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Sample records for alpha satellite dna

  1. Locational diversity of alpha satellite DNA and intergeneric hybridization aspects in the Nomascus and Hylobates genera of small apes.

    Science.gov (United States)

    Baicharoen, Sudarath; Miyabe-Nishiwaki, Takako; Arsaithamkul, Visit; Hirai, Yuriko; Duangsa-ard, Kwanruen; Siriaroonrat, Boripat; Domae, Hiroshi; Srikulnath, Kornsorn; Koga, Akihiko; Hirai, Hirohisa

    2014-01-01

    Recently, we discovered that alpha satellite DNA has unique and genus-specific localizations on the chromosomes of small apes. This study describes the details of alpha satellite localization in the genera Nomascus and Hylobates and explores their usefulness in distinguishing parental genome sets in hybrids between these genera. Fluorescence in situ hybridization was used to establish diagnostic criteria of alpha satellite DNA markers in discriminating small ape genomes. In particular we established the genus specificity of alpha satellite distribution in three species of light-cheeked gibbons (Nomascus leucogenys, N. siki, and N. gabriellae) in comparison to that of Hylobates lar. Then we determined the localization of alpha satellite DNA in a hybrid individual which resulted from a cross between these two genera. In Nomascus the alpha satellite DNA blocks were located at the centromere, telomere, and four interstitial regions. In Hylobates detectable amounts of alpha satellite DNA were seen only at centromeric regions. The differences in alpha satellite DNA locations between Nomascus and Hylobates allowed us to easily distinguish the parental chromosomal sets in the genome of intergeneric hybrid individuals found in Thai and Japanese zoos. Our study illustrates how molecular cytogenetic markers can serve as diagnostic tools to identify the origin of individuals. These molecular tools can aid zoos, captive breeding programs and conservation efforts in managing small apes species. Discovering more information on alpha satellite distribution is also an opportunity to examine phylogenetic and evolutionary questions that are still controversial in small apes.

  2. A neocentromere on human chromosome 3 without detectable alpha-satellite DNA forms morphologically normal kinetochores

    DEFF Research Database (Denmark)

    Wandall, A; Tranebjaerg, L; Tommerup, Niels

    1998-01-01

    A neocentromere at 3q26 was observed in a father and his daughter on a chromosome 3 with deleted centromeric region. No alpha-satellite DNA was detectable at the 3q26 neocentromere, but it was weakly positive with anticentromere (CREST) antibodies. Electron microscopy showed that the neocentromere...

  3. A neocentromere on human chromosome 3 without detectable alpha-satellite DNA forms morphologically normal kinetochores

    DEFF Research Database (Denmark)

    Wandall, A; Tranebjaerg, L; Tommerup, Niels

    1998-01-01

    A neocentromere at 3q26 was observed in a father and his daughter on a chromosome 3 with deleted centromeric region. No alpha-satellite DNA was detectable at the 3q26 neocentromere, but it was weakly positive with anticentromere (CREST) antibodies. Electron microscopy showed that the neocentromere...... formed microtubule-associated kinetochores with normal morphology and of the same size as the kinetochores of other large chromosomes. The deleted centromere formed a small linear marker chromosome that reacted strongly with anticentromere antibodies, but showed reduced kinetochore size. The 3q26...... neokinetochore was stable under adverse growth conditions, which often caused kinetochore loss in the original 3-centromere on the small marker....

  4. Cloning and comparative mapping of a human chromosome 4-specific alpha satellite DNA sequence

    Energy Technology Data Exchange (ETDEWEB)

    D' Aiuto, L.; Marzella, R.; Archidiacono, N.; Rocchi, M. (Universita di Bari (Italy)); Antonacci, R. (Instituto Anatomia Umana Normale, Modena (Italy))

    1993-11-01

    The authors have isolated and characterized two human alphoid DNA clones: p4n1/4 and pZ4.1. Clone p4n1/4 identifies specifically the centromeric region of chromosome 4; pZ4.1 recognizes a subset of alphoid DNA shared by chromosomes 4 and 9. The specificity was determined using fluorescence in situ hybridization experiments on metaphase spreads and Southern blotting analysis of human-hamster somatic cell hybrids. The genomic organization of both subsets was also investigated. Comparative mapping on chimpanzee and gorilla chromosomes was performed. p4n1/4 hybridizes to chimpanzee chromosomes 11 and 13, homologs of human chromosomes 9 and 2q, respectively. On gorilla metaphase spreads, p4n1/4 hybridizes exclusively to the centromeric region of chromosome 19, partially homologous to human chromosome 17. No hybridization signal was detected on chromosome 3 of both chimpanzee and gorilla, in both species homolog of human chromosome 4. Identical comparative mapping results were obtained using pZ4.1 probe, although the latter recognizes an alphoid subset distinct from the one recognized by p4n1/4. The implications of these results in the evolution of centromeric regions of primate chromosomes are discussed. 33 refs., 4 figs.

  5. Satellite DNA and related diseases

    Directory of Open Access Journals (Sweden)

    Rich J.

    2014-07-01

    Full Text Available Satellite DNA, also known as tandemly repeated DNA, consists of clusters of repeated sequences and represents a diverse class of highly repetitive elements. Satellite DNA can be divided into several classes according to the size of an individual repeat: microsatellites, minisatellites, midisatellites, and macrosatellites. Originally considered as «junk» DNA, satellite DNA has more recently been reconsidered as having various functions. Moreover, due to the repetitive nature of the composing elements, their presence in the genome is associated with high frequency mutations, epigenetic changes and modifications in gene expression patterns, with a potential to lead to human disease. Therefore, the satellite DNA study will be beneficial for developing a treatment of satellite-related diseases, such as FSHD, neurological, developmental disorders and cancers.

  6. DNA methylation at a bovine alpha satellite I repeat CpG site during development following fertilization and somatic cell nuclear transfer.

    Directory of Open Access Journals (Sweden)

    Christine Couldrey

    Full Text Available Incomplete epigenetic reprogramming is postulated to contribute to the low developmental success following somatic cell nuclear transfer (SCNT. Here, we describe the epigenetic reprogramming of DNA methylation at an alpha satellite I CpG site (αsatI-5 during development of cattle generated either by artificial insemination (AI or in vitro fertilization (IVF and SCNT. Quantitative methylation analysis identified that SCNT donor cells were highly methylated at αsatI-5 and resulting SCNT blastocysts showed significantly more methylation than IVF blastocysts. At implantation, no difference in methylation was observed between SCNT and AI in trophoblast tissue at αsatI-5, however, SCNT embryos were significantly hyper-methylated compared to AI controls at this time point. Following implantation, DNA methylation at αsatI-5 decreased in AI but not SCNT placental tissues. In contrast to placenta, the proportion of methylation at αsatI-5 remained high in adrenal, kidney and muscle tissues during development. Differences in the average proportion of methylation were smaller in somatic tissues than placental tissues but, on average, SCNT somatic tissues were hyper-methylated at αsatI-5. Although sperm from all bulls was less methylated than somatic tissues at αsatI-5, on average this site remained hyper-methylated in sperm from cloned bulls compared with control bulls. This developmental time course confirms that epigenetic reprogramming does occur, at least to some extent, following SCNT. However, the elevated methylation levels observed in SCNT blastocysts and cellular derivatives implies that there is either insufficient time or abundance of appropriate reprogramming factors in oocytes to ensure complete reprogramming. Incomplete reprogramming at this CpG site may be a contributing factor to low SCNT success rates, but more likely represents the tip of the iceberg in terms of incompletely reprogramming. Until protocols ensure the epigenetic

  7. Satellite DNA: An Evolving Topic.

    Science.gov (United States)

    Garrido-Ramos, Manuel A

    2017-09-18

    Satellite DNA represents one of the most fascinating parts of the repetitive fraction of the eukaryotic genome. Since the discovery of highly repetitive tandem DNA in the 1960s, a lot of literature has extensively covered various topics related to the structure, organization, function, and evolution of such sequences. Today, with the advent of genomic tools, the study of satellite DNA has regained a great interest. Thus, Next-Generation Sequencing (NGS), together with high-throughput in silico analysis of the information contained in NGS reads, has revolutionized the analysis of the repetitive fraction of the eukaryotic genomes. The whole of the historical and current approaches to the topic gives us a broad view of the function and evolution of satellite DNA and its role in chromosomal evolution. Currently, we have extensive information on the molecular, chromosomal, biological, and population factors that affect the evolutionary fate of satellite DNA, knowledge that gives rise to a series of hypotheses that get on well with each other about the origin, spreading, and evolution of satellite DNA. In this paper, I review these hypotheses from a methodological, conceptual, and historical perspective and frame them in the context of chromosomal organization and evolution.

  8. Characterization of a chromosome-specific chimpanzee alpha satellite subset: Evolutionary relationship to subsets on human chromosomes

    Energy Technology Data Exchange (ETDEWEB)

    Warburton, P.E.; Gosden, J.; Lawson, D. [Western General Hospital, Edinburgh (United Kingdom)] [and others

    1996-04-15

    Alpha satellite DNA is a tandemly repeated DNA family found at the centromeres of all primate chromosomes examined. The fundamental repeat units of alpha satellite DNA are diverged 169- to 172-bp monomers, often found to be organized in chromosome-specific higher-order repeat units. The chromosomes of human (Homo sapiens (HSA)), chimpanzee (Pan troglodytes (PTR) and Pan paniscus), and gorilla (Gorilla gorilla) share a remarkable similarity and synteny. It is of interest to ask if alpha satellite arrays at centromeres of homologous chromosomes between these species are closely related (evolving in an orthologous manner) or if the evolutionary processes that homogenize and spread these arrays within and between chromosomes result in nonorthologous evolution of arrays. By using PCR primers specific for human chromosome 17-specific alpha satellite DNA, we have amplified, cloned, and characterized a chromosome-specific subset from the PTR chimpanzee genome. Hybridization both on Southern blots and in situ as well as sequence analysis show that this subset is most closely related, as expected, to sequences on HSA 17. However, in situ hybridization reveals that this subset is not found on the homologous chromosome in chimpanzee (PTR 19), but instead on PTR 12, which is homologous to HSA 2p. 40 refs., 3 figs.

  9. Function of Junk: Pericentromeric Satellite DNA in Chromosome Maintenance.

    Science.gov (United States)

    Jagannathan, Madhav; Yamashita, Yukiko M

    2018-04-02

    Satellite DNAs are simple tandem repeats that exist at centromeric and pericentromeric regions on eukaryotic chromosomes. Unlike the centromeric satellite DNA that comprises the vast majority of natural centromeres, function(s) for the much more abundant pericentromeric satellite repeats are poorly understood. In fact, the lack of coding potential allied with rapid divergence of repeat sequences across eukaryotes has led to their dismissal as "junk DNA" or "selfish parasites." Although implicated in various biological processes, a conserved function for pericentromeric satellite DNA remains unidentified. We have addressed the role of satellite DNA through studying chromocenters, a cytological aggregation of pericentromeric satellite DNA from multiple chromosomes into DNA-dense nuclear foci. We have shown that multivalent satellite DNA-binding proteins cross-link pericentromeric satellite DNA on chromosomes into chromocenters. Disruption of chromocenters results in the formation of micronuclei, which arise by budding off the nucleus during interphase. We propose a model that satellite DNAs are critical chromosome elements that are recognized by satellite DNA-binding proteins and incorporated into chromocenters. We suggest that chromocenters function to preserve the entire chromosomal complement in a single nucleus, a fundamental and unquestioned feature of eukaryotic genomes. We speculate that the rapid divergence of satellite DNA sequences between closely related species results in discordant chromocenter function and may underlie speciation and hybrid incompatibility. © 2017 Jagannathan and Yamashita; Published by Cold Spring Harbor Laboratory Press.

  10. Action of radiation and serotin on DNA and satellite DNA of thermodynamic parameters

    International Nuclear Information System (INIS)

    Sanaya, T.V.

    1987-01-01

    A study was made on the effect of X-rays on thermal denaturation of DNA and satellite DNA of cattle spleen against the background of 10 -3 M serotonin influence. The minimal dose at which the damage of satellite DNA is observed, is equal to 38 Gy; similar damage of DNA requires the double dose. Serotonin with 10 -3 M concentration doesn't change thermodynamic DNA characteristics, but its presence in the moment of irradiation even at 152 Gy dose reveals the clearly pronounced protection effect on satellite DNA damage

  11. Similarity of satellite DNA properties in the order Rodentia

    Energy Technology Data Exchange (ETDEWEB)

    Mazrimas, J.A.; Hatch, F.T.

    1977-09-01

    Satellite DNAs from 9 species of kangaroo rat (Dipodomys) have been characterized and have shown that the HS-..cap alpha.. and HS-..beta.. satellites, where present, are nearly identical in all species as to melting transition midpoint (Tm), and density in neutral CsCl, alkaline CsCl, and Cs/sub 2/SO/sub 4/-Ag/sup +/ gradients. However, the MS satellites exist in two internally similar classes. The satellite DNAs from three other rodents were characterized (densities listed are in neutral CsCl). The pocket gopher, Thomomys bottae, contains Th-..cap alpha.. (1.713 g/ml) and Th..beta.. (1.703 g/ml). The guinea pig (Cavia porcellus) contains Ca-..cap alpha.., Ca-..beta.. and Ca-..gamma.. at densities of 1.706 g/ml, 1.704 g/ml and 1.704 g/ml, respectively. The antelope ground squirrel (Ammospermophilus harrisi) contains Am-..cap alpha.., 1.708 g/ml, Am-..beta.., 1.717 g/ml, and Am-..gamma.., 1.707 g/ml. The physical and chemical properties of the alpha-satellites from the above four rodents representing four different families in two suborders of Rodentia were compared. They show nearly identical Tm, nucleoside composition of single strands, and single strand densities in alkaline CsCl. Similar comparisons on the second or third satellite DNAs from these rodents also indicate a close relationship to each other. Thus the high degree of similarity of satellite sequences found in such a diverse group of rodents suggests a cellular function that is subject to natural selection, and implies that these sequences have been conserved over a considerable span of evolutionary time since the divergence of these rodents about 50 million years ago.

  12. Similarity of satellite DNA properties in the order Rodentia

    Energy Technology Data Exchange (ETDEWEB)

    Mazrimas, J.A.; Hatch, F.T.

    1977-09-01

    We have characterized satellite DNAs from 9 species of kangaroo rat (Dipodomys) and have shown that the HS-..cap alpha.. and HS-..beta.. satellites, where present, are nearly identical in all species as to melting transition midpoint (Tm), and density in neutral CsCl, alkaline CsCl, and Cs/sub 2/SO/sub 4/-Ag/sup +/ gradients. However, the MS satellites exist in two internally similar classes. The satellite DNAs from three other rodents were characterized (densities listed are in neutral CsCl). The pocket gopher, Thomomys bottae, contains Th-..cap alpha.. (1.713 g/ml) and Th-..beta.. (1.703 g/ml). The guinea pig (Cavia porcellus) contains Ca-..cap alpha.., Ca-..beta.., and Ca-..gamma.. at densities of 1.706 g/ml, 1.704 g/ml, and 1.704 g/ml, respectively. The antelope ground squirrel (Ammospermophilus harrisi) contains Am-..cap alpha.., 1.708 g/ml, Am-..beta.., 1.717 g/ml, and Am-..gamma.., 1.707 g/ml. The physical and chemical properties of the alpha-satellites from the above four rodents representing four different families in two suborders of Rodentia were compared. They show nearly identical Tm, nucleoside composition of single strands, and single strand densities in alkaline CsCl. Similar comparisons on the second or third satellite DNAs from these rodents also indicate a close relationship to each other. Thus the high degree of similarity of satellite sequences found in such a diverse group of rodents suggests a cellular function that is subject to natural selection, and implies that these sequences have been conserved over a considerable span of evolutionary time since the divergence of these rodents about 50 million years ago.

  13. SPS-ALPHA: The First Practical Solar Power Satellite via Arbitrarily Large PHased Array

    Data.gov (United States)

    National Aeronautics and Space Administration — SPS-ALPHA (Solar Power Satellite via Arbitrarily Large Phased Array) is a novel, bio-mimetic approach to the challenge of space solar power. If successful, this...

  14. Deficient repair of chemical adducts in alpha DNA of monkey cells

    International Nuclear Information System (INIS)

    Zolan, M.E.; Cortopassi, G.A.; Smith, C.A.; Hanawalt, P.C.

    1982-01-01

    Researchers have examined excision repair of DNA damage in the highly repeated alpha DNA sequence of cultured African green monkey cells. Irradiation of cells with 254 nm ultraviolet light resulted in the same frequency of pyrimidine dimers in alpha DNA and the bulk of the DNA. The rate and extent of pyrimidine dimer removal, as judged by measurement of repair synthesis, was also similar for alpha DNA and bulk DNA. In cells treated with furocoumarins and long-wave-length ultraviolet light, however, repair synthesis in alpha DNA was only 30% of that in bulk DNA, although it followed the same time course. Researchers found that this reduced repair was not caused by different initial amounts of furocoumarin damage or by different sizes of repair patches, as researchers found these to be similar in the two DNA species. Direct quantification demonstrated that fewer furocoumarin adducts were removed from alpha DNA than from bulk DNA. In cells treated with another chemical DNA-damaging agent, N-acetoxy-2-acetylaminofluorene, repair synthesis in alpha DNA was 60% of that in bulk DNA. These results show that the repair of different kinds of DNA damage can be affected to different extents by some property of this tandemly repeated heterochromatic DNA. To our knowledge, this is the first demonstration in primate cells of differential repair of cellular DNA sequences

  15. Inhibition of DNA replication, DNA repair synthesis, and DNA polymerases. cap alpha. and delta by butylphenyl deoxyguanosine triphosphate

    Energy Technology Data Exchange (ETDEWEB)

    Dreslor, S.L.; Frattini, M.G.

    1987-05-01

    Semiconservative DNA replication in growing mammalian cells and ultraviolet (UV)-induced DNA repair synthesis in nongrowing mammalian cells are mediated by one or both of the aphidicolin-sensitive DNA polymerases, ..cap alpha.. and/or delta. They have studied the inhibition of replication and repair synthesis in permeable human cells by N/sup 2/ (p-n-butylphenyl)-2'-deoxyguanosine-5'-triphosphate (BuPh dGTP), an agent which inhibits polymerase ..cap alpha.. strongly and polymerase delta weakly. Both processes are inhibited by BuPh-dGTP in competition with dGTP. The K/sub i/'s are, for replication, 2-3 ..mu..M and, for repair synthesis, 3-4 ..mu..M, consistent with the involvement of the same DNA polymerase in both processes. Inhibition of isolated human polymerase ..cap alpha.. by BuPh-dGTP is also competitive with dGTP, but the K/sub i/ is approximately 10 nM, several hundred-fold lower than the K/sub i/'s of replication and repair synthesis. Isolated polymerase delta is inhibited by BuPh-dGTP at doses similar to those which inhibit replication and repair synthesis, however, attempts to determine the K/sub i/ of polymerase delta were hampered by the finding that the dependence of delta activity on deoxyribunucleotide concentration is parabolic at low doses. This behavior differs from the behavior of polymerase ..cap alpha.. and of cellular DNA replication and repair synthesis, all of which show a simple, hyperbolic relationship between activity and deoxyribonucleotide concentration. Thus, inhibition of DNA replication and UV induced DNA repair synthesis by BuPh dGTP is quantitatively similar to DNA polymerase delta, but some other characteristics of the cellular processes are more similar to those of polymerase ..cap alpha...

  16. RNA Pol II promotes transcription of centromeric satellite DNA in beetles.

    Directory of Open Access Journals (Sweden)

    Zeljka Pezer

    Full Text Available Transcripts of centromeric satellite DNAs are known to play a role in heterochromatin formation as well as in establishment of the kinetochore. However, little is known about basic mechanisms of satellite DNA expression within constitutive heterochromatin and its regulation. Here we present comprehensive analysis of transcription of abundant centromeric satellite DNA, PRAT from beetle Palorus ratzeburgii (Coleoptera. This satellite is characterized by preservation and extreme sequence conservation among evolutionarily distant insect species. PRAT is expressed in all three developmental stages: larvae, pupae and adults at similar level. Transcripts are abundant comprising 0.033% of total RNA and are heterogeneous in size ranging from 0.5 kb up to more than 5 kb. Transcription proceeds from both strands but with 10 fold different expression intensity and transcripts are not processed into siRNAs. Most of the transcripts (80% are not polyadenylated and remain in the nucleus while a small portion is exported to the cytoplasm. Multiple, irregularly distributed transcription initiation sites as well as termination sites have been mapped within the PRAT sequence using primer extension and RLM-RACE. The presence of cap structure as well as poly(A tails in a portion of the transcripts indicate RNA polymerase II-dependent transcription and a putative polymerase II promoter site overlaps the most conserved part of the PRAT sequence. The treatment of larvae with alpha-amanitin decreases the level of PRAT transcripts at concentrations that selectively inhibit pol II activity. In conclusion, stable, RNA polymerase II dependant transcripts of abundant centromeric satellite DNA, not regulated by RNAi, have been identified and characterized. This study offers a basic understanding of expression of highly abundant heterochromatic DNA which in beetle species constitutes up to 50% of the genome.

  17. Genomic organization and transcription of satellite DNA in the ant Aphaenogaster subterranea (Hymenoptera, Formicidae).

    Science.gov (United States)

    Lorite, P; Renault, S; Rouleux-Bonnin, F; Bigot, S; Periquet, G; Palomeque, T

    2002-08-01

    A satellite DNA family (APSU) was isolated and characterized in the ant Aphaenogaster subterranea. This satellite DNA is organized in tandem repeats of 162 bp and is relatively AT rich (51.9%). Sequence analysis showed a high level of homogeneity between monomers. Loss of satellite DNA has been detected in queens in relation to workers, because the amount of satellite DNA in queens is about 25% of the amount found in workers. Restriction analysis of the total DNA with methylation-sensitive enzymes suggests that this DNA is not methylated. Analysis of the electrophoretic mobility of satellite DNA on non-denaturing polyacrylamide showed that this satellite DNA is only very lightly curved. Their possible transcription was analyzed using reverse transcription and polymerase chain reaction (RT-PCR). The satellite DNA is transcribed on the two DNA strands at the same level in worker and queen pupae, as well as in worker adults.

  18. Pericentric satellite DNA sequences in Pipistrellus pipistrellus (Vespertilionidae; Chiroptera).

    Science.gov (United States)

    Barragán, M J L; Martínez, S; Marchal, J A; Fernández, R; Bullejos, M; Díaz de la Guardia, R; Sánchez, A

    2003-09-01

    This paper reports the molecular and cytogenetic characterization of a HindIII family of satellite DNA in the bat species Pipistrellus pipistrellus. This satellite is organized in tandem repeats of 418 bp monomer units, and represents approximately 3% of the whole genome. The consensus sequence from five cloned monomer units has an A-T content of 62.20%. We have found differences in the ladder pattern of bands between two populations of the same species. These differences are probably because of the absence of the target sites for the HindIII enzyme in most monomer units of one population, but not in the other. Fluorescent in situ hybridization (FISH) localized the satellite DNA in the pericentromeric regions of all autosomes and the X chromosome, but it was absent from the Y chromosome. Digestion of genomic DNAs with HpaII and its isoschizomer MspI demonstrated that these repetitive DNA sequences are not methylated. Other bat species were tested for the presence of this repetitive DNA. It was absent in five Vespertilionidae and one Rhinolophidae species, indicating that it could be a species/genus specific, repetitive DNA family.

  19. Molecular cloning of goat 20alpha-hydroxysteroid dehydrogenase cDNA.

    Science.gov (United States)

    Jayasekara, Walimuni Samantha Nilanthi; Yonezawa, Tomohiro; Ishida, Maho; Yamanouchi, Keitaro; Nishihara, Masugi

    2004-06-01

    20Alpha-hydroxysteroid dehydrogenase (20alpha-HSD), which catalyzes the conversion of progesterone to its inactive form 20alpha-dihydroprogesterone, is expressed in murine placenta and has been suggested to play roles in maintaining pregnancy. To understand the role of 20alpha-HSD during pregnancy in the goat, as a first step, cloning and sequencing of 20alpha-HSD cDNA were performed. The full nucleotide sequence of 20alpha-HSD cDNA was determined on samples obtained from the corpus luteum at the luteal phase of the estrous cycle and the placenta in late pregnancy by RT-PCR and 3' and 5' RACE systems. Cloned 20alpha-HSD cDNA consisted of 1124 bp and belonged to the aldo-keto reductase superfamily. From the start codon to stop codon there were 323 amino acids, the same as in other species. To verify whether the protein derived from goat 20alpha-HSD cDNA had 20alpha-HSD activity, the cDNA was expressed by bacteria. Bacterially expressed goat 20alpha-HSD protein showed 20alpha-HSD enzyme activity. A tissue distribution study demonstrated that 20alpha-HSD was expressed in the placenta, but not in the adrenal gland, liver and spleen during pregnancy. The present study suggests that goat 20alpha-HSD is another member of the aldo-keto reductase superfamily and that it plays a role in the placenta during pregnancy.

  20. Plantago lagopus B Chromosome Is Enriched in 5S rDNA-Derived Satellite DNA

    Czech Academy of Sciences Publication Activity Database

    Kumke, K.; Macas, Jiří; Fuchs, J.; Altschmied, L.; Kour, J.; Dhar, M.K.; Houben, A.

    2016-01-01

    Roč. 148, č. 1 (2016), s. 68-73 ISSN 1424-8581 R&D Projects: GA ČR GBP501/12/G090 Institutional support: RVO:60077344 Keywords : Polymorhpic A chromosome segment * Satellite repeat * Supernumerary chromosome * 5S rDNA Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.354, year: 2016

  1. Hypoxia-inducible factor-1alpha DNA induced angiogenesis in a rat cerebral ischemia model.

    Science.gov (United States)

    Matsuda, Takeshi; Abe, Tatsuya; Wu, Jian Liang; Fujiki, Minoru; Kobayashi, Hidenori

    2005-07-01

    Hypoxia-inducible factor-1 (HIF-1) is a transcription factor that regulates the adaptive response to hypoxia in mammalian cells. It consists of a regulatory subunit HIF-1alpha, which accumulates under hypoxic conditions, and a constitutively expressed subunit, HIF-1beta. In this study, we investigated HIF-1alpha naked DNA-induced angiogenesis in a cerebral ischemic model in vivo. We utilized a rat encephalo-myo-synangiosis (EMS) model and inoculated HIF-1alpha DNA into the brain surface or the temporal muscle. We analysed whether HIF-1alpha induced angiogenic factors and collateral circulation. A histological section treated with HIF-1alpha DNA showed an increased expression of HIF1 a and VEGF with collateral circulation, in comparison with control DNA (p angiogenesis development. These results suggest the feasibility of a novel approach for therapeutic collateral circulation of cerebral ischemia in which neovascularization may be achieved indirectly using a transcriptional regulatory strategy.

  2. Cloning a cDNA for the lysosomal alpha-glucosidase

    NARCIS (Netherlands)

    KONINGS, A.; HUPKES, P.; Versteeg, R.; Grosveld, G.; Reuser, A.; Galjaard, H.

    1984-01-01

    Messenger RNA was isolated from monkey testes and size-fractionated on sucrose gradients. In vitro translation of these mRNA fractions resulted in nascent, labeled alpha-glucosidase that could be precipitated with anti human alpha-glucosidase antiserum. A cDNA library was constructed from the most

  3. The dnaE173 mutator mutation confers on the alpha subunit of Escherichia coli DNA polymerase III a capacity for highly processive DNA synthesis and stable binding to primer/template DNA.

    Science.gov (United States)

    Yanagihara, Fusamitsu; Yoshida, Shohei; Sugaya, Yutaka; Maki, Hisaji

    2007-08-01

    The strong mutator mutation dnaE173 which causes an amino-acid substitution in the alpha subunit of DNA polymerase III is unique in its ability to induce sequence-substitution mutations. We showed previously that multiple biochemical properties of DNA polymerase III holoenzyme of Escherichia coli are simultaneously affected by the dnaE173 mutation. These effects include a severely reduced proofreading capacity, an increased resistance to replication-pausing on the template DNA, a capability to readily promote strand-displacement DNA synthesis, a reduced rate of DNA chain elongation, and an ability to catalyze highly processive DNA synthesis in the absence of the beta-clamp subunit. Here we show that, in contrast to distributive DNA synthesis exhibited by wild-type alpha subunit, the dnaE173 mutant form of alpha subunit catalyzes highly processive DNA chain elongation without the aid of the beta-clamp. More surprisingly, the dnaE173 alpha subunit appeared to form a stable complex with primer/template DNA, while no such affinity was detected with wild-type alpha subunit. We consider that the highly increased affinity of alpha subunit for primer/template DNA is the basis for the pleiotropic effects of the dnaE173 mutation on DNA polymerase III, and provides a clue to the molecular mechanisms underlying sequence substitution mutagenesis.

  4. Molecular analysis and genomic organization of major DNA satellites in banana (Musa spp.).

    Science.gov (United States)

    Čížková, Jana; Hřibová, Eva; Humplíková, Lenka; Christelová, Pavla; Suchánková, Pavla; Doležel, Jaroslav

    2013-01-01

    Satellite DNA sequences consist of tandemly arranged repetitive units up to thousands nucleotides long in head-to-tail orientation. The evolutionary processes by which satellites arise and evolve include unequal crossing over, gene conversion, transposition and extra chromosomal circular DNA formation. Large blocks of satellite DNA are often observed in heterochromatic regions of chromosomes and are a typical component of centromeric and telomeric regions. Satellite-rich loci may show specific banding patterns and facilitate chromosome identification and analysis of structural chromosome changes. Unlike many other genomes, nuclear genomes of banana (Musa spp.) are poor in satellite DNA and the information on this class of DNA remains limited. The banana cultivars are seed sterile clones originating mostly from natural intra-specific crosses within M. acuminata (A genome) and inter-specific crosses between M. acuminata and M. balbisiana (B genome). Previous studies revealed the closely related nature of the A and B genomes, including similarities in repetitive DNA. In this study we focused on two main banana DNA satellites, which were previously identified in silico. Their genomic organization and molecular diversity was analyzed in a set of nineteen Musa accessions, including representatives of A, B and S (M. schizocarpa) genomes and their inter-specific hybrids. The two DNA satellites showed a high level of sequence conservation within, and a high homology between Musa species. FISH with probes for the satellite DNA sequences, rRNA genes and a single-copy BAC clone 2G17 resulted in characteristic chromosome banding patterns in M. acuminata and M. balbisiana which may aid in determining genomic constitution in interspecific hybrids. In addition to improving the knowledge on Musa satellite DNA, our study increases the number of cytogenetic markers and the number of individual chromosomes, which can be identified in Musa.

  5. Molecular analysis and genomic organization of major DNA satellites in banana (Musa spp..

    Directory of Open Access Journals (Sweden)

    Jana Čížková

    Full Text Available Satellite DNA sequences consist of tandemly arranged repetitive units up to thousands nucleotides long in head-to-tail orientation. The evolutionary processes by which satellites arise and evolve include unequal crossing over, gene conversion, transposition and extra chromosomal circular DNA formation. Large blocks of satellite DNA are often observed in heterochromatic regions of chromosomes and are a typical component of centromeric and telomeric regions. Satellite-rich loci may show specific banding patterns and facilitate chromosome identification and analysis of structural chromosome changes. Unlike many other genomes, nuclear genomes of banana (Musa spp. are poor in satellite DNA and the information on this class of DNA remains limited. The banana cultivars are seed sterile clones originating mostly from natural intra-specific crosses within M. acuminata (A genome and inter-specific crosses between M. acuminata and M. balbisiana (B genome. Previous studies revealed the closely related nature of the A and B genomes, including similarities in repetitive DNA. In this study we focused on two main banana DNA satellites, which were previously identified in silico. Their genomic organization and molecular diversity was analyzed in a set of nineteen Musa accessions, including representatives of A, B and S (M. schizocarpa genomes and their inter-specific hybrids. The two DNA satellites showed a high level of sequence conservation within, and a high homology between Musa species. FISH with probes for the satellite DNA sequences, rRNA genes and a single-copy BAC clone 2G17 resulted in characteristic chromosome banding patterns in M. acuminata and M. balbisiana which may aid in determining genomic constitution in interspecific hybrids. In addition to improving the knowledge on Musa satellite DNA, our study increases the number of cytogenetic markers and the number of individual chromosomes, which can be identified in Musa.

  6. Role of DNA polymerase. cap alpha. in chromosomal aberration production by ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Bender, M.A.

    1983-01-01

    Aphidicolin is a tetracyclic diterpinoid fungal antibiotic which inhibits DNA synthesis in eukaryotic cells by interfering specifically with DNA polymerase ..cap alpha.., apparently by binding to and inactivating the DNA-polymerase ..cap alpha.. complex. We have shown that aphidicolin, like other inhibitors of DNA synthesis, both induces chromosomal aberrations in human peripheral lymphocytes, and, as a post-treatment, interacts synergistically with x rays to produce greatly enhanced aberration yields. The present experiments explore the effects of aphidicolin in human lymphocytes in the post-DNA-synthetic G/sub 2/ phase of the cell cycle. These experiments utilized labeling with tritiated thymidine to positively identify cells in the S phase at the time of treatment, and used serial colcemid collections and fixations to determine aberration yields over as much of the G/sub 2/ phase as feasible. Because DNA polymerase ..cap alpha.. is the only DNA synthetic or repair enzyme known to be affected by aphidicolin, we infer that this enzyme is directly involved in the repair of DNA lesions which can result in visible chromosomal aberrations. (DT)

  7. Distribution of DTHS3 satellite DNA across 12 bivalve species Eva ...

    Indian Academy of Sciences (India)

    Windows User

    In this work, characterization of DTHS3 satellite DNA was further expanded within the Class. Bivalvia. Monomer variants of DTHS3 satDNA were compared in 12 bivalve species belonging to two different Subclasses, Heterodonta and Pteriomorphia. This satDNA, whose age is estimated to a minimum of 516 Ma, ...

  8. DNA locus HLA-DQ alpha polymorphism in human population of the north-eastern Poland.

    Science.gov (United States)

    Pepiński, W; Skawrońska, M; Janica, J

    1996-01-01

    Investigations on DNA polymorphism locus HLA-DQ alpha were carried out on a sample of 117 adult unrelated inhabitants from the north-eastern Poland. The polymerase chain reaction and the reverse dot-blot hybridisation were employed to detect 6 different HLA-DQ alpha alleles. Population data on 20 different genotypes served as a basis for statistic evaluation. The results of genotype analysis were in Hardy-Weinberg equilibrium. Other population data were compared.

  9. Molecular mechanism of DNA recognition by the alpha subunit of the Oxytricha telomere binding protein.

    Science.gov (United States)

    Laporte, L; Benevides, J M; Thomas, G J

    1999-01-12

    Interactions between telomeric DNA and the alpha subunit of the heterodimeric telomere binding protein of Oxytricha nova have been probed by Raman spectroscopy, CD spectroscopy, and nondenaturing gel electrophoresis. Telomeric sequences investigated include the Oxytricha 3' overhang, d(T4G4)2, and the related sequence dT6(T4G4)2, which incorporates a 5'-thymidylate leader. Corresponding nontelomeric isomers, d(TG)8 and dT6(TG)8, have also been investigated. Both d(T4G4)2 and dT6(T4G4)2 form stable hairpins that contain Hoogsteen G.G base pairs [Laporte, L., and Thomas, G. J., Jr. (1998) J. Mol. Biol. 281, 261-270]. The alpha subunit binds specifically and stoichiometrically to the dT6(T4G4)2 hairpin and alters its secondary structure by inducing conformational changes in the 5'-thymidylate leader without extensive disruption of G.G base pairing. Conversely, binding of the alpha subunit to d(T4G4)2 eliminates G.G pairing and unfolds the hairpin. DNA unfolding is accompanied by conformational changes affecting both the backbone and dG residues, as evidenced by Raman and CD spectra. Interestingly, the alpha subunit also forms complexes with the nontelomeric isomers, d(TG)8 and dT6(TG)8, evidenced by altered electrophoretic mobility in nondenaturing gels; however, Raman and CD spectra of complexes of the alpha subunit with nontelomeric DNA suggest no significant changes in backbone or deoxynucleoside conformations. Similarly, the alpha subunit binds to but does not appreciably alter the secondary structure of duplex DNA. The present results show that while the alpha subunit has the capacity to bind to Watson-Crick and different non-Watson-Crick motifs, DNA refolding is specific to the Oxytricha telomeric hairpin and the retention of G.G pairing is specific to the telomeric sequence incorporating the 5' leading sequence. A model is proposed for alpha subunit binding to telomeric DNA, and the physiological role of the alpha subunit in telomere organization is discussed.

  10. Increased humoral immunity by DNA vaccination using an alpha-tocopherol-based adjuvant

    DEFF Research Database (Denmark)

    Karlsson, Ingrid; Borggren, Marie; Nielsen, Jens

    2017-01-01

    DNA vaccines induce broad immunity, which involves both humoral and strong cellular immunity, and can be rapidly designed for novel or evolving pathogens such as influenza. However, the humoral immunogenicity in humans and higher animals has been suboptimal compared to that of traditional vaccine...... approaches. We tested whether the emulsion-based and alpha-tocopherol containing adjuvant Diluvac Forte® has the ability to enhance the immunogenicity of a naked DNA vaccine (i.e., plasmid DNA). As a model vaccine, we used plasmids encoding both a surface-exposed viral glycoprotein (hemagglutinin......). The animals received two intracutaneous immunizations spaced 3 weeks apart. When combined with Diluvac Forte® or the emulsion containing alpha-tocopherol, the DNA vaccine induced a more potent and balanced immunoglobulin G (IgG)1 and IgG2c response, and both IgG subclass responses were significantly enhanced...

  11. Satellite DNA Sequences in Canidae and Their Chromosome Distribution in Dog and Red Fox.

    Science.gov (United States)

    Vozdova, Miluse; Kubickova, Svatava; Cernohorska, Halina; Fröhlich, Jan; Rubes, Jiri

    2016-01-01

    Satellite DNA is a characteristic component of mammalian centromeric heterochromatin, and a comparative analysis of its evolutionary dynamics can be used for phylogenetic studies. We analysed satellite and satellite-like DNA sequences available in NCBI for 4 species of the family Canidae (red fox, Vulpes vulpes, VVU; domestic dog, Canis familiaris, CFA; arctic fox, Vulpes lagopus, VLA; raccoon dog, Nyctereutes procyonoides procyonoides, NPR) by comparative sequence analysis, which revealed 86-90% intraspecies and 76-79% interspecies similarity. Comparative fluorescence in situ hybridisation in the red fox and dog showed signals of the red fox satellite probe in canine and vulpine autosomal centromeres, on VVUY, B chromosomes, and in the distal parts of VVU9q and VVU10p which were shown to contain nucleolus organiser regions. The CFA satellite probe stained autosomal centromeres only in the dog. The CFA satellite-like DNA did not show any significant sequence similarity with the satellite DNA of any species analysed and was localised to the centromeres of 9 canine chromosome pairs. No significant heterochromatin block was detected on the B chromosomes of the red fox. Our results show extensive heterogeneity of satellite sequences among Canidae and prove close evolutionary relationships between the red and arctic fox. © 2017 S. Karger AG, Basel.

  12. Uncoupling of satellite DNA and centromeric function in the genus Equus.

    Science.gov (United States)

    Piras, Francesca M; Nergadze, Solomon G; Magnani, Elisa; Bertoni, Livia; Attolini, Carmen; Khoriauli, Lela; Raimondi, Elena; Giulotto, Elena

    2010-02-12

    In a previous study, we showed that centromere repositioning, that is the shift along the chromosome of the centromeric function without DNA sequence rearrangement, has occurred frequently during the evolution of the genus Equus. In this work, the analysis of the chromosomal distribution of satellite tandem repeats in Equus caballus, E. asinus, E. grevyi, and E. burchelli highlighted two atypical features: 1) several centromeres, including the previously described evolutionary new centromeres (ENCs), seem to be devoid of satellite DNA, and 2) satellite repeats are often present at non-centromeric termini, probably corresponding to relics of ancestral now inactive centromeres. Immuno-FISH experiments using satellite DNA and antibodies against the kinetochore protein CENP-A demonstrated that satellite-less primary constrictions are actually endowed with centromeric function. The phylogenetic reconstruction of centromere repositioning events demonstrates that the acquisition of satellite DNA occurs after the formation of the centromere during evolution and that centromeres can function over millions of years and many generations without detectable satellite DNA. The rapidly evolving Equus species gave us the opportunity to identify different intermediate steps along the full maturation of ENCs.

  13. Uncoupling of satellite DNA and centromeric function in the genus Equus.

    Directory of Open Access Journals (Sweden)

    Francesca M Piras

    2010-02-01

    Full Text Available In a previous study, we showed that centromere repositioning, that is the shift along the chromosome of the centromeric function without DNA sequence rearrangement, has occurred frequently during the evolution of the genus Equus. In this work, the analysis of the chromosomal distribution of satellite tandem repeats in Equus caballus, E. asinus, E. grevyi, and E. burchelli highlighted two atypical features: 1 several centromeres, including the previously described evolutionary new centromeres (ENCs, seem to be devoid of satellite DNA, and 2 satellite repeats are often present at non-centromeric termini, probably corresponding to relics of ancestral now inactive centromeres. Immuno-FISH experiments using satellite DNA and antibodies against the kinetochore protein CENP-A demonstrated that satellite-less primary constrictions are actually endowed with centromeric function. The phylogenetic reconstruction of centromere repositioning events demonstrates that the acquisition of satellite DNA occurs after the formation of the centromere during evolution and that centromeres can function over millions of years and many generations without detectable satellite DNA. The rapidly evolving Equus species gave us the opportunity to identify different intermediate steps along the full maturation of ENCs.

  14. Uncoupling of Satellite DNA and Centromeric Function in the Genus Equus

    Science.gov (United States)

    Magnani, Elisa; Bertoni, Livia; Attolini, Carmen; Khoriauli, Lela; Raimondi, Elena; Giulotto, Elena

    2010-01-01

    In a previous study, we showed that centromere repositioning, that is the shift along the chromosome of the centromeric function without DNA sequence rearrangement, has occurred frequently during the evolution of the genus Equus. In this work, the analysis of the chromosomal distribution of satellite tandem repeats in Equus caballus, E. asinus, E. grevyi, and E. burchelli highlighted two atypical features: 1) several centromeres, including the previously described evolutionary new centromeres (ENCs), seem to be devoid of satellite DNA, and 2) satellite repeats are often present at non-centromeric termini, probably corresponding to relics of ancestral now inactive centromeres. Immuno-FISH experiments using satellite DNA and antibodies against the kinetochore protein CENP-A demonstrated that satellite-less primary constrictions are actually endowed with centromeric function. The phylogenetic reconstruction of centromere repositioning events demonstrates that the acquisition of satellite DNA occurs after the formation of the centromere during evolution and that centromeres can function over millions of years and many generations without detectable satellite DNA. The rapidly evolving Equus species gave us the opportunity to identify different intermediate steps along the full maturation of ENCs. PMID:20169180

  15. Diagnosis of alpha-1-antitrypsin deficiency by DNA analysis of children with liver disease

    Directory of Open Access Journals (Sweden)

    De TOMMASO Adriana Maria Alves

    2001-01-01

    Full Text Available Background - Alpha-1-antitrypsin deficiency is a genetic disorder which is transmitted in a co-dominant, autosomal form. Alpha-1-antitrypsin deficiency affects mainly the lungs and the liver leading, in the latter case, to neonatal cholestasis, chronic hepatitis or cirrhosis. A precise diagnosis of Alpha-1-antitrypsin deficiency may be obtained by biochemical or molecular analysis. Objective - The purpose of this study was to use DNA analysis to examine the presence of an alpha-1-antitrypsin deficiency in 12 children suspected of having this deficiency and who showed laboratory and clinical characteristics of the disease. Patients and Methods - Twelve patients, aged 3 months to 19 years, who had serum alpha-1-antitrypsin levels lower than normal and/or had hepatic disease of undefined etiology were studied. The mutant alleles S and Z of the alpha-1-antitrypsin gene were investigated in the 12 children. Alpha-1-antitrypsin gene organization was analyzed by amplification of genoma through the polymerase chain reaction and digestion with the restriction enzymes Xmnl (S allele and Taq 1 (Z allele. Results - Seven of the 12 patients had chronic liver disease of undefined etiology and the other five patients had low serum levels of alpha-1-antitrypsin as well as a diagnosis of neonatal cholestasis and/or chronic liver disease of undefined etiology. Five of the 12 patients were homozygous for the Z allele (ZZ and two had the S allele with another allele (*S different from Z. Conclusion - These results show that alpha-1-antitrypsin deficiency is relatively frequent in children with chronic hepatic disease of undefined etiology and/or low alpha-1-antitrypsin levels (41.6%. A correct diagnosis is important for effective clinical follow-up and for genetic counseling.

  16. TAREAN: a computational tool for identification and characterization of satellite DNA from unassembled short reads.

    Science.gov (United States)

    Novák, Petr; Ávila Robledillo, Laura; Koblížková, Andrea; Vrbová, Iva; Neumann, Pavel; Macas, Jirí

    2017-07-07

    Satellite DNA is one of the major classes of repetitive DNA, characterized by tandemly arranged repeat copies that form contiguous arrays up to megabases in length. This type of genomic organization makes satellite DNA difficult to assemble, which hampers characterization of satellite sequences by computational analysis of genomic contigs. Here, we present tandem repeat analyzer (TAREAN), a novel computational pipeline that circumvents this problem by detecting satellite repeats directly from unassembled short reads. The pipeline first employs graph-based sequence clustering to identify groups of reads that represent repetitive elements. Putative satellite repeats are subsequently detected by the presence of circular structures in their cluster graphs. Consensus sequences of repeat monomers are then reconstructed from the most frequent k-mers obtained by decomposing read sequences from corresponding clusters. The pipeline performance was successfully validated by analyzing low-pass genome sequencing data from five plant species where satellite DNA was previously experimentally characterized. Moreover, novel satellite repeats were predicted for the genome of Vicia faba and three of these repeats were verified by detecting their sequences on metaphase chromosomes using fluorescence in situ hybridization. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  17. GlaI digestion of mouse γ-satellite DNA: study of primary structure and ACGT sites methylation

    Directory of Open Access Journals (Sweden)

    Gonchar Danila A

    2009-07-01

    Full Text Available Abstract Background Patterns of mouse DNA hydrolysis with restriction enzymes are coincided with calculated diagrams of genomic DNA digestion in silico, except presence of additional bright bands, which correspond to monomer and dimer of γ-satellite DNA. Only small portion of mouse γ-satellite DNA sequences are presented in databases. Methyl-directed endonuclease GlaI cleaves mouse DNA and may be useful for a detailed study of primary structure and CG dinucleotides methylation in γ-satellite DNA. Results We have constructed a physical map and produced experimental patterns of mouse γ-satellite DNA hydrolysis with unique site-specific methyl-directed endonuclease GlaI and several restriction endonucleases. Fifty two DNA fragments of γ-satellite DNA have been cloned and sequenced. We have not observed any mutations of CG dinucleotide in position 208 of monomeric γ-satellite DNA and confirmed 50% methylation of this CG dinucleoitide. A comparison of consensus sequences of arrayed γ-satellite DNA and small blocks of satellite DNA (140 monomers and less has shown a higher level of mutations and an absence of conserved CG dinucleotide in last ones. A replacement of CG dinucleotide by CA-dinucleotide in positions 178 and 17 in chromosomes 9 and 3, respectively, has been observed in blocks of monomers. Conclusion Arrayed γ-satellite DNA from mouse has at least one conservative CG-dinucleotide. Consensus sequences of this DNA and γ-satellite DNA in small blocks of monomers are differing. The last one displays a higher level of CG dinucleotides mutations and an absence of conservative CG-dinucleotide. Presence of conservative and half-methylated CG-dinucleotide supports an idea of importance of this CG dinucleotide methylation/demethylation in arrayed γ-satellite DNA functioning.

  18. A novel class of DNA satellites associated with New World begomoviruses.

    Science.gov (United States)

    Fiallo-Olivé, Elvira; Martínez-Zubiaur, Yamila; Moriones, Enrique; Navas-Castillo, Jesús

    2012-04-25

    Begomoviruses (family Geminiviridae) are whitefly-transmitted plant DNA viruses that have been shown to be helper viruses for a number of distinct DNA satellites, including betasatellites and alphasatellites. Replication of the satellites interferes to some degree with replication of the helper and in some cases they affect the disease symptoms. To date, betasatellites and related molecules such as the satellite associated with Tomato leaf curl virus (ToLCV-sat), have only been associated with Old World begomoviruses. Here, we report the discovery and characterization of subviral molecules associated with bipartite begomoviruses from the New World, which constitute a novel class of DNA satellites, in two malvaceous plant species. These molecules, in addition to sharing some genetic features with betasatellites and ToLCV-sat, contain nucleotide stretches of begomoviral origin, presumably the remains of recombination events involved in their origin. Copyright © 2012 Elsevier Inc. All rights reserved.

  19. The major horse satellite DNA family is associated with centromere competence.

    Science.gov (United States)

    Cerutti, Federico; Gamba, Riccardo; Mazzagatti, Alice; Piras, Francesca M; Cappelletti, Eleonora; Belloni, Elisa; Nergadze, Solomon G; Raimondi, Elena; Giulotto, Elena

    2016-01-01

    The centromere is the specialized locus required for correct chromosome segregation during cell division. The DNA of most eukaryotic centromeres is composed of extended arrays of tandem repeats (satellite DNA). In the horse, we previously showed that, although the centromere of chromosome 11 is completely devoid of tandem repeat arrays, all other centromeres are characterized by the presence of satellite DNA. We isolated three horse satellite DNA sequences (37cen, 2P1 and EC137) and described their chromosomal localization in four species of the genus Equus. In the work presented here, using the ChIP-seq methodology, we showed that, in the horse, the 37cen satellite binds CENP-A, the centromere-specific histone-H3 variant. The 37cen sequence bound by CENP-A is GC-rich with 221 bp units organized in a head-to-tail fashion. The physical interaction of CENP-A with 37cen was confirmed through slot blot experiments. Immuno-FISH on stretched chromosomes and chromatin fibres demonstrated that the extension of satellite DNA stretches is variable and is not related to the organization of CENP-A binding domains. Finally, we proved that the centromeric satellite 37cen is transcriptionally active. Our data offer new insights into the organization of horse centromeres. Although three different satellite DNA families are cytogenetically located at centromeres, only the 37cen family is associated to the centromeric function. Moreover, similarly to other species, CENP-A binding domains are variable in size. The transcriptional competence of the 37cen satellite that we observed adds new evidence to the hypothesis that centromeric transcripts may be required for centromere function.

  20. Genome analysis of DNA repair genes in the alpha proteobacterium Caulobacter crescentus

    Directory of Open Access Journals (Sweden)

    Menck Carlos FM

    2007-03-01

    Full Text Available Abstract Background The integrity of DNA molecules is fundamental for maintaining life. The DNA repair proteins protect organisms against genetic damage, by removal of DNA lesions or helping to tolerate them. DNA repair genes are best known from the gamma-proteobacterium Escherichia coli, which is the most understood bacterial model. However, genome sequencing raises questions regarding uniformity and ubiquity of these DNA repair genes and pathways, reinforcing the need for identifying genes and proteins, which may respond to DNA damage in other bacteria. Results In this study, we employed a bioinformatic approach, to analyse and describe the open reading frames potentially related to DNA repair from the genome of the alpha-proteobacterium Caulobacter crescentus. This was performed by comparison with known DNA repair related genes found in public databases. As expected, although C. crescentus and E. coli bacteria belong to separate phylogenetic groups, many of their DNA repair genes are very similar. However, some important DNA repair genes are absent in the C. crescentus genome and other interesting functionally related gene duplications are present, which do not occur in E. coli. These include DNA ligases, exonuclease III (xthA, endonuclease III (nth, O6-methylguanine-DNA methyltransferase (ada gene, photolyase-like genes, and uracil-DNA-glycosylases. On the other hand, the genes imuA and imuB, which are involved in DNA damage induced mutagenesis, have recently been described in C. crescentus, but are absent in E. coli. Particularly interesting are the potential atypical phylogeny of one of the photolyase genes in alpha-proteobacteria, indicating an origin by horizontal transfer, and the duplication of the Ada orthologs, which have diverse structural configurations, including one that is still unique for C. crescentus. Conclusion The absence and the presence of certain genes are discussed and predictions are made considering the particular

  1. Two food-borne heterocyclic amines: Metabolism and DNA adduct formation of amino-alpha-carbolines

    DEFF Research Database (Denmark)

    Frederiksen, Hanne

    2005-01-01

    or proteins of animal or vegetable origin, furthermore they are found in many cooked foods, such as fish, meat, and chicken. The specific mutagenicity of the amino-a-carbolines are lower in the Ames Salmonella assay than other heterocyclic amines, but in rodent studies the carcinogenicity of the aminoa, alpha......-carbolines are comparable to other heterocyclic amines. The metabolic pathways of the amino-alpha-carbolines have been studied in vitro and in vivo, and the detoxified phase I and phase II metabolites characterized and quantified. The metabolic activation of the amino-a-carbolines and the formation of DNA-adducts have also...

  2. cDNA clone for the alpha-chain of human beta-hexosaminidase: deficiency of alpha-chain mRNA in Ashkenazi Tay-Sachs fibroblasts.

    Science.gov (United States)

    Myerowitz, R; Proia, R L

    1984-09-01

    We have isolated a cDNA clone containing sequences complementary to mRNA encoding the alpha-chain of the lysosomal enzyme beta-hexosaminidase. RNA from a human lung fibroblast strain, IMR90, was enriched for beta-hexosaminidase messenger by polysome immunoselection with antiserum against beta-hexosaminidase A. This preparation was used to construct cDNA recombinant plasmids by the Okayama-Berg vector primer procedure. After transformation of Escherichia coli, 385 ampicillin-resistant colonies were obtained, 44 of which contained inserts in the plasmid DNA. Differential hybridization, with cDNA probes prepared from polysomal RNA enriched or depleted for beta-hexosaminidase messenger, was used to screen the recombinant plasmids for sequences encoding beta-hexosaminidase. One clone, p beta H alpha-1, containing a cDNA insert of approximately equal to 240 base pairs, was identified in this manner. The plasmid hybrid-selected a messenger from placental RNA that programed a translation system to synthesize the alpha-chain of beta-hexosaminidase. p beta H alpha-1 hybridized to an mRNA of approximately equal to 1.9 kilobases in preparations enriched separately in messenger for the alpha-chain or for both alpha- and beta-chains (by polysome immunoselection with antiserum against isolated alpha-chain or against beta-hexosaminidase A, respectively). It did not hybridize to an RNA preparation enriched for messenger of beta-chain by immunoselection with antiserum against beta-hexosaminidase B. The 1.9-kilobase mRNA was observed in poly(A)+ RNA preparations from control fibroblasts and from fibroblasts of a Tay-Sachs patient that synthesize an altered alpha-chain; however, it was not seen in similar preparations from fibroblasts of four Ashkenazi Tay-Sachs patients.

  3. Human β satellite DNA: Genomic organization and sequence definition of a class of highly repetitive tandem DNA

    International Nuclear Information System (INIS)

    Waye, J.S.; Willard, H.F.

    1989-01-01

    The authors describe a class of human repetitive DNA, called β satellite, that, at a most fundamental level, exists as tandem arrays of diverged ∼68-base-pair monomer repeat units. The monomer units are organized as distinct subsets, each characterized by a multimeric higher-order repeat unit that is tandemly reiterated and represents a recent unit of amplification. They have cloned, characterized, and determined the sequence of two β satellite higher-order repeat units: one located on chromosome 9, the other on the acrocentric chromosomes (13, 14, 15, 21, and 22) and perhaps other sites in the genome. Analysis by pulsed-field gel electrophoresis reveals that these tandem arrays are localized in large domains that are marked by restriction fragment length polymorphisms. In total, β-satellite sequences comprise several million base pairs of DNA in the human genome. Analysis of this DNA family should permit insights into the nature of chromosome-specific and nonspecific modes of satellite DNA evolution and provide useful tools for probing the molecular organization and concerted evolution of the acrocentric chromosomes

  4. Alpha particle induced DNA damage and repair in normal cultured thyrocytes of different proliferation status

    DEFF Research Database (Denmark)

    Lyckesvärd, Madeleine Nordén; Delle, Ulla; Kahu, Helena

    2014-01-01

    and much less is known of high-LET irradiation. In this paper we investigated the DNA damage response and biological consequences to photons from Cobolt-60 ((60)Co) and alpha particles from (211)At in normal primary thyrocytes of different cell cycle status. For both radiation qualities the intensity...... mechanism as (131)I [1], in cancer treatment has increased during recent years because of its high efficiency in inducing biological damage and beneficial dose distribution when compared to low-LET radiation. Most knowledge of the DNA damage response in thyroid is from studies using low-LET irradiation...

  5. Cloning and structural analysis of alpha-latroinsectotoxin cDNA. Abundance of ankyrin-like repeats.

    Science.gov (United States)

    Kiyatkin, N; Dulubova, I; Grishin, E

    1993-04-01

    alpha-Latroinsectotoxin (alpha-LIT), purified from venom glands of the black widow spider Latrodectus mactans tredecimguttatus, is a presynaptic neurotoxin selective only for insects. A cDNA encoding the putative alpha-LIT precursor was isolated from a spider venom gland cDNA library. The cDNA contains a 4236-base-pair open reading frame corresponding to a 157826-Da protein composed of 1411 amino acids. The mature alpha-LIT, with molecular mass approximately 130 kDa, is probably derived from double processing in the N-terminal and C-terminal regions of the primary translation product. The structure region, extending over residues 464-1176, is composed almost entirely of ankyrin-like repeats which represent a motif also found in the alpha-latrotoxin (alpha-LTX), which has selective action on vertebrates. Total alignment of the alpha-LIT and alpha-LTX amino acid sequences reveals an overall similarity of 34.1%. Strong sequence divergence is observed in analogous cysteine-rich regions situated within the ankyrin-repeat domains of both alpha-LIT and alpha-LTX.

  6. Amplification of marine methanotrophic enrichment DNA with 16S rDNA PCR primers for type II alpha proteobacteria methanotrophs.

    Science.gov (United States)

    Rockne, Karl J; Strand, Stuart E

    2003-09-01

    Type II alpha proteobacteria methanotrophs are capable of a wide range of cometabolic transformations of chlorinated solvents and polycyclic aromatic hydrocarbons (PAHs), and this activity has been exploited in many terrestrial bioremediation systems. However, at present, all known obligately marine methanotrophic isolates are Type I gamma proteobacteria which do not have this activity to the extent of Type II methanotrophs. In previous work in our laboratory, determining the presence of Type II alpha proteobacteria methanotrophs in marine enrichment cultures that co-metabolized PAHs required a more sensitive assay. 16S rDNA PCR primers were designed based on oligonucleotide probes for serine pathway methanotrophs and serine pathway methylotrophs with an approximate amplification fragment size of 870 base pairs. Comparison of the primers using double primer BLAST searches in established nucleotide databases showed potential amplification with all Methylocystis and Methylosinus spp., as well as potential amplification with Methylocella palustrus. DNA from Methylosinus trichosporium OB3b, a Type II methanotroph, amplified with the primers with a fragment size of approximately 850 base pairs, whereas DNA extracted from Methylomonas methanica, a Type I methanotroph, did not. The primers were used to amplify DNA extracted from two marine methanotrophic enrichment cultures: a low nitrogen/low copper enrichment to select for Type II methanotrophs and a high nitrogen/high copper enrichment to select for Type I methanotrophs. Although DNA from both cultures amplified with the PCR primers, amplification was stronger in cultures that were specifically enriched for Type II methanotrophs, suggesting the presence of higher numbers of Type II methanotrophs. These results provide further evidence for the existence of Type II marine methanotrophs, suggesting the possibility of exploiting cometabolic activity in marine systems.

  7. Isolation and characterization of the murine alpha-L-iduronidase cDNA

    Energy Technology Data Exchange (ETDEWEB)

    Clarke, L.A.; Zhang, H. Nasir, J. [Univ. of British Columbia, Vancouver (Canada)] [and others

    1994-09-01

    Mucopolysaccharidosis I (MPS I) are a group of disorders caused by deficiency of the lysosomal enzyme alpha-L-iduronidase. The characterization of the human gene and the identification of mutations underlying MPS I in humans has led to the delineation of the molecular basis of this disorder. Model systems are now needed for the evaluation and development of therapeutics for this disorder. Both canine and feline models for MPS type I have been described but only the canine gene has been isolated and characterized. We report here the cloning and expression of the murine alpha-L-iduronidase cDNA. The murine cDNA was obtained by screening a mouse liver cDNA library with a probe from the human cDNA. The full length murine cDNA is 3120 base pairs in length and thus is considerably larger than both the human and canine transcripts. The increase in size is due to a 1.2 kb 3{prime} untranslated region in the murine cDNA that contains a CA dinucleotide repeat. Within the coding region the murine cDNA shows sequences. At the protein level the murine protein shows 77% similarity with the human protein and 75% similarity with the canine protein. There are significant differences in both the start and stop sites with the murine protein 9 amino acids shorter at both the N terminal signal peptide region and the C terminus. Expression of the murine cDNA in COS-1 cells resulted in a 20 fold increase in intracellular alpha-L-iduronidase activity as well as the detection of considerable enzyme activity in the culture medium. Comparison of the reported missense mutations underlying MPS I in humans (A75T, H82P, R89Q, L218P, P533R, Q310X, T366P) has shown conservation of these amino acid residues in the murine protein. The isolation of the murine iduronidase cDNA will now allow for the development of a murine model for MPS I.

  8. Alpha particle induced DNA damage and repair in normal cultured thyrocytes of different proliferation status

    Energy Technology Data Exchange (ETDEWEB)

    Lyckesvärd, Madeleine Nordén, E-mail: madeleine.lyckesvard@oncology.gu.se [Department of Oncology, Sahlgrenska Academy, University of Gothenburg (Sweden); Delle, Ulla; Kahu, Helena [Department of Oncology, Sahlgrenska Academy, University of Gothenburg (Sweden); Lindegren, Sture [Department of Radiation Physics, Sahlgrenska Academy, University of Gothenburg (Sweden); Jensen, Holger [The PET and Cyclotron Unit Copenhagen University Hospital, Rigshospitalet (Denmark); Bäck, Tom [Department of Radiation Physics, Sahlgrenska Academy, University of Gothenburg (Sweden); Swanpalmer, John [Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Gothenburg (Sweden); Elmroth, Kecke [Department of Oncology, Sahlgrenska Academy, University of Gothenburg (Sweden)

    2014-07-15

    Highlights: • We study DNA damage response to low-LET photons and high-LET alpha particles. • Cycling primary thyrocytes are more sensitive to radiation than stationary cells. • Influence of radiation quality varies due to cell cycle status of normal cells. • High-LET radiation gives rise to a sustained DNA damage response. - Abstract: Childhood exposure to ionizing radiation increases the risk of developing thyroid cancer later in life and this is suggested to be due to higher proliferation of the young thyroid. The interest of using high-LET alpha particles from Astatine-211 ({sup 211}At), concentrated in the thyroid by the same mechanism as {sup 131}I [1], in cancer treatment has increased during recent years because of its high efficiency in inducing biological damage and beneficial dose distribution when compared to low-LET radiation. Most knowledge of the DNA damage response in thyroid is from studies using low-LET irradiation and much less is known of high-LET irradiation. In this paper we investigated the DNA damage response and biological consequences to photons from Cobolt-60 ({sup 60}Co) and alpha particles from {sup 211}At in normal primary thyrocytes of different cell cycle status. For both radiation qualities the intensity levels of γH2AX decreased during the first 24 h in both cycling and stationary cultures and complete repair was seen in all cultures but cycling cells exposed to {sup 211}At. Compared to stationary cells alpha particles were more harmful for cycling cultures, an effect also seen at the pChk2 levels. Increasing ratios of micronuclei per cell nuclei were seen up to 1 Gy {sup 211}At. We found that primary thyrocytes were much more sensitive to alpha particle exposure compared with low-LET photons. Calculations of the relative biological effectiveness yielded higher RBE for cycling cells compared with stationary cultures at a modest level of damage, clearly demonstrating that cell cycle status influences the relative

  9. Diversity of DNA β, a satellite molecule associated with some monopartite begomoviruses

    International Nuclear Information System (INIS)

    Briddon, Rob W.; Bull, Simon E.; Amin, Imran; Idris, Ali M.; Mansoor, Shahid; Bedford, Ian D.; Dhawan, Poonam; Rishi, Narayan; Siwatch, Surender S.; Abdel-Salam, Aly M.; Brown, Judith K.; Zafar, Yusuf; Markham, Peter G.

    2003-01-01

    DNA β molecules are symptom-modulating, single-stranded DNA satellites associated with monopartite begomoviruses (family Geminiviridae). Such molecules have thus far been shown to be associated with Ageratum yellow vein virus from Singapore and Cotton leaf curl Multan virus from Pakistan. Here, 26 additional DNA β molecules, associated with diverse plant species obtained from different geographical locations, were cloned and sequenced. These molecules were shown to be widespread in the Old World, where monopartite begomoviruses are known to occur. Analysis of the sequences revealed a highly conserved organization for DNA β molecules consisting of a single conserved open reading frame, an adenine-rich region, and a region of high sequence conservation [the satellite conserved region (SCR)]. The SCR contains a potential hairpin structure with the loop sequence TAA/GTATTAC; similar to the origins of replication of geminiviruses and nanoviruses. Two major groups of DNA β satellites were resolved by phylogenetic analyses. One group originated from hosts within the Malvaceae and the second from a more diverse group of plants within the Solanaceae and Compositae. Within the two clusters, DNA β molecules showed relatedness based both on host and geographic origin. These findings strongly support coadaptation of DNA β molecules with their respective helper begomoviruses

  10. Population variation in the A chromosome distribution of satellite DNA and ribosomal DNA in the grasshopper Eyprepocnemis plorans.

