterization of loops which have an alternative but not associative, loop ring. Furthermore, there is a very close relationship between the algebraic structures of loop rings and of group rings over 2-groups. Another major topic of research is the study of the unit loop of the integral loop ring. Here the interaction between loop rings and group ri

  6. Bacterial Artificial Chromosome Mutagenesis Using Recombineering

    Directory of Open Access Journals (Sweden)

    Kumaran Narayanan

    2011-01-01

    Full Text Available Gene expression from bacterial artificial chromosome (BAC clones has been demonstrated to facilitate physiologically relevant levels compared to viral and nonviral cDNA vectors. BACs are large enough to transfer intact genes in their native chromosomal setting together with flanking regulatory elements to provide all the signals for correct spatiotemporal gene expression. Until recently, the use of BACs for functional studies has been limited because their large size has inherently presented a major obstacle for introducing modifications using conventional genetic engineering strategies. The development of in vivo homologous recombination strategies based on recombineering in E. coli has helped resolve this problem by enabling facile engineering of high molecular weight BAC DNA without dependence on suitably placed restriction enzymes or cloning steps. These techniques have considerably expanded the possibilities for studying functional genetics using BACs in vitro and in vivo.

  7. Dissipative Stern-Gerlach recombination experiment

    International Nuclear Information System (INIS)

    Oliveira, Thiago R. de; Caldeira, A. O.

    2006-01-01

    The possibility of obtaining the initial pure state in a usual Stern-Gerlach experiment through the recombination of the two emerging beams is investigated. We have extended the previous work of Englert, Schwinger, and Scully [Found Phys. 18, 1045 (1988)] including the fluctuations of the magnetic field generated by a properly chosen magnet. As a result we obtained an attenuation factor to the possible revival of coherence when the beams are perfectly recombined. When the source of the magnetic field is a superconducting quantum interference device (SQUID) the attenuation factor can be controlled by external circuits and the spin decoherence directly measured. For the proposed SQUID with dimensions in the scale of microns the attenuation factor has been shown unimportant when compared with the interaction time of the spin with the magnet

  8. Charge exchange recombination x-ray laser

    International Nuclear Information System (INIS)

    Kawachi, Tetsuya; Namba, Shinichi; Kado, Masataka; Tanaka, Momoko; Hasegawa, Noboru; Nagashima, Keisuke; Kato, Yoshiaki

    2001-01-01

    A recombining plasma x-ray laser using charge exchange recombination (CXR) is proposed. Fully stripped carbon ions collide with neutral He atoms and become excited hydrogenlike carbon ions, in which the excited levels with n=3 or 4 are mainly populated. We calculate the gain coefficients of the Balmer α and the Lyman β line of the hydrogenlike carbon ions by the use of a collisional-radiative model in which the CXR process is included. The calculated result shows that substantial gain can be generated for the Lyman β and Balmer α lines and that the gain of the Balmer α line can be strongly enhanced by the effect of CXR. We also report a preliminary experiment of this scheme. (author)

  9. Thermostable exoshells fold and stabilize recombinant proteins.

    Science.gov (United States)

    Deshpande, Siddharth; Masurkar, Nihar D; Girish, Vallerinteavide Mavelli; Desai, Malan; Chakraborty, Goutam; Chan, Juliana M; Drum, Chester L

    2017-11-13

    The expression and stabilization of recombinant proteins is fundamental to basic and applied biology. Here we have engineered a thermostable protein nanoparticle (tES) to improve both expression and stabilization of recombinant proteins using this technology. tES provides steric accommodation and charge complementation to green fluorescent protein (GFPuv), horseradish peroxidase (HRPc), and Renilla luciferase (rLuc), improving the yields of functional in vitro folding by ~100-fold. Encapsulated enzymes retain the ability to metabolize small-molecule substrates, presumably via four 4.5-nm pores present in the tES shell. GFPuv exhibits no spectral shifts in fluorescence compared to a nonencapsulated control. Thermolabile proteins internalized by tES are resistant to thermal, organic, chaotropic, and proteolytic denaturation and can be released from the tES assembly with mild pH titration followed by proteolysis.

  10. CFD Analysis of Passive Autocatalytic Recombiner

    Directory of Open Access Journals (Sweden)

    B. Gera

    2011-01-01

    Full Text Available In water-cooled nuclear power reactors, significant quantities of hydrogen could be produced following a postulated loss-of-coolant accident (LOCA along with nonavailability of emergency core cooling system (ECCS. Passive autocatalytic recombiners (PAR are implemented in the containment of water-cooled power reactors to mitigate the risk of hydrogen combustion. In the presence of hydrogen with available oxygen, a catalytic reaction occurs spontaneously at the catalyst surfaces below conventional ignition concentration limits and temperature and even in presence of steam. Heat of reaction produces natural convection flow through the enclosure and promotes mixing in the containment. For the assessment of the PAR performance in terms of maximum temperature of catalyst surface and outlet hydrogen concentration an in-house 3D CFD model has been developed. The code has been used to study the mechanism of catalytic recombination and has been tested for two literature-quoted experiments.

  11. Multiple Exponential Recombination for Differential Evolution.

    Science.gov (United States)

    Xin Qiu; Kay Chen Tan; Jian-Xin Xu

    2017-04-01

    Differential evolution (DE) is a popular population-based metaheuristic approach for solving numerical optimization problems. In recent years, considerable research has been devoted to the development of new mutation strategies and parameter adaptation mechanisms. However, as one of the basic algorithmic components of DE, the crossover operation has not been sufficiently examined in existing works. Most of the main DE variants solely employ traditional binomial recombination, which has intrinsic limitations in handling dependent subsets of variables. To fill this research niche, we propose a multiple exponential recombination that inherits all the main advantages of existing crossover operators while possessing a stronger ability in managing dependent variables. Multiple segments of the involved solutions will be exchanged during the proposed operator. The properties of the new scheme are examined both theoretically and empirically. Experimental results demonstrate the robustness of the proposed operator in solving problems with unknown variable interrelations.

  12. Recombination clumping factor during cosmic reionization

    International Nuclear Information System (INIS)

    Kaurov, Alexander A.; Gnedin, Nickolay Y.

    2014-01-01

    We discuss the role of recombinations in the intergalactic medium, and the related concept of the clumping factor, during cosmic reionization. The clumping factor is, in general, a local quantity that depends on both the local overdensity and the scale below which the baryon density field can be assumed smooth. That scale, called the filtering scale, depends on over-density and local thermal history. We present a method for building a self-consistent analytical model of inhomogeneous reionization, assuming the linear growth rate of the density fluctuation, which simultaneously accounts for these effects. We show that taking into account the local clumping factor introduces significant corrections to the total recombination rate, compared to the model with a globally uniform clumping factor.

  13. Regulation of Homologous Recombination by SUMOylation

    DEFF Research Database (Denmark)

    Pinela da Silva, Sonia Cristina

    , deletions, and genome rearrangements that can lead to cell death or cancer in humans. The post-translational modification by SUMO (small ubiquitinlike modifier) has proven to be an important regulator of HR and genome integrity, but the molecular mechanisms responsible for these roles are still unclear......Double-strand breaks (DSBs) are one of the most deleterious types of DNA lesions challenging genome integrity. The DNA damage response (DDR) promotes fast and effective detection and repair of the damaged DNA, leading to cell cycle arrest through checkpoint activation and the recruitment of repair...... factors such as the homologous recombination (HR) machinery. HR constitutes the main DSB repair pathway in Saccharomyces cerevisiae and despite being largely considered an error-free process and essential for genome stability, uncontrolled recombination can lead to loss of heterozygosity, translocations...

  14. Recombinant cells and organisms having persistent nonstandard amino acid dependence and methods of making them

    Science.gov (United States)

    Church, George M.; Mandell, Daniel J.; Lajoie, Marc J.

    2017-12-05

    Recombinant cells and recombinant organisms persistently expressing nonstandard amino acids (NSAAs) are provided. Methods of making recombinant cells and recombinant organisms dependent on persistently expressing NSAAs for survival are also provided. These methods may be used to make safe recombinant cells and recombinant organisms and/or to provide a selective pressure to maintain one or more reassigned codon functions in recombinant cells and recombinant organisms.

  15. Expression, purification and characterization of recombinant ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-19

    Oct 19, 2009 ... aggregation activity analysis, we found that the anti-thrombin activity of the fusion protein did not change comparing with the ... the recombinant protein r-HV into the expression vector pPIC9K and pPIC9K1 and pPIC9K2 were ..... coagulation proteases (Dodt et al., 1984; Seemmuller et al., 1986). Hirudin is a ...

  16. DSMC Modeling of Flows with Recombination Reactions

    Science.gov (United States)

    2017-06-23

    Reactions S. Gimelshein, I. Wysong Air Force Research Laboratory (AFMC) AFRL/RQRC 10 E. Saturn Blvd. Edwards AFB, CA 93524-7680 Air Force Research...dimensional flows, modeling is usually con- ducted for Knudsen numbers Kn > 0.001, where the impact of recombination reactions is almost always minor, so...prac- tical applicability of the DSMC method. These methods have already been tested for reacting air flows.20 Today, modeling of gas flows at

  17. Modelling of procecces in catalytic recombiners

    International Nuclear Information System (INIS)

    Boehm, J.

    2007-01-01

    In order to achieve a high degree of safety in nuclear power plants and prevent possible accident scenarios, their consequences are calculated and analysed with numeric codes. One of the most important part of nuclear safety research of hazardous incidents are development and validation of these numeric models, which are implemented into accident codes. The severe hydrogen release during a core meltdown is one of the considered scenario of performed accident analyses. One of the most important measure for the elimination of the hydrogen is catalytic recombiners. Converting the hydrogen with the atmospheric oxygen to water vapor in an exothermic reaction will prevent possible detonation of the hydrogen/air atmosphere. Within the dissertation the recombiner simulation REKO-DIREKT was developed and validated by an extensive experimental database. The performance of recombiners with regard to the conversion of the hydrogen and the temperature development is modelled. The REKO-DIREKT program is unique and has made significant revolution in research of hydrogen safety. For the first time it has been possible to show the performance of the recombiner so great in detail by using REKO-DIREKT. In the future engineers of nuclear power plants will have opportunity to have precise forecasts about the process of the possible accidents with hydrogen release. Also with presence of water vapor or with oxygen depletion which are included in the model. The major discussion of the hydrogen ignition at hot catalyst steel plates can be evaluated in the future with REKO-DIREKT more reliably than the existing used models. (orig.)

  18. Cultivating Insect Cells To Produce Recombinant Proteins

    Science.gov (United States)

    Spaulding, Glenn; Goodwin, Thomas; Prewett, Tacey; Andrews, Angela; Francis, Karen; O'Connor, Kim

    1996-01-01

    Method of producing recombinant proteins involves growth of insect cells in nutrient solution in cylindrical bioreactor rotating about cylindrical axis, oriented horizontally and infecting cells with viruses into which genes of selected type cloned. Genes in question those encoding production of desired proteins. Horizontal rotating bioreactor preferred for use in method, denoted by acronym "HARV", described in "High-Aspect-Ratio Rotating Cell-Culture Vessel" (MSC-21662).

  19. Ancestries of a recombining diploid population.

    Science.gov (United States)

    Sainudiin, R; Thatte, B; Véber, A

    2016-01-01

    We derive the exact one-step transition probabilities of the number of lineages that are ancestral to a random sample from the current generation of a bi-parental population that is evolving under the discrete Wright-Fisher model with n diploid individuals. Our model allows for a per-generation recombination probability of r . When r = 1, our model is equivalent to Chang's (Adv Appl Probab 31:1002-1038, 1999) model for the karyotic pedigree. When r = 0, our model is equivalent to Kingman's (Stoch Process Appl 13:235-248, 1982) discrete coalescent model for the cytoplasmic tree or sub-karyotic tree containing a DNA locus that is free of intra-locus recombination. When 0 r r . Thus, our family of models indexed by r ∈ [0, 1] connects Kingman's discrete coalescent to Chang's pedigree in a continuous way as r goes from 0 to 1. For large populations, we also study three properties of the ancestral process corresponding to a given r ∈ (0, 1): the time Tn to a most recent common ancestor (MRCA) of the population, the time Un at which all individuals are either common ancestors of all present day individuals or ancestral to none of them, and the fraction of individuals that are common ancestors at time Un. These results generalize the three main results of Chang's (Adv Appl Probab 31:1002-1038, 1999). When we appropriately rescale time and recombination probability by the population size, our model leads to the continuous time Markov chain called the ancestral recombination graph of Hudson (Theor Popul Biol 23:183-201, 1983) and Griffiths (The two-locus ancestral graph, Institute of Mathematical Statistics 100-117, 1991).

  20. Dissociation of recombinant prion autocatalysis from infectivity

    OpenAIRE

    Noble, Geoffrey P; Supattapone, Surachai

    2015-01-01

    Within the mammalian prion field, the existence of recombinant prion protein (PrP) conformers with self-replicating (ie. autocatalytic) activity in vitro but little to no infectious activity in vivo challenges a key prediction of the protein-only hypothesis of prion replication – that autocatalytic PrP conformers should be infectious. To understand this dissociation of autocatalysis from infectivity, we recently performed a structural and functional comparison between a highly infectious and ...

  1. Development of Mycoplasma hyopneumoniae Recombinant Vaccines.

    Science.gov (United States)

    Marchioro, Silvana Beutinger; Simionatto, Simone; Dellagostin, Odir

    2016-01-01

    Mycoplasma hyopneumoniae is the etiological agent of swine enzootic pneumonia (EP), a disease that affects swine production worldwide. Vaccination is the most cost-effective strategy for the control and prevention of the disease. Research using genome-based approach has the potential to elucidate the biology and pathogenesis of M. hyopneumoniae and contribute to the development of more effective vaccines. Here, we describe the protocol for developing M. hyopneumoniae recombinant vaccines using reverse vaccinology approaches.

  2. Kinetic studies of ion - recombination in gases

    Energy Technology Data Exchange (ETDEWEB)

    Caulfield, K.J.; Bhave, R.N.; Cooper, R. [Melbourne Univ., Parkville, VIC (Australia). Dept. of Chemistry

    1996-12-31

    Full text: Subsequent to primary ionisation/excitation and dissociation events in irradiated systems, the medium relaxes by various secondary processes which may also be precursors to lasting chemical and physical changes in the system. Pulse radiolysis techniques can be successfully utilised to directly observe such processes so that kinetic parameters may be determined to subsequently accurately model these processes in irradiated systems. Time resolved microwave absorption techniques on a Febetron 706 pulsed electron beam system have been used to study ion recombination in simple gas systems. The microwave absorption method relies on the mobility of charged species within the system and effectively measures an ac-conductivity of the irradiated medium. The technique has a time resolution of about one nanosecond. The decay of conductivity in irradiated gases over the pressure range 50 to 1500 torr has been measured on time scales from 10 nanoseconds to 10 microseconds. Bulk gas pressure and ion densities were such that measurements yielded recombination coefficients for dimeric rare gas cations with thermal electrons. The recombination rate constant, {alpha}{sub T}, is shown to be both independent and dependent on the total pressure in the system ({alpha}{sub T} = {alpha}{sub 2} + {alpha}{sub 3} [M]; {alpha}{sub T} has values up to approx 10{sup +14} L. M{sup -1} s{sup -1} ). Total recombination coefficients {alpha}{sub T} have been measured for the noble gases helium, neon, argon, krypton and xenon. Measurements have also been made for the simple diatomic molecules nitrogen and hydrogen. All the systems studied, except for argon, show both two and three body processes occurring. The three body or assisted process requires the thermalisation of electrons in the neighborhood of the positive ion prior capture. The two body effect is thought to be a radiative or dissociative process. The mechanistic implications of the pulse radiolysis results will be discussed in

  3. Recent advances in DNA repair and recombination.

    Science.gov (United States)

    Iwanejko, L A; Jones, N J

    1998-09-11

    The subjects of the talks at this 1-day DNA Repair Network meeting, held at City University, London on December 15, 1997, encompassed a range of topics and reflected some of the current areas of research in the United Kingdom. Topics included DNA double-strand break repair, V(D)J recombination, DNA ligases, the RecQ family of helicases and Bloom's syndrome, UVB and immunosuppression, the repair of oxidative damage and mismatch repair mechanisms.

