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Sample records for rer nat thesis

  1. ISCCP TOVS NAT

    Atmospheric Science Data Center

    2016-02-12

    ISCCP TOVS NAT Atmospheric Profiles, NATIVE file format Project Title:  ... Parameters:  Cloud Amount Cloud Top Pressure Ozone Precipitable Water Profiles Surface Pressure Surface Temperature Temperature Profiles Tropopause Pressure ...

  2. Genetic polymorphism in N-Acetyltransferase (NAT): Population distribution of NAT1 and NAT2 activity.

    PubMed

    Walker, Katy; Ginsberg, Gary; Hattis, Dale; Johns, Douglas O; Guyton, Kathryn Z; Sonawane, Babasaheb

    2009-01-01

    N-Acetyltransferases (NAT) are key enzymes in the conjugation of certain drugs and other xenobiotics with an arylamine structure. Polymorphisms in NAT2 have long been recognized to modulate toxicity produced by the anti-tubercular drug isoniazid, with molecular epidemiologic studies suggesting a link between acetylator phenotype and increased risk for bladder cancer. Recent evidence indicates that the other major NAT isozyme, NAT1, is also polymorphic. The current analysis characterizes the main polymorphisms in both NAT2 and NAT1 in terms of their effect on enzyme activity and frequency in the population. Multiple NAT2 alleles (NAT2*5, *6, *7, and *14) have substantially decreased acetylation activity and are common in Caucasians and populations of African descent. In these groups, most individuals carry at least one copy of a slow acetylator allele, and less than 10% are homozygous for the wild type (fast acetylator) trait. Incorporation of these data into a Monte Carlo modeling framework led to a population distribution of NAT2 activity that was bimodal and associated with considerable variability in each population assessed. The ratio of the median to the first percentile of NAT2 activity ranged from 7 in Caucasians to 18 in the Chinese population. This variability indicates the need for more quantitative approaches (e.g., physiologically based pharmacokinetic [PBPK] modeling) to assess the full distribution of internal dose and adverse responses to aromatic amines and other NAT2 substrates. Polymorphisms in NAT1 are generally associated with relatively minor effects on acetylation function, with Monte Carlo analysis indicating less interindividual variability than seen in NAT2 analysis. PMID:20183529

  3. Metastable NAT in Ice-Clouds

    NASA Astrophysics Data System (ADS)

    Weiss, Fabian; Kubel, Frank; Gálvez, Óscar; Hoelzel, Markus; Parker, Stewart F.; Iannarelli, Riccardo; Rossi, Michel J.; Grothe, Hinrich

    2015-04-01

    Polar Stratospheric Clouds and Cirrus Clouds contain, besides pure water ice, a rather large fraction of various hydrates. These are very important for the formation of the cloud, which is a yet not well understood process. We recently solved the structure of a metastable NAT phase (alpha-NAT), we believe to not only be present, but playing a major role in the formation of clouds. On the basis of previous work on this phase by Grothe et al. [1], we enhanced the production of alpha-NAT to the point, where we could produce enough sample to do neutron diffraction. This enabled us to solve the structure. Our quantum mechanical calculations, using this newly found structure, show a large affinity towards water-ice. With this in mind, we interlaced our results with the experiments of R. Iannarelli [2] to derive a new 3-step NAT-formation mechanism in ice-clouds, which could explain some of the observed kinetics better than the mechanism postulated in Zondlo et al. [3]. 1. Grothe, H., Tizek, H., Waller, D. & Stokes, D. The crystallization kinetics and morphology of nitric acid trihydrate. Phys. Chem. Chem. Phys., 8, 2232-2239 (2006) 2. Iannarelli, R. Multidiagnostic Observations on HCl and HNO3 Hydrate Films in the Temperature Range 170-205K: A Kinetic Study. PhD Thesis 21791, ETH Zürich, (2013). 3. Zondlo, M.A., Hudson, P.K., Prenni A.J. & Tolbert, M.A. Chemistry and microphysics of polar stratospheric clouds and Cirrus clouds. Ann. Rev. Phys. Chem., 51, 473-499 (2000).

  4. NAT Usage in Residential Broadband Networks

    NASA Astrophysics Data System (ADS)

    Maier, Gregor; Schneider, Fabian; Feldmann, Anja

    Many Internet customers use network address translation (NAT) when connecting to the Internet. To understand the extend of NAT usage and its implications, we explore NAT usage in residential broadband networks based on observations from more than 20,000 DSL lines. We present a unique approach for detecting the presence of NAT and for estimating the number of hosts connected behind a NAT gateway using IP TTLs and HTTP user-agent strings. Furthermore, we study when each of the multiple hosts behind a single NAT gateway is active. This enables us to detect simultaneous use. In addition, we evaluate the accuracy of NAT analysis techniques when fewer information is available.

  5. NAT: perspectives for cellular components.

    PubMed

    Barbara, J A

    1999-12-01

    The introduction of routine testing to detect viral genomes in donated blood was originally driven by requirements for plasma fractionation in relation to exclusion of hepatitis C virus (HCV) RNA. Nevertheless, it was obvious from the outset that a dual standard for fractionated products and individual blood components would be untenable. In many countries therefore, planning for introduction of nucleic acid testing (NAT) of blood incorporated progression to release of HCV RNA tested components. HCV was singled out because of its long seronegative 'window period', relatively high prevalence and incidence in blood donors, rapid burst time and high genome copy number during seroconversion. The latter properties made HCV particularly suitable for detection in pools of samples. If HCV RNA testing is required for release of labile components such as platelets, rapid provision of NAT results is vital because of short shelf life of platelets and the problems of delays when resolving the infectious unit in a reactive pool. For NAT release of labile components smaller sample pool sizes allow faster resolution of RNA positive units. Smaller pools involve high test throughput, the likely need for more testing laboratories and ensuing increased costs. Single sample testing is the ultimate extrapolation of reducing sample pool size. With reduced pool sizes or single sample testing, the option of testing for other viruses (e.g. HIV or HBV) singly or in multiplex also arises. The cost-benefit and incremental yield of such strategies in the light of 'combo' assays for HIV Ag/Ab and the recently described HCV Ag assay will require careful and objective assessment, together with re-appraisal of anti-HBc screening for detection of HBV infected donors at the "tail-end" of carriage. PMID:10686060

  6. P-CSCF's Algorithm for Solving NAT Traversal

    NASA Astrophysics Data System (ADS)

    Kim, Jung-Ho; Cho, Jae-Hyoung; Lee, Jae-Oh

    Many ways for efficient use of limited IP address of IPv4 are existed. The one of these ways is to construct the private network using Network Address Translator (NAT). NAT filtering rule makes network management easier. However, NAT Filtering rule makes NAT Traversal. Many solutions like Simple Traversal of UDP through NAT (STUN), Traversal Using Relay NAT (TURN) and Media Relay method exist. But these solutions require additional servers or devices. So, we suggest that P-CSCFs in the IP Multimedia Subsystem (IMS) change the packet's header and solve the NAT Traversal without any additional equipment.

  7. NAT THE RAT - PUPIL'S BOOK. (TITLE SUPPLIED).

    ERIC Educational Resources Information Center

    ROJAS, PAULINE M.; AND OTHERS

    THE EXPERIMENTAL EDITION OF "NAT THE RAT" REPRESENTS LEVEL TWO OF THE "MIAMI LINGISTIC READERS" DESIGNED TO BE USED IN TEACHING BEGINNING READING TO PUPILS WHOSE PRESCHOOL LANGUAGE WAS OTHER THAN ENGLISH. THE FIVE MAJOR CHARACTERS IN THE STORY ARE INTRODUCED ON THE FIRST FIVE PAGES OF THE PUPILS' BOOK. ILLUSTRATIONS (BLACK AND WHITE) TO REINFORCE…

  8. Worldwide distribution of NAT2 diversity: Implications for NAT2 evolutionary history

    PubMed Central

    Sabbagh, Audrey; Langaney, André; Darlu, Pierre; Gérard, Nathalie; Krishnamoorthy, Rajagopal; Poloni, Estella S

    2008-01-01

    Background The N-acetyltransferase 2 (NAT2) gene plays a crucial role in the metabolism of many drugs and xenobiotics. As it represents a likely target of population-specific selection pressures, we fully sequenced the NAT2 coding region in 97 Mandenka individuals from Senegal, and compared these sequences to extant data on other African populations. The Mandenka data were further included in a worldwide dataset composed of 41 published population samples (6,727 individuals) from four continental regions that were adequately genotyped for all common NAT2 variants so as to provide further insights into the worldwide haplotype diversity and population structure at NAT2. Results The sequencing analysis of the NAT2 gene in the Mandenka sample revealed twelve polymorphic sites in the coding exon (two of which are newly identified mutations, C345T and C638T), defining 16 haplotypes. High diversity and no molecular signal of departure from neutrality were observed in this West African sample. On the basis of the worldwide genotyping survey dataset, we found a strong genetic structure differentiating East Asians from both Europeans and sub-Saharan Africans. This pattern could result from region- or population-specific selective pressures acting at this locus, as further suggested in the HapMap data by extremely high values of FST for a few SNPs positions in the NAT2 coding exon (T341C, C481T and A803G) in comparison to the empirical distribution of FST values accross the whole 400-kb region of the NAT gene family. Conclusion Patterns of sequence variation at NAT2 are consistent with selective neutrality in all sub-Saharan African populations investigated, whereas the high level of population differentiation between Europeans and East Asians inferred from SNPs could suggest population-specific selective pressures acting at this locus, probably caused by differences in diet or exposure to other environmental signals. PMID:18304320

  9. Recoil studies of photonuclear reactions on natCu, natAg, natTa, and 197Au at intermediate energies

    NASA Astrophysics Data System (ADS)

    Fujiwara, I.; Haba, H.; Matsumura, H.; Sakamoto, K.; Miyamoto, Y.; Oura, Y.; Shibata, S.; Furukawa, M.

    1999-01-01

    The recoil properties of nuclides produced in the photonuclear reactions on natCu, natAg, natTa, and 197Au induced by bremsstrahlung of end-point energies (E o) of 250 to 1000 MeV have been investigated using the thick-target thick-catcher method. The obtained mean ranges of produced nuclides smoothly increase with an increase of the mass difference (ΔA) between products and target, and show E 0-independence at E 0≥600 MeV, reflecting the limiting behavior above (3, 3) resonance region. The mean kinetic energies, T, deduced from the mean ranges show the following two components; (1) (γ, xn) products by giant-resonance and/or quasi-deuteron resonance absorption, (2) (γ, xnyp) products by mainly (3, 3) resonance absorption. Slightly rapid increase of T was found around ΔA=15, 18, 24, and 25 for natCu, natAg, natTa and 197Au, respectively, reflecting a change in mechanism. Kinematic properties of the product nuclei were calculated by using the PICA (Photon-Induced Intranuclear Cascade Analysis) code. The T calculated by the PICA code at E 0=400 MeV well reproduced the experimental results of natCu, but the same calculation for natAg, natTa, and 197Au gave lower mean kinetic energies than the experimental results.

  10. Recoil studies of photonuclear reactions on natCu, natAg, natTa, and 197Au at intermediate energies

    NASA Astrophysics Data System (ADS)

    Fujiwara, I.; Haba, H.; Matsumura, H.; Sakamoto, K.; Miyamoto, Y.; Oura, Y.; Shibata, S.; Furukawa, M.

    1999-01-01

    The recoil properties of nuclides produced in the photonuclear reactions on natCu, natAg, natTa, and 197Au induced by bremsstrahlung of end-point energies ( E o) of 250 to 1000 MeV have been investigated using the thick-target thick-catcher method. The obtained mean ranges of produced nuclides smoothly increase with an increase of the mass difference (ΔA) between products and target, and show E 0-independence at E 0≥600 MeV, reflecting the limiting behavior above (3, 3) resonance region. The mean kinetic energies, T, deduced from the mean ranges show the following two components; (1) (γ, xn) products by giant-resonance and/or quasi-deuteron resonance absorption, (2) (γ, xnyp) products by mainly (3, 3) resonance absorption. Slightly rapid increase of T was found around ΔA=15, 18, 24, and 25 for natCu, natAg, natTa and 197Au, respectively, reflecting a change in mechanism. Kinematic properties of the product nuclei were calculated by using the PICA (Photon-Induced Intranuclear Cascade Analysis) code. The T calculated by the PICA code at E 0=400 MeV well reproduced the experimental results of natCu, but the same calculation for natAg, natTa, and 197Au gave lower mean kinetic energies than the experimental results.

  11. Extreme Nat Supersaturations In Mountain Wave Pscs - A Clue To

    NASA Astrophysics Data System (ADS)

    Luo, B. P.; Voigt, C.; Fuglistaler, S.; Peter, T.

    There is evidence for the existence of nitric acid trihydrate (NAT) in polar stratospheric clouds (PSCs) and for its role in sedimentary denitrification enhancing chlorine- catalyzed ozone reduction. However, the scientific understanding of NAT formation mechanisms is vague. We show that strong cooling rates in mountain waves, though causing only moderate NAT saturation ratio over supercooled ternary solution (STS) droplets (SNAT < 30) lead to NAT saturation ratios exceeding 500 within the gas phase. Laboratory measurements suggest that such extreme supersaturations promote NAT deposition nucleation on ice or other solid surfaces, as long as they are not coated by STS. Based on airborne lidar PSC observations in three Arctic winters and a com- bined microphysical/optical model, we derive a simple parameterization for a NAT deposition nucleation rate which depends only on NAT supersaturation and tempera- ture. The results indicate that deposition nucleation of NAT on ice driven by extreme NAT supersaturations is able to explain the formation of NAT particle number densi- ties in the observed wide range between 10-4 to 10 cm-3.

  12. Effect of arylamine acetyltransferase Nat3 gene knockout on N-acetylation in the mouse.

    PubMed

    Sugamori, K S; Brenneman, D; Wong, S; Gaedigk, A; Yu, V; Abramovici, H; Rozmahel, R; Grant, D M

    2007-07-01

    Arylamine N-acetyltransferases (NAT) catalyze the biotransformation of many important arylamine drugs and procarcinogens. NAT can either detoxify or activate procarcinogens, complicating the manner in which these enzymes may participate in enhancing or preventing toxic responses to particular agents. Mice possess three NAT isoenzymes: Nat1, Nat2, and Nat3. Whereas Nat1 and Nat2 can efficiently acetylate many arylamines, few substrates appear to be appreciably metabolized by Nat3. We generated a Nat3 knockout mouse strain and used it along with our double Nat1/2(-/-) knockout strain to further investigate the functional role of Nat3. Nat3(-/-) mice showed normal viability and reproductive capacity. Nat3 expression was very low in wild-type animals and completely undetectable in Nat3(-/-) mice. In contrast, greatly elevated expression of Nat3 transcript was observed in Nat1/2(-/-) mice. We used a transcribed marker polymorphism approach to establish that the increased expression of Nat3 in Nat1/2(-/-) mice is a positional artifact of insertion of the phosphoglycerate kinase-neomycin resistance cassette in place of the Nat1/Nat2 gene region and upstream of the intact Nat3 gene, rather than a biological compensatory mechanism. Despite the increase in Nat3 transcript, the N-acetylation of p-aminosalicylate, sulfamethazine, 2-aminofluorene, and 4-aminobiphenyl was undetectable either in vivo or in vitro in Nat1/2(-/-) animals. In parallel, no difference was observed in the in vivo clearance or in vitro metabolism of any of these substrates between wild-type and Nat3(-/-) mice. Thus, Nat3 is unlikely to play a significant role in the N-acetylation of arylamines either in wild-type mice or in mice lacking Nat1 and Nat2 activities. PMID:17403913

  13. Association Between NAT2 Polymorphisms and Lung Cancer Susceptibility.

    PubMed

    Liu, Chang; Cui, Wei; Cong, Lin; Wang, Li; Ruan, Xinjian; Jia, Jia; Liu, Yanfang; Jia, Xiaoyan; Zhang, Xia

    2015-12-01

    To further investigate the association between NAT2 polymorphisms and lung cancer susceptibility.In terms of phenotypes, we investigated the acetylator status of NAT2 polymorphisms associated with lung cancer risk. Additionally, in view of genotypes, we mainly analyzed 5 single nucleotide polymorphisms (SNPs) in NAT2 gene, namely C282T, A803G, C481T, G590A, and G857A. Twenty-six eligible studies were included in our meta-analysis by searching PubMed, Embase, and CNKI databases. We used odds ratios (ORs) with corresponding 95% confidence intervals (CIs) to evaluate the susceptibility to lung cancer associated with NAT2 polymorphisms.Overall, based on phenotypes, the pooled ORs showed no significant association between NAT2 polymorphisms and lung cancer susceptibility. In the subgroup analyses by ethnicity and source of control, there was still no significant association. In terms of genotypes, overall, no obvious relationship was observed between NAT2 polymorphisms and lung cancer risk. But increased risk of lung cancer was found in association with NAT2 C282T polymorphism (TT vs. CC + TC: OR = 1.58, 95% CI = 1.11-2.25).Our meta-analysis demonstrates that TT genotype in NAT2 C282T polymorphism may be a risk factor for lung cancer susceptibility. Additionally, the acetylator status of 5 SNPs in NAT2 gene may not be associated with lung cancer risk. PMID:26656326

  14. Teaching the Thesis

    ERIC Educational Resources Information Center

    Carroll, Joyce Armstrong

    2012-01-01

    Writing a good thesis provides a successful foundation for composing an essay. Teaching how to do that, however, is quite another matter. Teachers often say to students, "Find a thesis," or "Get a thesis," or "Bring in a thesis statement tomorrow," as if students could order one like a pizza, command it like a pet pooch, or grasp one out of thin…

  15. Determination of NAT2 acetylation status in the Greenlandic population.

    PubMed

    Geller, Frank; Soborg, Bolette; Koch, Anders; Michelsen, Sascha Wilk; Bjorn-Mortensen, Karen; Carstensen, Lisbeth; Birch, Emilie; Nordholm, Anne Christine; Johansen, Marie Mila Broby; Børresen, Malene Landbo; Feenstra, Bjarke; Melbye, Mads

    2016-04-01

    N-acetyltransferase 2 (NAT2) is a well-studied phase II xenobiotic metabolizing enzyme relevant in drug metabolism and cancerogenesis. NAT2 activity is largely determined by genetic polymorphisms in the coding region of the corresponding gene. We investigated NAT2 acetylation status in 1556 individuals from Greenland based on four different single nucleotide polymorphism (SNP) panels and the tagging SNP rs1495741. There was good concordance between the NAT2 status inferred by the different SNP combinations. Overall, the fraction of slow acetylators was low with 17.5 % and varied depending on the degree of Inuit ancestry; in individuals with <50 % Inuit ancestry, we observed more than 25 % slow acetylators reflecting European ancestry. Greenland has a high incidence of tuberculosis, and individual dosing of isoniazid according to NAT2 status has been shown to improve treatment and reduce side effects. Our findings could be a first step in pharmacogenetics-based tuberculosis therapy in Greenland. PMID:25794903

  16. Genetic variation in N-acetyltransferase 1 (NAT1) and 2 (NAT2) and risk of non-Hodgkin lymphoma

    PubMed Central

    Morton, Lindsay M.; Schenk, Maryjean; Hein, David W.; Davis, Scott; Zahm, Shelia Hoar; Cozen, Wendy; Cerhan, James R.; Hartge, Patricia; Welch, Robert; Chanock, Stephen J.; Rothman, Nathaniel; Wang, Sophia S.

    2007-01-01

    Background Animal studies suggest that lymphomagenesis can be induced by exposure to carcinogenic aromatic and heterocyclic amines found in diet, cigarette smoke, and the environment, but human epidemiologic investigations of these exogenous exposures have yielded conflicting results. As part of our evaluation of the role of aromatic and heterocyclic amines, which are metabolized by N-acetyltransferase (NAT) enzymes, in the etiology of non-Hodgkin lymphoma (NHL), we examined NHL risk in relation to genetic variation in NAT1 and NAT2 and exposure to cigarette smoke and dietary heterocyclic amines and mutagens. Methods We genotyped ten common single nucleotide polymorphisms (SNPs) in NAT1 and NAT2 among 1136 cases and 922 controls from a population-based case–control study in four geographic areas of the US. Relative risk of NHL for NAT1 and NAT2 genotypes, NAT2 acetylation phenotype, and exposure to cigarette smoke and dietary heterocyclic amines and mutagens was estimated using odds ratios (ORs) and 95% confidence intervals (CIs) derived from unconditional logistic regression models. Results We observed increased risk of NHL among individuals with the NAT1*10/*10 genotype compared with individuals with other NAT1 genotypes (OR=1.60, 95% CI 1.04–2.46, p=0.03). We also observed increased NHL risk in a dose-dependent model among NAT2 intermediate- and rapid-acetylators in comparison with slow-acetylators, although only the trend was statistically significant (intermediate: OR=1.18, 95% CI 0.97–1.44, p=0.1; rapid: OR=1.43, 95% CI 0.97–2.14, p=0.07; p for linear trend=0.03). Compared with nonsmokers, NHL risk estimates for current cigarette smoking were increased only among NAT2 intermediate/rapid-acetylators (OR=2.44, 95% CI 1.15–5.20, p=0.02). Conclusions Our data provide evidence that NAT1 and NAT2 genotypes are associated with NHL risk and support a contributory role for carcinogenic aromatic and/or heterocyclic amines in the multi-factorial etiology of

  17. Using Albrecht Dürer's "Instruction on Measurement" for Projects in the Mathematics Classroom

    ERIC Educational Resources Information Center

    Tamulis, Andrius

    2014-01-01

    Albrecht Dürer is well known as a Renaissance artist, but his 1525 work, the "Underweysung der Messung," or "Manual on Measurement," also contains a significant amount of mathematics. This article outlines four projects inspired by parts of this work, with additional material coming from Staigmüller's 1891 "Dürer als…

  18. The tractable cognition thesis.

    PubMed

    Van Rooij, Iris

    2008-09-01

    The recognition that human minds/brains are finite systems with limited resources for computation has led some researchers to advance the Tractable Cognition thesis: Human cognitive capacities are constrained by computational tractability. This thesis, if true, serves cognitive psychology by constraining the space of computational-level theories of cognition. To utilize this constraint, a precise and workable definition of "computational tractability" is needed. Following computer science tradition, many cognitive scientists and psychologists define computational tractability as polynomial-time computability, leading to the P-Cognition thesis. This article explains how and why the P-Cognition thesis may be overly restrictive, risking the exclusion of veridical computational-level theories from scientific investigation. An argument is made to replace the P-Cognition thesis by the FPT-Cognition thesis as an alternative formalization of the Tractable Cognition thesis (here, FPT stands for fixed-parameter tractable). Possible objections to the Tractable Cognition thesis, and its proposed formalization, are discussed, and existing misconceptions are clarified. PMID:21585437

  19. The Tractable Cognition Thesis

    ERIC Educational Resources Information Center

    van Rooij, Iris

    2008-01-01

    The recognition that human minds/brains are finite systems with limited resources for computation has led some researchers to advance the "Tractable Cognition thesis": Human cognitive capacities are constrained by computational tractability. This thesis, if true, serves cognitive psychology by constraining the space of computational-level theories…

  20. NAT nucleation and denitrification in the polar stratosphere

    NASA Astrophysics Data System (ADS)

    Grooß, Jens-Uwe; Engel, Ines; Hoyle, Christopher R.; Luo, Beiping; Peter, Thomas; Frey, Wiebke; Molleker, Sergej; Borrmann, Stephan; Schlager, Hans; Vömel, Holger; Kivi, Rigel; Walker, Kaley A.; Santee, Michelle L.; Stiller, Gabriele; Pitts, Michael; Müller, Rolf

    2013-04-01

    Nitric acid trihydrate (NAT) particles in the polar stratosphere are known to influence the chemistry of ozone depletion. NAT particles, along with other liquid and crystalline particles, provide heterogeneous surfaces for chlorine activation. More importantly, they can take up significant amounts of HNO3 from the gas phase and transport HNO3 downward by sedimentation. This can lead to denitrification, in the Arctic typically at altitudes above about 20 km, and a re-nitrification below, at the level where the NAT particles evaporate. The nucleation rate of NAT particles is a critical parameter for the simulation of this process. Very low NAT nucleation rates around 2?10-9cm-3s-1 have been deduced for low NAT supersaturations from observations. In previous studies, vertical HNO3 transport has been successfully simulated by Lagrangian 3-D simulations using a constant NAT nucleation rate of around 2?10-9cm-3s-1, for the Arctic winters in the years 2003 and 2005. However, for winter 2009/2010, this approach does not generate satisfying results. Here, saturation dependent NAT nucleation rates were derived from Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO), observations under the assumption that NAT nucleates heterogeneously on dust particles that are characterized by active sites with a certain occurrence probability distribution depending on the contact angle. Simulations with the Zurich Optical and Microphysical box Model (ZOMM) along back-trajectories starting from points where PSCs were observed by CALIPSO allow the parametrisation of heterogeneous nucleation rates for NAT and ice on dust, and the reproduction of the different PSC classes observed. We present simulations by the Chemical Lagrangian Model of the Stratosphere (CLaMS) of the winter 2009/2010 applying this new parametrisation of heterogeneous NAT nucleation rates. The CLaMS simulation is initialized using a combination of MLS, MIPAS-ENVISAT and ACE-FTS data. The simulation

  1. Degree by Thesis

    ERIC Educational Resources Information Center

    Courtis, Barbara

    1974-01-01

    Discusses a student's experience with a research project on the synthesis and reactions of an organo-platinum complex with an organo-Group IV linkage, including the advantages and disadvantages of such a degree by thesis course. (CC)

  2. The Faces of Saturn: Images and Texts from Augustus through Dürer to Galileo

    NASA Astrophysics Data System (ADS)

    Shank, M. H.

    2013-04-01

    This paper follows the thread(s) of Saturn in astrology and art from the Babylonians to Galileo, paying special attention to the planet's political importance from Augustus to the Medici and to its medical/psychological significance from Ficino through Dürer. In passing, I extend David Pingree's astrological interpretation of Dürer's Melencholia I and propose a very personal rationale for the engraving, namely as a memorial to his mother.

  3. PlantNATsDB: a comprehensive database of plant natural antisense transcripts

    PubMed Central

    Chen, Dijun; Yuan, Chunhui; Zhang, Jian; Zhang, Zhao; Bai, Lin; Meng, Yijun; Chen, Ling-Ling; Chen, Ming

    2012-01-01

    Natural antisense transcripts (NATs), as one type of regulatory RNAs, occur prevalently in plant genomes and play significant roles in physiological and pathological processes. Although their important biological functions have been reported widely, a comprehensive database is lacking up to now. Consequently, we constructed a plant NAT database (PlantNATsDB) involving approximately 2 million NAT pairs in 69 plant species. GO annotation and high-throughput small RNA sequencing data currently available were integrated to investigate the biological function of NATs. PlantNATsDB provides various user-friendly web interfaces to facilitate the presentation of NATs and an integrated, graphical network browser to display the complex networks formed by different NATs. Moreover, a ‘Gene Set Analysis’ module based on GO annotation was designed to dig out the statistical significantly overrepresented GO categories from the specific NAT network. PlantNATsDB is currently the most comprehensive resource of NATs in the plant kingdom, which can serve as a reference database to investigate the regulatory function of NATs. The PlantNATsDB is freely available at http://bis.zju.edu.cn/pnatdb/. PMID:22058132

  4. Going beyond the Thesis

    ERIC Educational Resources Information Center

    Smith, Andrew C.

    2010-01-01

    Most every writing teacher can relate to the curse of reading yet another incoherent essay, the contents of which resemble an unorganized junk drawer of thoughts. Such essays cry out for a main idea. The remedy is a thesis, and teachers rightly take pains to help students discover this. Yet in spite of this, writing teachers ought to bear in mind…

  5. Writing a Thesis Differently

    ERIC Educational Resources Information Center

    Honan, Eileen; Bright, David

    2016-01-01

    In this paper we explore the contributions that Deleuze and Guattari have made to thinking/writing language and how these ideas can be put to work in producing a doctoral thesis. We contribute to the field of work within what Patti Lather and Elizabeth St Pierre have called the "post-qualitative" movement, where researchers attempt to…

  6. The Las Vegas Thesis

    ERIC Educational Resources Information Center

    Sughrua, William

    2010-01-01

    Following "reflexive ethnography" and utilizing an approach of "performative narrative" and "layered text", this article explores how Bachelor of Arts students in the Teaching of English as a Foreign Language program at a public university in Mexico successfully manage the writing of an inductive-oriented thesis in English by resisting…

  7. NAT2 genetic variations among South Indian populations.

    PubMed

    Lakkakula, Saikrishna; Mohan Pathapati, Ram; Chaubey, Gyaneshwer; Munirajan, Arasambattu Kannan; Lakkakula, Bhaskar Vks; Maram, Rajasekhar

    2014-01-01

    The N-acetyltransferases (NATs) are xenobiotic-metabolizing enzymes involved in the metabolism of drugs, environmental toxins and the aromatic amine carcinogens present in cigarette smoke. Genetic variations in NAT2 have long been recognized as the cause of variable enzymatic activity or stability, leading to slow or rapid acetylation. In the present study, we genotyped three single-nucleotide polymorphisms (SNPs) from the NAT2 gene (rs1799929, rs1799930 and rs1799931), using TaqMan allelic discrimination, among 212 individuals from six major South Indian populations and compared the results with other available Indian and worldwide data. All three of the markers followed Hardy-Weinberg equilibrium and were highly polymorphic in the studied populations. The constructed haplotypes showed a high level of heterozygosity. All of the populations in the present study commonly shared only four haplotypes out of the eight possible three-site haplotypes. The haplotypes exhibited fairly high frequencies across multiple populations, where three haplotypes were shared by all six populations with a cumulative frequency ranging from 88.2% (Madiga) to 97.0% (Balija). We also observed a tribal-specific haplotype. A strong linkage disequilibrium (LD) between rs1799929 and rs1799930 was consistent in all of the studied populations, with the exception of the Madiga. A comparison of the genomic regions 20-kb up- and downstream of rs1799930 in a large number of worldwide samples showed a strong LD of this SNP with another NAT2 SNP, rs1112005, among the majority of the populations. Moreover, our lifestyle test (hunter-gatherer versus agriculturist) in comparison with the NAT2 variant suggested that two of the studied populations (Balija and Madiga) have likely shifted their diet more recently. PMID:27081506

  8. Identification of N-Acetyltransferase 2 (NAT2) Transcription Start Sites and Quantitation of NAT2-specific mRNA in Human Tissues

    PubMed Central

    Husain, Anwar; Zhang, Xiaoyan; Doll, Mark A.; States, J. Christopher; Barker, David F.; Hein, David W.

    2007-01-01

    Human N-acetyltransferase 2 (NAT2) genetic polymorphism is associated with drug toxicity and/or carcinogenesis in various tissues. Knowledge of NAT2 gene structure and expression are critical for understanding these associations. Previous findings suggest that human NAT2 expression is highest in liver and gut, but expressed at functional levels in other tissues. A sensitive and specific TaqMan reverse transcriptase polymerase chain reaction (RT-PCR) assay with intron-spanning primers was developed and used, together with a second TaqMan RT-PCR assay based on amplification of a NAT2 open reading frame (ORF) exon segment, to measure NAT2 mRNA in 29 different human tissues. Cap-dependent amplification of mRNA 5′ termini and review of public database information was done to more precisely define the NAT2 promoter(s) and to validate the quantitative RT-PCR assay design. The great majority (40/41) of NAT2 liver cDNAs had 5′ termini between 8682 and 8752 nucleotides upstream of the NAT2 ORF exon, and 34/40 5′-termini were at the -8711 and -8716 adenines. All of 59 NAT2 cDNAs with 5′ termini in this vicinity, including 40 of the liver isolates and 19 cDNAs in public databases from liver and other sources, showed direct splicing to the ORF exon, with no other non-coding exon detected. NAT2 mRNA was highest in liver, small intestine and colon and readily detected in most other tissues albeit at much lower levels. NAT2 expression in diverse human tissues provides further mechanistic support underlying associations between NAT2 genetic polymorphism, drug toxicity and/or chemical carcinogenesis. PMID:17287389

  9. [Albert Schwietzer's doctoral thesis].

    PubMed

    Gorn, M F

    1993-06-01

    A review on Albert Schweitzer's doctoral thesis "The psychiatric study on Jesus" and his analysis of the delirium of persecution, megalomania and hallucination in order to refuse different authors hypothesis about the Jesus, psychosis or paranoia. The author highlights the symbolism of Schweitzer's decision for studying medicine and dedicating his life and efforts to the full of need men of Africa so the importance of his philosophic studies on the western culture. PMID:11640683

  10. Improvements in algorithms for phenotype inference: the NAT2 example.

    PubMed

    Selinski, Silvia; Blaszkewicz, Meinolf; Ickstadt, Katja; Hengstler, Jan G; Golka, Klaus

    2014-02-01

    Numerous studies have analyzed the impact of N-acetyltransferase 2 (NAT2) polymorphisms on drug efficacy, side effects as well as cancer risk. Here, we present the state of the art of deriving haplotypes from polymorphisms and discuss the available software. PHASE v2.1 is currently considered a gold standard for NAT2 haplotype assignment. In vitro studies have shown that some slow acetylation genotypes confer reduced protein stability. This has been observed particularly for G191A, T341C and G590A. Substantial ethnic variations of the acetylation status have been described. Probably, upcoming agriculture and the resulting change in diet caused a selection pressure for slow acetylation. In recent years much research has been done to reduce the complexity of NAT2 genotyping. Deriving the haplotype from seven SNPs is still considered a gold standard. However, meanwhile several studies have shown that a two-SNP combination, C282T and T341C, results in a similarly good distinction in Caucasians. However, attempts to further reduce complexity to only one 'tagging SNP' (rs1495741) may lead to wrong predictions where phenotypically slow acetylators were genotyped as intermediate or rapid. Numerous studies have shown that slow NAT2 haplotypes are associated with increased urinary bladder cancer risk and increased risk of anti-tuberculosis drug-induced hepatotoxicity. A drawback of the current practice of solely discriminating slow, intermediate and rapid genotypes for phenotype inference is limited resolution of differences between slow acetylators. Future developments to differentiate between slow and ultra-slow genotypes may further improve individualized drug dosing and epidemiological studies of cancer risk. PMID:24524665

  11. Closed system respirometry may underestimate tissue gas exchange and bias the respiratory exchange ratio (RER).

    PubMed

    Malte, Christian Lind; Nørgaard, Simon; Wang, Tobias

    2016-02-01

    Closed respirometry is a commonly used method to measure gas exchange in animals due to its apparent simplicity. Typically, the rates of O2 uptake and CO2 excretion (VO2 and VCO2, respectively) are assumed to be in steady state, such that the measured rates of gas exchange equal those at tissue level. In other words, the respiratory gas exchange ratio (RER) is assumed to equal the respiratory quotient (RQ). However, because the gas concentrations change progressively during closure, the animal inspires air with a progressively increasing CO2 concentration and decreasing O2 concentration. These changes will eventually affect gas exchange causing the O2 and CO2 stores within the animal to change. Because of the higher solubility/capacitance of CO2 in the tissues of the body, VCO2 will be more affected than VO2, and we hypothesize therefore that RER will become progressively underestimated as closure time is prolonged. This hypothesis was addressed by a combination of experimental studies involving closed respirometry on ball pythons (Python regius) as well as mathematical models of gas exchange. We show that increased closed duration of the respirometer reduces RER by up to 13%, and these findings may explain previous reports of RER values being below 0.7. Our model reveals that the maximally possible reduction in RER is determined by the storage capacity of the body for CO2 (product of size and specific capacitance) relative to the respirometer storage capacity. Furthermore, modeling also shows that pronounced ventilatory and circulatory response to hypercapnia can alleviate the reduction in RER. PMID:26523499

  12. Production cross section of At radionuclides from 7Li+natPb and 9Be+natTl reactions

    NASA Astrophysics Data System (ADS)

    Maiti, Moumita; Lahiri, Susanta

    2011-12-01

    Earlier we reported theoretical studies on the probable production of astatine radionuclides from 6,7Li- and 9Be-induced reactions on natural lead and thallium targets, respectively. The production of astatine radionuclides were investigated experimentally with two heavy-ion-induced reactions: 9Be + natTl and 7Li + natPb. Formation cross sections of the evaporation residues, 207,208,209,210At, produced in the (HI,xn) channel, were measured by the stacked-foil technique followed by off-line γ spectrometry at low incident energies (<50 MeV). Measured excitation functions were interpreted in terms of a compound nuclear reaction mechanism using Weisskopf-Ewing and Hauser-Feshbach models. Measured cross-section values are lower than the respective theoretical predictions.

  13. Specific patterns of chromosomal abnormalities are associated with RER status in sporadic colorectal cancer.

    PubMed

    Curtis, L J; Georgiades, I B; White, S; Bird, C C; Harrison, D J; Wyllie, A H

    2000-12-01

    Current opinion of the genetic events driving colorectal tumourigenesis focuses on genomic instability. At least two apparently independent mechanisms are recognized, microsatellite instability and chromosomal instability. The genetic defects underlying each type of instability are only partially understood and controversy remains as to the role of p53 in the generation of chromosomal defects in colorectal cancer. This study sought to clarify the relationships between chromosomal abnormalities and defects of both p53 and mismatch repair. Extensive chromosomal analysis was undertaken, using flow cytometry and comparative genomic hybridization, of a series of sporadic colorectal cancers which had been grown to early passage as subcutaneous xenografts in SCID mice. Overall levels of chromosomal defects were observed to be low in RER+ cancers compared with RER- and distinctive patterns of chromosomal anomalies were found to be associated with both the RER+ and RER- phenotype. No particular level or pattern of chromosomal anomalies appeared to be associated with p53 status, supporting recent observations that abnormal p53 function is not sufficient to cause chromosomal anomalies in colorectal tumours. PMID:11113860

  14. Proton and deuteron induced reactions on natGa: Experimental and calculated excitation functions

    NASA Astrophysics Data System (ADS)

    Hermanne, A.; Adam-Rebeles, R.; Tárkányi, F.; Takács, S.; Ditrói, F.

    2015-09-01

    Cross-sections for reactions on natGa, induced by protons (up to 65 MeV) and deuterons (up to 50 MeV), producing γ-emitting radionuclides with half-lives longer than 1 h were measured in a stacked-foil irradiation using thin Ga-Ni alloy (70-30%) targets electroplated on Cu or Au backings. Excitation functions for generation of 68,69Ge, 66,67,68,72Ga and 65,69mZn on natGa are discussed, relative to the monitor reactions natAl(d,x)24,22Na, natAl(p,x)24,22Na, natCu(p,x)62Zn and natNi(p,x)57Ni. The results are compared to our earlier measurements, the scarce literature values and to the results of the code TALYS 1.6 (online database TENDL-2014).

  15. Evidence for a KATP Channel in Rough Endoplasmic Reticulum (rerKATP Channel) of Rat Hepatocytes

    PubMed Central

    Fahanik-Babaei, Javad; Saghiri, Reza; Sauve, Remy; Eliassi, Afsaneh

    2015-01-01

    We report in a previous study the presence of a large conductance K+ channel in the membrane of rough endoplasmic reticulum (RER) from rat hepatocytes incorporated into lipid bilayers. Channel activity in this case was found to decrease in presence of ATP 100 µM on the cytoplasmic side and was totally inhibited at ATP concentrations greater than 0.25 mM. Although such features would be compatible with the presence of a KATP channel in the RER, recent data obtained from a brain mitochondrial inner membrane preparation have provided evidence for a Maxi-K channel which could also be blocked by ATP within the mM concentration range. A series of channel incorporation experiments was thus undertaken to determine if the ATP-sensitive channel originally observed in the RER corresponds to KATP channel. Our results indicate that the gating and permeation properties of this channel are unaffected by the addition of 800 nM charybdotoxin and 1 µM iberiotoxin, but appeared sensitive to 10 mM TEA and 2.5 mM ATP. Furthermore, adding 100 µM glibenclamide at positive potentials and 400 µM tolbutamide at negative or positive voltages caused a strong inhibition of channel activity. Finally Western blot analyses provided evidence for Kir6.2, SUR1 and/or SUR2B, and SUR2A expression in our RER fractions. It was concluded on the basis of these observations that the channel previously characterized in RER membranes corresponds to KATP, suggesting that opening of this channel may enhance Ca2+ releases, alter the dynamics of the Ca2+ transient and prevent accumulation of Ca2+ in the ER during Ca2+ overload. PMID:25950903

  16. Global analysis of cis-natural antisense transcripts and their heat-responsive nat-siRNAs in Brassica rapa

    PubMed Central

    2013-01-01

    Background Brassica rapa includes several important leaf vegetable crops whose production is often damaged by high temperature. Cis-natural antisense transcripts (cis-NATs) and cis-NATs-derived small interfering RNAs (nat-siRNAs) play important roles in plant development and stress responses. However, genome-wide cis-NATs in B. rapa are not known. The NATs and nat-siRNAs that respond to heat stress have never been well studied in B. rapa. Here, we took advantage of RNA-seq and small RNA (sRNA) deep sequencing technology to identify cis-NATs and heat responsive nat-siRNAs in B. rapa. Results Analyses of four RNA sequencing datasets revealed 1031 cis-NATs B. rapa ssp. chinensis cv Wut and B. rapa ssp. pekinensis cv. Bre. Based on sequence homology between Arabidopsis thaliana and B. rapa, 303 conserved cis-NATs in B. rapa were found to correspond to 280 cis-NATs in Arabidopsis; the remaining 728 novel cis-NATs were identified as Brassica-specific ones. Using six sRNA libraries, 4846 nat-siRNAs derived from 150 cis-NATs were detected. Differential expression analysis revealed that nat-siRNAs derived from 12 cis-NATs were responsive to heat stress, and most of them showed strand bias. Real-time PCR indicated that most of the transcripts generating heat-responsive nat-siRNAs were upregulated under heat stress, while the transcripts from the opposite strands of the same loci were downregulated. Conclusions Our results provide the first subsets of genome-wide cis-NATs and heat-responsive nat-siRNAs in B. rapa; these sRNAs are potentially useful for the genetic improvement of heat tolerance in B. rapa and other crops. PMID:24320882

  17. The NatA Acetyltransferase Couples Sup35 Prion Complexes to the [PSI+] Phenotype

    PubMed Central

    Pezza, John A.; Langseth, Sara X.; Raupp Yamamoto, Rochele; Doris, Stephen M.; Ulin, Samuel P.; Salomon, Arthur R.

    2009-01-01

    Protein-only (prion) epigenetic elements confer unique phenotypes by adopting alternate conformations that specify new traits. Given the conformational flexibility of prion proteins, protein-only inheritance requires efficient self-replication of the underlying conformation. To explore the cellular regulation of conformational self-replication and its phenotypic effects, we analyzed genetic interactions between [PSI+], a prion form of the S. cerevisiae Sup35 protein (Sup35[PSI+]), and the three Nα-acetyltransferases, NatA, NatB, and NatC, which collectively modify ∼50% of yeast proteins. Although prion propagation proceeds normally in the absence of NatB or NatC, the [PSI+] phenotype is reversed in strains lacking NatA. Despite this change in phenotype, [PSI+] NatA mutants continue to propagate heritable Sup35[PSI+]. This uncoupling of protein state and phenotype does not arise through a decrease in the number or activity of prion templates (propagons) or through an increase in soluble Sup35. Rather, NatA null strains are specifically impaired in establishing the translation termination defect that normally accompanies Sup35 incorporation into prion complexes. The NatA effect cannot be explained by the modification of known components of the [PSI+] prion cycle including Sup35; thus, novel acetylated cellular factors must act to establish and maintain the tight link between Sup35[PSI+] complexes and their phenotypic effects. PMID:19073888

  18. N-acetyltransferase 2 (Nat2) polymorphism in the sand rat Psammomys obesus.

    PubMed

    Khelil, Malika; Djerdjouri, Bahia; Tayebi, Bouchentouf

    2010-10-01

    Human arylamine N-acetyltransferase 1 (NAT1) and its homologue in rodents (Nat2) are polymorphic xenobiotic metabolizing enzymes and also seem to play a role in endogenous metabolism. NAT1 and Nat2 polymorphism was associated to cancers under xenobiotic procarcinogens metabolism as well as under endogenous substrate metabolism. This study investigated the p-aminobenzoic acid (PABA) -Nat2 catalytic activity and its polymorphism in liver homogenates of adult sand rats Psammomys obesus Cretzschmar, 1828. These Saharian sand rats develop high incidence of spontaneous cancers under standard laboratory diet. The average value of PABA-Nat2 specific activity tested in nine sand rats was significant (2.96 ± 2.16 nmoles/min/mg). The N-acetylation exhibited a bimodal distribution. There was a significant difference (p<0.01) between PABA-Nat2 activity in the fast acetylators group (4.10 ± 1.67 nmol/min/mg) and slow acetylators group (0.7 ± 0.27 nmol/min/mg). The percentage of the fast acetylator group was 66.66%. These results support the presence of Nat2 polymorphism in the liver of the strain sand rats Psammomys obesus. This strain is useful for investigating the role of Nat2 polymorphisms in susceptibility to cancers related to arylamine carcinogen exposures as well as to endogenous substrate metabolism. PMID:20550432

  19. Standardization of NAT for Blood-Borne Pathogens

    PubMed Central

    Baylis, Sally A.; Chudy, Michael; Nübling, C. Micha

    2015-01-01

    Summary Assays based on nucleic acid amplification technology (NAT) are increasingly used for screening of blood and for diagnosis or monitoring of patients. Both regulatory requirements for blood screening and international recommendations for the treatment of patients are based on common reference materials available globally for the standardization of NAT assays. World Health Organization International Standards (WHO ISs) and International Reference Panels (WHO IRPs) are primary reference materials. The characterization and manufacture of WHO reference materials as well as their evaluation is performed on behalf of the WHO by collaborating centers; their establishment is decided upon by the WHO Expert Committee on Biological Standardization (ECBS). The potency of the first WHO IS is defined by the ‘international unit’ (IU) which should be maintained upon replacement of the IS. The IU, unlike copy number or genome equivalent, is defined by the IS with a physical existence, is available worldwide, and allows traceability and comparability of results. The anticipated use of WHO ISs is the calibration of secondary standards or the validation of essential assay features, e.g. limit of detection. PMID:26557812

  20. Neutron emission asymmetries from linearly polarized γ rays on ^natCd, ^natSn, and ^181Ta

    NASA Astrophysics Data System (ADS)

    Clarke Smith, W.; Feldman, Gerald

    2011-10-01

    Azimuthal asymmetries in neutron yields produced by bombarding targets with linearly polarized photons via (γ,n), (γ,2n), and (γ,f) reactions are being investigated as a possible means of identifying various nuclear isotopes. The High Intensity γ-ray Source (HIγS) at Duke University provides nearly monochromatic, circularly or linearly polarized γ rays with high intensity by Compton backscattering free-electron-laser photons from stored electrons. Linearly polarized γ rays produced by HIγS were incident on ^natCd, ^natSn, and ^181Ta targets at six energies Eγ between 11.0 and 15.5 MeV and emitted neutrons were detected both parallel and perpendicular to the plane of polarization by an array of 18 liquid-scintillator detectors at angles in the range θ=55^o--142^o. Detected neutrons were distinguished from Compton scattered photons by pulse-shape-discrimination and timing cuts, and their energies (En) were determined using time-of-flight information over a 0.5 m flight path. The characteristic plots of Rn, the ratio of neutron counts parallel to neutron counts perpendicular to the plane of the incident γ-ray polarization, against En were constructed for each value of Eγ and θ and then compared to those for other targets studied at HIγS, including fissile nuclei ^235U and ^238U.

  1. A Study Guide for Stephen B. Oates' "The Fires of Jubilee: Nat Turner's Fierce Rebellion"

    ERIC Educational Resources Information Center

    Briley, Ron

    2006-01-01

    This document is a study guide for Stephen B. Oates biography of Nat Turner, "The Fires of Jubilee." The book is a practical reading vehicle for introducing Nat Turner to secondary students in grades 11 and 12. Oates divides his work into four parts, which could provide the basis for four reading assignments, although the sections are not of equal…

  2. Nucleic acid testing (NAT) in high prevalence-low resource settings.

    PubMed

    El Ekiaby, Magdy; Lelie, Nico; Allain, Jean-Pierre

    2010-01-01

    Blood screening by NAT for major transfusion transmitted viral infections (TTIs) was originally intended to complement serology for detection of infected donations. Reports from developed countries showed limited marginal value to NAT blood screening in improving blood safety. Reports on NAT results from Europe indicated yield of 1:0.6 million donations for HBV, <1:M for HCV and HIV-1-related to low prevalence of TTI. In contrast, prevalence of TTI in resource-limited countries is almost always high. As a result, more incident cases can be expected among first-time blood donors. Most reports of NAT blood donation screening in these countries showed NAT confirmed yield as high as 1/2800 for HBV and 1/3100 blood donations for HCV as reported from Thailand and Egypt, respectively. The issues for low resource countries are mostly the high cost of NAT but also the requirements of staff qualification, adequate facilities, reagent procurement and maintenance of delicate equipment. Alternatives to commercial NAT are the use of combos antigen-antibody for HIV and HCV, anti-HBc for HBV and in-house NAT. Most of these alternatives have been reported but very few comparisons are available. Once yield data is available, models for estimation of feasibility and cost-effectiveness are proposed to help decision-making. PMID:20079664

  3. NAT10, a nucleolar protein, localizes to the midbody and regulates cytokinesis and acetylation of microtubules

    SciTech Connect

    Shen, Qi; Zheng, Xingzheng; McNutt, Michael A.; Guang, Lizhao; Sun, Ying; Wang, Jiaochen; Gong, Yilei; Hou, Lin; Zhang, Bo

    2009-06-10

    The midbody is a structural organelle formed in late phase mitosis which is responsible for completion of cytokinesis. Although various kinds of proteins have been found to distribute or immigrate to this organelle, their functions have still not been completely worked out. In this study, we demonstrated that NAT10 (N-acetyltransferase 10, NAT10) is not only predominantly distributed in the nucleolus in interphase, but is also concentrated in the mitotic midbody during telophase. The domain in N-terminal residues 549-834 of NAT10 specifically mediated its subcellular localization. Treatment with genotoxic agents or irradiation increased concentration of NAT10 in both the nucleolus and midbody. Moreover, DNA damage induced increase of NAT10 in the midbody apparently accompanied by in situ elevation of the level of acetylated {alpha}-tubulin, suggesting that it plays a role in maintaining or enhancing stability of {alpha}-tubulin. The depletion of NAT10 induced defects in nucleolar assembly, cytokinesis and decreased acetylated {alpha}-tubulin, leading to G2/M cell cycle arrest or delay of mitotic exit. In addition, over-expression of NAT10 was found in a variety of soft tissue sarcomas, and correlated with tumor histological grading. These results indicate that NAT10 may play an important role in cell division through facilitating reformation of the nucleolus and midbody in the late phase of cell mitosis, and stabilization of microtubules.

  4. Genetic Variation at the N-acetyltransferase (NAT) Genes in Global Populations

    EPA Science Inventory

    Functional variability at the N-acetyltransferase (NAT) genes is associated with adverse drug reactions and cancer susceptibility in humans. Previous studies of small sets of ethnic groups have indicated that the NAT genes have high levels of amino acid variation that differ in f...

  5. Antarctic NAT PSC Belt of June 2003: Observational Validation of the Mountain Wave Seeding Hypothesis

    NASA Technical Reports Server (NTRS)

    Eckermann, S. D.; Hoffmann, L.; Hoepfner, M.; Wu, D. L.; Alexander, M. J.

    2009-01-01

    Satellite observations of polar stratospheric clouds (PSCs) over Antarctica in June 2003 revealed small nitric acid trihydrate (NAT) particles forming suddenly along the vortex edge. Models suggest the trigger was mountain waves over the Antarctic Peninsula (AP) forming ice for NAT nucleation. We test this hypothesis by analyzing perturbations in stratospheric radiances from the Atmospheric Infrared Sounder (AIRS). AIRS data show mountain waves over the AP on 10-14 June, with no resolved wave activity before or after. Peak wave temperature amplitudes derived from independent 40 hPa channels all return values of 10-12 K, in agreement with values used to model this NAT event. These observations support a NAT wake from a small region of mountain wave activity over the AP as the source of this circumpolar NAT outbreak.

  6. EEG markers for characterizing anomalous activities of cerebral neurons in NAT (neuronal activity topography) method.

    PubMed

    Musha, Toshimitsu; Matsuzaki, Haruyasu; Kobayashi, Yohei; Okamoto, Yoshiwo; Tanaka, Mieko; Asada, Takashi

    2013-08-01

    A pair of markers, sNAT and vNAT, is derived from the electroencephalogram (EEG) power spectra (PS) recorded for 5 min with 21 electrodes (4-20 Hz) arranged according to the 10-20 standard. These markers form a new diagnosis tool "NAT" aiming at characterizing various brain disorders. Each signal sequence is divided into segments of 0.64 s and its discrete PS consists of eleven frequency components from 4.68 (3 × 1.56) Hz through 20.34 (13 × 1.56) Hz. PS is normalized to its mean and the bias of PS components on each frequency component across the 21 signal channels is reset to zero. The marker sNAT consists of ten frequency components on 21 channels, characterizing neuronal hyperactivity or hypoactivity as compared with NLc (normal controls). The marker vNAT consists of ten ratios between adjacent PS components denoting the over- or undersynchrony of collective neuronal activities as compared with NLc. The likelihood of a test subject to a specified brain disease is defined in terms of the normalized distance to the template NAT state of the disease in the NAT space. Separation of MCI-AD patients (developing AD in 12-18 months) from NLc is made with a false alarm rate of 15%. Locations with neuronal hypoactivity and undersynchrony of AD patients agree with locations of rCBF reduction measured by SPECT. The 2-D diagram composed of the binary likelihoods between ADc and NLc in the two representations of sNAT and vNAT enables tracing the NAT state of a test subject approaching the AD area, and the follow-up of the treatment effects. PMID:23559020

  7. Heterogeneous Formation of Polar Stratospheric Clouds- Part 1: Nucleation of Nitric Acid Trihydrate (NAT)

    NASA Technical Reports Server (NTRS)

    Hoyle, C. R.; Engel, I.; Luo, B. P.; Pitts, M. C.; Poole, L. R.; Grooss, J.-U.; Peter, T.

    2013-01-01

    Satellite-based observations during the Arctic winter of 2009/2010 provide firm evidence that, in contrast to the current understanding, the nucleation of nitric acid trihydrate (NAT) in the polar stratosphere does not only occur on preexisting ice particles. In order to explain the NAT clouds observed over the Arctic in mid-December 2009, a heterogeneous nucleation mechanism is required, occurring via immersion freezing on the surface of solid particles, likely of meteoritic origin. For the first time, a detailed microphysical modelling of this NAT formation pathway has been carried out. Heterogeneous NAT formation was calculated along more than sixty thousand trajectories, ending at Cloud Aerosol Lidar with Orthogonal Polarization (CALIOP) observation points. Comparing the optical properties of the modelled NAT with these observations enabled a thorough validation of a newly developed NAT nucleation parameterisation, which has been built into the Zurich Optical and Microphysical box Model (ZOMM). The parameterisation is based on active site theory, is simple to implement in models and provides substantial advantages over previous approaches which involved a constant rate of NAT nucleation in a given volume of air. It is shown that the new method is capable of reproducing observed polar stratospheric clouds (PSCs) very well, despite the varied conditions experienced by air parcels travelling along the different trajectories. In a companion paper, ZOMM is applied to a later period of the winter, when ice PSCs are also present, and it is shown that the observed PSCs are also represented extremely well under these conditions.

  8. Heterogeneous formation of polar stratospheric clouds - Part 1: Nucleation of nitric acid trihydrate (NAT)

    NASA Astrophysics Data System (ADS)

    Hoyle, C. R.; Engel, I.; Luo, B. P.; Pitts, M. C.; Poole, L. R.; Grooß, J.-U.; Peter, T.

    2013-09-01

    Satellite-based observations during the Arctic winter of 2009/2010 provide firm evidence that, in contrast to the current understanding, the nucleation of nitric acid trihydrate (NAT) in the polar stratosphere does not only occur on preexisting ice particles. In order to explain the NAT clouds observed over the Arctic in mid-December 2009, a heterogeneous nucleation mechanism is required, occurring via immersion freezing on the surface of solid particles, likely of meteoritic origin. For the first time, a detailed microphysical modelling of this NAT formation pathway has been carried out. Heterogeneous NAT formation was calculated along more than sixty thousand trajectories, ending at Cloud Aerosol Lidar with Orthogonal Polarization (CALIOP) observation points. Comparing the optical properties of the modelled NAT with these observations enabled a thorough validation of a newly developed NAT nucleation parameterisation, which has been built into the Zurich Optical and Microphysical box Model (ZOMM). The parameterisation is based on active site theory, is simple to implement in models and provides substantial advantages over previous approaches which involved a constant rate of NAT nucleation in a given volume of air. It is shown that the new method is capable of reproducing observed polar stratospheric clouds (PSCs) very well, despite the varied conditions experienced by air parcels travelling along the different trajectories. In a companion paper, ZOMM is applied to a later period of the winter, when ice PSCs are also present, and it is shown that the observed PSCs are also represented extremely well under these conditions.