    Science.gov (United States)

    Cabrero, J; Perfectti, F; Gómez, R; Camacho, J P M; López-León, M D

    2003-01-01

    The double FISH analysis of two repetitive DNAs (a satellite DNA and ribosomal DNA) in 12 natural populations of the grasshopper Eyprepocnemis plorans collected at the south (Granada and Málaga provinces) and south-east (Albacete and Murcia provinces) of the Iberian Peninsula has shown their wide-spread presence throughout the whole genome as well as extensive variation among populations. Both DNAs are found in most A chromosomes. Regularly, both DNAs occurred in the S11 and X chromosomes, rDNA in the S10 and satDNA in the L2 and M3. No correlation was found between the number of satDNA and rDNA clusters in the A genomes of the 12 populations analysed, and both figures were independent of the presence of B chromosomes. The genomic distribution of both DNAs showed no association with the geographical localization of the populations analysed. Finally, we provide evidence that the supernumerary chromosome segment proximally located on the S11 chromosome is, in most cases, the result of satDNA amplification but, in some cases, it might also derive from amplification of both satDNA and rDNA.

  11. Satellites

    International Nuclear Information System (INIS)

    Burns, J.A.; Matthews, M.S.

    1986-01-01

    The present work is based on a conference: Natural Satellites, Colloquium 77 of the IAU, held at Cornell University from July 5 to 9, 1983. Attention is given to the background and origins of satellites, protosatellite swarms, the tectonics of icy satellites, the physical characteristics of satellite surfaces, and the interactions of planetary magnetospheres with icy satellite surfaces. Other topics include the surface composition of natural satellites, the cratering of planetary satellites, the moon, Io, and Europa. Consideration is also given to Ganymede and Callisto, the satellites of Saturn, small satellites, satellites of Uranus and Neptune, and the Pluto-Charon system

  12. Molecular Cytogenetic Mapping of Satellite DNA Sequences in Aegilops geniculata and Wheat

    Czech Academy of Sciences Publication Activity Database

    Koo, D.H.; Tiwari, V.K.; Hřibová, Eva; Doležel, Jaroslav; Friebe, B.; Gill, B.S.

    2016-01-01

    Roč. 148, č. 4 (2016), s. 314-321 ISSN 1424-8581 R&D Projects: GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : in-situ hybridization * chromosome addition lines * resistance genes lr57 * repetitive dna * triticum-ovatum * powdery mildew * plant genome * bread wheat * leaf rust * identification * Aegilops geniculata * Chromosome identification * Fluorescence in situ hybridization * Satellite DNA * Wheat Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.354, year: 2016

  13. The CHH motif in sugar beet satellite DNA: a modulator for cytosine methylation.

    Science.gov (United States)

    Zakrzewski, Falk; Schubert, Veit; Viehoever, Prisca; Minoche, André E; Dohm, Juliane C; Himmelbauer, Heinz; Weisshaar, Bernd; Schmidt, Thomas

    2014-06-01

    Methylation of DNA is important for the epigenetic silencing of repetitive DNA in plant genomes. Knowledge about the cytosine methylation status of satellite DNAs, a major class of repetitive DNA, is scarce. One reason for this is that arrays of tandemly arranged sequences are usually collapsed in next-generation sequencing assemblies. We applied strategies to overcome this limitation and quantified the level of cytosine methylation and its pattern in three satellite families of sugar beet (Beta vulgaris) which differ in their abundance, chromosomal localization and monomer size. We visualized methylation levels along pachytene chromosomes with respect to small satellite loci at maximum resolution using chromosome-wide fluorescent in situ hybridization complemented with immunostaining and super-resolution microscopy. Only reduced methylation of many satellite arrays was obtained. To investigate methylation at the nucleotide level we performed bisulfite sequencing of 1569 satellite sequences. We found that the level of methylation of cytosine strongly depends on the sequence context: cytosines in the CHH motif show lower methylation (44-52%), while CG and CHG motifs are more strongly methylated. This affects the overall methylation of satellite sequences because CHH occurs frequently while CG and CHG are rare or even absent in the satellite arrays investigated. Evidently, CHH is the major target for modulation of the cytosine methylation level of adjacent monomers within individual arrays and contributes to their epigenetic function. This strongly indicates that asymmetric cytosine methylation plays a role in the epigenetic modification of satellite repeats in plant genomes. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

  14. cDNA clone for the alpha-chain of human beta-hexosaminidase: deficiency of alpha-chain mRNA in Ashkenazi Tay-Sachs fibroblasts.

    OpenAIRE

    Myerowitz, R; Proia, R L

    1984-01-01

    We have isolated a cDNA clone containing sequences complementary to mRNA encoding the alpha-chain of the lysosomal enzyme beta-hexosaminidase. RNA from a human lung fibroblast strain, IMR90, was enriched for beta-hexosaminidase messenger by polysome immunoselection with antiserum against beta-hexosaminidase A. This preparation was used to construct cDNA recombinant plasmids by the Okayama-Berg vector primer procedure. After transformation of Escherichia coli, 385 ampicillin-resistant colonies...

  15. Plant highly repeated satellite DNA: molecular evolution, distribution and use for identification of hybrids

    Czech Academy of Sciences Publication Activity Database

    Hemleben, V.; Kovařík, Aleš; Torres-Ruiz, R.A.; Volkov, R.A.; Beridze, T.

    2007-01-01

    Roč. 5, č. 3 (2007), s. 277-289 ISSN 1477-2000 R&D Projects: GA ČR(CZ) GA521/04/0775 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : satellite DNA * evolution * allopolyploidy Subject RIV: BO - Biophysics Impact factor: 2.818, year: 2007

  16. Distribution of DTHS3 satellite DNA across 12 bivalve species Eva ...

    Indian Academy of Sciences (India)

    Windows User

    Long-term conservation vs high sequence divergence: the case of an extraordinarily old satellite DNA in bivalve mollusks. Heredity. 104, 543–551. Salser W., Bowen S., Browne D., el-Adli F., Fedoroff N., Fry K., Heindell H., Paddock G.,. Poon R., Wallace B., Whitcome P. 1976 Investigation of the organization of mammalian.

  17. Integration of hepatitis B virus DNA in chromosome-specific satellite sequences

    International Nuclear Information System (INIS)

    Shaul, Y.; Garcia, P.D.; Schonberg, S.; Rutter, W.J.

    1986-01-01

    The authors previously reported the cloning and detailed analysis of the integrated hepatitis B virus sequences in a human hepatoma cell line. They report here the integration of at least one of hepatitis B virus at human satellite DNA sequences. The majority of the cellular sequences identified by this satellite were organized as a multimeric composition of a 0.6-kilobase EcoRI fragment. This clone hybridized in situ almost exclusively to the centromeric heterochromatin of chromosomes 1 and 16 and to a lower extent to chromosome 2 and to the heterochromatic region of the Y chromosome. The immediate flanking host sequence appeared as a hierarchy of repeating units which were almost identical to a previously reported human satellite III DNA sequence

  18. Satellite DNA Modulates Gene Expression in the Beetle Tribolium castaneum after Heat Stress.

    Directory of Open Access Journals (Sweden)

    Isidoro Feliciello

    2015-08-01

    Full Text Available Non-coding repetitive DNAs have been proposed to perform a gene regulatory role, however for tandemly repeated satellite DNA no such role was defined until now. Here we provide the first evidence for a role of satellite DNA in the modulation of gene expression under specific environmental conditions. The major satellite DNA TCAST1 in the beetle Tribolium castaneum is preferentially located within pericentromeric heterochromatin but is also dispersed as single repeats or short arrays in the vicinity of protein-coding genes within euchromatin. Our results show enhanced suppression of activity of TCAST1-associated genes and slower recovery of their activity after long-term heat stress relative to the same genes without associated TCAST1 satellite DNA elements. The level of gene suppression is not influenced by the distance of TCAST1 elements from the associated genes up to 40 kb from the genes' transcription start sites, but it does depend on the copy number of TCAST1 repeats within an element, being stronger for the higher number of copies. The enhanced gene suppression correlates with the enrichment of the repressive histone marks H3K9me2/3 at dispersed TCAST1 elements and their flanking regions as well as with increased expression of TCAST1 satellite DNA. The results reveal transient, RNAi based heterochromatin formation at dispersed TCAST1 repeats and their proximal regions as a mechanism responsible for enhanced silencing of TCAST1-associated genes. Differences in the pattern of distribution of TCAST1 elements contribute to gene expression diversity among T. castaneum strains after long-term heat stress and might have an impact on adaptation to different environmental conditions.

  19. New satellite DNA in Lacerta s. str. lizards (Sauria: Lacertidae): evolutionary pathways and phylogenetic impact.

    Science.gov (United States)

    Ciobanu, Doina; Grechko, Vernata V; Darevsky, Ilya S; Kramerov, Dmitri A

    2004-11-15

    A new tandemly repeated (satellite) DNA family namely Agi160, from Lacerta agilis and Lacerta strigata (Lacerta sensu stricto (s. str.), Linnaeus 1758) have been cloned and sequenced. Agi160 is found in the above two species, as well as two other representatives of the same genus, L. viridis and L. media. DNA hybridization did not reveal it in Darevskia, Podarcis, Zootoca, Eremias, Ophisops, and Gallotia - the other genera of the family Lacertidae. The results suggest that Agi160 is a Lacerta s. str. specific family of tandem DNA repeats. However, a comparison between sequences of Agi160 and CLsat repeat units revealed 60 bp regions 62-74% identical. The latter is a satellite DNA family typical for Darevskia (syn. "L. saxicola complex") (Grechko et al., Molecular-genetic classification and phylogenetic relatedness of some species of Lacertidae lizards by taxonoprint data. Mol Biol 32:172-183, 1988.). Both Agi160 and CLsat tandem repeats share several common features (e.g., the same AT content and distribution of multiple short A-T runs, internal structure of repeated units, the presence of conservative regions). These data are indicative of their common origin and a possibly strong selective pressure upon conserving both satellites. A comparative analysis of structure, organization, and abundance of these two families of satDNA reveals evolutionary pathways that led to their formation and divergence. The data are consistent with the hypotheses of the concerted evolution of satellite DNA families. The possibility of use of Agi160 as a phylogenetic tool, defining relationships within Lacerta s. str., as well as within the whole family of Lacertidae is discussed. Copyright 2004 Wiley-Liss, Inc.

  20. Phaeophytins from Thyrsacanthus ramosissimus Moric. with inhibitory activity on human DNA topoisomerase II-{alpha}

    Energy Technology Data Exchange (ETDEWEB)

    Cabral, Analucia Guedes Silveira; Tenorio-Souza, Fabio Henrique; Moura, Marcelo Dantas; Mota, Sabrina Gondim Ribeiro; Silva Lins, Antonio Claudio da; Dias, Celidarque da Silva; Barbosa-Filho, Jose Maria [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil). Dept. de Ciencias Frmaceuticas; Giulietti, Ana Maria [Universidade Estadual de Feira de Santana, Feira de Santana, BA (Brazil). Dept. de Ciencias Biologicas; Silva, Tania Maria Sarmento da [Universidade Federal Rural de Pernambuco, Recife, PE (Brazil). Dept. de Ciencias Moleculares; Santos, Creusioni Figueredo dos, E-mail: jbarbosa@ltf.ufpb.br [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil). Dept. de Biologia Molecular

    2012-07-01

    Our study reports the extraction and isolation of a new phaeophytin derivative 15{sup 1}-hydroxy-(15{sup 1}-S)-porphyrinolactone, designated anamariaine (1) herein, isolated from the chloroform fraction of aerial parts of Thyrsacanthus ramosissimus Moric. along with the known 15{sup 1}-ethoxy-(15{sup 1}-S)-porphyrinolactone (2). These compounds were identified by usual spectroscopic methods. Both compounds were subjected to in vitro (inhibitory activity) tests by means of supercoiled DNA relaxation techniques and were shown to display inhibitory activity against human DNA topoisomerase II-{alpha} at 50 {mu}M. Interconversion of these two pigments under the mild conditions of the isolation techniques should be highly unlikely but cannot be entirely ruled out. (author)

  1. Evaluation of the neutral comet assay for detection of alpha-particle induced DNA-double-strand-breaks

    International Nuclear Information System (INIS)

    Hofbauer, Daniela

    2010-01-01

    Aim of this study was to differentiate DNA-double-strand-breaks from DNA-single-strand-breaks on a single cell level, using the comet assay after α- and γ-irradiation. Americium-241 was used as a alpha-irradiation-source, Caesium-137 was used for γ-irradiation. Because of technical problems with both the neutral and alkaline comet assay after irradiation of gastric cancer cells and human lymphocytes, no definite differentiation of DNA-damage was possible.

  2. Formation Mechanism of alpha-Fe2O3 Nanotubes via Electrospinning and Their Adsorption Characteristics of BSA and DNA.

    Science.gov (United States)

    Liu, Ruijiang; Wang, Peng; Tao, Yuting; Liu, Yifan; Shen, Xiangqian

    2016-02-01

    The alpha-Fe2O3 nanotubes with diameters of 400-700 nm have been prepared via the sol-gel assisted electrospinning and subsequent one-step heat treatment with ferric nitrate, ethanol and poly(vinyl pyrrolidone) as starting regents. The resultant alpha-Fe2O3 nanotubes were characterized by XRD, SEM, TEM, and VSM techniques. The hollow structure is mainly influenced by the water content in the gel precursor and the heating rate, and the hollow formation mechanism of alpha-Fe2O9 nanotubes is discussed. Adsorption of BSA onto the as-prepared alpha-Fe2O3 nanotubes exhibits a good capacity of 56.5 mg/g with the initial BSA concentration of 1.0 mg/mL, which demonstrates their feasibility in delivery of biomacromolecules. Subsequently, the adsorption characteristics of DNA onto the alpha-Fe2O3 nanotubes were investigated, and the adsorbance of DNA can achieve a maximum value of 4.19 microg/g when the initial DNA concentration is 50 microg/mL. The adsorption process of DNA onto alpha-Fe2O3 nanotubes can be described well by the pseudo-first-order kinetic model at room temperature according to the correlation coefficient R2 = 0.9978.

  3. Is radon emission in caves causing deletions in satellite DNA sequences of cave-dwelling crickets?

    Science.gov (United States)

    Allegrucci, Giuliana; Sbordoni, Valerio; Cesaroni, Donatella

    2015-01-01

    The most stable isotope of radon, 222Rn, represents the major source of natural radioactivity in confined environments such as mines, caves and houses. In this study, we explored the possible radon-related effects on the genome of Dolichopoda cave crickets (Orthoptera, Rhaphidophoridae) sampled in caves with different concentrations of radon. We analyzed specimens from ten populations belonging to two genetically closely related species, D. geniculata and D. laetitiae, and explored the possible association between the radioactivity dose and the level of genetic polymorphism in a specific family of satellite DNA (pDo500 satDNA). Radon concentration in the analyzed caves ranged from 221 to 26,000 Bq/m3. Specimens coming from caves with the highest radon concentration showed also the highest variability estimates in both species, and the increased sequence heterogeneity at pDo500 satDNA level can be explained as an effect of the mutation pressure induced by radon in cave. We discovered a specific category of nuclear DNA, the highly repetitive satellite DNA, where the effects of the exposure at high levels of radon-related ionizing radiation are detectable, suggesting that the satDNA sequences might be a valuable tool to disclose harmful effects also in other organisms exposed to high levels of radon concentration.

  4. Is radon emission in caves causing deletions in satellite DNA sequences of cave-dwelling crickets?

    Directory of Open Access Journals (Sweden)

    Giuliana Allegrucci

    Full Text Available The most stable isotope of radon, 222Rn, represents the major source of natural radioactivity in confined environments such as mines, caves and houses. In this study, we explored the possible radon-related effects on the genome of Dolichopoda cave crickets (Orthoptera, Rhaphidophoridae sampled in caves with different concentrations of radon. We analyzed specimens from ten populations belonging to two genetically closely related species, D. geniculata and D. laetitiae, and explored the possible association between the radioactivity dose and the level of genetic polymorphism in a specific family of satellite DNA (pDo500 satDNA. Radon concentration in the analyzed caves ranged from 221 to 26,000 Bq/m3. Specimens coming from caves with the highest radon concentration showed also the highest variability estimates in both species, and the increased sequence heterogeneity at pDo500 satDNA level can be explained as an effect of the mutation pressure induced by radon in cave. We discovered a specific category of nuclear DNA, the highly repetitive satellite DNA, where the effects of the exposure at high levels of radon-related ionizing radiation are detectable, suggesting that the satDNA sequences might be a valuable tool to disclose harmful effects also in other organisms exposed to high levels of radon concentration.

  5. Prediction of Active Site and Distal Residues in E. coli DNA Polymerase III alpha Polymerase Activity.

    Science.gov (United States)

    Parasuram, Ramya; Coulther, Timothy A; Hollander, Judith M; Keston-Smith, Elise; Ondrechen, Mary Jo; Beuning, Penny J

    2018-02-20

    The process of DNA replication is carried out with high efficiency and accuracy by DNA polymerases. The replicative polymerase in E. coli is DNA Pol III, which is a complex of 10 different subunits that coordinates simultaneous replication on the leading and lagging strands. The 1160-residue Pol III alpha subunit is responsible for the polymerase activity and copies DNA accurately, making one error per 10 5 nucleotide incorporations. The goal of this research is to determine the residues that contribute to the activity of the polymerase subunit. Homology modeling and the computational methods of THEMATICS and POOL were used to predict functionally important amino acid residues through their computed chemical properties. Site-directed mutagenesis and biochemical assays were used to validate these predictions. Primer extension, steady-state single-nucleotide incorporation kinetics, and thermal denaturation assays were performed to understand the contribution of these residues to the function of the polymerase. This work shows that the top 15 residues predicted by POOL, a set that includes the three previously known catalytic aspartate residues, seven remote residues, plus five previously unexplored first-layer residues, are important for function. Six previously unidentified residues, R362, D405, K553, Y686, E688, and H760, are each essential to Pol III activity; three additional residues, Y340, R390, and K758, play important roles in activity.

  6. A novel satellite DNA isolated in Pecten jacobaeus shows high sequence similarity among molluscs.

    Science.gov (United States)

    Petraccioli, Agnese; Odierna, Gaetano; Capriglione, Teresa; Barucca, Marco; Forconi, Mariko; Olmo, Ettore; Biscotti, Maria Assunta

    2015-10-01

    The aim of this work is to investigate the sequence conservation and the evolution of repeated DNA in related species. Satellite DNA is a component of eukaryotic genomes and is made up of tandemly repeated sequences. These sequences are affected by high rates of mutation that lead to the occurrence of species-specific satellite DNAs, which are different in terms of both quantity and quality. In this work, a novel repetitive DNA family, named PjHhaI sat, is described in Pecten jacobaeus. The quantitative analyses revealed a different abundance of this element in the molluscan species investigated in agreement with the "library hypothesis" even if, in this case, at a high taxonomic level. In addition, the qualitative analysis demonstrated an astonishing sequence conservation not only among scallops but also in six other molluscan species belonging to three classes. These findings suggest that the PjHhaI sat may be considered as the most ancients of DNA described so far, which remained "frozen" during molluscan evolution. The widespread distribution of this sat DNA in molluscs as well as its long evolutionary preservation open up questions on the functional role of this element. A future challenge might be the identification of proteins or molecules which interact with the PjHhaI sat.

  7. Satellite DNA and Transposable Elements in Seabuckthorn (Hippophae rhamnoides), a Dioecious Plant with Small Y and Large X Chromosomes.

    Science.gov (United States)

    Puterova, Janka; Razumova, Olga; Martinek, Tomas; Alexandrov, Oleg; Divashuk, Mikhail; Kubat, Zdenek; Hobza, Roman; Karlov, Gennady; Kejnovsky, Eduard

    2017-01-01

    Seabuckthorn (Hippophae rhamnoides) is a dioecious shrub commonly used in the pharmaceutical, cosmetic, and environmental industry as a source of oil, minerals and vitamins. In this study, we analyzed the transposable elements and satellites in its genome. We carried out Illumina DNA sequencing and reconstructed the main repetitive DNA sequences. For data analysis, we developed a new bioinformatics approach for advanced satellite DNA analysis and showed that about 25% of the genome consists of satellite DNA and about 24% is formed of transposable elements, dominated by Ty3/Gypsy and Ty1/Copia LTR retrotransposons. FISH mapping revealed X chromosome-accumulated, Y chromosome-specific or both sex chromosomes-accumulated satellites but most satellites were found on autosomes. Transposable elements were located mostly in the subtelomeres of all chromosomes. The 5S rDNA and 45S rDNA were localized on one autosomal locus each. Although we demonstrated the small size of the Y chromosome of the seabuckthorn and accumulated satellite DNA there, we were unable to estimate the age and extent of the Y chromosome degeneration. Analysis of dioecious relatives such as Shepherdia would shed more light on the evolution of these sex chromosomes. © The Author(s) 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  8. Statistical Analysis on Detecting Recombination Sites in DNASatellites Associated with Old World Geminiviruses

    Science.gov (United States)

    Xu, Kai; Yoshida, Ruriko

    2010-01-01

    Although exchange of genetic information by recombination plays an important role in the evolution of viruses, it is not clear how it generates diversity. Understanding recombination events helps with the study of the evolution of new virus strains or new viruses. Geminiviruses are plant viruses which have ambisense single-stranded circular DNA genomes and are one of the most economically important plant viruses in agricultural production. Small circular single-stranded DNA satellites, termed DNA-β, have recently been found to be associated with some geminivirus infections. In this paper we analyze several DNA-β sequences of geminiviruses for recombination events using phylogenetic and statistical analysis and we find that one strain from ToLCMaB has a recombination pattern and is a recombinant molecule between two strains from two species, PaLCuB-[IN:Chi:05] (major parent) and ToLCB-[IN:CP:04] (minor parent). We propose that this recombination event contributed to the evolution of the strain of ToLCMaB in South India. The Hidden Markov Chain (HMM) method developed by Webb et al. (2009) estimating phylogenetic tree through out the whole alignment provide us a recombination history of these DNA-β strains. It is the first time that this statistic method has been used on DNA-β recombination study and give a clear recombination history of DNA-β recombination. PMID:21423447

  9. cDNA isolation, functional expression, and characterization of (+)-alpha-pinene synthase and (-)-alpha-pinene synthase from loblolly pine (Pinus taeda): stereocontrol in pinene biosynthesis.

    Science.gov (United States)

    Phillips, Michael A; Wildung, Mark R; Williams, David C; Hyatt, David C; Croteau, Rodney

    2003-03-15

    The complex mixture of monoterpenes, sesquiterpenes, and diterpenes that comprises oleoresin provides the primary defense of conifers against bark beetles and their associated fungal pathogens. Monoterpene synthases produce the turpentine fraction of oleoresin, which allows mobilization of the diterpene resin acid component (rosin) and is also toxic toward invading insects; this is particularly the case for alpha-pinene, a prominent bicyclic monoterpene of pine turpentine. The stereochemistry of alpha-pinene is a critical determinant of host defense capability and has implications for host selection, insect pheromone biosynthesis, and tritrophic-level interactions. Pines produce both enantiomers of alpha-pinene, which appear to arise through antipodal reaction mechanisms by distinct enzymes. Using a cDNA library constructed with mRNA from flushing needles of loblolly pine (Pinus taeda), we employed a homology-based cloning strategy to isolate, and confirm by functional expression, the genes encoding (+)-(3R:5R)-alpha-pinene synthase, (-)-(3S:5S)-alpha-pinene synthase, and several other terpene synthases. The pinene synthases, which produce mirror-image products, share only 66% amino acid identity (72% similarity) but are similar in general properties to other monoterpene synthases of gymnosperms. The stereochemical control of monoterpene cyclization reactions, the evolution of "antipodal" enzymes, and the implications of turpentine composition in ecological interactions are discussed.

  10. Alpha Particles and X Rays Interact in Inducing DNA Damage in U2OS Cells.

    Science.gov (United States)

    Sollazzo, Alice; Brzozowska, Beata; Cheng, Lei; Lundholm, Lovisa; Haghdoost, Siamak; Scherthan, Harry; Wojcik, Andrzej

    2017-10-01

    Survivors of the atomic bombings of Hiroshima and Nagasaki are monitored for health effects within the Life Span Study (LSS). The LSS results represent the most important source of data about cancer effects from ionizing radiation exposure, which forms the foundation for the radiation protection system. One uncertainty connected to deriving universal risk factors from these results is related to the problem of mixed radiation qualities. The A-bomb explosions generated a mixed beam of the sparsely ionizing gamma radiation and densely ionizing neutrons. However, until now the possible interaction of the two radiation types of inducing biological effects has not been taken into consideration. The existence of such interaction would suggest that the application of risk factors derived from the LSS to predict cancer effects after pure gamma-ray irradiation (such as in the Fukushima prefecture) leads to an overestimation of risk. To analyze the possible interaction of radiation types, a mixed-beam exposure facility was constructed where cells can be exposed to sparsely ionizing X rays and densely ionizing alpha particles. U2OS cells were used, which are stably transfected with a plasmid coding for the DNA repair gene 53BP1 coupled to a gene coding for the green fluorescent protein (GFP). The induction and repair of DNA damage, which are known to be related to cancer induction, were analyzed. The results suggest that alpha particles and X rays interact, leading to cellular and possibly cancer effects, which cannot be accurately predicted based on assuming simple additivity of the individual mixed-beam components.

  11. Rapid One-Step Selection Method for Generating Nucleic Acid Aptamers: Development of a DNA Aptamer against alpha-Bungarotoxin

    DEFF Research Database (Denmark)

    Lauridsen, Lasse Holm; Shamaileh, Hadi A.; Edwards, Stacey L.

    2012-01-01

    in one-step, technique is required for developing aptamers in limited time period. Principal Findings: Herein, we present a simple one-step selection of DNA aptamers against alpha-bungarotoxin. A toxin immobilized glass coverslip was subjected to nucleic acid pool binding and extensive washing followed...

  12. Satellite DNA content illuminates the ancestry of a supernumerary (B) chromosome.

    Science.gov (United States)

    Ruiz-Ruano, Francisco J; Cabrero, Josefa; López-León, María Dolores; Camacho, Juan Pedro M

    2017-08-01

    B chromosomes are supernumerary genomic elements most likely derived from the standard (A) chromosomes, whose dispensability has freed their DNA sequences to evolve fast, thus making it difficult to uncover their ancestry. Here, we show the ancestry of a B chromosome in the grasshopper Eumigus monticola by means of the high-throughput analysis of the satellitome, i.e., the whole collection of satellite DNA (satDNA). The satellitome found in this species consists of 27 satDNA families, with monomer length between 5 and 325 nt and A + T content between 42.9 and 83.3 %. Two out of the 20 clustered satDNA families (EmoSat26-41 and EmoSat27-102) were observed only on the B chromosome. The A chromosome carrying the highest number of satDNA families was the megameric S8 (13 families), six of which were also present in the B chromosome, and three of these were exclusive of the S8 and B chromosomes. The absence in the B chromosome of the H3 histone gene cluster (located interstitially on S8) and three satDNA families (located distally on S8) allowed delimiting the possible origin of the B chromosome to the proximal third of the S8 autosome, through a breakpoint between EmoSat11-122 and the H3 cluster. Interestingly, bioinformatic analysis revealed the presence of seeds for the two B-specific satDNAs in the A chromosomes, suggesting their massive amplification in the B chromosome after its origin. Therefore, intraspecifically arisen B chromosomes can harbor DNA sequences apparently being B-specific.

  13. Synthesis, cloning, and identification of DNA sequences complementary to mRNAs for alpha and beta subunits of thyrotropin.

    OpenAIRE

    Vamvakopoulos, N C; Monahan, J J; Kourides, I A

    1980-01-01

    Double-stranded cDNA sequences were synthesized, by using as templates mRNA for alpha and beta subunits of thyrotropin purified from mouse thyrotrophic pituitary tumours and cloned in Escherichia coli RR1 by insertion in the Pst I site of the bacterial plasmid pBR322 by use of poly(dA) x poly(dT) homopolymeric extensions. Plasmids containing inserted cDNA sequences were selected by resistance to tetracycline and sensitivity to ampicillin; those containing thyrotropin cDNA sequences were ident...

  14. FA-SAT Is an Old Satellite DNA Frozen in Several Bilateria Genomes

    Science.gov (United States)

    Chaves, Raquel; Ferreira, Daniela; Mendes-da-Silva, Ana; Meles, Susana; Adega, Filomena

    2017-01-01

    Abstract In recent years, a growing body of evidence has recognized the tandem repeat sequences, and specifically satellite DNA, as a functional class of sequences in the genomic “dark matter.” Using an original, complementary, and thus an eclectic experimental design, we show that the cat archetypal satellite DNA sequence, FA-SAT, is “frozen” conservatively in several Bilateria genomes. We found different genomic FA-SAT architectures, and the interspersion pattern was conserved. In Carnivora genomes, the FA-SAT-related sequences are also amplified, with the predominance of a specific FA-SAT variant, at the heterochromatic regions. We inspected the cat genome project to locate FA-SAT array flanking regions and revealed an intensive intermingling with transposable elements. Our results also show that FA-SAT-related sequences are transcribed and that the most abundant FA-SAT variant is not always the most transcribed. We thus conclude that the DNA sequences of FA-SAT and their transcripts are “frozen” in these genomes. Future work is needed to disclose any putative function that these sequences may play in these genomes.

  15. Evidence for mutagenic repair in V79 cell mutant with aphidicolin-resistant DNA polymerce-alpha

    International Nuclear Information System (INIS)

    Liu, P.K.; Chang, C.C.; Trosko, J.E.

    1984-01-01

    An aphidicolin-resistant (aphr) mutant of Chinese hamster V79 cells, aphr -4-2, is shown to be slow-growing, sensitive to ultraviolet (UV) irradiation, hypermutable for spontaneous and UV-induced mutations, and known to contain an aphr mutant DNA polymerase-alpha, with a 10-fold reduction in the Km for dCTP but not for dATP. We show here that the mutant had a normal repair replication measured by unscheduled DNA synthesis assay. The mutant was specifically sensitive and hypermutable to UV and N-methyl-N'-nitro-N-nitrosoguanidine, but it had normal sensitivity to ionizing radiation and dimethyl sulfate. Unlike the V79 (wt) cells, the mutant exhibited further enhancement in the already elevated mutability following UV and conditioned medium treatment. The mutant characteristic is explained by the presence of an error-prone long-patch excision repair synthesis. The association in the mutant properties--an aphr DNA polymerase-alpha, UV sensitivity, and hypermutability to UV-induced mutation--provides the genetic evidence that DNA polymerase-alpha is likely to be involved in UV-induced DNA repair synthesis

  16. Begomovirus-Associated Satellite DNA Diversity Captured Through Vector-Enabled Metagenomic (VEM) Surveys Using Whiteflies (Aleyrodidae).

    Science.gov (United States)

    Rosario, Karyna; Marr, Christian; Varsani, Arvind; Kraberger, Simona; Stainton, Daisy; Moriones, Enrique; Polston, Jane E; Breitbart, Mya

    2016-02-02

    Monopartite begomoviruses (Geminiviridae), which are whitefly-transmitted single-stranded DNA viruses known for causing devastating crop diseases, are often associated with satellite DNAs. Since begomovirus acquisition or exchange of satellite DNAs may lead to adaptation to new plant hosts and emergence of new disease complexes, it is important to investigate the diversity and distribution of these molecules. This study reports begomovirus-associated satellite DNAs identified during a vector-enabled metagenomic (VEM) survey of begomoviruses using whiteflies collected in various locations (California (USA), Guatemala, Israel, Puerto Rico, and Spain). Protein-encoding satellite DNAs, including alphasatellites and betasatellites, were identified in Israel, Puerto Rico, and Guatemala. Novel alphasatellites were detected in samples from Guatemala and Puerto Rico, resulting in the description of a phylogenetic clade (DNA-3-type alphasatellites) dominated by New World sequences. In addition, a diversity of small (~640-750 nucleotides) satellite DNAs similar to satellites associated with begomoviruses infecting Ipomoea spp. were detected in Puerto Rico and Spain. A third class of satellite molecules, named gammasatellites, is proposed to encompass the increasing number of reported small (satellite DNAs. This VEM-based survey indicates that, although recently recovered begomovirus genomes are variations of known genetic themes, satellite DNAs hold unexplored genetic diversity.

  17. Characterization of Non-coding DNA Satellites Associated with Sweepoviruses (Genus Begomovirus, Geminiviridae) - Definition of a Distinct Class of Begomovirus-Associated Satellites.

    Science.gov (United States)

    Lozano, Gloria; Trenado, Helena P; Fiallo-Olivé, Elvira; Chirinos, Dorys; Geraud-Pouey, Francis; Briddon, Rob W; Navas-Castillo, Jesús

    2016-01-01

    Begomoviruses (family Geminiviridae) are whitefly-transmitted, plant-infecting single-stranded DNA viruses that cause crop losses throughout the warmer parts of the World. Sweepoviruses are a phylogenetically distinct group of begomoviruses that infect plants of the family Convolvulaceae, including sweet potato (Ipomoea batatas). Two classes of subviral molecules are often associated with begomoviruses, particularly in the Old World; the betasatellites and the alphasatellites. An analysis of sweet potato and Ipomoea indica samples from Spain and Merremia dissecta samples from Venezuela identified small non-coding subviral molecules in association with several distinct sweepoviruses. The sequences of 18 clones were obtained and found to be structurally similar to tomato leaf curl virus-satellite (ToLCV-sat, the first DNA satellite identified in association with a begomovirus), with a region with significant sequence identity to the conserved region of betasatellites, an A-rich sequence, a predicted stem-loop structure containing the nonanucleotide TAATATTAC, and a second predicted stem-loop. These sweepovirus-associated satellites join an increasing number of ToLCV-sat-like non-coding satellites identified recently. Although sharing some features with betasatellites, evidence is provided to suggest that the ToLCV-sat-like satellites are distinct from betasatellites and should be considered a separate class of satellites, for which the collective name deltasatellites is proposed.

  18. Characterization of Non-coding DNA Satellites Associated with Sweepoviruses (Genus Begomovirus, Geminiviridae) – Definition of a Distinct Class of Begomovirus-Associated Satellites

    Science.gov (United States)

    Lozano, Gloria; Trenado, Helena P.; Fiallo-Olivé, Elvira; Chirinos, Dorys; Geraud-Pouey, Francis; Briddon, Rob W.; Navas-Castillo, Jesús

    2016-01-01

    Begomoviruses (family Geminiviridae) are whitefly-transmitted, plant-infecting single-stranded DNA viruses that cause crop losses throughout the warmer parts of the World. Sweepoviruses are a phylogenetically distinct group of begomoviruses that infect plants of the family Convolvulaceae, including sweet potato (Ipomoea batatas). Two classes of subviral molecules are often associated with begomoviruses, particularly in the Old World; the betasatellites and the alphasatellites. An analysis of sweet potato and Ipomoea indica samples from Spain and Merremia dissecta samples from Venezuela identified small non-coding subviral molecules in association with several distinct sweepoviruses. The sequences of 18 clones were obtained and found to be structurally similar to tomato leaf curl virus-satellite (ToLCV-sat, the first DNA satellite identified in association with a begomovirus), with a region with significant sequence identity to the conserved region of betasatellites, an A-rich sequence, a predicted stem–loop structure containing the nonanucleotide TAATATTAC, and a second predicted stem–loop. These sweepovirus-associated satellites join an increasing number of ToLCV-sat-like non-coding satellites identified recently. Although sharing some features with betasatellites, evidence is provided to suggest that the ToLCV-sat-like satellites are distinct from betasatellites and should be considered a separate class of satellites, for which the collective name deltasatellites is proposed. PMID:26925037

  19. Characterization of non-coding DNA satellites associated with sweepoviruses (genus Begomovirus, Geminiviridae - definition of a distinct class of begomovirus-associated satellites

    Directory of Open Access Journals (Sweden)

    Gloria eLozano

    2016-02-01

    Full Text Available Begomoviruses (family Geminiviridae are whitefly-transmitted, plant-infecting single-stranded DNA viruses that cause crop losses throughout the warmer parts of the World. Sweepoviruses are a phylogenetically distinct group of begomoviruses that infect plants of the family Convolvulaceae, including sweet potato (Ipomoea batatas. Two classes of subviral molecules are often associated with begomoviruses, particularly in the Old World; the betasatellites and the alphasatellites. An analysis of sweet potato and Ipomoea indica samples from Spain and Merremia dissecta samples from Venezuela identified small non-coding subviral molecules in association with several distinct sweepoviruses. The sequences of 18 clones were obtained and found to be structurally similar to tomato leaf curl virus–satellite (ToLCV-sat, the first DNA satellite identified in association with a begomovirus, with a region with significant sequence identity to the conserved region of betasatellites, an A-rich sequence, a predicted stem-loop structure containing the nonanucleotide TAATATTAC, and a second predicted stem-loop. These sweepovirus-associated satellites join an increasing number of ToLCV-sat-like non-coding satellites identified recently. Although sharing some features with betasatellites, evidence is provided to suggest that the ToLCV-sat-like satellites are distinct from betasatellites and should be considered a separate class of satellites, for which the collective name deltasatellites is proposed.

  20. Calculation of the Electronic Parameters of an Al/DNA/p-Si Schottky Barrier Diode Influenced by Alpha Radiation

    Directory of Open Access Journals (Sweden)

    Hassan Maktuff Jaber Al-Ta'ii

    2015-02-01

    Full Text Available Many types of materials such as inorganic semiconductors have been employed as detectors for nuclear radiation, the importance of which has increased significantly due to recent nuclear catastrophes. Despite the many advantages of this type of materials, the ability to measure direct cellular or biological responses to radiation might improve detector sensitivity. In this context, semiconducting organic materials such as deoxyribonucleic acid or DNA have been studied in recent years. This was established by studying the varying electronic properties of DNA-metal or semiconductor junctions when exposed to radiation. In this work, we investigated the electronics of aluminium (Al/DNA/silicon (Si rectifying junctions using their current-voltage (I-V characteristics when exposed to alpha radiation. Diode parameters such as ideality factor, barrier height and series resistance were determined for different irradiation times. The observed results show significant changes with exposure time or total dosage received. An increased deviation from ideal diode conditions (7.2 to 18.0 was observed when they were bombarded with alpha particles for up to 40 min. Using the conventional technique, barrier height values were observed to generally increase after 2, 6, 10, 20 and 30 min of radiation. The same trend was seen in the values of the series resistance (0.5889–1.423 Ω for 2–8 min. These changes in the electronic properties of the DNA/Si junctions could therefore be utilized in the construction of sensitive alpha particle detectors.

  1. S1 satellite DNA repetitive units display identical structure and overall variability in all Anatolian brown frog taxa.

    Science.gov (United States)

    Picariello, Orfeo; Feliciello, Isidoro; Chinali, Gianni

    2016-02-01

    S1 satellite DNA from Palearctic brown frogs has a species-specific structure in all European species. We characterized S1 satellite DNA from the Anatolian brown frogs Rana macrocnemis, R. camerani, and R. holtzi in order to define their taxonomic rank and the structure of this satellite in this frog lineage. Southern blots of genomic DNA digested with KpnI, EcoRV, NdeI, NheI, or StuI produced the same pattern of satellite DNA bands. Moreover, quantitative dot blots showed that this satellite DNA accounts for 0.1 % of the genome in all taxa. Analysis of the overall genomic variability of the S1a repeat sequence in specimens from various populations demonstrated that this repetitive unit also has the same size (476 bp), the same most common sequence (MCS) and the same overall variability in all three taxa, and also in R. macrocnemis tavasensis. The S1a repetitive unit presents three deletions of 9, 8 and 1 bp compared to the 494-bp S1a repeat from European frogs. The S1a MCS has three variable positions (sequence WWTK in positions 183-186), due to the presence of two repeat subpopulations with motifs AATG and WWTT in all taxa. Unlike previously analyzed mitochondrial and nuclear sequences that show considerable variations among these taxa, no difference could be detected in the structure and variability of the S1 satellite repetitive units. This suggests that these taxa should belong to a single species. Our results indicate that this satellite DNA variety probably formed when the Anatolian lineage radiated from common ancestor about 4 mya, and since then has maintained its structure in all four taxa examined.

  2. Obesity-induced sperm DNA methylation changes at satellite repeats are reprogrammed in rat offspring

    Directory of Open Access Journals (Sweden)

    Neil A Youngson

    2016-01-01

    Full Text Available There is now strong evidence that the paternal contribution to offspring phenotype at fertilisation is more than just DNA. However, the identity and mechanisms of this nongenetic inheritance are poorly understood. One of the more important questions in this research area is: do changes in sperm DNA methylation have phenotypic consequences for offspring? We have previously reported that offspring of obese male rats have altered glucose metabolism compared with controls and that this effect was inherited through nongenetic means. Here, we describe investigations into sperm DNA methylation in a new cohort using the same protocol. Male rats on a high-fat diet were 30% heavier than control-fed males at the time of mating (16-19 weeks old, n = 14/14. A small (0.25% increase in total 5-methyl-2Ͳ-deoxycytidine was detected in obese rat spermatozoa by liquid chromatography tandem mass spectrometry. Examination of the repetitive fraction of the genome with methyl-CpG binding domain protein-enriched genome sequencing (MBD-Seq and pyrosequencing revealed that retrotransposon DNA methylation states in spermatozoa were not affected by obesity, but methylation at satellite repeats throughout the genome was increased. However, examination of muscle, liver, and spermatozoa from male 27-week-old offspring from obese and control fathers (both groups from n = 8 fathers revealed that normal DNA methylation levels were restored during offspring development. Furthermore, no changes were found in three genomic imprints in obese rat spermatozoa. Our findings have implications for transgenerational epigenetic reprogramming. They suggest that postfertilization mechanisms exist for normalising some environmentally-induced DNA methylation changes in sperm cells.

  3. Alpha-momorcharin: a ribosome-inactivating protein from Momordica charantia, possessing DNA cleavage properties.

    Science.gov (United States)

    Wang, Shuzhen; Zheng, Yinzhen; Yan, Junjie; Zhu, Zhixuan; Wu, Zhihua; Ding, Yi

    2013-11-01

    Ribosome-inactivating proteins (RIPs) function to inhibit protein synthesis through the removal of specific adenine residues from eukaryotic ribosomal RNA and rending the 60S subunit unable to bind elongation factor 2. They have received much attention in biological and biomedical research due to their unique activities toward tumor cells, as well as the important roles in plant defense. Alpha-momorcharin (α-MC), a member of the type I family of RIPs, is rich in the seeds of Momordica charantia L. Previous studies demonstrated that α-MC is an effective antifungal and antibacterial protein. In this study, a detailed analysis of the DNase-like activity of α-MC was conducted. Results showed that the DNase-like activity toward plasmid DNA was time-dependent, temperature-related, and pH-stable. Moreover, a requirement for divalent metal ions in the catalytic domain of α-MC was confirmed. Additionally, Tyr(93) was found to be a critical residue for the DNase-like activity, while Tyr(134), Glu(183), Arg(186), and Trp(215) were activity-related residues. This study on the chemico-physical properties and mechanism of action of α-MC will improve its utilization in scientific research, as well as its potential industrial uses. These results may also assist in the characterization and elucidation of the DNase-like enzymatic properties of other RIPs.

  4. Evaluation criteria of rat hepatocytes transcriptome analysis under the influence of interferon alpha by DNA microarray

    Directory of Open Access Journals (Sweden)

    Kuklin A. V.

    2013-10-01

    Full Text Available The changes induced in transcriptome of rat hepatocytes treated with interferon alpha (IFN during three and six hours were analyzed by DNA microarray. Aim. To conduct a stepwise analysis of the results of microarray experiment and to determine whether they meet/fail to the conventional requirements. Methods. The files obtained after scanning microarrays were subjected to the analysis in statistical environment R by Bioconductor’s packages «affy», «simpleaffy», «affyPLM» and BRB Array Tools software for paired T-test. Results. All microarrays had quality metrics lying within recommended ranges, passed quality control, were normalized and are comparable with each other. The T-test revealed 28 and 124 differentially expressed genes after three and six hours of cells cultivation with IFNα , respectively. Conclusions. The obtained data meet the conventional criteria of quality and are applicable for further evaluation of their biological significance. The R-codes used in this study can be used for the analysis of the microarrays data.

  5. Modeling proton and alpha elastic scattering in liquid water in Geant4-DNA

    Energy Technology Data Exchange (ETDEWEB)

    Tran, H.N., E-mail: tranngochoang@tdt.edu.vn [Division of Nuclear Physics, Ton Duc Thang University, Tan Phong Ward, District 7, Ho Chi Minh City (Viet Nam); Faculty of Applied Sciences, Ton Duc Thang University, Tan Phong Ward, District 7, Ho Chi Minh City (Viet Nam); El Bitar, Z. [Institut Pluridisciplinaire Hubert Curien/IN2P3/CNRS, Strasbourg (France); Champion, C. [Univ. Bordeaux, CENBG, UMR 5797, F-33170 Gradignan (France); CNRS, IN2P3, CENBG, UMR 5797, F-33170 Gradignan (France); Karamitros, M. [Univ. Bordeaux, CENBG, UMR 5797, F-33170 Gradignan (France); CNRS, IN2P3, CENBG, UMR 5797, F-33170 Gradignan (France); CNRS, INCIA, UMR 5287, F-33400 Talence (France); Bernal, M.A. [Instituto de FísicaGleb Wataghin, Universida de Estadual de Campinas, SP (Brazil); Francis, Z. [Université Saint Joseph, Faculty of Science, Department of Physics, Beirut (Lebanon); The Open University, Faculty of Science, Department of Physical Sciences, Walton Hall, MK7 6AA Milton Keynes (United Kingdom); Ivantchenko, V. [Ecoanalytica, 119899 Moscow (Russian Federation); Lee, S.B.; Shin, J.I. [Proton Therapy Center, National Cancer Center, 323 Ilsan-ro, Ilsandong-gu, Goyang-si, Gyeonggi-do 410-769 (Korea, Republic of); Incerti, S. [Univ. Bordeaux, CENBG, UMR 5797, F-33170 Gradignan (France); CNRS, IN2P3, CENBG, UMR 5797, F-33170 Gradignan (France)

    2015-01-15

    Elastic scattering of protons and alpha (α) particles by water molecules cannot be neglected at low incident energies. However, this physical process is currently not available in the “Geant4-DNA” extension of the Geant4 Monte Carlo simulation toolkit. In this work, we report on theoretical differential and integral cross sections of the elastic scattering process for 100 eV–1 MeV incident protons and for 100 eV–10 MeV incident α particles in liquid water. The calculations are performed within the classical framework described by Everhart et al., Ziegler et al. and by the ICRU 49 Report. Then, we propose an implementation of the corresponding classes into the Geant4-DNA toolkit for modeling the elastic scattering of protons and α particles. Stopping powers as well as ranges are also reported. Then, it clearly appears that the account of the elastic scattering process in the slowing-down of the charged particle improves the agreement with the existing data in particular with the ICRU recommendations.

  6. DNA homologous recombination factor SFR1 physically and functionally interacts with estrogen receptor alpha.

    Directory of Open Access Journals (Sweden)

    Yuxin Feng

    Full Text Available Estrogen receptor alpha (ERα, a ligand-dependent transcription factor, mediates the expression of its target genes by interacting with corepressors and coactivators. Since the first cloning of SRC1, more than 280 nuclear receptor cofactors have been identified, which orchestrate target gene transcription. Aberrant activity of ER or its accessory proteins results in a number of diseases including breast cancer. Here we identified SFR1, a protein involved in DNA homologous recombination, as a novel binding partner of ERα. Initially isolated in a yeast two-hybrid screen, the interaction of SFR1 and ERα was confirmed in vivo by immunoprecipitation and mammalian one-hybrid assays. SFR1 co-localized with ERα in the nucleus, potentiated ER's ligand-dependent and ligand-independent transcriptional activity, and occupied the ER binding sites of its target gene promoters. Knockdown of SFR1 diminished ER's transcriptional activity. Manipulating SFR1 expression by knockdown and overexpression revealed a role for SFR1 in ER-dependent and -independent cancer cell proliferation. SFR1 differs from SRC1 by the lack of an intrinsic activation function. Taken together, we propose that SFR1 is a novel transcriptional modulator for ERα and a potential target in breast cancer therapy.

  7. Identification of four genomic loci highly related to casein-kinase-2-alpha cDNA and characterization of a casein kinase-2-alpha pseudogene within the mouse genome

    DEFF Research Database (Denmark)

    Boldyreff, B; Wehr, K; Hecht, R

    1992-01-01

    Using the coding region of the human CK-2 alpha cDNA as a probe for screening a genomic mouse library, positive clones representing four different genomic loci were isolated. Partial DNA sequences of these loci encompassing the first 120 nucleotides of the putative coding region are reported. One...

  8. Alpha-lipoic acid potently inhibits peroxynitrite-mediated DNA strand breakage and hydroxyl radical formation: implications for the neuroprotective effects of alpha-lipoic acid.

    Science.gov (United States)

    Jia, Zhenquan; Zhu, Hong; Vitto, Michael J; Misra, Bhaba R; Li, Yunbo; Misra, Hara P

    2009-03-01

    Alpha-lipoic acid (LA) has recently been reported to afford protection against neurodegenerative disorders in humans and experimental animals. However, the mechanisms underlying LA-mediated neuroprotection remain an enigma. Because peroxynitrite has been extensively implicated in the pathogenesis of various forms of neurodegenerative disorders, this study was undertaken to investigate the effects of LA in peroxynitrite-induced DNA strand breaks, a critical event leading to peroxynitrite-elicited cytotoxicity. Incubation of phi X-174 plasmid DNA with the 3-morpholinosydnonimine (SIN-1), a peroxynitrite generator, led to the formation of both single- and double-stranded DNA breaks in a concentration- and time-dependent fashion. The presence of LA at 100-1,600 microM was found to significantly inhibit SIN-1-induced DNA strand breaks in a concentration-dependent manner. The consumption of oxygen induced by 250 microM SIN-1 was found to be decreased in the presence of high concentrations of LA (400-1,600 microM), indicating that LA at these concentrations may affect the generation of peroxynitrite from auto-oxidation of SIN-1. It is observed that incubation of the plasmid DNA with authentic peroxynitrite resulted in a significant formation of DNA strand breaks, which could also be dramatically inhibited by the presence of LA (100-1,600 microM). EPR spectroscopy in combination with spin-trapping experiments, using 5,5-dimethylpyrroline-N-oxide (DMPO) as spin trap, resulted in the formation of DMPO-hydroxyl radical adduct (DMPO-OH) from authentic peroxynitrite and LA at 50-1,600 microM inhibited the adduct signal. Taken together, these studies demonstrate for the first time that LA can potently inhibit peroxynitrite-mediated DNA strand breakage and hydroxyl radical formation. In view of the critical involvement of peroxynitrite in the pathogenesis of various neurodegenerative diseases, the inhibition of peroxynitrite-mediated DNA damage by LA may be responsible, at least

  9. Human placental Na/sup +/, K/sup +/-ATPase. cap alpha. subunit: cDNA cloning, tissue expression, DNA polymorphism, and chromosomal localization

    Energy Technology Data Exchange (ETDEWEB)

    Chehab, F.F.; Kan, Y.W.; Law, M.L.; Hartz, J.; Kao, F.T.; Blostein, R.

    1987-11-01

    A 2.2-kilobase clone comprising a major portion of the coding sequence of the Na/sup +/, K/sup +/-ATPase ..cap alpha.. subunit was cloned from human placenta and its sequence was identical to that encoding the ..cap alpha.. subunit of human kidney and HeLa cells. Transfer blot analysis of the mRNA products of the Na/sup +/, K/sup +/-ATPase gene from various human tissues and cell lines revealed only one band (approx. = 4.7 kilobases) under low and high stringency washing conditions. The levels of expression in the tissues were intestine > placenta > liver > pancreas, and in the cell lines the levels were human erythroleukemia > butyrate-induced colon > colon > brain > HeLa cells. mRNA was undetectable in reticulocytes, consistent with the authors failure to detect positive clones in a size-selected ( > 2 kilobases) lambdagt11 reticulocyte cDNA library. DNA analysis revealed by a polymorphic EcoRI band and chromosome localization by flow sorting and in situ hybridization showed that the ..cap alpha.. subunit is on the short is on the short arm (band p11-p13) of chromosome 1.

  10. Anatomy of the primase-alpha DNA polymerase reaction accomplished by nucleoprotein complexes harboring an exrachromosomal DNA identical with avian myeloblastosis virus core-bound DNA: influencing by carbonyldiphosphonate, mimosine and butylphenil deoxyguanosine-5-triphosphate

    Czech Academy of Sciences Publication Activity Database

    Říman, Josef

    2001-01-01

    Roč. 45, č. 1 (2001), s. 109-124 ISSN 0001-723X Institutional research plan: CEZ:AV0Z5052915 Keywords : primase * alpha DNA-polymerase * enzyme complex Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.644, year: 2001

  11. Alpha, beta-unsaturated lactones 2-furanone and 2-pyrone induce cellular DNA damage, formation of topoisomerase I- and II-DNA complexes and cancer cell death.

    Science.gov (United States)

    Calderón-Montaño, José Manuel; Burgos-Morón, Estefanía; Orta, Manuel Luis; Pastor, Nuria; Austin, Caroline A; Mateos, Santiago; López-Lázaro, Miguel

    2013-09-12

    The alpha, beta-unsaturated lactones 2-furanone and 2-pyrone are part of the chemical structure of a variety of naturally occurring compounds (e.g., cardenolides, bufadienolides, acetogenins, coumarins, and food-flavoring furanones), some of which have shown anticancer activity and/or DNA damaging effects. Here we report that 2-furanone and 2-pyrone induce cellular DNA damage (assessed by the comet assay and the gamma-H2AX focus assay) and the formation of topoisomerase I- and topoisomerase II-DNA complexes in cells (visualized and quantified in situ by the TARDIS assay). Cells mutated in BRCA2 (deficient in homologous recombination repair) were significantly hypersensitive to the cytotoxic activity of 2-pyrone, therefore suggesting that BRCA2 plays an important role in the repair of DNA damage induced by this lactone. Both lactones were cytotoxic in A549 lung cancer cells at lower concentrations than in MRC5 non-malignant lung fibroblasts. The possible involvement of 2-furanone and 2-pyrone in the anticancer and DNA-damaging activities of compounds containing these lactones is discussed. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  12. Synthesis of novel naphthoquinone-spermidine conjugates and their effects on DNA-topoisomerases I and II-{alpha}

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, Andrea S.; Lima, Edson L.S.; Pinto, Angelo C.; Esteves-Souza, Andressa; Torrese, Jose C. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Quimica; Echevarria, Aurea [Universidade Federal Rural do Rio de Janeiro, RJ (Brazil). Dept. de Quimica; Camara, Celso A. [Paraiba Univ., Joao Pessoa, PB (Brazil). Lab. de Tecnologia Farmaceutica; Vargas, Maria D. [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Inst. de Quimica]. E-mail: mdvargas@vm.uff.br

    2006-05-15

    Novel derivatives of lapachol 2, nor-lapachol 3 and lawsone 4 have been synthesized by nucleophilic displacement of the methoxynaphthoquinones 2a, 3a and 4a with the polyamine (PA) N{sup 1}-Boc-N{sup 5}-Bn-spermidine 1a. The respective products 2b-4b were obtained in good yields and characterized by spectroscopic and analytical methods. The inhibitory action of these naphthoquinone-PA conjugates on DNA-topoisomerases (topo) I and II-{alpha} was evaluated by relaxation assay of supercoiled DNA plasmid. All compounds (1a 2b, 3b and 4b) presented significant inhibition of topo II-{alpha} catalytic activity at the 2 {mu}M dose. Considering that only PA 1a did not inhibit the enzyme catalytic activity at the 0.2 {mu}M dose, the appended naphthoquinone moiety acts as a 'value added' fragment. Compounds 1a 2b, 3b and 4b did not inhibit the enzyme DNA-topo I at the 200 {mu}M dose. (author)

  13. Synthesis of novel naphthoquinone-spermidine conjugates and their effects on DNA-topoisomerases I and II-alpha

    Directory of Open Access Journals (Sweden)

    Cunha Andréa S.

    2006-01-01

    Full Text Available Novel derivatives of lapachol 2, nor-lapachol 3 and lawsone 4 have been synthesized by nucleophilic displacement of the methoxynaphthoquinones 2a, 3a and 4a with the polyamine (PA N¹-Boc-N5-Bn-spermidine 1a. The respective products 2b-4b were obtained in good yields and characterized by spectroscopic and analytical methods. The inhibitory action of these naphthoquinone-PA conjugates on DNA-topoisomerases (topo I and II-alpha was evaluated by relaxation assay of supercoiled DNA plasmid. All compounds (1a 2b, 3b and 4b presented significant inhibition of topo II-alpha catalytic activity at the 2 µM dose. Considering that only PA 1a did not inhibit the enzyme catalytic activity at the 0.2 µM dose, the appended naphthoquinone moiety acts as a "value added" fragment. Compounds 1a 2b, 3b and 4b did not inhibit the enzyme DNA-topo I at the 200 µM dose.

  14. Acquisition of multiple nuclei and the activity of DNA polymerase alpha and reinitiation of DNA replication in terminally differentiated adult cardiac muscle cells in culture

    Energy Technology Data Exchange (ETDEWEB)

    Claycomb, W.C.; Bradshaw, H.D. Jr.

    1983-10-01

    Terminally differentiated ventricular cardiac muscle cells isolated from the adult rat and maintained in cell culture have been observed to acquire multiple nuclei. In one cultured myocyte as many as 10 nuclei have been counted. Apparently, these multiple nuclei are formed by DNA replication followed by karyokinesis; the cells must then fail to complete mitosis and divide. To investigate whether DNA synthesis was occurring, the cells were cultured in the presence of (3H)thymidine and then processed for autoradiography. Mononucleated, binucleated, and multinucleated cells incorporate (3H)thymidine into DNA as evidenced by the high concentration of silver grains over their nuclei. Peak periods of incorporation were observed to occur at 10- to 12-day intervals; at 11, 23, and 33 days after initially placing the cells in culture. When the cells were maintained in the presence of (3H)thymidine continuously from Day 7 to Day 17 of culture, 23% of the cells became labeled. If the cells were cultured continuously for 30 days in the presence of (3H)thymidine, from Day 10 to Day 40, 56% of the cells were labeled. Isopycnic gradient analysis indicates that this thymidine incorporation was into DNA that was being replicated semiconservatively; these experiments did not eliminate the possibility, however, that this incorporation was due to amplification of specific genes, such as those coding for the contractile proteins. The activity of DNA polymerase alpha also returns to these cells. These studies demonstrate that the terminally differentiated mammalian ventricular cardiac muscle cell, previously thought to have permanently lost the capacity to replicate DNA during early development, is able to reinitiate semiconservative DNA replication when grown in culture.

  15. Evaluation of zearalenone and alpha-zearalenol toxicity on boar sperm DNA integrity.

    Science.gov (United States)

    Tsakmakidis, Ioannis A; Lymberopoulos, Aristoteles G; Khalifa, Tarek A A; Boscos, Constanten M; Saratsi, Aikaterini; Alexopoulos, Costas

    2008-07-01

    This study aimed at investigating the in vitro effects of zearalenone (zen) and alpha-zearalenol (alpha-zen) on motility and nuclear chromatin integrity (NCI) of boar spermatozoa. Mycotoxins were tested, at levels ranging from 10 to 30 microg ml(-1) of diluted semen. Four boars were used for semen collection (eight replicates per boar, four per mycotoxin). After the addition of zen or alpha-zen, semen samples were incubated for 4 h at 38.5 degrees C, 5% CO(2) and 96% humidified air. Motility and NCI were assessed at 0 and 4 h of incubation. No significant differences were noticed in motility among the experimental groups (P > 0.05) for all tested boars. Chromatin instability was significantly higher (P < 0.05) in spermatozoa of only one boar treated with zen and alpha-zen independently of the dose. In conclusion, under our experimental conditions, zen and alpha-zen did not affect the motility of boar sperm, whereas the effects of these toxins on sperm NCI were individual-dependent. 2008 John Wiley & Sons, Ltd

  16. Extinction of alpha1-antitrypsin expression in cell hybrids is independent of HNF1alpha and HNF4 and involves both promoter and internal DNA sequences.

    OpenAIRE

    Bulla, G A

    1999-01-01

    In rat hepatoma x fibroblast somatic cell hybrids, extinction of rat alpha1-antitrypsin (alpha1AT) gene expression is accompanied by the loss of liver-enriched transcription factors hepatocyte nuclear factor 1 (HNF1alpha) and hepatocyte nuclear factor 4 (HNF4). Previous analysis showed that forced expression of functional HNF1alpha failed to prevent extinction of the rat alpha1AT locus in cell hybrids. Here I show that ectopic co-expression of HNF1alpha plus HNF4 fails to prevent extinction o...

  17. Evaluation of the neutral comet assay for detection of alpha-particle induced DNA-double-strand-breaks; Evaluation des Comet Assays bei neutralem pH zur Detektion von α-Partikel induzierten DNA-Doppelstrangbruechen

    Energy Technology Data Exchange (ETDEWEB)

    Hofbauer, Daniela

    2010-10-20

    Aim of this study was to differentiate DNA-double-strand-breaks from DNA-single-strand-breaks on a single cell level, using the comet assay after α- and γ-irradiation. Americium-241 was used as a alpha-irradiation-source, Caesium-137 was used for γ-irradiation. Because of technical problems with both the neutral and alkaline comet assay after irradiation of gastric cancer cells and human lymphocytes, no definite differentiation of DNA-damage was possible.

  18. Non-linearity issues and multiple ionization satellites in the PIXE portion of spectra from the Mars alpha particle X-ray spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, John L., E-mail: icampbel@uoguelph.ca; Heirwegh, Christopher M.; Ganly, Brianna

    2016-09-15

    Spectra from the laboratory and flight versions of the Curiosity rover’s alpha particle X-ray spectrometer were fitted with an in-house version of GUPIX, revealing departures from linear behavior of the energy-channel relationships in the low X-ray energy region where alpha particle PIXE is the dominant excitation mechanism. The apparent energy shifts for the lightest elements present were attributed in part to multiple ionization satellites and in part to issues within the detector and/or the pulse processing chain. No specific issue was identified, but the second of these options was considered to be the more probable. Approximate corrections were derived and then applied within the GUAPX code which is designed specifically for quantitative evaluation of APXS spectra. The quality of fit was significantly improved. The peak areas of the light elements Na, Mg, Al and Si were changed by only a few percent in most spectra. The changes for elements with higher atomic number were generally smaller, with a few exceptions. Overall, the percentage peak area changes are much smaller than the overall uncertainties in derived concentrations, which are largely attributable to the effects of rock heterogeneity. The magnitude of the satellite contributions suggests the need to incorporate these routinely in accelerator-based PIXE using helium beams.

  19. An unusual satellite DNA from Zamia paucijuga (Cycadales) characterised by two different organisations of the repetitive unit in the plant genome.

    Science.gov (United States)

    Cafasso, Donata; Cozzolino, Salvatore; De Luca, Paolo; Chinali, Gianni

    2003-06-05

    We have cloned and characterised a highly repetitive DNA family that represents about 5% of the nuclear genome of Zamia paucijuga, a member of Cycadales, an ancient and rare group of seed plants. The unit repeat, cloned from EcoRV digested genomic DNA, has a length of about 323 bp, an high GC content (65-70%) and a subtelomeric localisation. The DNA of Z. paucijuga was digested with various restriction enzymes and analysed by Southern blot using the cloned unit repeat as a probe. These experiments indicated that the repeat is present in the plant genome in an unusual organisation, as tandem arrays typical of satellite DNA and as dispersed elements. The characterisation of these unusual "dispersed satellite DNA" elements required a complex series of experiments using combined Southern blot analyses, PCR, cloning and sequencing. Our results indicate that most of these dispersed elements are formed by few units of the GC-rich satellite DNA repeats arranged in tandem and flanked at both sites by one copy of a 0.6 kb AT-rich direct repeat. This unusual satellite DNA organisation of GC-rich repeats is present in many species of genus Zamia, and, thus, likely represent an ancient rearrangement of the satellite DNA repeats that spread in the genome as dispersed elements.

  20. Formation of tamoxifen-DNA adducts via O-sulfonation, not O-acetylation, of alpha-hydroxytamoxifen in rat and human livers.

    Science.gov (United States)

    Kim, Sung Yeon; Laxmi, Y R Santosh; Suzuki, Naomi; Ogura, Kenichiro; Watabe, Tadashi; Duffel, Michael W; Shibutani, Shinya

    2005-11-01

    Tamoxifen (TAM) is used as the standard endocrine therapy for breast cancer patients and as a chemopreventive agent for women at high risk for this disease. Unfortunately, treatment of TAM increases the incidence of endometrial cancer; this may be due to the genotoxic damage induced by TAM metabolites. Formation of TAM-DNA adducts in rat liver correlates with the development of hepatocarcinoma. TAM-DNA adducts are proposed to be formed through O-sulfonation and/or O-acetylation of alpha-hydroxylated TAM and its metabolites. However, the role of O-sulfonation and O-acetylation in the formation of TAM-DNA adducts has not been extensively investigated. Rat or human hydroxysteroid sulfotransferases (HST), acetyltransferases, and liver cytosol were incubated with calf thymus DNA, alpha-OHTAM, and either 3'-phosphoadenosine 5'-phosphosulfate (PAPS) or acetyl coenzyme A (acetyl-CoA) as a cofactor and analyzed for TAM-DNA adduct formation, using 32P postlableling/polyacrylamide gel electrophoresis analysis. TAM-DNA adduct was formed when PAPS, not acetyl-CoA, was used. No TAM-DNA adducts were produced using human N-acetyltransferase I and II. HST antibody inhibited approximately 90% of TAM-DNA adduct formation generated by the cytosol or HST, suggesting that HST is primarily involved in the formation of TAM-DNA adducts. The formation of TAM-DNA adducts with rat liver cytosol and HST was much higher than that of human liver cytosol and HST. Our results indicate that TAM-DNA adducts are formed via O-sulfonation, not O-acetylation, of alpha-hydroxylated TAM and its metabolites.

  1. DNA sequence functionalized with heterogeneous core-satellite nanoassembly for novel energy-transfer-based photoelectrochemical bioanalysis.