  4. Engineering the oxygen sensing regulation results in an enhanced recombinant human hemoglobin production by Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Martinez Ruiz, José Luis; Liu, Lifang; Petranovic, Dina

    2015-01-01

    Efficient production of appropriate oxygen carriers for transfusions (blood substitutes or artificial blood) has been pursued for many decades, and to date several strategies have been used, from synthetic polymers to cell-free hemoglobin carriers. The recent advances in the field of metabolic...... engineering also allowed the generation of different genetically modified organisms for the production of recombinant human hemoglobin. Several studies have showed very promising results using the bacterium Escherichia coli as a production platform, reporting hemoglobin titers above 5% of the total cell...... protein content. However, there are still certain limitations regarding the protein stability and functionality of the recombinant hemoglobin produced in bacterial systems. In order to overcome these limitations, yeast systems have been proposed as the eukaryal alternative. We recently reported...

  5. New recombinants within the MHC (B-complex) of the chicken

    DEFF Research Database (Denmark)

    Koch, C; Skjødt, K; Toivanen, A

    1983-01-01

    In a search for genetic recombinations within the major histocompatibility complex (MHC) of the chicken, the B-complex, the offspring from matings between heterozygous B15/B21 and B4/B6 animals were analysed by red cell agglutination. Among the progeny, 8,912 informative typings were performed...... followed B-F/B-L. The mapping distance between the two loci B-F and B-G is in the range of 0.04 centimorgan. The lack of recombinants separating individual B-F loci in this study and in the studies of others might indicate that chicken MHC is less complex than those of mammalian species, but alternative...

  6. Inactivated recombinant plant virus protects dogs from a lethal challenge with canine parvovirus

    DEFF Research Database (Denmark)

    Langeveld, J.P.M.; Brennan, F.R.; Martinez-Torrecuadrada, J.L.

    2001-01-01

    A vaccine based upon a recombinant plant virus (CPMV-PARVO1), displaying a peptide derived from the VP2 capsid protein of canine parvovirus (CPV), has previously been described. To date, studies with the vaccine have utilized viable plant chimaeric particles (CVPs). In this study, CPMV-PARVO1...... was inactivated by UV treatment to remove the possibility of replication of the recombinant plant virus in a plant host after manufacture of the vaccine. We show that the inactivated CVP is able to protect dogs from a lethal challenge with CPV following parenteral immunization with the vaccine. Dogs immunized...... were comparable to those seen in dogs immunized with the same VP2-peptide coupled to keyhole limpet hemocyanin (KLH). Since plant virus-derived vaccines have the potential for cost-effective manufacture and are not known to replicate in mammalian cells, they represent a viable alternative to cut...

  7. Recombinant snakebite antivenoms: A cost-competitive solution to a neglected tropical disease?

    DEFF Research Database (Denmark)

    Laustsen, Andreas Hougaard; Johansen, Kristoffer H.; Engmark, Mikael

    2017-01-01

    Snakebite envenoming is a major public health burden in tropical parts of the developing world. In sub-Saharan Africa, neglect has led to a scarcity of antivenoms threatening the lives and limbs of snakebite victims. Technological advances within antivenom are warranted, but should be evaluated n...... price of USD 640 per treatment for an average snakebite. Recombinant antivenoms may therefore in the future be a cost-competitive alternative to existing serum-based antivenoms....... not only on their possible therapeutic impact, but also on their cost-competitiveness. Recombinant antivenoms based on oligoclonal mixtures of human IgG antibodies produced by CHO cell cultivation may be the key to obtaining better snakebite envenoming therapies. Based on industry data, the cost...

  8. Islands of speciation or mirages in the desert? Examining the role of restricted recombination in maintaining species.

    Science.gov (United States)

    Noor, M A F; Bennett, S M

    2009-12-01

    Over the past decade, many studies documented high genetic divergence between closely related species in genomic regions experiencing restricted recombination in hybrids, such as within chromosomal rearrangements or areas adjacent to centromeres. Such regions have been called 'islands of speciation' because of their presumed role in maintaining the integrity of species despite gene flow elsewhere in the genome. Here, we review alternative explanations for such patterns. Segregation of ancestral variation or artifacts of nucleotide diversity within species can readily lead to higher F(ST) in regions of restricted recombination than other parts of the genome, even in the complete absence of interspecies gene flow, and thereby cause investigators to erroneously conclude that islands of speciation exist. We conclude by discussing strengths and weaknesses of various means for testing the role of restricted recombination in maintaining species.

  9. Islands of Speciation or Mirages in the Desert? Examining the Role of Restricted Recombination in Maintaining Species*

    Science.gov (United States)

    Noor, Mohamed A. F.; Bennett, Sarah M.

    2010-01-01

    Over the past decade, many studies documented high genetic divergence between closely related species in genomic regions experiencing restricted recombination in hybrids, such as within chromosomal rearrangements or areas adjacent to centromeres. Such regions have been called “islands of speciation” because of their presumed role in maintaining the integrity of species despite gene flow elsewhere in the genome. Here, we review alternative explanations for such patterns. Segregation of ancestral variation or artifacts of nucleotide diversity within species can readily lead to higher FST in regions of restricted recombination than other parts of the genome, even in the complete absence of interspecies gene flow, and thereby cause investigators to erroneously conclude that islands of speciation exist. We conclude by discussing strengths and weaknesses of various means for testing the role of restricted recombination in maintaining species. PMID:19920849

  10. Dissociative recombination of small molecular ions

    International Nuclear Information System (INIS)

    Mul, P.M.

    1981-01-01

    In this thesis an analysis is given of merged electron-ion beam experiment and work on dissociative recombination of molecular ions and electrons is described. Chapter II covers a brief introduction of the theory of dissociative recombination. In chapter III, a description is given of the merged electron-ion beam experiment and a method is described which allows the determination of the mean angle between the electron and ion trajectories in a merged electron-ion beam experiment. In chapter IV a paper on the three dominant atmospheric diatomic ions NO + , O 2 + and N 2 + is presented and in chapter V the dissociative recombination for N 2 H + and N 2 D + is discussed. In chapter VI two papers on the polyatomic ions of the carbon-containing molecular ions are presented, and in chapter VII a letter with some results of the work presented in more detail in the chapters IV, V and VI is presented. The magnitude and the energy dependence of the cross-section measured by the merged beam technique and by other techniques is compared and discussed. (Auth.)

  11. Heavy-ion cooling and radiative recombination

    International Nuclear Information System (INIS)

    Beyer, H.F.

    1988-09-01

    There is presently a large number of ion storage rings under construction which will use electron cooling for increasing the phase-space density of the stored ions in order to gain luminosity and resolution advantages for a variety of experiments. In this review a more general introduction to the electron-cooling technique is given. The atomic-physics aspects of electron-ion interactions at low relative velocity are identified. One of the most important processes is electron-ion radiative recombination because it can have strong implications on the operation of a storage ring employing electron cooling. Estimates are given of the ion-beam lifetime, as limited by recombination losses, as a function of electron density and temperature and for all values of the atomic number Z of the ions. The use of recombination processes in the electron cooler for atomic spectroscopy of few-electron heavy ions is discussed along with their implication on diagnostics of electron cooling. (orig.)

  12. Recombination-dependent concatemeric viral DNA replication.

    Science.gov (United States)

    Lo Piano, Ambra; Martínez-Jiménez, María I; Zecchi, Lisa; Ayora, Silvia

    2011-09-01

    The initiation of viral double stranded (ds) DNA replication involves proteins that recruit and load the replisome at the replication origin (ori). Any block in replication fork progression or a programmed barrier may act as a factor for ori-independent remodelling and assembly of a new replisome at the stalled fork. Then replication initiation becomes dependent on recombination proteins, a process called recombination-dependent replication (RDR). RDR, which is recognized as being important for replication restart and stability in all living organisms, plays an essential role in the replication cycle of many dsDNA viruses. The SPP1 virus, which infects Bacillus subtilis cells, serves as a paradigm to understand the links between replication and recombination in circular dsDNA viruses. SPP1-encoded initiator and replisome assembly proteins control the onset of viral replication and direct the recruitment of host-encoded replisomal components at viral oriL. SPP1 uses replication fork reactivation to switch from ori-dependent θ-type (circle-to-circle) replication to σ-type RDR. Replication fork arrest leads to a double strand break that is processed by viral-encoded factors to generate a D-loop into which a new replisome is assembled, leading to σ-type viral replication. SPP1 RDR proteins are compared with similar proteins encoded by other viruses and their possible in vivo roles are discussed. Copyright © 2011 Elsevier B.V. All rights reserved.

  13. CFD modeling of passive autocatalytic recombiners*

    Directory of Open Access Journals (Sweden)

    Orszulik Magdalena

    2015-06-01

    Full Text Available This study deals with numerical modeling of passive autocatalytic hydrogen recombiners (PARs. Such devices are installed within containments of many nuclear reactors in order to remove hydrogen and convert it to steam. The main purpose of this work is to develop a numerical model of passive autocatalytic recombiner (PAR using the commercial computational fluid dynamics (CFD software ANSYS-FLUENT and tuning the model using experimental results. The REKO 3 experiment was used for this purpose. Experiment was made in the Institute for Safety Research and Reactor Technology in Julich (Germany. It has been performed for different hydrogen concentrations, different flow rates, the presence of steam, and different initial temperatures of the inlet mixture. The model of this experimental recombiner was elaborated within the framework of this work. The influence of mesh, gas thermal conductivity coefficient, mass diffusivity coefficients, and turbulence model was investigated. The best results with a good agreement with REKO 3 data were received for k-ɛ model of turbulence, gas thermal conductivity dependent on the temperature and mass diffusivity coefficients taken from CHEMKIN program. The validated model of the PAR was next implemented into simple two-dimensional simulations of hydrogen behavior within a subcompartment of a containment building.

  14. Identification of Novel Recombinant Forms of Hepatitis B Virus Generated from Genotypes Ae and G in HIV-1-Positive Japanese Men Who Have Sex with Men.

    Science.gov (United States)

    Kojima, Yoko; Kawahata, Takuya; Mori, Haruyo; Furubayashi, Keiichi; Taniguchi, Yasushi; Itoda, Ichiro; Komano, Jun

    2015-07-01

    The rare hepatitis B virus (HBV) genotype G (HBV/G) coinfects HIV-1-positive individuals along with HBV/A and generates recombinants. However, the circulation of HBV A/G recombinants remains poorly understood. This molecular epidemiologic study examined HBV A/G recombinants in Japanese HIV-1-positive men who have sex with men (MSM). Initially, blood specimens submitted for confirmatory tests of HIV infection in Osaka and Tokyo, Japan, from 2006 to 2013 were examined for HIV-1, and HIV-1-positive specimens were screened for HBV. Among 817 specimens from HIV-1-positive individuals, HBsAg was detected in 59 specimens; of these, HBV/Ae (alternatively A2), a subgenotype of HBV/A prevalent in Europe and North America, was identified in 70.2%, HBV/C in 17.5%, and HBV/G in 10.5%, and HBV/E in 1.8% according to the core gene sequence. The full-length genome analysis of HBV was performed on HBV/G-positive specimens because some HBV A/G recombinants were historically overlooked by genotyping based on a partial genome analysis. It revealed that five of the specimens contained novel Ae/G recombinants, the core gene of which had a high sequence similarity to HBV/G. Detailed analyses showed that novel recombinants were coinfected with HBV/Ae in a recombinant-dominant fashion. No major drug-resistant mutations were found in the newly identified HBV Ae/G recombinants. Some of the individuals asymptomatically coinfected with HIV/HBV suffered mild liver injury. This study demonstrated that novel Ae/G HBV recombinants were identified in Japanese HIV-1-positive MSM. The pathogenicity of novel HBV Ae/G recombinants should be examined in a future longitudinal study. Surveillance of such viruses in HIV-1-positive individuals should be emphasized.

  15. Alternative medicine: Soul healers

    Directory of Open Access Journals (Sweden)

    Stojanović Marko

    2005-01-01

    Full Text Available The wars and subsequent crisis in the former Yugoslavia have brought about a different, distressed value system to the populations in Serbia. One of its reflections is seen in an establishment of the so-called alternative healing systems. The contemporary, modern medicine holds that illnesses are caused by various psycho-somatic agents, therefore, I take contemporary healers to be alternative psychiatrists and therapists which balance and cure individual distresses. Crisis in societies are psycho-physical triggers that initiate structural disturbances in personalities of active and passive participants, and initiate a search for psycho-therapeutic methods which include transcendental. The processes of globalization and urbanization have helped clear up the fact that the official/established and alternative/traditional medicines have structural determination and corresponding status with the prevailing value system and religious affiliation of the population. Cultural-historic processes are often established in the alternative, and the opposite.

  16. Alternative disinfectant water treatments

    Science.gov (United States)

    Alternative disinfestant water treatments are disinfestants not as commonly used by the horticultural industry. Chlorine products that produce hypochlorous acid are the main disinfestants used for treating irrigation water. Chlorine dioxide will be the primary disinfestant discussed as an alternativ...

  17. Alternative gravity theories

    International Nuclear Information System (INIS)

    Francaviglia, M.

    1990-01-01

    Although general relativity is a well-established discipline the theory deserves efforts aimed at producing alternative or more general frameworks for investigating the classical properties of gravity. These are either devoted to producing alternative viewpoints or interpretations of standard general relativity, or at constructing, discussing and proposing experimental tests for alternative descriptions of the dynamics of the gravitational field and its interaction (or unification) with external matter fields. Classical alternative theories of gravitation can roughly classified as follows; theories based on a still 4-dimensional picture, under the assumption that the dynamics of the gravitational field is more complicated than Einstein's and theories based on higher-dimensional pictures. This leads to supergravity and strings which are not included here. Theories based on higher-dimensional pictures on the assumption that space-time is replaced by a higher-dimensional manifold. Papers on these classifications are reviewed. (author)

  18. Seal design alternatives study

    International Nuclear Information System (INIS)

    Van Sambeek, L.L.; Luo, D.D.; Lin, M.S.; Ostrowski, W.; Oyenuga, D.