  9. Heterogeneous formation of polar stratospheric clouds - Part 1: Nucleation of nitric acid trihydrate (NAT)

    NASA Astrophysics Data System (ADS)

    Hoyle, C. R.; Engel, I.; Luo, B. P.; Pitts, M. C.; Poole, L. R.; Grooß, J.-U.; Peter, T.

    2013-03-01

    Satellite based observations during the Arctic winter of 2009/2010 provide firm evidence that, in contrast to the current understanding, the nucleation of nitric acid trihydrate (NAT) in the polar stratosphere does not only occur on preexisting ice particles. In order to explain the NAT clouds observed over the Arctic in mid December 2009, a heterogeneous nucleation mechanism is required, occurring via immersion freezing on the surface of solid particles, likely of meteoritic origin. For the first time, a detailed microphysical modelling of this NAT formation pathway has been carried out. Heterogeneous NAT formation was calculated along more than sixty thousand trajectories, ending at Cloud Aerosol Lidar with Orthogonal Polarisation (CALIOP) observation points. Comparing the optical properties of the modelled NAT with these observations enabled the thorough validation of a newly developed NAT nucleation parameterisation, which has been built into the Zurich Optical and Microphysical box Model (ZOMM). The parameterisation is based on active site theory, is simple to implement in models and provides substantial advantages over previous approaches which involved a constant rate of NAT nucleation in a given volume of air. It is shown that the new method is capable of reproducing observed PSCs very well, despite the varied conditions experienced by air parcels travelling along the different trajectories. In a companion paper, ZOMM is applied to a later period of the winter, when ice PSCs are also present, and it is shown that the observed PSCs are also represented extremely well under these conditions.

  10. Effect of NAT2 gene polymorphism on bladder cancer risk in Slovak population.

    PubMed

    Klimčáková, Lucia; Habalová, Viera; Sivoňová, Monika; Nagy, Vincent; Šalagovič, Ján; Židzik, Jozef

    2011-02-01

    N-acetyltransferase 2 (NAT2) is phase II enzyme with major roles in catalyzing the detoxification of aromatic amines, which are known risk factors for bladder cancer, and are ubiquitously present in the environment. We assessed the association between common polymorphisms in NAT2 gene and the risk of bladder cancer in 90 Slovak patients and 274 ethnicity-matched healthy controls. Effect modifications by smoking, age and gender were also evaluated. Overall, NAT2 slow acetylation was associated with significantly increased risk of bladder cancer (OR = 1.90; 95% CI, 1.15-3.16). In stratified analyses by age and gender, the elevated risk conferred by slow acetylator genotype was evident in older individuals (OR = 3.55; 95% CI, 1.77-7.35) and males (OR = 4.65; 95% CI, 1.68-16.10), with further increasing in NAT2*5B/*6A genotype carriers. Smoking was confirmed to be important risk factor, moreover, the risk was markedly increased in smokers with NAT2 slow acetylator genotype, and NAT2*5B/*6A carriers especially. In summary, these findings are consistent with previous literature suggesting that individual susceptibility to bladder cancer may be modulated by NAT2 polymorphisms, particularly in interaction with relevant environmental exposures such as smoking. PMID:20568013

  11. Baruch Plan revisited. Master's thesis

    SciTech Connect

    Johnson, R.M.

    1993-09-15

    The primary concern in world politics is the proliferation of nuclear weapons. With the end of the Cold War, and dramatic democratic changes in Eastern Europe, many experts believe that international control of nuclear weapons is possible. This thesis examines the Baruch Plan as a model for international control of nuclear weapons. In doing so, this thesis outlines the original plan and details the initial criticism. The International Atomic Energy Agency is examined for its capability in the areas of inspections and verification. The enforcement capability of the United Nations is also discussed. This thesis concludes that the political climate is favorable for such dramatic changes however, the organizations which would be responsible for the maintenance of the system, namely the IAEA and the United Nations are not yet ready to assume their role.

  12. Challenges for Better thesis supervision

    PubMed Central

    Ghadirian, Laleh; Sayarifard, Azadeh; Majdzadeh, Reza; Rajabi, Fatemeh; Yunesian, Masoud

    2014-01-01

    Background: Conduction of thesis by the students is one of their major academic activities. Thesis quality and acquired experiences are highly dependent on the supervision. Our study is aimed at identifing the challenges in thesis supervision from both students and faculty members point of view. Methods: This study was conducted using individual in-depth interviews and Focus Group Discussions (FGD). The participants were 43 students and faculty members selected by purposive sampling. It was carried out in Tehran University of Medical Sciences in 2012. Data analysis was done concurrently with data gathering using content analysis method. Results: Our data analysis resulted in 162 codes, 17 subcategories and 4 major categories, "supervisory knowledge and skills", "atmosphere", "bylaws and regulations relating to supervision" and "monitoring and evaluation". Conclusion: This study showed that more attention and planning in needed for modifying related rules and regulations, qualitative and quantitative improvement in mentorship training, research atmosphere improvement and effective monitoring and evaluation in supervisory area. PMID:25250273

  13. Investigations of natTi(d,x)48V nuclear reactions for beam monitoring purposes

    NASA Astrophysics Data System (ADS)

    Khandaker, Mayeen Uddin; Haba, Hiromitsu; Kanaya, Jumpei; Otuka, Naohiko; Kassim, Hasan Abu; Amin, Yusoff Mohd

    2013-05-01

    We investigated the natTi(d,x)48V reaction cross-sections by using a stacked-foil activation technique in combination with HPGe γ-ray spectrometry at the AVF cyclotron facility of the RIKEN RI Beam Factory, Wako, Japan. An overall good agreement is found between the measured data and the literature ones, whereas partial agreement is obtained with the theoretical data extracted from the TENDL-2011 library provided by the TALYS model calculations. Measured cross-sections of natTi(d,x)48V reactions find significance in monitoring of deuteron beam parameters from threshold to 50 MeV. Furthermore, IAEA recommended cross-sections of natTi(d,x)48V reaction has been verified here, and found a very good agreement. Additionally, measured cross-sections of the natTi(d,x)48V reactions find significance in various practical applications including nuclear medicine.

  14. Expression of NAT2 in immune system cells and the relation of NAT2 gene polymorphisms in the anti-tuberculosis therapy in Mexican mestizo population.

    PubMed

    Salazar-González, R; Gómez, R; Romano-Moreno, S; Medellín-Garibay, S; Núñez-Ruíz, A; Magaña-Aquino, M; Milán-Segovia, R C; Portales-Pérez, D P

    2014-12-01

    Arylamine N-acetyltransferase 2 (NAT2) metabolizes isoniazid (INH) and Single Nucleotide Polymorphisms (SNP) responsible for its activity has been reported. The aim of this study in the Mexican mestizo population was to evaluate NAT2 expression at the protein level in immune cells, as well as the distribution and frequency of six NAT2 SNPs and their association with anti-TB therapy, by measuring the plasma levels of INH and Acetyl-INH (AcINH). We performed genotyping assays of NAT2 SNPs in 40 TB patients and 121 healthy volunteers by real-time PCR. A method for detecting NAT2 in immune cells using flow cytometry was developed. Plasma concentrations of INH and AcINH were obtained by HPLC in TB patients and the Metabolic Ratio (MR) was calculated. The phenotypes obtained in the healthy volunteers were as follows; 18.87 % of subjects had the rapid acetylator phenotype, 45.45 % had the intermediate phenotype and 39.66 % exhibited the slow acetylator phenotype. In the TB patient group, 35 % of patients had the rapid acetylator phenotype, 32.5 % were intermediate and 32.5 % showed the slow acetylator phenotype. A higher expression level of NAT2 in innate immune cells from TB patients compared to those from healthy volunteers was detected (P < 0.013). In TB patients the MR showed a bimodal distribution with an antimode of 0.7, which was used as a threshold value for acetylator classification. A high correspondence between the rapid and slow acetylator phenotype with MR was demonstrated. In conclusion, the 282C>T, 341T>C, 481C>T, 590G>A, 803A>G, 857G>A SNPs of NAT2 gene provides accurate for prediction of the acetylator phenotype in Mexican mestizo population. A statistical difference was found in frequency of rapid metabolizer phenotype, which was higher in TB patients. In addition, the expression of NAT2 protein in immune cells can lead to further studies related to its functional role in the innate immune response against M. tuberculosis and other xenobiotics

  15. Comparison of CYP1A2 and NAT2 Phenotypes between Black and White Smokers

    PubMed Central

    Muscat, Joshua E.; Pittman, Brian; Kleinman, Wayne; Lazarus, Philip; Stellman, Steven D.; Richie, John P.

    2008-01-01

    The lower incidence rate of transitional cell carcinoma of the urinary bladder in blacks than in whites may be due to racial differences in the catalytic activity of enzymes that metabolize carcinogenic arylamines in tobacco smoke. To examine this, we compared cytochrome P4501A2 (CYP1A2) and N-acetyltransferase-2 activities (NAT2) in black and white smokers using urinary caffeine metabolites as a probe for enzyme activity in a community-based study of 165 black and 183 white cigarette smokers. The paraxanthine (1,7-dimethylxanthine, 17X)/caffeine (trimethylxanthine, 137X) ratio or [17X + 1,7-dimethyluric acid (17U)]/137X ratio was used as an indicator of CYP1A2 activity. The 5-acetyl-amino-6-formylamino-3-methyluracil (AFMU)/1-methylxanthine (1X) ratio indicated NAT2 activity. The odds ratio for the slow NAT2 phenotype associated with black race was 0.4; 95% confidence intervals 0.2–0.7. The putative combined low risk phenotype (slow CYP1A2/rapid NAT2) was more common in blacks than in whites (25% vs. 15%, P<0.02). There were no significant racial differences in slow and rapid CYP1A2 phenotypes, and in the combined slow NAT2/rapid CYP1A2 phenotype. Age, education, cigarette smoking amount, body mass index, GSTM1 and GSTM3 genotypes were unrelated to CYP1A2 and NAT2 activity. Intake of cruciferous vegetables (primarily broccoli), red meat, carrots, grapefruit and onions predicted CYP1A2 activity either for all subjects or in race-specific analyses. Carrot and grapefruit consumption was related to NAT2 activity. Collectively, these results indicated that phenotypic differences in NAT2 alone or in combination with CYP1A2 might help explain the higher incidence rates of transitional cell bladder cancer in whites. PMID:18703023

  16. Detection of Mycobacterium tuberculosis by EasyNAT diagnostic kit in sputum samples from Tanzania.

    PubMed

    Mhimbira, Francis A; Bholla, Maira; Sasamalo, Mohamed; Mukurasi, William; Hella, Jerry J; Jugheli, Levan; Reither, Klaus

    2015-04-01

    The EasyNAT assay was evaluated for the detection of tuberculosis in sputum smears from presumptive pulmonary tuberculosis (TB) patients in an African high-TB and high-HIV setting. The sensitivity of the EasyNAT assay was 66.7%, and the specificity and positive predictive value were 100% for the culture-positive patients. The sensitivity was only 10% in the smear-negative and culture-positive patients. PMID:25609720

  17. NAT2 gene polymorphisms in three indigenous groups in the Colombian Caribbean Coast region

    PubMed Central

    Arias, Isis; Lecompte, Nelly; Visbal, Lila; Curiel, Iliana; Hernández, Enio; Garavito, Pilar

    2014-01-01

    Objective: To study the NAT2 gene polymorphisms 481T, 590A and 857A in the Chimila, Wiwa and Wayuu indigenous groups of the Colombian Caribbean to determine the frequencies of the alleles NAT2*4, NAT2*5, NAT2*6, and NAT2*7 and to determine the types of acetylators present in these populations. Methods: A total of 202 subjects were studied: 47 Chimila, 55 Wiwa, and 100 Wayuu. The polymorphisms were identified using a real-time PCR method for allelic discrimination designed using Taqman of Applied Biosystems. Results: The following alleles were found at the highest frequency in the following groups: the NAT2*4 allele (wild type) in the Wayuu group (55.3%), the NAT2*5 allele in the Wiwa group (34.5%), and the NAT2*7 allele in the Chimila group (24.2%). A higher frequency of the rapid acetylator status was found in the Wayuu group (31.3%) and Chimila group (29.5%) compared with the Wiwa group (12.7%). The intermediate acetylator status distribution was very similar in all three groups, and the frequency of the slow acetylator status was higher in the Wiwa group (32.7%) compared with the Chimila and Wayuu groups (20.5% and 21.2%, respectively). Conclusion: The results demonstrated the allelic distribution and pharmacogenetic differences of the three groups studied and revealed the most frequent acetylator status and phenotype. Because of the high prevalence of slow acetylators, a greater incidence of tuberculosis (TB) drug-induced hepatotoxicity is predicted in these populations, with a higher frequency in the Wiwa group. PMID:25767302

  18. Comparison of CYP1A2 and NAT2 phenotypes between black and white smokers.

    PubMed

    Muscat, Joshua E; Pittman, Brian; Kleinman, Wayne; Lazarus, Philip; Stellman, Steven D; Richie, John P

    2008-10-01

    The lower incidence rate of transitional cell carcinoma of the urinary bladder in blacks than in whites may be due to racial differences in the catalytic activity of enzymes that metabolize carcinogenic arylamines in tobacco smoke. To examine this, we compared cytochrome P4501A2 (CYP1A2) and N-acetyltransferase-2 activities (NAT2) in black and white smokers using urinary caffeine metabolites as a probe for enzyme activity in a community-based study of 165 black and 183 white cigarette smokers. The paraxanthine (1,7-dimethylxanthine, 17X)/caffeine (trimethylxanthine, 137X) ratio or [17X+1,7-dimethyluric acid (17U)]/137X ratio was used as an indicator of CYP1A2 activity. The 5-acetyl-amino-6-formylamino-3-methyluracil (AFMU)/1-methylxanthine (1X) ratio indicated NAT2 activity. The odds ratio for the slow NAT2 phenotype associated with black race was 0.4; 95% confidence intervals 0.2-0.7. The putative combined low risk phenotype (slow CYP1A2/rapid NAT2) was more common in blacks than in whites (25% vs. 15%, P<0.02). There were no significant racial differences in slow and rapid CYP1A2 phenotypes, and in the combined slow NAT2/rapid CYP1A2 phenotype. Age, education, cigarette smoking amount, body mass index, GSTM1 and GSTM3 genotypes were unrelated to CYP1A2 and NAT2 activity. Intake of cruciferous vegetables (primarily broccoli), red meat, carrots, grapefruit and onions predicted CYP1A2 activity either for all subjects or in race-specific analyses. Carrot and grapefruit consumption was related to NAT2 activity. Collectively, these results indicated that phenotypic differences in NAT2 alone or in combination with CYP1A2 might help explain the higher incidence rates of transitional cell bladder cancer in whites. PMID:18703023

  19. SP-100 GES/NAT radiation shielding systems design and development testing

    NASA Astrophysics Data System (ADS)

    Disney, Richard K.; Kulikowski, Henry D.; McGinnis, Cynthia A.; Reese, James C.; Thomas, Kevin; Wiltshire, Frank

    The design approach and development testing to support the design, fabrication, and assembly of three shield components for use within the vacuum vessel of the SP-100 Ground Engineering System Nuclear Assembly Test (GES/NAT) are described. The GES/NAT shields must be designed to operate in a high vacuum which simulates space operations. Shielding, thermal, and structural performance have been demonstrated by a combination of detailed analyses. Key tests to obtain critical design data and design feature performance are reviewed.

  20. Clarifying haplotype ambiguity of NAT2 in multi-national cohorts.

    PubMed

    Selinski, Silvia; Blaszkewicz, Meinolf; Agundez, Jose A G; Martinez, Carmen; Garcia-Martin, Elena; Hengstler, Jan G; Golka, Klaus

    2013-01-01

    N-Acetyltransferase 2 (NAT2) is the key enzyme in aromatic amine metabolism. NAT2 genotyping requires a subsequent determination of the haplotype pairs (formerly: alleles) to derive the acetylation status. The chromosomal phase of the single nucleotide polymorphisms (SNPs) is unclear for about 2/3 of the genotypes. We investigated NAT2 genotypes of 1,234 bladder cancer cases and 2,207 controls from Germany, Hungary, Pakistan and Venezuela plus 696 further German cancer cases. We reconstructed NAT2 haplotypes using PHASE v2.1.1. We analysed if the variability of the NAT2 haplotypes affected the haplotype reconstruction. Furthermore, we compared population haplotype frequencies in three Caucasian control cohorts (German, Hungarian, Spanish), in Pakistanis and Venezuelans and the impact on bladder cancer. We conclude that a common haplotype reconstruction is feasible, enhances precision and reliability. Hungarian controls showed the largest intra-ethnic variability whereas the Pakistanis showed a haplotype distribution typical for Caucasians. The main differences could be observed for the slow haplotypes *5B, *6A and *7B. The association of slow NAT2 genotypes with bladder cancer risk was most prominent in the Venezuelan study group. PMID:23277078

  1. Arylamine N-Acetyltransferase 2 (NAT2) Genetic Diversity and Traditional Subsistence: A Worldwide Population Survey

    PubMed Central

    Sabbagh, Audrey; Darlu, Pierre; Crouau-Roy, Brigitte; Poloni, Estella S.

    2011-01-01

    Arylamine N-acetyltransferase 2 (NAT2) is involved in human physiological responses to a variety of xenobiotic compounds, including common therapeutic drugs and exogenous chemicals present in the diet and the environment. Many questions remain about the evolutionary mechanisms that have led to the high prevalence of slow acetylators in the human species. Evidence from recent surveys of NAT2 gene variation suggests that NAT2 slow-causing variants might have become targets of positive selection as a consequence of the shift in modes of subsistence and lifestyle in human populations in the last 10,000 years. We aimed to test more extensively the hypothesis that slow acetylation prevalence in humans is related to the subsistence strategy adopted by the past populations. To this end, published frequency data on the most relevant genetic variants of NAT2 were collected from 128 population samples (14,679 individuals) representing different subsistence modes and dietary habits, allowing a thorough analysis at both a worldwide and continent scale. A significantly higher prevalence of the slow acetylation phenotype was observed in populations practicing farming (45.4%) and herding (48.2%) as compared to populations mostly relying on hunting and gathering (22.4%) (P = 0.0007). This was closely mirrored by the frequency of the slow 590A variant that was found to occur at a three-fold higher frequency in food producers (25%) as compared to hunter-gatherers (8%). These findings are consistent with the hypothesis that the Neolithic transition to subsistence economies based on agricultural and pastoral resources modified the selective regime affecting the NAT2 acetylation pathway. Furthermore, the vast amount of data collected enabled us to provide a comprehensive and up-to-date description of NAT2 worldwide genetic diversity, thus building up a useful resource of frequency data for further studies interested in epidemiological or anthropological research questions involving

  2. Master's thesis policies in nursing education.

    PubMed

    May, K M; Holzemer, W L

    1985-01-01

    A telephone survey of 25 schools of nursing with doctoral programs was conducted to inquire about their master's thesis policies. Six programs require a thesis. Sixteen programs provide both thesis and other options, described in the paper. Other policy issues are discussed which include: relation of thesis to faculty research, criteria for serving on a master's thesis committee, and requirements for doctoral admission. Responses to the survey indicate a variety of types and degrees of research experience in master's programs. PMID:2981987

  3. [The celestial phenomena in A. Dürer's engraving Melancholia I].

    PubMed

    Weitzel, Hans

    2009-01-01

    The celestial body of Dürer's engraving Melencolia I is connected with his painting of a meteor, the Raveningham-painting; it is shown that the origin of this painting owns to the impact of the meteor of Ensisheim in 1492. Until now the celestial body, the balance, and the magic square are nearly consistently interpreted as the planet Saturn, the zodiac sign Libra, and the planet Jupiter, and the melancholy woman is subject to these heavenly bodies. Consequently, neoplatonic astrology has been the main focus of the engraving; including the rainbow, the engraving has also been interpreted biblically. The present paper, however, places emphasis on problems of the geometry as the reason of melancholy. Any astronomical meaning of the configuration of the numbers of the magic square is discarded. PMID:20336927

  4. Spörer's law and relationship between the latitude and amplitude parameters of solar activity

    NASA Astrophysics Data System (ADS)

    Ivanov, V. G.; Miletsky, E. V.

    2014-12-01

    The equatorward drift of average sunspot latitudes (Spörer's law) and its relationship with other characteristics of the 11-year solar cycle are analyzed. The notion of cycle latitude phase (CLP) is introduced, which is calculated from behavior of average sunspot latitudes. The latter are shown to be expressed, with known accuracy, as a universal monotonic decreasing function of the CLP and to be independent of the cycle strength. The same applies to the latitudinal drift velocity of the sunspot generating zone. The shifts in the CLP reference times relative to the cycle minima are, on the contrary, well correlated with the amplitudes of the corresponding cycles. Solar activity in the declining phase of the solar cycle is found to be tightly related to the average sunspot latitude and CLP. The relationships found in the study can be used to reconstruct average sunspot latitudes in the pre-Greenwich epoch based on the available information on cycle amplitudes.

  5. 78 FR 4585 - Culturally Significant Objects Imported for Exhibition Determinations: “Albrecht Dürer: Master...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-22

    ... Culturally Significant Objects Imported for Exhibition Determinations: ``Albrecht D rer: Master Drawings... Delegation of Authority No. 236-3 of August 28, 2000 (and, as appropriate, Delegation of Authority No. 257 of April 15, 2003), I hereby determine that the objects to be included in the exhibition ``Albrecht D...

  6. Rer1p maintains ciliary length and signaling by regulating γ-secretase activity and Foxj1a levels

    PubMed Central

    Jurisch-Yaksi, Nathalie; Rose, Applonia J.; Lu, Huiqi; Raemaekers, Tim; Munck, Sebastian; Baatsen, Pieter; Baert, Veerle; Vermeire, Wendy; Scales, Suzie J.; Verleyen, Daphne; Vandepoel, Roel; Tylzanowski, Przemko; Yaksi, Emre; de Ravel, Thomy; Yost, H. Joseph; Froyen, Guy; Arrington, Cammon B.

    2013-01-01

    Cilia project from the surface of most vertebrate cells and are important for several physiological and developmental processes. Ciliary defects are linked to a variety of human diseases, named ciliopathies, underscoring the importance of understanding signaling pathways involved in cilia formation and maintenance. In this paper, we identified Rer1p as the first endoplasmic reticulum/cis-Golgi–localized membrane protein involved in ciliogenesis. Rer1p, a protein quality control receptor, was highly expressed in zebrafish ciliated organs and regulated ciliary structure and function. Both in zebrafish and mammalian cells, loss of Rer1p resulted in the shortening of cilium and impairment of its motile or sensory function, which was reflected by hearing, vision, and left–right asymmetry defects as well as decreased Hedgehog signaling. We further demonstrate that Rer1p depletion reduced ciliary length and function by increasing γ-secretase complex assembly and activity and, consequently, enhancing Notch signaling as well as reducing Foxj1a expression. PMID:23479743

  7. Purification, crystallization and preliminary X-ray characterization of Bacillus cereus arylamine N-acetyltransferase 3 [(BACCR)NAT3].

    PubMed

    Kubiak, Xavier; Pluvinage, Benjamin; Li de la Sierra-Gallay, Inès; Weber, Patrick; Haouz, Ahmed; Dupret, Jean-Marie; Rodrigues-Lima, Fernando

    2012-02-01

    Arylamine N-acetyltransferases (NATs) are xenobiotic metabolizing enzymes (XMEs) that catalyze the acetylation of arylamines. All functional NATs described to date possess a strictly conserved Cys-His-Asp catalytic triad. Here, the purification, crystallization and preliminary X-ray characterization of Bacillus cereus arylamine N-acetyltransferase 3 [(BACCR)NAT3], a putative NAT isoenzyme that possesses a unique catalytic triad containing a glutamate residue, is reported. The crystal diffracted to 2.42 Å resolution and belonged to the monoclinic space group C121, with unit-cell parameters a = 90.44, b = 44.52, c = 132.98 Å, β = 103.8°. PMID:22297998

  8. Rapid birth-and-death evolution of the xenobiotic metabolizing NAT gene family in vertebrates with evidence of adaptive selection

    PubMed Central

    2013-01-01

    Background The arylamine N-acetyltransferases (NATs) are a unique family of enzymes widely distributed in nature that play a crucial role in the detoxification of aromatic amine xenobiotics. Considering the temporal changes in the levels and toxicity of environmentally available chemicals, the metabolic function of NATs is likely to be under adaptive evolution to broaden or change substrate specificity over time, making NATs a promising subject for evolutionary analyses. In this study, we trace the molecular evolutionary history of the NAT gene family during the last ~450 million years of vertebrate evolution and define the likely role of gene duplication, gene conversion and positive selection in the evolutionary dynamics of this family. Results A phylogenetic analysis of 77 NAT sequences from 38 vertebrate species retrieved from public genomic databases shows that NATs are phylogenetically unstable genes, characterized by frequent gene duplications and losses even among closely related species, and that concerted evolution only played a minor role in the patterns of sequence divergence. Local signals of positive selection are detected in several lineages, probably reflecting response to changes in xenobiotic exposure. We then put a special emphasis on the study of the last ~85 million years of primate NAT evolution by determining the NAT homologous sequences in 13 additional primate species. Our phylogenetic analysis supports the view that the three human NAT genes emerged from a first duplication event in the common ancestor of Simiiformes, yielding NAT1 and an ancestral NAT gene which in turn, duplicated in the common ancestor of Catarrhini, giving rise to NAT2 and the NATP pseudogene. Our analysis suggests a main role of purifying selection in NAT1 protein evolution, whereas NAT2 was predicted to mostly evolve under positive selection to change its amino acid sequence over time. These findings are consistent with a differential role of the two human isoenzymes

  9. NATb/NAT1*4 promotes greater arylamine N-acetyltransferase 1 mediated DNA adducts and mutations than NATa/NAT1*4 following exposure to 4-aminobiphenyl

    PubMed Central

    Millner, Lori M.; Doll, Mark A.; Cai, Jian; States, J. Christopher; Hein, David W.

    2011-01-01

    N -acetyltransferase 1 (NAT1) is a phase II metabolic enzyme responsible for the biotransformation of aromatic and heterocyclic amine carcinogens such as 4-aminobiphenyl (ABP). NAT1 catalyzes N-acetylation of arylamines as well as the O-acetylation of N-hydroxylated arylamines. O-acetylation leads to the formation of electrophilic intermediates that result in DNA adducts and mutations. NAT1 is transcribed from a major promoter, NATb, and an alternative promoter, NATa, resulting in mRNAs with distinct 5′-untranslated regions (UTR). NATa mRNA is expressed primarily in the kidney, liver, trachea and lung while NATb mRNA has been detected in all tissues studied. To determine if differences in 5′-UTR have functional effect upon NAT1 activity and DNA adducts or mutations following exposure to ABP, pcDNA5/FRT plasmid constructs were prepared for transfection of full length human mRNAs including the 5′-UTR derived from NATa or NATb, the open reading frame, and 888 nucleotides of the 3′-UTR. Following stable transfection of NATb/NAT1*4 or NATa/NAT1*4 into nucleotide excision repair (NER) deficient Chinese hamster ovary cells, N-acetyltransferase activity (in vitro and in situ), mRNA, and protein expression were higher in NATb/NAT1*4 than NATa/NAT1*4 transfected cells (p<0.05). Consistent with NAT1 expression and activity, ABP-induced DNA adducts and hypoxanthine phosphoribosyl transferase mutants were significantly higher (p<0.05) in NATb/NAT1*4 than in NATa/NAT1*4 transfected cells following exposure to ABP. These differences observed between NATa and NATb suggest that the 5′-UTRs are differentially regulated. PMID:21837760

  10. Lessons from a doctoral thesis.

    PubMed

    Peiris, A N; Mueller, R A; Sheridan, D P

    1990-01-01

    The production of a doctoral thesis is a time-consuming affair that until recently was done in conjunction with professional publishing services. Advances in computer technology have made many sophisticated desktop publishing techniques available to the microcomputer user. We describe the computer method used, the problems encountered, and the solutions improvised in the production of a doctoral thesis by computer. The Apple Macintosh was selected for its ease of use and intrinsic graphics capabilities. A scanner was used to incorporate text from published papers into a word processing program. The body of the text was updated and supplemented with new sections. Scanned graphics from the published papers were less suitable for publication, and the original data were replotted and modified with a graphics-drawing program. Graphics were imported and incorporated in the text. Final hard copy was produced by a laser printer and bound with both conventional and rapid new binding techniques. Microcomputer-based desktop processing methods provide a rapid and cost-effective means of communicating the written word. We anticipate that this evolving technology will have increased use by physicians in both the private and academic sectors. PMID:2308505

  11. Pooled analysis of NAT2 genotypes as risk factors for asbestos-related malignant mesothelioma.

    PubMed

    Betti, Marta; Neri, Monica; Ferrante, Daniela; Landi, Stefano; Biava, Alessandra; Gemignani, Federica; Bertolotti, Marinella; Mirabelli, Dario; Padoan, Marina; Ugolini, Donatella; Botta, Mario; Bonassi, Stefano; Magnani, Corrado; Dianzani, Irma

    2009-05-01

    Malignant mesothelioma (MM) is a rare and aggressive tumor of the pleura. The most important causal factor for the development of MM is occupational exposure to asbestos. Different lines of evidence suggest a role of genetic background in MM development, as for other cancers. Two published studies observed an association between MM and N-acetyl-transferase 2 (NAT2) polymorphisms. First, a Finnish study observed that the NAT2 slow acetylator phenotype was associated with an increased risk of MM. Conversely, MM risk was higher in Italian subjects carrying the NAT2 fast acetylator genotypes. The conflicting results obtained in Finland and Italy could be ascribed to random chance, considering the small panel of patients and controls in the two studies, but also ethnic or other differences may have been important. To ascertain the role of NAT2 genotype, we performed a study on 252 MM patients and 262 controls recruited in two Northern Italy areas that were characterized by high asbestos exposure, due to intense industrial activities (an asbestos cement factory in Casale Monferrato, mainly shipyards and refineries in Liguria). Unconditional multivariate logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). NAT2 fast acetylator genotypes showed an increased OR, although not statistically significant, both in asbestos-exposed subjects (OR=1.47; 95% CI=0.96-2.26) and in the entire population (OR=1.38; 95% CI=0.93-2.04). These results suggest that NAT2 polymorphisms do not exert a strong effect on individual susceptibility to MM. PMID:18838334

  12. SP-100 GES/NAT radiation shielding systems design and development testing

    SciTech Connect

    Disney, R.K.; Kulikowski, H.D.; McGinnis, C.A.; Reese, J.C.; Thomas, K. ); Wiltshire, F. )

    1991-01-10

    Advanced Energy Systems (AES) of Westinghouse Electric Corporation is under subcontract to the General Electric Company to supply nuclear radiation shielding components for the SP-100 Ground Engineering System (GES) Nuclear Assembly Test to be conducted at Westinghouse Hanford Company at Richland, Washington. The radiation shielding components are integral to the Nuclear Assembly Test (NAT) assembly and include prototypic and non-prototypic radiation shielding components which provide prototypic test conditions for the SP-100 reactor subsystem and reactor control subsystem components during the GES/NAT operations. W-AES is designing three radiation shield components for the NAT assembly; a prototypic Generic Flight System (GFS) shield, the Lower Internal Facility Shield (LIFS), and the Upper Internal Facility Shield (UIFS). This paper describes the design approach and development testing to support the design, fabrication, and assembly of these three shield components for use within the vacuum vessel of the GES/NAT. The GES/NAT shields must be designed to operate in a high vacuum which simulates space operations. The GFS shield and LIFS must provide prototypic radiation/thermal environments and mechanical interfaces for reactor system components. The NAT shields, in combination with the test facility shielding, must provide adequate radiation attenuation for overall test operations. Special design considerations account for the ground test facility effects on the prototypic GFS shield. Validation of the GFS shield design and performance will be based on detailed Monte Carlo analyses and developmental testing of design features. Full scale prototype testing of the shield subsystems is not planned.

  13. NAT2 polymorphisms combining with smoking associated with breast cancer susceptibility: a meta-analysis.

    PubMed

    Zhang, Jian; Qiu, Li-Xin; Wang, Zhong-Hua; Wang, Jia-Lei; He, Shuang-Shuang; Hu, Xi-Chun

    2010-10-01

    To derive a more precise estimation of the relationship between the slow or rapid acetylation resulting from N-acetyltransferase 2 (NAT2) polymorphisms and breast cancer risk, a meta-analysis was performed. PubMed, Medline, Embase, and Web of Science were searched. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess strength of association. The pooled ORs were performed for slow versus rapid acetylation genotypes. A total of 26 studies including 9,215 cases and 10,443 controls were included in the meta-analysis. Overall, no significantly elevated breast cancer risk was associated with NAT2 slow genotypes when all studies were pooled into the meta-analysis (OR = 1.026, 95% CI = 0.968-1.087). In the subgroup analysis by ethnicity, increased risks were not found for either Caucasians (OR = 1.001, 95% CI = 0.938-1.068) or Asians (OR = 1.155, 95% CI = 0.886-1.506). When stratified by study design, statistically significantly elevated risk associated with NAT2 slow genotypes was only found among hospital-based studies (OR = 1.178, 95% CI = 1.037-1.339). In the subgroup analysis by menopausal status, no statistically significantly increased risk was found in either premenopausal (OR = 1.053, 95% CI = 0.886-1.252) or postmenopausal women (OR = 0.965, 95% CI = 0.844-1.104). When stratified by cumulative smoking exposure, in the subgroup of smokers with high pack-years, NAT2 slow genotypes were significantly associated with increased breast cancer risk (OR = 1.400, 95% CI = 1.099-1.784). In conclusion, this meta-analysis suggested that there is overall lack of association between NAT2 genotypes and breast cancer risk, however, NAT2 polymorphisms when combining with heavy smoking history may contribute to breast cancer susceptibility. PMID:20180012

  14. Red meat intake, NAT2, and risk of colorectal cancer: A pooled analysis of 11 studies

    PubMed Central

    Ananthakrishnan, Ashwin N.; Du, Mengmeng; Berndt, Sonja I.; Brenner, Hermann; Caan, Bette J.; Casey, Graham; Chang-Claude, Jenny; Duggan, David; Fuchs, Charles S.; Gallinger, Steven; Giovannucci, Edward L.; Harrison, Tabitha A.; Hayes, Richard B.; Hoffmeister, Michael; Hopper, John L.; Hou, Lifang; Hsu, Li; Jenkins, Mark A.; Kraft, Peter; Ma, Jing; Nan, Hongmei; Newcomb, Polly A.; Ogino, Shuji; Potter, John D.; Seminara, Daniela; Slattery, Martha L.; Thornquist, Mark; White, Emily; Wu, Kana; Peters, Ulrike; Chan, Andrew T.

    2014-01-01

    Background Red meat intake has been associated with risk of colorectal cancer (CRC), potentially mediated through heterocyclic amines. The metabolic efficiency of N-acetyltransferase 2 (NAT2) required for the metabolic activation of such amines is influenced by genetic variation. The interaction between red meat intake, NAT2 genotype, and CRC has been inconsistently reported. Methods We used pooled individual-level data from the Colon Cancer Family Registry (CCFR) and the Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO). Red meat intake was collected by each study. We inferred NAT2 phenotype based on polymorphism at rs1495741, highly predictive of enzyme activity. Interaction was assessed using multiplicative interaction terms in multivariate-adjusted models. Results From 11 studies, 8,290 CRC cases and 9,115 controls were included. The highest quartile of red meat intake was associated with increased risk of CRC compared to the lowest quartile (OR 1.41, 95%CI 1.29 – 1.55). However, a significant association was observed only for studies with retrospective diet data, not for studies with diet prospectively assessed before cancer diagnosis. Combining all studies, high red meat intake was similarly associated with CRC in those with a rapid/intermediate NAT2 genotype (OR 1.38, 95%CI 1.20 – 1.59) as with a slow genotype (OR 1.43, 95%CI 1.28 – 1.61) (p- interaction=0.9). Conclusion We found that high red meat intake was associated with increased risk of CRC only from retrospective case-control studies and not modified by NAT2 enzyme activity. Impact Our results suggest no interaction between NAT2 genotype and red-meat intake in mediating risk of CRC. PMID:25342387

  15. SP-100 GES/NAT radiation shielding systems design and development testing

    NASA Astrophysics Data System (ADS)

    Disney, Richard K.; Kulikowski, Henry D.; McGinnis, Cynthia A.; Reese, James C.; Thomas, Kevin; Wiltshire, Frank

    1991-01-01

    Advanced Energy Systems (AES) of Westinghouse Electric Corporation is under subcontract to the General Electric Company to supply nuclear radiation shielding components for the SP-100 Ground Engineering System (GES) Nuclear Assembly Test to be conducted at Westinghouse Hanford Company at Richland, Washington. The radiation shielding components are integral to the Nuclear Assembly Test (NAT) assembly and include prototypic and non-prototypic radiation shielding components which provide prototypic test conditions for the SP-100 reactor subsystem and reactor control subsystem components during the GES/NAT operations. W-AES is designing three radiation shield components for the NAT assembly; a prototypic Generic Flight System (GFS) shield, the Lower Internal Facility Shield (LIFS), and the Upper Internal Facility Shield (UIFS). This paper describes the design approach and development testing to support the design, fabrication, and assembly of these three shield components for use within the vacuum vessel of the GES/NAT. The GES/NAT shields must be designed to operate in a high vacuum which simulates space operations. The GFS shield and LIFS must provide prototypic radiation/thermal environments and mechanical interfaces for reactor system components. The NAT shields, in combination with the test facility shielding, must provide adequate radiation attenuation for overall test operations. Special design considerations account for the ground test facility effects on the prototypic GFS shield. Validation of the GFS shield design and performance will be based on detailed Monte Carlo analyses and developmental testing of design features. Full scale prototype testing of the shield subsystems is not planned.

  16. Induction of neuronal axon outgrowth by Shati/Nat8l by energy metabolism in mice cultured neurons.

    PubMed

    Sumi, Kazuyuki; Uno, Kyosuke; Matsumura, Shohei; Miyamoto, Yoshiaki; Furukawa-Hibi, Yoko; Muramatsu, Shin-Ichi; Nabeshima, Toshitaka; Nitta, Atsumi

    2015-09-01

    A novel N-acetyltransferase, Shati/Nat8l, was identified in the nucleus accumbens of mice repeatedly treated with methamphetamine (METH). Shati/Nat8l has been reported to inhibit the pharmacological action induced by METH. Shati/Nat8l produces N-acetylaspartate from aspartate and acetyl-CoA. Previously, we reported that overexpression of Shati/Nat8l in nucleus accumbens attenuates the response to METH by N-acetylaspartylglutamate (which is derived from N-acetylaspartate)-mGluR3 signaling in the mice brain. In the present study, to clarify the type of cells that produce Shati/Nat8l, we carried out in-situ hybridization for the detection of Shati/Nat8l mRNA along with immunohistochemical studies using serial sections of mice brain. Shati/Nat8l mRNA was detected in neuronal cells, but not in astrocytes or microglia cells. Next, we investigated the function of Shati/Nat8l in the neuronal cells in mice brain; then, we used an adeno-associated virus vector containing Shati/Nat8l for transfection and overexpression of Shati/Nat8l protein into the primary cultured neurons to investigate the contribution toward the neuronal activity of Shati/Nat8l. Overexpression of Shati/Nat8l in the mice primary cultured neurons induced axonal growth, but not dendrite elongation at day 1.5 (DIV). This finding indicated that Shati/Nat8l contributes toward neuronal development. LY341495, a selective group II mGluRs antagonist, did not abolish this axonal growth, and N-acetylaspartylglutamate itself did not abolish axon outgrowth in the same cultured system. The cultured neurons overexpressing Shati/Nat8l contained high ATP, suggesting that axon outgrowth is dependent on energy metabolism. This study shows that Shati/Nat8l in the neuron may induce axon outgrowth by ATP synthesis and not through mGluR3 signaling. PMID:26164607

  17. Suitability of the HAM-Nat test and TMS module "basic medical-scientific understanding" for medical school selection

    PubMed Central

    Hissbach, Johanna; Feddersen, Lena; Sehner, Susanne; Hampe, Wolfgang

    2012-01-01

    Aims: Tests with natural-scientific content are predictive of the success in the first semesters of medical studies. Some universities in the German speaking countries use the ‘Test for medical studies’ (TMS) for student selection. One of its test modules, namely “medical and scientific comprehension”, measures the ability for deductive reasoning. In contrast, the Hamburg Assessment Test for Medicine, Natural Sciences (HAM-Nat) evaluates knowledge in natural sciences. In this study the predictive power of the HAM-Nat test will be compared to that of the NatDenk test, which is similar to the TMS module “medical and scientific comprehension” in content and structure. Methods: 162 medical school beginners volunteered to complete either the HAM-Nat (N=77) or the NatDenk test (N=85) in 2007. Until spring 2011, 84.2% of these successfully completed the first part of the medical state examination in Hamburg. Via different logistic regression models we tested the predictive power of high school grade point average (GPA or “Abiturnote”) and the test results (HAM-Nat and NatDenk) with regard to the study success criterion “first part of the medical state examination passed successfully up to the end of the 7th semester” (Success7Sem). The Odds Ratios (OR) for study success are reported. Results: For both test groups a significant correlation existed between test results and study success (HAM-Nat: OR=2.07; NatDenk: OR=2.58). If both admission criteria are estimated in one model, the main effects (GPA: OR=2.45; test: OR=2.32) and their interaction effect (OR=1.80) are significant in the HAM-Nat test group, whereas in the NatDenk test group only the test result (OR=2.21) significantly contributes to the variance explained. Conclusions: On their own both HAM-Nat and NatDenk have predictive power for study success, but only the HAM-Nat explains additional variance if combined with GPA. The selection according to HAM-Nat and GPA has under the current

  18. NAT8L (N-Acetyltransferase 8-Like) Accelerates Lipid Turnover and Increases Energy Expenditure in Brown Adipocytes*

    PubMed Central

    Pessentheiner, Ariane R.; Pelzmann, Helmut J.; Walenta, Evelyn; Schweiger, Martina; Groschner, Lukas N.; Graier, Wolfgang F.; Kolb, Dagmar; Uno, Kyosuke; Miyazaki, Toh; Nitta, Atsumi; Rieder, Dietmar; Prokesch, Andreas; Bogner-Strauss, Juliane G.

    2013-01-01

    NAT8L (N-acetyltransferase 8-like) catalyzes the formation of N-acetylaspartate (NAA) from acetyl-CoA and aspartate. In the brain, NAA delivers the acetate moiety for synthesis of acetyl-CoA that is further used for fatty acid generation. However, its function in other tissues remained elusive. Here, we show for the first time that Nat8l is highly expressed in adipose tissues and murine and human adipogenic cell lines and is localized in the mitochondria of brown adipocytes. Stable overexpression of Nat8l in immortalized brown adipogenic cells strongly increases glucose incorporation into neutral lipids, accompanied by increased lipolysis, indicating an accelerated lipid turnover. Additionally, mitochondrial mass and number as well as oxygen consumption are elevated upon Nat8l overexpression. Concordantly, expression levels of brown marker genes, such as Prdm16, Cidea, Pgc1α, Pparα, and particularly UCP1, are markedly elevated in these cells. Treatment with a PPARα antagonist indicates that the increase in UCP1 expression and oxygen consumption is PPARα-dependent. Nat8l knockdown in brown adipocytes has no impact on cellular triglyceride content, lipogenesis, or oxygen consumption, but lipolysis and brown marker gene expression are increased; the latter is also observed in BAT of Nat8l-KO mice. Interestingly, the expression of ATP-citrate lyase is increased in Nat8l-silenced adipocytes and BAT of Nat8l-KO mice, indicating a compensatory mechanism to sustain the acetyl-CoA pool once Nat8l levels are reduced. Taken together, our data show that Nat8l impacts on the brown adipogenic phenotype and suggests the existence of the NAT8L-driven NAA metabolism as a novel pathway to provide cytosolic acetyl-CoA for lipid synthesis in adipocytes. PMID:24155240

  19. Knockdown of a nutrient amino acid transporter gene LdNAT1 reduces free neutral amino acid contents and impairs Leptinotarsa decemlineata pupation

    PubMed Central

    Fu, Kai-Yun; Guo, Wen-Chao; Ahmat, Tursun; Li, Guo-Qing

    2015-01-01

    A Leptinotarsa decemlineata SLC6 NAT gene (LdNAT1) was cloned. LdNAT1 was highly expressed in the larval alimentary canal especially midgut. LdNAT1 mRNA levels were high right after the molt and low just before the molt. JH and a JH analog pyriproxyfen activated LdNAT1 expression. RNAi of an allatostatin gene LdAS-C increased JH and upregulated LdNAT1 transcription. Conversely, silencing of a JH biosynthesis gene LdJHAMT decreased JH and reduced LdNAT1 expression. Moreover, 20E and an ecdysteroid agonist halofenozide repressed LdNAT1 expression, whereas a decrease in 20E by RNAi of an ecdysteroidogenesis gene LdSHD and disruption of 20E signaling by knockdown of LdE75 and LdFTZ-F1 activated LdNAT1 expression. Thus, LdNAT1 responded to both 20E and JH. Moreover, knockdown of LdNAT1 reduced the contents of cysteine, histidine, isoleucine, leucine, methionine, phenylalanine and serine in the larval bodies and increased the contents of these amino acids in the larval feces. Furthermore, RNAi of LdNAT1 inhibited insulin/target of rapamycin pathway, lowered 20E and JH titers, reduced 20E and JH signaling, retarded larval growth and impaired pupation. These data showed that LdNAT1 was involved in the absorption of several neutral amino acids critical for larval growth and metamorphosis. PMID:26657797

  20. Proper regulation of a sperm-specific cis-nat-siRNA is essential for double fertilization in Arabidopsis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    /Cis/-nat-siRNAs are a recently characterized class of small regulatory RNAs that are widespread in eukaryotes. Despite their abundance the importance of their regulatory activity is largely unknown. The only functional role for eukaryotic /cis/-nat-siRNAs that has been described to date is in envir...

  1. An Experiment in Thesis: A Universal Approach

    ERIC Educational Resources Information Center

    Noteboom, Jay

    1975-01-01

    This experimental lesson gives students practice at writing a one sentence thesis statement. Each student chooses a song or short poem for which he must provide a thesis statement. The exercise not only teaches development of the thesis statement, but also stimulates student interest and discussion. Examples are presented. (AH)

  2. Excitation functions of alpha particle induced reactions on natTi up to 40 MeV

    NASA Astrophysics Data System (ADS)

    Uddin, M. S.; Scholten, B.

    2016-08-01

    Excitation functions of the reactions natTi(α,x)48Cr, natTi(α,x)48V and natTi(α,x)46,48Sc were determined by the stacked-foil activation technique up to 40 MeV. The radioactivities produced in the natTi target were measured by γ-ray spectrometry using HPGe detector. The reaction natTi(α,x)51Cr was used to determine the beam parameters. New experimental values for the above reactions have been obtained. An intercomparison of our data with the available literature values has been done. The cross section results obtained in this work could be useful in defining new monitor reactions, radiation safety and isotope production.

  3. The Pharmacogenetics of NAT2 Enzyme Maturation in Perinatally HIV Exposed Infants Receiving Isoniazid

    PubMed Central

    Zhu, Rui; Kiser, Jennifer J.; Seifart, Heiner I.; Werely, Cedric J.; Mitchell, Charles D.; D’Argenio, David Z.; Fletcher, Courtney V.

    2011-01-01

    The roles of the NAT2 genotype and enzyme maturation on isoniazid pharmacokinetics were investigated in South African infants with perinatal HIV exposure enrolled in a randomized, double-blind, controlled trial of isoniazid for prevention of tuberculosis disease and latent infection. Plasma concentration-time measurements of isoniazid from 151 infants (starting at 3-4 months of age) receiving isoniazid 10 to 20 mg/kg/d orally during the course of the 24-month study were incorporated in a population analysis along with NAT2 genotype, body weight, age, and sex. The results showed a different NAT2 enzyme maturation profile for each of the 3 acetylation groups, with the 70-kg body weight–normalized typical apparent clearance for the fast and intermediate acetylators increasing from 14.25 L/h and 10.88 L/h at 3 months of age to 22.84 L/h and 15.58 L/h at 24 months of age, respectively, with no significant change in the apparent clearance of the slow group during this period. A hypothesis is proposed to explain the genotype-dependent enzyme maturation processes for the NAT2 enzyme. PMID:21558457

  4. AmeriFlux US-SP1 Slashpine-Austin Cary- 65yrs nat regen

    SciTech Connect

    Martin, Tim

    2016-01-01

    This is the AmeriFlux version of the carbon flux data for the site US-SP1 Slashpine-Austin Cary- 65yrs nat regen. Site Description - The ACMF site is a 67 hectare naturally regenerated Pinus palustris and Pinus elliottii mixed stand.

  5. National Carbon Sequestration Database and Geographic Information System (NatCarb)

    SciTech Connect

    Kenneth Nelson; Timothy Carr

    2009-03-31

    This annual and final report describes the results of the multi-year project entitled 'NATional CARBon Sequestration Database and Geographic Information System (NatCarb)' (http://www.natcarb.org). The original project assembled a consortium of five states (Indiana, Illinois, Kansas, Kentucky and Ohio) in the midcontinent of the United States (MIDCARB) to construct an online distributed Relational Database Management System (RDBMS) and Geographic Information System (GIS) covering aspects of carbon dioxide (CO{sub 2}) geologic sequestration. The NatCarb system built on the technology developed in the initial MIDCARB effort. The NatCarb project linked the GIS information of the Regional Carbon Sequestration Partnerships (RCSPs) into a coordinated regional database system consisting of datasets useful to industry, regulators and the public. The project includes access to national databases and GIS layers maintained by the NatCarb group (e.g., brine geochemistry) and publicly accessible servers (e.g., USGS, and Geography Network) into a single system where data are maintained and enhanced at the local level, but are accessed and assembled through a single Web portal to facilitate query, assembly, analysis and display. This project improves the flow of data across servers and increases the amount and quality of available digital data. The purpose of NatCarb is to provide a national view of the carbon capture and storage potential in the U.S. and Canada. The digital spatial database allows users to estimate the amount of CO{sub 2} emitted by sources (such as power plants, refineries and other fossil-fuel-consuming industries) in relation to geologic formations that can provide safe, secure storage sites over long periods of time. The NatCarb project worked to provide all stakeholders with improved online tools for the display and analysis of CO{sub 2} carbon capture and storage data through a single website portal (http://www.natcarb.org/). While the external project is

  6. Digitization of sunspot drawings by Spörer made in 1861-1894

    NASA Astrophysics Data System (ADS)

    Diercke, A.; Arlt, R.; Denker, C.

    2015-01-01

    Most of our knowledge about the Sun's activity cycle arises from sunspot observations over the last centuries since telescopes have been used for astronomy. The German astronomer Gustav Spörer observed almost daily the Sun from 1861 until the beginning of 1894 and assembled a 33-year collection of sunspot data covering a total of 445 solar rotation periods. These sunspot drawings were carefully placed on an equidistant grid of heliographic longitude and latitude for each rotation period, which were then copied to copper plates for a lithographic reproduction of the drawings in astronomical journals. In this article, we describe in detail the process of capturing these data as digital images, correcting for various effects of the aging print materials, and preparing the data for contemporary scientific analysis based on advanced image processing techniques. With the processed data we create a butterfly diagram aggregating sunspot areas, and we present methods to measure the size of sunspots (umbra and penumbra) and to determine tilt angles of active regions. A probability density function of the sunspot area is computed, which conforms to contemporary data after rescaling.

  7. Effects of Dietary Factors and the NAT2 Acetylator Status on Gastric Cancer in Koreans

    PubMed Central

    Zhang, Yan Wei; Eom, Sang-Yong; Kim, Yong-Dae; Song, Young-Jin; Yun, Hyo-Yung; Park, Joo-Seung; Youn, Sei-Jin; Kim, Byung Sik; Kim, Heon; Hein, David W.

    2009-01-01

    Environmental dietary carcinogens and genetic polymorphisms in metabolic enzymes have been reported to be risk factors for gastric cancer. This study was undertaken to investigate the effects of the diet, the N-acetyltransferase (NAT) 2 acetylation status, and their interaction on gastric cancer risk. The study population consisted of 471 gastric cancer patients and 471 age- and sex-matched control subjects. NAT2 genotypes were identified using single-nucleotide primer extension reaction methods. Thirty-one alleles related to 12 polymorphism sites were assayed in this study. Significantly increased odds ratios were observed in former smokers (OR = 2.39, 95%CI = 1.57-3.62), heavy drinkers (OR = 1.28, 95%CI = 1.06-1.55), and individuals who eat well-done meat (OR = 1.24, 95%CI = 1.09-1.41). The odds ratios (95% CI) for high intake of kimchi, stews, and soybean paste were 3.27 (2.44-4.37), 1.96 (1.50-2.58), and 1.63 (1.24-2.14), respectively. The NAT2 genotype alone was not associated with gastric cancer risk. A significant gene-environment interaction was observed between environmental carcinogens and NAT2 genotypes. The odds ratios for kimchi, stews, and soybean paste were higher in slow/intermediate acetylators than in rapid acetylators. The odds ratios for slow/intermediate acetylators were 2.28 (95% CI: 1.29-4.04) for light smokers and 3.42 (95% CI: 2.06-5.68) for well-done meat intake. The NAT2 acetylator genotype may be an important modifier of the effects of environmental factors on gastric cancer risk. PMID:19350634

  8. Gender and functional CYP2C and NAT2 polymorphisms determine the metabolic profile of metamizole.

    PubMed

    Martínez, Carmen; Andreu, Inmaculada; Amo, Gemma; Miranda, Miguel A; Esguevillas, Gara; Torres, María José; Blanca-López, Natalia; Blanca, Miguel; García-Martín, Elena; Agúndez, José A G

    2014-12-01

    Metamizole is a pain-killer drug that has been banned in some countries because of its toxicity, but it is still used in many countries due to its effective analgesic and antispasmodic properties. Although large variability in the biodisposition and adverse effects of metamizole are known, factors underlying this variability are poorly understood. We analyzed the urinary recovery of metabolites, as well as the association of these profiles with genetic and non-genetic factors, in a group of 362 healthy individuals. Gender and functional polymorphisms are strongly related to metabolic profiles. N-demethylation of the active metabolite MAA is diminished in carriers of the CYP2C19*2 allele and in NAT2-slow acetylators. Acetylation of the secondary metabolite AA is decreased in men, in drinkers and in NAT2-slow acetylators with a differential effect of NAT2*5 and NAT2*6 alleles. The formylation of MAA is diminished in older subjects and in carriers of defect CYP2C9 and CYP2C19 alleles. Two novel arachidonoyl metabolites were identified for the first time in humans. Women and NAT2-slow acetylators show higher concentrations, whereas the presence of the rapid CYP2C19*17 allele is associated with lower concentrations of these metabolites. All genetic associations show a gene-dose effect. We identified for the first time genetic and non-genetic factors related to the oxidative metabolism of analgesic drug metamizole, as well as new active metabolites in humans. The phenotypic and genetic factors identified in this study have a potential application as biomarkers of metamizole biotransformation and toxicity. PMID:25241292

  9. Interactions of Cigarette Smoking with NAT2 Polymorphisms Impact Rheumatoid Arthritis Risk in African Americans

    PubMed Central

    Mikuls, Ted R.; LeVan, Tricia; Gould, Karen A.; Yu, Fang; Thiele, Geoffrey M.; Bynote, Kimberly K.; Conn, Doyt; Jonas, Beth L.; Callahan, Leigh F.; Smith, Edwin; Brasington, Richard; Moreland, Larry W.; Reynolds, Richard; Gaffo, Angelo; Bridges, S. Louis

    2011-01-01

    Objective To examine whether polymorphisms in genes coding for drug metabolizing enzymes (DMEs) impact rheumatoid arthritis (RA) risk due to cigarette smoking in African Americans. Methods Smoking status was evaluated in African American RA cases and non-RA controls categorized as heavy (≥ 10 pack-years) vs. other. Individuals were genotyped for a homozygous deletion polymorphism in glutathione S-transferase Mu-1 (GSTM1-null) in addition to tagging single nucleotide polymorphisms (SNPs) in N-acetyltransferase (NAT)1, NAT2, and epoxide hydrolase (EPXH1). Associations of genotypes with RA were examined using logistic regression and gene-smoking interactions were assessed. Results There were no significant associations of any DME genotype with RA. After adjustment for multiple comparisons, there were significant additive interactions between heavy smoking and NAT2 SNPs rs9987109 (Padd = 0.000003) and rs1208 (Padd = 0.00001); attributable proportions (APs) due to interaction ranged from 0.61 to 0.67. None of the multiplicative gene-smoking interactions examined remained significant after adjustment for multiple testing in overall disease risk. There was no evidence of significant gene-smoking interactions in analyses of GSTM1-null, NAT1, or EPXH1. DME gene-smoking interactions were similar when cases were limited to anti-citrullinated protein antibody (ACPA) positive individuals. Conclusion Among African Americans, RA risk imposed by heavy smoking appears to be mediated in part by genetic variation in NAT2. While further studies are needed to elucidate mechanisms underpinning these interactions, these SNPs appear to identify African American smokers at a much higher risk for RA with relative risks that are at least two-fold higher compared to non-smokers lacking these risk alleles. PMID:21989592

  10. N-Acetyltransferase 1 (NAT1) Genotype: A Risk Factor for Urinary Bladder Cancer in a Lebanese Population.

    PubMed

    Yassine, Ibrahim A; Kobeissi, Loulou; Jabbour, Michel E; Dhaini, Hassan R

    2012-01-01

    In Lebanon, bladder cancer is the second most incident cancer among men. This study investigates a possible association between N-acetyltransferase 1 (NAT1) genotype, a drug-metabolizing enzyme coding gene, and bladder cancer in Lebanese men. A case-control study (54 cases and 105 hospital-based controls) was conducted in two major hospitals in Beirut. Cases were randomly selected from patients diagnosed in the period of 2002-2008. Controls were conveniently identified and selected from the same settings. Data was collected using interview questionnaire and blood analysis. NAT1 genotypes were determined by PCR-RFLP. Statistical analysis revolved around univariate, bivariate, and multivariate logistic regression models, along with checks for effect modification. Results showed NAT1(∗)14A allele, smoking, occupational exposure to combustion fumes, and prostate-related symptoms, to be risk factors for bladder cancer. The odds of carrying at least one NAT1(∗)14A allele are 7 times higher in cases compared to controls (OR = 7.86, 95% CI: 1.53-40.39). A gene-environment interaction was identified for NAT1(∗)14A allele with occupational exposure to combustion fumes. Among carriers of NAT1(∗)14A allele, the odds of bladder cancer dropped to 2.03 from 3.72. Our study suggests NAT1(∗)14A allele as a possible biomarker for bladder cancer. Further research is recommended to confirm this association. PMID:22956951

  11. N-Acetyltransferase 1 (NAT1) Genotype: A Risk Factor for Urinary Bladder Cancer in a Lebanese Population

    PubMed Central

    Yassine, Ibrahim A.; Kobeissi, Loulou; Jabbour, Michel E.; Dhaini, Hassan R.