    Science.gov (United States)

    Zhu, Yuan-Cheng; Xu, Fei; Zhang, Nan; Zhao, Wei-Wei; Xu, Jing-Juan; Chen, Hong-Yuan

    2017-05-15

    This work reports the use of compositionally heterogeneous asymmetric Ag@Au core-satellite nanoassembly functionalized with DNA sequence as unique signaling nanoprobes for the realization of new energy-transfer-based photoelectrochemical (PEC) immunoassay of prostate- specific antigen (PSA). Specifically, the Ag@Au asymmetric core-satellite nanoassemblies (Ag@Au ACS) were fabricated on a two-dimensional glass substrate by a modified controlled assembly technique, and then functionalized with DNA sequences containing PSA aptamers as signaling nanoprobes. Then, the sandwich complexing between the PSA, its antibodies, and the signaling nanoprobes was performed on a CdS QDs modified indium tin oxide (ITO) electrode. The single stranded DNA can server as a facile mediator that place the Ag@Au ACS in proximity of CdS QDs, stimulating the interparticle exciton-plasmon interactions between Ag@Au ACS and CdS QDs and thus quenching the excitonic states in the latter. Since the damping effect is closely related to the target concentration, a novel energy-transfer-based PEC bioanalysis could be achieved for the sensitive and specific PSA assay. The developed biosensor displayed a linear range from 1.0×10 -11 gmL -1 to 1.0×10 -7 gmL -1 and the detection limit was experimentally found to be of 0.3×10 -13 gmL -1 . This strategy used the Ag@Au ACS-DNA signaling nanoprobes and overcame the deficiency of short operating distance of the energy transfer process for feasible PEC immunoassay. More significantly, it provided a way to couple the plasmonic properties of the Ag NPs and Au NPs in a single PEC bioanalytical system. We expected this work could inspire more interests and further investigations on the advanced engineering of the core-satellite or other judiciously designed nanostructures for new PEC bioanalytical uses with novel properties. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Nitric oxide mediated DNA double strand breaks induced in proliferating bystander cells after {alpha}-particle irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Han Wei [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong (Hong Kong); Chen Shaopeng [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong (Hong Kong); Key Laboratory of Ion Beam Bioengineering, Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Yu, K.N., E-mail: peter.yu@cityu.edu.hk [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong (Hong Kong); Wu Lijun [Key Laboratory of Ion Beam Bioengineering, Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)

    2010-02-03

    Low-dose {alpha}-particle exposures comprise 55% of the environmental dose to the human population and have been shown to induce bystander responses. Previous studies showed that bystander effect could induce stimulated cell growth or genotoxicity, such as excessive DNA double strand breaks (DSBs), micronuclei (MN), mutation and decreased cell viability, in the bystander cell population. In the present study, the stimulated cell growth, detected with flow cytometry (FCM), and the increased MN and DSB, detected with p53 binding protein 1 (53BP1) immunofluorescence, were observed simultaneously in the bystander cell population, which were co-cultured with cells irradiated by low-dose {alpha}-particles (1-10 cGy) in a mixed system. Further studies indicated that nitric oxide (NO) and transforming growth factor {beta}1 (TGF-{beta}1) played very important roles in mediating cell proliferation and inducing MN and DSB in the bystander population through treatments with NO scavenger and TGF-{beta}1 antibody. Low-concentrations of NO, generated by spermidine, were proved to induce cell proliferation, DSB and MN simultaneously. The proliferation or shortened cell cycle in bystander cells gave them insufficient time to repair DSBs. The increased cell division might increase the probability of carcinogenesis in bystander cells since cell proliferation increased the probability of mutation from the mis-repaired or un-repaired DSBs.

  3. Screening and Identifying a Novel ssDNA Aptamer against Alpha-fetoprotein Using CE-SELEX

    Science.gov (United States)

    Dong, Lili; Tan, Qiwen; Ye, Wei; Liu, Dongli; Chen, Haifeng; Hu, Hongwei; Wen, Duo; Liu, Yang; Cao, Ya; Kang, Jingwu; Fan, Jia; Guo, Wei; Wu, Weizhong

    2015-01-01

    Alpha-fetoprotein (AFP) is a liver cancer associated protein and has long been utilized as a serum tumor biomarker of disease progression. AFP is usually detected in HCC patients by an antibody based system. Recently, however, aptamers generated from systematic evolution of ligands by exponential enrichment (SELEX) were reported to have an alternative potential in targeted imaging, diagnosis and therapy. In this study, AFP-bound ssDNA aptamers were screened and identified using capillary electrophoresis (CE) SELEX technology. After cloning, sequencing and motif analysis, we successfully confirmed an aptamer, named AP273, specifically targeting AFP. The aptamer could be used as a probe in AFP immunofluorescence imaging in HepG2, one AFP positive cancer cell line, but not in A549, an AFP negative cancer cell line. More interesting, the aptamer efficiently inhibited the migration and invasion of HCC cells after in vivo transfection. Motif analysis revealed that AP273 had several stable secondary motifs in its structure. Our results indicate that CE-SELEX technology is an efficient method to screen specific protein-bound ssDNA, and AP273 could be used as an agent in AFP-based staining, diagnosis and therapy, although more works are still needed. PMID:26497223

  4. Human nuclear respiratory factor 2 alpha subunit cDNA: isolation, subcloning, sequencing, and in situ hybridization of transcripts in normal and monocularly deprived macaque visual system.

    Science.gov (United States)

    Guo, A; Nie, F; Wong-Riley, M

    2000-02-07

    Nuclear respiratory factor 2 (NRF-2) has been shown to contribute to the transcriptional regulation of a number of subunits of respiratory chain enzymes, including cytochrome c oxidase (CO). Our recent study demonstrated a parallel distribution of the alpha subunit proteins of NRF-2 (NRF-2 alpha) with CO in the monkey striate cortex, and that it can be regulated by neuronal activity. To determine whether this regulation is at the transcriptional level, the present study examined the expression of NRF-2 alpha mRNA in normal and monocularly deprived adult monkeys. A partial NRF-2 alpha cDNA was isolated from a human brain cDNA library. Sequence analysis revealed that it shared 99% identity with the published sequence from human HeLa cells. Riboprobes of NRF-2 alpha was generated and labeled with digoxigenin-11-UTP for in situ hybridization. The expression pattern of NRF-2 alpha mRNA in the normal striate cortex paralleled that of CO activity. It was highly expressed in layers IVC and VI, which contained high levels of CO, and more densely expressed in puffs of layers II and III than in interpuffs. In monkeys monocularly treated with tetrodotoxin for 1 day to 2 weeks, both NRF-2 alpha expression and CO activity were reduced in deprived ocular dominance columns of the visual cortex and in deprived layers of the lateral geniculate nucleus. These data indicate that, in the normal and visually deprived adult monkeys, NRF-2 alpha is regulated by neuronal activity at the transcriptional level.

  5. DNA Protection against Oxidative Damage Using the Hydroalcoholic Extract of Garcinia mangostana and Alpha-Mangostin

    Directory of Open Access Journals (Sweden)

    Ronaldo Carvalho-Silva

    2016-01-01

    Full Text Available Garcinia mangostana, popularly known as “mangosteen fruit,” originates from Southeast Asia and came to Brazil about 80 years ago where it mainly grows in the states of Pará and Bahia. Although mangosteen or its extracts have been used for ages in Asian folk medicine, data on its potential genotoxicity is missing. We, therefore, evaluated genotoxicity/mutagenicity of hydroethanolic mangosteen extract [HEGM, 10 to 640 μg/mL] in established test assays (Comet assay, micronucleus test, and Salmonella/microsome test. In the Comet assay, HEGM-exposed human leukocytes showed no DNA damage. No significant HEGM-induced mutation in TA98 and TA100 strains of Salmonella typhimurium (with or without metabolic activation was observed and HEGM-exposed human lymphocytes had no increase of micronuclei. However, HEGM suggested exposure concentration-dependent antigenotoxic potential in leukocytes and antioxidant potential in the yeast Saccharomyces cerevisiae. HEGM preloading effectively protected against H2O2-induced DNA damage in leukocytes (Comet assay. Preloading of yeast with HEGM for up to 4 h significantly protected the cells from lethality of chronic H2O2-exposure, as expressed in better survival. Absence of genotoxicity and demonstration of an antigenotoxic and antioxidant potential suggest that HEGM or some substances contained in it may hold promise for pharmaceutical or nutraceutical application.

  6. Evidence of DNA double strand breaks formation in Escherichia coli bacteria exposed to alpha particles of different LET assessed by the SOS response

    International Nuclear Information System (INIS)

    Serment-Guerrero, Jorge; Breña-Valle, Matilde; Aguilar-Moreno, Magdalena; Balcázar, Miguel

    2012-01-01

    Ionizing radiation produces a plethora of lesion upon DNA which sometimes is generated among a relatively small region due to clustered energy deposition events, the so called locally multiply damaged sites that could change to DSB. Such clustered damages are more likely to occur in high LET radiation exposures. The effect of alpha particles of different LET was evaluated on the bacterium Escherichia coli either by survival properties or the SOS response activity. Alpha radiation and LET distribution was controlled by means of Nuclear Track Detectors. The results suggest that alpha particles produce two types of lesion: lethal lesions and SOS inducing-mutagenic, a proportion that varies depending on the LET values. The SOS response as a sensitive parameter to assess RBE is mentioned. - Highlights: ► High LET radiation produce locally multiple damaged sites upon DNA. ► Bacteria were exposed to alpha particles of different LET. ► Results suggest that alpha particles produce lethal and SOS inducing/mutagenic. ► The proportion of such lesions varies depending on the LET values.

  7. DNA-Assembled Core-Satellite Upconverting-Metal-Organic Framework Nanoparticle Superstructures for Efficient Photodynamic Therapy.

    Science.gov (United States)

    He, Liangcan; Brasino, Michael; Mao, Chenchen; Cho, Suehyun; Park, Wounjhang; Goodwin, Andrew P; Cha, Jennifer N

    2017-06-01

    DNA-mediated assembly of core-satellite structures composed of Zr(IV)-based porphyrinic metal-organic framework (MOF) and NaYF 4 ,Yb,Er upconverting nanoparticles (UCNPs) for photodynamic therapy (PDT) is reported. MOF NPs generate singlet oxygen ( 1 O 2 ) upon photoirradiation with visible light without the need for additional small molecule, diffusional photosensitizers such as porphyrins. Using DNA as a templating agent, well-defined MOF-UCNP clusters are produced where UCNPs are spatially organized around a centrally located MOF NP. Under NIR irradiation, visible light emitted from the UCNPs is absorbed by the core MOF NP to produce 1 O 2 at significantly greater amounts than what can be produced from simply mixing UCNPs and MOF NPs. The MOF-UCNP core-satellite superstructures also induce strong cell cytotoxicity against cancer cells, which are further enhanced by attaching epidermal growth factor receptor targeting affibodies to the PDT clusters, highlighting their promise as theranostic photodynamic agents. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Ultraviolet B, melanin and mitochondrial DNA: Photo-damage in human epidermal keratinocytes and melanocytes modulated by alpha-melanocyte-stimulating hormone [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Markus Böhm

    2016-05-01

    Full Text Available Alpha-melanocyte-stimulating hormone (alpha-MSH increases melanogenesis and protects from UV-induced DNA damage. However, its effect on mitochondrial DNA (mtDNA damage is unknown. We have addressed this issue in a pilot study using human epidermal keratinocytes and melanocytes incubated with alpha-MSH and irradiated with UVB. Real-time touchdown PCR was used to quantify total and deleted mtDNA. The deletion detected encompassed the common deletion but was more sensitive to detection. There were 4.4 times more mtDNA copies in keratinocytes than in melanocytes. Irradiation alone did not affect copy numbers. Alpha-MSH slightly increased copy numbers in both cell types in the absence of UVB and caused a similar small decrease in copy number with dose in both cell types. Deleted copies were nearly twice as frequent in keratinocytes as in melanocytes. Alpha-MSH reduced the frequency of deleted copies by half in keratinocytes but not in melanocytes. UVB dose dependently led to an increase in the deleted copy number in alpha-MSH-treated melanocytes. UVB irradiation had little effect on deleted copy number in alpha-MSH-treated keratinocytes. In summary, alpha-MSH enhances mtDNA damage in melanocytes presumably by increased melanogenesis, while α-MSH is protective in keratinocytes, the more so in the absence of irradiation.

  9. Lack of satellite DNA species-specific homogenization and relationship to chromosomal rearrangements in monitor lizards (Varanidae, Squamata).

    Science.gov (United States)

    Prakhongcheep, Ornjira; Thapana, Watcharaporn; Suntronpong, Aorarat; Singchat, Worapong; Pattanatanang, Khampee; Phatcharakullawarawat, Rattanin; Muangmai, Narongrit; Peyachoknagul, Surin; Matsubara, Kazumi; Ezaz, Tariq; Srikulnath, Kornsorn

    2017-08-16

    Satellite DNAs (stDNAs) are highly repeated sequences that constitute large portions of any genome. The evolutionary dynamics of stDNA (e.g. copy number, nucleotide sequence, location) can, therefore, provide an insight into genome organization and evolution. We investigated the evolutionary origin of VSAREP stDNA in 17 monitor lizards (seven Asian, five Australian, and five African) at molecular and cytogenetic level. Results revealed that VSAREP is conserved in the genome of Asian and Australian varanids, but not in African varanids, suggesting that these sequences are either differentiated or lost in the African varanids. Phylogenetic and arrangement network analyses revealed the existence of at least four VSAREP subfamilies. The similarity of each sequence unit within the same VSAREP subfamily from different species was higher than those of other VSAREP subfamilies belonging to the same species. Additionally, all VSAREP subfamilies isolated from the three Australian species (Varanus rosenbergi, V. gouldii, and V. acanthurus) were co-localized near the centromeric or pericentromeric regions of the macrochromosomes, except for chromosomes 3 and 4 in each Australian varanid. However, their chromosomal arrangements were different among species. The VSAREP stDNA family lack homogenized species-specific nucleotide positions in varanid lineage. Most VSAREP sequences were shared among varanids within the four VSAREP subfamilies. This suggests that nucleotide substitutions in each varanid species accumulated more slowly than homogenization rates in each VSAREP subfamily, resulting in non-species-specific evolution of stDNA profiles. Moreover, changes in location of VSAREP stDNA in each Australian varanid suggests a correlation with chromosomal rearrangements, leading to karyotypic differences among these species.

  10. The satellite DNA AflaSAT-1 in the A and B chromosomes of the grasshopper Abracris flavolineata.

    Science.gov (United States)

    Milani, Diogo; Ramos, Érica; Loreto, Vilma; Martí, Dardo Andrea; Cardoso, Adauto Lima; de Moraes, Karen Cristiane Martinez; Martins, Cesar; Cabral-de-Mello, Diogo Cavalcanti

    2017-08-29

    Satellite DNAs (satDNAs) are organized in repetitions directly contiguous to one another, forming long arrays and composing a large portion of eukaryote genomes. These sequences evolve according to the concerted evolution model, and homogenization of repeats is observed at the intragenomic level. Satellite DNAs are the primary component of heterochromatin, located primarily in centromeres and telomeres. Moreover, satDNA enrichment in specific chromosomes has been observed, such as in B chromosomes, that can provide clues about composition, origin and evolution of this chromosome. In this study, we isolated and characterized a satDNA in A and B chromosomes of Abracris flavolineata by integrating cytogenetic, molecular and genomics approaches at intra- and inter-population levels, with the aim to understand the evolution of satDNA and composition of B chromosomes. AflaSAT-1 satDNA was shared with other species and in A. flavolineata, was associated with another satDNA, AflaSAT-2. Chromosomal mapping revealed centromeric blocks variable in size in almost all chromosomes (except pair 11) of A complement for both satDNAs, whereas for B chromosome, only a small centromeric signal occurred. In distinct populations, variable number of AflaSAT-1 chromosomal sites correlated with variability in copy number. Instead of such variability, low sequence diversity was observed in A complement, but monomers from B chromosome were more variable, presenting also exclusive mutations. AflaSAT-1 was transcribed in five tissues of adults in distinct life cycle phases. The sharing of AflaSAT-1 with other species is consistent with the library hypothesis and indicates common origin in a common ancestor; however, AflaSAT-1 was highly amplified in the genome of A. flavolineata. At the population level, homogenization of repeats in distinct populations was documented, but dynamic expansion or elimination of repeats was also observed. Concerning the B chromosome, our data provided new

  11. Complementary DNA sequences encoding the multimammate rat MHC class II DQ alpha and beta chains and cross-species sequence comparison in rodents.

    Science.gov (United States)

    de Bellocq, J Goüy; Leirs, H

    2009-09-01

    Sequences of the complete open reading frame (ORF) for rodents major histocompatibility complex (MHC) class II genes are rare. Multimammate rat (Mastomys natalensis) complementary DNA (cDNA) encoding the alpha and beta chains of MHC class II DQ gene was cloned from a rapid amplifications of cDNA Emds (RACE) cDNA library. The ORFs consist of 801 and 771 bp encoding 266 and 256 amino acid residues for DQB and DQA, respectively. The genomic structure of Mana-DQ genes is globally analogous to that described for other rodents except for the insertion of a serine residue in the signal peptide of Mana-DQB, which is unique among known rodents.

  12. Evolutionary dynamics of an at-rich satellite DNA and its contribution to karyotype differentiation in wild diploid Arachis species.

    Science.gov (United States)

    Samoluk, Sergio Sebastián; Robledo, Germán; Bertioli, David; Seijo, José Guillermo

    2017-04-01

    Satellite DNA (satDNA) is a major component of the heterochromatic regions of eukaryote genomes and usually shows a high evolutionary dynamic, even among closely related species. Section Arachis (genus Arachis) is composed of species belonging to six different genomes (A, B, D, F, G and K). The most distinguishing features among these genomes are the amount and distribution of the heterochromatin in the karyotypes. With the objective of gaining insight into the sequence composition and evolutionary dynamics of the heterochromatin fraction in Arachis, we investigated here the sequence diversity, genomic abundance, and chromosomal distribution of a satDNA family (ATR-2) among seven diploid species of section Arachis. All of the isolated sequences were AT-rich and highly conserved at both intraspecific and interspecific levels, without any species-specific polymorphism. Pairwise comparisons of isolated ATR-2 monomers revealed that most of the nucleotide sites were in the first two transitional stages of Strachan's model. However, the abundance of ATR-2 was significantly different among genomes according to the 'library hypothesis'. Fluorescent in situ hybridization revealed that ATR-2 is a main component of the DAPI + centromeric heterochromatin of the A, F, and K genomes. Thus, the evolution of the different heterochromatin patterns observed in Arachis genomes can be explained, at least in part, by the differential representation of ATR-2 among the different species or even among the chromosomes of the same complement. These findings are the first to demonstrate the participation of satDNA sequences in the karyotype diversification of wild diploid Arachis species.

  13. Inhibition of the synthesis of polyamines and DNA in activated lymphocytes by a combination of alpha-methylornithine and methylglyoxal bis(guanylhydrazone).

    Science.gov (United States)

    Morris, D R; Jorstad, C M; Seyfried, C E

    1977-09-01

    The cancer chemotherapeutic drug, methylglyoxal bis(guanylhydrazone), inhibits the synthesis of spermidine and spermine, but allows continued putrescine production in small lymphocytes stimulated by concanavalin A. DNA replication in these cells is inhibited 50% while the synthesis of protein and RNA continues normally. When excess putrescine accumulation in the presence of methylglyoxal bis(guanylhydrazone) was inhibited with alpha-methylornithine, a competitive inhibitor of ornithine decarboxylase, the inhibition of DNA replication was accentuated, with still no effect on protein or RNA synthesis. No inhibition of DNA synthesis by the combination of alpha-methylornithine and methylglyoxal bis(guanylhydrazone) was observed when the inhibitors were added after accumulation of cellular polyamines. In addition, inhibition was reversed by exogenous putrescine, spermidine, or spermine. We conclude that putrescine can fulfill in part the role normally played by spermidine and spermine in DNA replication, and that blocking putrescine synthesis in the presence of methylglyoxal bis(guanylhydrazone) amplifies the polyamine requirement. The implications of this with regard to polyamine synthesis as a site of chemotherapy are discussed.

  14. An ancient satellite DNA has maintained repetitive units of the original structure in most species of the living fossil plant genus Zamia.

    Science.gov (United States)

    Cafasso, Donata; Chinali, Gianni

    2014-03-01

    ZpS1 satellite DNA is specific to the genus Zamia and presents repetitive units organized as long arrays and also as very short arrays dispersed in the genome. We have characterized the structure of the ZpS1 repeats in 12 species representative of the whole geographic distribution of the genus. In most species, the clone most common sequences (cMCS) were so similar that a general most common sequence (GMCS) of the ZpS1 repetitive unit in the genus could be obtained. The few partial variations from the GMCS found in cMCS of some species correspond to variable positions present in most other species, as indicated by the clone consensus sequences (cCS). Two species have an additional species-specific variety of ZpS1 satellite. The dispersed repeats were found to contain more mutations than repeats from long arrays. Our results indicate that all or most species of Zamia inherited the ZpS1 satellite from a common ancestor in Miocene and have maintained repetitive units of the original structure till present. The features of ZpS1 satellite in the genus Zamia are poorly compatible with the model of concerted evolution, but they are perfectly consistent with a new model of satellite evolution based on experimental evidences indicating that a specific amplification-substitution repair mechanism maintains the homogeneity and stability of the repeats structure in each satellite DNA originally present in a species as long as the species exists.

  15. IL-1alpha is a DNA damage sensor linking genotoxic stress signaling to sterile inflammation and innate immunity

    NARCIS (Netherlands)

    Idan, C.; Peleg, R.; Elena, V.; Martin, T.; Cicerone, T.; Mareike, W.; Lydia, B.; Marina, F.; Gerhard, M.; Elisa, F.M.; Dinarello, C.A.; Ron, A.N.; Robert, S.

    2015-01-01

    Environmental signals can be translated into chromatin changes, which alter gene expression. Here we report a novel concept that cells can signal chromatin damage from the nucleus back to the surrounding tissue through the cytokine interleukin-1alpha (IL-1alpha). Thus, in addition to its role as a

  16. Ambivalent incorporation of the fluorescent cytosine analogues tC and tCo by human DNA polymerase alpha and Klenow fragment.

    Science.gov (United States)

    Stengel, Gudrun; Purse, Byron W; Wilhelmsson, L Marcus; Urban, Milan; Kuchta, Robert D

    2009-08-11

    We studied the incorporation of the fluorescent cytidine analogues 1,3-diaza-2-oxophenothiazine (tC) and 1,3-diaza-2-oxophenoxazine (tCo) by human DNA polymerase alpha and Klenow fragment of DNA polymerase I (Escherichia coli). These tricyclic nucleobases possess the regular hydrogen bonding interface of cytosine but are significantly expanded in size toward the major groove. Despite the size alteration, both DNA polymerases insert dtCTP and dtCoTP with remarkable catalytic efficiency. Polymerization opposite guanine is comparable to the insertion of dCTP, while the insertion opposite adenine is only approximately 4-11 times less efficient than the formation of a T-A base pair. Both enzymes readily extend the formed tC(o)-G and tC(o)-A base pairs and can incorporate at least four consecutive nucleotide analogues. Consistent with these results, both DNA polymerases efficiently polymerize dGTP and dATP when tC and tCo are in the template strand. Klenow fragment inserts dGTP with a 4-9-fold higher probability than dATP, while polymerase alpha favors dGTP over dATP by a factor of 30-65. Overall, the properties of tC(o) as a templating base and as an incoming nucleotide are surprisingly symmetrical and may be universal for A and B family DNA polymerases. This finding suggests that the aptitude for ambivalent base pairing is a consequence of the electronic properties of tC(o).

  17. QUANTITATION OF DNA TOPOISOMERASE-II-ALPHA MESSENGER-RIBONUCLEIC-ACID LEVELS IN A SMALL-CELL LUNG-CANCER CELL-LINE AND 2 DRUG-RESISTANT SUBLINES USING A POLYMERASE CHAIN REACTION-AIDED TRANSCRIPT TITRATION ASSAY

    NARCIS (Netherlands)

    WITHOFF, S; SMIT, EF; MEERSMA, GJ; van den Berg, Anke; TIMMERBOSSCHA, H; KOK, K; POSTMUS, PE; MULDER, NH; DEVRIES, EGE; BUYS, CHCM

    BACKGROUND: We have modified a polymerase chain reaction (PCR)-aided transcript titration assay (1) in order to allow quantitation of low amounts of DNA topoisomerase II alpha mRNA in small RNA samples. EXPERIMENTAL DESIGN: The titration assay was used to quantitate the amount of DNA topoisomerase

  18. Genetic Diversity and Population Structure of a Threatened African Tree Species, Milicia excelsa, Using Nuclear Micro satellites DNA Markers

    International Nuclear Information System (INIS)

    Ouinsavi, Ch.; Sokpon, N.; Ouinsavi, Ch.; Khasa, D.P.

    2009-01-01

    To accurately estimate the genetic diversity and population structure for improved conservation planning of Milicia excelsa tree, 212 individuals from twelve population samples covering the species' range in Benin were surveyed at seven specific micro satellite DNA loci. All loci were variable, with the mean number of alleles per locus ranging from 5.86 to 7.69. Considerable genetic variability was detected for all populations at the seven loci (AR=4.60; HE=0.811). Moderate but statistically significant genetic differentiation was found among populations considering both FST (0.112) and RST (0.342). All of the populations showed heterozygosity deficits in test of Hardy-Weinberg Equilibrium and significantly positive FIS values due to inbreeding occurring in the species. Pairwise FST values were positively and significantly correlated with geographical distances (r=0.432; P=.007, Mantel's test) indicating that populations are differentiated by isolation by distance. Bayesian analysis of population structure showed division of the genetic variation into four clusters revealing the existence of heterogeneity in population genetic structure. Altogether, these results indicate that genetic variation in Milicia excelsa is geographically structured. Information gained from this study also emphasized the need for in situ conservation of the relict populations and establishment of gene flow corridors through agroforestry systems for interconnecting these remnant populations.

  19. Improved silica-guanidiniumthiocyanate DNA isolation procedure based on selective binding of bovine alpha-casein to silica particles

    NARCIS (Netherlands)

    Boom, R.; Sol, C.; Beld, M.; Weel, J.; Goudsmit, J.; Wertheim-van Dillen, P.

    1999-01-01

    DNA purified from clinical cerebrospinal fluid and urine specimens by a silica-guanidiniumthiocyanate procedure frequently contained an inhibitor(s) of DNA-processing enzymes which may have been introduced by the purification procedure itself. Inhibition could be relieved by the use of a novel lysis

  20. Advances toward DNA-based identification and phylogeny of North American Armillaria species using elongation factor-1 alpha gene

    Science.gov (United States)

    Amy L. Ross-Davis; John W. Hanna; Mee-Sook Kim; Ned B. Klopfenstein

    2012-01-01

    The translation elongation factor-1 alpha gene was used to examine the phylogenetic relationships among 30 previously characterized isolates representing ten North American Armillaria species: A. solidipes (=A. ostoyae), A. gemina, A. calvescens, A. sinapina, A. mellea, A. gallica, A. nabsnona, North American biological species X, A. cepistipes, and A. tabescens. The...

  1. A Pilot Study of Noninvasive Prenatal Diagnosis of Alpha- and Beta-Thalassemia with Target Capture Sequencing of Cell-Free Fetal DNA in Maternal Blood.

    Science.gov (United States)

    Wang, Wenjuan; Yuan, Yuan; Zheng, Haiqing; Wang, Yaoshen; Zeng, Dan; Yang, Yihua; Yi, Xin; Xia, Yang; Zhu, Chunjiang

    2017-07-01

    Thalassemia is a dangerous hematolytic genetic disease. In south China, ∼24% Chinese carry alpha-thalassemia or beta-thalassemia gene mutations. Given the fact that the invasive sampling procedures can only be performed by professionals in experienced centers, it may increase the risk of miscarriage or infection. Thus, most people are worried about the invasive operation. As such, a noninvasive and accurate prenatal diagnosis is needed for appropriate genetic counseling for families with high risks. Here we sought to develop capture probes and their companion analysis methods for the noninvasive prenatal detection of deletional and nondeletional thalassemia. Two families diagnosed as carriers of either beta-thalassemia gene or Southeast Asian deletional alpha-thalassemia gene mutation were recruited. The maternal plasma and amniotic fluid were collected for prenatal diagnosis. Probes targeting exons of the genes of interest and the highly heterozygous SNPs within the 1Mb flanking region were designed. The target capture sequencing was performed with plasma DNA from the pregnant woman and genomic DNA from the couples and their children. Then the parental haplotype was constructed by the trios-based strategy. The fetal haplotype was deduced from the parental haplotype with a hidden Markov model-based algorithm. The fetal genotypes were successfully deduced in both families noninvasively. The noninvasively constructed haplotypes of both fetuses were identical to the invasive prenatal diagnosis results with an accuracy rate of 100% in the target region. Our study demonstrates that the effective noninvasive prenatal diagnosis of alpha-thalassemia and beta-thalassemia can be achieved with the targeted capture sequencing and the haplotype-assisted analysis method.

  2. The significance of Epstein Barr Virus (EBV & DNA Topoisomerase II alpha (DNA-Topo II alpha immunoreactivity in normal oral mucosa, Oral Epithelial Dysplasia (OED and Oral Squamous Cell Carcinoma (OSCC

    Directory of Open Access Journals (Sweden)

    Osman Mohamed M

    2008-11-01

    Full Text Available Abstract Background Head and neck cancer including oral cancer is considered to develop by accumulated genetic alterations and the major pathway is cancerization from lesions such as intraepithelial dysplasia in oral leukoplakia and erythroplakia. The relationship of proliferation markers with the grading of dysplasia is uncertain. The involvement of EBV in oral carcinogenesis is not fully understood. Aim The present study was designed to investigate the role of EBV and DNA Topoisomerase II∝ (DNA-Topo II∝ during oral carcinogenesis and to examine the prognostic significance of these protein expressions in OSCCs. Methods Using specific antibodies for EBV and DNA-Topo II∝, we examined protein expressions in archival lesion tissues from 16 patients with oral epithelial dysplasia, 22 oral squamous cell carcinoma and 20 normal oral mucosa by immunohistochemistry. Clinical information was obtained through the computerized retrospective database from the tumor registry. Results DNA-Topo II∝ was expressed in all examined specimens. Analysis of Variance ANOVA revealed highly significant difference (P 0.05 in inferior surface of tongue and in hard palatal tissues. Significant differences were observed between OEDs and NSE (P Conclusion EBV and DNA Topo II-αLI expression are possible indicators in oral carcinogenesis and may be valuable diagnostic and prognostic indices in oral carcinoma.

  3. A Viral Satellite DNA Vector (TYLCCNV) for Functional Analysis of miRNAs and siRNAs in Plants.

    Science.gov (United States)

    Ju, Zheng; Cao, Dongyan; Gao, Chao; Zuo, Jinhua; Zhai, Baiqiang; Li, Shan; Zhu, Hongliang; Fu, Daqi; Luo, Yunbo; Zhu, Benzhong

    2017-04-01

    With experimental and bioinformatical methods, numerous small RNAs, including microRNAs (miRNAs) and short interfering RNAs (siRNAs), have been found in plants, and they play vital roles in various biological regulation processes. However, most of these small RNAs remain to be functionally characterized. Until now, only several viral vectors were developed to overexpress miRNAs with limited application in plants. In this study, we report a new small RNA overexpression system via viral satellite DNA associated with Tomato yellow leaf curl China virus (TYLCCNV) vector, which could highly overexpress not only artificial and endogenous miRNAs but also endogenous siRNAs in Nicotiana benthamiana First, we constructed basic TYLCCNV-amiRPDS(319L) vector with widely used AtMIR319a backbone, but the expected photobleaching phenotype was very weak. Second, through comparing the effect of backbones ( AtMIR319a , AtMIR390a , and SlMIR159 ) on specificity and significance of generating small RNAs, the AtMIR390a backbone was optimally selected to construct the small RNA overexpression system. Third, through sRNA-Seq and Degradome-Seq, the small RNAs from AtMIR390a backbone in TYLCCNV-amiRPDS(390) vector were confirmed to highly overexpress amiRPDS and specifically silence targeted PDS gene. Using this system, rapid functional analysis of endogenous miRNAs and siRNAs was carried out, including miR156 and athTAS3a 5'D8(+). Meanwhile, through designing corresponding artificial miRNAs, this system could also significantly silence targeted endogenous genes and show specific phenotypes, including PDS , Su , and PCNA These results demonstrated that this small RNA overexpression system could contribute to investigating not only the function of endogenous small RNAs, but also the functional genes in plants. © 2017 American Society of Plant Biologists. All Rights Reserved.

  4. Exploring the Diversity of Plant DNA Viruses and Their Satellites Using Vector-Enabled Metagenomics on Whiteflies

    Science.gov (United States)

    Ng, Terry Fei Fan; Duffy, Siobain; Polston, Jane E.; Bixby, Elise; Vallad, Gary E.; Breitbart, Mya

    2011-01-01

    Current knowledge of plant virus diversity is biased towards agents of visible and economically important diseases. Less is known about viruses that have not caused major diseases in crops, or viruses from native vegetation, which are a reservoir of biodiversity that can contribute to viral emergence. Discovery of these plant viruses is hindered by the traditional approach of sampling individual symptomatic plants. Since many damaging plant viruses are transmitted by insect vectors, we have developed “vector-enabled metagenomics” (VEM) to investigate the diversity of plant viruses. VEM involves sampling of insect vectors (in this case, whiteflies) from plants, followed by purification of viral particles and metagenomic sequencing. The VEM approach exploits the natural ability of highly mobile adult whiteflies to integrate viruses from many plants over time and space, and leverages the capability of metagenomics for discovering novel viruses. This study utilized VEM to describe the DNA viral community from whiteflies (Bemisia tabaci) collected from two important agricultural regions in Florida, USA. VEM successfully characterized the active and abundant viruses that produce disease symptoms in crops, as well as the less abundant viruses infecting adjacent native vegetation. PCR assays designed from the metagenomic sequences enabled the complete sequencing of four novel begomovirus genome components, as well as the first discovery of plant virus satellites in North America. One of the novel begomoviruses was subsequently identified in symptomatic Chenopodium ambrosiodes from the same field site, validating VEM as an effective method for proactive monitoring of plant viruses without a priori knowledge of the pathogens. This study demonstrates the power of VEM for describing the circulating viral community in a given region, which will enhance our understanding of plant viral diversity, and facilitate emerging plant virus surveillance and management of viral

  5. Hypoxia inducible factor-1 alpha expression is increased in infected positive HPV16 DNA oral squamous cell carcinoma and positively associated with HPV16 E7 oncoprotein

    Directory of Open Access Journals (Sweden)

    Di Fede Olga

    2011-10-01

    Full Text Available Abstract Background There is increasing evidence for the role of High Risk (HR Human PapillomaVirus (HPV in the pathogenesis of Oral Squamous Cell Carcinoma (OSCC. The E6 and E7 oncogenes from HR HPVs are responsible for the deregulation of p53 and pRB proteins involved in cell cycle and apoptotic pathways. In cell lines experiments, the HPV E7 protein seems to be able to enhance Hypoxia Inducible Factor-1 alpha (HIF-1α activity, normally involved in the response to hypoxia and able to enhance angiogenesis. Results We studied tumor specimens from 62 OSCC; a higher prevalence of tumors in TNM stage II and also in pT2 class between OSCC infected positive HPV16 DNA than non-infected ones was observed. HIF-1α positivity was detected throughout the analysed fields, not associated with areas of necrosis and also observed in cells immediately adjacent to blood vessels. A significant increase in mean values of the HIF-1α labeling indexes was observed for pT1-T2, as well for stage I-II, in the infected positive HPV16 DNA tumors than non-infected ones. HIF-1α and HPV16 E7 labeling indexes showed a significantly positive correlation which suggested a positive association between HPV16 E7 and HIF-1α expression. Conclusions In our specimens HIF-1α immunoreactivity hints for an O2-independent regulatory mechanism in infected positive HPV16 DNA tumors, especially for pT1-T2 and stage I-II tumors, suggesting a very early involvement in the development of HPV-induced OSCC. HIF-1α and HPV16 E7 labeling indexes suggest also a positive association between the two proteins in infected positive HPV16 DNA OSCC.

  6. Boom-Bust Turnovers of Megabase-Sized Centromeric DNA in Solanum Species: Rapid Evolution of DNA Sequences Associated with Centromeres

    Czech Academy of Sciences Publication Activity Database

    Zhang, H.Q.; Koblížková, Andrea; Wang, K.; Gong, Z.Y.; Oliveira, L.; Torres, G.A.; Wu, Y.; Zhang, W.; Novák, Petr; Buell, C.R.; Macas, Jiří; Jiang, J.

    2014-01-01

    Roč. 26, č. 4 (2014), s. 1436-1447 ISSN 1040-4651 Institutional support: RVO:60077344 Keywords : Alpha-satellite DNA * repetitive sequences * rice centromeres Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 9.338, year: 2014

  7. Protective immunity against acute toxoplasmosis in BALB/c mice induced by a DNA vaccine encoding Toxoplasma gondii elongation factor 1-alpha.

    Science.gov (United States)

    Wang, Shuai; Wang, YuJian; Sun, XiaoNi; Zhang, ZhenChao; Liu, TingQi; Gadahi, Javaid Ali; Hassan, Ibrahim Adam; Xu, LiXin; Yan, RuoFeng; Song, XiaoKai; Li, XiangRui

    2015-10-24

    Toxoplasma gondii can infect almost all warm-blood animals including human beings. The high incidence and severe damage that can be caused by T. gondii infection clearly indicates the need for the development of a vaccine. T. gondii elongation factor 1-alpha (TgEF-1α) plays an important role in pathogenesis and host cell invasion for this parasite. The aim of this study was to evaluate the immune protective efficacy of a DNA vaccine encoding TgEF-1α gene against acute T. gondii infection in mice. A DNA vaccine (pVAX-EF-1α) encoding T. gondii EF-1a (TgEF-1α) gene was constructed and its immune response and protective efficacy against lethal challenge in BALB/c mice were evaluated. Mice inoculated with the pVAX-EF-1α vaccine had a high level of specific anti-T. gondii antibodies and produced high levels of IFN-gamma, interleukin (IL)-4, and IL-17. The expression levels of MHC-I and MHC-II molecules as well as the percentages of both CD4(+) and CD8(+) T cells in mice vaccinated with pVAX-EF-1α were significantly increased (p control groups (blank control, PBS, and pVAXI). Immunization with pVAX-EF-1α significantly (p control groups which died within 8 days. DNA vaccination with pVAX-EF-1α triggered strong humoral and cellular responses and induced effective protection in mice against acute T. gondii infection, indicating that TgEF-1α is a promising vaccine candidate against acute toxoplasmosis.

  8. Molecular cloning and characterization of satellite DNA sequences from constitutive heterochromatin of the habu snake (Protobothrops flavoviridis, Viperidae) and the Burmese python (Python bivittatus, Pythonidae).

    Science.gov (United States)

    Matsubara, Kazumi; Uno, Yoshinobu; Srikulnath, Kornsorn; Seki, Risako; Nishida, Chizuko; Matsuda, Yoichi

    2015-12-01

    Highly repetitive DNA sequences of the centromeric heterochromatin provide valuable molecular cytogenetic markers for the investigation of genomic compartmentalization in the macrochromosomes and microchromosomes of sauropsids. Here, the relationship between centromeric heterochromatin and karyotype evolution was examined using cloned repetitive DNA sequences from two snake species, the habu snake (Protobothrops flavoviridis, Crotalinae, Viperidae) and Burmese python (Python bivittatus, Pythonidae). Three satellite DNA (stDNA) families were isolated from the heterochromatin of these snakes: 168-bp PFL-MspI from P. flavoviridis and 196-bp PBI-DdeI and 174-bp PBI-MspI from P. bivittatus. The PFL-MspI and PBI-DdeI sequences were localized to the centromeric regions of most chromosomes in the respective species, suggesting that the two sequences were the major components of the centromeric heterochromatin in these organisms. The PBI-MspI sequence was localized to the pericentromeric region of four chromosome pairs. The PFL-MspI and the PBI-DdeI sequences were conserved only in the genome of closely related species, Gloydius blomhoffii (Crotalinae) and Python molurus, respectively, although their locations on the chromosomes were slightly different. In contrast, the PBI-MspI sequence was also in the genomes of P. molurus and Boa constrictor (Boidae), and additionally localized to the centromeric regions of eight chromosome pairs in B. constrictor, suggesting that this sequence originated in the genome of a common ancestor of Pythonidae and Boidae, approximately 86 million years ago. The three stDNA sequences showed no genomic compartmentalization between the macrochromosomes and microchromosomes, suggesting that homogenization of the centromeric and/or pericentromeric stDNA sequences occurred in the macrochromosomes and microchromosomes of these snakes.

  9. Alpha taxonomy of the genus Kessleria Nowicki, 1864, revisited in light of DNA-barcoding (Lepidoptera, Yponomeutidae

    Directory of Open Access Journals (Sweden)

    Peter Huemer

    2015-05-01

    Full Text Available The taxonomy of Kessleria, a highly specialized montane genus of Yponomeutidae with larval host restriction to Saxifragaceae and Celastraceae (Saxifraga spp. – subgenus Kessleria; Saxifraga spp. and Parnassia spp. – subgenus Hofmannia, is revised based on external morphology, genitalia and DNA barcodes. An integrative taxonomic approach supports the existence of 29 species in Europe (the two known species from Asia and North America are not treated herein. A full 658 bp fragment of COI was obtained from 135 specimens representing 24 species, a further seven sequences are >560 bp. Five new species are described: Kessleria cottiensis sp. n. (Prov. Torino, Italy; Dep. Hautes Alpes, France, Kessleria dimorpha sp. n. (Dep. Alpes-de-Haute-Provence, France, Kessleria alpmaritimae sp. n. (Dep. Alpes-Maritimes, France, Kessleria apenninica sp. n. (Prov. Rieti, Prov. L´Aquila, Italy, and Kessleria orobiae sp. n. (Prov. Bergamo, Italy.

  10. Phylogenetic footprinting of non-coding RNA: hammerhead ribozyme sequences in a satellite DNA family of Dolichopoda cave crickets (Orthoptera, Rhaphidophoridae

    Directory of Open Access Journals (Sweden)

    Venanzetti Federica

    2010-01-01

    Full Text Available Abstract Background The great variety in sequence, length, complexity, and abundance of satellite DNA has made it difficult to ascribe any function to this genome component. Recent studies have shown that satellite DNA can be transcribed and be involved in regulation of chromatin structure and gene expression. Some satellite DNAs, such as the pDo500 sequence family in Dolichopoda cave crickets, have a catalytic hammerhead (HH ribozyme structure and activity embedded within each repeat. Results We assessed the phylogenetic footprints of the HH ribozyme within the pDo500 sequences from 38 different populations representing 12 species of Dolichopoda. The HH region was significantly more conserved than the non-hammerhead (NHH region of the pDo500 repeat. In addition, stems were more conserved than loops. In stems, several compensatory mutations were detected that maintain base pairing. The core region of the HH ribozyme was affected by very few nucleotide substitutions and the cleavage position was altered only once among 198 sequences. RNA folding of the HH sequences revealed that a potentially active HH ribozyme can be found in most of the Dolichopoda populations and species. Conclusions The phylogenetic footprints suggest that the HH region of the pDo500 sequence family is selected for function in Dolichopoda cave crickets. However, the functional role of HH ribozymes in eukaryotic organisms is unclear. The possible functions have been related to trans cleavage of an RNA target by a ribonucleoprotein and regulation of gene expression. Whether the HH ribozyme in Dolichopoda is involved in similar functions remains to be investigated. Future studies need to demonstrate how the observed nucleotide changes and evolutionary constraint have affected the catalytic efficiency of the hammerhead.

  11. Evaluation through comet assay of DNA damage induced in human lymphocytes by alpha particles. Comparison with protons and Co-60 gamma rays

    International Nuclear Information System (INIS)

    Di Giorgio, M.; Kreiner, A. J.; Schuff, J. A.; Vallerga, M. B.; Taja, M. R.; Lopez, F. O.; Alvarez, D. E.; Saint Martin, G.; Burton, A.; Debray, M. E.; Kesque, J. M.; Somacal, H.; Stoliar, P.; Valda, A.; Davidson, J.; Davidson, M.; Ozafran, M. J.; Vazquez, M. E.

    2004-01-01

    Several techniques with different sensitivity to single-strand breaks and/or double strand breaks were applied to detect DNA breaks generated by high LET particles. Tests that assess DNA damage in single cells might be the appropriate tool to estimate damage induced by particles, facilitating the assessment of heterogeneity of damage in a cell population. The microgel electrophoresis (comet) assay is a sensitive method for measuring DNA damage in single cells. The objective of this work was to evaluate the proficiency of comet assay to assess the effect of high LET radiation on peripheral blood lymphocytes, compared to protons and Co-60 gamma rays. Materials and methods: Irradiations of blood samples were performed at TANDAR laboratory (Argentina). Thin samples of human peripheral blood were irradiated with different doses (0-2.5 Gy) of 20.2 MeV helium-4 particles in the track segment mode, at nearly constant LET. Data obtained were compared with the effect induced by a MeV protons and Co-60 gamma rays. Alkaline comet assay was applied. Comets were quantified by the Olive tail moment. Distribution of the helium-4 particle and protons were evaluated considering Poisson distribution in lymphocyte nuclei. The mean dose per nucleus per particle result 0.053 Gy for protons and 0.178 Gy for helium-4 particles. When cells are exposed to a dose of 0.1 Gy, the hit probability model predicts that 43% of the nuclei should have experienced and alpha traversal while with protons, 85% of the nuclei should be hit. The experimental results show a biphasic response for helium-4 particles (0.1 Gy), indicating the existence of two subpopulations: unhit and hit. Distributions of tail moment as a function of fluence and experimental dose for comets induced by helium-4 particles, protons and Co-60 gamma rays were analyzed. With helium-4 irradiations, lymphocyte nuclei show an Olive tail moment distribution flattened to higher tail moments a dose increase. However, for irradiations with

  12. Triplication of alpha-globin genes is responsible for unusual alpha 113Leu/alpha 113His-globin chain ratios in sheep.

    Science.gov (United States)

    Vestri, R; Masina, P; Rando, A; Testa, A; Di Gregorio, P

    1987-10-01

    By investigations at the DNA and protein level, it has been shown that in sheep a previously detected, presumed quantitative allele of the II alpha 113His gene, displaying a reduced efficiency (called the II alpha 113His decreases gene), is carried by a chromosome bearing three alpha-globin loci. In particular, five sheep having an alpha 113Leu/alpha 113His-chain ratio of about 13:1 (13:1 phenotype) possessed the -I alpha 113Leu-II alpha 113Leu-/-I alpha 113Leu-II alpha 113Leu-III alpha 113His decreases genotype. One sheep showing a alpha 113Leu/alpha 113His-chain ratio of about 3:1 (3:1 phenotype) had the -I alpha 113Leu-II alpha 113His-/-I alpha 113Leu-II alpha 113Leu-III alpha 113His decreases genotype, while one sheep having a chain ratio of about 6:1 (6:1 phenotype) carried the -I alpha 113Leu-II alpha 113Leu-II alpha 113His decreases-/-I alpha 113Leu-II alpha 113Leu-III alpha 113His decreases genotype. Nineteen sheep, displaying the common phenotypes, all possessed the alpha alpha/alpha alpha gene arrangement. Furthermore, the possible location of the gene with reduced efficiency and the expression of the three genes in the triple alpha-globin loci chromosome are discussed.

  13. Human circulating ribosomal DNA content significantly increases while circulating satellite III (1q12) content decreases under chronic occupational exposure to low-dose gamma- neutron and tritium beta-radiation.

    Science.gov (United States)

    Korzeneva, Inna B; Kostuyk, Svetlana V; Ershova, Elizaveta S; Skorodumova, Elena N; Zhuravleva, Veronika F; Pankratova, Galina V; Volkova, Irina V; Stepanova, Elena V; Porokhovnik, Lev N; Veiko, Natalia N

    A single exposure to ionizing radiation (IR) results in an elevated cell-free DNA (cfDNA) content in the blood plasma. In this case, the cfDNA concentration can be a marker of the cell death in the organism. However, a chronic exposure to a low-dose IR enhances both the endonuclease activity and titer of antibodies to DNA in blood plasma, resulting in a decrease of the total concentration of circulating cfDNA in exposed people. In this case, the total cfDNA concentration should not be considered as a marker of the cell death in an exposed body. We assumed that a pool of the cfDNA circulating in the exposed people contains DNA fragments, which are resistant to a double-strand break formation in the environment of the elevated plasma endonuclease activity, and can be accumulated in the blood plasma. In order to test this hypothesis, we studied the content of GC-rich sequences (69%GC) of the transcribed region of human ribosomal repeat (rDNA), as well as the content of AT-rich repeat (63%AT) of satellite III (1q12) in the cfDNA samples obtained from 285 individuals. We have found that a chronic exposure to gamma-neutron radiation (N=88) and tritium β-radiation (N=88) evokes an increase of the rDNA content (RrDNA index) and a decrease of the satellite III content (RsatIII index) in the circulating cfDNA as compared with the cfDNA of non-exposed people (N=109). Such index that simultaneously displays both the increase of rDNA content and decrease of satellite III content in the cfDNA (RrDNA/RsatIII) can be recommended as a marker of chronic processes in the body that involve the elevated cell death rate and/or increased blood plasma endonuclease activity. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Virophages or satellite viruses?

    Science.gov (United States)

    Krupovic, Mart; Cvirkaite-Krupovic, Virginija

    2011-11-01

    It has been argued that the smaller viruses associated with giant DNA viruses are a new biological entity. However, Mart Krupovic and Virginija Cvirkaite-Krupovic argue here that these smaller viruses should be classified with the satellite viruses.

  15. DNA double strand breaks as predictor of efficacy of the alpha-particle emitter Ac-225 and the electron emitter Lu-177 for somatostatin receptor targeted radiotherapy.

    Directory of Open Access Journals (Sweden)

    Franziska Graf

    Full Text Available RATIONALE: Key biologic effects of the alpha-particle emitter Actinium-225 in comparison to the beta-particle emitter Lutetium-177 labeled somatostatin-analogue DOTATOC in vitro and in vivo were studied to evaluate the significance of γH2AX-foci formation. METHODS: To determine the relative biological effectiveness (RBE between the two isotopes (as - biological consequence of different ionisation-densities along a particle-track, somatostatin expressing AR42J cells were incubated with Ac-225-DOTATOC and Lu-177-DOTATOC up to 48 h and viability was analyzed using the MTT assay. DNA double strand breaks (DSB were quantified by immunofluorescence staining of γH2AX-foci. Cell cycle was analyzed by flow cytometry. In vivo uptake of both radiolabeled somatostatin-analogues into subcutaneously growing AR42J tumors and the number of cells displaying γH2AX-foci were measured. Therapeutic efficacy was assayed by monitoring tumor growth after treatment with activities estimated from in vitro cytotoxicity. RESULTS: Ac-225-DOTATOC resulted in ED50 values of 14 kBq/ml after 48 h, whereas Lu-177-DOTATOC displayed ED50 values of 10 MBq/ml. The number of DSB grew with increasing concentration of Ac-225-DOTATOC and similarly with Lu-177-DOTATOC when applying a factor of 700-fold higher activity compared to Ac-225. Already 24 h after incubation with 2.5-10 kBq/ml, Ac-225-DOTATOC cell-cycle studies showed up to a 60% increase in the percentage of tumor cells in G2/M phase. After 72 h an apoptotic subG1 peak was also detectable. Tumor uptake for both radio peptides at 48 h was identical (7.5%ID/g, though the overall number of cells with γH2AX-foci was higher in tumors treated with 48 kBq Ac-225-DOTATOC compared to tumors treated with 30 MBq Lu-177-DOTATOC (35% vs. 21%. Tumors with a volume of 0.34 ml reached delayed exponential tumor growth after 25 days (44 kBq Ac-225-DOTATOC and after 21 days (34 MBq Lu-177-DOTATOC. CONCLUSION: γH2AX-foci formation, triggered

  16. Diverse retrotransposon families and an AT-rich satellite DNA revealed in giant genomes of Fritillaria lilies

    Czech Academy of Sciences Publication Activity Database

    Ambrožová, K.; Mandáková, T.; Bureš, P.; Neumann, Pavel; Leitch, I. J.; Koblížková, Andrea; Macas, Jiří; Lysák, M.

    2011-01-01

    Roč. 107, č. 2 (2011), s. 255-268 ISSN 0305-7364 R&D Projects: GA ČR GA521/07/0284; GA MŠk(CZ) LC06004 Institutional research plan: CEZ:AV0Z50510513 Keywords : Fritillaria * Liliaceae * repetitive DNA Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.030, year: 2011

  17. Satellite DNA and Transposable Elements in Seabuckthorn (Hippophae rhamnoides), a Dioecious Plant with Small Y and Large X Chromosomes

    Czech Academy of Sciences Publication Activity Database

    Puterová, J.; Razumova, O.; Martínek, T.; Alexandrov, O.; Divashuk, M.; Kubát, Z.; Hobza, Roman; Karlov, G.; Kejnovský, E.

    2017-01-01

    Roč. 9, č. 1 (2017), s. 197-212 ISSN 1759-6653 R&D Projects: GA ČR GBP501/12/G090 Institutional support: RVO:61389030 Keywords : sex-chromosomes * repetitive sequences * silene-latifolia * molecular cytogenetics * arabidopsis-thaliana * genome size * evolution * organization * alignment * data base * sex chromosomes * genome composition * chromosomal localization * repetitive DNA Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Plant sciences, botany Impact factor: 3.979, year: 2016

  18. Uncovering the evolutionary history of neo-XY sex chromosomes in the grasshopper Ronderosia bergii (Orthoptera, Melanoplinae) through satellite DNA analysis.

    Science.gov (United States)

    Palacios-Gimenez, Octavio M; Milani, Diogo; Lemos, Bernardo; Castillo, Elio R; Martí, Dardo A; Ramos, Erica; Martins, Cesar; Cabral-de-Mello, Diogo C

    2018-01-08

    Neo-sex chromosome systems arose independently multiple times in evolution, presenting the remarkable characteristic of repetitive DNAs accumulation. Among grasshoppers, occurrence of neo-XY was repeatedly noticed in Melanoplinae. Here we analyzed the most abundant tandem repeats of R. bergii (2n = 22, neo-XY♂) using deep Illumina sequencing and graph-based clustering in order to address the neo-sex chromosomes evolution. The analyses revealed ten families of satDNAs comprising about ~1% of the male genome, which occupied mainly C-positive regions of autosomes. Regarding the sex chromosomes, satDNAs were recorded within centromeric or interstitial regions of the neo-X chromosome and four satDNAs occurred in the neo-Y, two of them being exclusive (Rber248 and Rber299). Using a combination of probes we uncovered five well-defined cytological variants for neo-Y, originated by multiple paracentric inversions and satDNA amplification, besides fragmented neo-Y. These neo-Y variants were distinct in frequency between embryos and adult males. The genomic data together with cytogenetic mapping enabled us to better understand the neo-sex chromosome dynamics in grasshoppers, reinforcing differentiation of neo-X and neo-Y and revealing the occurrence of multiple additional rearrangements involved in the neo-Y evolution of R. bergii. We discussed the possible causes that led to differences in frequency for the neo-Y variants between embryos and adults. Finally we hypothesize about the role of DNA satellites in R. bergii as well as putative historical events involved in the evolution of the R. bergii neo-XY.

  19. Analytical performance of a multiplex Real-Time PCR assay using TaqMan probes for quantification of Trypanosoma cruzi satellite DNA in blood samples.

    Directory of Open Access Journals (Sweden)

    Tomas Duffy

    Full Text Available BACKGROUND: The analytical validation of sensitive, accurate and standardized Real-Time PCR methods for Trypanosoma cruzi quantification is crucial to provide a reliable laboratory tool for diagnosis of recent infections as well as for monitoring treatment efficacy. METHODS/PRINCIPAL FINDINGS: We have standardized and validated a multiplex Real-Time quantitative PCR assay (qPCR based on TaqMan technology, aiming to quantify T. cruzi satellite DNA as well as an internal amplification control (IAC in a single-tube reaction. IAC amplification allows rule out false negative PCR results due to inhibitory substances or loss of DNA during sample processing. The assay has a limit of detection (LOD of 0.70 parasite equivalents/mL and a limit of quantification (LOQ of 1.53 parasite equivalents/mL starting from non-boiled Guanidine EDTA blood spiked with T. cruzi CL-Brener stock. The method was evaluated with blood samples collected from Chagas disease patients experiencing different clinical stages and epidemiological scenarios: 1- Sixteen Venezuelan patients from an outbreak of oral transmission, 2- Sixty three Bolivian patients suffering chronic Chagas disease, 3- Thirty four Argentinean cases with chronic Chagas disease, 4- Twenty seven newborns to seropositive mothers, 5- A seronegative receptor who got infected after transplantation with a cadaveric kidney explanted from an infected subject. CONCLUSIONS/SIGNIFICANCE: The performing parameters of this assay encourage its application to early assessment of T. cruzi infection in cases in which serological methods are not informative, such as recent infections by oral contamination or congenital transmission or after transplantation with organs from seropositive donors, as well as for monitoring Chagas disease patients under etiological treatment.

  20. DNA sequence polymorphisms within the bovine guanine nucleotide-binding protein Gs subunit alpha (Gsα-encoding (GNAS genomic imprinting domain are associated with performance traits

    Directory of Open Access Journals (Sweden)

    Mullen Michael P

    2011-01-01

    Full Text Available Abstract Background Genes which are epigenetically regulated via genomic imprinting can be potential targets for artificial selection during animal breeding. Indeed, imprinted loci have been shown to underlie some important quantitative traits in domestic mammals, most notably muscle mass and fat deposition. In this candidate gene study, we have identified novel associations between six validated single nucleotide polymorphisms (SNPs spanning a 97.6 kb region within the bovine guanine nucleotide-binding protein Gs subunit alpha gene (GNAS domain on bovine chromosome 13 and genetic merit for a range of performance traits in 848 progeny-tested Holstein-Friesian sires. The mammalian GNAS domain consists of a number of reciprocally-imprinted, alternatively-spliced genes which can play a major role in growth, development and disease in mice and humans. Based on the current annotation of the bovine GNAS domain, four of the SNPs analysed (rs43101491, rs43101493, rs43101485 and rs43101486 were located upstream of the GNAS gene, while one SNP (rs41694646 was located in the second intron of the GNAS gene. The final SNP (rs41694656 was located in the first exon of transcripts encoding the putative bovine neuroendocrine-specific protein NESP55, resulting in an aspartic acid-to-asparagine amino acid substitution at amino acid position 192. Results SNP genotype-phenotype association analyses indicate that the single intronic GNAS SNP (rs41694646 is associated (P ≤ 0.05 with a range of performance traits including milk yield, milk protein yield, the content of fat and protein in milk, culled cow carcass weight and progeny carcass conformation, measures of animal body size, direct calving difficulty (i.e. difficulty in calving due to the size of the calf and gestation length. Association (P ≤ 0.01 with direct calving difficulty (i.e. due to calf size and maternal calving difficulty (i.e. due to the maternal pelvic width size was also observed at the rs

  1. DNA sequence polymorphisms within the bovine guanine nucleotide-binding protein Gs subunit alpha (Gsα)-encoding (GNAS) genomic imprinting domain are associated with performance traits

    Science.gov (United States)

    2011-01-01

    Background Genes which are epigenetically regulated via genomic imprinting can be potential targets for artificial selection during animal breeding. Indeed, imprinted loci have been shown to underlie some important quantitative traits in domestic mammals, most notably muscle mass and fat deposition. In this candidate gene study, we have identified novel associations between six validated single nucleotide polymorphisms (SNPs) spanning a 97.6 kb region within the bovine guanine nucleotide-binding protein Gs subunit alpha gene (GNAS) domain on bovine chromosome 13 and genetic merit for a range of performance traits in 848 progeny-tested Holstein-Friesian sires. The mammalian GNAS domain consists of a number of reciprocally-imprinted, alternatively-spliced genes which can play a major role in growth, development and disease in mice and humans. Based on the current annotation of the bovine GNAS domain, four of the SNPs analysed (rs43101491, rs43101493, rs43101485 and rs43101486) were located upstream of the GNAS gene, while one SNP (rs41694646) was located in the second intron of the GNAS gene. The final SNP (rs41694656) was located in the first exon of transcripts encoding the putative bovine neuroendocrine-specific protein NESP55, resulting in an aspartic acid-to-asparagine amino acid substitution at amino acid position 192. Results SNP genotype-phenotype association analyses indicate that the single intronic GNAS SNP (rs41694646) is associated (P ≤ 0.05) with a range of performance traits including milk yield, milk protein yield, the content of fat and protein in milk, culled cow carcass weight and progeny carcass conformation, measures of animal body size, direct calving difficulty (i.e. difficulty in calving due to the size of the calf) and gestation length. Association (P ≤ 0.01) with direct calving difficulty (i.e. due to calf size) and maternal calving difficulty (i.e. due to the maternal pelvic width size) was also observed at the rs43101491 SNP. Following

  2. The All-Alpha Domains of Coupling Proteins from the Agrobacterium tumefaciens VirB/VirD4 and Enterococcus faecalis pCF10-Encoded Type IV Secretion Systems Confer Specificity to Binding of Cognate DNA Substrates.

    Science.gov (United States)

    Whitaker, Neal; Chen, Yuqing; Jakubowski, Simon J; Sarkar, Mayukh K; Li, Feng; Christie, Peter J

    2015-07-01

    Bacterial type IV coupling proteins (T4CPs) bind and mediate the delivery of DNA substrates through associated type IV secretion systems (T4SSs). T4CPs consist of a transmembrane domain, a conserved nucleotide-binding domain (NBD), and a sequence-variable helical bundle called the all-alpha domain (AAD). In the T4CP structural prototype, plasmid R388-encoded TrwB, the NBD assembles as a homohexamer resembling RecA and DNA ring helicases, and the AAD, which sits at the channel entrance of the homohexamer, is structurally similar to N-terminal domain 1 of recombinase XerD. Here, we defined the contributions of AADs from the Agrobacterium tumefaciens VirD4 and Enterococcus faecalis PcfC T4CPs to DNA substrate binding. AAD deletions abolished DNA transfer, whereas production of the AAD in otherwise wild-type donor strains diminished the transfer of cognate but not heterologous substrates. Reciprocal swaps of AADs between PcfC and VirD4 abolished the transfer of cognate DNA substrates, although strikingly, the VirD4-AADPcfC chimera (VirD4 with the PcfC AAD) supported the transfer of a mobilizable plasmid. Purified AADs from both T4CPs bound DNA substrates without sequence preference but specifically bound cognate processing proteins required for cleavage at origin-of-transfer sequences. The soluble domains of VirD4 and PcfC lacking their AADs neither exerted negative dominance in vivo nor specifically bound cognate processing proteins in vitro. Our findings support a model in which the T4CP AADs contribute to DNA substrate selection through binding of associated processing proteins. Furthermore, MOBQ plasmids have evolved a docking mechanism that bypasses the AAD substrate discrimination checkpoint, which might account for their capacity to promiscuously transfer through many different T4SSs. For conjugative transfer of mobile DNA elements, members of the VirD4/TraG/TrwB receptor superfamily bind cognate DNA substrates through mechanisms that are largely undefined. Here

  3. Effect of N-Acetyl-L-Cysteine and alpha-Tocopherol Administration on Endogenous Antioxidant Protection of Liver DNA and RNA and plasma Lipid Profile in gamma-Irradiated Rats

    International Nuclear Information System (INIS)

    Abou-Safi, H.M.; Ashry, O.M.; Kafafy, Y.A.

    2005-01-01

    The present study wasundertaken to evaluate the combined antioxidative capacity of N-acetyl-L-cysteine (NAC, 120 mg/100g b. wt) and alpha tocopherol (10mg/100g b. wt.) injected intra peritoneally one h before irradiation of male rats. Whole body gamma irradiation (2Gy) induced significant elevation in liver DNA and significant drop in liver protein content, while liver RNA showed no significant changes. Triglycerides and LDL-cholesterol elevated significantly after irradiation, whereas no significant changes were observed in total cholesterol, while HDL-cholesterol significantly decreased. Blood and liver glutathione were significantly decreased, whereas plasma MDA was significantly increased. NAC and alpha-tocopherol injection elevated RNA and blood glutathione levels compared to control and depressed total cholesterol and LDL-cholesterol levels, as well as MDA in the liver. The combined treatment prior to irradiation decreased DNA, elevated RNA and normalized liver protein content. Triglycerides were decreased after 1 and 3 days and total cholesterol dropped significantly on the 1 st and 7 th days. LDL was ameliorated while HDL was significantly declined then elevated after 7 days. Blood glutathione was normalized while liver glutathione was significantly elevated and MDA was reduced both in liver and plasma. This combined treatment has proven to be recommended to enhance the natural defenses against deleterious effects of oxidative stress

  4. Coordination of the Ser2056 and Thr2609 Clusters of DNA-PKcs in Regulating Gamma Rays and Extremely Low Fluencies of Alpha-Particle Irradiation to G0/G1 Phase Cells.