    1993-06-01

    This report presents the results from a study of various sealing alternatives for the WIPP sealing system. Overall, the sealing system has the purpose of reducing to the extent possible the potential for fluids (either gas or liquid) from entering or leaving the repository. The sealing system is divided into three subsystems: drift and panel seals within the repository horizon, shaft seals in each of the four shafts, and borehole seals. Alternatives to the baseline configuration for the WIPP seal system design included evaluating different geometries and schedules for seal component installations and the use of different materials for seal components. Order-of-magnitude costs for the various alternatives were prepared as part of the study. Firm recommendations are not presented, but the advantages and disadvantages of the alternatives are discussed. Technical information deficiencies are identified and studies are outlined which can provide required information

  19. Alternative and Integrative Medicine

    Science.gov (United States)

    ... government and regulatory agencies. In conventional medicine, effective cancer treatment is defined as one that causes a tumor to reduce in size or remain stable. Description Many alternative therapies seek to treat illness by helping the body ...

  20. Antagonistic experimental coevolution with a parasite increases host recombination frequency

    Directory of Open Access Journals (Sweden)

    Kerstes Niels AG

    2012-02-01

    Full Text Available Abstract Background One of the big remaining challenges in evolutionary biology is to understand the evolution and maintenance of meiotic recombination. As recombination breaks down successful genotypes, it should be selected for only under very limited conditions. Yet, recombination is very common and phylogenetically widespread. The Red Queen Hypothesis is one of the most prominent hypotheses for the adaptive value of recombination and sexual reproduction. The Red Queen Hypothesis predicts an advantage of recombination for hosts that are coevolving with their parasites. We tested predictions of the hypothesis with experimental coevolution using the red flour beetle, Tribolium castaneum, and its microsporidian parasite, Nosema whitei. Results By measuring recombination directly in the individuals under selection, we found that recombination in the host population was increased after 11 generations of coevolution. Detailed insights into genotypic and phenotypic changes occurring during the coevolution experiment furthermore helped us to reconstruct the coevolutionary dynamics that were associated with this increase in recombination frequency. As coevolved lines maintained higher genetic diversity than control lines, and because there was no evidence for heterozygote advantage or for a plastic response of recombination to infection, the observed increase in recombination most likely represented an adaptive host response under Red Queen dynamics. Conclusions This study provides direct, experimental evidence for an increase in recombination frequency under host-parasite coevolution in an obligatory outcrossing species. Combined with earlier results, the Red Queen process is the most likely explanation for this observation.

  1. Monitoring homologous recombination in rice (Oryza sativa L.)

    Energy Technology Data Exchange (ETDEWEB)

    Yang Zhuanying; Tang Li [Guangdong Provincial Key Lab of Biotechnology for Plant Development, College of Life Sciences, South China Normal University, Guangzhou 510631 (China); Li Meiru [South China Botanic Garden, Chinese Academy of Sciences, Guangzhou 510650 (China); Chen Lei; Xu Jie [Guangdong Provincial Key Lab of Biotechnology for Plant Development, College of Life Sciences, South China Normal University, Guangzhou 510631 (China); Wu Goujiang [South China Botanic Garden, Chinese Academy of Sciences, Guangzhou 510650 (China); Li Hongqing, E-mail: hqli@scnu.edu.cn [Guangdong Provincial Key Lab of Biotechnology for Plant Development, College of Life Sciences, South China Normal University, Guangzhou 510631 (China)

    2010-09-10

    Here we describe a system to assay homologous recombination during the complete life cycle of rice (Oryza sativa L.). Rice plants were transformed with two copies of non-functional GUS reporter overlap fragments as recombination substrate. Recombination was observed in all plant organs examined, from the seed stage until the flowering stage of somatic plant development. Embryogenic cells exhibited the highest recombination ability with an average of 3 x 10{sup -5} recombination events per genome, which is about 10-fold of that observed in root cells, and two orders of that observed in leaf cells. Histological analysis revealed that recombination events occurred in diverse cell types, but preferentially in cells with small size. Examples of this included embryogenic cells in callus, phloem cells in the leaf vein, and cells located in the root apical meristem. Steady state RNA analysis revealed that the expression levels of rice Rad51 homologs are positively correlated with increased recombination rates in embryogenic calli, roots and anthers. Finally, radiation treatment of plantlets from distinct recombination lines increased the recombination frequency to different extents. These results showed that homologous recombination frequency can be effectively measured in rice using a transgene reporter assay. This system will facilitate the study of DNA damage signaling and homologous recombination in rice, a model monocot.

  2. FASEB Summer Research Conference. Genetic Recombination and Chromosome Rearrangements

    Energy Technology Data Exchange (ETDEWEB)

    Jinks-Robertson, Sue

    2002-02-01

    The 2001 meeting entitled ''Genetic Recombination and Genome Rearrangements'' was held July 21-26 in Snowmass, Colorado. The goal of the meeting was to bring together scientists using diverse approaches to study all aspects of genetic recombination. This goal was achieved by integrating talks covering the genetics, biochemistry and structural biology of homologous recombination, site-specific recombination, and nonhomologous recombination. The format of the meeting consisted of a keynote address on the opening evening, two formal plenary sessions on each of the four full meeting days, a single afternoon workshop consisting of short talks chosen from among submitted abstracts, and afternoon poster sessions on each of the four full meeting days. The eight plenary session were entitled: (1) Recombination Mechanisms, (2) Prokaryotic Recombination, (3) Repair and Recombination, (4) Site-specific Recombination and Transposition, (5) Eukaryotic Recombination I, (6) Genome Rearrangements, (7) Meiosis, and (8) Eukaryotic Recombination II. Each session included a mix of genetic, biochemical and structural talks; talks were limited to 20 minutes, followed by 10 minutes of very lively, general discussion. Much of the data presented in the plenary sessions was unpublished, thus providing attendees with the most up-to-date knowledge of this rapidly-moving field.

  3. V(D)J recombination frequency is affected by the sequence interposed between a pair of recombination signals: sequence comparison reveals a putative recombinational enhancer element

    DEFF Research Database (Denmark)

    Roch, F A; Hobi, R; Berchtold, M W

    1997-01-01

    this activity suggests that the effect is no mediated through attachment of the recombination substrate to a nuclear matrix-associated recombination complex but through cis-activation. The presence of a 26 bp A-T-rich sequence motif in the 5' and 3' MARs of Emu and in all of the other upregulating fragments....... These we prepared by interposing between the recombination signal sequences (RSS) of the plasmid pBlueRec various fragments, including Emu, possibly affecting V(D)J recombination. Our work shows that sequences inserted between RSS 23 and RSS 12, with distances from their proximal ends of 26 and 284 bp...

  4. Alternative fuel cycles

    International Nuclear Information System (INIS)

    Penn, W.J.

    1979-05-01

    Uranium resource utilization and economic considerations provide incentives to study alternative fuel cycles as future options to the PHWR natural uranium cycle. Preliminary studies to define the most favourable alternatives and their possible introduction dates are discussed. The important and uncertain components which influence option selection are reviewed, including nuclear capacity growth, uranium availability and demand, economic potential, and required technological developments. Finally, a summary of Ontario Hydro's program to further assess cycle selection and define development needs is given. (auth)

  5. Mechanisms and factors that influence high frequency retroviral recombination

    DEFF Research Database (Denmark)

    Delviks-Frankenberry, Krista; Galli, Andrea; Nikolaitchik, Olga

    2011-01-01

    With constantly changing environmental selection pressures, retroviruses rely upon recombination to reassort polymorphisms in their genomes and increase genetic diversity, which improves the chances for the survival of their population. Recombination occurs during DNA synthesis, whereby reverse...... transcriptase undergoes template switching events between the two copackaged RNAs, resulting in a viral recombinant with portions of the genetic information from each parental RNA. This review summarizes our current understanding of the factors and mechanisms influencing retroviral recombination, fidelity...... of the recombination process, and evaluates the subsequent viral diversity and fitness of the progeny recombinant. Specifically, the high mutation rates and high recombination frequencies of HIV-1 will be analyzed for their roles in influencing HIV-1 global diversity, as well as HIV-1 diagnosis, drug treatment...

  6. Alternative drugs of abuse.

    Science.gov (United States)

    Sutter, M E; Chenoweth, J; Albertson, T E

    2014-02-01

    The incidence of drug abuse with alternative agents is increasing. The term "alternative drugs of abuse" is a catch-all term for abused chemicals that do not fit into one of the classic categories of drugs of abuse. The most common age group abusing these agents range from 17 to 25 years old and are often associated with group settings. Due to their diverse pharmacological nature, legislative efforts to classify these chemicals as a schedule I drug have lagged behind the development of new alternative agents. The potential reason for abuse of these agents is their hallucinogenic, dissociative, stimulant, anti-muscarinic, or sedative properties. Some of these drugs are easily obtainable such as Datura stramonium (Jimson Weed) or Lophophora williamsii (Peyote) because they are natural plants indigenous to certain regions. The diverse pharmacology and clinical effects of these agents are so broad that they do not produce a universal constellation of signs and symptoms. Detailed physical exams are essential for identifying clues leading one to suspect an alternative drug of abuse. Testing for the presence of these agents is often limited, and even when available, the results do not return in a timely fashion. Intoxications from these agents pose unique challenges for health care providers. Physician knowledge of the physiological effects of these alternative agents and the local patterns of drug of abuse are important for the accurate diagnosis and optimal care of poisoned patients. This review summarizes the current knowledge of alternative drugs of abuse and highlights their clinical presentations.

  7. Evolution of recombination in eutherian mammals: insights into mechanisms that affect recombination rates and crossover interference.

    Science.gov (United States)

    Segura, Joana; Ferretti, Luca; Ramos-Onsins, Sebastián; Capilla, Laia; Farré, Marta; Reis, Fernanda; Oliver-Bonet, Maria; Fernández-Bellón, Hugo; Garcia, Francisca; Garcia-Caldés, Montserrat; Robinson, Terence J; Ruiz-Herrera, Aurora

    2013-11-22

    Recombination allows faithful chromosomal segregation during meiosis and contributes to the production of new heritable allelic variants that are essential for the maintenance of genetic diversity. Therefore, an appreciation of how this variation is created and maintained is of critical importance to our understanding of biodiversity and evolutionary change. Here, we analysed the recombination features from species representing the major eutherian taxonomic groups Afrotheria, Rodentia, Primates and Carnivora to better understand the dynamics of mammalian recombination. Our results suggest a phylogenetic component in recombination rates (RRs), which appears to be directional, strongly punctuated and subject to selection. Species that diversified earlier in the evolutionary tree have lower RRs than those from more derived phylogenetic branches. Furthermore, chromosome-specific recombination maps in distantly related taxa show that crossover interference is especially weak in the species with highest RRs detected thus far, the tiger. This is the first example of a mammalian species exhibiting such low levels of crossover interference, highlighting the uniqueness of this species and its relevance for the study of the mechanisms controlling crossover formation, distribution and resolution.

  8. [Gene fusion of egfp & kan and recombinant plasmid construction by red mediated in vivo homologous recombination].

    Science.gov (United States)

    Wu, Yang; Li, Shan-Hu; Shi, Qing-Guo; Liu, Dang-Sheng; Zhou, Jian-Guang

    2007-07-01

    Recombineering, a new genetic engineering technology based on high efficiency in vivo homologous recombination, can be used in target DNA knock-in, knock-out and gene cloning. In the process of gene subcloning mediated by Recombineering technique, high-quality target DNA fragments were difficult to obtain using in vitro overlapping PCR,therefore the efficiency of in vivo homologous recombination was severely interrupted. To solve this problem, some technology improvements have been established based on the principle of Red recombinases. The PCR DNA fragments of egfp and kan genes with complementary sequences on the end of each fragment were co-introduced into a pcDNA3.1 vector and Red recombinases containing E. coli DY331 host cells by electroporation. A recombinant plasmid pcDNA3.1-egfp-kan was screened directly by antibiotic marker. The positive rates can reach to 45%. The EGFP gene expression of pcDNA3.1-egfp-kan can be observed by transient transfection of 293 eukaryotic cells.

  9. Mobility dependent recombination models for organic solar cells

    Science.gov (United States)

    Wagenpfahl, Alexander

    2017-09-01

    Modern solar cell technologies are driven by the effort to enhance power conversion efficiencies. A main mechanism limiting power conversion efficiencies is charge carrier recombination which is a direct function of the encounter probability of both recombination partners. In inorganic solar cells with rather high charge carrier mobilities, charge carrier recombination is often dominated by energetic states which subsequently trap both recombination partners for recombination. Free charge carriers move fast enough for Coulomb attraction to be irrelevant for the encounter probability. Thus, charge carrier recombination is independent of charge carrier mobilities. In organic semiconductors charge carrier mobilities are much lower. Therefore, electrons and holes have more time react to mutual Coulomb-forces. This results in the strong charge carrier mobility dependencies of the observed charge carrier recombination rates. In 1903 Paul Langevin published a fundamental model to describe the recombination of ions in gas-phase or aqueous solutions, known today as Langevin recombination. During the last decades this model was used to interpret and model recombination in organic semiconductors. However, certain experiments especially with bulk-heterojunction solar cells reveal much lower recombination rates than predicted by Langevin. In search of an explanation, many material and device properties such as morphology and energetic properties have been examined in order to extend the validity of the Langevin model. A key argument for most of these extended models is, that electron and hole must find each other at a mutual spatial location. This encounter may be limited for instance by trapping of charges in trap states, by selective electrodes separating electrons and holes, or simply by the morphology of the involved semiconductors, making it impossible for electrons and holes to recombine at high rates. In this review, we discuss the development of mobility limited

  10. Multiple barriers to recombination between divergent HIV-1 variants revealed by a dual-marker recombination assay

    DEFF Research Database (Denmark)

    Nikolaitchik, Olga A; Galli, Andrea; Moore, Michael D

    2011-01-01

    Recombination is a major force for generating human immunodeficiency virus type 1 (HIV-1) diversity and produces numerous recombinants circulating in the human population. We previously established a cell-based system using green fluorescent protein gene (gfp) as a reporter to study the mechanisms...... between variants from different groups is further reduced compared with green fluorescent protein, indicating that sequence divergence interferes with recombination efficiency in the gag gene. Compared with identical sequences, we estimate that recombination rates are reduced by 3-fold and by 10- to 13...... of HIV-1 recombination. We now report an improved system capable of detecting recombination using authentic viral sequences. Frameshift mutations were introduced into the gag gene so that parental viruses do not express full-length Gag; however, recombination can generate a progeny virus that expresses...