    2012-01-01

    In Lebanon, bladder cancer is the second most incident cancer among men. This study investigates a possible association between N-acetyltransferase 1 (NAT1) genotype, a drug-metabolizing enzyme coding gene, and bladder cancer in Lebanese men. A case-control study (54 cases and 105 hospital-based controls) was conducted in two major hospitals in Beirut. Cases were randomly selected from patients diagnosed in the period of 2002–2008. Controls were conveniently identified and selected from the same settings. Data was collected using interview questionnaire and blood analysis. NAT1 genotypes were determined by PCR-RFLP. Statistical analysis revolved around univariate, bivariate, and multivariate logistic regression models, along with checks for effect modification. Results showed NAT1∗14A allele, smoking, occupational exposure to combustion fumes, and prostate-related symptoms, to be risk factors for bladder cancer. The odds of carrying at least one NAT1∗14A allele are 7 times higher in cases compared to controls (OR = 7.86, 95% CI: 1.53–40.39). A gene-environment interaction was identified for NAT1∗14A allele with occupational exposure to combustion fumes. Among carriers of NAT1∗14A allele, the odds of bladder cancer dropped to 2.03 from 3.72. Our study suggests NAT1∗14A allele as a possible biomarker for bladder cancer. Further research is recommended to confirm this association. PMID:22956951

  12. NAT10 regulates p53 activation through acetylating p53 at K120 and ubiquitinating Mdm2.

    PubMed

    Liu, Xiaofeng; Tan, Yuqin; Zhang, Chunfeng; Zhang, Ying; Zhang, Liangliang; Ren, Pengwei; Deng, Hongkui; Luo, Jianyuan; Ke, Yang; Du, Xiaojuan

    2016-03-01

    As a genome guardian, p53 maintains genome stability by arresting cells for damage repair or inducing cell apoptosis to eliminate the damaged cells in stress response. Several nucleolar proteins stabilize p53 by interfering Mdm2-p53 interaction upon cellular stress, while other mechanisms by which nucleolar proteins activate p53 remain to be determined. Here, we identify NAT10 as a novel regulator for p53 activation. NAT10 acetylates p53 at K120 and stabilizes p53 by counteracting Mdm2 action. In addition, NAT10 promotes Mdm2 degradation with its intrinsic E3 ligase activity. After DNA damage, NAT10 translocates to nucleoplasm and activates p53-mediated cell cycle control and apoptosis. Finally, NAT10 inhibits cell proliferation and expression of NAT10 decreases in human colorectal carcinomas. Thus, our data demonstrate that NAT10 plays a critical role in p53 activation via acetylating p53 and counteracting Mdm2 action, providing a novel pathway by which nucleolar protein activates p53 as a cellular stress sensor. PMID:26882543

  13. Automated Triplex (HBV, HCV and HIV) NAT Assay Systems for Blood Screening in India

    PubMed Central

    2016-01-01

    This review is confined to triplex nucleic acid testing (NAT) assays to be used on fully automated platform. Around the world, these assays are being used at various transfusion medicine centres or blood banks to screen blood units for HBV, HCV and HIV. These assay systems can screen up to 1000 blood units for HBV, HCV and HIV simultaneously in a day. This area has been dominated by mainly two manufacturers: M/s Gen-Probe-Novartis and M/s Roche Molecular Systems. The triplex NAT assay systems of both manufacturers are licensed by United States Food and Drug Administration. There is not much awareness about the technology and procedures used in these assays. The main objective of this review is to create awareness about the technology and procedure of these assays. PMID:27042485

  14. The NatCarb geoportal: Linking distributed data from the Carbon Sequestration Regional Partnerships

    USGS Publications Warehouse

    Carr, T.R.; Rich, P.M.; Bartley, J.D.

    2007-01-01

    The Department of Energy (DOE) Carbon Sequestration Regional Partnerships are generating the data for a "carbon atlas" of key geospatial data (carbon sources, potential sinks, etc.) required for rapid implementation of carbon sequestration on a broad scale. The NATional CARBon Sequestration Database and Geographic Information System (NatCarb) provides Web-based, nation-wide data access. Distributed computing solutions link partnerships and other publicly accessible repositories of geological, geophysical, natural resource, infrastructure, and environmental data. Data are maintained and enhanced locally, but assembled and accessed through a single geoportal. NatCarb, as a first attempt at a national carbon cyberinfrastructure (NCCI), assembles the data required to address technical and policy challenges of carbon capture and storage. We present a path forward to design and implement a comprehensive and successful NCCI. ?? 2007 The Haworth Press, Inc. All rights reserved.

  15. Automated Triplex (HBV, HCV and HIV) NAT Assay Systems for Blood Screening in India.

    PubMed

    Rajput, Manoj Kumar

    2016-02-01

    This review is confined to triplex nucleic acid testing (NAT) assays to be used on fully automated platform. Around the world, these assays are being used at various transfusion medicine centres or blood banks to screen blood units for HBV, HCV and HIV. These assay systems can screen up to 1000 blood units for HBV, HCV and HIV simultaneously in a day. This area has been dominated by mainly two manufacturers: M/s Gen-Probe-Novartis and M/s Roche Molecular Systems. The triplex NAT assay systems of both manufacturers are licensed by United States Food and Drug Administration. There is not much awareness about the technology and procedures used in these assays. The main objective of this review is to create awareness about the technology and procedure of these assays. PMID:27042485

  16. The Master's Thesis in Applied Psychology Training.

    ERIC Educational Resources Information Center

    Shultz, Kenneth S.; Kottke, Janet L.

    1996-01-01

    Recommends the inclusion of a master's thesis in industrial and organizational psychology programs. Argues that the thesis serves several critical educational purposes and is relevant to applied psychology. Offers suggestions for increasing the relationship between the educational requirement and the professional tasks. (MJP)

  17. Activation cross-sections of proton induced reactions on natSm up to 65 MeV

    NASA Astrophysics Data System (ADS)

    Tárkányi, F.; Hermanne, A.; Takács, S.; Ditrói, F.; Ignatyuk, A. V.

    2015-03-01

    Activation cross sections for proton induced reactions on Sm are presented for the first time for natSm(p,xn)154,152m2,152m1,152g,150m,150g,149,148,147,146,145Eu, natSm(p,x)153,145Sm, natSm(p,x)151,150,149,148g,148m,146,144,143Pm and natSm(p,x)141Nd up to 65 MeV. The cross sections were measured via activation method by using a stacked-foil irradiation technique and high resolution gamma ray spectroscopy. The results were compared with results of the nuclear reaction codes ALICE, EMPIRE and TALYS (results taken from TENDL libraries). Integral yields of the activation products were calculated from the excitation functions.

  18. Cysteamine effects on somatostatin, catecholamines, pineal NAT and melatonin in rats

    SciTech Connect

    Webb, S.M.; Champney, T.H.; Steger, R.W.; Vaughan, M.K.; Reiter, R.J.

    1986-03-01

    The thiol reagent cysteamine was administered to adult male rats with the aim of investigating its effect on different neural and pineal components. As expected, immunoreactive somatostatin decreased in the median eminence (ME) (p less than 0.05) and gastric antrum (p less than 0.05) after cysteamine; however, no significant change was observed in the pineal IRS content after drug treatment. A decrease in norepinephrine was observed in the ME (p less than 0.001), hypothalamus (p less than 0.001) and pineal gland (p less than 0.05), together with a rise in ME (p less than 0.005) and hypothalamic dopamine (p less than 0.005) content; these results are consistent with a dopamine-beta-hydroxylase inhibiting effect of cysteamine. No effect was observed on hypothalamic serotonin and 5-hydroxyindole-acetic acid content. Pineal N-acetyltransferase (NAT) activity was significantly higher (p less than 0.05) after cysteamine than after saline, but no statistically significant effect was observed on pineal melatonin content. The mechanism involved in the NAT rise is presumably not related to the known stimulatory effect of norepinephrine, which fell after cysteamine. It is suggested that cysteamine may act at an intracellular level, inhibiting NAT degradation, an effect demonstrated in vitro and thought to be related to a thiol:disulfide exchange mechanism.

  19. The profibrinolytic enzyme subtilisin NAT purified from Bacillus subtilis Cleaves and inactivates plasminogen activator inhibitor type 1.

    PubMed

    Urano, T; Ihara, H; Umemura, K; Suzuki, Y; Oike, M; Akita, S; Tsukamoto, Y; Suzuki, I; Takada, A

    2001-07-01

    In this report, we demonstrate an interaction between subtilisin NAT (formerly designated BSP, or nattokinase), a profibrinolytic serine proteinase from Bacillus subtilis, and plasminogen activator inhibitor 1 (PAI-1). Subtilisin NAT was purified to homogeneity (molecular mass, 27.7 kDa) from a saline extract of B. subtilis (natto). Subtilisin NAT appeared to cleave active recombinant prokaryotic PAI-1 (rpPAI-1) into low molecular weight fragments. Matrix-assisted laser desorption/ionization in combination with time-of-flight mass spectroscopy and peptide sequence analysis revealed that rpPAI-1 was cleaved at its reactive site (P1-P1': Arg(346)-Met(347)). rpPAI-1 lost its specific activity after subtilisin NAT treatment in a dose-dependent manner (0.02-1.0 nm; half-maximal effect at approximately 0.1 nm). Subtilisin NAT dose dependently (0.06-1 nm) enhanced tissue-type plasminogen activator-induced fibrin clot lysis both in the absence of rpPAI-1 (48 +/- 1.4% at 1 nm) and especially in the presence of rpPAI-1 (78 +/- 2.0% at 1 nm). The enhancement observed in the absence of PAI-1 seems to be induced through direct fibrin dissolution by subtilisin NAT. The stronger enhancement by subtilisin NAT of rpPAI-1-enriched fibrin clot lysis seems to involve the cleavage and inactivation of active rpPAI-1. This mechanism is suggested to be important for subtilisin NAT to potentiate fibrinolysis. PMID:11325965

  20. Elevated arylalkylamine-N-acetyltransferase (AA-NAT) gene expression in medial habenular and suprachiasmatic nuclei of hibernating ground squirrels.

    PubMed

    Yu, Erik Z; Hallenbeck, John M; Cai, Decheng; McCarron, Richard M

    2002-06-15

    Hibernation, an adaptive response for energy conservation in mammals, involves a variety of physiological changes. Melatonin is linked with the regulation of core body temperature and intervenes in generating circadian cycles; its role in seasonal (circannual) rhythms of hibernation is explored here. Melatonin is primarily produced in the pineal gland. Since arylalkylamine-N-acetyltransferase (AA-NAT) is the rate-limiting enzyme for synthesizing melatonin, AA-NAT gene expression was investigated to assess the possible role of melatonin in hibernation. The findings presented here utilized combined in situ hybridization and immunohistochemistry methodologies to evaluate the AA-NAT mRNA expression in brains of both hibernating and non-hibernating ground squirrels. Brains were examined for the expression of AA-NAT mRNA using a oligonucleotide AA-NAT probe; antibody against neurofilament-70 (NF-70) was used as a neuronal marker. All hibernating animals expressed significantly (P<0.01) elevated levels of AA-NAT mRNA in both the epithalamic medial habenular nuclei (MHb) area and the hypothalamic suprachiasmatic nuclei (SCN), which is also known as the master biologic clock. These findings represent the first demonstration of the expression of mRNA encoding for AA-NAT in the extra-pineal (i.e. SCN and MHb) sites of thirteen-lined ground squirrels and indicate that the habenular nucleus may be an important supplementary location for melatonin biosynthesis. The data presented here indicate that AA-NAT gene is one of the few specific genes up-regulated during hibernation and suggest that elevation of its expression in SCN and MHb may play an essential role in the generation and maintenance of hibernation. PMID:12191489

  1. Genotype and allele frequencies of isoniazid-metabolizing enzymes NAT2 and GSTM1 in Latvian tuberculosis patients.

    PubMed

    Igumnova, Viktorija; Capligina, Valentina; Krams, Alvils; Cirule, Andra; Elferts, Didzis; Pole, Ilva; Jansone, Inta; Bandere, Dace; Ranka, Renate

    2016-07-01

    Pharmacogenomic testing of tuberculosis drug-metabolizing enzyme genes was proposed as a strategy to identify patients at risk for suboptimal responses to medications. However, variations of the genotype frequencies among ethnic groups exist and new alleles are been identified. The aim of this study was to identify polymorphisms of genes encoding metabolic enzymes NAT2 and GSTM1 in tuberculosis patients in Latvia and to estimate the frequency of NAT2 slow acetylator and GSTM1 null genotypes. In total, 85 DNA samples were genotyped, all individuals were Caucasian. An ethnic heterogeneity reflecting the multiethnic population of the country was observed. 49 patients were Latvians, 30 were Russians and 6 of other ethnicity. In total, 7 NAT2 alleles were identified: *4, *5, *6, *7, *11, *12, * and *13. The most frequent was the slow acetylation allele NAT2*6 (frequency 0.388) followed by the slow acetylation allele NAT2*5 and the rapid acetylation allele NAT2*4 (frequencies 0.306 and 0.194, respectively). The predominance of slow (51.8%) and intermediate (43.5%) acetylators compared with rapid acetylators (4.7%) was observed. The GSTM1 null genotype was detected in 48.2% of tuberculosis patients. When subgroup analysis was performed according to ethnicity, the results showed that neither NAT2 allele frequencies nor GSTM1 null genotype frequency did not differ significantly in TB patients of Latvian or Russian ethnicity. Overall, genotyping results were similar with previous reports of a NAT2 gene variation and GSTM1 null genotype frequency in Caucasians. Our findings have a contribution for the pharmacogenetics-based tuberculosis therapy in Latvia in future. PMID:27236516

  2. Special issue: Culham Thesis Prize winners

    NASA Astrophysics Data System (ADS)

    Ham, C. J.

    2015-01-01

    The Culham Thesis Prize is awarded annually to the nominee who has displayed an excellence in the execution of the scientific method as witnessed by the award of Doctor of Philosophy in Plasma Science from a UK or Irish university. The thesis content should exhibit significant new work and originality, clearly driven by the nominee, be well explained and demonstrate a good understanding of the subject. The prize is awarded at the Institute of Physics Plasma Physics Group Spring Conference and the prize winner gives an invited talk about their thesis work. The prize is sponsored by Culham Centre for Fusion Energy.

  3. Contribution of the N‐acetyltransferase 2 polymorphism NAT2*6A to age‐related hearing impairment

    PubMed Central

    Van Eyken, E; Van Camp, G; Fransen, E; Topsakal, V; Hendrickx, J J; Demeester, K; Van de Heyning, P; Mäki‐Torkko, E; Hannula, S; Sorri, M; Jensen, M; Parving, A; Bille, M; Baur, M; Pfister, M; Bonaconsa, A; Mazzoli, M; Orzan, E; Espeso, A; Stephens, D; Verbruggen, K; Huyghe, J; Dhooge, I; Huygen, P; Kremer, H; Cremers, C W R J; Kunst, S; Manninen, M; Pyykkö, I; Lacava, A; Steffens, M; Wienker, T F; Van Laer, L

    2007-01-01

    Background Age‐related hearing impairment (ARHI) is the most common sensory impairment in older people, affecting 50% of those aged 80 years. The proportion of older people is increasing in the general population, and as a consequence, the number of people affected with ARHI is growing. ARHI is a complex disorder, with both environmental and genetic factors contributing to the disease. The first studies to elucidate these genetic factors were recently performed, resulting in the identification of the first two susceptibility genes for ARHI, NAT2 and KCNQ4. Methods In the present study, the association between ARHI and polymorphisms in genes that contribute to the defence against reactive oxygen species, including GSTT1, GSTM1 and NAT2, was tested. Samples originated from seven different countries and were combined into two test population samples, the general European population and the Finnish population. Two distinct phenotypes for ARHI were studied, Zlow and Zhigh, representing hearing in the low and high frequencies, respectively. Statistical analysis was performed for single polymorphisms (GSTM1, GSTT1, NAT2*5A, NAT2*6A, and NAT2*7A), haplotypes, and gene–environment and gene–gene interactions. Results We found an association between ARHI and GSTT1 and GSTM1 in the Finnish population sample, and with NAT2*6A in the general European population sample. The latter finding replicates previously published data. Conclusion As replication is considered the ultimate proof of true associations in the study of complex disorders, this study provides further support for the involvement of NAT2*6A in ARHI. PMID:17513527

  4. NAT2 and NER genetic variants and sporadic prostate cancer susceptibility in African Americans.

    PubMed

    Hooker, S; Bonilla, C; Akereyeni, F; Ahaghotu, C; Kittles, R A

    2008-01-01

    Prostate cancer is a common malignancy that disproportionately affects African-American men. Environmental factors and variation in genes responsible for chemical and dietary carcinogen metabolism and DNA damage repair may modulate risk. Fourteen single nucleotide polymorphisms in NAT2 and four NER genes (ERCC1, XPF/ERCC4, XPG/ERCC5 and CSB/ERCC6) were genotyped in a case-control study of 254 African-American prostate cancer cases and 301 healthy controls from Washington, DC. Smoking status, BMI, age and genetic ancestry were included as covariates in the association analyses. We found that individuals homozygous for the XPG/ERCC5 -72C/T promoter polymorphism had a significant reduction in risk, for prostate cancer (OR=0.12; 95% CI=0.03-0.48). A haplotype trend regression test also revealed a protective effect for the haplotype bearing the T allele (P=0.003). In silica analyses suggest a functional implication for the promoter variant since it deletes a GCF transcriptional factor-binding site responsible for the downregulation of transcription. The protective effect of the promoter SNP on risk for prostate cancer was independent of smoking. In contrast, none of the SNPs typed for NAT2, ERCC1, ERCC4 and ERCC6 showed significant association with risk. Additional tests for genotype interactions were not significant. We note that there may be other factors, such as dietary exposures, which may modulate prostate cancer risk in combination with genetic variation within the NAT2 and NER genes. Our results, in combination with previous observations of LOH for ERCC5 in prostate tumors, provide further evidence for a role of XPG/ERCC5 in the etiology of prostate cancer. PMID:18026184

  5. Infrared spectroscopic characterization of dehydration and accompanying phase transition behaviors in NAT-topology zeolites

    SciTech Connect

    Wang, Hsiu-Wen; Bishop, David

    2012-01-01

    Relative humidity (PH2O, partial pressure of water)-dependent dehydration and accompanying phase transitions in NAT-topology zeolites (natrolite, scolecite, and mesolite) were studied under controlled temperature and known PH2O conditions by in situ diffuse-reflectance infrared Fourier transform spectroscopy and parallel X-ray powder diffraction. Dehydration was characterized by the disappearance of internal H2O vibrational modes. The loss of H2O molecules caused a sequence of structural transitions in which the host framework transformation path was coupled primarily via the thermal motion of guest Na?/Ca2? cations and H2O molecules. The observation of different interactions of H2O molecules and Na?/Ca2? cations with host aluminosilicate frameworks under highand low-PH2O conditions indicated the development of different local strain fields, arising from cation H2O interactions in NAT-type channels. These strain fields influence the Si O/Al O bond strength and tilting angles within and between tetrahedra as the dehydration temperature is approached. The newly observed infrared bands (at 2,139 cm-1 in natrolite, 2,276 cm-1 in scolecite, and 2,176 and 2,259 cm-1 in mesolite) result from strong cation H2O Al Si framework interactions in NAT-type channels, and these bands can be used to evaluate the energetic evolution of Na?/Ca2? cations before and after phase transitions, especially for scolecite and mesolite. The 2,176 and 2,259 cm-1 absorption bands in mesolite also appear to be related to Na?/Ca2? order disorder that occur when mesolite loses its Ow4 H2O molecules.

  6. Introduction of the HAM-Nat examination – applicants and students admitted to the Medical Faculty in 2012-2014

    PubMed Central

    Werwick, Katrin; Winkler-Stuck, Kirstin; Hampe, Wolfgang; Albrecht, Peggy; Robra, Bernt-Peter

    2015-01-01

    Background/aim: In the 2012/13 winter semester, the Magdeburg Medical Faculty introduced a test of knowledge for the selection of applicants. The Hamburg Assessment Test for Medicine - Natural Sciences (HAM-Nat) comprises a multiple-choice test with questions on the aspects of biology, physics, chemistry and mathematics relevant to medicine, which was specifically developed for the selection of medicine applicants. The aim is to study how the HAM-Nat influences student selection, the reasons why students decide to take the test as part of their application procedure and what expectations they have of their course of study. Methods: The selection procedures applied at the university in 2011 (without HAM-Nat) and in 2012-2014 (with HAM-Nat) are compared. On the basis of the results of exploratory interviews, university entrants in winter semester 2013/2014 participated in a written survey on why they chose their subject and place of study and their expectations of their course of study. Results: No problems were encountered in introducing the extended selection procedure that included the HAM-Nat Test. The HAM-Nat had a great influence on the selection decision. About 65% of the students admitted would not have obtained a place if the decision had been based exclusively on their Abitur grade [grade obtained in the German school-leaving examination]. On average, male applicants obtained better HAM-Nat results than female ones. The questionnaire was answered by 147 out of 191 university entrants (77%). In the case of applicants from Saxony-Anhalt, the principle reasons for choosing the regional capital are its proximity, the social environment offered, good conditions for studying and the feel-good factor at the university. For the majority of applicants, however, particularly applicants from other federal states, the relatively good chances of admission in Magdeburg were the main reason. Conclusion: The Magdeburg Medical Faculty regards the HAM-Nat as a suitable tool

  7. A national look at carbon capture and storage-National carbon sequestration database and geographical information system (NatCarb)

    USGS Publications Warehouse

    Carr, T.R.; Iqbal, A.; Callaghan, N.; Dana-Adkins-Heljeson; Look, K.; Saving, S.; Nelson, K.

    2009-01-01

    The US Department of Energy's Regional Carbon Sequestration Partnerships (RCSPs) are responsible for generating geospatial data for the maps displayed in the Carbon Sequestration Atlas of the United States and Canada. Key geospatial data (carbon sources, potential storage sites, transportation, land use, etc.) are required for the Atlas, and for efficient implementation of carbon sequestration on a national and regional scale. The National Carbon Sequestration Database and Geographical Information System (NatCarb) is a relational database and geographic information system (GIS) that integrates carbon storage data generated and maintained by the RCSPs and various other sources. The purpose of NatCarb is to provide a national view of the carbon capture and storage potential in the U.S. and Canada. The digital spatial database allows users to estimate the amount of CO2 emitted by sources (such as power plants, refineries and other fossil-fuel-consuming industries) in relation to geologic formations that can provide safe, secure storage sites over long periods of time. The NatCarb project is working to provide all stakeholders with improved online tools for the display and analysis of CO2 carbon capture and storage data. NatCarb is organizing and enhancing the critical information about CO2 sources and developing the technology needed to access, query, model, analyze, display, and distribute natural resource data related to carbon management. Data are generated, maintained and enhanced locally at the RCSP level, or at specialized data warehouses, and assembled, accessed, and analyzed in real-time through a single geoportal. NatCarb is a functional demonstration of distributed data-management systems that cross the boundaries between institutions and geographic areas. It forms the first step toward a functioning National Carbon Cyberinfrastructure (NCCI). NatCarb provides access to first-order information to evaluate the costs, economic potential and societal issues of

  8. Genotyping of the polymorphic N-acetyltransferase (NAT2) and loss of heterozygosity in bladder cancer patients.

    PubMed

    Schnakenberg, E; Ehlers, C; Feyerabend, W; Werdin, R; Hübotter, R; Dreikorn, K; Schloot, W

    1998-05-01

    Acetylation is one of the major routes in metabolism and detoxification of a large number of drugs, chemicals and carcinogens. Slow acetylators are said to be more susceptible to developing bladder cancer and because of investigations about tumor risk based on phenotyping procedures, it was our aim to study the distribution of allelic constellations of the N-acetyltransferase (NAT2) by genotyping patients with bladder cancer. We analysed NAT2 gene of blood and tumor DNA from 60 patients with primary bladder cancer and DNA of blood samples from 154 healthy individuals. Using ASO-PCR/RFLP techniques we identified 70% of patients with bladder cancer (n = 42) to be slow acetylators while genotyping of controls resulted in 61% with slow acetylators (n = 94). In addition, dividing bladder cancer patients in males and females the genotype NAT2*5B/NAT2*6A occured with much higher frequencies in males (OR = 4, 95%); CI = 1.8-8.9). Furthermore, investigating bladder cancer tissues we could detect loss of heterozygosity (LOH) in slow and rapid acetylator genotypes. In eleven out of 60 tumor samples (18.3%) we observed allelic loss at the NAT2 locus while in control DNA of blood from the same patients both alleles were still detectable. PMID:9660060

  9. Structures and functions of insect arylalkylamine N-acetyltransferase (iaaNAT); a key enzyme for physiological and behavioral switch in arthropods

    PubMed Central

    Hiragaki, Susumu; Suzuki, Takeshi; Mohamed, Ahmed A. M.; Takeda, Makio

    2015-01-01

    The evolution of N-acetyltransfeases (NATs) seems complex. Vertebrate arylalkylamine N-acetyltransferase (aaNAT) has been extensively studied since it leads to the synthesis of melatonin, a multifunctional neurohormone prevalent in photoreceptor cells, and is known as a chemical token of the night. Melatonin also serves as a scavenger for reactive oxygen species. This is also true with invertebrates. NAT therefore has distinct functional implications in circadian function, as timezymes (aaNAT), and also xenobiotic reactions (arylamine NAT or simply NAT). NATs belong to a broader enzyme group, the GCN5-related N-acetyltransferase superfamily. Due to low sequence homology and a seemingly fast rate of structural differentiation, the nomenclature for NATs can be confusing. The advent of bioinformatics, however, has helped to classify this group of enzymes; vertebrates have two distinct subgroups, the timezyme type and the xenobiotic type, which has a wider substrate range including imidazolamine, pharmacological drugs, environmental toxicants and even histone. Insect aaNAT (iaaNAT) form their own clade in the phylogeny, distinct from vertebrate aaNATs. Arthropods are unique, since the phylum has exoskeleton in which quinones derived from N-acetylated monoamines function in coupling chitin and arthropodins. Monoamine oxidase (MAO) activity is limited in insects, but NAT-mediated degradation prevails. However, unexpectedly iaaNAT occurs not only among arthropods but also among basal deuterostomia, and is therefore more apomorphic. Our analyses illustrate that iaaNATs has unique physiological roles but at the same time it plays a role in a timezyme function, at least in photoperiodism. Photoperiodism has been considered as a function of circadian system but the detailed molecular mechanism is not well understood. We propose a molecular hypothesis for photoperiodism in Antheraea pernyi based on the transcription regulation of NAT interlocked by the circadian system

  10. Novel polymorphism of AA-NAT gene in Indian goat breeds differing in reproductive traits.

    PubMed

    Sharma, R; Ahlawat, S; Tantia, M S

    2015-01-01

    This is the first description of the polymorphisms of arylalkylamine-N-acetyltransferase (AA-NAT) gene in Indian goats with different reproductive traits (twinning percentage and age of sexual maturity). Based on the important role of AA-NAT in reproduction, it is considered as a possible candidate gene for this trait. Two novel synonymous SNPs, C825T (exon2) and C1249T (exon3) were identified. All three possible genotypes (CC, CT and TT) were identified for C825T mutation whereas two genotypes were observed (CC and CT) for C1249T mutation. SNPs C825T and C1249T changed recognition site of restriction enzyme BtsCI (GGA T G) and AciI (C C GC) and thus can be genotyped by the relatively simple and cost effective technique of PCR-RFLP for establishing further association with reproductive traits. Present results add to the meager existing knowledge and extend the spectrum of genetic variation of caprine candidate genes of reproductive traits, which is another step towards improvement of goat genetic resources and breeding. PMID:27175207

  11. Preparing for thesis and viva: some practicalities.

    PubMed

    Lee, Nancy-Jane

    2010-01-01

    Presenting a thesis and then undertaking the viva is challenging even for the most experienced of researchers. This paper offers stylistic practicalities, reflects on thesis and viva preparation, and discusses the research regulations and submission requirements of higher education institutions (HEIs). Issues such as the use of the first person, how best to locate research in the professional setting, research regulations and codes of practice are discussed, along with some guiding principles to enable effective viva preparation. It is derived from experience as a doctoral student, supervisor and examiner, and focuses on questions most frequently asked by doctoral students. PMID:20450089

  12. Activation cross-sections of deuteron induced reactions on natSm up to 50 MeV

    NASA Astrophysics Data System (ADS)

    Tárkányi, F.; Hermanne, A.; Takács, S.; Ditrói, F.; Csikai, J.; Ignatyuk, A. V.

    2014-08-01

    Activation cross-sections for deuteron induced reactions on Sm are presented for the first time for natSm(d,xn)155,154,152m2,152m1,152g,150m,150g,149,148,147,146Eu, natSm(d,x) 153,145Sm and natSm(d,x)151,150,149,145,144,143Pm up to 50 MeV. The cross-sections were measured by the stacked-foil irradiation technique and high resolution γ-ray spectrometry. The results were compared with results of nuclear reaction codes ALICE-D, EMPIRE-D and TALYS (from TENDL libraries). Integral yields of the products were calculated from the excitation functions.

  13. Finding the Genesis for a Thesis

    ERIC Educational Resources Information Center

    Caroll, Joyce Armstrong

    2013-01-01

    This article describes a prewriting heuristics strategy that can help students find the genesis of their thesis. The 3 functions of the heuristic procedure are that it aids in retrieving relevant information stored in the mind; draws attention to important information that can be further researched or accessed; and prepares the mind for the…

  14. The Thesis, the Pendulum and the Battlefield

    ERIC Educational Resources Information Center

    Ameri, Amir

    2015-01-01

    The debate over the design thesis is often entangled in the dialectics of the practical and the theoretical. Whether the argument is waged and weighted in favour of a practical emphasis or a theoretical emphasis, or more insidious, a judicious balance between the two, what is inevitably assumed in the debate is the possibility of drawing and/or…

  15. Writing a Structured Abstract for the Thesis

    ERIC Educational Resources Information Center

    Hartley, James

    2010-01-01

    This article presents the author's suggestions on how to improve thesis abstracts. The author describes two books on writing abstracts: (1) "Creating Effective Conference Abstracts and Posters in Biomedicine: 500 tips for Success" (Fraser, Fuller & Hutber, 2009), a compendium of clear advice--a must book to have in one's hand as one prepares a…

  16. Dancing the Thesis, Writing on the Body

    ERIC Educational Resources Information Center

    Mills, Dana

    2014-01-01

    This article explores the connection between dance and politics through reflection on the process of writing a thesis about those two fields. Similarities and differences in the educational and disciplinary processes of academic practice and dance training are brought out, while focusing on the technique developed by Martha Graham: in particular…

  17. The Ubiquitin Ligase Synoviolin Up-regulates Amyloid β Production by Targeting a Negative Regulator of γ-Secretase, Rer1, for Degradation*

    PubMed Central

    Tanabe, Chiaki; Maeda, Tomoji; Zou, Kun; Liu, Junjun; Liu, Shuyu; Nakajima, Toshihiro; Komano, Hiroto

    2012-01-01

    Alzheimer's disease is characterized by the deposition of Aβ, which is generated from the amyloid precursor protein through its cleavage by β- and γ-secretases. The γ-secretase complex component nicastrin (NCT) plays significant roles in the assembly and proper trafficking of the γ-secretase complex and in the recognition of amyloid precursor protein. NCT is incorporated into the γ-secretase complex in the endoplasmic reticulum (ER) and glycosylated in the Golgi. In contrast, unassembled NCT is retrieved or retained in the ER by the protein Retention in endoplasmic reticulum 1 (Rer1). We reported previously that synoviolin (Syvn), an E3 ubiquitin ligase, degrades NCT and affects the generation of Aβ. Here, we examined in more detail the effect of Syvn on the generation of Aβ. We found that overexpression of a dominant negative form of Syvn (C307A mutant) and a Syvn-RNAi decreased the generation of Aβ. These results indicate that the ubiquitin ligase activity of Syvn up-regulates the generation of Aβ. We hypothesized, therefore, that Syvn regulates the assembly or localization of the γ-secretase complex by ubiquitinating Rer1, resulting in its subsequent degradation. Our findings that the level of Rer1 was increased in Syvn knockout fibroblasts because of inhibition of its degradation support this hypothesis. Moreover, we found that Rer1 interacts with Syvn in the ER, is ubiquitinated by Syvn, and is then degraded via the proteasome or lysosomal pathways. Finally, we showed that localization of mature NCT to the plasma membrane as well as γ-secretase complex levels are decreased in fibroblasts of Syvn knockout mice. Thus, it is likely that Syvn regulates the assembly of the γ-secretase complex via the degradation of Rer1, which results in the generation of Aβ. PMID:23129766

  18. Comparison of Procleix Ultrio Elite and Procleix Ultrio NAT Assays for Screening of Transfusion Transmitted Infections among Blood Donors in India

    PubMed Central

    Chaurasia, Rahul; Rout, Diptiranjan; Zaman, Shamsuz; Chatterjee, Kabita; Pandey, Hem Chandra; Maurya, Abhishek Kumar

    2016-01-01

    Background. Introduction of nucleic acid testing (NAT) has helped in decreasing window period donations, resulting in increased safety of blood supplies. NAT combines the advantages of direct and highly sequence-specific detection of viral genomes. We analysed the performance of newer Procleix Ultrio Elite (PUE) and Procleix Ultrio assay (PUA) for the screening of the viral markers in our donor population. Material and Methods. 10,015 donor samples were screened by routine immunoassays and both versions of NAT. NAT yields detected were subjected to viral load estimation and to other serological markers. Results. A total of 21 NAT yields were detected; three were positive by both NAT systems, whereas 18 samples were reactive by PUE only. NAT yields include 18 HBV and 3 HCV yields, of which 17 HBV yields were occult infections and 1 was window period (WP) infection. All 3 HCV yields were WP infections. No HIV-1/HIV-2 yield was found. Conclusion. Efficient target capture chemistry in the new TMA assay version significantly improved sensitivity. NAT is superior to serological immunoassays for screening of the viral markers; and the efficient target capture system in the newer TMA assay, namely, the PUE system, has significantly improved sensitivity over the earlier versions. PMID:26904124

  19. Human NAT10 Is an ATP-dependent RNA Acetyltransferase Responsible for N4-Acetylcytidine Formation in 18 S Ribosomal RNA (rRNA)*

    PubMed Central

    Ito, Satoshi; Horikawa, Sayuri; Suzuki, Tateki; Kawauchi, Hiroki; Tanaka, Yoshikazu; Suzuki, Takeo; Suzuki, Tsutomu

    2014-01-01

    Human N-acetyltransferase 10 (NAT10) is known to be a lysine acetyltransferase that targets microtubules and histones and plays an important role in cell division. NAT10 is highly expressed in malignant tumors, and is also a promising target for therapies against laminopathies and premature aging. Here we report that NAT10 is an ATP-dependent RNA acetyltransferase responsible for formation of N4-acetylcytidine (ac4C) at position 1842 in the terminal helix of mammalian 18 S rRNA. RNAi-mediated knockdown of NAT10 resulted in growth retardation of human cells, and this was accompanied by high-level accumulation of the 30 S precursor of 18 S rRNA, suggesting that ac4C1842 formation catalyzed by NAT10 is involved in rRNA processing and ribosome biogenesis. PMID:25411247

  20. Neutron Elastic and Inelastic Scattering Cross Sections on ^NatFe and ^23Na

    NASA Astrophysics Data System (ADS)

    Kersting, Luke; Lueck, Collin J.; Hicks, S. F.; Crider, B. P.; McEllistrem, M. T.; Peters, E. E.; Vanhoy, J. R.

    2010-10-01

    Neutron elastic and inelastic scattering angular distributions from ^NatFe and ^23Na at incident neutron energies of 3.57 and 3.81 MeV have been measured at the University of Kentucky 7 MV Van de Graaff laboratory using neutron time-of-flight techniques. The neutron beam was produced using the ^3H(p,n)He^3reaction. The scattered neutrons were detected at angles between 20 and 150 in 10 intervals with a hexafluorbenzene detector located approximately 3 m from the scattering samples. Neutron scattering differential cross sections were deduced. These cross sections and their uncertainties are important for understanding neutron-induced reactions in fission reactors and are important for fission reactor criticality calculations.

  1. The Legacy of Nat Sternberg: The Genesis of Cre-lox Technology.

    PubMed

    Yarmolinsky, Michael; Hoess, Ronald

    2015-11-01

    Cre-lox of bacteriophage P1 has become one of the most widely used tools for genetic engineering in eukaryotes. The origins of this tool date to more than 30 years ago when Nat L. Sternberg discovered the recombinase, Cre, and its specific locus of crossover, lox, while studying the maintenance of bacteriophage P1 as a stable plasmid. Recombinations mediated by Cre assist in cyclization of the DNA of infecting phage and in resolution of prophage multimers created by generalized recombination. Early in vitro work demonstrated that, although it shares similarities with the well-characterized bacteriophage λ integration, Cre-lox is in many ways far simpler in its requirements for carrying out recombination. These features would prove critical for its development as a powerful and versatile tool in genetic engineering. We review the history of the discovery and characterization of Cre-lox and touch upon the present direction of Cre-lox research. PMID:26958905

  2. Measurement of excitation functions in alpha induced reactions on natCu

    NASA Astrophysics Data System (ADS)

    Shahid, Muhammad; Kim, Kwangsoo; Kim, Guinyun; Zaman, Muhammad; Nadeem, Muhammad

    2015-09-01

    The excitation functions of 66,67,68Ga, 62,63,65Zn, 61,64Cu, and 58,60Co radionuclides in the natCu(α, x) reaction were measured in the energy range from 15 to 42 MeV by using a stacked-foil activation method at the MC-50 cyclotron of the Korean Institute of Radiological and Medical Sciences. The measured results were compared with the literature data as well as the theoretical values obtained from the TENDL-2013 and TENDL-2014 libraries based on the TALYS-1.6 code. The integral yields for thick targets of the produced radionuclides were also determined from the measured excitation functions and the stopping power of natural copper.

  3. GSTM1 null and NAT2 slow acetylation genotypes, smoking intensity and bladder cancer risk: results from the New England bladder cancer study and NAT2 meta-analysis.

    PubMed

    Moore, L E; Baris, D R; Figueroa, J D; Garcia-Closas, M; Karagas, M R; Schwenn, M R; Johnson, A T; Lubin, J H; Hein, D W; Dagnall, C L; Colt, J S; Kida, M; Jones, M A; Schned, A R; Cherala, S S; Chanock, S J; Cantor, K P; Silverman, D T; Rothman, N

    2011-02-01

    Associations between bladder cancer risk and NAT2 and GSTM1 polymorphisms have emerged as some of the most consistent findings in the genetic epidemiology of common metabolic polymorphisms and cancer, but their interaction with tobacco use, intensity and duration remain unclear. In a New England population-based case-control study of urothelial carcinoma, we collected mouthwash samples from 1088 of 1171 cases (92.9%) and 1282 of 1418 controls (91.2%) for genotype analysis of GSTM1, GSTT1 and NAT2 polymorphisms. Odds ratios and 95% confidence intervals of bladder cancer among New England Bladder Cancer Study subjects with one or two inactive GSTM1 alleles (i.e. the 'null' genotype) were 1.26 (0.85-1.88) and 1.54 (1.05-2.25), respectively (P-trend = 0.008), compared with those with two active copies. GSTT1 inactive alleles were not associated with risk. NAT2 slow acetylation status was not associated with risk among never (1.04; 0.71-1.51), former (0.95; 0.75-1.20) or current smokers (1.33; 0.91-1.95); however, a relationship emerged when smoking intensity was evaluated. Among slow acetylators who ever smoked at least 40 cigarettes/day, risk was elevated among ever (1.82; 1.14-2.91, P-interaction = 0.07) and current heavy smokers (3.16; 1.22-8.19, P-interaction = 0.03) compared with rapid acetylators in each category; but was not observed at lower intensities. In contrast, the effect of GSTM1-null genotype was not greater among smokers, regardless of intensity. Meta-analysis of the NAT2 associations with bladder cancer showed a highly significant relationship. Findings from this large USA population-based study provided evidence that the NAT2 slow acetylation genotype interacts with tobacco smoking as a function of exposure intensity. PMID:21037224

  4. Multiple Advantageous Amino Acid Variants in the NAT2 Gene in Human Populations

    PubMed Central

    Luca, Francesca; Bubba, Giuseppina; Basile, Massimo; Brdicka, Radim; Michalodimitrakis, Emmanuel; Rickards, Olga; Vershubsky, Galina; Quintana-Murci, Lluis; Kozlov, Andrey I.; Novelletto, Andrea

    2008-01-01

    Background Genetic variation at NAT2 has been long recognized as the cause of differential ability to metabolize a wide variety of drugs of therapeutic use. Here, we explore the pattern of genetic variation in 12 human populations that significantly extend the geographic range and resolution of previous surveys, to test the hypothesis that different dietary regimens and lifestyles may explain inter-population differences in NAT2 variation. Methodology/Principal Findings The entire coding region was resequenced in 98 subjects and six polymorphic positions were genotyped in 150 additional subjects. A single previously undescribed variant was found (34T>C; 12Y>H). Several aspects of the data do not fit the expectations of a neutral model, as assessed by coalescent simulations. Tajima's D is positive in all populations, indicating an excess of intermediate alleles. The level of between-population differentiation is low, and is mainly accounted for by the proportion of fast vs. slow acetylators. However, haplotype frequencies significantly differ across groups of populations with different subsistence. Conclusions/Significance Data on the structure of haplotypes and their frequencies are compatible with a model in which slow-causing variants were present in widely dispersed populations before major shifts to pastoralism and/or agriculture. In this model, slow-causing mutations gained a selective advantage in populations shifting from hunting-gathering to pastoralism/agriculture. We suggest the diminished dietary availability of folates resulting from the nutritional shift, as the possible cause of the fitness increase associated to haplotypes carrying mutations that reduce enzymatic activity. PMID:18773084

  5. Experimental cross-sections for proton-induced nuclear reactions on natMo

    NASA Astrophysics Data System (ADS)

    Červenák, Jaroslav; Lebeda, Ondřej

    2016-08-01

    In the framework of the Co-ordinated Research Project of the IAEA, we measured in detail cross-sections of the nuclear reactions natMo(p,x)93gTc, 93mTc, 93m+gTc, 94gTc, 94mTc, 95gTc, 95mTc, 96m+gTc, 97mTc, 99mTc, 90Mo, 93mMo, 99Mo, 88gNb, 88mNb, 89gNb, 89mNb, 90m+gNb, 90m+gNbcum, 91mNb, 92mNb, 95gNb, 95mNb, 95m+gNb, 96Nb, 97m+gNb, 88m+gZrcum and 89m+gZrcum in the energy range of 6.9-35.8 MeV. The data for formation of 97mTc, 88gNb, 88mNb and 89mNb are reported for the first time. The obtained results were compared to the prediction of the nuclear reaction model code TALYS adopted from the TENDL-2015 library and to the previously published cross-sections. The thick target yields for all the radionuclides were calculated from the measured data. We suggest recommended cross-sections and thick target yields for the 100Mo(p,2n)99mTc, 100Mo(p,x)99Mo and natMo(p,x)96m+gTc nuclear reactions deduced from the selected experimental data.

  6. 75 FR 22814 - Guidance for Industry: Nucleic Acid Testing (NAT) for Human Immunodeficiency Virus Type 1 (HIV-1...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-30

    ... (70 FR 43439), FDA announced the availability of the draft guidance of the same title. FDA received...: Nucleic Acid Testing (NAT) for Human Immunodeficiency Virus Type 1 (HIV-1) and Hepatitis C Virus (HCV... Immunodeficiency Virus Type 1 (HIV-1) and Hepatitis C Virus (HCV): Testing, Product Disposition, and Donor...

  7. Evaluation of the Procleix Ultrio Plus ID NAT assay for detection of HIV 1, HBV and HCV in blood donors

    PubMed Central

    Makroo, Raj Nath; Chowdhry, Mohit; Bhatia, Aakanksha; Antony, Minimol

    2015-01-01

    Introduction: The Procleix Ultrio Plusassay is a new-generation qualitative in vitro nucleic acid amplification test used to screen for human immunodeficiency virus type 1 (HIV-1) RNA, hepatitis C virus (HCV) RNA and hepatitis B virus (HBV) DNA in blood donors. This study was performed to compare the Procleix Ultrio assay with the new-generation Procleix Ultrio Plus Nucleic Acid Test (NAT) assays. Materials and Methods: Ten thousand three hundred and two donor samples were run in parallel for ID NAT using the Procleix Ultrio and the Procleix Ultrio Plus assay. Simultaneously, enzyme-linked immunosorbent assay testing was performed on an EVOLIS Walk away System for HIV, HCV, HBsAg and anti-HBc. Reactive samples were confirmed using polymerase chain reaction. Results: In the 10,302 samples tested during the study period, we identified 15 NAT yields, and all these revealed HBV DNA in the discriminatory assays. Eight of these were exclusive yields from the Ultrio Plus assay and the remaining seven cases were determined as HBV NAT yield, both by the Procleix Ultrio as well as the Ultrio Plus assays, i.e. “Combined” yields. No HCV or HIV 1 yields were detected during the study period by either of two assays. Conclusion: With an overall yield rate of 1 in 687 and an exclusive yield rate of 1 in 1287, the Procleix Ultrio Plus assay proved to be highly sensitive in detecting occult HBV infections. PMID:25722569

  8. 14 CFR Appendix C to Part 91 - Operations in the North Atlantic (NAT) Minimum Navigation Performance Specifications (MNPS) Airspace

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Operations in the North Atlantic (NAT) Minimum Navigation Performance Specifications (MNPS) Airspace C Appendix C to Part 91 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND...

  9. 14 CFR Appendix C to Part 91 - Operations in the North Atlantic (NAT) Minimum Navigation Performance Specifications (MNPS) Airspace

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Operations in the North Atlantic (NAT) Minimum Navigation Performance Specifications (MNPS) Airspace C Appendix C to Part 91 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND...

  10. 14 CFR Appendix C to Part 91 - Operations in the North Atlantic (NAT) Minimum Navigation Performance Specifications (MNPS) Airspace

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Operations in the North Atlantic (NAT) Minimum Navigation Performance Specifications (MNPS) Airspace C Appendix C to Part 91 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND...

  11. The thesis of stages fourteen years later

    NASA Astrophysics Data System (ADS)

    Beeby, C. E.

    1980-12-01

    The author indicates the changes and additions he would make to his book ` The Quality of Education in Developing Countries' (1966) if he were re-writing it in 1980. He would make clearer that his primary interest is in a continuum of change, the process of growth of a school system, and that the `stages' are only a convenient non-mathematical artifact to make the thesis more useful to administrators and planners. In the light of more recent developments and experiences, he now gives new stress to the pluralism of objectives at the stage of Meaning, and discusses the political, social, cultural and financial reasons why a country may choose not to take the difficult step from stage III to stage IV. Recent forms of alternative education, particularly those embodying plans for lifelong education, offer some hope of bypassing his thesis of stages. More consideration is given to constraints other than that of teacher qualification, though the difficulty of changing the skills, habits, attitudes and purposes in the teaching profession remain the chief obstacle to qualitative growth. Particular attention is paid to `crash' programmes where processes that are, by their very nature, successive are compressed into simultaneous or almost simultaneous ones. Some implications of the thesis of stages for teacher training are briefly dealt with. Regarding the application of the thesis to secondary education, he maintains that a better model of growth would be one based on the capacity of secondary education to respond to the changing economic and social demands of the community. Finally, he suggests three methods of testing his hypotheses and pleads that more consideration be given to building up a body of educational, theory based on the experience of developing countries over the past three decades.

  12. N-acetyltransferase (nat) Is a Critical Conjunct of Photoperiodism between the Circadian System and Endocrine Axis in Antheraea pernyi

    PubMed Central

    Bembenek, Jadwiga; Hiragaki, Susumu; Suzuki, Takeshi; Takeda, Makio

    2014-01-01

    Since its discovery in 1923, the biology of photoperiodism remains a mystery in many ways. We sought the link connecting the circadian system to an endocrine switch, using Antheraea pernyi. PER-, CLK- and CYC-ir were co-expressed in two pairs of dorsolateral neurons of the protocerebrum, suggesting that these are the circadian neurons that also express melatonin-, NAT- and HIOMT-ir. The results suggest that a melatonin pathway is present in the circadian neurons. Melatonin receptor (MT2 or MEL-1B-R)-ir in PTTH-ir neurons juxtaposing clock neurons suggests that melatonin gates PTTH release. RIA showed a melatonin rhythm with a peak four hours after lights off in adult brain both under LD16∶8 (LD) and LD12∶12 (SD), and both the peak and the baseline levels were higher under LD than SD, suggesting a photoperiodic influence. When pupae in diapause were exposed to 10 cycles of LD, or stored at 4°C for 4 months under constant darkness, an increase of NAT activity was observed when PTTH released ecdysone. DNA sequence upstream of nat contained E-boxes to which CYC/CLK could bind, and nat transcription was turned off by clk or cyc dsRNA. dsRNANAT caused dysfunction of photoperiodism. dsRNAPER upregulated nat transcription as anticipated, based on findings in the Drosophila melanogaster circadian system. Transcription of nat, cyc and clk peaked at ZT12. RIA showed that dsRNANAT decreased melatonin while dsRNAPER increased melatonin. Thus nat, a clock controlled gene, is the critical link between the circadian clock and endocrine switch. MT-binding may release PTTH, resulting in termination of diapause. This study thus examined all of the basic functional units from the clock: a photoperiodic counter as an accumulator of mRNANAT, to endocrine switch for photoperiodism in A. pernyi showing this system is self-complete without additional device especially for photoperiodism. PMID:24667367

  13. Homology modelling and structural analysis of human arylamine N-acetyltransferase NAT1: evidence for the conservation of a cysteine protease catalytic domain and an active-site loop.

    PubMed Central

    Rodrigues-Lima, F; Deloménie, C; Goodfellow, G H; Grant, D M; Dupret, J M

    2001-01-01

    Arylamine N-acetyltransferases (EC 2.3.1.5) (NATs) catalyse the biotransformation of many primary arylamines, hydrazines and their N-hydroxylated metabolites, thereby playing an important role in both the detoxification and metabolic activation of numerous xenobiotics. The recently published crystal structure of the Salmonella typhimurium NAT (StNAT) revealed the existence of a cysteine protease-like (Cys-His-Asp) catalytic triad. In the present study, a three-dimensional homology model of human NAT1, based upon the crystal structure of StNAT [Sinclair, Sandy, Delgoda, Sim and Noble (2000) Nat. Struct. Biol. 7, 560-564], is demonstrated. Alignment of StNAT and NAT1, together with secondary structure predictions, have defined a consensus region (residues 29-131) in which 37% of the residues are conserved. Homology modelling provided a good quality model of the corresponding region in human NAT1. The location of the catalytic triad was found to be identical in StNAT and NAT1. Comparison of active-site structural elements revealed that a similar length loop is conserved in both species (residues 122-131 in NAT1 model and residues 122-133 in StNAT). This observation may explain the involvement of residues 125, 127 and 129 in human NAT substrate selectivity. Our model, and the fact that cysteine protease inhibitors do not affect the activity of NAT1, suggests that human NATs may have adapted a common catalytic mechanism from cysteine proteases to accommodate it for acetyl-transfer reactions. PMID:11368758

  14. MeIQx-induced DNA adduct formation and mutagenesis in DNA repair deficient CHO cells expressing human CYP1A1 and rapid or slow acetylator NAT2

    PubMed Central

    Bendaly, Jean; Zhao, Shuang; Neale, Jason R.; Metry, Kristin J.; Doll, Mark A.; States, J. Christopher; Pierce, William M.; Hein, David W.

    2007-01-01

    2-Amino-3,8-dimethylimidazo-[4,5-f]quinoxaline (MeIQx) is one of the most potent and abundant mutagens in the western diet. Bioactivation includes N-hydroxylation catalyzed by cytochrome P450s followed by O-acetylation catalyzed by N-acetyltransferase 2 (NAT2). Nucleotide excision repair-deficient chinese hamster ovary (CHO) cells were constructed by stable transfection of human cytochrome P4501A1 (CYP1A1) and a single copy of either NAT2*4 (rapid acetylator) or NAT2*5B (slow acetylator) alleles. CYP1A1 and NAT2 catalytic activities were undetectable in untransfected CHO cell lines. CYP1A1 activity did not differ significantly (p > 0.05) among the CYP1A1-transfected cell lines. Cells transfected with NAT2*4 had significantly higher levels of sulfamethazine N-acetyltransferase (p = 0.0001) and N-hydroxy-MeIQx O-acetyltransferase (p = 0.0093) catalytic activity than cells transfected with NAT2*5B. Only cells transfected with both CYP1A1 and NAT2*4 showed concentration-dependent cytotoxicity and hypoxanthine phosphoribosyl transferase (hprt) mutagenesis following MeIQx treatment. dG-C8-MeIQx was the primary DNA adduct formed and levels were dose-dependent in each cell line and in the order: untransfected < transfected with CYP1A1 < transfected with CYP1A1 & NAT2*5B < transfected with CYP1A1 & NAT2*4. MeIQx DNA adduct levels were significantly higher (p < 0.001) in CYP1A1/NAT2*4 than CYP1A1/NAT2*5B cells at all concentrations of MeIQx tested. MeIQx-induced DNA adduct levels correlated very highly (r2 = 0.88) with MeIQx-induced mutants. These results strongly support extrahepatic activation of MeIQx by CYP1A1 and a robust effect of human NAT2 genetic polymorphism on MeIQx –induced DNA adducts and mutagenesis. The results provide laboratory-based support for epidemiological studies reporting higher frequency of heterocyclic amine-related cancers in rapid NAT2 acetylators. PMID:17627018

  15. Implementation of an HIV-1 Triple-Target NAT Assay in the Routine Screening at Three German Red Cross Blood Centres

    PubMed Central

    Zolt, Silke De; Thermann, Rolf; Bangsow, Thorsten; Pichl, Lutz; Müller, Benjamin; Jork, Christine; Weber-Schehl, Marijke; Hedges, Doris; Schupp, Ingo; Unverzagt, Patrick; de Rue, Katrin; Roth, W. Kurt

    2016-01-01

    Summary Background Blood product safety was significantly improved by the introduction of NAT testing in the late 1990s, resulting in a strong decrease of transfusion-transmitted infections (TTIs). Due to the occurrence of HIV-1 NAT test failures as a consequence of mismatch mutations in the amplicon regions of mono-target NAT assays, the Paul Ehrlich Institute mandated the implementation of multi-target NAT assays for HIV-1 in 2014. Commercial suppliers mostly developed dual-target NAT assays, with only one implementing a triple-target NAT assay. Methods The HIV-1 triple-target NAT assay v3 (GFE Blut) was tested on mutated specimens and synthetic DNA bearing mutations that resulted in sample underquantification or false-negative test results. In addition, data from 2 years routine testing at three German Red Cross Blood centres were analysed. Results The HIV-1 triple-target PCR could compensate for all mutations tested and could compensate the loss of one amplicon without a significant loss of sensitivity. Data from 2 years routine testing showed a solid performance. Conclusion The HIV-1 triple-target v3 assay (GFE Blut) can compensate mutations in target sequences better than a dual-target assay and is applicable to high-throughput screening, thus increasing blood product safety. PMID:27403090

  16. The Molecular Basis for Histone H4- and H2A-Specific Amino-Terminal Acetylation by NatD

    PubMed Central

    Magin, Robert S.; Liszczak, Glen P.; Marmorstein, Ronen

    2014-01-01

    SUMMARY N-terminal acetylation is among the most common protein modifications in eukaryotes and is mediated by evolutionarily conserved N-terminal acetyltransferases (NATs). NatD is among the most selective NATs; its only known substrates are histones H4 and H2A, containing the N-terminal sequence SGRGK in humans. Here we characterize the molecular basis for substrate-specific acetylation by NatD by reporting its crystal structure bound to cognate substrates and performing related biochemical studies. A novel N-terminal segment wraps around the catalytic core domain to make stabilizing interactions, and the α1-α2 and β6-β7 loops adopt novel conformations to properly orient the histone N termini in the binding site. Ser1 and Arg3 of the histone make extensive contacts to highly conserved NatD residues in the substrate binding pocket, and flanking glycine residues also appear to contribute to substrate-specific binding by NatD, together defining a Ser-Gly-Arg-Gly recognition sequence. These studies have implications for understanding substrate-specific acetylation by NAT enzymes. PMID:25619998

  17. Adaptive identification by systolic arrays. Master's thesis

    SciTech Connect

    Willis, P.A.