    Science.gov (United States)

    Nagasawa, Hatsumi; Lin, Yu-Fen; Kato, Takamitsu A; Brogan, John R; Shih, Hung-Ying; Kurimasa, Akihiro; Bedford, Joel S; Chen, Benjamin P C; Little, John B

    2017-02-01

    The catalytic subunit of DNA dependent protein kinase (DNA-PKcs) and its kinase activity are critical for mediation of non-homologous end-joining (NHEJ) of DNA double-strand breaks (DSB) in mammalian cells after gamma-ray irradiation. Additionally, DNA-PKcs phosphorylations at the T2609 cluster and the S2056 cluster also affect DSB repair and cellular sensitivity to gamma radiation. Previously we reported that phosphorylations within these two regions affect not only NHEJ but also homologous recombination repair (HRR) dependent DSB repair. In this study, we further examine phenotypic effects on cells bearing various combinations of mutations within either or both regions. Effects studied included cell killing as well as chromosomal aberration induction after 0.5-8 Gy gamma-ray irradiation delivered to synchronized cells during the G 0 /G 1 phase of the cell cycle. Blocking phosphorylation within the T2609 cluster was most critical regarding sensitization and depended on the number of available phosphorylation sites. It was also especially interesting that only one substitution of alanine in each of the two clusters separately abolished the restoration of wild-type sensitivity by DNA-PKcs. Similar patterns were seen for induction of chromosomal aberrations, reflecting their connection to cell killing. To study possible change in coordination between HRR and NHEJ directed repair in these DNA-PKcs mutant cell lines, we compared the induction of sister chromatid exchanges (SCEs) by very low fluencies of alpha particles with mutant cells defective in the HRR pathway that is required for induction of SCEs. Levels of true SCEs induced by very low fluence of alpha-particle irradiation normally seen in wild-type cells were only slightly decreased in the S2056 cluster mutants, but were completely abolished in the T2609 cluster mutants and were indistinguishable from levels seen in HRR deficient cells. Again, a single substitution in the S2056 together with a single

  5. ALPHA-BETA SEPARATION PORTFOLIO STRATEGIES FOR ISLAMIC FINANCE

    OpenAIRE

    Valentyn Khokhlov

    2016-01-01

    The purpose of this paper is to develop a mathematical alpha-beta separation model that can be used to create a core-satellite portfolio management strategy that complies with the principles of Islamic finance. Methodology. Core-satellite portfolio construction methodology is used to implement the alpha-beta separation approach, where the core part of the portfolio is managed using the tracking error minimization strategy, and the satellite part of the portfolio is managed using the mean-vari...

  6. Differential radiosensitivity phenotypes of DNA-PKcs mutations affecting NHEJ and HRR systems following irradiation with gamma-rays or very low fluences of alpha particles.

    Science.gov (United States)

    Lin, Yu-Fen; Nagasawa, Hatsumi; Little, John B; Kato, Takamitsu A; Shih, Hung-Ying; Xie, Xian-Jin; Wilson, Paul F; Brogan, John R; Kurimasa, Akihiro; Chen, David J; Bedford, Joel S; Chen, Benjamin P C

    2014-01-01

    We have examined cell-cycle dependence of chromosomal aberration induction and cell killing after high or low dose-rate γ irradiation in cells bearing DNA-PKcs mutations in the S2056 cluster, the T2609 cluster, or the kinase domain. We also compared sister chromatid exchanges (SCE) production by very low fluences of α-particles in DNA-PKcs mutant cells, and in homologous recombination repair (HRR) mutant cells including Rad51C, Rad51D, and Fancg/xrcc9. Generally, chromosomal aberrations and cell killing by γ-rays were similarly affected by mutations in DNA-PKcs, and these mutant cells were more sensitive in G1 than in S/G2 phase. In G1-irradiated DNA-PKcs mutant cells, both chromosome- and chromatid-type breaks and exchanges were in excess than wild-type cells. For cells irradiated in late S/G2 phase, mutant cells showed very high yields of chromatid breaks compared to wild-type cells. Few exchanges were seen in DNA-PKcs-null, Ku80-null, or DNA-PKcs kinase dead mutants, but exchanges in excess were detected in the S2506 or T2609 cluster mutants. SCE induction by very low doses of α-particles is resulted from bystander effects in cells not traversed by α-particles. SCE seen in wild-type cells was completely abolished in Rad51C- or Rad51D-deficient cells, but near normal in Fancg/xrcc9 cells. In marked contrast, very high levels of SCEs were observed in DNA-PKcs-null, DNA-PKcs kinase-dead and Ku80-null mutants. SCE induction was also abolished in T2609 cluster mutant cells, but was only slightly reduced in the S2056 cluster mutant cells. Since both non-homologous end-joining (NHEJ) and HRR systems utilize initial DNA lesions as a substrate, these results suggest the possibility of a competitive interference phenomenon operating between NHEJ and at least the Rad51C/D components of HRR; the level of interaction between damaged DNA and a particular DNA-PK component may determine the level of interaction of such DNA with a relevant HRR component.

  7. Buffett's Alpha

    DEFF Research Database (Denmark)

    Frazzini, Andrea; Kabiller, David; Heje Pedersen, Lasse

    Berkshire Hathaway has realized a Sharpe ratio of 0.76, higher than any other stock or mutual fund with a history of more than 30 years, and Berkshire has a significant alpha to traditional risk factors. However, we find that the alpha becomes insignificant when controlling for exposures to Betting-Against-Beta...... in publicly traded stocks versus wholly-owned private companies, we find that the former performs the best, suggesting that Buffett's returns are more due to stock selection than to his effect on management. These results have broad implications for market efficiency and the implementability of academic...

  8. Suppression of RNA silencing by a plant DNA virus satellite requires a host calmodulin-like protein to repress RDR6 expression.

    Directory of Open Access Journals (Sweden)

    Fangfang Li

    2014-02-01

    Full Text Available In plants, RNA silencing plays a key role in antiviral defense. To counteract host defense, plant viruses encode viral suppressors of RNA silencing (VSRs that target different effector molecules in the RNA silencing pathway. Evidence has shown that plants also encode endogenous suppressors of RNA silencing (ESRs that function in proper regulation of RNA silencing. The possibility that these cellular proteins can be subverted by viruses to thwart host defense is intriguing but has not been fully explored. Here we report that the Nicotiana benthamiana calmodulin-like protein Nbrgs-CaM is required for the functions of the VSR βC1, the sole protein encoded by the DNA satellite associated with the geminivirus Tomato yellow leaf curl China virus (TYLCCNV. Nbrgs-CaM expression is up-regulated by the βC1. Transgenic plants over-expressing Nbrgs-CaM displayed developmental abnormities reminiscent of βC1-associated morphological alterations. Nbrgs-CaM suppressed RNA silencing in an Agrobacterium infiltration assay and, when over-expressed, blocked TYLCCNV-induced gene silencing. Genetic evidence showed that Nbrgs-CaM mediated the βC1 functions in silencing suppression and symptom modulation, and was required for efficient virus infection. Moreover, the tobacco and tomato orthologs of Nbrgs-CaM also possessed ESR activity, and were induced by betasatellite to promote virus infection in these Solanaceae hosts. We further demonstrated that βC1-induced Nbrgs-CaM suppressed the production of secondary siRNAs, likely through repressing RNA-DEPENDENT RNA POLYMERASE 6 (RDR6 expression. RDR6-deficient N. benthamiana plants were defective in antiviral response and were hypersensitive to TYLCCNV infection. More significantly, TYLCCNV could overcome host range restrictions to infect Arabidopsis thaliana when the plants carried a RDR6 mutation. These findings demonstrate a distinct mechanism of VSR for suppressing PTGS through usurpation of a host ESR, and

  9. Diphtheria toxin- and Pseudomonas A toxin-mediated apoptosis. ADP ribosylation of elongation factor-2 is required for DNA fragmentation and cell lysis and synergy with tumor necrosis factor-alpha.

    Science.gov (United States)

    Morimoto, H; Bonavida, B

    1992-09-15

    We have reported that diphtheria toxin (DTX) mediates target cell lysis and intranucleosomal DNA fragmentation (apoptosis) and also synergizes with TNF-alpha. In this paper, we examined which step in the pathway of DTX-mediated inhibition of protein synthesis was important for induction of cytolytic activity and for synergy. Using a DTX-sensitive tumor cell line, we first examined the activity of the mutant CRM 197, which does not catalyze the ADP ribosylation of elongation factor-2 (EF-2). CRM 197 was not cytolytic for target cells and did not mediate intranucleosomal DNA fragmentation of viable cells. The failure of CRM 197 to mediate target cell lysis suggested that the catalytic activity of DTX is prerequisite for target cell lysis. This was corroborated by demonstrating that MeSAdo, which blocks the biosynthesis of diphthamide, inhibited DTX-mediated protein synthesis inhibition and also blocked target cell lysis. Furthermore, the addition of nicotinamide, which competes with NAD+ on the DTX action site of EF-2, also blocked DTX-mediated lysis. These findings suggest that ADP-ribosylation of EF-2 may be a necessary step in the pathway leading to target cell lysis. In contrast to the sensitive line, the SKOV-3 tumor cell line is sensitive to protein synthesis inhibition by DTX but is not susceptible to cytolysis and apoptosis by DTX. Thus, protein synthesis inhibition by DTX is not sufficient to mediate target cell lysis. The synergy in cytotoxicity obtained with the combination of DTX and TNF-alpha was examined in order to determine the pathway mediated by DTX in synergy. Like the direct lysis by DTX, synergy was significantly reduced by MeSAdo and by nicotinamide. Furthermore, synergy was not observed with combination of CRM 197 and TNF-alpha. These results demonstrate that, in synergy, DTX may utilize the same pathway required for its cytolytic activity. Pseudomonas aeruginosa exotoxin shared most the properties shown for DTX. Altogether, these findings

  10. Design and docking of novel series of hybrid xanthones as anti-cancer agent to target human DNA topoisomerase 2-alpha

    Directory of Open Access Journals (Sweden)

    Lalit Mohan Nainwal

    2014-06-01

    Full Text Available Topoisomerase (topo IIα is a homodimeric protein catalyzes topological vicissitudes by adding or by soothing super coiling transpiration, occurs in human DNA during DNA replication as an outcome chromosome segregation and condensation occurs during meiosis I and recombination. To prevent the cleavage and religation activity we administered novel hybrid substituted Xanthone series of drugs. The toxicity prediction showed outstanding results which impetus to study its anticancer activities by targeting topoisomerase (topo IIα. We developed the homology model of the topoisomerase (topo IIα due to the unavailability of 3D structure in the Protein Data Bank. Structural assessment of the modeled protein and confirmed the quality of the model. The ligands were docked using Autodock4.2 software and binding energy was reported. The compound XM9, XN2, XM7, XLNU and XNS scored lowest binding energy and highest binding affinity. The interaction sites and the hydrogen bond were observed.

  11. Heterochromatin marks HP1gamma, HP1alpha and H3K9me3, and DNA damage response activation in human testis development and germ cell tumours

    Czech Academy of Sciences Publication Activity Database

    Bartkova, J.; Moudrý, Pavel; Hodný, Zdeněk; Lukas, J.; Rajpert-De Meyts, E.; Bartek, Jiří

    2011-01-01

    Roč. 34, 4 Pt 2 (2011), e103-e113 ISSN 0105-6263 R&D Projects: GA ČR GA301/08/0353 Grant - others:Lundbeck Foundation(DK) R13-A1287; EU FP7(XE) TRIREME 223575 Institutional research plan: CEZ:AV0Z50520514 Keywords : heterochromatinization * DNA damage response * germinal tumours Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.591, year: 2011

  12. Activator protein 2alpha mediates parathyroid TGF-alpha self-induction in secondary hyperparathyroidism.

    Science.gov (United States)

    Arcidiacono, Maria Vittoria; Cozzolino, Mario; Spiegel, Noah; Tokumoto, Masanori; Yang, Jing; Lu, Yan; Sato, Tetsuhiko; Lomonte, Carlo; Basile, Carlo; Slatopolsky, Eduardo; Dusso, Adriana S

    2008-10-01

    In secondary hyperparathyroidism, enhanced expression of TGF-alpha in the parathyroid leads to its own upregulation, generating a feed-forward loop for TGF-alpha activation of its receptor, EGFR receptor (EGFR), which promotes parathyroid hyperplasia. These studies examined the role of activator protein 2alpha (AP2), an inducer of TGF-alpha gene transcription, in the upregulation of parathyroid TGF-alpha in secondary hyperparathyroidism. In rat and human secondary hyperparathyroidism, parathyroid AP2 expression strongly correlated with TGF-alpha levels and with the rate of parathyroid growth, as expected. Furthermore, the increases in rat parathyroid content of AP2 and its binding to a consensus AP2 DNA sequence preceded the increase in TGF-alpha induced by high dietary phosphate. More significant, in A431 cells, which provide a model of enhanced TGF-alpha and TGF-alpha self-induction, mutating the core AP2 site of the human TGF-alpha promoter markedly impaired promoter activity induced by endogenous or exogenous TGF-alpha. Important for therapy, in five-sixths nephrectomized rats fed high-phosphate diets, inhibition of parathyroid TGF-alpha self-induction using erlotinib, a highly specific inhibitor of TGF-alpha/EGFR-driven signals, reduced AP2 expression dosage dependently. This suggests that the increases in parathyroid AP2 occur downstream of EGFR activation by TGF-alpha and are required for TGF-alpha self-induction. Indeed, in A431 cells, erlotinib inhibition of TGF-alpha self-induction caused parallel reductions in AP2 expression and nuclear localization, as well as TGF-alpha mRNA and protein levels. In summary, increased AP2 expression and transcriptional activity at the TGF-alpha promoter determine the severity of the hyperplasia driven by parathyroid TGF-alpha self-upregulation in secondary hyperparathyroidism.

  13. Time elements. [for transformations in satellite equations

    Science.gov (United States)

    Nacozy, P. E.

    1974-01-01

    Time elements are introduced for use with Sundman time transformations of the type dt = r(alpha)ds for satellite equations of motion. Two time elements are given, one providing maximum accuracy for alpha = 1, the other for alpha = 2. Time elements and time transformations reduce local truncation error and Liapunov (in track) instability, and provide analytical step size control. Numerical results show accuracy improvements of more than one order of magnitude when time elements are employed with time transformations in the numerical integration of the satellite equations, compared with using time transformations alone.

  14. Macromolecular organization of human centromeric regions reveals high-frequency, polymorphic macro DNA repeats.

    OpenAIRE

    Jabs, E W; Goble, C A; Cutting, G R

    1989-01-01

    To analyze the macromolecular organization of human centromeric regions, we used alpha-satellite, or alphoid, repetitive DNA sequences specific to the centromeres of human chromosomes 6 (D6Z1), X (XC), and Y (YC-2) and the technique of pulsed-field gel electrophoresis. Genomic DNA from 24 normal, unrelated individuals was digested and separated into fragments ranging from 23 kilobases (kb) to 2 megabases (Mb) in length. Digestion with 12 different restriction enzymes with 4- to 8-base-pair re...

  15. Human DNA polymerase alpha uses a combination of positive and negative selectivity to polymerize purine dNTPs with high fidelity

    Czech Academy of Sciences Publication Activity Database

    Beckman, J.; Kincaid, K.; Hocek, Michal; Spratt, T.; Engels, J.; Cosstick, R.; Kuchta, R. D.

    2007-01-01

    Roč. 46, č. 2 (2007), s. 448-460 ISSN 0006-2960 R&D Projects: GA MŠk LC512 Grant - others:NIH(US) GM54194; NIH(US) TW007372-01; Army Research Office(US) W911NF-05-1-0172; DFG(DE) SFB 579 Institutional research plan: CEZ:AV0Z40550506 Keywords : DNA polymerase * nucleoside triphosphates * modified nucleobases Subject RIV: CC - Organic Chemistry Impact factor: 3.368, year: 2007

  16. Saturn satellites

    International Nuclear Information System (INIS)

    Ruskol, E.L.

    1981-01-01

    The characteristics of the Saturn satellites are discussed. The satellites close to Saturn - Janus, Mimas, Enceladus, Tethys, Dione and Rhea - rotate along the circular orbits. High reflectivity is attributed to them, and the density of the satellites is 1 g/cm 3 . Titan is one of the biggest Saturn satellites. Titan has atmosphere many times more powerful than that of Mars. The Titan atmosphere is a peculiar medium with a unique methane and hydrogen distribution in the whole Solar system. The external satellites - Hyperion, Japetus and Phoebe - are poorly investigated. Neither satellite substance density, nor their composition are known. The experimental data on the Saturn rings obtained on the ''Pioneer-11'' and ''Voyager-1'' satellites are presented [ru

  17. DNA repair synthesis in human fibroblasts requires DNA polymerase delta

    International Nuclear Information System (INIS)

    Nishida, C.; Reinhard, P.; Linn, S.

    1988-01-01

    When UV-irradiated cultured diploid human fibroblasts were permeabilized with Brij-58 then separated from soluble material by centrifugation, conservative DNA repair synthesis could be restored by a soluble factor obtained from the supernatant of similarly treated HeLa cells. Extensive purification of this factor yielded a 10.2 S, 220,000-dalton polypeptide with the DNA polymerase and 3'- to 5'-exonuclease activities reported for DNA polymerase delta II. Monoclonal antibody to KB cell DNA polymerase alpha, while binding to HeLa DNA polymerase alpha, did not bind to the HeLa DNA polymerase delta. Moreover, at micromolar concentrations N2-(p-n-butylphenyl)-2'-deoxyguanosine 5'-triphosphate (BuPdGTP) and 2-(p-n-butylanilino)-2'-deoxyadenosine 5'-triphosphate (BuAdATP) were potent inhibitors of DNA polymerase alpha, but did not inhibit the DNA polymerase delta. Neither purified DNA polymerase alpha nor beta could promote repair DNA synthesis in the permeabilized cells. Furthermore, under conditions which inhibited purified DNA polymerase alpha by greater than 90%, neither monoclonal antibodies to DNA polymerase alpha, BuPdGTP, nor BuAdATP was able to inhibit significantly the DNA repair synthesis mediated by the DNA polymerase delta. Thus, it appears that a major portion of DNA repair synthesis induced by UV irradiation might be catalyzed by DNA polymerase delta. When xeroderma pigmentosum human diploid fibroblasts were utilized, DNA repair synthesis dependent upon ultraviolet light could be restored by addition of both T4 endonuclease V and DNA polymerase delta, but not by addition of either one alone

  18. Satellite RNAs and Satellite Viruses.

    Science.gov (United States)

    Palukaitis, Peter

    2016-03-01

    Satellite RNAs and satellite viruses are extraviral components that can affect either the pathogenicity, the accumulation, or both of their associated viruses while themselves being dependent on the associated viruses as helper viruses for their infection. Most of these satellite RNAs are noncoding RNAs, and in many cases, have been shown to alter the interaction of their helper viruses with their hosts. In only a few cases have the functions of these satellite RNAs in such interactions been studied in detail. In particular, work on the satellite RNAs of Cucumber mosaic virus and Turnip crinkle virus have provided novel insights into RNAs functioning as noncoding RNAs. These effects are described and potential roles for satellite RNAs in the processes involved in symptom intensification or attenuation are discussed. In most cases, models describing these roles involve some aspect of RNA silencing or its suppression, either directly or indirectly involving the particular satellite RNA.

  19. Centriolar satellites

    DEFF Research Database (Denmark)

    Tollenaere, Maxim A X; Mailand, Niels; Bekker-Jensen, Simon

    2015-01-01

    Centriolar satellites are small, microscopically visible granules that cluster around centrosomes. These structures, which contain numerous proteins directly involved in centrosome maintenance, ciliogenesis, and neurogenesis, have traditionally been viewed as vehicles for protein trafficking towa...... highlight newly discovered regulatory mechanisms targeting centriolar satellites and their functional status, and we discuss how defects in centriolar satellite components are intimately linked to a wide spectrum of human diseases.......Centriolar satellites are small, microscopically visible granules that cluster around centrosomes. These structures, which contain numerous proteins directly involved in centrosome maintenance, ciliogenesis, and neurogenesis, have traditionally been viewed as vehicles for protein trafficking...... towards the centrosome. However, the recent identification of several new centriolar satellite components suggests that this model offers only an incomplete picture of their cellular functions. While the mechanisms controlling centriolar satellite status and function are not yet understood in detail...

  20. Satellite theory

    Science.gov (United States)

    Kozai, Y.

    1981-04-01

    The dynamical characteristics of the natural satellite of Mars, Jupiter, Saturn, Uranus and Neptune are analyzed on the basis of the solar tidal perturbation factor and the oblateness factor of the primary planet for each satellite. For the inner satellites, for which the value of the solar tidal factor is much smaller than the planetary oblateness factor, it is shown that the eccentricity and inclination of satellite orbits are generally very small and almost constant; several pairs of inner satellites are also found to exhibit commensurable mean motions, or secular accelerations in mean longitude. In the case of the outer satellites, for which solar perturbations are dominant, secular perturbations and long-period perturbations may be derived by the solution of equations of motion reduced to one degree of freedom. The existence of a few satellites, termed intermediary satellites, for which the solar tidal perturbation is on the order of the planetary oblateness factor, is also observed, and the pole of the orbital plane of the satellite is noted to execute a complex motion around the pole of the planet or the orbital plane of the planet.

  1. Satellite Radio

    Indian Academy of Sciences (India)

    Satellites have been a highly effective platform for multi- form broadcasts. This has led to a revival of the radio era. The satellite radio is a natural choice to bridge the digital gap. It has several novel features like selective addressing and error control. The value-added services from such systems are of particular interest.

  2. Satellite Communications

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Satellite Communications. Arthur C Clarke wrote a seminal paper in 1945 in wireless world. Use three satellites in geo-synchronous orbit to enable intercontinental communications. System could be realised in '50 to 100 years'

  3. Coulomb correction to elastic. alpha. -. alpha. scattering

    Energy Technology Data Exchange (ETDEWEB)

    Bera, P.K.; Jana, A.K.; Haque, N.; Talukdar, B. (Department of Physics, Visva-Bharati University, Santiniketan-731235, West Bengal, India (IN))

    1991-02-01

    The elastic {alpha}-{alpha} scattering is treated within the framework of a generalized phase-function method (GPFM). This generalization consists in absorbing the effect of Coulomb interaction in the comparison functions for developing the phase equation. Based on values of scattering phase shifts computed by the present method, it is concluded that the GPFM provides an uncomplicated approach to rigorous Coulomb correction in the {alpha}-{alpha} scattering.

  4. Intrahepatic expression of interferon alpha & interferon alpha ...

    African Journals Online (AJOL)

    kemrilib

    Alpha m-RNA while 30% only expressed Interferon Alpha Receptor m-RNA. Responders and non-responders to Interferon therapy ... expression of IFN Alpha Receptor mRNA. Regardless of the response to interferon, histological .... generation reverse hybridisation, line probe assay. (Inno-LiPA HCV II; Innogenetics, Ghent,.

  5. Variation in the number of alpha-globin loci in sheep.

    Science.gov (United States)

    Rando, A; Ramunno, L; Masina, P

    1986-03-01

    Southern blot analysis was used to compare sheep and goat restriction-endonuclease maps of the DNA region containing the alpha-globin genes. The identical digestion patterns observed in both species with three endonucleases (BamHI, BstEII, and PstI) show that in sheep a single chromosome normally bears two nonallelic alpha-globin genes positioned at the same distance as in goat. Variant digestion patterns with enzymes that cleave outside (BamHI and HindIII) and within (EcoRI) the alpha-globin loci allowed us to infer that chromosomes with different numbers of alpha-globin loci are also present in sheep. In particular, in the 60 sheep considered, four individuals were heterozygous (alpha alpha/alpha alpha alpha) and one was homozygous (alpha alpha alpha/alpha alpha alpha) for chromosomes with three loci and one individual was heterozygous for a chromosome with four loci (alpha alpha/alpha alpha alpha alpha). This variation in the number of copies of alpha-globin loci can be explained by means of unequal crossovers.

  6. Satellite Communications

    CERN Document Server

    Pelton, Joseph N

    2012-01-01

    The field of satellite communications represents the world's largest space industry. Those who are interested in space need to understand the fundamentals of satellite communications, its technology, operation, business, economic, and regulatory aspects. This book explains all this along with key insights into the field's future growth trends and current strategic challenges. Fundamentals of Satellite Communications is a concise book that gives all of the key facts and figures as well as a strategic view of where this dynamic industry is going. Author Joseph N. Pelton, PhD, former Dean of the International Space University and former Director of Strategic Policy at Intelstat, presents a r

  7. Use of a D17Z1 oligonucleotide probe for human DNA quantitation prior to PCR analysis of polymorphic DNA markers

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, S.; Alavaren, M.; Varlaro, J. [Roche Molecular Systems, Alameda, CA (United States)] [and others

    1994-09-01

    The alpha-satellite DNA locus D17Z1 contains primate-specific sequences which are repeated several hundred times per chromosome 17. A probe that was designed to hybridize to a subset of the D17Z1 sequence can be used for very sensitive and specific quantitation of human DNA. Sample human genomic DNA is immobilized on nylon membrane using a slot blot apparatus, and then hybridized with a biotinylated D17Z1 oligonucleotide probe. The subsequent binding of streptavidin-horseradish peroxidase to the bound probe allows for either calorimetric (TMB) or chemiluminescent (ECL) detection. Signals obtained for sample DNAs are then compared to the signals obtained for a series of human DNA standards. For either detection method, forty samples can be quantitated in less than two hours, with a sensitivity of 150 pg. As little as 20 pg of DNA can be quantitated when using chemiluminescent detection with longer film exposures. PCR analysis of several VNTR and STR markers has indicated that optimal typing results are generally obtained within a relatively narrow range of input DNA quantities. Too much input DNA can lead to PCR artifacts such as preferential amplification of smaller alleles, non-specific amplification products, and exaggeration of the DNA synthesis slippage products that are seen with STR markers. Careful quantitation of human genomic DNA prior to PCR can avoid or minimize these problems and ultimately give cleaner, more unambiguous PCR results.

  8. Satellite myths

    Science.gov (United States)

    Easton, Roger L.; Hall, David

    2008-01-01

    Richard Corfield's article “Sputnik's legacy” (October 2007 pp23-27) states that the satellite on board the US Vanguard rocket, which exploded during launch on 6 December 1957 two months after Sputnik's successful take-off, was “a hastily put together contraption of wires and circuitry designed only to send a radio signal back to Earth”. In fact, the Vanguard satellite was developed over a period of several years and put together carefully using the best techniques and equipment available at the time - such as transistors from Bell Laboratories/Western Electric. The satellite contained not one but two transmitters, in which the crystal-controlled oscillators had been designed to measure both the temperature of the satellite shell and of the internal package.

  9. Satellite Geomagnetism

    DEFF Research Database (Denmark)

    Olsen, Nils; Stolle, Claudia

    2012-01-01

    Observations of Earth’s magnetic field from space began more than 50 years ago. A continuous monitoring of the field using low Earth orbit (LEO) satellites, however, started only in 1999, and three satellites have taken highprecision measurements of the geomagnetic field during the past decade....... The unprecedented time-space coverage of their data opened revolutionary new possibilities for monitoring, understanding, and exploring Earth’s magnetic field. In the near future, the three-satellite constellation Swarm will ensure continuity of such measurement and provide enhanced possibilities to improve our...... ability to characterize and understand the many sources that contribute to Earth’s magnetic field. In this review, we summarize investigations of Earth’s interior and environment that have been possible through the analysis of high-precision magnetic field observations taken by LEO satellites....

  10. Chromosome-specific DNA Repeat Probes

    Energy Technology Data Exchange (ETDEWEB)

    Baumgartner, Adolf; Weier, Jingly Fung; Weier, Heinz-Ulrich G.

    2006-03-16

    In research as well as in clinical applications, fluorescence in situ hybridization (FISH) has gained increasing popularity as a highly sensitive technique to study cytogenetic changes. Today, hundreds of commercially available DNA probes serve the basic needs of the biomedical research community. Widespread applications, however, are often limited by the lack of appropriately labeled, specific nucleic acid probes. We describe two approaches for an expeditious preparation of chromosome-specific DNAs and the subsequent probe labeling with reporter molecules of choice. The described techniques allow the preparation of highly specific DNA repeat probes suitable for enumeration of chromosomes in interphase cell nuclei or tissue sections. In addition, there is no need for chromosome enrichment by flow cytometry and sorting or molecular cloning. Our PCR-based method uses either bacterial artificial chromosomes or human genomic DNA as templates with {alpha}-satellite-specific primers. Here we demonstrate the production of fluorochrome-labeled DNA repeat probes specific for human chromosomes 17 and 18 in just a few days without the need for highly specialized equipment and without the limitation to only a few fluorochrome labels.

  11. Effects of alpha particles on zebrafish embryos

    International Nuclear Information System (INIS)

    Yum, E.H.W.; Choi, V.W.Y.; Yu, K.N.; Li, V.W.T.; Cheng, S.H.

    2008-01-01

    Full text: Ionizing radiation such as X-ray and alpha particles can damage cellular macromolecules, which can lead to DNA single- and double-strand breaks. In the present work, we studied the effects of alpha particles on dechorionated zebrafish embryos. Thin polyallyldiglycol carbonate (PADC) films with a thickness of 16 μm were prepared from commercially available PADC films (with thickness of 100 μm) by chemical etching and used as support substrates for holding zebrafish embryos for alpha-particle irradiation. These films recorded alpha-particle hit positions, quantified the number and energy of alpha particles actually incident on the embryo cells, and thus enabled the calculation of the dose absorbed by the embryo cells. Irradiation was made at 1.25 hours post fertilization (hpf) with various absorbed dose. TdT-mediated dUTP Nick-End Labeling (TUNEL) assay was performed on the embryos at different time stages after irradiation. Marked apoptosis was detected only in embryos at earlier time stages. The results showed that DNA double-strand break during zebrafish embryogenesis can be induced by alpha-particle irradiation, which suggests that zebrafish is a potential model for assessing the effects of alpha-particle radiation

  12. Association of satellites with a mastrevirus in natural infection: complexity of Wheat dwarf India virus disease.

    Science.gov (United States)

    Kumar, Jitendra; Kumar, Jitesh; Singh, Sudhir P; Tuli, Rakesh

    2014-06-01

    In contrast to begomoviruses, mastreviruses have not previously been shown to interact with satellites. This study reports the first identification of the association of satellites with a mastrevirus in field-grown plants. Two alphasatellite species were detected in different field samples of wheat infected with Wheat Dwarf India Virus (WDIV), a Cotton leaf curl Multan alphasatellite (CLCuMA) and a Guar leaf curl alphasatellite (GLCuA). In addition to the alphasatellites, a betasatellite, Ageratum yellow leaf curl betasatellite (AYLCB), was also identified in the wheat samples. No begomovirus was detected in the wheat samples, thus establishing association of the above-named satellites with WDIV. Agrobacterium-mediated inoculation of WDIV in wheat, in the presence of either of the alphasatellites or the betasatellite, resulted in infections inducing more severe symptoms. WDIV efficiently maintained each of the alphasatellites and the betasatellite in wheat. The satellites enhanced the level of WDIV DNA in wheat. Inoculation of the satellites isolated from wheat with various begomoviruses into Nicotiana tabacum demonstrated that these remain capable of interacting with the viruses with which they were first identified. Virus-specific small RNAs accumulated in wheat upon infection with WDIV but were lower in abundance in plants coinfected with the satellites, suggesting that both the alphasatellites and the betasatellite suppress RNA silencing. These results suggest that the selective advantage for the maintenance of the alphasatellites and the betasatellite by WDIV in the field is in overcoming RNA silencing-mediated host defense. Wheat is the most widely cultivated cereal crop in the world. A number of viruses are important pathogens of wheat, including the viruses of the genus Mastrevirus, family Geminiviridae. This study reports the association of subgenomic components, called satellites (alpha- and betasatellites), with a mastrevirus, Wheat Dwarf India Virus

  13. Complex rearrangements within the human J delta-C delta/J alpha-C alpha locus and aberrant recombination between J alpha segments

    NARCIS (Netherlands)

    Baer, R.; Boehm, T.; Yssel, H.; Spits, H.; Rabbitts, T. H.

    1988-01-01

    We have examined DNA rearrangements within a 120 kb cloned region of the human T cell receptor J delta-C delta/J alpha-C alpha locus. Three types of pattern emerge from an analysis of T cell lines and clones. Firstly, cells with two rearrangements within J delta-C delta; secondly, cells with one

  14. Organization and evolution of primate centromeric DNA from whole-genome shotgun sequence data.

    Science.gov (United States)

    Alkan, Can; Ventura, Mario; Archidiacono, Nicoletta; Rocchi, Mariano; Sahinalp, S Cenk; Eichler, Evan E

    2007-09-01

    The major DNA constituent of primate centromeres is alpha satellite DNA. As much as 2%-5% of sequence generated as part of primate genome sequencing projects consists of this material, which is fragmented or not assembled as part of published genome sequences due to its highly repetitive nature. Here, we develop computational methods to rapidly recover and categorize alpha-satellite sequences from previously uncharacterized whole-genome shotgun sequence data. We present an algorithm to computationally predict potential higher-order array structure based on paired-end sequence data and then experimentally validate its organization and distribution by experimental analyses. Using whole-genome shotgun data from the human, chimpanzee, and macaque genomes, we examine the phylogenetic relationship of these sequences and provide further support for a model for their evolution and mutation over the last 25 million years. Our results confirm fundamental differences in the dispersal and evolution of centromeric satellites in the Old World monkey and ape lineages of evolution.

  15. Organization and evolution of primate centromeric DNA from whole-genome shotgun sequence data.

    Directory of Open Access Journals (Sweden)

    Can Alkan

    2007-09-01

    Full Text Available The major DNA constituent of primate centromeres is alpha satellite DNA. As much as 2%-5% of sequence generated as part of primate genome sequencing projects consists of this material, which is fragmented or not assembled as part of published genome sequences due to its highly repetitive nature. Here, we develop computational methods to rapidly recover and categorize alpha-satellite sequences from previously uncharacterized whole-genome shotgun sequence data. We present an algorithm to computationally predict potential higher-order array structure based on paired-end sequence data and then experimentally validate its organization and distribution by experimental analyses. Using whole-genome shotgun data from the human, chimpanzee, and macaque genomes, we examine the phylogenetic relationship of these sequences and provide further support for a model for their evolution and mutation over the last 25 million years. Our results confirm fundamental differences in the dispersal and evolution of centromeric satellites in the Old World monkey and ape lineages of evolution.

  16. Production of secreted guar alpha-galactosidase by Lactococcus lactis

    NARCIS (Netherlands)

    Leenhouts, KJ; Bolhuis, A; Ledeboer, A; Venema, G; Kok, J

    1995-01-01

    A plant alpha-galactosidase gene was inserted in the expression vector pGKV259. The resulting plasmid pGAL2 consisted of the replication functions of the broad-host-range lactococcal plasmid pWVO1, the lactococcal promoter P59, and the DNA sequences encoding the alpha-amylase signal sequence from

  17. Satellite Radio

    Indian Academy of Sciences (India)

    communications as well as for point-to-multipoint broadcasting. GENERAL I ARTICLE. Radio is perceived to be an individual's possession because of its portability. It can be ... (See Box 1.) Gsa satellites are used for point-to-point communications as ... digital modulations one uses perceptual coding using auditory masking.

  18. DNA fragmentation and cytotoxicity by recombinant human tumor necrosis factor in L929 fibroblast cells

    International Nuclear Information System (INIS)

    Kosaka, T.; Kuwabara, M.; Koide, F.

    1992-01-01

    Induction of cell DNA fragmentation by treatment of recombinant human Tumor Necrosis Factor alpha (rhTNF alpha) was examined by using mouse L929 cells derived from mouse fibroblast cells. The amount of DNA fragments derived from rhTNF alpha-treated cells, detected by alkaline elution technique, was smaller than that derived from X-irradiated cells. The rhTNF alpha caused the DNA fragmentation depending on its incubation time and concentration. The DNA damage caused by rhTNF alpha treatment correlated with its cytotoxicity. This result suggested that the DNA fragmentation is one of causes of cell death. The treatment with proteinase K of DNA obtained from rhTNF alpha-treated cells did not increase the amount of DNA fragmentation, which indicates that rhTNF alpha causes DNA-fragmentation but not DNA-protein cross-linking

  19. Correlation of repressed transcription of alpha-tocopherol transfer protein with serum alpha-tocopherol during hepatocarcinogenesis

    NARCIS (Netherlands)

    Wu, C. G.; Hoek, F. J.; Groenink, M.; Reitsma, P. H.; van Deventer, S. J.; Chamuleau, R. A.

    1997-01-01

    Using a subtraction-enhanced display technique, we identified a rodent alpha-tocopherol transfer protein (alpha-TTP) cDNA which exhibited markedly lower messenger RNA (mRNA) amounts in rat hepatocellular carcinoma (HCC) than in healthy controls. Several lines of evidence have substantiated that

  20. Scientific Satellites

    Science.gov (United States)

    1967-01-01

    Justification for this approach stems, first, from the sheer cost of trying to test at all levels. More significant is the fact that system-level tests are...specific impulses have been well worth the price until recently, when large production runs of small rockets (Scouts) and the sheer size of boosters in the...length: about 12 meters. Energy in unwanted oscillations is dissipated as heat in the damping spring. 348 SCIENTIFIC SATELLITES S/-- Piano Wire Silicone

  1. Problems connected with the use of oligonucleotide probes with a high degree of degeneracy. Identification of mRNA and of cDNA clones corresponding to the gene of the. cap alpha. -subunit of Na/sup +/, K/sup +/-ATPase

    Energy Technology Data Exchange (ETDEWEB)

    Petrukhin, K.E.; Grishin, A.V.; Arsenyan, S.G.; Broude, N.E.; Grinkevich, V.A.; Filippova, L.Yu.; Severtsova, I.V.; Modyanov, N.N.

    1986-10-01

    To identify and search for nucleotide sequences containing the structural part of the gene of the ..cap alpha..-subunit of Na/sup +/, K/sup +/-ATPase, 17-membered oligonucleotide probes corresponding to the peptide Lys-Asp-Ala-Phe-Gln-Asn have been synthesized. It has been shown that, with a 64-fold degeneracyd, the 17-membered probe is suitable only for the identification of a specific sequence in mRNA. To search for clones containing cDNA fragments, preliminary fractionation of the probes with the aid of HPLC or the resynthesis of groups of oligonucleotides with a lower degeneracy is necessary.

  2. The determination of $\\alpha_s$ by the ALPHA collaboration

    CERN Document Server

    Bruno, Mattia

    2016-01-01

    We review the ALPHA collaboration strategy for obtaining the QCD coupling at high scale. In the three-flavor effective theory it avoids the use of perturbation theory at $\\alpha > 0.2$ and at the same time has the physical scales small compared to the cutoff $1/a$ in all stages of the computation. The result $\\Lambda_\\overline{MS}^{(3)}=332(14)$~MeV is translated to $\\alpha_\\overline{MS}(m_Z)=0.1179(10)(2)$ by use of (high order) perturbative relations between the effective theory couplings at the charm and beauty quark "thresholds". The error of this perturbative step is discussed and estimated as $0.0002$.

  3. Molecular characterization of an. alpha. sub 2B -adrenergic receptor

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, J.K.; Dewan Zeng; D' Angelo, D.D.; Tucker, A.L.; Zhihong Lu; Barber, C.M.; Lynch, K.R. (Univ. of Virginia Health Sciences Center, Charlottesville (United States))

    1990-02-26

    {alpha}{sub 2}-Adrenergic receptors comprise a heterogeneous population based on pharmacologic and molecular evidence. The authors have isolated a cDNA clone (pRNG{alpha}2) encoding a previously undescribed third subtype of an {alpha}{sub 2}-adrenergic receptor from a rat kidney cDNA library. The library was screened with an oligonucleotide encoding a highly conserved region found in all biogenic amine receptors described to date. The deduced amino acid sequence displays many features of G-protein coupled receptors with exception of the absence of the consensus N-linked glycosylation site at the amino terminus. Membranes prepared from COS-1 cells transfected with pRNG{alpha}2 display high affinity and saturable binding to {sup 3}H-rauwolscine (K{sub d}=2 nM).Competition curve data analysis shows that pRNG{alpha}2 protein binds to a variety of adrenergic drugs with the following rank order of potency: yohimbine {ge} cholorpromazine > prazosin {ge} clonidine > norepinephrine {ge} oxymetazoline. pRNG{alpha}2 RNA accumulates in both adult rat kidney and rat neonatal lung (predominant species is 4.0 kb). They conclude that pRNG{alpha}2 likely represents a cDNA for the {alpha}{sub 2B}-adrenergic receptor.

  4. Biosynthesis of Tcr-alpha, beta and Tcr-gamma, delta/CD3 complexes

    DEFF Research Database (Denmark)

    Bauguil-Caspar, S; Arnaud, J; Kuhlmann, J

    1993-01-01

    Jurkat J76 clone, LYON L12.37 clone and L12.37 cells transfected with J76-alpha cDNA or J76 Tcr-alpha mutated cDNA (J79) were analysed for membrane expression of Tcr/CD3 complex using WT31 mAb (Tcr-alpha, beta) or Tcr-delta 1 mAb (Tcr-gamma, delta): LYON cells express V beta 9 bearing Tcr-beta...... chains. J76 Tcr-alpha cDNA transfected LYON cells have intracellular Tcr-gamma, delta chains and J79 Tcr-alpha cDNA transfected LYON cells have intracellular Tcr-alpha (M), beta chains....

  5. Advances in understanding begomovirus satellites.

    Science.gov (United States)

    Zhou, Xueping

    2013-01-01

    Begomoviruses are numerous and geographically widespread viruses that cause devastating diseases in many crops. Monopartite begomoviruses are frequently associated with betasatellites or alphasatellites. Both betasatellite and alphasatellite DNA genomes are approximately half the size of begomovirus DNA genomes. Betasatellites are essential for induction of typical disease symptoms. The βC1 genes encoded by the betasatellites have important roles in symptom induction, in suppression of transcriptional and posttranscriptional gene silencing, and they can affect jasmonic acid responsive genes. Host plants of begomoviruses have evolved diverse innate defense mechanisms against the βC1 protein to counter these challenges. Alphasatellites have been identified mainly in monopartite begomoviruses that associate with betasatellites and have no known contributions to pathogenesis of begomovirus-betasatellite disease complexes. Applications of current molecular tools are facilitating viral diagnosis and the discovery of novel species of geminiviruses and satellite DNAs and are also advancing our understanding of the global diversity and evolution of satellite DNAs.

  6. Lyman Alpha Control

    CERN Document Server

    Nielsen, Daniel Stefaniak

    2015-01-01

    This document gives an overview of how to operate the Lyman Alpha Control application written in LabVIEW along with things to watch out for. Overview of the LabVIEW code itself as well as the physical wiring of and connections from/to the NI PCI-6229 DAQ box is also included. The Lyman Alpha Control application is the interface between the ALPHA sequencer and the HighFinesse Wavelength Meter as well as the Lyman Alpha laser setup. The application measures the wavelength of the output light from the Lyman Alpha cavity through the Wavelength Meter. The application can use the Wavelength Meter’s PID capabilities to stabilize the Lyman Alpha laser output as well as switch between up to three frequencies.

  7. New ALPHA-2 magnet

    CERN Multimedia

    Anaïs Schaeffer

    2012-01-01

    On 21 June, members of the ALPHA collaboration celebrated the handover of the first solenoid designed for the ALPHA-2 experiment. The magnet has since been successfully installed and is working well.   Khalid Mansoor, Sumera Yamin and Jeffrey Hangst in front of the new ALPHA-2 solenoid. “This was the first of three identical solenoids that will be installed between now and September, as the rest of the ALPHA-2 device is installed and commissioned,” explains ALPHA spokesperson Jeffrey Hangst. “These magnets are designed to allow us to transfer particles - antiprotons, electrons and positrons - between various parts of the new ALPHA-2 device by controlling the transverse size of the particle bunch that is being transferred.” Sumera Yamin and Khalid Mansoor, two Pakistani scientists from the National Centre for Physics in Islamabad, came to CERN in February specifically to design and manufacture these magnets. “We had the chance to work on act...

  8. Systemic Targeted Alpha Radiotherapy for Cancer

    Directory of Open Access Journals (Sweden)

    Allan B. J.

    2013-09-01

    Full Text Available Background: The fundamental principles of internal targeted alpha therapy for cancer were established many decades ago.The high linear energy transfer (LET of alpha radiation to the targeted cancer cellscauses double strand breaks in DNA. At the same time, the short range radiation spares adjacent normal tissues. This targeted approach complements conventional external beam radiotherapy and chemotherapy. Such therapies fail on several fronts, such as lack of control of some primary cancers (e.g.glioblastoma multiformeand to inhibit the development of lethal metastatic cancer after successful treatment of the primary cancer. Objective: This review charts the developing role of systemic high LET, internal radiation therapy. Method: Targeted alpha therapy is a rapidly advancing experimental therapy that holds promise to deliver high cytotoxicity to targeted cancer cells. Initially thought to be indicated for leukemia and micrometastases, there is now evidence that solid tumors can also be regressed. Results: Alpha therapy may be molecular or physiological in its targeting. Alpha emitting radioisotopes such as Bi-212, Bi-213, At-211 and Ac-225 are used to label monoclonal antibodies or proteins that target specifc cancer cells. Alternatively, Radium-233 is used for palliative therapy of breast and prostate cancers because of its bone seeking properties. Conclusion: Preclinical studies and clinical trials of alpha therapy are discussed for leukemia, lymphoma, melanoma, glioblastoma multiforme, bone metastases, ovarian cancer, pancreatic cancer and other cancers.

  9. The promise of gene therapy for the treatment of alpha-1 antitrypsin deficiency.

    Science.gov (United States)

    Cruz, Pedro E; Mueller, Christian; Flotte, Terence R

    2007-09-01

    In the last 13 years, three gene therapy trials for the treatment of alpha-1 antitrypsin deficiency have been conducted. The first trial delivered plasmid encoding the alpha-1 antitrypsin cDNA to the nasal epithelium using cationic liposomes. The last two trials delivered recombinant adeno-associated vectors encoding the alpha-1 antitrypsin cDNA by intramuscular injection. In this review, the progress of ongoing clinical trials and new gene therapy technologies is discussed.

  10. Biosynthesis of Tcr-alpha, beta and Tcr-gamma, delta/CD3 complexes

    DEFF Research Database (Denmark)

    Bauguil-Caspar, S; Arnaud, J; Kuhlmann, J

    1993-01-01

    Jurkat J76 clone, LYON L12.37 clone and L12.37 cells transfected with J76-alpha cDNA or J76 Tcr-alpha mutated cDNA (J79) were analysed for membrane expression of Tcr/CD3 complex using WT31 mAb (Tcr-alpha, beta) or Tcr-delta 1 mAb (Tcr-gamma, delta): LYON cells express V beta 9 bearing Tcr...

  11. Cloning and sequencing of the casein kinase 2 alpha subunit from Zea mays

    DEFF Research Database (Denmark)

    Dobrowolska, G; Boldyreff, B; Issinger, O G

    1991-01-01

    The nucleotide sequence of the cDNA coding for the alpha subunit of casein kinase 2 of Zea mays has been determined. The cDNA clone contains an open reading frame of 996 nucleotides encoding a polypeptide comprising 332 amino acids. The primary amino acid sequence exhibits 75% identity to the alpha...... subunit and 71% identity to the alpha' subunit of human casein kinase 2....

  12. ALPHA-BETA SEPARATION PORTFOLIO STRATEGIES FOR ISLAMIC FINANCE

    Directory of Open Access Journals (Sweden)

    Valentyn Khokhlov

    2016-11-01

    Full Text Available The purpose of this paper is to develop a mathematical alpha-beta separation model that can be used to create a core-satellite portfolio management strategy that complies with the principles of Islamic finance. Methodology. Core-satellite portfolio construction methodology is used to implement the alpha-beta separation approach, where the core part of the portfolio is managed using the tracking error minimization strategy, and the satellite part of the portfolio is managed using the mean-variance optimization strategy. Results of the portfolio dynamics clearly show that a significant amount of value was created by alpha-beta separation. The typical alpha ranges from 4% to 5.7%. The most aggressive portfolio strategies that allow short positions in the satellite portfolio work best with frequent rebalancing and benefit from the active bets. Smoothing technique that was introduced to decrease the portfolio turnover and stabilize its composition works better when active bets are less efficient, particularly with less frequent rebalancing. The best risk-return combinations are achieved with modest (3% to 10% allocation of the total portfolio to the satellite, and the remaining part (90% to 97% being managed in order to minimize the tracking error. Practical implications. The alpha-beta separation framework suggested in this paper can be used to enhance the portfolio management techniques for the hedge funds that operate under tight restrictions, particularly under the Islamic finance principles. The mathematical models developed in this paper allow practical implementation of the alphabeta separation concept. Originality/value. While the idea of alpha-beta separation existed in hedge fund management before, there was no comprehensive mathematical model under it, so its implementation was based on the ad hoc approach. This paper introduces such a mathematical model and demonstrates how portfolio managers can create value for their clients using it.

  13. Alpha Shapes and Proteins

    DEFF Research Database (Denmark)

    Winter, Pawel; Sterner, Henrik; Sterner, Peter

    2009-01-01

    We provide a unified description of (weighted) alpha shapes, beta shapes and the corresponding simplicialcomplexes. We discuss their applicability to various protein-related problems. We also discuss filtrations of alpha shapes and touch upon related persistence issues.We claim that the full...... potential of alpha-shapes and related geometrical constructs in protein-related problems yet remains to be realized and verified. We suggest parallel algorithms for (weighted) alpha shapes, and we argue that future use of filtrations and kinetic variants for larger proteins will need such implementation....

  14. Ancient DNA

    DEFF Research Database (Denmark)

    Willerslev, Eske; Cooper, Alan

    2004-01-01

    ancient DNA, palaeontology, palaeoecology, archaeology, population genetics, DNA damage and repair......ancient DNA, palaeontology, palaeoecology, archaeology, population genetics, DNA damage and repair...

  15. Targeted Alpha Therapy: From Alpha to Omega

    International Nuclear Information System (INIS)

    Allen, Barry J; Clarke, Raymond; Huang Chenyu

    2013-01-01

    This review covers the broad spectrum of Targeted Alpha Therapy (TAT) research in Australia; from in vitro and in vivo studies to clinical trials. The principle of tumour anti-vascular alpha therapy (TAVAT) is discussed in terms of its validation by Monte Carlo calculations of vascular models and the potential role of biological dosimetry is examined. Summmary of this review is as follows: 1. The essence of TAT 2. Therapeutic objectives 3. TAVAT and Monte Carlo microdosimetry 4. Biological dosimetry 5. Preclinical studies 6. Clinical trials 7. What next? 8. Obstacles. (author)

  16. Alpha1-antitrypsin deficiency

    DEFF Research Database (Denmark)

    Stolk, Jan; Seersholm, Niels; Kalsheker, Noor

    2006-01-01

    The Alpha One International Registry (AIR), a multinational research program focused on alpha1-antitrypsin (AAT) deficiency, was formed in response to a World Health Organization recommendation. Each of the nearly 20 participating countries maintains a national registry of patients with AAT defic...... epidemiology, inflammatory and signalling processes, therapeutic advances, and lung imaging techniques....

  17. Alpha clustering in nuclei

    International Nuclear Information System (INIS)

    Hodgson, P.E.

    1990-01-01

    The effects of nucleon clustering in nuclei are described, with reference to both nuclear structure and nuclear reactions, and the advantages of using the cluster formalism to describe a range of phenomena are discussed. It is shown that bound and scattering alpha-particle states can be described in a unified way using an energy-dependent alpha-nucleus potential. (author)

  18. Evolution of geminiviruses and their satellites.

    Science.gov (United States)

    Nawaz-ul-Rehman, Muhammad Shah; Fauquet, Claude M

    2009-06-18

    Geminiviruses and their satellites have circular single stranded DNA genomes, infecting many crops and weeds across the globe. To successfully invade new hosts, break host resistance, move virus particles within and between plants, geminiviruses and their satellites have evolved a coordinated network of protein interactions, showing a possible evolutionary path. Humans have played an important role in the last century to promote the emergence of many geminivirus diseases, thereby impacting their evolution. The greatest molecular diversity of geminiviruses and their satellites resides in Southeast Asia revealing a possible center of origin. This minireview leads us to a possible general grand scheme of their evolution.

  19. Geostationary Satellite (GOES) Images

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Visible and Infrared satellite imagery taken from radiometer instruments on SMS (ATS) and GOES satellites in geostationary orbit. These satellites produced...

  20. Different AT-rich satellite DNAs in Cucurbita pepo and Cucurbita maxima.

    Science.gov (United States)

    Ganal, M; Hemleben, V

    1986-11-01

    The AT-rich highly repeated satellite DNA of Cucurbita pepo (zucchini) and Cucurbita maxima (pumpkin) were cloned and their DNA structure was investigated. DNA sequencing revealed that the repeat length of satellite DNA in Cucurbita pepo is 349-352 base pairs. The percentage of AT-base pairs is about 61%. This satellite is highly conserved in restriction enzyme pattern and DNA sequence; sequence heterogeneity is about 10%. In contrast, the satellite DNA of Cucurbita maxima has a repeat length of 168-169 base pairs. This satellite is also rich in AT-base pairs (64%), existing in at least three different variants as revealed by restriction enzyme analysis and DNA sequencing. The sequence heterogeneity between these variants is about 15%. The two satellite DNAs showed no cross-hybridization to each other and sequence homology is only limited. Nevertheless, we found in the C. pepo genome a high amount of sequences resembling the satellite of C. maxima. In contrast, the satellite repeat of C. pepo is found in the C. maxima DNA only in a few copies. These observations were discussed with respect to satellite DNA evolution and compared to the data received from monocotyledonous species.

  1. Genetics Home Reference: alpha thalassemia

    Science.gov (United States)

    ... Facebook Twitter Home Health Conditions Alpha thalassemia Alpha thalassemia Printable PDF Open All Close All Enable Javascript to view the expand/collapse boxes. Description Alpha thalassemia is a blood disorder that reduces the production ...

  2. Iodine Satellite

    Science.gov (United States)

    Dankanich, John; Kamhawi, Hani; Szabo, James

    2015-01-01

    This project is a collaborative effort to mature an iodine propulsion system while reducing risk and increasing fidelity of a technology demonstration mission concept. 1 The FY 2014 tasks include investments leveraged throughout NASA, from multiple mission directorates, as a partnership with NASA Glenn Research Center (GRC), a NASA Marshall Space Flight Center (MSFC) Technology Investment Project, and an Air Force partnership. Propulsion technology is often a critical enabling technology for space missions. NASA is investing in technologies to enable high value missions with very small and low-cost spacecraft, even CubeSats. However, these small spacecraft currently lack any appreciable propulsion capability. CubeSats are typically deployed and drift without any ability to transfer to higher value orbits, perform orbit maintenance, or deorbit. However, the iodine Hall system can allow the spacecraft to transfer into a higher value science orbit. The iodine satellite (iSAT) will be able to achieve a (Delta)V of >500 m/s with 1,300 s. The iSAT spacecraft, illustrated in figure 1, is currently a 12U CubeSat. The spacecraft chassis will be constructed from aluminum with a finish to prevent iodine-driven corrosion. The iSAT spacecraft includes full three-axis control using wheels, magnetic torque rods, inertial management unit, and a suite of sensors and optics. The spacecraft will leverage heat generated by spacecraft components and radiators for a passive thermal control system.

  3. Characteristics of alpha males in Nepal gray langurs.

    Science.gov (United States)

    Borries, Carola; Perlman, Rachel F; Koenig, Andreas

    2017-07-01

    In species with strong male-male competition, access to females in multimale-multifemale groups is usually regulated via a dominance hierarchy. The highest ranking (alpha) male often has priority of access and sires most offspring. The alpha male can change in three basic ways: (i) a recent immigrant or a resident challenges and becomes the new alpha; (ii) formation of a new group; (iii) succession-becoming alpha after higher ranking males have left. When, in a given primate population, the alpha male changes in different ways, two questions arise: (a) which is the most successful tactic and (b) do male attributes, such as age, aggressiveness or propensity to commit infanticide, affect the outcome? We examined these questions in the seasonally breeding Nepal gray langurs (Semnopithecus schistaceus) at Ramnagar, where new alpha males were either recent immigrants or residents. Success was measured as alpha tenure, residency duration, and the number of offspring sired (paternity exclusion based on DNA analysis, 28 infants). We documented 12 alpha-male tenures across two multimale-multifemale groups between 1991 and 1997. The predominant mode of change was the immigrant tactic. Age had no effect perhaps because alpha males were among the youngest adult males in their group. As expected, infanticidal males performed similarly to non-infanticidal ones. Alpha tenure was highly variable and longer for immigrant alphas and hyper-aggressive ones. However, none of the tactics or attributes examined resulted in significantly longer residencies or more offspring, likely because of the timing of immigrations and stochastic effects (i.e., the number of conceptions occurring per alpha tenure). The influence of female mate choice on male reproductive success requires further investigation. Furthermore, it remains to be examined why resident alpha males-with their presumed better knowledge of their opponents -performed so poorly. Am. J. Primatol. 79:e22437, 2017. © 2015 Wiley

  4. Assignment of casein kinase 2 alpha sequences to two different human chromosomes

    DEFF Research Database (Denmark)

    Boldyreff, B; Klett, C; Göttert, E

    1992-01-01

    Human casein kinase 2 alpha gene (CK-2-alpha) sequences have been localized within the human genome by in situ hybridization and somatic cell hybrid analysis using a CK-2 alpha cDNA as a probe. By in situ hybridization, the CK-2 alpha cDNA could be assigned to two different loci, one on 11p15.1-ter...... and one on 20p13. The existence of two separate chromosomal loci suggests that CK-2 alpha is a member of a gene family. Only the locus on chromosome 11 was confirmed by somatic cell hybrid analysis. The analysis was based on the presence of a CK-2-alpha-specific 20-kb fragment. However, the CK-2 alpha c...

  5. Iodine Satellite

    Science.gov (United States)

    Kamhawi, Hani; Dankanich, John; Martinez, Andres; Petro, Andrew

    2015-01-01

    The Iodine Satellite (iSat) spacecraft will be the first CubeSat to demonstrate high change in velocity from a primary propulsion system by using Hall thruster technology and iodine as a propellant. The mission will demonstrate CubeSat maneuverability, including plane change, altitude change and change in its closest approach to Earth to ensure atmospheric reentry in less than 90 days. The mission is planned for launch in fall 2017. Hall thruster technology is a type of electric propulsion. Electric propulsion uses electricity, typically from solar panels, to accelerate the propellant. Electric propulsion can accelerate propellant to 10 times higher velocities than traditional chemical propulsion systems, which significantly increases fuel efficiency. To enable the success of the propulsion subsystem, iSat will also demonstrate power management and thermal control capabilities well beyond the current state-of-the-art for spacecraft of its size. This technology is a viable primary propulsion system that can be used on small satellites ranging from about 22 pounds (10 kilograms) to more than 1,000 pounds (450 kilograms). iSat's fuel efficiency is ten times greater and its propulsion per volume is 100 times greater than current cold-gas systems and three times better than the same system operating on xenon. iSat's iodine propulsion system consists of a 200 watt (W) Hall thruster, a cathode, a tank to store solid iodine, a power processing unit (PPU) and the feed system to supply the iodine. This propulsion system is based on a 200 W Hall thruster developed by Busek Co. Inc., which was previously flown using xenon as the propellant. Several improvements have been made to the original system to include a compact PPU, targeting greater than 80 percent reduction in mass and volume of conventional PPU designs. The cathode technology is planned to enable heaterless cathode conditioning, significantly increasing total system efficiency. The feed system has been designed to

  6. Alpha Thalassemia (For Parents)

    Science.gov (United States)

    ... the body has a problem producing alpha globin Beta thalassemia : when the body has a problem producing beta ... Transfusion Blood Test: Hemoglobin Electrophoresis Sickle Cell Disease Beta Thalassemia Blood All About Genetics Prenatal Genetic Counseling Genetic ...

  7. ALPHA-2: the sequel

    CERN Multimedia

    Katarina Anthony

    2012-01-01

    While many experiments are methodically planning for intense works over the long shutdown, there is one experiment that is already working at full steam: ALPHA-2. Its final components arrived last month and will completely replace the previous ALPHA set-up. Unlike its predecessor, this next generation experiment has been specifically designed to measure the properties of antimatter.   The ALPHA team lower the new superconducting solenoid magnet into place. The ALPHA collaboration is working at full speed to complete the ALPHA-2 set-up for mid-November – this will give them a few weeks of running before the AD shutdown on 17 December. “We really want to get some experience with this device this year so that, if we need to make any changes, we will have time during the long shutdown in which to make them,” says Jeffrey Hangst, ALPHA spokesperson. “Rather than starting the 2014 run in the commissioning stage, we will be up and running from the get go.&...

  8. Trends in communications satellites

    CERN Document Server

    Curtin, Denis J

    1979-01-01

    Trends in Communications Satellites offers a comprehensive look at trends and advances in satellite communications, including experimental ones such as NASA satellites and those jointly developed by France and Germany. The economic aspects of communications satellites are also examined. This book consists of 16 chapters and begins with a discussion on the fundamentals of electrical communications and their application to space communications, including spacecraft, earth stations, and orbit and wavelength utilization. The next section demonstrates how successful commercial satellite communicati

  9. Expression of triplicated and quadruplicated alpha globin genes in sheep.

    Science.gov (United States)

    Vestri, R; Pieragostini, E; Yang, F; di Gregorio, P; Rando, A; Masina, P

    1991-01-01

    In the sheep alpha alpha alpha globin gene haplotype, the three genes display from the 5' to the 3' end the percentage efficiencies of about 30:14:6, as indicated by the amounts of the three types of alpha chain produced in the alpha alpha alpha/alpha alpha alpha homozygotes. The 3' gene in the alpha alpha alpha alpha haplotype appears to have an efficiency around 1%, as suggested by analysis of one quadruple alpha homozygote. Moreover, the total outputs of the alpha alpha alpha as well as of the alpha alpha alpha alpha haplotypes do not substantially differ from that of the common alpha alpha haplotype.

  10. 5 alpha-reductase inhibitors and prostatic disease.

    Science.gov (United States)

    Schröder, F H

    1994-08-01

    5 alpha-Reductase inhibitors are a new class of substances with very specific effects on type I and type II 5 alpha R which may be of use in the treatment of skin disease, such as male pattern baldness, male acne and hirsutism, as well as prostatic hyperplasia and prostate cancer. At least two types of 5 alpha R inhibitors with a different pH optimum have been described. cDNA encoding for both the type I and the type II enzyme has been cloned. Most of the orally effective 5 alpha R inhibitors belong to the class of 4-azasteroids. The radical substituted in the 17 position of the steroid ring seems to be related to species specific variations and to the types of 5 alpha R enzymes in different species and organ systems. 5 alpha R inhibitors lead to a decrease of plasma DHT by about 65% while there is a slight rise in plasma testosterone. The decrease of tissue DHT in the ventral prostate of the intact rat, the dog and in humans is more pronounced and amounts to about 85%. There is a reciprocal rise of tissue T in these systems. The application of an inhibitor of 5 alpha R type II leads to a shrinkage of BPH in men by about 30%. In the rat a similar shrinkage accompanied by a significant decrease of total organ DNA occurs. This decrease, however, is not as pronounced as can be achieved with castration.(ABSTRACT TRUNCATED AT 250 WORDS)

  11. Molecular biology of fuselloviruses and their satellites.

    Science.gov (United States)

    Contursi, Patrizia; Fusco, Salvatore; Cannio, Raffaele; She, Qunxin

    2014-05-01

    Fuselloviruses, also known as Sulfolobus Spindle-shaped viruses (SSVs), are "lemon"- or "spindle"-shaped double-stranded DNA viruses. Among them, SSV1, SSV2 and the satellite viruses pSSVx and pSSVi have been investigated at the structural, genetic, transcriptomic, proteomic and biochemical levels, thus becoming models for dissecting DNA replication/gene expression in Archaea. Important progress has been made including elucidation of temporal genome expression during virus infection and induction of replication, SSV1 lysogeny maintenance as well as differentially expression of pSSVx replicase. Future researches focusing on these model systems would yield insightful knowledge of life cycle and DNA replication of fuselloviruses.

  12. Diversity of Dicotyledenous-Infecting Geminiviruses and Their Associated DNA Molecules in Southern Africa, Including the South-West Indian Ocean Islands

    Directory of Open Access Journals (Sweden)

    Lindy L. Esterhuizen

    2012-09-01

    Full Text Available The family Geminiviridae comprises a group of plant-infecting circular ssDNA viruses that severely constrain agricultural production throughout the temperate regions of the world, and are a particularly serious threat to food security in sub-Saharan Africa. While geminiviruses exhibit considerable diversity in terms of their nucleotide sequences, genome structures, host ranges and insect vectors, the best characterised and economically most important of these viruses are those in the genus Begomovirus. Whereas begomoviruses are generally considered to be either monopartite (one ssDNA component or bipartite (two circular ssDNA components called DNA-A and DNA-B, many apparently monopartite begomoviruses are associated with additional subviral ssDNA satellite components, called alpha- (DNA-as or betasatellites (DNA-βs. Additionally, subgenomic molecules, also known as defective interfering (DIs DNAs that are usually derived from the parent helper virus through deletions of parts of its genome, are also associated with bipartite and monopartite begomoviruses. The past three decades have witnessed the emergence and diversification of various new begomoviral species and associated DI DNAs, in southern Africa, East Africa, and proximal Indian Ocean islands, which today threaten important vegetable and commercial crops such as, tobacco, cassava, tomato, sweet potato, and beans. This review aims to describe what is known about these viruses and their impacts on sustainable production in this sensitive region of the world.

  13. A polymerase chain reaction (PCR) method for sex and species determination with novel controls for deoxyribonucleic acid (DNA) template length.

    Science.gov (United States)

    Gaensslen, R E; Berka, K M; Grosso, D A; Ruano, G; Pagliaro, E M; Messina, D; Lee, H C

    1992-01-01

    Human X and Y chromosome alpha-satellite sequences lying within higher order repeats were amplified by the polymerase chain reaction (PCR) in genomic deoxyribonucleic acid (DNA) isolated from blood, bone, and several other tissues and specimens of potential forensic science interest. X and Y sequences could be coamplified under some of the PCR conditions employed. Monomorphic sequences in the 3'-apolipoprotein B gene (designated "H") and in an alpha-satellite higher order repeat on Chromosome 17 (p17H8, D17Z1) were likewise amplified in the specimens. X and Y sequence amplification can provide information about the sex of origin. Amplification of the X, H, and D17Z1 sequences was found to be primate-specific among the common animals tested and can thus provide species of origin information about a specimen. The authors suggest that amplification of X and D17Z1 or H sequences might provide "relaxed" and "stringent" controls for appropriate PCR amplification tests on forensic science specimens. Testing was carried out using PCR protocols that employed Thermophilus aquaticus (Taq) and Thermus flavis (Replinase) thermostable DNA polymerases.

  14. Monte Carlo alpha calculation

    Energy Technology Data Exchange (ETDEWEB)

    Brockway, D.; Soran, P.; Whalen, P.

