WorldWideScience

Sample records for alternate unbalanced recombinants

  1. Transient analysis of unbalanced short circuits of the ERDA-NASA 100 kW wind turbine alternator

    Science.gov (United States)

    Hwang, H. H.; Gilbert, L. J.

    1976-01-01

    Unbalanced short-circuit faults on the alternator of the ERDA-NASA Mod-O100-kW experimental wind turbine are studied. For each case, complete solutions for armature, field, and damper-circuit currents; short-circuit torque; and open-phase voltage are derived directly by a mathematical analysis. Formulated results are tabulated. For the Mod-O wind turbine alternator, numerical calculations are given, and results are presented by graphs. Comparisons for significant points among the more important cases are summarized. For these cases the transients are found to be potentially severe. The effect of the alternator neutral-to-ground impedance is evaluated.

  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. Estimating survival rates in ecological studies with small unbalanced sample sizes: an alternative Bayesian point estimator

    Directory of Open Access Journals (Sweden)

    Christian Damgaard

    2011-12-01

    Full Text Available Increasingly, the survival rates in experimental ecology are presented using odds ratios or log response ratios, but the use of ratio metrics has a problem when all the individuals have either died or survived in only one replicate. In the empirical ecological literature, the problem often has been ignored or circumvented by different, more or less ad hoc approaches. Here, it is argued that the best summary statistic for communicating ecological results of frequency data in studies with small unbalanced samples may be the mean of the posterior distribution of the survival rate. The developed approach may be particularly useful when effect size indexes, such as odds ratios, are needed to compare frequency data between treatments, sites or studies.

  4. Human cell lines: A promising alternative for recombinant FIX production.

    Science.gov (United States)

    de Sousa Bomfim, Aline; Cristina Corrêa de Freitas, Marcela; Picanço-Castro, Virgínia; de Abreu Soares Neto, Mário; Swiech, Kamilla; Tadeu Covas, Dimas; Maria de Sousa Russo, Elisa

    2016-05-01

    Factor IX (FIX) is a vitamin K-dependent protein, and it has become a valuable pharmaceutical in the Hemophilia B treatment. We evaluated the potential of recombinant human FIX (rhFIX) expression in 293T and SK-Hep-1 human cell lines. SK-Hep-1-FIX cells produced higher levels of biologically active protein. The growth profile of 293T-FIX cells was not influenced by lentiviral integration number into the cellular genome. SK-Hep-1-FIX cells showed a significantly lower growth rate than SK-Hep-1 cells. γ-carboxylation process is significant to FIX biological activity, thus we performed a expression analysis of genes involved in this process. The 293T gene expression suggests that this cell line could efficiently carboxylate FIX, however only 28% of the total secreted protein is active. SK-Hep-1 cells did not express high amounts of VKORC1 and carboxylase, but this cell line secreted large amounts of active protein. Enrichment of culture medium with Ca(+2) and Mg(+2) ions did not affect positively rhFIX expression in SK-Hep-1 cells. In 293T cells, the addition of 0.5 mM Ca(+2) and 1 mM Mg(+2) resulted in higher rhFIX concentration. SK-Hep-1 cell line proved to be very effective in rhFIX production, and it can be used as a novel biotechnological platform for the production of recombinant proteins.

  5. Human cell lines: A promising alternative for recombinant FIX production.

    Science.gov (United States)

    de Sousa Bomfim, Aline; Cristina Corrêa de Freitas, Marcela; Picanço-Castro, Virgínia; de Abreu Soares Neto, Mário; Swiech, Kamilla; Tadeu Covas, Dimas; Maria de Sousa Russo, Elisa

    2016-05-01

    Factor IX (FIX) is a vitamin K-dependent protein, and it has become a valuable pharmaceutical in the Hemophilia B treatment. We evaluated the potential of recombinant human FIX (rhFIX) expression in 293T and SK-Hep-1 human cell lines. SK-Hep-1-FIX cells produced higher levels of biologically active protein. The growth profile of 293T-FIX cells was not influenced by lentiviral integration number into the cellular genome. SK-Hep-1-FIX cells showed a significantly lower growth rate than SK-Hep-1 cells. γ-carboxylation process is significant to FIX biological activity, thus we performed a expression analysis of genes involved in this process. The 293T gene expression suggests that this cell line could efficiently carboxylate FIX, however only 28% of the total secreted protein is active. SK-Hep-1 cells did not express high amounts of VKORC1 and carboxylase, but this cell line secreted large amounts of active protein. Enrichment of culture medium with Ca(+2) and Mg(+2) ions did not affect positively rhFIX expression in SK-Hep-1 cells. In 293T cells, the addition of 0.5 mM Ca(+2) and 1 mM Mg(+2) resulted in higher rhFIX concentration. SK-Hep-1 cell line proved to be very effective in rhFIX production, and it can be used as a novel biotechnological platform for the production of recombinant proteins. PMID:26802680

  6. 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. PMID:25170075

  7. Alternative lengthening of telomeres pathway: recombination-mediated telomere maintenance mechanism in human cells.

    OpenAIRE

    Nabetani, Akira; Ishikawa, Fuyuki

    2011-01-01

    Unlimitedly proliferating cells need to acquire the telomere DNA maintenance mechanism, to counteract possible shortening through multiple rounds of replication and segregation of linear chromosomes. Most human cancer cells express telomerase whereas the other cells utilize the alternative lengthening of telomeres (ALT) pathway to elongate telomere DNA. It is suggested that ALT depends on the recombination between telomere repetitive DNAs. However, the molecular details remain unknown. Recent...

  8. 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.

  9. Alternate oscillations of self-terminating and recombination lasers in univalent calcium and strontium ions

    Institute of Scientific and Technical Information of China (English)

    Pan Bai-Liang; Chen Gang; Fang Ben-Min; Mao Bang-Ning; Yao Zhi-Xin

    2004-01-01

    The univalent calcium and strontium ions have been confirmed as ideal lasing substances both for self-terminating laser and recombination laser by theoretically analysing their energy level structures and lasing mechanisms. With the optimization of the excitation circuit and the improvement of the laser cavity as well as the laser discharge tube, the alternate laser oscillations of the two laser mechanisms were successfully realized by longitudinal pulsed discharge in mixture vapours of helium and univalent ions of calcium or strontium, respectively. The dependences of laser performance on working parameters, together with the characteristics of the photoelectric pulse waveforms were elementally studied and analysed.

  10. 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

    BACKGROUND: Heparan sulfate glycosaminoglycans are diverse components of certain proteoglycans and are known to interact with growth factors as a co-receptor necessary to induce signalling and growth factor activity. In this report we characterize heterogeneously glycosylated recombinant human pe...

  11. Similarity of Recombinant Human Perlecan Domain 1 by Alternative Expression Systems Bioactive Heterogenous Recombinant Human Perlecan D1

    OpenAIRE

    Ellis April L; Pan Wensheng; Yang Guang; Jones Kim; Chuang Christine; Whitelock John M; DeCarlo Arthur A

    2010-01-01

    Abstract Background Heparan sulfate glycosaminoglycans are diverse components of certain proteoglycans and are known to interact with growth factors as a co-receptor necessary to induce signalling and growth factor activity. In this report we characterize heterogeneously glycosylated recombinant human 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 SD...

  12. CtIP promotes microhomology-mediated alternative end joining during class-switch recombination.

    Science.gov (United States)

    Lee-Theilen, Mieun; Matthews, Allysia J; Kelly, Dierdre; Zheng, Simin; Chaudhuri, Jayanta

    2011-01-01

    Immunoglobulin heavy chain (Igh locus) class-switch recombination (CSR) requires targeted introduction of DNA double strand breaks (DSBs) into repetitive 'switch'-region DNA elements in the Igh locus and subsequent ligation between distal DSBs. Both canonical nonhomologous end joining (C-NHEJ) that seals DNA ends with little or no homology and a poorly defined alternative end joining (A-NHEJ, also known as alt-NHEJ) process that requires microhomology ends for ligation have been implicated in CSR. Here, we show that the DNA end-processing factor CtIP is required for microhomology-directed A-NHEJ during CSR. Additionally, we demonstrate that microhomology joins that are enriched upon depletion of the C-NHEJ component Ku70 require CtIP. Finally, we show that CtIP binds to switch-region DNA in a fashion dependent on activation-induced cytidine deaminase. Our results establish CtIP as a bona fide component of microhomology-dependent A-NHEJ and unmask a hitherto unrecognized physiological role of microhomology-mediated end joining in a C-NHEJ-proficient environment.

  13. Graph Construction for Learning with Unbalanced Data

    OpenAIRE

    Qian, Jing; Saligrama, Venkatesh; Zhao, Manqi

    2011-01-01

    Unbalanced data arises in many learning tasks such as clustering of multi-class data, hierarchical divisive clustering and semisupervised learning. Graph-based approaches are popular tools for these problems. Graph construction is an important aspect of graph-based learning. We show that graph-based algorithms can fail for unbalanced data for many popular graphs such as k-NN, \\epsilon-neighborhood and full-RBF graphs. We propose a novel graph construction technique that encodes global statist...

  14. Redundant function of DNA ligase 1 and 3 in alternative end-joining during immunoglobulin class switch recombination.

    Science.gov (United States)

    Masani, Shahnaz; Han, Li; Meek, Katheryn; Yu, Kefei

    2016-02-01

    Nonhomologous end-joining (NHEJ) is the major DNA double-strand break (DSB) repair pathway in mammals and resolves the DSBs generated during both V(D)J recombination in developing lymphocytes and class switch recombination (CSR) in antigen-stimulated B cells. In contrast to the absolute requirement for NHEJ to resolve DSBs associated with V(D)J recombination, DSBs associated with CSR can be resolved in NHEJ-deficient cells (albeit at a reduced level) by a poorly defined alternative end-joining (A-EJ) pathway. Deletion of DNA ligase IV (Lig4), a core component of the NHEJ pathway, reduces CSR efficiency in a mouse B-cell line capable of robust cytokine-stimulated CSR in cell culture. Here, we report that CSR levels are not further reduced by deletion of either of the two remaining DNA ligases (Lig1 and nuclear Lig3) in Lig4(-/-) cells. We conclude that in the absence of Lig4, Lig1, and Lig3 function in a redundant manner in resolving switch region DSBs during CSR. PMID:26787901

  15. Recombinant Human Erythropoietin as an Alternative to Blood Transfusion in Cancer-Related Anaemia

    OpenAIRE

    Andreas Engert

    2000-01-01

    As physicians become more aware of the need to treat anaemia in their patients with cancer, they have to consider 2 treatment options: red blood cell transfusion or recombinant human erythropoietin [epoetin alfa; epoetin beta]. Healthcare systems are under increasing pressure to lower costs while maintaining quality of care; therefore, treatment of cancer-related anaemia requires a disease management strategy aimed at achieving optimal clinical and economic outcomes. Although blood transfusio...

  16. Co-cultivation of Aspergillus nidulans Recombinant Strains Produces an Enzymatic Cocktail as Alternative to Alkaline Sugarcane Bagasse Pretreatment

    Science.gov (United States)

    Lima, Matheus S.; Damasio, André R. de L.; Crnkovic, Paula M.; Pinto, Marcelo R.; da Silva, Ana M.; da Silva, Jean C. R.; Segato, Fernando; de Lucas, Rosymar C.; Jorge, João A.; Polizeli, Maria de L. T. de M.

    2016-01-01

    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. PMID:27199917

  17. 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.

  18. Co-cultivation of Aspergillus nidulans Recombinant Strains Produces an Enzymatic Cocktail as Alternative to Alkaline Sugarcane Bagasse Pretreatment.

    Science.gov (United States)

    Lima, Matheus S; Damasio, André R de L; Crnkovic, Paula M; Pinto, Marcelo R; da Silva, Ana M; da Silva, Jean C R; Segato, Fernando; de Lucas, Rosymar C; Jorge, João A; Polizeli, Maria de L T de M

    2016-01-01

    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. PMID:27199917

  19. [Infantile pyknocytosis: A cause of noenatal hemolytic anemia. Is recombinant erythropoietin an alternative to transfusion?].

    Science.gov (United States)

    Bagou, M; Rolland, E; Gay, C; Patural, H

    2016-01-01

    Infantile pyknocytosis is a neonatal hemolytic disorder which causes anemia and icterus and is characterized by the presence of an increased number of distorted red blood cells called pyknocytes. Resolution spontaneously occurs in the first semester of life. It has been generally described as a rare entity, with an occasional family history. We report seven cases of infantile pyknocytosis observed in our hospital in 3 years. Most of the infants presented with hemolytic icterus and profound anemia that was reaching its peak by the 3rd week of life. Three neonates received one to three red blood cell transfusions, according to former recommendations. However, the following four received a treatment with recombinant erythropoietin administered subcutaneously. Only one of these four cases required a transfusion. All of them were free of hematological disease 2-3 months after completion of treatment. Infantile pyknocytosis is a recognized cause of neonatal hemolytic anemia, which requires careful examination of red cell morphology on a peripheral blood smear. The cause of this transient disorder remains unknown. Our observations show that recombinant erythropoietin therapy is effective in treating infantile pyknocytosis and increases the reticulocyte response, thus improving the hemoglobin level. PMID:26563723

  20. Precise Wavefront Correction with an Unbalanced Nulling Interferometer for Exo-Planet Imaging Coronagraphs

    CERN Document Server

    Nishikawa, J; Murakami, N; Kotani, T

    2008-01-01

    Very high dynamical range coronagraphs targeting direct exo-planet detection (10^9 - 10^10 contrast) at small angular separation (few lambda/D units) usually require an input wavefront quality on the order of ten thousandths of wavelength RMS. We propose a novel method based on a pre-optics setup that behaves partly as a low-efficiency coronagraph, and partly as a high-sensitivity wavefront aberration compensator (phase and amplitude). The combination of the two effects results in a highly accurate corrected wavefront. First, an (intensity-) unbalanced nulling interferometer (UNI) performs a rejection of part of the wavefront electric field. Then the recombined output wavefront has its input aberrations magnified. Because of the unbalanced recombination scheme, aberrations can be free of phase singular points (zeros) and can therefore be compensated by a downstream phase and amplitude correction (PAC) adaptive optics system, using two deformable mirrors. In the image plane, the central star's peak intensity a...

  1. Nanostructured recombinant cytokines: A highly stable alternative to short-lived prophylactics.

    Science.gov (United States)

    Torrealba, Débora; Parra, David; Seras-Franzoso, Joaquin; Vallejos-Vidal, Eva; Yero, Daniel; Gibert, Isidre; Villaverde, Antonio; Garcia-Fruitós, Elena; Roher, Nerea

    2016-11-01

    Cytokines have been widely used as adjuvants and therapeutic agents in treatments of human diseases. Despite their recognized potential as drugs, the medical use of cytokines has considerable drawbacks, mainly related to their low stability and short half-life. Such intrinsic limitations imply the administration of high doses, often prompting toxicity, undesirable side effects and greater production costs. Here, we describe a new category of mechanically stable nanostructured cytokines (TNFα and CCL4/MIP-1β) that resist harsh physicochemical conditions in vitro (pH and temperature), while maintaining functionality. These bio-functional materials are produced in recombinant cell factories through cost-effective and fully scalable processes. Notably, we demonstrate their prophylactic potential in vivo showing they protect zebrafish from a lethal infection by Pseudomonas aeruginosa. PMID:27614162

  2. Mutant Telomeric Repeats in Yeast Can Disrupt the Negative Regulation of Recombination-Mediated Telomere Maintenance and Create an Alternative Lengthening of Telomeres-Like Phenotype▿

    OpenAIRE

    Bechard, Laura H.; Butuner, Bilge D.; Peterson, George J.; McRae, Will; Topcu, Zeki; McEachern, Michael J.

    2008-01-01

    Some human cancers maintain telomeres using alternative lengthening of telomeres (ALT), a process thought to be due to recombination. In Kluyveromyces lactis mutants lacking telomerase, recombinational telomere elongation (RTE) is induced at short telomeres but is suppressed once telomeres are moderately elongated by RTE. Recent work has shown that certain telomere capping defects can trigger a different type of RTE that results in much more extensive telomere elongation that is reminiscent o...

  3. A Mutation in the STN1 Gene Triggers an Alternative Lengthening of Telomere-Like Runaway Recombinational Telomere Elongation and Rapid Deletion in Yeast

    OpenAIRE

    Iyer, Shilpa; Chadha, Ashley D.; McEachern, Michael J.

    2005-01-01

    Some human cancer cells achieve immortalization by using a recombinational mechanism termed ALT (alternative lengthening of telomeres). A characteristic feature of ALT cells is the presence of extremely long and heterogeneous telomeres. The molecular mechanism triggering and maintaining this pathway is currently unknown. In Kluyveromyces lactis, we have identified a novel allele of the STN1 gene that produces a runaway ALT-like telomeric phenotype by recombination despite the presence of an a...

  4. A recombinant two-module form of human properdin is an inhibitor of the complement alternative pathway.

    Science.gov (United States)

    Kouser, Lubna; Abdul-Aziz, Munirah; Tsolaki, Anthony G; Singhal, Dipti; Schwaeble, Wilhelm J; Urban, Britta C; Khan, Haseeb A; Sim, Robert B; Kishore, Uday

    2016-05-01

    Properdin upregulates the alternative complement pathway by binding and stabilising the C3 convertase complex (C3bBb). Properdin is a soluble glycoprotein and its flexible rod-like 53kDa monomers form cyclic polymers (dimers, trimers, tetramers and pentamers). The properdin monomer consists of seven thrombospondin type I repeats (TSR 0-6), which are similar and homologous to domains found in circumsporozoite and thrombospondin-related anonymous proteins of Plasmodium species, ETP100 of Eimeria tenella, various complement components C6-C9, and thrombospondin I and II. Using deletion constructs, TSR4 and TSR5 of human properdin were implicated in C3b binding and stabilising C3 convertase. However, individually expressed TSR4 or TSR5 failed to bind properdin ligands. Here, we have expressed and characterized biologically active TSR4 and TSR5 together (TSR4+5) in tandem in Escherichia coli, fused to maltose-binding protein. MBP-TSR4+5 bind solid-phase C3b, sulfatides and glycosaminoglycans. In addition, functionally active recombinant TSR4+5 modules inhibit the alternative pathway of complement. PMID:27060503

  5. Black diholes with unbalanced magnetic charges

    CERN Document Server

    Liang, Y C; Teo, Edward

    2001-01-01

    We present a technique that can be used to generate a static, axisymmetric solution of the Einstein-Maxwell-Dilaton equations from a stationary, axisymmetric solution of the vacuum Einstein equations. Starting from the Kerr solution, Davidson and Gedalin have previously made use of this technique to obtain a pair of oppositely charged, extremal dilatonic black holes, known as a black dihole. In this paper, we shall instead start from the Kerr-NUT solution. It will be shown that the new solution can also be interpreted as a dihole, but with the black holes carrying unbalanced magnetic charges. The effect of the NUT-parameter is to introduce a net magnetic charge into the system. Finally, we uplift our solution to ten dimensions to describe a system consisting of D6 and anti-D6-branes with unbalanced charges. The limit in which they coincide agrees with a solution recently derived by Brax et al..

  6. The Unbalanced Matching in a Director Market

    OpenAIRE

    Changmin Lee

    2007-01-01

    I construct an intertemporal searching model ("take it or leave it offer") in a frictional directorship market to explain the unbalanced matching between the director and the firm. In this model, potential candidates for outside directors and firms have heterogeneous (also, well ordered) quality levels. Also, both parties have strictly ordered preferences over the quality of counterpart from high levels to low levels. A candidate considers his quality ranking to compare the value of accepting...

  7. The Unbalanced Physical Movements of International Trade

    OpenAIRE

    Liu, Haiyang

    2014-01-01

    The goods produced in developed nations are often of higher quality, advanced technology and better design, hence goods even with little physical mass have higher value than goods produced in developing nations. This means that if the payment is balanced between developed and developing nations, the physical mass must be unbalanced. As a result, developed nations will become increasingly heavier, and the northern hemisphere where developed nations are clustered will also become more and more ...

  8. 53BP1 regulates DNA resection and the choice between classical and alternative end joining during class switch recombination.

    Science.gov (United States)

    Bothmer, Anne; Robbiani, Davide F; Feldhahn, Niklas; Gazumyan, Anna; Nussenzweig, Andre; Nussenzweig, Michel C

    2010-04-12

    Class switch recombination (CSR) diversifies antibodies by joining highly repetitive DNA elements, which are separated by 60-200 kbp. CSR is initiated by activation-induced cytidine deaminase, an enzyme that produces multiple DNA double-strand breaks (DSBs) in switch regions. Switch regions are joined by a mechanism that requires an intact DNA damage response and classical or alternative nonhomologous end joining (A-NHEJ). Among the DNA damage response factors, 53BP1 has the most profound effect on CSR. We explore the role of 53BP1 in intrachromosomal DNA repair using I-SceI to introduce paired DSBs in the IgH locus. We find that the absence of 53BP1 results in an ataxia telangiectasia mutated-dependent increase in DNA end resection and that resected DNA is preferentially repaired by microhomology-mediated A-NHEJ. We propose that 53BP1 favors long-range CSR in part by protecting DNA ends against resection, which prevents A-NHEJ-dependent short-range rejoining of intra-switch region DSBs.

  9. 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.

  10. Analysis about Unbalanced International Payment and Suggestions

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ 1.The cause of unbalanced international payment Since the implementation of reform and opening-up from the end of 1970's,due to the economic development and the gradually improved reliance on import,China used to witness the situation that exchange supply could not meet the demand, foreign exchange became a kind of resource in shortage. Therefore, we had to try every way to promote the export and increase the exchange reserve, it was an important economic task during that period.

  11. Minimal Model for an Unbalanced Holographic Superconductor

    CERN Document Server

    Musso, Daniele

    2013-01-01

    We describe the simplest holographic model for an s-wave unbalanced superconductor in 2+1 dimensions. We study its phase diagram and linear response features with particular attention to the possibility of spatially modulated phases (LOFF) and mixed spin-electric properties. The normal phase of the model at hand allows us to analyze a strong-coupling generalization of Mott two-current model for spintronic systems; the superconducting phase features an interesting DC spin-superconductivity without spin-symmetry breaking .

  12. Assisted large fragment insertion by Red/ET-recombination (ALFIRE)—an alternative and enhanced method for large fragment recombineering

    OpenAIRE

    Rivero-Müller, Adolfo; Lajić, Svetlana; Huhtaniemi, Ilpo

    2007-01-01

    Functional genomics require manipulation and modification of large fragments of the genome. Such manipulation has only recently become more efficient due to the discovery of different techniques based on homologous recombination. However, certain limitations of these strategies still exist since insertion of homology arms (HAs) is often based on amplification of DNA sequences with PCR. Large quantities of PCR products longer than 4–5 kb can be difficult to obtain and the risk of mutations or ...

  13. Characterization of an Sf-rhabdovirus-negative Spodoptera frugiperda cell line as an alternative host for recombinant protein production in the baculovirus-insect cell system.

    Science.gov (United States)

    Maghodia, Ajay B; Geisler, Christoph; Jarvis, Donald L

    2016-06-01

    Cell lines derived from the fall armyworm, Spodoptera frugiperda (Sf), are widely used as hosts for recombinant protein production in the baculovirus-insect cell system (BICS). However, it was recently discovered that these cell lines are contaminated with a virus, now known as Sf-rhabdovirus [1]. The detection of this adventitious agent raised a potential safety issue that could adversely impact the BICS as a commercial recombinant protein production platform. Thus, we examined the properties of Sf-RVN, an Sf-rhabdovirus-negative Sf cell line, as a potential alternative host. Nested RT-PCR assays showed Sf-RVN cells had no detectable Sf-rhabdovirus over the course of 60 passages in continuous culture. The general properties of Sf-RVN cells, including their average growth rates, diameters, morphologies, and viabilities after baculovirus infection, were virtually identical to those of Sf9 cells. Baculovirus-infected Sf-RVN and Sf9 cells produced equivalent levels of three recombinant proteins, including an intracellular prokaryotic protein and two secreted eukaryotic glycoproteins, and provided similar N-glycosylation patterns. In fact, except for the absence of Sf-rhabdovirus, the only difference between Sf-RVN and Sf9 cells was SF-RVN produced higher levels of infectious baculovirus progeny. These results show Sf-RVN cells can be used as improved, alternative hosts to circumvent the potential safety hazard associated with the use of Sf-rhabdovirus-contaminated Sf cells for recombinant protein manufacturing with the BICS.

  14. Multi-frequency proportional-resonant (MFPR) current controller for PWM VSC under unbalanced supply conditions

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This letter presents a multi-frequency proportional-resonant (MFPR) current controller developed for PWM voltage source converter (VSC) under the unbalanced supply voltage conditions. The delta operator is used in place of the shift operator for the implementation of MFPR by using a low-cost fixed-point DSP. The experimental results with an alternative control strategy validated the feasibility of the proposed MFPR current controller for the PWM VSC during voltage unbalance.

  15. Real-Time Control of Shunt Active Power Filter under Distorted Grid Voltage and Unbalanced Load Condition Using Self Tuning Filter

    OpenAIRE

    Biricik, Samet; Redif, Soydan; Ozerdem, Ozgur; Shafiuzzaman K. Khadem; Basu, Malabika

    2014-01-01

    In this paper, an alternative control method is proposed to improve the harmonic suppression efficiency of the active power filter in a distorted and an unbalanced power system to compensate for the perturbations caused by the unbalanced non-linear loads. The proposed method uses a self-tuning filter (STF) to process the grid voltage in order to provide a uniform reference voltage to obtain the correct angular position of the phase locked loop. Moreover, the required compensation currents are...

  16. 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…

  17. Multiple target implementation for a doubly fed induction generator based on direct power control under unbalanced and distorted grid voltage

    Institute of Scientific and Technical Information of China (English)

    Heng NIAN; Yi-peng SONG

    2015-01-01

    This paper presents a multiple target implementation technique for a doubly fed induction generator (DFIG) under unbalanced and distorted grid voltage based on direct power control (DPC). Based on the mathematical model of DFIG under unbalanced and distorted voltage, the proportional and integral (PI) regulator is adopted to regulate the DFIG average active and reactive powers, while the vector PI (VPI) resonant regulator is used to achieve three alternative control targets: (1) balanced and sinusoidal stator current; (2) smooth instantaneous stator active and reactive powers; (3) smooth electromagnetic torque and instantaneous stator reactive power. The major advantage of the proposed control strategy over the conventional method is that neither negative and harmonic sequence decomposition of grid voltage nor complicated control reference calculation is required. The insensitivity of the proposed control strategy to DFIG parameter deviation is analyzed. Finally, the DFIG experimental system is developed to validate the availability of the proposed DPC strategy under unbalanced and distorted grid voltage.

  18. Excitation correlation photoluminescence in the presence of Shockley-Read-Hall recombination

    International Nuclear Information System (INIS)

    Excitation correlation photoluminescence (ECPL) measurements are often analyzed in the approximation of a cross correlation of charge carrier populations generated by the two delayed pulses. In semiconductors, this approach is valid for a linear non-radiative recombination path, but not for a non-linear recombination rate as in the general Shockley-Read-Hall recombination scenario. Here, the evolution of the ECPL signal was studied for deep trap recombination following Shockley-Read-Hall statistics. Analytic solutions can be obtained for a fast minority trapping regime and steady state recombination. For the steady state case, our results show that the quadratic radiative term plays only a minor role, and that the shape of the measured signal is mostly determined by the non-linearity of the recombination itself. We find that measurements with unbalanced intense pump and probe pulses can directly provide information about the dominant non-radiative recombination mechanism. The signal traces follow the charge carrier concentrations, despite the complex origins of the signal, thus showing that ECPL can be applied to study charge carrier dynamics in semiconductors without requiring elaborate calculations. The model is compared with measurements on a reference sample with alternating layers of InGaAs/InAlAs that were additionally cross-checked with time resolved optical pump terahertz probe measurements and found to be in excellent agreement

  19. Excitation correlation photoluminescence in the presence of Shockley-Read-Hall recombination

    Energy Technology Data Exchange (ETDEWEB)

    Borgwardt, M., E-mail: mario.borgwardt@helmholtz-berlin.de [Joint Laboratory for Ultrafast Dynamics in Solutions and at Interfaces (JULiq), Institute of Methods for Material Development, Helmholtz-Zentrum Berlin, Albert-Einstein-Strasse 15, D-12489 Berlin (Germany); Sippel, P.; Eichberger, R. [Institute of Solar Fuels, Helmholtz-Zentrum Berlin, Albert-Einstein-Strasse 15, Berlin D-12489 (Germany); Semtsiv, M. P.; Masselink, W. T. [Department of Physics, Humboldt-Universität of Berlin, Newtonstrasse 15, D-12489 Berlin (Germany); Schwarzburg, K., E-mail: schwarzburg@helmholtz-berlin.de [Institute Nano-architectures for Energy Conversion, Helmholtz-Zentrum Berlin, Albert-Einstein-Strasse 15, D-12489 Berlin (Germany)

    2015-06-07

    Excitation correlation photoluminescence (ECPL) measurements are often analyzed in the approximation of a cross correlation of charge carrier populations generated by the two delayed pulses. In semiconductors, this approach is valid for a linear non-radiative recombination path, but not for a non-linear recombination rate as in the general Shockley-Read-Hall recombination scenario. Here, the evolution of the ECPL signal was studied for deep trap recombination following Shockley-Read-Hall statistics. Analytic solutions can be obtained for a fast minority trapping regime and steady state recombination. For the steady state case, our results show that the quadratic radiative term plays only a minor role, and that the shape of the measured signal is mostly determined by the non-linearity of the recombination itself. We find that measurements with unbalanced intense pump and probe pulses can directly provide information about the dominant non-radiative recombination mechanism. The signal traces follow the charge carrier concentrations, despite the complex origins of the signal, thus showing that ECPL can be applied to study charge carrier dynamics in semiconductors without requiring elaborate calculations. The model is compared with measurements on a reference sample with alternating layers of InGaAs/InAlAs that were additionally cross-checked with time resolved optical pump terahertz probe measurements and found to be in excellent agreement.

  20. Unbalanced estrogen metabolism in ovarian cancer.

    Science.gov (United States)

    Zahid, Muhammad; Beseler, Cheryl L; Hall, James B; LeVan, Tricia; Cavalieri, Ercole L; Rogan, Eleanor G

    2014-05-15

    Greater exposure to estrogens is a risk factor for ovarian cancer. To investigate the role of estrogens in ovarian cancer, a spot urine sample and a saliva sample were obtained from 33 women with ovarian cancer and 34 age-matched controls. Thirty-eight estrogen metabolites, conjugates and DNA adducts were analyzed in the urine samples using ultraperformance liquid chromatography/tandem mass spectrometry, and the ratio of adducts to metabolites and conjugates was calculated for each sample. The ratio of depurinating estrogen-DNA adducts to estrogen metabolites and conjugates was significantly higher in cases compared to controls (p < 0.0001), demonstrating high specificity and sensitivity. DNA was purified from the saliva samples and analyzed for genetic polymorphisms in the genes for two estrogen-metabolizing enzymes. Women with two low-activity alleles of catechol-O-methyltransferase plus one or two high-activity alleles of cytochrome P450 1B1 had higher levels of estrogen-DNA adducts and were more likely to have ovarian cancer. These findings indicate that estrogen metabolism is unbalanced in ovarian cancer and suggest that formation of estrogen-DNA adducts plays a critical role in the initiation of ovarian cancer. PMID:24170413

  1. Massive and massless neutrinos on unbalanced seesaws

    Institute of Scientific and Technical Information of China (English)

    XING Zhi-Zhong

    2008-01-01

    The observation of neutrino oscillations requires new physics beyond the standard model (SM).A SM-like gauge theory with p lepton families can be extended by introducing q heavy right-handed Majorana neutrinos but preserving its SU(2)L x U(1)y gauge symmetry.The overall neutrino mass matrix M turns out to be a symmetric (p+q) x (p+q) matrix.Given p>q,the rank of M is in general equal to 2q,corresponding to 2q non-zero mass eigenvalues.The existence of (p-q) massless left-handed Majorana neutrinos is an exact consequence of the model,independent of the usual approximation made in deriving the Type-I seesaw relation between the effective p x p light Majorana neutrino mass matrix M,and the q x q heavy Majorana neutrino mass matrix MR.In other words,the numbers of massive left- and right-handed neutrinos are fairly matched.A good example to illustrate this "seesaw fair play rule"is the minimal seesaw model with p = 3 and q = 2,in which one masslese neutrino sits on the unbalanced seesaw.

  2. TRANSFORMER FOR JOINING UNBALANCED TO BALANCED TRANSMISSION MEANS

    Science.gov (United States)

    Bittner, B.J.; Opperman, R.H.

    1960-06-28

    An improved transformer is invented for joining an unbalanced transmission means to a balanced transmission means and is useful, for example, in transmitting an electromagnetic signal from a coaxial cable to a balanced dipole antenna.

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

    OpenAIRE

    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 ...

  4. Approaching Long Genomic Regions and Large Recombination Rates with msParSm as an Alternative to MaCS

    Science.gov (United States)

    Montemuiño, Carlos; Espinosa, Antonio; Moure, Juan C.; Vera, Gonzalo; Hernández, Porfidio; Ramos-Onsins, Sebastián

    2016-01-01

    The msParSm application is an evolution of msPar, the parallel version of the coalescent simulation program ms, which removes the limitation for simulating long stretches of DNA sequences with large recombination rates, without compromising the accuracy of the standard coalescence. This work introduces msParSm, describes its significant performance improvements over msPar and its shared memory parallelization details, and shows how it can get better, if not similar, execution times than MaCS. Two case studies with different mutation rates were analyzed, one approximating the human average and the other approximating the Drosophila melanogaster average. Source code is available at https://github.com/cmontemuino/msparsm. PMID:27721650

  5. 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.

  6. Functional Recombinant Extra Membrane Loop of Human CD20, an Alternative of the Full Length CD20 Antigen

    OpenAIRE

    Anbouhi, Mahdi Habibi; Baraz, Aida Feiz; Bouzari, Saeid; Abolhassani, Mohsen; Khanahmad, Hossein; Golkar, Majid; Aghasadeghi, Mohammad Reza; Behdani, Mahdi; Najafabadi, Ali Jahanian; Shokrgozar, Mohammad Ali

    2012-01-01

    Background: Targeting of CD20 antigen with monoclonal antibodies has become the mainstay in the treatment of non-Hodgkin's lymphomas and immunotherapeutic depletion of malignant B cells. Accessibility of antigen is one of the crucial factors in development of monoclonal antibodies against this antigen. One major problem in expression of full length CD20 is aggregation and misfolding. Therefore, production of an alternative polypeptide is easer and favorable comparing to that of a full length ...

  7. Clinical Expression of an Inherited Unbalanced Translocation in Chromosome 6

    Directory of Open Access Journals (Sweden)

    Bani Bandana Ganguly

    2011-01-01

    Full Text Available Unbalanced chromosomal rearrangements are not common; however, they have a significant clinical expression. The parental balanced translocation produces unbalanced chromosome, which is transmitted to next generation through fertilization of gametes carrying the derivative chromosome. The carriers of balanced rearrangements mostly do not have recognizable phenotypic expression. We report a family comprising of healthy and non-consanguineous young parents and their preemie newborn severely affected with congenital anomalies and systemic disorders. Conventional Gbanding analysis of somatic chromosomes identified a balanced translocation, t(6;10(p23;q24, in mother and an unbalanced rearrangement, der(6t(6:10(p23;q24mat, in the child. The child has inherited a derivative chromosome 6 with partial deletion of 6(p23-pter and partial trisomy 10(q24-qter, which has resulted in fusion of genes of two different chromosomes. The prominent phenotypic features of del(6p, including high forehead, flat nasal bridge, agenesis of left ear, atrial septal defect (ASD, craniosynostosis, and growth retardation, are overlapping with specific Axenfeld-Reiger-, Larsen-, and Ritscher-Sinzel/3-C syndromes, however, lacking in ocular anomalies, skeletal laxity, or cerebellar malformation. Therefore, this paper rules out the isolated effect of del(6p23 or trisomy 10(q24 on distinct previously reported syndromes and proposes the combined effect of unbalanced chromosomal alteration.

  8. 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 abnorma

  9. An Alternative Method to Facilitate cDNA Cloning for Expression Studies in Mammalian Cells by Introducing Positive Blue White Selection in Vaccinia Topoisomerase I-Mediated Recombination.

    Directory of Open Access Journals (Sweden)

    Hiroshi Udo

    Full Text Available One of the most basic techniques in biomedical research is cDNA cloning for expression studies in mammalian cells. Vaccinia topoisomerase I-mediated cloning (TOPO cloning by Invitrogen allows fast and efficient recombination of PCR-amplified DNAs. Among TOPO vectors, a pcDNA3.1 directional cloning vector is particularly convenient, since it can be used for expression analysis immediately after cloning. However, I found that the cloning efficiency was reduced when RT-PCR products were used as inserts (about one-quarter. Since TOPO vectors accept any PCR products, contaminating fragments in the insert DNA create negative clones. Therefore, I designed a new mammalian expression vector enabling positive blue white selection in Vaccinia topoisomerase I-mediated cloning. The method utilized a short nontoxic LacZα peptide as a linker for GFP fusion. When cDNAs were properly inserted into the vector, minimal expression of the fusion proteins in E. coli (harboring lacZΔM15 resulted in formation of blue colonies on X-gal plates. This method improved both cloning efficiency (75% and directional cloning (99% by distinguishing some of the negative clones having non-cording sequences, since these inserts often disturbed translation of lacZα. Recombinant plasmids were directly applied to expression studies using GFP as a reporter. Utilization of the P2A peptide allowed for separate expression of GFP. In addition, the preparation of Vaccinia topoisomerase I-linked vectors was streamlined, which consisted of successive enzymatic reactions with a single precipitation step, completing in 3 hr. The arrangement of unique restriction sites enabled further modification of vector components for specific applications. This system provides an alternative method for cDNA cloning and expression in mammalian cells.

  10. Practical Method for Transient Stability with Unbalanced Condition based on Symmetric Coordinates

    Science.gov (United States)

    Fujiwara, Shuhei; Kono, Yoshiyuki; Kitayama, Masashi; Goda, Tadahiro

    The symmetric coordinates are very popular method to model unbalanced faults in power system analysis. It is not only easy to handle with a single fault, but also it can be extended to multiple faults. But it is not easy to model situations that those unbalanced situation will continuously change, like a SVC (Static Var Compensator) with unbalanced fault in power system or an unbalanced nonlinear load. Under these situations, we propose a practical use of multiple fault calculation method based on symmetric coordinates that can handle with these kinds of unbalanced situations.

  11. 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.

  12. Unbalanced Load Simulation of Electronic Power Transformer in Distribution System

    Institute of Scientific and Technical Information of China (English)

    Wang Dan; Mao Chengxiong; Lu Jiming; Fan Shu; Cao Jiewei; Wang Ben

    2006-01-01

    A control scheme of electronic power transformer (EPT) in a three-phase four-wire distribution system, which included an input section, an isolating section and an output section, was researched under unbalanced loads. The simple and appropriate control scheme was developed through analyzing the system requirements of the primary side and the load requirements of the secondary side. In the input section, a dual-loop control in synchronous rotating d-q coordinates was introduced, and in the output section, a dual-loop control based on instantaneous output voltage wasused. Load characteristics of EPT were investigated by using Matlab/Simulink software. Simulation results showed that, with the proposed control scheme, the EPT has good performances and the sinusoidal input current and constant output voltage can be realized under both balanced and unbalanced loads.

  13. Voltage Support Provided by STATCOM in Unbalanced Power Systems

    Directory of Open Access Journals (Sweden)

    Ana Rodríguez

    2014-02-01

    Full Text Available The presence of an unbalanced voltage at the point of common coupling (PCC results in the appearance of a negative sequence current component that deteriorates the control performance. Static synchronous compensators (STATCOMs are well-known to be a power application capable of carrying out the regulation of the PCC voltage in distribution lines that can suffer from grid disturbances. This article proposes a novel PCC voltage controller in synchronous reference frame to compensate an unbalanced PCC voltage by means of a STATCOM, allowing an independent control of both positive and negative voltage sequences. Several works have been proposed in this line but they were not able to compensate an unbalance in the PCC voltage. Furthermore, this controller includes aspects as antiwindup and droop control to improve the control system performance.

  14. Control of DFIG-WT under unbalanced grid voltage conditions

    OpenAIRE

    Luna Alloza, Álvaro; Rodríguez Cortés, Pedro; Lima, Kleber; Córcoles López, Felipe; Edson H. Watanabe; Teodorescu, R.

    2009-01-01

    The voltage oriented control in the synchronous reference frame (VOC-SRF) have been extensively used for controlling wind turbines based on doubly fed induction generators (DFIG-WTs) through the rotor side converter of a back to back power processor. Although its performance is fast and accurate under balanced conditions its behaviour is not good enough when the voltage of the mains is unbalanced, unless an independent control for the positive and the negative sequence...

  15. Enhanced control of DFIG-used back-to-back PWM VSC under unbalanced grid voltage conditions

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This paper presents a unified positive- and negative-sequence dual-dq dynamic model of wind-turbine driven doublyfed induction generator (DFIG) under unbalanced grid voltage conditions. Strategies for enhanced control and operation of a DFIG-used back-to-back (BTB) PWM voltage source converter (VSC) are proposed. The modified control design for the grid-side converter in the stationary αβ frames diminishes the amplitude of DC-link voltage ripples of twice the grid frequency, and the two proposed control targets for the rotor-side converter are alternatively achieved, which, as a result, improve the fault-ride through (FRT) capability of the DFIG based wind power generation systems during unbalanced network supply. A complete unbalanced control scheme with both grid- and rotor-side converters included is designed. Finally, simulation was carried out on a 1.5 MW wind-turbine driven DFIG system and the validity of the developed unified model and the feasibility of the proposed control strategies are all confirmed by the simulated results.

  16. Unbalanced Magnetic Force Calculation in Brushless DC Motors

    Directory of Open Access Journals (Sweden)

    Z. Valipoor

    2015-03-01

    Full Text Available In this paper, an analytical method to calculate the unbalance magnetic pull forces (UMP due to the eccentricity of the rotor with considering the slots impact, is presented. Unbalanced magnetic pull is important because it affects the wear on the bearings as well as noise and vibration. The results of the analytical method, using finite element analysis for a prototype motor, were valid. Some force harmonics have the potential to produce noise and vibration. In order to detect harmonics of unbalance magnet forces, Depending on the fault frequency, the stator currents and spectrum of the vibrations have been analyzed

  17. Design and Implementation of Three Phase Unbalanced Voltage Motor Controller

    Directory of Open Access Journals (Sweden)

    M. A. A. Mashud

    2013-09-01

    Full Text Available A state-of-the-art-technology was used to design the unbalanced three phase motor controller. The fluctuation of line voltage has been questioned in recent times due to the use of heavy powered machine with three phases. This paper is focused on deriving a control scheme to drive a three phase motor that could be used in industry or households. The very simple circuitry has been employed in this design. To do this, extensive MATLAB analysis and PSpice software was conducted in order to optimize the control system and finally the results are practically verified.