    1987-12-01

    This thesis is concerned with the implementation of an adaptive-identification algorithm using parallel processing and systolic arrays. In particular, discrete samples of input and output data of a system with uncertain characteristics are used to determine the parameters of its model. The identification algorithm is based on recursive least squares, QR decomposition, and block-processing techniques with covariance resetting. Along similar lines as previous approaches, the identification process is based on the use of Givens rotations. This approach uses the Cordic algorithm for improved numerical efficiency in performing the rotations. Additionally, floating-point and fixed-point arithmetic implementations are compared.

  18. Simulations of the Vertical Redistribution of HNO3 by NAT or NAD PSCs: The Sensitivity to the Number of Cloud Particles Formed and the Cloud Lifetime

    NASA Technical Reports Server (NTRS)

    Jensen, Eric J.; Tabazadeh, Azadeh; Drdla, Katja; Toon, Owen B.; Gore, Warren J. (Technical Monitor)

    2000-01-01

    Recent satellite and in situ measurements have indicated that limited denitrification can occur in the Arctic stratosphere. In situ measurements from the SOLVE campaign indicate polar stratospheric clouds (PSCs) composed of small numbers (about 3 x 10^ -4 cm^-3) of 10-20 micron particles (probably NAT or NAD). These observations raise the issue of whether low number density NAT PSCs can substantially denitrify the air with reasonable cloud lifetimes. In this study, we use a one dimensional cloud model to investigate the verticle redistribution of HNO3 by NAT/NAD PSCs. The cloud formation is driven by a temperature oscillation which drops the temperature below the NAT/NAD formation threshold (about 195 K) for a few days. We assume that a small fraction of the available aerosols act as NAT nuclei when the saturation ratio of HNO3 over NAT(NAD) exceeds 10(l.5). The result is a cloud between about 16 and 20 km in the model, with NAT/NAD particle effective radii as large as about 10 microns (in agreement with the SOLVE data). We find that for typical cloud lifetimes of 2-3 days or less, the net depletion of HNO3 is no more than 1-2 ppbv, regardless of the NAT or NAD particle number density. Repeated passes of the air column through the cold pool build up the denitrification to 3-4 ppbv, and the cloud altitude steadily decreases due to the downward transport of nitric acid. Increasing the cloud lifetime results in considerably more effective denitrification, even with very low cloud particle number densities. As expected, the degree of denitrification by NAT clouds is much larger than that by NAD Clouds. Significant denitrification by NAD Clouds is only possible if the cloud lifetime is several days or more. The clouds also cause a local maximum HNO3 mixing ratio at cloud base where the cloud particles sublimate.

  19. Interaction between Red Meat Intake and NAT2 Genotype in Increasing the Risk of Colorectal Cancer in Japanese and African Americans

    PubMed Central

    Wang, Hansong; Iwasaki, Motoki; Haiman, Christopher A.; Kono, Suminori; Wilkens, Lynne R.; Keku, Temitope O.; Berndt, Sonja I.; Tsugane, Shoichiro; Le Marchand, Loïc

    2015-01-01

    Heterocyclic aromatic amines formed in cooked meat may be an underlying mechanism for the red meat-colorectal cancer (CRC) association. These compounds require bioactivaction by N-acetyltransferase 2 (NAT2). An interaction effect between red meat consumption and NAT2 in increasing CRC risk has been inconsistently reported in whites. We investigated this interaction in two populations in which the high-activity rapid NAT2 phenotype is 10- and 2-fold more common than in whites. We meta-analyzed four studies of Japanese (2,217 cases, 3,788 controls) and three studies of African Americans (527 cases, 4,527 controls). NAT2 phenotype was inferred from an optimized seven-SNP genotyping panel. Processed and total red meat intakes were associated with an increased CRC risk in Japanese and in both ethnic groups combined (P’s ≤ 0.002). We observed an interaction between processed meat intake and NAT2 in Japanese (P = 0.04), African Americans (P = 0.02), and in both groups combined (P = 0.006). The association of processed meat with CRC was strongest among individuals with the rapid NAT2 phenotype (combined analysis, OR for highest vs. lowest quartile: 1.62, 95% CI: 1.28–2.05; Ptrend = 8.0×10−5), intermediate among those with the intermediate NAT2 phenotype (1.29, 95% CI: 1.05–1.59; Ptrend = 0.05) and null among those with the slow phenotype (Ptrend = 0.45). A similar interaction was found for NAT2 and total red meat (Pinteraction = 0.03). Our findings support a role for NAT2 in modifying the association between red meat consumption and CRC in Japanese and African Americans. PMID:26683305

  20. Interaction between Red Meat Intake and NAT2 Genotype in Increasing the Risk of Colorectal Cancer in Japanese and African Americans.

    PubMed

    Wang, Hansong; Iwasaki, Motoki; Haiman, Christopher A; Kono, Suminori; Wilkens, Lynne R; Keku, Temitope O; Berndt, Sonja I; Tsugane, Shoichiro; Le Marchand, Loïc

    2015-01-01

    Heterocyclic aromatic amines formed in cooked meat may be an underlying mechanism for the red meat-colorectal cancer (CRC) association. These compounds require bioactivaction by N-acetyltransferase 2 (NAT2). An interaction effect between red meat consumption and NAT2 in increasing CRC risk has been inconsistently reported in whites. We investigated this interaction in two populations in which the high-activity rapid NAT2 phenotype is 10- and 2-fold more common than in whites. We meta-analyzed four studies of Japanese (2,217 cases, 3,788 controls) and three studies of African Americans (527 cases, 4,527 controls). NAT2 phenotype was inferred from an optimized seven-SNP genotyping panel. Processed and total red meat intakes were associated with an increased CRC risk in Japanese and in both ethnic groups combined (P's ≤ 0.002). We observed an interaction between processed meat intake and NAT2 in Japanese (P = 0.04), African Americans (P = 0.02), and in both groups combined (P = 0.006). The association of processed meat with CRC was strongest among individuals with the rapid NAT2 phenotype (combined analysis, OR for highest vs. lowest quartile: 1.62, 95% CI: 1.28-2.05; Ptrend = 8.0×10-5), intermediate among those with the intermediate NAT2 phenotype (1.29, 95% CI: 1.05-1.59; Ptrend = 0.05) and null among those with the slow phenotype (Ptrend = 0.45). A similar interaction was found for NAT2 and total red meat (Pinteraction = 0.03). Our findings support a role for NAT2 in modifying the association between red meat consumption and CRC in Japanese and African Americans. PMID:26683305

  1. Rer1 and calnexin regulate endoplasmic reticulum retention of a peripheral myelin protein 22 mutant that causes type 1A Charcot-Marie-Tooth disease

    PubMed Central

    Hara, Taichi; Hashimoto, Yukiko; Akuzawa, Tomoko; Hirai, Rika; Kobayashi, Hisae; Sato, Ken

    2014-01-01

    Peripheral myelin protein 22 (PMP22) resides in the plasma membrane and is required for myelin formation in the peripheral nervous system. Many PMP22 mutants accumulate in excess in the endoplasmic reticulum (ER) and lead to the inherited neuropathies of Charcot-Marie-Tooth (CMT) disease. However, the mechanism through which PMP22 mutants accumulate in the ER is unknown. Here, we studied the quality control mechanisms for the PMP22 mutants L16P and G150D, which were originally identified in mice and patients with CMT. We found that the ER-localised ubiquitin ligase Hrd1/SYVN1 mediates ER-associated degradation (ERAD) of PMP22(L16P) and PMP22(G150D), and another ubiquitin ligase, gp78/AMFR, mediates ERAD of PMP22(G150D) as well. We also found that PMP22(L16P), but not PMP22(G150D), is partly released from the ER by loss of Rer1, which is a Golgi-localised sorting receptor for ER retrieval. Rer1 interacts with the wild-type and mutant forms of PMP22. Interestingly, release of PMP22(L16P) from the ER was more prominent with simultaneous knockdown of Rer1 and the ER-localised chaperone calnexin than with the knockdown of each gene. These results suggest that CMT disease-related PMP22(L16P) is trapped in the ER by calnexin-dependent ER retention and Rer1-mediated early Golgi retrieval systems and partly degraded by the Hrd1-mediated ERAD system. PMID:25385046

  2. Enhancing international earth science competence in natural hazards through 'geoNatHaz

    NASA Astrophysics Data System (ADS)

    Giardino, Marco; Clague, John J.

    2010-05-01

    "geoNatHaz" is a Transatlantic Exchange Partnership project (TEP 2009-2012) within the framework of the EU-Canada programme for co-operation in higher education, training, and youth. The project is structured to improve knowledge and skills required to assess and manage natural hazards in mountain regions. It provides student exchanges between European and Canadian universities in order to enhance international competence in natural hazard research. The university consortium is led by Simon Fraser University (Canada) and Università degli studi di Torino (Italy). Partner universities include the University of British Columbia, Queen's University, Università di Bologna, Université de Savoie, and the University of Athens. Université de Lausanne (Switzerland) supports the geoNatHaz advisory board through its bilateral agreements with Canadian partner universities. The geoNatHaz project promotes cross-cultural understanding and internationalization of university natural hazard curricula through common lectures, laboratory exercises, and field activities. Forty graduate students from the seven Canadian and European partner universities will benefit from the project between 2009 and 2012. Some students enrolled in graduate-level earth science and geologic engineering programs spend up to five months at the partner universities, taking courses and participating in research teams under the direction of project scientists. Other students engage in short-term (four-week) exchanges involving training in classic natural hazard case-studies in mountain regions of Canada and Europe. Joint courses are delivered in English, but complementary cultural activities are offered in the languages of the host countries. Supporting organizations offer internships and technical and scientific support. Students benefit from work-study programs with industry partners. Supporting organizations include government departments and agencies (Geological Survey of Canada; CNR-IRPI National

  3. Genotyping NAT2 with only two SNPs (rs1041983 and rs1801280) outperforms the tagging SNP rs1495741 and is equivalent to the conventional 7-SNP NAT2 genotype.

    PubMed

    Selinski, Silvia; Blaszkewicz, Meinolf; Lehmann, Marie-Louise; Ovsiannikov, Daniel; Moormann, Oliver; Guballa, Christoph; Kress, Alexander; Truss, Michael C; Gerullis, Holger; Otto, Thomas; Barski, Dimitri; Niegisch, Günter; Albers, Peter; Frees, Sebastian; Brenner, Walburgis; Thüroff, Joachim W; Angeli-Greaves, Miriam; Seidel, Thilo; Roth, Gerhard; Dietrich, Holger; Ebbinghaus, Rainer; Prager, Hans M; Bolt, Hermann M; Falkenstein, Michael; Zimmermann, Anna; Klein, Torsten; Reckwitz, Thomas; Roemer, Hermann C; Löhlein, Dietrich; Weistenhöfer, Wobbeke; Schöps, Wolfgang; Hassan Rizvi, Syed Adibul; Aslam, Muhammad; Bánfi, Gergely; Romics, Imre; Steffens, Michael; Ekici, Arif B; Winterpacht, Andreas; Ickstadt, Katja; Schwender, Holger; Hengstler, Jan G; Golka, Klaus

    2011-10-01

    Genotyping N-acetyltransferase 2 (NAT2) is of high relevance for individualized dosing of antituberculosis drugs and bladder cancer epidemiology. In this study we compared a recently published tagging single nucleotide polymorphism (SNP) (rs1495741) to the conventional 7-SNP genotype (G191A, C282T, T341C, C481T, G590A, A803G and G857A haplotype pairs) and systematically analysed if novel SNP combinations outperform the latter. For this purpose, we studied 3177 individuals by PCR and phenotyped 344 individuals by the caffeine test. Although the tagSNP and the 7-SNP genotype showed a high degree of correlation (R=0.933, P<0.0001) the 7-SNP genotype nevertheless outperformed the tagging SNP with respect to specificity (1.0 vs. 0.9444, P=0.0065). Considering all possible SNP combinations in a receiver operating characteristic analysis we identified a 2-SNP genotype (C282T, T341C) that outperformed the tagging SNP and was equivalent to the 7-SNP genotype. The 2-SNP genotype predicted the correct phenotype with a sensitivity of 0.8643 and a specificity of 1.0. In addition, it predicted the 7-SNP genotype with sensitivity and specificity of 0.9993 and 0.9880, respectively. The prediction of the NAT2 genotype by the 2-SNP genotype performed similar in populations of Caucasian, Venezuelan and Pakistani background. A 2-SNP genotype predicts NAT2 phenotypes with similar sensitivity and specificity as the conventional 7-SNP genotype. This procedure represents a facilitation in individualized dosing of NAT2 substrates without losing sensitivity or specificity. PMID:21750470

  4. Superconducting technology for electric propulsion. Master's thesis

    SciTech Connect

    Keamy, E.F.

    1988-06-01

    This thesis analyzes the superconducting technology for a shipboard electric propulsion system. Superconductor operational operational limits, and magnet-design requirements were established. The magnetic-field requirements for a large-scale superconducting propulsion plant were analyzed from experimental information on copper and aluminum-stabilized NbTi superconductors. Experimental results were followed with a feasibility study in the conversion of a DD963 Spruance Class Destroyer from mechanical to superconducting electric drive. The results of the conversion are an increase in survivability, speed, usable deck area (4,954 ftS, maintainability, propeller efficiency and endurance range (+71%) along with a decrease in displacement (-2.83%) and self-radiated noise without compromising existing mission capabilities. The estimated cost of the conversion is $118.8 million dollars.

  5. Thermal Signature Identification System (TheSIS)

    NASA Technical Reports Server (NTRS)

    Merritt, Scott; Bean, Brian

    2015-01-01

    We characterize both nonlinear and high order linear responses of fiber-optic and optoelectronic components using spread spectrum temperature cycling methods. This Thermal Signature Identification System (TheSIS) provides much more detail than conventional narrowband or quasi-static temperature profiling methods. This detail allows us to match components more thoroughly, detect subtle reversible shifts in performance, and investigate the cause of instabilities or irreversible changes. In particular, we create parameterized models of athermal fiber Bragg gratings (FBGs), delay line interferometers (DLIs), and distributed feedback (DFB) lasers, then subject the alternative models to selection via the Akaike Information Criterion (AIC). Detailed pairing of components, e.g. FBGs, is accomplished by means of weighted distance metrics or norms, rather than on the basis of a single parameter, such as center wavelength.

  6. Single link flexible beam testbed project. Thesis

    NASA Technical Reports Server (NTRS)

    Hughes, Declan

    1992-01-01

    This thesis describes the single link flexible beam testbed at the CLaMS laboratory in terms of its hardware, software, and linear model, and presents two controllers, each including a hub angle proportional-derivative (PD) feedback compensator and one augmented by a second static gain full state feedback loop, based upon a synthesized strictly positive real (SPR) output, that increases specific flexible mode pole damping ratios w.r.t the PD only case and hence reduces unwanted residual oscillation effects. Restricting full state feedback gains so as to produce a SPR open loop transfer function ensures that the associated compensator has an infinite gain margin and a phase margin of at least (-90, 90) degrees. Both experimental and simulation data are evaluated in order to compare some different observer performance when applied to the real testbed and to the linear model when uncompensated flexible modes are included.

  7. Arylamine N-acetyltransferase (NAT2) mutations and their allelic linkage in unrelated caucasian individuals: Correlation with phenotypic activity

    SciTech Connect

    Cascorbi, I.; Drakoulis, N.; Brockmoeller, J.

    1995-09-01

    The polymorphic arylamine N-acetyltransferase (NAT2; EC2.3.1.5) is supposed to be a susceptibility factor for several drug side effects and certain malignancies. A group of 844 unrelated German subjects was genotyped for their acetylation type, and 563 of them were also phenotyped. Seven mutations of the NAT2 gene were evaluated by allele-specific PCR (mutation 341C to T) and PCR-RFLP for mutations at nt positions 191, 282, 481, 590, 803, and 857. From the mutation pattern eight different alleles, including the wild type coding for rapid acetylation and seven alleles coding for slow phenotype, were determined. Four hundred ninety-seven subjects had a genotype of slow acetylation (58.9%; 95% confidence limits 55.5%-62.2%). Phenotypic acetylation capacity was expressed as the ratio of 5-acetylamino-6-formylamino-3-methyluracil and 1-methylxanthine in urine after caffeine intake. Some 6.7% of the cases deviated in genotype and phenotype, but sequencing DNA of these probands revealed no new mutations. Furthermore, linkage pattern of the mutations was always confirmed, as tested in 533 subjects. In vivo acetylation capacity of homozygous wild-type subjects (NAT2{sup *}4/{sup *}4) was significantly higher than in heterozygous genotypes (P = .001). All mutant alleles showed low in vivo acetylation capacities, including the previously not-yet-defined alleles {sup *}5A, {sup *}5C, and {sup *}13. Moreover, distinct slow genotypes differed significantly among each other, as reflected in lower acetylation capacity of {sup *}6A, {sup *}7B, and {sup *}13 alleles than the group of {sup *}5 alleles. The study demonstrated differential phenotypic activity of various NAT2 genes and gives a solid basis for clinical and molecular-epidemiological investigations. 34 refs., 4 figs., 7 tabs.

  8. Contribution of liquid, NAT and ice particles to chlorine activation and ozone depletion in Antarctic winter and spring

    NASA Astrophysics Data System (ADS)

    Kirner, O.; Müller, R.; Ruhnke, R.; Fischer, H.

    2015-02-01

    Heterogeneous reactions in the Antarctic stratosphere are the cause of chlorine activation and ozone depletion, but the relative roles of different types of polar stratospheric clouds (PSCs) in chlorine activation is an open question. We use multi-year simulations of the chemistry-climate model ECHAM5/MESSy for Atmospheric Chemistry (EMAC) to investigate the impact that the various types of PSCs have on Antarctic chlorine activation and ozone loss. One standard and three sensitivity EMAC simulations have been performed. In all simulations a Newtonian relaxation technique using the ERA-Interim reanalysis was applied to simulate realistic synoptic conditions. In the three sensitivity simulations, we only changed the heterogeneous chemistry on PSC particles by switching the chemistry on liquid, nitric acid trihydrate (NAT) and ice particles on and off. The results of these simulations show that the significance of heterogeneous reactions on NAT and ice particles for chlorine activation and ozone depletion in Antarctic winter and spring is small in comparison to the significance of heterogeneous reactions on liquid particles. Liquid particles alone are sufficient to activate almost all of the available chlorine, with the exception of the upper PSC regions between 10 and 30 hPa, where temporarily ice particles show a relevant contribution. Shortly after the first PSC occurrence, NAT particles contribute a small fraction to chlorine activation. Heterogeneous chemistry on liquid particles is responsible for more than 90% of the ozone depletion in Antarctic spring in the model simulations. In high southern latitudes, heterogeneous chemistry on ice particles causes only up to 5 DU of additional ozone depletion in the column and heterogeneous chemistry on NAT particles less than 0.5 DU. The simulated HNO3, ClO and O3 results agree closely with observations from the Microwave Limb Sounder (MLS) onboard NASA's Aura satellite.

  9. MT1 receptor expression and AA-NAT activity in lymphatic tissue following melatonin administration in male golden hamster.

    PubMed

    Vishwas, Dipanshu Kumar; Haldar, Chandana

    2014-09-01

    Exogenous melatonin as a marker of the chemical expression of darkness is playing a key role in the synchronization of circadian functions and seasonal biological rhythms. Our study was designed to elucidate whether melatonin treatment can modulate the melatonin synthesis via the rate limiting enzyme arylalkylamine-N-acetyltransferase (AA-NAT) in spleen, thymus and bone marrow thereby the proliferation rate of splenocytes, thymocytes and bone marrow mononuclear cells (BM-MNCs) of golden hamsters. The AA-NAT activity in different lymphoid tissue documented the synthesis of melatonin in those organs. Exogenous melatonin treatment to hamsters enhanced the AA-NAT activity in spleen and thymus along with an increase in the inflammatory response by DTH reactions that could be related to the increased level of interleukin-2 and IFN-γ by T lymphocytes in serum/culture medium, proliferation rate and expression of melatonin membrane receptor MT(1). Thus, the relevance of melatonin synthesis by lymphatic tissues might be maintaining surveillance and local defence responses. PMID:25023124

  10. Structure and function of human Naa60 (NatF), a Golgi-localized bi-functional acetyltransferase

    PubMed Central

    Chen, Ji-Yun; Liu, Liang; Cao, Chun-Ling; Li, Mei-Jun; Tan, Kemin; Yang, Xiaohan; Yun, Cai-Hong

    2016-01-01

    N-terminal acetylation (Nt-acetylation), carried out by N-terminal acetyltransferases (NATs), is a conserved and primary modification of nascent peptide chains. Naa60 (also named NatF) is a recently identified NAT found only in multicellular eukaryotes. This protein was shown to locate on the Golgi apparatus and mainly catalyze the Nt-acetylation of transmembrane proteins, and it also harbors lysine Nε-acetyltransferase (KAT) activity to catalyze the acetylation of lysine ε-amine. Here, we report the crystal structures of human Naa60 (hNaa60) in complex with Acetyl-Coenzyme A (Ac-CoA) or Coenzyme A (CoA). The hNaa60 protein contains an amphipathic helix following its GNAT domain that may contribute to Golgi localization of hNaa60, and the β7-β8 hairpin adopted different conformations in the hNaa60(1-242) and hNaa60(1-199) crystal structures. Remarkably, we found that the side-chain of Phe 34 can influence the position of the coenzyme, indicating a new regulatory mechanism involving enzyme, co-factor and substrates interactions. Moreover, structural comparison and biochemical studies indicated that Tyr 97 and His 138 are key residues for catalytic reaction and that a non-conserved β3-β4 long loop participates in the regulation of hNaa60 activity. PMID:27550639

  11. Structure and function of human Naa60 (NatF), a Golgi-localized bi-functional acetyltransferase.

    PubMed

    Chen, Ji-Yun; Liu, Liang; Cao, Chun-Ling; Li, Mei-Jun; Tan, Kemin; Yang, Xiaohan; Yun, Cai-Hong

    2016-01-01

    N-terminal acetylation (Nt-acetylation), carried out by N-terminal acetyltransferases (NATs), is a conserved and primary modification of nascent peptide chains. Naa60 (also named NatF) is a recently identified NAT found only in multicellular eukaryotes. This protein was shown to locate on the Golgi apparatus and mainly catalyze the Nt-acetylation of transmembrane proteins, and it also harbors lysine N(ε)-acetyltransferase (KAT) activity to catalyze the acetylation of lysine ε-amine. Here, we report the crystal structures of human Naa60 (hNaa60) in complex with Acetyl-Coenzyme A (Ac-CoA) or Coenzyme A (CoA). The hNaa60 protein contains an amphipathic helix following its GNAT domain that may contribute to Golgi localization of hNaa60, and the β7-β8 hairpin adopted different conformations in the hNaa60(1-242) and hNaa60(1-199) crystal structures. Remarkably, we found that the side-chain of Phe 34 can influence the position of the coenzyme, indicating a new regulatory mechanism involving enzyme, co-factor and substrates interactions. Moreover, structural comparison and biochemical studies indicated that Tyr 97 and His 138 are key residues for catalytic reaction and that a non-conserved β3-β4 long loop participates in the regulation of hNaa60 activity. PMID:27550639

  12. Mutation of an Arabidopsis NatB N-Alpha-Terminal Acetylation Complex Component Causes Pleiotropic Developmental Defects

    PubMed Central

    Ferrández-Ayela, Almudena; Alonso-Peral, María Magdalena; Micol, José Luis; Ponce, María Rosa

    2013-01-01

    N-α-terminal acetylation is one of the most common, but least understood modifications of eukaryotic proteins. Although a high degree of conservation exists between the N-α-terminal acetylomes of plants and animals, very little information is available on this modification in plants. In yeast and humans, N-α-acetyltransferase complexes include a single catalytic subunit and one or two auxiliary subunits. Here, we report the positional cloning of TRANSCURVATA2 (TCU2), which encodes the auxiliary subunit of the NatB N-α-acetyltransferase complex in Arabidopsis. The phenotypes of loss-of-function tcu2 alleles indicate that NatB complex activity is required for flowering time regulation and for leaf, inflorescence, flower, fruit and embryonic development. In double mutants, tcu2 alleles synergistically interact with alleles of ARGONAUTE10, which encodes a component of the microRNA machinery. In summary, NatB-mediated N-α-terminal acetylation of proteins is pleiotropically required for Arabidopsis development and seems to be functionally related to the microRNA pathway. PMID:24244708

  13. What Examiners Do: What Thesis Students Should Know

    ERIC Educational Resources Information Center

    Golding, Clinton; Sharmini, Sharon; Lazarovitch, Ayelet

    2014-01-01

    Although many articles have been written about thesis assessment, none provide a comprehensive, general picture of what examiners do as they assess a thesis. To synthesise this diverse literature, we reviewed 30 articles, triangulated their conclusions and identified 11 examiner practices. Thesis examiners tend to be broadly consistent in their…

  14. Evaluation of the Procleix Ultrio Elite Assay and the Panther-System for Individual NAT Screening of Blood, Hematopoietic Stem Cell, Tissue and Organ Donors

    PubMed Central

    Heim, Albert

    2016-01-01

    Summary Background The performance of the multiplex Procleix Ultrio Elite assay as individual donor nucleic acid test (ID-NAT) for the detection of HIV-1, HIV-2, HCV, and HBV was evaluated in a retrospective, single center study. Methods ID-NAT results of 21,181 blood donors, 984 tissue donors, 293 hematopoietic stem cell donors and 4 organ donors were reviewed in synopsis with results of serological screening and additional discriminatory and repetitive NAT in case of positive donors. Results Specificity of the initial Procleix Ultrio Elite assay was 99.98% and after discriminatory testing 100.00%. Initially invalid results were observed in 75 of 21,181 blood donors (0.35%) but 16 of 984 tissue donors (1.62%, p < 0.001) which included non-heart-beating (‘cadaveric’) donors. All these had valid negative ID-NAT results after repeated testing or testing of 1:5 diluted specimens in case of tissue donors. Occult hepatitis B (defined here as HBV DNAemia without HBsAg detection) was demonstrated by ID-NAT in two anti-HBc-positive tissue donors and suspected in two other tissue donors, where a definite diagnosis was not achieved due to the insufficient sample volumes available. Conclusion The Procleix Ultrio Elite assay proved to be specific, robust and rapid. Therefore, routine ID-NAT may also be feasible for organ and granulocyte donors.

  15. Towards flash flood disaster prevention: the SciNetNat Haz proposal

    NASA Astrophysics Data System (ADS)

    Konstantinos, Papatheodorou; Elena, Tzanou; Carmen, Maftei; Ozgur, Kirca; Hafzullah, Aksoy

    2015-04-01

    Floods occur with a continuously increasing frequency due to climatic changes and cause serious damage in the wider Black Sea area, endangering human life and property. As societies continuously expand, these phenomena are expected to play an increasingly important role, blocking sustainable development unless properly tackled. Flash flood prevention seems at this point, to be the target of effectively mitigating the potential threat. Since in many cases, there is a cross-border character of the problem, collaborative efforts have to be made involving cooperation between countries. To this end, a variety of problems exist, including the "information gap" related to the unavailability of data and the multitude of methodologies used to assess flood hazard; a fact that renders comparison of hazard assessment results and cross border cooperation ineffective. An effort made within the context of the SciNetNatHaz project, suggests a two step approach to produce reliable the results which can lead to decision making regarding designing preventive measures. The first step aims at defining the flood prone areas on a regional scale, using geomorphometric models and readily available topographic data; thus overcoming the problem of data availability for any region of interest. The second step follows a vulnerability and risk assessment of the flood prone areas of interest and focuses on the calculation of flood parameters on a local scale using hydraulic models. Implementation of the full process is based on Open Source software tools so that it can be implemented with minimal costs by anyone interested. Implementation of the proposed procedure in three different cases in Greece and in Romania shows that it can provide accurate and reliable results to support decision making regarding the design of preventive measures. Keywords: Flash floods, hazard assessment, flood disaster prevention, HEC-RAS, SAGA GIS . Acknowledgements: This work is partially funded by the EU through the

  16. NAT1, NOS3, and TYMS Genotypes and the Risk of Conotruncal Cardiac Defects

    PubMed Central

    Lupo, Philip J.; Mitchell, Laura E.; Goldmuntz, Elizabeth

    2015-01-01

    Background Although congenital heart defects (CHDs) are a common and serious group of birth defects, relatively little is known about the causes of these conditions, and there are no established prevention strategies. There is, however, evidence suggesting that the risk of CHDs in general, and conotruncal and related defects (CTRDs) in particular, may be associated with maternal folate status and genetic variants of folate-related genes. Although several folate-related genes have been studied as they relate to CHDs and CTRDs (e.g., MTHFR), others have not been adequately assessed. Methods Case-parent triads were examined using log-linear analyses to assess the associations between CTRDs and both the genotype inherited by the case and the maternal genotype for the following variants: NAT1 1095C>A, NOS3 894G>T, and TYMS 1494del6. Subgroup analyses were also conducted among cases with classic conotruncal defects and cases with normally related great arteries. Results The results provided little evidence that CTRD risk was associated with the genotype inherited by the case for any of the analyzed variants. However, our results suggest that CTRD risk may be associated with the maternal genotype for NOS3 894G>T (p = 0.024 in the subgroup with normally related great arteries) and TYMS 1494del6 (p = 0.048 in the subgroup with classic conotruncal defects). However, these results were not significant after correcting for multiple comparisons. Conclusion This study provides further evidence that CTRD risk may be related to variation within folate-pathway genes and suggests that these associations are, at least in part, mediated through the maternal genotype. PMID:21254360

  17. Electron scattering from silicon 30. Master's thesis

    SciTech Connect

    Bernhardt, G.P. IV

    1983-01-01

    In 1940, the first experiments on electron excitation of nuclei to discrete levels were done by Collins and Waldman. The first theoretical discussions of this inelastic electron scattering were due to Mamasachlisor in 1943 and Snedden and Touschek in 1948. Lyman et al. in 1951, using a betatron, clearly saw effects due to deviations from point Coulomb scattering, thus allowing nuclear sizes to be measured using electron elastic scattering. Since that time, linear accelerators have become the standard source of high-energy electrons for such work. However, due to the limited resolution, an experiment of the type done in this thesis was not possible before the current generation of linear accelerators and spectrometers. The machine used in the 1950's allowed electron scattering with a resolution of delta p/p 3/5x10 and with currents of a few tenths of a microampre. Work done using these machines, although including some excellent work such as that done by Hofstadter was limited to a few nuclei with well-isolated levels due to inability to resolve closely spaced levels.

  18. Towards a doctoral thesis through published works.

    PubMed

    Breimer, L H; Mikhailidis, D P

    1993-01-01

    Doctoral theses submitted in medical schools under a system dependent on publications (Sweden) and one which was not (UK) were compared. A subset consisting of UK theses containing papers (about 1/3 of all UK theses) was used. The publication-based theses gave candidates a significantly higher (P < 0.03) profile in terms of key authorship positions. Nevertheless, in 66% of the UK theses with papers the candidate was either the first or sole author. Swedish and UK theses with papers were of equal quality when assessed by the number of papers in journals: a) ranked in the top 100 (14% vs 10%) or 200 (26% vs 32%); or b) used more than once and either ranked in the top 1000 (median 224 vs 218) or in the top two thirds by subject section (98 vs 100%). UK theses benefitted from the greater impact of journals emanating from the UK compared to continental Europe (P < 0.001). An estimated 13% of UK PhD theses overall included three or more papers per thesis despite no requirement of publication. A publication-based doctorate should be introduced on trial in parallel with the existing systems to ensure efficiency and international comparability. PMID:8068863

  19. Evaluation of polymorphisms in the sulfonamide detoxification genes NAT2, CYB5A, and CYB5R3 in patients with sulfonamide hypersensitivity

    PubMed Central

    Sacco, James; Abouraya, Mahmoud; Motsinger-Reif, Alison; Yale, Steven; McCarty, Catherine; Trepanier, Lauren

    2013-01-01

    Objective To determine whether polymorphisms in the sulfonamide detoxification genes, CYB5A (encoding cytochrome b5), CYB5R3 (encoding cytochrome b5 reductase), or NAT2 (encoding N-acetyltransferase 2) were over-represented in patients with delayed sulfonamide drug hypersensitivity, compared to control patients that tolerated a therapeutic course of trimethoprim-sulfamethoxazole without adverse event. Methods DNA from 99 non-immunocompromised patients with sulfonamide hypersensitivity that were identified from the Personalized Medicine Research Project at the Marshfield Clinic, and from 99 age-, race-, and gender-matched drug-tolerant controls, were genotyped for four CYB5A and five CYB5R3 polymorphisms, and for all coding NAT2 SNPs. Results CYB5A and CYB5R3 SNPs were found at low allele frequencies (less than 3–4%), which did not differ between hypersensitive and tolerant patients. NAT2 allele and haplotype frequencies, as well as inferred NAT2 phenotypes, also did not differ between groups (60% vs. 59% slow acetylators). Finally, no difference in NAT2 status was found in a subset of patients with more severe hypersensitivity signs (drug reaction with eosinophilia and systemic symptoms; DRESS) compared to tolerant patients. Conclusions We found no evidence for a substantial involvement of these 9 CYB5A or CYB5R3 polymorphisms in sulfonamide HS risk, although minor effects cannot be completely ruled out. Despite careful medical record review and full re-sequencing of the NAT2 coding region, we found no association of NAT2 coding alleles with sulfonamide hypersensitivity (predominantly cutaneous eruptions) in this adult Caucasian population. PMID:22850190

  20. NatF Contributes to an Evolutionary Shift in Protein N-Terminal Acetylation and Is Important for Normal Chromosome Segregation

    PubMed Central

    Helsens, Kenny; Vandekerckhove, Joël; Martinho, Rui G.; Gevaert, Kris; Arnesen, Thomas

    2011-01-01

    N-terminal acetylation (N-Ac) is a highly abundant eukaryotic protein modification. Proteomics revealed a significant increase in the occurrence of N-Ac from lower to higher eukaryotes, but evidence explaining the underlying molecular mechanism(s) is currently lacking. We first analysed protein N-termini and their acetylation degrees, suggesting that evolution of substrates is not a major cause for the evolutionary shift in N-Ac. Further, we investigated the presence of putative N-terminal acetyltransferases (NATs) in higher eukaryotes. The purified recombinant human and Drosophila homologues of a novel NAT candidate was subjected to in vitro peptide library acetylation assays. This provided evidence for its NAT activity targeting Met-Lys- and other Met-starting protein N-termini, and the enzyme was termed Naa60p and its activity NatF. Its in vivo activity was investigated by ectopically expressing human Naa60p in yeast followed by N-terminal COFRADIC analyses. hNaa60p acetylated distinct Met-starting yeast protein N-termini and increased general acetylation levels, thereby altering yeast in vivo acetylation patterns towards those of higher eukaryotes. Further, its activity in human cells was verified by overexpression and knockdown of hNAA60 followed by N-terminal COFRADIC. NatF's cellular impact was demonstrated in Drosophila cells where NAA60 knockdown induced chromosomal segregation defects. In summary, our study revealed a novel major protein modifier contributing to the evolution of N-Ac, redundancy among NATs, and an essential regulator of normal chromosome segregation. With the characterization of NatF, the co-translational N-Ac machinery appears complete since all the major substrate groups in eukaryotes are accounted for. PMID:21750686

  1. Arylamine N-acetyl Transferase (NAT) in the blue secretion of Telescopium telescopium: xenobiotic metabolizing enzyme as a biomarker for detection of environmental pollution.

    PubMed

    Gorain, Bapi; Chakraborty, Sumon; Pal, Murari Mohan; Sarkar, Ratul; Samanta, Samir Kumar; Karmakar, Sanmoy; Sen, Tuhinadri

    2014-01-01

    Telescopium telescopium, a marine mollusc collected from Sundarban mangrove, belongs to the largest mollusca phylum in the world and exudes a blue secretion when stimulated mechanically. The blue secretion was found to metabolize (preferentially) para-amino benzoic acid, a substrate for N-acetyl transferase (NAT), thereby indicating acetyl transferase like activity of the secretion. Attempts were also made to characterise bioactive fraction of the blue secretion and to further use this as a biomarker for monitoring of marine pollution. NAT like enzyme from marine mollusc is a potential candidate for detoxification of different harmful chemicals. A partially purified extract of blue secretion was obtained by fractional precipitation with (NH4)2SO4. From different fractions obtained by precipitation, the 0-30% fraction (30S) displayed NAT like activity (using para amino benzoic acid as a substrate with para nitrophenyl phosphate or acetyl coenzyme A as acetyl group donors). Maximum NAT like enzyme activity was attained at 25°C and at a pH of 6. The enzyme activity was found to be inhibited by 5 mM phenyl methyl sulfonyl fluoride. The divalent metal ions reduced NAT like activity of 30S. Moreover, Cu(2+) and Zn(2+) (at concentration of 1 mM) completely inhibited NAT activity. The thermal stability and bench-top stability studies were performed and it was found that the enzyme was stable at room temperature for more than 24 hours. Results from the present study further indicate that heavy metal content in blue secretion gradually decreased from pre-monsoon to post-monsoon season, which also corresponded to the change in NAT like activity. Therefore, this article stresses the importance of biomarker research for monitoring pollution. PMID:26034680

  2. N-acetyltransferase 2 (NAT2) gene polymorphism as a predisposing factor for phenytoin intoxication in tuberculous meningitis or tuberculoma patients having seizures - A pilot study

    PubMed Central

    Adole, Prashant S.; Kharbanda, Parampreet S.; Sharma, Sadhna

    2016-01-01

    Background & objectives: Simultaneous administration of phenytoin and isoniazid (INH) in tuberculous meningitis (TBM) or tuberculoma patients with seizures results in higher plasma phenytoin level and thus phenytoin intoxication. N-acetyltransferase 2 (NAT2) enzyme catalyses two acetylation reactions in INH metabolism and NAT2 gene polymorphism leads to slow and rapid acetylators. The present study was aimed to evaluate the effect of allelic variants of N-acetyltransferase 2 (NAT2) gene as a predisposing factor for phenytoin toxicity in patients with TBM or tuberculoma having seizures, and taking INH and phenytoin simultaneously. Methods: Sixty patients with TBM or tuberculoma with seizures and taking INH and phenytoin simultaneously for a minimum period of seven days were included in study. Plasma phenytoin was measured by high performance liquid chromatography. NAT2 gene polymorphism was studied using restriction fragment length polymorphism and allele specific PCR. Results: The patients were grouped into those having phenytoin intoxication and those with normal phenytoin level, and also classified as rapid or slow acetylators by NAT2 genotyping. Genotypic analysis showed that of the seven SNPs (single nucleotide polymorphisms) of NAT2 gene studied, six mutations were found to be associated with phenytoin intoxication. For rs1041983 (C282T), rs1799929 (C481T), rs1799931 (G857A), rs1799930 (G590A), rs1208 (A803G) and rs1801280 (T341C) allelic variants, the proportion of homozygous mutant was higher in phenytoin intoxicated group than in phenytoin non-intoxicated group. Interpretation & conclusions: Homozygous mutant allele of NAT2 gene at 481site may act as a predisposing factor for phenytoin intoxication among TBM or tuberculoma patients having seizures. PMID:27488001

  3. Instructable autonomous agents. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Huffman, Scott Bradley

    1994-01-01

    In contrast to current intelligent systems, which must be laboriously programmed for each task they are meant to perform, instructable agents can be taught new tasks and associated knowledge. This thesis presents a general theory of learning from tutorial instruction and its use to produce an instructable agent. Tutorial instruction is a particularly powerful form of instruction, because it allows the instructor to communicate whatever kind of knowledge a student needs at whatever point it is needed. To exploit this broad flexibility, however, a tutorable agent must support a full range of interaction with its instructor to learn a full range of knowledge. Thus, unlike most machine learning tasks, which target deep learning of a single kind of knowledge from a single kind of input, tutorability requires a breadth of learning from a broad range of instructional interactions. The theory of learning from tutorial instruction presented here has two parts. First, a computational model of an intelligent agent, the problem space computational model, indicates the types of knowledge that determine an agent's performance, and thus, that should be acquirable via instruction. Second, a learning technique, called situated explanation specifies how the agent learns general knowledge from instruction. The theory is embodied by an implemented agent, Instructo-Soar, built within the Soar architecture. Instructo-Soar is able to learn hierarchies of completely new tasks, to extend task knowledge to apply in new situations, and in fact to acquire every type of knowledge it uses during task performance - control knowledge, knowledge of operators' effects, state inferences, etc. - from interactive natural language instructions. This variety of learning occurs by applying the situated explanation technique to a variety of instructional interactions involving a variety of types of instructions (commands, statements, conditionals, etc.). By taking seriously the requirements of flexible

  4. Talc use, variants of the GSTM1, GSTT1, and NAT2 genes, and risk of epithelial ovarian cancer.

    PubMed

    Gates, Margaret A; Tworoger, Shelley S; Terry, Kathryn L; Titus-Ernstoff, Linda; Rosner, Bernard; De Vivo, Immaculata; Cramer, Daniel W; Hankinson, Susan E

    2008-09-01

    Epidemiologic evidence suggests a possible association between genital use of talcum powder and risk of epithelial ovarian cancer; however, the biological basis for this association is not clear. We analyzed interactions between talc use and genes in detoxification pathways [glutathione S-transferase M1 (GSTM1), glutathione S-transferase T1 (GSTT1), and N-acetyltransferase 2 (NAT2)] to assess whether the talc/ovarian cancer association is modified by variants of genes potentially involved in the response to talc. Our analysis included 1,175 cases and 1,202 controls from a New England-based case-control study and 210 cases and 600 controls from the prospective Nurses' Health Study. We genotyped participants for the GSTM1 and GSTT1 gene deletions and three NAT2 polymorphisms. We used logistic regression to analyze the main effect of talc use, genotype, and gene-talc interactions in each population and pooled the estimates using a random-effects model. Regular talc use was associated with increased ovarian cancer risk in the combined study population (RR, 1.36; 95% CI, 1.14-1.63; P(trend) < 0.001). Independent of talc, the genes examined were not clearly associated with risk. However, the talc/ovarian cancer association varied by GSTT1 genotype and combined GSTM1/GSTT1 genotype. In the pooled analysis, the association with talc was stronger among women with the GSTT1-null genotype (P(interaction) = 0.03), particularly in combination with the GSTM1-present genotype (P(interaction) = 0.03). There was no clear evidence of an interaction with GSTM1 alone or NAT2. These results suggest that women with certain genetic variants may have a higher risk of ovarian cancer associated with genital talc use. Additional research is needed on these interactions and the underlying biological mechanisms. PMID:18768514

  5. Characterization of ARGON-40 + Silver-Nat Reactions: Timescales and Emission Orders

    NASA Astrophysics Data System (ADS)

    Gelderloos, Carl James

    Studies have been made of ejectile coincidences resulting from ^{40}Ar + ^{nat}Ag reactions at bombarding energies of 17A-34A MeV. Correlations at both large and small relative angles are used to characterize the emission of light charged particles and fragments on a timescale of ~10^ {-22} s. Average delay times and emission orders between ejectiles are inferred by comparison to simulation calculations. Correlation functions in relative momentum, and spectra of the velocity differences between ejectiles emitted at small relative angles have been used to infer reaction dynamics. Trajectories of ejectile coincidences are particularly sensitive to the initial spatial and temporal relationship between the ejectiles and source. As the excitation energy of the emitter increases, the time delays between emissions decrease. The excitation energy deposited in central collisions increases from ~3 MeV per emitter nucleon at 17A MeV to nearly 6A MeV at 34A MeV. The measured delay times between ejectiles decrease steadily over this range. A simulation was developed to probe the degree of equilibration that is achieved by the composite nuclear system. It consists of a statistical model description of the emission of particles and a trajectory model calculation of the three-body interactions. Empirical lifetimes are substantially shorter than those predicted by model calculations, suggesting a regime in which partial, but not complete, equilibration is achieved. A novel method is also developed for measuring the average emission order for different ejectile pairs. The interactions between ejectiles differentiate between coincident events with different velocity relationships. At small relative angles these interactions are sufficiently strong to preferentially select events of a particular emission order. This method provides a new experimental observable with which to further constrain model descriptions. It is implemented to test for differences in average emission order

  6. Multiple Conformations of the Loop Region Confers Heat-Resistance on SsArd1, a Thermophilic NatA.

    PubMed

    Chang, Yu-Yung; Hsu, Chun-Hua

    2016-02-01

    Structural comparison indicates that the loop region between β3 and β4 of SsArd1 is extended relative to the corresponding region in mesophilic Nats, and forms a plastic hydrogen-bond network mainly at two serine residues. Strikingly, two single-point mutants showed ∼3 °C decrease in melting temperature, and two other variants showed ∼7 °C decrease; this correlated with significantly reduced enzymatic activity. To our knowledge, this is the first discovery of a loop region capable of remarkably improving protein thermostability. This provides a novel route to engineer heat-resistant proteins. PMID:26593285

  7. Spectroscopic evidence of large aspherical β-NAT particles involved in denitrification in the December 2011 Arctic stratosphere

    NASA Astrophysics Data System (ADS)

    Woiwode, Wolfgang; Höpfner, Michael; Bi, Lei; Pitts, Michael C.; Poole, Lamont R.; Oelhaf, Hermann; Molleker, Sergej; Borrmann, Stephan; Klingebiel, Marcus; Belyaev, Gennady; Ebersoldt, Andreas; Griessbach, Sabine; Grooß, Jens-Uwe; Gulde, Thomas; Krämer, Martina; Maucher, Guido; Piesch, Christof; Rolf, Christian; Sartorius, Christian; Spang, Reinhold; Orphal, Johannes

    2016-07-01

    We analyze polar stratospheric cloud (PSC) signatures in airborne MIPAS-STR (Michelson Interferometer for Passive Atmospheric Sounding - STRatospheric aircraft) observations in the spectral regions from 725 to 990 and 1150 to 1350 cm-1 under conditions suitable for the existence of nitric acid trihydrate (NAT) above northern Scandinavia on 11 December 2011. The high-resolution infrared limb emission spectra of MIPAS-STR show a characteristic "shoulder-like" signature in the spectral region around 820 cm-1, which is attributed to the ν2 symmetric deformation mode of NO3- in β-NAT. Using radiative transfer calculations involving Mie and T-Matrix methods, the spectral signatures of spherical and aspherical particles are simulated. The simulations are constrained using collocated in situ particle measurements. Simulations assuming highly aspherical spheroids with aspect ratios (AR) of 0.1 or 10.0 and a lognormal particle mode with a mode radius of 4.8 µm reproduce the observed spectra to a high degree. A smaller lognormal mode with a mode radius of 2.0 µm, which is also taken into account, plays only a minor role. Within the scenarios analyzed, the best overall agreement is found for elongated spheroids with AR = 0.1. Simulations of spherical particles and spheroids with AR = 0.5 and 2.0 return results very similar to each other and do not allow us to reproduce the signature around 820 cm-1. The observed "shoulder-like" signature is explained by the combination of the absorption/emission and scattering characteristics of large highly aspherical β-NAT particles. The size distribution supported by our results corresponds to ˜ 9 ppbv of gas-phase equivalent HNO3 at the flight altitude of ˜ 18.5 km. The results are compared with the size distributions derived from the in situ observations, a corresponding Chemical Lagrangian Model of the Stratosphere (CLaMS) simulation, and excess gas-phase HNO3 observed in a nitrification layer directly below the observed PSC. The

  8. Thesis and Dissertation Writing: Preparing ESL Students for Research.

    ERIC Educational Resources Information Center

    Paltridge, Brian

    1997-01-01

    Describes a program created to assist students of English as a Second Language in their preparation for thesis and dissertation writing by focusing on the thesis proposal as an important part of that process. Notes that they often experience difficulty meeting the demands of the kind of writing required at this level and often are unaware of the…

  9. What Works for Doctoral Students in Completing Their Thesis?

    ERIC Educational Resources Information Center

    Lindsay, Siân

    2015-01-01

    Writing a thesis is one of the most challenging activities that a doctoral student must undertake and can represent a barrier to timely completion. This is relevant in light of current and widespread concerns regarding doctoral completion rates. This study explored thesis writing approaches of students post or near Ph.D. completion through…

  10. An Investigation of Generic Structures of Pakistani Doctoral Thesis Acknowledgements

    ERIC Educational Resources Information Center

    Rofess, Sakander; Mahmood, Muhammad Asim

    2015-01-01

    This paper investigates Pakistani doctoral thesis acknowledgements from genre analysis perspective. A corpus of 235 PhD thesis acknowledgements written in English was taken from Pakistani doctoral theses collected from eight different disciplines. HEC Research Repository of Pakistan was used as a data sources. The theses written by Pakistani…

  11. Collaborating for Success: Team Teaching the Engineering Technical Thesis

    ERIC Educational Resources Information Center

    Keating, Terrence; Long, Mike

    2012-01-01

    This paper will examine the collaborative teaching process undertaken at College of the North Atlantic-Qatar (CNA-Q) by Engineering and the Communication faculties to improve the overall quality of engineering students' capstone projects known as the Technical Thesis. The Technical Thesis is divided into two separate components: a proposal stage…

  12. Thesis: A Combined-light Mission For Exoplanet Molecular Spectroscopy

    NASA Astrophysics Data System (ADS)

    Deroo, Pieter; Swain, M. R.; Tinetti, G.; Griffith, C.; Vasisht, G.; Deming, D.; Henning, T.; Beaulieu, J.

    2010-01-01

    THESIS, the Transiting Habitable-zone Exoplanet Spectroscopy Infrared Spacecraft, is a concept for a MIDEX/Discovery class exoplanet mission. Building on the recent Spitzer and Hubble successes in exoplanet characterization and molecular spectroscopy, THESIS would extend these types of measurements to a large population of planets including non-transiting planets and super-Earths. The ability to acquire high-stability, spectroscopic data from the near-visible to the mid-infrared is a unique aspect of THESIS. A strength of the THESIS concept is simplicity low technical risk, and modest cost. By enabling molecular spectroscopy of exoplanet atmospheres, THESIS mission has the potential to dramatically advance our understanding of conditions on extrasolar worlds while serving as a stepping stone to more ambitious future missions.

  13. Excitation functions for production of 46Sc by deuteron and proton beams in natTi: A basis for additional monitor reactions

    NASA Astrophysics Data System (ADS)

    Hermanne, A.; Tárkányi, F.; Takács, S.; Ditrói, F.; Amjed, N.

    2014-11-01

    An objective of a new Coordinated Research Program launched recently by IAEA is to strengthen and broaden the cross section database for monitoring of charged particle beams given in IAEA-TECDOC-1211. One of the suggestions is to complement the widely used natTi(d,x)48V monitor reaction by the natTi(d,x)46Sc reaction having a maximum in a somewhat higher energy. After compilation of the data sets for this reaction available in literature and unpublished data from our earlier experiments, a selection of 20 sets is proposed for statistical fitting and extraction of recommended values. A similar analysis is presented for the natTi(p,x)46Sc reaction where 16 datasets are finally selected.

  14. Decreased DNA Methylation in the Shati/Nat8l Promoter in Both Patients with Schizophrenia and a Methamphetamine-Induced Murine Model of Schizophrenia-Like Phenotype

    PubMed Central

    Uno, Kyosuke; Kikuchi, Yuu; Iwata, Mina; Uehara, Takashi; Matsuoka, Tadasu; Sumiyoshi, Tomiki; Okamoto, Yoshinori; Jinno, Hideto; Takada, Tatsuyuki; Furukawa-Hibi, Yoko; Nabeshima, Toshitaka; Miyamoto, Yoshiaki

    2016-01-01

    The number of patients with schizophrenia has increased over the past decade. Previously, many studies have been performed to establish its diagnostic criteria, prophylactic methods, and effective therapies. In this study, we analyzed whether the ratios of DNA methylation in CpG islands of the Shati/Nat8l is decreased in model mice of schizophrenia-like phenotype using genomic DNA collected from brain regions and peripheral blood, since the mouse model of schizophrenia-like phenotype, mice treated repeatedly with methamphetamine showed increase of Shati/Nat8l mRNA expression in our previous experiment. The ratios of Shati/Nat8l CpG island methylation were significantly decreased in both the nucleus accumbens and the peripheral blood of model mice compared with those of control mice. We also investigated Shati/Nat8l methylation in the blood of patients with schizophrenia. We found that Shati/Nat8l CpG island methylation ratios were lower in the patients with schizophrenia than in the healthy controls, which is consistent with our findings in the mice model. To our knowledge, this is the first study to show similar alterations in methylation status of a particular genomic DNA site in both the brain and peripheral blood of mice. Furthermore, the same phenomenon was observed in corresponding human genomic sequences of the DNA extracted from the peripheral blood of patients with schizophrenia. Based on our findings, DNA methylation profiles of the CpG island of Shati/Nat8l might be a diagnostic biomarker of schizophrenia. PMID:27348532

  15. Decreased DNA Methylation in the Shati/Nat8l Promoter in Both Patients with Schizophrenia and a Methamphetamine-Induced Murine Model of Schizophrenia-Like Phenotype.

    PubMed

    Uno, Kyosuke; Kikuchi, Yuu; Iwata, Mina; Uehara, Takashi; Matsuoka, Tadasu; Sumiyoshi, Tomiki; Okamoto, Yoshinori; Jinno, Hideto; Takada, Tatsuyuki; Furukawa-Hibi, Yoko; Nabeshima, Toshitaka; Miyamoto, Yoshiaki; Nitta, Atsumi

    2016-01-01

    The number of patients with schizophrenia has increased over the past decade. Previously, many studies have been performed to establish its diagnostic criteria, prophylactic methods, and effective therapies. In this study, we analyzed whether the ratios of DNA methylation in CpG islands of the Shati/Nat8l is decreased in model mice of schizophrenia-like phenotype using genomic DNA collected from brain regions and peripheral blood, since the mouse model of schizophrenia-like phenotype, mice treated repeatedly with methamphetamine showed increase of Shati/Nat8l mRNA expression in our previous experiment. The ratios of Shati/Nat8l CpG island methylation were significantly decreased in both the nucleus accumbens and the peripheral blood of model mice compared with those of control mice. We also investigated Shati/Nat8l methylation in the blood of patients with schizophrenia. We found that Shati/Nat8l CpG island methylation ratios were lower in the patients with schizophrenia than in the healthy controls, which is consistent with our findings in the mice model. To our knowledge, this is the first study to show similar alterations in methylation status of a particular genomic DNA site in both the brain and peripheral blood of mice. Furthermore, the same phenomenon was observed in corresponding human genomic sequences of the DNA extracted from the peripheral blood of patients with schizophrenia. Based on our findings, DNA methylation profiles of the CpG island of Shati/Nat8l might be a diagnostic biomarker of schizophrenia. PMID:27348532

  16. Molecular basis of essential amino acid transport from studies of insect nutrient amino acid transporters of the SLC6 family (NAT-SLC6)

    PubMed Central

    Boudko, Dmitri Y.