  11. Adaptive evolution by recombination is not associated with increased mutation rates in Maize streak virus.

    Science.gov (United States)

    Monjane, Adérito L; Pande, Daniel; Lakay, Francisco; Shepherd, Dionne N; van der Walt, Eric; Lefeuvre, Pierre; Lett, Jean-Michel; Varsani, Arvind; Rybicki, Edward P; Martin, Darren P

    2012-12-27

    Single-stranded (ss) DNA viruses in the family Geminiviridae are proving to be very useful in real-time evolution studies. The high mutation rate of geminiviruses and other ssDNA viruses is somewhat mysterious in that their DNA genomes are replicated in host nuclei by high fidelity host polymerases. Although strand specific mutation biases observed in virus species from the geminivirus genus Mastrevirus indicate that the high mutation rates in viruses in this genus may be due to mutational processes that operate specifically on ssDNA, it is currently unknown whether viruses from other genera display similar strand specific mutation biases. Also, geminivirus genomes frequently recombine with one another and an alternative cause of their high mutation rates could be that the recombination process is either directly mutagenic or produces a selective environment in which the survival of mutants is favoured. To investigate whether there is an association between recombination and increased basal mutation rates or increased degrees of selection favoring the survival of mutations, we compared the mutation dynamics of the MSV-MatA and MSV-VW field isolates of Maize streak virus (MSV; Mastrevirus), with both a laboratory constructed MSV recombinant, and MSV recombinants closely resembling MSV-MatA. To determine whether strand specific mutation biases are a general characteristic of geminivirus evolution we compared mutation spectra arising during these MSV experiments with those arising during similar experiments involving the geminivirus Tomato yellow leaf curl virus (Begomovirus genus). Although both the genomic distribution of mutations and the occurrence of various convergent mutations at specific genomic sites indicated that either mutation hotspots or selection for adaptive mutations might elevate observed mutation rates in MSV, we found no association between recombination and mutation rates. Importantly, when comparing the mutation spectra of MSV and TYLCV we

  12. Adaptive evolution by recombination is not associated with increased mutation rates in Maize streak virus

    Directory of Open Access Journals (Sweden)

    Monjane Adérito L

    2012-12-01

    Full Text Available Abstract Background Single-stranded (ss DNA viruses in the family Geminiviridae are proving to be very useful in real-time evolution studies. The high mutation rate of geminiviruses and other ssDNA viruses is somewhat mysterious in that their DNA genomes are replicated in host nuclei by high fidelity host polymerases. Although strand specific mutation biases observed in virus species from the geminivirus genus Mastrevirus indicate that the high mutation rates in viruses in this genus may be due to mutational processes that operate specifically on ssDNA, it is currently unknown whether viruses from other genera display similar strand specific mutation biases. Also, geminivirus genomes frequently recombine with one another and an alternative cause of their high mutation rates could be that the recombination process is either directly mutagenic or produces a selective environment in which the survival of mutants is favoured. To investigate whether there is an association between recombination and increased basal mutation rates or increased degrees of selection favoring the survival of mutations, we compared the mutation dynamics of the MSV-MatA and MSV-VW field isolates of Maize streak virus (MSV; Mastrevirus, with both a laboratory constructed MSV recombinant, and MSV recombinants closely resembling MSV-MatA. To determine whether strand specific mutation biases are a general characteristic of geminivirus evolution we compared mutation spectra arising during these MSV experiments with those arising during similar experiments involving the geminivirus Tomato yellow leaf curl virus (Begomovirus genus. Results Although both the genomic distribution of mutations and the occurrence of various convergent mutations at specific genomic sites indicated that either mutation hotspots or selection for adaptive mutations might elevate observed mutation rates in MSV, we found no association between recombination and mutation rates. Importantly, when comparing

  13. Recombinant pinoresinol/lariciresinol reductase, recombinant dirigent protein, and methods of use

    Science.gov (United States)

    Lewis, Norman G.; Davin, Laurence B.; Dinkova-Kostova, Albena T.; Fujita, Masayuki; Gang, David R.; Sarkanen, Simo; Ford, Joshua D.

    2001-04-03

    Dirigent proteins and pinoresinol/lariciresinol reductases have been isolated, together with cDNAs encoding dirigent proteins and pinoresinol/lariciresinol reductases. Accordingly, isolated DNA sequences are provided which code for the expression of dirigent proteins and pinoresinol/lariciresinol reductases. In other aspects, replicable recombinant cloning vehicles are provided which code for dirigent proteins or pinoresinol/lariciresinol reductases or for a base sequence sufficiently complementary to at least a portion of dirigent protein or pinoresinol/lariciresinol reductase DNA or RNA to enable hybridization therewith. In yet other aspects, modified host cells are provided that have been transformed, transfected, infected and/or injected with a recombinant cloning vehicle and/or DNA sequence encoding dirigent protein or pinoresinol/lariciresinol reductase. Thus, systems and methods are provided for the recombinant expression of dirigent proteins and/or pinoresinol/lariciresinol reductases.

  14. Alternative fuels for vehicles; Alternative drivmidler

    Energy Technology Data Exchange (ETDEWEB)

    2012-02-15

    Up until 2020 and onwards the analysis indicates that especially electricity, biogas and natural gas as propellants is economically attractive compared to conventional gasoline and diesel while other fuels have the same or higher costs for petrol and diesel. Especially biogas and electricity will also offer significant reductions in CO{sub 2} emissions, but also hydrogen, methanol, DME and to a lesser extent the second generation bioethanol and most of the other alternative fuels reduce CO{sub 2} emissions. Use of the traditional food-based first generation biofuels involves, at best, only modest climate benefits if land use changes are counted, and at worst, significant negative climate effects. Natural gas as a propellant involves a moderate climate gain, but may play a role for building infrastructure and market for gaseous fuels in large fleets, thereby contributing to the phasing in of biogas for transport. The electric-based automotive fuels are the most effective due to a high efficiency of the engine and an increasing proportion of wind energy in the electricity supply. The methanol track also has a relatively high efficiency. Among the others, the track based on diesel engines (biodiesel) is more effective than the track based on gasoline/Otto engines (gas and ethanol) as a result of the diesel engine's better efficiency. For the heavy vehicles all the selected alternative fuels to varying degrees reduce emissions of CO{sub 2}, particularly DME based on wood. The only exception to this is - as for passenger cars - the propellant synthetic diesel based on coal. (LN).

  15. Late replicating domains are highly recombining in females but have low male recombination rates: implications for isochore evolution.

    Directory of Open Access Journals (Sweden)

    Catherine J Pink

    Full Text Available In mammals sequences that are either late replicating or highly recombining have high rates of evolution at putatively neutral sites. As early replicating domains and highly recombining domains both tend to be GC rich we a priori expect these two variables to covary. If so, the relative contribution of either of these variables to the local neutral substitution rate might have been wrongly estimated owing to covariance with the other. Against our expectations, we find that sex-averaged recombination rates show little or no correlation with replication timing, suggesting that they are independent determinants of substitution rates. However, this result masks significant sex-specific complexity: late replicating domains tend to have high recombination rates in females but low recombination rates in males. That these trends are antagonistic explains why sex-averaged recombination is not correlated with replication timing. This unexpected result has several important implications. First, although both male and female recombination rates covary significantly with intronic substitution rates, the magnitude of this correlation is moderately underestimated for male recombination and slightly overestimated for female recombination, owing to covariance with replicating timing. Second, the result could explain why male recombination is strongly correlated with GC content but female recombination is not. If to explain the correlation between GC content and replication timing we suppose that late replication forces reduced GC content, then GC promotion by biased gene conversion during female recombination is partly countered by the antagonistic effect of later replicating sequence tending increase AT content. Indeed, the strength of the correlation between female recombination rate and local GC content is more than doubled by control for replication timing. Our results underpin the need to consider sex-specific recombination rates and potential covariates in

  16. Late Replicating Domains Are Highly Recombining in Females but Have Low Male Recombination Rates: Implications for Isochore Evolution

    Science.gov (United States)

    Pink, Catherine J.; Hurst, Laurence D.

    2011-01-01

    In mammals sequences that are either late replicating or highly recombining have high rates of evolution at putatively neutral sites. As early replicating domains and highly recombining domains both tend to be GC rich we a priori expect these two variables to covary. If so, the relative contribution of either of these variables to the local neutral substitution rate might have been wrongly estimated owing to covariance with the other. Against our expectations, we find that sex-averaged recombination rates show little or no correlation with replication timing, suggesting that they are independent determinants of substitution rates. However, this result masks significant sex-specific complexity: late replicating domains tend to have high recombination rates in females but low recombination rates in males. That these trends are antagonistic explains why sex-averaged recombination is not correlated with replication timing. This unexpected result has several important implications. First, although both male and female recombination rates covary significantly with intronic substitution rates, the magnitude of this correlation is moderately underestimated for male recombination and slightly overestimated for female recombination, owing to covariance with replicating timing. Second, the result could explain why male recombination is strongly correlated with GC content but female recombination is not. If to explain the correlation between GC content and replication timing we suppose that late replication forces reduced GC content, then GC promotion by biased gene conversion during female recombination is partly countered by the antagonistic effect of later replicating sequence tending increase AT content. Indeed, the strength of the correlation between female recombination rate and local GC content is more than doubled by control for replication timing. Our results underpin the need to consider sex-specific recombination rates and potential covariates in analysis of GC

  17. Poliovirus Polymerase Leu420 Facilitates RNA Recombination and Ribavirin Resistance.

    Science.gov (United States)

    Kempf, Brian J; Peersen, Olve B; Barton, David J

    2016-10-01

    RNA recombination is important in the formation of picornavirus species groups and the ongoing evolution of viruses within species groups. In this study, we examined the structure and function of poliovirus polymerase, 3D(pol), as it relates to RNA recombination. Recombination occurs when nascent RNA products exchange one viral RNA template for another during RNA replication. Because recombination is a natural aspect of picornavirus replication, we hypothesized that some features of 3D(pol) may exist, in part, to facilitate RNA recombination. Furthermore, we reasoned that alanine substitution mutations that disrupt 3D(pol)-RNA interactions within the polymerase elongation complex might increase and/or decrease the magnitudes of recombination. We found that an L420A mutation in 3D(pol) decreased the frequency of RNA recombination, whereas alanine substitutions at other sites in 3D(pol) increased the frequency of recombination. The 3D(pol) Leu420 side chain interacts with a ribose in the nascent RNA product 3 nucleotides from the active site of the polymerase. Notably, the L420A mutation that reduced recombination also rendered the virus more susceptible to inhibition by ribavirin, coincident with the accumulation of ribavirin-induced G→A and C→U mutations in viral RNA. We conclude that 3D(pol) Leu420 is critically important for RNA recombination and that RNA recombination contributes to ribavirin resistance. Recombination contributes to the formation of picornavirus species groups and the emergence of circulating vaccine-derived polioviruses (cVDPVs). The recombinant viruses that arise in nature are occasionally more fit than either parental strain, especially when the two partners in recombination are closely related, i.e., members of characteristic species groups, such as enterovirus species groups A to H or rhinovirus species groups A to C. Our study shows that RNA recombination requires conserved features of the viral polymerase. Furthermore, a polymerase

  18. Recombination: the good, the bad and the variable.

    Science.gov (United States)

    Stapley, Jessica; Feulner, Philine G D; Johnston, Susan E; Santure, Anna W; Smadja, Carole M

    2017-12-19

    Recombination, the process by which DNA strands are broken and repaired, producing new combinations of alleles, occurs in nearly all multicellular organisms and has important implications for many evolutionary processes. The effects of recombination can be good , as it can facilitate adaptation, but also bad when it breaks apart beneficial combinations of alleles, and recombination is highly variable between taxa, species, individuals and across the genome. Understanding how and why recombination rate varies is a major challenge in biology. Most theoretical and empirical work has been devoted to understanding the role of recombination in the evolution of sex-comparing between sexual and asexual species or populations. How recombination rate evolves and what impact this has on evolutionary processes within sexually reproducing organisms has received much less attention. This Theme Issue focusses on how and why recombination rate varies in sexual species, and aims to coalesce knowledge of the molecular mechanisms governing recombination with our understanding of the evolutionary processes driving variation in recombination within and between species. By integrating these fields, we can identify important knowledge gaps and areas for future research, and pave the way for a more comprehensive understanding of how and why recombination rate varies. © 2017 The Authors.

  19. Use of recombinant human antithrombin concentrate in pregnancy

    Directory of Open Access Journals (Sweden)

    Baumann Kreuziger LM

    2013-09-01

    Full Text Available Lisa M Baumann Kreuziger,1 Tracy L Prosen,2 Mark T Reding1 1Division of Hematology, Oncology, and Transplantation, University of Minnesota, MN, USA; 2Obstetrics and Gynecology, Maternal Fetal Medicine Center, University of Minnesota, MN, USAWe read with great interest James et al’s article "Prevention and treatment of venous thromboembolism in pregnancy in patients with hereditary antithrombin deficiency." The authors reported a case series of six women with antithrombin (AT deficiency treated with plasma derived antithrombin concentrate (pdAT; Thrombate III®, Grifols Therapeutics, Clayton, NC, USA.1 In contrast to these cases, we have managed three AT-deficient women over the past two years with low-molecular-weight-heparin during pregnancy and recombinant human antithrombin concentrate (rhAT; ATryn®, GTC Biotherapeutics, Framingham, MA, USA at delivery. In the Phase III trial leading to approval of rhAT, pregnant women required frequent dose modifications, and an alternate dosing regimen is currently recommended by the manufacturer.2,3 The detailed information provided in these cases may assist future providers in managing pregnant patients with AT deficiency.View original paper by James and colleagues.

  20. Recombinant tagging system using ribosomal frameshifting to monitor protein expression.

    Science.gov (United States)

    Han, Se Jong; Cho, Sayeon; Lowehhaupt, Ky; Park, So-Young; Sim, Sang Jun; Kim, Yang-Gyun

    2013-03-01

    For rapid and accurate quantitation of recombinant proteins during expression and after purification, we introduce a new tagging strategy that expresses both target proteins and limitedly tagged target proteins together in a single cell at a constant ratio by utilizing cis-elements of programmed -1 ribosomal frameshifting (-1RFS) as an embedded device. -1RFS is an alternative reading mechanism that effectively controls protein expression by many viruses. When a target gene is fused to the enhanced green fluorescent protein (EGFP) gene with a -1RFS element implanted between them, the unfused target and the target-GFP fusion proteins are expressed at a fixed ratio. The expression ratio between these two protein products is adjustable simply by changing -1RFS signals. This limited-tagging system would be valuable for the real-time monitoring of protein expression when optimizing expression condition for a new protein, and in monitoring large-scale bioprocesses without a large metabolic burden on host cells. Furthermore, this strategy allows for the direct measurement of the quantity of a protein on a chip surface and easy application to proteomewide study of gene products. Copyright © 2012 Wiley Periodicals, Inc.

  1. Production of Bioactive Recombinant Bovine Chymosin in Tobacco Plants

    Directory of Open Access Journals (Sweden)

    Zheng-Yi Wei

    2016-04-01

    Full Text Available Chymosin (also known as rennin plays an essential role in the coagulation of milk in the cheese industry. Chymosin is traditionally extracted from the rumen of calves and is of high cost. Here, we present an alternative method to producing bovine chymosin from transgenic tobacco plants. The CYM gene, which encodes a preprochymosin from bovine, was introduced into the tobacco nuclear genome under control of the viral 35S cauliflower mosaic promoter. The integration and transcription of the foreign gene were confirmed with Southern blotting and reverse transcription PCR (RT-PCR analyses, respectively. Immunoblotting analyses were performed to demonstrate expression of chymosin, and the expression level was quantified by enzyme-linked immunosorbent assay (ELISA. The results indicated recombinant bovine chymosin was successfully expressed at an average level of 83.5 ng/g fresh weight, which is 0.52% of the total soluble protein. The tobacco-derived chymosin exhibited similar native milk coagulation bioactivity as the commercial product extracted from bovine rumen.