  18. Successive projection method for solving the unbalanced Procrustes problem

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhenyue; DU Keqin

    2006-01-01

    We present a successive projection method for solving the unbalanced Procrustes problem: given matrix A ∈ Rn×n and B ∈ Rn×κ, n >κ, minimize the residual ‖AQ - B‖F with the orthonormal constraint QTQ = Iκ on the variant Q ∈ Rn×κ. The presented algorithm consists of solving k least squares problems with quadratic constraints and an expanded balance problem at each sweep. We give a detailed convergence analysis. Numerical experiments reported in this paper show that our new algorithm is superior to other existing methods.

  19. 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...

  20. Lithium-Ion Batteries: Thermal Behaviour Investigation of Unbalanced Modules

    Directory of Open Access Journals (Sweden)

    Odile Capron

    2015-06-01

    Full Text Available In this paper, the thermal behaviour of an unbalanced battery module made of large lithium iron phosphate cylindrical cells of 18 Ah nominal capacity is investigated during its discharge with 18 A, 54 A and 90 A currents. For this study, several cells were assigned in the module to 5%, 10% and 20% initial depth of discharge (DoD. The thermal management of the cells in the module is achieved based on a forced air cooling. The computations of the temperature distribution inside the cells and the module are performed with a two-dimensional modelling approach. During the discharges, the cells with a non-zero initial DoD show a more pronounced temperature increase up to 5% compared to the reference cells. In the end of the three discharges, the highest temperatures 26.5 °C (18 A, 29.6 °C  (54 A and 32.3 °C  (90 A, respectively, are reached for the cells with the highest initial DoD. For these cells, with the increase in the current rate, the highest amount of total heat exceeds 25 W. The reactive and the active heats are found to be the main contributors to the total heat generated by the cells. This study provides the effect of the initial DoD of the cells on the temperature development occurring in an unbalanced battery module during its discharge.

  1. Rank-Based Analysis of Unbalanced Repeated Measures Data

    Directory of Open Access Journals (Sweden)

    M. Mushfiqur Rashid

    2012-07-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";} In this article, we have developed a rank (intra-subject based analysis of clinical trials with unbalanced repeated measures data. We assume that the errors within each patient are exchangeable and continuous random variables. This rank-based inference is valid when the unbalanced data are missing either completely at random or by design. A drop in dispersion test is developed for general linear hypotheses. A numerical example is given to illustrate the procedure.

  2. Accurate parameter estimation for unbalanced three-phase system.

    Science.gov (United States)

    Chen, Yuan; So, Hing Cheung

    2014-01-01

    Smart grid is an intelligent power generation and control console in modern electricity networks, where the unbalanced three-phase power system is the commonly used model. Here, parameter estimation for this system is addressed. After converting the three-phase waveforms into a pair of orthogonal signals via the α β-transformation, the nonlinear least squares (NLS) estimator is developed for accurately finding the frequency, phase, and voltage parameters. The estimator is realized by the Newton-Raphson scheme, whose global convergence is studied in this paper. Computer simulations show that the mean square error performance of NLS method can attain the Cramér-Rao lower bound. Moreover, our proposal provides more accurate frequency estimation when compared with the complex least mean square (CLMS) and augmented CLMS.

  3. Classification approach based on association rules mining for unbalanced data

    CERN Document Server

    Ndour, Cheikh

    2012-01-01

    This paper deals with the supervised classification when the response variable is binary and its class distribution is unbalanced. In such situation, it is not possible to build a powerful classifier by using standard methods such as logistic regression, classification tree, discriminant analysis, etc. To overcome this short-coming of these methods that provide classifiers with low sensibility, we tackled the classification problem here through an approach based on the association rules learning because this approach has the advantage of allowing the identification of the patterns that are well correlated with the target class. Association rules learning is a well known method in the area of data-mining. It is used when dealing with large database for unsupervised discovery of local patterns that expresses hidden relationships between variables. In considering association rules from a supervised learning point of view, a relevant set of weak classifiers is obtained from which one derives a classification rule...

  4. A method for unbalanced transportation problems in fuzzy environment

    Indian Academy of Sciences (India)

    Deepika Rani; T R Gulati; Amit Kumar

    2014-06-01

    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 availability is not transported at all and is held back at one or more origins. The method proposed in this paper gives the additional information that to which of the destination(s) the excess availability be transported for future demand at minimum cost. The advantage of the proposed method over the existing method is that the fuzzy optimal solution obtained does not involve the dummy destination. The method has been illustrated with the help of an example.

  5. Unbalanced-Mode Spiral Antenna Backed by an Extremely Shallow Cavity

    OpenAIRE

    Nakano, Hisamatsu; Igarashi, Tatsuya; Oyanagi, Hiroshi; Iitsuka, Yasushi; Yamauchi, Junji

    2009-01-01

    This paper describes a two-arm Archimedean spiral antenna backed by a conducting cavity, where only one arm is directly excited, with the other arm being parasitically excited; in other words, the spiral arms are excited in an unbalanced mode. A balun circuit required for a conventional two-arm spiral is not used for this unbalanced-mode spiral. The design of the unbalanced-mode spiral is performed over a frequency range of fLd = 3 GHz to fHd = 9 GHz (1:3 bandwidth), where the antenna height ...

  6. 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

    . The voltage problems dealt with in this paper are to show how to mitigate unbalanced voltage sags and voltage unbalance in the CIGRE Low Voltage (LV) test network and net-works like this. The voltage unbalances, for the tested cases in the CIGRE LV test network are mainly due to single phase loads and due...... 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....

  7. An Alternative Method to Facilitate cDNA Cloning for Expression Studies in Mammalian Cells by Introducing Positive Blue White Selection in Vaccinia Topoisomerase I-Mediated Recombination

    OpenAIRE

    Udo, Hiroshi

    2015-01-01

    One of the most basic techniques in biomedical research is cDNA cloning for expression studies in mammalian cells. Vaccinia topoisomerase I-mediated cloning (TOPO cloning by Invitrogen) allows fast and efficient recombination of PCR-amplified DNAs. Among TOPO vectors, a pcDNA3.1 directional cloning vector is particularly convenient, since it can be used for expression analysis immediately after cloning. However, I found that the cloning efficiency was reduced when RT-PCR products were used as...

  8. 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.

  9. Recombination instability

    DEFF Research Database (Denmark)

    D'Angelo, N.

    1967-01-01

    A recombination instability is considered which may arise in a plasma if the temperature dependence of the volume recombination coefficient, alpha, is sufficiently strong. Two cases are analyzed: (a) a steady-state plasma produced in a neutral gas by X-rays or high energy electrons; and (b...

  10. Power Controllability of Three-phase Converter with Unbalanced AC Source

    DEFF Research Database (Denmark)

    Ma, Ke; Chen, Wenjie; Liserre, Marco;

    2015-01-01

    Three-phase DC-AC power converters suffer from power oscillation and overcurrent problems in case of unbalanced AC source voltage that can be caused by grid/generator faults. Existing solutions to handle these problems are properly selecting and controlling the positive and negative sequence...... converter can enable more flexible control targets, achieving better performances in the delivered power and load current when suffering from unbalanced AC voltage....

  11. Power Controllability of Three-phase Converter with Unbalanced AC Source

    DEFF Research Database (Denmark)

    Ma, Ke; Liserre, Marco; Blaabjerg, Frede

    2013-01-01

    Three-phase DC-AC power converters suffer from power oscillation and overcurrentt problems in case of unbalanced AC source voltage that can be caused by grid/generator faults. Existing solutions to handle these problems are properly selecting and controlling the positive and negative sequence...... converter can enable more flexible control targets, achieving better performances in the delivered power and load current when suffering from unbalanced AC sources....

  12. Integral Sliding Mode Control Strategy of D-STATCOM for Unbalanced Load Compensation under Various Disturbances

    OpenAIRE

    Mingchao Xia; Yanhui Mao

    2013-01-01

    Control strategies of D-STATCOM for unbalanced load compensation under internal and external disturbances were discussed. Linear control strategies do not have a satisfactory dynamic performance and become invalid under internal or external disturbances. To guarantee a good precision and robustness, a control strategy combining input-output feedback linearization technique with integral sliding mode control (ISMC) method was applied to D-STATCOM for unbalanced load compensation. The strategy ...

  13. Control strategies based on effective power factor for distributed generation power plants during unbalanced grid voltage

    OpenAIRE

    Camacho Santiago, Antonio; Castilla Fernández, Miguel; Miret Tomàs, Jaume; Matas Alcalá, José; Guzmán Solà, Ramon; de Sousa Pérez, Óscar; Martí Colom, Pau; García de Vicuña Muñoz de la Nava, José Luis

    2013-01-01

    Unbalanced voltages in three-phase power systems is a common perturbation propagated along the grid. Distributed Generation plants have gained widespread attention due to their capability to improve power quality in a distributed manner, including voltage unbalance mitigation. A conventional control strategy to command power plants during balanced grid voltages, is the use of power factor to inject/absorb reactive power depending on grid conditions. Advanced control strategies during unbalanc...

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

    Science.gov (United States)

    Wang, Zhaocai; Pu, Jun; Cao, Liling; Tan, Jian

    2015-10-23

    The unbalanced assignment problem (UAP) is to optimally resolve the problem of assigning n jobs to m individuals (m 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.

  15. Modeling and Verification of Distributed Generation and Voltage Regulation Equipment for Unbalanced Distribution Power Systems; Annual Subcontract Report, June 2007

    Energy Technology Data Exchange (ETDEWEB)

    Davis, M. W.; Broadwater, R.; Hambrick, J.

    2007-07-01

    This report summarizes the development of models for distributed generation and distribution circuit voltage regulation equipment for unbalanced power systems and their verification through actual field measurements.

  16. Load mitigation of unbalanced wind turbines using PI-R individual pitch control

    DEFF Research Database (Denmark)

    Zhang, Yunqian; Cheng, Ming; Chen, Zhe

    2015-01-01

    unbalance will cause extra loads and fatigue on the wind turbine rotor, which has not been taken into consideration by the traditional IPC method. This study presents a new control strategy to mitigate the loads of the unbalance wind turbines. An IPC scheme consisting of a proportional-integral (PI......) controller and two resonant (R) compensators is presented. The PI-R regulator is implemented in the hub reference frame to reduce both the balanced and unbalanced loads of the turbine. The wind turbine code FAST (fatigue, aerodynamics, structures and turbulence) is used for the wind turbine load modelling......This study discusses the load mitigation of unbalanced wind turbines, including balanced and unbalanced loads. Regarding the wind turbine load reduction, it has been shown that individual pitch control (IPC) is more promising in comparison with collective pitch control. However, wind turbine...

  17. Unbalanced and Minimal Point Equivalent Estimation Second-Order Split-Plot Designs

    Science.gov (United States)

    Parker, Peter A.; Kowalski, Scott M.; Vining, G. Geoffrey

    2007-01-01

    Restricting the randomization of hard-to-change factors in industrial experiments is often performed by employing a split-plot design structure. From an economic perspective, these designs minimize the experimental cost by reducing the number of resets of the hard-to- change factors. In this paper, unbalanced designs are considered for cases where the subplots are relatively expensive and the experimental apparatus accommodates an unequal number of runs per whole-plot. We provide construction methods for unbalanced second-order split- plot designs that possess the equivalence estimation optimality property, providing best linear unbiased estimates of the parameters; independent of the variance components. Unbalanced versions of the central composite and Box-Behnken designs are developed. For cases where the subplot cost approaches the whole-plot cost, minimal point designs are proposed and illustrated with a split-plot Notz design.

  18. 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...

  19. 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...... of these parameters to account for sudden load changes. The proposed study deals with unbalanced systems which is the typical case of small distribution systems and shows how the power losses term varies as the regulators parameters vary as well, thus showing that these are sensitive parameters that could have...... an important role in optimal management of such systems....

  20. Enhanced Decoupled Double Synchronous Reference Frame Current Controller for Unbalanced Grid-Voltage Conditions

    DEFF Research Database (Denmark)

    Reyes, M.; Rodriguez, Pedro; Vazquez, S.;

    2012-01-01

    . In these codes, the injection of positive- and negative-sequence current components becomes necessary for fulfilling, among others, the low-voltage ride-through requirements during balanced and unbalanced grid faults. However, the performance of classical dq current controllers, applied to power converters......, under unbalanced grid-voltage conditions is highly deficient, due to the unavoidable appearance of current oscillations. This paper analyzes the performance of the double synchronous reference frame controller and improves its structure by adding a decoupling network for estimating and compensating...

  1. Unbalanced Impedance of the Aperture Coils of Some LHC Main Dipole Magnets

    NARCIS (Netherlands)

    Ravaioli, E.; Verweij, A.P.; Kate, ten H.H.J.

    2013-01-01

    During the Large Hadron Collider operation in 2010 and 2011, it was observed that about 50% of the main dipole magnets exhibiting two apertures showed unbalanced dynamic-impedance behavior not well understood. When a main dipole circuit is switched off, voltage waves with a frequency of 28 Hz travel

  2. Characterization of human PGD blastocysts with unbalanced chromosomal translocations and human embryonic stem cell line derivation?

    Science.gov (United States)

    Frydman, N; Féraud, O; Bas, C; Amit, M; Frydman, R; Bennaceur-Griscelli, A; Tachdjian, G

    2009-01-01

    Novel embryonic stem cell lines derived from embryos carrying structural chromosomal abnormalities obtained after preimplantation genetic diagnosis (PGD) are of interest to study in terms of the influence of abnormalities on further development. A total of 22 unbalanced blastocysts obtained after PGD were analysed for structural chromosomal defects. Morphological description and chromosomal status of these blastocysts was established and they were used to derive human embryonic stem cell (ESC) lines. An outgrowth of cells was observed for six blastocysts (6/22; 27%). For two blastocysts, the exact morphology was unknown since they were at early stage, and for four blastocysts, the inner cell mass was clearly visible. Fifteen blastocysts carried an unbalanced chromosomal defect linked to a reciprocal translocation, resulting in a positive outgrowth of cells for five blastocysts. One human ESC line was obtained from a blastocyst carrying a partial chromosome-21 monosomy and a partial chromosome-1 trisomy. Six blastocysts carried an unbalanced chromosomal defect linked to a Robertsonian translocation, and one showed a positive outgrowth of cells. One blastocyst carried an unbalanced chromosomal defect linked to an insertion and no outgrowth was observed. The efficiency of deriving human ESC lines with constitutional chromosomal disorders was low and probably depends on the initial morphological aspect of the blastocysts and/or the type of the chromosomal disorders.

  3. 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...

  4. Revised sequence components power system models for unbalanced power system studies

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-Akher, M. [Tunku Abdul Rahman Univ., Kuala Lumpur (Malaysia); Nor, K.-M. [Univ. of Technology Malaysia, Johor (Malaysia); Rashid, A.H.A. [Univ. of Malaya, Kuala Lumpur (Malaysia)

    2007-07-01

    The principle method of analysis using positive, negative, and zero-sequence networks has been used to examine the balanced power system under both balanced and unbalanced loading conditions. The significant advantage of the sequence networks is that the sequence networks become entirely uncoupled in the case of balanced three-phase power systems. The uncoupled sequence networks then can be solved in independent way such as in fault calculation programs. However, the hypothesis of balanced power systems cannot be considered in many cases due to untransposed transmission lines; multiphase line segments in a distribution power system; or transformer phase shifts which cannot be incorporated in the existing models. A revised sequence decoupled power system models for analyzing unbalanced power systems based on symmetrical networks was presented in this paper. These models included synchronous machines, transformers, transmission lines, and voltage regulators. The models were derived from their counterpart's models in phase coordinates frame of reference. In these models, the three sequence networks were fully decoupled with a three-phase coordinates features such as transformer phase shifts and transmission line coupling. The proposed models were used to develop an unbalanced power-flow program for analyzing both balanced and unbalanced networks. The power flow solution was identical to results obtained from a full phase coordinate three-phase power-flow program. 11 refs., 3 tabs.

  5. Control strategy for permanent magnet synchronous motor with contra-rotating rotors under unbalanced loads condition

    DEFF Research Database (Denmark)

    Cheng, Shuangyin; Luo, Derong; Huang, Shoudao;

    2015-01-01

    is developed and the instability of the system with unbalanced loads is analysed. Based on the analysis, a control strategy which can keep synchronism of the two rotors under varying load is implemented. In addition, a method for starting the motor reliably is proposed, which is applicable to ship or under...

  6. Unbalanced 2 x 2 factorial designs and the interaction effect : A troublesome combination

    NARCIS (Netherlands)

    Landsheer, Johannes A.; Van Wittenboer, Godfried Den

    2015-01-01

    In this power study, ANOVAs of unbalanced and balanced 2 x 2 datasets are compared (N = 120). Datasets are created under the assumption that H1 of the effects is true. The effects are constructed in two ways, assuming: 1. contributions to the effects solely in the treatment groups; 2. contrasting co

  7. Prenatal Diagnosis of Rare Familial Unbalanced Translocation of Chromosomes 7 and 12

    Directory of Open Access Journals (Sweden)

    Berrin Tezcan

    2015-01-01

    Full Text Available Case Details. We report rare familial unbalanced translocation of chromosomes 7 and 12, which was diagnosed prenatally at 20+3 weeks of gestation. Woman’s partner had been tested in the past and was found to be a carrier of a balanced translocation; his karyotype showed a balanced reciprocal translocation of 46, XY, t(7;12(q34;q24,32. Partner’s brother had an unbalanced form of the translocation with severe learning disability. The diagnosis of the anomaly was based on two- and three-dimensional ultrasound and microarray analysis. Ultrasonography findings included fetal microcephaly and alobar holoprosencephaly, dysmorphic face (flat occiput, absent nasal bone, microphthalmia, hypotelorism, and single nostril, and hyperechogenic bowel. Genome-wide array analysis and cytogenetic results from the amniotic fluid showed unbalanced translocation in chromosomes 7 and 12 with deletion of an approximately 16.5 Mb and a duplication of 6.1 Mb, respectively, Arr 7q34q36.3(142,668,576-159,161,648x1,12q24.32q24.33(127,708,720-133,777,560x3, karyotype (der (7 t(7;12 (q34;q24pat. This unbalanced translocation was due to the segregation of the father’s balanced translocation. In this particular case, the recurrence of an unbalanced translocation in the subsequent pregnancies is estimated to be 20%. Understanding the individuals’ phenotype in association with the gain and loss of copy number is important and can further provide us with information on that particular region of the named chromosomes.

  8. Telomere recombination and alternative telomere lengthening mechanisms

    NARCIS (Netherlands)

    Draskovic, I.; Londono Vallejo, A.

    2013-01-01

    Telomeres are nucleoprotein structures at the ends of linear chromosomes that protect them from being recognized as DNA double stranded breaks. Telomeres shorten with every cell division and in the absence of the checkpoint mechanisms critical telomere shortening leads to chromosome end fusions and

  9. 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.

  10. 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. PMID:18164773

  11. Predictions of Unbalanced Response of Turbo Compressor Equipped with Active Magnetic Bearings through System Identification

    Energy Technology Data Exchange (ETDEWEB)

    Baek, SeongKi; NOh, Myounggyu; Park, Young Woo [Chungnam National Univ., Daejeon (Korea, Republic of); Lee, Kiwook; Lee, Nam Soo; Jeog, Jinhee [LG Electronics, Gumi (Korea, Republic of)

    2016-01-15

    Since vibrations in rotating machinery is a direct cause of performance degradation and failures, it is very important to predict the level of vibrations as well as have a method to lower the vibrations to an acceptable level. However, the changes in balancing during installation and the vibrational modes of the support structure are difficult to predict. This paper presents a method for predicting the unbalanced response of a turbo-compressor supported by active magnetic bearings (AMBs). Transfer functions of the rotor are obtained through system identification using AMBs. These transfer functions contain not only the dynamics of the rotor but also the vibrational modes of the support structure. Using these transfer functions, the unbalanced response is calculated and compared with the run-up data obtained from a compressor prototype. The predictions revealed the effects of the support structure, validating the efficacy of the method.

  12. 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

    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......, 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...

  13. Dynamics of Flexible Rotor Systems with an Interim Mass Unbalanced Disk Using a Spectral Element Model

    Directory of Open Access Journals (Sweden)

    Sangkyu Choi

    2014-01-01

    Full Text Available A frequency domain spectral element model is developed for a rotor system that consists of two spinning shafts and an interim disk or blade system. In this study, the shafts are represented by spinning Timoshenko beam models, and the interim disk system is represented by a uniform thick rigid disk with an unbalanced mass. In our derivation of the governing equations of motion of the disk system, the disk is considered to be wobbling about the geometric center of the disk at which the spinning shafts are attached. The high accuracy of the proposed spectral element model is evaluated by comparison with the natural frequencies obtained using the conventional finite element method (FEM. The spectral element model is then used to investigate the effects of the unbalanced mass on the natural frequencies and dynamic responses of an example rotor system.

  14. A SMALL UNBALANCED MAGNETRON SPUTTERING SOURCE WITH MULTIPOLE MAGNETIC FIELD ANODE

    Institute of Scientific and Technical Information of China (English)

    郑思孝; 孙官清; 等

    1994-01-01

    A small unbalanced magnetron atom source with multipole cusp magnetic field anode is described.The co-axial magnetron rpinciple is extended to the circular planar magnetron atom source,which raises the efficiency of sputtering target area up to 60%.The multipole magnetic field is put in the anode.which makes the unbalanced magnetron atom source run in a higher discharge current at a lower arc voltage condition.Meanwhile.the sputtering atoms through out the anode can be ionized partially,because the electron reaching the anode have to suffer multiple collisons in order to advance across the multipole magnetic field lines in the anode,which enhances the chemical reactivity of the ejecting atoms in film growth and improve the property of film depositing.

  15. Nonlinear dynamic analysis of an unbalanced rotor supported by roller bearing

    International Nuclear Information System (INIS)

    In this paper, the non-linear dynamic analysis of an unbalanced rotor supported by roller bearings has been made. The non-linearity in the rotor bearing system is due to Hertzian contact, unbalanced rotor effect and radial internal clearance. The system can excite bi-periodically by the varying compliance frequency and the rotational frequency. The results show the appearance of instability and chaos in the dynamic response as the speed of the rotor-bearing system is changed. Period doubling and mechanism of intermittency have been observed that lead to chaos. Poincare maps, phase plots, time displacement responses and FFT are used to elucidate and illustrate the diversity of the system behavior

  16. Adaptive Neuro-Fuzzy Controller Experimental Design for DC Motor Connected to Unbalanced Load

    Directory of Open Access Journals (Sweden)

    Reza Nejati

    2007-09-01

    Full Text Available In two recent decades, fuzzy controllers have been used in controlling different systems successfully. In this article, a new method is given for controlling of permanent magnetic DC motor connected to unbalanced load. Imbalance of load leads to machine vibrations, fluctuation of power, making exhaustion in machine shaft, and equipment depreciation. In this article neuro-fuzzy controllers are used for controlling unbalanced load. Because of non-linear nature of load and machine, machine fluctuations are different in various speeds. For making controller adaptive with machine, using an artificial neural network, the input-output coefficients are be updated in any speed. Optimized coefficients obtained by using of direct search method, and with these coefficients, artificial neural network trained with Lauvenberg-Marcoardet method. Operational results obtained from developed system, shows the efficiency of given method.

  17. Integral Sliding Mode Control Strategy of D-STATCOM for Unbalanced Load Compensation under Various Disturbances

    Directory of Open Access Journals (Sweden)

    Mingchao Xia

    2013-01-01

    Full Text Available Control strategies of D-STATCOM for unbalanced load compensation under internal and external disturbances were discussed. Linear control strategies do not have a satisfactory dynamic performance and become invalid under internal or external disturbances. To guarantee a good precision and robustness, a control strategy combining input-output feedback linearization technique with integral sliding mode control (ISMC method was applied to D-STATCOM for unbalanced load compensation. The strategy has features of simple structure and is easy to implement. A 10 MVar/10 kV D-STATCOM simulation system was built in PSCAD/EMTDC to verify the effectiveness and robustness of the control strategy proposed. Simulation results show that the control strategy can compensate reactive power and eliminate unbalance simultaneously under various disturbances.

  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. 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

    Renewable energy sources require accurate and appropriate performance not only under normal grid operation but also under abnormal and faulty grid conditions according to the modern grid codes. This paper proposes a novel phase-locked loop algorithm (MSHDC-PLL), which can enable the fast...... 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...... out the oscillation of the positive sequence voltage vector, produced by the existence of unbalanced and harmonic distorted voltage. The fast and accurate response of the proposed PLL under abnormal grid conditions is very important for the appropriate synchronization and control of the interconnected...

  20. A unified approach for processing unbalanced conditions in transient stability calculations

    OpenAIRE

    Ni, Y; Bai, X.; Jiang, T.; Guo, Z.; Yan, Z.

    2006-01-01

    A unified approach has been proposed in the paper for processing unbalanced operating conditions in transient stability calculations. The suggested method combined advantages of both abc phase coordinates and 012 sequence coordinates. The former is used to describe faults since it is suitable to modeling simultaneous faults and the latter is used for time simulation for its sparse nature. Novel fault description and coordinate conversion formulation is presented. The equivalent positive seque...

  1. Power flow solution for multiphase unbalanced distribution networks with high penetration of photovoltaics

    OpenAIRE

    Hooshyar, Hossein; Vanfretti, Luigi

    2013-01-01

    Power flow analysis on a Photovoltaic System (PV)dominated distribution network is rather different than a conventional distribution system. This paper proposes a new three-phase power flow solution for such networks that considers the multiphase unbalanced nature of distribution systems together with different system topologies. Power flow contributions of PVs and different types of loads are also considered. The performance of the proposed method has been assessed by simulations on a sample...

  2. Predicting protein-protein interactions in unbalanced data using the primary structure of proteins

    Directory of Open Access Journals (Sweden)

    Chou Lih-Ching

    2010-04-01

    Full Text Available Abstract Background Elucidating protein-protein interactions (PPIs is essential to constructing protein interaction networks and facilitating our understanding of the general principles of biological systems. Previous studies have revealed that interacting protein pairs can be predicted by their primary structure. Most of these approaches have achieved satisfactory performance on datasets comprising equal number of interacting and non-interacting protein pairs. However, this ratio is highly unbalanced in nature, and these techniques have not been comprehensively evaluated with respect to the effect of the large number of non-interacting pairs in realistic datasets. Moreover, since highly unbalanced distributions usually lead to large datasets, more efficient predictors are desired when handling such challenging tasks. Results This study presents a method for PPI prediction based only on sequence information, which contributes in three aspects. First, we propose a probability-based mechanism for transforming protein sequences into feature vectors. Second, the proposed predictor is designed with an efficient classification algorithm, where the efficiency is essential for handling highly unbalanced datasets. Third, the proposed PPI predictor is assessed with several unbalanced datasets with different positive-to-negative ratios (from 1:1 to 1:15. This analysis provides solid evidence that the degree of dataset imbalance is important to PPI predictors. Conclusions Dealing with data imbalance is a key issue in PPI prediction since there are far fewer interacting protein pairs than non-interacting ones. This article provides a comprehensive study on this issue and develops a practical tool that achieves both good prediction performance and efficiency using only protein sequence information.

  3. Synchronization and Stability of Two Unbalanced Rotors with Fast Antirotation considering Energy Balance

    OpenAIRE

    Yongjun Hou; Pan Fang

    2015-01-01

    We consider synchronization and stability of two unbalanced rotors reversely and fast excited by induction motors fixed on an oscillating body. We explore the energy balance of the system and show how the energy is transferred between the rotors via the oscillating body allowing the implementation of the synchronization of the two rotors. An approximate analytical analysis, energy balance method, allows deriving the synchronization condition, and the stability criterion of the synchronization...

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

    OpenAIRE

    Lee, Chaeyoung

    2012-01-01

    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, wi...

  5. Mixed-signal power system emulator extension to solve unbalanced fault transient stability analysis

    OpenAIRE

    Lanz, Guillaume; Kyriakidis, Theodoras; Cherkaoui, Rachid; Kayal, Maher

    2014-01-01

    This paper presents the extension of a platform originally devoted to symmetrical transient stability analysis, into the domain of unbalanced faults. The aim of this solver is to increase the speed of dynamic stability assessment for power systems. It is based on an analog representation of the grid alongside dedicated digital resources for the simulation of the models of power network components. Using the symmetrical components theory, this platform can be adapted to handle unsymmetrical di...

  6. Speed Control of Induction Machine Based on Matrix Converter with Unbalanced Input Voltage

    OpenAIRE

    Malek Mohammadrezaei; Gholam Reza Arab; Arash Daghighi; Jafar Soltani

    2011-01-01

    Matrix Converter (MC) is a direct energy conversion device with high input power factor. As a device without dc link elements, its output characteristic and reliability can be degraded by ac line side disturbances. This has attracted many researchers to make efforts to solve this problem. In this paper, under unbalanced input voltage conditions, behaviors of the MC controlled with Venturini method are analyzed. The output voltage is estimated and a PI controller compensation method to prevent...

  7. A novel control strategy for load converter of DC isolated distribution system under unbalanced loading conditions

    Institute of Scientific and Technical Information of China (English)

    R. NOROOZIAN; M. ABEDI; G.B. GHAREHPETIAN; S. H. HOSSEINI

    2009-01-01

    A novel control strategy for the load converter supplying the unbalanced AC load in a DC isolated distribution system is presented. The control algorithm results in balanced and sinusoidal load voltages under unbalanced AC loading. The unbalanced load is characterized in the d-q-0 rotating coordinate based on symmetrical sequence components. Also, the mathematical model of the load converter in both a-b-c and d-q-0 coordinates is derived by using the average large signal model. Then, two control strategies for the load converter are presented. The first one uses the conventional d-q-0 controller to ensure the voltage and current regulation. The second one is a newly proposed control strategy based on the decomposition of the voltage and current into instantaneous positive, negative, and zero sequences. These three sequences are controlled independently in their own reference frames as DC signals. The performance of the load converter using these two control strategies is compared. Simulation results show the validity and capability of the newly proposed control strategy.

  8. The Effect of Unbalanced Coefficient of Magnetron on the Structure and Properties of CNx Coatings

    Institute of Scientific and Technical Information of China (English)

    WEN Xiaobin; LI Xian; WANG Tao; JIANG Bailing

    2011-01-01

    The effect of unbalanced coefficient of magnetron (UCM) on the structure and tribological properties of CrNx hard coatings was studied. The CrNx coatings were deposited on both Si wafer and hardened tool steel substrates using a closed-field unbalanced magnetron sputtering ion plating technique in a gas mixture of Ar+N2 under different unbalanced magnetron conditions. The coatings were characterized by means of XRD, XPS, SEM, microhardness tester and pin-on-disc tribometer to study respectively their structure, chemical bonding state, microstructure, hardness and tribological properties. The experimental results show that the UCM has a profound effect on the structure, hardness and tribological properties of the CrNx coatings. With increasing the values of UCM, the dominant phases in the deposited coatings evolved from Cr+Cr2N to Cr2N+CrN, the microstructure became denser and the hardness increased; in addition, reduced coefficient of friction and improved wear resistance of CrNx coatings were also observed under a larger UCM.

  9. Three-Phase Unbalanced Transient Dynamics and Powerflow for Modeling Distribution Systems With Synchronous Machines

    Energy Technology Data Exchange (ETDEWEB)

    Elizondo, Marcelo A.; Tuffner, Francis K.; Schneider, Kevin P.

    2016-01-01

    Unlike transmission systems, distribution feeders in North America operate under unbalanced conditions at all times, and generally have a single strong voltage source. When a distribution feeder is connected to a strong substation source, the system is dynamically very stable, even for large transients. However if a distribution feeder, or part of the feeder, is separated from the substation and begins to operate as an islanded microgrid, transient dynamics become more of an issue. To assess the impact of transient dynamics at the distribution level, it is not appropriate to use traditional transmission solvers, which generally assume transposed lines and balanced loads. Full electromagnetic solvers capture a high level of detail, but it is difficult to model large systems because of the required detail. This paper proposes an electromechanical transient model of synchronous machine for distribution-level modeling and microgrids. This approach includes not only the machine model, but also its interface with an unbalanced network solver, and a powerflow method to solve unbalanced conditions without a strong reference bus. The presented method is validated against a full electromagnetic transient simulation.

  10. 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

    loop. The rejection capability to the unbalanced grid voltage and the stability of the proposed control system are discussed. The second-order harmonic current in the dc capacitor as well as dc-voltage fluctuation is very well eliminated. Hence, the dc capacitors will be more reliable under unbalanced......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...... method for a grid-side converter (GSC) to eliminate the negative impact of unbalanced grid voltage on the dc-capacitors. In this method, a dc-capacitor current control loop, where a negative-sequence resonant controller is used to increase the loop gain, is added to the conventional GSC current control...

  11. Multiphase unbalanced power flow and fault analysis of distribution networks with high penetration of inverter-interfaced DERs

    OpenAIRE

    Hooshyar, Hossein; Vanfretti, Luigi

    2015-01-01

    The traditional power flow and fault analysis methods fail to meet the requirements in both performance and accuracy aspects in the distribution network applications. This is due to the unbalanced multiphase nature of the distribution network and also due to the emerging penetration of renewable generation at the distribution level. This paper proposes a comprehensive method for power flow solution and fault analysis of multiphase unbalanced distribution networks with high penetration of inve...

  12. Modeling And Analysis of A Jeffcott Rotor As A Continuous Cantilever Beam And An Unbalanced Disk System

    OpenAIRE

    GUNDOGDU, Ömer; ALNEFAIE, Khaled; DIKEN, Hamza

    2014-01-01

    The paper presents simulations of a continuous cantilever beam and an unbalanced disk system by extending classical Jeffcott rotor approach to a model that gives the first three (or more) modes of the flexible beam. Normal modes of a constrained structure method are used to develop the equations of motion including gyroscopic effects. Centrifugal force created by the unbalanced mass of the disk is considered as a constraint for the flexible beam. The first three modes of the flexible beam hav...

  13. 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.

  14. Synchronization of the four identical unbalanced rotors in a vibrating system of plane motion

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A new mechanism is proposed to implement the synchronization of the four unbalanced rotors in a vibrating system, which consists of a main rigid frame (MRF) and two accessorial rigid frames (ARF). An analytical approach is developed to study the coupling dynamic characteristics of the four unbalanced rotors, which converts the problem of synchronization of the four unbalanced rotors into the existence and the stability of zero solutions for the non-dimensional differential equations of the angular velocity disturbance parameters (NDDEDP). The stability of zero solutions of the NDDEDP is decomposed into that of its generalized system and a system of the three first order differential equations for the disturbance parameters of the phase differences. The coupling dynamic characteristic of the four unbalanced rotors includes the inertia coupling, the stiffness coupling of angular velocity and the load torque coupling. The non-dimensional inertia coupling matrix is symmetric, the non dimensional matrix of the stiffness coupling of angular velocity is antisymmetric and its diagonal elements are all negative. Hence, the general system of the NDDEDP automatically satisfies the generalized Lyapunov equations when the non-dimensional inertia coupling matrix is positive definite and its elements are all positive. Using Routh-Hurwitz criterion the condition of stability of differential equations for the disturbance parameters of the phase differences is obtained. The load torque coupling makes the vibrating system have the dynamic characteristic of selecting motions and self-synchronization of the four unbalanced rotors arises from the dynamic characteristic of selecting motion of the vibrating system. When the two coefficients of coupling cosine effect of phase angles are all greater than 0 and the three indexes of synchronization are all far greater than 1, the vibrating system can implement an elliptical motion of the main rigid frame required in engineering. Numeric

  15. Recombinant Technology and Probiotics

    Directory of Open Access Journals (Sweden)

    Icy D’Silva

    2011-09-01

    Full Text Available Recombinant technology has led the way to monumental advances in the development of useful molecules, including the development of safe probiotics. The development of novel approaches using recombinant technology and probiotics that allow accurate targeting of therapeutics to the mucosa is an interesting area of research. The creation and use of recombinant probiotics expressing recombinantovalbumin, recombinant ovalbumin mutants and yet-to-be-designed recombinant hypo/non-allergenic molecules offer the opportunity to further investigate their effects for food, nutrition, environment andhealth. This review highlights advances in native probiotics and recombinant probiotics expressing native and recombinant molecules for food, nutrition, environment and health.

  16. Unbalanced Trade

    OpenAIRE

    Jonathan Eaton; Robert Dekle; Samuel Kortum

    2007-01-01

    We incorporate trade imbalances into a quantitative model of bilateral trade in manufactures, dividing the world into forty countries. Fitting the model to 2004 data on GDP and bilateral trade we calculate how relative wages, real wages, and welfare would differ in a counterfactual world with all current accounts balancing. Our results indicate that closing the current accounts requires modest changes in relative wages. The country with the largest deficit (the United States) needs its wage t...

  17. Tx-Rx Isolation Exploiting Tunable Balanced-Unbalanced Antennas Architecture

    DEFF Research Database (Denmark)

    Tatomirescu, Alexandru; Alrabadi, Osama; Pedersen, Gert Frølund

    2012-01-01

    The duplex filter is probably still the most expensive component in mobile handsets for the significant Transmitter (Tx) — Receiver (Rx) isolation required. This paper suggests to relax or even replace the duplex filter by equipping the Tx and the Rx with two separate antennas. The two antennas...... are different in the sense that one is balanced and the other is unbalanced. By properly controlling the two arms of the balanced antenna, impressive Tx-Rx isolation is obtained by canceling the coupling trans-impedance between the two antennas....

  18. Rabi oscillation induced $\\pi$-phase flip in an unbalanced Ramsey atom interferometer

    CERN Document Server

    Li, R B; Wang, K; Lu, S B; Cao, L; Wang, J; Zhan, M S

    2016-01-01

    We present an observation of zero to $\\pi$ phase flips induced by Rabi oscillation in an unbalanced Ramsey atom interferometer. The phase shift and visibility are experimentally investigated by modulating either the polarization or the pulse duration of Raman lasers, and they are well explained by a theoretical model. In an atom interferometer, the $\\pi$-phase flips are caused not only by the sign of Rabi frequency but also by the amplitude of Rabi oscillation. Considering these $\\pi$-phase flips, we propose a composite-light-pulse sequence for realizing cold atom interferometers, which has advantages of the large momentum transfer and the better noise immunity.

  19. Dynamics of Flexible Rotor Systems with an Interim Mass Unbalanced Disk Using a Spectral Element Model

    OpenAIRE

    Sangkyu Choi; Usik Lee

    2014-01-01

    A frequency domain spectral element model is developed for a rotor system that consists of two spinning shafts and an interim disk or blade system. In this study, the shafts are represented by spinning Timoshenko beam models, and the interim disk system is represented by a uniform thick rigid disk with an unbalanced mass. In our derivation of the governing equations of motion of the disk system, the disk is considered to be wobbling about the geometric center of the disk at which the spinning...

  20. THREE-PHASE ACTIVE POWER FILTER CONTROLLER FOR BALANCED AND UNBALANCED NON-LINEAR LOAD

    Directory of Open Access Journals (Sweden)

    G.NAGESWARA RAO

    2010-09-01

    Full Text Available The active power filter produces equal but opposite harmonic currents to the point of connection with the nonlinear load. This results in a reduction of the original distortion and correction of the power factor. A threephase insulated gate bipolar transistor based current controlled voltage source inverter with a dc bus capacitor is used as an active filter. The firing pulses to the shunt active filter will be generated by using sine PWM method. The models for three-phase active power filter controller for balanced and unbalanced non-linear load is made and is simulated using Matlab/simulink software.

  1. Shunt Connected STATCOM Control Grid of Wind Turbine System for Balanced and Unbalanced Non Linear Loads

    Directory of Open Access Journals (Sweden)

    Vinay Kumar. Polishetty

    2014-01-01

    Full Text Available Injection of wind power into the grid affects the power quality resulting in poor performance of the system. The power arising out of the wind turbine when connected to a grid system concerning the power quality measurements are active power, reactive power, voltage sag, voltage sell, flicker, harmonics, and electrical behavior of switching operation. This paper proposes a control scheme based on instantaneous reactive power theory for compensating reactive power requirements of wind turbine generator as well as the harmonics produced by balanced and unbalanced.non linear loads. The proposed control scheme is simulated l using MATLAB/SIMULINK in power system block set

  2. Dynamic power balance for nonlinear waves in unbalanced gain and loss landscapes

    CERN Document Server

    Kominis, Yannis

    2015-01-01

    The presence of losses in nonlinear photonic structures is a crucial issue for modern applications. Active parts are introduced for wave power compensation resulting in unbalanced gain and loss landscapes where localized beam propagation is, in general, dynamically unstable. Here we provide generic sufficient conditions for the relation between the gain-loss and the refractive index profiles in order to ensure efficient wave trapping and stable propagation for a wide range of beam launching conditions such as initial power, angle of incidence and position. The stability is a consequence of an underlying dynamic power balance mechanism related to a conserved quantity of wave dynamics.

  3. Recombinant chromosome 9 possibly derived from breakage and reunion of sister chromatids within a paracentric inversion loop.

    Science.gov (United States)

    Phelan, M C; Stevenson, R E; Anderson, E V

    1993-05-15

    Chromosomally unbalanced offspring resulting from the recombination of parental paracentric inversions are uncommon. We report on a 20-month-old boy with a partial duplication of 9p due to the recombination of a paternal paracentric inversion. The patient's recombinant chromosome was designated rec(9)(p13-->p24::p12-->p24::p12-->qter). The patient's father and paternal aunt have a paracentric inversion of chromosome 9:inv(9)(p13p24). Although several mechanisms have been proposed to explain the chromosome imbalance generated from paracentric inversions, none of the previously described mechanisms can account for the structure of the recombinant chromosome observed in the propositus. We propose an unusual mechanism of formation involving breakage and unequal reunion of sister chromatids within the inversion loop to explain the structure of the patient's recombinant chromosome. PMID:8488876

  4. The Calculation of Unbalanced Voltage on the tertiary bus of a single phase auto transformer in case of Parallel Operation with Different Manufacturer

    Energy Technology Data Exchange (ETDEWEB)

    Shim, E.B.; Woo, J.W.; Kwak, J.S. [Korea Electric Power Research Institute (Korea); Joe, S.H.; Hur, Y.H. [KEPCO (Korea); Han, S.O. [Chungnam University (Korea)

    2001-07-01

    This paper described the unbalanced voltage on the tertiary bus of a single phase auto transformer in the case of parallel operation with different manufacturer at each phase. The unbalanced capacitances between primary to secondary winding, secondary to tertiary winding and primary to tertiary winding makes unbalanced bus voltage in the tertiary bus side. The unbalanced voltage let the surge arrester to operate in the power frequency range, and it causes the arrester to burn out. The failure of the arrester at one phase makes line to ground fault, which lead to the surge arrester failure of the other two phase on the tertiary bus. (author). 3 refs., 10 figs., 2 tabs.