    2012-01-01

    Two protein families that represent major components of essential amino acid transport in insects have been identified. They are annotated as the SLC6 and SLC7 families of transporters according to phylogenetic proximity to characterized amino acid transporters (HUGO nomenclature). Members of these families have been identified as important apical and basolateral parts of transepithelial essential amino acid absorption in the metazoan alimentary canal. Synergistically, they play critical physiological roles as essential substrate providers to diverse metabolic processes, including generic protein synthesis. This review briefly clarifies the requirements for amino acid transport and a variety of amino acid transport mechanisms, including the aforementioned families. Further it focuses on the large group of Nutrient Amino acid Transporters (NATs), which comprise a recently identified subfamily of the Neurotransmitter Sodium Symporter family (NSS or SLC6). The first insect NAT, cloned from the caterpillar gut, has a broad substrate spectrum similar to mammalian B0 transporters. Several new NAT-SLC6 members have been characterized in an effort to explore mechanisms for the essential amino acid absorption in model dipteran insects. The identification and functional characterization of new B0-like and narrow specificity transporters of essential amino acids in fruit fly and mosquitoes leads to a fundamentally important insight: that NATs evolved and act together as the integrated active core of a transport network that mediates active alimentary absorption and systemic distribution of essential amino acids. This role of NATs is projected from the most primitive prokaryotes to the most complex metazoan organisms, and represents an interesting platform for unraveling the molecular evolution of amino acid transport and modeling amino acid transport disorders. The comparative study of NATs elucidates important adaptive differences between essential amino acid transportomes

  17. THESIS: terrestrial and habitable zone infrared spectroscopy spacecraft

    NASA Astrophysics Data System (ADS)

    Vasisht, G.; Swain, M. R.; Akeson, R. L.; Burrows, A.; Deming, D.; Grillmair, C. J.; Greene, T. P.

    2008-07-01

    THESIS is a concept for a medium class mission designed for spectroscopic characterization of extrasolar planets between 2-14 microns. The concept leverages off the recent first-steps made by Spitzer and Hubble in characterizing the atmospheres of alien gas giants. Under favourable circumstances, THESIS is capable of identifying biogenic molecules in habitable-zone planets, thereby determining conditions on worlds where life might exist. By systematically characterizing many worlds, from rocky planets to gas-giants, THESIS would deliver transformational science of profound interest to astronomers and the general public.

  18. THESIS: the terrestrial habitable-zone exoplanet spectroscopy infrared spacecraft

    NASA Astrophysics Data System (ADS)

    Swain, Mark R.; Vasisht, Gautam; Henning, Thomas; Tinetti, Giovanna; Beaulieu, Jean-Phillippe

    2010-07-01

    THESIS, the Transiting Habitable-zone Exoplanet Spectroscopy Infrared Spacecraft, is a concept for a medium/Probe class exoplanet mission. Building on the recent Spitzer successes in exoplanet characterization, THESIS would extend these types of measurements to super-Earth-like planets. A strength of the THESIS concept is simplicity, low technical risk, and modest cost. The mission concept has the potential to dramatically advance our understanding of conditions on extrasolar worlds and could serve as a stepping stone to more ambitious future missions. We envision this mission as a joint US-European effort with science objectives that resonate with both the traditional astronomy and planetary science communities.

  19. Attitudes on Conducting Thesis Research in a Developing Country.

    ERIC Educational Resources Information Center

    Mason, S. C.; And Others

    1987-01-01

    Reports on a survey conducted to study attitudes toward agronomy graduate students conducting thesis research in developing countries. Compares perceptions of executive officers of international program offices and departments of agronomy, and major professors. (TW)

  20. Excitation functions of (nat)Zn(p,x) nuclear reactions with proton beam energy below 18 MeV.

    PubMed

    Asad, Ali H; Chan, Sun; Morandeau, Laurence; Cryer, David; Smith, Suzanne V; Price, Roger I

    2014-12-01

    We measured the excitation functions of (nat)Zn (p,x) reactions up to 17.6MeV, using the stacked-foils activation technique. High-purity natural zinc (and copper) foils were irradiated with proton beams generated by an 18MeV isochronous cyclotron. Activated foils were measured using high-purity Ge gamma spectroscopy to quantify the radionuclides (61)Cu, (66)Ga, (67)Ga, and (65)Zn produced from the reactions. Thick-target integral yields were also deduced from the measured excitation functions of the produced radioisotopes. These results were compared with the published literature and were found to be in good agreement with most reports, particularly those most recently compiled. PMID:25108597

  1. Measurement and theoretical analysis of the excitation functions for 3He induced reactions on natSn

    NASA Astrophysics Data System (ADS)

    Ali, B. M.; Al-Abyad, M.; Seddik, U.; El-Kameesy, S. U.; Ditrói, F.; Takács, S.; Tárkányi, F.

    2015-11-01

    Excitation functions of 3He induced nuclear reactions on natSn were measured up to 26 MeV using the stacked-foil technique, utilizing the MGC-20E cyclotron of ATOMKI. Using HPGe detector the following radioisotopes were identified: 116,117,118,119g,119m,121g,121m,123mTe, 115g,116m,117,118m,120m,122g,124gSb and 113g,117mSn. The experimental results are presented for the first time in this energy range. The results of theoretical calculations based on EMPIRE and TENDL library were compared with the present data. Integral yields for some isotopes were calculated.

  2. Comparative genomic survey, exon-intron annotation and phylogenetic analysis of NAT-homologous sequences in archaea, protists, fungi, viruses, and invertebrates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have previously published extensive genomic surveys [1-3], reporting NAT-homologous sequences in hundreds of sequenced bacterial, fungal and vertebrate genomes. We present here the results of our latest search of 2445 genomes, representing 1532 (70 archaeal, 1210 bacterial, 43 protist, 97 fungal,...

  3. The Hamburg Selection Procedure for Dental Students – Introduction of the HAM-Nat as subject-specific test for study aptitude

    PubMed Central

    Kothe, Christian; Hissbach, Johanna; Hampe, Wolfgang

    2013-01-01

    Introduction: The present study examines the question whether the selection of dental students should be based solely on average school-leaving grades (GPA) or whether it could be improved by using a subject-specific aptitude test. Methods: The HAM-Nat Natural Sciences Test was piloted with freshmen during their first study week in 2006 and 2007. In 2009 and 2010 it was used in the dental student selection process. The sample size in the regression models varies between 32 and 55 students. Results: Used as a supplement to the German GPA, the HAM-Nat test explained up to 12% of the variance in preclinical examination performance. We confirmed the prognostic validity of GPA reported in earlier studies in some, but not all of the individual preclinical examination results. Conclusion: The HAM-Nat test is a reliable selection tool for dental students. Use of the HAM-Nat yielded a significant improvement in prediction of preclinical academic success in dentistry. PMID:24282449

  4. A new parameterization of polar stratospheric clouds based on the effective growth of NAT particles in the chemistry-climate-model EMAC

    NASA Astrophysics Data System (ADS)

    Kirner, Ole; Ruhnke, Roland; Hoepfner, Michael

    2013-04-01

    Polar stratospheric clouds (PSCs), consisting of STS, NAT and ice particles, play a major role in polar ozone depletion. On the one hand there is the activation of chlorine reservoirs at the surface of the PSCs, on the other hand PSCs lead to the stratospheric denitrification with the effect of a delay in the deactivation of active chlorine in polar spring. Due to the relevance of a good representation of these PSCs in global chemistry-climate-models (CCMs) a new algorithm based on efficient growth of NAT particles, developed by van den Broek et al. [2004], has been implemented into the submodel PSC of the CCM ECHAM5/MESSy for Atmospheric Chemistry (EMAC). We present results of an EMAC simulation from 2000 to 2012, performed with the new NAT parameterization. The simulated results are analyzed regarding the composition of PSCs and their distribution in the polar regions as well as their influence to the ozone related chemistry. The new results are compared with an EMAC simulation with the old standard thermodynamical NAT parameterization. A comparison with PSC measurements retrieved by the satellite instrument MIPAS on ENVISAT [Höpfner et al., 2006] show the quality of the new PSC scheme in EMAC. With the help of an additional sensitivity simulation it can be shown that the significance of heterogeneous reactions on ice particles, in comparison to liquid particles, is subordinate regarding chlorine activation and ozone depletion in Antarctic winter and spring as noted in Drdla and Mueller [2012].

  5. The Impact of NAT2 Acetylator Genotype on Mutagenesis and DNA Adducts from 2-Amino-9H-Pyrido[2,3-b]Indole

    PubMed Central

    Turesky, Robert J.; Bendaly, Jean; Yasa, Isil; Doll, Mark A.; Hein, David W.

    2009-01-01

    2-Amino-9H-pyrido[2,3-b]indole (AαC) is a carcinogenic heterocyclic aromatic amine (HAA) that is produced in high quantities in tobacco smoke, and also forms in charred meats. The bioactivation of AαC occurs by cytochrome P450-mediated (P450 1A2) N-oxidation of the exocyclic amine group, to form 2-hydroxyamino-9H-pyrido[2,3-b]indole (HONH-AαC). The HONH-AαC metabolite can then undergo further activation by phase II enzymes to form the penultimate ester species, which bind to DNA. Some epidemiological studies suggest a role for NAT2 genetic polymorphisms in human susceptibilities to various cancers from tobacco smoke and from consumption of well-done meats, where the exposures to AαC can be substantial. In this investigation, we have measured the genotoxicity of AαC in nucleotide excision repair-deficient Chinese hamster ovary (CHO) cells stably transfected with human P450 1A2 and either the NAT2*4 (rapid, wild-type acetylator) or the NAT2*5B (the most common slow acetylator) allele, to determine the role of NAT2 phenotype in the biological effects of AαC. Mutations at the hypoxanthine phosphoribosyl transferase (hprt) locus were induced in a dose-dependent manner by AαC, and were found to be highest in cells transfected with P450 1A2 and NAT2*4, followed by cells transfected with P450 1A2 and NAT2*5B. The level of formation of the deoxyguanosine (dG) adduct N-(deoxyguanosin-8-yl)-2-amino-9H-pyrido[2,3-b]indole (dG-C8-AαC) paralleled the mutagenic potency, in these cell lines. However, AαC did not form DNA adducts or induce mutations in untransfected CHO cells, or in cells only expressing P450 1A2. These findings clearly demonstrate that NAT2 genetic polymorphism plays a major role in the genotoxic potency of AαC. PMID:19243127

  6. Excitation functions of the natTa(p,x)178m2Hf and natW(p,x)178m2Hf reactions at energies up to 2600 MeV

    SciTech Connect

    Titarenko, Yu. E.; Batyaev, V. F.; Pavlov, K. V.; Titarenko, A. Yu.; Zhivun, V. M.; Chauzova, M. V.; Ignatyuk, A. V.; Mashnik, Stepan Georgievich; Leray, S.; Boudard, A.; David, J. -C.; Mancusi, D.; Cugnon, J.; Yariv, Y.; Nishihara, K.; Matsuda, N.; Kumawat, H.; Stankovskiy, A. Yu.

    2015-04-29

    Due to potential level of energy intensity 178m2Hf is an extremely interesting isomer. One possible way to produce this isomer is irradiation of natTa or natW samples with high energy protons. Irradiation of natTa or natW samples performed for other purposes provides an opportunity to study the corresponding reactions. This paper presents the 178m2Hf independent production cross sections for both targets measured by the gamma-ray spectrometry method. The reaction excitation functions have been obtained for the proton energies from 40 up to 2600 MeV. The experimental results were compared with calculations by various versions of the intranuclear cascade model in the well-known codes: ISABEL, Bertini, INCL4.5+ABLA07, PHITS, CASCADE07 and CEM03.02. The isomer ratio for the natTa(p,x) 178m2Hf reaction is evaluated on the basis of the available data.

  7. The ultra-slow NAT2*6A haplotype is associated with reduced higher cognitive functions in an elderly study group.

    PubMed

    Selinski, Silvia; Getzmann, Stephan; Gajewski, Patrick D; Blaszkewicz, Meinolf; Hengstler, Jan G; Falkenstein, Michael; Golka, Klaus

    2015-12-01

    N-Acetyltransferase 2 (NAT2) genotype is associated with age-related declines in basic sensory hearing functions. However, the possible modulatory role of NAT2 for higher cognitive functions has not yet been studied. We tested auditory goal-directed behavior and attentional control in 120 NAT2 genotyped subjects (63-88 years), using an auditory distraction paradigm in which participants responded to the duration of long and short tone stimuli. We studied involuntary shifts in attention to task-irrelevant deviant stimuli and applied event-related potentials (ERPs) to examine which cognitive subprocesses are affected by NAT2 status on a neurophysiological level. Relative to the standard stimuli, deviant stimuli decreased performance in the recently described ultra-slow acetylators (NAT2*6A and *7B): The increase in error-corrected reaction times (a combined measure of response speed and accuracy) in ultra-slow acetylators (254 ms increase) was more than twice as high as in the rapid acetylator reference group (111 ms increase; p < 0.01). The increase was still higher than in the other slow acetylators (149 ms increase, p < 0.05). In addition, clear differences were found in the ERP results: Ultra-slow acetylators showed deficits specifically in the automatic detection of changes in the acoustic environment as evidenced by reduced mismatch negativity (MMN, p < 0.005 compared to rapid acetylators). Refocussing of attention after a distracting event was also impaired in the ultra-slow acetylators as evidenced by a reduced re-orienting negativity (RON, p < 0.01 compared to rapid acetylators). In conclusion, the ultra-slow acetylation status was associated with reduced higher cognitive functions. PMID:26615528

  8. Importance and benefits of the doctoral thesis for medical graduates

    PubMed Central

    Giesler, Marianne; Boeker, Martin; Fabry, Götz; Biller, Silke

    2016-01-01

    Introduction: The majority of medical graduates in Germany complete a doctorate, even though a doctoral degree is not necessary for the practice of medicine. So far, little is known about doctoral candidates’ view on the individual benefit a doctoral thesis has for them. Consequently, this is the subject of the present investigation. Method: Data from surveys with graduates of the five medical faculties of Baden-Württemberg from the graduation years 2007/2008 (N=514) and 2010/2011 (N=598) were analysed. Results: One and a half years after graduating 53% of those interviewed had completed their doctorate. When asked about their motivation for writing a doctoral thesis, participants answered most frequently “a doctorate is usual” (85%) and “improvement of job opportunities” (75%), 36% said that an academic career has been their primary motive. Less than 10% responded that they used their doctoral thesis as a means to apply for a job. The proportion of graduates working in health care is equally large among those who have completed a thesis and those who have not. Graduates who pursued a thesis due to scientific interest are also currently more interested in an academic career and recognise more opportunities for research. An implicit benefit of a medical thesis emerged with regard to the self-assessment of scientific competences as those who completed a doctorate rated their scientific competencies higher than those who have not. Discussion: Although for the majority of physicians research interest is not the primary motivation for completing a doctorate, they might nevertheless achieve some academic competencies. For graduates pursuing an academic career the benefit of completing a medical thesis is more obvious. PMID:26958656

  9. Ukraine: Independent nuclear weapons capability rising. Master's thesis

    SciTech Connect

    Dewing, M.J.

    1993-06-01

    This thesis argues that Ukraine will move from possession of CIS-controlled nuclear weapons to the development of an independent nuclear capability. It attempts to show how the factors driving Ukraine towards remaining a nuclear state outweigh the factors acting in restraint. This thesis describes the contents of the Ukrainian arsenal, reviews its current material condition and investigates the likelihood that Ukraine can directly control it. This thesis also shows why Ukraine's most likely course in developing and independent nuclear weapons capability will be to retain its 46 SS-24 ICBMs. United States, Ukraine, Russia, Strategic weapons, National strategy, Nuclear strategy, Arms control, Strategic stability, Nuclear weapons Strategic command and control, International relations.

  10. Overexpression of Shati/Nat8l, an N-acetyltransferase, in the nucleus accumbens attenuates the response to methamphetamine via activation of group II mGluRs in mice.

    PubMed

    Miyamoto, Yoshiaki; Ishikawa, Yudai; Iegaki, Noriyuki; Sumi, Kazuyuki; Fu, Kequan; Sato, Keiji; Furukawa-Hibi, Yoko; Muramatsu, Shin-Ichi; Nabeshima, Toshitaka; Uno, Kyosuke; Nitta, Atsumi

    2014-08-01

    A novel N-acetyltransferase, Shati/Nat8l, was identified in the nucleus accumbens (NAc) of mice with methamphetamine (METH) treatment. Previously we reported that suppression of Shati/Nat8l enhanced METH-induced behavioral alterations via dopaminergic neuronal regulation. However, the physiological mechanisms of Shati/Nat8l on the dopaminergic system in the brain are unclear. In this study, we injected adeno-associated virus (AAV) vector containing Shati/Nat8l into the NAc or dorsal striatum (dS) of mice, to increase Shati/Nat8l expression. Overexpression of Shati/Nat8l in the NAc, but not in the dS, attenuated METH-induced hyperlocomotion, locomotor sensitization, and conditioned place preference in mice. Moreover, the Shati/Nat8l overexpression in the NAc attenuated the elevation of extracellular dopamine levels induced by METH in in vivo microdialysis experiments. These behavioral and neurochemical alterations due to Shati/Nat8l overexpression in the NAc were inhibited by treatment with selective group II metabotropic glutamate receptor type 2 and 3 (mGluR2/3) antagonist LY341495. In the AAV vector-injected NAc, the tissue contents of both N-acetylaspartate and N-acetylaspartylglutamate (NAAG), endogenous mGluR3 agonist, were elevated. The injection of peptidase inhibitor of NAAG or the perfusion of NAAG itself reduced the basal levels of extracellular dopamine in the NAc of naive mice. These results indicate that Shati/Nat8l in the NAc, but not in the dS, plays an important suppressive role in the behavioral responses to METH by controlling the dopaminergic system via activation of group II mGluRs. PMID:24559655

  11. Excitation functions of the natCr(p,x)44Ti, 56Fe(p,x)44Ti, natNi(p,x)44Ti and 93Nb(p,x)44Ti reactions at energies up to 2.6 GeV

    NASA Astrophysics Data System (ADS)

    Titarenko, Yu. E.; Batyaev, V. F.; Pavlov, K. V.; Titarenko, A. Yu.; Zhivun, V. M.; Chauzova, M. V.; Balyuk, S. A.; Bebenin, P. V.; Ignatyuk, A. V.; Mashnik, S. G.; Leray, S.; Boudard, A.; David, J. C.; Mancusi, D.; Cugnon, J.; Yariv, Y.; Nishihara, K.; Matsuda, N.; Kumawat, H.; Stankovskiy, A. Yu.

    2016-06-01

    The paper presents the measured cumulative yields of 44Ti for natCr, 56Fe, natNi and 93Nb samples irradiated by protons at the energy range 0.04-2.6 GeV. The obtained excitation functions are compared with calculations of the well-known codes: ISABEL, Bertini, INCL4.2+ABLA, INCL4.5+ABLA07, PHITS, CASCADE07 and CEM03.02. The predictive power of these codes regarding the studied nuclides is analyzed.

  12. A functional programming interpreter. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Robison, Arch Douglas

    1987-01-01

    Functional Programming (FP) sup BAC87 is an alternative to conventional imperative programming languages. This thesis describes an FP interpreter implementation. Superficially, FP appears to be a simple, but very inefficient language. Its simplicity, however, allows it to be interpreted quickly. Much of the inefficiency can be removed by simple interpreter techniques. This thesis describes the Illinois Functional Programming (IFP) interpreter, an interactive functional programming implementation which runs under both MS-DOS and UNIX. The IFP interpreter allows functions to be created, executed, and debugged in an environment very similar to UNIX. IFP's speed is competitive with other interpreted languages such as BASIC.

  13. Deterring weapons of mass destruction terrorism. Master`s thesis

    SciTech Connect

    LeHardy, F.A.

    1997-12-01

    This thesis examines terrorist acts involving the use of weapons of mass destruction (WMD) against unsuspecting civilians by the Aum Shinrikyo and Rajneesh cults. The proliferation of WMD (i.e., nuclear, chemical, and biological weapons) has created a concern that terrorists might use WMD. Despite obvious signs, these groups were not identified as terrorists until after they committed terrorist attacks. This thesis identifies common characteristics of terrorists that have used WMD in the past and generates indicators of non-state actors that might commit WMD terrorism in the future.

  14. The "Jerk" Method for Predicting Intrusions and Eruptions of Piton De La Fournaise (La Réunion Island) from the Analysis of the Broadband Seismological Rer Station

    NASA Astrophysics Data System (ADS)

    Roult, G. C.; Beauducel, F.; Ferrazzini, V.; Boissier, P.; Villeneuve, N.

    2014-12-01

    The predictability of volcanic eruptions remains a challenging problem and forecast of volcano behavior (intrusion versus eruption) is a difficult task. Since 1979, the Volcano Observatory of Piton de la Fournaise (OVPF) maintains SP and BB seismic stations, tiltmeters, extensometers and GPS stations. In addition, the RER GEOSCOPE broadband station was installed in 1986, 8.5 km north of the summit crater. The analysis of 83 seismic crises from December 1985 to December 2010 (preceding 54 eruptions, 26 intrusions, 2 summit pit craters,1 caldera collapse) allowed us to identify short-term long period seismic transients (period > 100 s) for most events (Roult et al., 2012). These precursors observed on the horizontal components are tilt signals induced by the inflation/deflation of the volcano. We analyzed 17 eruptions and 7 intrusions spanning the 2005-2010 period with the aim of distinguishing whether an injection of magma will stop or if it can evolve towards an eruption. Transient signature is an acceleration step that can be large or not, with slopes more or less steep according to the acceleration rate. We show a clear differentiation between the acceleration rate of the intrusions (low rate) and the acceleration rate of the eruptions (high rate). With a ratio estimated to 7, the acceleration rate allows to determine a threshold value and to discriminate between intrusive and eruptive events. The real-time calculation of the ground acceleration of the horizontal components of the RER station after removal of the theoretical tide effect is integrated since April 2014 to the Piton de la Fournaise volcano monitoring. In June 2014, the "JERK"method predicted an eruption 50 minutes before the eruption onset. We applied the "material failure prediction" of Voight and Cornelius (1991) with the aim to predict the onset time of the eruptions. Preliminary tests on the 17 eruptions of the 2005-2010 period have shown that the summit eruptions were relatively well predicted

  15. iThesis: Polly's project

    ERIC Educational Resources Information Center

    Conti, Alvaro

    2013-01-01

    This paper outlines an attempt to loosen the existing role and structure of the traditional "thesis" as the key undergraduate learning instrument within universities in Thailand. It does so by describing an exemplary project -- Polly's project - that uses technology to facilitate an exit from the "regulatory space" in…

  16. Action Research within Organisations and University Thesis Writing.

    ERIC Educational Resources Information Center

    Zuber-Skerritt, Ortrun; Perry, Chad

    2002-01-01

    Clarifies differences between core collaborative action research in the field and independent action research for theses. Explains how core action research may be incorporated into thesis research in the social sciences, resulting in more useful outcomes for improving practice. (Contains 21 references.) (SK)

  17. Problem Definition and Thesis Writing. Workshops for the Postgraduate Student.

    ERIC Educational Resources Information Center

    Zuber-Skerritt, Ortrun; Knight, Nick

    1986-01-01

    Some innovative solutions to two key graduate research problems, definition of the research problem and planning and writing the thesis first draft, are outlined. Workshops are recommended as an effective format for assisting students in developing research skills through practical guidance, group support, and discussion. (MSE)

  18. The Thesis Black Market: Present State and Background

    ERIC Educational Resources Information Center

    Gang, Wang

    2007-01-01

    The superficial reason for the existence of the thesis black market is the glut of theses and the shortage of publishing space; behind that is the skewed academic assessment system. Today, the following circumstances can be found in virtually all institutions of higher education in China: (1) A master's degree student must, during the two or…

  19. Social Indicators of Education and the Model Minority Thesis.

    ERIC Educational Resources Information Center

    Macaranas, Federico M.

    The idea that Asian Americans constitute a "model minority" needing no special help with education or employment is quite widespread, even amongst government officials. This "model minority" thesis has not been investigated empirically, in part because of the lack of a theoretical construct. An interdisciplinary model focusing on educational and…

  20. Sponsoring congregations' answer to McGrath Thesis: corporate control.

    PubMed

    Maida, A J

    1980-04-01

    Fr. Maida refutes McGrath's Thesis and posits that Catholic health care facilities face special corporate, financial, and theological administrative issues. By maintaining corporate control of the institutions they sponsor, religious congregations can determine institutional policies consistent with church teachings. PMID:10245867

  1. Complete Your Dissertation or Thesis in Two Semesters or Less

    ERIC Educational Resources Information Center

    Ogden, Evelyn Hunt

    2006-01-01

    This newly updated guide describes how to effectively and efficiently manage the dissertation or thesis process in two semesters or less. Written for doctoral and master's degree students enrolled in on-campus programs and students pursuing accelerated and online-based degree programs, this book demystifies the seemingly daunting process. From…

  2. The Jailing of America's Homeless: Evaluating the Rabble Management Thesis

    ERIC Educational Resources Information Center

    Fitzpatrick, Kevin M.; Myrstol, Brad

    2011-01-01

    The authors of this article test hypotheses derived from Irwin's rabble management thesis. The analysis uses data from 47,592 interviews conducted with jailed adults in 30 U.S. cities as part of the Arrestee Drug Abuse Monitoring program. Clearly, homeless persons are overrepresented among those arrested and booked into local jails. Bivariate…

  3. The Doctoral Thesis and Supervision: The Student Perspective

    ERIC Educational Resources Information Center

    Kiguwa, Peace; Langa, Malose

    2009-01-01

    The doctoral thesis constitutes both a negotiation of the supervision relationship as well as mastery and skill in participating in a specific community of practice. Two models of supervision are discussed: the technical rationality model with its emphasis on technical aspects of supervision, and the negotiated order model with an emphasis on…

  4. Assessing the Doctoral Thesis When It Includes Published Work

    ERIC Educational Resources Information Center

    Sharmini, Sharon; Spronken-Smith, Rachel; Golding, Clinton; Harland, Tony

    2015-01-01

    In this article we explore how examiners assess a thesis that includes published work. An online survey was used to gather data on approaches to assessing publication-based theses (PBTs). The respondents were 62 supervisors who had experience examining PBTs across a range of disciplines at a research-intensive university in New Zealand. Nearly…

  5. Support for Different Roles in Software Engineering Master's Thesis Projects

    ERIC Educational Resources Information Center

    Host, M.; Feldt, R.; Luders, F.

    2010-01-01

    Like many engineering programs in Europe, the final part of most Swedish software engineering programs is a longer project in which the students write a Master's thesis. These projects are often conducted in cooperation between a university and industry, and the students often have two supervisors, one at the university and one in industry. In…

  6. Turning Points: Improving Honors Student Preparation for Thesis Completion

    ERIC Educational Resources Information Center

    Patino, Cynthia

    2012-01-01

    This dissertation is an action research study that had as its primary goal to increase retention of honors college students at Arizona State University by implementing an additional advising session during the fifth semester of their academic career. Introducing additional, strategically-timed support for the honors thesis and demystifying the…

  7. Intergroup Contact and Ingroup Reappraisal: Examining the Deprovincialization Thesis

    ERIC Educational Resources Information Center

    Verkuyten, Maykel; Thijs, Jochem; Bekhuis, Hidde

    2010-01-01

    According to the deprovincialization thesis, interethnic contact involves a reappraisal and distancing from the ingroup. Contact can broaden one's horizon by acknowledging and recognizing the value of other cultures and thereby putting the taken-for-granted own cultural standards into perspective. The current research uses data from three surveys…

  8. Thesis Writing Challenges for Non-Native MA Students

    ERIC Educational Resources Information Center

    Sadeghi, Karim; Shirzad Khajepasha, Arash

    2015-01-01

    Writing in a second (L2)/foreign language is generally a challenging activity, and writing an MA thesis, as an example of academic enterprise, can be daunting when done in a language in which the writer is not fully competent. The challenge such a genre of writing poses for L2 writers has not been properly addressed. To fill in the gap in this…

  9. A Supervisor's Roles for Successful Thesis and Dissertation

    ERIC Educational Resources Information Center

    Mhunpiew, Nathara

    2013-01-01

    The success of a thesis or a dissertation for a graduate student relies upon the roles of their supervisor. The student not only needs to be equipped with the knowledge, but also be able to manage others and external factors at the same time. The journey during the period of conducting research is mixed with various tasks. Five supportive roles of…

  10. Asking Better Questions: Approaching the Process of Thesis Supervision.

    ERIC Educational Resources Information Center

    Manderson, Desmond

    1996-01-01

    The questions typically asked by a law student in different stages of the process of thesis supervision are re-formulated to encourage more student reflection on the experience. The stages include approaching the supervision concept, selecting an appropriate supervisor, considering rights and responsibilities of both parties in developing a…

  11. Consistency and Inconsistency in PhD Thesis Examination

    ERIC Educational Resources Information Center

    Holbrook, Allyson; Bourke, Sid; Lovat, Terry; Fairbairn, Hedy

    2008-01-01

    This is a mixed methods investigation of consistency in PhD examination. At its core is the quantification of the content and conceptual analysis of examiner reports for 804 Australian theses. First, the level of consistency between what examiners say in their reports and the recommendation they provide for a thesis is explored, followed by an…

  12. Motivation in medical students: a PhD thesis report.

    PubMed

    Kusurkar, Rashmi

    2012-08-01

    The aims of this thesis were to gather insights and investigate the factors influencing, outcomes and applications of medical students' motivation. This thesis consists of three literature reviews, four research papers and two application papers. Two research studies investigated the relationships of student motivation with study strategy, effort and academic performance through structural equation modelling and cluster analysis. The relationships of age, maturity, gender and educational background with motivation were investigated through multiple regression analysis. The results of this thesis were 1. Developments in medical education appear to have undervalued student motivation. 2. Motivation is an independent variable in medical education; intrinsic motivation is significantly associated with deep study strategy, high study effort and good academic performance. 3. Motivation is a dependent variable in medical education and is significantly affected by age, maturity, gender, educational background; intrinsic motivation is enhanced by providing students with autonomy, feedback and emotional support. 4. Strength of motivation for medical school can be reliably measured by Strength of Motivation for Medical School questionnaire. The conclusion of this thesis was that it is important to give consideration to motivation in medical education because intrinsic motivation leads to better learning and performance and it can be enhanced through giving students autonomy in learning, feedback about competence and emotional support. PMID:23316471

  13. Magnus Strandqvist: 50th anniversary of his doctoral thesis.

    PubMed

    Kajanti, M J

    1994-01-01

    This article is dedicated to Magnus Strandqvist's famous doctoral thesis "Studien über die kumulative Wirkung der Röntgenstrahlen bei Fraktionierung. Erfahrungen aus dem Radiumhemmet an 280 Haut- und Lippenkarzinomen" published in Acta Radiologica in 1944. After a short biography of Strandqvist some central points of his work and their influence on future development of modern radiotherapy are presented. PMID:7993639

  14. A simple and cost-saving approach to optimize the production of subtilisin NAT by submerged cultivation of Bacillus subtilis natto.

    PubMed

    Ku, Ting-Wei; Tsai, Ruei-Lan; Pan, Tzu-Ming

    2009-01-14

    Subtilisin NAT, formerly designated nattokinase or subtilisin BSP, is a potent cardiovascular drug because of its strong fibrinolytic activity and safety. In this study, one Bacillus subtilis natto strain with high fibrinolytic activity was isolated. We further studied the optimal conditions for subtilisin NAT production by submerged cultivation and three variables/three levels of response surface methodology (RSM) using various inoculum densities, glucose concentrations, and defatted soybean concentrations as the three variables. According to the RSM analysis, while culturing by 2.93% defatted soybean, 1.75% glucose, and 4.00% inoculum density, we obtained an activity of 13.78 SU/mL. Processing the batch fermentation with this optimal condition, the activity reached 13.69 SU/mL, which is equal to 99.3% of the predicted value. PMID:19063639

  15. Independent isotopic yields in 25 MeV and 50 MeV proton-induced fission of natU

    NASA Astrophysics Data System (ADS)

    Penttilä, H.; Gorelov, D.; Elomaa, V.-V.; Eronen, T.; Hager, U.; Hakala, J.; Jokinen, A.; Kankainen, A.; Karvonen, P.; Moore, I. D.; Parkkonen, J.; Peräjärvi, K.; Pohjalainen, I.; Rahaman, S.; Rinta-Antila, S.; Rissanen, J.; Rubchenya, V. A.; Saastamoinen, A.; Simutkin, V.; Sonoda, T.; Weber, C.; Voss, A.; Äystö, J.

    2016-04-01

    Independent isotopic yields for elements from Zn to La in the 25 MeV proton-induced fission of {}^{nat}U were determined with the JYFLTRAP facility. In addition, isotopic yields for Zn, Ga, Rb, Sr, Zr, Pd and Xe in the 50 MeV proton-induced fission of {}^{nat}U were measured. The deduced isotopic yield distributions are compared with a Rubchenya model, the GEF model with universal parameters and the semi-empirical Wahl model. Of these, the Rubchenya model gives the best overall agreement with the obtained data. Combining the isotopic yield data with mass yield data to obtain the absolute independent yields was attempted. The result depends on the mass yield distribution.

  16. Inhibition of angiotensin I converting enzyme by subtilisin NAT (nattokinase) in natto, a Japanese traditional fermented food.

    PubMed

    Murakami, Keiko; Yamanaka, Naoki; Ohnishi, Katsunori; Fukayama, Minoru; Yoshino, Masataka

    2012-06-01

    Angiotensin I converting enzyme (ACE) was inhibited by the culture medium of Bacillus subtilis subsp. natto, which ferments boiled soy beans to natto, a Japanese traditional food. Subtilisin NAT (nattokinase) produced by B. subtilis also inhibited ACE, and the inhibition was markedly stimulated by heat treatment of subtilisin at 120 °C for 15 min. Inhibition of ACE by subtilisin was of a mixed type: the decrease in V(max) and the increase in K(m) value. SDS-polyacrylamide gel electrophoresis showed that heat treatment of subtilisin caused inactivation with fragmentation of the enzyme protein into small peptides. The inhibitory action of subtilisin was not due to an enzymatic action of protease, but may be ascribed to the potent ACE-inhibitory peptides such as LY and FY, amino acid sequences in subtilisin. HPLC-MS analysis of heat-inactivated subtilisin confirmed that LY and FY were liberated by fragmentation of the enzyme. Inhibition of ACE by subtilisin and its degradation peptides such as LY and FY may participate in the suppression of blood pressure by ingestion of natto. PMID:22453301

  17. Interdisziplinärer Arbeitskreis Bewegungsstörungen (IAB): an interdisciplinary working group for promoting multimodal therapy of movement disorders.

    PubMed

    Adib Saberi, Fereshte; Dressler, Dirk

    2013-04-01

    Increasing complexity of therapeutic strategies for movement disorders (MD) requires multimodal therapies involving various health care professionals and physicians. Coordinating all professions involved is difficult. An interdisciplinary working group (Interdisziplinärer Arbeitskreis Bewegungsstörungen, IAB) serves to promote and improve multimodal therapies of MD. IAB was started 6 years ago in Hamburg, Germany as an interdisciplinary special interest group with about 25 physiotherapists, occupational therapists, speech therapists, nurse specialists, physicians and invited guests regularly meeting each quarter. IAB expanded and now also includes a webpage with data bases, a special interest group for Parkinson assistants, a meeting arm for organising meetings accredited by continuous medical education authorities and a publication arm for production of educational materials including a communication form and a communication calendar developed by IAB. Recently, IAB acquired a video production enterprise producing educational MD videos. In the meantime, two more IAB groups were founded in other regions of Germany. IAB's stability over more than 6 years and its expansion into more regions and other tasks documents the demand for promotion of multimodal therapies for MD. PMID:23224693

  18. Active cigarette smoking and the risk of breast cancer at the level of N-acetyltransferase 2 (NAT2) gene polymorphisms.

    PubMed

    Kasajova, Petra; Holubekova, Veronika; Mendelova, Andrea; Lasabova, Zora; Zubor, Pavol; Kudela, Erik; Biskupska-Bodova, Kristina; Danko, Jan

    2016-06-01

    The aim of our study was to assess the correlation between the tobacco exposure and NAT2 gene (rs1041983 C/T, rs1801280 T/C, rs1799930 G/A) polymorphisms in association with breast cancer development. We wanted to determine the prognostic clinical importance of these polymorphisms in association with smoking and breast cancer. For the detection of possible association between smoking, NAT2 gene polymorphisms, and the risk of breast cancer, we designed a case-controlled study with 198 patients enrolled, 98 breast cancer patients and 100 healthy controls. Ten milliliters of peripheral blood from the cubital vein was withdrawn from every patient. The HRM (high resolution melting) analysis was used for the detection of three abovementioned NAT2 gene polymorphisms. When comparing a group of women smoking more than 5 cigarettes a day with the patients smoking fewer than 5 cigarettes a day, we found out that if women were the carriers of aberrant AA genotype for rs1799930, the first group of women had higher risk of breast carcinoma than the second group. If patients were the carriers of aberrant TT genotype for rs1041983, for rs1801280CC genotype, and rs1799930AA genotype and they smoked more than 5 cigarettes a day, they had higher risk of malignant breast disease than never-smoking women. Our results confirm the hypothesis that NAT2 gene polymorphisms (rs1041983 C/T, rs1801280 T/C, and rs1799930 G/A) in association with long-period active smoking could be the possible individual risk-predicting factors for breast cancer development in the population of Slovak women. PMID:26700672

  19. Refinement of the prediction of N-acetyltransferase 2 (NAT2) phenotypes with respect to enzyme activity and urinary bladder cancer risk.

    PubMed

    Selinski, Silvia; Blaszkewicz, Meinolf; Ickstadt, Katja; Hengstler, Jan G; Golka, Klaus

    2013-12-01

    Polymorphisms of N-acetyltransferase 2 (NAT2) are well known to modify urinary bladder cancer risk as well as efficacy and toxicity of pharmaceuticals via reduction in the enzyme's acetylation capacity. Nevertheless, the discussion about optimal NAT2 phenotype prediction, particularly differentiation between different degrees of slow acetylation, is still controversial. Therefore, we investigated the impact of single nucleotide polymorphisms and their haplotypes on slow acetylation in vivo and on bladder cancer risk. For this purpose, we used a study cohort of 1,712 bladder cancer cases and 2,020 controls genotyped for NAT2 by RFLP-PCR and for the tagSNP rs1495741 by TaqMan(®) assay. A subgroup of 344 individuals was phenotyped by the caffeine test in vivo. We identified an 'ultra-slow' acetylator phenotype based on combined *6A/*6A, *6A/*7B and *7B/*7B genotypes containing the homozygous minor alleles of C282T (rs1041983, *6A, *7B) and G590A (rs1799930, *6A). 'Ultra-slow' acetylators have significantly about 32 and 46 % lower activities of caffeine metabolism compared with other slow acetylators and with the *5B/*5B genotypes, respectively (P < 0.01, both). The 'ultra-slow' genotype showed an association with bladder cancer risk in the univariate analysis (OR = 1.31, P = 0.012) and a trend adjusted for age, gender and smoking habits (OR = 1.22, P = 0.082). In contrast, slow acetylators in general were not associated with bladder cancer risk, neither in the univariate (OR = 1.02, P = 0.78) nor in the adjusted (OR = 0.98, P = 0.77) analysis. In conclusion, this study suggests that NAT2 phenotype prediction should be refined by consideration of an 'ultra-slow' acetylation genotype. PMID:24221535

  20. Coffee and tea consumption, genotype-based CYP1A2 and NAT2 activity and colorectal cancer risk-results from the EPIC cohort study.

    PubMed

    Dik, Vincent K; Bueno-de-Mesquita, H B As; Van Oijen, Martijn G H; Siersema, Peter D; Uiterwaal, Cuno S P M; Van Gils, Carla H; Van Duijnhoven, Fränzel J B; Cauchi, Stéphane; Yengo, Loic; Froguel, Philippe; Overvad, Kim; Bech, Bodil H; Tjønneland, Anne; Olsen, Anja; Boutron-Ruault, Marie-Christine; Racine, Antoine; Fagherazzi, Guy; Kühn, Tilman; Campa, Daniele; Boeing, Heiner; Aleksandrova, Krasimira; Trichopoulou, Antonia; Peppa, Eleni; Oikonomou, Eleni; Palli, Domenico; Grioni, Sara; Vineis, Paolo; Tumino, Rosaria; Panico, Salvatore; Peeters, Petra H M; Weiderpass, Elisabete; Engeset, Dagrun; Braaten, Tonje; Dorronsoro, Miren; Chirlaque, María-Dolores; Sánchez, María-José; Barricarte, Aurelio; Zamora-Ros, Raul; Argüelles, Marcial; Jirström, Karin; Wallström, Peter; Nilsson, Lena M; Ljuslinder, Ingrid; Travis, Ruth C; Khaw, Kay-Tee; Wareham, Nick; Freisling, Heinz; Licaj, Idlir; Jenab, Mazda; Gunter, Marc J; Murphy, Neil; Romaguera-Bosch, Dora; Riboli, Elio

    2014-07-15

    Coffee and tea contain numerous antimutagenic and antioxidant components and high levels of caffeine that may protect against colorectal cancer (CRC). We investigated the association between coffee and tea consumption and CRC risk and studied potential effect modification by CYP1A2 and NAT2 genotypes, enzymes involved in the metabolization of caffeine. Data from 477,071 participants (70.2% female) of the European Investigation into Cancer and Nutrition (EPIC) cohort study were analyzed. At baseline (1992-2000) habitual (total, caffeinated and decaffeinated) coffee and tea consumption was assessed with dietary questionnaires. Cox proportional hazards models were used to estimate adjusted hazard ratio's (HR) and 95% confidence intervals (95% CI). Potential effect modification by genotype-based CYP1A2 and NAT2 activity was studied in a nested case-control set of 1,252 cases and 2,175 controls. After a median follow-up of 11.6 years, 4,234 participants developed CRC (mean age 64.7 ± 8.3 years). Total coffee consumption (high vs. non/low) was not associated with CRC risk (HR 1.06, 95% CI 0.95-1.18) or subsite cancers, and no significant associations were found for caffeinated (HR 1.10, 95% CI 0.97-1.26) and decaffeinated coffee (HR 0.96, 95% CI 0.84-1.11) and tea (HR 0.97, 95% CI 0.86-1.09). High coffee and tea consuming subjects with slow CYP1A2 or NAT2 activity had a similar CRC risk compared to non/low coffee and tea consuming subjects with a fast CYP1A2 or NAT2 activity, which suggests that caffeine metabolism does not affect the link between coffee and tea consumption and CRC risk. This study shows that coffee and tea consumption is not likely to be associated with overall CRC. PMID:24318358

  1. Metabolic activation and analgesic effect of flupirtine in healthy subjects, influence of the polymorphic NAT2, UGT1A1 and GSTP1

    PubMed Central

    Siegmund, Werner; Modess, Christiane; Scheuch, Eberhard; Methling, Karen; Keiser, Markus; Nassif, Ali; Rosskopf, Dieter; Bednarski, Patrick J; Borlak, Jürgen; Terhaag, Bernd

    2015-01-01

    Aims The rare association of flupirtine with liver injury is most likely caused by reactive quinone diimines and their oxidative formation may be influenced by the activities of N-acetyltransferases (NAT) that conjugate the less toxic metabolite D13223, and by glucuronosyltransferases (UGT) and glutathione S-transferases (GST) that generate stable terminal glucuronides and mercapturic acid derivatives, respectively. The influence of genetic polymorphisms of NAT2, UGT1A1 and GSTP1 on generation of the terminal mercapturic acid derivatives and analgesic effects was evaluated to identify potential genetic risk factors for hepatotoxicity of flupirtine. Methods Metabolic disposition of flupirtine was measured after intravenous administration (100 mg), after swallowing an immediate-release (IR) tablet (100 mg) and after repeated administration of modified release (MR) tablets (400 mg once daily 8 days) in 36 selected healthy subjects. Analgesic effects were measured using pain models (delayed onset of muscle soreness, electric pain). Results Flupirtine IR was rapidly but incompletely absorbed (∼72%). Repeated administration of flupirtine MR showed lower bioavailability (∼60%). Approximately 12% of bioavailable flupirtine IR and 8% of bioavailable flupiritine MR was eliminated as mercapturic acid derivatives into the urine independent of the UGT1A1, NAT2 and GSTP1 genotype. Carriers of variant GSTP1 alleles showed lower bioavailability but increased intestinal secretion of flupirtine and increased efficiency in experimental pain. Flupirtine was not a substrate for ABCB1 and ABCC2. Conclusions Formation of mercapturic acid derivatives is a major elimination route for flupirtine in man. However, the theoretically toxic pathway is not influenced by the frequent polymorphisms of UGT1A1, NAT2 and GSTP1. PMID:25264565

  2. Identification of ta-siRNAs and cis-nat-siRNAs in cassava and their roles in response to cassava bacterial blight.

    PubMed

    Quintero, Andrés; Pérez-Quintero, Alvaro L; López, Camilo

    2013-06-01

    Trans-acting small interfering RNAs (ta-siRNAs) and natural cis-antisense siRNAs (cis-nat-siRNAs) are recently discovered small RNAs (sRNAs) involved in post-transcriptional gene silencing. ta-siRNAs are transcribed from genomic loci and require processing by microRNAs (miRNAs). cis-nat-siRNAs are derived from antisense RNAs produced by the simultaneous transcription of overlapping antisense genes. Their roles in many plant processes, including pathogen response, are mostly unknown. In this work, we employed a bioinformatic approach to identify ta-siRNAs and cis-nat-siRNAs in cassava from two sRNA libraries, one constructed from healthy cassava plants and one from plants inoculated with the bacterium Xanthomonas axonopodis pv. manihotis (Xam). A total of 54 possible ta-siRNA loci were identified in cassava, including a homolog of TAS3, the best studied plant ta-siRNA. Fifteen of these loci were induced, while 39 were repressed in response to Xam infection. In addition, 15 possible cis-natural antisense transcript (cis-NAT) loci producing siRNAs were identified from overlapping antisense regions in the genome, and were found to be differentially expressed upon Xam infection. Roles of sRNAs were predicted by sequence complementarity and our results showed that many sRNAs identified in this work might be directed against various transcription factors. This work represents a significant step toward understanding the roles of sRNAs in the immune response of cassava. PMID:23665476

  3. Production of ⁶¹Cu by the natZn(p,α) reaction: Improved separation and specific activity determination by titration with three chelators

    DOE PAGESBeta

    Asad, Ali H.; Smith, Suzanne V.; Morandeau, Laurence M.; Chan, Sun; Jeffery, Charmaine M.; Price, Roger I.

    2015-09-01

    In this study, the cyclotron-based production of position-emitting ⁶¹Cu using the (p,α) reaction at 11.7 MeV was investigated starting from natural-zinc (natZn) and enriched ⁶⁴Zn-foil targets, as well as its subsequent purification. For natZn, a combination of three resins were assessed to separate ⁶¹Cu from contaminating 66,67,68Ga and natZn. The specific activity of the purified ⁶¹Cu determined using ICP-MS analysis ranged from 143.3±14.3(SD) to 506.2±50.6 MBq/μg while the titration method using p-SCN-Bn-DOTA, p-SCN-Bn-NOTA and diamsar gave variable results (4.7±0.2 to 412.5±15.3 MBq/μg), with diamsar lying closest to the ICP-MS values. Results suggest that the p-SCN-Bn-DOTA and p-SCN-Bn-NOTA titration methods aremore » significantly affected by the presence of trace-metal contaminants.« less

  4. Production of ⁶¹Cu by the natZn(p,α) reaction: Improved separation and specific activity determination by titration with three chelators

    SciTech Connect

    Asad, Ali H.; Smith, Suzanne V.; Morandeau, Laurence M.; Chan, Sun; Jeffery, Charmaine M.; Price, Roger I.

    2015-09-01

    In this study, the cyclotron-based production of position-emitting ⁶¹Cu using the (p,α) reaction at 11.7 MeV was investigated starting from natural-zinc (natZn) and enriched ⁶⁴Zn-foil targets, as well as its subsequent purification. For natZn, a combination of three resins were assessed to separate ⁶¹Cu from contaminating 66,67,68Ga and natZn. The specific activity of the purified ⁶¹Cu determined using ICP-MS analysis ranged from 143.3±14.3(SD) to 506.2±50.6 MBq/μg while the titration method using p-SCN-Bn-DOTA, p-SCN-Bn-NOTA and diamsar gave variable results (4.7±0.2 to 412.5±15.3 MBq/μg), with diamsar lying closest to the ICP-MS values. Results suggest that the p-SCN-Bn-DOTA and p-SCN-Bn-NOTA titration methods are significantly affected by the presence of trace-metal contaminants.

  5. Excitation functions of proton induced reactions on natOs up to 65 MeV: Experiments and comparison with results from theoretical codes

    NASA Astrophysics Data System (ADS)

    Hermanne, A.; Adam Rebeles, R.; Tárkányi, F.; Takács, S.

    2015-02-01

    Activation of thin natOs targets, electrodeposited on Ni backings, was investigated for the first time in stacked foil irradiations with 65 MeV and 34 MeV proton beams. Assessments of the produced radionuclides by high resolution gamma-ray spectroscopy yielded excitation functions for formation of 184, 185, 186m,m+g, 187m+g, 188m+g, 189m2+m1+g, 190m2,m1+g, 192m1+gIr and 185cum, 191m+gOs, 183m+gRe. Where available comparisons with the reaction cross sections obtained in 2 earlier studies on enriched 192Os were made. Reduced uncertainty on cross sections is obtained by simultaneous remeasurement of the 27Al(p,x)22,24Na, natNi(p,x)57Ni and natTi(p,x)48V monitor reactions over wide relevant energy ranges. Confirmation of monitoring took place by assessment of excitation functions of 61Cu, 56Ni, 55,56,57,58Co and 52Mn induced in the Ni backings and comparison with a recent compilation for most of these radionuclides. Contributing reactions and overall cross sections are discussed and were evaluated in comparison with the results of the theoretical code TALYS 1.6 (values from the on-line library TENDL-2013).

  6. Efficient graph algorithms for sequential and parallel computers. Doctoral thesis

    SciTech Connect

    Goldberg, A.V.

    1987-02-01

    This thesis studies graph algorithms, both in sequential and parallel contexts. In the outline of the thesis, algorithm complexities are stated in terms of the the number of vertices n, the number of edges m, the largest absolute value of capacities U, and the largest absolute value of costs C. Chapter 1 introduces a new approach to the maximum flow problem that leads to better algorithms for the problem. Chapter 2 is devoted to the minimum cost flow problem, which is a generalization of the maximum flow problem. Chapter 3 addresses implementation of parallel algorithms through a case study of an implementation of a parallel maximum flow algorithm. Parallel prefix operations play an important role in the implementation. Present experimental results achieved by the implementation are presented. Present parallel symmetry-breaking techniques are the main topic of Chapter 4.

  7. Optimization in solar heating/photovoltaic systems. Master's thesis

    SciTech Connect

    Vourazelis, D.G.

    1990-12-01

    This thesis is a design of an alternative system which may provide heating to the Naval Postgraduate School swimming pool. Particularly, it is a solar heating/photovoltaic system designed for a better efficiency and less cost of installation and maintenance. Principles of heat transfer, control and fluid dynamics theory are used for the determination of this heating system elements. The feasibility of its installation and use is analyzed.

  8. Dimensionality and predictive validity of the HAM-Nat, a test of natural sciences for medical school admission

    PubMed Central

    2011-01-01

    Background Knowledge in natural sciences generally predicts study performance in the first two years of the medical curriculum. In order to reduce delay and dropout in the preclinical years, Hamburg Medical School decided to develop a natural science test (HAM-Nat) for student selection. In the present study, two different approaches to scale construction are presented: a unidimensional scale and a scale composed of three subject specific dimensions. Their psychometric properties and relations to academic success are compared. Methods 334 first year medical students of the 2006 cohort responded to 52 multiple choice items from biology, physics, and chemistry. For the construction of scales we generated two random subsamples, one for development and one for validation. In the development sample, unidimensional item sets were extracted from the item pool by means of weighted least squares (WLS) factor analysis, and subsequently fitted to the Rasch model. In the validation sample, the scales were subjected to confirmatory factor analysis and, again, Rasch modelling. The outcome measure was academic success after two years. Results Although the correlational structure within the item set is weak, a unidimensional scale could be fitted to the Rasch model. However, psychometric properties of this scale deteriorated in the validation sample. A model with three highly correlated subject specific factors performed better. All summary scales predicted academic success with an odds ratio of about 2.0. Prediction was independent of high school grades and there was a slight tendency for prediction to be better in females than in males. Conclusions A model separating biology, physics, and chemistry into different Rasch scales seems to be more suitable for item bank development than a unidimensional model, even when these scales are highly correlated and enter into a global score. When such a combination scale is used to select the upper quartile of applicants, the proportion of

  9. The M68HC11 gripper controller software. Thesis

    NASA Technical Reports Server (NTRS)

    Tsai, Jodi Wei-Duk

    1991-01-01

    This thesis discusses the development of firmware for the 68HC11 gripper controller. A general description of the software and hardware interfaces is given. The C library interface for the gripper is then described and followed by a detailed discussion of the software architecture of the firmware. A procedure to assemble and download 68HC11 programs is presented in the form of a tutorial. The tools used to implement this environment are then described. Finally, the implementation of the configuration management scheme used to manage all CIRSSE software is presented.

  10. A Petri net controller for distributed hierarchical systems. Thesis

    NASA Technical Reports Server (NTRS)

    Peck, Joseph E.

    1991-01-01

    The solutions to a wide variety of problems are often best organized as a distributed hierarchical system. These systems can be graphically and mathematically modeled through the use of Petri nets, which can easily represent synchronous, asynchronous, and concurrent operations. This thesis presents a controller implementation based on Petri nets and a design methodology for the interconnection of distributed Petri nets. Two case studies are presented in which the controller operates a physical system, the Center for Intelligent Robotic Systems for Space Exploration Dual Arm Robotic Testbed.

  11. ERBE S7 NAT

    Atmospheric Science Data Center

    2016-06-15

    ... scanner instruments on board the NOAA-9 and NOAA-10 satellites provide global coverage, while the ERBE scanner instrument onboard ... have 136-degree FOV on ERBS and 126-degree FOV on the NOAA satellites. The MFOV instruments have footprints of approximately 5 geocentric ...

  12. ERBE S8 NAT

    Atmospheric Science Data Center

    2016-06-15

    ... ERBE instruments on board the NOAA-9 and NOAA-10 satellites provide global spatial coverage, while the scanner instruments on ... have 136-degree FOV on ERBS and 126-degree FOV on the NOAA satellites. The MFOV instruments have footprints of approximately 5 geocentric ...

  13. Remembering Nat Schoenfeld

    PubMed Central

    Catania, A. Charles

    1997-01-01

    William Nathan Schoenfeld was born in New York City on December 6, 1915, and died in Sun City West, Arizona, on August 3, 1996. He was an undergraduate at the College of the City of New York, where he received a BS degree in 1937. He received his PhD from Columbia University in 1942 and then continued there as a faculty member, advancing from lecturer to full professor. In 1966 he moved to Queens College of the City University of New York, where he remained until his retirement in 1983. During his years at Queens, he also took on visiting appointments in Brazil, Mexico, and Venezuela. In retirement, he spent roughly a decade in Israel, where he occasionally taught as a visiting professor at the Hebrew University of Jerusalem. He returned to the United States for his final years. He is survived by his wife, Melanie, their three children, Rivka, Joshua and Naomi, and a son, Mark, from a previous marriage.

  14. Intelligence database support for Naval arms control. Master's thesis

    SciTech Connect

    Shirer, R.H.

    1991-12-01

    The database contained in this thesis was put together from unclassified sources. It is stored on computer disk using the Lotus 123 software program and is easily updated and manipulated. This database was created to provide support to U.S. Naval arms control negotiators in the event that the Navy is forced to the negotiating table. This thesis does not advocate naval arms control. However, given the current political climate it is prudent to be prepared for such an eventuality. This assessment utilizes a methodology for determining excess naval forces of the Soviet Union that would be targetable in arms control talks. In order to quantify the excess, we constructed a Soviet naval model that would be adequate to meet Soviet security goals under 'defensive defense' doctrine. Our goal was not to present the Soviet Union with a plan of action but to come up with a reasonable estimate of what their force structure is likely to resemble. Again, it is the methodology which is important here, as specific numbers can easily be changed using the Lotus program to account for classified information or changing developments.

  15. TCP Packet Trace Analysis. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Shepard, Timothy J.

    1991-01-01

    Examination of a trace of packets collected from the network is often the only method available for diagnosing protocol performance problems in computer networks. This thesis explores the use of packet traces to diagnose performance problems of the transport protocol TCP. Unfortunately, manual examination of these traces can be so tedious that effective analysis is not possible. The primary contribution of this thesis is a graphical method of displaying the packet trace which greatly reduce, the tediousness of examining a packet trace. The graphical method is demonstrated by the examination of some packet traces of typical TCP connections. The performance of two different implementations of TCP sending data across a particular network path is compared. Traces many thousands of packets long are used to demonstrate how effectively the graphical method simplifies examination of long complicated traces. In the comparison of the two TCP implementations, the burstiness of the TCP transmitter appeared to be related to the achieved throughput. A method of quantifying this burstiness is presented and its possible relevance to understanding the performance of TCP is discussed.

  16. Alternative American foreign policy for Ukraine. Master's thesis

    SciTech Connect

    Williams, R.G.