  2. Catalysis for alternative energy generation

    CERN Document Server

    2012-01-01

    Summarizes recent problems in using catalysts in alternative energy generation and proposes novel solutions  Reconsiders the role of catalysis in alternative energy generation  Contributors include catalysis and alternative energy experts from across the globe

  3. Creating Porcine Biomedical Models Through Recombineering

    Directory of Open Access Journals (Sweden)

    Lawrence B. Schook

    2006-03-01

    Full Text Available Recent advances in genomics provide genetic information from humans and other mammals (mouse, rat, dog and primates traditionally used as models as well as new candidates (pigs and cattle. In addition, linked enabling technologies, such as transgenesis and animal cloning, provide innovative ways to design and perform experiments to dissect complex biological systems. Exploitation of genomic information overcomes the traditional need to choose naturally occurring models. Thus, investigators can utilize emerging genomic knowledge and tools to create relevant animal models. This approach is referred to as reverse genetics. In contrast to ‘forward genetics’, in which gene(s responsible for a particular phenotype are identified by positional cloning (phenotype to genotype, the ‘reverse genetics’ approach determines the function of a gene and predicts the phenotype of a cell, tissue, or organism (genotype to phenotype. The convergence of classical and reverse genetics, along with genomics, provides a working definition of a ‘genetic model’ organism (3. The recent construction of phenotypic maps defining quantitative trait loci (QTL in various domesticated species provides insights into how allelic variations contribute to phenotypic diversity. Targeted chromosomal regions are characterized by the construction of bacterial artificial chromosome (BAC contigs to isolate and characterize genes contributing towards phenotypic variation. Recombineering provides a powerful methodology to harvest genetic information responsible for phenotype. Linking recombineering with gene-targeted homologous recombination, coupled with nuclear transfer (NT technology can provide ‘clones’ of genetically modified animals.

  4. Recombinational DNA repair and human disease

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Larry H.; Schild, David

    2002-11-30

    We review the genes and proteins related to the homologous recombinational repair (HRR) pathway that are implicated in cancer through either genetic disorders that predispose to cancer through chromosome instability or the occurrence of somatic mutations that contribute to carcinogenesis. Ataxia telangiectasia (AT), Nijmegen breakage syndrome (NBS), and an ataxia-like disorder (ATLD), are chromosome instability disorders that are defective in the ataxia telangiectasia mutated (ATM), NBS, and Mre11 genes, respectively. These genes are critical in maintaining cellular resistance to ionizing radiation (IR), which kills largely by the production of double-strand breaks (DSBs). Bloom syndrome involves a defect in the BLM helicase, which seems to play a role in restarting DNA replication forks that are blocked at lesions, thereby promoting chromosome stability. The Werner syndrome gene (WRN) helicase, another member of the RecQ family like BLM, has very recently been found to help mediate homologous recombination. Fanconi anemia (FA) is a genetically complex chromosomal instability disorder involving seven or more genes, one of which is BRCA2. FA may be at least partially caused by the aberrant production of reactive oxidative species. The breast cancer-associated BRCA1 and BRCA2 proteins are strongly implicated in HRR; BRCA2 associates with Rad51 and appears to regulate its activity. We discuss in detail the phenotypes of the various mutant cell lines and the signaling pathways mediated by the ATM kinase. ATM's phosphorylation targets can be grouped into oxidative stress-mediated transcriptional changes, cell cycle checkpoints, and recombinational repair. We present the DNA damage response pathways by using the DSB as the prototype lesion, whose incorrect repair can initiate and augment karyotypic abnormalities.

  5. Alternative pricing methodologies

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    With the increased interest in competitive market forces and growing recognition of the deficiencies in current practices, FERC and others are exploring alternatives to embedded cost pricing. A number of these alternatives are discussed in this chapter. Marketplace pricing, discussed briefly here, is the subject of the next chapter. Obviously, the pricing formula may combine several of these methodologies. One utility of which the authors are aware is seeking a price equal to the sum of embedded costs, opportunity costs, line losses, value of service, FERC's percentage adder formula and a contract service charge

  6. A recombinant wheat serpin with inhibitory activity

    DEFF Research Database (Denmark)

    Rasmussen, Søren K; Dahl, Søren Weis; Nørgård, Anette

    1996-01-01

    , equipped with a histidine affinity tag at the N-terminus and expressed in Escherichia coli BL(21) DE3 pLysS. Recombinant WSZ1 from the soluble fraction was partially purified on Ni-NTA agarose and MonoQ columns and shown to form SDS-stable complexes with sc-chymotrypsin. Southern blots and amino acid...... sequencing indicated that only few serpins are encoded by wheat, but at least three distinct genes are expressed in the grain. Cleavage experiments on a chymotrypsin column suggested a Gln-Gln reactive site bond not previously observed in inhibitory serpins....

  7. Dissociative recombination of molecular ions H2+

    International Nuclear Information System (INIS)

    Abarenov, A.V.; Marchenko, V.S.

    1989-01-01

    The total cross sections of dissociation and dissociative recombination of slow electrons and molecular ions H 2 + have been calculated in terms of the quasiclassical and dipole approximations. In the calculations allowance was made for the quantum nature of vibrational motion of heavy particles and presence of autoionization of divergence states of the H 2 (Σ u , nl) molecules. It is shown that the H 2 + ion dissociation cross sections are dominant in increase of the electron energy in the ε >or approx. 2-3 eV region for H 2 + (v) ion distribution over the vibrational levels characteristic for the beam experiments. 15 refs.; 5 figs

  8. Population inversion in a stationary recombining plasma

    International Nuclear Information System (INIS)

    Otsuka, M.

    1980-01-01

    Population inversion, which occurs in a recombining plasma when a stationary He plasma is brought into contact with a neutral gas, is examined. With hydrogen as a contact gas, noticeable inversion between low-lying levels of H as been found. The overpopulation density is of the order of 10 8 cm -3 , which is much higher then that (approx. =10 5 cm -3 ) obtained previously with He as a contact gas. Relations between these experimental results and the conditions for population inversion are discussed with the CR model

  9. An introduction to recombination and linkage analysis

    Energy Technology Data Exchange (ETDEWEB)

    Mcpeek, M.S. [Univ. of Chicago, IL (United States)

    1996-12-31

    With a garden as his laboratory, Mendel was able to discern basic probabilistic laws of heredity. Although it first appeared as a baffling exception to one of Mendel`s principles, the phenomenon of variable linkage between characters was soon recognized to be a powerful tool in the process of chromosome mapping and location of genes of interest. In this introduction, we first describe Mendel`s work and the subsequent discovery of linkage. Next we describe the apparent cause of variable linkage, namely recombination, and we introduce linkage analysis. 33 refs., 1 fig., 2 tabs.

  10. Nanobodies and recombinant binders in cell biology

    Science.gov (United States)

    Helma, Jonas; Cardoso, M. Cristina; Muyldermans, Serge

    2015-01-01

    Antibodies are key reagents to investigate cellular processes. The development of recombinant antibodies and binders derived from natural protein scaffolds has expanded traditional applications, such as immunofluorescence, binding arrays, and immunoprecipitation. In addition, their small size and high stability in ectopic environments have enabled their use in all areas of cell research, including structural biology, advanced microscopy, and intracellular expression. Understanding these novel reagents as genetic modules that can be integrated into cellular pathways opens up a broad experimental spectrum to monitor and manipulate cellular processes. PMID:26056137

  11. Recombinant DNA. Rifkin's regulatory revivalism runs riot.

    Science.gov (United States)

    David, P

    Jeremy Rifkin, activist opponent of genetic engineering, has adopted tactics of litigation, persuasion, and confrontation in his campaign to halt genetic experimentation. The Recombinant DNA Advisory Committee of the National Institutes of Health has often been the target of his criticism, most recently for its failure to prepare an environmental risk assessment for some DNA tests it approved. Rifkin has won support for his position from religious organizations in the United States, and in June 1983 persuaded an ecumenical group of religious leaders to ask Congress to ban genetic experiments that would affect the human germ line.

  12. ReCombine: a suite of programs for detection and analysis of meiotic recombination in whole-genome datasets.

    Directory of Open Access Journals (Sweden)

    Carol M Anderson

    Full Text Available In meiosis, the exchange of DNA between chromosomes by homologous recombination is a critical step that ensures proper chromosome segregation and increases genetic diversity. Products of recombination include reciprocal exchanges, known as crossovers, and non-reciprocal gene conversions or non-crossovers. The mechanisms underlying meiotic recombination remain elusive, largely because of the difficulty of analyzing large numbers of recombination events by traditional genetic methods. These traditional methods are increasingly being superseded by high-throughput techniques capable of surveying meiotic recombination on a genome-wide basis. Next-generation sequencing or microarray hybridization is used to genotype thousands of polymorphic markers in the progeny of hybrid yeast strains. New computational tools are needed to perform this genotyping and to find and analyze recombination events. We have developed a suite of programs, ReCombine, for using short sequence reads from next-generation sequencing experiments to genotype yeast meiotic progeny. Upon genotyping, the program CrossOver, a component of ReCombine, then detects recombination products and classifies them into categories based on the features found at each location and their distribution among the various chromatids. CrossOver is also capable of analyzing segregation data from microarray experiments or other sources. This package of programs is designed to allow even researchers without computational expertise to use high-throughput, whole-genome methods to study the molecular mechanisms of meiotic recombination.

  13. Islands of Speciation or Mirages in the Desert? Examining the Role of Restricted Recombination in Maintaining Species*

    OpenAIRE

    Noor, Mohamed A. F.; Bennett, Sarah M.

    2009-01-01

    Over the past decade, many studies documented high genetic divergence between closely related species in genomic regions experiencing restricted recombination in hybrids, such as within chromosomal rearrangements or areas adjacent to centromeres. Such regions have been called “islands of speciation” because of their presumed role in maintaining the integrity of species despite gene flow elsewhere in the genome. Here, we review alternative explanations for such patterns. Segregation of ancestr...

  14. Synthesis of Amidines from Amides Using a Nickel-Catalyzed Decarbonylative Amination through CO Extrusion Intramolecular Recombination Fragment Coupling.

    Science.gov (United States)

    Liu, Xiangqian; Yue, Huifeng; Jia, Jiaqi; Guo, Lin; Rueping, Magnus

    2017-09-04

    A catalytic synthesis of amidines from amides has been established for the first time. The newly developed CO extrusion recombination process takes advantage of an inexpensive nickel(II) catalyst and provides the corresponding amidines with high efficiency. The intramolecular fragment coupling shows excellent chemoselectivity, starts from readily available amides, and provides a valuable alternative amidine synthesis protocol. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Expression and purification of recombinant hemoglobin in Escherichia coli

    DEFF Research Database (Denmark)

    Natarajan, Chandrasekhar; Jiang, Xiaoben; Fago, Angela

    2011-01-01

    BACKGROUND: Recombinant DNA technologies have played a pivotal role in the elucidation of structure-function relationships in hemoglobin (Hb) and other globin proteins. Here we describe the development of a plasmid expression system to synthesize recombinant Hbs in Escherichia coli, and we describe...... a protocol for expressing Hbs with low intrinsic solubilities. Since the alpha- and beta-chain Hbs of different species span a broad range of solubilities, experimental protocols that have been optimized for expressing recombinant human HbA may often prove unsuitable for the recombinant expression......-translational modifications. CONCLUSION/SIGNIFICANCE: Our protocol should prove useful for the experimental study of recombinant Hbs in many non-human animals. One of the chief advantages of our protocol is that we can express soluble recombinant Hb without co-expressing molecular chaperones, and without the need...

  16. Test tube systems with cutting/recombination operations

    Energy Technology Data Exchange (ETDEWEB)

    Freund, R. [Technische Universitaet Wien (Austria); Csuhaj-Varju, E. [Computer and Automation Institute, Budapest (Hungary); Wachtler, F. [Universitaet Wien (Austria)

    1996-12-31

    We introduce test tube systems based on operations that are closely related to the splicing operations, i.e. we consider the operations of cutting a string at a specific site into two pieces with marking them at the cut ends and of recombining two strings with specifically marked endings. Whereas in the splicing of two strings these strings are cut at specific sites and the cut pieces are recombined immediately in a crosswise way, in CR(cutting/recombination)-schemes cutting can happen independently from recombining the cut pieces. Test tube systems based on these operations of cutting and recombination turn out to have maximal generative power even if only very restricted types of input filters for the test tubes are used for the redistribution of the contents of the test tubes after a period of cuttings and recombinations in the test tubes. 10 refs.

  17. Alternate energy sources

    International Nuclear Information System (INIS)

    Stevens-Guille, P.D.

    1975-01-01

    The author highlights the interesting points made by the speeches during the conference on Energy and its Future in Southern Africa. He also draws attention to potential alternate energy sources such as power from tides, ocean waves, ocean temperature differences and geothermal power

  18. Energy conversion alternatives study

    Science.gov (United States)

    Shure, L. T.

    1979-01-01

    Comparison of coal based energy systems is given. Study identifies and compares various advanced energy conversion systems using coal or coal derived fuels for baselaoad electric power generation. Energy Conversion Alternatives Study (ECAS) reports provede government, industry, and general public with technically consistent basis for comparison of system's options of interest for fossilfired electric-utility application.

  19. Alternatives in solar energy

    Science.gov (United States)

    Schueler, D. G.

    1978-01-01

    Although solar energy has the potential of providing a significant source of clean and renewable energy for a variety of applications, it is expected to penetrate the nation's energy economy very slowly. The alternative solar energy technologies which employ direct collection and conversion of solar radiation as briefly described.

  20. TWTF design alternates

    International Nuclear Information System (INIS)

    Ayers, A.L. Sr.

    1982-03-01

    The Transuranic Waste Treatment Facility (TWTF) will process transuranic (TRU) waste in retrievable storage at the Idaho National Engineering Laboratory (INEL). The costs for a TWTF concept using a slagging pyrolysis incinerator were excessive. Alternate concepts using a slow speed shredder, a rotary kiln incinerator, and concrete immobilization should result in significant cost reductions. These will be included in future TWTF considerations

  1. Alternative Break Service Trips

    Science.gov (United States)

    DuPre, Carrie

    2010-01-01

    Even as educators understand how their millennial students learn in such different ways than previous generations (watching how-to videos downloaded from YouTube or engaging in experiential learning adventures), colleges still rely heavily on in-the-classroom learning. The author can't offer an alternative to this classroom format, but she…

  2. Alternative Energy Busing

    Science.gov (United States)

    LaFee, Scott

    2012-01-01

    In recent years, school districts have converted portions of their bus fleets to cleaner-burning, sometimes cheaper, alternative fossil fuels, such as compressed natural gas or propane. Others have adopted biodiesel, which combines regular diesel with fuel derived from organic sources, usually vegetable oils or animal fats. The number of biodiesel…

  3. Replication and recombination factors contributing to recombination-dependent bypass of DNA lesions by template switch.