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

    Science.gov (United States)

    Martínez-López, J. Israel; Mojica, Mauricio; Rodríguez, Ciro A.; Siller, Héctor R.

    2016-01-01

    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. PMID:27196904

  6. Influence and determinative factors of ion-to-atom arrival ratio in unbalanced magnetron sputtering systems

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Low pressure sputtering with a controlled ratio of ion flux to deposited atom flux at the condensing surface is one of the main directions of development of magnetron sputtering methods.Unbalanced magnetron sputtering,by producing dense secondary plasma around the substrate,provides a high ion current density.The closed-field unbalanced magnetron sputtering system (CFUBMS) has been established as a versatile technique for high-rate deposition high-quality metal,alloy,and ceramic thin films.The key factor in the CFUBMS system is the ability to transport high ion currents to the substrate,which can enhance the formation of full dense coatings at relatively low value homologous temperature.The investigation shows that the energy of ions incidenced at the substrate and the ratio of the flux of these ions to the flux of condensing atoms are the fundamental parameters in determining the structure and properties of films produced by ion-assisted deposition processes.Increasing ion bombardment during deposition combined with increasing mobility of the condensing atoms favors the formation of a dense microstructure and a smooth surface.

  7. 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.

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

    CERN Document Server

    Siemaszko, D

    2015-01-01

    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.

  9. Recombinant DNA in Medicine

    OpenAIRE

    Cederbaum, Stephen D.; Fareed, George C.; Lovett, Michael A.; Shapiro, Larry J.

    1984-01-01

    Studies in bacteria and bacterial viruses have led to methods to manipulate and recombine DNA in unique and reproducible ways and to amplify these recombined molecules millions of times. Once properly identified, the recombinant DNA molecules can be used in various ways useful in medicine and human biology. There are many applications for recombinant DNA technology. Cloned complementary DNA has been used to produce various human proteins in microorganisms. Insulin and growth hormone have been...

  10. Improving baculovirus recombination

    OpenAIRE

    Zhao, Yuguang; Chapman, David A. G.; Jones, Ian M.

    2003-01-01

    Recombinant baculoviruses have established themselves as a favoured technology for the high-level expression of recombinant proteins. The construction of recombinant viruses, however, is a time consuming step that restricts consideration of the technology for high throughput developments. Here we use a targeted gene knockout technology to inactivate an essential viral gene that lies adjacent to the locus used for recombination. Viral DNA prepared from the knockout fails to initiate an infecti...

  11. Selection of Recombinant Human Antibodies.

    Science.gov (United States)

    Tomszak, Florian; Weber, Susanne; Zantow, Jonas; Schirrmann, Thomas; Hust, Michael; Frenzel, André

    2016-01-01

    Since the development of therapeutic antibodies the demand of recombinant human antibodies is steadily increasing. Traditionally, therapeutic antibodies were generated by immunization of rat or mice, the generation of hybridoma clones, cloning of the antibody genes and subsequent humanization and engineering of the lead candidates. In the last few years, techniques were developed that use transgenic animals with a human antibody gene repertoire. Here, modern recombinant DNA technologies can be combined with well established immunization and hybridoma technologies to generate already affinity maturated human antibodies. An alternative are in vitro technologies which enabled the generation of fully human antibodies from antibody gene libraries that even exceed the human antibody repertoire. Specific antibodies can be isolated from these libraries in a very short time and therefore reduce the development time of an antibody drug at a very early stage.In this review, we describe different technologies that are currently used for the in vitro and in vivo generation of human antibodies. PMID:27236551

  12. Speed Control of Induction Machine Based on Matrix Converter with Unbalanced Input Voltage

    Directory of Open Access Journals (Sweden)

    Malek Mohammadrezaei

    2011-07-01

    Full Text Available Matrix Converter (MC is a direct energy conversion device with high input power factor. As a device without dc link elements, its output characteristic and reliability can be degraded by ac line side disturbances. This has attracted many researchers to make efforts to solve this problem. In this paper, under unbalanced input voltage conditions, behaviors of the MC controlled with Venturini method are analyzed. The output voltage is estimated and a PI controller compensation method to prevent negative effects of the input voltage harmonics is proposed. Using this technique, output harmonic contents are reduced and stable control of the load voltages and currents is ensured. The MC is used for fed induction motor that reference voltage for converter is computed with controller based on input-output feed-back linearization. Simulation results are presented in the paper to verify effectiveness of the approach.

  13. A Capacitive Displacement Sensing Technique for Early Detection of Unbalanced Loads in a Washing Machine

    Directory of Open Access Journals (Sweden)

    Karthik Tiruthani

    2009-11-01

    Full Text Available Horizontal axis washing machines are water and energy efficient and becoming popular in the USA. Unlike a vertical axis washer, these do not have an agitator and depend solely on tumbling for the agitation of laundry during the wash cycle. However, due to the constant shifting of laundry during washing, the load distribution is often unbalanced during the high speed spin cycle. We present a displacement-based sensing method to detect unbalance early while the spin rate (rpm is well below the resonance frequency so that corrective actions may be taken prior to the high speed spin cycle. Experimental and analytical characterizations of the sensor configuration are presented. Results show that the displacement sensor is more appropriate than an accelerometer for this application and offer the potential for a simple, reliable, low cost detection of unbalance.

  14. Characterization of ZrO2 Films Deposited by Reactive Unbalanced Magnetron Sputtering

    Institute of Scientific and Technical Information of China (English)

    ZHAO Sha; XU Ke-wei; WANG Yuan

    2004-01-01

    ZrO2 thin films were deposited by r.f. reactive unbalanced magnetron sputtering. The influence of electromagnetic coil current on microstructure and optical properties of the films was investigated. At low coil current of 0.2A, small grains are produced. With the increase of coil current, the deposition rate and surface roughness are decreased and the packing density in proportion to the refractive index is increased remarkably. The refractive index is as high as 2.236 (at λ=600nm) at 0.4A. At the high coil current of 0.6A, grains appear to grow up due to thermal effects and therefore optical properties of the films are deteriorated a little.

  15. Fabrication of Diamond-like Carbon Films by Ion Assisted Middle Frequency Unbalanced Magnetron Sputtering

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yi-chen; SUN Shao-ni; ZHOU Yi; MA Sheng-ge; BA De-chun

    2006-01-01

    Diamond-like carbon (DLC) films are deposited by the Hall ion source assisted by the mid-frequency unbalanced magnetron sputtering technique. The effects of the substrate voltage bias, the substrate temperature, the Hall discharging current and the argon/nitrogen ratio on the DLC film's performance were studied. The experimental results show that the film's surface roughness, the hardness and the Young's modulus increase firstly and then decrease with the bias voltage incrementally increases. Also when the substrate temperature rises, the surface roughness of the film varies slightly, but its hardness and Young's modulus firstly increase followed by a sharp decrease when the temperature surpassing 120 ℃. With the Hall discharging current incrementally rising, the hardness and Young's modulus of the film decrease and the surface roughness of the film on 316L stainless steel firstly decreased and then remains constant.

  16. Analysis of motion stability of the flexible rotor-bearing system with two unbalanced disks

    Science.gov (United States)

    Wenhui, Xie; Yougang, Tang; Yushu, Chen

    2008-02-01

    The complicated dynamical behavior of a flexible rotor-bearing system is studied in this paper. The unsteady oil-film force model described by three functions is considered. The bifurcation and chaos behaviors were revealed by calculating the maximum Lyapunov exponent of the system. Two new phenomena were found in this system: first, the chaos with two attracting areas which cannot be distinguished from the stable period doubling motion on Poincarè section; second, for the flexible rotor system with two unbalanced disks, the response varies in a large extent when the phase angle between the eccentricities of disks is different. The experiments were also carried out. Comparison between experimental and calculated results shows that the significant use of the max Lyapunov exponent in revealing the bifurcation and chaos characteristics of the rotor-bearing system.

  17. Properties of Diamond-Like Carbon Films Synthesized by Dual-Target Unbalanced Magnetron Sputtering

    Institute of Scientific and Technical Information of China (English)

    LIU Cui; LI Guo-Qing; GOU Wei; MU Zong-Xin; ZHANG Cheng-Wu

    2004-01-01

    @@ Smooth, dense and uniform diamond-like carbon films (DLC films) for industrial applications have successfully been prepared by dual-target unbalanced magnetron sputtering and the DLC characteristics of the films are confirmed by Raman spectra. It is found that the sputtering current of target plays an important role in the DLC film deposition. Deposition rate of 3.5μm/h is obtained by using the sputtering current of 30 A. The friction coefficient of the films is 0.2-0.225 measured by using a pin-on-disc microtribometer. The structure of the films tends to have a growth of sp3 bonds content at high sputtering current. The compressive residual stress in the films increases with the increasing sputtering current of the target.

  18. Characteristics of W Doped Nanocrystalline Carbon Films Prepared by Unbalanced Magnetron Sputtering.

    Science.gov (United States)

    Park, Yong Seob; Park, Chul Min; Kim, Nam-Hoon; Kim, Jae-Moon

    2016-05-01

    Nanocrystalline tungsten doped carbon (WC) films were prepared by unbalanced magnetron sputtering. Tungsten was used as the doping material in carbon thin films with the aim of application as a contact strip in an electric railway. The structural, physical, and electrical properties of the fabricated WC films with various DC bias voltages were investigated. The films had a uniform and smooth surface. Hardness and frication characteristics of the films were improved, and the resistivity and sheet resistance decreased with increasing negative DC bias voltage. These results are associated with the nanocrystalline WC phase and sp(2) clusters in carbon networks increased by ion bombardment enhanced with increasing DC bias voltage. Consequently, the increase of sp(2) clusters containing WC nanocrystalline in the carbon films is attributed to the improvement in the physical and electrical properties.

  19. 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.

  20. Speed Sensorless Vector Control of Unbalanced Three-Phase Induction Motor with Adaptive Sliding Mode Control

    Directory of Open Access Journals (Sweden)

    Mohammad Jannati

    2014-05-01

    Full Text Available This paper presents a technique for speed sensorless Rotor Flux Oriented Control (RFOC of 3-phase Induction Motor (IM under open-phase fault (unbalanced or faulty IM. The presented RFOC strategy is based on rotational transformation. An adaptive sliding mode control system with an adaptive switching gain is proposed instead of the speed PI controller. Using an adaptive sliding mode control causes the proposed speed sensorless RFOC drive system to become insensitive to uncertainties such as load disturbances and parameter variations. Moreover, with adaptation of the sliding switching gain, calculation of the system uncertainties upper bound is not needed. Finally, simulation results have been presented to confirm the good performance of the proposed method.

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

    DEFF Research Database (Denmark)

    Kumar, Dinesh; Davari, Pooya; Zare, Firuz;

    2016-01-01

    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...... 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....... 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...

  2. Photoionization and Recombination

    Science.gov (United States)

    Nahar, Sultana N.

    2000-01-01

    Theoretically self-consistent calculations for photoionization and (e + ion) recombination are described. The same eigenfunction expansion for the ion is employed in coupled channel calculations for both processes, thus ensuring consistency between cross sections and rates. The theoretical treatment of (e + ion) recombination subsumes both the non-resonant recombination ("radiative recombination"), and the resonant recombination ("di-electronic recombination") processes in a unified scheme. In addition to the total, unified recombination rates, level-specific recombination rates and photoionization cross sections are obtained for a large number of atomic levels. Both relativistic Breit-Pauli, and non-relativistic LS coupling, calculations are carried out in the close coupling approximation using the R-matrix method. Although the calculations are computationally intensive, they yield nearly all photoionization and recombination parameters needed for astrophysical photoionization models with higher precision than hitherto possible, estimated at about 10-20% from comparison with experimentally available data (including experimentally derived DR rates). Results are electronically available for over 40 atoms and ions. Photoionization and recombination of He-, and Li-like C and Fe are described for X-ray modeling. The unified method yields total and complete (e+ion) recombination rate coefficients, that can not otherwise be obtained theoretically or experimentally.

  3. African crop yield reductions due to increasingly unbalanced Nitrogen and Phosphorus consumption

    Science.gov (United States)

    van der Velde, Marijn; Folberth, Christian; Balkovič, Juraj; Ciais, Philippe; Fritz, Steffen; Janssens, Ivan A.; Obersteiner, Michael; See, Linda; Skalský, Rastislav; Xiong, Wei; Peñuealas, Josep

    2014-05-01

    The impact of soil nutrient depletion on crop production has been known for decades, but robust assessments of the impact of increasingly unbalanced nitrogen (N) and phosphorus (P) application rates on crop production are lacking. Here, we use crop response functions based on 741 FAO maize crop trials and EPIC crop modeling across Africa to examine maize yield deficits resulting from unbalanced N:P applications under low, medium, and high input scenarios, for past (1975), current, and future N:P mass ratios of respectively, 1:0.29, 1:0.15, and 1:0.05. At low N inputs (10 kg/ha), current yield deficits amount to 10% but will increase up to 27% under the assumed future N:P ratio, while at medium N inputs (50 kg N/ha), future yield losses could amount to over 40%. The EPIC crop model was then used to simulate maize yields across Africa. The model results showed relative median future yield reductions at low N inputs of 40%, and 50% at medium and high inputs, albeit with large spatial variability. Dominant low-quality soils such as Ferralsols, which are strongly adsorbing P, and Arenosols with a low nutrient retention capacity, are associated with a strong yield decline, although Arenosols show very variable crop yield losses at low inputs. Optimal N:P ratios, i.e. those where the lowest amount of applied P produces the highest yield (given N input) where calculated with EPIC to be as low as 1:0.5. Finally, we estimated the additional P required given current N inputs, and given N inputs that would allow Africa to close yield gaps (ca. 70%). At current N inputs, P consumption would have to increase 2.3-fold to be optimal, and to increase 11.7-fold to close yield gaps. The P demand to overcome these yield deficits would provide a significant additional pressure on current global extraction of P resources.

  4. 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

    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...

  5. 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…

  6. Optimization of Unbalanced Multi-stage Logistics Systems Based on Prüfer Number and Effective Capacity Coding

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Unbalanced multi-stage logistics systems are optimized using an improved genetic algorithm based on the Prüfer number and the effective capacity coding. The improved decoding procedure uses the node capacity of the logistics system as an important factor, which influences the decoding procedure. As a result, any Prüfer number produced stochastically can be decoded to a feasible logistics pattern, which matchs the node capacities of the logistics system. With effective capacity coding, an unbalanced logistics system can be converted to a set of balanced systems. The effective capacity coding was combined with the Prüfer number to construct the chromosome for the new method to search the whole solution space of the unbalanced multi-stage logistics system. Simulation results show that the new method finds a better solution with less computational time than st-GA. Although using a little more memory, the new method is still an efficient and robust method for optimizing unbalanced multi-stage logistics systems.

  7. Recombineering Homologous Recombination Constructs in Drosophila

    OpenAIRE

    Carreira-Rosario, Arnaldo; Scoggin, Shane; Shalaby, Nevine A.; Williams, Nathan David; Hiesinger, P. Robin; Buszczak, Michael

    2013-01-01

    The continued development of techniques for fast, large-scale manipulation of endogenous gene loci will broaden the use of Drosophila melanogaster as a genetic model organism for human-disease related research. Recent years have seen technical advancements like homologous recombination and recombineering. However, generating unequivocal null mutations or tagging endogenous proteins remains a substantial effort for most genes. Here, we describe and demonstrate techniques for using recombineeri...

  8. Alternative security

    International Nuclear Information System (INIS)

    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

  9. Alternative energies; Energies alternatives

    Energy Technology Data Exchange (ETDEWEB)

    Bonal, J.; Rossetti, P

    2007-07-01

    The earth took millions years to made the petroleum, the gas the coal and the uranium. Only a few centuries will be needed to exhaust these fossil fuels and some years to reach expensive prices. Will the wold continue on this way of energy compulsive consumption? The renewable energies and some citizen attitudes are sufficient to break this spiral. This book proposes to discuss these alternative energies. It shows that this attitude must be supported by the government. It takes stock on the more recent information concerning the renewable energies. it develops three main points: the electricity storage, the housing and the transports. (A.L.B.)

  10. 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.

  11. 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.

  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. Surface treatment effect on Si (111) substrate for carbon deposition using DC unbalanced magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Aji, A. S., E-mail: aji.ravazes70@gmail.com; Sahdan, M. F.; Hendra, I. B.; Dinari, P.; Darma, Y. [Quantum Semiconductor and Devices Lab., Physics of Material Electronics Research Division, Department of Physics, Institut Teknologi Bandung (Indonesia)

    2015-04-16

    In this work, we studied the effect of HF treatment in silicon (111) substrate surface for depositing thin layer carbon. We performed the deposition of carbon by using DC Unbalanced Magnetron Sputtering with carbon pallet (5% Fe) as target. From SEM characterization results it can be concluded that the carbon layer on HF treated substrate is more uniform than on substrate without treated. Carbon deposition rate is higher as confirmed by AFM results if the silicon substrate is treated by HF solution. EDAX characterization results tell that silicon (111) substrate with HF treatment have more carbon fraction than substrate without treatment. These results confirmed that HF treatment on silicon Si (111) substrates could enhance the carbon deposition by using DC sputtering. Afterward, the carbon atomic arrangement on silicon (111) surface is studied by performing thermal annealing process to 900 °C. From Raman spectroscopy results, thin film carbon is not changing until 600 °C thermal budged. But, when temperature increase to 900 °C, thin film carbon is starting to diffuse to silicon (111) substrates.

  14. Unbalanced oil filled sphere as rolling pendulum on a flat surface to damp horizontal structural vibrations

    Science.gov (United States)

    Bransch, Martin

    2016-04-01

    The passive damping of horizontal structural vibrations by means of an unbalanced oil filled sphere as a tuned mass damper (TMD) is examined. Due to the unbalance contained in the TMD, a pendulum-like motion is produced. The TMD lies unconstrained on the structure. As a result, forces are only transferred through the static friction between the TMD and the structure. The TMD is filled with oil to enable energy dissipation. This paper investigates the mechanical system of the proposed TMD and calculation methods for its tuning. Furthermore, experimental results of the TMD are presented. To determine the advantages and disadvantages of the proposed TMD, it will be compared to other passive tuned mass dampers. The advantages of the presented TMD are its robust design, simple mounting/demounting onto the main system and its adjustability after mounting. The oil filling makes the damper construction simple, as an additional container for the oil is no longer needed. Furthermore, the energy dissipating effect of breaking waves is used when the oil level inside the TMD is shallow. The disadvantages of the presented TMD when compared to a conventional tuned mass damper (linear spring-mass-damper-system) are its slightly lower performance and its complex tuning.

  15. Growth characteristics of MoS2 coatings prepared by unbalanced bipolar DC magnetron sputtering

    Institute of Scientific and Technical Information of China (English)

    WANG Ji-hui; XIA Yang; E.Wieers; L.M.Stals; J.P.Celis

    2005-01-01

    MoS2 coatings were prepared by unbalanced bipolar DC magnetron sputtering under different argon pressures and for different deposition times, and the structure and morphology of MoS2 coatings were determined and observed respectively by X-ray diffractometry and scanning electron microscopy. The results show that at lower argon pressures of 0.15Pa and 0.40Pa, MoS2 coatings are formed with the (002) basal plane parallel to the surface, whereas the coating deposited at the argon pressure above 0.60Pa has the (002) basal plane perpendicular to the surface. Two stages can be classified for the formation of MoS2 coating. At the initial stage of coating formation, the (002) basal plane with S-Mo-S layer structure grows on the substrate whatever the argon pressure is. And then the coating under 0.40Pa argon pressure still grows with (002) laminate structure, but the coatings under 0.88Pa and 1.60Pa argon pressures turn to grow with the mixed basal and edge orientations. The morphology and structure of MoS2 coatings are highly related to their growth rate and the energy of sputtered particles.

  16. Unbalanced der(5)t(5;20) translocation associated with Megalencephaly, perisylvian Polymicrogyria, Polydactyly and Hydrocephalus

    Science.gov (United States)

    Verkerk, Annemieke J.M.H.; Schot, Rachel; van Waterschoot, Laura; Douben, Hannie; Poddighe, Pino J.; Lequin, Maarten H.; de Vries, Linda S.; Terhal, Paulien; Hahnemann, Johanne M.D.; de Coo, Irenaeus F.M.; de Wit, Marie-Claire Y.; Wafelman, Leontien S.; Garavelli, Livia; Dobyns, William B.; Van der Spek, Peter J.; de Klein, Annelies; Mancini, Grazia M.S.

    2010-01-01

    The combination of megalencephaly, perisylvian polymicrogyria, polydactyly and hydrocephalus (MPPH) is a rare syndrome of unknown cause. We observed two first cousins affected by an MPPH-like phenotype with a submicroscopic chromosome 5q35 deletion as a result of an unbalanced der(5)t(5;20)(q35.2;q13.3) translocation, including the NSD1 Sotos syndrome locus. We describe the phenotype and the deletion breakpoints of the two MPPH-like patients and compare these with five unrelated MPPH and Sotos patients harboring a 5q35 microdeletion. Mapping of the breakpoints in the two cousins was performed by MLPA, FISH, high density SNP-arrays and Q-PCR for the 5q35 deletion and 20q13 duplication. The 5q35 deletion area of the two cousins almost completely overlaps with earlier described patients with an atypical Sotos microdeletion, except for the DRD1 gene. The five unrelated MPPH patients neither showed submicroscopic chromosomal aberrations nor DRD1 mutations. We reviewed the brain MRI of 10 Sotos patients and did not detect polymicrogyria in any of them. In our two cousins, the MPPH-like phenotype is probably caused by the contribution of genes on both chromosome 5q35 and 20q13. Some patients with MPPH may harbor a submicroscopic chromosomal aberration and therefore high-resolution array analysis should be part of the diagnostic workup. PMID:20503325

  17. Nonlinear dynamic behaviors of permanent magnet synchronous motors in electric vehicles caused by unbalanced magnetic pull

    Science.gov (United States)

    Xiang, Changle; Liu, Feng; Liu, Hui; Han, Lijin; Zhang, Xun

    2016-06-01

    Unbalanced magnetic pull (UMP) plays a key role in nonlinear dynamic behaviors of permanent magnet synchronous motors (PMSM) in electric vehicles. Based on Jeffcott rotor model, the stiffness characteristics of the rotor system of the PMSM are analyzed and the nonlinear dynamic behaviors influenced by UMP are investigated. In free vibration study, eigenvalue-based stability analysis for multiple equilibrium points is performed which offers an insight in system stiffness. Amplitude modulation effects are discovered of which the mechanism is explained and the period of modulating signal is carried out by phase analysis and averaging method. The analysis indicates that the effects are caused by the interaction of the initial phases of forward and backward whirling motions. In forced vibration study, considering dynamic eccentricity, frequency characteristics revealing softening type are obtained by harmonic balance method, and the stability of periodic solution is investigated by Routh-Hurwitz criterion. The frequency characteristics analysis indicates that the response amplitude is limited in the range between the amplitudes of the two kinds of equilibrium points. In the vicinity of the continuum of equilibrium points, the system hardly provides resistance to bending, and hence external disturbances easily cause loss of stability. It is useful for the design of the PMSM with high stability and low vibration and acoustic noise.

  18. SPEEDY babies: A putative new behavioral syndrome of unbalanced motor-speech development

    Directory of Open Access Journals (Sweden)

    Marja-Leena Haapanen

    2008-09-01

    Full Text Available Marja-Leena Haapanen1, Tuomo Aro1, Elina Isotalo21Deparment of Otorhinolaryngology, Phoniatric Division, Helsinki University Central Hospital, Helsinki, Finland; 2Department of Neurology, Peijas Hospital, Helsinki University Central Hospital, Helsinki, FinlandAbstract: Even though difficulties in motor development in children with speech and language disorders are widely known, hardly any attention is paid to the association between atypically rapidly occurring unassisted walking and delayed speech development. The four children described here presented with a developmental behavioral triad: 1 atypically speedy motor development, 2 impaired expressive speech, and 3 tongue carriage dysfunction resulting in related misarticulations. Those characteristics might be phenotypically or genetically clustered. These children didn’t have impaired cognition, neurological or mental disease, defective sense organs, craniofacial dysmorphology or susceptibility to upper respiratory infections, particularly recurrent otitis media. Attention should be paid on discordant and unbalanced achievement of developmental milestones. Present children are termed SPEEDY babies, where SPEEDY refers to rapid independent walking, SPEE and DY to dyspractic or dysfunctional speech development and lingual dysfunction resulting in linguoalveolar misarticulations. SPEEDY babies require health care that recognizes and respects their motor skills and supports their needs for motor activities and on the other hand include treatment for impaired speech. The parents may need advice and support with these children.Keywords: speedy walking, speech disorder, misarticulations

  19. Analysis of variance with unbalanced data: an update for ecology & evolution.

    Science.gov (United States)

    Hector, Andy; von Felten, Stefanie; Schmid, Bernhard

    2010-03-01

    1. Factorial analysis of variance (anova) with unbalanced (non-orthogonal) data is a commonplace but controversial and poorly understood topic in applied statistics. 2. We explain that anova calculates the sum of squares for each term in the model formula sequentially (type I sums of squares) and show how anova tables of adjusted sums of squares are composite tables assembled from multiple sequential analyses. A different anova is performed for each explanatory variable or interaction so that each term is placed last in the model formula in turn and adjusted for the others. 3. The sum of squares for each term in the analysis can be calculated after adjusting only for the main effects of other explanatory variables (type II sums of squares) or, controversially, for both main effects and interactions (type III sums of squares). 4. We summarize the main recent developments and emphasize the shift away from the search for the 'right'anova table in favour of presenting one or more models that best suit the objectives of the analysis.

  20. 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.

  1. Performance Improvement of DFIG-based Wind Farm Using Multilevel Cascaded H-bridge Converter under Unbalanced Grid Voltage Conditions

    DEFF Research Database (Denmark)

    Shokri, Yunes; Ebrahimzadeh, Esmaeil; Lesani, Hamid;

    2014-01-01

    This paper presents a new configuration of doubly fed induction generator (DFIG)-based wind farm with multilevel cascaded H-bridge (CHB) converter and its control system, which is suitable not only for unbalanced grid voltage conditions, but also for small voltage sags. The proposed configuration...... of DFIG can balance the point of common coupling (PCC) voltage without needing additional DC link capacitor or energy storage unlike other configurations and methods. Consequently, the stator voltage and the other loads voltage connected to the PCC are kept constant at the nominal value. The new...... configuration improves all the DFIG signals under unbalanced grid voltage and small voltage sag conditions unlike other methods. Some of the DFIG units in wind farm require to connect the CHB converter, therefore, it is cost-effective. Matlab/Simulink is used for simulation of a 13.5-MW wind farm consisting of...

  2. An Unbalanced Nested Error Component Model for Estimating Pest Damage Functions and the Value of Rootworm Bt Corn

    OpenAIRE

    Dun, Zhe; Mitchell, Paul D.

    2010-01-01

    We apply Antweiler’s (2001) double-nested unbalanced panel data model to estimate a western corn rootworm damage function using data from field trials in Illinois and Nebraska. Results imply that expected yield losses for a one unit difference in the node injury scale are 16.4%. Estimated random year and state effects are statistically significant, as is the estimated random experimental effect. The experimental effect is relatively large indicating the tremendous variability in yield losses ...

  3. 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.

  4. Unbalanced Baseline in School-Based Interventions to Prevent Obesity: Adjustment Can Lead to Bias - a Systematic Review

    Directory of Open Access Journals (Sweden)

    Rosely Sichieri

    2014-06-01

    Full Text Available Background/Aims: Cluster designs favor unbalanced baseline measures. The aim of the present study was to determine the frequency of unbalanced baseline BMI on school-based randomized controlled trials (RCT aimed at obesity reduction and to evaluate the analysis strategies. We hypothesized that the adjustment of unbalanced baseline measures may explain the great discrepancy among studies. Methods: The source of data was the Medline database content from January 1995 until May 2012. Our search strategy combined key words related to school-based interventions with such related to weight and was not limited by language. The participants' ages were restricted to 6-18 years. Results: We identified 146 school-based studies on obesity prevention (or overweight or excessive weight change. Of the 146 studies, 36 were retained for the analysis after excluding reviews, feasibility studies, other outcomes, and repeated publications. 13 (35% of the reviewed studies had statistically significant (p Conclusion: Adjustment for the baseline BMI is frequently done in cluster randomized studies, and there is no standardization for this procedure. Thus, procedures that disentangle the effects of group, time and changes in time, such as mixed effects models, should be used as standard methods in school-based studies on the prevention of weight gain.

  5. Recombinant methods and materials

    Energy Technology Data Exchange (ETDEWEB)

    Roizman, B.; Post, L.E.

    1988-09-06

    This patent describes a method for stably effecting the insertion or deletion of a selected DNA sequence at a specific site in a viral genome. The method consists of: (1) isolating from the genome a linear DNA fragment comprising both (a) the specific site determined for insertion or deletion of selected DNA sequence and (b) flanking DNA sequences normally preceding and following the site; (2) preparing first and second altered genome fragments from the fragment isolated in step (1). (a) the first altered fragment comprising the fragment comprising a thymidine kinase gene in a position intermediate the ends of the fragment, and (b) the second altered fragment comprising the fragment having the selected DNA sequence inserted therein or deleted therefrom; (3) contacting the genome with the first altered fragment under conditions permitting recombination at sites of DNA sequence homology, selecting for a recombinant genome comprising the thymidine kinase gene, and isolating the recombinant genome; and (4) contacting the recombinant genome isolated in step (3) with the second altered fragment under conditions permitting recombination at sites of DNA sequence homology, selecting for a recombinant genome lacking the thymidine kinase gene, and isolating the recombinant genome product.

  6. Optimum capacitor allocation in unbalanced distribution systems by using genetic algorithms; Alocacao otima de capacitores em sistemas de distribuicao desequilibrados usando algoritmos geneticos

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Paulo Augusto N.; Carneiro Junior, Sandoval [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. E-mail: pgarcia@fusoes.com.br; sandoval@dee.ufrj.br; Pereira, Jose Luiz R. [Juiz de Fora Univ., MG (Brazil). Faculdade de Engenharia. E-mail: jluiz@lacee.ufjf.br

    1999-07-01

    This paper presents a methodology for capacitor optimum determination in unbalanced distribution systems. The methodology aims to minimize losses of energy and power during the peak hours considering the capacitor costs. Restrictions were adopted for voltage limits representation and unbalancing between phases. A three phase modelling is presented, allowing the precise representation of the elements constituting the distribution systems. Tests are presented of a three phase system consisted of single, two and three phases, resulting in significant efficiency of the study methodology.

  7. 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. PMID:24292553

  8. Expression of Recombinant Antibodies

    OpenAIRE

    Frenzel, André; Hust, Michael; Schirrmann, Thomas

    2013-01-01

    Recombinant antibodies are highly specific detection probes in research, diagnostics, and have emerged over the last two decades as the fastest growing class of therapeutic proteins. Antibody generation has been dramatically accelerated by in vitro selection systems, particularly phage display. An increasing variety of recombinant production systems have been developed, ranging from Gram-negative and positive bacteria, yeasts and filamentous fungi, insect cell lines, mammalian cells to transg...

  9. Production of recombinant antibodies using bacteriophages

    OpenAIRE

    Shukra, A. M.; Sridevi, N. V.; Dev Chandran,; Kapil Maithal,

    2014-01-01

    Recombinant antibody fragments such as Fab, scFv, diabodies, triabodies, single domain antibodies and minibodies have recently emerged as potential alternatives to monoclonal antibodies, which can be engineered using phage display technology. These antibodies match the strengths of conventionally produced monoclonal antibodies and offer advantages for the development of immunodiagnostic kits and assays. These fragments not only retain the specificity of the whole monoclonal ...

  10. 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

  11. 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.

  12. 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

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

    International Nuclear Information System (INIS)

    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. Improving Output Performance of a Z-Source Sparse Matrix Converter Under Unbalanced Input-Voltage Conditions

    DEFF Research Database (Denmark)

    Park, Kiwoo; Lee, Kyo Beum; Blaabjerg, Frede

    2011-01-01

    In this paper, we present a novel Z-source sparse matrix converter (ZSMC) and a compensation method based on a fuzzy logic controller to compensate unbalanced input voltages. The ZSMC is developed based on the structure of an SMC to reduce the number of unipolar power semiconductor switches...... of the ZSMC and its compensation method....... and employs a Z-source network to overcome the inherent limitation of the low voltage transfer ratio of conventional matrix converters. Although the ZSMC is a two-stage converter, it directly connects between a source and a load through a Z-source network, which is designed to have smaller passive components...

  15. Further results on bias in dynamic unbalanced panel data models with an application to firm R&D investment

    OpenAIRE

    Lokshin, B

    2008-01-01

    This paper extends the LSDV bias-corrected estimator in [Bun, M., Carree, M.A. 2005. Bias-corrected estimation in dynamic panel data models, Journal of Business and Economic Statistics, 23(2): 200-10] to unbalanced panels and discusses the analytic method of obtaining the solution. Using a Monte Carlo approach the paper compares the performance of this estimator with three other available techniques for dynamic panel data models. Simulation reveals that LSDV-bc estimator is a good choice exce...

  16. Recombinant Helicobacter pylori catalase

    Institute of Scientific and Technical Information of China (English)

    Yang Bai; Ya-Li Zhang; Jian-Feng Jin; Ji-De Wang; Zhao-Shan Zhang

    2003-01-01

    AIM: To construct a recombinant strain which highly expresses catalase of Helicobacter pylori(H.pylori) and assay the activity of H. pylori catalase.METHODS: The catalase DNA was amplified from H. pylori chromosomal DNA with PCR techniques and inserted into the prokaryotie expression vector pET-22b (+), and then was transformed into the BL21 (DE3) E. coli strain which expressed catalase recombinant protein. The activity of H.pylori catalase was assayed by the Beers & Sizers.RESULTS: DNA sequence analysis showed that the sequence of catalase DNA was the same as GenBank's research. The catalase recombinant protein amounted to 24.4 % of the total bacterial protein after induced with IPTG for 3 hours at 37 ℃ and the activity of H. pylori catalase was high in the BL21 (DE3) E. coli strain.CONCLUSION: A clone expressing high activity H. pylori catalase is obtained, laying a good foundation for further studies.

  17. Recombination in ionized gases

    International Nuclear Information System (INIS)

    In this paper it is shown how capture-stabilized methodology (both macroscopic and microscopic) can provide a generic basis for a unified treatment of all of the above recombination mechanisms. A new semiclassical theory of dissociative recombination is also presented in an effort to gain further insight into the physics not included in the first-order treatment and difficult to extract from numerical quantal treatments based on configuration mixing and on multichannel quantum defect theory. A simple analytical expression more accurate than the standard first-order result is obtained for the cross section σ and rate coefficient α. (author)

  18. Unwinding Protein Complexes in ALTernative Telomere Maintenance

    OpenAIRE

    Bhattacharyya, Saumitri; Sandy, April; Groden, Joanna

    2010-01-01

    Telomeres are composed of specialized chromatin that includes DNA repair/recombination proteins, telomere DNA-binding proteins and a number of three dimensional nucleic acid structures including G-quartets and D-loops. A number of studies suggest that the BLM and WRN recQ-like helicases play important roles in recombination-mediated mechanisms of telomere elongation or Alternative Lengthening of Telomeres (ALT), processes that maintain/elongate telomeres in the absence of telomerase. BLM and ...

  19. Recombinant DNA for Teachers.

    Science.gov (United States)

    Duvall, James G., III

    1992-01-01

    A science teacher describes his experience at a workshop to learn to teach the Cold Spring Harbor DNA Science Laboratory Protocols. These protocols lead students through processes for taking E. coli cells and transforming them into a new antibiotic resistant strain. The workshop featured discussions of the role of DNA recombinant technology in…

  20. Recombineering Pseudomonas syringae

    Science.gov (United States)

    Here we report the identification of functions that promote genomic recombination of linear DNA introduced into Pseudomonas cells by electroporation. The genes encoding these functions were identified in Pseudomonas syringae pv. syringae B728a based on similarity to the lambda Red Exo/Beta and RecE...

  1. Cytogenetic, molecular and testicular tissue studies in an infertile 45,X male carrying an unbalanced (Y;22) translocation: case report.

    Science.gov (United States)

    Brisset, S; Izard, V; Misrahi, M; Aboura, A; Madoux, S; Ferlicot, S; Schoevaert, D; Soufir, J C; Frydman, R; Tachdjian, G

    2005-08-01

    (Y;autosome) translocations have been reported in association with male infertility. Different mechanisms have been suggested to explain the male infertility, such as deletion of the azoospermic factor (AZF) on the long arm of the Y chromosome, or meiosis impairment. We describe a new case with a de novo unbalanced translocation t(Y;22) and discuss the genotype-phenotype correlation. A 36 year old male with azoospermia was found to have a mosaic 45,X/46,X, + mar karyotype. Fluorescence in situ hybridization (FISH) showed the presence of a derivative Y chromosome containing the short arm, the centromere and a small proximal part of the long-arm euchromatin of the Y chromosome and the long arm of chromosome 22. The unstable small marker chromosome included the short arm and the centromere of chromosome 22. This unbalanced translocation t(Y;22)(q11.2;q11.1) generated the loss of the long arm of the Y chromosome involving a large part of AZFb, AZFc and Yq heterochromatin regions. Testicular tissue analyses showed sperm in the wet preparation. Our case shows the importance of documenting (Y;autosome) translocations with molecular and testicular tissue analyses.

  2. 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.

  3. Electrical, optical, and structural properties of InZnSnO electrode films grown by unbalanced radio frequency magnetron sputtering

    International Nuclear Information System (INIS)

    We have investigated the electrical, optical, structural, and annealing properties of indium zinc tin oxide (IZTO) films prepared by an unbalanced radio frequency (RF) magnetron sputtering at room temperature, in a pure Ar ambient environment. It was found that the electrical and optical properties of unbalanced RF sputter grown IZTO films at room temperature were influenced by RF power and working pressure. At optimized growth condition, we could obtain the IZTO film with the low resistivity of 3.77 x 10-4 Ω cm, high transparency of ∼ 87% and figure of merit value of 21.2 x 10-3Ω-1, without the post annealing process, even though it was completely an amorphous structure due to low substrate temperature. In addition, the field emission scanning electron microscope analysis results showed that all IZTO films are amorphous structures with very smooth surfaces regardless of the RF power and working pressure. However, the rapid thermal annealing process above the temperature of 400 oC lead to an abrupt increase in resistivity and sheet resistance due to the transition of film structure from amorphous to crystalline, which was confirmed by X-ray diffraction examination.

  4. Telomere elongation chooses TERRA ALTernatives

    OpenAIRE

    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 ...

  5. Superhard nanocomposite Ti-Al-Si-N films deposited by reactive unbalanced magnetron sputtering

    International Nuclear Information System (INIS)

    Nanocomposite Ti-Al-Si-N films (Al content ranging from 0 to 16.7 at.% and Si from 0 to 11.8 at.%, respectively) were prepared on Si(1 0 0) substrates at 500 deg. C by reactive close-field unbalanced magnetron sputtering in an Ar-N2 mixture. The chemical composition, bonding structure, surface morphology, microstructure, stress and mechanical properties of these films were systematically investigated by means of energy dispersive spectrometry (EDS), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), X-ray diffraction (XRD), optical interference system and nanoindentation measurements. The XPS measurements reveal evolution of chemical composition and bonding structure of the deposited Ti-Al-Si-N films. The observed nonlinear peak shift of Ti 2p and N 1s indicates the bonding evolution of crystalline TiN. The spectra from Al 2p at 73.7 eV and Si 2p at 101.1 eV indicates the evolution of film composition from TiSiN to TiAlN with the incorporation of Al, and also implies that their chemical states are mainly in the form of SiN x and AlN, respectively. The (1 1 1) diffraction peak from the XRD θ-2θ patterns shows a variation either on peak width or on peak position, indicating the variation of grain size and lattice constant. The calculated lattice constant reveals a mixture of different phases whose structures are similar to TiN. The nonlinear variation of grain size and lattice constant is considered due to the competition between two processes, i.e. Al addition and the underlying Si reduction. In order to further understand the microstructure evolution, the XRD spectra and corresponding calculations of the Ti-Al-Si-N films without heating during deposition are also shown for comparison. The effect of substrate heating is discussed. The present results show that the influence of Si and Al addition on the grain growth is different. The surface roughness of Ti-Al-Si-N films also exhibits a nonlinear variation, which is due to the variation of grain

  6. 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 inje......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...

  7. Alternative Treatments

    Science.gov (United States)

    ... Find your chapter: search by state Home > Alzheimer's Disease > Treatments > Alternative Treatments Overview What Is Dementia? What Is Alzheimer's? Younger/Early Onset Facts and Figures Know the 10 Signs Stages Inside the Brain: ...

  8. AECL passive autocatalytic recombiners

    Energy Technology Data Exchange (ETDEWEB)

    Gardner, L.B.; Marcinkowska, K. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

    2012-03-15

    Atomic Energy of Canada Limited's (AECL) Passive Autocatalytic Recombiner (PAR) is a passive device used for hydrogen mitigation under post-accident conditions in nuclear reactor containment. The PAR employs a proprietary AECL catalyst which promotes the exothermal reaction between hydrogen and oxygen to form water vapour. The heat of reaction combined with the PAR geometry establishes a convective flow through the recombiner, where ambient hydrogen-rich gas enters the PAR inlet and hot, humid, hydrogen-depleted gas exits the outlet. AECL's PAR has been extensively qualified for CANDU and light water reactors (LWRs), and has been supplied to France, Finland, Ukraine, South Korea and is currently being deployed in Canadian nuclear power plants. (author)

  9. AECL passive autocatalytic recombiners

    Energy Technology Data Exchange (ETDEWEB)

    Gardner, L.B.; Marcinkowska, K. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

    2011-07-01

    Atomic Energy of Canada Limited's (AECL) Passive Autocatalytic Recombiner (PAR) is a passive device used for hydrogen mitigation under post-accident conditions in nuclear reactor containment. The PAR employs a proprietary AECL catalyst which promotes the exothermal reaction between hydrogen and oxygen to form water vapour. The heat of reaction combined with the PAR geometry establishes a convective flow through the recombiner, where ambient hydrogen-rich gas enters the PAR inlet and hot, humid, hydrogen-depleted gas exits the outlet. AECL's PAR has been extensively qualified for CANDU and light water reactors (LWRs), and has been supplied to France, Finland, Ukraine, South Korea and is currently being deployed in Canadian nuclear power plants. (author)

  10. RECOMBINANT INFLUENZA VACCINES

    OpenAIRE

    Sedova, E.; Shcherbinin, D.; Migunov, A.; Smirnov, Iu; Logunov, D.; Shmarov, M.; Tsybalova, L.; Naroditskiĭ, B.; O. Kiselev; Gintsburg, A.