    1993-06-01

    American policy makers have largely ignored Ukraine in their global policy planning. This lack of consideration shows a neglect of the potential for conflict in Eastern Europe. American foreign policy toward Ukraine, that is rooted in the START and NPT Treaties, is doomed to fail, and will actually sow the seeds of chaos, unless the United States: (1) comes to understand the motivations that drive Ukrainian foreign policy, and (2) facilitate significant positive alterations to the security and economic environment that has developed since the breakup of the Soviet Union. This thesis examines Western security goals and analyzes the current means available to achieve those goals. The contention of this thesis is that present Western policy pursuits will lead to a regenerated authoritarian Russian superpower that will be a threat to the security of Ukraine and Europe. The potentially dangerous consequences of an authoritarian Russia could be avoided by facilitating the development of a strong and stable Ukraine to act as a balance to Russian power in Eastern Europe. United States, Ukraine, Foreign policy, Nuclear arms negotiations, Economic aid, Russia.

  17. Understanding the economic power of oil. Master's thesis

    SciTech Connect

    Belanger, J.C.

    1992-12-01

    Oil has become a single global market in which oil price fluctuations now have the ability to rock the world economy. The purpose of this thesis is to examine the changing nature of this threat and by doing so, show that Saudi Arabia, which has acted as the primary stabilizing tool by American foreign policy makers, will no longer suffice in this capacity. Rather, Saudi Arabia, which has for the most part cooperated with the United States in helping to stabilize oil price and supply disruptions, will become increasingly less cooperative in a much shorter time frame than night be anticipated with regard to oil supplies. This thesis proposes possible avenues for US national security policy by exploring pathways that might further ensure economic security and stability of the Middle East region in light of the new nature of the oil threat. The goal of economic security and stability can only be realized through an understanding of the oil producing nations and their relationships with the international community and world economy.... Oil, Persian Gulf Security Policy, Middle East Oil Reserves.

  18. Fragment charge and energy distributions in the 1.8-4.8 GeV {sup 3}He + {sup nat}Ag, {sup 197}Au reactions

    SciTech Connect

    Bracken, D.S.; Foxford, E.R.; Kwiatkowski, K.

    1995-10-01

    Moving source fits have been performed for IMFs as a function of observables related to collision violence in the 1.8-4.8 GeV {sup 3}He +{sup nat}Ag, {sup l97}Au reactions. The systematic behavior of the source properties and fragment charge distributions will be reviewed. The evolution of the spectral Coulomb parameters provides evidence for nuclear expansion prior to multifragmentation, suggesting a breakup density of p/p{sub o} {approximately} 1/3. The charge distributions will be examined in terms of power-law fits and moment analyses.

  19. Computational investigation of ⁹⁹Mo production yield via proton irradiation of natU and ²³²Th targets.

    PubMed

    Mirvakili, Seyed Mohammad; Alizadeh, Masoumeh; Vaziri, Atyeh Joze; Gholamzadeh, Zohreh; Davari, Amin

    2015-07-01

    Accelerators have some advantages such as safety and cheaper operating and decommissioning costs for (99)Mo production. Yield theoretical calculation using computational codes can powerfully estimate usefulness of a proposed nuclear reaction for a routine manufacturing. In this work, Monte Carlo-based code was used to compute (99)Mo yield in (232)Th and (nat)U proton-irradiated targets, as well as maximum applicable beam current. Results showed that the code well agrees with published experimental data. The targets can bear maximum beam current of 30 µA. Targets from (232)Th provides higher (99)Mo yield. PMID:25898237

  20. GST, NAT, SULT1A1, CYP1B1 genetic polymorphisms, interactions with environmental exposures and bladder cancer risk in a high-risk population.

    PubMed

    Hung, Rayjean J; Boffetta, Paolo; Brennan, Paul; Malaveille, Christian; Hautefeuille, Agnès; Donato, Francesco; Gelatti, Umberto; Spaliviero, Massimiliano; Placidi, Donatella; Carta, Angela; Scotto di Carlo, Antonio; Porru, Stefano

    2004-07-01

    Tobacco smoking and occupation are major risk factors of bladder cancer via exposure to polycyclic aromatic hydrocarbons (PAHs) and aromatic amines. Glutathione S-transferase (GST) M1, T1 and P1 are involved in the detoxification of PAH reactive metabolites. Two N-acetyltransferase isozymes, NAT2 and NAT1, have major roles in catalyzing the N-acetylation and O-acetylation of aromatic amines. Cytochrome p450 1B1 (CYP1B1) and sulfotransferase 1A1 (SULT1A1) are also involved in the metabolism of PAHs and aromatic amines. It is hypothesized that the genetic polymorphisms of these metabolic enzymes have an effect on the individual susceptibility to bladder cancer in particular by interacting with relevant environmental exposures. A hospital-based case-control study among men in Brescia, Northern Italy recruited 201 incidence cases and 214 controls from 1997-2000. Occupational exposures were blindly coded by occupational physicians. Genotyping of polymorphisms were carried out with PCR-RFLP method. Unconditional multivariate logistic regression was applied to model the association between genetic polymorphisms and bladder cancer risk. Effect modifications by age of onset, smoking and occupational exposures to PAHs and aromatic amines were evaluated. We also conducted an analysis of interaction between genetic factors. GSTM1 and GSTT1 null genotype were associated with an increased risk of bladder cancer with an odds ratio (OR) of 1.69 (95% confidence interval [CI] = 1.11-2.56) and 1.74 (95% CI = 1.02-2.95), respectively. The effect of GSTM1 null was seen particularly in heavy smokers, and there was a combined effect with occupational exposure of aromatic amines (OR = 2.77, 95% CI = 1.08-7.10). We observed a trend (p-value < 0.01) of increasing cancer risk comparing subjects with normal GSTM1 and T1 activity to subjects with one (OR = 1.82, 95% CI = 1.16-2.85) or both null genotypes (OR = 2.58, 95% CI = 1.27-5.23). NAT2 slow acetylator was associated with marginally

  1. The challenge of giving written thesis feedback to nursing students.

    PubMed

    Tuvesson, Hanna; Borglin, Gunilla

    2014-11-01

    Providing effective written feedback on nursing student's assignments can be a challenging task for any assessor. Additionally, as the student groups tend to become larger, written feedback is likely to gain an overall more prominent position than verbal feedback. Lack of formal training or regular discussion in the teaching faculty about the skill set needed to provide written feedback could negatively affect the students' learning abilities. In this brief paper, we discuss written feedback practices, whilst using the Bachelor of Science in Nursing thesis as an example. Our aim is to highlight the importance of an informed understanding of the impact written feedback can have on students. Creating awareness about this can facilitate the development of more strategic and successful written feedback strategies. We end by offering examples of some relatively simple strategies for improving this practice. PMID:25042741

  2. Energy management and control system verification study. Master's thesis

    SciTech Connect

    Boulware, K.E.; Williamson, G.C.

    1983-09-01

    Energy Management and Control Systems (EMCS) are being installed and operated throughout the Air Force. Millions of dollars have been spent on EMCS, but no study has conclusively proved that EMCS has actually saved the Air Force energy. This thesis used the Regression subprogram of Statistical Packages for the Social Sciences (SPSS) to determine if these systems are indeed saving the Air Force energy. Previous studies have shown that Multiple Linear Regression (MLR) is the best statistical predictor of base energy consumption. Eight bases were selected that had an operational EMCS. Two EMCS bases were compared with one control base for each of four CONUS winter heating zones. The results indicated small (less than 2%) energy savings have occurred at half of the EMCS bases studied. Therefore, this study does not conclusively prove that EMCS's have saved energy on Air Force bases. However, the methodology developed in this report could be applied on a broader scale to develop a more conclusive result.

  3. The polarizability of diatomic helium. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Fortune, P. J.

    1974-01-01

    The calculation of the electric dipole polarizability tensor of the He 2 dimer is described, and the results are used in the computation of several dielectric and optical properties of helium gas, at both high (322 K) and low (4 K) temperatures. The properties considered are the second dielectric virial coefficient, the second Kerr virial coefficient, and the depolarization ratio of the integrated intensities for the Raman scattering experiments. The thesis consists of five parts: the polarizability and various properties are defined; the calculation of the polarizability in the long-range region in terms of a quantum mechanical multipole expansion is described; the calculation of the He2 polarizability in the overlap region via coupled Hartree-Fock perturbation theory is described; the calculation of the quantum pair distribution function for both the He-3 and He-4 isotopes at 4 K is discussed; and the calculated values of the properties of helium gas are given.

  4. Models for proliferation interdiction response analysis. Master`s thesis

    SciTech Connect

    Reed, B.K.

    1994-09-01

    The proliferation of nuclear weapons poses a serious threat to the United States, its allies, and over-all world security. The United States seeks to dissuade or prevent new countries from acquiring nuclear weapons capabilities. This thesis constructs two models to aid decision makers in selecting strategies to interdict these proliferation efforts. The first, a what-if PERT/CPM model, provides an overall picture of the proliferation process. The graphical display is used to select activities to interdict, and to analyze the outcome of the choices. The second, an optimal interdiction model, selects the optimal activity(ies) or interdiction subject to risk constraints. Several runs with different numbers of interdiction points were made to test the optimal interdiction model. These results are further analyzed with the aid of the PERT/CPM model. The models, when used together, prove to be useful in selecting the optimal activities to interdict in the proliferation process.

  5. The functional matrix hypothesis revisited. 3. The genomic thesis.

    PubMed

    Moss, M L

    1997-09-01

    Although the initial versions of the functional matrix hypothesis (FMH) theoretically posited the ontogenetic primacy of "function," it is only in recent years that advances in the morphogenetic, engineering, and computer sciences provided an integrated experimental and numerical data base that permitted recent significant revisions of the FMH--revisions that strongly support the primary role of function in craniofacial growth and development. Acknowledging that the currently dominant scientific paradigm suggests that genomic, instead of epigenetic (functional) factors, regulate (cause, control) such growth, an analysis of this continuing controversy was deemed useful. Accordingly the method of dialectical analysis, is employed, stating a thesis, an antithesis, and a resolving synthesis based primarily on an extensive review of the pertinent current literature. This article extensively reviews the genomic hypothesis and offers a critique intended to remove some of the unintentional conceptual obscurantism that has recently come to surround it. PMID:9294365

  6. Hybrid Formulations of Liposomes and Bioadhesive Polymers Improve the Hypotensive Effect of the Melatonin Analogue 5-MCA-NAT in Rabbit Eyes

    PubMed Central

    Palma, Santiago; Allemandi, Daniel; Herrero-Vanrell, Rocío; Molina-Martínez, Irene T.

    2014-01-01

    For the treatment of chronic ocular diseases such as glaucoma, continuous instillations of eye drops are needed. However, frequent administrations of hypotensive topical formulations can produce adverse ocular surface effects due to the active substance or other components of the formulation, such as preservatives or other excipients. Thus the development of unpreserved formulations that are well tolerated after frequent instillations is an important challenge to improve ophthalmic chronic topical therapies. Furthermore, several components can improve the properties of the formulation in terms of efficacy. In order to achieve the mentioned objectives, we have developed formulations of liposomes (150–200 nm) containing components similar to those in the tear film and loaded with the hypotensive melatonin analog 5-methoxycarbonylamino-N-acetyltryptamine (5-MCA-NAT, 100 µM). These formulations were combined with mucoadhesive (sodium hyaluronate or carboxymethylcellulose) or amphiphilic block thermosensitive (poloxamer) polymers to prolong the hypotensive efficacy of the drug. In rabbit eyes, the decrease of intraocular pressure with 5-MCA-NAT-loaded liposomes that were dispersed with 0.2% sodium hyaluronate, 39.1±2.2%, was remarkably higher compared to other liposomes formulated without or with other bioadhesive polymers, and the effect lasted more than 8 hours. According to the results obtained in the present work, these technological strategies could provide an improved modality for delivering therapeutic agents in patients with glaucoma. PMID:25329636

  7. Affinity of (nat/68)Ga-Labelled Curcumin and Curcuminoid Complexes for β-Amyloid Plaques: Towards the Development of New Metal-Curcumin Based Radiotracers.

    PubMed

    Rubagotti, Sara; Croci, Stefania; Ferrari, Erika; Iori, Michele; Capponi, Pier C; Lorenzini, Luca; Calzà, Laura; Versari, Annibale; Asti, Mattia

    2016-01-01

    Curcumin derivatives labelled with fluorine-18 or technetium-99m have recently shown their potential as diagnostic tools for Alzheimer's disease. Nevertheless, no study by exploiting the labelling with gallium-68 has been performed so far, in spite of its suitable properties (positron emitter, generator produced radionuclide). Herein, an evaluation of the affinity for synthetic β-amyloid fibrils and for amyloid plaques of three (nat/68)Ga-labelled curcumin analogues, namely curcumin curcumin (CUR), bis-dehydroxy-curcumin (bDHC) and diacetyl-curcumin (DAC), was performed. Affinity and specificity were tested in vitro on amyloid synthetic fibrils by using gallium-68 labelled compounds. Post-mortem brain cryosections from Tg2576 mice were used for the ex vivo visualization of amyloid plaques. The affinity of (68)Ga(CUR)₂⁺, (68)Ga(DAC)₂⁺, and (68)Ga(bDHC)₂⁺ for synthetic β-amyloid fibrils was moderate and their uptake could be observed in vitro. On the other hand, amyloid plaques could not be visualized on brain sections of Tg2576 mice after injection, probably due to the low stability of the complexes in vivo and of a hampered passage through the blood-brain barrier. Like curcumin, all (nat/68)Ga-curcuminoid complexes maintain a high affinity for β-amyloid plaques. However, structural modifications are still needed to improve their applicability as radiotracers in vivo. PMID:27608011

  8. Electronic Thesis Initiative: Pilot Project of McGill University, Montreal

    ERIC Educational Resources Information Center

    Park, Eun G.; Zou, Qing; McKnight, David

    2007-01-01

    Purpose: To set up a protocol for electronic thesis and dissertation (ETD) submission for the electronic thesis initiative pilot project at McGill University in Montreal, Canada. Design/methodology/approach: An electronic thesis and dissertation submission protocol was implemented and tested. To test authoring tools, we had 50 students submit…

  9. A coupled decadal-scale air-sea interaction theory: the NAT-NAO-AMO-AMOC coupled mode and its global impacts

    NASA Astrophysics Data System (ADS)

    Li, Jianping; Sun, Cheng; Jin, Fei-Fei

    2016-04-01

    Observational analysis shows that the North Atlantic Oscillation (NAO) leads the oceanic Atlantic Multidecadal Oscillation (AMO) by 15-20 years and the latter also leads the former by around 15 years. The Community Climate System Model (CCSM) version 4 is employed to investigate the relevant mechanism in the linkage between the NAO and AMO. The results show that the positive North Atlantic Oscillation (NAO) forces the strengthening of the Atlantic meridional overturning circulation (AMOC) and induces a basin-wide uniform sea surface temperature (SST) warming that corresponds to the Atlantic multidecadal oscillation (AMO). The SST field exhibits a delayed response to the preceding enhanced AMOC, and shows a pattern similar to the North Atlantic tripole (NAT), with SST warming in the northern North Atlantic and cooling in the southern part. This SST pattern (negative NAT phase) may lead to an atmospheric response that resembles the negative NAO phase, and subsequently the oscillation proceeds, but in the opposite sense. This implies a NAO-AMO-AMOC coupled mode in decadal scale. Based on these mechanisms, a simple delayed oscillator model is established to explain the quasi-periodic multidecadal variability of the NAO. The magnitude of the NAO forcing of the AMOC/AMO and the time delay of the AMOC/AMO feedback are two key parameters of the delayed oscillator. For a given set of parameters, the quasi 60-year cycle of the NAO can be well predicted. This delayed oscillator model is useful for understanding of the oscillatory mechanism of the NAO, which has significant potential for decadal predictions as well as the interpretation of proxy data records. The NAT-NAO-AMO-AMOC coupled mode has important influences on global and regional climate. The twentieth century Northern Hemisphere mean surface temperature (NHT) is characterized by a multidecadal warming-cooling-warming pattern followed by a flat trend since about 2000 (recent warming hiatus). Here we demonstrate that

  10. [Medical degree earned with a thesis in medical schools of Lima, 2011: characteristics, motivations and perceptions].

    PubMed

    Mejia, Christian R; Inga-Berrospi, Fiorella; Mayta-Tristán, Percy

    2014-01-01

    We surveyed physicians who obtained their medical degree with a thesis in 2011 from the seven medical schools in Lima to know the characteristics of the degree by thesis process, as well as participants’ motivations and perceptions of that process. We included 98 students who did a thesis (87% of total); 99% conducted observational thesis, 30% did so in groups of three. The main motivation was that it was good for their curriculum vitae (94%). At the university where the thesis is compulsory, the process began with the choice of topic and adviser. Perceived “greatest” and “least” difficulty in the process was the completion of administrative procedures (53%) and selection of their advisor (11%), respectively. Administrative timeliness and processes should be reviewed so as not to impede the completion of thesis, since the new University Act requires the completion of a thesis to graduate. PMID:25418650

  11. Geodetic measurement of deformation in California. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Sauber, Jeanne Marie

    1988-01-01

    The very long baseline interferometry (VLBI) measurements made in the western U.S. since 1979 as part of the NASA Crustal Dynamics Project provide discrete samples of the temporal and spatial deformation field. The interpretation of the VLBI-derived rates of deformation requires an examination of geologic information and more densely sampled ground-based geodetic data. In the first two of three related studies embodying this thesis triangulation and trilateration data measured on two regional networks are processed, one in the central Mojave Desert and one in the Coast Ranges east of the San Andreas fault. At the spatial scales spanned by these local geodetic networks, auxiliary geologic and geophysical data have been utilized to examine the relation between measured incremental strain and the accommodation of strain seen in local geological structures, strain release in earthquakes, and principal stress directions inferred from in situ measurements. In the third study, VLBI data from stations distributed across the Pacific - North American plate boundary zone in the western United States are processed. The VLBI data have been used to constrain the integrated rate of deformation across portions of the continental plate boundary in California and to provide a tectonic framework to interpret regional geodetic and geologic studies.

  12. Algorithmic study on systolic array structures. Master's thesis

    SciTech Connect

    Souza, L.J.

    1985-06-01

    Computation bound problems impose a severe burden on the CPU. In order to speed up computation, specific problems that are identified as the main burden can be done using parallel processing. In this way, the time consuming tasks can be executed on specially tailored hardware. This hardware is designed to implement an algorithm-oriented parallel-processing structure that works more efficiently than the CPU for these specific tasks. This thesis is a study of the mapping of the algorithms onto a kind of structure called systolic array. The development and utilization of a software tool designed to assist on such analysis is presented here. This tool, named Systolic Array Graphics Simulator (SYSGRAS), has the capability to represent any type of systolic array, no matter how complex the cells and structure are. Because of the capability of SYSGRAS, an interactive computer program simulator, the study of systolic arrays is simplified. The complexity of the time-space relationships is analyzed with the help of some color-graphics techniques. The visualization of the data interaction is thus enhanced and the user is alleviated from the burden of keeping track of partial results and can dedicate attention to the processing algorithm.

  13. Nuclear proliferation: Lessons learned from the Iraqi case. Master's thesis

    SciTech Connect

    Dixon, T.A.

    1992-12-01

    The nuclear weapons inspection regime implemented in Iraq following the United Nations coalition victory in Desert Storm is the most intrusive in history. Important conclusions about the current non-proliferation regime can therefore be determined from a study of Iraq's progress. This thesis examines Iraq's efforts to acquire nuclear weapons. The supply side of the equation is also studied, with a concentration upon the contributions of NATO nations. The strategic culture of Iraq is discussed, in an effort to discover why Iraq sought nuclear weapons. Finally, policy prescriptions are advanced. The current non-proliferation regime needs to be improved if the spread of nuclear weapons is to be halted, or even slowed. The most promising way to improve this regime is to involve the U.N. Special Commission and the U.N. Security Council in the management of the problem of nuclear proliferation.... Iraq, Strategic culture, Non-Proliferation treaty, International atomic energy agency, Nuclear weapons, Middle east security, Nuclear suppliers group, United Nations.

  14. The History and Significance of the Incommensurability Thesis

    NASA Astrophysics Data System (ADS)

    Pearce, James Jacob

    The incommensurability thesis (IT) maintains that there are no non-prejudicial means of choosing between competing theories in the empirical sciences. If true, IT would entail that natural science is a fundamentally subjective or irrational activity. Should this latter claim prove justifiable, then empirical science cannot be regarded as an organ of objective knowledge, and "scientific realism" is eo ipso false. I follow the origin of IT from its pre-history in Logical Positivism, through certain preliminary philosophical developments in the work of Karl Popper, W. V. O. Quine, Stephen Toulmin and N. R. Hanson, to the eventual formulation and introduction of IT by Thomas Kuhn and Paul Feyerabend. I then examine the rigorous criticism of IT by various philosophers since about 1964, and discuss different methods of objective theory comparison which have been advanced by such philosophers as Hilary Putnam, W. H. Newton-Smith, Michael Devitt, Hartry Field, Philip Kitcher and Howard Sankey. I conclude by arguing for two counterintuitive claims: (1) Even if true, IT fails to provide evidence against scientific realism. (2) In fact, the truth of IT actually furnishes evidence for a necessary condition for scientific realism, and hence evidence which can be construed as indirectly favorable to scientific realism.

  15. Nuclear terrorism: Rethinking the unthinkable. Master`s thesis

    SciTech Connect

    Marrs, R.W.

    1994-12-01

    Many policymakers and scholars contend that nuclear weapons remain inaccessible to terrorists, and that nuclear means are inconsistent with or disproportionate to their goals. Nevertheless, the historical pattern of nuclear proliferation suggests a trend toward nonstate actor acquisition, a notion supported by recent developments in the black market. Additional evidence suggests that some specific groups have expressed an interest in nuclear weapons. This thesis proposes that there is a terrorist demand for nuclear weapons. Further, its findings suggest that the possibility of terrorist acquisition has grown; and that these nonstate adversaries will enjoy significant advantage over states during nuclear crisis. Terrorists, like states, pursue political objectives and have similar concerns regarding power and security. Lacking state resources, terrorists employ instrumental targeting in pursuit of those objectives, while remaining relatively invulnerable to retaliation. This dynamic will encourage terrorists to acquire and exploit nuclear potential, thereby overturning traditional theories of deterrence. Wishful thinking about nuclear terrorism has discouraged thoughtful analiysis of this dilemma. The prospect is sufficiently dire that a preventive campaign must be launched to stop terrorist acquisition of nuclear capabilities. Policymakers must also prepare for the possible failure of preventive efforts, and search for options that may mitigate nuclear terrorism.

  16. [Research in general medicine, role of the medical thesis].

    PubMed

    Levasseur, G; Schweyer, F X

    2003-06-01

    General practice doctors are naturally presented as being actors on the front lines of public health. The ability of general practitioners to be aware of and deal with public health questions largely depends upon their training. Perhaps one could consider the general practitioner's thesis as a preparatory analytical work within the area of their future field of practice. Do these theses serve to provide food for thought on general practice and its contribution to public health, and if not, could they? An analysis conducted within four medical schools in western France demonstrates that the work produced for general medicine identified as such only constitutes a fraction of the overall number of medical (non-university) theses (approximately 5%). Two possible explanations may be put forward. First, on the one hand, the theses highly depend on the context of the training and the work produced is a direct result of this. Second, on the other hand, the current methods of indexing notes in the university databases does not enable general medicine to be clearly seen and visibly recognised as an academic discipline. Two questions then remain: Can medical theses be considered as research? Should research in general medicine be carried out solely by general practitioners? It is vital that resources from outside the medical field be raised and mobilised for general practice research, whose themes are multi-disciplinary and not only clinical. PMID:12891817

  17. Economic model for seaborne oil trade. Master`s thesis

    SciTech Connect

    Kian-Wah, H.

    1996-03-01

    This thesis aims to provide some insights as to how oil prices and oil flows might vary with the carrying capacity of the tanker fleet as affected by political events. It provides an econometric analysis of tanker freight rates in the modern era and proposes a mathematical (quadratic) programming economic model that links the crude oil market to the supply elasticity of the world oil tanker fleet based on a competitive economy. The economic model can be considered as a version of the Walras-Cassel general-equilibrium system which possesses an economically meaningful equilibrium solution in terms of oil prices, freight rates and the pattern of oil distribution. The implementation of the model is completed using the General Algebraic Modeling System (GAMS). The study concludes with a scenario study showing how the model could be used to examine the importance of South East Asia`s sealanes in world seaborne oil trade. The model shows the economic vulnerability of oil importing nations, especially Japan, the United States, and Western Europe, to a possible closure of South East Asian sealanes.

  18. Soviet concepts of ballistic missile defense. Master's thesis

    SciTech Connect

    Seavey, K.P.

    1988-06-01

    This thesis characterizes the Soviet concept of ballistic missile defense (BMD) in order to better understand and predict future Soviet BMD decision making. The Soviet concept of BMD is fundamentally different from that in the West. Soviet BMD is clearly an integral component of a much larger Soviet strategic defense effort which consists of strategic air defense as well as passive measures, such as mobility, deep underground command and control facilities, and civil defense. As the Soviet military literature demonstrates, Soviet strategic air defense encompasses defense against a continuum of threats -- from aircraft to ballistic missiles to satellites to 'space-strike weapons'. Soviet strategic air defense weapons therefore appear optimized to counter a wide range of airborne threats. In the Soviet view, surface-to-air missiles may be a primary tactical BMD weapon. Additionally, Soviet strategic BMD weapons may be a primary Soviet anti-satellite weapon. Furthermore, manned space platforms play a particularly significant role in Soviet thinking about the future of BMD and space warfare.

  19. Nozzle Flow with Vibrational Nonequilibrium. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Landry, John Gary

    1995-01-01

    Flow of nitrogen gas through a converging-diverging nozzle is simulated. The flow is modeled using the Navier-Stokes equations that have been modified for vibrational nonequilibrium. The energy equation is replaced by two equations. One equation accounts for energy effects due to the translational and rotational degrees of freedom, and the other accounts for the affects due to the vibrational degree of freedom. The energy equations are coupled by a relaxation time which measures the time required for the vibrational energy component to equilibrate with the translational and rotational energy components. An improved relaxation time is used in this thesis. The equations are solved numerically using the Steger-Warming flux vector splitting method and the Implicit MacCormack method. The results show that uniform flow is produced outside of the boundary layer. Nonequilibrium exists in both the converging and diverging nozzle sections. The boundary layer region is characterized by a marked increase in translational-rotational temperature. The vibrational temperature remains frozen downstream of the nozzle, except in the boundary layer.

  20. Communication-efficient parallel-graph algorithms. Master's thesis

    SciTech Connect

    Maggs, B.M.

    1986-06-01

    Communication bandwidth is a resource ignored by most parallel random-access machine (PRAM) models. This thesis shows that many graph problems can be solved in parallel, not only with polylogarithmic performance, but with efficient communication at each step of the computation. The communication requirements of an algorithm are measured in a restricted PRAM model called the distributed random-access machine (DRAM), which can be viewed as an abstraction of volume-universal networks such as fat trees. In this model, communication cost is measured in terms of the congestion of memory accesses across cuts of the machine. It is demonstrated that the recursive doubling technique frequently used in PRAM algorithms is wasteful of communication resources, and that recursive pairing can be used to perform many of the same functions more efficiently. The prefix computation is generalized on linear lists to trees and show that these tree-fix computations, which can be performed in a communication-efficient fashion using a variant of the tree-contraction technique of Miller and Reif, simplify many parallel graph algorithms in the literature.

  1. Nuclear-electric magnetohydrodynamic propulsion for submarine. Master's thesis

    SciTech Connect

    Bednarczyk, A.A.

    1989-05-01

    The thesis analyzes the superconducting technology for a shipboard magnetohydrodynamic propulsion system. Based on the the principles of magnetohydrodynamics (MHD), the concept of open-water efficiency was used to optimize the preliminary design of the MHD thruster. After the baseline submarine hull modeled after the Los Angeles class submarine was selected, propulsive efficiency and the top speed for four variant MHD submarines were evaluated. The design criteria were set at a 100-MWt nuclear reactor power upper limit and a requirement of 30 knots for the top speed. This required advanced reactor plants and advanced energy conversion systems. The selection of High Temperature Gas Reactor (HTGR) and Liquid-Metal Fast Breeder Reactor (LMFBR) was based on the combined merits of safety, environmental impact, high source temperature and maximum-volume power density (KW/L). With the reactor outlet temperatures of 2000 K, direct-cycle energy conversion-systems gave the best results in terms of thermal efficiency and propulsion plant power density. Two energy conversion systems selected were closed-cycle gas turbine geared to a superconducting generator, and closed-cycle liquid-metal MHD generator. Based on submarine reliability and safety, the option of using an intermediate heat exchanger was also considered. Finally, non-nuclear support systems affected by the advanced power plant and MHD propulsion, stressing submarine safety, are proposed.

  2. Pakistan: Frontline state again. Master`s thesis

    SciTech Connect

    Rivard, D.S.

    1995-12-01

    The objective of this study is to determine Pakistan`s place in contemporary U.S. national security strategy. Today, U.S.-Pakistan relations are strained due to the Pressler Amendment to the Foreign Assistance Act. The Pressler Amendment prohibits arms transfers from the United States to Pakistan in response to Pakistani efforts to develop a nuclear weapon capability. This thesis provides a historical background to the current impasse by examining Pakistani foreign policy since 1947. Next, the study examines the evolution of U.S. interests and security objectives in South and Southwest Asia. Current security objectives analyzed are the U.S. strategies to contain Iran and Iraq and to prevent nuclear proliferation in the region. In order to attain security objectives in the region, the author concludes that the U.S. needs a close cooperative relationship with Pakistan. Since the Pressler Amendment stands as the greatest obstacle to improved U.S.-Pakistan relations, the amendment should be repealed.

  3. Criticality Safety Analysis on the Mixed Be, Nat-U, and C (Graphite) Reflectors in 55-Gallon Waste Drums and Their Equivalents for HWM Applications

    SciTech Connect

    Chou, P

    2011-12-14

    The objective of this analysis is to develop and establish the technical basis on the criticality safety controls for the storage of mixed beryllium (Be), natural uranium (Nat-U), and carbon (C)/graphite reflectors in 55-gallon waste containers and/or their equivalents in Hazardous Waste Management (HWM) facilities. Based on the criticality safety limits and controls outlined in Section 3.0, the operations involving the use of mixed-reflector drums satisfy the double-contingency principle as required by DOE Order 420.1 and are therefore criticality safe. The mixed-reflector mass limit is 120 grams for each 55-gallon drum or its equivalent. a reflector waiver of 50 grams is allowed for Be, Nat-U, or C/graphite combined. The waived reflectors may be excluded from the reflector mass calculations when determining if a drum is compliant. The mixed-reflector drums are allowed to mix with the typical 55-gallon one-reflector drums with a Pu mass limit of 120 grams. The fissile mass limit for the mixed-reflector container is 65 grams of Pu equivalent each. The corresponding reflector mass limits are 300 grams of Be, and/or 100 kilograms of Nat-U, and/or 110 kilograms of C/graphite for each container. All other unaffected control parameters for the one-reflector containers remain in effect for the mixed-reflector drums. For instance, Superior moderators, such as TrimSol, Superla white mineral oil No. 9, paraffin, and polyethylene, are allowed in unlimited quantities. Hydrogenous materials with a hydrogen density greater than 0.133 gram/cc are not allowed. Also, an isolation separation of no less than 76.2 cm (30-inch) is required between a mixed array and any other array. Waste containers in the action of being transported are exempted from this 76.2-cm (30-inch) separation requirement. All deviations from the CS controls and mass limits listed in Section 3.0 will require individual criticality safety analyses on a case-by-case basis for each of them to confirm their

  4. Situationally driven local navigation for mobile robots. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Slack, Marc Glenn

    1990-01-01

    For mobile robots to autonomously accommodate dynamically changing navigation tasks in a goal-directed fashion, they must employ navigation plans. Any such plan must provide for the robot's immediate and continuous need for guidance while remaining highly flexible in order to avoid costly computation each time the robot's perception of the world changes. Due to the world's uncertainties, creation and maintenance of navigation plans cannot involve arbitrarily complex processes, as the robot's perception of the world will be in constant flux, requiring modifications to be made quickly if they are to be of any use. This work introduces navigation templates (NaT's) which are building blocks for the construction and maintenance of rough navigation plans which capture the relationship that objects in the world have to the current navigation task. By encoding only the critical relationship between the objects in the world and the navigation task, a NaT-based navigation plan is highly flexible; allowing new constraints to be quickly incorporated into the plan and existing constraints to be updated or deleted from the plan. To satisfy the robot's need for immediate local guidance, the NaT's forming the current navigation plan are passed to a transformation function. The transformation function analyzes the plan with respect to the robot's current location to quickly determine (a few times a second) the locally preferred direction of travel. This dissertation presents NaT's and the transformation function as well as the needed support systems to demonstrate the usefulness of the technique for controlling the actions of a mobile robot operating in an uncertain world.

  5. Spectral Domain Optical Coherence Tomography for Glaucoma (An AOS Thesis)

    PubMed Central

    Schuman, Joel S.

    2008-01-01

    Purpose Optical coherence tomography (OCT) is a rapidly evolving, robust technology that has profoundly changed the practice of ophthalmology. Spectral domain OCT (SD-OCT) increases axial resolution 2- to 3-fold and scan speed 60- to 110-fold vs time domain OCT (TD-OCT). SD-OCT enables novel scanning, denser sampling, and 3-dimensional imaging. This thesis tests my hypothesis that SD-OCT improves reproducibility, sensitivity, and specificity for glaucoma detection. Methods OCT progress is reviewed from invention onward, and future development is discussed. To test the hypothesis, TD-OCT and SD-OCT reproducibility and glaucoma discrimination are evaluated. Forty-one eyes of 21 subjects (SD-OCT) and 21 eyes of 21 subjects (TD-OCT) are studied to test retinal nerve fiber layer (RNFL) thickness measurement reproducibility. Forty eyes of 20 subjects (SD-OCT) and 21 eyes of 21 subjects (TD-OCT) are investigated to test macular parameter reproducibility. For both TD-OCT and SD-OCT, 83 eyes of 83 subjects are assessed to evaluate RNFL thickness and 74 eyes of 74 subjects to evaluate macular glaucoma discrimination. Results Compared to conventional TD-OCT, SD-OCT had statistically significantly better reproducibility in most sectoral macular thickness and peripapillary RNFL sectoral measurements. There was no statistically significant difference in overall mean macular or RNFL reproducibility, or between TD-OCT and SD-OCT glaucoma discrimination. Surprisingly, TD-OCT macular RNFL thickness showed glaucoma discrimination superior to SD-OCT. Conclusions At its current development state, SD-OCT shows better reproducibility than TD-OCT, but glaucoma discrimination is similar for TD-OCT and SD-OCT. Technological improvements are likely to enhance SD-OCT reproducibility, sensitivity, specificity, and utility, but these will require additional development. PMID:19277249

  6. Marine microbial production of dimethylsulfide from dissolved dimethylsulfoniopropionate. Doctoral thesis

    SciTech Connect

    Ledyard, K.M.

    1993-02-01

    Dimethylsulfide (DMS) plays a central role in the transfer of sulfur from the ocean to the atmosphere, and ultimately to land. The most abundant volatile organosulfur compound in seawater, DMS is believed to account for the bulk of the sea-to-air biogenic sulfur flux. DMS has also been implicated as the major precursor of submicron-sized sulfate aerosol over the ocean. This aerosol acts as an effective site for cloud droplet condensation, suggesting a possibly important role for DMS in marine cloud formation. In the ocean, the precursor of DMS is presumed to be the zwitterionic sulfonium compound dimethylsulfoniopropionate (DMSP), a common osmoticum in certain classes of marine algae. While some algae can cleave DMSP intracellularly to form DMS, correlation of DMS concentrations with indicators of algal productivity on a local scale is poor. This thesis focuses on an alternative pathway of DMS formation: microbial cleavage of dissolved (extracellular) DMSP. In laboratory studies, bacteria able to cleave DMSP to form DMS were isolated from seawater by a DMSP enrichment technique, and the kinetics of DMSP uptake and DMS production were examined closely in pure cultures of a bacterial isolate from the Sargasso Sea. The isolate could grow with both DMSP and acrylic acid, one of the products of DMSP cleavage, as the sole source of carbon and energy, and the enzyme catalyzing DMSP cleavage appeared to be induced by both of these compounds. Kinetic parameters were estimated for DMSP uptake and cleavage by whole cells. Comparison of the 16S rRNA sequence of this isolate with that of known eubacteria showed that it was most closely related to Erythrobacter longus, an aerobic, bacteriochlorophyll-containing member of the alpha proteobacteria.

  7. Global lightning activity and climate change. Ph.D. Thesis

    SciTech Connect

    Price, C.G.

    1993-01-01

    The relationship between global lightning frequencies and global climate change is examined in this thesis. In order to study global impacts of climate change, global climate models or General Circulations Models (GCM`s) need to be utilized. Since these models have coarse resolutions many atmospheric phenomena that occur at subgrid scales, such as lightning, need to be parameterized whenever possible. The first chapter introduces a simple parameterization used to simulate total (intracloud and cloud-to-ground) lightning frequencies. The parameterization uses convective cloud top height to approximate lightning frequencies. The second chapter deals with a parameterization for simulating cloud-to-ground (CG) lightning around the globe. This parameterization uses the thickness of the cold cloud sector in thunderstorms (0 C to cloud top) to calculate the proportion of CG flashes in a particular thunderstorm. The third chapter deals with the modelling of lightning in the Goddard Institute for Space Studies (GISS) GCM. This chapter presents results from the model`s control run. The fourth chapter presents two climate change scenarios. One for a climate where the solar constant is reduced by 2% (5.9 C global cooling), and one for a climate with twice the present concentration of CO2 in the atmosphere (4.2 C global warming). The results imply a 24% / 30% decrease/increase in global lightning frequencies for the cooler/warmer climate. The fifth chapter considers the possibility of using the above findings to monitor future global warming. The results show that the earth`s ionospheric potential, which is regulated by global thunderstorm activity, could possibly supply valuable information regarding global surface temperature fluctuations. The sixth and final chapter looks at the implications of changes in both lightning frequencies and the hydrological cycle, as a result of global warming, on natural forest fires.

  8. Production cross sections of products in the proton induced reactions on natNd in the energy region up to 45 MeV

    NASA Astrophysics Data System (ADS)

    Yang, Sung-Chul; Kim, Kwangsoo; Song, Tae-Yung; Lee, Young-Ouk; Kim, Guinyun

    2015-11-01

    The production cross sections of 141,143,144,146,148m,148g,149,150Pm, 139m,147,149Nd, 138m,142gPr, and 139gCe in the natNd(p,x) reactions were determined by a stacked-foil activation technique for the proton energy range up to 45 MeV using the MC-50 cyclotron of Korea Institute of Radiological and Medical Sciences. The measured cross sections were compared with literature data as well as data from the TENDL-2014 library based on TALYS 1.6. The production cross sections of the above radionuclides are slightly higher than the literature data but are in general agreement with values in TENDL-2014 library except for 148mPm, 148gPm, 139mNd, and 142gPr. The thick target integral yields of the produced radionuclides were also deducted from the measured cross sections.

  9. Neutron-induced fission cross section of {sup nat}Pb and {sup 209}Bi from threshold to 1 GeV: An improved parametrization

    SciTech Connect

    Tarrio, D.; Duran, I.; Paradela, C.; Tassan-Got, L.; Audouin, L.; Berthier, B.; Ferrant, L.; Isaev, S.; Le Naour, C.; Stephan, C.; Trubert, D.; David, S.; Aerts, G.; Andriamonje, S.; Berthoumieux, E.

    2011-04-15

    Neutron-induced fission cross sections for {sup nat}Pb and {sup 209}Bi were measured with a white-spectrum neutron source at the CERN Neutron Time-of-Flight (n{sub T}OF) facility. The experiment, using neutrons from threshold up to 1 GeV, provides the first results for these nuclei above 200 MeV. The cross sections were measured relative to {sup 235}U and {sup 238}U in a dedicated fission chamber with parallel plate avalanche counter detectors. Results are compared with previous experimental data. Upgraded parametrizations of the cross sections are presented, from threshold energy up to 1 GeV. The proposed new sets of fitting parameters improve former results along the whole energy range.

  10. NO3- Coordination in Aqueous Solutions by 15N/14N and 18O/natO Isotopic Substitution: What Can We Learn from Molecular Simulation?

    DOE PAGESBeta

    Chialvo, Ariel A.; Vlcek, Lukas

    2014-12-16

    We explore the deconvolution of the water-nitrate correlations by the first-order difference approach involving neutron diffraction of heavy- and null-aqueous solutions of KNO3 under 14N 15N and natON 18ON substitutions to achieve a full characterization of the first water coordination around the nitrate ion. For that purpose we performed isobaric-isothermal simulations of 3.5m KNO3 aqueous solutions at ambient conditions to generate the relevant radial distribution functions (RDF) required in the analysis (a) to identify the individual partial contributions to the total neutron weighted distribution function, (b) to isolate and assess the contribution of NO3 -!K+ pair formation, (c) to testmore » the accuracy of the NDIS-based coordination calculations and XRDbased assumptions, and (d) to describe the water coordination around both the nitrogen and oxygen sites of the nitrate ion.« less

  11. Excitation functions of deuteron induced reactions on natOs up to 50 MeV: Experiments and comparison with theoretical codes

    NASA Astrophysics Data System (ADS)

    Hermanne, A.; Adam Rebeles, R.; Tárkányi, F.; Takács, S.; Takács, M. P.; Ignatyuk, A.; Uddin, M. S.

    2013-02-01

    Activation of thin electrodeposited natural Os targets was investigated in a stacked foil irradiation with a 50 MeV deuteron beam. Assessments of the produced radionuclides by high resolution gamma spectroscopy yielded excitation functions for production of 184,185,186m1,g,187m1+g,188m1+g,189m2+m1+g,190m2,190m2,m1+g,192m1+gIr and 185Os. Reduced uncertainty on cross sections is obtained by simultaneous remeasurement of the 27Al(d,x)24Na monitor reaction over the whole energy range. Thick target yield for deuteron induced production route of 192m1+gIr and comparison with the natIr(n,γ) route are reviewed. A comparison with updated theoretical codes (ALICE-D, EMPIRE-D and the TENDL2011 on-line library) is discussed.

  12. Calculation of induced reactions of 3He-particles on natSb in 10-34MeV energy range.

    PubMed

    Gul, K

    2009-01-01

    Calculations for the excitation functions of the (121)Sb((3)He, xn) (121,122,123)I, and (123)Sb((3)He xn) (122,123,124,125)I reactions have been carried out using statistical and pre-equilibrium nuclear reaction models in 10-34MeV energy range. These excitation functions have been used to derive the excitation functions of the (nat)Sb((3)He, xn)(121,123,124)I reactions and compared with reported measurements. For studying the improvement with measurements two values of the diffuseness parameter a(w) equal to 0.9 and 0.7fm have been used in the calculations. The dependence of pre-equilibrium calculations on the initial exciton numbers has also been considered. PMID:18951811

  13. Dietary intake of vegetables and fruits and the modification effects of GSTM1 and NAT2 genotypes on bladder cancer risk.

    PubMed

    Lin, Jie; Kamat, Ashish; Gu, Jian; Chen, Meng; Dinney, Colin P; Forman, Michele R; Wu, Xifeng

    2009-07-01

    We analyzed the association between intakes of vegetables and fruits as defined by the U.S. Department of Agriculture pyramid food groups and bladder cancer risk using data collected in a large case-control study. The study included 884 histologically confirmed bladder cancer cases and 878 healthy controls matched to cases by age (+/-5 years), gender, and ethnicity. Significant inverse associations were observed for intakes of total vegetables, cruciferous vegetables, orange vegetables, dark green vegetables, and bladder cancer risk. Compared with those in the lowest quartile of total vegetable intake, the odds ratios for the 2nd, 3rd, and 4th quartiles of total vegetable intake were 0.84 [95% confidence interval (95% CI), 0.64-1.10], 0.71 (95% CI, 0.54-0.95), and 0.67 (95% CI, 0.50-0.90), respectively (P for trend = 0.004). Compared with those in the lowest quartile, those in the highest quartile of cruciferous vegetable intake had an odds ratio of 0.69 (95% CI, 0.52-0.92; P for trend = 0.001) and those in the highest quartile of orange vegetable intake had an odds ratio of 0.68 (95% CI, 0.52-0.91; P for trend = 0.006). Furthermore, the protective effect of cruciferous vegetables was more evident in subjects carrying GSTM1-null (odds ratio, 0.43; 95% CI, 0.25-0.73 for the 4th quartile of intake) and NAT2-slow genotypes (odds ratio, 0.56; 95% CI, 0.33-0.97 for the 4th quartile of intake). No association was observed for intakes of total fruits or citrus fruits. Our data strongly support that high vegetable consumption, especially cruciferous vegetable intake, may protect against bladder cancer and that genetic variants of GSTM1 and NAT2 may modify the association. PMID:19549811

  14. Acetylator genotype-dependent formation of 2-aminofluorene-hemoglobin adducts in rapid and slow acetylator Syrian hamsters congenic at the NAT2 locus.

    PubMed

    Feng, Y; Rustan, T D; Ferguson, R J; Doll, M A; Hein, D W

    1994-01-01

    Arylamine-hemoglobin adducts are a valuable dosimeter for assessing arylamine exposures and carcinogenic risk. The effects of age, sex, time-course, dose, and acetylator genotype on levels of 2-aminofluorene-hemoglobin adducts were investigated in homozygous rapid (Bio. 82.73/H-Patr) and slow (Bio. 82.73/H-Pats) acetylator hamsters congenic at the polymorphic (NAT2) acetylator locus. Following administration of a single ip dose of [3H]2-aminofluorene, peak 2-aminofluorene-hemoglobin adduct levels were achieved at 12-18 hr and retained a plateau up to 72 hr postinjection in both rapid and slow acetylator congenic hamsters. 2-Aminofluorene-hemoglobin adduct levels did not differ significantly between young (5-6 weeks) and old (32-49 weeks) hamsters or between male and female hamsters within either acetylator genotype. 2-Aminofluorene-hemoglobin adduct levels increased in a dose-dependent manner (r = 0.95, p = 0.0001) and were consistently higher in slow versus rapid acetylator congenic hamsters in studies of both time-course and dose-effect. The magnitude of the acetylator genotype-dependent difference was a function of dose; 2-aminofluorene-hemoglobin adduct levels were 1.5-fold higher in slow acetylator congenic hamsters following a 60 mg/kg 2-aminofluorene dose (p = 0.0013) but 2-fold higher following a 100 mg/kg 2-aminofluorene dose (p < 0.0001). These results show a specific and significant role for NAT2 acetylator genotype in formation of arylamine-hemoglobin adducts, which may reflect the relationship between acetylator genotype and the incidence of different cancers from arylamine exposures. PMID:8291051

  15. Yeast Kre33 and human NAT10 are conserved 18S rRNA cytosine acetyltransferases that modify tRNAs assisted by the adaptor Tan1/THUMPD1

    PubMed Central

    Sharma, Sunny; Langhendries, Jean-Louis; Watzinger, Peter; Kötter, Peter; Entian, Karl-Dieter; Lafontaine, Denis L.J.

    2015-01-01

    The function of RNA is subtly modulated by post-transcriptional modifications. Here, we report an important crosstalk in the covalent modification of two classes of RNAs. We demonstrate that yeast Kre33 and human NAT10 are RNA cytosine acetyltransferases with, surprisingly, specificity toward both 18S rRNA and tRNAs. tRNA acetylation requires the intervention of a specific and conserved adaptor: yeast Tan1/human THUMPD1. In budding and fission yeasts, and in human cells, we found two acetylated cytosines on 18S rRNA, one in helix 34 important for translation accuracy and another in helix 45 near the decoding site. Efficient 18S rRNA acetylation in helix 45 involves, in human cells, the vertebrate-specific box C/D snoRNA U13, which, we suggest, exposes the substrate cytosine to modification through Watson–Crick base pairing with 18S rRNA precursors during small subunit biogenesis. Finally, while Kre33 and NAT10 are essential for pre-rRNA processing reactions leading to 18S rRNA synthesis, we demonstrate that rRNA acetylation is dispensable to yeast cells growth. The inactivation of NAT10 was suggested to suppress nuclear morphological defects observed in laminopathic patient cells through loss of microtubules modification and cytoskeleton reorganization. We rather propose the effects of NAT10 on laminopathic cells are due to reduced ribosome biogenesis or function. PMID:25653167

  16. Yeast Kre33 and human NAT10 are conserved 18S rRNA cytosine acetyltransferases that modify tRNAs assisted by the adaptor Tan1/THUMPD1.

    PubMed

    Sharma, Sunny; Langhendries, Jean-Louis; Watzinger, Peter; Kötter, Peter; Entian, Karl-Dieter; Lafontaine, Denis L J

    2015-02-27

    The function of RNA is subtly modulated by post-transcriptional modifications. Here, we report an important crosstalk in the covalent modification of two classes of RNAs. We demonstrate that yeast Kre33 and human NAT10 are RNA cytosine acetyltransferases with, surprisingly, specificity toward both 18S rRNA and tRNAs. tRNA acetylation requires the intervention of a specific and conserved adaptor: yeast Tan1/human THUMPD1. In budding and fission yeasts, and in human cells, we found two acetylated cytosines on 18S rRNA, one in helix 34 important for translation accuracy and another in helix 45 near the decoding site. Efficient 18S rRNA acetylation in helix 45 involves, in human cells, the vertebrate-specific box C/D snoRNA U13, which, we suggest, exposes the substrate cytosine to modification through Watson-Crick base pairing with 18S rRNA precursors during small subunit biogenesis. Finally, while Kre33 and NAT10 are essential for pre-rRNA processing reactions leading to 18S rRNA synthesis, we demonstrate that rRNA acetylation is dispensable to yeast cells growth. The inactivation of NAT10 was suggested to suppress nuclear morphological defects observed in laminopathic patient cells through loss of microtubules modification and cytoskeleton reorganization. We rather propose the effects of NAT10 on laminopathic cells are due to reduced ribosome biogenesis or function. PMID:25653167

  17. Evaluation of the Whole-Blood Alere Q NAT Point-of-Care RNA Assay for HIV-1 Viral Load Monitoring in a Primary Health Care Setting in Mozambique.

    PubMed

    Jani, Ilesh V; Meggi, Bindiya; Vubil, Adolfo; Sitoe, Nádia E; Bhatt, Nilesh; Tobaiwa, Ocean; Quevedo, Jorge I; Loquiha, Osvaldo; Lehe, Jonathan D; Vojnov, Lara; Peter, Trevor F

    2016-08-01

    Viral load testing is the WHO-recommended monitoring assay for patients on HIV antiretroviral therapy (ART). Point-of-care (POC) assays may help improve access to viral load testing in resource-limited settings. We compared the performance of the Alere Q NAT POC viral load technology (Alere Technologies, Jena, Germany), measuring total HIV RNA using finger prick capillary whole-blood samples collected in a periurban health center, with that of a laboratory-based plasma RNA test (Roche Cobas Ampliprep/Cobas TaqMan v2) conducted on matched venous blood samples. The whole-blood Alere Q NAT POC assay produced results with a bias of 0.8593 log copy/ml compared to the laboratory-based plasma assay. However, at above 10,000 copies/ml, the bias was 0.07 log copy/ml. Using the WHO-recommended threshold to determine ART failure of 1,000 copies/ml, the sensitivity and specificity of the whole-blood Alere Q NAT POC assay were 96.83% and 47.80%, respectively. A cutoff of 10,000 copies/ml of whole blood with the Alere Q NAT POC assay appears to be a better predictor of ART failure threshold (1,000 copies/ml of plasma), with a sensitivity of 84.0% and specificity of 90.3%. The precision of the whole-blood Alere Q NAT POC assay was comparable to that observed with the laboratory technology (5.4% versus 7.5%) between detectable paired samples. HIV POC viral load testing is feasible at the primary health care level. Further research on the value of whole-blood viral load to monitor antiretroviral therapy is warranted. PMID:27252459

  18. Factors Mediating the Interactions between Adviser and Advisee during the Master's Thesis Project: A Quantitative Approach

    ERIC Educational Resources Information Center

    Rodrigues Jr., Jose Florencio; Lehmann, Angela Valeria Levay; Fleith, Denise De Souza

    2005-01-01

    Building on previous studies centred on the interaction between adviser and advisee in masters thesis projects, in which a qualitative approach was used, the present study uses factor analysis to identify the factors that determine either a successful or unsuccessful outcome for the masters thesis project. There were five factors relating to the…

  19. The Focus of Supervisor Written Feedback to Thesis/Dissertation Students

    ERIC Educational Resources Information Center

    Bitchener, John; Basturkmen, Helen; East, Martin

    2010-01-01

    Written feedback on drafts of a thesis or dissertation is arguably the most important source of input on what is required or expected of thesis-writing students by the academic community. Despite its importance, relatively little is known about what type of information supervisors focus on when giving feedback. This article presents the findings…

  20. Application of security concepts to the personnel database for the Indonesian Navy. Master's thesis

    SciTech Connect

    Wibisono, M.

    1983-09-01

    This thesis is a continuation of the study work done by Moedjiono (M.S. thesis, Naval Postgraduate School, 1982) concerning personnel database in the Indonesian Navy. It discusses the current database security and the concept of Multics (Multiplexed Information and Computing System) to propose a personnel database security model in the Indonesian Navy.

  1. The "Progress of Language" Thesis: Its Relevance for the Development of Readers and Writers.

    ERIC Educational Resources Information Center

    Sulzby, Elizabeth

    E. D. Hirsch's "Philosophy of Composition" (in press) reintroduces to communication theorists the "progress of language" thesis first developed, by Henry Bradley and Otto Jespersen around 1900, in the context of oral language. The thesis states that languages--English in particular--tend to become more simplified and flexible over time. This paper…

  2. The Maldistribution Thesis of Poverty: How Much of Rural Southern Poverty Can It Explain?

    ERIC Educational Resources Information Center

    Thomas, George

    The Maldistribution Thesis (whether a maldistribution in skilled manpower, accumulated wealth, and their implied production of income, goods, and services is demonstrable and the extent to which the thesis explains poverty) is at least in part testable by the amount that redressing old imbalances contributes to the increased income, improved life…

  3. A Response to Shelby Gilbert's "A Study of Ogbu and Simons' Thesis"

    ERIC Educational Resources Information Center

    Hawkins, C. Matthew

    2009-01-01

    This article responds to Shelby Gilbert's "A Study of Ogbu and Simon's Thesis." The author begins by saying that he thinks that this study of examining Ogbu and Simons' thesis (to investigate school performance of Black immigrant and non-immigrant students in the United States) makes a thought-provoking contribution to overall discussions…

  4. Understanding the Up, Back, and Forward-Component in Master's Thesis Supervision with Adaptivity

    ERIC Educational Resources Information Center

    de Kleijn, Renske A. M.; Bronkhorst, Larike H.; Meijer, Paulien C.; Pilot, Albert; Brekelmans, Mieke

    2016-01-01

    Despite the importance of goals in educational theories, goals in master's thesis projects are rarely investigated. Therefore, this study explores how goals play a role in master's thesis supervision in terms of: defining the goals (up-component); locating where the student stands in relation to the goals (back-component); and how the student can…

  5. Pre-Service Teachers' Beliefs about the Roles of Thesis Supervisors: A Case Study

    ERIC Educational Resources Information Center

    Tapia Carlín, Rebeca Elena

    2013-01-01

    Trainee beliefs about the roles of thesis supervisors can exert an important influence on timely and successful completion of theses. This research article explores pre-service teacher beliefs about the roles of thesis supervisors through the analysis of their learning diaries. The aim of this study is to identify ways to improve supervisory…

  6. An Analysis of Current Graduation Thesis Writing by English Majors in Independent Institute

    ERIC Educational Resources Information Center

    Han, Ying

    2014-01-01

    The paper takes 414 graduates from ZJU in 2011 and 2012, NIT as a case, analyzing the status of their writing of graduation thesis. It is found that a considerable number of students have problems in selection and report of topics, writing of each part and debating in the whole process of graduation thesis. In view of the situation, based on the…

  7. Strategies for Finding and Selecting an Ideal Thesis or Dissertation Topic: A Review of Literature

    ERIC Educational Resources Information Center

    Lei, Simon A.

    2009-01-01

    Choosing an ideal master's thesis or doctoral dissertation topic is probably one of the most important decisions students will make while in graduate school. Some graduate students may spend a year or even longer looking for potential topics before finally selecting one for their thesis or dissertation. There are a number of successful strategies…

  8. Thesis by Publication in Education: An Autoethnographic Perspective for Educational Researchers

    ERIC Educational Resources Information Center

    Merga, Margaret K.