    1985-01-01

    A Monte Carlo algorithm to efficiently calculate static alpha eigenvalues, N = ne/sup ..cap alpha..t/, for supercritical systems has been developed and tested. A direct Monte Carlo approach to calculating a static alpha is to simply follow the buildup in time of neutrons in a supercritical system and evaluate the logarithmic derivative of the neutron population with respect to time. This procedure is expensive, and the solution is very noisy and almost useless for a system near critical. The modified approach is to convert the time-dependent problem to a static ..cap alpha../sup -/eigenvalue problem and regress ..cap alpha.. on solutions of a/sup -/ k/sup -/eigenvalue problem. In practice, this procedure is much more efficient than the direct calculation, and produces much more accurate results. Because the Monte Carlo codes are intrinsically three-dimensional and use elaborate continuous-energy cross sections, this technique is now used as a standard for evaluating other calculational techniques in odd geometries or with group cross sections.

  15. Handbook of satellite applications

    CERN Document Server

    Madry, Scott; Camacho-Lara, Sergio

    2017-01-01

    The first edition of this ground breaking reference work was the most comprehensive reference source available about the key aspects of the satellite applications field. This updated second edition covers the technology, the markets, applications and regulations related to satellite telecommunications, broadcasting and networking—including civilian and military systems; precise satellite navigation and timing networks (i.e. GPS and others); remote sensing and meteorological satellite systems. Created under the auspices of the International Space University based in France, this brand new edition is now expanded to cover new innovative small satellite constellations, new commercial launching systems, innovation in military application satellites and their acquisition, updated appendices, a useful glossary and more.

  16. Small satellite product assurance

    Science.gov (United States)

    Demontlivault, J.; Cadelec, Jacques

    1993-01-01

    In order to increase the interest in small satellites, their cost must be reduced; reducing product assurance costs induced by quality requirements is a major objective. For a logical approach, small satellites are classified in three main categories: satellites for experimental operations with a short lifetime, operational satellites manufactured in small mass with long lifetime requirements, operational satellites (long lifetime required), of which only a few models are produced. The various requirements as regards the product assurance are examined for each satellite category: general requirements for space approach, reliability, electronic components, materials and processes, quality assurance, documentation, tests, and management. Ideal product assurance system integrates quality teams and engineering teams.

  17. alpha-Amanitin induced apoptosis in primary cultured dog hepatocytes.

    Directory of Open Access Journals (Sweden)

    Adam Szelag

    2010-06-01

    Full Text Available Amatoxin poisoning is caused by mushroom species belonging to the genera Amanita, Galerina and Lepiota with the majority of lethal mushroom exposures attributable to Amanita phalloides. High mortality rate in intoxications with these mushrooms is principally a result of the acute liver failure following significant hepatocyte damage due to hepatocellular uptake of amatoxins. A wide variety of amatoxins have been isolated; however, alpha-amanitin (alpha-AMA appears to be the primary toxin. Studies in vitro and in vivo suggest that alpha-AMA does not only cause hepatocyte necrosis, but also may lead to apoptotic cell death. The objective of this study was to evaluate the complex hepatocyte apoptosis in alpha-AMA cytotoxicity. All experiments were performed on primary cultured canine hepatocytes. The cells were incubated for 12 h with alpha-AMA at a final concentration of 1, 5, 10 and 20 microM. Viability test (MTT assay, apoptosis evaluation (TUNEL reaction, detection of DNA laddering and electron microscopy were performed at 6 and 12 h of exposure to alpha-AMA. There was a clear correlation between hepatocyte viability, concentration of alpha-AMA and time of exposure to this toxin. The decline in cultured dog hepatocyte viability during the exposure to alpha-AMA is most likely preceded by enhanced cellular apoptosis. Our results demonstrate that apoptosis might contribute to pathogenesis of the severe liver injury in the course of amanitin intoxication, particularly during the early phase of poisoning.

  18. DNA probe for lactobacillus delbrueckii

    Energy Technology Data Exchange (ETDEWEB)

    Delley, M.; Mollet, B.; Hottinger, H. (Nestle Research Centre, Lausanne (Switzerland))

    1990-06-01

    From a genomic DNA library of Lactobacillus delbrueckii subsp. bulgaricus, a clone was isolated which complements a leucine auxotrophy of an Escherichia coli strain (GE891). Subsequent analysis of the clone indicated that it could serve as a specific DNA probe. Dot-blot hybridizations with over 40 different Lactobacillus strains showed that this clone specifically recognized L. delbrueckii subsp. delbrueckii, bulgaricus, and lactis. The sensitivity of the method was tested by using an {alpha}-{sup 32}P-labeled probe.

  19. Monte Carlo alpha deposition

    International Nuclear Information System (INIS)

    Talley, T.L.; Evans, F.

    1988-01-01

    Prior work demonstrated the importance of nuclear scattering to fusion product energy deposition in hot plasmas. This suggests careful examination of nuclear physics details in burning plasma simulations. An existing Monte Carlo fast ion transport code is being expanded to be a test bed for this examination. An initial extension, the energy deposition of fast alpha particles in a hot deuterium plasma, is reported. The deposition times and deposition ranges are modified by allowing nuclear scattering. Up to 10% of the initial alpha particle energy is carried to greater ranges and times by the more mobile recoil deuterons. 4 refs., 5 figs., 2 tabs

  20. Buffett’s Alpha

    DEFF Research Database (Denmark)

    Frazzini, Andrea; Kabiller, David; Heje Pedersen, Lasse

    Berkshire Hathaway has realized a Sharpe ratio of 0.76, higher than any other stock or mutual fund with a history of more than 30 years, and Berkshire has a significant alpha to traditional risk factors. However, we find that the alpha becomes insignificant when controlling for exposures to Betting......-Against-Beta and Quality-Minus-Junk factors. Further, we estimate that Buffett’s leverage is about 1.6-to-1 on average. Buffett’s returns appear to be neither luck nor magic, but, rather, reward for the use of leverage combined with a focus on cheap, safe, quality stocks. Decomposing Berkshires’ portfolio into ownership...

  1. Satellite RNAs and Satellite Viruses of Plants.

    Science.gov (United States)

    Hu, Chung-Chi; Hsu, Yau-Heiu; Lin, Na-Sheng

    2009-12-01

    The view that satellite RNAs (satRNAs) and satellite viruses are purely molecular parasites of their cognate helper viruses has changed. The molecular mechanisms underlying the synergistic and/or antagonistic interactions among satRNAs/satellite viruses, helper viruses, and host plants are beginning to be comprehended. This review aims to summarize the recent achievements in basic and practical research, with special emphasis on the involvement of RNA silencing mechanisms in the pathogenicity, population dynamics, and, possibly, the origin(s) of these subviral agents. With further research following current trends, the comprehensive understanding of satRNAs and satellite viruses could lead to new insights into the trilateral interactions among host plants, viruses, and satellites.

  2. GPS Satellite Simulation Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The GPS satellite simulation facility consists of a GPS satellite simulator controlled by either a Silicon Graphics Origin 2000 or PC depending upon unit under test...

  3. Satellite Tags- Hawaii EEZ

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Satellite tagging was implemented in 2013. Satellite tagging is conducted using a Dan Inject air rifle and deployment arrows designed by Wildlife Computers. Two...

  4. Two novel nonradioactive polymerase chain reaction-based assays of dried blood spots, genomic DNA, or whole cells for fast, reliable detection of Z and S mutations in the alpha 1-antitrypsin gene

    DEFF Research Database (Denmark)

    Andresen, B S; Knudsen, I; Jensen, P K

    1992-01-01

    from individuals who are normal, heterozygous, or homozygous for the mutations. We show that the two assays can be performed with purified genomic DNA as well as with boiled blood spots. The new assays were validated by parallel testing with a technique in which PCR is combined with allele......-specific oligonucleotide (ASO) probes. In all cases tested the results obtained by the different techniques were in accordance. The new assays can be used for prenatal diagnostics and can be performed directly with boiled tissue samples. Because the new assays are easy to perform and reliable, we conclude...

  5. Differential interaction between cassava mosaic geminiviruses and geminivirus satellites.

    Science.gov (United States)

    Patil, Basavaprabhu L; Fauquet, Claude M

    2010-07-01

    Geminiviruses are often associated with subviral agents called DNA satellites that require proteins encoded by the helper virus for their replication, movement and encapsidation. Hitherto, most of the single-stranded DNA satellites reported to be associated with members of the family Geminiviridae have been associated with monopartite begomoviruses. Cassava mosaic disease is known to be caused by viruses belonging to nine different begomovirus species in the African continent and the Indian subcontinent. In addition to these species, several strains have been recognized that exhibit contrasting phenotypes and infection dynamics. It is established that Sri Lankan cassava mosaic virus can trans-replicate betasatellites and can cross host barriers. To extend these studies further, we carried out an exhaustive investigation of the ability of geminiviruses, selected to represent all cassava-infecting geminivirus species, to trans-replicate betasatellites (DNA-beta) and to interact with alphasatellites (nanovirus-like components; previously called DNA-1). Each of the cassava-infecting geminiviruses showed a contrasting and differential interaction with the DNA satellites, not only in the capacity to interact with these molecules but also in the modulation of symptom phenotypes by the satellites. These observations could be extrapolated to field situations in order to hypothesize about the possibility of acquisition of such DNA satellites currently associated with other begomoviruses. These results call for more detailed analyses of these subviral components and an investigation of their possible interaction with the cassava mosaic disease complex.

  6. Case Study - Alpha

    Directory of Open Access Journals (Sweden)

    Stephen Leybourne

    2016-11-01

    Full Text Available This case study was developed from an actual scenario by Dr. Steve Leybourne of Boston University.  The case documents the historical evolution of an organization, and has been used successfully in courses dealing with organizational and cultural change, and the utilization of ‘soft skills’ in project-based management. This is a short case, ideal for classroom use and discussion.  The issues are easily accessible to students, and there is a single wide ranging question that allows for the inclusion of many issues surrounding strategic decision-making, and behavioural and cultural change. Alpha was one of the earlier companies in the USA to invest in large, edge-of-town superstores, with plentiful free vehicle parking, selling food and related household products. Alpha was created in the 1950s as a subsidiary of a major publicly quoted retail group.  It started business by opening a string of very large discount stores in converted industrial and warehouse premises in the south of the United States. In the early days shoppers were offered a limited range of very competitively priced products. When Alpha went public in 1981 it was the fourth largest food retailer in the US, selling an ever-widening range of food and non-food products.  Its success continued to be based on high volume, low margins and good value for money, under the slogan of ‘Alpha Price.’

  7. Alpha-mannosidosis

    DEFF Research Database (Denmark)

    Borgwardt, Line; Stensland, Hilde Monica Frostad Riise; Olsen, Klaus Juul

    2015-01-01

    of the three subgroups of genotype/subcellular localisation and the clinical and biochemical data were done to investigate the potential relationship between genotype and phenotype in alpha-mannosidosis. Statistical analyses were performed using the SPSS software. Analyses of covariance were performed...

  8. alpha-Globin genes: thalassemic and structural alterations in a Brazilian population

    Directory of Open Access Journals (Sweden)

    M.R.S.C. Wenning

    2000-09-01

    Full Text Available Seven unrelated patients with hemoglobin (Hb H disease and 27 individuals with alpha-chain structural alterations were studied to identify the alpha-globin gene mutations present in the population of Southeast Brazil. The -alpha3.7, --MED and -(alpha20.5 deletions were investigated by PCR, whereas non-deletional alpha-thalassemia (alphaHphalpha, alphaNcoIalpha, aaNcoI, alphaIcalpha and alphaTSaudialpha was screened with restriction enzymes and by nested PCR. Structural alterations were identified by direct DNA sequencing. Of the seven patients with Hb H disease, all of Italian descent, two had the -(alpha20.5/-alpha3.7 genotype, one had the --MED/-alpha3.7 genotype, one had the --MED/alphaHphalpha genotype and three showed interaction of the -alpha3.7 deletion with an unusual, unidentified form of non-deletional alpha-thalassemia [-alpha3.7/(aaT]. Among the 27 patients with structural alterations, 15 (of Italian descent had Hb Hasharon (alpha47Asp->His associated with the -alpha3.7 deletion, 4 (of Italian descent were heterozygous for Hb J-Rovigo (alpha53Ala->Asp, 4 (3 Blacks and 1 Caucasian were heterozygous for Hb Stanleyville-II (alpha78Asn->Lys associated with the alpha+-thalassemia, 1 (Black was heterozygous for Hb G-Pest (alpha74Asp->Asn, 1 (Caucasian was heterozygous for Hb Kurosaki (alpha7Lys->Glu, 1 (Caucasian was heterozygous for Hb Westmead (alpha122His->Gln, and 1 (Caucasian was the carrier of a novel silent variant (Hb Campinas, alpha26Ala->Val. Most of the mutations found reflected the Mediterranean and African origins of the population. Hbs G-Pest and Kurosaki, very rare, and Hb Westmead, common in southern China, were initially described in individuals of ethnic origin differing from those of the carriers reported in the present study and are the first cases to be reported in the Brazilian population.

  9. Hemoglobin alpha 2 gene +861 G>A polymorphism in Turkish ...

    African Journals Online (AJOL)

    Dilay Ciglidag Dungul

    Alpha thalassemia is caused by mutations in the alpha chain of the hemoglobin molecule. ... According to Human Gene Mutation Database (HGMD) more than 48 different .... Electroferogram of the DNA sequence, showing a G to A polymorphism in the downstream untranslated region of the HBA2 gene. Table 3 The ...

  10. Intraethnic variation in steroid-5-alpha-reductase polymorphisms in ...

    Indian Academy of Sciences (India)

    2015-06-01

    Jun 1, 2015 ... Herrera-Ramos E., Rodríguez-Gallego C. and Lara P. C. 2015 Intraethnic variation in steroid-5-alpha-reductase polymorphisms in prostate ... generation. This study was approved by the Research and. Ethics Committee of each institution participant in the study. DNA was isolated from 300 µL of ...

  11. Theory of geostationary satellites

    CERN Document Server

    Zee, Chong-Hung

    1989-01-01

    Geostationary or equatorial synchronous satellites are a daily reminder of our space efforts during the past two decades. The nightly television satellite weather picture, the intercontinental telecommunications of television transmissions and telephone conversations, and the establishrnent of educational programs in remote regions on Earth are constant reminders of the presence of these satellites. As used here, the term 'geo­ stationary' must be taken loosely because, in the long run, the satellites will not remain 'stationary' with respect to an Earth-fixed reference frame. This results from the fact that these satellites, as is true for all satellites, are incessantly subject to perturbations other than the central-body attraction of the Earth. Among the more predominant pertur­ bations are: the ellipticity of the Earth's equator, the Sun and Moon, and solar radiation pressure. Higher harmonics of the Earth's potential and tidal effects also influence satellite motion, but they are of second­ order whe...

  12. Meteorological satellite systems

    CERN Document Server

    Tan, Su-Yin

    2014-01-01

    “Meteorological Satellite Systems” is a primer on weather satellites and their Earth applications. This book reviews historic developments and recent technological advancements in GEO and polar orbiting meteorological satellites. It explores the evolution of these remote sensing technologies and their capabilities to monitor short- and long-term changes in weather patterns in response to climate change. Satellites developed by various countries, such as U.S. meteorological satellites, EUMETSAT, and Russian, Chinese, Japanese and Indian satellite platforms are reviewed. This book also discusses international efforts to coordinate meteorological remote sensing data collection and sharing. This title provides a ready and quick reference for information about meteorological satellites. It serves as a useful tool for a broad audience that includes students, academics, private consultants, engineers, scientists, and teachers.

  13. Non-CpG methylation of the PGC-1alpha promoter through DNMT3B controls mitochondrial density

    DEFF Research Database (Denmark)

    Barres, Romain; Osler, Megan E; Yan, Jie

    2009-01-01

    Epigenetic modification through DNA methylation is implicated in metabolic disease. Using whole-genome promoter methylation analysis of skeletal muscle from normal glucose-tolerant and type 2 diabetic subjects, we identified cytosine hypermethylation of peroxisome proliferator-activated receptor......-CpG nucleotides. Non-CpG methylation was acutely increased in human myotubes by exposure to tumor necrosis factor-alpha (TNF-alpha) or free fatty acids, but not insulin or glucose. Selective silencing of the DNA methyltransferase 3B (DNMT3B), but not DNMT1 or DNMT3A, prevented palmitate-induced non......-CpG methylation of PGC-1alpha and decreased mtDNA and PGC-1alpha mRNA. We provide evidence for PGC-1alpha hypermethylation, concomitant with reduced mitochondrial content in type 2 diabetic patients, and link DNMT3B to the acute fatty-acid-induced non-CpG methylation of PGC-1alpha promoter....

  14. Demystifying AlphaGo Zero as AlphaGo GAN

    OpenAIRE

    Dong, Xiao; Wu, Jiasong; Zhou, Ling

    2017-01-01

    The astonishing success of AlphaGo Zero\\cite{Silver_AlphaGo} invokes a worldwide discussion of the future of our human society with a mixed mood of hope, anxiousness, excitement and fear. We try to dymystify AlphaGo Zero by a qualitative analysis to indicate that AlphaGo Zero can be understood as a specially structured GAN system which is expected to possess an inherent good convergence property. Thus we deduct the success of AlphaGo Zero may not be a sign of a new generation of AI.

  15. $\\alpha$-Representation for QCD

    OpenAIRE

    Tuan, Richard Hong

    1998-01-01

    An $\\alpha$-parameter representation is derived for gauge field theories.It involves, relative to a scalar field theory, only constants and derivatives with respect to the $\\alpha$-parameters. Simple rules are given to obtain the $\\alpha$-representation for a Feynman graph with an arbitrary number of loops in gauge theories in the Feynman gauge.

  16. Alpha Theta Meditation: Phenomenological, neurophysiologic ...

    African Journals Online (AJOL)

    Alpha Theta Meditation: Phenomenological, neurophysiologic, mindfulness, mood, health and sport implications. ... the single alpha theta meditation was associated with elevated alpha and theta activity, as well as decrease in negative mood perceptions, especially with regard to anxiety, sadness and confusion scores.

  17. Alpha scintillation radon counting

    International Nuclear Information System (INIS)

    Lucas, H.F. Jr.

    1977-01-01

    Radon counting chambers which utilize the alpha-scintillation properties of silver activated zinc sulfide are simple to construct, have a high efficiency, and, with proper design, may be relatively insensitive to variations in the pressure or purity of the counter filling. Chambers which were constructed from glass, metal, or plastic in a wide variety of shapes and sizes were evaluated for the accuracy and the precision of the radon counting. The principles affecting the alpha-scintillation radon counting chamber design and an analytic system suitable for a large scale study of the 222 Rn and 226 Ra content of either air or other environmental samples are described. Particular note is taken of those factors which affect the accuracy and the precision of the method for monitoring radioactivity around uranium mines

  18. Combining Alphas via Bounded Regression

    Directory of Open Access Journals (Sweden)

    Zura Kakushadze

    2015-11-01

    Full Text Available We give an explicit algorithm and source code for combining alpha streams via bounded regression. In practical applications, typically, there is insufficient history to compute a sample covariance matrix (SCM for a large number of alphas. To compute alpha allocation weights, one then resorts to (weighted regression over SCM principal components. Regression often produces alpha weights with insufficient diversification and/or skewed distribution against, e.g., turnover. This can be rectified by imposing bounds on alpha weights within the regression procedure. Bounded regression can also be applied to stock and other asset portfolio construction. We discuss illustrative examples.

  19. Kinetics and mechanism of the general-acid-catalyzed ring-closure of the malondialdehyde-DNA adduct, N2-(3-oxo-1-propenyl)deoxyguanosine (N2OPdG-), to 3-(2'-Deoxy-beta-D-erythro-pentofuranosyl)pyrimido[1,2-alpha]purin- 10(3H)-one (M1dG).

    Science.gov (United States)

    Riggins, James N; Pratt, Derek A; Voehler, Markus; Daniels, J Scott; Marnett, Lawrence J

    2004-09-01

    3-(2'-Deoxy-beta-D-erythro-pentofuranosyl)pyrimido[1,2-alpha]purin-10(3H)-one (M1dG) is the major product of the reaction of deoxyguanosine with malondialdehyde (MDA). M1dG blocks replication by DNA polymerases in vitro and is mutagenic in vivo. M1dG reacts with hydroxide to form the N2-(3-oxo-1-propenyl)deoxyguanosine anion (N2OPdG-). This reaction is pH-dependent and reverses under neutral and acidic conditions to form M1dG. Here we describe the kinetics and mechanism of the ring-closure reaction in both the nucleoside and oligonucleotides. Kinetic analysis of absorbance and fluorescence changes demonstrates that ring-closure is biphasic, leading to the rapid formation of an intermediate that slowly converts to M1dG in a general-acid-catalyzed reaction. The dependence of the rate of the rapid phase on pH reveals the pKa for protonated N2OPdG is 6.9. One-dimensional 1H NMR and DQF-COSY experiments identified two distinct intermediates, N2OPdG-H and 8-hydroxy-6,7-propenodeoxyguanosine (HO-Prene-dG), that are formed upon acidification of N2OPdG-. Characterization of ring-closure in single-stranded and in melted duplex oligonucleotides shows M1dG formation is also acid-catalyzed in single-stranded oligonucleotides and that the denaturation of an oligonucleotide duplex enhances ring-closure. This work details the complexity of ring-closure in the nucleoside and oligonucleotides and provides new insight into the role of duplex DNA in catalyzing ring-opening and ring-closing of M1dG and N2OPdG. Copyright 2004 American Chemical Society

  20. Cloning and expression of a rat brain. alpha. sub 2B -adrenergic receptor

    Energy Technology Data Exchange (ETDEWEB)

    Flordellis, C.S.; Handy, D.E.; Bresnahan, M.R.; Zannis, V.I.; Gavras, H. (Boston Univ. School of Medicine, MA (United States))

    1991-02-01

    The authors isolated a cDNA clone (RB{alpha}{sub 2B}) and its homologous gene (GR{alpha}{sub 2B}) encoding an {alpha}{sub 2B}-adrenergic receptor subtype by screening a rat brain cDNA and a rat genomic library. Nucleotide sequence analysis showed that both clones code for a protein of 458 amino acids, which is 87% homologous to the human kidney glycosylated adrenergic receptor ({alpha}{sub 2}-C4) and divergent from the rat kidney nonglycosylated {alpha}{sub 2B} subtype (RNG{alpha}{sub 2}). Transient expression of RB{alpha}{sub 2B} in COS-7 cells resulted in high-affinity saturable binding for ({sup 3}H)rauwolscine and a high receptor number in the membranes of transfected COS-7 cells. Pharmacological analysis demonstrated that the expressed receptor bound adrenergic ligands with the following order of potency: rauwolscine {gt} yohimbine {gt} prazosin {gt} oxymetazoline, with a prazosin-to-oxymetazoline K{sub i} ratio of 0.34. This profile is characteristic of the {alpha}{sub 2B}-adrenergic receptor subtype. Blotting analysis of rat brain mRNA gave one major and two minor mRNA species, and hybridization with strand-specific probes showed that both DNA strands of GR{alpha}{sub 2B} may be transcriptionally active. These findings show that rat brain expresses an {alpha}{sub 2B}-adrenergic receptor subtype that is structurally different from the rat kidney nonglycosylated {alpha}{sub 2B} subtype. Thus the rat expresses at least two divergent {alpha}{sub 2B}-adrenergic receptors.

  1. The anti-aromatase effect of progesterone and of its natural metabolites 20alpha- and 5alpha-dihydroprogesterone in the MCF-7aro breast cancer cell line.

    Science.gov (United States)

    Pasqualini, J R; Chetrite, G

    2008-01-01

    Progesterone is metabolized in the normal breast mainly into 4-ene-pregnenes (e.g. 20alpha-dihydroprogesterone, 20alphaDHP) but, in contrast, in breast cancer tissue the 5alpha-dihydropregnanes (e.g. 5alpha-dihydroprogesterone, 5alphaDHP) are prevalent. In the present study the effect of progesterone and its main metabolites 20alphaDHP and 5alphaDHP on the aromatase activity in a stable aromatase-expressing estrogen receptor-positive human breast cancer cell line, MCF-7aro, was explored. The MCF-7aro cells were stripped of endogenous steroids and incubated with physiological concentrations of [3H]-testosterone ([3H]-testos: 5 x 10(-9)M) alone or in the presence of progesterone, 20alphaDHP or 5alphaDHP (5 x 10(-6) or 5 x 10(-8)M) for 24 h at 37 degrees C. The cellular radioactivity uptake was determined in the ethanolic supernatant and the DNA content in the remaining pellet. [3H]-Estradiol (E2), [3H]-estrone (E1) and [3H]-testos were characterized by thin layer chromatography and quantified using the corresponding standard. Aromatase activity was present at a high level in the MCF-7aro cells after incubation with [3H]-testos when the concentration of [3H]-E2 was 3.70 pmol/mg DNA; 20alphaDHP at concentrations of 5 x 10(-6)M or 5 x 10(-8)M significantly inhibited this conversion by 50.3% and 36.5%, respectively. No significant effect was found with the metabolite 5alphaDHP or the parent hormone, progesterone. The MCF-7aro cell line shows high detectable aromatase activity. The present data indicate that the progesterone metabolite 20alphaDHP, found mainly in normal breast tissue, can act as an anti-aromatase agent.

  2. Synthesis of a Bacillus subtilis small, acid-soluble spore protein in Escherichia coli causes cell DNA to assume some characteristics of spore DNA

    International Nuclear Information System (INIS)

    Setlow, B.; Hand, A.R.; Setlow, P.

    1991-01-01

    Small, acid-soluble proteins (SASP) of the alpha/beta-type are associated with DNA in spores of Bacillus subtilis. Induction of synthesis of alpha/beta-type SASP in Escherichia coli resulted in rapid cessation of DNA synthesis, followed by a halt in RNA and then protein accumulation, although significant mRNA and protein synthesis continued. There was a significant loss in viability associated with SASP synthesis in E. coli: recA+ cells became extremely long filaments, whereas recA mutant cells became less filamentous. The nucleoids of cells with alpha/beta-type SASP were extremely condensed, as viewed in both light and electron microscopes, and immunoelectron microscopy showed that the alpha/beta-type SASP were associated with the cell DNA. Induction of alpha/beta-type SASP synthesis in E. coli increased the negative superhelical density of plasmid DNA by approximately 20%; UV irradiation of E. coli with alpha/beta-type SASP gave reduced yields of thymine dimers but significant amounts of the spore photoproduct. These changes in E. coli DNA topology and photochemistry due to alpha/beta-type SASP are similar to the effects of alpha/beta-type SASP on the DNA in Bacillus spores, further suggesting that alpha/beta-type SASP are a major factor determining DNA properties in bacterial spores

  3. Meteorological satellite accomplishments

    Science.gov (United States)

    Allison, L. J.; Arking, A.; Bandeen, W. R.; Shenk, W. E.; Wexler, R.

    1975-01-01

    Meteorological satellites include experimental satellites operated by NASA and operational satellites operated by the National Oceanic and Atmospheric Administration (NOAA). The operational system currently provides pictures of the entire globe, temperature measurements throughout the world, and wind measurements in selected parts of the Atlantic and Pacific oceans. Aspects of vertical sounding are discussed along with questions of parameter extraction technique development, macroscale phenomena, the heat budget of the earth-atmosphere system and the climate, and studies of ocean surface and hydrology.

  4. DNA methyltransferase 1/3a overexpression in sporadic breast cancer is associated with reduced expression of estrogen receptor-alpha/breast cancer susceptibility gene 1 and poor prognosis.

    Science.gov (United States)

    Yu, Zhaojin; Xiao, Qinghuan; Zhao, Lin; Ren, Jie; Bai, Xuefeng; Sun, Mingli; Wu, Huizhe; Liu, Xiaojian; Song, Zhiguo; Yan, Yuanyuan; Mi, Xiaoyi; Wang, Enhua; Jin, Feng; Wei, Minjie

    2015-09-01

    DNA methyltransferases (DNMTs), including DNMT1, 3a, and 3b, play an important role in the progression of many malignant tumors. However, it remains unclear whether expression of DNMTs is associated with the development of breast cancer. This study aimed to explore the clinical significance of DNMT proteins in sporadic breast cancer. We investigated the expression of DNMT1, 3a, and 3b in 256 breast cancer and 36 breast fibroadenoma, using immunohistochemistry. The expression of DNMT1 and 3a was significantly higher in breast cancer than in fibroadenoma. In breast cancer, the expression of DNMT1 was significantly correlated with lymph node metastasis (P = 0.020), and the expression of DNMT3a and 3b was significantly correlated with advanced clinical stages (P = 0.046 and 0.012, respectively). Overexpression of DNMT1/3a was correlated with promoter hypermethylation and reduced expression of ERα and BRCA1. The expression levels of DNMT1 or DNMT3a were associated with a significantly shorter DFS or OS in a subgroup of breast cancer patients (patients with the age ≤50 years old, ERα-negative status, or HER2-postive status). The expression of DNMT1 or a combined expression of DNMT1 and 3a was associated with poor prognosis in patients who received chemotherapy and endocrine therapy, but not in patients who received chemotherapy alone. These findings suggest that DNMT1 and 3a may be involved in the progression and prognosis of sporadic breast cancer. © 2014 Wiley Periodicals, Inc.

  5. Study on cellular genotoxicities induced by alpha particles irradiation in combination with NNK treatment

    International Nuclear Information System (INIS)

    Li Ping; Yang Zhihua; Pan Xiujie; Cao Zhenshan; Mi Na; Chen Zhongmin; Liu Gang; Wei Han; Li Huiying; Zhu Maoxiang

    2006-01-01

    Objective: To investigate cellular genotoxicities of aplha particles irradiation in combination with NNK treatment. Methods: Exponentially growing immortalized human bronchial epithelial cells were divided into the normal control group (NC), alpha particles irradiation (α), NNK administration group (NNK), NNK administration (100 μg/ml) followed by alpha particles irradiation group (NNK + α), and alpha particles irradiation followed by NNK administration (100 μg/ml) group (μ + NNK). DNA damage were detected by single cell gel electrophoresis (SCGE); multinuclear cell assay was used to detect the frequency of the HPRT gene mutation; cell micronucleus frequency were detected by cytogenetic methods. Results: In the group exposed to both alpha particles irradiation and NNK, DNA damage, HPRT gene mutation frequency, and cell micronucleus frequency were significantly higher than those in the same dose groups irradiated with alpha particles or NNK administration alone. Subtracted the NNK effect, DNA damage, HPRT gene mutation frequency and cell micronucleus frequency in the group irradiated by alpha particles in combination with NNK administration were significantly higher than those of alpha particles irradiation alone. Conclusion: The genotoxicity of alpha particles irradiation in combination with NNK administration had synergistic effect. (authors)

  6. alpha-MSH activates immediate defense responses to UV-induced oxidative stress in human melanocytes.

    Science.gov (United States)

    Song, Xiuzu; Mosby, Nicole; Yang, Jennifer; Xu, Aie; Abdel-Malek, Zalfa; Kadekaro, Ana Luisa

    2009-12-01

    Exposure of cultured human melanocytes to ultraviolet radiation (UV) results in DNA damage. In melanoma, UV-signature mutations resulting from unrepaired photoproducts are rare, suggesting the possible involvement of oxidative DNA damage in melanocyte malignant transformation. Here we present data demonstrating immediate dose-dependent generation of hydrogen peroxide in UV-irradiated melanocytes, which correlated directly with a decrease in catalase activity. Pretreatment of melanocytes with alpha-melanocortin (alpha-MSH) reduced the UV-induced generation of 7,8-dihydro-8-oxyguanine (8-oxodG), a major form of oxidative DNA damage. Pretreatment with alpha-MSH also increased the protein levels of catalase and ferritin. The effect of alpha-MSH on 8-oxodG induction was mediated by activation of the melanocortin 1 receptor (MC1R), as it was absent in melanocytes expressing loss-of-function MC1R, and blocked by concomitant treatment with an analog of agouti signaling protein (ASIP), ASIP-YY. This study provides unequivocal evidence for induction of oxidative DNA damage by UV in human melanocytes and reduction of this damage by alpha-MSH. Our data unravel some mechanisms by which alpha-MSH protects melanocytes from oxidative DNA damage, which partially explain the strong association of loss-of-function MC1R with melanoma.

  7. Mutagenicity of acrolein and acrolein-induced DNA adducts.

    Science.gov (United States)

    Liu, Xing-yu; Zhu, Mao-xiang; Xie, Jian-ping

    2010-01-01

    Acrolein mutagenicity relies on DNA adduct formation. Reaction of acrolein with deoxyguanosine generates alpha-hydroxy-1, N(2)-propano-2'-deoxyguanosine (alpha-HOPdG) and gamma-hydroxy-1, N(2)-propano-2'-deoxyguanosine (gamma-HOPdG) adducts. These two DNA adducts behave differently in mutagenicity. gamma-HOPdG is the major DNA adduct and it can lead to interstrand DNA-DNA and DNA-peptide/protein cross-links, which may induce strong mutagenicity; however, gamma-HOPdG can be repaired by some DNA polymerases complex and lessen its mutagenic effects. alpha-HOPdG is formed much less than gamma-HOPdG, but difficult to be repaired, which contributes to accumulation in vivo. Results of acrolein mutagenicity studies haven't been confirmed, which is mainly due to the conflicting mutagenicity data of the major acrolein adduct (gamma-HOPdG). The minor alpha-HOPdG is mutagenic in both in vitro and in vivo test systems. The role of alpha-HOPdG in acrolein mutagenicity needs further investigation. The inconsistent result of acrolein mutagenicity can be attributed, at least partially, to a variety of acrolein-DNA adducts formation and their repair in diverse detection systems. Recent results of detection of acrolein-DNA adduct in human lung tissues and analysis of P53 mutation spectra in acrolein-treated cells may shed some light on mechanisms of acrolein mutagenicity. These aspects are covered in this mini review.

  8. Treatment of alpha bearing wastes

    International Nuclear Information System (INIS)

    1988-01-01

    This report deals with the current state of the art of alpha waste treatment, which is an integral part of the overall nuclear waste management system. The International Atomic Energy Agency (IAEA) defines alpha bearing waste as 'waste containing one or more alpha emitting radionuclides, usually actinides, in quantities above acceptable limits'. The limits are established by national regulatory bodies. The limits above which wastes are considered as alpha contaminated refer to the concentrations of alpha emitters that need special consideration for occupational exposures and/or potential safety, health, or environmental impact during one or more steps from generation through disposal. Owing to the widespread use of waste segregation by source - that is, based upon the 'suspect origin' of the material - significant volumes of waste are being handled as alpha contaminated which, in fact, do not require such consideration by reason of risk or environmental concern. The quantification of de minimis concepts by national regulatory bodies could largely contribute to the safe reduction of waste volumes and associated costs. Other factors which could significantly contribute to the reduction of alpha waste arisings are an increased application of assaying and sorting, instrumentation and the use of feedback mechanisms to control or modify the processes which generate these wastes. Alpha bearing wastes are generated during fabrication and reprocessing of nuclear fuels, decommissioning of alpha contaminated facilities, and other activities. Most alpha wastes are contact handled, but a small portion may require shielding or remote handling because of high levels of neutron (n), beta (β), or gamma (γ) emissions associated with the waste material. This report describes the sources and characteristics of alpha wastes and strategies for alpha waste management. General descriptions of treatment processes for solid and liquid alpha wastes are included. 71 refs, 14 figs, 9 tabs

  9. The alpha effect

    International Nuclear Information System (INIS)

    Anon.

    1982-01-01

    Much of the recent interest in RAM system reliability stems from concern over alpha particle soft error rates reported for the initial 64 k RAMs. With increasing memory density likely in the next few years the problem of soft errors is rearing its head again. A few years ago ITT carried out experiments on 16k RAMs and found no significant problems. However, recent tests have shown a raise in the number of soft errors with 64k RAMs, and the launch of 256k and 512k memories is likely to make the problem acute

  10. Alpha-mannosidosis

    Directory of Open Access Journals (Sweden)

    Nilssen Øivind

    2008-07-01

    Full Text Available Abstract Alpha-mannosidosis is an inherited lysosomal storage disorder characterized by immune deficiency, facial and skeletal abnormalities, hearing impairment, and intellectual disability. It occurs in approximately 1 of 500,000 live births. The children are often born apparently normal, and their condition worsens progressively. Some children are born with ankle equinus or develop hydrocephalus in the first year of life. Main features are immune deficiency (manifested by recurrent infections, especially in the first decade of life, skeletal abnormalities (mild-to-moderate dysostosis multiplex, scoliosis and deformation of the sternum, hearing impairment (moderate-to-severe sensorineural hearing loss, gradual impairment of mental functions and speech, and often, periods of psychosis. Associated motor function disturbances include muscular weakness, joint abnormalities and ataxia. The facial trait include large head with prominent forehead, rounded eyebrows, flattened nasal bridge, macroglossia, widely spaced teeth, and prognathism. Slight strabismus is common. The clinical variability is significant, representing a continuum in severity. The disorder is caused by lysosomal alpha-mannosidase deficiency. Alpha-mannosidosis is inherited in an autosomal recessive fashion and is caused by mutations in the MAN2B1 gene located on chromosome 19 (19 p13.2-q12. Diagnosis is made by measuring acid alpha-mannosidase activity in leukocytes or other nucleated cells and can be confirmed by genetic testing. Elevated urinary secretion of mannose-rich oligosaccharides is suggestive, but not diagnostic. Differential diagnoses are mainly the other lysosomal storage diseases like the mucopolysaccharidoses. Genetic counseling should be given to explain the nature of the disease and to detect carriers. Antenatal diagnosis is possible, based on both biochemical and genetic methods. The management should be pro-active, preventing complications and treating

  11. Alpha activity measurement with lsc

    International Nuclear Information System (INIS)

    Dobrin, R. I.; Dulama, C. N.; Ciocirlan, C. N.; Toma, A.; Stoica, S. M.; Valeca, M.

    2013-01-01

    Recently, we showed that the alpha activity in liquid samples can be measured using a liquid scintillation analyzer without alpha/beta discrimination capability. The purpose of this work was to evaluate the performances of the method and to optimize the procedure of the sample preparation. A series of tests was performed to validate the procedure of alpha emitting radionuclides extraction in aqueous samples with Actinide Resin, especially regarding to the contact time required to extract all alpha nuclides. The main conclusions were that a minimum 18 hours stirring time is needed to achieve a percent recovery of the alpha nuclides grater than 90% and that the counting efficiency of alphas measurements with LSC is nearly 100%. (authors)

  12. Satellite Communications Industry

    Science.gov (United States)

    1993-04-01

    Ariane $loom SAJAC 1 Hughes Satellite Japan 06/94 $150m SAJAC 2 Hughes Satellite Japan -- (spare) $150m SatcomHl GE GE Americom /95 $50m SOLIDARIDAD ...1 Hughes SCT (Mexico) 11/93 Ariane $loom SOLIDARIDAD 2 Hughes SCT (Mexico) /94 $loom Superbird Al Loral Space Com Gp (Jap) 11/92 Ariane $175m

  13. Partnership via Satellite.

    Science.gov (United States)

    Powell, Marie Clare

    1980-01-01

    Segments of the 1980 National Catholic Educational Association (NCEA) conference were to be telecast nationally by satellite. The author briefly explains the satellite transmission process and advises Catholic educators on how to pick up the broadcast through their local cable television system. (SJL)

  14. The satellite situation center

    International Nuclear Information System (INIS)

    Teague, M.J.; Sawyer, D.M.; Vette, J.I.

    1982-01-01

    Considerations related to the early planning for the International Magnetospheric Study (IMS) took into account the desirability of an establishment of specific entities for generating and disseminating coordination information for both retrospective and predictive periods. The organizations established include the IMS/Satellite Situation Center (IMS/SSC) operated by NASA. The activities of the SSC are related to the preparation of reports on predicted and actually achieved satellite positions, the response to inquiries, the compilation of information on satellite experiments, and the issue of periodic status summaries. Attention is given to high-altitude satellite services, other correlative satellite services, non-IMS activities of the SSC, a summary of the SSC request activity, and post-IMS and future activities

  15. A satellite for Asia

    Science.gov (United States)

    Lawrence, John D. R.

    In April 1990, an American satellite will be launched by China on the Long March 3 rocket. This satellite, called AsiaSat 1 will provide domestic telecommunications service to the countries of Asia. AsiaSat 1 is designed to provide satellite communications services to China, Thailand and Pakistan. These services will also be available for the use of neighboring countries such as Korea, Hong Kong, Burma and Nepal. As an independently financed satellite, it will provide services to each of these countries on an equal access basis and will be shared by these countries depending on their needs. The satellite's 24 C-band transponders will be leased or sold to customers in each of these countries. Transponders will be used for many purposes including back-up to national telephone networks, new private network services and the distribution of television programs.

  16. Molecular characterization of alpha 1- and alpha 2-adrenoceptors.

    Science.gov (United States)

    Harrison, J K; Pearson, W R; Lynch, K R

    1991-02-01

    Three 'alpha 1-adrenoceptors' and three 'alpha 2-adrenoceptors' have now been cloned. How closely do these receptors match the native receptors that have been identified pharmacologically? What are the properties of these receptors, and how do they relate to other members of the cationic amine receptor family? Kevin Lynch and his colleagues discuss these questions in this review.

  17. Elimination of double strand nuclease activity from S1 nuclease prepared from crude alpha amylase.

    Science.gov (United States)

    Hahn, W E; Van Ness, J

    1976-01-01

    Single strand-specific s1 nuclease prepared as previously described from crude alpha amylase by DEAE-cellulose chromatography also contains nuclease which degrades double strand nucleic acid. The double strand activity can be removed by repeating the DEAE-cellulose chromatography procedure at least two additional times. S1 nuclease prepared by this procedure does not degrade double strand sheared DNA as measured by Sephadex chromatography. Under the same conditions single strand DNA is completely degraded. Thus, S1 nuclease prepared by this procedure is suitable for use in removing single strand regions in DNA/DNA duplexes and DNA/RNA hybrids. PMID:940774

  18. Alpha wastes treatment

    International Nuclear Information System (INIS)

    Thouvenot, P.

    2000-01-01

    Alter 2004, the alpha wastes issued from the Commissariat a l'Energie Atomique installations will be sent to the CEDRA plant. The aims of this installation are decontamination and wastes storage. Because of recent environmental regulations concerning ozone layer depletion, the use of CFC 113 in the decontamination unit, as previously planned, is impossible. Two alternatives processes are studied: the AVD process and an aqueous process including surfactants. Best formulations for both processes are defined issuing degreasing kinetics. It is observed that a good degreasing efficiency is linked to a good decontamination efficiency. Best results are obtained with the aqueous process. Furthermore, from the point of view of an existing waste treatment unit, the aqueous process turns out to be more suitable than the AVD process. (author)

  19. Mechanisms of cell sensitization to alpha radioimmunotherapy by doxorubicin or paclitaxel in multiple myeloma cell lines.

    Science.gov (United States)

    Supiot, Stephane; Gouard, Sebastien; Charrier, Josiane; Apostolidis, Christos; Chatal, Jean-Francois; Barbet, Jacques; Davodeau, François; Cherel, Michel

    2005-10-01

    The purpose of this study was to analyze different mechanisms (cell cycle synchronization, DNA damage, and apoptosis) that might underlie potential synergy between chemotherapy (paclitaxel or doxorubicin) and radioimmunotherapy with alpha radionuclides. Three multiple myeloma cell lines (LP1, RMI 8226, and U266) were treated with 213Bi-radiolabeled B-B4, a monoclonal antibody that recognizes syndecan-1 (CD138) 24 hours after paclitaxel (1 nmol/L) or doxorubicin (10 nmol/L) treatment. Cell survival was assessed using a clonogenic survival assay. Cell cycle modifications were assessed by propidium iodide staining and DNA strand breaks by the comet assay. Level of apoptosis was determined by Apo 2.7 staining. Radiation enhancement ratio showed that paclitaxel and doxorubicin were synergistic with alpha radioimmunotherapy. After a 24-hour incubation, paclitaxel and doxorubicin arrested all cell lines in the G2-M phase of the cell cycle. Doxorubicin combined with alpha radioimmunotherapy increased tail DNA in the RPMI 8226 cell line but not the LP1 or U266 cell lines compared with doxorubicin alone or alpha radioimmunotherapy alone. Neither doxorubicin nor paclitaxel combined with alpha radioimmunotherapy increased the level of apoptosis induced by either drug alone or alpha radioimmunotherapy alone. Both cell cycle arrest in the G2-M phase and an increase in DNA double-strand breaks could lead to radiosensitization of cells by doxorubicin or paclitaxel, but apoptosis would not be involved in radiosensitization mechanisms.

  20. Mind Your p's and Alphas.

    Science.gov (United States)

    Stallings, William M.

    In the educational research literature alpha, the a priori level of significance, and p, the a posteriori probability of obtaining a test statistic of at least a certain value when the null hypothesis is true, are often confused. Explanations for this confusion are offered. Paradoxically, alpha retains a prominent place in textbook discussions of…

  1. Summary of Alpha Particle Transport

    Energy Technology Data Exchange (ETDEWEB)

    Medley, S.S.; White, R.B.; Zweben, S.J.

    1998-08-19

    This paper summarizes the talks on alpha particle transport which were presented at the 5th International Atomic Energy Agency's Technical Committee Meeting on "Alpha Particles in Fusion Research" held at the Joint European Torus, England in September 1997.

  2. Mitochondrial DNA.

    Science.gov (United States)

    Wright, Russell G.; Bottino, Paul J.

    1986-01-01

    Provides background information for teachers on mitochondrial DNA, pointing out that it may have once been a free-living organism. Includes a ready-to-duplicate exercise titled "Using Microchondrial DNA to Measure Evolutionary Distance." (JN)

  3. Overview of commercial satellite communications

    Science.gov (United States)

    Beakley, G. W.

    1984-07-01

    A brief history of communications satellites is presented, taking into account the launching of Sputnik 1 in October 1957, the Explorer 1 in January of 1958, the launch of the Score as the world's first active communications satellite in December 1958, the Communications Satellite Act in 1962, and the launch of 'Early Bird' in 1964. The Intelsat satellites are considered along with maritime satellite communications, the U.S. domestic satellite systems, Alaskan satellite communications, cable television, broadcast TV stations, print media, the hotel/motel industry as a large market for satellite communications terminals, the opening of a minicable and satellite master antenna TV market for TV receive-only systems, and business telecommunications earth terminals. Attention is also given to future directions regarding satellite positions, the concept of 'video-plus', and direct broadcast satellites.

  4. Development of a transmission alpha particle dosimetry technique using A549 cells and a Ra-223 source for targeted alpha therapy.

    Science.gov (United States)

    Al Darwish, R; Staudacher, A H; Li, Y; Brown, M P; Bezak, E

    2016-11-01

    In targeted radionuclide therapy, regional tumors are targeted with radionuclides delivering therapeutic radiation doses. Targeted alpha therapy (TAT) is of particular interest due to its ability to deliver alpha particles of high linear energy transfer within the confines of the tumor. However, there is a lack of data related to alpha particle distribution in TAT. These data are required to more accurately estimate the absorbed dose on a cellular level. As a result, there is a need for a dosimeter that can estimate, or better yet determine the absorbed dose deposited by alpha particles in cells. In this study, as an initial step, the authors present a transmission dosimetry design for alpha particles using A549 lung carcinoma cells, an external alpha particle emitting source (radium 223; Ra-223) and a Timepix pixelated semiconductor detector. The dose delivery to the A549 lung carcinoma cell line from a Ra-223 source, considered to be an attractive radionuclide for alpha therapy, was investigated in the current work. A549 cells were either unirradiated (control) or irradiated for 12, 1, 2, or 3 h with alpha particles emitted from a Ra-223 source positioned below a monolayer of A549 cells. The Timepix detector was used to determine the number of transmitted alpha particles passing through the A549 cells and DNA double strand breaks (DSBs) in the form of γ-H2AX foci were examined by fluorescence microscopy. The number of transmitted alpha particles was correlated with the observed DNA DSBs and the delivered radiation dose was estimated. Additionally, the dose deposited was calculated using Monte Carlo code SRIM. Approximately 20% of alpha particles were transmitted and detected by Timepix. The frequency and number of γ-H2AX foci increased significantly following alpha particle irradiation as compared to unirradiated controls. The equivalent dose delivered to A549 cells was estimated to be approximately 0.66, 1.32, 2.53, and 3.96 Gy after 12, 1, 2, and 3 h

  5. Proteinaceous alpha-araylase inhibitors

    DEFF Research Database (Denmark)

    Svensson, Birte; Fukuda, Kenji; Nielsen, P.K.

    2004-01-01

    Proteins that inhibit alpha-amylases have been isolated from plants and microorganisms. These inhibitors can have natural roles in the control of endogenous a-amylase activity or in defence against pathogens and pests; certain inhibitors are reported to be antinutritional factors. The alpha-amylase...... inhibitors belong to seven different protein structural families, most of which also contain evolutionary related proteins without inhibitory activity. Two families include bifunctional inhibitors acting both on alpha-amylases and proteases. High-resolution structures are available of target alpha-amylases...... in complex with inhibitors from five families. These structures indicate major diversity but also some similarity in the structural basis of alpha-amylase inhibition. Mutational analysis of the mechanism of inhibition was performed in a few cases and various protein engineering and biotechnological...

  6. Total alpha-globin gene cluster deletion has high frequency in Filipinos

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, J.A.; Haruyama, A.Z.; Chu, B.M. [Kapiolani Medical Center, Honolulu, HI (United States)] [and others

    1994-09-01

    Most {alpha}-thalassemias [Thal] are due to large deletions. In Southeast Asians, the (--{sup SEA}) double {alpha}-globin gene deletion is common, 3 (--{sup Tot}) total {alpha}-globin cluster deletions are known: Filipino (--{sup Fil}), Thai (--{sup Thai}), and Chinese (--{sup Chin}). In a Hawaii Thal project, provisional diagnosis of {alpha}-Thal-1 heterozygotes was based on microcytosis, normal isoelectric focusing, and no iron deficiency. One in 10 unselected Filipinos was an {alpha}-Thal-1 heterozygote, 2/3 of these had a (--{sup Tot}) deletion: a {var_sigma}-cDNA probe consistently showed fainter intensity of the constant 5.5 kb {var_sigma}{sub 2} BamHI band, with no heterzygosity for {var_sigma}-globin region polymorphisms; {alpha}-cDNA or {var_sigma}-cDNA probes showed no BamHI or BglII bands diagnostic of the (--{sup SEA}) deletion; bands for the (-{alpha}) {alpha}-Thal-2 single {alpha}-globin deletions were only seen in Hb H cases. A reliable monoclonal anti-{var_sigma}-peptide antibody test for the (--{sup SEA}) deletion was always negative in (--{sup Tot}) samples. Southern digests with the Lo probe, a gift from D. Higgs of Oxford Univ., confirmed that 49 of 50 (--{sup Tot}) chromosomes in Filipinos were (--{sup Fil}). Of 20 {alpha}-Thal-1 hydrops born to Filipinos, 11 were (--{sup Fil}/--{sup SEA}) compound heterozygotes; 9 were (--{sup SEA}/--{sup SEA}) homozygotes, but none was a (--{sup Fil}/--{sup Fil}).

  7. Alpha-defensin overexpression in patients with Bell's palsy and Ramsay Hunt syndrome.

    Science.gov (United States)

    Furuta, Yasushi; Oridate, Nobuhiko; Takeichi, Norihito; Fukuda, Satoshi; Sawa, Hirofumi

    2012-06-01

    To investigate the biological factors related to the onset of Bell's palsy, we sought to identify differentially expressed genes in peripheral blood mononuclear cells (PBMCs) and plasma of patients with Bell's palsy and Ramsay Hunt syndrome (RHS). We carried out DNA microarray analyses using PBMCs taken from patients with Bell's palsy at their initial visit and 2 to 4 weeks later. To validate these analyses, we measured the relative messenger RNA levels of alpha-defensin in paired PBMCs by reverse transcription-polymerase chain reaction. The plasma concentrations of alpha-defensin in patients and healthy volunteers were quantified by enzyme-linked immunosorbent assay. The DNA microarray analysis identified alpha-defensin as a candidate gene related to the onset of Bell's palsy. Reverse transcription-polymerase chain reaction analysis showed that the relative alpha-defensin messenger RNA levels in PBMCs from the later visit were increased at least twofold in 9 of 13 patients (69%) with Bell's palsy and in 4 of 6 patients (67%) with RHS. The plasma alpha-defensin concentrations in the patients with RHS were significantly higher than those in healthy volunteers (p = 0.0013) and in the patients with Bell's palsy (p = 0.0306). Elevations of plasma alpha-defensin were observed in 5 of the 9 patients with Bell's palsy who demonstrated alpha-defensin overexpression in PBMCs. alpha-Defensin may be one of the biological factors related to the onset of Bell's palsy and RHS.

  8. Modeling DNA

    Science.gov (United States)

    Robertson, Carol

    2016-01-01

    Deoxyribonucleic acid (DNA) is life's most amazing molecule. It carries the genetic instructions that almost every organism needs to develop and reproduce. In the human genome alone, there are some three billion DNA base pairs. The most difficult part of teaching DNA structure, however, may be getting students to visualize something as small as a…

  9. Multiple Satellite Trajectory Optimization

    National Research Council Canada - National Science Library

    Mendy Jr, Paul B

    2004-01-01

    This thesis develops and validates a satellite trajectory optimization model. A summary is given of the general mathematical principles of dynamic optimal control to minimize fuel consumed or transfer time...

  10. Handbook of satellite applications

    CERN Document Server

    Madry, Scott; Camacho-Lara, Sergio

    2013-01-01

    Top space experts from around the world have collaborated to produce this comprehensive, authoritative, and clearly illustrated reference guide to the fast growing, multi-billion dollar field of satellite applications and space communications. This handbook, done under the auspices of the International Space University based in France, addresses not only system technologies but also examines market dynamics, technical standards and regulatory constraints. The handbook is a completely multi-disciplinary reference book that covers, in an in-depth fashion, the fields of satellite telecommunications, Earth observation, remote sensing, satellite navigation, geographical information systems, and geosynchronous meteorological systems. It covers current practices and designs as well as advanced concepts and future systems. It provides a comparative analysis of the common technologies and design elements for satellite application bus structures, thermal controls, power systems, stabilization techniques, telemetry, com...

  11. Domestic Communication Satellites

    Science.gov (United States)

    Horowitz, Andrew

    1974-01-01

    A discussion of the Federal Communications Commission's new policy on domestic satellites in light of our 1) military and economic history; 2) corporate interests; 3) citizen surveillance; and 4) media control. (HB)

  12. SATELLITE CONSTELLATION DESIGN PARAMETER

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. SATELLITE CONSTELLATION DESIGN PARAMETER. 1. ORBIT CHARACTERISTICS. ORBITAL HEIGHT >= 20,000 KM. LONGER VISIBILITY; ORBITAL PERIOD. PERTURBATIONS(MINIMUM). SOLAR RADIATION PRESSURE (IMPACTS ECCENTRICITY); LUNI ...

  13. Small Satellite Transporter Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The primary objective is to determine whether this small satellite transporter is capable of transporting at least four 6U CubeSats is possible for a given set of...

  14. ASTRID II satellit projekt

    DEFF Research Database (Denmark)

    Jørgensen, John Leif; Primdahl, Fritz

    1997-01-01

    The report describes the instruments developed for the Swedish micro satellite "ASTRID II". Specifications of the two instruments realized under this contract, a Stellar Compass and a CSC magnetometer are given follwed by a description of the project status and plan.......The report describes the instruments developed for the Swedish micro satellite "ASTRID II". Specifications of the two instruments realized under this contract, a Stellar Compass and a CSC magnetometer are given follwed by a description of the project status and plan....

  15. Single Purpose Satellite Systems

    OpenAIRE

    Watkins, Warren

    1989-01-01

    This paper examines the need for tactically responsive space systems capable of supporting battlefield and fleet commanders. Terminology used to describe this category of satellite system varies according to organization or agency. The Defense Advanced Research Projects Agency's Lightsat, the Naval Space Command's SPINSAT, and the Air Force Space Command s TACSAT, are reviewed. The United State Space Command's space support mission IS addressed and the role single-purpose satellites can play ...

  16. Investigating the polar electrojet using Swarm satellite magnetic data

    DEFF Research Database (Denmark)

    Aakjær, Cecilie Drost; Olsen, Nils; Finlay, Chris

    The aim of this study is to investigate the magnetic perturbations caused by the polar electrojets, which are described by means of a model consisting of a series of infinite line currents placed at the height of the ionosphere along QD latitudes. The method is applied to Swarm magnetic scalar...... of the polar electrojets as well as their temporal evolution. In addition, applying the method to data taken by the Swarm satellites Alpha and Beta allows investigating longitudinal differences of the electrojets....

  17. Dna Sequencing

    Science.gov (United States)

    Tabor, Stanley; Richardson, Charles C.

    1995-04-25

    A method for sequencing a strand of DNA, including the steps off: providing the strand of DNA; annealing the strand with a primer able to hybridize to the strand to give an annealed mixture; incubating the mixture with four deoxyribonucleoside triphosphates, a DNA polymerase, and at least three deoxyribonucleoside triphosphates in different amounts, under conditions in favoring primer extension to form nucleic acid fragments complementory to the DNA to be sequenced; labelling the nucleic and fragments; separating them and determining the position of the deoxyribonucleoside triphosphates by differences in the intensity of the labels, thereby to determine the DNA sequence.

  18. Winds observed in the Northern European seas with wind lidars, meteorological masts and satellite

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Stein, D.; Peña, Alfredo

    2013-01-01

    of them for up to two years when the project campaign ended. The NORSEWInD database on lidar data in total contains around 11 years worth of observations (> 280.000 10 min data). The wind lidars were mounted such that winds were mapped at or very near 100 m above sea level. The lidars provide wind profile...... directional bins. The latter resulted in so-called ‘alpha roses’, similar to wind roses but with the values of alpha given. Satellite ocean surface winds were collected from synthetic aperture radar (SAR), scatterometer and passive microwave instruments. All satellite wind data provide winds at 10 m above sea...

  19. ALPHA freezes antiprotons

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    Laboratories like CERN can routinely produce many different types of antiparticles. In 1995, the PS210 experiment formed the first antihydrogen atoms and a few years later, in 2002, ATRAP and ATHENA were already able to produce several thousand of them. However, no experiment in the world has succeeded in ‘trapping’ these anti-atoms in order to study them. This is the goal of the ALPHA experiment, which has recently managed to cool down the antiprotons to just a few Kelvin. This represents a major step towards trapping the anti-atom, thus opening a new avenue into the investigation of antimatter properties.   Members of the ALPHA collaboration working on the apparatus in the Antiproton Decelerator experimental hall at CERN. Just like the atom, the anti-atom is neutral. Unlike the atom, the anti-atom is made up of antiprotons (as opposed to protons in the atom) and positrons (as opposed to electrons). In order to thoroughly study the properties of the anti-atoms, scien...

  20. Alpha-1-antitrypsin deficiency.

    Science.gov (United States)

    Bals, Robert

    2010-10-01

    Alpha-1-antitrypsin deficiency (AATD) is a rare genetic disorder associated with the development of liver and lung disease. AAT is a 52-kD glycoprotein, produced mainly by hepatocytes and secreted into the blood. Agglomeration of the AAT-protein in hepatocytes can result in liver disease. Exposure to smoke is the major risk factor for the development of lung disease characterised as early chronic obstructive lung disease (COPD). Diagnosis is based on the analysis of the AAT genotype and phenotype. The measurement of the AAT serum level is useful as screening test. Liver biopsy is not necessary to establish the diagnosis. Therapy for AAT-related liver disease is supportive, a specific therapy is not available. AATD is a rare condition (1:5000-10000) and, as a consequence, data and information on diagnosis and treatment are not easily accessible. This chapter provides a comprehensive overview on AATD, covering basic biology, diagnostic and therapeutic approaches. Copyright © 2010 Elsevier Ltd. All rights reserved.

  1. ISDN - The case for satellites

    Science.gov (United States)

    Pelton, J. N.; McDougal, P. J.

    1987-05-01

    The role of satellites in the proposed Integrated Services Digital Network (ISDN) is examined. ISDN is to be a unified global network providing international telecommunication services. The delay time connected with satellite communications is considered. The advantages of using satellites in ISDN are: (1) the digital services available with satellites (time-division multiple access, intermediate data rate, and Intelsat business services); (2) satellite networking features; (3) flexibility; and (4) global interconnectivity. It is noted that with the use of powerful transmitters on satellites, the growth of small earth stations, and developments in band switching and intersatellite links that satellites are applicable to ISDN.

  2. Satellite Communications for ATM

    Science.gov (United States)

    Shamma, Mohammed A.

    2003-01-01

    This presentation is an overview on Satellite Communication for the Aeronautical Telecommunication Management (ATM) research. Satellite Communications are being considered by the FAA and NASA as a possible alternative to the present and future ground systems supporting Air Traffic Communications. The international Civil Aviation Organization (ICAO) have in place Standards and Recommended Practices (SARPS) for the Aeronautical Mobile Satellite Services (AMSS) which is mainly derived from the pre-existing Inmarsat service that has been in service since the 1980s. The Working Group A of the Aeronautical Mobile Communication Panel of ICAO has also been investigating SARPS for what is called the Next Generation Satellite Service (NGSS) which conforms less to the Inmarsat based architecture and explores wider options in terms of satellite architectures. Several designs are being proposed by Firms such as Boeing, ESA, NASA that are geared toward full or secondary usage of satellite communications for ATM. Satellite communications for ATM can serve several purposes ranging from primary usage where ground services would play a minimal backup role, to an integrated solution where it will be used to cover services, or areas that are less likely to be supported by the proposed and existing ground infrastructure. Such Integrated roles can include usage of satellite communications for oceanic and remote land areas for example. It also can include relieving the capacity of the ground network by providing broadcast based services of Traffic Information Services messages (TIS-B), or Flight Information Services (FIS-B) which can take a significant portion of the ground system capacity. Additionally, satellite communication can play a backup role to support any needs for ground replacement, or additional needed capacity even after the new digital systems are in place. The additional bandwidth that can be provided via satellite communications can also open the door for many new

  3. Measurement of $\\alpha_{s}$ with Radiative Hadronic Events

    CERN Document Server

    Abbiendi, G; Åkesson, P F; Alexander, G; Anagnostou, G; Anderson, K J; Asai, S; Axen, D; Bailey, I; Barberio, E; Barillari, T; Barlow, R J; Batley, R J; Bechtle, P; Behnke, T; Bell, K W; Bell, P J; Bella, G; Bellerive, A; Benelli, G; Bethke, S; Biebel, O; Boeriu, O; Bock, P; Boutemeur, M; Braibant, S; Brown, R M; Burckhart, H J; Campana, S; Capiluppi, P; Carnegie, R K; Carter, A A; Carter, J R; Chang, C Y; Charlton, D G; Ciocca, C; Csilling, A; Cuffiani, M; Dado, S; Dallavalle, M; de Roeck, A; De Wolf, E A; Desch, K; Dienes, B; Dubbert, J; Duchovni, E; Duckeck, G; Duerdoth, I P; Etzion, E; Fabbri, F; Ferrari, P; Fiedler, F; Fleck, I; Ford, M; Frey, A; Gagnon, P; Gary, J W; Geich-Gimbel, C; Giacomelli, G; Giacomelli, P; Giunta, M; Goldberg, J; Gross, E; Grunhaus, J; Gruwé, M; Sen-Gupta, A; Hajdu, C; Hamann, M; Hanson, G G; Harel, A; Hauschild, M; Hawkes, C M; Hawkings, R; Herten, G; Heuer, R D; Hill, J C; Horváth, D; Igo-Kemenes, P; Ishii, K; Jeremie, H; Jovanovic, P; Junk, T R; Kanzaki, J; Karlen, D; Kawagoe, K; Kawamoto, T; Keeler, R K; Kellogg, R G; Kennedy, B W; Kluth, S; Kobayashi, T; Kobel, M; Komamiya, S; Kramer, T; Krasznahorkays, A Jr; Krieger, P; Von Krogh, J; Kühl, T; Kupper, M; Lafferty, G D; Landsman, H; Lanske, D; Lellouch, D; Letts, J; Levinson, L; Lillich, J; Lloyd, S L; Loebinger, F K; Lü, J; Ludwig, A; Ludwig, J; Mader, W; Marcellini, S; Martin, A J; Mashimo, T; Mättig, P; McKenna, J; McPherson, R A; Meijers, F; Menges, W; Merritt, F S; Mes, H; Meyer, N; Michelini, A; Mihara, S; Mikenberg, G; Miller, D J; Mohr, W; Mori, T; Mutter, A; Nagai, K; Nakamura, I; Nanjo, H; Neal, H A; O'Neale, S W; Oh, A; Oreglia, M J; Orito, S; Pahl, C; Pásztor, G; Pater, J R; Pilcher, J E; Pinfold, J L; Plane, D E; Pooth, O; Przybycien, M; Quadt, A; Rabbertz, K; Rembser, C; Renkel, P; Roney, J M; Rossi, A M; Rozen, Y; Runge, K; Sachs, K; Saeki, T; Sarkisyan-Grinbaum, E; Schaile, A D; Schaile, O; Scharff-Hansen, P; Schiecks, J; Schörner-Sadenius, T; Schröder, M; Schumacher, M; Seuster, R; Shears, T G; Shen, B C; Sherwood, P; Skuja, A; Smith, A M; Sobie, R J; Söldner-Rembold, S; Spanó, F; Stahl, A; Strom, D; Ströhmer, R; Tarem, S; Tasevsky, M; Teuscher, R; Thomson, M A; Torrence, E; Toya, D; Trigger, I; Trócsányi, Z L; Tsur, E; Turner-Watson, M F; Ueda, I; Ujvári, B; Vollmer, C F; Vannerem, P; Vertesi, R; Verzocchi, M; Voss, H; Vossebeld, J; Ward, C P; Ward, D R; Watkins, P M; Watson, A T; Watson, N K; Wells, P S; Wengler, T; Wermes, N; Wilson, G W; Wilson, J A; Wolf, G; Wyatt, T R; Yamashita, S; Zer-Zion, D; Zivkovic, L

    2008-01-01

    Hadronic final states with a hard isolated photon are studied using data taken at centre-of-mass energies around the mass of the Z0 boson with the OPAL detector at LEP. The strong coupling alpha S is extracted by comparing data and QCD predictions for event shape observables at average reduced centre-of-mass energies ranging from 24 GeV to 78 GeV, and the energy dependence of alpha S is studied. Our results are consistent with the running of alpha S as predicted by QCD and show that within the uncertainties of our analysis event shapes in hadronic Z0 decays with hard and isolated photon radiation can be described by QCD at reduced centre-of-mass energies. Combining all values from different event shape observables and energies gives alpha S (Mz)=0.1182 pm 0.0015(stat.) pm 0.0101(syst.).