    2012-01-01

    This review covers the problems encountered in the construction and production of new recombinant influenza vaccines. New approaches to the development of influenza vaccines are investigated; they include reverse genetics methods, production of virus-like particles, and DNA- and viral vector-based vaccines. Such approaches as the delivery of foreign genes by DNA- and viral vector-based vaccines can preserve the native structure of antigens. Adenoviral vectors are a promising gene-delivery pla...

  11. Soluble recombinant influenza vaccines.

    OpenAIRE

    Fiers, W; Neirynck, S; Deroo, T; Saelens, X; Jou, W M

    2001-01-01

    Soluble, recombinant forms of influenza A virus haemagglutinin and neuraminidase have been produced in cells of lower eukaryotes, and shown in a mouse model to induce complete protective immunity against a lethal virus challenge. Soluble neuraminidase, produced in a baculovirus system, consisted of tetramers, dimers and monomers. Only the tetramers were enzymatically active. The immunogenicity decreased very considerably in the order tetra > di > mono. Therefore, we fused the head part of the...

  12. Characteristics of Nitrogen Doped Diamond-Like Carbon Films Prepared by Unbalanced Magnetron Sputtering for Electronic Devices.

    Science.gov (United States)

    Lee, Jaehyeong; Choi, Byung Hui; Yun, Jung-Hyun; Park, Yong Seob

    2016-05-01

    Synthetic diamond-like carbon (DLC) is a carbon-based material used mainly in cutting tool coatings and as an abrasive material. The market for DLC has expanded into electronics, optics, and acoustics because of its distinct electrical and optical properties. In this work, n-doped DLC (N:DLC) films were deposited on p-type silicon substrates using an unbalanced magnetron sputtering (UBMS) method. We investigated the effect of the working pressure on the microstructure and electrical properties of n-doped DLC films. The structural properties of N:DLC films were investigated by Raman spectroscopy and SEM-EDX, and the electrical properties of films were investigated by observing the changes in the resistivity and current-voltage (I-V) properties. The N:DLC films prepared by UBMS in this study demonstrated good conducting and physical properties with n-doping. PMID:27483841

  13. 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...... of the negative-sequence current provided by the PMSG-based wind farm under different average active power output and different VUF conditions is deduced, and the impacts of its phase angle on the VUF mitigation control effect are further studied. The improved control strategy of injecting negative......-sequence current from the PMSG-based wind farm by the modified negative-sequence voltage and current double closed-loop control system is then developed. Finally, the correctness of theoretical analysis and the effectiveness of the proposed control strategy are validated by the experimental results....

  14. 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.

  15. 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.

  16. Unbalanced 15;22 translocation in a patient with manifestations of DiGeorge and velocardiofacial syndrome.

    Science.gov (United States)

    Jaquez, M; Driscoll, D A; Li, M; Emanuel, B S; Hernandez, I; Jaquez, F; Lembert, N; Ramirez, J; Matalon, R

    1997-05-01

    We report on an 8-year-old girl with an unbalanced 15;22 translocation and manifestations of DiGeorge syndrome (DGS), velocardiofacial syndrome (VCFS), and other abnormalities. The main manifestations of our patient were feeding difficulties, respiratory infections, short stature, peculiar face with hypertelorism, prominent nose, abnormal ears, microstomia and crowded teeth, short broad neck and shield chest with pectus deformity and widely spaced nipples with abnormal fat distribution, heart defect, scoliosis, asymmetric limb development, abnormal hands and feet, and hyperchromic skin patches. Cytogenetic studies demonstrated a 45,XX,der(15)t(15;22)(p11.2;q11.2), -22 karyotype. Fluorescence in situ hybridization (FISH) studies confirmed loss of the proximal DiGeorge chromosomal region (DGCR). This case adds to the diversity of clinical abnormalities caused by deletions within 22q11.2.

  17. The Tragedy of Unbalanced Personality-The Common Personality Psy-chological Reasons of the Destruction of Emily and Usher

    Institute of Scientific and Technical Information of China (English)

    胡星

    2014-01-01

    A Rose for Emily is the masterpiece of William Faulkner, who is regarded as the founder of Southern literature. The Fall of the House of Usher is one of the most popular short stories written by the great American writer Edgar Allan Poe. They have common ends that the main characters of the two novels-Emily and Usher are all destruction of their unbalanced personality. This thesis will set a new point from a branch view of psychology-personality psychology to analyze the two characters Emily and Usher, how they change from pathological personality to abnormal personality, and finally destruct from flesh to soul. The deep meaning is to announce the human inner world will distract by the outside world.

  18. Characteristics of Nitrogen Doped Diamond-Like Carbon Films Prepared by Unbalanced Magnetron Sputtering for Electronic Devices.

    Science.gov (United States)

    Lee, Jaehyeong; Choi, Byung Hui; Yun, Jung-Hyun; Park, Yong Seob

    2016-05-01

    Synthetic diamond-like carbon (DLC) is a carbon-based material used mainly in cutting tool coatings and as an abrasive material. The market for DLC has expanded into electronics, optics, and acoustics because of its distinct electrical and optical properties. In this work, n-doped DLC (N:DLC) films were deposited on p-type silicon substrates using an unbalanced magnetron sputtering (UBMS) method. We investigated the effect of the working pressure on the microstructure and electrical properties of n-doped DLC films. The structural properties of N:DLC films were investigated by Raman spectroscopy and SEM-EDX, and the electrical properties of films were investigated by observing the changes in the resistivity and current-voltage (I-V) properties. The N:DLC films prepared by UBMS in this study demonstrated good conducting and physical properties with n-doping.

  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. PMID:25243215

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

    Energy Technology Data Exchange (ETDEWEB)

    Yasui, Masayuki; Ota, Kiichiro [Wakayama Medical Coll. (Japan); Sasajima, Kazuhisa

    1995-02-01

    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).

  2. 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.

  3. 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.

  4. Cosmic alternatives?

    Science.gov (United States)

    Gregory, Ruth

    2009-04-01

    "Cosmologists are often in error but never in doubt." This pithy characterization by the Soviet physicist Lev Landau sums up the raison d'être of Facts and Speculations in Cosmology. Authors Jayant Narlikar and Geoffrey Burbidge are proponents of a "steady state" theory of cosmology, and they argue that the cosmological community has become fixated on a "Big Bang" dogma, suppressing alternative viewpoints. This book very much does what it says on the tin: it sets out what is known in cosmology, and puts forward the authors' point of view on an alternative to the Big Bang.

  5. 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

  6. 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.

  7. First-trimester combined screening is effective for the detection of unbalanced chromosomal translocations at 11 to 12 weeks of gestation.

    Science.gov (United States)

    Huang, Shangyu; Chang, Chialin; Cheng, Pojen; Hsiao, Chinghua; Soong, Yungkuei; Duan, Tao

    2014-05-01

    The first trimester combined screening, which analyzes fetal nuchal translucency and levels of free β-human chorionic gonadotropin (β-hCG) and pregnancy-associated plasma protein A (PAPP-A) in maternal serum, is routinely used to detect abnormal pregnancies associated with Down syndrome and other trisomy aneuploidies. Based on the hypothesis that major chromosomal translocations could lead to similar biochemical and developmental outcomes during early embryo development, we compared these markers among pregnancies with normal, balanced, or unbalanced fetal karyotypes. Among the parents, 71 (73%) carry balanced reciprocal translocation and 26 (27%) have Robertsonian translocation. Of the 97 pregnancies tested, 39 (40%), 37 (37%), and 22 (23%) fetuses had normal karyotype, balanced chromosomal translocations, and unbalanced chromosomal translocations, respectively. Importantly, we found that pregnancies with an unbalanced translocation had significantly higher free β-hCG multiple of the median (MoM) and larger nuchal translucency thickness than those with normal karyotype or balanced translocations. Analysis showed that the area under a receiver operating characteristic curve (AUC) is 0.716, 0.820, and 0.936 for free β-hCG MoM, PAPP-A MoM, and fetal nuchal translucency, respectively. When these 3 independent factors were combined, the AUC reached 0.976. In addition, logistic regression showed that the most optimal model for predicting an unbalanced chromosomal translocation is a combination of PAPP-A and nuchal translucency with an AUC of 0.980. Therefore, the first trimester combined screening is not only effective in the screening of Down syndrome and other trisomy abnormalities but also has high sensitivity for the detection of unbalanced chromosomal translocations in fetuses. PMID:24177714

  8. Primordial magnetogenesis before recombination

    CERN Document Server

    Fabre, Ophélia

    2015-01-01

    The origin of large magnetic fields in the Universe remains currently unknown. We investigate here a mechanism before recombination based on known physics. The source of the vorticity is due to the changes in the photon distribution function caused by the fluctuations in the background photons. We show that the magnetic field generated in the MHD limit, due to the Coulomb scattering, is of the order $10^{-49}$ G. We explicitly show that the magnetic fields generated from this process are sustainable and are not erased by resistive diffusion. We compare the results with current observations and discuss the implications.

  9. 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...

  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. Primordial magnetogenesis before recombination

    Science.gov (United States)

    Fabre, Ophélia; Shankaranarayanan, S.

    2016-04-01

    The origin of large magnetic fields in the Universe remains currently unknown. We investigate here a mechanism before recombination based on known physics. The source of the vorticity is due to the changes in the photon distribution function caused by the fluctuations in the background photons. We show that the magnetic field generated in the MHD limit, due to the Coulomb scattering, is of the order 10-49 G on a coherence scale of 10 kpc. We explicitly show that the magnetic fields generated from this process are sustainable and are not erased by resistive diffusion. We compare the results with current observations and discuss the implications. Our seed magnetic fields are generated on small scales whereas the main mechanisms studied in the literature are on scale bigger than 1 Mpc. However, compared to more exotic theories generating seed magnetic fields on similar scales, the strength of our fields are generally smaller.

  12. 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.

  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 w...

  14. The microstructure and properties of unbalanced magnetron sputtered CrN sub x coatings

    CERN Document Server

    Hurkmans, A P A

    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 mu m), reasonably hard (approx 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 sub x coatings, XRD, SEM, SNMS and tribological an...

  15. Bimolecular recombination in organic photovoltaics.

    Science.gov (United States)

    Lakhwani, Girish; Rao, Akshay; Friend, Richard H

    2014-01-01

    The recombination of electrons and holes is a major loss mechanism in photovoltaic devices that controls their performance. We review scientific literature on bimolecular recombination (BR) in bulk heterojunction organic photovoltaic devices to bring forward existing ideas on the origin and nature of BR and highlight both experimental and theoretical work done to quantify its extent. For these systems, Langevin theory fails to explain BR, and recombination dynamics turns out to be dependent on mobility, temperature, electric field, charge carrier concentration, and trapped charges. Relationships among the photocurrent, open-circuit voltage, fill factor, and morphology are discussed. Finally, we highlight the recent emergence of a molecular-level picture of recombination, taking into account the spin and delocalization of charges. Together with the macroscopic picture of recombination, these new insights allow for a comprehensive understanding of BR and provide design principles for future materials and devices.

  16. Alternative crops

    International Nuclear Information System (INIS)

    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.)

  17. 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.

  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. A prescription and fast code for the long-term evolution of star clusters II: unbalanced and core evolution

    CERN Document Server

    Gieles, Mark; Lamers, Henny; Baumgardt, Holger

    2013-01-01

    We introduce version two of the fast star cluster evolution code Evolve Me A Cluster of StarS (EMACSS). The first version (Alexander & Gieles) assumed that cluster evolution is balanced for the majority of the life-cycle, meaning that the rate of energy generation in the core of the cluster equals the diffusion rate of energy by two-body relaxation, which makes the code suitable for modelling clusters in weak tidal fields. In this new version we extend the model to include an unbalanced phase of evolution to describe the pre-collapse evolution and the accompanying escape rate such that clusters in strong tidal fields can also be modelled. We also add a prescription for the evolution of the core radius and density and a related cluster concentration parameter. The model simultaneously solves a series of first-order ordinary differential equations for the rate of change of the core radius, half-mass radius and the number of member stars N. About two thousand integration steps in time are required to solve f...

  20. Influence of the interface composition on the corrosion behavior of unbalanced magnetron grown niobium coatings on steel

    International Nuclear Information System (INIS)

    Niobium is well known as a chemically extremely stable material. However, the corrosion performance of 0.3 to 1.3 μm thick, unbalanced magnetron (UBM) grown niobium coatings on stainless steel substrates depends not only on the deposition parameters, but also significantly on the in vacuo etching pretreatment of the substrates prior to coating. Corrosion tests, transmission electron microscopy, and scanning transmission electron microscopy analyses have shown, that a dense fine grained, partially implanted, 5-10 nm thick niobium interface layer formed during the metal ion etching pretreatment is paramount to protect stainless steel substrates thoroughly against corrosion in chlorine containing aqueous electrolytes, whereas the pretreatment with Ar and Cr ions leads to comparably inferior corrosion results. Moreover the energy of the impinging Nb ions used during the etching process plays an important role. For 0.3 μm thick Nb coatings, maximum pitting potentials (+1000 mV) and minimum corrosion currents (-6 A cm-2) were found for bias voltages between -600 and -1000 V. In summary, the results suggest that the UBM deposited Nb coatings are not completely dense and that the major justification for niobium as corrosion barrier depends on the existence of the thin interface layer generated by high-energy ion bombardment during the etching step. The UBM deposited coating (US=75 V) acts therefore as itself a chemically stable mechanical spacer protecting the thin interface layer against mechanical damage

  1. 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.

  2. Effect of ion bombardment and substrate orientation on structure and properties of titanium nitride films deposited by unbalanced magnetron sputtering

    CERN Document Server

    Guruvenket, S

    2002-01-01

    The effect of substrate orientation and ion bombardment during the growth on the structure and properties of TiN films deposited by reactive unbalanced magnetron sputtering has been reported. Films deposited at a nitrogen partial pressure of 5x10 sup - sup 5 mbar and a current density of 2.50 mA cm-2 were golden yellow in color, characteristic of stoichiometric TiN. The effect of Si(100) and Si(111) substrates on the TiN film along with the substrate bias has been investigated. With an increase in the substrate bias on Si(111) substrate, TiN(111) is the most preferred orientation. On a Si(100) substrate with an increase in the substrate bias, TiN(220) orientation has been observed. The influence of the substrate on the growth of TiN films has been explained in terms of surface energy. The variation of grain size, resistivity, and the internal stress of TiN films as the function of substrate bias have also been investigated.

  3. Al-doped ZnO films deposited on a slightly reduced buffer layer by reactive dc unbalanced magnetron sputtering

    International Nuclear Information System (INIS)

    Al-doped ZnO (AZO) films were deposited on a fused silica glass substrate by reactive dc unbalanced magnetron sputtering using a Zn–Al (Al: 3.6 at.%) alloy target with an impedance control system. A very thin slightly reduced AZO buffer layer was inserted between the glass substrate and AZO films. For the AZO films deposited at 200 °C, the lowest resistivity in the absence of the buffer layer was 8.0 × 10−4 Ω cm, whereas this was reduced to 5.9 × 10−4 Ω cm after introducing a 5-nm-thick buffer layer. The transmittance for all the films was above 80% in the visible region. The effects of the buffer layer were analysed and discussed in detail. It is found that the insertion of the buffer layer can improve the crystallinity of the AZO film. - Highlights: • Al-doped ZnO (AZO) films with AZO buffer layers were deposited. • Reactive dc unbalance magnetron sputtering with impedance control was used. • Insertion of a buffer layer can lead to a lower resistivity. • Insertion of a buffer layer improved the crystallinity of AZO films

  4. Analysis of Wind Generator Operations under Unbalanced Voltage Dips in the Light of the Spanish Grid Code

    Directory of Open Access Journals (Sweden)

    Joaquín Montañana-Romeu

    2011-08-01

    Full Text Available Operation of doubly fed induction generators subjected to transient unbalanced voltage dips is analyzed in this article to verify the fulfillment of the Spanish grid code. Akagi’s p-q theory is not used for this study, because control of the electronic converter is not the main goal of the paper, but rather to know the physical phenomena involved in the wind turbine when voltage dips occur. Hence, the magnetizing reactive power of the induction generators and their components, which are related with the magnetic fields and determine operation of these machines, are expressed through the reactive power formulations established in the technical literature by three well-known approaches: the delayed voltage (DV method, Czarnecki’s Current’s Physical Components (CPC theory and Emanuel’s approach. Non-fundamental and negative-sequence components of the magnetizing reactive power are respectively established to define the effects of the distortion and voltage imbalances on the magnetic fields and electromagnetic torques. Also, fundamental-frequency positive-sequence and negative-sequence reactive powers are decomposed into two components: due to the reactive loads and caused by the imbalances. This decomposition provides additional information about the effects of the imbalances on the main magnetic field and electromagnetic torque of the induction generator. All the above mentioned reactive powers are finally applied to one actual wind turbine subjected to a two-phase voltage dip in order to explain its operation under such transient conditions.

  5. Thickness Effects of TiC Interlayer on Tribological Properties of Diamond-Like Carbon Prepared by Unbalanced Magnetron Sputtering Method.

    Science.gov (United States)

    Park, Chulmin; Lee, Jaehyeong; Park, Yong Seob

    2015-11-01

    We investigated the tribological properties of diamond-like carbon (DLC) films prepared with TiC interlayer of various thicknesses as the adhesive layer. DLC and TiC thin films were prepared using unbalanced magnetron (UBM) sputtering method using graphite and titanium as targets. TiC films as the interlayer were deposited under DLC films and various physical, tribological, and structural properties of the films fabricated with various TiC interlayer thicknesses were investigated. With various TiC interlayer thicknesses under DLC films, the tribological properties of films were improved with increasing thickness and the DLC/TiC layer fabricated by unbalanced magnetron sputtering method are exhibited maximum high hardness over 27 GPa and high elastic modulus over 242 GPa, and a smooth surface below 0.09 nm.

  6. 铂电阻非平衡电桥温度计的设计%Design of the Unbalanced Bridge Thermometer Using Platinum Resistance

    Institute of Scientific and Technical Information of China (English)

    冯叶; 蒋方为; 张宇鹍; 王吉有

    2016-01-01

    利用Matlab和Origin软件,从理论上分析了电压型非平衡电桥铂金属温度计设计中,各种参数对温度线性度的影响。设计了0~100℃范围的温度计,获得电桥的输出电压和测量温度具有很好的线性关系。%The influence of a variety of parameters on the linear of the thermometer in the design of the unbal-anced bridge are theoretically analyzed using Matlab software and Origin software. The thermometer was de-signed to obtain 0~100℃range.It was found that it has a good linear relationship between the output voltage of unbalanced bridge and temperature.

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

    OpenAIRE

    Ilknur Erol; Semra Saygi; Senay Demir; Fusun Alehan; Feride Iffet Sahin

    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 h...

  8. Identification of an unbalanced cryptic translocation t(9;17)(q34.3;p13.3) in a child with dysmorphic features

    OpenAIRE

    Estop, A M; Mowery-Rushton, P A; Cieply, K M; Kochmar, S J; Sherer, C R; Clemens, M; Surti, U; McPherson, E.

    1995-01-01

    We report a case of an unbalanced cryptic telomeric translocation 46,XY,der(17),t(9;17)(q34.3;p13.3) in a boy with dysmorphic features and developmental delay. The proband had intrauterine growth retardation, postnatal short stature, and mild microcephaly. Magnetic resonance imaging showed incomplete myelination, but no evidence of lissencephaly. Cytogenetic analysis of the proband's peripheral blood showed an abnormal 17p. Fluorescence in situ hybridisation (FISH) with a Miller-Dieker cosmid...

  9. Design and Experimental Implementation of a Beam-Type Twin Dynamic Vibration Absorber for a Cantilevered Flexible Structure Carrying an Unbalanced Rotor: Numerical and Experimental Observations

    OpenAIRE

    Abdullah Özer; Mojtaba Ghodsi; Akio Sekiguchi; Ashraf Saleem; Mohammed Nasser Al-Sabari

    2015-01-01

    This paper presents experimental and numerical results about the effectiveness of a beam-type twin dynamic vibration absorber for a cantilevered flexible structure carrying an unbalanced rotor. An experimental laboratory prototype setup has been built and implemented in our laboratory and numerical investigations have been performed through finite element analysis. The proposed system design consists of a primary cantilevered flexible structure with an attached dual-mass cantilevered secondar...

  10. Alternative Energies

    Energy Technology Data Exchange (ETDEWEB)

    Planting, A.; De saint Jacob, Y.; Verwijs, H.; Belin, H.; Preesman, L.

    2009-03-15

    In two articles, one interview and one column attention is paid to alternative energies. The article 'A new light on saving energy' discusses the option to save energy by modernising lighting systems in urban areas. The column 'View from Paris' focuses on investment decisions in France with regard to renewable energy and energy savings. The article 'Europe turns a blind eye to big battery' discusses developments in batteries to store energy. The interview concerns fuel cell expert and formerly President of UTC Power Jan van Dokkum. The last article gives a brief overview of the European Energy Research Alliance (EERA) and the challenges this alliance will have to face with regard to climate change and energy security.

  11. Energy alternatives

    International Nuclear Information System (INIS)

    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

  12. Analysis of interchromosomal mitotic recombination.

    Science.gov (United States)

    McGill, C B; Shafer, B K; Higgins, D R; Strathern, J N

    1990-07-01

    A novel synthetic locus is described that provides a simple assay system for characterizing mitotic recombinants. The locus consists of the TRP1 and HIS3 genes inserted into chromosome III of S. cerevisiae between the CRY1 and MAT loci. Defined trp1 and his3 alleles have been generated that allow the selection of interchromosomal recombinants in this interval. Trp+ or His+ recombinants can be divided into several classes based on coupling of the other alleles in the interval. The tight linkage of the CRY1 and MAT loci, combined with the drug resistance and cell type phenotypes that they respectively control, facilitates the classification of the recombinants without resorting to tetrad dissection. We present the distribution of spontaneous recombinants among the classes defined by this analysis. The data suggest that the recombination intermediate can have regions of symmetric strand exchange and that co-conversion tracts can extend over 1-3 kb. Continuous conversion tracts are favored over discontinuous tracts. The distribution among the classes defined by this analysis is altered in recombinants induced by UV irradiation.

  13. Design and Experimental Implementation of a Beam-Type Twin Dynamic Vibration Absorber for a Cantilevered Flexible Structure Carrying an Unbalanced Rotor: Numerical and Experimental Observations

    Directory of Open Access Journals (Sweden)

    Abdullah Özer

    2015-01-01

    Full Text Available This paper presents experimental and numerical results about the effectiveness of a beam-type twin dynamic vibration absorber for a cantilevered flexible structure carrying an unbalanced rotor. An experimental laboratory prototype setup has been built and implemented in our laboratory and numerical investigations have been performed through finite element analysis. The proposed system design consists of a primary cantilevered flexible structure with an attached dual-mass cantilevered secondary dynamic vibration absorber arrangement. In addition, an unbalanced rotor system is attached to the tip of the flexible cantilevered structure to inspect the system response under harmonic excitations. Numerical findings and experimental observations have revealed that significant vibration reductions are possible with the proposed dual-mass, cantilevered dynamic vibration absorber on a flexible cantilevered platform carrying an unbalanced rotor system at its tip. The proposed system is efficient and it can be practically tuned for variety of design and operating conditions. The designed setup and the results in this paper can serve for practicing engineers, researchers and can be used for educational purposes.

  14. 试论工程量清单模式下不平衡报价的应对策略%Response Strategy of Unbalanced Bids under the Mode of Bill of Quantities

    Institute of Scientific and Technical Information of China (English)

    熊文亮; 李慧英

    2011-01-01

    现行的工程量清单计价模式下,大量承包商往往采用不平衡报价手法,严重影响了建设工程施工合同的生成和实施.本文描述了不平衡报价的分类,列举了承包商不平衡报价的常用手法,提出防范不平衡报价的应对策略.%Under the current mode of Bill of Quantities, the large number of contractors often quoted the unbalanced way which seriously affects the formation and implementation of construction contract. This paper describes the classification of unbalanced bids, lists common way of unbalanced bid of the contractor, and proposes the response strategy to prevent unbalanced bids.

  15. Aspergillus: sex and recombination.

    Science.gov (United States)

    Varga, János; Szigeti, Gyöngyi; Baranyi, Nikolett; Kocsubé, Sándor; O'Gorman, Céline M; Dyer, Paul S

    2014-12-01

    The genus Aspergillus is one of the most widespread groups of fungi on Earth, comprised of about 300-350 species with very diverse lifestyles. Most species produce asexual propagula (conidia) on conidial heads. Despite their ubiquity, a sexual cycle has not yet been identified for most of the aspergilli. Where sexual reproduction is present, species exhibit either homothallic (self fertile) or heterothallic (obligate outcrossing) breeding systems. A parasexual cycle has also been described in some Aspergillus species. As in other fungi, sexual reproduction is governed by mating-type (MAT) genes, which determine sexual identity and are involved in regulating later stages of sexual development. Previous population genetic studies have indicated that some supposedly asexual aspergilli exhibit evidence of a recombining population structure, suggesting the presence of a cryptic sexual cycle. In addition, genome analyses have revealed networks of genes necessary for sexual reproduction in several Aspergillus species, again consistent with latent sexuality in these fungi. Knowledge of MAT gene presence has then successfully been applied to induce sexual reproduction between MAT1-1 and MAT1-2 isolates of certain supposedly asexual aspergilli. Recent progress in understanding the extent and significance of sexual reproduction is described here, with special emphasis on findings that are relevant to clinically important aspergilli. PMID:25118872

  16. Controlled release from recombinant polymers.

    Science.gov (United States)

    Price, Robert; Poursaid, Azadeh; Ghandehari, Hamidreza

    2014-09-28

    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.

  17. Cell encoding recombinant human erythropoietin

    Energy Technology Data Exchange (ETDEWEB)

    Beck, A.K.; Withy, R.M.; Zabrecky, J.R.; Masiello, N.C.

    1990-09-04

    This patent describes a C127 cell transformed with a recombinant DNA vector. It comprises: a DNA sequence encoding human erythropoietin, the transformed cell being capable of producing N-linked and O-linked glycosylated human erythropoietin.

  18. 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

  19. Unbalanced Biding Model Based on Anticipated Variation%基于预期变更的不平衡报价模型研究

    Institute of Scientific and Technical Information of China (English)

    杜永杰; 任宏; 叶堃辉

    2014-01-01

    The principle of"quantity and price separation"is adopted in China’s current engineering quantity list quotation. In the unit price contract,the employer is to assume the risk of quantity adjustment,and the contractor has to bear the risk of price variation. Moreover,China's relevant laws and regulations on unbalanced bids have not yet offered clear and effective restrictions and adjustment provisions,which provides possibility for the generation of unbalanced bids. It is because of this situation,using the unbalanced bidding,which is based on anticipated changes,offers a very important way of improving the contractors’ economic benefit. Seek-evaluation-design-analyze(SEDA)model is used to solve the technical problems of adopting unbalanced bidding to achieve contractors’ income. The model offers four steps:opportunity point identifying-opportunity point evaluating-bidding scheme design-implementation mechanism analysis to determine the realization of unbalanced bids.%我国现行的清单报价采用“量价分离”原则,在单价合同中,发包商承担工程量调整的风险,承包商承受价格变动的风险,并且我国现行的相关法律、法规并未对不平衡报价行为有针对性地限制以及约束条款,这就为不平衡报价策略的实现提供了可能。因此,承包商基于预期变更利用不平衡报价创收是个很重要的方法。Seek-Evaluation-Design-Analyze(SEDA)模型用以解决承包商采用不平衡报价方式实现创收的技术问题,该模型通过机会点识别、机会点评价、报价方案设计、实现机理分析4个步骤确定不平衡报价的实现途径,为承包商实现创收提供了有效的工具和手段。

  20. Progenitors of Recombining Supernova Remnants

    OpenAIRE

    Moriya, Takashi J.

    2012-01-01

    Usual supernova remnants have either ionizing plasma or plasma in collisional ionization equilibrium, i.e., the ionization temperature is lower than or equal to the electron temperature. However, the existence of recombining supernova remnants, i.e., supernova remnants with the ionization temperature higher than the electron temperature, is recently confirmed. One suggested way to have recombining plasma in a supernova remnant is to have a dense circumstellar medium at the time of the superno...

  1. Recombinant snake venom prothrombin activators

    OpenAIRE

    Lövgren, 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 ...

  2. Plasmid recombination in Haemophilus influenzae

    Energy Technology Data Exchange (ETDEWEB)

    McCarthy, D.

    1982-01-01

    DNA recombination in exponential phase and competent Haemophilus influenzae was measured by an electron microscopic assay that relies on the conversion of plasmid RSF0885 monomers into multimeric forms. Dimer circles were present at a frequency of 2% in plasmid preparations from competent Rd (wild-type) cells; multimers were present at a frequency of 0.2% in preparations from exponential phase cells. Thus, plasmid recombination was stimulated in competent cells. Multimer formation occurred efficiently in cells of the transformation defective mutant rec2, implying that the rec2 gene product is not required for plasmid recombination. However, the absence of multimer plasmids in preparations from competent cells of the transformation defective mutant rec1 suggests that the rec1 gene product is required. Digestion of purified plasmids with restriction endonuclease PvuII, which makes a single cut in the monomer, revealed the presence of recombination intermediates composed of two linear plasmids joined to form two pairs of arms resembling the Greek letter chi. Length measurements of these arms taken from a population of recombination intermediates gave evidence that the plasmids were joined at sites of homology. The distributions of individual DNA strands, at the intersections of the four arms, could be resolved in some recombination intermediates and were of two types. The first type of junction appeared as a single-stranded arm appended to each corner. The second type of junction consisted of a single strand of DNA linking the two linear plasmids at a site of homology. The single-stranded linker was frequently situated at the edge of a short gap on one of the plasmids in the pair. The fine structures of the recombinational joints have been interpreted in terms of previously proposed models of recombination.

  3. [Telomere Recombination in Normal Mammalian Cells].

    Science.gov (United States)

    Zhdanova, N S; Rubtsov, N B

    2016-01-01

    Two mechanisms of telomere length maintenance are known to date. The first includes the use of a special enzymatic telomerase complex to solve the problems that arise during the replication of linear DNA in a normal diploid and part of tumor cells. Alternative lengthening of telomeres (ALT), which is based on the homologous recombination of telomere DNA, represents the second mechanism. Until recently, ALT was assumed to be expressed only in 15-20% of tumors lacking active telomerase and, together with telomerase reactivation represented one of two possibilities to overcome the replicative senescence observed in somatic mammalian cells due to aging or during cell culturing in vitro. Previously described sporadic cases of combinations of the two mechanisms of telomere length maintenance in several cell lines in vitro were attributed to the experimental design rather than to a real biological phenomenon, since active cellular division without active telomerase was considered to be the "gold standard" of ALT. The present review describes the morphological and functional reorganizations of mammalian telomeres observed with ALT activation, as well as recently observed,and well-documented cases of combinations between ALT-like and telomerase-dependent mechanisms in mammalian cells. The possible role of telomere recombination in telomerase-dependent cells is discussed. PMID:27183789

  4. CARBON NITRIDE FILMS PREPARED AT DIFFERENT N2/Ar RATIOS BY CLOSED FIELD UNBALANCED REACTIVE MAGNETRON SPUTTERING

    Institute of Scientific and Technical Information of China (English)

    A. Vyas; K.Y. Li; Z.F. Zhou; Y.G. Shen

    2005-01-01

    Carbon nitride (CNx) thin films have been deposited onto Si(100) (for structural and mechanical analyses) and M42 high-speed-steel (for tribological measurements) substrates at room temperature by closed-field unbalanced magnetron sputtering. The mechanical and tribological properties of these films were highly dependent on the N/C concentration ratio that was adjusted by the F(N2)/F(Ar) flow-rate ratio at fixed substrate biasing of -60V during deposition. The films were characterized by employing scanning electron microscopy (SEM), atomic force microscopy(AFM), nano-indentation measurements, X-ray photoelectron spectroscopy (XPS), Raman scattering and Fourier transform infrared (FTIR) spectroscopy, pin-on-disc tribometer, scratch tester, and Rockwell-C tester. The results showed that the N content in the films increased with the N2 pressure. However, the maximum N/C ratio obtained was 0.25. The nanohardness was measured to be in the range of 11.7-20.8GPa depending on the N/C ratios. The XPS N 1s spectra showed the existence of both N-C sp2 and N-C sp3 bonds in films. Raman and FTIR spectra exhibited that N-C bonds were fewer when compared to other N-C bonds. The friction coefficient of the film deposited onto steel substrate with N/C=0.26 was measured to be ~0.08and for film with N/C=0.22 a high critical load of 70N was obtained. The tribological data also showed that the wear rates of these films were in the range of~10-16m3/Nm, indicating excellent wear resistance for CNxfilms.

  5. Short Telomeres Initiate Telomere Recombination in Primary and Tumor Cells

    OpenAIRE

    Morrish, Tammy A.; Greider, Carol W

    2009-01-01

    Human tumors that lack telomerase maintain telomeres by alternative lengthening mechanisms. Tumors can also form in telomerase-deficient mice; however, the genetic mechanism responsible for tumor growth without telomerase is unknown. In yeast, several different recombination pathways maintain telomeres in the absence of telomerase-some result in telomere maintenance with minimal effects on telomere length. To examine non-telomerase mechanisms for telomere maintenance in mammalian cells, we us...

  6. A multi-Fc-species system for recombinant antibody production

    OpenAIRE

    Nizak Clément; Vielemeyer Ole; El Marjou Ahmed; Moutel Sandrine; Benaroch Philippe; Dübel Stefan; Perez Franck

    2009-01-01

    Abstract Background Genomic, transcriptomic and proteomic projects often suffer from a lack of functional validation creating a strong demand for specific and versatile antibodies. Antibody phage display represents an attractive approach to select rapidly in vitro the equivalent of monoclonal antibodies, like single chain Fv antibodies, in an inexpensive and animal free way. However, so far, recombinant antibodies have not managed to impose themselves as efficient alternatives to natural anti...

  7. FluBlok, a recombinant hemagglutinin influenza vaccine

    OpenAIRE

    Cox, Manon M.J.; Patriarca, Peter A.; Treanor, John

    2008-01-01

    Abstract  FluBlok, a recombinant trivalent hemagglutinin (HA) vaccine produced in insect cell culture using the baculovirus expression system, provides an attractive alternative to the current egg‐based trivalent inactivated influenza vaccine (TIV) manufacturing process. FluBlok contains three times more HA than TIV and does not contain egg‐protein or preservatives. This review discusses the four main clinical studies that were used to support licensure of FluBlok under the ‘Accelerated Appro...

  8. New algorithm to detect voltage disturbances in three phases alternative current systems

    Energy Technology Data Exchange (ETDEWEB)

    Benslimane, T.; Chetate, B. [University of Boumerdes (Algeria)

    2006-07-01

    In this paper is presented a new algorithm based on logical functions to detect different disturbances in alternative voltage in electrical power networks such as over-voltage, under-voltage, unbalanced voltage, short circuit besides the safe operating condition. This algorithm is based on RMS values of three phases voltages as input values to detection system that is basically based on logical functions. This system is applied on three phase electrical power network of sinusoidal voltage. It can also be applied on PWM voltage that must be filtered to get its fundamental RMS value. Simulation program was developed in Matlab/Simulinksoftware. Simulation results are presented. (orig.)

  9. Alternative Splice in Alternative Lice.

    Science.gov (United States)

    Tovar-Corona, Jaime M; Castillo-Morales, Atahualpa; Chen, Lu; Olds, Brett P; Clark, John M; Reynolds, Stuart E; Pittendrigh, Barry R; Feil, Edward J; Urrutia, Araxi O

    2015-10-01

    Genomic and transcriptomics analyses have revealed human head and body lice to be almost genetically identical; although con-specific, they nevertheless occupy distinct ecological niches and have differing feeding patterns. Most importantly, while head lice are not known to be vector competent, body lice can transmit three serious bacterial diseases; epidemictyphus, trench fever, and relapsing fever. In order to gain insights into the molecular bases for these differences, we analyzed alternative splicing (AS) using next-generation sequencing data for one strain of head lice and one strain of body lice. We identified a total of 3,598 AS events which were head or body lice specific. Exon skipping AS events were overrepresented among both head and body lice, whereas intron retention events were underrepresented in both. However, both the enrichment of exon skipping and the underrepresentation of intron retention are significantly stronger in body lice compared with head lice. Genes containing body louse-specific AS events were found to be significantly enriched for functions associated with development of the nervous system, salivary gland, trachea, and ovarian follicle cells, as well as regulation of transcription. In contrast, no functional categories were overrepresented among genes with head louse-specific AS events. Together, our results constitute the first evidence for transcript pool differences in head and body lice, providing insights into molecular adaptations that enabled human lice to adapt to clothing, and representing a powerful illustration of the pivotal role AS can play in functional adaptation. PMID:26169943

  10. Looking for an Alternative.

    Science.gov (United States)

    Kennedy, Jack

    1999-01-01

    Argues that high school newspapers might do well to create stronger ties with alternative weeklies. Discusses issues of niche marketing, alternative content, and alternative presentation. Notes that high school papers could learn a lot from alternative newspapers. (SR)

  11. ATRX represses alternative lengthening of telomeres

    OpenAIRE

    Napier, Christine E.; Huschtscha, Lily I.; Harvey, Adam; Bower, Kylie; Noble, Jane R.; Hendrickson, Eric A.; Reddel, Roger R

    2015-01-01

    The unlimited proliferation of cancer cells requires a mechanism to prevent telomere shortening. Alternative Lengthening of Telomeres (ALT) is an homologous recombination-mediated mechanism of telomere elongation used in tumors, including osteosarcomas, soft tissue sarcoma subtypes, and glial brain tumors. Mutations in the ATRX/DAXX chromatin remodeling complex have been reported in tumors and cell lines that use the ALT mechanism, suggesting that ATRX may be an ALT repressor. We show here th...

  12. A universal cloning method based on yeast homologous recombination that is simple, efficient, and versatile

    OpenAIRE

    Joska, Tammy M.; Mashruwala, Ameya; Boyd, Jeffrey M.; Belden, William J.

    2014-01-01

    Cloning by homologous recombination (HR) in Saccharomyces cerevisiae is an extremely efficient and cost-effective alternative to other methods of recombinant DNA technologies. Unfortunately, it is incompatible with all the various specialized plasmids currently used in microbiology and biomedical research laboratories, and is therefore, not widely adopted. In an effort to dramatically improve the versatility of yeast gap-repair cloning and make it compatible with any DNA plasmid, we demonstra...

  13. Tuning Mesenchymal Stem Cell Response onto Titanium-Niobium-Hafnium Alloy by Recombinant Fibronectin Fragments

    OpenAIRE

    Herranz-Diez, Carolina; Mas Moruno, Carlos; Neubauer, S.; Kessler, H.; Gil Mur, Javier; Pegueroles Neyra, Marta; Manero Planella, José María; Guillem Martí, Jordi

    2016-01-01

    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 recombin...

  14. Recombination at Long Mutant Telomeres Produces Tiny Single- and Double-Stranded Telomeric Circles

    OpenAIRE

    Groff-Vindman, Cindy; Cesare, Anthony J.; Natarajan, Shobhana; Griffith, Jack D.; McEachern, Michael J.

    2005-01-01

    Recombinational telomere elongation (RTE) known as alternate lengthening of telomeres is the mechanism of telomere maintenance in up to 5 to 10% of human cancers. The telomeres of yeast mutants lacking telomerase can also be maintained by recombination. Previously, we proposed the roll-and-spread model to explain this elongation in the yeast Kluveromyces lactis. This model suggests that a very small (∼100-bp) circular molecule of telomeric DNA is copied by a rolling circle event to generate a...

  15. Inter-telomeric recombination is present in telomerase-positive human cells

    OpenAIRE

    Dlaska, Margit; Schöffski, Patrick; Bechter, Oliver E.

    2013-01-01

    Immortal cells require a mechanism of telomere length control in order to divide infinitely. One mechanism is telomerase, an enzyme that compensates the loss of telomeric DNA. The second mechanism is the alternative lengthening of telomeres (ALT) pathway. In ALT pathway cells, homologous recombination between telomeric DNA is the mechanism by which telomere homeostasis is achieved. We developed a novel homologous recombination reporter system that is able to measure inter-telomeric recombinat...

  16. 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…

  17. The roles of WRN and BLM RecQ helicases in the Alternative Lengthening of Telomeres

    OpenAIRE

    Mendez-Bermudez, Aaron; Hidalgo-Bravo, Alberto; Cotton, Victoria E.; Gravani, Athanasia; Jeyapalan, Jennie N.; Royle, Nicola J.

    2012-01-01

    Approximately 10% of all cancers, but a higher proportion of sarcomas, use the recombination-based alternative lengthening of telomeres (ALT) to maintain telomeres. Two RecQ helicase genes, BLM and WRN, play important roles in homologous recombination repair and they have been implicated in telomeric recombination activity, but their precise roles in ALT are unclear. Using analysis of sequence variation present in human telomeres, we found that a WRN– ALT+ cell line lacks the class of complex...

  18. Recombinant snake venom prothrombin activators.

    Science.gov (United States)

    Lövgren, Ann

    2013-01-01

    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 for additional cofactors, but does not discriminate non-carboxylated prothrombin from biologically active γ-carboxylated prothrombin. Here we report that recombinant trocarin and oscutarin could not efficiently generate thrombin without additional protein co-factors. We confirm that both trocarin and oscutarin are similar to human coagulation Factor X (FX), explaining the need for additional cofactors. Sequencing of a genomic fragment containing 7 out of the 8 exons coding for oscutarin further confirmed the similarity to human FX. PMID:23111318

  19. Heterogeneity in recombinant protein production

    DEFF Research Database (Denmark)

    Schalén, Martin; Johanson, Ted; Lundin, Luisa;

    2012-01-01

    . the cell physiology is affected. Cells are stressed, and this may severely affect growth, by-product accumulation, biomass yield and recombinant product yield. The stress caused by exposure to divergent microenvironments, genetic differences of individual cells, differing cell cycle stage and cell age, all...... 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...... 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....