    2015-01-01

    Despite its growing popularity, the thesis by publication is a less conventional format for doctoral dissertations in the field of education. The author successfully undertook a thesis by publication in education from 2012, to submission in 2014. This paper draws on both the literature in the field and the experiences of the author through an…

  9. Student Engagement, Ideological Contest and Elective Affinity: The Zepke Thesis Reviewed

    ERIC Educational Resources Information Center

    Trowler, Paul

    2015-01-01

    This paper takes up issues raised in two articles by Nick Zepke and portrayed here as "the Zepke thesis". This thesis argues that the literature on, interest in and practices around student engagement in higher education have an elective affinity with neo-liberal ideology. At one level this paper counters many of the assertions that…

  10. Supporting the Thesis Writing Process of International Research Students through an Ongoing Writing Group

    ERIC Educational Resources Information Center

    Li, Linda Y.; Vandermensbrugghe, Joelle

    2011-01-01

    Evidence from research suggests writing support is particularly needed for international research students who have to tackle the challenges of thesis writing in English as their second language in Western academic settings. This article reports the development of an ongoing writing group to support the thesis writing process of international…

  11. "Breaking the Mold" in the Dissertation: Implementing a Problem-Based, Decision-Oriented Thesis Project

    ERIC Educational Resources Information Center

    Archbald, Doug

    2010-01-01

    This article offers lessons from an initiative refashioning the doctoral thesis in an education leadership program. The program serves a practitioner clientele; most are teachers and administrators. The new model for the thesis emphasizes leadership, problem solving, decision making, and organizational improvement. The former model was a…

  12. Climbing out of the Void: Moving from Chaos to Concepts in the Presentation of a Thesis.

    ERIC Educational Resources Information Center

    Hunt, Cheryl

    2001-01-01

    Describes how and why, after a supervisor's feedback prompted a Ph.D. thesis to be abandoned for over a year, writing resumed in a deliberately reflective style. Highlights parallels between the content of the thesis and the process of writing it. Describes how the experience of writing can be mapped against three models of ways of knowing. (EV)

  13. Role of signal-to-cut-off ratios of anti-hepatitis C virus antibody by enzyme immunoassays along with ID-NAT for screening of whole blood donors in India

    PubMed Central

    Arora, Satyam; Doda, Veena

    2016-01-01

    Background: The use of elevated signal-to-cut off ratios (S/CO) as an alternate to further supplemental testing (i.e., RIBA) has been included in the guidelines provided by the Centres for Disease Control and Prevention for HCV diagnostic purposes since 2003. With availability of screening by NAT and non availability of RIBA, further confirmation of HCV infection has been possible at the molecular level (RNA). Aims: To study the role of S/CO ratios of anti hepatitis C virus antibody detection by enzyme immunoassays (EIA) along with ID-NAT for screening of whole blood donors. Methods: In this study we reviewed the donor screening status for anti HCV from January 2013 to May 2014. All the donations were screened for anti HCV with fourth generation ELISA (BioRad Monolisa Ag-Ab Ultra) as well as with ID NAT (Procleix Ultrio). The S/CO ratio of all the anti-HCV reactive samples were analysed for their presence of HCV RNA. Results: On screening 21,115 donors for HCV, 83 donors (0.39%) were found reactive on pilot tube and repeat plasma bag testing (S/Co ratio ≥1) by ELISA. 41 donors were HCV RNA reactive with ID-NAT. 4 samples out of 41 were NAT yields and 37 were concordant reactive with ELISA. The S/Co ratio of anti-HCV reactive samples ranged from 0.9-11.1 [mean = 5.1; SD ± 2.9] whereas S/Co ratio of anti HCV and NAT reactive samples (concordant positives) ranged from 4.1-11.1 [mean 7.3]. In our analysis we found that S/CO ratio of 4 showed positive predictive value (PPV) and sensitivity of 100%. Summary/Conclusions: Our study showed that S/CO of 4 for anti HCV on ELISA would have maximum positive predictive value of having donor with HCV RNA. S/CO ratio of 4 is very close to 3.8 which was the CDC guideline. The presence of anti-HCV does not distinguish between current or past infections but a confirmed anti-HCV-positive result indicates the need for counseling and medical evaluation for HCV infection. PMID:27011676

  14. CYP1A2 and NAT2 phenotyping and 3-aminobiphenyl and 4-aminobiphenyl hemoglobin adduct levels in smokers and non-smokers

    SciTech Connect

    Sarkar, Mohamadi; Stabbert, Regina; Kinser, Robin D.; Oey, Jan; Rustemeier, Klaus; Holt, Klaus von; Schepers, Georg; Walk, Roger A.; Roethig, Hans J.

    2006-06-15

    Some aromatic amines are considered to be putative bladder carcinogens. Hemoglobin (Hb) adducts of 3-aminobiphenyl (3-ABP) and 4-aminobiphenyl (4-ABP) have been used as biomarkers of exposure to aromatic amines from cigarette smoke. One of the goals of this study was to determine intra- and inter-individual variability in 3-ABP and 4-ABP Hb adducts and to explore the predictability of ABP Hb adduct levels based on caffeine phenotyping. The study was conducted in adult smokers (S, n = 65) and non-smokers (NS, n 65). The subjects were phenotyped for CYP1A2 and NAT2 using urinary caffeine metabolites. Blood samples were collected twice within 6 weeks and adducts measured by GC/MS. The levels of 4-ABP Hb adducts were significantly (p < 0.0001) greater in S (34.5 {+-} 21.06 pg/g Hb) compared to NS (6.3 {+-} 3.02 pg/g Hb). The levels of 3-ABP Hb adducts were below the limit of quantification (BLOQ) in most (82%) of the NS and about 10-fold lower in S (3.6 {+-} 3.29 pg/g Hb) compared to 4-ABP Hb adducts. No differences were observed in the adduct levels between weeks 1 and 6 in the smokers, suggesting that a single sample would be adequate to monitor cigarette smoke exposure. The regression model developed with CYP1A2, NAT2 phenotype and number of cigarettes smoked (NCIG) accounted for 47% of the variability in 3-ABP adducts, whereas 32% variability in 4-ABP adducts was accounted by CYP1A2 and NCIG. The ratio of 4-ABP Hb adducts in adult S:NS was {approx} 5:1, whereas 3-ABP Hb adducts levels were BLOQ in some S, exhibited large interindividual variability ({approx} 91% compared to 57% for 4-ABP Hb) and poor dose response relationship. Therefore, 4-ABP Hb adduct levels may be a more useful biomarker of aminobiphenyl exposure from cigarette smoke.

  15. Alpha particle induced reactions on natCr up to 39 MeV: Experimental cross-sections, comparison with theoretical calculations and thick target yields for medically relevant 52gFe production

    NASA Astrophysics Data System (ADS)

    Hermanne, A.; Adam Rebeles, R.; Tárkányi, F.; Takács, S.

    2015-08-01

    Thin natCr targets were obtained by electroplating, using 23.75 μm Cu foils as backings. In five stacked foil irradiations, followed by high resolution gamma spectroscopy, the cross sections for production of 52gFe, 49,51cumCr, 52cum,54,56cumMn and 48cumV in Cr and 61Cu,68Ga in Cu were measured up to 39 MeV incident α-particle energy. Reduced uncertainty is obtained by simultaneous remeasurement of the natCu(α,x)67,66Ga monitor reactions over the whole energy range. Comparisons with the scarce literature values and results from the TENDL-2013 on-line library, based on the theoretical code family TALYS-1.6, were made. A discussion of the production routes for 52gFe with achievable yields and contamination rates was made.

  16. Reaction of ClONO{sub 2} with HCl on NAT, NAD, and frozen sulfuric acid and hydrolysis of N{sub 2}O{sub 5} and ClONO{sub 2} on frozen sulfuric acid

    SciTech Connect

    Hanson, D.R.; Ravishankara, A.R. |

    1993-12-20

    The reaction of ClONO{sub 2} with HCl on the nitric acid trihydrate (NAT) and dihydrate (NAD) and on frozen sulfuric acid solutions was studied as functions of reactant concentration and temperature representative of the stratosphere. A flow tube reactor equipped with a chemical ionization mass spectrometer detector was used. The measured reactive uptake coefficient shows a strong dependence on temperature at constant H{sub 2}O partial pressure. These results for NAT are qualitatively similar to but quantitatively different from those of Abbatt and Molina. The hydrolysis of N{sub 2}O{sub 5} and ClONO{sub 2} on frozen sulfuric acid were measured to be far less efficient than that in liquid solutions. The implications of these results to the heterogeneous chemistry of the stratosphere are discussed. 19 refs., 5 figs., 2 tabs.

  17. NatB Domain-Containing CRA-1 Antagonizes Hydrolase ACER-1 Linking Acetyl-CoA Metabolism to the Initiation of Recombination during C. elegans Meiosis

    PubMed Central

    Gao, Jinmin; Kim, Hyun-Min; Elia, Andrew E.; Elledge, Stephen J.; Colaiácovo, Monica P.

    2015-01-01

    The formation of DNA double-strand breaks (DSBs) must take place during meiosis to ensure the formation of crossovers, which are required for accurate chromosome segregation, therefore avoiding aneuploidy. However, DSB formation must be tightly regulated to maintain genomic integrity. How this regulation operates in the context of different chromatin architectures and accessibility, and how it is linked to metabolic pathways, is not understood. We show here that global histone acetylation levels undergo changes throughout meiotic progression. Moreover, perturbations to global histone acetylation levels are accompanied by changes in the frequency of DSB formation in C. elegans. We provide evidence that the regulation of histone acetylation requires CRA-1, a NatB domain-containing protein homologous to human NAA25, which controls the levels of acetyl-Coenzyme A (acetyl-CoA) by antagonizing ACER-1, a previously unknown and conserved acetyl-CoA hydrolase. CRA-1 is in turn negatively regulated by XND-1, an AT-hook containing protein. We propose that this newly defined protein network links acetyl-CoA metabolism to meiotic DSB formation via modulation of global histone acetylation. PMID:25768301

  18. Production of (28)Mg by bombardment of (nat)Cl with 200MeV protons: Proof-of-concept study for a stacked LiCl target.

    PubMed

    van der Meulen, N P; Steyn, G F; Vermeulen, C; van Rooyen, T J

    2016-09-01

    A stacked target consisting of ten Al-encapsulated LiCl discs, for producing (28)Mg via the (nat)Cl(p,X)(28)Mg process in the energy region 50-200MeV, is described. This target was irradiated with a 200MeV beam at an intensity of 100nA, providing information on both yield and outscattering losses. Results of a Monte Carlo modelling of the beam and target, by means of the code MCNPX, are also presented. Similar Al-encapsulated LiCl discs were individually irradiated with 66MeV proton beams of 65 and 90μA, respectively, to study their behaviour under high-intensity bombardment. Once removed from the Al encapsulation, the (28)Mg can be separated from the LiCl target material efficiently, using a 12.5cm x 1cm(2) column containing Purolite S950 chelating resin. The eluate contains (7)Be but no other measurable radio-contaminants. The removal of the (7)Be contaminant is performed by cation exchange chromatography in malate media, with (28)Mg being retained by the resin and (7)Be eluted. PMID:27372806

  19. Alba from Thermoplasma volcanium belongs to α-NAT's: An insight into the structural aspects of Tv Alba and its acetylation by Tv Ard1.

    PubMed

    Ma, Chao; Pathak, Chinar; Lee, Sang Jae; Lee, Ki-Young; Jang, Sun-Bok; Nam, Minjoo; Im, Hookang; Yoon, Hye-Jin; Lee, Bong-Jin

    2016-01-15

    The Alba superfamily proteins have been regarded as a conserved group of proteins in archaea and eukarya, which have shown to be important in nucleic acid binding, chromatic organization and gene regulation. These proteins often belong to the N-acetyltransferase (NAT) category (N(α)-acetyltransferases or N(ε)-acetyltransferases) and undergo post-translational modifications. Here, we report the crystal structure of Alba from Thermoplasma volcanium (Tv Alba) at 2.4 Å resolution. The acetylation of Tv Alba was monitored and the N-terminal of Tv Alba has been shown to interact with acetyl coenzyme A (Ac-CoA). The chemical shift perturbation experiments of Tv Alba were performed in the presence of Ac-CoA and/or Tv Ard1, another T. volcanium protein that treats Tv Alba as a substrate. To examine the DNA binding capabilities of Tv Alba alone and in the presence of Ac-CoA and/or Tv Ard1, EMSA experiments were carried out. It is shown that although Tv Alba binds to Ac-CoA, the acetylation of Tv Alba is not related with its binding to dsDNA, and the involvement of the N-terminus in Ac-CoA binding demonstrates that Tv Alba belongs to the N(α)-acetyltransferase family. PMID:26657068

  20. Projectile-like fragments from {sup 129}Xe+{sup nat}Cu reactions at E/A = 40 MeV

    SciTech Connect

    Russ, D.E.; Mignerey, A.C.; Garcia-Solis, E.J.

    1996-02-01

    The bombarding of heavy nuclei with energetic heavy projectiles has been one of the most important experimental tools for nuclear science. At low beam energies, (E/A) beam <10 MeV, the reactions appear to be dominated by mean field consideration. At higher beam energies, (E/A) beams > 100 MeV, these mean field effects are less important and nucleon-nucleon interactions dominate. Within the intermediate energy region, the situation is less clear because of both the mean field and nucleon-nucleon effects contribute. There is no consensus on the theoretical treatment of nuclear reaction in the intermediate energy regime and statistical, dynamical, and hybrid models have been used with limited success. Previous studies of {sup 136}Xe + {sup 209}Bi at E/A = 28 MeV carried out at Michigan State University (MSU) have been well described by a damped reaction mechanism. On the other hand, {sup 129}Xe + {sup nat}Cu at E/A = 50 MeV also at MSU has been compared with a hybrid model with reasonable success. In order to see a transition from a damped reaction mechanism to more fragmentation-like processes, an experiment was carried out at MSU using {sup 129}Xe beams at E/A = 30, 40, 50, and 60 MeV. The targets were Cu, Sc, and Au. The current study only looks at the projectile-like fragments (PLF) detected in the Maryland Forward Array (MFA).

  1. The effect of chronic morphine or methadone exposure and withdrawal on clock gene expression in the rat suprachiasmatic nucleus and AA-NAT activity in the pineal gland.

    PubMed

    Pačesová, D; Novotný, J; Bendová, Z

    2016-07-18

    The circadian rhythms of many behavioral and physiological functions are regulated by the major circadian pacemaker in the suprachiasmatic nucleus. Long-term opiate addiction and drug withdrawal may affect circadian rhythmicity of various hormones or the sleep/activity pattern of many experimental subjects; however, limited research has been done on the long-term effects of sustained opiate administration on the intrinsic rhythmicity in the suprachiasmatic nucleus and pineal gland. Here we compared the effects of repeated daily treatment of rats with morphine or methadone and subsequent naloxone-precipitated withdrawal on the expression of the Per1, Per2, and Avp mRNAs in the suprachiasmatic nucleus and on arylalkylamine N-acetyltransferase activity in the pineal gland. We revealed that 10-day administration and withdrawal of both these drugs failed to affect clock genes and Avp expression in the SCN. Our results indicate that opioid-induced changes in behavioral and physiological rhythms originate in brain structures downstream of the suprachiasmatic nucleus regulatory output pathway. Furthermore, we observed that acute withdrawal from methadone markedly extended the period of high night AA-NAT activity in the pineal gland. This suggests that withdrawal from methadone, a widely used drug for the treatment of opioid dependence, may have stronger impact on melatonin synthesis than withdrawal from morphine. PMID:27070740

  2. Design of an integrated team project as bachelor thesis in bioscience engineering

    NASA Astrophysics Data System (ADS)

    Peeters, Marie-Christine; Londers, Elsje; Van der Hoeven, Wouter

    2014-11-01

    Following the decision at the KU Leuven to implement the educational concept of guided independent learning and to encourage students to participate in scientific research, the Faculty of Bioscience Engineering decided to introduce a bachelor thesis. Competencies, such as communication, scientific research and teamwork, need to be present in the design of this thesis. Because of the high number of students and the multidisciplinary nature of the graduates, all research divisions of the faculty are asked to participate. The yearly surveys and hearings were used for further optimisation. The actual design of this bachelor thesis is presented and discussed in this paper.

  3. Photo-neutron reaction cross-sections for natMo in the bremsstrahlung end-point energies of 12-16 and 45-70 MeV

    NASA Astrophysics Data System (ADS)

    Naik, H.; Kim, G. N.; Kapote Noy, R.; Schwengner, R.; Kim, K.; Zaman, M.; Shin, S. G.; Gey, Y.; Massarczyk, R.; John, R.; Junghans, A.; Wagner, A.; Cho, M.-H.

    2016-07-01

    The natMo( γ, xn)90, 91, 99Mo reaction cross-sections were experimentally determined for the bremsstrahlung end-point energies of 12, 14, 16, 45, 50, 55, 60 and 70MeV by activation and off-line γ -ray spectrometric technique and using the 20MeV electron linac (ELBE) at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany, and the 100MeV electron linac at the Pohang Accelerator Laboratory (PAL), Pohang, Korea. The natMo( γ, xn)88, 89, 90, 91, 99Mo reaction cross-sections as a function of photon energy were also calculated using the computer code TALYS 1.6. The flux-weighted average cross-sections were obtained from the literature data and the calculated values of TALYS based on mono-energetic photons and are found to be in general agreement with the present results. The flux-weighted average experimental and theoretical cross-sections for the natMo( γ, xn)88, 89, 90, 91, 99Mo reactions increase with the bremsstrahlung end-point energy, which indicates the role of excitation energy. After a certain energy, the individual natMo( γ, xn) reaction cross-sections decrease with the increase of bremsstrahlung energy due to opening of other reactions, which indicates sharing of energy in different reaction channels. The 100Mo( γ, n) reaction cross-section is important for the production of 99Mo , which is a probable alternative to the 98Mo(n, γ) and 235U(n, f ) reactions.

  4. NF-κB Drives the Synthesis of Melatonin in RAW 264.7 Macrophages by Inducing the Transcription of the Arylalkylamine-N-Acetyltransferase (AA-NAT) Gene

    PubMed Central

    Muxel, Sandra Marcia; Pires-Lapa, Marco Antonio; Monteiro, Alex Willian Arantes; Cecon, Erika; Tamura, Eduardo Koji; Floeter-Winter, Lucile Maria; Markus, Regina P.

    2012-01-01

    We demonstrate that during inflammatory responses the nuclear factor kappa B (NF-κB) induces the synthesis of melatonin by macrophages and that macrophage-synthesized melatonin modulates the function of these professional phagocytes in an autocrine manner. Expression of a DsRed2 fluorescent reporter driven by regions of the aa-nat promoter, that encodes the key enzyme involved in melatonin synthesis (arylalkylamine-N-acetyltransferase), containing one or two upstream κB binding sites in RAW 264.7 macrophage cell lines was repressed when NF-κB activity was inhibited by blocking its nuclear translocation or its DNA binding activity or by silencing the transcription of the RelA or c-Rel NF-κB subunits. Therefore, transcription of aa-nat driven by NF-κB dimers containing RelA or c-Rel subunits mediates pathogen-associated molecular patterns (PAMPs) or pro-inflammatory cytokine-induced melatonin synthesis in macrophages. Furthermore, melatonin acts in an autocrine manner to potentiate macrophage phagocytic activity, whereas luzindole, a competitive antagonist of melatonin receptors, decreases macrophage phagocytic activity. The opposing functions of NF-κB in the modulation of AA-NAT expression in pinealocytes and macrophages may represent the key mechanism for the switch in the source of melatonin from the pineal gland to immune-competent cells during the development of an inflammatory response. PMID:23284853

  5. 4{pi} studies of the 1.8{endash}4.8 GeV {sup 3}He+{sup nat}Ag, {sup 197}Au reactions. I. Energy deposition

    SciTech Connect

    Morley, K.B.; Kwiatkowski, K.; Bracken, D.S.; Renshaw Foxford, E.; Viola, V.E.; Woo, L.W.; Yoder, N.R.; Legrain, R.; Pollacco, E.C.; Volant, C.; Korteling, R.G.; Breuer, H.; Brzychczyk, J.

    1996-08-01

    The Indiana Silicon Sphere 4{pi} detector has been used to measure light-charged particles and intermediate-mass fragments (IMFs) emitted in the 18{endash}4.8 GeV {sup 3}He+{sup nat}Ag, {sup 197}Au reactions. Ejectile multiplicity and total event kinetic energy distributions scale systematically with projectile energy and target mass, except for the {sup nat}Ag target at 3.6 and 4.8 GeV. For this system, a saturation in deposition energy is indicated by the data, suggesting the upper projectile energy for stopping has been reached. Maximum deposition energies of {approximately}950 MeV for the {sup nat}Ag target and {approximately}1600 MeV for the {sup 197}Au target are inferred from the data. The results also demonstrate the importance of accounting for fast cascade processes in defining the excitation energy of the targetlike residue. Correlations between various observables and the average IMF multiplicity indicate that the total thermal energy and total observed charge provide useful gauges of the excitation energy of the fragmenting system. Comparison of the experimental distributions with intranuclear cascade predictions shows qualitative agreement. {copyright} {ital 1996 The American Physical Society.}

  6. Preventing ballistic missile proliferation: Lessons from Iraq. Master`s thesis

    SciTech Connect

    Talay, B.J.

    1996-12-01

    This thesis examines the case of Iraq to assess the performance of the missile nonproliferation regime since 1970. By analyzing the methods used by Iraq to obtain missile systems and missile technology, this thesis assesses the ability of the international community to prevent ballistic missile proliferation. Understanding Iraq`s past capabilities as well as its post-war efforts to rebuild weapons programs and procurement networks, this thesis provides suggestions for improving the regime`s performance. This thesis finds that (1) prior to 1992, the Missile Technology Control Regime (MTCR) failed in its attempts to prevent proliferation; (2) the existence of the MTCR, while necessary to slow proliferation, is not sufficient to prevent proliferation; and (3) additional enforcement is needed to counter weapons of mass destruction acquisition by resourceful and determined states.

  7. Command and control in new nuclear states: Implications for stability. Master's thesis

    SciTech Connect

    Foley, D.C.

    1994-06-01

    Command and control systems of new nuclear states are likely to fail when placed under stress. This thesis will demonstrate that such failures can dramatically affect regional or international stability. Describing the current argument over the consequences of nuclear proliferation between proliferation pessimists and deterrence optimists, this thesis shows how C2 is in fact the crux of the debate. This thesis develops an analytical tool that may be applied to new nuclear states in order to classify their C2 systems and to predict when and how these evolving systems might fail. To show the tool's usefulness, it is applied to Ukraine, an important new nuclear state. This thesis also suggests several implications for U.S. foreign policy. Nuclear weapons, Command and control, Proliferation, Arms control, Regional stability, Russia, United States, Ukraine, Nuclear capabilities, U.S. Security policy.

  8. Studies of an x ray selected sample of cataclysmic variables. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Silber, Andrew D.

    1986-01-01

    Just prior to the thesis research, an all-sky survey in hard x rays with the HEAO-1 satellite and further observations in the optical resulted in a catalog of about 700 x-ray sources with known optical counterparts. This sample includes 43 cataclysmic variables, which are binaries consisting of a detached white-dwarf and a Roche lobe filling companion star. This thesis consists of studies of the x-ray selected sample of catalcysmic variables.

  9. Dissertations and Theses Roles Highlighted at Annual Meeting Session. California State University System's Thesis in Master's Degree Programs Discussed.

    ERIC Educational Resources Information Center

    Stanford, Serena W.

    1987-01-01

    The role of the thesis in graduate education at the 19 campuses of the California State University (CSU) was surveyed. It was found that a minimal number of disciplines at CSU restrict the choice of culminating the degree with the thesis. Only 15% of the programs systemwide force the thesis. The comprehensive examination was as popular as the…

  10. The Honors Thesis: A Handbook for Honors Directors, Deans, and Faculty Advisors. National Collegiate Honors Council Monograph Series

    ERIC Educational Resources Information Center

    Anderson, Mark; Lyons, Karen; Weiner, Norman

    2014-01-01

    This handbook is intended to help all those who design, administer, and implement honors thesis programs--honors directors, deans, staff, faculty, and advisors--evaluate their thesis programs, solve pressing problems, select more effective requirements or procedures, or introduce an entirely new thesis program. The authors' goal is to provide…

  11. Assessment of dental student satisfaction with regard to process of thesis educational courses

    PubMed Central

    Eslamipour, Faezeh; Noroozi, Zahra; Hosseinpour, Kobra

    2015-01-01

    Introduction: Ensuring achievement of research experience by students is one of the most important goals of the thesis-conduction process and evaluation of student satisfaction with this process is one of the most imperative challenges herein. Aims: The aim of this study is to investigate the satisfaction of dental students passing the thesis educational course from the Isfahan Dental School. Settings and Design: Sixty-two dental students who had graduated in2011, from the Isfahan Dental School, participated in this descriptive cross-sectional study Materials and Methods: The postgraduate Research Experience Questionnaire (PREQ) was used for data collection. The questionnaire evaluated student satisfaction in seven domains: Thesis supervision, skill development, intellectual climate, infrastructure, thesis examination, goals and expectations, and overall satisfaction. Statistical Analysis Used: The data were analyzed on an SPSS software using descriptive and inferential statistics. Results: The mean score of satisfaction of the participants was 75 ± 12. On the basis of their scores, satisfaction in 3.2% of them was slow, in 33.9%was medium, in 61.3% was good and in 1.6% was high. The highest satisfaction was found to be in thesis supervision and the least was in the intellectual climate domain. There was no significant statistical difference between satisfaction and gender (P = 0.46). Conclusions: Considering the results, to increase student satisfaction for passing the thesis courses, it is necessary to improve the intellectual climate in dental schools and also increase the research budget for more financial support of students to carry out their projects. PMID:27462643

  12. An Auto-management Thesis Program WebMIS Based on Workflow

    NASA Astrophysics Data System (ADS)

    Chang, Li; Jie, Shi; Weibo, Zhong

    An auto-management WebMIS based on workflow for bachelor thesis program is given in this paper. A module used for workflow dispatching is designed and realized using MySQL and J2EE according to the work principle of workflow engine. The module can automatively dispatch the workflow according to the date of system, login information and the work status of the user. The WebMIS changes the management from handwork to computer-work which not only standardizes the thesis program but also keeps the data and documents clean and consistent.

  13. Application of a neptune propulsion concept to a manned mars excursion. Master's thesis

    SciTech Connect

    Finley, C.J.

    1993-04-01

    NEPTUNE is a multimegawatt electric propulsion system. It uses a proven compact nuclear thermal rocket, NERVA, in a closed cycle with a magnetohydrodynamic (MHD) generator to power a magnetoplasmadynamic (MPD) thruster. This thesis defines constraints on an externally sourced propulsion system intended to carry out a manned Martian excursion. It assesses NEPTUNE's ability to conform to these constraints. Because an unmodified NEPTUNE system is too large, the thesis develops modifications to the system which reduce its size. The result is a far less proven, but more useful derivative of the unmodified NEPTUNE system.

  14. Nuclear model analysis of excitation functions of proton induced reactions on ⁸⁶Sr, ⁸⁸Sr and natZr: Evaluation of production routes of ⁸⁶Y.

    PubMed

    Zaneb, H; Hussain, M; Amjed, N; Qaim, S M

    2015-10-01

    The proton induced nuclear reactions on (86)Sr, (88)Sr and (nat)Zr were investigated for the production of (86)Y. The literature data were compared with the results of nuclear model calculations using the codes ALICE-IPPE, TALYS 1.6 and EMPIRE 3.2. The thick target yields of (86)Y were calculated from the recommended excitation functions. Analysis of radioyttrium impurities was also performed. A comparison of the various production routes showed that for medical applications of (86)Y, the reaction (86)Sr(p,n)(86)Y is the method of choice, which gives efficient yield with minimum impurities. PMID:26210800

  15. Measurement and simulation of the cross sections for the production of {sup 148}Gd in thin {sup nat}W and {sup 181}Ta targets irradiated with 0.4- to 2.6-GeV protons

    SciTech Connect

    Titarenko, Yu. E. Batyaev, V. F.; Titarenko, A. Yu.; Butko, M. A.; Pavlov, K. V.; Florya, S. N.; Tikhonov, R. S.; Zhivun, V. M.; Ignatyuk, A. V.; Mashnik, S. G.; Leray, S.; Boudard, A.; Cugnon, J.; Mancusi, D.; Yariv, Y.; Nishihara, K.; Matsuda, N.; Kumawat, H.; Mank, G.; Gudowski, W.

    2011-04-15

    The cross sections for the production of {sup 148}Gd in {sup nat}W and {sup 181}Ta targets irradiated by 0.4-, 0.6-, 0.8-, 1.2-, 1.6-, and 2.6-GeV protons at the ITEP accelerator complex have been measured by direct {alpha} spectrometry without chemical separation. The experimental data have been compared with the data obtained at other laboratories and with the theoretical simulations of the yields on the basis of the BERTINI, ISABEL, CEM03.02, INCL4.2, INCL4.5, CASCADE07, and PHITS codes.

  16. Contesting the Limond Thesis on British Influence in Irish Education since 1922: A Comparative Perspective

    ERIC Educational Resources Information Center

    O'Donoghue, Tom; Harford, Judith

    2012-01-01

    This paper is a response to David Limond's exposition, "[An] historical culture ... rapidly, universally, and thoroughly restored"? British influence on Irish education since 1922, which appeared in "Comparative Education", Vol. 46, No. 4, November 2010, pp. 449-462. Limond's overall thesis is that "a post-colonial overhang affects Irish…

  17. Edgeware Security Risk Management: A Three Essay Thesis on Cloud, Virtualization and Wireless Grid Vulnerabilities

    ERIC Educational Resources Information Center

    Brooks, Tyson T.

    2013-01-01

    This thesis identifies three essays which contribute to the foundational understanding of the vulnerabilities and risk towards potentially implementing wireless grid Edgeware technology in a virtualized cloud environment. Since communication networks and devices are subject to becoming the target of exploitation by hackers (e.g. individuals who…

  18. Adaptive Research Supervision: Exploring Expert Thesis Supervisors' Practical Knowledge

    ERIC Educational Resources Information Center

    de Kleijn, Renske A. M.; Meijer, Paulien C.; Brekelmans, Mieke; Pilot, Albert

    2015-01-01

    Several researchers have suggested the importance of being responsive to students' needs in research supervision. Adapting support strategies to students' needs in light of the goals of a task is referred to as "adaptivity." In the present study, the practice of adaptivity is explored by interviewing expert thesis supervisors…

  19. Evaluability Assessment Thesis and Dissertation Studies in Graduate Professional Degree Programs

    ERIC Educational Resources Information Center

    Walser, Tamara M.; Trevisan, Michael S.

    2016-01-01

    Evaluability assessment (EA) has potential as a design option for thesis and dissertation studies, serving as a practical training experience for both technical and nontechnical evaluation skills. Based on a content review of a sample of EA theses and dissertations from graduate professional degree programs, the authors of this article found that…

  20. The Two-Semester Thesis Model: Emphasizing Research in Undergraduate Technical Communication Curricula

    ERIC Educational Resources Information Center

    Ford, Julie Dyke; Bracken, Jennifer L.; Wilson, Gregory D.

    2009-01-01

    This article addresses previous arguments that call for increased emphasis on research in technical communication programs. Focusing on the value of scholarly-based research at the undergraduate level, we present New Mexico Tech's thesis model as an example of helping students develop familiarity with research skills and methods. This two-semester…

  1. Increasing the Number of Feminist Scientists: Why Feminist Aims Are Not Served by the Underdetermination Thesis

    ERIC Educational Resources Information Center

    Intemann, Kristen

    2008-01-01

    Recent feminist philosophers of science have argued that feminist values can contribute to rational decisions about which scientific theories to accept. On this view, increasing the number of feminist scientists is important for ensuring rational and objective theory acceptance. The Underdetermination Thesis has played a key role in arguments for…

  2. Rapid X-Ray Variability of Active Galaxies. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Tennant, A. F., Jr.

    1983-01-01

    Active galactic nuclei are luminous sources of X-rays. The thesis that the X-rays are generated within 10 gravitational radii from the central object is tested. A very sensitive search for rapid ( 1 day) X-ray variability from active galaxies was made.

  3. Perceptions of the Difficulties of Postgraduate L2 Thesis Students Writing the Discussion Section

    ERIC Educational Resources Information Center

    Bitchener, John; Basturkmen, Helen

    2006-01-01

    In postgraduate study, students including L2 students are often required to write a thesis and, as a growing literature reveals, L2 students often experience difficulties in the writing of this genre. While most of this research has involved surveys (questionnaires and interviews) and case studies of supervisor perceptions, only a few studies have…

  4. Want to Improve Undergraduate Thesis Writing? Engage Students and Their Faculty Readers in Scientific Peer Review

    ERIC Educational Resources Information Center

    Reynolds, Julie A.; Thompson, Robert J., Jr.

    2011-01-01

    One of the best opportunities that undergraduates have to learn to write like a scientist is to write a thesis after participating in faculty-mentored undergraduate research. But developing writing skills doesn't happen automatically, and there are significant challenges associated with offering writing courses and with individualized mentoring.…

  5. Response to Hewes's "The Influence of Communication Processes on Group Outcomes: Antithesis and Thesis"

    ERIC Educational Resources Information Center

    Gouran, Dennis S.

    2009-01-01

    This article presents the author's response to Professor Hewes's "The Influence of Communication Processes on Group Outcomes: Antithesis and Thesis." The author believes that Hewes could have been more helpful to the reader and to those who are apt to find inspiration in the steps he has taken in his essay to promote a "return to basic theorizing…

  6. China's nuclear agenda and the implications for United States foreign policy. Master's thesis

    SciTech Connect

    Olmo, E.D.

    1993-09-01

    This thesis covers the history of China's nuclear development and examines the changes in its nuclear policies over the past three decades. It examines the issues of China's nuclear and defense strategies, nuclear and defense policies, arms transfers policies, proliferation policies and its foreign policies. Implications for American foreign policy vis-a-vis China's evolving nuclear status are discussed.

  7. Thesis and Dissertation Writing: An Examination of Published Advice and Actual Practice.

    ERIC Educational Resources Information Center

    Paltridge, Brian

    2002-01-01

    Explores the extent to which published advice on the organization and structure of theses and dissertations concurs with what happens in actual practice. Examines guides and handbooks that focus on thesis and dissertation writing and postgraduate research. Found that only a few books devoted a substantial amount of space to this topic. Discusses…

  8. Diversity in Collaborative Research Communities: A Multicultural, Multidisciplinary Thesis Writing Group in Public Health

    ERIC Educational Resources Information Center

    Guerin, Cally; Xafis, Vicki; Doda, Diana V.; Gillam, Marianne H.; Larg, Allison J.; Luckner, Helene; Jahan, Nasreen; Widayati, Aris; Xu, Chuangzhou

    2013-01-01

    Writing groups for doctoral students are generally agreed to provide valuable learning spaces for Ph.D. candidates. Here an academic developer and the eight members of a writing group formed in a Discipline of Public Health provide an account of their experiences of collaborating in a multicultural, multidisciplinary thesis writing group. We…

  9. "On Course" for Supporting Expanded Participation and Improving Scientific Reasoning in Undergraduate Thesis Writing

    ERIC Educational Resources Information Center

    Dowd, Jason E.; Roy, Christopher P.; Thompson, Robert J., Jr.; Reynolds, Julie A.

    2015-01-01

    The Department of Chemistry at Duke University has endeavored to expand participation in undergraduate honors thesis research while maintaining the quality of the learning experience. Accomplishing this goal has been constrained by limited departmental resources (including faculty time) and increased diversity in students' preparation to…

  10. Unblocking Occluded Genres in Graduate Writing: Thesis and Dissertation Support Services at North Carolina State University

    ERIC Educational Resources Information Center

    Autry, Meagan Kittle; Carter, Michael

    2015-01-01

    In 2013, the Graduate School at North Carolina State University launched Thesis and Dissertation Support Services, a rhetorical, genre-based approach to assisting students with their graduate writing. Through a description of the program's founding, goals, and first year of services, we summarize this genre-based approach that is informed by the…

  11. Episodic stress associated with writing a graduation thesis and free cortisol secretion after awakening.

    PubMed

    Izawa, Shuhei; Sugaya, Nagisa; Ogawa, Namiko; Nagano, Yuichiro; Nakano, Masako; Nakase, Emiko; Shirotsuki, Kentaro; Yamada, Kosuke Chris; Machida, Kazuhiko; Kodama, Masahisa; Nomura, Shinobu

    2007-05-01

    Cortisol secretion after awakening, an index of hypothalamus-pituitary-adrenal axis activity, appears to be related to psychosocial stressors, or to symptoms caused by psychosocial stressors. The relationship between the quality, duration, and magnitude of psychosocial factors and cortisol secretion is however, unclear. Therefore, the effect of episodic stress associated with writing a graduation thesis on cortisol secretion after awakening was investigated. Saliva samples were collected from 10 undergraduate students at awakening, and 30, 45, and 60 min after awakening 1 month, 2 weeks, and a few days before the thesis submission and 1 week after the submission. They also completed the Short form of Profile of Moods Scale (POMS-S) on the night before each sampling. Results indicated that cortisol levels were higher a few days before the thesis submission compared to 1 month before submission. Scores of "Fatigue" and "Tension-Anxiety" in POMS-S were also higher a few days before submission. These results suggest that episodic stress associated with writing a graduation thesis caused an increase in cortisol levels after awakening. PMID:17316855

  12. The "Write" Skills and More: A Thesis Writing Group for Doctoral Students

    ERIC Educational Resources Information Center

    Ferguson, Therese

    2009-01-01

    Writing groups facilitate the development of research students' written communication skills, which are critical for the competent preparation of theses and publications. This paper describes a Thesis Writing Group for social science doctoral students. Participants indicated that the group not only served a practical role, providing an impetus for…

  13. [High frequency of plagiarism in medical thesis from a Peruvian public university].

    PubMed

    Saldaña-Gastulo, J Jhan C; Quezada-Osoria, C Claudia; Peña-Oscuvilca, Américo; Mayta-Tristán, Percy

    2010-03-01

    An observational study was conducted to describe the presence of plagiarism in medical thesis in 2008 performed at a public university in Peru. Search for plagiarism in 33 thesis introductions using a Google search algorithm, characterizes of the study type and we search in electronic form if the thesis mentor have published articles in scientific journals. We found evidence of plagiarism in 27/33 introductions, 37.3% (171/479) of all the paragraphs analyzed had some degree of plagiarism, literal plagiarism was the most frequent (20/27) and journals were the most common sources of plagiarism (19/27). The characteristics of the studies were observational (32/33), cross-sectional (30/33), descriptive (25/33) and retrospective (19/33). None of the authors had published in a scientific journal, and only nine of his tutors of them had at least one publication. No association was found between the characteristics of the thesis and the presence of plagiarism. In conclusion, we found a high frequency of plagiarism in theses analyzed. Is responsibility of medical schools take the necessary actions to detect and avoid plagiarism among their students. PMID:21072452

  14. Master's Thesis Projects: Student Perceptions of Supervisor Feedback

    ERIC Educational Resources Information Center

    de Kleijn, Renske A. M.; Mainhard, M. Tim; Meijer, Paulien C.; Brekelmans, Mieke; Pilot, Albert

    2013-01-01

    A growing body of research has investigated student perceptions of written feedback in higher education coursework, but few studies have considered feedback perceptions in one-on-one and face-to-face contexts such as master's thesis projects. In this article, student perceptions of feedback are explored in the context of the supervision of…

  15. Testing the Protestant Ethic Thesis with Quantitative Historical Data: A Research Note

    ERIC Educational Resources Information Center

    Sanderson, Stephen K.; Abrutyn, Seth B.; Proctor, Kristopher R.

    2011-01-01

    We provide a test of the thesis that Protestantism influenced the development of modern capitalism by using quantitative data from 1500 through 1870. Results show that during this period the percentage of a country's population that is Protestant is unrelated to both its level of per capita GDP and the average rate of its annual growth in per…

  16. Curricular Goals and Personal Goals in Master's Thesis Projects: Dutch Student-Supervisor Dyads

    ERIC Educational Resources Information Center

    de Kleijn, Renske A. M.; Meijer, Paulien C.; Brekelmans, Mieke; Pilot, Albert

    2013-01-01

    To be effective, feedback should be goal-related. In order to better understand goal-related feedback in Master's thesis projects, the present study explores the goals of supervisors and students in supervision dyads and similarities and differences within and between these dyads. Twelve supervisors and students were interviewed, and their goals…

  17. The Quality of an Action Research Thesis in the Social Sciences

    ERIC Educational Resources Information Center

    Zuber-Skerrit, Ortrun; Fletcher, Margaret

    2007-01-01

    Purpose: The paper seeks to identify the quality characteristics of critical action research and action research theses compared to traditional research thesis writing. Design/methodology/approach: Drawing on the literature and the authors' experience with supervising and examining action research theses, the paper identifies key problem areas in…

  18. Reading in Preparation for Writing a PhD Thesis: Case Studies of Experiences

    ERIC Educational Resources Information Center

    Kwan, Becky S. C.

    2009-01-01

    The paper presents stories of how a group of doctoral students chose the key disciplinary literature that they read in preparation for their thesis-undertaking (RT). The stories were analyzed in light of current understanding of literature reviewing as a situated practice and theory of doctoral education as socio-cognitive apprenticeship. As the…

  19. Senior Thesis Camp: Partnerships in Practice at the University of Notre Dame

    ERIC Educational Resources Information Center

    Smith, Cheri; Kayongo, Jessica

    2011-01-01

    The article describes the process of developing a week long thesis camp for seniors in the College of Arts and Letters at the University of Notre Dame. The library and other university groups worked together to provide the students with workshops, ready access to research assistance, and dedicated space to work on their theses. This inaugural…

  20. Design of an Integrated Team Project as Bachelor Thesis in Bioscience Engineering

    ERIC Educational Resources Information Center

    Peeters, Marie-Christine; Londers, Elsje; Van der Hoeven, Wouter

    2014-01-01

    Following the decision at the KU Leuven to implement the educational concept of guided independent learning and to encourage students to participate in scientific research, the Faculty of Bioscience Engineering decided to introduce a bachelor thesis. Competencies, such as communication, scientific research and teamwork, need to be present in the…

  1. Why Should I Present a Thesis on Computer Assisted Ndjebbana on DVD?

    ERIC Educational Resources Information Center

    Auld, Glenn

    This paper justifies the presentation of a Ph.D. thesis about computer-assisted Ndjebbana on a digital video disc (DVD). Ndjebbana is a language spoken by 200 Kunibidji, the indigenous landowners of Maningrida on the north coast of Arnhem Land, Australia. Simple digital talking books about the community were created in Ndjebbana and then presented…

  2. An Analysis of Written Feedback on a PhD Thesis

    ERIC Educational Resources Information Center

    Kumar, Vijay; Stracke, Elke

    2007-01-01

    This paper offers an interim analysis of written feedback on a first draft of a PhD thesis. It first looks at two sources of data: in-text feedback and overall feedback. Looking at how language is used in its situational context, we then coded the feedback and developed a model for analysis based on three fundamental functions of speech:…

  3. The Experienced Meaning of Working with a PhD Thesis

    ERIC Educational Resources Information Center

    Stubb, Jenni; Pyhalto, Kirsi; Lonka, Kirsti

    2012-01-01

    There is a variation in terms of how researchers perceive the nature of research work. Previous research has mainly looked at the members of academia who already have established themselves in the scholarly community. We aimed at exploring the ways in which doctoral students perceived their thesis project and further, the relations of such…

  4. The Empirical Status of the Sub-culture of Violence Thesis

    ERIC Educational Resources Information Center

    Erlanger, Howard S.

    1974-01-01

    Reviews some of the literature bearing on the thesis that violence results from certain values, reports the results of a re-analysis of survey data collected for the President's Commission on the Causes and Prevention of Violence, and presents new data on peer esteem and social psychological correlates of fighting among males. (Author/JM)

  5. Authority and the Freshman Writer: The Ideology of the Thesis Statement.

    ERIC Educational Resources Information Center

    Perdue, Virginia

    1992-01-01

    Suggests writing instructors reconsider the way they represent to students the nature and function of thesis statements, particularly in their first-year rhetorics. Notes that the conventions of disputation and argument are increasingly challenged by the growing value various disciplines are placing on uncertainty, mediation, and exploration in…

  6. Measurements of 67Ga production cross section induced by protons on natZn in the low energy range from 1.678 to 2.444 MeV

    NASA Astrophysics Data System (ADS)

    Wachter, J. A.; Miranda, P. A.; Morales, J. R.; Cancino, S. A.; Correa, R.

    2015-02-01

    The experimental production cross section for the reaction natZn(p,x)67Ga has been measured in the energy range from 1.678 to 2.444 MeV. The methodology used in this work is based on characteristic X-ray emitted after irradiation by the daughter nuclei that decays by electron capture (EC) and the use of a complementary PIXE experiment. By doing so, expressions needed to determine cross section values are simplified since experimental factors such as geometric setup and an detector efficiency are avoided. 67Ga is a radionuclide particularly suited for this method since it decays by electron capture in 100% and the subsequent characteristic X-ray emission is easily detected. Natural zinc targets were fabricated by PVD technique and afterwards their thicknesses were determined by Rutherford Backscattering Spectrometry. Cross sections measurements were carried out by using the Van de Graaff accelerator located at Faculty of Sciences, University of Chile. It was found that our data for the natZn(p,x)67Ga reaction are, in general, in good agreement when compared to existing experimental data and to those calculated ALICE/ASH nuclear code. On the other hand, values predicted by Talys-1.6 are showing systematically lower magnitudes than our measured data.

  7. Probability density functions characterizing PSC particle size distribution parameters for NAT and STS derived from in situ measurements between 1989 and 2010 above McMurdo Station, Antarctica, and between 1991-2004 above Kiruna, Sweden

    NASA Astrophysics Data System (ADS)

    Deshler, Terry

    2016-04-01

    Balloon-borne optical particle counters were used to make in situ size resolved particle concentration measurements within polar stratospheric clouds (PSCs) over 20 years in the Antarctic and over 10 years in the Arctic. The measurements were made primarily during the late winter in the Antarctic and in the early and mid-winter in the Arctic. Measurements in early and mid-winter were also made during 5 years in the Antarctic. For the analysis bimodal lognormal size distributions are fit to 250 meter averages of the particle concentration data. The characteristics of these fits, along with temperature, water and nitric acid vapor mixing ratios, are used to classify the PSC observations as either NAT, STS, ice, or some mixture of these. The vapor mixing ratios are obtained from satellite when possible, otherwise assumptions are made. This classification of the data is used to construct probability density functions for NAT, STS, and ice number concentration, median radius and distribution width for mid and late winter clouds in the Antarctic and for early and mid-winter clouds in the Arctic. Additional analysis is focused on characterizing the temperature histories associated with the particle classes and the different time periods. The results from theses analyses will be presented, and should be useful to set bounds for retrievals of PSC properties from remote measurements, and to constrain model representations of PSCs.

  8. Measurement of Isomeric Yield Ratio of 143m,gSm from natSm(γ,xn) Reaction with End-Point Bremsstrahlung Energies of 40-60 MeV

    NASA Astrophysics Data System (ADS)

    Yang, S. C.; Kim, K.; Kim, G. N.; Kim, H. I.; Lee, Y. O.; Lee, M. W.; Pham, D. K.; Nguyen, V. D.; Shin, S. G.; Cho, M. H.

    2014-05-01

    The isomeric yield ratios (IR) of 143m,gSm from the natSm(γ, xn) reaction with the end-point bremsstrahlung energies of 40, 50 and 60 MeV were measured by the activation method and using the 100 MeV electron linac of the Pohang Accelerator Laboratory (PAL), Korea. A high-purity natSm foil in disc shape was used for the irradiation and the induced photo-peak activity of the γ-rays of 143m,gSm in the irradiated sample was measured with a HPGe detector. The experimental data were analyzed through the Gamma Vision program and IR was obtained using a decay equation. The present results are compared with the literature data at other energies. It was found that the IR of 143m,gSm increases sharply from 12 to 20 MeV due to the GDR effect and thereafter remains nearly constant or increases slowly with the end-point bremsstrahlung energy.

  9. Publishing a Master’s Thesis: A Guide for Novice Authors

    PubMed Central

    Resta, Robert G.; McCarthy Veach, Patricia; Charles, Sarah; Vogel, Kristen; Blase, Terri

    2010-01-01

    Publication of original research, clinical experiences, and critical reviews of literature are vital to the growth of the genetic counseling field, delivery of genetic counseling services, and professional development of genetic counselors. Busy clinical schedules, lack of time and funding, and training that emphasizes clinical skills over research skills may make it difficult for new genetic counselors to turn their thesis projects into publications. This paper summarizes and elaborates upon a presentation aimed at de-mystifying the publishing process given at the 2008 National Society of Genetic Counselors Annual Education Conference. Specific topics include familiarizing prospective authors, particularly genetic counseling students, with the basics of the publication process and related ethical considerations. Former students’ experiences with publishing master’s theses also are described in hopes of encouraging new genetic counselors to submit for publication papers based on their thesis projects. PMID:20076994

  10. Protestant Clergy and the Culture Wats: An Empirical Test of Hunter’s Thesis

    PubMed Central

    Uecker, Jeremy E.; Lucke, Glenn

    2013-01-01

    This study instead focuses on culture wars among religious elites—clergy—and tests three aspects of the culture wars thesis: (1) whether cultural wars exist at all among religious elites, (2) whether clergy attitudes are polarized on these issues, and (3) whether religious authority or religious affiliation is more salient in creating culture wars cleavages. Using data from a large random sample of Protestant clergy, we find a substantial amount of engagement in culture wars by all types of Protestant clergy. The amount of polarization is more attributable to views of religious authority (i.e., biblical inerrancy) than to religious tradition. Moreover, polarization among clergy is somewhat more evident on culture wars issues than on other social and political issues. These findings are generally supportive of the culture wars thesis and should help return examinations of culture wars back to where they were originally theorized to be waged: among elites. PMID:24072933

  11. Development and implementation of information systems at two California water districts. Master's thesis

    SciTech Connect

    Howe, J.G.

    1992-09-01

    This thesis examines the contrasting approaches taken in the development and implementation of computer based information systems at two water districts. The first water district, a relatively large organization, employed only professionals to plan and closely monitor its information system installation. Eventually, the installation was completed ahead of schedule and below the estimated cost. The second water district, a relatively small organization, primarily used in-house to plan and install its information system. This project experienced time and cost overruns. Besides personnel factors, the following issues affected the markedly different experiences of these two districts: (1) planning; (2) implementation management; and (3) the degree of end user involvement in the project. The goal of this thesis is to assist organizations that may be planning similar projects by analyzing the successes of and mistakes made by these two water districts.

  12. Facilities requirements for a flash x-ray machine. Master's thesis

    SciTech Connect

    Zurey, E.C.

    1985-06-01

    This thesis discusses the impact and benefits of installing a 1.5-MeV flash X-ray machine at the Naval Postgraduate School. It reviews the specifications and applications of the 100 MeV linear accelerator currently in operation at NPS and compares it with the performance of the proposed equipment. Estimates of radiation production and area dosages from the flash X-ray machine, as well as proposals for equipment location and shielding design, are presented. Laboratory requirements for electrical power, space, rediation monitoring, equipment interlocks and safety awareness, as well as federal regulation application to and installation of this type, are considered. Finally, research and thesis opportunities through the improved and unique capabilities of the flash X-ray machine are presented, along with some suggestions for proposed experiments and applications.

  13. Two arm robot path planning in a static environment using polytopes and string stretching. Thesis

    NASA Technical Reports Server (NTRS)

    Schima, Francis J., III

    1990-01-01

    The two arm robot path planning problem has been analyzed and reduced into components to be simplified. This thesis examines one component in which two Puma-560 robot arms are simultaneously holding a single object. The problem is to find a path between two points around obstacles which is relatively fast and minimizes the distance. The thesis involves creating a structure on which to form an advanced path planning algorithm which could ideally find the optimum path. An actual path planning method is implemented which is simple though effective in most common situations. Given the limits of computer technology, a 'good' path is currently found. Objects in the workspace are modeled with polytopes. These are used because they can be used for rapid collision detection and still provide a representation which is adequate for path planning.

  14. Soviet political objectives in the Federal Republic of Germany: instruments and assessments. Master's thesis

    SciTech Connect

    Goebel, S.E.

    1988-06-01

    This thesis examines apparent Soviet attempts to use its detente policy to exploit the Federal Republic of Germany's membership in NATO and thereby expand its influence in the FRG and Europe as a whole. It is hypothesized that the Soviet Union chooses to exploit the FRG's position in NATO by cultivating a special relationship with it and thereby accessing the U.S. and NATO as a whole, rather than making overt efforts to force a near-term split between West Germany and the U.S. The thesis focuses on the instruments the Soviet Union uses to maximize its influence in the FRG and the region. These instruments include West Germany's concerns regarding nuclear war in Europe, Ostpolitik and German-German relations.

  15. Canada: the decision to procure nuclear-attack submarines and its significance for NATO. Master's thesis

    SciTech Connect

    Guillory, T.

    1988-09-01

    In June 1987 the Canadian government announced plans to procure 10 to 12 nuclear attack submarines (SSNs). The evidence suggests that, for some Canadians, a primary purpose for this submarine program may not be to enhance the security of NATO, but instead to assert Canada's sovereignty, principally against the United States, in the Arctic region. The thesis discusses this decision and its possible implications for the security of North America and NATO. It is argued that the United States must continue to have unimpeded access to the Arctic region to counter the ever-increasing threat posed by Soviet nuclear ballistic missile submarines (SSBNs). Finally, the thesis suggests a possible solution to the current sovereignty debate and a potential strategy for employing these SNN to enhance the security of North America and NATO as a whole.

  16. Limited war, escalation control, and command, control and communications. Master's thesis

    SciTech Connect

    Waltensperger, G.M.

    1986-03-01

    This thesis is an unclassified examination from a Western perspective of the concepts of limited war, and escalation control in the context of nuclear conflict and command, control and communications (C3). Limited war and escalation control are intrinsically related. To better understand the relationships betweenlimited war, escalation control and C3, as applied to the question of protracted nuclear war, this thesis considers strategic control from a cybernetic view, using a widely accepted model for the command and control process. US strategic C3 systems are discussed from the perspective of limiting war and controlling escalation. Requirements such as, a viable National Command Authority, effective command and control, positive/negative control, damage control/assessment, a shared concept of limited war, civil defense, and a mechanism to terminate conflict are presented as necessary to control escalation, thus, limiting war.

  17. India`s nuclear weapons posture: The end of ambiguity. Master`s thesis

    SciTech Connect

    Davis, S.D.

    1996-12-01

    This thesis examines the future of India`s nuclear weapons posture. Since testing a nuclear device in 1974, India been able to produce weapons material within its civilian nuclear power program. Despite having this nuclear weapons capability, India prefers to maintain an ambiguous nuclear posture. New pressures in the post-cold war era -- the loss of the Soviet Union as a strategic ally, the indefinite extension of the nuclear nonproliferation treaty, the rise of Hindu nationalism, and India`s growing participation in the global economy -- have the potential to derail India`s current nuclear policy. This thesis identifies the domestic and international pressures on India, and assesses the prospects for India to retain its ambiguous policy, renounce the nuclear option, or assemble an overt nuclear arsenal.

  18. Increasing the number of feminist scientists: why feminist aims are not served by the Underdetermination Thesis

    NASA Astrophysics Data System (ADS)

    Intemann, Kristen

    2008-11-01

    Recent feminist philosophers of science have argued that feminist values can contribute to rational decisions about which scientific theories to accept. On this view, increasing the number of feminist scientists is important for ensuring rational and objective theory acceptance. The Underdetermination Thesis has played a key role in arguments for this view [Anderson (1995) Hypatia 10(3), 50 84; Hankinson Nelson (1990) Who knows? From Quine to a feminist empiricism. Temple University Press, Philadelphia; Longino (1990) Science as social knowledge. Princeton University Press, Princeton; Longino (2002) The fate of knowledge. Princeton University Press, Princeton; Kourany (2003) Philosophy of Science 70, 1 14]. This thesis is alleged to open an argumentative “gap” between evidence and theory acceptance and provide a rationale for filling the gap with feminist values. While I agree with the conclusion that feminist values can contribute to rational decisions about which theories to accept, I argue that the Underdetermination Thesis cannot support this claim. First, using earlier arguments [Laudan (1990) in: R. Giere (ed) Minnesota studies in the philosophy of science, vol 14, pp 267 297; Slezak (1991) International Studies in Philosophy of Science 5, 241 256; Pinnick (1994) Philosophy of Science 61, 664 657] I show that Underdetermination cannot, by itself, establish that feminist values should fill the gap in theory acceptance. Secondly, I argue that the very use of the Underdetermination Thesis concedes that feminist values are extra-scientific, a-rational, factors in theory acceptance. This concession denies feminists grounds to explain why their values contribute to rational scientific reasoning. Finally, I propose two alternative ways to explain how feminist values can contribute to rational theory acceptance that do not rely on Underdetermination.