  4. What Powers Lyman alpha Blobs?

    OpenAIRE

    Ao, Y.; Matsuda, Y.; Beelen, A.; Henkel, C.; Cen, R.; De Breuck, C.; Francis, P.; Kovacs, A.; Lagache, G.; Lehnert, M.; Mao, M.; Menten, K. M.; Norris, R.; Omont, A.; Tatemastu, K.

    2015-01-01

    Lyman alpha blobs (LABs) are spatially extended lyman alpha nebulae seen at high redshift. The origin of Lyman alpha emission in the LABs is still unclear and under debate. To study their heating mechanism(s), we present Australia Telescope Compact Array (ATCA) observations of the 20 cm radio emission and Herschel PACS and SPIRE measurements of the far-infrared (FIR) emission towards the four LABs in the protocluster J2143-4423 at z=2.38. Among the four LABs, B6 and B7 are detected in the rad...

  5. Alpha heating in toroidal devices

    Energy Technology Data Exchange (ETDEWEB)

    Miley, G.H.

    1978-01-01

    Ignition (or near-ignition) by alpha heating is a key objective for the achievement of economic fusion reactors. While good confinement of high-energy alphas appears possible in larger reactors, near-term tokamak-type ignition experiments as well as some concepts for small reactors (e.g., the Field-Reversed Mirror or FRM) potentially face marginal situations. Consequently, there is a strong motivation to develop methods to evaluate alpha losses and heating profiles in some detail. Such studies for a TFTR-size tokamak and for a small FRM are described here.

  6. Impacts of satellite galaxies on the redshift-space distortions

    International Nuclear Information System (INIS)

    Hikage, Chiaki; Yamamoto, Kazuhiro

    2013-01-01

    We study the impacts of the satellite galaxies on the redshift-space distortions. In our multipole power spectrum analysis of the luminous red galaxies (LRGs) samples of the Sloan digital sky survey (SDSS), we have clearly detected the non-zero signature of the hexadecapole and tetrahexadecapole spectrum, which almost disappears in the power spectrum with the sample of the brightest LRGs only. We thus demonstrate that the satellite LRGs in multiple systems make a significant contribution to the multipole power spectrum though its fraction is small. The behavior can be understood by a simple halo model, in which the one-halo term, describing the Finger of God (FoG) effect from the satellite galaxies, makes the dominant contribution to the higher multipole spectra. We demonstrate that the small-scale information of higher multipole spectrum is useful for calibrating the satellite FoG effect and improves the measurement of the cosmic growth rate dramatically. We further demonstrate that the fiber collision in the galaxy survey influences the one-halo term and the higher multipole spectra, because the number of satellite galaxies in the halo occupation distribution (HOD) is changed. We also discuss about the impact of satellite galaxies on future high-redshift surveys targeting the H-alpha emitters

  7. AVS on satellite

    Science.gov (United States)

    Zhao, Haiwu; Wang, Guozhong; Hou, Gang

    2005-07-01

    AVS is a new digital audio-video coding standard established by China. AVS will be used in digital TV broadcasting and next general optical disk. AVS adopted many digital audio-video coding techniques developed by Chinese company and universities in recent years, it has very low complexity compared to H.264, and AVS will charge very low royalty fee through one-step license including all AVS tools. So AVS is a good and competitive candidate for Chinese DTV and next generation optical disk. In addition, Chinese government has published a plan for satellite TV signal directly to home(DTH) and a telecommunication satellite named as SINO 2 will be launched in 2006. AVS will be also one of the best hopeful candidates of audio-video coding standard on satellite signal transmission.

  8. Solar Power Satellites

    CERN Document Server

    Flournoy, Don M

    2012-01-01

    Communication satellites are a $144 billion industry. Is there any space-based industry that could possibly beat that market? 'Solar Power Satellites' shows why and how the space satellite industry will soon begin expanding its market from relaying signals to Earth to generating energy in space and delivering it to the ground as electricity. In all industrialized nations, energy demand is growing exponentially. In the developing world, the need for energy is as basic as food and water. The Sun's energy is available everywhere, and it is non-polluting. As business plans demonstrate its technical feasibility, commercial potential, and environmental acceptability, every country on Earth will look to space for the power it needs.

  9. Satellite Control Laboratory

    DEFF Research Database (Denmark)

    Wisniewski, Rafal; Bak, Thomas

    2001-01-01

    The Satellite Laboratory at the Department of Control Engineering of Aalborg University (SatLab) is a dynamic motion facility designed for analysis and test of micro spacecraft. A unique feature of the laboratory is that it provides a completely gravity-free environment. A test spacecraft...... is suspended on an air bearing, and rotates freely in 3 degrees of freedom. In order to avoid any influence of the gravitational force the centre of mass of the satellite is placed in the geometric centre of the air bearing by an automatic balancing system. The test spacecraft is equipped with a three......-axis magnetometer, three piezoelectric gyros, and four reaction wheels in a tetrahedron configuration. The operation of the spacecraft is fully autonomous. The data flow between the transducers and the onboard computer placed physically outside the satellite is provided by a radio link. The purpose...

  10. Nanodosimetry and nanodosimetric-based models of radiation action for radon alpha particles

    International Nuclear Information System (INIS)

    1992-01-01

    The objective of our research work is to provide -- with the aid of biophysical models of radiation action -- information on human risks following exposure to radon alpha particles. The approach proposed consists of (1) developing appropriate models (parametric and non-parametric) for alpha radiation induction of relevant end points (survival, cellular transformation), (2) providing an accurate physical characterization of the particle tracks in terms of nanodosimetric distributions, (3) supporting the models by detailed, molecular studies of the direct and indirect effects of alpha particles on DNA. Activities in the second year of this project are described

  11. Biased DNA Segregation during Stem Cell Division

    OpenAIRE

    Anversa, Piero; Leri, Annarosa; Kajstura, Jan

    2012-01-01

    Adult skeletal muscle stem cells are a heterogeneous cell population characterized by a small subset of undifferentiated cells that express at high level the paired/homeodomain gene Pax7. This category of satellite cells divides predominantly by asymmetric chromatid segregation generating a daughter cell that carries the mother DNA and retains stem cell property, and a daughter cell that inherits the newly-synthesized DNA and acquires the myocyte lineage.1

  12. Tissue-specific expression of the human laminin alpha5-chain, and mapping of the gene to human chromosome 20q13.2-13.3 and to distal mouse chromosome 2 near the locus for the ragged (Ra) mutation

    DEFF Research Database (Denmark)

    Durkin, M E; Loechel, F; Mattei, M G

    1997-01-01

    To investigate the function of the laminin alpha5-chain, previously identified in mice, cDNA clones encoding the 953-amino-acid carboxy terminal G-domain of the human laminin alpha5-chain were characterized. Northern blot analysis showed that the laminin alpha5-chain is expressed in human placenta...

  13. [Cloning and structure of gene encoded alpha-latrocrustoxin from the Black widow spider venom].

    Science.gov (United States)

    Danilevich, V N; Luk'ianov, S A; Grishin, E V

    1999-07-01

    The primary structure of the crusta gene encoding alpha-latrocrustoxin (alpha-LCT), a high molecular mass neurotoxin specific to crustaceans, was determined in the black widow spider Latrodectus mactans tredicimguttatus genome. The total length of the sequenced DNA was 4693 bp. The structural part of the black widow spider chromosome gene encoding alpha-LCT does not contain introns. The sequenced DNA contains a single extended open reading frame (4185 bp) and encodes a protein precursor of alpha-LCT, comprising 1395 aa. We assume the Met residue at position -10 relative to the N-terminal residue of Glu1 of the mature toxin to be the first one in the protein precursor. The calculated molecular mass of the precursor (156147 Da) exceeds that of the mature toxin by approximately 30 kDa. These data are in agreement with the notion that over the course of maturation the protein precursor undergoes double processing--cleavage of a decapeptide from the N-terminal part and of a approximately 200-aa fragment from the C-terminal part. alpha-LCT displayed a number of imperfect ankyrin-like repeats and areas of structural homology with earlier studied latrotoxins; the highest homology degree (62%) was revealed with alpha-latroinsectotoxin (alpha-LIT).

  14. Domestic satellite communications overview

    Science.gov (United States)

    Nickelson, R. L.

    1984-09-01

    The current status and future planning of satellite systems for intranational communication are examined in a summary of presentations given at the CCIR international seminar on domestic satellite communications held in Shanghai in October 1983. Topics discussed include operational and planned systems in Australia, Japan, the U.S., India, China, France, Brazil, Italy, Thailand, and the European region; development and planning by NASA and Intelsat; systems for rural areas or light traffic; modulation and multiple access; antennas, propagation, and interference; geostationary orbits; and economics, planning, and implementation.

  15. MIST Student Satellite

    OpenAIRE

    Gårdebäck, Agnes; Haugdahl, Vincent

    2015-01-01

    In this report, parts of the systems engineering of a spacecraft are presented. In 2014 the Royal Institute of Technology KTH initiated a new space technology and research platform, the KTH Space Centre. The first student project at KTH Space Centre was the MIST student satellite with the scope of the system design and construction of a real satellite due for launch in 2017. As part of the MIST project this bachelor thesis covers the mission analysis and parts of the system design. The system...

  16. GPS satellite surveying

    CERN Document Server

    Leick, Alfred; Tatarnikov, Dmitry

    2015-01-01

    THE MOST COMPREHENSIVE, UP-TO-DATE GUIDE ON GPS TECHNOLOGY FOR SURVEYING Three previous editions have established GPS Satellite Surveying as the definitive industry reference. Now fully updated and expanded to reflect the newest developments in the field, this Fourth Edition features cutting-edge information on GNSS antennas, precise point positioning, real-time relative positioning, lattice reduction, and much more. Expert authors examine additional tools and applications, offering complete coverage of geodetic surveying using satellite technologies. The past decade has seen a major evolut

  17. DNA polymorphism at the casein loci in sheep.

    Science.gov (United States)

    Di Gregorio, P; Rando, A; Pieragostini, E; Masina, P

    1991-01-01

    By using seven endonucleases and four bovine cDNA probes specific for alpha S1-, alpha S2-, beta-, and kappa-casein genes, nine restriction fragment length polymorphisms (RFLPs) have been found in the sheep orthologous DNA regions. In contrast to the low level of variation observed at the protein level, these DNA polymorphisms determine a high level of heterozygosity and, therefore, represent useful tools for genetic analyses since they can also be obtained without the need for gene expression. In fact, informative matings suggest that in sheep, as in cattle, the four loci are linked.

  18. Integrated Satellite-HAP Systems

    DEFF Research Database (Denmark)

    Cianca, Ernestina; De Sanctis, Mauro; De Luise, Aldo

    2005-01-01

    Thus far, high-altitude platform (HAP)-based systems have been mainly conceived as an alternative to satellites for complementing the terrestrial network. This article aims to show that HAP should no longer be seen as a competitor technology by investors of satellites, but as a key element...... for an efficient hybrid terrestrial-satellite communication system. Two integrated HAP-satellite scenarios are presented, in which the HAP is used to overcome some of the shortcomings of satellite- based communications. Moreover, it is shown that the integration of HAPs with satellite systems can be used...

  19. Classification of alpha 1-adrenoceptor subtypes

    NARCIS (Netherlands)

    Michel, M. C.; Kenny, B.; Schwinn, D. A.

    1995-01-01

    Two alpha 1-adrenoceptor subtypes (alpha 1A and alpha 1B) have been detected in various tissues by pharmacological techniques, and three distinct cDNAs encoding alpha 1-adrenoceptor subtypes have been cloned. The profile of an increasing number of subtype-selective compounds at cloned and endogenous

  20. Interactions of foot-and-mouth disease virus with soluble bovine alphaVbeta3 and alphaVbeta6 integrins.

    Science.gov (United States)

    Duque, Hernando; LaRocco, Michael; Golde, William T; Baxt, Barry

    2004-09-01

    At least four members of the integrin family of receptors, alphaVbeta1, alphaVbeta3, alphaVbeta6, and alphaVbeta8, have been identified as receptors for foot-and-mouth disease virus (FMDV) in vitro. Our investigators have recently shown that the efficiency of receptor usage appears to be related to the viral serotype and may be influenced by structural differences on the viral surface (H. Duque and B. Baxt, J. Virol. 77:2500-2511, 2003). To further examine these differences, we generated soluble alphaVbeta3 and alphaVbeta6 integrins. cDNA plasmids encoding the individual complete integrin alphaV, beta3, and beta6 subunits were used to amplify sequences encoding the subunits' signal peptide and ectodomain, resulting in subunits lacking transmembrane and cytoplasmic domains. COS-1 cells were transfected with plasmids encoding the soluble alphaV subunit and either the soluble beta3 or beta6 subunit and labeled with [35S]methionine-cysteine. Complete subunit heterodimeric integrins were secreted into the medium, as determined by radioimmunoprecipitation with specific monoclonal and polyclonal antibodies. For the examination of the integrins' biological activities, stable cell lines producing the soluble integrins were generated in HEK 293A cells. In the presence of divalent cations, soluble alphaVbeta6 bound to representatives of type A or O viruses, immobilized on plastic dishes, and significantly inhibited viral replication, as determined by plaque reduction assays. In contrast, soluble alphaVbeta3 was unable to bind to immobilized virus of either serotype; however, virus bound to the immobilized integrin, suggesting that FMDV binding to alphaVbeta3 is a low-affinity interaction. In addition, soluble alphaVbeta3 did not neutralize virus infectivity. Incubation of soluble alphaVbeta6 with labeled type A12 or O1 resulted in a significant inhibition of virus adsorption to BHK cells, while soluble alphaVbeta3 caused a low (20 to 30%), but consistent, inhibition of virus

  1. DNA glue

    DEFF Research Database (Denmark)

    Filichev, Vyacheslav V; Astakhova, Irina V.; Malakhov, Andrei D.

    2008-01-01

    Significant alterations in thermal stability of parallel DNA triplexes and antiparallel duplexes were observed upon changing the attachment of ethynylpyrenes from para to ortho in the structure of phenylmethylglycerol inserted as a bulge into DNA (TINA). Insertions of two ortho-TINAs as a pseudo...

  2. DNA Vaccines

    Indian Academy of Sciences (India)

    DNA vaccine, immune response, antibodies, infectious diseases. GENERAL I ARTICLE. DNA Vaccines. P N Rangarajan. History of Vaccine Development. The year 1996 marked the 200th anniversary of the first vaccine developed against smallpox by Edward Jenner. In the now- famous 1796 experiment, Jenner scratched ...

  3. Hyperstretching DNA

    NARCIS (Netherlands)

    Schakenraad, Koen; Biebricher, Andreas S.; Sebregts, Maarten; Ten Bensel, Brian; Peterman, Erwin J.G.; Wuite, Gijs J L; Heller, Iddo; Storm, Cornelis; Van Der Schoot, Paul

    2017-01-01

    The three-dimensional structure of DNA is highly susceptible to changes by mechanical and biochemical cues in vivo and in vitro. In particular, large increases in base pair spacing compared to regular B-DNA are effected by mechanical (over)stretching and by intercalation of compounds that are widely

  4. Satellite Surveillance: Domestic Issues

    National Research Council Canada - National Science Library

    Best, Jr., Richard A; Elsea, Jennifer K

    2008-01-01

    ... and law enforcement purposes, in addition to the civil applications that have been supported for years. In 2007, it moved to transfer responsibility for coordinating civilian use of satellites to the Department of Homeland Security. The transfer occurred, however, apparently without notification of key congressional oversight committees.

  5. Simulation of satellite breakups

    Science.gov (United States)

    Culp, R. D.; McKnight, D. S.

    1986-08-01

    Nearly ninety satellites have fragmented in orbit since the first satellite breakup in 1961 and the resulting debris constitutes over half of the trackable objects now orbiting the earth. The analysis of these events is severely limited since an estimated sixty to ninety percent of the debris produced is too small to be detected with present tracking devices. The inability to track most orbital debris makes distinguishing the cause of breakup and the accurate assessment of the debris environment difficult. Computer simulations of satellite breakups are used to bridge this gap. A program has been written to produce fragmentation events whose magnitude, mass distribution, velocity distribution, geometry, and location of breakup may all be controlled. After breakup, the particles' orbits are propagated under the influence of drag and the J2 gravitational term. Constraints are applied to the model to replicate characteristics of collision-induced and explosion-induced breakups. It is shown that simulation aids in the classification of satellite breakups and in providing a more accurate assessment of the debris environment.

  6. Contribution to the study of the alpha-alpha interaction

    International Nuclear Information System (INIS)

    Darriulat, Pierre

    1965-01-01

    The new variable energy cyclotron at Berkeley that can accelerate an alpha beam up to an energy of 130 MeV and the mass production of lithium diffused junctions have enabled us to perform 2 series of measurement, in the first one we use alpha beams with an energy ranging between 50 and 120 MeV to study alpha-alpha forces in the second one we use the flexibility of the variable energy cyclotron the resonances around 40 MeV, region that can not yet be reached by tandem accelerators. This work is divided into 6 chapters. The first chapter is dedicated to the formalism of partial wave analysis and the theory of the compound nucleus. In the second chapter the author presents the 88 cyclotron at Berkeley and the diffusion chamber, the alpha detectors are lithium diffused junctions made of silicon. The third chapter deals with the experimental methods used and the issue of the reduction of the volume of data. In the fourth chapter the results obtained in the upper part of the energy range are described in terms of complex shifts that allow the description of the α-α interaction at high energy. The very low impact parameter has enabled us to find 2 new components (l=6 and l=8) of the rotational spectrum and to define a more accurate phenomenological potential. The fifth chapter is dedicated to the narrow resonances we have found between 12 and 27 MeV. We present in the last chapter a calculation of the binding energy of C 12 in which we have considered the 12 C nucleus as formed by 3 alpha particles interacting with each other through the phenomenological potential defined above

  7. Cibola flight experiment satellite

    Science.gov (United States)

    Davies, P.; Liddle, Doug; Paffett, John; Sweeting, Martin; Curiel, A.; Sun, Wei; Eves, Stuart

    2004-11-01

    In order to achieve an "economy of scale" with respect to payload capacity the major trend in telecommunications satellites is for larger and larger platforms. With these large platforms the level of integration between platform and payload is increasing leading to longer delivery schedules. The typical lifecycle for procurement of these large telecommunications satellites is now 3-6 years depending on the level of non-recurring engineering needed. Surrey Satellite Technology Ltd (SSTL) has designed a low-cost platform aimed at telecommunications and navigation applications. SSTL's Geostationary Minisatellite Platform (GMP) is a new entrant addressing the lower end of the market with payloads up to 250kg requiring less than 1.5 kW power. The British National Space Centre through the MOSAIC Small Satellite Initiative supported the development of GMP. The main design goals for GMP are low-cost for the complete mission including launch and operations and a platform allowing flexible payload accommodation. GMP is specifically designed to allow rapid development and deployment with schedules typically between 1 and 2 years from contract signature to flight readiness. GMP achieves these aims by a modular design where the level of integration between the platform and payload is low. The modular design decomposes the satellite into three major components - the propulsion bay, the avionics bay and the payload module. Both the propulsion and avionics bays are reusable, largely unchanged, and independent of the payload configuration. Such a design means that SSTL or a 3rd party manufacturer can manufacture the payload in parallel to the platform with integration taking place quite late in the schedule. In July 2003 SSTL signed a contract for ESA's first Galileo navigation satellite known as GSTBV2/A. The satellite is based on GMP and ESA plan to launch it into a MEO orbit late in 2005. The second flight of GMP is likely to be in 2006 carrying a geostationary payload

  8. Workshop on Precision Measurements of $\\alpha_s$

    Energy Technology Data Exchange (ETDEWEB)

    Bethke, Siegfried; /Munich, Max Planck Inst.; Hoang, Andre H.; /Vienna U.; Kluth, Stefan; /Munich, Max Planck Inst.; Schieck, Jochen; /Munich U.; Stewart, Iain W.; Aoki, S.; Beneke, M.; Bethke, S.; Blumlein, J.; Brambilla, N.; Brodsky, S.; /MIT, LNS

    2011-10-01

    These are the proceedings of the Workshop on Precision Measurements of {alpha}{sub s} held at the Max-Planck-Institute for Physics, Munich, February 9-11, 2011. The workshop explored in depth the determination of {alpha}{sub s}(m{sub Z}) in the {ovr MS} scheme from the key categories where high precision measurements are currently being made, including DIS and global PDF fits, {tau}-decays, electro-weak precision observables and Z-decays, event-shapes, and lattice QCD. These proceedings contain a short summary contribution from the speakers, as well as the lists of authors, conveners, participants, and talks.

  9. Defense Meteorological Satellite Program (DMSP)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Defense Meteorological Satellite Program (DMSP) satellites collect visible and infrared cloud imagery as well as monitoring the atmospheric, oceanographic,...

  10. Monitoring Cyanobacteria with Satellites Webinar

    Science.gov (United States)

    real-world satellite applications can quantify cyanobacterial harmful algal blooms and related water quality parameters. Provisional satellite derived cyanobacteria data and different software tools are available to state environmental and health agencies.

  11. Satellite business networks and systems

    Science.gov (United States)

    Kadar, I.; Eaves, R. E.

    1985-07-01

    A compilation of articles concerning the technical aspects of satellite business networks is presented. Among the topics discussed are: flexible satellite data services; service satellite systems for the Atlantic Ocean region; and the design of a 30/20 GHz international business teleconferencing system. Consideration is also given to issues of network architecture including the performance of computer networks in accessing satellite links; advanced satellite communications systems with integrated transponders; full duplex teleconferencing via Intelsat V F-2 and OTS-2 at ll/14 GHz; and digital facsimile communication over satellite links. Among other topics discussed are: cryptographic techniques for satellite networks; a Codec system for world wide video conferencing; and regenerative SCPC satellite communications systems.

  12. Hurricane Satellite (HURSAT) Microwave (MW)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Hurricane Satellite (HURSAT) from Microwave (MW) observations of tropical cyclones worldwide data consist of raw satellite observations. The data derive from the...

  13. Satellite Ocean Heat Content Suite

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This collection contains an operational Satellite Ocean Heat Content Suite (SOHCS) product generated by NOAA National Environmental Satellite, Data, and Information...

  14. CDDIS_GNSS_satellite_data

    Data.gov (United States)

    National Aeronautics and Space Administration — Global Navigation Satellite System (GNSS) data consists of the U.S. Global Positioning System (GPS) and the Russian GLObal NAvigation Satellite System (GLONASS)...

  15. DNA probes

    International Nuclear Information System (INIS)

    Castelino, J.

    1992-01-01

    The creation of DNA probes for detection of specific nucleotide segments differs from ligand detection in that it is a chemical rather than an immunological reaction. Complementary DNA or RNA is used in place of the antibody and is labelled with 32 P. So far, DNA probes have been successfully employed in the diagnosis of inherited disorders, infectious diseases, and for identification of human oncogenes. The latest approach to the diagnosis of communicable and parasitic infections is based on the use of deoxyribonucleic acid (DNA) probes. The genetic information of all cells is encoded by DNA and DNA probe approach to identification of pathogens is unique because the focus of the method is the nucleic acid content of the organism rather than the products that the nucleic acid encodes. Since every properly classified species has some unique nucleotide sequences that distinguish it from every other species, each organism's genetic composition is in essence a finger print that can be used for its identification. In addition to this specificity, DNA probes offer other advantages in that pathogens may be identified directly in clinical specimens

  16. Mobile satellite service for Canada

    Science.gov (United States)

    Sward, David

    1988-01-01

    The Mobile Satellite (MSAT) system and a special program designed to provide interim mobile satellite services (IMSS) during the construction phase of MSAT are described. A mobile satellite system is a key element in extending voice and and data telecommunications to all Canadians.

  17. Telelibrary: Library Services via Satellite.

    Science.gov (United States)

    Liu, Rosa

    1979-01-01

    Investigates the provision of library services via satellite, explains briefly the operation and advantages of communication satellites, and discusses the various telecommunications equipment and services which, when coupled with satellite transmission, will enhance library activities. Demand trend projections for telecommunications services…

  18. Conditioning of alpha bearing wastes

    International Nuclear Information System (INIS)

    1991-01-01

    Alpha bearing wastes are generated during the reprocessing of spent fuel, mixed oxide fuel fabrication, decommissioning and other activities. The safe and effective management of these wastes is of particular importance owing to the radiotoxicity and long lived characteristics of certain transuranic (TRU) elements. The management of alpha bearing wastes involves a number of stages which include collection, characterization, segregation, treatment, conditioning, transport, storage and disposal. This report describes the currently available matrices and technologies for the conditioning of alpha wastes and relates them to their compatibility with the other stages of the waste management process. The selection of a specific immobilization process is dependent on the waste treatment state and the subsequent handling, transport, storage and disposal requirements. The overall objectives of immobilization are similar for all waste producers and processors, which are to produce: (a) Waste forms with sufficient mechanical, physical and chemical stability to satisfy all stages of handling, transport and storage (referred to as the short term requirements), and (b) Waste forms which will satisfy disposal requirements and inhibit the release of radionuclides to the biosphere (referred to as the long term requirements). Cement and bitumen processes have already been successfully applied to alpha waste conditioning on the industrial scale in many of the IAEA Member States. Cement systems based on BFS and pozzolanic cements have emerged as the principal encapsulation matrices for the full range of alpha bearing wastes. Alternative technologies, such as polymers and ceramics, are being developed for specific waste streams but are unlikely to meet widespread application owing to cost and process complexity. The merits of alpha waste conditioning are improved performance in transport, storage and disposal combined with enhanced public perception of waste management operations. These

  19. Relation of solar wind fluctuations to differential flow between protons and alphas

    Science.gov (United States)

    Neugebauer, M.

    1974-01-01

    An analysis is made of the difference between the alpha particle and proton flow velocities in the solar wind as observed by the OGO 5 satellite. The alpha and proton velocities from each of 962 spectral scans are compared with the variance of 32 solar wind flux measurements made during the scans. The average velocity difference is plotted for each of 10 logarithmic variance intervals and is seen to decrease and approach zero when the variance is high. It is shown that such an anticorrelation may be due to the fact the wave/particle interactions provide the drag force between two streams of different velocity in a collisionless plasma.

  20. Small Sar Satellite Using Small Standard Bus

    OpenAIRE

    Ono, Kiyonobu; Fujimura, Takashi; Ogawa, Toshiaki; Kimura, Tsunekazu

    2011-01-01

    This paper introduces a new small SAR (Synthetic Aperture Radar) satellite that follows the small optical sensor satellite, ASNARO. USEF, NEDO and NEC are developing ASNARO satellite, which is a small LEO satellite (total mass

  1. Macromolecular organization of human centromeric regions reveals high-frequency, polymorphic macro DNA repeats.

    Science.gov (United States)

    Jabs, E W; Goble, C A; Cutting, G R

    1989-01-01

    To analyze the macromolecular organization of human centromeric regions, we used alpha-satellite, or alphoid, repetitive DNA sequences specific to the centromeres of human chromosomes 6 (D6Z1), X (XC), and Y (YC-2) and the technique of pulsed-field gel electrophoresis. Genomic DNA from 24 normal, unrelated individuals was digested and separated into fragments ranging from 23 kilobases (kb) to 2 megabases (Mb) in length. Digestion with 12 different restriction enzymes with 4- to 8-base-pair recognition sequences and hybridization with alphoid sequences revealed chromosome-specific hybridization patterns. Similarities in the organization of the centromeric regions of the three chromosomes included NotI, SfiI, and SalI fragments of greater than 2 Mb and Sau3A1 and Alu I fragments of less than 150 kb. Each restriction enzyme with a 6-base-pair recognition sequence (Ava II, BamHI, HindIII, Hpa I, Pst I, Sal I, Sst I, and Xba I) detected polymorphic DNA fragments of 50 kb to 2 Mb. Forty percent or more of the individuals screened revealed a unique hybridization pattern with these enzymes and at least one of the three chromosome-specific alphoid probes. Five individuals differed from one another in hybridization pattern for each of the three enzymes HindIII, HpaI, and SstI and for each of the three centromeric probes. All 24 individuals could be distinguished on the basis of unique hybridization patterns with only two enzymes and one chromosome-specific alphoid probe. Family studies showed that these polymorphisms are inherited. The high frequency of these macro restriction fragment length polymorphisms illustrates the high degree of variability of the centromeric region among normal individuals and demonstrates its usefulness for DNA fingerprinting and pericentromeric mapping by linkage analysis.

  2. DNA data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Raw DNA chromatogram data produced by the ABI 373, 377, 3130 and 3730 automated sequencing machines in ABI format. These are from fish (primarily Sebastes spp.,...

  3. DNA methylation

    DEFF Research Database (Denmark)

    Williams, Kristine; Christensen, Jesper; Helin, Kristian

    2012-01-01

    DNA methylation is involved in key cellular processes, including X-chromosome inactivation, imprinting and transcriptional silencing of specific genes and repetitive elements. DNA methylation patterns are frequently perturbed in human diseases such as imprinting disorders and cancer. The recent...... discovery that the three members of the TET protein family can convert 5-methylcytosine (5mC) into 5-hydroxymethylcytosine (5hmC) has provided a potential mechanism leading to DNA demethylation. Moreover, the demonstration that TET2 is frequently mutated in haematopoietic tumours suggests that the TET...... proteins are important regulators of cellular identity. Here, we review the current knowledge regarding the function of the TET proteins, and discuss various mechanisms by which they contribute to transcriptional control. We propose that the TET proteins have an important role in regulating DNA methylation...

  4. DNA nanotechnology

    Science.gov (United States)

    Seeman, Nadrian C.; Sleiman, Hanadi F.

    2018-01-01

    DNA is the molecule that stores and transmits genetic information in biological systems. The field of DNA nanotechnology takes this molecule out of its biological context and uses its information to assemble structural motifs and then to connect them together. This field has had a remarkable impact on nanoscience and nanotechnology, and has been revolutionary in our ability to control molecular self-assembly. In this Review, we summarize the approaches used to assemble DNA nanostructures and examine their emerging applications in areas such as biophysics, diagnostics, nanoparticle and protein assembly, biomolecule structure determination, drug delivery and synthetic biology. The introduction of orthogonal interactions into DNA nanostructures is discussed, and finally, a perspective on the future directions of this field is presented.

  5. Thematic mapping from satellite imagery

    CERN Document Server

    Denègre, J

    2013-01-01

    Thematic Mapping from Satellite Imagery: A Guidebook discusses methods in producing maps using satellite images. The book is comprised of five chapters; each chapter covers one stage of the process. Chapter 1 tackles the satellite remote sensing imaging and its cartographic significance. Chapter 2 discusses the production processes for extracting information from satellite data. The next chapter covers the methods for combining satellite-derived information with that obtained from conventional sources. Chapter 4 deals with design and semiology for cartographic representation, and Chapter 5 pre

  6. Cooperative and cognitive satellite systems

    CERN Document Server

    Chatzinotas, Symeon; De Gaudenzi, Riccardo

    2015-01-01

    Cooperative and Cognitive Satellite Systems provides a solid overview of the current research in the field of cooperative and cognitive satellite systems, helping users understand how to incorporate state-of-the-art communication techniques in innovative satellite network architectures to enable the next generation of satellite systems. The book is edited and written by top researchers and practitioners in the field, providing a comprehensive explanation of current research that allows users to discover future technologies and their applications, integrate satellite and terrestrial systems

  7. Role of oxidative DNA damage in genome instability and cancer

    International Nuclear Information System (INIS)

    Bignami, M.; Kunkel, T.

    2009-01-01

    Inactivation of mismatch repair (MMR) is associated with a dramatic genomic instability that is observed experimentally as a mutator phenotype and micro satellite instability (MSI). It has been implicit that the massive genetic instability in MMR defective cells simply reflects the accumulation of spontaneous DNA polymerase errors during DNA replication. We recently identified oxidation damage, a common threat to DNA integrity to which purines are very susceptible, as an important cofactor in this genetic instability

  8. Small Satellites Big Business?

    OpenAIRE

    A. Marchetto, Carl

    2008-01-01

    Biography-Carl A. Marchetto is Senior Vice President and President, ATK Space Systems for Alliant Tech¬systems (ATK). Prior to joining ATK in January 2008, Carl was Executive Vice President and General Manager Space Sys¬tems group for Orbital Sciences, where he led an organization designing, building, and servicing communication, space research and earth imaging satellites for commercial, gov¬ernment and academic customers. Carl’s previous experience includes a decade at Eastman Kodak that sa...

  9. Apoptotic effect of alpha-mangostin on head and neck squamous carcinoma cells.

    Science.gov (United States)

    Kaomongkolgit, Ruchadaporn; Chaisomboon, Niratcha; Pavasant, Prasit

    2011-05-01

    The purposes of this study were to measure the cytotoxic effect of alpha-mangostin on head and neck squamous cell carcinoma (HNSCC) cell lines, to evaluate the apoptotic aspect of dead cells, and to identify the molecular mechanism involved in apoptosis. The human HNSCC cell lines HN-22, HN-30 and HN-31 were treated with alpha-mangostin. The apoptotic effects of alpha-mangostin on HNSCC cells were determined by observation the morphological changes of cells, immunofluorescence for single-stranded DNA (ssDNA), and DNA fragmentation analysis. The expression of bax, bcl-2, and p53 were detected by RT-PCR and Western blot analysis. Alpha-mangostin showed excellent apoptotic effects on HNSCC cell lines, which induced the down-regulation of bcl-2, but up-regulation of bax and p53 in HN-22, HN-30 and HN-31. The present study suggests that the induction of apoptosis by alpha-mangostin seemed to be modulated by bcl-2, bax and p53 level in HNSCC cell lines. Copyright © 2010 Elsevier Ltd. All rights reserved.

  10. Improved Alpha Testing Using Hashed Sampling.

    Science.gov (United States)

    Wyman, Chris; McGuire, Morgan

    2017-08-14

    We further describe and analyze the idea of hashed alpha testing from Wyman and McGuire [1], which builds on stochastic alpha testing and simplifies stochastic transparency. Typically, alpha testing provides a simple mechanism to mask out complex silhouettes using simple proxy geometry with applied alpha textures. While widely used, alpha testing has a long-standing problem: geometry can disappear entirely as alpha mapped polygons recede with distance. As foveated rendering for virtual reality spreads, this problem worsens as peripheral minification and prefiltering introduce this problem on nearby objects.

  11. Laser satellite power systems

    Energy Technology Data Exchange (ETDEWEB)

    Walbridge, E.W.

    1980-01-01

    A laser satellite power system (SPS) converts solar power captured by earth-orbiting satellites into electrical power on the earth's surface, the satellite-to-ground transmission of power being effected by laser beam. The laser SPS may be an alternative to the microwave SPS. Microwaves easily penetrate clouds while laser radiation does not. Although there is this major disadvantage to a laser SPS, that system has four important advantages over the microwave alternative: (1) land requirements are much less, (2) radiation levels are low outside the laser ground stations, (3) laser beam sidelobes are not expected to interfere with electromagnetic systems, and (4) the laser system lends itself to small-scale demonstration. After describing lasers and how they work, the report discusses the five lasers that are candidates for application in a laser SPS: electric discharge lasers, direct and indirect solar pumped lasers, free electron lasers, and closed-cycle chemical lasers. The Lockheed laser SPS is examined in some detail. To determine whether a laser SPS will be worthy of future deployment, its capabilities need to be better understood and its attractiveness relative to other electric power options better assessed. First priority should be given to potential program stoppers, e.g., beam attenuation by clouds. If investigation shows these potential program stoppers to be resolvable, further research should investigate lasers that are particularly promising for SPS application.

  12. A satellite anemometer

    Science.gov (United States)

    Hanson, W. B.; Heelis, R. A.

    1995-01-01

    This report describes the design, development, and testing of components of a satellite anemometer, an instrument for measuring neutral winds in the upper atmosphere from a satellite platform. The device, which uses four nearly identical pressure sensors, measures the angle of arrival of the bulk neutral flow in the satellite frame of reference. It could also be used in a feedback loop to control spacecraft attitude with respect to the ram velocity direction. We have now developed miniaturized ionization pressure gauges that will work well from the slip flow region near 115 km up to the base of the exosphere, which covers the entire altitude range currently being considered for Tether. Laboratory tests have demonstrated a very linear response to changes in ram angle out to +/- 20 deg. (transverse wind component of 2.7 km s(exp -1)) from the ram, and a monotonic response to out beyond 45 deg. Pitch (vertical wind) and yaw (horizontal wind) can be sampled simultaneously and meaningfully up to 10 Hz. Angular sensitivity of 30 arc seconds (approximately 1 ms(exp -1) is readily attainable, but absolute accuracy for winds will be approximately 1 deg (130 m/s) unless independent attitude knowledge is available. The critical elements of the design have all been tested in the laboratory.

  13. DNA expressions - A formal notation for DNA

    NARCIS (Netherlands)

    Vliet, Rudy van

    2015-01-01

    We describe a formal notation for DNA molecules that may contain nicks and gaps. The resulting DNA expressions denote formal DNA molecules. Different DNA expressions may denote the same molecule. Such DNA expressions are called equivalent. We examine which DNA expressions are minimal, which

  14. Two Bg1II RFLPs of the human. alpha. -globin gene cluster in the American sickle cell population

    Energy Technology Data Exchange (ETDEWEB)

    Embury, S.H.; Blachman, T.; Kroop, G.L.; Suzuki, J.K.; Boyle, M. (Univ. of California and Northern California Comprehensive Sickle Cell Center, San Fransicso (USA))

    1989-11-11

    Human {alpha}-globin cDNA cloned into plasmid pMB9(JW101) was used as a hybridization probe for assessing the {alpha}-globin genotypes of 2271 Americans with sickle cell anemia. The normal duplicated human {alpha}-globin genes, {alpha}2 and {alpha}1, residue on separate Bg1 II fragments, each of which is cleaved by Hin dIII. Both {alpha} loci reside on a single 14 kb Bam HI fragment. The authors performed single Bg1 II and BAM HI digests to detect {alpha}-globin gene deletions in 2271 subjects enrolled in the National Cooperative Study of Sickel Cell Disease (NCSSCD). In addition to gene deletions and duplications, two Bg1 II RFLP were found. The human {alpha}-globin genes reside on the short arm of chromosome 16. The {alpha}2-specific RFLP occurs in linkage dysequilibrium and the mother of one subject with the {alpha}1-specific RFLP had this RFLP, suggesting their Mendelian inheritance.

  15. ALPHA,·ANTITRYPSIN DEFICIENCY*

    African Journals Online (AJOL)

    1971-02-06

    Feb 6, 1971 ... Lieberman," in fact, found that 15·2% of 66 patients hospitalized with pulmonary emphysema had heterozygous alpha,-antitrypsin deficiency. The over-all incidence of the deficiency was 25'8% in this group. Of patients under the age of 50 years, 47·8% had deficient levels. If such observations are confirmed ...

  16. Alpha sources deposit by sublimation

    International Nuclear Information System (INIS)

    Amoudry, F.; Eloy, J.F.

    1983-09-01

    We studied and realized a device able to perform some very thin substracts used for alpha spectrometry measurements. Sources are prepared by sublimation of the sample in a vacuum container. The energy required for this sublimation is furnished by a laser beam [fr

  17. The p53 inhibitor, pifithrin-{alpha}, suppresses self-renewal of embryonic stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Abdelalim, Essam Mohamed, E-mail: essam_abdelalim@yahoo.com [Molecular Neuroscience Research Center, Shiga University of Medical Science, Setatsukinowa-cho, Otsu, Shiga 520-2192 (Japan); Department of Cytology and Histology, Faculty of Veterinary Medicine, Suez Canal University, Ismailia 41522 (Egypt); Tooyama, Ikuo [Molecular Neuroscience Research Center, Shiga University of Medical Science, Setatsukinowa-cho, Otsu, Shiga 520-2192 (Japan)

    2012-04-13

    Highlights: Black-Right-Pointing-Pointer We determine the role of p53 in ES cells under unstressful conditions. Black-Right-Pointing-Pointer PFT-{alpha} suppresses ES cell proliferation. Black-Right-Pointing-Pointer PFT-{alpha} induces ES cell cycle arrest. Black-Right-Pointing-Pointer PFT-{alpha} downregulates Nanog and cyclin D1. -- Abstract: Recent studies have reported the role of p53 in suppressing the pluripotency of embryonic stem (ES) cells after DNA damage and blocking the reprogramming of somatic cells into induced pluripotent stem (iPS) cells. However, to date no evidence has been presented to support the function of p53 in unstressed ES cells. In this study, we investigated the effect of pifithrin (PFT)-{alpha}, an inhibitor of p53-dependent transcriptional activation, on self-renewal of ES cells. Our results revealed that treatment of ES cells with PFT-{alpha} resulted in the inhibition of ES cell propagation in a dose-dependent manner, as indicated by a marked reduction in the cell number and colony size. Also, PFT-{alpha} caused a cell cycle arrest and significant reduction in DNA synthesis. In addition, inhibition of p53 activity reduced the expression levels of cyclin D1 and Nanog. These findings indicate that p53 pathway in ES cells rather than acting as an inactive gene, is required for ES cell proliferation and self-renewal under unstressful conditions.

  18. NcoI restriction fragment length polymorphism (RFLP) of the tumour necrosis factor (TNF alpha) region in primary biliary cirrhosis and in healthy Danes

    DEFF Research Database (Denmark)

    Fugger, L; Morling, N; Ryder, L P

    1989-01-01

    The restriction fragment length polymorphism of the human tumour necrosis factor (TNF alpha) region was investigated by means of 20 different restriction enzymes and a human TNF alpha cDNA probe. Only one of the enzymes, NcoI, revealed a polymorphic pattern consisting of fragments of 10.5 and 5...

  19. Cloning, chromosomal localization, and functional expression of the alpha 1 subunit of the L-type voltage-dependent calcium channel from normal human heart

    NARCIS (Netherlands)

    Schultz, D; Mikala, G; Yatani, A; Engle, D B; Iles, D E; Segers, B; Sinke, R J; Weghuis, D O; Klöckner, U; Wakamori, M

    1993-01-01

    A unique structural variant of the cardiac L-type voltage-dependent calcium channel alpha 1 subunit cDNA was isolated from libraries derived from normal human heart mRNA. The deduced amino acid sequence shows significant homology to other calcium channel alpha 1 subunits. However, differences from

  20. NcoI restriction fragment length polymorphism (RFLP) of the tumour necrosis factor (TNF alpha) region in primary biliary cirrhosis and in healthy Danes

    DEFF Research Database (Denmark)

    Fugger, L; Morling, N; Ryder, L P

    1989-01-01

    The restriction fragment length polymorphism of the human tumour necrosis factor (TNF alpha) region was investigated by means of 20 different restriction enzymes and a human TNF alpha cDNA probe. Only one of the enzymes, NcoI, revealed a polymorphic pattern consisting of fragments of 10.5 and 5.5...

  1. What Is Mitochondrial DNA?

    Science.gov (United States)

    ... DNA What is mitochondrial DNA? What is mitochondrial DNA? Although most DNA is packaged in chromosomes within ... proteins. For more information about mitochondria and mitochondrial DNA: Molecular Expressions, a web site from the Florida ...

  2. Solution structure and DNA binding of the zinc-finger domain from DNA ligase IIIalpha.

    Science.gov (United States)

    Kulczyk, Arkadiusz W; Yang, Ji-Chun; Neuhaus, David

    2004-08-13

    DNA ligase IIIalpha carries out the final ligation step in the base excision repair (BER) and single strand break repair (SSBR) mechanisms of DNA repair. The enzyme recognises single-strand nicks and other damage features in double-stranded DNA, both through the catalytic domain and an N-terminal domain containing a single zinc finger. The latter is homologous to other zinc fingers that recognise damaged DNA, two in the N terminus of poly(adenosine-ribose)polymerase and three in the N terminus of the Arabidopsis thaliana nick-sensing DNA 3'-phosphoesterase. Here, we present the solution structure of the zinc-finger domain of human DNA ligase IIIalpha, the first structure of a finger from this group. It is related to that of the erythroid transcription factor GATA-1, but has an additional N-terminal beta-strand and C-terminal alpha-helix. Chemical shift mapping using a DNA ligand containing a single-stranded break showed that the DNA-binding surface of the DNA-ligase IIIalpha zinc finger is substantially different from that of GATA-1, consistent with the fact that the two proteins recognise very different features in the DNA. Likely implications for DNA binding are discussed.

  3. The effect of a metalloproteinase inhibitor (GI5402) on tumor necrosis factor-alpha (TNF-alpha) and TNF-alpha receptors during human endotoxemia

    NARCIS (Netherlands)

    Dekkers, P. E.; Lauw, F. N.; ten Hove, T.; te Velde, A. A.; Lumley, P.; Becherer, D.; van Deventer, S. J.; van der Poll, T.

    1999-01-01

    Tumor necrosis factor-alpha (TNF-alpha) is released from the cell surface by cleavage of pro-TNF-alpha by metalloproteinases (MPs). In cell cultures, inhibition of MPs has been found not only to reduce the release of TNF-alpha, but also to enhance the surface expression of TNF-alpha and TNF-alpha

  4. Calibration of sources for alpha spectroscopy systems

    International Nuclear Information System (INIS)

    Freitas, I.S.M.; Goncalez, O.L.

    1992-01-01

    This paper describes the calibration methodology for measuring the total alpha activity of plane and thin sources with the Alpha Spectrometer for Silicon Detector in the Nuclear Measures and Dosimetry laboratory at IEAv/CTA. (author)

  5. The diversity and evolution of cell cycle regulation in alpha-proteobacteria: a comparative genomic analysis

    Directory of Open Access Journals (Sweden)

    Mengoni Alessio

    2010-04-01

    Full Text Available Abstract Background In the bacterium Caulobacter crescentus, CtrA coordinates DNA replication, cell division, and polar morphogenesis and is considered the cell cycle master regulator. CtrA activity varies during cell cycle progression and is modulated by phosphorylation, proteolysis and transcriptional control. In a phosphorylated state, CtrA binds specific DNA sequences, regulates the expression of genes involved in cell cycle progression and silences the origin of replication. Although the circuitry regulating CtrA is known in molecular detail in Caulobacter, its conservation and functionality in the other alpha-proteobacteria are still poorly understood. Results Orthologs of Caulobacter factors involved in the regulation of CtrA were systematically scanned in genomes of alpha-proteobacteria. In particular, orthologous genes of the divL-cckA-chpT-ctrA phosphorelay, the divJ-pleC-divK two-component system, the cpdR-rcdA-clpPX proteolysis system, the methyltransferase ccrM and transcriptional regulators dnaA and gcrA were identified in representative genomes of alpha-proteobacteria. CtrA, DnaA and GcrA binding sites and CcrM putative methylation sites were predicted in promoter regions of all these factors and functions controlled by CtrA in all alphas were predicted. Conclusions The regulatory cell cycle architecture was identified in all representative alpha-proteobacteria, revealing a high diversification of circuits but also a conservation of logical features. An evolutionary model was proposed where ancient alphas already possessed all modules found in Caulobacter arranged in a variety of connections. Two schemes appeared to evolve: a complex circuit in Caulobacterales and Rhizobiales and a simpler one found in Rhodobacterales.

  6. Mobile satellite service communications tests using a NASA satellite

    Science.gov (United States)

    Chambers, Katherine H.; Koschmeder, Louis A.; Hollansworth, James E.; ONeill, Jack; Jones, Robert E.; Gibbons, Richard C.

    1995-01-01

    Emerging applications of commercial mobile satellite communications include satellite delivery of compact disc (CD) quality radio to car drivers who can select their favorite programming as they drive any distance; transmission of current air traffic data to aircraft; and handheld communication of data and images from any remote corner of the world. Experiments with the enabling technologies and tests and demonstrations of these concepts are being conducted before the first satellite is launched by utilizing an existing NASA spacecraft.

  7. Satellite Laser Ranging Satellite Orbit Product from NASA CDDIS

    Data.gov (United States)

    National Aeronautics and Space Administration — SLR Satellite Orbit solutions available from the Crustal Dynamics Data Information System (CDDIS). Precise Orbit Determination (POD) solutions in Standard Product 3...

  8. Aberrant activity of the DNA repair enzyme AlkB.

    Science.gov (United States)

    Henshaw, Timothy F; Feig, Michael; Hausinger, Robert P

    2004-05-01

    Escherichia coli AlkB is a DNA/RNA repair enzyme containing a mononuclear Fe(II) site that couples the oxidative decomposition of alpha-ketoglutarate (alphaKG) to the hydroxylation of 1-methyladenine or 3-methylcytosine lesions in DNA or RNA, resulting in release of formaldehyde and restoration of the normal bases. In the presence of Fe(II), alphaKG, and oxygen, but the absence of methylated DNA, AlkB was found to catalyze an aberrant reaction that generates a blue chromophore. The color is proposed to derive from Fe(III) coordinated by a hydroxytryptophan at position 178 as revealed by mass spectrometric analysis. Protein structural modeling confirms that Trp 178 is reasonably positioned to react with the Fe(IV)-oxo intermediate proposed to form at the active site.

  9. Enzyme replacement therapy for alpha-mannosidosis

    DEFF Research Database (Denmark)

    Borgwardt, Line Gutte; Dali, Christine I.; Fogh, J

    2013-01-01

    Alpha-mannosidosis (OMIM 248500) is a rare lysosomal storage disease (LSD) caused by alpha-mannosidase deficiency. Manifestations include intellectual disabilities, facial characteristics and hearing impairment. A recombinant human alpha-mannosidase (rhLAMAN) has been developed for weekly intrave...... intravenous enzyme replacement therapy (ERT). We present the preliminary data after 12 months of treatment....

  10. THE ALPHA/BETA-HYDROLASE FOLD

    NARCIS (Netherlands)

    OLLIS, DL; CHEAH, E; CYGLER, M; FROLOW, F; FRANKEN, SM; HAREL, M; REMINGTON, SJ; SILMAN, [No Value; SCHRAG, J; SUSSMAN, JL; VERSCHUEREN, KHG; GOLDMAN, A

    We have identified a new protein fold-the alpha/beta-hydrolase fold-that is common to several hydrolytic enzymes of widely differing phylogenetic origin and catalytic function. The core of each enzyme is similar: an alpha/beta-sheet, not barrel, of eight beta-sheets connected by alpha-helices. These

  11. Nano-Satellite Avionics

    Science.gov (United States)

    Culver, Harry

    1999-01-01

    Abstract NASA's Goddard Space Flight Center (GSFC) is currently developing a new class of satellites called the nano-satellite (nano-sat). A major objective of this development effort is to provide the technology required to enable a constellation of tens to hundreds of nano-satellites to make both remote and in-situ measurements from space. The Nano-sat will be a spacecraft weighing a maximum of 10 kg, including the propellant mass, and producing at least 5 Watts of power to operate the spacecraft. The electronics are required to survive a total radiation dose rate of 100 krads for a mission lifetime of two years. There are many unique challenges that must be met in order to develop the avionics for such a spacecraft. The first challenge is to develop an architecture that will operate on the allotted 5 Watts and meet the diverging requirements of multiple missions. This architecture will need to incorporate a multitude of new advanced microelectronic technologies. The microelectronics developed must be a modular and scalable packaging of technology to solve the problem of developing a solution to both reduce cost and meet the requirements of various missions. This development will utilize the most cost effective approach, whether infusing commercially driven semiconductor devices into spacecraft applications or partnering with industry to design and develop low cost, low power, low mass, and high capacity data processing devices. This paper will discuss the nano-sat architecture and the major technologies that will be developed. The major technologies that will be covered include: (1) Light weight Low Power Electronics Packaging, (2) Radiation Hard/Tolerant, Low Power Processing Platforms, (3) High capacity Low Power Memory Systems (4) Radiation Hard reconfiguragble field programmable gate array (rFPGA)

  12. China Satellite Navigation Conference

    CERN Document Server

    Liu, Jingnan; Fan, Shiwei; Wang, Feixue

    2016-01-01

    These Proceedings present selected research papers from CSNC2016, held during 18th-20th May in Changsha, China. The theme of CSNC2016 is Smart Sensing, Smart Perception. These papers discuss the technologies and applications of the Global Navigation Satellite System (GNSS), and the latest progress made in the China BeiDou System (BDS) especially. They are divided into 12 topics to match the corresponding sessions in CSNC2016, which broadly covered key topics in GNSS. Readers can learn about the BDS and keep abreast of the latest advances in GNSS techniques and applications.

  13. Understanding satellite navigation

    CERN Document Server

    Acharya, Rajat

    2014-01-01

    This book explains the basic principles of satellite navigation technology with the bare minimum of mathematics and without complex equations. It helps you to conceptualize the underlying theory from first principles, building up your knowledge gradually using practical demonstrations and worked examples. A full range of MATLAB simulations is used to visualize concepts and solve problems, allowing you to see what happens to signals and systems with different configurations. Implementation and applications are discussed, along with some special topics such as Kalman Filter and Ionosphere. W

  14. Radio broadcasting via satellite

    Science.gov (United States)

    Helm, Neil R.; Pritchard, Wilbur L.

    1990-10-01

    Market areas offering potential for future narrowband broadcast satellites are examined, including international public diplomacy, government- and advertising-supported, and business-application usages. Technical issues such as frequency allocation, spacecraft types, transmission parameters, and radio receiver characteristics are outlined. Service and system requirements, advertising revenue, and business communications services are among the economic issues discussed. The institutional framework required to provide an operational radio broadcast service is studied, and new initiatives in direct broadcast audio radio systems, encompassing studies, tests, in-orbit demonstrations of, and proposals for national and international commercial broadcast services are considered.

  15. China Satellite Navigation Conference

    CERN Document Server

    Liu, Jingnan; Yang, Yuanxi; Fan, Shiwei; Yu, Wenxian

    2017-01-01

    These proceedings present selected research papers from CSNC2017, held during 23th-25th May in Shanghai, China. The theme of CSNC2017 is Positioning, Connecting All. These papers discuss the technologies and applications of the Global Navigation Satellite System (GNSS), and the latest progress made in the China BeiDou System (BDS) especially. They are divided into 12 topics to match the corresponding sessions in CSNC2017, which broadly covered key topics in GNSS. Readers can learn about the BDS and keep abreast of the latest advances in GNSS techniques and applications.

  16. Nature of the pygmy dipole resonance in Ce-140 studied in (alpha, alpha 'gamma) experiments

    NARCIS (Netherlands)

    Savran, D.; Babilon, M.; van den Berg, A.M.; Harakeh, M.N.; Hasper, J.; Matic, A.; Wörtche, H.J.; Zilges, A.

    2006-01-01

    A concentration of electric-dipole excitations below the particle threshold, which is frequently denoted as the pygmy dipole resonance, has been studied in the semimagic nucleus Ce-140 in (alpha, alpha(')gamma) experiments at E-alpha=136 MeV. The technique of alpha-gamma coincidence experiments

  17. DNA nanotechnology

    OpenAIRE

    Nadrian C Seeman

    2003-01-01

    Since Watson and Crick’s determination of its structure nearly 50 years ago, DNA has come to fill our lives in many areas, from genetic counseling to forensics, from genomics to gene therapy. These, and other ways in which DNA affects human activities, are related to its function as genetic material, not just our genetic material, but the genetic material of all living organisms. Here, we will ignore DNA’s biological role; rather, we will discuss how the properties that make it so successful ...

  18. Induction studies with satellite data

    DEFF Research Database (Denmark)

    Olsen, Nils

    1999-01-01

    The natural variations of the Earth's magnetic field of periods spanning from milliseconds to decades can be used to infer the conductivity-depth profile of the Earth's interior. Satellites provide a good spatial coverage of magnetic measurements, and forthcoming missions will probably allow....... This paper reviews and discusses the possibilities for induction studies using high-precision magnetic measurements from low-altitude satellites. The different methods and various transfer functions are presented, with special emphasis on the differences in analysing data from ground stations and from...... satellites. The results of several induction studies with scalar satellite data (from the POGO satellites) and with vector data (from the Magsat mission) demonstrate the ability to probe the Earth's conductivity from space. However, compared to the results obtained with ground data the satellite results...

  19. Alternative splicing of T cell receptor (TCR) alpha chain transcripts containing V alpha 1 or V alpha 14 elements.

    Science.gov (United States)

    Mahotka, C; Hansen-Hagge, T E; Bartram, C R

    1995-10-01

    Human acute lymphoblastic leukemia cell lines represent valuable tools to investigate distinct steps of the complex regulatory pathways underlying T cell receptor recombination and expression. A case in point are V delta 2D delta 3 and subsequent V delta 2D delta 3J alpha rearrangements observed in human leukemic pre-B cells as well as in normal lymphopoiesis. The functional expression of these unusual (VD) delta (JC) alpha hybrids is almost exclusively prevented by alternative splicing events. In this report we show that alternative splicing at cryptic splice donor sites within V elements is not a unique feature of hybrid TCR delta/alpha transcripts. Among seven V alpha families analyzed by RT-PCR, alternatively spliced products were observed in TCR alpha recombinations containing V alpha 1 or V alpha 14 elements. In contrast to normal peripheral blood cells and thymocytes, the leukemia cell line JM expressing functional V alpha 1J alpha 3C alpha transcripts lacked evidence of aberrant TCR alpha RNA species.

  20. Living antennas on communication satellites

    DEFF Research Database (Denmark)

    Lumholt, Michael

    2003-01-01

    Crises change the global pattern of communication. The communications problems occur because the satellites are optimized to cover specific geographic areas, and these areas cannot be altered once the satellites are in Earth orbit. An effective solution to the problem is to equip communication...... satellites with "living" antennas that can adjust their radiation coverage areas according to the new demands. The development of living antennas is, therefore, among the focus areas identified and supported by the European Space Agency, ESA....

  1. Communication Satellites 1958 to 1986

    Science.gov (United States)

    1984-10-01

    CATALOG NUMBER S. TYRE OF REPORT * PERIOD COVERED Interim S. PERFORMING ORG. REPORT NUMBER TR-0084A(5417-03)-l S. CONTRACT OR GRANT NUMRERT...Intelsat Leases 7-211 Other Systems 7-215 The Philippines 7-215 Malaysia 7-215 Planned Systems 7-215 OTHER SATELLITES 8-1 Satellites for... industry . ( The purpose of this report is to describe and summarize the technical details of each type of communication satellite for the years 1958 to

  2. Alpha particles detection in nitrocellulose

    International Nuclear Information System (INIS)

    Romero C, M.

    1976-01-01

    The method for the manufacturing of the detection films follows these steps: preparation of the mass which includes nitrocellulose in the form of cotton as raw material ethyl acetate, cellosolve acetate, isopropyl and butyl alcohols as solvents and dioctyl phtalate as plasticiser; dilution of the paste; pouring of the diluted mass; and drying of the detection films. The results obtained experimentally are: The determination of the development times of the different thicknesses of the manufactured films. Response linearity of the detectors, variation of the number of tracks according to the distance of the source to the detector. Sizes of the diameter of the tracks depending of the distance detector-alpha emmission source. As a conclusion we can say the the nitrocellulose detectors are specific for alpha radiation; the more effective thicknesses in uranium prospecting works were those of 60 microns, since for the laboratory works the thicknesses of 30 to 40 microns were the ideal; the development technique of the detection films is simple and cheap and can be realized even in another place than the laboratory; this way of the manufacturing of nitrocellulose detection film sensitive to alpha nuclear radiation is open to future research. (author)

  3. Parachute satellites for earth observation

    Science.gov (United States)

    Massonnet, Didier

    2008-07-01

    The "parachute" concept presented here is a generic definition for earth observation systems essentially made of a reflector under which a detector associated with a telemetry antenna is suspended [D. Massonnet, (Applicant), Satellite, method and a fleet of satellites for observing a celestial body, Patent 0509-1112, 2006. [1]; D. Massonnet, (Déposant), Satellite, procédé et flotte de satellites d'observation d'un corps céleste, Priorité 04-04327, 2004. [2

  4. Magnetic Satellite Missions and Data

    DEFF Research Database (Denmark)

    Olsen, Nils; Kotsiaros, Stavros

    2011-01-01

    Although the first satellite observations of the Earth’s magnetic field were already taken more than 50 years ago, continuous geomagnetic measurements from space are only available since 1999. The unprecedented time-space coverage of this recent data set opened revolutionary new possibilities...... for exploring the Earth’s magnetic field from space. In this chapter we discuss characteristics of satellites measuring the geomagnetic field and report on past, present and upcoming magnetic satellite missions. We conclude with some basics about space magnetic gradiometry as a possible path for future...... exploration of Earth’s magnetic field with satellites....

  5. Measurement and analysis of $\\alpha$ particle induced reactions on yttrium

    CERN Document Server

    Singh, N L; Chintalapudi, S N

    2000-01-01

    Excitation functions for /sup 89/Y[( alpha ,3n); ( alpha ,4n); ( alpha , p3n); ( alpha , alpha n); ( alpha , alpha 2n)] reactions were measured up to 50 MeV using stacked foil activation technique and HPGe gamma ray spectroscopy method. The experimental data were compared with calculations considering equilibrium as well as preequilibrium reactions according to the hybrid model of Blann (ALICE/90). For ( alpha , xnyp) type of reactions, the precompound contributions are described by the model. There seems to be indications of direct inelastic scattering effects in ( alpha , alpha xn) type of reactions. To the best of our knowledge, the excitation functions for ( alpha ,4n), ( alpha , p3n), ( alpha , alpha n) and ( alpha , alpha 2n) reactions were measured for the first time. (23 refs).

  6. Measurement and analysis of alpha particle induced reactions on yttrium

    Energy Technology Data Exchange (ETDEWEB)

    Singh, N.L.; Gadkari, M.S. [Baroda Univ. (India). Dept. of Physics; Chintalapudi, S.N. [IUC-DAEF Calcutta Centre, Calcutta (India)

    2000-05-01

    Excitation functions for {sup 89}Y[({alpha},3n);({alpha},4n);({alpha},p3n);({alpha},{alpha}n);({alpha},{alpha}2n)] reactions were measured up to 50 MeV using stacked foil activation technique and HPGe gamma ray spectroscopy method. The experimental data were compared with calculations considering equilibrium as well as preequilibrium reactions according to the hybrid model of Blann (ALICE/90). For ({alpha},xnyp) type of reactions, the precompound contributions are described by the model. There seems to be indications of direct inelastic scattering effects in ({alpha},{alpha}xn) type of reactions. To the best of our knowledge, the excitation functions for ({alpha},4n), ({alpha},p3n), ({alpha},{alpha}n) and ({alpha},{alpha}2n) reactions were measured for the first time. (orig.)

  7. DNA Investigations.

    Science.gov (United States)

    Mayo, Ellen S.; Bertino, Anthony J.

    1991-01-01

    Presents a simulation activity that allow students to work through the exercise of DNA profiling and to grapple with some analytical and ethical questions involving a couple arranging with a surrogate mother to have a baby. Can be used to teach the principles of restriction enzyme digestion, gel electrophoresis, and probe hybridization. (MDH)

  8. Gigabit Satellite Network for NASA's Advanced Communication Technology Satellite (ACTS)

    Science.gov (United States)

    Hoder, Douglas; Bergamo, Marcos

    1996-01-01

    The advanced communication technology satellite (ACTS) gigabit satellite network provides long-haul point-to-point and point-to-multipoint full-duplex SONET services over NASA's ACTS. at rates up to 622 Mbit/s (SONET OC-12), with signal quality comparable to that obtained with terrestrial fiber networks. Data multiplexing over the satellite is accomplished using time-division multiple access (TDMA) techniques coordinated with the switching and beam hopping facilities provided by ACTS. Transmissions through the satellite are protected with Reed-Solomon encoding. providing virtually error-free transmission under most weather conditions. Unique to the system are a TDMA frame structure and satellite synchronization mechanism that allow: (a) very efficient utilization of the satellite capacity: (b) over-the-satellite dosed-loop synchronization of the network in configurations with up to 64 ground stations: and (c) ground station initial acquisition without collisions with existing signalling or data traffic. The user interfaces are compatible with SONET standards, performing the function of conventional SONET multiplexers and. as such. can be: readily integrated with standard SONET fiber-based terrestrial networks. Management of the network is based upon the simple network management protocol (SNMP). and includes an over-the-satellite signalling network and backup terrestrial internet (IP-based) connectivity. A description of the ground stations is also included.

  9. Interferon Alpha in Systemic Lupus Erythematosus

    Directory of Open Access Journals (Sweden)

    Timothy B. Niewold

    2010-01-01

    Full Text Available The pleiotropic cytokine interferon alpha is involved in multiple aspects of lupus etiology and pathogenesis. Interferon alpha is important under normal circumstances for antiviral responses and immune activation. However, heightened levels of serum interferon alpha and expression of interferon response genes are common in lupus patients. Lupus-associated autoantibodies can drive the production of interferon alpha and heightened levels of interferon interfere with immune regulation. Several genes in the pathways leading to interferon production or signaling are associated with risk for lupus. Clinical and cellular manifestations of excess interferon alpha in lupus combined with the genetic risk factors associated with interferon make this cytokine a rare bridge between genetic risk and phenotypic effects. Interferon alpha influences the clinical picture of lupus and may represent a therapeutic target. This paper provides an overview of the cellular, genetic, and clinical aspects of interferon alpha in lupus.

  10. Novel alpha-mannosidase inhibitors; Nye alfa-mannosidaseinhibitorer

    Energy Technology Data Exchange (ETDEWEB)

    Farr, R.A.; Kang, M.S.; Peet, N.P.; Sunkara, S.P.

    1997-05-20

    [4S-(4{alpha}, 4a{beta}, 6{alpha}, 7{alpha}, 7a{alpha})]-Octahydro-1H-1-pyridine-4,5,6,7-tetrols and [4R-(4{alpha}, 4a{alpha}, 5{alpha}, 6{beta}, 7{beta}, 7a{beta})]-octahydro-1H-1-pyridine-4,5,6,7-tetrols are useful inhibitors of alpha-mannosidase and are useful immunostimulants, chemoprotective and radioprotective agents and antimetastatic agents.