  20. Corrosion resistance of zirconium oxynitride coatings deposited via DC unbalanced magnetron sputtering and spray pyrolysis-nitriding

    Energy Technology Data Exchange (ETDEWEB)

    Cubillos, G.I., E-mail: gcubillos@unal.edu.co [Department of Chemistry, Group of Materials and Chemical Processes, Universidad Nacional de Colombia, Av. Cra. 30 No 45-03, Bogotá (Colombia); Bethencourt, M., E-mail: manuel.bethencourt@uca.es [Department of Materials Science, Metallurgy Engineering and Inorganic Chemistry, International Campus of Excellence of the Sea - CEI-MAR, University of Cadiz, Avda. República Saharaui s/n, 11510 Puerto Real, Cádiz (Spain); Olaya, J.J., E-mail: jjolayaf@unal.edu.co [Faculty of Engineering, Group of Materials and Chemical Processes, Universidad Nacional de Colombia, Av. Cra. 30 No 45-03, Bogotá (Colombia)

    2015-02-01

    Highlights: • New ZrO{sub x}N{sub y} films were deposited on stainless steel 316L using PSY-N and UBMS. • ZrO{sub x}N{sub y} rhombohedral polycrystalline film grew with PSY-N. • Zr{sub 2}ON{sub 2} crystalline structures, mostly oriented along the (2 2 2) plane, grew with UBMS. • Layers improved corrosion behavior in NaCl media, especially those deposited by UBMS. - Abstract: ZrO{sub x}N{sub y}/ZrO{sub 2} thin films were deposited on stainless steel using two different methods: ultrasonic spray pyrolysis-nitriding (SPY-N) and the DC unbalanced magnetron sputtering technique (UBMS). Using the first method, ZrO{sub 2} was initially deposited and subsequently nitrided in an anhydrous ammonia atmosphere at 1023 K at atmospheric pressure. For UBMS, the film was deposited in an atmosphere of air/argon with a Φair/ΦAr flow ratio of 3.0. Structural analysis was carried out through X-ray diffraction (XRD), and morphological analysis was done through scanning electron microscopy (SEM) and atomic force microscopy (AFM). Chemical analysis was carried out using X-ray photoelectron spectroscopy (XPS). ZrO{sub x}N{sub y} rhombohedral polycrystalline film was produced with spray pyrolysis-nitriding, whereas using the UBMS technique, the oxynitride films grew with cubic Zr{sub 2}ON{sub 2} crystalline structures preferentially oriented along the (2 2 2) plane. Upon chemical analysis of the surface, the coatings exhibited spectral lines of Zr3d, O1s, and N1s, characteristic of zirconium oxynitride/zirconia. SEM analysis showed the homogeneity of the films, and AFM showed morphological differences according to the deposition technique of the coatings. Zirconium oxynitride films enhanced the stainless steel's resistance to corrosion using both techniques. The protective efficacy was evaluated using electrochemical techniques based on linear polarization (LP). The results indicated that the layers provide good resistance to corrosion when exposed to chloride

  1. 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...

  2. Short telomeres initiate telomere recombination in primary and tumor cells.

    Directory of Open Access Journals (Sweden)

    Tammy A Morrish

    2009-01-01

    Full Text Available Human tumors that lack telomerase maintain telomeres by alternative lengthening mechanisms. Tumors can also form in telomerase-deficient mice; however, the genetic mechanism responsible for tumor growth without telomerase is unknown. In yeast, several different recombination pathways maintain telomeres in the absence of telomerase-some result in telomere maintenance with minimal effects on telomere length. To examine non-telomerase mechanisms for telomere maintenance in mammalian cells, we used primary cells and lymphomas from telomerase-deficient mice (mTR-/- and Emumyc+mTR-/- and CAST/EiJ mouse embryonic fibroblast cells. These cells were analyzed using pq-ratio analysis, telomere length distribution outliers, CO-FISH, Q-FISH, and multicolor FISH to detect subtelomeric recombination. Telomere length was maintained during long-term growth in vivo and in vitro. Long telomeres, characteristic of human ALT cells, were not observed in either late passage or mTR-/- tumor cells; instead, we observed only minimal changes in telomere length. Telomere length variation and subtelomeric recombination were frequent in cells with short telomeres, indicating that length maintenance is due to telomeric recombination. We also detected telomere length changes in primary mTR-/- cells that had short telomeres. Using mouse mTR+/- and human hTERT+/- primary cells with short telomeres, we found frequent length changes indicative of recombination. We conclude that telomere maintenance by non-telomerase mechanisms, including recombination, occurs in primary cells and is initiated by short telomeres, even in the presence of telomerase. Most intriguing, our data indicate that some non-telomerase telomere maintenance mechanisms occur without a significant increase in telomere length.

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

    Directory of Open Access Journals (Sweden)

    Ilknur Erol

    2015-01-01

    Full Text Available 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. 大功率IGBT串联电压不平衡机制研究%Unbalancing Voltage of High Power Series Connected IGBT Valve

    Institute of Scientific and Technical Information of China (English)

    庞辉; 温家良; 贺之渊; 汤广福

    2011-01-01

    With the fast development and widely application of power electronic technologies, the requirement for high power converters has been constantly increased. The connection of high power insulation gate bipolar transistor (IGBT) in series is a key issue in the high voltage and power self-commuted converter application. The bottleneck for the operation of series connected high power IGBTs is the unbalanced voltage distributed among the IGBTs. But systematic theories and studies in this respect have always been absent. The systematic study must be commenced on the unbalanced voltage to advance the research on high power converter equipment. Based on the static and dynamic processes during operation of the seriesly connected IGBT valve and considering the IGBT characteristics, the corresponding influences of the unbalancing voltage on the series connected IGBT valve were induced; and the grade of unbalancing voltage among the devices was analyzed, which laid a foundation for keeping the voltage balance of the seriesly connected IGBT.%随着电力电子技术及其应用的快速发展,高压大功率换流器的应用越来越多。大功率绝缘栅双极晶体管(insulationgatebipolartransistor,IGBT1串联是实现高压大功率自换相换流器的一个重要基础。大功率串联IGBT运行中,最难解决的是串联IGBT之间的电压不平衡问题。为推进高压大功率换流器的研究,对大功率串联IGBT中器件间的电压不平衡机制进行了系统的研究。根据IGBT阀在串联运行时的主要静态、动态过程,结合IGBT自身的特性,得出了影响产生串联IGBT电压不平衡的各个因素,并对各个元件

  5. Evolution from increased cardiac mechanical function towards cardiomyopathy in the obese rat due to unbalanced high fat and abundant equilibrated diets

    OpenAIRE

    Mourmoura Evangelia; Chaté Valérie; Couturier Karine; Malpuech-Brugère Corinne; Azarnoush Kasra; Demaison Luc

    2015-01-01

    The aim of our study was to know whether high dietary energy intake (HDEI) with equilibrated and unbalanced diets in term of lipid composition modify the fatty acid profile of cardiac phospholipids and function of various cardiac cells and to know if the changes in membrane lipid composition can explain the modifications of cellular activity. Wistar rats were fed either a control or high-fat (HF) diet for 12 weeks and Zucker diabetic fatty (ZDF) rats as well as their lean littermate (ZL) a co...

  6. Preparing Recombinant Gonad Organ Cultures

    OpenAIRE

    sprotocols

    2014-01-01

    Authors: Blanche Capel and Jordan Batchvarov Corresponding author ([]()) ### INTRODUCTION It can be useful to assay migration between any two adjacent tissues during development. This protocol assays cell migration between the gonad and mesonephros using tissue recombination between genetically marked and unmarked tissue, combined with an organ culture technique. First, agar blocks are prepared in a custom-built mold. The size and sh...

  7. Controlled Release from Recombinant Polymers

    OpenAIRE

    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 tempor...

  8. The many facets of homologous recombination at telomeres

    Directory of Open Access Journals (Sweden)

    Clémence Claussin

    2015-07-01

    Full Text Available The ends of linear chromosomes are capped by nucleoprotein structures called telomeres. A dysfunctional telomere may resemble a DNA double-strand break (DSB, which is a severe form of DNA damage. The presence of one DSB is sufficient to drive cell cycle arrest and cell death. Therefore cells have evolved mechanisms to repair DSBs such as homologous recombination (HR. HR-mediated repair of telomeres can lead to genome instability, a hallmark of cancer cells, which is why such repair is normally inhibited. However, some HR-mediated processes are required for proper telomere function. The need for some recombination activities at telomeres but not others necessitates careful and complex regulation, defects in which can lead to catastrophic consequences. Furthermore, some cell types can maintain telomeres via telomerase-independent, recombination-mediated mechanisms. In humans, these mechanisms are called alternative lengthening of telomeres (ALT and are used in a subset of human cancer cells. In this review, we summarize the different recombination activities occurring at telomeres and discuss how they are regulated. Much of the current knowledge is derived from work using yeast models, which is the focus of this review, but relevant studies in mammals are also included.

  9. 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 protect

  10. Recombinant innovation and endogenous technological transitions

    NARCIS (Netherlands)

    K. Frenken; L.R. Izquierdo; P. Zeppini

    2012-01-01

    We propose a model of technological transitions based on two different types of innovations. Branching innovations refer to technological improvements along a particular path, while recombinant innovations represent fusions of multiple paths. Recombinant innovations create "short-cuts" which reduce

  11. DC-bus voltage control of grid-connected voltage source converter by using space vector modulated direct power control under unbalanced network conditions

    DEFF Research Database (Denmark)

    Xiao, Lei; Huang, Shoudao; Lu, Kaiyuan

    2013-01-01

    Unbalanced grid voltage will cause large dc-bus voltage ripple and introduce high harmonic current components on the grid side. This will severely threaten the safety of the grid-connected voltage source converter (VSC) and consequently, affect the healthy operation condition of the load. In this......Unbalanced grid voltage will cause large dc-bus voltage ripple and introduce high harmonic current components on the grid side. This will severely threaten the safety of the grid-connected voltage source converter (VSC) and consequently, affect the healthy operation condition of the load....... In this study, a new proportional-integral-resonant (PI-RES) controller-based, space vector modulated direct power control topology is proposed to suppress the dc-bus voltage ripple and in the same time, controlling effectively the instantaneous power of the VSC. A special ac reactive power reference component...... is introduced in the controller, which is necessary in order to reduce the dc-bus voltage ripple and active power harmonics at the same time. The proposed control topology is implemented in the lab. Simulation and experimental results are provided to validate its performance and the analysis presented...

  12. 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...

  13. 基于柔性接地技术的配电网三相不平衡过电压抑制方法%Suppressing Method of Three-phase Unbalanced Overvoltage Based on Distribution Networks Flexible Grounding Control

    Institute of Scientific and Technical Information of China (English)

    曾祥君; 胡京莹; 王媛媛; 熊婷婷

    2014-01-01

    配电网三相对地参数不平衡会产生三相不平衡电压,一般采用投切电容器或电抗器补偿三相不平衡参数,抑制不平衡电压,但该方法补偿的精度和速度有限,难以彻底而迅速地实现三相不平衡过电压抑制。因此,在前期发明的柔性接地技术(专利201110006701.2)基础上,提出配电网三相不平衡过电压抑制新方法。通过PWM有源逆变向配电网注入零序电流补偿三相对地不平衡电流,实现对零序电压的控制,从而抑制三相不平衡过电压。仿真分析结果表明,所提方法可有效抑制三相不平衡过电压,能够将中性点位移电压限制为零。%Unbalanced three-phase parameters to ground can result in the three-phase unbalanced voltage in distribution networks. Generally switched capacitors and reactors are applied in the compensation of three-phase unbalanced parameters to limit the unbalanced voltage. Whereas, the compensation method has limited precision and speed, it is difficult to satisfy the requirement of the three-phase unbalanced voltage suppressing thoroughly and rapidly. In order to improve it, a new method based on the invention patent of flexible grounding technique (Patent number 201110006701.2) was presented in this paper. The three-phase unbalanced current to ground was compensated by the injecting zero sequence current to distribution network through pulse width modulation (PWM) inverter. The zero sequence voltage was controlled and the three-phase unbalanced overvoltage was thus suppressed. Simulation results showed that the proposed method limited the unbalanced overvoltage effectively, and the neutral displacement voltage could be limited to zero.

  14. Mechanisms of sister chromatid recombination

    International Nuclear Information System (INIS)

    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-G2 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.)

  15. Recombinant erythropoietin in clinical practice

    OpenAIRE

    Ng, T; Marx, G.; Littlewood, T; Macdougall, I

    2003-01-01

    The introduction of recombinant human erythropoietin (RHuEPO) has revolutionised the treatment of patients with anaemia of chronic renal disease. Clinical studies have demonstrated that RHuEPO is also useful in various non-uraemic conditions including haematological and oncological disorders, prematurity, HIV infection, and perioperative therapies. Besides highlighting both the historical and functional aspects of RHuEPO, this review discusses the applications of RHuEPO in clinical practice a...

  16. Recombinant antibodies and tumor targeting

    OpenAIRE

    Sheikholvaezin, Ali

    2006-01-01

    Different antibody derived constructs are rapidly advancing as putative tools for treatment of malignant diseases. Antibody engineering has added significant new technologies to modify size, affinities, solubility, stability and biodistribution properties for immunoconjugates. In the present thesis, the aim was to increase our knowledge on how new recombinant antibodies could be tailored to optimize localization to experimental tumors in mice. One hybridoma, producing the monoclonal antibody ...

  17. 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...

  18. 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.

  19. Loss of ATRX Suppresses Resolution of Telomere Cohesion to Control Recombination in ALT Cancer Cells.

    Science.gov (United States)

    Ramamoorthy, Mahesh; Smith, Susan

    2015-09-14

    The chromatin-remodeler ATRX is frequently lost in cancer cells that use ALT (alternative lengthening of telomeres) for telomere maintenance, but its function in telomere recombination is unknown. Here we show that loss of ATRX suppresses the timely resolution of sister telomere cohesion that normally occurs prior to mitosis. In the absence of ATRX, the histone variant macroH2A1.1 binds to the poly(ADP-ribose) polymerase tankyrase 1, preventing it from localizing to telomeres and resolving cohesion. The resulting persistent telomere cohesion promotes recombination between sister telomeres, while it suppresses inappropriate recombination between non-sisters. Forced resolution of sister telomere cohesion induces excessive recombination between non-homologs, genomic instability, and impaired cell growth, indicating the ATRX-macroH2A1.1-tankyrase axis as a potential therapeutic target in ALT tumors. PMID:26373281

  20. Targeted in vivo inhibition of specific protein-protein interactions using recombinant antibodies.

    Directory of Open Access Journals (Sweden)

    Matej Zábrady

    Full Text Available With the growing availability of genomic sequence information, there is an increasing need for gene function analysis. Antibody-mediated "silencing" represents an intriguing alternative for the precise inhibition of a particular function of biomolecules. Here, we describe a method for selecting recombinant antibodies with a specific purpose in mind, which is to inhibit intrinsic protein-protein interactions in the cytosol of plant cells. Experimental procedures were designed for conveniently evaluating desired properties of recombinant antibodies in consecutive steps. Our selection method was successfully used to develop a recombinant antibody inhibiting the interaction of ARABIDOPSIS HISTIDINE PHOSPHOTRANSFER PROTEIN 3 with such of its upstream interaction partners as the receiver domain of CYTOKININ INDEPENDENT HISTIDINE KINASE 1. The specific down-regulation of the cytokinin signaling pathway in vivo demonstrates the validity of our approach. This selection method can serve as a prototype for developing unique recombinant antibodies able to interfere with virtually any biomolecule in the living cell.

  1. Lysostaphin: use of a recombinant bactericidal enzyme as a mastitis therapeutic.

    Science.gov (United States)

    Oldham, E R; Daley, M J

    1991-12-01

    A recombinant mucolytic protein, lysostaphin, was evaluated as a potential intramammary therapeutic for Staphylococcus aureus mastitis in dairy cattle. Lysostaphin, a product of Staphylococcus simulans, enzymatically degrades the cell wall of Staphylococcus aureus and is bactericidal. Thirty Holstein-Freisian dairy cattle in their first lactation were infected with Staphylococcus aureus (Newbould 305, ATCC 29740) in all quarters. Infections were established and monitored for somatic cell counts and Staphylococcus aureus colony-forming units 3 wk prior to subsequent treatment. Infected animals were injected through the teat canal with a single dose of recombinant lysostaphin (dose response 1 to 500 mg) or after three successive p.m. milkings with 100 mg of recombinant lysostaphin in 60 ml of sterile phosphate-buffered saline. Animals were considered cured if the milk remained free of Staphylococcus aureus for a total of 28 milkings after last treatment. Kinetic analysis of immunologically active recombinant lysostaphin demonstrated that a minimum bactericidal concentration was maintained in the milk for up to 36 to 48 h after a single infusion of 100 mg of recombinant lysostaphin. The cure rate of quarters receiving recombinant lysostaphin (100 mg in sterile phosphate-buffered saline, administered over three consecutive p.m. milkings) was 20% compared with 29% for sodium cephapirin in saline and 57% for a commercial antibiotic formulation, respectively. An improved formulation of recombinant lysostaphin may prove to be an effective alternative to antibiotic therapy for bovine mastitis.

  2. Charge recombination mechanism to explain the negative capacitance in dye-sensitized solar cells

    Science.gov (United States)

    Lie-Feng, Feng; Kun, Zhao; Hai-Tao, Dai; Shu-Guo, Wang; Xiao-Wei, Sun

    2016-03-01

    Negative capacitance (NC) in dye-sensitized solar cells (DSCs) has been confirmed experimentally. In this work, the recombination behavior of carriers in DSC with semiconductor interface as a carrier’s transport layer is explored theoretically in detail. Analytical results indicate that the recombination behavior of carriers could contribute to the NC of DSCs under small signal perturbation. Using this recombination capacitance we propose a novel equivalent circuit to completely explain the negative terminal capacitance. Further analysis based on the recombination complex impedance show that the NC is inversely proportional to frequency. In addition, analytical recombination resistance is composed by the alternating current (AC) recombination resistance (Rrac) and the direct current (DC) recombination resistance (Rrdc), which are caused by small-signal perturbation and the DC bias voltage, respectively. Both of two parts will decrease with increasing bias voltage. Project supported by the National Natural Science Foundation of China (Grant Nos. 11204209 and 60876035) and the Natural Science Foundation of Tianjin City, China (Grant No. 13JCZDJC32800).

  3. Recombinants proteins for industrial uses: utilization of Pichia pastoris expression system

    OpenAIRE

    Claudia Rabert; Daniel Weinacker; Adalberto Pessoa Jr; Farías, Jorge G.

    2013-01-01

    The innovation in industrial process with impact in the efficient production is the major challenge for actual industry. A high numerous of enzymes are utilized in at different level of process; the search for new alternatives with better characteristic has become a field of study of great interest, the recombinant protein achievement in a different host system is an alternative widely assessed for production of this. The microorganism Pichia pastoris has been used like a successful expressio...

  4. 不平衡转子涡动对鼓筒振动特性影响%Effect of unbalanced rotor whirl on drum vibration

    Institute of Scientific and Technical Information of China (English)

    曹登庆; 孙述鹏; 刘伦

    2014-01-01

    Taking into account the coupling between rotor whirl and drum vibration,the dynamic model of a disk-drum-shaft system was established for the drum-disk type rotors in turbo-machines.Based on the model,the effect of unbalanced rotor whirl on drum vibration was studied.The results show that the unbalanced rotor whirl is coupled only with the drum vibration modes which carry one circumferential wavenumber.If the support stiffness of the shaft is linear, the centroid motion locus of the shaft will be a circle and the steady-state vibration of drum cannot be maintained. However,the centroid motion locus will be complex provided that the support stiffness of the shaft is nonlinear.Under this circumstance,slight and steady-state vibration of drum will be induced by the whirl of the unbalanced rotor.%针对叶轮机械中鼓盘式转子,考虑转子涡动与鼓筒振动间耦合作用,建立轮盘-鼓筒-转轴系统动力学模型,分析不平衡转子涡动对鼓筒振动特性影响。结果表明,不平衡转子涡动仅与环向波数为1的鼓筒弹性振动模态耦合;转轴支撑刚度为线性时,转子稳态运动轴心轨迹为圆形,不平衡转子涡动不直接引发鼓筒稳态弹性振动;转轴为非线性支撑时,转子稳态运动轴心轨迹变复杂,不平衡转子涡动会引起鼓筒小幅稳态振动。

  5. Recombinant phage probes for Listeria monocytogenes

    International Nuclear Information System (INIS)

    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 104 cells ml-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

  6. 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.

  7. 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.

  8. Recombinant phage probes for Listeria monocytogenes

    Science.gov (United States)

    Carnazza, S.; Gioffrè, G.; Felici, F.; Guglielmino, S.

    2007-10-01

    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 104 cells ml-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.

  9. Down syndrome due to a recombination of a chromosome 21 paracentric inversion in 1 of 2 cases with a review of paracentric recombinants

    Energy Technology Data Exchange (ETDEWEB)

    Jewett, T.; Rao, P.N.; Berry, M. [Wake Forest Univ., Winston-Salem, NC (United States)] [and others

    1994-09-01

    We recently identified 2 paracentric inversions (PAI) of chromosome 21. Case 1 was identified prenatally and paternally inherited: 46,XY,inv(21)(q21.2q22.13). The outcome is pending. Case 2 was a newborn male infant with clinical features of Down syndrome and an apparent inversion-duplication within chromosome 21. Parental chromosome analysis showed a maternal PAI: 46,XX,inv(21)(q21.2q22.3). The resulting child`s karyotype was: 46,XY,rec(21)(pter{yields}q21.2::q22.3{yields}q21.2::q22.3{yields}pter). Duplication of chromosome region q22.3{yields}qter was confirmed by FISH using a Down syndrome region specific probe (Cambio). Cytologically, the cornerstone of meiotic recombination from a paracentric inversion is the {open_quotes}reverse loop{close_quotes} model. In this model, a crossover event in the inversion loop results in the formation of gametes carrying either a dicentric chromatid, an acentric fragment, a normal chromatid or a chromatid with an inversion. However, a literature review of 326 PAI identified only 2 dicentrics and 15 other recombinants: 1 duplication/deletion; 6 deletions; 8 duplications. A U-type exchange model during meiosis within the inversion loop may best account for duplication/deletion recombinants. In contrast, the recombination in our case 2 would have occurred outside the loop. It is possible that no single explanation for PAI recombination may account for all outcomes. Alternative models of PAI recominational events will be presented. The literature suggests a low risk for prenatal loss due to abnormal PAI recombinants. In our review, viable offspring with recombinant chromosomes occurred in 3.8% of the PAI. Considering the potential for an increased incidence of recombination, prenatal diagnosis for all PAI carriers is warranted.

  10. Exploration of Priority Strategies for Harmonious Development between Urbanization and the Construction of New Countryside in China Based on the Theory of Unbalanced Growth

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Based on the theory of unbalanced growth,we analyze priority strategy of different regions in China.It is prior to enhance the quality of urbanization in the East,make a long-term planning for construction of small towns,focus on harmony between human and nature,so as to realize its development to integrate with international urbanization level.For the middle areas,urbanization and construction of new countryside should be developed simultaneously,take a road of interactive development of urban and rural areas,finally to raise the level of urbanization.As to the western areas,it is required to firstly build new countryside,focus on construction of infrastructural facilities,adjust and optimize structure of agricultural production,and push forward the agricultural industrialization.

  11. Simultaneous Unbalanced Shared Local Oscillator Heterodyne Interferometry (SUSHI) for high SNR, minimally destructive dispersive detection of time-dependent atomic spins

    CERN Document Server

    Locke, Mary

    2013-01-01

    We demonstrate "Simultaneous Unbalanced Shared Local Oscillator Heterodyne Interferometry (SUSHI)," a new method for minimally destructive, high SNR dispersive detection of atomic spins. In SUSHI a dual-frequency probe laser interacts with atoms in one arm of a Mach-Zehnder interferometer, then beats against a bright local oscillator beam traversing the other arm, resulting in two simultaneous, independent heterodyne measurements of the atom-induced phase shift. Measurement noise due to mechanical disturbances of beam paths is strongly rejected by the technique of \\emph{active subtraction} in which anti-noise is actively written onto the local oscillator beam via an optical phase-locked-loop. In SUSHI, technical noise due to phase, amplitude, and frequency fluctuations of the various laser fields is strongly rejected (i) for any mean phase bias between the interferometer arms, (ii) without the use of piezo actuated mirrors, and (iii) without signal balancing. We experimentally demonstrate an ultra-low technic...

  12. 农村电网不对称负荷补偿方法研究%Study on compensation method of unbalanced load in rural power grid

    Institute of Scientific and Technical Information of China (English)

    房俊龙; 于洪涛; 马文川; 蔡银哿; 杨庆忠; 杨国良

    2014-01-01

    The paper proposed TCR type static var compensator based on Steinmetz theory which it could be used in the rural power grid, it could compensate unbalanced load and improve power factor in the meantime. The results showed that method could effectively make three-phase load balance, while increasing the power factor, had a certain theoretical and application value.%文章提出在农村电网中采用基于Steinmetz电路理论的TCR型静止无功补偿器,平衡三相不对称负荷,提高系统功率因数。仿真验证结果表明,该方法能使三相负荷平衡,提高功率因数,具有一定理论意义及应用价值。

  13. 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.

  14. Substrate Heating Effect on c-Axis Texture and Piezoelectric Properties of AlN Thin Films Deposited by Unbalanced Magnetron Sputtering

    Science.gov (United States)

    Hasheminiasari, Masood; Lin, Jianliang

    2016-06-01

    Aluminum nitride (AlN) thin films with highly preferred (002) orientations have been reactively deposited by a pulsed-closed field unbalanced magnetron sputtering system using TiN/Ti as the seed/adhesion layer with various substrate temperatures. The texture, orientation and piezoelectric properties of AlN films were characterized by means of x-ray diffraction, rocking curves and laser interferometry. A Michelson laser interferometer was designed and built to obtain the converse piezoelectric response of the deposited AlN thin films. It was found that a slight substrate temperature increase would significantly affect the (002) orientation and the piezoelectric coefficient of AlN thin films compared to the coating obtained with no intentional substrate heating, while higher temperature applications on substrate deteriorated the c-axis texture of the coatings without significant improvement in the piezoelectric response of AlN films.

  15. 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. PMID:12393964

  16. Unbalanced fermentation of glycerol in Escherichia coli via heterologous production of an electron transport chain and electrode interaction in microbial electrochemical cells.

    Science.gov (United States)

    Sturm-Richter, Katrin; Golitsch, Frederik; Sturm, Gunnar; Kipf, Elena; Dittrich, André; Beblawy, Sebastian; Kerzenmacher, Sven; Gescher, Johannes

    2015-06-01

    Microbial electrochemical cells are an emerging technology for achieving unbalanced fermentations. However, organisms that can serve as potential biocatalysts for this application are limited by their narrow substrate spectrum. This study describes the reprogramming of Escherichia coli for the efficient use of anodes as electron acceptors. Electron transfer into the periplasm was accelerated by 183% via heterologous expression of the c-type cytochromes CymA, MtrA and STC from Shewanella oneidensis. STC was identified as a target for heterologous expression via a two-stage screening approach. First, mass spectroscopic analysis revealed natively expressed cytochromes in S. oneidensis. Thereafter, the corresponding genes were cloned and expressed in E. coli to quantify periplasmic electron transfer activity using methylene blue. This redox dye was further used to expand electron transfer to carbon electrode surfaces. The results demonstrate that E. coli can be reprogrammed from glycerol fermentation to respiration upon production of the new electron transport chain.

  17. Bacteriophage recombination systems and biotechnical applications.

    Science.gov (United States)

    Nafissi, Nafiseh; Slavcev, Roderick

    2014-04-01

    Bacteriophage recombination systems have been widely used in biotechnology for modifying prokaryotic species, for creating transgenic animals and plants, and more recently, for human cell gene manipulation. In contrast to homologous recombination, which benefits from the endogenous recombination machinery of the cell, site-specific recombination requires an exogenous source of recombinase in mammalian cells. The mechanism of bacteriophage evolution and their coexistence with bacterial cells has become a point of interest ever since bacterial viruses' life cycles were first explored. Phage recombinases have already been exploited as valuable genetic tools and new phage enzymes, and their potential application to genetic engineering and genome manipulation, vectorology, and generation of new transgene delivery vectors, and cell therapy are attractive areas of research that continue to be investigated. The significance and role of phage recombination systems in biotechnology is reviewed in this paper, with specific focus on homologous and site-specific recombination conferred by the coli phages, λ, and N15, the integrase from the Streptomyces phage, ΦC31, the recombination system of phage P1, and the recently characterized recombination functions of Yersinia phage, PY54. Key steps of the molecular mechanisms involving phage recombination functions and their application to molecular engineering, our novel exploitations of the PY54-derived recombination system, and its application to the development of new DNA vectors are discussed.

  18. Bacteriophage recombination systems and biotechnical applications.

    Science.gov (United States)

    Nafissi, Nafiseh; Slavcev, Roderick

    2014-04-01

    Bacteriophage recombination systems have been widely used in biotechnology for modifying prokaryotic species, for creating transgenic animals and plants, and more recently, for human cell gene manipulation. In contrast to homologous recombination, which benefits from the endogenous recombination machinery of the cell, site-specific recombination requires an exogenous source of recombinase in mammalian cells. The mechanism of bacteriophage evolution and their coexistence with bacterial cells has become a point of interest ever since bacterial viruses' life cycles were first explored. Phage recombinases have already been exploited as valuable genetic tools and new phage enzymes, and their potential application to genetic engineering and genome manipulation, vectorology, and generation of new transgene delivery vectors, and cell therapy are attractive areas of research that continue to be investigated. The significance and role of phage recombination systems in biotechnology is reviewed in this paper, with specific focus on homologous and site-specific recombination conferred by the coli phages, λ, and N15, the integrase from the Streptomyces phage, ΦC31, the recombination system of phage P1, and the recently characterized recombination functions of Yersinia phage, PY54. Key steps of the molecular mechanisms involving phage recombination functions and their application to molecular engineering, our novel exploitations of the PY54-derived recombination system, and its application to the development of new DNA vectors are discussed. PMID:24442504

  19. [Cytogenetic analysis of alloplasmic recombinant lines (H. vulgare)-T. aestivum with unstable fertility and viability].

    Science.gov (United States)

    Badaeva, E D; Pershina, L A; Bil'danova, L L

    2006-02-01

    Comparative cytogenetic analysis was performed with four alloplasmic recombinant (Hordeum vulgare)-Triticum aestivum lines differing in morphological traits, number of seeds per spike, and seed plumpness. None of the lines displayed introgression of the barley genetic material: the karyotypes included only common wheat chromosomes. Two lines, 79(B) and 79(D), were cytogenetically stable. Plants of lines 79(A) and 79(C) displayed a high frequency of unbalanced chromosome aberrations, including dicentric and polycentric chromosomes, terminal deletions varying in size, acentric fragments, and multiple unidentifiable translocations. Previous studies of the mitochondrial genome showed that the two cytologically unstable lines, which were also unstable in fertility and viability, are characterized by heteroplasmy at the mitochondrial 18S-5S locus (simultaneous presence of barley and wheat fragments). Stable lines 79(B) and 79(D) with normal fertility contained only wheat mitochondrial markers. It was assumed that the substantial instability of the nuclear genome in lines 79(C) and 79(A) was a result of nuclear-cytoplasmic incompatibility and was associated with heteroplasmy, while elimination or considerable reduction of barley material in the mitochondrial genome stabilized the nuclear genome of lines 79(B) and 79(D). In turn, the instability of the nuclear genome was responsible for a decrease in viability and fertility of plants. PMID:16583704

  20. Estimation of the proportion of genetically unbalanced spermatozoa in the semen of boars carrying chromosomal rearrangements using FISH on sperm nuclei

    Directory of Open Access Journals (Sweden)

    Yerle Martine

    2004-01-01

    Full Text Available Abstract Many chromosomal rearrangements are detected each year in France on young boars candidates for reproduction. The possible use of these animals requires a good knowledge of the potential effect of the rearrangements on the prolificacy of their mates. This effect can be estimated by an accurate determination of the rate of unbalanced spermatozoa in the semen of boars which carry the rearrangements. Indeed, these spermatozoa exhibiting normal fertilizing ability are responsible for an early embryonic mortality, and then, for a decrease of the litter sizes. The "spermFISH" technique, i.e. fluorescent in situ hybridization on decondensed sperm heads, has been used on several occasions in Man, in this perspective. In livestock species, this method was formerly used mainly for semen sexing purposes. We used it, for the first time, to estimate the rates of imbalance in the semen of four boars carrying chromosomal rearrangements: two reciprocal translocations, rcp(3;15(q27;q13 and rcp(12;14(q13;q21, as well as two independent cases of trisomy 18 mosaicism. The rates of unbalanced gametes were relatively high for the two reciprocal translocations (47.83% and 24.33%, respectively. These values differed from the apparent effects of the rearrangements estimated using a limited number of litters: a decrease in prolificacy of 23% (estimation obtained using the results of 6 litters and 39% (57 litters, respectively for the 3/15 and 12/14 translocations. The imbalance rates were much lower for the trisomy mosaics (0.58% and 1.13%, suggesting a very moderate effect of this special kind of chromosomal rearrangement.

  1. 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)

    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 (αrβr) reference frames. - Abstract: In this study, novel hybrid proportional-integral-harmonic resonant (PI-R) controllers implemented in the both (dq)+ and rotor (αrβr) 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 (αrβr) 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

  2. The Effect of Alternating Bars Migration on River Bifurcation Dynamics

    Science.gov (United States)

    Miori, S.; Bertoldi, W.; Repetto, R.; Zanoni, L.; Tubino, M.

    2007-12-01

    Recent theoretical analysis, field and laboratory observations pointed out that fluvial bifurcation show an intrinsic instability, leading to the establishment of an unbalanced flow and sediments distribution in the downstream branches. The existence of equilibrium configurations has been proved, which mainly depend on the hydraulic and morphologic conditions of the upstream flow. However, flow and sediment transport in braided networks are highly unsteady, so that the bifurcation can hardly reach an equilibrium configuration. One of the main causes of temporal fluctuations is the migration of alternate bars in the upstream channel, that can affect and control the flow partition in the distributaries. We analysed the bar - bifurcation interactions by experimental and analytical investigations. We performed a set of flume experiments on a Y shaped fixed banks and movable bed bifurcation. Laboratory results show that bar formation in the upstream channel perturbs the discharge distribution with a series of fluctuations strictly related to the period of bar migration. Four different behaviours have been identified, characterised by small perturbations of the equilibrium state (balanced or unbalanced), by the occurrence of large fluctuations or by the closure of one of the distributaries. The character of the bifurcation is controlled by the amplitude and speed of alternate bars that directly influence the amplitude and period of discharge oscillations. Consequently, at large values of the aspect ratio (high bars) and low sediment mobility (slow bars) the bifurcation dynamics is likely to be dominated by bars migration. Extending the one-dimensional model proposed by Bolla Pittaluga et al. (2003), we introduce the effect of bars migrating in the upstream channel. In the present model, the bifurcation is forced with spatial crosswise fluctuations of feeding conditions, in order to reproduce the transverse distribution of sediment and water of an alternate bar pattern as

  3. 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...

  4. Telomeric circles are abundant in the stn1-M1 mutant that maintains its telomeres through recombination

    OpenAIRE

    Evelina Y Basenko; Cesare, Anthony J.; Iyer, Shilpa; Griffith, Jack D.; McEachern, Michael J.

    2009-01-01

    Some human cancers maintain their telomeres using the alternative lengthening of telomeres (ALT) mechanism; a process thought to involve recombination. Different types of recombinational telomere elongation pathways have been identified in yeasts. In senescing yeast telomerase deletion (ter1-Δ) mutants with very short telomeres, it has been hypothesized that copying a tiny telomeric circle (t-circle) by a rolling circle mechanism is the key event in telomere elongation. In other cases more cl...

  5. Vaccination with recombinant Boophilus annulatus Bm86 ortholog protein, Ba86, protects cattle against B. annulatus and B. microplus infestations

    OpenAIRE

    Jongejan Frans; Naranjo Victoria; Almazán Consuelo; Canales Mario; de la Fuente José

    2009-01-01

    Abstract Background The cattle ticks, Boophilus spp., affect cattle production in tropical and subtropical regions of the world. Tick vaccines constitute a cost-effective and environmentally friendly alternative to tick control. The recombinant B. microplus Bm86 protective antigen has been shown to protect cattle against tick infestations. Recently, the gene coding for B. annulatus Bm86 ortholog, Ba86, was cloned and the recombinant protein was secreted and purified from the yeast Pichia past...

  6. Comparison of 2 synthetically generated recombinant prions

    OpenAIRE

    Zhang, Yi; Wang, Fei; Wang, Xinhe; Zhang, Zhihong; Xu, Yuanyuan; Yu, Guohua; Yuan, Chonggang; Ma, Jiyan

    2014-01-01

    Prion is a protein-conformation-based infectious agent causing fatal neurodegenerative diseases in humans and animals. Our previous studies revealed that in the presence of cofactors, infectious prions can be synthetically generated in vitro with bacterially expressed recombinant prion protein (PrP). Once initiated, the recombinant prion is able to propagate indefinitely via serial protein misfolding cyclic amplification (sPMCA). In this study, we compared 2 separately initiated recombinant p...

  7. How well do we understand cosmological recombination?

    OpenAIRE

    Wong, Wan Yan; Moss, Adam; Scott, Douglas

    2007-01-01

    The major theoretical limitation for extracting cosmological parameters from the CMB sky lies in the precision with which we can calculate the cosmological recombination process. Uncertainty in the details of hydrogen and helium recombination could effectively increase the errors or bias the values of the cosmological parameters derived from the Planck satellite, for example. Here we modify the cosmological recombination code RECFAST by introducing one more parameter to reproduce the recent n...

  8. Role of ubiquitination in meiotic recombination repair

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Programmed and unprogrammed double-strand breaks (DSBs) often arise from such physiological requirements as meiotic recombination, and exogenous insults, such as ionizing radiation (IR). Due to deleterious impacts on genome stability, DSBs must be appropriately processed and repaired in a regulatory manner. Recent investigations have indicated that ubiquitination is a critical factor in DNA damage response and meiotic recombination repair. This review summarizes the effects of proteins and complexes associated with ubiquitination with regard to homologous recombination (HR)-dependent DSB repair.

  9. Rapid purification of recombinant histones.

    Directory of Open Access Journals (Sweden)

    Henrike Klinker

    Full Text Available 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.

  10. Complementary and Alternative Medicine

    Science.gov (United States)

    ... Help a Friend Who Cuts? Complementary and Alternative Medicine KidsHealth > For Teens > Complementary and Alternative Medicine Print ... replacement. continue How Is CAM Different From Conventional Medicine? Conventional medicine is based on scientific knowledge of ...

  11. Alternative medicine - pain relief

    Science.gov (United States)

    Alternative medicine refers to treatments that are used instead of conventional (standard) ones. If you use an alternative ... considered complementary therapy. There are many forms of ... Acupuncture involves stimulating certain acupoints on the body ...

  12. Human Insulin from Recombinant DNA Technology

    Science.gov (United States)

    Johnson, Irving S.

    1983-02-01

    Human insulin produced by recombinant DNA technology is the first commercial health care product derived from this technology. Work on this product was initiated before there were federal guidelines for large-scale recombinant DNA work or commercial development of recombinant DNA products. The steps taken to facilitate acceptance of large-scale work and proof of the identity and safety of such a product are described. While basic studies in recombinant DNA technology will continue to have a profound impact on research in the life sciences, commercial applications may well be controlled by economic conditions and the availability of investment capital.

  13. Comparative Genomics and Extensive Recombinations in Phage Communities

    Science.gov (United States)

    Poisson, Guylaine; Belcaid, Mahdi; Bergeron, Anne

    Comparing the genomes of two closely related viruses often produces mosaics where nearly identical sequences alternate with sequences that are unique to each genome. When several closely related genomes are compared, the unique sequences are likely to be shared with third genomes, leading to virus mosaic communities. Here we present comparative analysis of sets of Staphylococcus aureus phages that share large identical sequences with up to three other genomes, and with different partners along their genomes. We introduce mosaic graphs to represent these complex recombination events, and use them to illustrate the breath and depth of sequence sharing: some genomes are almost completely made up of shared sequences, while genomes that share very large identical sequences can adopt alternate functional modules. Mosaic graphs also allow us to identify breakpoints that could eventually be used for the construction of recombination networks. These findings have several implications on phage metagenomics assembly, on the horizontal gene transfer paradigm, and more generally on the understanding of the composition and evolutionary dynamics of virus communities.

  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. Conditions for charge transport without recombination in low mobility organic solar cells and photodiodes (Presentation Recording)

    Science.gov (United States)

    Stolterfoht, Martin; Armin, Ardalan; Philippa, Bronson; White, Ronald D.; Burn, Paul L.; Meredith, Paul; Juška, Gytis; Pivrikas, Almantas

    2015-10-01

    Organic semiconductors typically possess low charge carrier mobilities and Langevin-type recombination dynamics, which both negatively impact the performance of organic solar cells and photodetectors. Charge transport in organic solar cells is usually characterized by the mobility-lifetime product. Using newly developed transient and steady state photocurrent measurement techniques we show that the onset of efficiency limiting photocarrier recombination is determined by the charge that can be stored on the electrodes of the device. It is shown that significant photocarrier recombination can be avoided when the total charge inside the device, defined by the trapped, doping-induced and mobile charge carriers, is less than the electrode charge. Based upon this physics we propose the mobility-recombination coefficient product as an alternative and more convenient figure of merit to minimize the recombination losses. We validate the results in 3 different organic semiconductor-based light harvesting systems with very different charge transport properties. The findings allow the determination of the charge collection efficiency in fully operational devices. In turn, knowing the conditions under which non-geminate recombination is eliminated enables one to quantify the generation efficiency of free charge carriers. The results are relevant to a wide range of light harvesting systems, particularly those based upon disordered semiconductors, and require a rethink of the critical parameters for charge transport.

  16. Fundamental Studies of Recombinant Hydrogenases

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Michael W

    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.

  17. Titania Photocatalysis beyond Recombination: A Critical Review

    Directory of Open Access Journals (Sweden)

    Bunsho Ohtani

    2013-11-01

    Full Text Available This short review paper shows the significance of recombination of a photoexcited electron and a hole in conduction and valence bands, respectively, of a titania photocatalyst, since recombination has not yet been fully understood and has not been evaluated adequately during the past several decades of research on heterogeneous photocatalysis.

  18. Recombinant organisms for production of industrial products

    OpenAIRE

    Adrio, Jose-Luis; Demain, Arnold L.