    Directory of Open Access Journals (Sweden)

    Fabio Vanoli

    2010-11-01

    Full Text Available Damage tolerance mechanisms mediating damage-bypass and gap-filling are crucial for genome integrity. A major damage tolerance pathway involves recombination and is referred to as template switch. Template switch intermediates were visualized by 2D gel electrophoresis in the proximity of replication forks as X-shaped structures involving sister chromatid junctions. The homologous recombination factor Rad51 is required for the formation/stabilization of these intermediates, but its mode of action remains to be investigated. By using a combination of genetic and physical approaches, we show that the homologous recombination factors Rad55 and Rad57, but not Rad59, are required for the formation of template switch intermediates. The replication-proficient but recombination-defective rfa1-t11 mutant is normal in triggering a checkpoint response following DNA damage but is impaired in X-structure formation. The Exo1 nuclease also has stimulatory roles in this process. The checkpoint kinase, Rad53, is required for X-molecule formation and phosphorylates Rad55 robustly in response to DNA damage. Although Rad55 phosphorylation is thought to activate recombinational repair under conditions of genotoxic stress, we find that Rad55 phosphomutants do not affect the efficiency of X-molecule formation. We also examined the DNA polymerase implicated in the DNA synthesis step of template switch. Deficiencies in translesion synthesis polymerases do not affect X-molecule formation, whereas DNA polymerase δ, required also for bulk DNA synthesis, plays an important role. Our data indicate that a subset of homologous recombination factors, together with DNA polymerase δ, promote the formation of template switch intermediates that are then preferentially dissolved by the action of the Sgs1 helicase in association with the Top3 topoisomerase rather than resolved by Holliday Junction nucleases. Our results allow us to propose the choreography through which different

  4. Homologous recombination-mediated cloning and manipulation of genomic DNA regions using Gateway and recombineering systems.

    Science.gov (United States)

    Rozwadowski, Kevin; Yang, Wen; Kagale, Sateesh

    2008-11-17

    Employing genomic DNA clones to characterise gene attributes has several advantages over the use of cDNA clones, including the presence of native transcription and translation regulatory sequences as well as a representation of the complete repertoire of potential splice variants encoded by the gene. However, working with genomic DNA clones has traditionally been tedious due to their large size relative to cDNA clones and the presence, absence or position of particular restriction enzyme sites that may complicate conventional in vitro cloning procedures. To enable efficient cloning and manipulation of genomic DNA fragments for the purposes of gene expression and reporter-gene studies we have combined aspects of the Gateway system and a bacteriophage-based homologous recombination (i.e. recombineering) system. To apply the method for characterising plant genes we developed novel Gateway and plant transformation vectors that are of small size and incorporate selectable markers which enable efficient identification of recombinant clones. We demonstrate that the genomic coding region of a gene can be directly cloned into a Gateway Entry vector by recombineering enabling its subsequent transfer to Gateway Expression vectors. We also demonstrate how the coding and regulatory regions of a gene can be directly cloned into a plant transformation vector by recombineering. This construct was then rapidly converted into a novel Gateway Expression vector incorporating cognate 5' and 3' regulatory regions by using recombineering to replace the intervening coding region with the Gateway Destination cassette. Such expression vectors can be applied to characterise gene regulatory regions through development of reporter-gene fusions, using the Gateway Entry clones of GUS and GFP described here, or for ectopic expression of a coding region cloned into a Gateway Entry vector. We exemplify the utility of this approach with the Arabidopsis PAP85 gene and demonstrate that the expression

  5. The estimation of recombination rates from population genetic data

    OpenAIRE

    2007-01-01

    Genetic recombination is an important process that generates new combinations of genes on which natural selection can operate. As such, an understanding of recombination in the human genome will provide insight into the evolutionary processes that have shaped our genetic history. The aim of this thesis is to use samples of population genetic data to explore the patterns of variation in the rate of recombination in the human genome. To do this I introduce a novel means of estimating recombinat...

  6. Modified Fragmentation Function from Quark Recombination

    Energy Technology Data Exchange (ETDEWEB)

    Majumder, A.; Wang, Enke; Wang, Xin-Nian

    2005-07-26

    Within the framework of the constituent quark model, it isshown that the single hadron fragmentation function of a parton can beexpressed as a convolution of shower diquark or triquark distributionfunction and quark recombination probability, if the interference betweenamplitudes of quark recombination with different momenta is neglected.Therecombination probability is determined by the hadron's wavefunction inthe constituent quark model. The shower diquark or triquark distributionfunctions of a fragmenting jet are defined in terms of overlappingmatrices of constituent quarks and parton field operators. They aresimilar in form to dihadron or trihadron fragmentation functions in termsof parton operator and hadron states. Extending the formalism to thefield theory at finite temperature, we automatically derive contributionsto the effective single hadron fragmentation function from therecombination of shower and thermal constituent quarks. Suchcontributions involve single or diquark distribution functions which inturn can be related to diquark or triquark distribution functions via sumrules. We also derive QCD evolution equations for quark distributionfunctions that in turn determine the evolution of the effective jetfragmentation functions in a thermal medium.

  7. Sweetness characterization of recombinant human lysozyme.

    Science.gov (United States)

    Matano, Mami; Nakajima, Kana; Kashiwagi, Yutaka; Udaka, Shigezo; Maehashi, Kenji

    2015-10-01

    Lysozyme, a bacteriolytic enzyme, is widely distributed in nature and is a component of the innate immune system. It is established that chicken egg lysozyme elicits sweetness. However, the sweetness of human milk lysozyme, which is vital for combating microbial infections of the gastrointestinal tract of breast-fed infants, has not been characterized. This study aimed to assess the elicitation of sweetness using recombinant mammalian lysozymes expressed in Pichia pastoris. Recombinant human lysozyme (h-LZ) and other mammalian lysozymes of mouse, dog, cat and bovine milk elicited similar sweetness as determined using a sensory test, whereas bovine stomach lysozyme (bs-LZ) did not. Assays of cell cultures showed that h-LZ activated the human sweet taste receptor hT1R2/hT1R3, whereas bs-LZ did not. Point mutations confirmed that the sweetness of h-LZ was independent of enzyme activity and substrate-binding sites, although acidic amino acid residues of bs-LZ played a significant role in diminishing sweetness. Therefore, we conclude that elicitation of sweetness is a ubiquitous function among all lysozymes including mammalian lysozymes. These findings may provide novel insights into the biological implications of T1R2/T1R3-activation by mammalian lysozyme in the oral cavity and gastrointestinal tract. However, the function of lysozyme within species lacking the functional sweet taste receptor gene, such as cat, is currently unknown. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Simulation and Optimisation of CLIC's recombination complex

    CERN Document Server

    Costa, Raul; Barroso, Manuel

    In this thesis we present the first Placet2 recombination simulations of the drive beam recombination complex (DBRC) design for the compact linear collider (CLIC). We start by presenting a review of the CLIC project and the DBRC’s role and design within it. We then discuss some of the core principles of beam dynamics and how tracking codes like Placet2 implement them. We follow that by presenting the design issues raised by our simulations and our proposed strategy to address them, key among which is a previously unknown parabolic dependency of the longitudinal position to the momentum (T 566 ), which threat- ens the efficiency of the power extraction structures. Through iterative opti- misation of the design, we eliminated this aberration both in the delay loop and in combiner ring 1. We also found the beam’s horizontal emittance to be significantly over the design budget (150 μm) and attempted to meet that budget, reaching 157 μm. In order to obtain this emittance value, an update to the combiner ring...

  9. The landscape of recombination in African Americans

    Science.gov (United States)

    Hinch, Anjali G.; Tandon, Arti; Patterson, Nick; Song, Yunli; Rohland, Nadin; Palmer, Cameron D.; Chen, Gary K.; Wang, Kai; Buxbaum, Sarah G.; Akylbekova, Meggie; Aldrich, Melinda C.; Ambrosone, Christine B.; Amos, Christopher; Bandera, Elisa V.; Berndt, Sonja I.; Bernstein, Leslie; Blot, William J.; Bock, Cathryn H.; Boerwinkle, Eric; Cai, Qiuyin; Caporaso, Neil; Casey, Graham; Cupples, L. Adrienne; Deming, Sandra L.; Diver, W. Ryan; Divers, Jasmin; Fornage, Myriam; Gillanders, Elizabeth M.; Glessner, Joseph; Harris, Curtis C.; Hu, Jennifer J.; Ingles, Sue A.; Isaacs, Williams; John, Esther M.; Kao, W. H. Linda; Keating, Brendan; Kittles, Rick A.; Kolonel, Laurence N.; Larkin, Emma; Le Marchand, Loic; McNeill, Lorna H.; Millikan, Robert C.; Murphy, Adam; Musani, Solomon; Neslund-Dudas, Christine; Nyante, Sarah; Papanicolaou, George J.; Press, Michael F.; Psaty, Bruce M.; Reiner, Alex P.; Rich, Stephen S.; Rodriguez-Gil, Jorge L.; Rotter, Jerome I.; Rybicki, Benjamin A.; Schwartz, Ann G.; Signorello, Lisa B.; Spitz, Margaret; Strom, Sara S.; Thun, Michael J.; Tucker, Margaret A.; Wang, Zhaoming; Wiencke, John K.; Witte, John S.; Wrensch, Margaret; Wu, Xifeng; Yamamura, Yuko; Zanetti, Krista A.; Zheng, Wei; Ziegler, Regina G.; Zhu, Xiaofeng; Redline, Susan; Hirschhorn, Joel N.; Henderson, Brian E.; Taylor, Herman A.; Price, Alkes L.; Hakonarson, Hakon; Chanock, Stephen J.; Haiman, Christopher A.; Wilson, James G.; Reich, David; Myers, Simon R.

    2011-01-01

    Recombination, together with mutation, is the ultimate source of genetic variation in populations. We leverage the recent mixture of people of African and European ancestry in the Americas to build a genetic map measuring the probability of crossing-over at each position in the genome, based on about 2.1 million crossovers in 30,000 unrelated African Americans. At intervals of more than three megabases it is nearly identical to a map built in Europeans. At finer scales it differs significantly, and we identify about 2,500 recombination hotspots that are active in people of West African ancestry but nearly inactive in Europeans. The probability of a crossover at these hotspots is almost fully controlled by the alleles an individual carries at PRDM9 (P<10−245). We identify a 17 base pair DNA sequence motif that is enriched in these hotspots, and is an excellent match to the predicted binding target of African-enriched alleles of PRDM9. PMID:21775986

  10. Recombinant protein scaffolds for tissue engineering

    International Nuclear Information System (INIS)

    Werkmeister, Jerome A; Ramshaw, John A M

    2012-01-01

    New biological materials for tissue engineering are now being developed using common genetic engineering capabilities to clone and express a variety of genetic elements that allow cost-effective purification and scaffold fabrication from these recombinant proteins, peptides or from chimeric combinations of these. The field is limitless as long as the gene sequences are known. The utility is dependent on the ease, product yield and adaptability of these protein products to the biomedical field. The development of recombinant proteins as scaffolds, while still an emerging technology with respect to commercial products, is scientifically superior to current use of natural materials or synthetic polymer scaffolds, in terms of designing specific structures with desired degrees of biological complexities and motifs. In the field of tissue engineering, next generation scaffolds will be the key to directing appropriate tissue regeneration. The initial period of biodegradable synthetic scaffolds that provided shape and mechanical integrity, but no biological information, is phasing out. The era of protein scaffolds offers distinct advantages, particularly with the combination of powerful tools of molecular biology. These include, for example, the production of human proteins of uniform quality that are free of infectious agents and the ability to make suitable quantities of proteins that are found in low quantity or are hard to isolate from tissue. For the particular needs of tissue engineering scaffolds, fibrous proteins like collagens, elastin, silks and combinations of these offer further advantages of natural well-defined structural scaffolds as well as endless possibilities of controlling functionality by genetic manipulation. (topical review)

  11. Tuning Mesenchymal Stem Cell Response onto Titanium-Niobium-Hafnium Alloy by Recombinant Fibronectin Fragments.

    Science.gov (United States)

    Herranz-Diez, C; Mas-Moruno, C; Neubauer, S; Kessler, H; Gil, F J; Pegueroles, M; Manero, J M; Guillem-Marti, J

    2016-02-03

    Since metallic biomaterials used for bone replacement possess low bioactivity, the use of cell adhesive moieties is a common strategy to improve cellular response onto these surfaces. In recent years, the use of recombinant proteins has emerged as an alternative to native proteins and short peptides owing to the fact that they retain the biological potency of native proteins, while improving their stability. In the present study, we investigated the biological effect of two different recombinant fragments of fibronectin, spanning the 8-10th and 12-14th type III repeats, covalently attached to a new TiNbHf alloy using APTES silanization. The fragments were studied separately and mixed at different concentrations and compared to a linear RGD, a cyclic RGD and the full-length fibronectin protein. Cell culture studies using rat mesenchymal stem cells demonstrated that low to medium concentrations (30% and 50%) of type III 8-10th fragment mixed with type III 12-14th fragment stimulated cell spreading and proliferation compared to RGD peptides and the fragments separately. On the other hand, type III 12-14th fragment alone or mixed at low volume percentages ≤50% with type III 8-10th fragment increased alkaline phosphatase levels compared to the other molecules. These results are significant for the understanding of the role of fibronectin recombinant fragments in cell responses and thus to design bioactive coatings for biomedical applications.

  12. Improved insecticidal activity of a recombinant baculovirus expressing spider venom cyto-insectotoxin.

    Science.gov (United States)

    Ali, M P; Kato, Tatsuya; Park, Enoch Y

    2015-12-01

    Baculoviruses have a long history of safe use as specific, environmentally friendly insecticides that provide alternatives to chemical pesticides for controlling insect pests. However, their use has been limited by several factors, particularly their slow pathogenicity. In this study, we constructed a recombinant Bombyx mori nucleopolyhedrovirus (BmNPV) and an Autographa californica multiple nucleopolyhedrovirus (AcMNPV) that expressed an insect-specific cyto-insectotoxin (Cit1a) from the venom of the central Asian spider Lachesana tarabaevi. Cit1a is a comparatively long linear cytolytic molecule that contains a predicted α-helix structure composed of two short membrane-acting antimicrobial peptides (MAMPs) that are joined together in a "head-to-tail" shape. Cit1a fused to polyhedrin gene (polh) (polh-cit1a) was expressed in the nuclei as polyhedra in silkworm larvae, Bm5 and Sf9 cells. An early death of Bm5 and Sf9 cells by recombinant BmNPV/Polh-Cit1a and AcMNPV/Polh-Cit1a was observed compared with control viruses that lacked the toxin gene. The infected cells showed a loss of cytoplasm, membrane integrity, and structural changes, suggesting that recombinant baculovirus-infected cells were killed by the necrosis caused by Cit1a. In addition, the BmNPV/Polh-Cit1a showed a significant reduction in the median lethal time (LT50) against silkworm larvae compared with those of control BmNPV that lacked the cit1a gene.

  13. Online optimisation of the CLIC Drive Beam bunch train recombination at CTF3

    CERN Document Server

    AUTHOR|(CDS)2082483; Tecker, Frank

    The Compact Linear Collider (CLIC) design is the leading alternative for a future multi-TeV "e^+e^−" linear collider. One of the key aspects of the design is the use of a Drive Beam as power source for the acceleration of the colliding beams. This work is focused on the optimisation of the set-up and the operations of the CLIC Drive Beam recombination at the CLIC Test Facility (CTF3) at CERN. The main effects that may affect the beam quality during the recombination are studied, with emphasis on orbit, transverse dynamics and beam energy effects. A custom methodology is used to analyse the problem, both from a theoretical and a numerical point of view. The aim is to provide first-order orbit and transverse optics constraints, which can be used as guidelines during the set-up of the beam recombination process. The developed techniques are applied at the CTF3, and the results are reported. The non-linear beam energy effects have been investigated by means of MAD-X simulations. The results show that these effe...