  11. Global Navigation Satellite System and Augmentation

    Indian Academy of Sciences (India)

    Global Navigation Satellite System (GNSS) is a generic name given to a group of several satellite constellations such as the. Global Positioning System (GPS), GLObal NAvigation Satellite. System (GLONASS), Galileo, and Compass. The satellite con- stellations (navigation satellites) broadcast their positions and tim-.

  12. The Future of Satellite Communications Technology.

    Science.gov (United States)

    Nowland, Wayne

    1985-01-01

    Discusses technical advances in satellite technology since the 1960s, and the International Telecommunications Satellite Organization's role in these developments; describes how AUSSAT, Australia's domestic satellite system, exemplifies the latest developments in satellite technology; and reviews satellite system features, possible future…

  13. Structure and function of DnaA N-terminal domains: specific sites and mechanisms in inter-DnaA interaction and in DnaB helicase loading on oriC.

    Science.gov (United States)

    Abe, Yoshito; Jo, Takaaki; Matsuda, Yusaku; Matsunaga, Chika; Katayama, Tsutomu; Ueda, Tadashi

    2007-06-15

    DnaA forms a homomultimeric complex with the origin of chromosomal replication (oriC) to unwind duplex DNA. The interaction of the DnaA N terminus with the DnaB helicase is crucial for the loading of DnaB onto the unwound region. Here, we determined the DnaA N terminus structure using NMR. This region (residues 1-108) consists of a rigid region (domain I) and a flexible region (domain II). Domain I has an alpha-alpha-beta-beta-alpha-beta motif, similar to that of the K homology (KH) domain, and has weak affinity for oriC single-stranded DNA, consistent with KH domain function. A hydrophobic surface carrying Trp-6 most likely forms the interface for domain I dimerization. Glu-21 is located on the opposite surface of domain I from the Trp-6 site and is crucial for DnaB helicase loading. These findings suggest a model for DnaA homomultimer formation and DnaB helicase loading on oriC.

  14. A study of the antioxidant effect of alpha lipoic acids on sperm quality

    Directory of Open Access Journals (Sweden)

    Siti Fatimah Ibrahim

    2008-01-01

    Full Text Available OBJECTIVE: Assisted reproductive techniques are useful in helping infertile couples achieve successful conception. Initial studies have shown that sperm cryopreservation, one step in assisted reproduction, causes a dramatic reduction in sperm quality. This has been attributed to, among other things, free radical activities. The aim of the present study was to minimize this oxidative attack by adding an antioxidant into the sperm microenvironment. Alpha lipoic acids were selected for this purpose for their efficient free radical scavenging properties and solubility in lipid and aqueous phases. METHODS: For this investigation, semen from six Boer bucks was pooled. Seminal analysis of the baseline prior to incubation of samples with different concentrations of Alpha lipoic acids (0.00625, 0.0125, 0.025, 0.05, 0.1 mmol/ml was performed, and post-seminal analysis was conducted after a one-hour incubation. The comet assay was used to observe the effect of Alpha lipoic acids on sperm DNA integrity. Statistical analysis using an unpaired t-test with a significance level of p<0.05 was then performed. RESULTS: Our results indicate that the sperm motility rate was improved after incubation with Alpha lipoic acids at a concentration of 0.02 mmol/ml. This concentration was also capable of reducing DNA damage. CONCLUSION: In conclusion, Alpha lipoic acids renders cryoprotection to sperm, thereby improving sperm quality.

  15. LCS-1: A high-resolution global model of the lithospheric magnetic field derived from CHAMP and Swarm satellite observations

    DEFF Research Database (Denmark)

    Olsen, Nils; Ravat, Dhananjay; Finlay, Chris

    2017-01-01

    We derive a new model, named LCS-1, of Earth’s lithospheric field based on four years (Sept 2006 – Sept 2010) of magnetic observations taken by the CHAMP satellite at altitudes lower than 350 km, as well as almost three years (April 2014 to December 2016) of measurements taken by the two lower...... Swarm satellites Alpha and Charlie. The model is determined entirely from magnetic “gradient” data (approximated by finite differences): the North-South gradient is approximated by first differences of 15 second along-track data (for CHAMP and each of the two Swarm satellites), while the East...

  16. Satellite Control Laboratory

    DEFF Research Database (Denmark)

    Wisniewski, Rafal; Bak, Thomas

    2001-01-01

    The Satellite Laboratory at the Department of Control Engineering of Aalborg University (SatLab) is a dynamic motion facility designed for analysis and test of micro spacecraft. A unique feature of the laboratory is that it provides a completely gravity-free environment. A test spacecraft...... of the laboratory is to conduct dynamic tests of the control and attitude determination algorithms during nominal operation and in abnormal conditions. Further it is intended to use SatLab for validation of various algorithms for fault detection, accommodation and supervisory control. Different mission objectives...... can be implemented in the laboratory, e.g. three-axis attitude control, slew manoeuvres, spins stabilization using magnetic actuation and/or reaction wheels. The spacecraft attitude can be determined applying magnetometer measurements....

  17. Leucocytes, cytokines and satellite cells

    DEFF Research Database (Denmark)

    Paulsen, Gøran; Mikkelsen, Ulla Ramer; Raastad, Truls

    2012-01-01

    damage. With the exception of IL-6, the sources of systemic cytokines following exercise remain unclear The satellite cell response to severe muscle damage is related to regeneration, whereas the biological significance of satellite cell proliferation after mild damage or non-damaging exercise remains...

  18. Mobility management in satellite networks

    Science.gov (United States)

    Johanson, Gary A.

    1995-01-01

    This paper addresses the methods used or proposed for use in multi-beam and/or multi-satellite networks designed to provide Mobile Satellite Services (MSS). Specific topics include beam crossover in the North American Mobile Satellite (MSAT) system as well as registration and live call hand-off for a multi-regional geosynchronous (GEO) satellite based system and a global coverage Low Earth Orbiting (LEO) system. In the MSAT system, the individual satellite beams cover very large geographic areas so the need for live call hand-off was not anticipated. This paper discusses the methods used to keep track of the beam location of the users so that incoming call announcements or other messages may be directed to them. Proposed new GEO systems with large numbers of beams will provide much smaller geographic coverage in individual beams and thus the need arises to keep track of the user's location as well as to provide live call hand-off as the user traverses from beam to beam. This situation also occurs in proposed LEO systems where the problems are worsened by the need for satellite to satellite hand-off as well as beam to beam hand-off within a single satellite. The paper discusses methods to accomplish these handoffs and proposes system architectures to address the various hand-off scenarios.

  19. Newspaper Uses of Satellite Technology.

    Science.gov (United States)

    Johns, David

    Replacing slower mail service, satellite transmission now gives the newspaper industry a practical and almost spontaneous method for sending all kinds of information to any newspaper across the country. Unlike other communication industries, newspapers did not begin to make widespread use of satellite technology until 1979, when government…

  20. Satellite Demonstration: The Videodisc Technology.

    Science.gov (United States)

    Propp, George; And Others

    1979-01-01

    Originally part of a symposium on educational media for the deaf, the paper describes a satellite demonstration of video disc materials. It is explained that a panel of deaf individuals in Washington, D.C. and another in Nebraska came into direct two-way communication for the first time, and video disc materials were broadcast via the satellite.…

  1. A Primer on Satellite Equipment.

    Science.gov (United States)

    Doan, Michael

    1992-01-01

    Information provided for school districts desiring to offer distance education courses to their students describes the kind of satellite dish needed; its size, sturdiness, placement, and number of dishes needed; satellite receivers; the function of a descrambler; copyright restrictions; features of an Integrated Receiver/Descrambler; selecting a…

  2. The Skeletal Muscle Satellite Cell

    Science.gov (United States)

    2011-01-01

    The skeletal muscle satellite cell was first described and named based on its anatomic location between the myofiber plasma and basement membranes. In 1961, two independent studies by Alexander Mauro and Bernard Katz provided the first electron microscopic descriptions of satellite cells in frog and rat muscles. These cells were soon detected in other vertebrates and acquired candidacy as the source of myogenic cells needed for myofiber growth and repair throughout life. Cultures of isolated myofibers and, subsequently, transplantation of single myofibers demonstrated that satellite cells were myogenic progenitors. More recently, satellite cells were redefined as myogenic stem cells given their ability to self-renew in addition to producing differentiated progeny. Identification of distinctively expressed molecular markers, in particular Pax7, has facilitated detection of satellite cells using light microscopy. Notwithstanding the remarkable progress made since the discovery of satellite cells, researchers have looked for alternative cells with myogenic capacity that can potentially be used for whole body cell-based therapy of skeletal muscle. Yet, new studies show that inducible ablation of satellite cells in adult muscle impairs myofiber regeneration. Thus, on the 50th anniversary since its discovery, the satellite cell’s indispensable role in muscle repair has been reaffirmed. PMID:22147605

  3. Launching the First Indian Satellite

    Indian Academy of Sciences (India)

    made in recent years in India in electronics. In comparison, information on rocket technology is much more restricted. Thus it came about that when in 1972 the USSR. Academy of Sciences offered us assistances to launch an Indian made satellite with a. Soviet rocket - the Indian Scientific Satellite Project came into being.

  4. Accumulation of satellites

    International Nuclear Information System (INIS)

    Safronov, V.S.; Ruskol, E.L.

    1977-01-01

    Formation and evolution of circumplanetary satellite swarms are investigated. Characteristic times of various processes are estimated. The characteristic time for the accumulation of the bodies in the swarm was several orders of magnitude shorter than that of the planet, i.e. than the time of the replenishment of the material by the swarm (10 8 yr). The model of the accumulation of the swarm is constructed taking into account the increase of its mass due to trapping of heliocentrically moving particles and its decrease due to outfall of the inner part of the swarm onto the growing planet. The accumulation of circumplanetary bodies is also considered. The main features of the evolution of the swarm essentially depend on the size distribution of bodies in the swarm and in the zone of the planet and also on the degree of the concentration of the swarm mass toward the planet. If the sum of the exponents of the inverse power laws of these distributions is less than 7, the model of the transparent swarm developed in this paper should be preferred. When this sum is greater than 7, the model of opaque swarm suggested by A. Harris and W.M. Kaula is better. There is predominant trapping of small particles into the swarm due to their more frequent collisions. Optical thickness of the protoplanetary cloud in radial direction is estimated. It is shown that at the final stage of the planetary accumulation, the cloud was semitransparent in the region of terrestrial planets and volatile substances evaporated at collisions could be swept out from the outer parts of the satellite swarm by the solar wind

  5. Sky alert! when satellites fail

    CERN Document Server

    Johnson, Les

    2013-01-01

    How much do we depend on space satellites? Defense, travel, agriculture, weather forecasting, mobile phones and broadband, commerce...the list seems endless. But what would our live be like if the unimaginable happened and, by accident or design, those space assets disappeared? Sky Alert! explores what our world would be like, looking in turn at areas where the loss could have catastrophic effects. The book - demonstrates our dependence on space technology and satellites; - outlines the effect on our economy, defense, and daily lives if satellites and orbiting spacecraft were destroyed; - illustrates the danger of dead satellites, spent rocket stages, and space debris colliding with a functioning satellites; - demonstrates the threat of dramatically increased radiation levels associated with geomagnetic storms; - introduces space as a potential area of conflict between nations.

  6. DNA Chip

    Indian Academy of Sciences (India)

    Imagine a world without identity cards; no I-cards for the college or office or bank account or anything! All you are carrying is a small (say, 2cm x 2cm) 'DNA-chip', which has the whole of your genetic profile on it. Your identity cannot get more authentic than that. Imagine a world where marriages are not decided by matching ...

  7. DNA repair

    International Nuclear Information System (INIS)

    Setlow, R.

    1978-01-01

    Some topics discussed are as follows: difficulty in extrapolating data from E. coli to mammalian systems; mutations caused by UV-induced changes in DNA; mutants deficient in excision repair; other postreplication mechanisms; kinds of excision repair systems; detection of repair by biochemical or biophysical means; human mutants deficient in repair; mutagenic effects of UV on XP cells; and detection of UV-repair defects among XP individuals

  8. Alpha particle studies during JET DT experiments

    International Nuclear Information System (INIS)

    1999-01-01

    The 1997 DT experiment (DTE1) at the Joint European Torus included studies of the behaviour of alpha particles in high temperature plasmas. Clear alpha particle heating was observed in a series of otherwise similar 10MW hot-ion H-modes by scanning the DT mixture from 0%T to 93%T. Maxima in central temperature and energy content were obtained which corresponded with the maximum in fusion yield. Alfven Eigenmodes (AEs) have been detected in JET, driven by NBI or ICRH fast ions. However, in agreement with theory, no AE activity was observed in DT plasmas which could be attributed to alpha particle drive, except in the afterglow of some Optimised Shear pulses. Ion Cyclotron Emission (ICE) was detected at harmonics of the alpha particle cyclotron frequency at the outer edge of the plasma. The ICE is interpreted as being close to magnetoacoustic cyclotron instability, driven by inverted alpha distributions at the plasma edge. The high-energy neutral particle spectra showed features, which are ascribed to a mixture of alphas, neutralised by helium-like impurities, and deuterons, born from elastic collisions with alpha particles and neutralised by hydrogen-like impurities. The results of all these studies are consistent with classical alpha particle trapping and slowing-down. Future DT experiments will aim to increase alpha particle pressure, so interactions with plasma instabilities can be studied. The measurement of knock-on neutral triton spectra offers a clean way to determine confined alpha densities in these future experiments. (author)

  9. Alpha particle studies during JET DT experiments

    International Nuclear Information System (INIS)

    2001-01-01

    The 1997 DT experiment (DTE1) at the Joint European Torus included studies of the behaviour of alpha particles in high temperature plasmas. Clear alpha particle heating was observed in a series of otherwise similar 10MW hot-ion H-modes by scanning the DT mixture from 0%T to 93%T. Maxima in central temperature and energy content were obtained which corresponded with the maximum in fusion yield. Alfven Eigenmodes (AEs) have been detected in JET, driven by NBI or ICRH fast ions. However, in agreement with theory, no AE activity was observed in DT plasmas which could be attributed to alpha particle drive, except in the afterglow of some Optimised Shear pulses. Ion Cyclotron Emission (ICE) was detected at harmonics of the alpha particle cyclotron frequency at the outer edge of the plasma. The ICE is interpreted as being close to magnetoacoustic cyclotron instability, driven by inverted alpha distributions at the plasma edge. The high-energy neutral particle spectra showed features, which are ascribed to a mixture of alphas, neutralised by helium-like impurities, and deuterons, born from elastic collisions with alpha particles and neutralised by hydrogen-like impurities. The results of all these studies are consistent with classical alpha particle trapping and slowing-down. Future DT experiments will aim to increase alpha particle pressure, so interactions with plasma instabilities can be studied. The measurement of knock-on neutral triton spectra offers a clean way to determine confined alpha densities in these future experiments. (author)

  10. Stool DNA Test

    Science.gov (United States)

    ... The stool DNA test is a noninvasive laboratory test that identifies DNA changes in the cells of a stool sample. ... the presence of cancer. If a stool DNA test detects abnormal DNA, additional testing may be used to investigate the ...

  11. The Alpha Magnetic Spectrometer (AMS)

    CERN Document Server

    Alcaraz, J; Ambrosi, G; Anderhub, H; Ao, L; Arefev, A; Azzarello, P; Babucci, E; Baldini, L; Basile, M; Barancourt, D; Barão, F; Barbier, G; Barreira, G; Battiston, R; Becker, R; Becker, U; Bellagamba, L; Bene, P; Berdugo, J; Berges, P; Bertucci, B; Biland, A; Bizzaglia, S; Blasko, S; Bölla, G; Boschini, M; Bourquin, Maurice; Brocco, L; Bruni, G; Buénerd, M; Burger, J D; Burger, W J; Cai, X D; Camps, C; Cannarsa, P; Capell, M; Casadei, D; Casaus, J; Castellini, G; Cecchi, C; Chang, Y H; Chen, H F; Chen, H S; Chen, Z G; Chernoplekov, N A; Tzi Hong Chiueh; Chuang, Y L; Cindolo, F; Commichau, V; Contin, A; Crespo, P; Cristinziani, M; Cunha, J P D; Dai, T S; Deus, J D; Dinu, N; Djambazov, L; Dantone, I; Dong, Z R; Emonet, P; Engelberg, J; Eppling, F J; Eronen, T; Esposito, G; Extermann, P; Favier, Jean; Fiandrini, E; Fisher, P H; Flügge, G; Fouque, N; Galaktionov, Yu; Gervasi, M; Giusti, P; Grandi, D; Grimm, O; Gu, W Q; Hangarter, K; Hasan, A; Hermel, V; Hofer, H; Huang, M A; Hungerford, W; Ionica, M; Ionica, R; Jongmanns, M; Karlamaa, K; Karpinski, W; Kenney, G; Kenny, J; Kim, W; Klimentov, A; Kossakowski, R; Koutsenko, V F; Kraeber, M; Laborie, G; Laitinen, T; Lamanna, G; Laurenti, G; Lebedev, A; Lee, S C; Levi, G; Levchenko, P M; Liu, C L; Liu, H T; Lopes, I; Lu, G; Lü, Y S; Lübelsmeyer, K; Luckey, D; Lustermann, W; Maña, C; Margotti, A; Mayet, F; McNeil, R R; Meillon, B; Menichelli, M; Mihul, A; Mourao, A; Mujunen, A; Palmonari, F; Papi, A; Park, I H; Pauluzzi, M; Pauss, Felicitas; Perrin, E; Pesci, A; Pevsner, A; Pimenta, M; Plyaskin, V; Pozhidaev, V; Postolache, V; Produit, N; Rancoita, P G; Rapin, D; Raupach, F; Ren, D; Ren, Z; Ribordy, M; Richeux, J P; Riihonen, E; Ritakari, J; Röser, U; Roissin, C; Sagdeev, R; Sartorelli, G; Schwering, G; Scolieri, G; Seo, E S; Shoutko, V; Shoumilov, E; Siedling, R; Son, D; Song, T; Steuer, M; Sun, G S; Suter, H; Tang, X W; Ting, Samuel C C; Ting, S M; Tornikoski, M; Torsti, J; Ulbricht, J; Urpo, S; Usoskin, I; Valtonen, E; Vandenhirtz, J; Velcea, F; Velikhov, E P; Verlaat, B; Vetlitskii, I; Vezzu, F; Vialle, J P; Viertel, Gert M; Vitè, Davide F; Gunten, H V; Wallraff, W; Wang, B C; Wang, J Z; Wang, Y H; Wiik, K; Williams, C; Wu, S X; Xia, P C; Yan, J L; Yan, L G; Yang, C G; Yang, M; Ye, S W; Yeh, P; Xu, Z Z; Zhang, H Y; Zhang, Z P; Zhao, D X; Zhu, G Y; Zhu, W Z; Zhuang, H L; Zichichi, A; Zimmermann, B

    2002-01-01

    The Alpha Magnetic Spectrometer (AMS) is a large acceptance (0.65 sr m sup 2) detector designed to operate in the International Space Station (ISS) for three years. The purposes of the experiment are to search for cosmic antimatter and dark matter and to study the composition and energy spectrum of the primary cosmic rays. A 'scaled-down' version has been flown on the Space Shuttle Discovery for 10 days in June 1998. The complete AMS is programmed for installation on the ISS in October 2003 for an operational period of 3 yr. This contribution reports on the experimental configuration that will be installed on the ISS.

  12. Targeted alpha therapy for cancer

    Energy Technology Data Exchange (ETDEWEB)

    Allen, Barry J [Centre for Experimental Radiation Oncology, St George Cancer Care Centre, Gray St, Kogarah 2217, NSW (Australia); Raja, Chand [Centre for Experimental Radiation Oncology, St George Cancer Care Centre, Gray St, Kogarah 2217, NSW (Australia); Rizvi, Syed [Centre for Experimental Radiation Oncology, St George Cancer Care Centre, Gray St, Kogarah 2217, NSW (Australia); Li Yong [Centre for Experimental Radiation Oncology, St George Cancer Care Centre, Gray St, Kogarah 2217, NSW (Australia); Tsui, Wendy [Centre for Experimental Radiation Oncology, St George Cancer Care Centre, Gray St, Kogarah 2217, NSW (Australia); Zhang, David [Centre for Experimental Radiation Oncology, St George Cancer Care Centre, Gray St, Kogarah 2217, NSW (Australia); Song, Emma [Centre for Experimental Radiation Oncology, St George Cancer Care Centre, Gray St, Kogarah 2217, NSW (Australia); Qu, C F [Centre for Experimental Radiation Oncology, St George Cancer Care Centre, Gray St, Kogarah 2217, NSW (Australia); Kearsley, John [Centre for Experimental Radiation Oncology, St George Cancer Care Centre, Gray St, Kogarah 2217, NSW (Australia); Graham, Peter [Centre for Experimental Radiation Oncology, St George Cancer Care Centre, Gray St, Kogarah 2217, NSW (Australia); Thompson, John [Sydney Melanoma Unit, Royal Prince Alfred Hospital, Camperdown 2050 NSW (Australia)

    2004-08-21

    Targeted alpha therapy (TAT) offers the potential to inhibit the growth of micrometastases by selectively killing isolated and preangiogenic clusters of cancer cells. The practicality and efficacy of TAT is tested by in vitro and in vivo studies in melanoma, leukaemia, colorectal, breast and prostate cancers, and by a phase 1 trial of intralesional TAT for melanoma. The alpha-emitting radioisotope used is Bi-213, which is eluted from the Ac-225 generator and chelated to a cancer specific monoclonal antibody (mab) or protein (e.g. plasminogen activator inhibitor-2 PAI2) to form the alpha-conjugate (AC). Stable alpha-ACs have been produced which have been tested for specificity and cytotoxicity in vitro against melanoma (9.2.27 mab), leukaemia (WM60), colorectal (C30.6), breast (PAI2, herceptin), ovarian (PAI2, herceptin, C595), prostate (PAI2, J591) and pancreatic (PAI2, C595) cancers. Subcutaneous inoculation of 1-1.5 million human cancer cells into the flanks of nude mice causes tumours to grow in all mice. Tumour growth is compared for untreated controls, nonspecific AC and specific AC, for local (subcutaneous) and systemic (tail vein or intraperitoneal) injection models. The {sup 213}Bi-9.2.27 AC is injected into secondary skin melanomas in stage 4 patients in a dose escalation study to determine the effective tolerance dose, and to measure kinematics to obtain the equivalent dose to organs. In vitro studies show that TAT is one to two orders of magnitude more cytotoxic to targeted cells than non-specific ACs, specific beta emitting conjugates or free isotopes. In vivo local TAT at 2 days post-inoculation completely prevents tumour formation for all cancers tested so far. Intra-lesional TAT can completely regress advanced sc melanoma but is less successful for breast and prostate cancers. Systemic TAT inhibits the growth of sc melanoma xenografts and gives almost complete control of breast and prostate cancer tumour growth. Intralesional doses up to 450 {mu

  13. The Alpha Magnetic Spectrometer (ams)

    Science.gov (United States)

    Ionica, Maria

    2004-01-01

    The Alpha Magnetic Spectrometer (AMS), once installed on the International Space Station will provide precise measurements of the cosmic ray spectra up to TeV energy range, and will search for cosmological antimatter and missing matter. A prototype version of the detector was operated successfully on the space shuttle Discovery in June 1998 (STS-91). Here we briefly report on the design of the AMS apparatus and present the results of the measurements of the fluxes of proton, electron, positron and helium from the STS-91 flight.

  14. Crossing symmetry in Alpha space

    CERN Multimedia

    CERN. Geneva

    2017-01-01

    The conformal bootstrap program aims to catalog all conformal field theories (second-order phase transitions) in D dimensions. Despite its ambitious scope much progress has been made over the past decade, e.g. in computing critical exponents for the 3D O(N) models to high precision. At this stage, analytic methods to explore the CFT landscape are not as well developed. In this talk I will describe a new mathematical framework for the bootstrap known as "alpha space", which reduces crossing symmetry to a set of integral equations. Based on arXiv:1702.08471 (with Balt van Rees) and arXiv:1703.08159.

  15. The Alpha Magnetic Spectrometer (AMS)

    International Nuclear Information System (INIS)

    Alcaraz, J.; Alpat, B.; Ambrosi, G.; Anderhub, H.; Ao, L.; Arefiev, A.; Azzarello, P.; Babucci, E.; Baldini, L.; Basile, M.; Barancourt, D.; Barao, F.; Barbier, G.; Barreira, G.; Battiston, R.; Becker, R.; Becker, U.; Bellagamba, L.; Bene, P.; Berdugo, J.; Berges, P.; Bertucci, B.; Biland, A.; Bizzaglia, S.; Blasko, S.; Boella, G.; Boschini, M.; Bourquin, M.; Brocco, L.; Bruni, G.; Buenerd, M.; Burger, J.D.; Burger, W.J.; Cai, X.D.; Camps, C.; Cannarsa, P.; Capell, M.; Casadei, D.; Casaus, J.; Castellini, G.; Cecchi, C.; Chang, Y.H.; Chen, H.F.; Chen, H.S.; Chen, Z.G.; Chernoplekov, N.A.; Chiueh, T.H.; Chuang, Y.L.; Cindolo, F.; Commichau, V.; Contin, A.; Crespo, P.; Cristinziani, M.; Cunha, J.P. da; Dai, T.S.; Deus, J.D.; Dinu, N.; Djambazov, L.; DAntone, I.; Dong, Z.R.; Emonet, P.; Engelberg, J.; Eppling, F.J.; Eronen, T.; Esposito, G.; Extermann, P.; Favier, J.; Fiandrini, E.; Fisher, P.H.; Fluegge, G.; Fouque, N.; Galaktionov, Yu.; Gervasi, M.; Giusti, P.; Grandi, D.; Grimm, O.; Gu, W.Q.; Hangarter, K.; Hasan, A.; Hermel, V.; Hofer, H.; Huang, M.A.; Hungerford, W.; Ionica, M.; Ionica, R.; Jongmanns, M.; Karlamaa, K.; Karpinski, W.; Kenney, G.; Kenny, J.; Kim, W.; Klimentov, A.; Kossakowski, R.; Koutsenko, V.; Kraeber, M.; Laborie, G.; Laitinen, T.; Lamanna, G.; Laurenti, G.; Lebedev, A.; Lee, S.C.; Levi, G.; Levtchenko, P.; Liu, C.L.; Liu, H.T.; Lopes, I.; Lu, G.; Lu, Y.S.; Luebelsmeyer, K.; Luckey, D.; Lustermann, W.; Mana, C.; Margotti, A.; Mayet, F.; McNeil, R.R.; Meillon, B.; Menichelli, M.; Mihul, A.; Mourao, A.; Mujunen, A.; Palmonari, F.; Papi, A.; Park, I.H.; Pauluzzi, M.; Pauss, F.; Perrin, E.; Pesci, A.; Pevsner, A.; Pimenta, M.; Plyaskin, V.; Pojidaev, V.; Postolache, V.; Produit, N.; Rancoita, P.G.; Rapin, D.; Raupach, F.; Ren, D.; Ren, Z.; Ribordy, M.; Richeux, J.P.; Riihonen, E.; Ritakari, J.; Roeser, U.; Roissin, C.; Sagdeev, R.; Sartorelli, G.; Schultz von Dratzig, A.; Schwering, G.; Scolieri, G.; Seo, E.S.; Shoutko, V.; Shoumilov, E.; Siedling, R.; Son, D.; Song, T.; Steuer, M.; Sun, G.S.; Suter, H.; Tang, X.W.; Ting, S.C.C.Samuel C.C.; Ting, S.M.; Tornikoski, M.; Torsti, J.; Tr umper, J.; Ulbricht, J.; Urpo, S.; Usoskin, I.; Valtonen, E.; Vandenhirtz, J.; Velcea, F.; Velikhov, E.; Verlaat, B.; Vetlitsky, I.; Vezzu, F.; Vialle, J.P.; Viertel, G.; Vite, D.; Gunten, H. Von; Wicki, S.W.S. Waldmeier; Wallraff, W.; Wang, B.C.; Wang, J.Z.; Wang, Y.H.; Wiik, K.; Williams, C.; Wu, S.X.; Xia, P.C.; Yan, J.L.; Yan, L.G.; Yang, C.G.; Yang, M.; Ye, S.W.; Yeh, P.; Xu, Z.Z.; Zhang, H.Y.; Zhang, Z.P.; Zhao, D.X.; Zhu, G.Y.; Zhu, W.Z.; Zhuang, H.L.; Zichichi, A.; Zimmermann, B.

    2002-01-01

    The Alpha Magnetic Spectrometer (AMS) is a large acceptance (0.65 sr m 2 ) detector designed to operate in the International Space Station (ISS) for three years. The purposes of the experiment are to search for cosmic antimatter and dark matter and to study the composition and energy spectrum of the primary cosmic rays. A 'scaled-down' version has been flown on the Space Shuttle Discovery for 10 days in June 1998. The complete AMS is programmed for installation on the ISS in October 2003 for an operational period of 3 yr. This contribution reports on the experimental configuration that will be installed on the ISS

  16. Polar-Orbiting Satellite (POES) Images

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Visible and Infrared satellite imagery taken from camera systems or radiometer instruments on satellites in orbit around the poles. Satellite campaigns include...

  17. AB088. Prevalence of alpha thalassemia mutations in Filipino patients

    Science.gov (United States)

    Silao, Catherine Lynn Tipton; Fabella, Terence Diane F.; Naranjo, Maria Liza T.; Padilla, Carmencita D.; Yuson, Ernesto D. J.

    2017-01-01

    Background Alpha (α)-thalassemia results from the absent or reduced synthesis of the α-globin subunit of hemoglobin. Mutational variants in the HBA1 and HBA2 genes, which code for α-globin, have been reported and cause varying degrees of disease severity. These variants are unique for every population. Local data on alpha-globin gene mutations in Filipino alpha-thalassemia is currently lacking. Methods This study aimed to identify the prevalence of common α-globin gene mutations in Filipinos highly suspected for α-thalassemia through evaluation of CBC results, red cell indices and upon ruling-out iron deficiency anemia. Sixty five [65] patients underwent DNA extraction and Alpha Globin StripAssay mutational analysis. Results The four gene deletion, (--SEA/--SEA), the three gene deletion, (-α 3.7/--FIL), (-α 3.7/--SEA), (-α 4.2/--SEA), the cis two gene, (--SEA/αα), (--FIL/αα), the trans two gene deletion, (-α3.7/-α3.7), the one gene deletion, (-α3.7/αα), and the (α2 cd 59/αα) were found in 1.54%, 21.54%, 56.92%, 1.54%, 6.15% and 1.54% of patients, respectively. Conclusions These results suggest that cis two gene deletions identified are prevalent in Filipinos tested. The high prevalence of cis two gene deletion of HBA1 and HBA2 in this study is important as these alleles may increase the risk of Hb H and Hb Bart’s hydrops fetalis cases in the population.

  18. Alpha-proteobacteria cultivated from marine sponges display branching rod morphology.

    Science.gov (United States)

    Olson, Julie B; Harmody, Dedra K; McCarthy, Peter J

    2002-06-04

    Most isolates recovered from marine environments are Gram-negative proteobacteria, even with the use of various media and media additions to enhance recoverability. Cultivation studies with two genera of deep-water sponges yielded nine isolates that demonstrated bulbous branching rod morphology, which is usually associated with microorganisms staining Gram-positive. Gram reactions indicated that the isolates were Gram-negative, which was confirmed by partial 16S rDNA sequencing. All nine isolates were shown to be alpha-proteobacteria most closely related to other alpha-proteobacteria isolated from various sponges.

  19. Immunogenicity of a DNA-launched replicon-based canine parvovirus DNA vaccine expressing VP2 antigen in dogs.

    Science.gov (United States)

    Dahiya, Shyam S; Saini, Mohini; Kumar, Pankaj; Gupta, Praveen K

    2012-10-01

    A replicon-based DNA vaccine encoding VP2 gene of canine parvovirus (CPV) was developed by cloning CPV-VP2 gene into a replicon-based DNA vaccine vector (pAlpha). The characteristics of a replicon-based DNA vaccine like, self-amplification of transcripts and induction of apoptosis were analyzed in transfected mammalian cells. When the pAlpha-CPV-VP2 was injected intradermal as DNA-launched replicon-based DNA vaccine in dogs, it induced CPV-specific humoral and cell mediated immune responses. The virus neutralization antibody and lymphocyte proliferative responses were higher than conventional CPV DNA vaccine and commercial CPV vaccine. These results indicated that DNA-launched replicon-based CPV DNA vaccine was effective in inducing both CPV-specific humoral and cellular immune responses and can be considered as effective alternative to conventional CPV DNA vaccine and commercial CPV vaccine. Crown Copyright © 2012. Published by Elsevier India Pvt Ltd. All rights reserved.

  20. Theory of satellite geodesy applications of satellites to geodesy

    CERN Document Server

    Kaula, William M

    2000-01-01

    The main purpose of this classic text is to demonstrate how Newtonian gravitational theory and Euclidean geometry can be used and developed in the earth's environment. The second is to collect and explain some of the mathematical techniques developed for measuring the earth by satellite.Book chapters include discussions of the earth's gravitational field, with special emphasis on spherical harmonies and the potential of the ellipsoid; matrices and orbital geometry; elliptic motion, linear perturbations, resonance, and other aspects of satellite orbit dynamics; the geometry of satellite obser

  1. Reduced Dnmt3a increases Gdf5 expression with suppressed satellite cell differentiation and impaired skeletal muscle regeneration.

    Science.gov (United States)

    Hatazawa, Yukino; Ono, Yusuke; Hirose, Yuma; Kanai, Sayaka; Fujii, Nobuharu L; Machida, Shuichi; Nishino, Ichizo; Shimizu, Takahiko; Okano, Masaki; Kamei, Yasutomi; Ogawa, Yoshihiro

    2018-03-01

    DNA methylation is an epigenetic mechanism regulating gene expression. In this study, we observed that DNA methyltransferase 3a (Dnmt3a) expression is decreased after muscle atrophy. We made skeletal muscle-specific Dnmt3a-knockout (Dnmt3a-KO) mice. The regeneration capacity after muscle injury was markedly decreased in Dnmt3a-KO mice. Diminished mRNA and protein expression of Dnmt3a were observed in skeletal muscles as well as in satellite cells, which are important for muscle regeneration, in Dnmt3a-KO mice. Dnmt3a-KO satellite cell showed smaller in size (length/area), suggesting suppressed myotube differentiation. Microarray analysis of satellite cells showed that expression of growth differentiation factor 5 (Gdf5) mRNA was markedly increased in Dnmt3a-KO mice. The DNA methylation level of the Gdf5 promoter was markedly decreased in Dnmt3a-KO satellite cells. In addition, DNA methylation inhibitor azacytidine treatment increased Gdf5 expression in wild-type satellite cells, suggesting Gdf5 expression is regulated by DNA methylation. Also, we observed increased inhibitor of differentiation (a target of Gdf5) mRNA expression in Dnmt3a-KO satellite cells. Thus, Dnmt3a appears to regulate satellite cell differentiation via DNA methylation. This mechanism may play a role in the decreased regeneration capacity during atrophy such as in aged sarcopenia.-Hatazawa, Y., Ono, Y., Hirose, Y., Kanai, S., Fujii, N. L., Machida, S., Nishino, I., Shimizu, T., Okano, M., Kamei, Y., Ogawa, Y. Reduced Dnmt3a increases Gdf5 expression with suppressed satellite cell differentiation and impaired skeletal muscle regeneration.

  2. Weighing the Low-Redshift Lyman-alpha Forest

    Science.gov (United States)

    Shull, Mike

    2005-01-01

    In 2003-2004, our FUSE research group prepared several major surveys of the amount of baryonic matter in the intergalactic medium (IGM), using the Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. These surveys include measurements of the Lyman-alpha absorption line of neutral hydrogen (H I), the far-ultraviolet (1032,1038 Angstrom) doublet of highly ionized oxygen ( O VI), the higher Lyman-series lines (Ly-beta, Ly-gamma, etc) of H I, and the 977 Angstrom line of c III. As an overview, our FUSE spectroscopic studies, taken together with data from the Hubble Space Telescope, show that approximately 30% of the normal matter is contained in intergalactic hydrogen gas clouds (the Lyman-alpha forest). Another 5-10% resides in hotter gas at temperatures of 10(exp 5) to 10(exp 6) K, visible in 0 VI and C III absorption. Along with the matter attributed to galaxies, we have now accounted for approximately HALF of all the baryonic matter in the universe. Where is the other half? That matter my exist in even hotter gas, invisible through the ultraviolet absorption lines, but perhaps detectable through X-ray absorption lines of more highly ionized oxygen and neon.

  3. Muscle Satellite Cell Protein Teneurin-4 Regulates Differentiation During Muscle Regeneration.

    Science.gov (United States)

    Ishii, Kana; Suzuki, Nobuharu; Mabuchi, Yo; Ito, Naoki; Kikura, Naomi; Fukada, So-Ichiro; Okano, Hideyuki; Takeda, Shin'ichi; Akazawa, Chihiro

    2015-10-01

    Satellite cells are maintained in an undifferentiated quiescent state, but during muscle regeneration they acquire an activated stage, and initiate to proliferate and differentiate as myoblasts. The transmembrane protein teneurin-4 (Ten-4) is specifically expressed in the quiescent satellite cells; however, its cellular and molecular functions remain unknown. We therefore aimed to elucidate the function of Ten-4 in muscle satellite cells. In the tibialis anterior (TA) muscle of Ten-4-deficient mice, the number and the size of myofibers, as well as the population of satellite cells, were reduced with/without induction of muscle regeneration. Furthermore, we found an accelerated activation of satellite cells in the regenerated Ten-4-deficient TA muscle. The cell culture analysis using primary satellite cells showed that Ten-4 suppressed the progression of myogenic differentiation. Together, our findings revealed that Ten-4 functions as a crucial player in maintaining the quiescence of muscle satellite cells. © 2015 The Authors STEM CELLS published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

  4. Expression and characterization of a recombinant maize CK-2 alpha subunit

    DEFF Research Database (Denmark)

    Boldyreff, B; Meggio, F; Dobrowolska, G

    1993-01-01

    CKIIB, one of the CK-2 like enzymes which have been isolated from maize, has been shown to be a monomeric enzyme that cross-reacts with anti CK-2 alpha specific antibodies suggesting a possible relationship between the two proteins (Dobrowolska et al. (1992) Eur. J. Biochem. 204, 299-303). In order...... to support the immunological data also by biochemical and biophysical experiments the availability of a recombinant CK-2 alpha from maize was a prerequisite. A maize cDNA clone of maize CK-2 alpha was expressed in the bacterial strain BL21 (DE3). The recombinant protein was purified to homogeneity; its...... molecular mass on one-dimensional SDS PAGE was estimated to be 36.5 kDa. The calculated molecular mass according to the amino acid composition is 39,228 Da (332 amino acids). The recombinant maize CK-2 alpha (rmCK-2 alpha) exhibited mostly the same properties as the recombinant human CK-2 alpha (rhCK-2...

  5. Stochastic Capability Models for Degrading Satellite Constellations

    National Research Council Canada - National Science Library

    Gulyas, Cole W

    2005-01-01

    This thesis proposes and analyzes a new measure of functional capability for satellite constellations that incorporates the instantaneous availability and mission effectiveness of individual satellites...

  6. Quantum Estimates of Alpha Emitter Life Time

    Directory of Open Access Journals (Sweden)

    B. Santoso

    2006-01-01

    Full Text Available Quantum estimates of several alpha radioactive life time have been made using the probability of quantum tunneling through the nuclear potential barrier. It is assumed that for a given nucleus with mass number A and isotopic number Z, there exists an alpha particle moving freely back and forth in the nucleus with mass and isotopic numbers A -4 and Z-2. If the probability of penetrating the nuclear potential barrier is Τ, then after N times (N=1/Τ hitting the barrier an alpha particle is emitted. To obtain the elapsed time for emitting an alpha particle requires N times τ0, where τ0 is the time travel for alpha across the nuclear diameter, which is dependent on alpha energy. It is assumed here that this kinetic energy is the same as the emitted energy. The emitting alpha kinetic energies here are calculated by the difference of the masses of the parent and daughter nuclei and the alpha particles. They are in closed agreement with the experimental observations. While the alpha radioactive life time are not the same order of magnitudes but give the same linearity on the logarithmic scale as function of the inverse square root of energy.

  7. Sterically hindered C(alpha, alpha)-disubstituted alpha-amino acids: synthesis from alpha-nitroacetate and incorporation into peptides.

    Science.gov (United States)

    Fu, Y; Hammarström, L G; Miller, T J; Fronczek, F R; McLaughlin, M L; Hammer, R P

    2001-10-19

    The preparation of sterically hindered and polyfunctional C(alpha,alpha)-disubstituted alpha-amino acids (alpha alpha AAs) via alkylation of ethyl nitroacetate and transformation into derivatives ready for incorporation into peptides are described. Treatment of ethyl nitroacetate with N,N-diisopropylethylamine (DIEA) in the presence of a catalytic amount of tetraalkylammonium salt, followed by the addition of an activated alkyl halide or Michael acceptor, gives the doubly C-alkylated product in good to excellent yields. Selective nitro reduction with Zn in acetic acid or hydrogen over Raney Ni gives the corresponding amino ester that, upon saponification, can be protected with the fluorenylmethyloxycarbonyl (Fmoc) group. The first synthesis of an orthogonally protected, tetrafunctional C(alpha,alpha)-disubstituted analogue of aspartic acid, 2,2-bis(tert-butylcarboxymethyl)glycine (Bcmg), is described. Also, the sterically demanding C(alpha,alpha)-dibenzylglycine (Dbg) has been incorporated into a peptide using solid-phase synthesis. It was found that once sterically congested Dbg is at the peptide N-terminus, further chain extension becomes very difficult using uronium or phosphonium salts (PyAOP, PyAOP/HOAt, HATU). However, preformed amino acid symmetrical anhydride couples to N-terminal Dbg in almost quantitative yield in nonpolar solvent (dichloroethane-DMF, 9:1).

  8. DNA Microarrays

    Science.gov (United States)

    Nguyen, C.; Gidrol, X.

    Genomics has revolutionised biological and biomedical research. This revolution was predictable on the basis of its two driving forces: the ever increasing availability of genome sequences and the development of new technology able to exploit them. Up until now, technical limitations meant that molecular biology could only analyse one or two parameters per experiment, providing relatively little information compared with the great complexity of the systems under investigation. This gene by gene approach is inadequate to understand biological systems containing several thousand genes. It is essential to have an overall view of the DNA, RNA, and relevant proteins. A simple inventory of the genome is not sufficient to understand the functions of the genes, or indeed the way that cells and organisms work. For this purpose, functional studies based on whole genomes are needed. Among these new large-scale methods of molecular analysis, DNA microarrays provide a way of studying the genome and the transcriptome. The idea of integrating a large amount of data derived from a support with very small area has led biologists to call these chips, borrowing the term from the microelectronics industry. At the beginning of the 1990s, the development of DNA chips on nylon membranes [1, 2], then on glass [3] and silicon [4] supports, made it possible for the first time to carry out simultaneous measurements of the equilibrium concentration of all the messenger RNA (mRNA) or transcribed RNA in a cell. These microarrays offer a wide range of applications, in both fundamental and clinical research, providing a method for genome-wide characterisation of changes occurring within a cell or tissue, as for example in polymorphism studies, detection of mutations, and quantitative assays of gene copies. With regard to the transcriptome, it provides a way of characterising differentially expressed genes, profiling given biological states, and identifying regulatory channels.

  9. Absence of satellites of asteroids

    International Nuclear Information System (INIS)

    Gehrels, T.; Drummond, J.D.; Levenson, N.A.

    1987-01-01

    The absence of satellites within 0.1-7.0 arcmin of minor planets noted in the present CCD imaging survey is judged consistent with previous theoretical studies of collisions in which it is held that satellites would have to be larger than about 30 km in order to be collisionally stable. In view of tidal stability, the only main belt asteroid satellites which could conceivably possess stability over eons are near-contact binaries. Any recent collisional debris would be chaotic and collisionally unstable. 15 references

  10. Satellite communications principles and applications

    CERN Document Server

    Calcutt, David

    1994-01-01

    Satellites are increasingly used for global communications, as well as for radio and television transmissions. With the growth of mobile communications, and of digital technology, the use of satellite systems is set to expand substantially and already all students of electronics or communications engineering must study the subject.This book steers a middle path between offering a basic understanding of the process of communication by satellite and the methodology used; and the extensive mathematical analysis normally adopted in similar texts. It presents the basic concepts, using as mu

  11. Localization of specific sequences and DNA single-strand breaks in individual UV-A-irradiated human lymphocytes by COMET FISH

    Science.gov (United States)

    Bock, Claudia; Rapp, Alexander; Dittmar, Heike; Monajembashi, Shamci; Greulich, Karl-Otto

    1999-01-01

    The COMET assay, a single cell electrophoresis technique which allows to separate electrophoretically fractionated DNA according to size has been combined with fluorescence in situ hybridization (FISH) which allows to localize specific genes or gene regions. This combination (COMET FISH) allows the detection of DNA single strand breaks in specific regions of the genome of human lymphocytes at the single cell level. Various types of DNA probes, e.g. centromere-, (alpha) - satellite-, telomere-, whole chromosome-, single copy- and region specific DNA probes have been used to investigate whether the UV-A induced DNA single strand breaks are distributed randomly all over the human genome or induced at specific sites ('hot spots'). In the investigated human peripheral blood lymphocytes all but one centromere reveal low sensitivity for UV-A irradiation (500 kJ/m2), while telomeres are randomly distributed over COMET heads and tails. The human chromosome 1 is fractionated by irradiation, but remains in the COMET head, indicating an only moderate degree of fractionation. Among three tested single copy probes, c- myc, p53 and p58, the p53 gene located on chromosome 17p13.1 and the p58 gene (1p36) appear to be located in UV-A stable regions of the human genome in 95% of 65 investigated lymphocytes. In contrast, the c-myc proto-oncogene (8q24) is found in the COMET tail in 90% of the 27 investigated lymphocytes and thus appears to be more sensitive to UV-A irradiation.

  12. Brain 5alpha-dihydroprogesterone and allopregnanolone synthesis in a mouse model of protracted social isolation.

    Science.gov (United States)

    Dong, E; Matsumoto, K; Uzunova, V; Sugaya, I; Takahata, H; Nomura, H; Watanabe, H; Costa, E; Guidotti, A

    2001-02-27

    Allopregnanolone (ALLO), is a brain endogenous neurosteroid that binds with high affinity to gamma-aminobutyric acid type A (GABA(A)) receptors and positively modulates the action of GABA at these receptors. Unlike ALLO, 5alpha-dihydroprogesterone (5alpha-DHP) binds with high affinity to intracellular progesterone receptors that regulate DNA transcription. To investigate the physiological roles of ALLO and 5alpha-DHP synthesized in brain, we have adopted a mouse model involving protracted social isolation. In the frontal cortex of mice, socially isolated for 6 weeks, both neurosteroids were decreased by approximately 50%. After administration of (17beta)-17-(bis-1-methyl amino carbonyl) androstane-3,5-diene-3-carboxylic acid (SKF105,111), an inhibitor of the enzyme (5alpha-reductase Type I and II) that converts progesterone into 5alpha-DHP, the ALLO and 5alpha-DHP content of frontal cortex of both group-housed and socially isolated mice decreased exponentially to 10%-20% of control values in about 30 min. The fractional rate constants (k h(-1)) of ALLO and 5alpha-DHP decline multiplied by the ALLO and 5alpha-DHP concentrations at any given steady-state estimate the rate of synthesis required to maintain that steady state. After 6 weeks of social isolation, ALLO and 5alpha-DHP biosynthesis rates were decreased to 30% of the values calculated in group-housed mice. Moreover, in socially isolated mice, the expression of 5alpha-reductase Type I mRNA and protein was approximately 50% lower than in group-housed mice whereas 3alpha-hydroxysteroid oxidoreductase mRNA expression was equal in the two groups. Protracted social isolation in mice may provide a model to investigate whether 5alpha-DHP by a genomic action, and ALLO by a nongenomic mechanism down-regulate the action of drugs acting as agonists, partial agonists, or positive allosteric modulators of the benzodiazepine recognition sites expressed by GABA(A) receptors.

  13. Peroxisome proliferator-activated receptor gamma coactivator-1 alpha acts as a tumor suppressor in hepatocellular carcinoma.

    Science.gov (United States)

    Liu, Rui; Zhang, Haiyang; Zhang, Yan; Li, Shuang; Wang, Xinyi; Wang, Xia; Wang, Cheng; Liu, Bin; Zen, Ke; Zhang, Chen-Yu; Zhang, Chunni; Ba, Yi

    2017-04-01

    Peroxisome proliferator-activated receptor gamma coactivator-1 alpha plays a crucial role in regulating the biosynthesis of mitochondria, which is closely linked to the energy metabolism in various tumors. This study investigated the regulatory role of peroxisome proliferator-activated receptor gamma coactivator-1 alpha in the pathogenesis of hepatocellular carcinoma. In this study, the changes of peroxisome proliferator-activated receptor gamma coactivator-1 alpha messenger RNA levels between normal human liver and hepatocellular carcinoma tissue were examined by quantitative reverse transcription polymerase chain reaction. Knockdown of peroxisome proliferator-activated receptor gamma coactivator-1 alpha was conducted by RNA interference in the human liver cell line L02, while overexpression of peroxisome proliferator-activated receptor gamma coactivator-1 alpha was conducted by adenovirus encoding peroxisome proliferator-activated receptor gamma coactivator-1 alpha complementary DNA in the human hepatocarcinoma cell line HepG2. Cellular morphological changes were observed via optical and electron microscopy. Cellular apoptosis was determined by Hoechst 33258 staining. In addition, the expression levels of 21,400 genes in tissues and cells were detected by microarray. It was shown that peroxisome proliferator-activated receptor gamma coactivator-1 alpha expression was significantly downregulated in hepatocellular carcinoma compared with normal liver tissues. After knockdown of peroxisome proliferator-activated receptor gamma coactivator-1 alpha expression in L02 cells, cells reverted to immature and dedifferentiated morphology exhibiting cancerous tendency. Apoptosis occurred in the HepG2 cells after transfection by adenovirus encoding peroxisome proliferator-activated receptor gamma coactivator-1 alpha. Microarray analysis showed consistent results. The results suggest that peroxisome proliferator-activated receptor gamma coactivator-1 alpha acts as a tumor

  14. Problem-Solving Test: Analysis of DNA Damage Recognizing Proteins in Yeast and Human Cells

    Science.gov (United States)

    Szeberenyi, Jozsef

    2013-01-01

    The experiment described in this test was aimed at identifying DNA repair proteins in human and yeast cells. Terms to be familiar with before you start to solve the test: DNA repair, germline mutation, somatic mutation, inherited disease, cancer, restriction endonuclease, radioactive labeling, [alpha-[superscript 32]P]ATP, [gamma-[superscript…

  15. Searching for avidity by chemical ligation of combinatorially self-assembled DNA-encoded ligand libraries.

    Science.gov (United States)

    Matysiak, Stefan; Hellmuth, Klaus; El-Sagheer, Afaf H; Shivalingam, Arun; Ariyurek, Yavuz; de Jong, Marco; Hollestelle, Martine J; Out, Ruud; Brown, Tom

    2017-12-19

    DNA encoded ligands are self-assembled into bivalent complexes and chemically ligated to link their identities. To demonstrate their potential as a combinatorial screening platform for avidity interactions, the optimal bivalent aptamer design (examplar ligands) for human alpha-thrombin is determined in a single round of selection and the DNA scaffold replaced with minimal impact on the final design.

  16. Hypothalamic PGC-1 alpha Protects Against High-Fat Diet Exposure by Regulating ER alpha

    NARCIS (Netherlands)

    Morselli, Eugenia; Fuente-Martin, Esther; Finan, Brian; Kim, Min; Frank, Aaron; Garcia-Caceres, Cristina; Navas, Carlos Rodriguez; Gordillo, Ruth; Neinast, Michael; Kalainayakan, Sarada P.; Li, Dan L.; Gao, Yuanqing; Yi, Chun-Xia; Hahner, Lisa; Palmer, Biff F.; Tschöp, Matthias H.; Clegg, Deborah J.

    2014-01-01

    High-fat diets (HFDs) lead to obesity and inflammation in the central nervous system (CNS). Estrogens and estrogen receptor alpha (ER alpha) protect premenopausal females from the metabolic complications of inflammation and obesity-related disease. Here, we demonstrate that hypothalamic PGC-1 alpha

  17. Tumor necrosis factor alpha (TNF alpha) in human skin : A comparison of different antibodies for immunohistochemistry

    NARCIS (Netherlands)

    van der Laan, N; de Leij, LFMH; Buurman, W; Timens, W; ten Duis, HJ

    Conflicting results have been reported regarding the localization and presence of TNF alpha in normal human skin, To study TNF alpha expression, we tested a panel of antibodies directed against human TNF alpha, First, antibodies were tested for immunoreactivity on cytospots of isolated

  18. Study of the pygmy dipole resonance in Mo-94 using the (alpha, alpha ' gamma) coincidence technique

    NARCIS (Netherlands)

    Derya, V.; Endres, J.; Elvers, M.; Harakeh, M. N.; Pietralla, N.; Romig, C.; Savran, D.; Scheck, M.; Siebenhuehner, F.; Stoica, V. I.; Wortche, H. J.; Zilges, A.

    2013-01-01

    The (alpha, alpha' gamma) reaction at E-alpha = 136 MeV was used to study the electric dipole response in the open-shell vibrational nucleus Mo-94 below the neutron-separation threshold. The coincidence experiment has been performed at the Kernfysisch Versneller Instituut in Groningen, The

  19. Satellite Observations of Arctic Change

    Data.gov (United States)

    National Aeronautics and Space Administration — The purpose of this site is to expose NASA satellite data and research on Arctic change in the form of maps that illustrate the changes taking place in the Arctic...

  20. European global navigation satellite launches

    Science.gov (United States)

    Zielinski, Sarah

    The European Space Agency launched its first Galileo satellite on 28 December 2005.When fully deployed, the Galileo system will provide a European global navigation alternative to the U.S. global positioning system (GPS) and the Russian global navigation satellite system (Glonass).The Galileo system will consist of 30 satellites (27 operational plus three active spare satellites) that are scheduled to be launched and fully operational by the end of 2008.The system will provide real-time positioning within one meter of accuracy and be fully inter-operable with the U.S. and Russian systems. However, unlike GPS and Glonass, Galileo will be under civilian rather than military control.

  1. Satellite tracking of threatened species

    Science.gov (United States)

    Williams, M.; Lunsford, A.; Ellis, D.; Robinson, J.; Coronado, P.; Campbell, W.

    1998-01-01

    In 1990, a joint effort of two U.S. federal agencies, NASA Goddard Space Flight Center (GSFC) and the Patuxent Wildlife Research Center, began. We initially joined forces in a project that used satellite telemetry to discover the winter home of a tiny dwindling population of Siberian Cranes. Since then several projects have emerged, and a web site was created to follow some of these activities. This web site is called the Satellite Tracking of Threatened Species and its location is http://sdcd.gsfc.nasa.gov/ISTO/satellite_tracking. It describes the overall program, and links you to three subsections that describe the projects in more detail: Satellite Direct Readout, Birdtracks, and Birdworld.

  2. Satellite Teleconferencing in the Caribbean.

    Science.gov (United States)

    Sankar, Hollis C.

    1985-01-01

    Discusses the need for, and the development, use, and future trends of, the University of the West Indies Distance Teaching Experiment, which utilizes telephone and communications satellite technology teleconferencing to extend educational opportunities to the peoples of the Caribbean. (MBR)

  3. The Educational Satellite in Perspective

    Science.gov (United States)

    Fraser, D. O.

    1975-01-01

    A discussion which contends that there is merit in not gearing satellite systems solely to educational broadcasting and that they should be designed for general communication, including telephony and television entertainment. (Author/HB)

  4. Sea Turtle Satellite Telemetry Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Sea turtles captured in various fishing gear (pound nets, long haul seines, gill nets) were outfitted with satellite transmitters so that their movements, migratory...

  5. Leucocytes, cytokines and satellite cells

    DEFF Research Database (Denmark)

    Paulsen, Gøran; Mikkelsen, Ulla Ramer; Raastad, Truls

    2012-01-01

    -damaging exercise', primarily eccentric exercise. We review the evidence for the notion that the degree of muscle damage is related to the magnitude of the cytokine response. In the third and final section, we look at the satellite cell response to a single bout of eccentric exercise, as well as the role...... variation in individual responses to a given exercise should, however be expected. The link between cytokine and satellite cell responses and exercise-induced muscle damage is not so clear The systemic cytokine response may be linked more closely to the metabolic demands of exercise rather than muscle...... damage. With the exception of IL-6, the sources of systemic cytokines following exercise remain unclear The satellite cell response to severe muscle damage is related to regeneration, whereas the biological significance of satellite cell proliferation after mild damage or non-damaging exercise remains...

  6. Regenerative capacity of old muscle stem cells declines without significant accumulation of DNA damage.

    Directory of Open Access Journals (Sweden)

    Wendy Cousin

    Full Text Available The performance of adult stem cells is crucial for tissue homeostasis but their regenerative capacity declines with age, leading to failure of multiple organs. In skeletal muscle this failure is manifested by the loss of functional tissue, the accumulation of fibrosis, and reduced satellite cell-mediated myogenesis in response to injury. While recent studies have shown that changes in the composition of the satellite cell niche are at least in part responsible for the impaired function observed with aging, little is known about the effects of aging on the intrinsic properties of satellite cells. For instance, their ability to repair DNA damage and the effects of a potential accumulation of DNA double strand breaks (DSBs on their regenerative performance remain unclear. This work demonstrates that old muscle stem cells display no significant accumulation of DNA DSBs when compared to those of young, as assayed after cell isolation and in tissue sections, either in uninjured muscle or at multiple time points after injury. Additionally, there is no significant difference in the expression of DNA DSB repair proteins or globally assayed DNA damage response genes, suggesting that not only DNA DSBs, but also other types of DNA damage, do not significantly mark aged muscle stem cells. Satellite cells from DNA DSB-repair-deficient SCID mice do have an unsurprisingly higher level of innate DNA DSBs and a weakened recovery from gamma-radiation-induced DNA damage. Interestingly, they are as myogenic in vitro and in vivo as satellite cells from young wild type mice, suggesting that the inefficiency in DNA DSB repair does not directly correlate with the ability to regenerate muscle after injury. Overall, our findings suggest that a DNA DSB-repair deficiency is unlikely to be a key factor in the decline in muscle regeneration observed upon aging.

  7. Intra-enterprise telecommunication satellites

    Science.gov (United States)

    Henry, A. J.

    1981-11-01

    Information transfer in the mid 1980's is sketched. The use of geostationary satellites for internal requirements of businesses is an important factor in the growth of information transfer. Protection of transferred information is achieved through encryption. The companies which use satellites are those whose telecommunication costs are already significant; who have large computing capabilities including distributed data processing; who use national and international leased circuits; and whose establishments are dispersed. Uses include teleconferencing, voice and data transmission, and text and facsimile communication.

  8. Existence of undiscovered Uranian satellites

    International Nuclear Information System (INIS)

    Boice, D.C.

    1986-04-01

    Structure in the Uranian ring system as observed in recent occultations may contain indirect evidence for the existence of undiscovered satellites. Using the Alfven and Arrhenius (1975, 1976) scenario for the formation of planetary systems, the orbital radii of up to nine hypothetical satellites interior to Miranda are computed. These calculations should provide interesting comparisons when the results from the Voyager 2 encounter with Uranus are made public. 15 refs., 1 fig., 1 tab

  9. Communication Satellites, 1958-1992

    Science.gov (United States)

    1991-12-31

    by: cess capacity on its spare satellites. This is still true: hut iii addi- Argentina Israel tion. some older satellites not needed as spares ha\\e...additional telemetry subsystem and transmitter as its unique payload. This subsystem \\was built by radio amateurs in Argentina and is the first spare...International Telemarketing Conference Proceedings (Octo- Ohm, G., T. Wiesmann, and E. Hieber, "Design anti Pvformance ber 1983). of a Repeater for Optical

  10. Anomalous Temporal Behaviour of Broadband Ly Alpha Observations During Solar Flares from SDO/EVE

    Science.gov (United States)

    Milligan, Ryan O.; Chamberlin, Phillip C.

    2016-01-01

    broadband Ly-alpha observations of solar flares. Comparisons have also been made with other broadband Ly-alpha photometers such as PROBA2 (Project for On-Board Autonomy-2) / LYRA (Lyman Alpha Radiometer) and GOES (Geostationary Operational Environmental Satellite) / EUVE (Extreme Ultraviolet Explorer).

  11. Spanish Earth Observation Satellite System

    Science.gov (United States)

    Borges, A.; Cerezo, F.; Fernandez, M.; Lomba, J.; Lopez, M.; Moreno, J.; Neira, A.; Quintana, C.; Torres, J.; Trigo, R.; Urena, J.; Vega, E.; Vez, E.

    2010-12-01

    The Spanish Ministry of Industry, Tourism and Trade (MITyC) and the Ministry of Defense (MoD) signed an agreement in 2007 for the development of a "Spanish Earth Observation Satellite System" based, in first instance, on two satellites: a high resolution optical satellite, called SEOSAT/Ingenio, and a radar satellite based on SAR technology, called SEOSAR/Paz. SEOSAT/Ingenio is managed by MITyC through the Centre for the Development of Industrial Technology (CDTI), with technical and contractual support from the European Space Agency (ESA). HISDESA T together with the Spanish Instituto Nacional de Técnica Aeroespacial (INTA, National Institute for Aerospace Technology) will be responsible for the in-orbit operation and the commercial operation of both satellites, and for the technical management of SEOSAR/Paz on behalf of the MoD. In both cases EADS CASA Espacio (ECE) is the prime contractor leading the industrial consortia. The ground segment development will be assigned to a Spanish consortium. This system is the most important contribution of Spain to the European Programme Global Monitoring for Environment and Security, GMES. This paper presents the Spanish Earth Observation Satellite System focusing on SEOSA T/Ingenio Programme and with special emphasis in the potential contribution to the ESA Third Party Missions Programme and to the Global Monitoring for Environment and Security initiative (GMES) Data Access.

  12. Molecular cloning of a peptidylglycine alpha-hydroxylating monooxygenase from sea anemones

    DEFF Research Database (Denmark)

    Hauser, F; Williamson, M; Grimmelikhuijzen, C J

    1997-01-01

    sequentially, peptidyl-glycine alpha-hydroxylating monooxygenase (PHM) and peptidyl-alpha-hydroxyglycine alpha-amidating lyase (PAL). In mammals both enzymatic activities are contained within a bifunctional protein that is coded for by a single gene. Using PCR and degenerated oligonucleotides derived from...... conserved regions of PHM, we have now cloned a PHM from the sea anemone Calliactis parasitica showing 42% amino acid sequence identity with rat PHM. Among the conserved (identical) amino acid residues are five histidine and one methionine residue, which bind two Cu2+ atoms that are essential for PHM...... activity. No cDNA coding for PAL could be identified, suggesting that sea anemone PAL is coded for by a gene that is different from the sea anemone PHM gene, a situation similar to the one found in insects. This is the first report on the molecular cloning of a cnidarian PHM. Udgivelsesdato: 1997-Dec-18...

  13. Suppression of saccharin-induced mutagenicity by interferon-alpha in human RSa cells.

    Science.gov (United States)

    Suzuki, N; Suzuki, H

    1995-10-01

    Saccharin is an artificial sweetener commonly used in the formulation of foods and beverages. Sodium saccharin-induced mutagenicity is detectable in human RSa cells by estimation of cloning efficiency of ouabain-resistant mutant cells and determination of K-ras codon 12 mutation in genomic DNA, analyzed by PCR and differential dot-blot hybridization. However, in this study no phenotypic or genetic mutations were detected in RSa cells cultured with human IFN (HuIFN)-alpha before sodium saccharin treatment. The suppressive effect was lessened by transient treatment with antipain immediately after sodium saccharin treatment. Elevation of antipain-sensitive protease activity was found, furthermore, in RSa cells cultured with HuIFN-alpha and subsequently treated with sodium saccharin. Thus, antipain-sensitive protease induction in cells tested here may be involved in suppression of the mutagenicity of saccharin by HuIFN-alpha.

  14. Development of a defined-sequence DNA system for use in DNA misrepair studies

    International Nuclear Information System (INIS)

    Sutton, S.; Tobias, C.A.

    1984-01-01

    The authors have developed a system that allows them to study cellular DNA repair processes at the molecular level. In particular, the authors are using this system to examine the consequences of a misrepair of radiation-induced DNA damage, as a function of dose. The cells being used are specially engineered haploid yeast cells. Maintained in the cells, at one copy per cell, is a cen plasmid, a plasmid that behaves like a functional chromosome. This plasmid carries a small defined sequence of DNA from the E. coli lac z gene. It is this lac z region (called the alpha region) that serves as the target for radiation damage. Two copies of the complimentary portion of the lac z gene are integrated into the yeast genome. Irradiated cells are screened for possible mutation in the alpha region by testing the cells' ability to hydrolyze xgal, a lactose substrate. The DNA of interest is then extracted from the cells, sequenced, and the sequence is compared to that of the control. Unlike the usual defined-sequence DNA systems, theirs is an in vivo system. A disadvantage is the relatively high background mutation rate. Results achieved with this system, as well as future applications, are discussed

  15. Topoisomerase 3alpha and RMI1 suppress somatic crossovers and are essential for resolution of meiotic recombination intermediates in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Frank Hartung

    2008-12-01

    Full Text Available Topoisomerases are enzymes with crucial functions in DNA metabolism. They are ubiquitously present in prokaryotes and eukaryotes and modify the steady-state level of DNA supercoiling. Biochemical analyses indicate that Topoisomerase 3alpha (TOP3alpha functions together with a RecQ DNA helicase and a third partner, RMI1/BLAP75, in the resolution step of homologous recombination in a process called Holliday Junction dissolution in eukaryotes. Apart from that, little is known about the role of TOP3alpha in higher eukaryotes, as knockout mutants show early lethality or strong developmental defects. Using a hypomorphic insertion mutant of Arabidopsis thaliana (top3alpha-2, which is viable but completely sterile, we were able to define three different functions of the protein in mitosis and meiosis. The top3alpha-2 line exhibits fragmented chromosomes during mitosis and sensitivity to camptothecin, suggesting an important role in chromosome segregation partly overlapping with that of type IB topoisomerases. Furthermore, AtTOP3alpha, together with AtRECQ4A and AtRMI1, is involved in the suppression of crossover recombination in somatic cells as well as DNA repair in both mammals and A. thaliana. Surprisingly, AtTOP3alpha is also essential for meiosis. The phenotype of chromosome fragmentation, bridges, and telophase I arrest can be suppressed by AtSPO11 and AtRAD51 mutations, indicating that the protein is required for the resolution of recombination intermediates. As Atrmi1 mutants have a similar meiotic phenotype to Attop3alpha mutants, both proteins seem to be involved in a mechanism safeguarding the entangling of homologous chromosomes during meiosis. The requirement of AtTOP3alpha and AtRMI1 in a late step of meiotic recombination strongly hints at the possibility that the dissolution of double Holliday Junctions via a hemicatenane intermediate is indeed an indispensable step of meiotic recombination.