    2009-01-01

    A revolution in industrial microbiology was sparked by the discoveries of ther double-stranded structure of DNA and the development of recombinant DNA technology. Traditional industrial microbiology was merged with molecular biology to yield improved recombinant processes for the industrial production of primary and secondary metabolites, protein biopharmaceuticals and industrial enzymes. Novel genetic techniques such as metabolic engineering, combinatorial biosynthesis and molecular breeding...

  19. 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...

  20. 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 cerevi...

  1. Theoretic Study of CⅡ Recombination Line

    Institute of Scientific and Technical Information of China (English)

    彭永伦; 王民盛; 韩小英; 李家明

    2004-01-01

    Using the R-matrix method, we carry out theoretical calculations for recombination line λ 8794 A(3d'-3p') of CⅡ, which is important to estimate the abundances of carbon in planetary nebulae. Our calculations are based on three sets of target orbital basis, through which we elucidate the electron correlation and static polarization effects in the dielectronic recombination processes.

  2. Electron-ion recombination at low energy

    International Nuclear Information System (INIS)

    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.)

  3. Anticoagulation with recombinant hirudin and danaparoid sodium in pediatric patients.

    Science.gov (United States)

    Severin, Thomas; Zieger, Barbara; Sutor, Anton H

    2002-10-01

    Patients receiving heparin are at risk of developing heparin-induced thrombocytopenia (HIT). Whereas in HIT I only reversible mild thrombocytopenia occurs within the first days of heparin treatment, HIT II may lead to potentially life-threatening thromboembolic events. Pediatric patients suffering from HIT II have been reported in a study on newborns and in a few reports on children and adolescents. However, thrombotic complications can be as severe in children as they are in adults. In the case of HIT II, the withdrawal of heparin is required and alternative anticoagulation should be started. In contrast to numerous investigations in adult patients, including prospective studies, experience with alternative anticoagulants in pediatric patients is limited. The available data were analyzed according to HIT II complications, alternative anticoagulation, and clinical outcome. In conclusion, HIT II represents a potentially dangerous complication of heparin therapy in pediatric patients also. Alternative anticoagulation applied in pediatric patients mainly included danaparoid sodium and recombinant hirudin. In most patients treated with these anticoagulants, effective anticoagulation and clinical improvement were observed. Because of limited experience, more data are required for optimal management of HIT II in young patients. PMID:12420240

  4. Photoexcitation dynamics in an alternating polyfluorene copolymer

    Science.gov (United States)

    Westerling, M.; Aarnio, H.; Österbacka, R.; Stubb, H.; King, S. M.; Monkman, A. P.; Andersson, M. R.; Jespersen, K.; Kesti, T.; Yartsev, A.; Sundström, V.

    2007-06-01

    We have used transient photoinduced absorption on femtosecond to nanosecond time scales as well as delayed fluorescence up to microseconds to study the photogeneration and recombination of charges in thin films of the alternating polyfluorene copolymer poly[2,7-(9,9-dioctylfluorene)-alt-5,5-( 4',7' -di-2-thienyl- 2',1',3' -benzothiadiazole)]. We interpret the results using a coupled rate equation model and find that we can fit all our experimental results with a single set of parameters. The model includes prompt (polaron pairs, respectively. The intrachain polaron pairs are promptly generated from vibronically excited (hot) primary singlet excitons S1* and recombine geminately back to the lowest singlet exciton state S1 with a lifetime distribution having a mean lifetime of ˜2.4ps . The interchain polaron pairs, which can be seen as precursors to free charges, are formed via two channels: via singlet excitons being dissociated with a linear rate constant of ˜5ns as well as via a time-dependent bimolecular exciton-exciton annihilation process generating higher-energy exciton states Sn* of which a fraction subsequently dissociates into interchain polaron pairs. We observe a total yield of 12%-23% interchain polaron pairs (a precursor to free polarons), depending on the excitation intensity used. This also defines the upper limit of the free polaron yield at zero electric field in this material. The long-lived interchain polaron pairs recombine geminately back to the ground state or to singlet excitons with a broad distribution of lifetimes having a mean lifetime of ˜0.27μs . The fraction of interchain polaron pairs recombining back to singlet excitons, with subsequent radiative decay back to the ground state, gives rise to delayed fluorescence extending to microsecond time scales.

  5. 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. PMID:25975624

  6. 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.

  7. Three-phase anti-interference unbalanced electronic load simulator%三相抗干扰性不平衡电子负载模拟装置

    Institute of Scientific and Technical Information of China (English)

    田铭兴; 刘芳

    2011-01-01

    A three-phase unbalanced load electronic simulator is designed,which applies an AC/DC/AC bidirectional PWM inverter as its main circuit and the decoupled active and reactive power controls to simulate the three-phase unbalanced load and realize the bidirectional power flow. Based on the three-phase instantaneous reactive power theory,the command current is deduced by the real-time detection of single -phase current harmonies and reactive current to eliminate the impact of grid voltage initial phase for improving its anti-interference performance. Simulation with Matlab demonstrates the feasibility and rationality of its design and the simulative waveforms show that,with excellent anti-interference performance,the simulator eliminates the disturbances from power grid.%设计了一种三相不平衡电子负载模拟装置.该装置采用AC/DC/AC双PWM变流器为主电路结构,通过有功功率和无功功率的解耦控制来模拟三相不平衡电子负载特性,同时能实现能量的双向流动.提出以三相电路瞬时无功功率理论为基础的单相电路谐波和无功电流实时检测方法来推导指令电流,使指令电流不受电网电压初始相位的影响,从而提高装置的抗干扰性.通过Matlab仿真来验证该装置设计方案的可行性和合理性,仿真波形说明该电子负载模拟装置能够消除电网扰动所带来的干扰,具有较强的抗干扰作用.

  8. Modeling and optimization of unbalanced multi-stage logistic system%非平衡多阶段物流系统建模与优化方法

    Institute of Scientific and Technical Information of China (English)

    徐杭; 徐榕; 叶庆泰

    2005-01-01

    To decompose an unbalanced multi-stage logistic system to multiple independent single-stage logistic systems,a new notion of parameterized interface distribution is presented.For encoding the logistic pattern on each stage,the Prüfer number is used.With the improved decoding procedure,any Prüfer number produced stochastically can be decoded to a feasible logistic pattern,which can match with the capacities of the nodes of the logistic system.With these two innovations,a new modeling method based on parameterized interface distribution and the Prüfer number coding is put forward.The corresponding genetic algorithm,named as PIP-GA,can find better solutions and require less computational time than st-GA.Although requiring a little more consumption of memory,PIP-GA is still an efficient and robust method in the modeling and optimization of unbalanced multi-stage logistic systems.%首先提出了参数化界面分布的新概念,将一个非平衡多阶段物流系统转化为多个相互独立的单一阶段物流系统,然后采用Prüfer数对每个阶段上的物流模式进行编码.通过一种改进的解码方法,任何一个随机产生的Prüfer数都能够被解码为一个与物流系统的节点容量相匹配的可行的物流模式.基于这2点创新,建立了一种新的基于参数化界面分布和Prüfer数编码的系统建模方法,相应的遗传算法称为PIP-GA方法.与st-GA方法相比,PIP-GA不但具有更好的优化结果,而且需要的计算时间更少;虽然所需的存储空间有所增加,PIP-GA仍然是一种有效而稳健的非平衡多阶段物流系统建模与优化方法.

  9. 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.

  10. On an Alternative Cosmology

    CERN Document Server

    Vankov, A

    1998-01-01

    The suggested alternative cosmology is based on the idea of barion symmetric universe, in which our home universe is a representative of multitude of typical matter and antimatter universes. This alternative concept gives a physically reasonable explanation of all major problems of the Standard Cosmological Model. Classification Code MSC: Cosmology 524.8 Key words: standard cosmological model, alternative cosmology, barionic symmetry, typical universe, quasars, cosmic rays.

  11. Polyphase alternating codes

    CERN Document Server

    Markkanen, Markku

    2007-01-01

    This work introduces a method for constructing polyphase alternating codes in which the length of a code transmission cycle can be $p^m$ or $p-1$, where $p$ is a prime number and $m$ is a positive integer. The relevant properties leading to the construction alternating codes and the algorithm for generating alternating codes is described. Examples of all practical and some not that practical polyphase code lengths are given.

  12. Alternative Solar Indices

    Energy Technology Data Exchange (ETDEWEB)

    Lantz, L.J.

    1980-07-01

    Possible alternative Solar Indices which could either be a perturbation from the currently defined Solar Index or possible indices based on current technologies for other media markets are discussed. An overview is given of the current project, including the logic that was utilized in defining its current structure and then alternative indices and definitions are presented and finally, recommendations are made for adopting alternative indices.

  13. Complex Alternative Splicing

    OpenAIRE

    Park, Jung Woo; Graveley, Brenton R.

    2007-01-01

    Alternative splicing is a powerful means of controlling gene expression and increasing protein diversity. Most genes express a limited number of mRNA isoforms, but there are several examples of genes that use alternative splicing to generate hundreds, thousands, and even tens of thousands of isoforms. Collectively such genes are considered to undergo complex alternative splicing. The best example is the Drosophila Down syndrome cell adhesion molecule (Dscam) gene, which can generate 38,016 is...

  14. Electron Recombination in a Dense Hydrogen Plasma

    Energy Technology Data Exchange (ETDEWEB)

    Jana, M.R.; Johnstone, C.; Kobilarcik, T.; Koizumi, G.M.; Moretti, A.; Popovic, M.; Tollestrup, A.V.; Yonehara, K.; /Fermilab; Leonova, M.A.; Schwarz, T.A.; /Fermilab; Chung, M.; /Unlisted /IIT, Chicago /Fermilab /MUONS Inc., Batavia /Turin Polytechnic

    2012-05-01

    A high pressure hydrogen gas filled RF cavity was subjected to an intense proton beam to study the evolution of the beam induced plasma inside the cavity. Varying beam intensities, gas pressures and electric fields were tested. Beam induced ionized electrons load the cavity, thereby decreasing the accelerating gradient. The extent and duration of this degradation has been measured. A model of the recombination between ionized electrons and ions is presented, with the intent of producing a baseline for the physics inside such a cavity used in a muon accelerator. Analysis of the data taken during the summer of 2011 shows that self recombination takes place in pure hydrogen gas. The decay of the number of electrons in the cavity once the beam is turned off indicates self recombination rather than attachment to electronegative dopants or impurities. The cross section of electron recombination grows for larger clusters of hydrogen and so at the equilibrium of electron production and recombination in the cavity, processes involving H{sub 5}{sup +} or larger clusters must be taking place. The measured recombination rates during this time match or exceed the analytic predicted values. The accelerating gradient in the cavity recovers fully in time for the next beam pulse of a muon collider. Exactly what the recombination rate is and how much the gradient degrades during the 60 ns muon collider beam pulse will be extrapolated from data taken during the spring of 2012.

  15. Initiation of meiotic recombination in Ustilago maydis.

    Science.gov (United States)

    Kojic, Milorad; Sutherland, Jeanette H; Pérez-Martín, José; Holloman, William K

    2013-12-01

    A central feature of meiosis is the pairing and recombination of homologous chromosomes. Ustilago maydis, a biotrophic fungus that parasitizes maize, has long been utilized as an experimental system for studying recombination, but it has not been clear when in the life cycle meiotic recombination initiates. U. maydis forms dormant diploid teliospores as the end product of the infection process. Upon germination, teliospores complete meiosis to produce four haploid basidiospores. Here we asked whether the meiotic process begins when teliospores germinate or at an earlier stage in development. When teliospores homozygous for a cdc45 mutation temperature sensitive for DNA synthesis were germinated at the restrictive temperature, four nuclei became visible. This implies that teliospores have already undergone premeiotic DNA synthesis and suggests that meiotic recombination initiates at a stage of infection before teliospores mature. Determination of homologous recombination in plant tissue infected with U. maydis strains heteroallelic for the nar1 gene revealed that Nar(+) recombinants were produced at a stage before teliospore maturation. Teliospores obtained from a spo11Δ cross were still able to germinate but the process was highly disturbed and the meiotic products were imbalanced in chromosomal complement. These results show that in U. maydis, homologous recombination initiates during the infection process and that meiosis can proceed even in the absence of Spo11, but with loss of genomic integrity.

  16. Optimal Expression Condition of Recombinant RAP

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jie; ZHANG Hong; BI Hao; LIU Zhiguo; GUO Jianli; QU Shen

    2007-01-01

    In order to construct the expression recombinant of human receptor associated protein (RAP), optimize its expression condition and obtain the recombinant protein after expression with high efficiency, two prokaryotic expression vectors-pT7-PL and pET-28a(+) were used to construct the expression recombinant containing RAP cDNA, and the expression efficiency of two kinds of expression E. coli of BL21 strains was compared. The effect of different induction conditions on the expression of recombinant RAP was observed. After recombinant protein was purified with Ni+-nitrilotriacetic acid (Ni+-NTA) affinity chromatogram, its binding ability with microphage was observed. The results showed that two recombinant plasmids both obtained high expression of RAP. The expression levels of RAP in plasmid pT7-PL-RAP in BL21 (DE3, plysS) strain were significantly higher than in BL21 (DE3) strain. The expression of pT7-PL-RAP in the presence of chloramphenicol was higher than in the absence of chloramphenicol, and most of the inducible expressed RAP was soluble. The RAP which was purified by Ni+-NTA resin could strongly bind with the RAW264.7 cells rich in low density lipoprotein receptor (LDLR) family receptors. It was concluded that the expression condition of recombinant RAP was optimized and functional RAP was obtained, which offered a good foundation for the further production of RAP as research tool.

  17. 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.)

  18. Performance evaluation of reactive direct current unbalanced magnetron sputter deposited nanostructured TiN coated high-speed steel drill bits

    Indian Academy of Sciences (India)

    Harish C Barshilia; K S Rajam

    2007-12-01

    The stainless steels, in general, are considered to be difficult-to-machine materials. In order to machine these materials the surface of the tool is generally coated with physical vapour deposition (PVD) hard coatings such as titanium nitride (TiN), titanium aluminum nitride (TiAlN), etc. The adhesion is of vital importance for the performance of tools coated with PVD coatings. Proper surface treatments (in situ and ex situ) are required to achieve highly adherent PVD coatings on tools. 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 coatings. The process parameters have been optimized to achieve highly adherent thick good quality TiN coatings. These coatings have been characterized using X-ray diffraction, nanoindentation and atomic force microscopy techniques. The performance of the coated HSS drill bits is evaluated by drilling a 13 mm thick 304 stainless steel plate under wet conditions. The results show significant improvement in the performance of the TiN coated HSS drill bits.

  19. The Study of Deposition Parameters, Properties for PVD TixN and CrxN Coatings Using a Closed Field Unbalanced Magnetron Sputter Ion Plating System

    Institute of Scientific and Technical Information of China (English)

    Hailin Sun; Susan Field; Jian Chen; Dennis. G. Teer

    2004-01-01

    Closed Field Unbalanced Magnetron Sputter Ion Plating (CFUBMSIP) systems have been used increasingly for PVD coating in recent years. TiN and CrN coatings, commonly used as the basic coating for a number of different hard coatings, have been chosen to study the coating process parameters for the CFUBMSIP system. In this paper, the process parameters, such as substrate temperature, substrate bias and OEM control, have been carefully examined to achieve hard and wear-resistance coatings with good adhesion. The coating structure and orientation were found to change according to the coating parameters. The Rockwell test and Scratch test were carried out to examine the coating adhesion; pin-on-disc testing was used to estimate the wear-resistant; micro-hardness was also used to determine coating hardness. HSS drill testing has been carried out to study the general properties of the coating for cutting tool application. A combination of process parameters can be selected to achieve good performance for the TiN and CrN coatings.

  20. TRIBOLOGICAL AND HIGH SPEED TURNING PERFORMANCE IN Ti1-xAlxN COATINGS PREPARED BY CLOSE-FIELD UNBALANCED MAGNETRON SPUTTERING

    Institute of Scientific and Technical Information of China (English)

    P.W. Shum; M. Escursell; T.H. Wong; K.Y. Li; Z.F. Zhou; Y.G. Shen

    2005-01-01

    Titanium-aluminium-nitride (Ti1-xAlxN) coatings were deposited by close-field unbalanced magnetron sputtering on M42 steel substrates and WC-6wt%Co inserts at 450℃. The tribological behavior was analyzed by sliding against steel and WC-6wt%Co balls, while the turning performance was evaluated by a conventional turning machine at high cutting speeds without using coolants. In the tribological tests, the formation of transfer layer and the variations of hardness of the coatings played an important role for sliding against steel balls. For the coatings sliding against WC-6wt%Co balls, the Ti-A1-N coatings showed a similar friction coefficient, but the TiN coating exhibited a lower value. The difference could be explained by the tri-oxidation wear mechanism. In the turning tests, a superior cutting performance of the coating was found at x=0.45, which endured 38 minutes before the tool flank wear reached the maximum value of 0.3mm, whereas only 20 minutes were endured for the TiN coating. The excellent performance of the coatings in the turning tests could be explained by the enhanced mechanical properties and oxidation/diffusion resistance of the coatings.

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

    International Nuclear Information System (INIS)

    In this work, nanostructured NbxSiyNz 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 Si3N4 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.)

  2. Influence of unbalanced voltages on the movement of metallic particle in a three phase common enclosure gas insulated busduct

    Indian Academy of Sciences (India)

    G V Nagesh Kumar; J Amarnath; B P Singh; D Deepak Chowdary

    2010-08-01

    Sulphur Hexafluoride $(SF_6)$ is generally found to be very sensitive to field perturbations such as those caused by conductor surface imperfections and by conducting particle contaminants. A study of CIGRE group suggests that 20% of failures in Gas Insulated Substations (GIS) is due to the existence of various metallic contaminations in the form of loose particles. The presence of contamination can therefore be a problem with gas-insulated substations operating at high fields. If the effects of these particles could be eliminated, then this would improve the reliability of compressed gas insulated substation. It would also offer the possibility of operating at higher fields to affect a potential reduction in the GIS size with subsequent savings in the cost of manufacture and installation. The purpose of this paper is to develop techniques, which will formulate the basic equations that will govern the movement of metallic particles like aluminum, silver and copper in a bus duct. Simulation is carried out on particle movement with balanced and unbalanced voltages and the results have been presented and analysed.

  3. Up-scaled Teer-UDP850/4 Unbalanced Magnetron Deposition System Used for Mass-Production of CrTiAlN Hard Coatings

    Institute of Scientific and Technical Information of China (English)

    ZHANG Guo-jun; YANG Shi-cai; JIANG Bai-ling; BAI Li-jing; CHEN Di-chun; WEN Xiao-bin; TEER D.G.

    2004-01-01

    Up-scaled deposition process of Teer-UDP850/4 has been established and used for massive production of CrTiAlN hard coatings in applications of anti-wear, cutting and forming tools. This deposition system uses four magnetrons that are arranged by unbalanced magnets to form closed magnetic field enabling the system running in high current density.Elemental metals of Cr, Ti and Al are used as the target materials which are co-deposited with nitrogen forming multialloy nitride, nanoscale multi-layer or superlattice hard coatings. The substrate turntable is designed as planet rotation mechanism with three folds so that components or tools with complicate geometry can be uniformly coated onto all their surfaces and cutting edges. The power units for the magnetrons are straight dc whilst the substrate is biased by pulsed dc. Two solid heaters are installed in the system to enable running a wide range of deposition temperature from 200℃ to 500℃. The pumping system is powerful that incorporated with a polycold to pump the system to a good vacuum in a very short time. A front door and a movable substrate table are available to benefit easily loading and unloading. Deposition procedure,properties and performance of the coatings is also presented in this paper.

  4. Up-scaled Teer-UDP850/4 Unbalanced Magnetron Deposition System Used for Mass-Production of CrTiAlN Hard Coatings

    Institute of Scientific and Technical Information of China (English)

    ZHANGGuo-jun; YANGShi-cai; JIANGBai-ling; BAILi-jing; CHENDi-chum; WENXiao-bin; TEERD.G.

    2004-01-01

    Up-sca]ed deposition process of Teer-UDP850/4 has been established and used for massive production of CrTiAlN hard coatings in applications of anti-wear, cutting and forming tools. This deposition system uses four magnetrons that are arranged by unbalanced magnets to fomt closed magnetic field enabling the system running in high current density. Elemental metals of Cr, Ti and Al are used as the target materials which are co-deposited with nitrogen forming nlultialloy nitride, nanoscale multi-layer or superlattice hard coatings. The stthstrate turntable is designed as planet rotation mechanism with three folds so that components or tools with complicate geometry can be uniformly coated onto all their surfaces and cutting edges. The pawer units for the magnetrons are straight dc whilst the substrate is biased by pulsed de. Two solid heaters are installed in the system to enable running a wide range of deposition temperature from 200℃ to 500℃. The pumping system is powerful that incorporated with a polycold to pump the system to a good vacuum in a very shori time. A front door and a movable substrate table are available to benefit easily loading and unloading. Deposition procedure. properties and performance of the coatings is also presented in this paper.

  5. Regulation of unbalanced redox homeostasis induced by the expression of wild-type HIV-1 viral protein R (NL4-3Vpr) in fission yeast.

    Science.gov (United States)

    Gazdag, Zoltán; Stromájer-Rácz, Timea; Belagyi, Joseph; Zhao, Richard Y; Elder, Robert T; Virág, Eszter; Pesti, Miklós

    2015-09-01

    The wild-type viral protein R (Vpr) of human immunodeficiency virus type 1 exerts multiple effects on cellular activities during infection, including the induction of cell cycle G2 arrest and the death of human cells and cells of the fission yeast Schizosaccharomyces pombe. In this study, wild-type Vpr (NL4-3Vpr) integrated as a single copy gene in S. pombe chromosome was used to investigate the molecular impact of Vpr on cellular oxidative stress. NL4-3Vpr triggered an atypical response in early (14-h), and a wellregulated oxidative stress response in late (35-h) log-phase cultures. Specifically, NL4-3Vpr expression induced oxidative stress in the 14-h cultures leading, to decreased levels of superoxide anion (O(2)(·-)), hydroxyl radical (·OH) and glutathione (GSH), and significantly decreased activities of catalase, glutathione peroxidase, glutathione reductase, glucose-6-phosphate dehydrogenase and glutathione S-transferase. In the 35-h cultures, elevated levels of O(2)(·-) and peroxides were accompanied by increased activities of most antioxidant enzymes, suggesting that the Vpr-induced unbalanced redox state of the cells might contribute to the adverse effects in HIV-infected patients. PMID:26344028

  6. The effect of environmental performance and preference disclosure on financial performance: Empirical evidence from unbalanced panel data of heavy-pollution industries in China

    Directory of Open Access Journals (Sweden)

    Kai Chang

    2015-01-01

    Full Text Available Purpose: Environmental performance and propensity disclosure is important for stakeholders to estimate firms’ incentives in environmental management practices. The purpose of this article is to explore the impacts of environmental performance and propensity disclosure on financial performance using unbalanced panel data of eight heavy-pollution industries in China. Design/methodology/approach: Environmental performance and propensity exhibits mutual causality relationship with Tobin’s Q value using unit root and co-integration test of panel data. Using panel data analysis, we take the impacts of environmental performance and propensity disclosure on financial performance from 2008 to 2012. Findings: Environmental performance has a significantly negative impact on Tobin’s Q value at the significance levels of 1%, while environmental propensity has a significantly positive effect on Tobin’s Q value at the significance levels of 5%. Firm size, financial leverage and return of assets have significantly positive impacts on financial performance at the significance levels of 1%. Meanwhile the effect of corporate environmental performance and propensity on financial performance has a significantly periodic difference from 2008 to 2012. Research limitations/implications: Those results are helpful for environmental regulators to evaluate the implementing effect of voluntary environmental policy and for firms’ managers to increase market expectation and improve financial performance. Originality/value: Environmental performance is estimated by 30 environmental indicators in eight heavy-pollution industries in China. Environmental performance and propensity disclosure has a U-typed relationship with financial performance.

  7. Structural and tribological properties of CrTiAlN coatings on Mg alloy by closed-field unbalanced magnetron sputtering ion plating

    Science.gov (United States)

    Shi, Yongjing; Long, Siyuan; Yang, Shicai; Pan, Fusheng

    2008-09-01

    In this paper, a series of multi-layer hard coating system of CrTiAlN has been prepared by closed-field unbalanced magnetron sputtering ion plating (CFUBMSIP) technique in a gas mixture of Ar + N 2. The coatings were deposited onto AZ31 Mg alloy substrates. During deposition step, technological temperature and metallic atom concentration of coatings were controlled by adjusting the currents of different metal magnetron targets. The nitrogen level was varied by using the feedback control of plasma optical emission monitor (OEM). The structural, mechanical and tribological properties of coatings were characterized by means of X-ray photoelectron spectrometry, high-resolution transmission electron microscope, field emission scanning electron microscope (FESEM), micro-hardness tester, and scratch and ball-on-disc tester. The experimental results show that the N atomic concentration increases and the oxide on the top of coatings decreases; furthermore the modulation period and the friction coefficient decrease with the N 2 level increasing. The outstanding mechanical property can be acquired at medium N 2 level, and the CrTiAlN coatings on AZ31 Mg alloy substrates outperform the uncoated M42 high speed steel (HSS) and the uncoated 316 stainless steel (SS).

  8. 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.

  9. Discussion on unbalanced bid and coping strategy under bill pricing mode%清单计价模式下不平衡报价及应对策略探讨

    Institute of Scientific and Technical Information of China (English)

    王新杰; 侯庆德

    2011-01-01

    从建设单位角度,介绍了不平衡报价的常见做法,分析了存在的原因及后果,结合实践提出了几点实用的不平衡报价应对策略,以维护建设方正常利益和市场秩序,促进建筑业健康发展。%From the perspective of construction unit, this paper introduced the common method of unbalanced bid, analysed the existed reasons and consequences, combining with the practice put forward a few practical unbalanced bid coping strategies, so as to maintenance the normal profit of construction party and market order, promoted the healthy development of construction industry.

  10. Recombination every day: abundant recombination in a virus during a single multi-cellular host infection.

    Directory of Open Access Journals (Sweden)

    Remy Froissart

    2005-03-01

    Full Text Available Viral recombination can dramatically impact evolution and epidemiology. In viruses, the recombination rate depends on the frequency of genetic exchange between different viral genomes within an infected host cell and on the frequency at which such co-infections occur. While the recombination rate has been recently evaluated in experimentally co-infected cell cultures for several viruses, direct quantification at the most biologically significant level, that of a host infection, is still lacking. This study fills this gap using the cauliflower mosaic virus as a model. We distributed four neutral markers along the viral genome, and co-inoculated host plants with marker-containing and wild-type viruses. The frequency of recombinant genomes was evaluated 21 d post-inoculation. On average, over 50% of viral genomes recovered after a single host infection were recombinants, clearly indicating that recombination is very frequent in this virus. Estimates of the recombination rate show that all regions of the genome are equally affected by this process. Assuming that ten viral replication cycles occurred during our experiment-based on data on the timing of coat protein detection-the per base and replication cycle recombination rate was on the order of 2 x 10(-5 to 4 x 10(-5. This first determination of a virus recombination rate during a single multi-cellular host infection indicates that recombination is very frequent in the everyday life of this virus.

  11. Recombination analysis of Soybean mosaic virus sequences reveals evidence of RNA recombination between distinct pathotypes

    Directory of Open Access Journals (Sweden)

    Babu Mohan

    2008-11-01

    Full Text Available Abstract RNA recombination is one of the two major factors that create RNA genome variability. Assessing its incidence in plant RNA viruses helps understand the formation of new isolates and evaluate the effectiveness of crop protection strategies. To search for recombination in Soybean mosaic virus (SMV, the causal agent of a worldwide seed-borne, aphid-transmitted viral soybean disease, we obtained all full-length genome sequences of SMV as well as partial sequences encoding the N-terminal most (P1 protease and the C-terminal most (capsid protein; CP viral protein. The sequences were analyzed for possible recombination events using a variety of automatic and manual recombination detection and verification approaches. Automatic scanning identified 3, 10, and 17 recombination sites in the P1, CP, and full-length sequences, respectively. Manual analyses confirmed 10 recombination sites in three full-length SMV sequences. To our knowledge, this is the first report of recombination between distinct SMV pathotypes. These data imply that different SMV pathotypes can simultaneously infect a host cell and exchange genetic materials through recombination. The high incidence of SMV recombination suggests that recombination plays an important role in SMV evolution. Obtaining additional full-length sequences will help elucidate this role.

  12. Recombination every day: abundant recombination in a virus during a single multi-cellular host infection.

    Science.gov (United States)

    Froissart, Remy; Roze, Denis; Uzest, Marilyne; Galibert, Lionel; Blanc, Stephane; Michalakis, Yannis

    2005-03-01

    Viral recombination can dramatically impact evolution and epidemiology. In viruses, the recombination rate depends on the frequency of genetic exchange between different viral genomes within an infected host cell and on the frequency at which such co-infections occur. While the recombination rate has been recently evaluated in experimentally co-infected cell cultures for several viruses, direct quantification at the most biologically significant level, that of a host infection, is still lacking. This study fills this gap using the cauliflower mosaic virus as a model. We distributed four neutral markers along the viral genome, and co-inoculated host plants with marker-containing and wild-type viruses. The frequency of recombinant genomes was evaluated 21 d post-inoculation. On average, over 50% of viral genomes recovered after a single host infection were recombinants, clearly indicating that recombination is very frequent in this virus. Estimates of the recombination rate show that all regions of the genome are equally affected by this process. Assuming that ten viral replication cycles occurred during our experiment-based on data on the timing of coat protein detection-the per base and replication cycle recombination rate was on the order of 2 x 10(-5) to 4 x 10(-5). This first determination of a virus recombination rate during a single multi-cellular host infection indicates that recombination is very frequent in the everyday life of this virus. PMID:15737066

  13. Alternative Devices for Taking Insulin

    Science.gov (United States)

    ... KB). Alternate Language URL Alternative Devices for Taking Insulin Page Content On this page: What alternative devices ... the skin. [ Top ] What alternative devices for taking insulin are available? Insulin pens provide a convenient, easy- ...

  14. 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...

  15. A Study on the Photovoltaic Grid-connected Inverter Based on Parallel Unbalanced Power Units%基于不平衡功率单元并联的光伏并网逆变器研究

    Institute of Scientific and Technical Information of China (English)

    潘逸菎; 窦伟

    2014-01-01

    提出一种基于不平衡功率单元直接并联技术的1MW并网逆变器拓扑结构,可有效解决大功率逆变器在低功率条件下的效率和电能质量问题。详细论述了基于不平衡功率单元并联的1MW并网逆变器的特点及工作原理,并针对不平衡功率单元并联产生的环流问题,提出了控制策略的解决方案。基于MATLAB软件对并网逆变器进行了仿真验证,仿真结果表明逆变器能够有效提高低功率条件下的效率及电能质量,并抑制不平衡功率单元间的环流。%This paper proposes a 1 MW grid-connected inverter's topological structure based on direct parallel technology of unbalanced power units to improve the efficiency and power quality of the high-power inverter under low power conditions.The characteristics and working principle of the improved 1 MW grid-connected inverter based on unbalanced power units are described in detail,and a control strategy solution is presented for the circulating current generated through parallel connection between unbalanced power units. A MATLAB-based simulation experiment on the inverter is conducted,and the result shows this converter can greatly improve the efficiency and power quality under low power conditions,and suppress the circulating current between unbalanced power units.

  16. Alternative lengthening of telomeres: remodeling the telomere architecture

    OpenAIRE

    Conomos, Dimitri; Hilda A Pickett; Reddel, Roger R

    2013-01-01

    To escape from the normal limits on proliferative potential, cancer cells must employ a means to counteract the gradual telomere attrition that accompanies semi-conservative DNA replication. While the majority of human cancers do this by up-regulating telomerase enzyme activity, most of the remainder use a homologous recombination-mediated mechanism of telomere elongation known as alternative lengthening of telomeres (ALT). Many molecular details of the ALT pathway are unknown, and even less ...

  17. The Study of Unbalanced Based on Time Bid Model for Contractor Value of Money%基于资金时间价值的承包商不平衡报价模型研究

    Institute of Scientific and Technical Information of China (English)

    刘卫星; 周国强

    2011-01-01

    介绍了不平衡报价的概念,划分了不平衡报价法策略,并在此基础上,从投标方的角度出发,利用资金时间价值理论,建立了以工程实际付款终值最大化为目标函数的非线性规划模型,配以具体的工程实例通过计算机软件(lingo8.0)求得不平衡报价的最优解,并对不平衡报价模型的实际应用进行了探讨。%This paper introduces the conception and the classification of unbalanced bids. Then from the con- tractors" point of view and based on the principle of the time value of money construct a non - linear program- ming model, maximizing the future value of actual payment. Finally taking a engineering project as an example give the optimal solution of unbalanced bids by the computer software ( lingo8.0) , and analyze the applicationof unbalanced bids model in practice.

  18. Genetic Analyses of Meiotic Recombination in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Meiosis is essential for sexual reproduction and recombination is a critical step required for normal meiosis. Understanding the underlying molecular mechanisms that regulate recombination ie important for medical, agricultural and ecological reasons. Readily available molecular and cytological tools make Arabidopsis an excellent system to study meiosis. Here we review recent developments in molecular genetic analyses on meiotic recombination. These Include studies on plant homologs of yeast and animal genes, as well as novel genes that were first identified in plants. The characterizations of these genes have demonstrated essential functions from the initiation of recombination by double-strand breaks to repair of such breaks, from the formation of double-Holliday junctions to possible resolution of these junctions, both of which are critical for crossover formation. The recent advances have ushered a new era in plant meiosis, in which the combination of genetics, genomics, and molecular cytology can uncover important gene functions.

  19. Recombinant allergens: what does the future hold?

    Science.gov (United States)

    Valenta, Rudolf; Niespodziana, Katarzyna; Focke-Tejkl, Margit; Marth, Katharina; Huber, Hans; Neubauer, Angela; Niederberger, Verena

    2011-04-01

    This year we are celebrating not only the centenary of allergen-specific immunotherapy but also the 10-year anniversary of the first administration of recombinant allergen-based vaccines to allergic patients. By using recombinant DNA technology, defined and safe allergy vaccines can be produced that allow us to overcome many, if not all, of the problems associated with the use of natural allergen extracts, such as insufficient quality, allergenic activity, and poor immunogenicity. Here we provide an update of clinical studies with recombinant allergen-based vaccines, showing that some of these vaccines have undergone successful clinical evaluation up to phase III studies. Furthermore, we introduce a strategy for allergen-specific immunotherapy based on recombinant fusion proteins consisting of viral carrier proteins and allergen-derived peptides without allergenic activity, which holds the promise of being free of side effects and eventually being useful for prophylactic vaccination.

  20. 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.

  1. 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.

  2. 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.

  3. Regulation of Homologous Recombination by SUMOylation

    DEFF Research Database (Denmark)

    Pinela da Silva, Sonia Cristina

    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....... In this study I present new insights for the role of SUMOylation in regulating HR by dissecting the role of SUMO in the interaction between the central HR-mediator protein Rad52 and its paralogue Rad59 and the outcome of recombination. This data provides evidence for the importance of SUMO in promoting protein......-protein interactions at the sites of repair, enabling effective Rad51-mediated recombination through the concerted action of the Rad52-Rad59 complex and the helicase Srs2. In addition, I also peer into the role of Rad52 SUMOylation in the context of persistent DSBs and telomere homeostasis. Furthermore, I characterize...

  4. Biotinylated recombinant human erythropoietins: Bioactivity and utility as receptor ligand

    Energy Technology Data Exchange (ETDEWEB)

    Wojchowski, D.M.; Caslake, L. (Pennsylvania State Univ., University Park (USA))

    1989-08-15

    Recombinant human erythropoietin labeled covalently with biotin at sialic acid moieties has been prepared, and has been shown to possess high biological activity plus utility as a receptor ligand. Initially, the effects on biological activity of covalently attaching biotin to erythropoietin alternatively at carboxylate, amino, or sialic acid groups were compared. Biotinylation of erythropoietin at carboxylate groups using biotin-amidocaproyl hydrazide plus 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide led to substantial biological inactivation, although biotinylated molecules retained detectable activity when prepared at low stoichiometries. Biotinylation at amino groups using sulfosuccinimidyl 6-(biotinamido) hexanoate resulted in a high level of biological inactivation with little, if any, retention of biological activity, regardless of labeling stoichiometries. Biotinylation at sialic acid moieties using periodate and biotinamidocaproyl hydrazide proceeded efficiently (greater than 95% and 80% labeling efficiencies for human urinary and recombinant erythropoietin, respectively) and yielded stably biotinylated erythropoietin molecules possessing comparably high biological activity (ie, 45% of the activity of unmodified hormone). Utility of recombinant biotin-(sialyl)-erythropoietin (in combination with 125I-streptavidin) in the assay of cell surface receptors was demonstrated using two distinct murine erythroleukemia cell lines, Friend 745 and Rauscher Red 1. The densities and affinities of specific hormone binding sites were 116 +/- 4 sites, 3.3 +/- 0.4 nmol/L kd and 164 +/- 5 sites, 2.7 +/- 0.4 nmol/L kd, respectively. It is predicted that the present development of biotin-(sialyl)-erythropoietin as a chemically and biologically stable, bioactive ligand will assist in advancing an understanding of the regulated expression and physicochemistry of the human and murine erythropoietin receptors.

  5. Immunomodulatory effects of recombinant lactoferrin during MRSA infection.

    Science.gov (United States)

    Hwang, Shen-An; Kruzel, Marian L; Actor, Jeffrey K

    2014-05-01

    Methicillin-resistant Staphylococcus aureus (MRSA) infection remains a serious hazard to global health. The use of immune modulatory therapy to combat infection is gaining an interest as a novel treatment alternative. Lactoferrin (LF), an iron binding protein with immune modulating properties, has the potential to modify the course of systemic MRSA infection. Specifically, LF is capable of limiting deleterious inflammatory responses while promoting the development of antigen specific T-cell activity. The efficacy of a novel recombinant mouse LF (rmLF) to protect against MRSA infection was examined in a mouse peritonitis model. BALB/c mice were infected with a lethal dose of MRSA and treated at 2h post-infection with rmLF. Effects of rmLF on MRSA-infected primary monocytes and granulocytes were analyzed for inflammatory mediators. The rmLF treated mice demonstrated a modest increase in survival of more than 24h, albeit with reduced bacteremia. Serum cytokines, IL-17 and IL-6, were significantly reduced post-challenge post-rmLF treatment. The rmLF led to a minor decrease in IL-1b, and a slight increase in TNF-a production. Preliminary investigation towards human clinical relevance was accomplished using human blood derived monocytes and granulocytes infected with MRSA and treated with homologous recombinant human LF (rhLF). Treatment with (rhLF) led to increased production of IFN-g and IL-2. The human cell studies also showed a concurrent decrease in TNF-a, IL-6, IL-1b, IL-12p40, and IL-10. These results indicate that the rmLF and rhLF have a high degree of overlap to modify inflammatory responses, although differences in activities were observed between the two heterologous recombinant molecules.

  6. Recombinant horseradish peroxidase variants for targeted cancer treatment.

    Science.gov (United States)

    Bonifert, Günther; Folkes, Lisa; Gmeiner, Christoph; Dachs, Gabi; Spadiut, Oliver

    2016-06-01

    Cancer is a major cause of death. Common chemo- and radiation-therapies damage healthy tissue and cause painful side effects. The enzyme horseradish peroxidase (HRP) has been shown to activate the plant hormone indole-3-acetic acid (IAA) to a powerful anticancer agent in in vitro studies, but gene directed enzyme prodrug therapy (GDEPT) studies showed ambivalent results. Thus, HRP/IAA in antibody directed enzyme prodrug therapy (ADEPT) was investigated as an alternative. However, this approach has not been intensively studied, since the enzyme preparation from plant describes an undefined mixture of isoenzymes with a heterogenic glycosylation pattern incompatible with the human system. Here, we describe the recombinant production of the two HRP isoenzymes C1A and A2A in a Pichia pastoris benchmark strain and a glyco-engineered strain with a knockout of the α-1,6-mannosyltransferase (OCH1) responsible for hypermannosylation. We biochemically characterized the enzyme variants, tested them with IAA and applied them on cancer cells. In the absence of H2 O2 , HRP C1A turned out to be highly active with IAA, independent of its surface glycosylation. Subsequent in vitro cytotoxicity studies with human T24 bladder carcinoma and MDA-MB-231 breast carcinoma cells underlined the applicability of recombinant HRP C1A with reduced surface glycoslyation for targeted cancer treatment. Summarizing, this is the first study describing the successful use of recombinantly produced HRP for targeted cancer treatment. Our findings might pave the way for an increased use of the powerful isoenzyme HRP C1A in cancer research in the future. PMID:26990592

  7. Hadron Correlations from Recombination and Fragmentation

    CERN Document Server

    Fries, R J

    2005-01-01

    We review the formalism of quark recombination applied to the hadronization of a quark gluon plasma. Evidence in favor 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.

  8. Signals From the Epoch of Cosmological Recombination

    OpenAIRE

    Sunyaev, R. A.; Chluba, J.

    2009-01-01

    The physical ingredients to describe the epoch of cosmological recombination are amazingly simple and well-understood. This fact allows us to take into account a very large variety of physical processes, still finding potentially measurable consequences for the energy spectrum and temperature anisotropies of the Cosmic Microwave Background (CMB). In this contribution we provide a short historical overview in connection with the cosmological recombination epoch and its connection to the CMB. A...

  9. Algae-based oral recombinant vaccines

    OpenAIRE

    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 ...

  10. 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 (mtDNA o...... to a large overestimation of the substitution rate heterogeneity and the loss of the molecular clock. These results are discussed in relation to viral and mtDNA data sets. Udgivelsesdato: 2000-Oct...