  14. Expression of recombinant staphylokinase in the methylotrophic yeast Hansenula polymorpha

    Directory of Open Access Journals (Sweden)

    Moussa Manal

    2012-12-01

    Full Text Available Abstract Background Currently, the two most commonly used fibrinolytic agents in thrombolytic therapy are recombinant tissue plasminogen activator (rt-PA and streptokinase (SK. Whereas SK has the advantage of substantially lower costs when compared to other agents, it is less effective than either rt-PA or related variants, has significant allergenic potential, lacks fibrin selectivity and causes transient hypotensive effects in high dosing schedules. Therefore, development of an alternative fibrinolytic agent having superior efficacy to SK, approaching that of rt-PA, together with a similar or enhanced safety profile and advantageous cost-benefit ratio, would be of substantial importance. Pre-clinical data suggest that the novel fibrinolytic recombinant staphylokinase (rSAK, or related rSAK variants, could be candidates for such development. However, since an efficient expression system for rSAK is still lacking, it has not yet been fully developed or evaluated for clinical purposes. This study’s goal was development of an efficient fermentation process for the production of a modified, non-glycosylated, biologically active rSAK, namely rSAK-2, using the well-established single cell yeast Hansenula polymorpha expression system. Results The development of an efficient large scale (80 L Hansenula polymorpha fermentation process of short duration for rSAK-2 production is described. It evolved from an initial 1mL HTP methodology by successive scale-up over almost 5 orders of magnitude and improvement steps, including the optimization of critical process parameters (e.g. temperature, pH, feeding strategy, medium composition, etc.. Potential glycosylation of rSAK-2 was successfully suppressed through amino acid substitution within its only N-acetyl glycosylation motif. Expression at high yields (≥ 1g rSAK-2/L cell culture broth of biologically active rSAK-2 of expected molecular weight was achieved. Conclusion The optimized production process

  15. Radioactive waste management alternatives

    International Nuclear Information System (INIS)

    Baranowski, F.P.

    1976-01-01

    The information in the US ERDA ''Technical Alternatives Document'' is summarized. The first two points show that waste treatment, interim storage and transportation technologies for all wastes are currently available. Third, an assessment of integrated waste management systems is needed. One such assessment will be provided in our expanded waste management environmental statement currently planned for release in about one year. Fourth, geologies expected to be suitable for final geologic storage are known. Fifth, repository system assessment methods, that is a means to determine and assess the acceptability of a terminal storage facility for nonretrievable storage, must and will be prepared. Sixth, alternatives to geologic storage are not now available. Seventh, waste quantities and characteristics are sensitive to technologies and fuel-cycle modes, and therefore an assessment of these technologies and modes is important. Eighth, and most important, it is felt that the LWR fuel cycle can be closed with current technologies

  16. Alternative propulsion for automobiles

    CERN Document Server

    Stan, Cornel

    2017-01-01

    The book presents – based on the most recent research and development results worldwide - the perspectives of new propulsion concepts such as electric cars with batteries and fuel cells, and furthermore plug in hybrids with conventional and alternative fuels. The propulsion concepts are evaluated based on specific power, torque characteristic, acceleration behaviour, specific fuel consumption and pollutant emissions. The alternative fuels are discussed in terms of availability, production, technical complexity of the storage on board, costs, safety and infrastructure. The book presents summarized data about vehicles with electric and hybrid propulsion. The propulsion of future cars will be marked by diversity – from compact electric city cars and range extender vehicles for suburban and rural areas up to hybrid or plug in SUV´s, Pick up´s and luxury class automobiles.

  17. [Alternatives to animal testing].

    Science.gov (United States)

    Fabre, Isabelle

    2009-11-01

    The use of alternative methods to animal testing are an integral part of the 3Rs concept (refine, reduce, replace) defined by Russel & Burch in 1959. These approaches include in silico methods (databases and computer models), in vitro physicochemical analysis, biological methods using bacteria or isolated cells, reconstructed enzyme systems, and reconstructed tissues. Emerging "omic" methods used in integrated approaches further help to reduce animal use, while stem cells offer promising approaches to toxicologic and pathophysiologic studies, along with organotypic cultures and bio-artificial organs. Only a few alternative methods can so far be used in stand-alone tests as substitutes for animal testing. The best way to use these methods is to integrate them in tiered testing strategies (ITS), in which animals are only used as a last resort.

  18. Evidence of recombination in intrapatient populations of hepatitis C virus.

    Science.gov (United States)

    Sentandreu, Vicente; Jiménez-Hernández, Nuria; Torres-Puente, Manuela; Bracho, María Alma; Valero, Ana; Gosalbes, María José; Ortega, Enrique; Moya, Andrés; González-Candelas, Fernando

    2008-09-18

    Hepatitis C virus (HCV) is a major cause of liver disease worldwide and a potential cause of substantial morbidity and mortality in the future. HCV is characterized by a high level of genetic heterogeneity. Although homologous recombination has been demonstrated in many members of the family Flaviviridae, to which HCV belongs, there are only a few studies reporting recombination on natural populations of HCV, suggesting that these events are rare in vivo. Furthermore, these few studies have focused on recombination between different HCV genotypes/subtypes but there are no reports on the extent of intra-genotype or intra-subtype recombination between viral strains infecting the same patient. Given the important implications of recombination for RNA virus evolution, our aim in this study has been to assess the existence and eventually the frequency of intragenic recombination on HCV. For this, we retrospectively have analyzed two regions of the HCV genome (NS5A and E1-E2) in samples from two different groups: (i) patients infected only with HCV (either treated with interferon plus ribavirin or treatment naïve), and (ii) HCV-HIV co-infected patients (with and without treatment against HIV). The complete data set comprised 17712 sequences from 136 serum samples derived from 111 patients. Recombination analyses were performed using 6 different methods implemented in the program RDP3. Recombination events were considered when detected by at least 3 of the 6 methods used and were identified in 10.7% of the amplified samples, distributed throughout all the groups described and the two genomic regions studied. The resulting recombination events were further verified by detailed phylogenetic analyses. The complete experimental procedure was applied to an artificial mixture of relatively closely viral populations and the ensuing analyses failed to reveal artifactual recombination. From these results we conclude that recombination should be considered as a potentially

  19. Alternative REST Splicing Underappreciated

    OpenAIRE

    Chen, Guo-Lin; Miller, Gregory

    2017-01-01

    As a major orchestrator of the cellular epigenome, the repressor element-1 silencing transcription factor (REST) can either repress or activate thousands of genes depending on cellular context, suggesting a highly context-dependent REST function tuned by environmental cues. While REST shows cell-type non-selective active transcription, an N-terminal REST4 isoform caused by alternative splicing - inclusion of an extra exon (N3c) which introduces a pre-mature stop codon - has been implicated in...

  20. Metamaterials critique and alternatives

    CERN Document Server

    Munk, Ben A

    2009-01-01

    A Convincing and Controversial Alternative Explanation of Metamaterials with a Negative Index of Refraction In a book that will generate both support and controversy, one of the world's foremost authorities on periodic structures addresses several of the current fashions in antenna design-most specifically, the popular subject of double negative metamaterials. Professor Munk provides a comprehensive theoretical electromagnetic investigation of the issues and concludes that many of the phenomena claimed by researchers may be impossible. While denying the existence of negative refractio

  1. The renewable alternative

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This chapter discusses renewable energy sources as an alternative to a fossil fuel based economy. The topics discussed in the chapter include the historic aspects and current status of use of renewable energy, status of the renewable energy industry, market barriers to renewable energy, research and development and commercialization of renewable energy, the environmental and social costs associated with renewable energy, valuing future costs and benefits of energy use, and the potential market of renewable energy

  2. Alternatives to incineration. Technical area status report

    Energy Technology Data Exchange (ETDEWEB)

    Schwinkendorf, W.E. [BDM Federal, Inc., Albuquerque, NM (United States); McFee, J.; Devarakonda, M. [International Technology Corp., Albuquerque, NM (United States); Nenninger, L.L.; Fadullon, F.S. [Science Applications International Corp., Gaithersburg, MD (United States); Donaldson, T.L. [Oak Ridge National Lab., TN (United States); Dickerson, K. [Oak Ridge National Lab., TN (United States)]|[Rocky Flats Environmental Technology Site, Golden, CO (United States)

    1995-04-01

    Recently, the DOE`s Mixed Waste Integrated Program (MWIP) (superseded by the Mixed Waste Focus Area) initiated an evaluation of alternatives to incineration to identify technologies capable of treating DOE organically contaminated mixed wastes and which may be more easily permitted. These technologies have the potential of alleviating stakeholder concerns by decreasing off-gas volurties and the associated emissions of particulates, volatilized metals and radionuclides, PICs, NO{sub x}, SO{sub x}, and recombination products (dioxins and furans). Ideally, the alternate technology would be easily permitted, relatively omnivorous and effective in treating a variety of wastes with varying constituents, require minimal pretreatment or characterization, and be easy to implement. In addition, it would produce secondary waste stream volumes significantly smaller than the original waste stream, and would minimize the environmental health and safety effects on workers and the public. The purpose of this report is to provide an up-to-date (as of early 1995) compendium of iternative technologies for designers of mixed waste treatment facilities, and to identify Iternate technologies that may merit funding for further development. Various categories of non-thermal and thermal technologies have been evaluated and are summarized in Table ES-1. Brief descriptions of these technologies are provided in Section 1.7 of the Introduction. This report provides a detailed description of approximately 30 alternative technologies in these categories. Included in the report are descriptions of each technology; applicable input waste streams and the characteristics of the secondary, or output, waste streams; the current status of each technology relative to its availability for implementation; performance data; and costs. This information was gleaned from the open literature, governments reports, and discussions with principal investigators and developers.

  3. Alternatives to incineration. Technical area status report

    International Nuclear Information System (INIS)

    Schwinkendorf, W.E.; McFee, J.; Devarakonda, M.; Nenninger, L.L.; Fadullon, F.S.; Donaldson, T.L.; Dickerson, K.

    1995-04-01

    Recently, the DOE's Mixed Waste Integrated Program (MWIP) (superseded by the Mixed Waste Focus Area) initiated an evaluation of alternatives to incineration to identify technologies capable of treating DOE organically contaminated mixed wastes and which may be more easily permitted. These technologies have the potential of alleviating stakeholder concerns by decreasing off-gas volurties and the associated emissions of particulates, volatilized metals and radionuclides, PICs, NO x , SO x , and recombination products (dioxins and furans). Ideally, the alternate technology would be easily permitted, relatively omnivorous and effective in treating a variety of wastes with varying constituents, require minimal pretreatment or characterization, and be easy to implement. In addition, it would produce secondary waste stream volumes significantly smaller than the original waste stream, and would minimize the environmental health and safety effects on workers and the public. The purpose of this report is to provide an up-to-date (as of early 1995) compendium of iternative technologies for designers of mixed waste treatment facilities, and to identify Iternate technologies that may merit funding for further development. Various categories of non-thermal and thermal technologies have been evaluated and are summarized in Table ES-1. Brief descriptions of these technologies are provided in Section 1.7 of the Introduction. This report provides a detailed description of approximately 30 alternative technologies in these categories. Included in the report are descriptions of each technology; applicable input waste streams and the characteristics of the secondary, or output, waste streams; the current status of each technology relative to its availability for implementation; performance data; and costs. This information was gleaned from the open literature, governments reports, and discussions with principal investigators and developers

  4. Alternative Energy Sources

    CERN Document Server

    Michaelides, Efstathios E (Stathis)

    2012-01-01

    Alternative Energy Sources is designed to give the reader, a clear view of the role each form of alternative energy may play in supplying the energy needs of the human society in the near and intermediate future (20-50 years).   The two first chapters on energy demand and supply and environmental effects, set the tone as to why the widespread use of alternative energy is essential for the future of human society. The third chapter exposes the reader to the laws of energy conversion processes, as well as the limitations of converting one energy form to another. The sections on exergy give a succinct, quantitative background on the capability/potential of each energy source to produce power on a global scale. The fourth, fifth and sixth chapters are expositions of fission and fusion nuclear energy. The following five chapters (seventh to eleventh) include detailed descriptions of the most common renewable energy sources – wind, solar, geothermal, biomass, hydroelectric – and some of the less common sources...

  5. Alternative Respiratory Pathway

    Science.gov (United States)

    Siedow, James N.; Girvin, Mark E.

    1980-01-01

    Oxygen uptake during the first hours of imbibition in intact soybean and mung bean seeds showed a marked sensitivity to potassium cyanide but was unaffected by addition of either salicylhydroxamic acid or propyl gallate. However O2 uptake by finely ground seed particles was very sensitive to the addition of either compound. The results indicated that O2 uptake in intact, imbibing seeds was associated with a cyanide-sensitive process, most probably mitochondrial mediated respiration, and not the result of the cyanide-insensitive lipoxygenase activity which was readily detectable in ground seed particles. The antioxidant propyl gallate was found to inhibit specifically alternative pathway electron transfer in isolated mung bean mitochondria. Half-maximal inhibition occurred with 2 to 5 micromolar propyl gallate. Kinetic analysis indicated that propyl gallate inhibition of the alternative pathway occurred at, or very near, the site of inhibition of the alternative pathway by salicylhydroxamic acid. A high level of lipoxygenase activity was found to be associated with washed mitochondria isolated from a variety of etiolated plant tissues. Most of this lipoxygenase activity could be eliminated from mung bean mitochondria if the mitochondria were purified on a discontinuous sucrose gradient. This indicated that the mitochondrial-associated activity was probably the result of nonspecific adsorption of lipoxygenase onto the mitochondrial membranes during isolation. PMID:16661259

  6. Is garlic alternative medicine?

    Science.gov (United States)

    Rivlin, Richard S

    2006-03-01

    Garlic has been used medicinally since antiquity. In virtually every early civilization known, such as ancient India, Egypt, Rome, China, and Japan, garlic was part of the therapeutic regimen for a variety of maladies. Therefore, the ancient medicinal tradition of garlic use would qualify it as a folk medicine or as an alternative or complementary medicine. But is garlic an alternative to established methods of disease prevention or treatment? Scientists from around the world have identified a number of bioactive substances in garlic that are water soluble (e.g., S-allyl methylcysteine), and fat soluble (e.g., diallyldisulfide). Mechanisms of action are being elucidated by modern technology. The validity of ancient medicine is now being evaluated critically in cell-free systems, animal models, and human populations. Preventive and therapeutic trials of garlic are still in early stages. There are many promising lines of research suggesting the potential effects of garlic. The current state of knowledge does not recognize garlic as a true alternative, but it will likely find a place for garlic as a complement to established methods of disease prevention and treatment. Our goal should be to examine garlic together with other agents to evaluate its possible efficacy and toxicity under conditions of actual use in humans.