  16. Distinct evolutionary histories of the DNA-A and DNA-B components of bipartite begomoviruses

    Directory of Open Access Journals (Sweden)

    Nawaz-ul-Rehman Muhammad

    2010-04-01

    Full Text Available Abstract Background Viruses of the genus Begomovirus (family Geminiviridae have genomes consisting of either one or two genomic components. The component of bipartite begomoviruses known as DNA-A is homologous to the genomes of all geminiviruses and encodes proteins required for replication, control of gene expression, overcoming host defenses, encapsidation and insect transmission. The second component, referred to as DNA-B, encodes two proteins with functions in intra- and intercellular movement in host plants. The origin of the DNA-B component remains unclear. The study described here was initiated to investigate the relationship between the DNA-A and DNA-B components of bipartite begomoviruses with a view to unraveling their evolutionary histories and providing information on the possible origin of the DNA-B component. Results Comparative phylogenetic and exhaustive pairwise sequence comparison of all DNA-A and DNA-B components of begomoviruses demonstrates that the two molecules have very distinct molecular evolutionary histories and likely are under very different evolutionary pressures. The analysis highlights that component exchange has played a far greater role in diversification of begomoviruses than previously suspected, although there are distinct differences in the apparent ability of different groups of viruses to utilize this "sexual" mechanism of genetic exchange. Additionally we explore the hypothesis that DNA-B originated as a satellite that was captured by the monopartite progenitor of all extant bipartite begomoviruses and subsequently evolved to become the integral (essential genome component that we recognize today. The situation with present-day satellites associated with begomoviruses provides some clues to the processes and selection pressures that may have led to the "domestication" of a wild progenitor of the DNA-B component. Conclusions The analysis has highlighted the greater genetic variation of DNA-B components, in

  17. Psychiatric Symptoms in Alpha-Mannosidosis

    Science.gov (United States)

    Malm, D.; Pantel, J.; Linaker, O. M.

    2005-01-01

    Alpha-mannosidosis is characterized by mild to moderate intellectual disability (ID), moderate to severe neurosensory hearing loss, frequent infections, psychomotor disturbances and skeletal dysmorphism. For the first time, a panel of nine alpha-mannosidosis patients with psychiatric symptoms is presented. The clinical picture has several…

  18. Coefficient Alpha Bootstrap Confidence Interval under Nonnormality

    Science.gov (United States)

    Padilla, Miguel A.; Divers, Jasmin; Newton, Matthew

    2012-01-01

    Three different bootstrap methods for estimating confidence intervals (CIs) for coefficient alpha were investigated. In addition, the bootstrap methods were compared with the most promising coefficient alpha CI estimation methods reported in the literature. The CI methods were assessed through a Monte Carlo simulation utilizing conditions…

  19. Alpha Shape Topology of the Cosmic Web

    NARCIS (Netherlands)

    Weygaert, Rien van de; Platen, Erwin; Vegter, Gert; Eldering, Bob; Kruithof, Nico

    2010-01-01

    We study the topology of the Megaparsec Cosmic Web on the basis of the Alpha Shapes of the galaxy distribution. The simplicial complexes of the alpha shapes are used to determine the set of Betti numbers (βk, k = 1, . . . , D), which represent a complete characterization of the topology of a

  20. Central and peripheral alpha-adrenoceptors

    NARCIS (Netherlands)

    van Zwieten, P A; van Meel, J. C. A.; de Jonge, A; Wilffert, B; Timmermans, P B

    1982-01-01

    The recent interest in the characterization and functional, role of alpha-adrenoceptors has prompted us to study the following different, although interdigitated, lines of research: (a) The functional role of calcium ions in the process of vasoconstriction, induced by alpha 2-adrenoceptor

  1. Producing alpha-olefins using polyketide synthases

    Energy Technology Data Exchange (ETDEWEB)

    Fortman, Jeffrey L.; Katz, Leonard; Steen, Eric J.; Keasling, Jay D.

    2018-01-02

    The present invention provides for a polyketide synthase (PKS) capable of synthesizing an .alpha.-olefin, such as 1-hexene or butadiene. The present invention also provides for a host cell comprising the PKS and when cultured produces the .alpha.-olefin.

  2. Bayesian Meta-Analysis of Coefficient Alpha

    Science.gov (United States)

    Brannick, Michael T.; Zhang, Nanhua

    2013-01-01

    The current paper describes and illustrates a Bayesian approach to the meta-analysis of coefficient alpha. Alpha is the most commonly used estimate of the reliability or consistency (freedom from measurement error) for educational and psychological measures. The conventional approach to meta-analysis uses inverse variance weights to combine…

  3. ALPHA experiment facility and Prof. Jeffrey Hangst.

    CERN Multimedia

    Maximilien Brice

    2010-01-01

    Picture 01-07: General views of the ALPHA experiment Picture 5: Andrea Gutierrez, a PhD student from UBC, transfers liquid helium from a storage dewar into the cryostat containing the superconducting magnetic trap used by the ALPHA experiment.Picture 08-11: Jeffery Hangst, spokesperson for ALPHA Picture 12: The ALPHA silicon detector, which surrounds the trapping resion and is used for imaging antiproton annihilations (Credit University of Liverpool) Picture 13: Untrapped antihydrogen atoms annihilating on the inner surface of the ALPHA trap. These are measured by the ALPHA annihilation detector. The events are concentrated at the electrode radius of about 22.3 mm. The coordinates are defined in the Nature article, Figure 1b. Picture 14: The electrodes (gold) for the ALPHA Penning trap being inserted into the vacuum chamber and cryostat assembly. This is the trap used to combine or "mix" positrons and antiprotons to make antihydrogen. (Credit: Niels Madsen ALPHA/Swansea.) Picture 15: Top, a diagram of the...

  4. Alpha-1 Antitrypsin Deficiency (Inherited Emphysema)

    Science.gov (United States)

    ... antitrypsin inactivates elastase once it has finished its job. Without alpha 1 antitrypsin, elastase can destroy the air sacs of the lung. How is the diagnosis made? Because Alpha-1 related disease is COPD, the diagnosis is made by the same methods. Your doctor may have you do a number ...

  5. A stable lipid-induced aggregate of alpha-synuclein

    NARCIS (Netherlands)

    Drescher, Malte; van Rooijen, Bart D; Veldhuis, Gertjan; Subramaniam, Vinod; Huber, Martina

    2010-01-01

    The Parkinson's disease-related protein alpha-Synuclein (alphaS) is a 140 residue intrinsically disordered protein. Its membrane-binding properties are thought to be relevant for its physiological or pathologic activity. Here, the interaction of alphaS with POPG

  6. Satellites You Can See for Homework

    Science.gov (United States)

    Broderick, Stephen

    2012-01-01

    Artificial satellites are easily observed most nights when the weather is fine. The website called "Heavens Above" at www.heavens-above.com will help locate these satellites flying over one's location. It also includes how bright they will appear. The direction of travel of each satellite in the night sky also indicates the type of satellite. For…

  7. Improved peak shape fitting in alpha spectra.

    Science.gov (United States)

    Pommé, S; Caro Marroyo, B

    2015-02-01

    Peak overlap is a recurrent issue in alpha-particle spectrometry, not only in routine analyses but also in the high-resolution spectra from which reference values for alpha emission probabilities are derived. In this work, improved peak shape formulae are presented for the deconvolution of alpha-particle spectra. They have been implemented as fit functions in a spreadsheet application and optimum fit parameters were searched with built-in optimisation routines. Deconvolution results are shown for a few challenging spectra with high statistical precision. The algorithm outperforms the best available routines for high-resolution spectrometry, which may facilitate a more reliable determination of alpha emission probabilities in the future. It is also applicable to alpha spectra with inferior energy resolution. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  8. Technical Basis for the Use of Alpha Absorption Corrections on RCF Gross Alpha Data

    International Nuclear Information System (INIS)

    Ceffalo, G.M.

    1999-01-01

    This document provides the supporting data and rationale for making absorption corrections to gross alpha data to correct alpha data for loss due to absorption in the sample matrix. For some time there has been concern that the gross alpha data produced by the Environmental Restoration Contractor Radiological Counting Facility, particularly gross alpha analysis on soils, has been biased toward low results, as no correction for self-absorption was applied to the counting data. The process was investigated, and a new methodology for alpha self-absorption has been developed

  9. Elimination of alpha-gal xenoreactive epitope: alpha-galactosidase treatment of porcine heart valves.

    Science.gov (United States)

    Choi, Sun-Young; Jeong, Hee-Jin; Lim, Hong-Gook; Park, Seong-Sik; Kim, Soo-Hwan; Kim, Yong Jin

    2012-05-01

    Porcine heart valves are among the most widely used tissue valves in clinical heart valve implantation. However, immunologic responses have been implicated as potential causes of the limited durability of xenograft heart valves. The study aim was to determine the effectiveness of alpha-galactosidase treatment used to degrade the major xenoreactive antigens found in xenograft heart valves. Fresh porcine heart valves and pericardium treated with alpha-galactosidase were studied to evaluate the xenoreactive galactose (alpha1,3) galactose (alpha-gal) antigen. Removal of the alpha-gal epitope from the porcine heart valve was monitored via 3,3'-diaminobenzidine staining intensity, while the removal of alpha-gal from N-glycans on porcine heart valves treated with recombinant alpha-galactosidase was determined either qualitatively or quantitatively by mass fingerprinting using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The porcine pericardium was used for monitoring the change in mechanical properties after alpha-galactosidase treatment. In addition, the biomechanical modification property of collagen fiber rearrangement on tissue was assessed using transmission electron microscopy (TEM). Following a 24-h incubation at pH 7.2, 4 degrees C, employing 0.1 U/ml of Bacteroides thetaiotaomicron-derived recombinant alpha-galactosidase, the enzyme effectively removed the alpha-gal epitopes expressed on porcine heart valves. The identification type of alpha-gal N-glycan on fresh aortic valve, aortic wall, pulmonary valve, and pulmonary wall was 7.1%, 10.3%, 6% and 8%, respectively. In the presence of alpha-galactosidase treatment, alpha-gal-containing N-glycans were converted into alpha-gal-negative N-glycans. Likewise, alpha-gal-containing N-glycans were not detected when MALDI-TOF MS quantitative analysis was used. Furthermore, no significant difference was observed in the mechanical properties and findings from TEM in alpha

  10. Shadow imaging of geosynchronous satellites

    Science.gov (United States)

    Douglas, Dennis Michael

    Geosynchronous (GEO) satellites are essential for modern communication networks. If communication to a GEO satellite is lost and a malfunction occurs upon orbit insertion such as a solar panel not deploying there is no direct way to observe it from Earth. Due to the GEO orbit distance of ~36,000 km from Earth's surface, the Rayleigh criteria dictates that a 14 m telescope is required to conventionally image a satellite with spatial resolution down to 1 m using visible light. Furthermore, a telescope larger than 30 m is required under ideal conditions to obtain spatial resolution down to 0.4 m. This dissertation evaluates a method for obtaining high spatial resolution images of GEO satellites from an Earth based system by measuring the irradiance distribution on the ground resulting from the occultation of the satellite passing in front of a star. The representative size of a GEO satellite combined with the orbital distance results in the ground shadow being consistent with a Fresnel diffraction pattern when observed at visible wavelengths. A measurement of the ground shadow irradiance is used as an amplitude constraint in a Gerchberg-Saxton phase retrieval algorithm that produces a reconstruction of the satellite's 2D transmission function which is analogous to a reverse contrast image of the satellite. The advantage of shadow imaging is that a terrestrial based redundant set of linearly distributed inexpensive small telescopes, each coupled to high speed detectors, is a more effective resolved imaging system for GEO satellites than a very large telescope under ideal conditions. Modeling and simulation efforts indicate sub-meter spatial resolution can be readily achieved using collection apertures of less than 1 meter in diameter. A mathematical basis is established for the treatment of the physical phenomena involved in the shadow imaging process. This includes the source star brightness and angular extent, and the diffraction of starlight from the satellite

  11. Overexpression and purification of the primase domain of bacteriophage P4 gp alpha for structure determination by NMR

    NARCIS (Netherlands)

    de Planque, M.R.R.; Ziegelin, G.; Lanka, E.; Boelens, R.

    2003-01-01

    Bacteriophage P4 is a temperate phage of E. coli and other Gram-negative prokaryotes. Its alpha gene encodes a 777-residue multifunctional protein, gpa, that is essential and sufficient for the initiation of P4 DNA replication. The gpa protein attaches to the P4 origin of replication, unwinds the

  12. Identification of a common amino acid polymorphism in the p85alpha regulatory subunit of phosphatidylinositol 3-kinase

    DEFF Research Database (Denmark)

    Hansen, Torben; Andersen, C B; Echwald, Søren Morgenthaler

    1997-01-01

    in a phenotype study. Single-strand conformational polymorphism and heteroduplex analysis of the coding region of the regulatory p85alpha subunit in cDNA isolated from human muscle tissue from 70 insulin-resistant NIDDM patients and 12 control subjects revealed three silent polymorphisms and a missense mutation...

  13. Role of DNA repair in Bacillus subtilis spore resistance.

    OpenAIRE

    Setlow, B; Setlow, P

    1996-01-01

    Wet-heat or hydrogen peroxide treatment of wild-type Bacillus subtilis spores did not result in induction of lacZ fusions to three DNA repair-related genes (dinR, recA, and uvrC) during spore outgrowth. However, these genes were induced during outgrowth of wild-type spores treated with dry heat or UV. Wet-heat, desiccation, dry-heat, or UV treatment of spores lacking major DNA-binding proteins (termed alpha-beta- spores) also resulted in induction of the three DNA repair genes during spore ou...

  14. Satellite cluster concept for space communications. I - Holonic cluster satellite communications system

    Science.gov (United States)

    Wakana, H.; Kawase, S.

    A satellite cluster system is a promising candidate for future reliable satellite systems. This concept means the colocation of many different satellites, which are connected with each other by intersatellite links, on geostationary orbit. This paper presents the concept of an advanced satellite cluster system, the 'holonic satellite cluster system'.

  15. Cytotoxicity effects induced by Zearalenone metabolites, alpha Zearalenol and beta Zearalenol, on cultured Vero cells.

    Science.gov (United States)

    Othmen, Zouhour Ouanes-Ben; Golli, Emna El; Abid-Essefi, Salwa; Bacha, Hassen

    2008-10-30

    Zearalenone (Zen) is a non-steroidal estrogenic mycotoxin produced by several species of Fusarium. It has been implicated in several mycotoxicosis in farm animals and in humans. The major metabolites of this mycotoxin in various species are alpha and beta Zearalenol. In vivo, Zen is mainly reduced to these alcoholic metabolites which cause reproductive tract disorders and impaired fertility due to their estrogenic activities. In this study, we examined the cytotoxicity of alpha and beta Zearalenol in cultured cells. For this purpose, the MTT assay was carried out and the influence of alpha and beta Zearalenol on protein and DNA syntheses was assessed. To evaluate the cell stress caused by these two metabolites, oxidative stress measured by MDA induction and stress protein induction (Hsp 70, Hsp 27) were tested. Results showed that alpha and beta Zearalenol were metabolites that caused cytotoxicity by inhibiting cell viability, protein and DNA syntheses and inducing oxidative damage and over-expression of stress proteins. However, the Zen metabolites exhibited lower toxicity than Zen, with beta zearalenol being the more active of the two metabolites.

  16. Sequence-based identification of Japanese Armillaria species using the elongation factor-1 alpha gene.

    Science.gov (United States)

    Hasegawa, Eri; Ota, Yuko; Hattori, Tsutomu; Kikuchi, Taisei

    2010-01-01

    We analyzed the sequences of three DNA regions-the translation elongation factor-1 alpha (EF-1 alpha) gene and the internal transcribed spacer (ITS) and intergenic spacer (IGS) regions of ribosomal DNA-to compare their accuracy in identifying species of Japanese Armillaria. We studied 49 isolates of eight Armillaria species, A. mellea, A. ostoyae, A. nabsnona, A. cepistipes, A. gallica, A. sinapina, A. tabescens and the biological species Nagasawa E (Nag. E). Phylogenetic analyses of the ITS and IGS data helped in identifying A. mellea, A. ostoyae, A. nabsnona, A. tabescens and Nag. E but could not be used to identify A. gallica, A. cepistipes and A. sinapina. Nevertheless our analysis showed that the EF-1 alpha gene was clearly different in the eight examined species. Restriction fragment length polymorphisms (RFLP) of the IGS-1 region could be used to distinguish most species, but the RFLP profiles of some isolates of A. cepistipes and A. sinapina were the same even with four different restriction enzymes. In conclusion, among the techniques examined in this study, analyzing the EF-1 alpha sequence was found to be the most suitable method for identifying different species of Japanese Armillaria.

  17. Determination of alpha_s using jet cross section parameterizations at hadron colliders

    CERN Document Server

    Stenzel, H

    2001-01-01

    Precise measurements of the single inclusive jet cross section have been performed by the TEVATRON experiments and will be provided by the LHC experiments extending to larger values of transverse energy. Theoretical predictions of this observable at NLO in perturbative QCD depend both on the PDF parameterization set and on the value of the strong coupling constant alpha_s. In this paper the dependence of the jet cross section on alpha_s is investigated. A method is presented to extract alpha_s(E_T) from a cross section measurement based on a parameterization of the alpha_s dependence. Systematic uncertainties and the E_T-range of applicability are discussed. A comparative study is performed between the case of ppbar at sqrt{s}=1.8 TeV (TEVATRON) and pp scattering at sqrt{s}=14 TeV (LHC).

  18. Alpha1 and Alpha2 Integrins Mediate Invasive Activity of Mouse Mammary Carcinoma Cells through Regulation of Stromelysin-1 Expression

    Energy Technology Data Exchange (ETDEWEB)

    Lochter, Andre; Navre, Marc; Werb, Zena; Bissell, Mina J

    1998-06-29

    Tumor cell invasion relies on cell migration and extracellular matrix proteolysis. We investigated the contribution of different integrins to the invasive activity of mouse mammary carcinoma cells. Antibodies against integrin subunits {alpha}6 and {beta}1, but not against {alpha}1 and {alpha}2, inhibited cell locomotion on a reconstituted basement membrane in two-dimensional cell migration assays, whereas antibodies against {beta}1, but not against a6 or {alpha}2, interfered with cell adhesion to basement membrane constituents. Blocking antibodies against {alpha}1 integrins impaired only cell adhesion to type IV collagen. Antibodies against {alpha}1, {alpha}2, {alpha}6, and {beta}1, but not {alpha}5, integrin subunits reduced invasion of a reconstituted basement membrane. Integrins {alpha}1 and {alpha}2, which contributed only marginally to motility and adhesion, regulated proteinase production. Antibodies against {alpha}1 and {alpha}2, but not {alpha}6 and {beta}1, integrin subunits inhibited both transcription and protein expression of the matrix metalloproteinase stromelysin-1. Inhibition of tumor cell invasion by antibodies against {alpha}1 and {alpha}2 was reversed by addition of recombinant stromelysin-1. In contrast, stromelysin-1 could not rescue invasion inhibited by anti-{alpha}6 antibodies. Our data indicate that {alpha}1 and {alpha}2 integrins confer invasive behavior by regulating stromelysin-1 expression, whereas {alpha}6 integrins regulate cell motility. These results provide new insights into the specific functions of integrins during tumor cell invasion.

  19. Expression of folate receptor alpha in the mammalian retinol pigmented epithelium and retina.

    Science.gov (United States)

    Smith, S B; Kekuda, R; Gu, X; Chancy, C; Conway, S J; Ganapathy, V

    1999-04-01

    Folic acid is essential for DNA, RNA, and protein synthesis, and deficiencies in folate can lead to nutritional amblyopia and optic neuropathy. The transport of folate from the choroidal blood supply to the retina is only now beginning to be understood. The reduced-folate transporter was reported recently to be present in cultured human retinal pigment epithelial (RPE) cells and is thought to be localized to the apical region of these cells. The authors hypothesize that the RPE plays a role in the vectorial transport of folate from the choroidal blood to the neural retina and uses not only the reduced-folate transporter but also the folate receptor alpha in mediating this transport. The purpose of the present study was to determine whether the folate receptor alpha was present in the RPE and, if so, whether it was distributed along the basolateral membrane of the RPE, supporting a role for the protein in the initial steps of folate transport into the RPE. The expression of the folate receptor alpha in mouse RPE was analyzed by reverse transcription-polymerase chain reaction (RT-PCR), functional assays, in situ hybridization, immunohistochemistry, and laser scanning confocal microscopy. RT-PCR analysis, cloning of the RT-PCR product, and subsequent sequencing established that folate receptor alpha mRNA transcripts are expressed in the mouse RPE/choroid and are expressed also in the neural retina. A heterologous functional expression assay using MTX(R)-ZR-75-1 cells showed that the folate receptor alpha cDNA obtained by RT-PCR from the RPE/choroid complex and the neural retina was functional as assessed by the binding of folic acid and by the uptake of N5-methyltetrahydrofolate. In situ hybridization localized the folate receptor alpha mRNA to the mouse RPE cells and to cells of the neural retina. The folate receptor alpha was detected immunohistochemically in the mouse and rat RPE and in several layers of the neural retina. Laser scanning confocal microscopy

  20. Sequence of the dog immunoglobulin alpha and epsilon constant region genes

    Energy Technology Data Exchange (ETDEWEB)

    Patel, M.; Selinger, D.; Mark, G.E.; Hollis, G.F.; Hickey, G.J. [Merck Research Labs., Rathway, NJ (United States)

    1995-03-01

    The immunoglobulin alpha (IGHAC) and epsilon (IGHEC) germline constant region genes were isolated from a dog liver genomic DNA library. Sequence analysis indicates that the dog IGHEC gene is encoded by four exons spread out over 1.7 kilobases (kb). The IGHAC sequence encompasses 1.5 kb and includes all three constant region coding exons. The complete exon/intron sequence of these genes is described. 28 refs., 2 figs., 2 tabs.

  1. Weather Satellite Enterprise Information Chain

    Science.gov (United States)

    Jamilkowski, M. L.; Grant, K. D.; Miller, S. W.; Cochran, S.

    2015-12-01

    NOAA & NASA are acquiring the next-generation civilian operational weather satellite: Joint Polar Satellite System (JPSS). Contributing the afternoon orbit & ground system (GS) to replace current NOAA POES Satellites, its sensors will collect meteorological, oceanographic & climatological data. The JPSS Common Ground System (CGS), consisting of C3 and IDP segments, is developed by Raytheon. It now flies the Suomi National Polar-orbiting Partnership (S-NPP) satellite, transferring data between ground facilities, processing them into environmental products for NOAA weather centers, and expanding to support JPSS-1 in 2017. As a multi-mission system, CGS provides combinations of C3, data processing, and product delivery for numerous NASA, NOAA, DoD and international missions.The CGS provides a wide range of support to a number of missions: Command and control and mission management for the S-NPP mission today, expanding this support to the JPSS-1 satellite mission in 2017 Data acquisition for S-NPP, the JAXA's Global Change Observation Mission - Water (GCOM-W1), POES, and the Defense Meteorological Satellite Program (DMSP) and Coriolis/WindSat for the DoD Data routing over a global fiber network for S-NPP, JPSS-1, GCOM-W1, POES, DMSP, Coriolis/WindSat, NASA EOS missions, MetOp for EUMETSAT and the National Science Foundation Environmental data processing and distribution for S-NPP, GCOM-W1 and JPSS-1 The CGS plays a key role in facilitating the movement and value-added enhancement of data all the way from satellite-based sensor data to delivery to the consumers who generate forecasts and produce watches and warnings. This presentation will discuss the information flow from sensors, through data routing and processing, and finally to product delivery. It will highlight how advances in architecture developed through lessons learned from S-NPP and implemented for JPSS-1 will increase data availability and reduce latency for end user applications.

  2. Using Cell Phones From Satellites

    Science.gov (United States)

    Horan, Stephen

    2000-01-01

    During the past several years, an interest has grown in using commercial telecommunications techniques to supply Telemetry and Command (T&C) services. Recently, the National Aeronautics and Space Administration (NASA) Space Operations Management Office (SOMO) has outlined plans to utilize satellite-based telecommunications services to support space operations in space missions over the next several decades. NASA currently obtains the bulk of its telecommunications services for earth-orbiting satellites via the existing government-owned and controlled Space Network (SN) system. This system consists of the constellation of Tracking and Data Relay Satellites (TDRS) in Geostationary Earth Orbit (GEO) and the associated ground terminals and communications intrastructure. This system is valuable and effective for scientific satellites costing over one million dollars. However, for smaller satellites, this system becomes problematic due to the cost of transponders and support infrastructure. The nominal transponders for using the TDRS cannot be obtained for a cost in dollars, and size, weight, or power that the 3 Corner Satellite project can afford. For these types of nanosatellite missions, alternatives that fit the mission cost and satellite profiles are needed. In particular, low-cost access using existing commercial infrastructure would be useful to mission planners. In particular, the ability to obtain low data rate T&C services would be especially valuable. The nanosatellites generally have low T&C requirements and therefore would benefit from using commercial services that could operate in the 2400 bps - 9600 bps range, especially if contact times longer than the 5 - 10 minute ground station passes could be found.

  3. Electrochemical and calorimetric investigation of interaction of novel biscationic anticancer agents with DNA

    OpenAIRE

    Silva, Láuris Lucia da; Donnici, Claudio Luis; Lopes, Júlio César Dias; Goulart, Marília Oliveira Fonseca; Abreu, Fabiane Caxico de; Paula, Francine Santos de; Bravo, Carlos E. Salas; Santoro, Marcelo Matos; Denadai, Ângelo Márcio Leite; Santos, Alexandre Martins Costa; Montanari, Carlos Alberto

    2012-01-01

    ELECTROCHEMICAL AND CALORIMETRIC INVESTIGATION OF INTERACTION OF NOVEL BISCATIONIC ANTICANCER AGENTS WITH DNA. Biscationic amidines bind in the DNA minor groove and present biological activity against a range of infectious diseases. Two new biscationic compounds (bis-alpha,omega-S-thioureido, amino and sulfide analogues) were synthesized in good yields and fully characterized, and their interaction with DNA was also investigated. Isothermal titration calorimetry (ITC) was used to measure the ...

  4. Mapping High-Velocity H-alpha and Lyman-alpha Emission from Supernova 1987A

    Science.gov (United States)

    France, Kevin; McCray, Richard; Fransson, Claes; Larsson, Josefin; Frank, Kari A.; Burrows, David N.; Challis, Peter; Kirshner, Robert P.; Chevalier, Roger A.; Garnavich, Peter; hide

    2015-01-01

    We present new Hubble Space Telescope images of high-velocity H-alpha and Lyman-alpha emission in the outer debris of SN 1987A. The H-alpha images are dominated by emission from hydrogen atoms crossing the reverse shock. For the first time we observe emission from the reverse shock surface well above and below the equatorial ring, suggesting a bipolar or conical structure perpendicular to the ring plane. Using the H-alpha imaging, we measure the mass flux of hydrogen atoms crossing the reverse shock front, in the velocity intervals (-7,500 < V(sub obs) < -2,800 km/s) and (1,000 < V(sub obs) < 7,500 km/s), ?M(sub H) = 1.2 × 10(exp -3) M/ y. We also present the first Lyman-alpha imaging of the whole remnant and new Chandra X-ray observations. Comparing the spatial distribution of the Lyman-alpha and X-ray emission, we observe that the majority of the high-velocity Lyman-alpha emission originates interior to the equatorial ring. The observed Lyman-alpha/H-alpha photon ratio, R(L-alpha/H-alpha) approx. = 17, is significantly higher than the theoretically predicted ratio of approx. = 5 for neutral atoms crossing the reverse shock front. We attribute this excess to Lyman-alpha emission produced by X-ray heating of the outer debris. The spatial orientation of the Lyman-alpha and X-ray emission suggests that X-ray heating of the outer debris is the dominant Lyman-alpha production mechanism in SN 1987A at this phase in its evolution.

  5. Fidelity of a human cell DNA replication complex

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, J.D.; Kunkel, T.A. (National Institute of Environmental Health Sciences, Research Triangle Park, NC (USA))

    1988-10-01

    The authors have measured the fidelity of bidirectional, semiconservative DNA synthesis by a human DNA replication complex in vitro. Replication was performed by extracts of HeLa cells in the presence of simian virus 40 (SV40) large tumor antigen by using a double-stranded phage M13mp2 DNA template containing the SV40 origin of replication and either of two different target sequences for scoring mutations in the lacZ{alpha}-complementation gene, which encodes the {alpha} region (specifying the amino-terminal portion) of {beta}-galactosidase. Replicative synthesis was substantially more accurate than synthesis by the human DNA polymerase {alpha}-DNA primase complex purified from HeLa cell extracts by immunoaffinity chromatography, suggesting that additional factors or activities in the extract may increase fidelity during bidirectional replication. However, by using a sensitive opal codon reversion assay, single-base substitution errors were readily detected in the replication products at frequencies significantly higher than estimated spontaneous mutation rates in vivo. These data suggest that additional fidelity factors may be present during chromosomal replication in vivo and/or that the fidelity of replication alone does not account for the low spontaneous mutation rates in eukaryotes.

  6. Gene encoding the human. beta. -hexosaminidase. beta. chain: Extensive homology of intron placement in the. alpha. - and. beta. -chain genes

    Energy Technology Data Exchange (ETDEWEB)

    Proia, R.L. (National Institute of Diabetes, Digestive and Kidney Diseases, Bethesda, MD (USA))

    1988-03-01

    Lysosomal {beta}-hexosaminidase is composed of two structurally similar chains, {alpha} and {beta}, that are the products of different genes. Mutations in either gene causing {beta}-hexosaminidase deficiency result in the lysosomal storage disease GM2-gangliosidosis. To enable the investigation of the molecular lesions in this disorder and to study the evolutionary relationship between the {alpha} and {beta} chains, the {beta}-chain gene was isolated, and its organization was characterized. The {beta}-chain coding region is divided into 14 exons distributed over {approx}40 kilobases of DNA. Comparison with the {alpha}-chain gene revealed that 12 of the 13 introns interrupt the coding regions at homologous positions. This extensive sharing of intron placement demonstrates that the {alpha} and {beta} chains evolved by way of the duplication of a common ancestor.

  7. Direct binding of syndecan-4 cytoplasmic domain to the catalytic domain of protein kinase C alpha (PKC alpha) increases focal adhesion localization of PKC alpha

    DEFF Research Database (Denmark)

    Lim, Ssang-Taek; Longley, Robert L; Couchman, John R

    2003-01-01

    alpha. Full-length PKC alpha weakly interacted with 4V by yeast two-hybrid assays, but PKC alpha constructs that lack the pseudosubstrate region or constructs of the whole catalytic domain interacted more strongly. A mutated 4V sequence (4V(YF): LGKKPIFKK) did not interact with PKC alpha, indicating...

  8. Increased virulence and competitive advantage of a/alpha over a/a or alpha/alpha offspring conserves the mating system of Candida albicans.

    Science.gov (United States)

    Lockhart, Shawn R; Wu, Wei; Radke, Joshua B; Zhao, Rui; Soll, David R

    2005-04-01

    The majority of Candida albicans strains in nature are a/alpha and must undergo homozygosis to a/a or alpha/alpha to mate. Here we have used a mouse model for systemic infection to test the hypothesis that a/alpha strains predominate in nature because they have a competitive advantage over a/a and alpha/alpha offspring in colonizing hosts. Single-strain injection experiments revealed that a/alpha strains were far more virulent than either their a/a or alpha/alpha offspring. When equal numbers of parent a/alpha and offspring a/a or alpha/alpha cells were co-injected, a/alpha always exhibited a competitive advantage at the time of extreme host morbidity or death. When equal numbers of an engineered a/a/alpha2 strain and its isogenic a/a parent strain were co-injected, the a/a/alpha2 strain exhibited a competitive advantage at the time of host morbidity or death, suggesting that the genotype of the mating-type (MTL) locus, not associated genes on chromosome 5, provides a competitive advantage. We therefore propose that heterozygosity at the MTL locus not only represses white-opaque switching and genes involved in the mating process, but also affects virulence, providing a competitive advantage to the a/alpha genotype that conserves the mating system of C. albicans in nature.

  9. HPV DNA test

    Science.gov (United States)

    ... HPV testing in women; Cervical cancer - HPV DNA test; Cancer of cervix - HPV DNA test ... The HPV DNA test may be done during a Pap smear . You lie on a table and place your feet in stirrups. The ...

  10. Minisatellites as DNA markers to classify bermudagrasses (Cynodon ...

    Indian Academy of Sciences (India)

    Hyper variable repetitive DNA sequences such as microsatel- lites, minisatellites, midisatellites and satellites can be of great value in assessing a high level of polymorphism as they are distributed throughout the genomes. Here we used a polymerase chain reaction (PCR) technique, known as the directed amplification of ...

  11. Stream Gauges and Satellite Measurements

    Science.gov (United States)

    Alsdorf, D. E.

    2010-12-01

    Satellite measurements should not be viewed as a replacement for stream gauges. However, occasionally it is suggested that because satellite-based measurements can provide river discharge, a motivation for satellite approaches is an increasing lack of stream gauges. This is an argument for more stream gauges, but not necessarily for satellite measurements. Rather, in-situ and spaceborne methods of estimating discharge are complementary. Stream gauges provide frequent measurements at one point in the river reach whereas satellites have the potential to measure throughout all reaches but at orbital repeat intervals of days to weeks. The Surface Water and Ocean Topography satellite mission (SWOT) is an opportunity to further develop these complements. The motivation for SWOT, and indeed for any satellite based method of estimating discharge, should not be as a replacement for stream gauges. Scientific and application uses should motivate the measurements. For example, understanding floods with their dynamic water surfaces are best sampled from remote platforms that provide water surface elevations throughout the floodwave. As another example, today’s water and energy balance models are giving outputs at increasing spatial resolution and are making use of water surface elevations throughout the modeled basin. These models require a similar resolution in the calibrating and validating observations. We should also be aware of practical limitations. In addition to providing spatially distributed hydrodynamic measurements on rivers, SWOT will be able to measure storage changes in the estimated 30 million lakes in the world that are larger than a hectare. Knowing the storage changes in these lakes is especially important in certain regions such as the Arctic but gauging even a small fraction of these is impractical. Another motivator for satellite methods is that even in the presence of stream gauges, discharge data is not always well shared throughout all countries

  12. Petite Amateur Navy Satellite (PANSAT)

    Science.gov (United States)

    Sakoda, D.; Hiser, J. K.

    1989-01-01

    The Naval Postgraduate School's (NPS) Space Systems Academic Group (SSAG) is designing and developing a small communications satellite for launch aboard the shuttle as a complex autonomous payload (CAP). The objectives of PANSAT are three-fold. First, PANSAT will provide an ideal educational tool for the officer students at NPS supporting Space Systems Engineering and Space Systems Operations with hands-on hardware development. Second, the satellite will provide digital store-and-forward communications, or packet radio, for the amateur radio community. The third objective is to provide a low-cost, space-based platform for small experiments. PANSAT will be launched from the shuttle at a nominal altitude of 200 n.m. and an inclination of at least 37 degrees. The satellite weight is 150 lbs. Since there is no attitude control, eight dipole whip antennas will be used to provide isotropic ground coverage for communications. FM digital communications will be used with up-link and down-link on a single frequency in the amateur band of 437.25 MHz. A maximum 50 kHz of bandwidth is envisioned for the satellite. The expected lifetime of the satellite is 1 1/2 to 2 years before atmospheric reentry. The PANSAT design consists of the following: communications subsystem (COMM); computer, or data processor and sequencer (DP&S); power subsystem; structure subsystem; and experiment payload.

  13. Choosing ESRO's first scientific satellites

    Science.gov (United States)

    Russo, Arturo

    1992-11-01

    The choice of the scientific payloads of the European Space Research Organization's (ESRO's) first generation of satellites is analyzed. Concentration is on those aspects of the decision process that involved more directly the scientific community and that emerged as major issues in the discussion of the Launching Program Advisory Committee (LPAC). The main theme was the growing competition between the various fields of space science within the progressive retrenching of the Organization's financial resources available for the satellite program. A general overview of the status of the program by the end of 1966 is presented. The choice of the first small satellites' payloads (ESRO 1 and 2, and HEOS-A) and the difficult definition of the TD satellite program are discussed. This part covers a time span going from early 1963 to the spring of 1966. In the second part, the narrative starts from the spring of 1967, when the decision to recommend a second HEOS-type satellite was taken, and then analyzes the complex situation determined by the crisis of the TD program in 1968, and the debates which eventually led to the abandonment of TD-2 and the start of the far less ambitious ESRO 5 project.

  14. Satellite Cell Self-Renewal.

    Science.gov (United States)

    Giordani, Lorenzo; Parisi, Alice; Le Grand, Fabien

    2018-01-01

    Adult skeletal muscle is endowed with regenerative potential through partially recapitulating the embryonic developmental program. Upon acute injury or in pathological conditions, quiescent muscle-resident stem cells, called satellite cells, become activated and give rise to myogenic progenitors that massively proliferate, differentiate, and fuse to form new myofibers and restore tissue functionality. In addition, a proportion of activated cells returns back to quiescence and replenish the pool of satellite cells in order to maintain the ability of skeletal muscle tissue to repair. Self-renewal is the process by which stem cells divide to make more stem cells to maintain the stem cell population throughout life. This process is controlled by cell-intrinsic transcription factors regulated by cell-extrinsic signals from the niche and the microenvironment. This chapter provides an overview about the general aspects of satellite cell biology and focuses on the cellular and molecular aspects of satellite cell self-renewal. To date, we are still far from understanding how a very small proportion of the satellite cell progeny maintain their stem cell identity when most of their siblings progress through the myogenic program to construct myofibers. © 2018 Elsevier Inc. All rights reserved.

  15. Space Solar Power: Satellite Concepts

    Science.gov (United States)

    Little, Frank E.

    1999-01-01

    Space Solar Power (SSP) applies broadly to the use of solar power for space related applications. The thrust of the NASA SSP initiative is to develop concepts and demonstrate technology for applying space solar power to NASA missions. Providing power from satellites in space via wireless transmission to a receiving station either on earth, another celestial body or a second satellite is one goal of the SSP initiative. The sandwich design is a satellite design in which the microwave transmitting array is the front face of a thin disk and the back of the disk is populated with solar cells, with the microwave electronics in between. The transmitter remains aimed at the earth in geostationary orbit while a system of mirrors directs sunlight to the photovoltaic cells, regardless of the satellite's orientation to the sun. The primary advantage of the sandwich design is it eliminates the need for a massive and complex electric power management and distribution system for the satellite. However, it requires a complex system for focusing sunlight onto the photovoltaic cells. In addition, positioning the photovoltaic array directly behind the transmitting array power conversion electronics will create a thermal management challenge. This project focused on developing designs and finding emerging technology to meet the challenges of solar tracking, a concentrating mirror system including materials and coatings, improved photovoltaic materials and thermal management.

  16. Alpha intrusion on ovenight polysomnogram

    Directory of Open Access Journals (Sweden)

    Nahapetian R

    2014-06-01

    Full Text Available No abstract available. Article truncated after 150 words. A 30 year-old Army veteran with a past medical history significant for chronic lumbar back pain stemming from a fall-from-height injury sustained in 2006 was referred to the sleep laboratory for evaluation of chronic fatigue and excessive daytime hypersomnolence. His Epworth sleepiness scale score was 16. He denied a history of snoring and witnessed apnea. Body Mass Index (BMI was 25.7 kg/m2. His main sleep related complaints were frequent nocturnal arousals, poor sleep quality, un-refreshing sleep, prolonged latency to sleep onset, and nightmares. An In-lab attended diagnostic polysomnogram was performed. Sleep efficiency was reduced (73% and overall arousal index was not significantly elevated (3.2 events/hour. The sleep study showed rapid eye movement (REM related sleep disordered breathing that did not meet diagnostic criteria for sleep apnea. There was no evidence for period limb movement disorder. However, the study was significant for alpha wave intrusion in stage N2 non-REM and stage ...

  17. Diabetes and alpha lipoic acid

    Directory of Open Access Journals (Sweden)

    Issy eLaher

    2011-11-01

    Full Text Available Diabetes mellitus is a multi-faceted metabolic disorder where there is increased oxidative stress that contributes to the pathogenesis of this debilitating disease. This has prompted several investigations into the use of antioxidants as a complementary therapeutic approach. Alpha lipoic acid, a naturally occurring dithiol compound which plays an essential role in mitochondrial bioenergetic reactions, has gained considerable attention as an antioxidant for use in managing diabetic complications. Lipoic acid quenches reactive oxygen species, chelates metal ions, and reduces the oxidized forms of other antioxidants such as vitamin C, vitamin E and glutathione. It also boosts antioxidant defense system through Nrf2-mediated antioxidant gene expression and by modulation of peroxisome proliferator activated receptors-regulated genes. ALA inhibits nuclear factor kappa B and activates AMPK in skeletal muscles, which in turn have a plethora of metabolic consequences. These diverse actions suggest that a lipoic acid acts by multiple mechanisms, many of which have only been uncovered recently. In this review we briefly summarize the known biochemical properties of lipoic acid and then discussed the oxidative mechanisms implicated in diabetic complications and the mechanisms by which lipoic acid may ameliorate these reactions. The findings of some of the clinical trials in which lipoic acid administration has been tested in diabetic patients during the last 10 years are summarized. It appears that the clearest benefit of lipoic acid supplementation is in patients with diabetic neuropathy.

  18. Diagnostics for PLX-alpha

    Science.gov (United States)

    Gilmore, Mark; Hsu, Scott

    2015-11-01

    The goal of the Plasma Liner eXperiment PLX-alpha at Los Alamos National Laboratory is to establish the viability of creating a spherically imploding plasma liner for MIF and HED applications, using a spherical array of supersonic plasma jets launched by innovative contoured-gap coaxial plasma guns. PLX- α experiments will focus in particular on establishing the ram pressure and uniformity scalings of partial and fully spherical plasma liners. In order to characterize these parameters experimentally, a suite of diagnostics is planned, including multi-camera fast imaging, a 16-channel visible interferometer (upgraded from 8 channels) with reconfigurable, fiber-coupled front end, and visible and VUV high-resolution and survey spectroscopy. Tomographic reconstruction and data fusion techniques will be used in conjunction with interferometry, imaging, and synthetic diagnostics from modeling to characterize liner uniformity in 3D. Diagnostic and data analysis design, implementation, and status will be presented. Supported by the Advanced Research Projects Agency - Energy - U.S. Department of Energy.

  19. Cortical Alpha Activity in Schizoaffective Patients

    Directory of Open Access Journals (Sweden)

    Mahdi Moeini

    2017-02-01

    Full Text Available Objective: Electrophysiological studies have identified abnormal oscillatory activities in the cerebral cortex in schizophrenia and mood disorders. Biological and pathophysiological evidence suggests specific deficits in serotonin (5-HT receptor function in schizoaffective disorder (SA, a clinical syndrome with characteristics of both schizophrenia and bipolar disorder. This study investigated alpha oscillations in patients with SA.Method: Electroencephalography was used to measure ongoing and evoked alpha oscillations in 38 adults meeting Diagnostic and Statistical Manual of Mental Disorders–Fourth Edition (DSM–IV criteria for SA, and in 39 healthy controls.Results: Spontaneous alpha power of the participants with SA was significantly lower than that of healthy participants [F (1, 75 = 8.81, P < 0.01]. Evoked alpha activity was also decreased in SA compared to controls [F (1, 75 = 5.67, P = 0.025].Conclusion: A strong reduction of alpha power in the posterior regions may reflect abnormality in the thalamocortical circuits. It is shown that hypoxia and reduced cerebral blood flow is associated with reduced alpha activity among different regions of the brain. Therefore, it can be concluded that greatly decreased alpha activity, particularly in centro-parietal and occipital regions, is related to SA symptoms such as hallucinations.

  20. Synthesis of DNA

    Science.gov (United States)

    Mariella, Jr., Raymond P.

    2008-11-18

    A method of synthesizing a desired double-stranded DNA of a predetermined length and of a predetermined sequence. Preselected sequence segments that will complete the desired double-stranded DNA are determined. Preselected segment sequences of DNA that will be used to complete the desired double-stranded DNA are provided. The preselected segment sequences of DNA are assembled to produce the desired double-stranded DNA.

  1. Lucid dreaming and alpha activity: a preliminary report.

    Science.gov (United States)

    Ogilvie, R D; Hunt, H T; Tyson, P D; Lucescu, M L; Jeakins, D B

    1982-12-01

    10 good dream recallers spent 2 nights in the sleep lab during which they were awakened 4 times per night from REM sleep, twice during their highest alpha activity in REM, and twice during low REM alpha. 5 were given alpha feedback training prior to sleep onset. Arousals from high alpha REM sleep yielded significantly higher lucidity ratings. Alpha feedback had no effect upon lucidity or REM alpha levels. Similarities between lucid dreams and meditative phenomena are discussed.

  2. Phenotypic and genetic analysis of the cerebellar mutant tmgc26, a new ENU-induced ROR-alpha allele.

    Science.gov (United States)

    Swanson, Douglas J; Steshina, Ekaterina Y; Wakenight, Paul; Aldinger, Kimberly A; Goldowitz, Dan; Millen, Kathleen J; Chizhikov, Victor V

    2010-09-01

    ROR-alpha is an orphan nuclear receptor, inactivation of which cell-autonomously blocks differentiation of cerebellar Purkinje cells with a secondary loss of granule neurons. As part of our ENU mutagenesis screen we isolated the recessive tmgc26 mouse mutant, characterized by early-onset progressive ataxia, cerebellar degeneration and juvenile lethality. Detailed analysis of the tmgc26-/- cerebella revealed Purkinje cell and granule cell abnormalities, and defects in molecular layer interneurons and radial glia. Chimera studies suggested a cell-autonomous effect of the tmgc26 mutation in Purkinje cells and molecular layer interneurons, and a non-cell-autonomous effect in granule cells. The mutation was mapped to a 13-Mb interval on chromosome 9, a region that contains the ROR-alpha gene. Sequencing of genomic DNA revealed a T-to-A transition in exon 5 of the ROR-alpha gene, resulting in a nonsense mutation C257X and severe truncation of the ROR-alpha protein. Together, our data identify new roles for ROR-alpha in molecular layer interneurons and radial glia development and suggest tmgc26 as a novel ROR-alpha allele that may be used to further delineate the molecular mechanisms of ROR-alpha action. © 2010 The Authors. European Journal of Neuroscience © 2010 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

  3. In situ enzymology of DNA replication and ultraviolet-induced DNA repair synthesis in permeable human cells

    Energy Technology Data Exchange (ETDEWEB)

    Dresler, S.; Frattini, M.G.; Robinson-Hill, R.M. (Washington Univ., St. Louis, MO (USA))

    1988-09-20

    Using permeable diploid human fibroblasts, the authors have studied the deoxyribonucleoside triphosphate concentration dependences of ultraviolet- (UV-) induced DNA repair synthesis and semiconservative DNA replication. In both cell types (AG1518 and IMR-90) examined, the apparent K{sub m} values for dCTP, dGTP, and dTTP for DNA replication were between 1.2 and 2.9 {mu}M. For UV-induced DNA repair synthesis, the apparent K{sub m} values were substantially lower, ranging from 0.11 to 0.44 {mu}M for AG1518 cells and from 0.06 to 0.24 {mu}M for IMR-90 cells. Recent data implicate DNA polymerase {delta} in UV-induced repair synthesis and suggest that DNA polymerases {alpha} and {delta} are both involved in semiconservative replication. They measured K{sub m} values for dGTP and dTTP for polymerases {alpha} and {delta}, for comparison with the values for replication and repair synthesis. The deoxyribonucleotide K{sub m} values for DNA polymerase {delta} are much greater than the K{sub m} values for UV-induced repair synthesis, suggesting that when polymerase {delta} functions in DNA repair, its characteristics are altered substantially either by association with accessory proteins or by direct posttranslational modification. In contrast, the deoxyribonucleotide binding characteristics of the DNA replication machinery differ little from those of the isolated DNA polymerases. The K{sub m} values for UV-induced repair synthesis are 5-80-fold lower than deoxyribonucleotide concentrations that have been reported for intact cultured diploid human fibroblasts. For replication, however, the K{sub m} for dGTP is only slightly lower than the average cellular dGTP concentration that has been reported for exponentially growing human fibroblasts. This finding is consistent with the concept that nucleotide compartmentation is required for the attainment of high rates of DNA replication in vivo.

  4. Localization of pig Na[sup +], K[sup +]-ATPase [alpha] and [beta] subunit genes to chromosome 4 by radioactive in situ hybridization

    Energy Technology Data Exchange (ETDEWEB)

    Lahbib-Mansais, Y.; Yerle, M.; Dalens, M.; Chevalet, C.; Gellin, J. (Centre de Recherches de Toulouse (France))

    1993-01-01

    Two genes coding for Na[sup +],K[sup +] -ATPase [alpha] and [beta] subunits are localized on pig chromosome 4, to the q1.6[yields]q2.3 and 1.3[yields]q2.1 regions, respectively, by radioactive in situ hybridization. According to nucleotide and amino acid sequence comparisons with different human isoforms of Na[sup +] ,K[sup +]-ATPase, these pig [alpha] and [beta] ATPase genes show strong homologies with human [alpha]1 and [beta] subunit ATPase genes, respectively. These results are discussed with respect to comparative mapping data of conserved genes in mammalian species. We showed that the pig cDNA probes encoding ATPase [alpha] and, [beta] genes reveal DNA polymorphism in Meishan an Large White pigs. 35 refs., 4 figs., 2 tabs.

  5. Screening for mutations in human alpha-globin genes by nonradioactive single-strand conformation polymorphism

    Directory of Open Access Journals (Sweden)

    Jorge S.B.

    2003-01-01

    Full Text Available Point mutations and small insertions or deletions in the human alpha-globin genes may produce alpha-chain structural variants and alpha-thalassemia. Mutations can be detected either by direct DNA sequencing or by screening methods, which select the mutated exon for sequencing. Although small (about 1 kb, 3 exons and 2 introns, the alpha-globin genes are duplicate (alpha2 and alpha1 and highy G-C rich, which makes them difficult to denature, reducing sequencing efficiency and causing frequent artifacts. We modified some conditions for PCR and electrophoresis in order to detect mutations in these genes employing nonradioactive single-strand conformation polymorphism (SSCP. Primers previously described by other authors for radioactive SSCP and phast-SSCP plus denaturing gradient gel electrophoresis were here combined and the resultant fragments (6 new besides 6 original per alpha-gene submitted to silver staining SSCP. Nine structural and one thalassemic mutations were tested, under different conditions including two electrophoretic apparatus (PhastSystem(TM and GenePhor(TM, Amersham Biosciences, different polyacrylamide gel concentrations, run temperatures and denaturing agents, and entire and restriction enzyme cut fragments. One hundred percent of sensitivity was achieved with four of the new fragments formed, using the PhastSystem(TM and 20% gels at 15ºC, without the need of restriction enzymes. This nonradioactive PCR-SSCP approach showed to be simple, rapid and sensitive, reducing the costs involved in frequent sequencing repetitions and increasing the reliability of the results. It can be especially useful for laboratories which do not have an automated sequencer.

  6. Anomalous atomic volume of alpha-Pu

    DEFF Research Database (Denmark)

    Kollar, J.; Vitos, Levente; Skriver, Hans Lomholt

    1997-01-01

    We have performed full charge-density calculations for the equilibrium atomic volumes of the alpha-phase light actinide metals using the local density approximation (LDA) and the generalized gradient approximation (GGA). The average deviation between the experimental and the GGA atomic radii is 1.......3%. The comparison between the LDA and GGA results show that the anomalously large atomic volume of alpha-Pu relative to alpha-Np can be ascribed to exchange-correlation effects connected with the presence of low coordinated sites in the structure where the f electrons are close to the onset of localization...

  7. Alpha spectral analysis via artificial neural networks

    International Nuclear Information System (INIS)

    Kangas, L.J.; Hashem, S.; Keller, P.E.; Kouzes, R.T.; Troyer, G.L.

    1994-10-01

    An artificial neural network system that assigns quality factors to alpha particle energy spectra is discussed. The alpha energy spectra are used to detect plutonium contamination in the work environment. The quality factors represent the levels of spectral degradation caused by miscalibration and foreign matter affecting the instruments. A set of spectra was labeled with a quality factor by an expert and used in training the artificial neural network expert system. The investigation shows that the expert knowledge of alpha spectra quality factors can be transferred to an ANN system

  8. Production of alpha 1-proteinase inhibitor (human).

    Science.gov (United States)

    Hein, R H; Van Beveren, S M; Shearer, M A; Coan, M H; Brockway, W J

    1990-03-01

    A method for large scale isolation of alpha 1-proteinase inhibitor (alpha 1-PI) is described. This method employs waste Cohn Fraction IV-1 as the starting material and involves fractional precipitation with polyethylene glycol followed by ion exchange chromatography on diethylaminoethanol (DEAE)-Sepharose. The process also incorporates a ten hour, at 60 degrees C, heat-treatment step to reduce or eliminate the risk of transmission of viral disease. The final product, having a purity of approximately 60%, is freeze-dried. This preparation behaves almost identically to the alpha 1-PI in plasma and is suitable for replacement therapy in hereditary emphysema.

  9. Measurements of $\\alpha_s$ in $pp$ Collisions at the LHC

    CERN Document Server

    Warburton, Andreas; The ATLAS collaboration

    2015-01-01

    The coupling of the strong force, $\\alpha_s$, is deemed to be a fundamental parameter of Nature, and, beyond the quark masses, constitutes the only free parameter in the QCD Lagrangian. Provided is an overview of CERN Large Hadron Collider (LHC) measurements of $\\alpha_s(M_Z)$ evaluated at the $Z$-boson mass and of the running of $\\alpha_s(Q)$ as a function of energy-momentum transfer $Q$. The measurements were performed by the ATLAS and CMS Collaborations using proton-proton ($pp$) collisions with centre-of-mass energies of 7 TeV and data samples with time-integrated luminosities of up to 5 fb$^{-1}$. Four different categories of observable were used in the described extractions of $\\alpha_s$: inclusive jet cross sections, 3-jet to 2-jet inclusive cross-section ratios, 3-jet mass cross sections, and top-quark pair production cross sections. These results, which include the first NNLO measurement of $\\alpha_s$ at a hadron collider and the first determinations of $\\alpha_s$ at energy scales above 1 TeV, are co...

  10. A Quantitative Electrochemiluminescence Assay for Clostridium perfringens alpha toxin

    National Research Council Canada - National Science Library

    Merrill, Gerald A; Rivera, Victor R; Neal, Dwayne D; Young, Charles; Poli, Mark A

    2006-01-01

    .... Biotinylated antibodies to C. perfringens alpha toxin bound to streptavidin paramagnetic beads specifically immunoadsorbed soluble sample alpha toxin which subsequently selectively immunoadsorbed ruthenium (Ru...

  11. Landsat—Earth observation satellites

    Science.gov (United States)

    ,

    2015-11-25

    Since 1972, Landsat satellites have continuously acquired space-based images of the Earth’s land surface, providing data that serve as valuable resources for land use/land change research. The data are useful to a number of applications including forestry, agriculture, geology, regional planning, and education. Landsat is a joint effort of the U.S. Geological Survey (USGS) and the National Aeronautics and Space Administration (NASA). NASA develops remote sensing instruments and the spacecraft, then launches and validates the performance of the instruments and satellites. The USGS then assumes ownership and operation of the satellites, in addition to managing all ground reception, data archiving, product generation, and data distribution. The result of this program is an unprecedented continuing record of natural and human-induced changes on the global landscape.

  12. Advanced satellite servicing facility studies

    Science.gov (United States)

    Qualls, Garry D.; Ferebee, Melvin J., Jr.

    1988-01-01

    A NASA-sponsored systems analysis designed to identify and recommend advanced subsystems and technologies specifically for a manned Sun-synchronous platform for satellite management is discussed. An overview of system design, manned and unmanned servicing facilities, and representative mission scenarios are given. Mission areas discussed include facility based satellite assembly, checkout, deployment, refueling, repair, and systems upgrade. The ferrying of materials and consumables to and from manufacturing platforms, deorbit, removal, repositioning, or salvage of satellites and debris, and crew rescue of any other manned vehicles are also examined. Impacted subsytems discussed include guidance navigation and control, propulsion, data management, power, thermal control, structures, life support, and radiation management. In addition, technology issues which would have significant impacts on the system design are discussed.

  13. Small satellites and their regulation

    CERN Document Server

    Jakhu, Ram S

    2014-01-01

    Since the launch of UoSat-1 of the University of Surrey (United Kingdom) in 1981, small satellites proved regularly to be useful, beneficial, and cost-effective tools. Typical tasks cover education and workforce development, technology demonstration, verification and validation, scientific and engineering research as well as commercial applications. Today the launch masses range over almost three orders of magnitude starting at less than a kilogram up to a few hundred kilograms, with budgets of less than US$ 100.00 and up to millions within very short timeframes of sometimes less than two years. Therefore each category of small satellites provides specific challenges in design, development and operations. Small satellites offer great potentials to gain responsive, low-cost access to space within a short timeframe for institutions, companies, regions and countries beyond the traditional big players in the space arena. For these reasons (particularly the low cost of construction, launch and operation), small (m...

  14. Distinct kinetics of human DNA ligases I, IIIalpha, IIIbeta, and IV reveal direct DNA sensing ability and differential physiological functions in DNA repair

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xi; Ballin, Jeff D.; Della-Maria, Julie; Tsai, Miaw-Sheue; White, Elizabeth J.; Tomkinson, Alan E.; Wilson, Gerald M.

    2009-05-11

    The three human LIG genes encode polypeptides that catalyze phosphodiester bond formation during DNA replication, recombination and repair. While numerous studies have identified protein partners of the human DNA ligases (hLigs), there has been little characterization of the catalytic properties of these enzymes. In this study, we developed and optimized a fluorescence-based DNA ligation assay to characterize the activities of purified hLigs. Although hLigI joins DNA nicks, it has no detectable activity on linear duplex DNA substrates with short, cohesive single-strand ends. By contrast, hLigIII{beta} and the hLigIII{alpha}/XRCC1 and hLigIV/XRCC4 complexes are active on both nicked and linear duplex DNA substrates. Surprisingly, hLigIV/XRCC4, which is a key component of the major non-homologous end joining (NHEJ) pathway, is significantly less active than hLigIII on a linear duplex DNA substrate. Notably, hLigIV/XRCC4 molecules only catalyze a single ligation event in the absence or presence of ATP. The failure to catalyze subsequent ligation events reflects a defect in the enzyme-adenylation step of the next ligation reaction and suggests that, unless there is an in vivo mechanism to reactivate DNA ligase IV/XRCC4 following phosphodiester bond formation, the cellular NHEJ capacity will be determined by the number of adenylated DNA ligaseIV/XRCC4 molecules.

  15. CpSAT-1, a transcribed satellite sequence from the codling moth, Cydia pomonella.

    Science.gov (United States)

    Věchtová, Pavlína; Dalíková, Martina; Sýkorová, Miroslava; Žurovcová, Martina; Füssy, Zoltán; Zrzavá, Magda

    2016-08-01

    Satellite DNA (satDNA) is a non-coding component of eukaryotic genomes, located mainly in heterochromatic regions. Relevance of satDNA began to emerge with accumulating evidence of its potential yet hardly comprehensible role that it can play in the genome of many organisms. We isolated the first satDNA of the codling moth (Cydia pomonella, Tortricidae, Lepidoptera), a species with holokinetic chromosomes and a single large heterochromatic element, the W chromosome in females. The satDNA, called CpSAT-1, is located on all chromosomes of the complement, although in different amounts. Surprisingly, the satellite is almost missing in the heterochromatic W chromosome. Additionally, we isolated mRNA from all developmental stages (1st-5th instar larva, pupa, adult), both sexes (adult male and female) and several tissues (Malpighian tubules, gut, heart, testes, and ovaries) of the codling moth and showed the CpSAT-1 sequence was transcribed in all tested samples. Using CpSAT-1 specific primers we amplified, cloned and sequenced 40 monomers from cDNA and gDNA, respectively. The sequence analysis revealed a high mutation rate and the presence of potentially functional motifs, mainly in non-conserved regions of the monomers. Both the chromosomal distribution and the sequence analysis suggest that CPSAT-1 has no function in the C. pomonella genome.

  16. Integration of metal-resistant determinants from the plasmid of an Acidocella strain into the chromosome of Escherichia coli DH5alpha.

    Science.gov (United States)

    Ghosh, Sajalendu; Mahapatra, Nitish R; Nandi, Suvobroto; Banerjee, Pataki C

    2005-01-01

    Acidophilic bacteria of mine origin are ideal systems for studying microbial metal resistance because of their ability to grow in the presence of high concentrations of metal salts. We have previously shown that the metal-resistant transformants obtained after transformation of Escherichia coli DH5alpha with plasmid DNA preparation from Acidocella sp. strain GS19h did not contain any plasmid suggesting chromosomal integration of the plasmid(s) (Appl Environ Microbiol 1997; 63: 4523-4527). The present study provides evidence in support of this suggestion. The pulsed field gel electrophoresis (PFGE) pattern of genomic DNA of the plasmidless metal-resistant transformants differed markedly from that of the untransformed DH5alpha strain. Moreover, when the recombinant plasmids constructed by cloning plasmid DNA fragments of the Acidocella strain GS19h in the vector pBluescript II KS+ were used to transform E. coli DH5alpha strain, no plasmid DNA was detected in some of the zinc- and ampicillin-resistant (ZnrAmpr) clones. The PFGE pattern of genomic DNA of such a transformed clone also differed markedly from that of the parent strain, suggesting chromosomal integration of the recombinant plasmid(s) containing both ampicillin- and zinc-resistance determinants. This observation was further supported by hybridization of chromosomal DNA of the plasmidless ZnrAmpr E. coli DH5alpha clone with the probes made from the plasmid DNA of strain GS19h and the vector DNA. Thus, this study corroborates our previous finding and documents the phenomenon of integration of metal-resistant determinants from the Acidocella GS19h plasmid(s) into the chromosome of E. coli DH5alpha.

  17. Advanced Communications Technology Satellite (ACTS)

    Science.gov (United States)

    Olmstead, Dean A.; Schertler, Ronald J.

    The benefits that will be offered by the NASA-sponsored communication spacecraft ACTS which is scheduled for launch in 1992 are described together with examples of demonstrations on proposed data, video, and voice applications supported by the advanced ACTS technologies. Compared to existing satellite service, the ACTS will provide lower cost, better service, greater convenience, and improved service reliability of telecommunications to customers around the world. In addition, the pioneering ACTS technology will provide many capabilities qualitatively different from those of current satellite systems, such as on-demand assignment, frequency reuse, and the flexible targeting of spot beams directly to the very-small-aperture terminals at customer premises.

  18. Satellite communications: possibilities and problems

    International Nuclear Information System (INIS)

    Hine, M.

    1986-01-01

    Communication links via satellites are becoming available in Europe, both as part of the development of the telephone system and as special services aimed at data traffic. They offer the possibility of speeds between 50 kb/s and 2 Mb/s, without the problems and long term commitments of long distance land lines. Such links are provided by the PTT's as circuits which can be booked for variable periods, and have error rates which can be very low and well controlled. Problems in networking can arise from the satellite delay, particularly if errors occur in the local connections, and from the leased circuit and tariff philosophies of the PTT's. (Auth.)

  19. Leveraging the NPS Femto Satellite for Alternative Satellite Communication Networks

    Science.gov (United States)

    2017-09-01

    of the Experiment ....................................................53 Figure 26. A Snapshot of the First Step to Run the Python Program...54 Figure 27. A Snapshot of the Python Program Menu .................................................54 xiii LIST OF TABLES... learn about the satellite, even though I did not have a strong background in this area. He convinced me not to be afraid. I want to thank Dr. Alex

  20. Satellite switched FDMA advanced communication technology satellite program

    Science.gov (United States)

    Atwood, S.; Higton, G. H.; Wood, K.; Kline, A.; Furiga, A.; Rausch, M.; Jan, Y.

    1982-01-01

    The satellite switched frequency division multiple access system provided a detailed system architecture that supports a point to point communication system for long haul voice, video and data traffic between small Earth terminals at Ka band frequencies at 30/20 GHz. A detailed system design is presented for the space segment, small terminal/trunking segment at network control segment for domestic traffic model A or B, each totaling 3.8 Gb/s of small terminal traffic and 6.2 Gb/s trunk traffic. The small terminal traffic (3.8 Gb/s) is emphasized, for the satellite router portion of the system design, which is a composite of thousands of Earth stations with digital traffic ranging from a single 32 Kb/s CVSD voice channel to thousands of channels containing voice, video and data with a data rate as high as 33 Mb/s. The system design concept presented, effectively optimizes a unique frequency and channelization plan for both traffic models A and B with minimum reorganization of the satellite payload transponder subsystem hardware design. The unique zoning concept allows multiple beam antennas while maximizing multiple carrier frequency reuse. Detailed hardware design estimates for an FDMA router (part of the satellite transponder subsystem) indicate a weight and dc power budget of 353 lbs, 195 watts for traffic model A and 498 lbs, 244 watts for traffic model B.