  11. DNA-PKcs Is Involved in Ig Class Switch Recombination in Human B Cells.

    Science.gov (United States)

    Björkman, Andrea; Du, Likun; Felgentreff, Kerstin; Rosner, Cornelia; Pankaj Kamdar, Radhika; Kokaraki, Georgia; Matsumoto, Yoshihisa; Davies, E Graham; van der Burg, Mirjam; Notarangelo, Luigi D; Hammarström, Lennart; Pan-Hammarström, Qiang

    2015-12-15

    Nonhomologous end-joining (NHEJ) is one of the major DNA double-strand break repair pathways in mammalian cells and is required for both V(D)J recombination and class switch recombination (CSR), two Ig gene-diversification processes occurring during B cell development. DNA-dependent protein kinase, catalytic subunit (DNA-PKcs) is a component of the classical NHEJ machinery and has a critical function during V(D)J recombination. However, its role in CSR has been controversial. In this study, we examined the pattern of recombination junctions from in vivo-switched B cells from two DNA-PKcs-deficient patients. One of them harbored mutations that did not affect DNA-PKcs kinase activity but caused impaired Artemis activation; the second patient had mutations resulting in diminished DNA-PKcs protein expression and kinase activity. These results were compared with those from DNA-PKcs-deficient mouse B cells. A shift toward the microhomology-based alternative end-joining at the recombination junctions was observed in both human and mouse B cells, suggesting that the classical NHEJ pathway is impaired during CSR when DNA-PKcs is defective. Furthermore, cells from the second patient showed additional or more severe alterations in CSR and/or NHEJ, which may suggest that DNA-PKcs and/or its kinase activity have additional, Artemis-independent functions during these processes. PMID:26546606

  12. Recombination rate predicts inversion size in Diptera.

    Science.gov (United States)

    Cáceres, M; Barbadilla, A; Ruiz, A

    1999-09-01

    Most species of the Drosophila genus and other Diptera are polymorphic for paracentric inversions. A common observation is that successful inversions are of intermediate size. We test here the hypothesis that the selected property is the recombination length of inversions, not their physical length. If so, physical length of successful inversions should be negatively correlated with recombination rate across species. This prediction was tested by a comprehensive statistical analysis of inversion size and recombination map length in 12 Diptera species for which appropriate data are available. We found that (1) there is a wide variation in recombination map length among species; (2) physical length of successful inversions varies greatly among species and is inversely correlated with the species recombination map length; and (3) neither the among-species variation in inversion length nor the correlation are observed in unsuccessful inversions. The clear differences between successful and unsuccessful inversions point to natural selection as the most likely explanation for our results. Presumably the selective advantage of an inversion increases with its length, but so does its detrimental effect on fertility due to double crossovers. Our analysis provides the strongest and most extensive evidence in favor of the notion that the adaptive value of inversions stems from their effect on recombination.

  13. Recombination of U92+ ions with electrons

    International Nuclear Information System (INIS)

    Recombination of fully stripped U92+ ions with electrons has been investigated at the Experimental Storage Ring (ESR) in Darmstadt. Absolute recombination rate coefficients have been measured for relative energies from 0 to 33 eV. For energies greater than 20 meV the experimental result is well described by the theory for radiative recombination (RR). Below 20 meV the experimental rate increasingly exceeds the RR calculation as observed previously in the recombination of light bare ions as well as of Bi83+. This low-energy rate enhancement is shown to scale as Z2.6 for bare ions, where Z is the atomic number of the ion. The U92+ recombination rate enhancement is insensitive to changes of the electron density. Variation of the magnetic guiding field strength from 80 mT to 120 mT resulted in oscillations of the recombination rate at 0 eV. The oscillations are partly attributed to changes of the transverse electron temperature accompanying the change of the magnetic guiding field strength; partly they may be caused by uncompensated small changes of the interaction angle between the two beams. (orig.)

  14. Dissociation of recombinant prion autocatalysis from infectivity.

    Science.gov (United States)

    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 non-infectious pair of autocatalytic recombinant PrP conformers derived from the same initial prion strain. (1) We identified restricted, C-terminal structural differences between these 2 conformers and provided evidence that these relatively subtle differences prevent the non-infectious conformer from templating the conversion of native PrP(C) substrates containing a glycosylphosphatidylinositol (GPI) anchor. (1) In this article we discuss a model, consistent with these findings, in which recombinant PrP, lacking post-translational modifications and associated folding constraints, is capable of adopting a wide variety of autocatalytic conformations. Only a subset of these recombinant conformers can be adopted by post-translationally modified native PrP(C), and this subset represents the recombinant conformers with high specific infectivity. We examine this model's implications for the generation of highly infectious recombinant prions and the protein-only hypothesis of prion replication.

  15. 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

  16. 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.

  17. Systems biology of recombinant protein production using Bacillus megaterium.

    Science.gov (United States)

    Biedendieck, Rebekka; Borgmeier, Claudia; Bunk, Boyke; Stammen, Simon; Scherling, Christian; Meinhardt, Friedhelm; Wittmann, Christoph; Jahn, Dieter

    2011-01-01

    The Gram-negative bacterium Escherichia coli is the most widely used production host for recombinant proteins in both academia and industry. The Gram-positive bacterium Bacillus megaterium represents an increasingly used alternative for high yield intra- and extracellular protein synthesis. During the past two decades, multiple tools including gene expression plasmids and production strains have been developed. Introduction of free replicating and integrative plasmids into B. megaterium is possible via protoplasts transformation or transconjugation. Using His(6)- and StrepII affinity tags, the intra- or extracellular produced proteins can easily be purified in one-step procedures. Different gene expression systems based on the xylose controlled promoter P(xylA) and various phage RNA polymerase (T7, SP6, K1E) driven systems enable B. megaterium to produce up to 1.25g of recombinant protein per liter. Biomass concentrations of up to 80g/l can be achieved by high cell density cultivations in bioreactors. Gene knockouts and gene replacements in B. megaterium are possible via an optimized gene disruption system. For a safe application in industry, sporulation and protease-deficient as well as UV-sensitive mutants are available. With the help of the recently published B. megaterium genome sequence, it is possible to characterize bottle necks in the protein production process via systems biology approaches based on transcriptome, proteome, metabolome, and fluxome data. The bioinformatical platform (Megabac, http://www.megabac.tu-bs.de) integrates obtained theoretical and experimental data. PMID:21943898

  18. Recombinant Exon-Encoded Resilins for Elastomeric Biomaterials

    Science.gov (United States)

    Qin, Guokui; Rivkin, Amit; Lapidot, Shaul; Hu, Xiao; Arinus, Shira B.; Dgany, Or; Shoseyov, Oded; Kaplan, David L.

    2011-01-01

    Resilin is an elastomeric protein found in specialized regions of the cuticle of most insects, providing outstanding material properties including high resilience and fatigue lifetime for insect flight and jumping needs. Two exons (1 and 3) from the resilin gene in Drosophila melanogaster were cloned and the encoded proteins expressed as soluble products in Escherichia coli. A heat and salt precipitation method was used for efficient purification of the recombinant proteins. The proteins were solution cast from water and formed into rubber-like biomaterials via horseradish peroxidase-mediated cross-linking. Comparative studies of the two proteins expressed from the two different exons were investigated by Fourier Transform Infrared Spectroscopy (FTIR) and Circular Dichrosim (CD) for structural features. Little structural organization was found, suggesting structural order was not induced by the enzyme-mediateed dityrosine cross-links. Atomic Force Microscopy (AFM) was used to study the elastomeric properties of the uncross-linked and cross-linked proteins. The protein from exon 1 exhibited 90% resilience in comparison to 63% for the protein from exon 3, and therefore may be the more critical domain for functional materials to mimic native resilin. Further, the cross-linking of the recombinant exon 1 via the citrate-modified photo-Fenton reaction was explored as an alternative dityrosine mediated polymerization method and resulted in both highly elastic and adhesive materials. The citrate-modified photo-Fenton system may be suitable for in-vivo applications of resilin biomaterials. PMID:21963157

  19. Cloning of Rabbit HPRT Gene Using the Recombineering System

    Institute of Scientific and Technical Information of China (English)

    Jianjun SHI; Donghui CAI; Xuejin CHEN; Huizheng SHENG

    2007-01-01

    Hypoxanthine phosphoribosyltransferase (HPRT) plays an important role in the metabolic salvage of purines, and been used as an alternative pathway for mutant selection in many studies. To facilitate its application in rabbits, we have cloned the cDNA and genomic DNA of the rabbit HPRT gene using an approach that combines bioinformatics and recombineering methods. The cDNA is comprised of 1449 bp containing a coding sequence for a protein of 218 amino acids. The deduced amino acid sequence of the rabbit HPRT gene shares 98%, 97%, 98% and 94% identity with human, mouse, pig and cattle HPRT genes, respectively. Reverse transcription-polymerase chain reaction analysis showed that this gene is ubiquitously expressed in tissues of adult rabbit. The rabbit HPRT gene spans approximately 48 kb in length and consists of nine exons. The cloning of the rabbit HPRT gene shows the usefulness of the recombineering system in cloning genes of large size. This system may facilitate the subcloning of DNA from bacterial artificial chromosomes for cloning genes of large size or filling big gaps in genomic sequencing.

  20. 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

    2015-07-01

    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. PMID:25993527

  1. 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

    2015-05-01

    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

  2. Research on the Factor Endowment of Unbalanced Development in International Competitive Sports%国际竞技体育非均衡发展的要素禀赋研究

    Institute of Scientific and Technical Information of China (English)

    钟明宝; 张春燕; 王世杰; 王玉珠

    2016-01-01

    By the paper using unbalanced development theory and taking world Olympic sports scores and the layout of superior sports as the research object, the paper analyzed the basic situation of the unbalanced development in international competitive sports and explored the factor endowments of unbalanced development. This study shows that: international competitive sports presents the basic reality of unbalanced development, each country usedits own limited resources to build the superior project group, focused on developing superior project. The reality of unbalanced development is a kind of specific advantage after a cer-tain accumulation and affected by national economic, politics, environment and human factors, it is a reasonable choice, also is the basic path to realize maximum benefits of competitive sports. Revelations:we should follow the law of development of competi-tive sports, give full play to regional advantages, understand reasonably the essence of "balanced development" in the Olympic plan, make effective regional allocation of resources, optimize the project layout, improve the comprehensive benefit.%运用非均衡发展理论,以世界各国奥运项目成绩与优势项目布局为研究对象,分析国际竞技体育非均衡发展的基本状况,探讨非均衡发展的要素禀赋。研究认为:世界各国竞技体育项目呈现出非均衡发展基本现实,各国最大限度的利用自己有限的资源建立优势项目群,重点发展优势项目,这种非均衡发展的现实受各国经济、政治、文化、环境、人力要素影响,并经过一定积淀形成特定的优势,是一种合理的选择,也是实现竞技体育效益最大化的基本路径。启示我们,尊重竞技体育发展规律,充分发挥区域优势,合理理解奥运争光计划中“均衡发展”要义,有效进行区域资源配置,优化项目布局,提高综合效益。

  3. Production of Aromatic Plant Terpenoids in Recombinant Baker's Yeast.

    Science.gov (United States)

    Emmerstorfer-Augustin, Anita; Pichler, Harald

    2016-01-01

    Plant terpenoids are high-value compounds broadly applied as food additives or fragrances in perfumes and cosmetics. Their biotechnological production in yeast offers an attractive alternative to extraction from plants. Here, we provide two optimized protocols for the production of the plant terpenoid trans-nootkatol with recombinant S. cerevisiae by either (I) converting externally added (+)-valencene with resting cells or (II) cultivating engineered self-sufficient production strains. By synthesis of the hydrophobic compounds in self-sufficient production cells, phase transfer issues can be avoided and the highly volatile products can be enriched in and easily purified from n-dodecane, which is added to the cell broth as second phase. PMID:26843167

  4. 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. PMID:26982462

  5. 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.

  6. Long Telomeres are Preferentially Extended During Recombination-Mediated Telomere Maintenance

    OpenAIRE

    Chang, Michael; Dittmar, John C; Rothstein, Rodney

    2011-01-01

    Most human somatic cells do not express telomerase. Consequently, with each cell division their telomeres progressively shorten until replicative senescence is induced. Approximately 15% of human cancers maintain their telomeres using telomerase-independent, recombination-based mechanisms collectively termed Alternative Lengthening of Telomeres (ALT). In the yeast Saccharomyces cerevisiae, ALT cells are referred to as “survivors”. One type of survivor (type II) resembles human ALT cells in th...

  7. Recombination scheme in lithium-like ions for X-UV amplification

    Energy Technology Data Exchange (ETDEWEB)

    Jamelot, G.; Carillon, A.; Klisnick, A.; Jaegle, P. (LSAI, CNRS and Univ. Paris-Sud, 91 - Orsay (France) LULI, CNRS and Ecole Polytechnique, 91 - Palaiseau (France))

    1990-04-01

    Recombination in lithium-like ions in a fast cooling plasma is alternative attractive approach to the X-ray laser because, at a given lasing wavelength, it requires the lowest pumping energy of the main pumping schemes. In this paper we give a status report on recent experiments concerning the Li-like X-ray laser, and we discuss the problem of lengthening of the active medium necessary to obtain a true X-ray laser. (orig.).

  8. Aberrant recombination and repair during immunoglobulin class switching in BRCA1-deficient human B cells

    DEFF Research Database (Denmark)

    Björkman, Andrea; Qvist, Per; Du, Likun;

    2015-01-01

    machinery. A shift to the use of microhomology-based, alternative end-joining (A-EJ) and increased frequencies of intra-S region deletions as well as insertions of inverted S sequences were observed at the recombination junctions amplified from BRCA1-deficient human B cells. Furthermore, increased use of...... underlying BRCA1’s function in maintaining genome stability and tumor suppression but may also point to a previously unrecognized role of BRCA1 in B-cell lymphomagenesis....

  9. Antiangiogenic Gene Therapy of Cancer Utilizing a Recombinant Adenovirus to Elevate Systemic Endostatin Levels in Mice

    OpenAIRE

    Feldman, Andrew L.; Restifo, Nicholas P; Alexander, H. Richard; Bartlett, David L.; Hwu, Patrick; Seth, Prem; Libutti, Steven K.

    2000-01-01

    Gene therapy represents a possible alternative to the chronic delivery of recombinant antiangiogenic proteins to cancer patients. Inducing normal host tissues to produce high circulating levels of these proteins may be more effective than targeting antiangiogenic genes to tumor tissue specifically. Previously reported gene therapy approaches in mice have achieved peak circulating endostatin levels of 8–33 ng/ml. Here we report plasma endostatin levels of 1770 ng/ml after administration of a r...

  10. DNA annealing by Redβ is insufficient for homologous recombination and the additional requirements involve intra- and inter-molecular interactions

    Science.gov (United States)

    Subramaniam, Sivaraman; Erler, Axel; Fu, Jun; Kranz, Andrea; Tang, Jing; Gopalswamy, Mohanraj; Ramakrishnan, Saminathan; Keller, Adrian; Grundmeier, Guido; Müller, Daniel; Sattler, Michael; Stewart, A. Francis

    2016-01-01

    Single strand annealing proteins (SSAPs) like Redβ initiate homologous recombination by annealing complementary DNA strands. We show that C-terminally truncated Redβ, whilst still able to promote annealing and nucleoprotein filament formation, is unable to mediate homologous recombination. Mutations of the C-terminal domain were evaluated using both single- and double stranded (ss and ds) substrates in recombination assays. Mutations of critical amino acids affected either dsDNA recombination or both ssDNA and dsDNA recombination indicating two separable functions, one of which is critical for dsDNA recombination and the second for recombination per se. As evaluated by co-immunoprecipitation experiments, the dsDNA recombination function relates to the Redα-Redβ protein-protein interaction, which requires not only contacts in the C-terminal domain but also a region near the N-terminus. Because the nucleoprotein filament formed with C-terminally truncated Redβ has altered properties, the second C-terminal function could be due to an interaction required for functional filaments. Alternatively the second C-terminal function could indicate a requirement for a Redβ-host factor interaction. These data further advance the model for Red recombination and the proposition that Redβ and RAD52 SSAPs share ancestral and mechanistic roots. PMID:27708411

  11. Seal design alternatives study

    International Nuclear Information System (INIS)

    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

  12. Evaluation of Expenditure Alternates

    Science.gov (United States)

    Poehlein, Gary W.; And Others

    1973-01-01

    Illustrates a system of calculating dollar expenditures over periods of time in terms of present value. The system enables planners, school boards, and administrators to compare expenditure alternatives as a decisionmaking factor. (Author)

  13. Alternatives to Nursing Homes

    Science.gov (United States)

    ... this website may not be available. Alternatives to nursing homes Before you make any decisions about long ... live and what help you may need. A nursing home may not be your only choice. Discharge ...

  14. 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...

  15. Vaginal dryness alternative treatments

    Science.gov (United States)

    ... a day. Soybeans contain plant-based substances called isoflavones. These substances have an effect on the body ... soy for vasomotor symptoms: the Herbal Alternatives for Menopause (HALT) Study. Menopause . 2008;15(1):51-58. ...

  16. An alternative currency

    OpenAIRE

    Frendo, Mario; Duca, Edward

    2013-01-01

    Malta- a tiny island, a minute social reality, a precursory canovaccio of European unification- has a unique asset it ought to be prouder of: culture. http://www.um.edu.mt/think/an-alternative-currency/

  17. Alternative fuel information sources

    Energy Technology Data Exchange (ETDEWEB)

    1994-06-01

    This short document contains a list of more than 200 US sources of information (Name, address, phone number, and sometimes contact) related to the use of alternative fuels in automobiles and trucks. Electric-powered cars are also included.

  18. Seal design alternatives study

    Energy Technology Data Exchange (ETDEWEB)

    Van Sambeek, L.L. [RE/SPEC Inc., Rapid City, SD (US); Luo, D.D.; Lin, M.S.; Ostrowski, W.; Oyenuga, D. [Parsons Brinckerhoff Quade & Douglas, Inc., San Francisco, CA (US)

    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. Balance Component Decomposition and Compensation Method for Unbalanced Load%不平衡负载的平衡分量法分解及补偿方法

    Institute of Scientific and Technical Information of China (English)

    胡应宏; 王建赜; 任佳佳; 纪延超

    2012-01-01

    In order to make a better compensation for the three-phase unbalanced load, the unbalanced load was analyzed and a method of reactive compensation admittance calculation based on balance component method was proposed. Any neutral non-grounded three-phase load can be decomposed into a group of balanced load and single line load, and the load compensation admittance can be obtained by the decomposition of the three-phase unbalance load. The load compensation admittance calculation can be divided into three parts, the power factor compensation for the balanced load and the single line load together with the balanced compensation for the single line resistive load. Then, the ideal Steinmetz compensation network algorithm was amended under the condition of asymmetric voltage. A freedom degree existed in this case, and the asymmetry voltage compensation admittance can be accurately calculated according to the control objectives and the revised ideal compensation network calculation method. The rationality and validity of the method was verified using example and simulation. Compared with existing methods, the proposed method has easy calculation and convenient realization.%为了更好地对三相不平衡负荷进行平衡化补偿,对不平衡负载进行详细分析,提出一种新的基于平衡分量法的无功补偿导纳计算方法.首先,将任何中性点不接地的三相负载分解为平衡负载和一个线间负载之和,通过将三相负载进行分解,可以得到负载所需要补偿的导纳值.补偿导纳的计算可分为平衡负载功率因数补偿、线间负载功率因数补偿以及线间线阻性负载平衡化补偿3部分.然后,对系统电压不对称时的Steinmetz.理想补偿网络算法进行修正,根据控制目标和修正后的理想补偿网络算法,计算出系统电压不对称时所需的补偿导纳值.通过算例、仿真分析及实验验证,证明了所提无功补偿导纳计算方法的合理性和正确性,该方

  20. Alternative fuel cycles

    International Nuclear Information System (INIS)

    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)

  1. Insertion of nanocrystalline diamond film and the addition of hydrogen gas during deposition for adhesion improvement of cubic boron nitride thin film deposited by unbalanced magnetron sputtering method

    International Nuclear Information System (INIS)

    Cubic boron nitride (c-BN) thick film growth was attempted by the addition of hydrogen for residual stress reduction and by using a nanocrystalline diamond (NCD) buffer layer for stabilizing the turbostratic boron nitride interfacial layer. The c-BN films were deposited by the unbalanced magnetron sputtering method. Thin (100 μm) Si strips (3 × 40 mm2) were used as substrates. A boron nitride target was used, which was connected to a radio frequency power supply at 400 W. High frequency power connected to a substrate holder was used for self-biasing of − 40 V. The deposition pressure was 0.27 Pa with a flow of Ar (18 sccm)–N2 (2 sccm) mixed gas. Hydrogen gas of 2 sccm was added to the Ar–N2 mixed gas. The effect of the addition time of the hydrogen to the Ar–N2 gas during deposition was investigated and found to be critical to the occurrence of the delamination of the c-BN film on the NCD buffer layer. As the addition of the hydrogen was delayed, the delamination started later. C-BN film of 3 μm thickness adherent to the substrate was obtained. - Highlights: • A nanocrystalline diamond (NCD) buffer layer was applied to enhance the adhesion. • Hydrogen in the reaction gas caused delamination of the film at c-BN/NCD interface. • A delayed hydrogen addition was effective in inhibiting such delamination. • About 3 μm thick c-BN film could be grown

  2. 光伏发电系统不对称故障功率控制%Power Control of Photovoltaic Generation system under Unbalanced Grid Faults

    Institute of Scientific and Technical Information of China (English)

    夏刚; 杜跃明; 楼晓轩; 华赟; 李芳; 沈琦; 王强钢; 周念成

    2013-01-01

    The the characteristics of instance output power of photovoltaic inverters is analyzed under unbalanced grid faults and the power control algorithm of photovoltaic generation is put forward based on the derivation of total harmonic distortion of instruction current. The optimal parameters model of photovoltaic generation is then established with minimum integrated fluctuation amplitude of the active and reactive power as a goal when the restriction of output current harmonic distortion of photovoltaic inverters is taken into account. Finally, the overall model of photovoltaic generation system based on deadbeat current tracking is realized and the feasibility of proposed control strategy is verified with PSCAD/EMTDC simulation software.%研究电网不对称故障下光伏逆变器的瞬时输出功率特性,结合指令电流的总谐波畸变率的解析推导,提出光伏发电的功率控制算法。考虑光伏逆变器输出电流谐波畸变率限值约束,以有功和无功功率波动的综合幅值最小为目标,建立光伏发电功率控制参数的优化模型。基于无差拍电流跟踪建立光伏发电系统整体模型,利用PSCAD/EMTDC仿真平台验证了该控制策略的可行性。

  3. 三相不平衡负载无功补偿方法的研究%Research on Reactive Compensation Method for Unbalanced Load

    Institute of Scientific and Technical Information of China (English)

    黄国栋; 杨仁刚; 冯小明

    2011-01-01

    In view of the hazards caused by three - phase unbalanced load, combined with the actual placement of the capacitor, using programming idea, the paper presents a new compensation algorithm for three - phase four - wire systems. The algorithm considers the minimization of power loss as its objective function, and the algorithm can make full use of existing capacitors to achieve optimal compensation effect. It builds an experimental platform with AT91RM9200 as the controller, analyses and simulates the experimental data. Experimental results show that the algorithm not only can compensate the power factor, but also can reduce the three - phase current unbalance, which prove the theoretical analysis. A better power quality and energy - saving can be obtained according to the algorithm.%针对三相不平衡负载对电力系统造成的危害,结合实际电容器的配置,利用规划的思想,本文推导出了三相四线制下新的补偿算法.该算法以有功损耗最小为目标函数,能够充分利用已有的电容器,达到最优的补偿效果.以AT91RM9200为控制器搭建了实验平台,并对实验数据进行分析和仿真,以验证该算法.实验的结果表明,这种算法既能够补偿功率因数,又能够降低三相电流的不平衡度,证明了理论推导的正确性.该方法提高了电能质量,达到了节能效果.

  4. 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

  5. Evolution from increased cardiac mechanical function towards cardiomyopathy in the obese rat due to unbalanced high fat and abundant equilibrated diets

    Directory of Open Access Journals (Sweden)

    Mourmoura Evangelia

    2015-07-01

    Full Text Available The aim of our study was to know whether high dietary energy intake (HDEI with equilibrated and unbalanced diets in term of lipid composition modify the fatty acid profile of cardiac phospholipids and function of various cardiac cells and to know if the changes in membrane lipid composition can explain the modifications of cellular activity. Wistar rats were fed either a control or high-fat (HF diet for 12 weeks and Zucker diabetic fatty (ZDF rats as well as their lean littermate (ZL a control diet between week 7 to 11 of their life. Energy intake and abdominal obesity was increased in HF-fed and ZDF rats. Circulating lipids were also augmented in both strains although hyperglycemia was noticed only in ZDF rats. HDEI induced a decrease in linoleate and increase in arachidonate in membrane phospholipids which was more pronounced in the ZDF rats compared to the HF-fed rats. In vivo cardiac function (CF was improved in HF-fed rats whereas ex vivo cardiac function was unchanged, suggesting that environmental factors such as catecholamines stimulated the in vivo CF. The unchanged ex vivo CF was associated with an increased cardiac mass which indicated development of fibrosis and/or hypertrophy. The increased in vivo CF was sustained by an augmented coronary reserve which was related to the cyclooxygenase pathway and accumulation of arachidonate in membrane phospholipids. In conclusion, before triggering a diabetic cardiomyopathy, HDEI stimulated the CF. The development of cardiomyopathy seems to result from fibrosis and/or hypertrophy which augments myocardial stiffness and decreases contractility.

  6. Performance testing of passive autocatalytic recombiners (PARs)

    Energy Technology Data Exchange (ETDEWEB)

    Blanchat, T. [Sandia National Laboratories, Albuquerque, NM (United States); Malliakos, A. [U.S. Nuclear Regulatory Commission, Washington, DC (United States)

    1997-03-01

    Passive autocatalytic recombiners (PARs) have been under consideration in the U.S. as a combustible gas control system in advanced light water reactor (ALWR) containments for design basis and severe accidents. PARs do not require a source of power. Instead they use palladium or platinum as a catalyst to recombine hydrogen and oxygen gases into water vapor upon contact with the catalyst. Energy from the recombination of hydrogen with oxygen is released at a relatively slow but continuous rate into the containment which prevents the pressure from becoming too high. The heat produced creates strong buoyancy effects which increases the influx of the surrounding gases to the recombiner. These natural convective flow currents promote mixing of combustible gases in the containment. PARs are self-starting and self-feeding under a very wide range of conditions. The recombination rate of the PAR system needs to be great enough to keep the concentration of hydrogen (or oxygen) below acceptable limits. There are several catalytic recombiner concepts under development worldwide. The USNRC is evaluating a specific design of a PAR which is in an advanced stage of engineering development and has been proposed for ALWR designs. Sandia National laboratories (SNL), under the sponsorship and the direction of the USNRC, is conducting an experimental program to evaluate the performance of PARs. The PAR will be tested at the SURTSEY facility at SNL. The test plan currently includes the following experiments: experiments will be conducted to define the startup characteristics of PARs (i.e., to define what is the lowest hydrogen concentration that the PAR starts recombining the hydrogen with oxygen); experiments will be used to define the hydrogen depletion rate of PARs as a function of hydrogen concentration; and experiments will be used to define the PAR performance in the presence of high concentrations of steam. (author)

  7. 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).

  8. Maintenance of Very Long Telomeres by Recombination in the Kluyveromyces lactis stn1-M1 Mutant Involves Extreme Telomeric Turnover, Telomeric Circles, and Concerted Telomeric Amplification

    OpenAIRE

    Xu, Jianing; McEachern, Michael J.

    2012-01-01

    Some cancers utilize the recombination-dependent process of alternative lengthening of telomeres (ALT) to maintain long heterogeneous telomeres. Here, we studied the recombinational telomere elongation (RTE) of the Kluyveromyces lactis stn1-M1 mutant. We found that the total amount of the abundant telomeric DNA in stn1-M1 cells is subject to rapid variation and that it is likely to be primarily extrachromosomal. Rad50 and Rad51, known to be required for different RTE pathways in Saccharomyces...

  9. Recombination and population structure in Salmonella enterica.

    Directory of Open Access Journals (Sweden)

    Xavier Didelot

    2011-07-01

    Full Text Available Salmonella enterica is a bacterial pathogen that causes enteric fever and gastroenteritis in humans and animals. Although its population structure was long described as clonal, based on high linkage disequilibrium between loci typed by enzyme electrophoresis, recent examination of gene sequences has revealed that recombination plays an important evolutionary role. We sequenced around 10% of the core genome of 114 isolates of enterica using a resequencing microarray. Application of two different analysis methods (Structure and ClonalFrame to our genomic data allowed us to define five clear lineages within S. enterica subspecies enterica, one of which is five times older than the other four and two thirds of the age of the whole subspecies. We show that some of these lineages display more evidence of recombination than others. We also demonstrate that some level of sexual isolation exists between the lineages, so that recombination has occurred predominantly between members of the same lineage. This pattern of recombination is compatible with expectations from the previously described ecological structuring of the enterica population as well as mechanistic barriers to recombination observed in laboratory experiments. In spite of their relatively low level of genetic differentiation, these lineages might therefore represent incipient species.

  10. 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.

  11. Recombinant expression systems for allergen vaccines.

    Science.gov (United States)

    Singh, Mohan B; Bhalla, Prem L

    2006-01-01

    Allergen immunotherapy of future is likely to be based on allergy vaccines that contain engineered allergens modified to abolish or substantially reduce their IgE-binding activity in order to remove the risk of unwanted anaphylactic responses. The development of efficient systems for the production of recombinant allergens in sufficient quantities is requirement for establishing use of engineered allergens as components of allergy vaccines. This review outlines relative advantages and disadvantages of various heterologous systems for production of recombinant allergens. Microbial systems are most convenient and cost effective platforms for the production of recombinant allergens. However, lack of post-translational processing implies that some allergens have to be expressed in eukaryotic systems for proper folding and post-translational modifications such as glycosylation. Yeast systems can yield high levels of recombinant allergens but often are associated with hyper- glycosylation problems. Mammalian cell culture systems offer suitable post -translational modifications but are nearly hundred fold more expensive than microbial systems. The use of plants as bio-factories for production of recombinant allergens is emerging as a very attractive option as plants-based production system offer several advantages over other expression systems such as post translational processing of proteins, low production costs, scale up ability and enhanced safety due to absence of animal or human pathogens.

  12. 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

  13. 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

  14. Alternative Green Solvents Project

    Science.gov (United States)

    Maloney, Phillip R.

    2012-01-01

    Necessary for safe and proper functioning of equipment. Mainly halogenated solvents. Tetrachloride, Trichloroethylene (TCE), CFC-113. No longer used due to regulatory/safety concerns. Precision Cleaning at KSC: Small % of total parts. Used for liquid oxygen (LOX) systems. Dual solvent process. Vertrel MCA (decafluoropentane (DFP) and trons-dichloroethylene) HFE-7100. DFP has long term environmental concerns. Project Goals: a) Identify potential replacements. b) 22 wet chemical processes. c) 3 alternative processes. d) Develop test procedures. e) Contamination and cleaning. f) Analysis. g) Use results to recommend alternative processes. Conclusions: a) No alternative matched Vertrel in this study. b) No clear second place solvent. c) Hydrocarbons- easy; Fluorinated greases- difficult. d) Fluorinated component may be needed in replacement solvent. e) Process may need to make up for shortcoming of the solvent. f) Plasma and SCC02 warrant further testing.

  15. 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

  16. 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.

  17. Domestic energy alternatives

    International Nuclear Information System (INIS)

    These alternatives include biomass, clean coal, geothermal, hydropower, natural gas, nuclear, solar and photovoltaic, and wind. With the current, volatile situation in the Middle East, this nation's political leaders appear to be left scratching their heads in their attempts to come up with new, sound, energy policies to reduce our dependence on foreign oil. Therefore, the FORTNIGHTLY's editorial staff thought that this might be an opportune time to briefly examine some home-grown and environmentally responsible fuel alternatives to black gold. While some of these electricity-producing technologies are still on the horizon, others are available now

  18. Comparison of recombination models in organic bulk heterojunction solar cells

    International Nuclear Information System (INIS)

    Recombination in bulk-heterojunction (BHJ) organic solar cells is the key loss mechanism, and it directly affects characteristic parameters such as power conversion efficiency, short-circuit current, open-circuit voltage, and fill factor. However, which recombination mechanism dominates the loss in organic materials is unclear at present. In this work, we simulate state-of-art BHJ solar cells using five recombination models, including direct recombination, Langevin recombination, charge transfer state recombination, trap-assisted recombination, and recombination via tail. All processes are strongly dependent on charge carrier mobility and exhibit a similar recombination distribution in active layer. For high mobilities, all models present a similar behavior along with the increased mobilities, whereas, there are slight differences in open-circuit voltage between trap/tail model and other ones at lower mobilities, resulting from the interaction between photo-carriers and dark-carriers

  19. Unbalanced Neuronal Circuits in Addiction

    OpenAIRE

    Volkow, Nora D; Wang, Gen-Jack; Tomasi, Dardo; Baler, Ruben D.

    2013-01-01

    Through sequential waves of drug-induced neurochemical stimulation, addiction co-opts the brain's neuronal circuits that mediate reward, motivation, , to behavioral inflexibility and a severe disruption of self-control and compulsive drug intake. Brain imaging technologies have allowed neuroscientists to map out the neural landscape of addiction in the human brain and to understand how drugs modify it.

  20. Quantum Electrodynamics Theory of Laser Assisted Recombination

    Institute of Scientific and Technical Information of China (English)

    敖淑艳; 程太旺; 李晓峰; 潘守甫; 傅盘铭

    2003-01-01

    Using a formal scattering theoretical approach, we develop a nonperturbative quantum electrodynamics theory to describe laser assisted recombination (LAR), in which an electron initially in the quantized Volkov state recombines with an ion and emits a high-energy photon with frequency defined by energy conservation laws.The transition probability is expressed as an analytic closed form and the spectrum of LAR reflects mainly the properties of general Bessel functions. For the case of a fast electron the LAR spectrum is confined in a well-defined range, while for a slow electron, the LAR spectrum exhibits a double-plateau structure.

  1. Probabilistic divergence measures for detecting interspecies recombination.

    Science.gov (United States)

    Husmeier, D; Wright, F

    2001-01-01

    This paper proposes a graphical method for detecting interspecies recombination in multiple alignments of DNA sequences. A fixed-size window is moved along a given DNA sequence alignment. For every position, the marginal posterior probability over tree topologies is determined by means of a Markov chain Monte Carlo simulation. Two probabilistic divergence measures are plotted along the alignment, and are used to identify recombinant regions. The method is compared with established detection methods on a set of synthetic benchmark sequences and two real-world DNA sequence alignments.

  2. Thermal Recombination: Beyond the Valence Quark Approximation

    CERN Document Server

    Müller, B; Bass, S A

    2005-01-01

    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.

  3. SIR epidemics in monogamous populations with recombination

    CERN Document Server

    Zanette, Damián H

    2011-01-01

    We study the propagation of an SIR (susceptible-infectious-recovered) disease over an agent population which, at any instant, is fully divided into couples of agents. Couples are occasionally allowed to exchange their members. This process of couple recombination can compensate the instantaneous disconnection of the interaction pattern and thus allow for the propagation of the infection. We study the incidence of the disease as a function of its infectivity and of the recombination rate of couples, thus characterizing the interplay between the epidemic dynamics and the evolution of the population's interaction pattern.

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

    Science.gov (United States)

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

    2016-09-01

    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. PMID:27543014

  5. Alternative and Integrative Medicine

    Science.gov (United States)

    ... are the healthcare rituals practiced by a given culture (eg, Asian, Indian, African). Homeopathic Medicine: This alternative medicine system is based on the principle that “like cures like.” In other words, the same substance ... American Brain Tumor Association 8550 W. Bryn Mawr Ave. ...

  6. 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…

  7. Compensated pulsed alternator

    International Nuclear Information System (INIS)

    This invention relates to an electromechanical energy converter with inertial energy storage. The device, a single phase, two or multi-pole alternator with stationary field coils, and a rotating armature is provided. The rotor itself may be of laminated steel for slower pulses or for faster pulses should be nonmagnetic and electrically nonconductive in order to allow rapid penetration of the field as the armature coil rotates. The armature coil comprises a plurality of power generating conductors mounted on the rotor. The alternator may also include a stationary or counterrotating compensating coil to increase the output voltage thereof and to reduce the internal impedance of the alternator at the moment of peak output. As the machine voltage rises sinusoidally, an external trigger switch is adapted to be closed at the appropriate time to create the desired output current from said alternator to an external load circuit, and as the output current passes through zero a self-commutating effect is provided to allow the switch to disconnect the generator from the external circuit

  8. Alternatives to Violence.

    Science.gov (United States)

    Children Today, 1994

    1994-01-01

    Notes that our capacity to diffuse conflict rests in our ability to recognize and verbalize feelings, develop empathy, and think of alternatives to violence. Explores the influence of role models and culture on violence and how the media can use violent images effectively in helping us confront a culture of violence. (HTH)

  9. Alternatives to Traditional Notation.

    Science.gov (United States)

    Gaare, Mark

    1997-01-01

    Provides a introduction and overview to alternative music notation systems. Describes guitar tablature, accordion tablature, klavarskribo (a keyboard notational system developed by Cornelius Pot, a Dutch engineer), and the digital piano roll. Briefly discusses the history of notation reform and current efforts. Includes examples from scores. (MJP)

  10. 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.

  11. 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.

  12. Microstructure, mechanical properties and wetting behavior of F: Si–C–N films as bio-mechanical coating grown by DC unbalanced magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Zhifeng, E-mail: scut0533@126.com [School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China); Wang, Yingjun, E-mail: imwangyj@163.com [School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China); Huang, Nan [Key Lab. for Advanced Technologies of Materials, Ministry of Education, Southwest Jiaotong University, 610031 Chengdu (China); Ning, Chengyun; Wang, Lin [School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China)

    2013-03-05

    Highlights: ► The F: Si–C–N film coating on Co–Cr alloy as bio-mechanical coating was put forward. ► Significant role of F and C doped on structure and properties in the film was observed. ► The as-deposited F: Si–C–N films are amphipathic nature. ► F: Si–C–N coatings show improvement in the tribological behavior over the uncoated Co–Cr–Mo. ► Compared with Co–Cr alloy, F: Si–C–N films could improve hardness enhances 1.7 times. -- Abstract: A systematic structure and properties investigation on the deposition of fluorinated silicon–carbon–nitride (Si–C–N) films under varying CF{sub 4} flows was carried out by direct current unbalanced magnetron sputtering techniques. Significant role of fluorine and carbon-doped on growth characteristics and mechanical properties in the film was observed. The chemical bonding configurations, surface topography and mechanical properties were characterized by means of X-ray photoelectron spectroscopy (XPS), Raman and infrared spectroscopies, atomic force microscopy (AFM) and nano-indentation technique and CSM pin-on-disk tribometer. It was found that the as-deposited F: Si–C–N films are amphipathic nature, and large variations took place these films’ deposition rate, composition, microstructure and mechanical properties when CF{sub 4} flows varied from 0 to 9 sccm. At CF{sub 4} gas flow rate 9 sccm, the F: Si–C–N coatings demonstrated a fluorine content of 5.95 at.% and a moderate friction coefficient of 0.03. It is obvious from the hardness results that the F: Si–C–N coating enhances the hardness of the Co–Cr–Mo alloy to approximately 16.3 GPa on a smoother surface. The tribological characterization of Co–Cr–Mo alloy with F: Si–C–N coating sliding against ultrahigh molecular weight polyethylene (UHMWPE) counter-surface in fetal bovine serum, shows that the wear resistance of the F: Si–C–N coated Co–Cr–Mo alloy/UHMWPE sliding pair show much obviously

  13. A more economical compensation method for unbalanced load%不平衡负载的一种更加经济的补偿方法

    Institute of Scientific and Technical Information of China (English)

    傅军栋; 喻勇; 黄来福

    2015-01-01

    For low-voltage distribution network unbalanced load loss reduction, we think of the capacitance compensation, which can improve the power factor of power grid and reduce the loss of power transformers and transmission lines, as well as improve the efficiency of power supply improvement and environment in the power supply system. Traditional methods simply calculate the admittance compensation value required by the load, then configure the appropriate capacitor;a relatively new kind of admittance calculation method is the balance component method. This paper puts forward a "Line Adjustment Act" drop loss compensation method to perform three phase load line regulation, which only adjusts the access phase of users’ meter box. A commutation strategy based on intelligent optimization algorithm is proposed, which does not require additional investment, and through a numerical example, the validity and effectiveness of this method are verified. Therefore, the"Line Adjustment Act"is a more simple and more economical method of reducing loss.%针对低压配电网不平衡负载降损的问题,会联想到电容补偿器,其在供电系统中起到提高电网的功率因数与降低供电变压器及输送线路的损耗,提高供电效率以及改善供电环境的作用。传统方法只需计算出负载所需要补偿的导纳值,然后配置相应的电容器,比较新的一种导纳值计算方法如平衡分量法。提出一种“线路调整法”的降损补偿方法,进行负荷三相平衡线路调整,仅需对用户集表箱的接入相做调整。提出一种基于优化算法的智能换相策略,不需要增加额外投资,通过算例分析验证了此方法的正确性和有效性。因此,“线路调整法”是一种更简单、更经济的降损方法。

  14. Microstructure, mechanical properties and wetting behavior of F: Si–C–N films as bio-mechanical coating grown by DC unbalanced magnetron sputtering

    International Nuclear Information System (INIS)

    Highlights: ► The F: Si–C–N film coating on Co–Cr alloy as bio-mechanical coating was put forward. ► Significant role of F and C doped on structure and properties in the film was observed. ► The as-deposited F: Si–C–N films are amphipathic nature. ► F: Si–C–N coatings show improvement in the tribological behavior over the uncoated Co–Cr–Mo. ► Compared with Co–Cr alloy, F: Si–C–N films could improve hardness enhances 1.7 times. -- Abstract: A systematic structure and properties investigation on the deposition of fluorinated silicon–carbon–nitride (Si–C–N) films under varying CF4 flows was carried out by direct current unbalanced magnetron sputtering techniques. Significant role of fluorine and carbon-doped on growth characteristics and mechanical properties in the film was observed. The chemical bonding configurations, surface topography and mechanical properties were characterized by means of X-ray photoelectron spectroscopy (XPS), Raman and infrared spectroscopies, atomic force microscopy (AFM) and nano-indentation technique and CSM pin-on-disk tribometer. It was found that the as-deposited F: Si–C–N films are amphipathic nature, and large variations took place these films’ deposition rate, composition, microstructure and mechanical properties when CF4 flows varied from 0 to 9 sccm. At CF4 gas flow rate 9 sccm, the F: Si–C–N coatings demonstrated a fluorine content of 5.95 at.% and a moderate friction coefficient of 0.03. It is obvious from the hardness results that the F: Si–C–N coating enhances the hardness of the Co–Cr–Mo alloy to approximately 16.3 GPa on a smoother surface. The tribological characterization of Co–Cr–Mo alloy with F: Si–C–N coating sliding against ultrahigh molecular weight polyethylene (UHMWPE) counter-surface in fetal bovine serum, shows that the wear resistance of the F: Si–C–N coated Co–Cr–Mo alloy/UHMWPE sliding pair show much obviously improvement over that of

  15. 陕西义务教育失衡发展的症结所在%The Crux of the Unbalanced Development of Compulsory Education in Shaanxi

    Institute of Scientific and Technical Information of China (English)

    侯耀先

    2015-01-01

    Abstracts:With the rapid development of social economy ,the nine‐year compulsory education has been basically popularized in Shaanxi province ,basically eliminating the illiteracy of the young ,with school‐age children receiving compulsory education ,and so on .However ,in the development of compulsory education , there are many unbalanced phenomena between urban and rural compulsory education ,in terms of financial support ,teaching equipment ,teacher allocation ,curriculum ,enrollment rates ,and so on .Strategies and suggestions to solve these imbalances include :strengthening governmental responsibility ,financial investment and information construction ,promoting teacher professionalism ,establishing unified standardized schools , establishing the mechanism of resources sharing ,developing the rural economy ,and reducing the gap between urban and rural economy development .%随着社会经济的快速发展,陕西省九年义务教育已基本普及,全省已基本扫除了青壮年文盲,实现了适龄儿童入学接受义务教育等等。但在义务教育的发展过程中也表现出众多的失衡现象,如城乡之间义务教育经费投入不均等;城乡之间义务教育教学设施配套不均衡;城乡之间义务教育师资配置不均衡;城乡之间学科设置不均衡;城乡之间义务教育升学率不均衡。解决这些失衡发展现象的策略和建议是:强化政府职责,加强义务教育投入;建立统一的标准化学校,合理配置城乡教育资源;加大力度发展乡村经济,缩小城乡社会经济发展差距;加强信息化建设,建立资源共享机制;加强乡村地区师资队伍建设。

  16. 含负荷不平衡补偿的SVC复合控制方法研究%The Composite Control Method Research of the SVC with Unbalanced Load Compensation

    Institute of Scientific and Technical Information of China (English)

    李慧

    2012-01-01

    该文提出了一种通过加装带滤波器的静止无功补偿器(SVC),使负序引起的不平衡功率和谐波功率流入SVC,最终达到平衡系统目的的方法;提出基于前馈-反馈复合控制的SVC不平衡负荷补偿方法,将电压闭环控制与三相不平衡控制相结合、功率因数闭环控制与三相不平衡控制相结合,以达到适应各种工况的需求。最后,该文在SVC相关理论研究的基础上搭建了仿真模型,仿真结果表明该文提出控制方法的正确性和可行性。%Based on the analysis of three-phase unbalanced system's instantaneous power,this paper proposes a method that by installing SVC compensator with a filter to make the imbalance power caused by negative sequence and harmonic power flowing into the SVC and achieve the ultimate objective of a balanced system.A feedforward-feedback composite control method on the unbalanced load compensation of SVC is also given in this paper,which take the voltage loop control and three-phase unbalance control integrated as well as make power factor loop combining with the three-phase unbalanced control.It is proved that this method can meet the needs of various working conditions.The simulation model is built based on the SVC theory,simulation results show that this control method is correct and feasible.