  7. State alternative route designations

    International Nuclear Information System (INIS)

    1989-07-01

    Pursuant to the Hazardous Materials Transportation Act (HMTA), the Department of Transportation (DOT) has promulgated a comprehensive set of regulations regarding the highway transportation of high-level radioactive materials. These regulations, under HM-164 and HM-164A, establish interstate highways as the preferred routes for the transportation of radioactive materials within and through the states. The regulations also provide a methodology by which a state may select alternative routes. First,the state must establish a ''state routing agency,'' defined as an entity authorized to use the state legal process to impose routing requirements on carriers of radioactive material (49 CFR 171.8). Once identified, the state routing agency must select routes in accordance with Large Quantity Shipments of Radioactive Materials or an equivalent routing analysis. Adjoining states and localities should be consulted on the impact of proposed alternative routes as a prerequisite of final route selection. Lastly, the states must provide written notice of DOT of any alternative route designation before the routes are deemed effective

  8. Reversal of succinylcholine induced apnea with an organophosphate scavenging recombinant butyrylcholinesterase.

    Directory of Open Access Journals (Sweden)

    Brian C Geyer

    Full Text Available Concerns about the safety of paralytics such as succinylcholine to facilitate endotracheal intubation limit their use in prehospital and emergency department settings. The ability to rapidly reverse paralysis and restore respiratory drive would increase the safety margin of an agent, thus permitting the pursuit of alternative intubation strategies. In particular, patients who carry genetic or acquired deficiency of butyrylcholinesterase, the serum enzyme responsible for succinylcholine hydrolysis, are susceptible to succinylcholine-induced apnea, which manifests as paralysis, lasting hours beyond the normally brief half-life of succinylcholine. We hypothesized that intravenous administration of plant-derived recombinant BChE, which also prevents mortality in nerve agent poisoning, would rapidly reverse the effects of succinylcholine.Recombinant butyrylcholinesterase was produced in transgenic plants and purified. Further analysis involved murine and guinea pig models of succinylcholine toxicity. Animals were treated with lethal and sublethal doses of succinylcholine followed by administration of butyrylcholinesterase or vehicle. In both animal models vital signs and overall survival at specified intervals post succinylcholine administration were assessed.Purified plant-derived recombinant human butyrylcholinesterase can hydrolyze succinylcholine in vitro. Challenge of mice with an LD100 of succinylcholine followed by BChE administration resulted in complete prevention of respiratory inhibition and concomitant mortality. Furthermore, experiments in symptomatic guinea pigs demonstrated extremely rapid succinylcholine detoxification with complete amelioration of symptoms and no apparent complications.Recombinant plant-derived butyrylcholinesterase was capable of counteracting and reversing apnea in two complementary models of lethal succinylcholine toxicity, completely preventing mortality. This study of a protein antidote validates the feasibility

  9. Plant-produced recombinant influenza A vaccines based on the M2e peptide.

    Science.gov (United States)

    Mardanova, Eugenia S; Ravin, Nikolai V

    2018-03-09

    Influenza is a widely distributed infection that almost annually causes seasonal epidemics. The current egg-based platforms for influenza vaccine production are facing a number of challenges and are failing to satisfy the global demand in the case of pandemics due to the long production time. Recombinant vaccines are an alternative that can be quickly produced in high quantities in standard expression systems. Plants may become a promising biofactory for the large-scale production of recombinant proteins due to low cost, scalability, and safety. Plant-based expression systems have been used to produce recombinant vaccines against influenza based on two targets; the major surface antigen hemagglutinin and the transmembrane protein M2. Different forms of recombinant hemagglutinin were successfully expressed in plants, and some plant-produced vaccines based on hemagglutinin were successfully tested in clinical trials. However, these vaccines remain strain specific, while the highly conserved extracellular domain of M2 protein (M2e) could be used for the development of a universal influenza vaccine. In this review, the state of the art in developing plant-produced influenza vaccines based on M2e is presented and placed in perspective. A number of strategies to produce M2e in an immunogenic form in plants have been reported, including its presentation on the surface of plant viruses or virus-like particles formed by capsid proteins, linkage to bacterial flagellin, and targeting to protein bodies. Some M2e-based vaccine candidates were produced at high levels (up to 1 mg/g of fresh plant tissue) and were shown to be capable of stimulating broad-range protective immunity. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  10. Lactation performance of transgenic goats expressing recombinant human butyryl-cholinesterase in the milk.

    Science.gov (United States)

    Baldassarre, Hernan; Hockley, Duncan K; Doré, Monique; Brochu, Eric; Hakier, Bernard; Zhao, Xin; Bordignon, Vilceu

    2008-02-01

    The production of recombinant proteins in the milk of transgenic animals has attracted significant interest in the last decade, as a valuable alternative for the production of recombinant proteins that cannot be or are inefficiently produced using conventional systems based on microorganisms or animal cells. Several recombinant proteins of pharmaceutical and biomedical interest have been successfully expressed in high quantities (g/l) in the milk of transgenic animals. However, this productivity may be associated with a compromised mammary physiology resulting, among other things, from the extraordinary demand placed on the mammary secretory cells. In this study we evaluated the lactation performance of a herd of 50 transgenic goats expressing recombinant human butyryl-cholinesterase (rBChE) in the milk. Our findings indicate that high expression levels of rBChE (range 1-5 g/l) are produced in these animals at the expense of an impaired lactation performance. The key features characterizing these transgenic performances were the decreased milk production, the reduced milk fat content which was associated with an apparent disruption in the lipid secretory mechanism at the mammary epithelium level, and a highly increased presence of leukocytes in milk which is not associated with mammary infection. Despite of having a compromised lactation performance, the amount of rBChE produced per transgenic goat represents several orders of magnitude more than the amount of rBChE present in the blood of hundreds of human donors, the only other available source of rBChE for pharmaceutical and biodefense applications. As a result, this development constitutes another successful example in the application of transgenic animal technology.

  11. Expression and characterization of natural-like recombinant Der p 2 for sublingual immunotherapy.

    Science.gov (United States)

    Bordas-Le Floch, Véronique; Bussières, Laetitia; Airouche, Sabi; Lautrette, Aurélie; Bouley, Julien; Berjont, Nathalie; Horiot, Stéphane; Huet, Axelle; Jain, Karine; Lemoine, Pierrick; Chabre, Henri; Batard, Thierry; Mascarell, Laurent; Baron-Bodo, Véronique; Tourdot, Sophie; Nony, Emmanuel; Moingeon, Philippe

    2012-01-01

    Recombinant allergens with a native conformation represent an alternative to natural extracts for immunotherapy and diagnostic purposes. We produced the Der p 2 mite allergen in Pichia pastoris and Escherichia coli. After purification by cation exchange chromatography, recombinant molecules were compared to their natural counterpart based upon structural (disulfide bonds, secondary structure, thermal stability) and immunological properties (antibody reactivity, basophil and T cell activation, tolerance induction in a murine sublingual immunotherapy model). The Der p 2.0101 isoform was confirmed to be prevalent in Dermatophagoides pteronyssinus extracts. It was then produced as a secreted molecule in P. pastoris or refolded from E. coli inclusion bodies. The yeast-expressed rDer p 2 molecule exhibits a natural-like disulfide bridge distribution and secondary structure, whereas the E. coli-derived rDer p 2 presents some heterogeneity in cysteine bonds and a lower stability following thermal stress. The two recombinant as well as natural Der p 2 molecules exhibit comparable IgE recognition and activate basophil and CD4+ T cells. Sublingual immunotherapy of nDer p 2- sensitized mice using either one of the rDer p 2 molecules efficiently decreases airway hyperresponsiveness as well as Th2 responses. Natural and recombinant Der p 2 molecules produced in P. pastoris and E. coli exhibit comparable immunological properties despite distinct structural features. Natural-like cysteine pairing is a critical parameter to identify stable, well-folded and homogenous proteins appropriate for immunotherapy and diagnostic purposes. Copyright © 2012 S. Karger AG, Basel.

  12. Omenn Syndrome and DNA recombination defects.

    Science.gov (United States)

    Yachie, Akihiro

    2017-01-01

    Mutations in the RAG1/RAG2 genes are associated with a broad spectrum of clinical phenotypes, ranging from severe combined immunodeficiency to various autoimmune diseases. The diversity of the clinical symptoms is determined not only by the residual RAG recombinase enzyme activity as determined by the mutations, but also by multiple environmental factors and, in rare cases, by second site mutations within the RAG1/RAG2 genes. The residual recombinase activity is responsible for the oligoclonal expansion of autoreactive T cells. Omenn syndrome is the result of intense Th2 type inflammation involving the skin and multiple other organs triggered by these T cells. In this review, the molecular pathology of diseases caused by RAG1/RAG2 mutations, in particular Omenn syndrome, will be discussed. Furthermore, abnormalities in other molecules involved in V(D)J recombination will be discussed in relation to Omenn-like syndrome.

  13. Classification of Recombinant Biologics in the EU

    DEFF Research Database (Denmark)

    Klein, Kevin; De Bruin, Marie L; Broekmans, Andre W

    2015-01-01

    BACKGROUND AND OBJECTIVE: Biological medicinal products (biologics) are subject to specific pharmacovigilance requirements to ensure that biologics are identifiable by brand name and batch number in adverse drug reaction (ADR) reports. Since Member States collect ADR data at the national level...... before the data is aggregated at the European Union (EU) level, it is important that an unambiguous understanding of which medicinal products belong to the biological product category exists. This study aimed to identify the level of consistency between Member States regarding the classification...... of biologics by national authorities responsible for ADR reporting. METHODS: A sample list of recombinant biologics from the European Medicines Agency database of European Public Assessment Reports was created to analyze five Member States (Belgium, the Netherlands, Spain, Sweden, and the UK) according...

  14. Scavenging and recombination kinetics in radiation chemistry.

    Science.gov (United States)

    Al-Samra, Eyad H; Green, Nicholas J B

    2017-08-02

    This work describes stochastic models developed to study the competition between radical scavenging and recombination for simple model systems typical of radiation chemistry, where the reactive particles are tightly clustered and reactions are assumed fully diffusion limited. Three models are developed: a Monte Carlo random flights model with a periodic boundary condition for scavengers, Monte Carlo simulations in which the scavenging rate is calculated from the Smoluchowski theory for diffusion-limited reactions and a modification of the independent reaction times method where the scavengers close to the spur are explicitly included and the scavengers further away are treated as a continuum. The results indicate that the Smoluchowski theory makes a systematic overestimate of the scavenging rate when such competition is present. A correction for the Smoluchowski rate constant is suggested, an analytical justification is presented and it is tested against the simulations, and shown to be a substantial improvement.

  15. Recombinant expression of backbone-cyclized polypeptides.

    Science.gov (United States)

    Borra, Radhika; Camarero, Julio A

    2013-09-01

    Here we review the different biochemical approaches available for the expression of backbone-cyclized polypeptides, including peptides and proteins. These methods allow for the production of circular polypeptides either in vitro or in vivo using standard recombinant DNA expression techniques. Polypeptide circularization provides a valuable tool to study the effects of topology on protein stability and folding kinetics. Furthermore, having biosynthetic access to backbone-cyclized polypeptides makes the production of genetically encoded libraries of cyclic polypeptides possible. The production of such libraries, which was previously restricted to the domain of synthetic chemistry, now offers biologists access to highly diverse and stable molecular libraries that can be screened using high-throughput methods for the rapid selection of novel cyclic polypeptide sequences with new biological activities. Copyright © 2013 Wiley Periodicals, Inc.

  16. Soluble variants of human recombinant glutaminyl cyclase.

    Directory of Open Access Journals (Sweden)

    Cristiana Castaldo

    Full Text Available Recombinant human Glutaminyl Cyclase expressed in E. coli is produced as inclusion bodies. Lack of glycosylation is the main origin of its accumulation in insoluble aggregates. Mutation of single isolated hydrophobic amino acids into negative amino acids was not able to circumvent inclusion bodies formation. On the contrary, substitution with carboxyl-terminal residues of two or three aromatic residues belonging to extended hydrophobic patches on the protein surface provided soluble but still active forms of the protein. These mutants could be expressed in isotopically enriched forms for NMR studies and the maximal attainable concentration was sufficient for the acquisition of (1H-(15N HSQC spectra that represent the starting point for future drug development projects targeting Alzheimer's disease.

  17. MSD Recombination Method in Statistical Machine Translation

    Science.gov (United States)

    Gros, Jerneja Žganec

    2008-11-01

    Freely available tools and language resources were used to build the VoiceTRAN statistical machine translation (SMT) system. Various configuration variations of the system are presented and evaluated. The VoiceTRAN SMT system outperformed the baseline conventional rule-based MT system in all English-Slovenian in-domain test setups. To further increase the generalization capability of the translation model for lower-coverage out-of-domain test sentences, an "MSD-recombination" approach was proposed. This approach not only allows a better exploitation of conventional translation models, but also performs well in the more demanding translation direction; that is, into a highly inflectional language. Using this approach in the out-of-domain setup of the English-Slovenian JRC-ACQUIS task, we have achieved significant improvements in translation quality.

  18. Guiding recombinant antivenom development by omics technologies

    DEFF Research Database (Denmark)

    Laustsen, Andreas Hougaard

    2017-01-01

    , endogenous animal proteins with toxin-neutralizing capabilities, and recombinant monoclonal antibodies. Harnessing either of these approaches, antivenom development may benefit from an in-depth understanding of venom compositions and the medical importance of individual venom toxins. Focus is thus also...... directed towards the different omics technologies (particularly venomics, antivenomics, and toxicovenomics) that are being used to uncover novel animal toxins, shed light on venom complexity, and provide directions for how to determine the medical relevance of individual toxins within whole venoms. Finally......In this review, the different approaches that have been employed with the aim of developing novel antivenoms against animal envenomings are presented and discussed. Reported efforts have focused on the use of innovative immunization strategies, small molecule inhibitors against enzymatic toxins...

  19. Recombinant Brucella abortus gene expressing immunogenic protein

    Energy Technology Data Exchange (ETDEWEB)

    Mayfield, J.E.; Tabatabai, L.B.

    1991-06-11

    This patent describes a synthetic recombinant DNA molecule containing a DNA sequence. It comprises a gene of Brucella abortus encoding an immunogenic protein having a molecular weight of approximately 31,000 daltons as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis under denaturing conditions, the protein having an isoelectric point around 4.9, and containing a twenty-five amino acid sequence from its amino terminal end consisting of Gln-Ala-Pro-Thr-Phe-Phe-Arg-Ile-Gly-Thr-Gly-Gly-Thr-Ala-Gly-Thr-Tyr-Tyr-Pro-Ile-Gly-Gly-Leu-Ile-Ala, wherein Gln, Ala, Pro, Thr, Phe, Arg, Ile, Gly, Tyr, and Leu, respectively, represent glutamine, alanine, proline, threonine, phenylalanine, arginine, isolecuine, glycine, tyrosine, and leucine.

  20. Initiation of Meiotic Recombination in Mammals

    Directory of Open Access Journals (Sweden)

    Rajeev Kumar

    2010-12-01

    Full Text Available Meiotic recombination is initiated by the induction of programmed DNA double strand breaks (DSBs. DSB repair promotes homologous interactions and pairing and leads to the formation of crossovers (COs, which are required for the proper reductional segregation at the first meiotic division. In mammals, several hundred DSBs are generated at the beginning of meiotic prophase by the catalytic activity of SPO11. Currently it is not well understood how the frequency and timing of DSB formation and their localization are regulated. Several approaches in humans and mice have provided an extensive description of the localization of initiation events based on CO mapping, leading to the identification and characterization of preferred sites (hotspots of initiation. This review presents the current knowledge about the proteins known to be involved in this process, the sites where initiation takes place, and the factors that control hotspot localization.