  17. Recombinant microorganisms for increased production of organic acids

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Jian; Kleff, Susanne; Guettler, Michael V

    2013-04-30

    Disclosed are recombinant microorganisms for producing organic acids. The recombinant microorganisms express a polypeptide that has the enzymatic activity of an enzyme that is utilized in the pentose phosphate cycle. The recombinant microorganism may include recombinant Actinobacillus succinogenes that has been transformed to express a Zwischenferment (Zwf) gene. The recombinant microorganisms may be useful in fermentation processes for producing organic acids such as succinic acid and lactic acid. Also disclosed are novel plasmids that are useful for transforming microorganisms to produce recombinant microorganisms that express enzymes such as Zwf.

  18. 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

    The immunoglobulin heavy chain intron enhancer (Emu) not only stimulates transcription but also V(D)J recombination of chromosomally integrated recombination substrates. We aimed at reproducing this effect in recombination competent cells by transient transfection of extrachromosomal substrates...... respectively, can markedly affect the frequency of V(D)J recombination. We report that the entire Emu, the Emu core as well as its flanking 5' and 3' matrix associated regions (5' and 3' MARs) upregulate V(D)J recombination while the downstream section of the 3' MAR of Emu does not. Also, prokaryotic sequences...

  19. HP1-Mediated Formation of Alternative Lengthening of Telomeres-Associated PML Bodies Requires HIRA but Not ASF1a

    OpenAIRE

    Wei-Qin Jiang; Akira Nguyen; Ying Cao; Andy C-M Chang; Reddel, Roger R

    2011-01-01

    Approximately 10% of cancers use recombination-mediated Alternative Lengthening of Telomeres (ALT) instead of telomerase to prevent telomere shortening. A characteristic of cells that utilize ALT is the presence of ALT-associated PML nuclear bodies (APBs) containing (TTAGGG)n DNA, telomere binding proteins, DNA recombination proteins, and heterochromatin protein 1 (HP1). The function of APBs is unknown and it is possible that they are functionally heterogeneous. Most ALT cells lack functional...

  20. Recombinant protein blends: silk beyond natural design.

    Science.gov (United States)

    Dinjaski, Nina; Kaplan, David L

    2016-06-01

    Recombinant DNA technology and new material concepts are shaping future directions in biomaterial science for the design and production of the next-generation biomaterial platforms. Aside from conventionally used synthetic polymers, numerous natural biopolymers (e.g., silk, elastin, collagen, gelatin, alginate, cellulose, keratin, chitin, polyhydroxyalkanoates) have been investigated for properties and manipulation via bioengineering. Genetic engineering provides a path to increase structural and functional complexity of these biopolymers, and thereby expand the catalog of available biomaterials beyond that which exists in nature. In addition, the integration of experimental approaches with computational modeling to analyze sequence-structure-function relationships is starting to have an impact in the field by establishing predictive frameworks for determining material properties. Herein, we review advances in recombinant DNA-mediated protein production and functionalization approaches, with a focus on hybrids or combinations of proteins; recombinant protein blends or 'recombinamers'. We highlight the potential biomedical applications of fibrous protein recombinamers, such as Silk-Elastin Like Polypeptides (SELPs) and Silk-Bacterial Collagens (SBCs). We also discuss the possibility for the rationale design of fibrous proteins to build smart, stimuli-responsive biomaterials for diverse applications. We underline current limitations with production systems for these proteins and discuss the main trends in systems/synthetic biology that may improve recombinant fibrous protein design and production.

  1. 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

  2. Genetic Recombination as a Chemical Reaction Network

    OpenAIRE

    Müller, Stefan; Hofbauer, Josef

    2015-01-01

    The process of genetic recombination can be seen as a chemical reaction network with mass-action kinetics. We review the known results on existence, uniqueness, and global stability of an equilibrium in every compatibility class and for all rate constants, from both the population genetics and the reaction networks point of view.

  3. Why do bacteria engage in homologous recombination?

    NARCIS (Netherlands)

    Vos, M.

    2009-01-01

    Microbiologists have long recognized that the uptake and incorporation of homologous DNA from outside the cell is a common feature of bacteria, with important implications for their evolution. However, the exact reasons why bacteria engage in homologous recombination remain elusive. This Opinion art

  4. Evidence for homologous recombination in Chikungunya Virus.

    Science.gov (United States)

    Casal, Pablo E; Chouhy, Diego; Bolatti, Elisa M; Perez, Germán R; Stella, Emma J; Giri, Adriana A

    2015-04-01

    Chikungunya Virus (CHIKV), a mosquito-transmitted alphavirus, causes acute fever and joint pain in humans. Recently, endemic CHIKV infection outbreaks have jeopardized public health in wider geographical regions. Here, we analyze the phylogenetic associations of CHIKV and explore the potential recombination events on 152 genomic isolates deposited in GenBank database. The CHIKV genotypes [West African, Asian, East/Central/South African (ECSA)], and a clear division of ECSA clade into three sub-groups (I-II-III), were defined by Bayesian analysis; similar results were obtained using E1 gene sequences. A nucleotide identity-based approach is provided to facilitate CHIKV classification within ECSA clade. Using seven methods to detect recombination, we found a statistically significant event (p-values range: 1.14×10(-7)-4.45×10(-24)) located within the nsP3 coding region. This finding was further confirmed by phylogenetic networks (PHI Test, p=0.004) and phylogenetic tree incongruence analysis. The recombinant strain, KJ679578/India/2011 (ECSA III), derives from viruses of ECSA III and ECSA I. Our study demonstrates that recombination is an additional mechanism of genetic diversity in CHIKV that might assist in the cross-species transmission process.

  5. 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.

  6. 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.

  7. Vaccine development using recombinant DNA technology

    Science.gov (United States)

    Vaccines induce an immune response in the host that subsequently recognizes infectious agents and helps fight off the disease; vaccines must do this without causing the disease. This paper reviews the development of recombinant DNA technologies as a means of providing new ways for attenuating diseas...

  8. Selected techniques in recombinant DNA technology

    International Nuclear Information System (INIS)

    Recombined DNA technology comprises a complex of techniques in the fields of nucleic acid biochemistry and molecular biology. This presentation gives an introduction, a brief description and example of the procedures of some of the basic techniques in the DNA cloning work currently used. 8 refs

  9. Recombinant DNA: Scientific and Social Perspectives.

    Science.gov (United States)

    Vandegrift, Vaughn

    1979-01-01

    This article is designed to inform chemical educators not engaged in this technology as to the nature and methods used in the technology, the reasons for scientific and social concern, and the attempts made to assuage concerns involving recombinant DNA research. (author/BB)

  10. 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 in...

  11. 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.

  12. Recombinant protein blends: silk beyond natural design.

    Science.gov (United States)

    Dinjaski, Nina; Kaplan, David L

    2016-06-01

    Recombinant DNA technology and new material concepts are shaping future directions in biomaterial science for the design and production of the next-generation biomaterial platforms. Aside from conventionally used synthetic polymers, numerous natural biopolymers (e.g., silk, elastin, collagen, gelatin, alginate, cellulose, keratin, chitin, polyhydroxyalkanoates) have been investigated for properties and manipulation via bioengineering. Genetic engineering provides a path to increase structural and functional complexity of these biopolymers, and thereby expand the catalog of available biomaterials beyond that which exists in nature. In addition, the integration of experimental approaches with computational modeling to analyze sequence-structure-function relationships is starting to have an impact in the field by establishing predictive frameworks for determining material properties. Herein, we review advances in recombinant DNA-mediated protein production and functionalization approaches, with a focus on hybrids or combinations of proteins; recombinant protein blends or 'recombinamers'. We highlight the potential biomedical applications of fibrous protein recombinamers, such as Silk-Elastin Like Polypeptides (SELPs) and Silk-Bacterial Collagens (SBCs). We also discuss the possibility for the rationale design of fibrous proteins to build smart, stimuli-responsive biomaterials for diverse applications. We underline current limitations with production systems for these proteins and discuss the main trends in systems/synthetic biology that may improve recombinant fibrous protein design and production. PMID:26686863

  13. 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.

  14. Haemostatic effects of recombinant coagulation factor VIIa

    NARCIS (Netherlands)

    Lisman, Johannes Antonius

    2003-01-01

    Recombinant coagulation factor VIIa (rFVIIa) has recently become available for treatment of patients with inhibitor-complicated haemophilia. It has been postulated that rFVIIa could become a universal haemostatic agent. Case reports and small studies confirm efficacy and safety of rFVIIa in a variet

  15. Generation of Modified Pestiviruses by Targeted Recombination

    DEFF Research Database (Denmark)

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

    and hence is not limited to the use of internal restriction sites. Rescue of modified pestiviruses can be obtained by electroporation of cell cultures with full-length RNA transcripts in vitro transcribed from the recombined BAC clones. We have used this approach to generate a series of new pestivirus BACs...

  16. Ancient Male Recombination Shaped Genetic Diversity of Neo-Y Chromosome in Drosophila albomicans.

    Science.gov (United States)

    Satomura, Kazuhiro; Tamura, Koichiro

    2016-02-01

    Researchers studying Y chromosome evolution have drawn attention to neo-Y chromosomes in Drosophila species due to their resembling the initial stage of Y chromosome evolution. In the studies of neo-Y chromosome of Drosophila miranda, the extremely low genetic diversity observed suggested various modes of natural selection acting on the nonrecombining genome. However, alternative possibility may come from its peculiar origin from a single chromosomal fusion event with male achiasmy, which potentially caused and maintained the low genetic diversity of the neo-Y chromosome. Here, we report a real case where a neo-Y chromosome is in transition from an autosome to a typical Y chromosome. The neo-Y chromosome of Drosophila albomicans harbored a rich genetic diversity comparable to its gametologous neo-X chromosome and an autosome in the same genome. Analyzing sequence variations in 53 genes and measuring recombination rates between pairs of loci by cross experiments, we elucidated the evolutionary scenario of the neo-Y chromosome of D. albomicans having high genetic diversity without assuming selective force, i.e., it originated from a single chromosomal fusion event, experienced meiotic recombination during the initial stage of evolution and diverged from neo-X chromosome by the suppression of recombination tens or a few hundreds of thousand years ago. Consequently, the observed high genetic diversity on the neo-Y chromosome suggested a strong effect of meiotic recombination to introduce genetic variations into the newly arisen sex chromosome. PMID:26494844

  17. Expression of human DNA polymerase β in Escherichia coli and characterization of the recombinant enzyme

    International Nuclear Information System (INIS)

    The coding region of a human β-polymerase cDNA, predicting a 335 amino acid protein, was subcloned in the Escherichia coli expression plasmid pRC23. After induction of transformed cells, the crude soluble extract was found to contain a new protein immunoreactive with β-polymerase antibody and corresponding in size to the protein deduced from the cDNA. This protein was purified in a yield of 1-2 mg/50 g of cells. The recombinant protein had about the same DNA polymerase specific activity as β-polymerase purified from mammalian tissues, and template-primer specificity and immunological properties of the recombinant polymerase were similar to those of natural β-polymerases. The purified enzyme was free of nuclease activity. The authors studied detailed catalytic properties of the recombinant β-polymerase using defined template-primer systems. The results indicate that this β-polymerase is essentially identical with natural β-polymerases. The recombinant enzyme is distributive in mode of synthesis and is capable of detecting changes in the integrity of the single-stranded template, such as methylated bases and a double-stranded region. The enzyme recognizes a template region four to seven bases downstream of the primer 3' end and utilizes alternative primers if this downstream template region is double stranded. The enzyme is unable to synthesize past methylated bases N3-methyl-dT or O6-methyl-dG

  18. A new strategy for estimating two-locus recombination fractions under some natural inequality restrictions

    Indian Academy of Sciences (India)

    Ying Zhou; Weijun Ma; Xiaona Sheng; Huakun Wang

    2011-08-01

    Linkage analysis is now being widely used to map markers on each chromosome in the human genome, to map genetic diseases, and to identify genetic forms of common diseases. Two-locus linkage analysis and multi-locus analysis have been investigated comprehensively, and many computer programs have been developed to perform linkage analysis. Yet there exists a shortcoming in traditional methods, i.e., the parameter space of two-locus recombination fractions has not been emphasized sufficiently in the usual analyses. In this paper, we propose a new strategy for estimating the two-locus recombination fractions based on data of backcross family in the framework of some natural and necessary parameter restrictions. The new strategy is based on a restricted projection algorithm, which can provide fast reasonable estimates of recombination fraction, and can therefore serve as a superior alternative algorithm. Results obtained from both real and simulated data indicate that the new algorithm performs well in the estimation of recombination fractions and outperforms current methods.

  19. Lysostaphin: immunogenicity of locally administered recombinant protein used in mastitis therapy.

    Science.gov (United States)

    Daley, M J; Oldham, E R

    1992-03-01

    A recombinant bactericidal protein, recombinant lysostaphin (r-lysostaphin), that may be useful as an intramammary therapeutic for Staphylococcus aureus mastitis in dairy cattle, was evaluated for immunogenicity to various hosts. Although immunogenicity could be demonstrated in a variety of other species when administered parenterally, oral administration failed to elicit a significant immunological response. Similarly, intramammary infusion of r-lysostaphin failed to elicit significant serum titers in the bovine until 18-21 infusions were administered (total administered dose of 2-3 g of protein). Antibody titers from dairy cattle which did develop an immune response were predominantly of the IgG1 subclass. Dairy cattle with significant anti-lysostaphin titers showed no deleterious symptoms (anaphylaxis, etc.) upon subsequent infusion, and these titers did not effect the in vitro bacteriostatic activity of r-lysostaphin. Intramammary infusion of r-lysostaphin does not elicit any observable effects on the host animal or on the potential efficacy of the recombinant molecule. Intramammary recombinant proteins may be suitable effective and safe infusion products that provide an alternative to classical antibiotic therapy.

  20. Insecticidal activity of two proteases against Spodoptera frugiperda larvae infected with recombinant baculoviruses

    Directory of Open Access Journals (Sweden)

    Nagata Tatsuya

    2010-06-01

    Full Text Available Abstract Background Baculovirus comprise the largest group of insect viruses most studied worldwide, mainly because they efficiently kill agricutural insect pests. In this study, two recombinant baculoviruses containing the ScathL gene from Sarcophaga peregrina (vSynScathL, and the Keratinase gene from the fungus Aspergillus fumigatus (vSynKerat, were constructed. and their insecticidal properties analysed against Spodoptera frugiperda larvae. Results Bioassays of third-instar and neonate S. frugiperda larvae with vSynScathL and vSynKerat showed a decrease in the time needed to kill the infected insects when compared to the wild type virus. We have also shown that both recombinants were able to increase phenoloxidase activity in the hemolymph of S. frugiperda larvae. The expression of proteases in infected larvae resulted in destruction of internal tissues late in infection, which could be the reason for the increased viral speed of kill. Conclusions Baculoviruses and their recombinant forms constitute viable alternatives to chemical insecticides. Recombinant baculoviruses containing protease genes can be added to the list of engineered baculoviruses with great potential to be used in integrated pest management programs.

  1. High-level production of animal-free recombinant transferrin from saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Goldenberg Hans

    2010-11-01

    Full Text Available Abstract Background Animal-free recombinant proteins provide a safe and effective alternative to tissue or serum-derived products for both therapeutic and biomanufacturing applications. While recombinant insulin and albumin already exist to replace their human counterparts in cell culture media, until recently there has been no equivalent for serum transferrin. Results The first microbial system for the high-level secretion of a recombinant transferrin (rTf has been developed from Saccharomyces cerevisiae strains originally engineered for the commercial production of recombinant human albumin (Novozymes' Recombumin® USP-NF and albumin fusion proteins (Novozymes' albufuse®. A full-length non-N-linked glycosylated rTf was secreted at levels around ten-fold higher than from commonly used laboratory strains. Modification of the yeast 2 μm-based expression vector to allow overexpression of the ER chaperone, protein disulphide isomerase, further increased the secretion of rTf approximately twelve-fold in high cell density fermentation. The rTf produced was functionally equivalent to plasma-derived transferrin. Conclusions A Saccharomyces cerevisiae expression system has enabled the cGMP manufacture of an animal-free rTf for industrial cell culture application without the risk of prion and viral contamination, and provides a high-quality platform for the development of transferrin-based therapeutics.

  2. Purification and characterization of recombinant supersweet protein thaumatin II from tomato fruit.

    Science.gov (United States)

    Firsov, Aleksey; Shaloiko, Lyubov; Kozlov, Oleg; Vinokurov, Leonid; Vainstein, Alexander; Dolgov, Sergey

    2016-07-01

    Thaumatin, a supersweet protein from the African plant katemfe (Thaumatococcus daniellii Benth.), is a promising zero-calorie sweetener for use in the food and pharmaceutical industries. Due to limited natural sources of thaumatin, its production using transgenic plants is an advantageous alternative. We report a simple protocol for purification of recombinant thaumatin II from transgenic tomato. Thaumatin was extracted from ripe tomato fruit in a low-salt buffer and purified on an SP-Sephacryl column. Recombinant thaumatin yield averaged 50 mg/kg fresh fruit. MALDI-MS analysis showed correct processing of thaumatin in tomato plants. The recombinant thaumatin was indistinguishable from the native protein in a taste test. The purified tomato-derived thaumatin had an intrinsic sweetness with a threshold value in taste tests of around 50 nM. These results demonstrate the potential of an expression system based on transgenic tomato plants for production of recombinant thaumatin for the food and pharmaceutical industries. PMID:26965414

  3. Recombination-activating gene 1 and 2 (RAG1 and RAG2) in flounder (Paralichthys olivaceus)

    Indian Academy of Sciences (India)

    Xianlei Wang; Xungang Tan; Pei-Jun Zhang; Yuqing Zhang; Peng Xu

    2014-12-01

    During the development of B and T lymphocytes, Ig and TCR variable region genes are assembled from germline V, D, and J gene segments by a site-specific recombination reaction known as V(D)J recombination. The process of somatic V(D)J recombination, mediated by the recombination-activating gene (RAG) products, is the most significant characteristic of adaptive immunity in jawed vertebrates. Flounder (Paralichthys olivaceus) RAG1 and RAG2 were isolated by Genome Walker and RT-PCR, and their expression patterns were analysed by RT-PCR and in situ hybridization on sections. RAG1 spans over 7.0 kb, containing 4 exons and 3 introns, and the full-length ORF is 3207 bp, encoding a peptide of 1068 amino acids. The first exon lies in the 5′-UTR, which is an alternative exon. RAG2 full-length ORF is 1062 bp, encodes a peptide of 533 amino acids, and lacks introns in the coding region. In 6-month-old flounders, the expression of RAG1 and RAG2 was essentially restricted to the pronephros (head kidney) and mesonephros (truck kidney). Additionally, both of them were mainly expressed in the thymus. These results revealed that the thymus and kidney most likely serve as the primary lymphoid tissues in the flounder.

  4. Experimental Mg IX photo recombination rate coefficient

    International Nuclear Information System (INIS)

    The rate coefficient for radiative and dielectronic recombination of beryllium-like magnesium ions was measured with high resolution at the Heidelberg heavy-ion storage ring TSR. In the electron-ion collision energy range 0-207 eV resonances due to 2s → 2p (ΔN = 0) and 2s → 3l (ΔN = 1) core excitations were detected. At low energies below 0.15 eV the recombination rate coefficient is dominated by strong 1s2(2s2p 3P)7l resonances with the strongest one occurring at an energy of only 21 meV. These resonances decisively influence the Mg IX recombination rate coefficient in a low temperature plasma. The experimentally derived Mg IX dielectronic recombination rate coefficient (±15% systematical uncertainty) is compared with the recommendation by Mazzotta et al. (1998, AandAS, 133, 403) and the recent calculations by Gu (2003, ApJ, 590, 1131) and by Colgan et al. (2003, AandA, 412, 597). These results deviate from the experimental rate coefficient by 130%, 82% and 25%, respectively, at the temperature where the fractional abundance of Mg IX is expected to peak in a photoionized plasma. At this temperature a theoretical uncertainty in the 1s2(2s2p 3P)7l resonance positions of only 100 meV would translate into an uncertainty of the plasma rate coefficient of almost a factor 3. This finding emphasizes that an accurate theoretical calculation of the Mg IX recombination rate coefficient from first principles is challenging. (authors)

  5. Adaptive Alternating Minimization Algorithms

    CERN Document Server

    Niesen, Urs; Wornell, Gregory

    2007-01-01

    The classical alternating minimization (or projection) algorithm has been successful in the context of solving optimization problems over two variables or equivalently of finding a point in the intersection of two sets. The iterative nature and simplicity of the algorithm has led to its application to many areas such as signal processing, information theory, control, and finance. A general set of sufficient conditions for the convergence and correctness of the algorithm is quite well-known when the underlying problem parameters are fixed. In many practical situations, however, the underlying problem parameters are changing over time, and the use of an adaptive algorithm is more appropriate. In this paper, we study such an adaptive version of the alternating minimization algorithm. As a main result of this paper, we provide a general set of sufficient conditions for the convergence and correctness of the adaptive algorithm. Perhaps surprisingly, these conditions seem to be the minimal ones one would expect in ...

  6. [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. PMID:20669543

  7. 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

  8. Alternatives to Higgs scalars

    International Nuclear Information System (INIS)

    We discuss alternatives to the Higgs Scalar doublet Φ of the minimal standard model. In particular we review technicolor (TC) and extended technicolor (ETC), and show that the threat of flavour changing neutral currents (FCNC's) is avoided by walking TC and/or strongly coupled ETC. The phenomenology of minimal TC and the techni-family is discussed. Finally we consider the possibility that the Higgs doublet Φ is a composite bound state of quarks from the third (or fourth) family

  9. Alternatives to ECMO.

    OpenAIRE

    Donn, S M

    1994-01-01

    The past decade has witnessed technological advancements which are unparalleled in neonatology. ECMO has been demonstrated to be a powerful rescue treatment, but has perhaps been overutilised and is not universally available. Alternative treatments have been shown to be both safe and efficacious in the management of infants with respiratory failure. Direct head to head clinical trials will probably be necessary to establish appropriate criteria and indications for use, given the wide diversit...

  10. Alternative approaches in IVF

    OpenAIRE

    Fauser, Bart; Bouchard, P.; Coelingh Bennink, H.J.; Collins, John; Devroey, P.; Evers, Johannes; Van Steirteghem, A

    2002-01-01

    textabstractVarious new developments in clinical and basic science which may impact on IVF in the near or distant future will be discussed in this review. These key areas include the regulation of early follicle development and the extended in-vitro culture of oocytes and embryos. Moreover, alternative compounds and ovarian stimulation protocols will be discussed, along with highlights in the development of the cryopreservation of excess oocytes or embryos. Finally, the health economics of IV...

  11. 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

  12. Biological evaluation of recombinant human erythropoietin in pharmaceutical products

    Directory of Open Access Journals (Sweden)

    Ramos A.S.

    2003-01-01

    Full Text Available The potencies of mammalian cell-derived recombinant human erythropoietin pharmaceutical preparations, from a total of five manufacturers, were assessed by in vivo bioassay using standardized protocols. Eight-week-old normocythemic mice received a single subcutaneous injection followed by blood sampling 96 h later or multiple daily injections with blood sampling 24 h after the last injection. Reticulocyte counting by microscopic examination was employed as the end-point using the brilliant cresyl blue or selective hemolysis methods, together with automated flow cytometry. Different injection schedules were investigated and dose-response curves for the European Pharmacopoeia Biological Reference Preparation of erythropoietin were compared. Manual and automated methods of reticulocyte counting were correlated with respect to assay validity and precision. Using 8 mice per treatment group, intra-assay precision determined for all of the assays in the study showed coefficients of variation of 12.1-28.4% for the brilliant cresyl blue method, 14.1-30.8% for the selective hemolysis method and 8.5-19.7% for the flow cytometry method. Applying the single injection protocol, a combination of at least two independent assays was required to achieve the precision potency and confidence limits indicated by the manufacturers, while the multiple daily injection protocol yielded the same acceptable results within a single assay. Although the latter protocol using flow cytometry for reticulocyte counting gave more precise and reproducible results (intra-assay coefficients of variation: 5.9-14.2%, the well-characterized manual methods provide equally valid alternatives for the quality control of recombinant human erythropoietin therapeutic products.

  13. Outlook for alternative transportation fuels

    Energy Technology Data Exchange (ETDEWEB)

    Gushee, D.E. [Univ. of Illinois, Chicago, IL (United States)

    1996-12-31

    This presentation provides a brief review of regulatory issues and Federal programs regarding alternative fuel use in automobiles. A number of U.S. DOE initiatives and studies aimed at increasing alternative fuels are outlined, and tax incentives in effect at the state and Federal levels are discussed. Data on alternative fuel consumption and alternative fuel vehicle use are also presented. Despite mandates, tax incentives, and programs, it is concluded alternative fuels will have minimal market penetration. 7 refs., 5 tabs.

  14. Branching innovation, recombinant innovation, and endogenous technological transitions

    NARCIS (Netherlands)

    Frenken, K.; Izquierdo, L.; Zeppini, P.

    2012-01-01

    We propose a model of technological transitions based on two different types of innovations. Branching innovations refer to technological improvements along a particular path, while recombinant innovations represent fusions of multiple paths. Recombinant innovations create "short-cuts" which reduce

  15. 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.

  16. 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...

  17. State alternative route designations

    Energy Technology Data Exchange (ETDEWEB)

    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.

  18. State alternative route designations

    Energy Technology Data Exchange (ETDEWEB)

    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.

  19. Alternative Fuels: Research Progress

    Directory of Open Access Journals (Sweden)

    Maher A.R. Sadiq Al-Baghdadi

    2013-01-01

    Full Text Available Chapter 1: Pollutant Emissions and Combustion Characteristics of Biofuels and Biofuel/Diesel Blends in Laminar and Turbulent Gas Jet Flames. R. N. Parthasarathy, S. R. Gollahalli Chapter 2: Sustainable Routes for The Production of Oxygenated High-Energy Density Biofuels from Lignocellulosic Biomass. Juan A. Melero, Jose Iglesias, Gabriel Morales, Marta Paniagua Chapter 3: Optical Investigations of Alternative-Fuel Combustion in an HSDI Diesel Engine. T. Huelser, M. Jakob, G. Gruenefeld, P. Adomeit, S. Pischinger Chapter 4: An Insight into Biodiesel Physico-Chemical Properties and Exhaust Emissions Based on Statistical Elaboration of Experimental Data. Evangelos G. Giakoumis Chapter 5: Biodiesel: A Promising Alternative Energy Resource. A.E. Atabani Chapter 6: Alternative Fuels for Internal Combustion Engines: An Overview of the Current Research. Ahmed A. Taha, Tarek M. Abdel-Salam, Madhu Vellakal Chapter 7: Investigating the Hydrogen-Natural Gas Blends as a Fuel in Internal Combustion Engine. ?lker YILMAZ Chapter 8: Conversion of Bus Diesel Engine into LPG Gaseous Engine; Method and Experiments Validation. M. A. Jemni , G. Kantchev , Z. Driss , R. Saaidia , M. S. Abid Chapter 9: Predicting the Combustion Performance of Different Vegetable Oils-Derived Biodiesel Fuels. Qing Shu, ChangLin Yu Chapter 10: Production of Gasoline, Naphtha, Kerosene, Diesel, and Fuel Oil Range Fuels from Polypropylene and Polystyrene Waste Plastics Mixture by Two-Stage Catalytic Degradation using ZnO. Moinuddin Sarker, Mohammad Mamunor Rashid

  20. 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......, and vaccine development....

  1. Hyper-Recombining Recipient Strains in Bacterial Conjugation

    OpenAIRE

    Feinstein, Sheldon I.; Low, K. Brooks

    1986-01-01

    Using a direct enrichment and screening procedure, mutants of Escherichia coli have been isolated in which recombination frequencies for several intragenic Hfr x F- crosses are significantly higher (twofold to sixfold) than in the parental strains. These hyper-recombination mutations comprised five new mutS- and one new mutL- allele. Together with other known mut - alleles, they were analyzed for effects on intragenic recombination using several types of crosses. Hyper-recombination was fou...

  2. Orientation-dependent perimeter recombination in GaAs diodes

    Energy Technology Data Exchange (ETDEWEB)

    Stellwag, T.B.; Melloch, M.R.; Lundstrom, M.S.; Carpenter, M.S.; Pierret, R.F. (School of Electrical Engineering, Purdue University, West Lafayette, Indiana 47907 (USA))

    1990-04-23

    Perimeter recombination currents affect the performance of GaAs-based devices such as solar cells, heterojunction bipolar transistors, and injection lasers. We report that the {ital n}{congruent}2 perimeter recombination current has a strong orientation dependence. More than a factor of five variation in the surface recombination current at mesa-etched edges has been observed. These results suggest that with proper device design, perimeter recombination currents could be substantially reduced.

  3. Orientation-dependent perimeter recombination in GaAs diodes

    Science.gov (United States)

    Stellwag, T. B.; Melloch, M. R.; Lundstrom, M. S.; Carpenter, M. S.; Pierret, R. F.

    1990-04-01

    Perimeter recombination currents affect the performance of GaAs-based devices such as solar cells, heterojunction bipolar transistors, and injection lasers. We report that the n≂2 perimeter recombination current has a strong orientation dependence. More than a factor of five variation in the surface recombination current at mesa-etched edges has been observed. These results suggest that with proper device design, perimeter recombination currents could be substantially reduced.

  4. Ion-ion recombination at high ion density

    International Nuclear Information System (INIS)

    By appeal to a Thomson-style treatment of recombination, it is shown that the rate for recombination of ions generated with uniform frequency within a reaction volume is a factor of 9/4 times greater than the rate for recombination of ions which approach each other from infinite separation. A valuable relationship connecting the two problems is uncovered. The analysis is pertinent to recombination involving dilute and high degrees of ionisation. (author)

  5. Replication, recombination, and repair: going for the gold.

    Science.gov (United States)

    Klein, Hannah L; Kreuzer, Kenneth N

    2002-03-01

    DNA recombination is now appreciated to be integral to DNA replication and cell survival. Recombination allows replication to successfully maneuver through the roadblocks of damaged or collapsed replication forks. The signals and controls that permit cells to transition between replication and recombination modes are now being identified.

  6. The unconventional xer recombination machinery of Streptococci/Lactococci

    NARCIS (Netherlands)

    Le Bourgeois, Pascal; Bugarel, Marie; Campo, Nathalie; Daveran-Mingot, Marie-Line; Labonte, Jessica; Lanfranchi, Daniel; Lautier, Thomas; Pages, Carine; Ritzenthaler, Paul

    2007-01-01

    Homologous recombination between circular sister chromosomes during DNA replication in bacteria can generate chromosome dimers that must be resolved into monomers prior to cell division. In Escherichia coli, dimer resolution is achieved by site-specific recombination, Xer recombination, involving tw

  7. 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....

  8. Plasmid-to-plasmid recombination in Haemophilus influenzae

    Energy Technology Data Exchange (ETDEWEB)

    Balganesh, M.; Setlow, J.K.

    1986-01-01

    No recombination between plasmids was observed after conjugal transfer of a plasmid into a cell carrying another plasmid. Two types of such recombination took place after transformation, one type being Rec/sup +/ dependent and suggesting a preferred site of recombination. The other much rarer type was at least partially Rec/sup +/ independent.

  9. Treatment of type I and II hereditary angioedema with Rhucin, a recombinant human C1 inhibitor.

    Science.gov (United States)

    Varga, Lilian; Farkas, Henriette

    2008-11-01

    Hereditary and acquired angioedema are of outstanding clinical importance, as edematous attacks associated with these conditions can thrust afflicted patients into mortal danger. Currently, C1 inhibitor concentrate - a human blood product - is available as a replacement therapy. In view of the limited number of donors, as well as the risk of transmission of blood-borne infections, it is a reasonable expectation to develop a therapeutic alternative based on recombinant technology, which would eliminate all these shortcomings. Pharming (Leiden, The Netherlands) has developed Rhucin, a recombinant human C1 inhibitor, as a proprietary product, which is currently being evaluated in Phase III clinical trials. Ongoing studies conducted within the framework of the development program are almost complete and their interim findings are reassuring. This should facilitate successful regulatory approval in the near future, which is indispensable in order to make Rhucin available for patients with hereditary angioedema or other disorders amenable to C1 inhibitor replacement. PMID:20477114

  10. Evaluation of an in vitro cell culture assay for the potency assessment of recombinant human erythropoietin.

    Science.gov (United States)

    Machado, Francine T; Maldaner, Fernanda P S; Perobelli, Rafaela F; Xavier, Bruna; da Silva, Francielle S; de Freitas, Guilherme W; Bartolini, Paolo; Ribela, M Tereza C P; Dalmora, Sérgio L

    2016-05-01

    Recombinant human erythropoietin is a sialoglycoprotein that stimulates erythropoiesis. To assess potency of human erythropoietin produced by recombinant technology, we investigated an in vitro TF-1 cell proliferation assay, which was applied in conjunction with a reversed-phase liquid chromatography method for the determination of the content of sialic acids. The results obtained, which were higher than 126.8ng/μg, were compared with those obtained with the in vivo normocythaemic mouse bioassay. The in vitro assay resulted in a non-significant lower mean difference of the estimated potencies (0.61% ± 0.026, p > 0.05). The use of this combination of methods represents an advance toward the establishment of alternative in vitro approaches, in the context of the Three Rs, for the potency assessment of biotechnology-derived medicines. PMID:27256453

  11. Treatment of type I and II hereditary angioedema with Rhucin, a recombinant human C1 inhibitor.

    Science.gov (United States)

    Varga, Lilian; Farkas, Henriette

    2008-11-01

    Hereditary and acquired angioedema are of outstanding clinical importance, as edematous attacks associated with these conditions can thrust afflicted patients into mortal danger. Currently, C1 inhibitor concentrate - a human blood product - is available as a replacement therapy. In view of the limited number of donors, as well as the risk of transmission of blood-borne infections, it is a reasonable expectation to develop a therapeutic alternative based on recombinant technology, which would eliminate all these shortcomings. Pharming (Leiden, The Netherlands) has developed Rhucin, a recombinant human C1 inhibitor, as a proprietary product, which is currently being evaluated in Phase III clinical trials. Ongoing studies conducted within the framework of the development program are almost complete and their interim findings are reassuring. This should facilitate successful regulatory approval in the near future, which is indispensable in order to make Rhucin available for patients with hereditary angioedema or other disorders amenable to C1 inhibitor replacement.

  12. 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...

  13. 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.

  14. Alternatives to incineration. Technical area status report

    International Nuclear Information System (INIS)

    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, NOx, SOx, 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

  15. Cloning of a copper resistance gene cluster from the cyanobacterium Synechocystis sp. PCC 6803 by recombineering recovery.

    Science.gov (United States)

    Gittins, John R

    2015-07-01

    A copper resistance gene cluster (6 genes, ∼8.2 kb) was isolated from the cyanobacterium Synechocystis sp. PCC 6803 by recombineering recovery (RR). Following integration of a narrow-host-range plasmid vector adjacent to the target region in the Synechocystis genome (pSYSX), DNA was isolated from transformed cells and the plasmid plus flanking sequence circularized by recombineering to precisely clone the gene cluster. Complementation of a copper-sensitive Escherichia coli mutant demonstrated the functionality of the pcopM gene encoding a copper-binding protein. RR provides a novel alternative method for cloning large DNA fragments from species that can be transformed by homologous recombination. PMID:25980606

  16. Very low surface recombination velocities on p-type silicon wafers passivated with a dielectric with fixed negative charge

    Energy Technology Data Exchange (ETDEWEB)

    Agostinelli, G.; Delabie, A.; Dekkers, H.F.W.; De Wolf, S.; Beaucarne, G. [IMEC vzw, Kapeldreef 75, Leuven (Belgium); Vitanov, P.; Alexieva, Z. [CL SENES, Sofia (Bulgaria)

    2006-11-23

    Surface recombination velocities as low as 10cm/s have been obtained by treated atomic layer deposition (ALD) of Al{sub 2}O{sub 3} layers on p-type CZ silicon wafers. Low surface recombination is achieved by means of field induced surface passivation due to a high density of negative charges stored at the interface. In comparison to a diffused back surface field, an external field source allows for higher band bending, that is, a better performance. While this process yields state of the art results, it is not suited for large-scale production. Preliminary results on an industrially viable, alternative process based on a pseudo-binary system containing Al{sub 2}O{sub 3} are presented, too. With this process, surface recombination velocities of 500-1000cm/s have been attained on mc-Si wafers. (author)

  17. Mechanism and control of interspecies recombination in Escherichia coli. I. Mismatch repair, methylation, recombination and replication functions.

    OpenAIRE

    Stambuk, S; Radman, M

    1998-01-01

    A genetic analysis of interspecies recombination in Escherichia coli between the linear Hfr DNA from Salmonella typhimurium and the circular recipient chromosome reveals some fundamental aspects of recombination between related DNA sequences. The MutS and MutL mismatch binding proteins edit (prevent) homeologous recombination between these 16% diverged genomes by at least two distinct mechanisms. One is MutH independent and presumably acts by aborting the initiated recombination through the U...

  18. Alternate fuels; Combustibles alternos

    Energy Technology Data Exchange (ETDEWEB)

    Romero Paredes R, Hernando; Ambriz G, Juan Jose [Universidad Autonoma Metropolitana. Iztapalapa (Mexico)

    2003-07-01

    In the definition and description of alternate fuels we must center ourselves in those technological alternatives that allow to obtain compounds that differ from the traditional ones, in their forms to be obtained. In this article it is tried to give an overview of alternate fuels to the conventional derivatives of petroleum and that allow to have a clear idea on the tendencies of modern investigation and the technological developments that can be implemented in the short term. It is not pretended to include all the tendencies and developments of the present world, but those that can hit in a relatively short term, in accordance with agreed with the average life of conventional fuels. Nevertheless, most of the conversion principles are applicable to the spectrum of carbonaceous or cellulosic materials which are in nature, are cultivated or wastes of organic origin. Thus one will approach them in a successive way, the physical, chemical and biological conversions that can take place in a production process of an alternate fuel or the same direct use of the fuel such as burning the sweepings derived from the forests. [Spanish] En la definicion y descripcion de combustibles alternos nos debemos centrar en aquellas alternativas tecnologicas que permitan obtener compuestos que difieren de los tradicionales, al menos en sus formas de ser obtenidos. En este articulo se pretende dar un panorama de los combustibles alternos a los convencionales derivados del petroleo y que permita tener una idea clara sobre las tendencias de la investigacion moderna y los desarrollos tecnologicos que puedan ser implementados en el corto plazo. No se pretende abarcar todas las tendencias y desarrollos del mundo actual, sino aquellas que pueden impactar en un plazo relativamente corto, acordes con la vida media de los combustibles convencionales. Sin embargo, la mayor parte de los principios de conversion son aplicables al espectro de materiales carbonaceos o celulosicos los cuales se

  19. Alternate fusion concepts

    International Nuclear Information System (INIS)

    This review summarizes the status of alternate fusion concepts and plans for their future. The concepts selected for review are those employing electromagnetic confinement for which there have been reasonable predictions of net energy gain from pure fusion and which have shown significant recent development or are the subjects of ongoing international activity. They include advanced tokamaks, stellarators, the spherical torus, reversed-field pinch and dense z-field pinch devices, field reversed configuration, and spheromaks. In addition, an overall view of the status of each concept with respect to achieving ignition and to reactor designs is presented

  20. Alternate transportation system

    Science.gov (United States)

    Zertuche, Tony; Mckinnie, James

    1988-01-01

    Three missions have been identified by NASA for a Space Shuttle-supplementing Alternate Transportation System (ATS) encompassing combinations of booster vehicles, crew modules, and service modules: (1) to achieve manned access to orbit for Space Station crew rotation every 90 days, (2) the lofting of a logistics module resupplying the Space Station every 180 days, and (3) the simultaneous launch of both crews and logistics to the Space Station. A reentry glider is considered, in conjunction with the Space Shuttle's unmanned cargo version and the Apollo manned capsule, as an important ATS element. The Titan IV/NUS is used as a booster.