  19. The sonata form of musical composition as a framework for thesis writing.

    PubMed

    Drake, Maurice C

    2004-01-01

    In response to Watson's challenge to view the usual in new ways, this article introduces an innovation in writing Master's research and suggests that other structures may offer new and different frameworks for reporting nursing research. This is exemplified by reference to an example of nursing research which adopted the sonata-form of musical composition as the framework for presentation of the thesis. PMID:15125107

  20. Science as an ally of religion: a Muslim appropriation of 'the conflict thesis'.

    PubMed

    Yalcinkaya, M Alper

    2011-06-01

    John W. Draper's History of the Conflict between Religion and Science (1874) is commonly regarded as the manifesto of the 'conflict thesis'. The superficiality of this thesis has been demonstrated in recent studies, but to read Draper's work only as a text on 'science versus religion' is to miss half of its significance, as it also involved evaluations of individual religions with respect to their attitudes towards science. Due to Draper's favourable remarks on Islam, the Ottoman author Ahmed Midhat translated his work into Turkish, and published it along with his own comments on Draper's arguments. Midhat interpreted Islam using the cues provided by Draper, and portrayed it as the only religion compatible with science. While his Christian readers condemned Draper for his approach to Islam, Midhat transformed the 'conflict thesis' into a proclamation that Islam and science were allies in opposition to Christian encroachment on the Ottoman Empire. This paper analyses Midhat's appropriation of Draper's work and compares it to the reaction of Draper's Christian readers. It discusses the context that made an alliance between Islam and science so desirable for Midhat, and emphasizes the impact of the historico-geographical context on the encounters between and representations of science and religion. PMID:21879604

  1. Writing a bachelor thesis generates transferable knowledge and skills useable in nursing practice.

    PubMed

    Lundgren, Solveig M; Robertsson, Barbro

    2013-11-01

    Generic skills or transferable skills have been discussed in terms of whether or not skills learned in one context can be transferred into another context. The current study was aimed to explore nurses' self-perceptions of the knowledge and skills they had obtained while writing a Bachelor's thesis in nursing education, their experience of the extent of transfer and utilization in their current work. Responding nurses (N=42) had all worked from 1 to 1.5 years after their final examination and had completed a questionnaire that was structured with open-ended questions. Only five nurses reported that they were unable to use any of the knowledge and skills they had obtained from writing a thesis. A majority of the nurses (37/42) could give many examples of the practical application of the skills and knowledge they had obtained. Our findings indicate that writing a thesis as part of an undergraduate degree program plays a major role in the acquisition and development of knowledge and skills which can subsequently be transferred into and utilized in nursing practice. PMID:23141688

  2. Framework for understanding the Strategic Defense Initiatives' software debates. Master's thesis

    SciTech Connect

    Adams, R.C.

    1990-06-01

    On March 23, 1983, then-President Ronald Reagan challenged a group of engineers and scientists to make nuclear weapons impotent and obsolete. This challenge led to the beginning of a new era in space technology and strategic defense, thus creating the Strategic Defense Initiative (SDI), better known as Star Wars. By 1984, several studies had begun to show that software in conjunction with Battle Management/Command, Control, and Communications techniques would play a major role in determining the effectiveness of the SDI. The results from these studies caused numerous controversial debates on the reliability, dependability, and trustworthiness of the software. This thesis provides a framework for understanding the complexities of the SDI software and points out some of the major issues involved in the software debates. The structure for this thesis is based on presenting the opinions of various computer scientists and engineers, indicating the issues that are controversial and those that have been defined as a necessity for the SDI program. One of the major highlights is the SDI summary chart that provides the reader with a very brief narrative of each individuals' opinion on the software issues discussed in this thesis.

  3. Russian-American cooperation in weapons of mass destruction counterproliferation. Master`s thesis

    SciTech Connect

    Dabrowski, R.S.

    1996-09-01

    This thesis examines the opportunities and risks associated with a new form of military cooperation between the United States and Russia: joint strategic special operations for counterproliferation contingencies--to seize and secure or to disable or otherwise neutralize weapons of mass destruction (WMD) facilities or WMD-armed terrorists. This thesis compares Russian and U.S. views of the future security environment, looking for areas of overlap that could serve as the basis for mutually acceptable cooperative approaches to military options--especially in areas in or around the former Soviet Union-- to deal with new WMD threats. The most effective military options might require the creation of a Russian-American response force similar to the U.S. Department of Energy (DOE) Nuclear Emergency Search Team (NEST), expanded to be usable against a wide variety of WMD threats. This thesis analyzes the circumstances in which Russian-American SOF cooperation is more likely to succeed than U.S. unilateral action. The analysis concludes that information-sharing may be the most likely form of cooperation, although any Russian-American cooperative effort would reveal to the other side sensitive information about capabilities and vulnerabilities in that area of cooperation.

  4. [Doctoral thesis: Demographic growth and economic and social development in Mali].

    PubMed

    Dabo, K

    1999-12-01

    A doctoral thesis is described analyzing the relationships between demographic growth and economic and social development in Mali. The hypothesis is stated that demographic growth impedes economic development and any improvement in populations¿ standards of living. The hypothesis was verified using data for the period from 1960 to the present. Over that period, Mali conducted two general population censuses in 1976 and 1987, as well as several demographic research studies. The thesis is comprised of 4 parts, of which the first generally describes Mali. The second part analyzes the relationship between population growth and economic and social development in Mali. Study results are presented, followed by an analysis of the effects of economic and social development upon population growth in Mali through factors such as urbanization, education level, literacy, income, employment, occupation, gross domestic or gross national product by inhabitant, infant mortality rate, life expectancy at birth, contraceptive practice, fertility opinions and desires, women¿s status, and migration in Mali. Analysis indicates that Mali has not completely begun its demographic transition, but that traditional pronatalist behaviors are changing. Population policies and programs are explored in the third part of the thesis, followed by the fourth part which focuses upon methodological questions. PMID:12296197

  5. 7 CFR 3402.6 - Overview of the special international study and/or thesis/dissertation research travel allowance.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... thesis/dissertation research travel allowance. 3402.6 Section 3402.6 Agriculture Regulations of the.../dissertation research travel allowance. (a) For each USDA Graduate Fellow who desires to be considered for a special international study or thesis/dissertation research travel allowance, the Project Director...

  6. 7 CFR 3402.6 - Overview of the special international study and/or thesis/dissertation research travel allowance.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... thesis/dissertation research travel allowance. 3402.6 Section 3402.6 Agriculture Regulations of the... Overview of the special international study and/or thesis/dissertation research travel allowance. (a) For.../dissertation research travel allowance, the Project Director must apply to HEP for a supplemental grant...

  7. 7 CFR 3402.6 - Overview of the special international study and/or thesis/dissertation research travel allowance.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... thesis/dissertation research travel allowance. 3402.6 Section 3402.6 Agriculture Regulations of the... Overview of the special international study and/or thesis/dissertation research travel allowance. (a) For.../dissertation research travel allowance, the Project Director must apply to HEP for a supplemental grant...

  8. 7 CFR 3402.6 - Overview of the special international study and/or thesis/dissertation research travel allowance.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... thesis/dissertation research travel allowance. 3402.6 Section 3402.6 Agriculture Regulations of the... Overview of the special international study and/or thesis/dissertation research travel allowance. (a) For.../dissertation research travel allowance, the Project Director must apply to HEP for a supplemental grant...

  9. 7 CFR 3402.6 - Overview of the special international study and/or thesis/dissertation research travel allowance.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... thesis/dissertation research travel allowance. 3402.6 Section 3402.6 Agriculture Regulations of the... Overview of the special international study and/or thesis/dissertation research travel allowance. (a) For.../dissertation research travel allowance, the Project Director must apply to HEP for a supplemental grant...

  10. A Cross-Country Study on Research Students' Perceptions of the Role of Supervision and Cultural Knowledge in Thesis Development

    ERIC Educational Resources Information Center

    McGinty, Suzanne Claire; Koo, Yew Lie; Saeidi, Mahnaz

    2010-01-01

    This paper presents preliminary findings from a research study in Australia, Malaysia and Iran on students' perceptions of the roles of supervisor and student in the production of their thesis and the contribution of their cultural knowledge to thesis development. The 360 respondents who answered an online survey were studying for their Master's…

  11. Final Thesis Models in European Teacher Education and Their Orientation towards the Academy and the Teaching Profession

    ERIC Educational Resources Information Center

    Råde, Anders

    2014-01-01

    This study concerns different final thesis models in the research on teacher education in Europe and their orientation towards the academy and the teaching profession. In scientific journals, 33 articles support the occurrence of three models: the portfolio model, with a mainly teaching-professional orientation; the thesis model, with a mainly…

  12. Learning Cultures in Travel and Tourism: A Critique of Manuela du Bois-Reymond's Trendsetter Learner Thesis

    ERIC Educational Resources Information Center

    Morrison, Andrew

    2011-01-01

    This article aims to contribute to the discussion surrounding Manuela du Bois-Reymond's important "trendsetter learner" thesis and, in so doing, to join the wider debate about post-compulsory learning cultures. The article outlines the trendsetter learner thesis and then considers recent criticisms that it has attracted. While the author concurs…

  13. Measurement and simulation of the cross sections for nuclide production in {sup nat}W and {sup 181}Ta targets irradiated with 0.04- to 2.6-GeV protons

    SciTech Connect

    Titarenko, Yu. E. Batyaev, V. F.; Titarenko, A. Yu.; Butko, M. A.; Pavlov, K. V.; Florya, S. N.; Tikhonov, R. S.; Zhivun, V. M.; Ignatyuk, A. V.; Mashnik, S. G.; Leray, S.; Boudard, A.; Cugnon, J.; Mancusi, D.; Yariv, Y.; Nishihara, K.; Matsuda, N.; Kumawat, H.; Mank, G.; Gudowski, W.

    2011-04-15

    The cross sections for nuclide production in thin {sup nat}Wand {sup 181}Ta targets irradiated by 0.04-2.6-GeV protons have been measured by direct {gamma} spectrometry using two {gamma} spectrometers with the resolutions of 1.8 and 1.7 keV in the {sup 60}Co 1332-keV {gamma} line. As a result, 1895 yields of radioactive residual product nuclei have been obtained. The {sup 27}Al(p, x){sup 22}Na reaction has been used as a monitor reaction. The experimental data have been compared with the MCNPX (BERTINI, ISABEL), CEM03.02, INCL4.2, INCL4.5, PHITS, and CASCADE07 calculations.

  14. Measurement and simulation of the cross sections for nuclide production in {sup 93}Nb and {sup nat}Ni targets irradiated with 0.04- to 2.6-GeV protons

    SciTech Connect

    Titarenko, Yu. E. Batyaev, V. F.; Titarenko, A. Yu.; Butko, M. A.; Pavlov, K. V.; Florya, S. N.; Tikhonov, R. S.; Zhivun, V. M.; Ignatyuk, A. V.; Mashnik, S. G.; Leray, S.; Boudard, A.; Cugnon, J.; Mancusi, D.; Yariv, Y.; Nishihara, K.; Matsuda, N.; Kumawat, H.; Mank, G.; Gudowski, W.

    2011-04-15

    The cross sections for nuclide production in thin {sup 93}Nb and {sup nat}Ni targets irradiated by 0.04- to 2.6-GeV protons have been measured by direct {gamma} spectrometry using two {gamma} spectrometers with the resolutions of 1.8 and 1.7 keV in the {sup 60}Co 1332-keV {gamma} line. As a result, 1112 yields of radioactive residual nuclei have been obtained. The {sup 27}Al(p, x){sup 22}Na reaction has been used as a monitor reaction. The experimental data have been compared with the MCNPX (BERTINI, ISABEL), CEM03.02, INCL4.2, INCL4.5, PHITS, and CASCADE07 calculations.

  15. Photonuclear Studies for the Isomeric Yield Ratios in the Production of natFe(γ,xnp)52m,gMn with 50-,60-, and 70-MeV Bremsstrahlung

    NASA Astrophysics Data System (ADS)

    Shakilur Rahman, Md.; Kim, Guinyun; Kim, Kyung-Sook; Lee, Manwoo; Moinul Haque Meaze, A. K. M.

    2016-02-01

    The isomeric yield ratios in the production of natFe(γ,xnp)52m,gMn have been measured with photonuclear reactions. The high purity natural Fe metallic foils were used and irradiated with bremsstrahlung beams of end point energy 50-, 60-, and 70-MeV. The bremsstrahlung beams are produced with high energy electron beam struck with 0.1mm thin tungsten target. The activation method has been used and hence the induced activities in the irradiated foils were measured by off-line γ-ray spectrometric technique using HPGe detector coupled to a PC-based 4K MCA. The experimental values of isomeric ratios are compared with the theoretical values by statistical model code TALYS. The detail of the formation of isomers by photonuclear reactions together with the literature values of the investigated nuclides are compared and discussed.

  16. A numerical study of fundamental shock noise mechanisms. Ph.D. Thesis - Cornell Univ.

    NASA Technical Reports Server (NTRS)

    Meadows, Kristine R.

    1995-01-01

    The results of this thesis demonstrate that direct numerical simulation can predict sound generation in unsteady aerodynamic flows containing shock waves. Shock waves can be significant sources of sound in high speed jet flows, on helicopter blades, and in supersonic combustion inlets. Direct computation of sound permits the prediction of noise levels in the preliminary design stage and can be used as a tool to focus experimental studies, thereby reducing cost and increasing the probability of a successfully quiet product in less time. This thesis reveals and investigates two mechanisms fundamental to sound generation by shocked flows: shock motion and shock deformation. Shock motion is modeled by the interaction of a sound wave with a shock. During the interaction, the shock wave begins to move and the sound pressure is amplified as the wave passes through the shock. The numerical approach presented in this thesis is validated by the comparison of results obtained in a quasi-one dimensional simulation with linear theory. Analysis of the perturbation energy demonstrated for the first time that acoustic energy is generated by the interaction. Shock deformation is investigated by the numerical simulation of a ring vortex interacting with a shock. This interaction models the passage of turbulent structures through the shock wave. The simulation demonstrates that both acoustic waves and contact surfaces are generated downstream during the interaction. Analysis demonstrates that the acoustic wave spreads cylindrically, that the sound intensity is highly directional, and that the sound pressure level increases significantly with increasing shock strength. The effect of shock strength on sound pressure level is consistent with experimental observations of shock noise, indicating that the interaction of a ring vortex with a shock wave correctly models a dominant mechanism of shock noise generation.

  17. Improvement to low-level radioactive-waste vitrification processes. Master's thesis

    SciTech Connect

    Horton, W.S.

    1986-05-01

    Low-level radioactive waste vitrification (LLWV) is a technically feasible and cost-competitive alternative to the traditional immobilization options, i.e., cementation or bituminization. This thesis analyzes cementation, bituminization and vitrification, reviews the impact of the low-level Waste-stream composition on the vitrification process, then proposes and discusses several techniques to control the volatile radionuclides in a Process Improved LLWV system (PILLWV). The techniques that control the volatile radionuclides include chemical precipitation, electrodialysis, and ion exchange. Ion exchange is preferred. A comparison of the technical specifications, of the regulatory compliance, and of the cost considerations shows the PILLWV to be the superior LLW immobilization option.

  18. [Eleven thesis on the archive of scientific research, for a new patrimonial and scientific policy].

    PubMed

    Müller, Bertrand

    2015-12-01

    Abstracting the main content of a recent report on the bad state of the archives of scientific research, this paper puts forward eleven thesis likely to feed, in this time of numeric transition to a new documentary regime and to a new patrimonial policy. The recent numeric conditions impose to set new archival pratices, more proactive, anticipative and prospective. Archives of scientific research must be thought in a double memorial and scientific dimension, and not only as a patrimonial or historical one. PMID:26746647

  19. Design and implementation of a nuclear weapons management system submodule: Shipboard security force system. Master's thesis

    SciTech Connect

    Settlemyer, S.R.

    1991-09-01

    The Nuclear Weapons Management System combines the strengths of an expert system with the flexibility of a database management system to assist the Weapons Officer, Security Officer, and the Personnel Reliability Program Officer in the performance of administrative duties associated with the nuclear weapons programs in the United States Navy. This thesis examines the need for, and ultimately the design of, a system that will assist the Security Officer in administrative duties associated with the Shipboard Self Defense Force. This system, designed and coded utilizing dBASE IV, can be implemented as a stand alone system. Furthermore, it interfaces with the expert system submodule that handles the PRP screening process.

  20. Top tips for PhD thesis examination: nurse clinicians, researchers and novices.

    PubMed

    Cleary, Michelle; Horsfall, Jan; Hunt, Glenn E

    2012-01-01

    Interestingly, there are very few guidelines in the literature to assist novice nurse PhD examiners. In this paper, we aim to provide information to nurses, researchers or early career academics who have little experience in assessing a university thesis. The article provides background information about recent changes in the university sector; overviews some research on experienced examiners views; presents factors that differentiate between high and low quality PhD theses; and outlines some pointers that may be useful when marking at the doctoral level. PMID:21903305

  1. Indian naval development: Power projection in the Indian Ocean. Master's thesis

    SciTech Connect

    Haynes, A.M.

    1990-12-01

    This thesis examines the U.S.-India relationship in the context of a world power interacting with the predominant regional power. The growing Indian military's power projection and nuclear weapons capability make the Indian Ocean region a critical area for American foreign policy during the next decade. New Delhi's desire to be a hegemonic power in the region combined with the U.S. military drawdown in reaction to the changing strategic environment could threaten long-term U.S. interests. The United States can no longer afford to remain relatively disinterested in the region and must develop a comprehensive policy to promote regional security and stability.

  2. Intermediate design and analysis of the PANSAT electrical power subsystem. Master's thesis

    SciTech Connect

    Hand, G.F.

    1994-03-01

    This thesis examined three primary components of the electrical power subsystem (EPS) for the Petite Amateur Navy Satellite (PANSAT): (1) the solar array; (2) the power conditioning and control subsystem (PCCS); and (3) the batteries. The emphasis of this thesis was to analyze the output performance of the solar array. Additionally, the derivation of the hybrid PCCS proposed for the EPS was examined and the use of Nickel-Cadmium batteries as a candidate for the secondary power source was discussed. The investigation of the solar array's output performance led to PANSAM (PANSAT Solar Array Model), a computer model which simulates the power output of the solar array. The user can specify the sun's declination, the orbit's inclination, and the satellite's orientation and rate of rotation about each of its three axes. Once a simulation is complete, PANSAM provides the effective surface area illuminated by the sun, and the output current and power. The average effective area determined by PANSAM was 17.6% less than the 1259/sq cm originally proposed by the PANSAT staff. This contributed to a substantial reduction in predicted power. A preliminary transient thermal analysis of PANSAT was also conducted to provide temperature data for PANSAM.

  3. Environmental cost principle: Gone but not forgotten. Master`s thesis

    SciTech Connect

    Robb, J.L.

    1995-09-30

    This thesis has not focused on the myriad of environmental laws generating costs for government contractors. Compliance with such laws is not beyond the experience of government cost-reimbursement contracting. This thesis has not detailed the alternative to cost reimbursement; i.e., a contribution action against the United States for cleanup costs. Potential contribution action remains an issue when the contamination is related to the performance of a government contract. At the center of this analysis is the efficacy of the draft environmental cost principle. The draft cost principle forced the consideration of the many prickly issues that must someday be resolved. The draft cost principle is unlikely to return in present form. It may be gone, but it should not be forgotten. The environmental cost issues will resurface. Future attempts to address these issues will benefit from the careful consideration of the latest draft environmental cost principle. The core questions to be answered are what would be the impact of the cost principle on the treatment of various environmental costs, and whether such impact is for the good.

  4. Want to improve undergraduate thesis writing? Engage students and their faculty readers in scientific peer review.

    PubMed

    Reynolds, Julie A; Thompson, Robert J

    2011-01-01

    One of the best opportunities that undergraduates have to learn to write like a scientist is to write a thesis after participating in faculty-mentored undergraduate research. But developing writing skills doesn't happen automatically, and there are significant challenges associated with offering writing courses and with individualized mentoring. We present a hybrid model in which students have the structural support of a course plus the personalized benefits of working one-on-one with faculty. To optimize these one-on-one interactions, the course uses BioTAP, the Biology Thesis Assessment Protocol, to structure engagement in scientific peer review. By assessing theses written by students who took this course and comparable students who did not, we found that our approach not only improved student writing but also helped faculty members across the department--not only those teaching the course--to work more effectively and efficiently with student writers. Students who enrolled in this course were more likely to earn highest honors than students who only worked one-on-one with faculty. Further, students in the course scored significantly better on all higher-order writing and critical-thinking skills assessed. PMID:21633069

  5. Privatization of utilities in government owned housing: A model approach. Master`s thesis

    SciTech Connect

    Autrey, J.L.

    1997-06-01

    This thesis examines the option of privatizing electricity and gas utilities, requiring residents of Navy Family Housing (NFH) to pay for all consumption. To assist in the payment, an Utility Housing Allowance (UHA) would be provided to residents based on the average consumption of local Private Sector Housing (PSH) residents. The goal of this thesis is to determine if implementing an UHA would reduce the overall energy consumption in NFH. Specifically, it determines the historical usage of electricity and gas in the Naval Postgraduate School`s La Mesa housing village (LMV) area and the local PSH areas. It then develops forecasting models for both areas to predict the future consumption of utilities, sets a baseline consumption rate for LMV residents, and identifies the savings that would be generated from implementing the UHA program. After validating the forecasting models and comparing costs under the UHA concept, this study concludes that the UHA concept would save approximately $268,300 annually at LMV alone. Additionally, in meeting the Navy`s Year 2005 goal of reducing energy consumption by 30% per square foot, by implementing an UHA concept, the projected savings in LMV alone are approximately 50% per square foot/month. Although the study focuses on LMV, it is assumed that similar energy inefficiencies are being demonstrated in other NFH areas. Therefore, this study provides the necessary steps to conduct comparative analysis in other NFH areas.

  6. [The thesis of judicialization of health care by the elites: medication for mucopolysaccharidosis].

    PubMed

    Medeiros, Marcelo; Diniz, Debora; Schwartz, Ida Vanessa Doederlein

    2013-04-01

    This paper evaluates the hypothesis that the judicialization of medicine for mucopolysaccharidosis in Brazil is an action promoted by economic elites. Previous studies upholding the thesis of judicialization by elites in the case of other types of medication that are more costly for the Unified Health Service are discussed. An analysis of all 196 processes containing information about judicial processes brought to court between February 2006 and December 2010 that ended by determining that the State should provide such medication free of charge to patients was conducted. There is evidence that attorneys' fees were covered by entities interested in the results of judicialization, such as the distributors or pharmaceutical industries. Patients may also be migrating for diagnosis and treatment to university centers that are a benchmark for medical innovation in the country, as the option for public health services is related to their higher technical and scientific capacity. Therefore, the resort to private lawyers, indicators of social exclusion based on the address of patients and the use of public health services, are not adequate class information to corroborate or refute the thesis of judicialization by the elites. PMID:23670386

  7. A doctoral thesis about Carol Davila written in Paris in 1936.

    PubMed

    Rogozea, Liliana; Dumitrascu, Dinu I; Triff, Dorin; Leasu, Florin; Dumitraşcu, Dan L

    2014-01-01

    Carol Davila, the father of the Romanian modern medicine, made decisive contributions to the development of health sciences in the Romanian Principalities in the last decades of the nineteenth century. The merit of his scientific work was recognized beyond the borders of his country. His life (not devoid of anecdotic instances and unknown episodes) and especially his work have aroused considerable interest among numerous medical historians. This paper presents a historical study elaborated in France, but until recently ignored, dedicated to the biography of Carol Davila. It concerns the medical doctoral thesis (State Diploma) elaborated by Joseph Adler (born 1910 in Botoşani, Romania) under the supervision of professor Maxime Laignel-Lavastine, whose interest in Romania is well-known. Professor Laignel-Lavastine held the office of Secretary General of the International Society of History of Medicine (ISHM), founded in 1921, (replaced in this position by another French professor with links to Romania: Jules Guiart). The thesis comprises 48 pages and an exhaustive bibliography. It represents a token of the appreciation given to Davila's achievements by Europe's medical community. PMID:26527997

  8. Optimizing the post-START (Strategic Arms Reduction Treaty) US strategic nuclear force mix. Master's thesis

    SciTech Connect

    Leary, D.A.

    1989-06-01

    This thesis examines the impact a START agreement might have on the United States and Soviet strategic nuclear forces. It then proposes an optimum post-START force mix for the United States and the Soviet Union. The current, as well as projected, post-START targeting policies are discussed. It is concluded that the impact of a START agreement on the current U.S. strategic targeting policy will be minimal. Although the target data base will not shrink as much as the forces tasked to cover it, a prioritization of targets is all that should be necessary with a post-START force. A START agreement will mean major reductions in U.S. and Soviet strategic nuclear forces. As proposed in this thesis, only the ICBM leg of the Triad will require any major re-structuring. This would include the addition of mobile ICBM systems. The SLBM and bomber legs will feel minimal changes (i.e., retiring POSEIDON SSBNs and retiring or converting some older B-52s). It is recommended that the B-52 program be cancelled, and funding be re-directed into mobile ICBM systems. By doing so the United States could utilize technology available today to strengthen its forces and not gamble on the low-observable technology which a stealth bomber might have.

  9. Indo-Pakistani nuclear issue: A US policy perspective. Master's thesis

    SciTech Connect

    Wolf, J.L.

    1992-06-01

    This thesis examines U.S. nonproliferation policy and the problem of nuclear proliferation in India and Pakistan. Its central hypothesis is that the end of the Cold War has created an opportunity to advance U.S. nonproliferation interests and work with both India and Pakistan to reduce the threat of a nuclear confrontation on the Indian Subcontinent. The thesis assesses both the motives for and the current status of the nuclear weapons programs in India and Pakistan. It also presents some plausible scenarios concerning future courses those programs could take. Finally, it presents a set of policy recommendations directed toward reducing Indo-Pakistani nuclear tensions and laying the foundations to make a future South Asian nuclear nonproliferation regime possible. Ultimately, this approach would create safer, more stable security arrangements for India and Pakistan and further reduce the threat from nuclear weapons in the post-Cold War world. United States, India, Pakistan, U.S.-Indian Relations, U.S.-Pakistan Relations, Nuclear Weapons, Nonproliferation, U.S. Foreign Policy.

  10. Radiation and scattering from cylindrically conformal printed antennas. Ph.D. Thesis Final Report

    NASA Technical Reports Server (NTRS)

    Kempel, Leo C.; Volakis, John L.

    1994-01-01

    Microstrip patch antennas offer considerable advantages in terms of weight, aerodynamic drag, cost, flexibility, and observables over more conventional protruding antennas. These flat patch antennas were first proposed over thirty years ago by Deschamps in the United States and Gutton and Baisinot in France. Such antennas have been analyzed and developed for planar as well as curved platforms. However, the methods used in these designs employ gross approximations, suffer from extreme computational burden, or require expensive physical experiments. The goal of this thesis is to develop accurate and efficient numerical modeling techniques which represent actual antenna structures mounted on curved surfaces with a high degree of fidelity. In this thesis, the finite element method is extended to cavity-backed conformal antenna arrays embedded in a circular, metallic, infinite cylinder. Both the boundary integral and absorbing boundary mesh closure conditions will be used for terminating the mesh. These two approaches will be contrasted and used to study the scattering and radiation behavior of several useful antenna configurations. An important feature of this study will be to examine the effect of curvature and cavity size on the scattering and radiation properties of wraparound conformal antenna arrays.

  11. A doctoral thesis about Carol Davila written in Paris in 1936

    PubMed Central

    ROGOZEA, LILIANA; DUMITRASCU, DINU I.; TRIFF, DORIN; LEASU, FLORIN; DUMITRAŞCU, DAN L.

    2014-01-01

    Carol Davila, the father of the Romanian modern medicine, made decisive contributions to the development of health sciences in the Romanian Principalities in the last decades of the nineteenth century. The merit of his scientific work was recognized beyond the borders of his country. His life (not devoid of anecdotic instances and unknown episodes) and especially his work have aroused considerable interest among numerous medical historians. This paper presents a historical study elaborated in France, but until recently ignored, dedicated to the biography of Carol Davila. It concerns the medical doctoral thesis (State Diploma) elaborated by Joseph Adler (born 1910 in Botoşani, Romania) under the supervision of professor Maxime Laignel-Lavastine, whose interest in Romania is well-known. Professor Laignel-Lavastine held the office of Secretary General of the International Society of History of Medicine (ISHM), founded in 1921, (replaced in this position by another French professor with links to Romania: Jules Guiart). The thesis comprises 48 pages and an exhaustive bibliography. It represents a token of the appreciation given to Davila’s achievements by Europe’s medical community. PMID:26527997

  12. THE WEBER THESIS OF CALVINISM AND CAPITALISM--ITS VARIOUS VERSIONS AND THEIR "FATE" IN SOCIAL SCIENCE.

    PubMed

    Zafirovski, Milan

    2016-01-01

    The paper identifies and examines various multiple renditions of the so-called Weber Thesis of an historical association and convergence between ascetic Protestantism, above all Calvinism, and the emergence and development of modern capitalism as an economic spirit and system. Specifically, it detects at least four different versions and formulations or interpretations, thus casting doubt in the common view of the Weber Thesis as a single and monolithic theory or hypothesis. The paper also considers the status of the multiple versions of the Weber Thesis in post-Weberian and contemporary sociology and related disciplines like economics and history. It concludes that the weaker, relaxed renditions of the Weber Thesis have attained a greater success and more endured in contemporary social science than have its stronger, stricter versions. PMID:26550794

  13. Unified approach to the analysis and synthesis of systolic arrays. Master's thesis

    SciTech Connect

    Hornick, S.W.

    1985-04-01

    This thesis takes the first steps toward the development of a theoretical framework to unify the analysis and synthesis of systolic networks. A class of transformations on systolic networks is described that alter the topology of a network while preserving the timing of its computations. These transformations may be used to demonstrate the equivalence of two existing systolic designs or to obtain a new design from an existing one, according to particular design specifications. The model of a systolic network is presented, and the parameters are identified that are used to characterize one. Next, the author proves the correctness of two types of transformations on these parameters. He shows how these transformations can account for different processor types and multiple-processor states. Finally, he demonstrates these transformations and characterizes those that avoid the phenomenon of crossing.

  14. Decision support system for control and automation of dynamical processes. Master's thesis

    SciTech Connect

    Nann, S.

    1990-03-01

    The thesis presents the concept and development of a diagnostic decision support system for real-time control and automation of dynamic processes. This system, known as DECA (Diagnostic Evaluation and Corrective Action), will take advantage of the computer's ability to manipulate vast amounts of data, and employ qualitative reasoning for the monitoring and diagnosis of dynamical processes during time-constrained, routine, and emergency situations where an immediate response is necessary to avoid catastrophic failure of the system. The software system's architecture has been structured in such a manner that is can be applied to any dynamic process without reprogramming. DECA is written in Lisp and was verified using the data from the Three Mile Island Nuclear Reactor Accident.

  15. Dependability analysis of parallel systems using a simulation-based approach. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Sawyer, Darren Charles

    1994-01-01

    The analysis of dependability in large, complex, parallel systems executing real applications or workloads is examined in this thesis. To effectively demonstrate the wide range of dependability problems that can be analyzed through simulation, the analysis of three case studies is presented. For each case, the organization of the simulation model used is outlined, and the results from simulated fault injection experiments are explained, showing the usefulness of this method in dependability modeling of large parallel systems. The simulation models are constructed using DEPEND and C++. Where possible, methods to increase dependability are derived from the experimental results. Another interesting facet of all three cases is the presence of some kind of workload of application executing in the simulation while faults are injected. This provides a completely new dimension to this type of study, not possible to model accurately with analytical approaches.

  16. Utility cost accounting and market pricing of electricity at the Naval Postgraduate School. Master's thesis

    SciTech Connect

    Murdter, M.J.

    1994-06-01

    This thesis demonstrates that significant cost savings may be realized at the Naval Postgraduate School by accounting for utilities costs with market pricing methods instead of engineering estimates of consumption for nonmetered users and by streamlining the current invoice processing procedures. Electricity demand curves for each element of the supplier rate structure were constructed from recent consumption data and price elasticities of demand from the literature. The deadweight losses from overconsumption were calculated and compared to the costs of installing meters capable of recording time-of-use and peak demand. The current invoice processing procedures were analyzed and spreadsheet tools were developed to streamline the processes and avoid interest charges from late payment. The results of the research indicate that market pricing of electricity and accelerated invoice processing would result in significant savings to the Naval Postgraduate School. Utilities, Electricity, Deadweight loss.

  17. Design and implementation of a Multimedia DBMS: Sound management integration. Master's thesis

    SciTech Connect

    Atila, Y.V.

    1990-12-01

    Today, in addition to standard data like numerics and alphanumerics, it is possible to capture, sort, manage, retrieve and present different media information, e.g. sound, image, graphics, text and signals, by using the current, modern computer technology. The Multimedia Database Management System (MDBMS) project, which started at the Computer Science Department of the Naval Postgraduate School in 1988, studies not only the storing, managing and retrieving different media information, but also the management of the interrelationships among the data. This thesis concentrates on the Sound Management Integration of the MDBMS prototype, which includes the storage and management of the sound records in an IBM compatible personal computer, and the connection and integration of it to the database system in the SUN environment through a local area network, after presenting the general overview of the MDBMS, the system environment, the user interface and the catalog designs.

  18. Origin and evolution of US Naval strategic nuclear policy to 1960. Master's thesis

    SciTech Connect

    Kreitlein, H.C.

    1986-12-01

    This thesis treats the impact of the atomic bomb on traditional naval strategy as that strategy had developed under the influence of Captain Alfred T. Mahan, how traditional naval strategy was modified by the development of naval aviation, the lessons of World War II, and the leadership of James Forrestal, and how the adoption of atomic weapons into naval strategic planning was integrally tied to naval aviation. The growth of the Soviet Union as a threat to world peace, and interservice rivalry over roles and missions are compared as factors that influenced the development of post-World War II naval strategic thinking. The Navy's reaction to the adoption of massive retaliation as the foundation of the national strategic nuclear policy is discussed and analyzed.

  19. Deregulation of electric utilities in California and its effect on navy installations. Master`s thesis

    SciTech Connect

    O`Shea, P.J.

    1997-06-01

    On January 1, 1998, California will be the first state to deregulate its electricity industry. Deregulation is expected to reduce the high rates paid throughout the state by allowing competition, not regulators, to determine rates. Deregulation will dissolve the monopoly of the electricity industry by allowing customers to choose who will supply their electricity. Competition will emerge in the generation market, where transactions between consumers and suppliers will be free and open. Under regulation, most customers do not have a choice in their electricity supplier. Their supplier is usually determined by their geographic location. This thesis researches the differences between the regulated and deregulated rate structures and provides a cost comparison for a Navy organization classified as a large commercial/industrial user of electricity. There are many aspects of deregulation that are not yet determined, but the initial comparison indicates deregulation may save Navy installations money. If deregulation progresses as planned, additional future saving may occur.

  20. A matrix safety frame approach to robot safety for space applications. Thesis

    NASA Technical Reports Server (NTRS)

    Montgomery, T. D.; Lauderbaugh, L. Ken

    1988-01-01

    The planned use of autonomous robots in space applications has generated many new safety problems. This thesis assesses safety of autonomous robot systems through the structure of a proposed three-dimensional matrix safety frame. By identifying the common points of accidents and fatalities involving terrestrial robots, reviewing terrestrial robot safety standards, and modifying and extending these results to space applications, hazards are identified and their associated risks assessed. Three components of the safeguarding dimension of the matrix safety frame, safeguarding through design and operation for intrinsic safety, and incorporation of add-on safety systems are explained through examples for both terrestrial and space robots. A space robot hazard identification checklist, a qualitative tool for robot systems designers, is developed using the structure imparted by the matrix safety frame. The development of an expert system from the contents of the checklist is discussed.

  1. Quantification for complex assessment: uncertainty estimation in final year project thesis assessment

    NASA Astrophysics Data System (ADS)

    Kim, Ho Sung

    2013-12-01

    A quantitative method for estimating an expected uncertainty (reliability and validity) in assessment results arising from the relativity between four variables, viz examiner's expertise, examinee's expertise achieved, assessment task difficulty and examinee's performance, was developed for the complex assessment applicable to final year project thesis assessment including peer assessment. A guide map can be generated by the method for finding expected uncertainties prior to the assessment implementation with a given set of variables. It employs a scale for visualisation of expertise levels, derivation of which is based on quantified clarities of mental images for levels of the examiner's expertise and the examinee's expertise achieved. To identify the relevant expertise areas that depend on the complexity in assessment format, a graphical continuum model was developed. The continuum model consists of assessment task, assessment standards and criterion for the transition towards the complex assessment owing to the relativity between implicitness and explicitness and is capable of identifying areas of expertise required for scale development.

  2. Thesis - keeping the management system {open_quotes}live{close_quotes} and reaching the workforce

    SciTech Connect

    Primrose, M.J.; Bentley, P.D.; Graaf, G.C. van der

    1996-12-31

    Previous papers given to SPE conferences have described the Shell Group approach to Safety Management Systems and to Safety Cases. Their extension to HSE MS and to HSE Cases has also been addressed. Since 1984 the Enhanced Safety Management (ESM) programme within Shell companies has led to a significant improvement in the management of safety but it was only when structured management systems (based upon an understanding of the business processes) were introduced that true integration of HSE as a line responsibility became a reality. This paper describes the THESIS software package and the way that management systems have been made {open_quote}live{close_quote} and how workforce involvement can be demonstrated.

  3. [Building knowledge in collective health: an analysis of thesis and dissertations].

    PubMed

    Egry, Emiko Yoshikawa; da Fonseca, Rosa Maria Godoy Serpa; Bertolozzi, Maria Rita; de Oliveira, Maria Amélia Campos; Takahashi, Renata Ferreira

    2005-12-01

    The aim of this study was to analyze scientific production in Collective Health developed by Collective Health Nursing Department of the School of Nursing Sao Paulo University within 1992 and 2004. A total of 86 master dissertations and doctoral thesis were produced, concerning a variety of study objects, mainly epidemiologic profiles and social reproduction, connected to health-illness processes of social groups. Qualitative analysis predominated, as well as the historical and dialectical theoretical referential. Empirical data were obtained predominantly from different social groups of specific territories. The adoption of analytical categories such as social production and reproduction, gender and generation enabled approaching to comprehend and propose intervention on the study objects, thus improving Collective Health scientific knowledge. PMID:16440947

  4. Analysis of the asbestos permissible-exposure-level threshold standard. Master's thesis

    SciTech Connect

    Peterson, M.W.

    1991-06-01

    This thesis examines the reasoning of the Occupational Safety and Health Administration's (OSHA) decision to set stringent exposure levels for airborne asbestos in the work place. Technical recommendations from the National Institute for Occupational Safety and Health (NIOSH), the Bureau of Mines, and the American conference of Governmental Industrial Hygienists were presented to OSHA for consideration. OSHA and the Environmental Protection Agency (EPA) set industry standards for permissible exposure levels (PEL) of airborne asbestos. Exposure to asbestos poses a health hazard to workers, their families, and consumers of asbestos products. Because it poses an unreasonable risk human life, OSHA has repeatedly lowered the Permissible Exposure Levels and the EPA will ban the manufacture, importation, processing and commercial distribution of asbestos containing products from the United States in phases by 1997. These decisions may have been made too hastily because of the long latency (15-40 years) period before cancer develops, and the added risks that smoking imposes.

  5. Analyzing remediation technologies for Department of Energy sites contaminated with DNAPL pollutants. Master`s thesis

    SciTech Connect

    Papatyi, A.F.

    1997-03-01

    The Department of Energy is in the process of conducting a Remedial Investigation/Feasibility Study for a site contaminated with Dense Non-Aqueous Phase Liquid (DNAPL) pollutants at their Paducah Kentucky facility. This thesis effort focuses on acquiring insight into a number of remediation technology trains that are candidates for the Paducah site. This insight is used to recommend and justify the screening of candidate technology trains. The research makes use of two decision analysis models (one is deterministic, the other is probabilistic) built to provide a quantitative assessment of the candidate technology trains. Dominance considerations and multi-attribute utility theory are utilized to make the quantitative assessments and to gain insight into each candidate technology train. The results of the analysis provide the DOE with a rational justification for screening 55 of the 58 candidate technology trains from further consideration.

  6. Distributed ray casting for high-speed volume rendering. Master's thesis

    SciTech Connect

    Brightbill, P.L.

    1992-01-01

    The volume rendering technique known as ray casting or ray tracing is notoriously slow for large volume sizes, yet provides superior images. A technique is needed to accelerate ray tracing volumes without depending on special purpose or parallel computers. The realization and improvements in distributed computing over the past two decades has motivated its use in this work. This thesis explores a technique to speedup ray casting by distributed programming. The work investigates the possibility of dividing the volume among general purpose workstations and casting rays (using Levoy's front-to-back algorithm) through each subvolume independently. The final step being the composition of all subvolume rendered images. Results indicate a 75 percent savings in rendering time by distributed processing over eight processors versus a single processor.

  7. Proposal for a longitudinal study to assess the hazards of radiation in space flight. Master's thesis

    SciTech Connect

    Reeves, G.I.

    1985-06-01

    This thesis involves the establishment of a registry of all United States astronuats, past and future, plus non-astronaut controls. The registry will record the incidences of malignant neoplastic disease and diabetes mellitus, and the space radiation exposure received. Data will be carefully analyzed to see if there is a dose-related increase in these diseases related to the exposure to ionizing radiation, with an eventual goal of establishing reliable risk estimates related to dose received. The history of cancer related to radiation exposure is summarized, and the space radiation environment briefly described. Physiological changes accompanying space flight and their potential effects on radiation tolerance and carcinogenesis are discussed. The reasons why data from animal experiments and human occupational, medical, and nuclear-weapon exposure cannot be extrapolated to the long-term health risks of astronauts are discussed at length, and the study instruments for establishing a long-term descriptive surveillance study are described.

  8. The Antarctic Ice Sheet during the last Interglaciation: Insights from my Thesis

    NASA Astrophysics Data System (ADS)

    Whipple, Matthew; Lunt, Dan; Singarayer, Joy; Bradley, Sarah; Milne, Glenn; Wolff, Eric; Siddall, Mark

    2015-04-01

    The last interglaciation represents a period of warmer climates and higher sea levels, and a useful analogue to future climate. While many studies have focussed on the response of the Greenland Ice sheet, far less is known about the response of the Antarctic ice sheet. Here, I present the summarised results of my PhD thesis "Constraints on the minimum extent of the Antarctic ice sheet during the last interglaciation". Firstly, I cover the timings of interglaciation in Antarctica, and their differences with respect to the Northern Hemisphere timings, based on paleo sea level indicators, and oceanic temperature records. I move on to cover climate forcings, and how they influence the ice sheet, relative to present, and early Holocene. Secondly, I present thesis results, from looking at ice core stable water isotopes. These are compared with Isostatic and Climatic modelling results, for various different Ice sheet scenarios, as to the resulting Climate, from changes in Elevation, Temperature, Precipitation, and Sublimation, all contributing to the recorded stable water isotope record. Thirdly, I move on to looking at the mid-field relative sea level records, from Australia and Argentina. Using isostatic modelling, these are used to assess the relative contribution of the Eastern and Western Antarctic Ice sheets. Although data uncertainties result in us being to identify the contribution from West Antarctica. Overall, using model-data comparison, we find a lack of evidence for a substantial retreat of the Wilkes Subglacial basin. No data location is close enough to determine the existence of the marine based West Antarctic Ice sheet. Model uncertainty is unable to constrain evidence of variations in ice thickness in East Antarctica.

  9. Deep venous thrombosis: The valve cusp hypoxia thesis and its incompatibility with modern orthodoxy.

    PubMed

    Malone, P Colm; Agutter, Paul S

    2016-01-01

    The valve cusp hypoxia thesis (VCHT) of the aetiology of deep venous thrombosis (DVT) was adumbrated in this journal in 1977 and fully articulated in 2008, the original hypothesis having been strongly corroborated by experiments published in 1981 and 1984. It presents a unitary account of the pathogenesis of venous thrombosis and embolism that is rooted in the pathophysiological tradition of Hunter, Virchow, Lister, Welch and Aschoff, a tradition traceable back to Harvey. In this paper we summarise the thesis in its mature form, consider its compatibility with recent advances in the DVT field, and ask why it has not yet been assimilated into the mainstream literature, which during the past half century has been dominated by a haematology-orientated 'consensus model'. We identify and discuss seven ways in which the VCHT is incompatible with these mainstream beliefs about the aetiology of venous thrombosis, drawing attention to: (1) the spurious nature of 'Virchow's triad'; (2) the crucial differences between 'venous thrombus' and 'clot'; the facts that (3) venous thrombi form in the valve pockets (VVPs), (4) DVT is not a primarily haematological condition, (5) the so-called 'thrombophilias' are not thrombogenic per se; (6) the conflict between the single unitary aetiology of DVT and the tacit assumption that the condition is 'multicausal'; (7) the inability of anticoagulants to prevent the initiation of venous thrombogenesis, though they do prevent the growth of thrombi to clinically significant size. In discussing point (7), we show that the VCHT indicates new approaches to mechanical prophylaxis against DVT. These approaches are then formulated as experimentally testable hypotheses, and we suggest methods for testing them preclinically using animal trials. PMID:26804599

  10. [Historical studies and medicine. A study in Swedish doctoral thesis concerning history of medicine 1970-2004].

    PubMed

    Qvarsell, Roger

    2006-01-01

    This article is a study in ninety doctoral thesis published in Sweden between 1970 and 2004 concerning history of the science of medicine and hospital care, patients and practicioners, causes of death and public health, doctors and nurses, health movements and lay medicine and other aspects of the history of medicine. A quantitative part of the study shows that most thesis have been written at departments of history or history of ideas, but sociological and mulitdisciplinary studies are also rather common. Only six of the thesis have been written at departments within the medical faculties. The second half of the 19th and the first half of the 20th centuries has been investigated more often than other historical periods. More than ninety percent of the thesis has been published in Swedish and concerns history of medicine in Sweden. A wide range of methods and theories has been used and history of medicine does not as a field deviate from historical research in general in this respect. A chronological bibliography of the ninety thesis ends the article. PMID:17575638

  11. Measurements of production cross sections of 10Be and 26Al by 120 GeV and 392 MeV proton bombardment of 89Y, 159Tb, and natCu targets

    DOE PAGESBeta

    Sekimoto, S.; Okumura, S.; Yashima, H.; Matsushi, Y.; Matsuzaki, H.; Matsumura, H.; Toyoda, A.; Oishi, K.; Matsuda, N.; Kasugai, Y.; et al

    2015-08-12

    The production cross sections of 10Be and 26Al were measured by accelerator mass spectrometry using 89Y, 159Tb, and natCu targets bombarded by protons with energies Ep of 120 GeV and 392 MeV. The production cross sections obtained for 10Be and 26Al were compared with those previously reported using Ep = 50 MeV–24 GeV and various targets. It was found that the production cross sections of 10Be monotonically increased with increasing target mass number when the proton energy was greater than a few GeV. On the other hand, it was also found that the production cross sections of 10Be decreased asmore » the target mass number increased from that of carbon to those near the mass numbers of nickel and zinc when the proton energy was below approximately 1 GeV. They also increased as the target mass number increased from near those of nickel and zinc to that of bismuth, in the same proton energy range. Similar results were observed in the production cross sections of 26Al, though the absolute values were quite different between 10Be and 26Al. As a result, the difference between these production cross sections may depend on the impact parameter (nuclear radius) and/or the target nucleus stiffness.« less

  12. NO3- Coordination in Aqueous Solutions by 15N/14N and 18O/natO Isotopic Substitution: What Can We Learn from Molecular Simulation?

    SciTech Connect

    Chialvo, Ariel A.; Vlcek, Lukas

    2014-12-16

    We explore the deconvolution of the water-nitrate correlations by the first-order difference approach involving neutron diffraction of heavy- and null-aqueous solutions of KNO3 under 14N 15N and natON 18ON substitutions to achieve a full characterization of the first water coordination around the nitrate ion. For that purpose we performed isobaric-isothermal simulations of 3.5m KNO3 aqueous solutions at ambient conditions to generate the relevant radial distribution functions (RDF) required in the analysis (a) to identify the individual partial contributions to the total neutron weighted distribution function, (b) to isolate and assess the contribution of NO3 -!K+ pair formation, (c) to test the accuracy of the NDIS-based coordination calculations and XRDbased assumptions, and (d) to describe the water coordination around both the nitrogen and oxygen sites of the nitrate ion.

  13. Exclusive studies of 130-270 MeV {sup 3}He- and 200-MeV proton-induced reactions on {sup 27}Al, {sup nat}Ag, and {sup 197}Au

    SciTech Connect

    Ginger, D. S.; Kwiatkowski, K.; Wang, G.; Hsi, W.-C.; Hudan, S.; Cornell, E.; Souza, R. T. de; Viola, V. E.; Korteling, R. G.

    2008-09-15

    Exclusive light-charged-particle and IMF spectra have been measured with the ISiS detector array for bombardments of {sup 27}Al, {sup nat}Ag, and {sup 197}Au nuclei with 130-270-MeV {sup 3}He and 200-MeV protons. The results are consistent with previous interpretations based on inclusive data that describe the global yield of complex fragments in terms of a time-dependent process. The emission mechanism for energetic nonequilibrium fragments observed at forward angles with momenta up to twice the beam momentum is also investigated. This poorly understood mechanism, for which the angular distributions indicate formation on a time scale comparable to the nuclear transit time, are accompanied primarily by thermal-like emissions. The data are most consistent with a schematic picture in which nonequilibrium fragments are formed in a localized region of the target nucleus at an early stage in the energy-dissipation process, where the combined effects of high energy density and Fermi motion produce the observed suprathermal spectra.

  14. Study of the peripheral projectile-like fragments from the reaction {sup 129}Xe on {sup 27}Al, {sup nat}Cu, {sup 139}La and {sup 165}Ho, at E/A = 50 MeV

    SciTech Connect

    Garcia-Solis, E.J.; Russ, D.E.; Madani, H.

    1996-02-01

    There are several reaction mechanisms identified for peripheral heavy-ion collisions. For low bombarding energies (E/A {approx} 10 MeV) the predominant reaction channel is the deep-inelastic reaction mechanism. In this process, the projectile and target form a rotating binary system, interchanging nucleons and angular momentum until they separate. At higher bombarding energies (E/A {approx} 50 to 100 MeV) incomplete fusion is thought to be the prevailing reaction channel. In this type of interaction part of the projectile merges with the target during the collision. Finally, for energies greater than 100 MeV/A, the main reaction channel is characterized by the formation of a highly-excited separate fragment (fireball) produced during the overlap between the projectile and the target. The data set studied was from an experiment designed to characterize the projectile-like products of the {sup 27}Al, {sup nat}Cu, {sup 139}La, and {sup 165}Ho reactions at E/A = 50 MeV, which was performed at the Michigan State University Super Cyclotron Laboratory (MSU-NSCL). The Maryland Forward Array (MFA), was used to measure projectile-like fragments in coincidence with target-like fragments and light-charge particles in the MSU 4{pi} detector.

  15. Experimental cross-sections of deuteron-induced reaction on 89Y up to 20 MeV; comparison of natTi(d,x)48V and 27Al(d,x)24Na monitor reactions

    NASA Astrophysics Data System (ADS)

    Lebeda, Ondřej; Štursa, Jan; Ráliš, Jan

    2015-10-01

    We measured cross-sections of the deuteron-induced reactions on 89Y in the energy range of 3.9-19.5 MeV. Excitation functions for formation of 88Zr, 89mZr, 89Zr, 88Y, 90mY and 87mSr were determined and compared with previously published data and prediction of the TALYS code. Thick target yields for production of 88Zr, 89Zrcum, 88Y, 90mY and 87mSr were calculated from the measured cross-sections. Achievable activity versus radionuclidic purity of medically relevant 89Zr is discussed and compared with the production via the 89Y(p,n) reaction. Parallel use of titanium and aluminium beam monitors revealed systematic difference between the recommended cross-sections of both monitoring reactions and provided new cross-section data for formation of 24Na, 27Mg, 43Sc, 44mSc, 44Sc, 46Sc, 47Sc and 48Sc. The cross-sections for the natTi(d,x)46Sc reactions agree very well with recently proposed recommended values.

  16. Complete and incomplete momentum transfer components in the [sup nat]Si([sup 16]O,[ital X]) reaction at 96. 4, 112. 4, and 127. 8 MeV

    SciTech Connect

    Zingarelli, R.A.; Dennis, L.C.; Tiede, M.A.; Kline, R.C.; Kemper, K.W.; Mitchell, S.V. )

    1993-08-01

    Angular distributions and inclusive energy spectra of isotopes with masses 23--41 were measured for the reaction [sup nat]Si([sup 16]O,[ital X]) at bombarding energies of 96.4, 112.4, and 127.8 MeV. Complete and incomplete projectile momentum transfer components of the resulting velocity distributions were separated by kinematic transforms which rely on an angular distribution function fitted to the data using center-of-mass frame symmetry conditions. Characteristics of the extracted complete momentum transfer component spectra, mass distributions, and laboratory frame angular distributions are consistent with fusion-evaporation models. Comparison with the Glas-Mosel parametrization and predictions for the angular momentum barrier to fusion indicate that at 112.4 and 127.8 MeV, competing entrance channel processes, rather than compound nucleus formation limits, restrict the fusion cross section. Spectra and cross sections of the incomplete momentum transfer component are consistent with sequential two-body breakup/fusion calculations.

  17. Complete and incomplete momentum transfer components in the natSi(16O,X) reaction at 96.4, 112.4, and 127.8 MeV

    NASA Astrophysics Data System (ADS)

    Zingarelli, R. A.; Dennis, L. C.; Tiede, M. A.; Kline, R. C.; Kemper, K. W.; Mitchell, S. V.

    1993-08-01

    Angular distributions and inclusive energy spectra of isotopes with masses 23-41 were measured for the reaction natSi(16O,X) at bombarding energies of 96.4, 112.4, and 127.8 MeV. Complete and incomplete projectile momentum transfer components of the resulting velocity distributions were separated by kinematic transforms which rely on an angular distribution function fitted to the data using center-of-mass frame symmetry conditions. Characteristics of the extracted complete momentum transfer component spectra, mass distributions, and laboratory frame angular distributions are consistent with fusion-evaporation models. Comparison with the Glas-Mosel parametrization and predictions for the angular momentum barrier to fusion indicate that at 112.4 and 127.8 MeV, competing entrance channel processes, rather than compound nucleus formation limits, restrict the fusion cross section. Spectra and cross sections of the incomplete momentum transfer component are consistent with sequential two-body breakup/fusion calculations.

  18. Net effect of many gravitational fields on the intensity of celestial light sources. Master's thesis

    SciTech Connect

    Cipperly, G.E.

    1982-12-01

    This thesis investigates the lens-like action of the gravitational fields of celestial bodies, which can alter the apparent intensity of more distant sources. Previous work in this area has shown that the chance of an individual body being sufficiently well aligned with a source to cause a very large gravitational intensity change is small. The issue addressed in this study is the possibility of there being a significant total change in the intensity of a source due to the combined effects of the gravitational fields of all celestial bodies, and in particular, the potential impact on intensity distance measurements, that is, determination of the distances of celestial light sources by means of intensity comparisons. It is first shown that the problem can be treated in flat space by associating an appropriate index of refraction with gravitational fields. A wave approach is taken in deriving the total deflection of a ray by the field of a single point mass. A statistical analysis is then performed to determine the expression for the mean total change in the intensity of celestial light sources due to the combined fields of all intervening bodies.

  19. Robust control design with real parameter uncertainty using absolute stability theory. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    How, Jonathan P.; Hall, Steven R.

    1993-01-01

    The purpose of this thesis is to investigate an extension of mu theory for robust control design by considering systems with linear and nonlinear real parameter uncertainties. In the process, explicit connections are made between mixed mu and absolute stability theory. In particular, it is shown that the upper bounds for mixed mu are a generalization of results from absolute stability theory. Both state space and frequency domain criteria are developed for several nonlinearities and stability multipliers using the wealth of literature on absolute stability theory and the concepts of supply rates and storage functions. The state space conditions are expressed in terms of Riccati equations and parameter-dependent Lyapunov functions. For controller synthesis, these stability conditions are used to form an overbound of the H2 performance objective. A geometric interpretation of the equivalent frequency domain criteria in terms of off-axis circles clarifies the important role of the multiplier and shows that both the magnitude and phase of the uncertainty are considered. A numerical algorithm is developed to design robust controllers that minimize the bound on an H2 cost functional and satisfy an analysis test based on the Popov stability multiplier. The controller and multiplier coefficients are optimized simultaneously, which avoids the iteration and curve-fitting procedures required by the D-K procedure of mu synthesis. Several benchmark problems and experiments on the Middeck Active Control Experiment at M.I.T. demonstrate that these controllers achieve good robust performance and guaranteed stability bounds.

  20. Soviet Nordic nuclear-weapon free-zone proposal. Master's thesis

    SciTech Connect

    Lumsden, C.A.

    1990-06-01

    This thesis examines the Soviet proposal and its ramifications for the United States and the West. The central theme running through each Soviet proposal has been removal of American nuclear guarantees. Preservation of US national security interests and hence US ability to extend its forward defense would be gravely threatened by such a NWFZ. However, unilateral agreement on a NWFZ is unlikely by the anticipated members of the Nordic NWFZ the US, USSR, Denmark, Norway, Finland, Iceland, Greenland, and Sweden. The US has military installations in Iceland and Greenland and banning of nuclear weapons during wartime is inconceivable. The question then arises as to which nation or groups of nations will dominate and which will acquiesce. Inevitably the debate breaks down to a tug of war between the two superpowers. It is really the politics surrounding the nuclear weapons that is the heart of the nuclear-free-zone debate. Changing world politics demand that the West develop a unified strategy toward the USSR. Through NATO it must preserve its vital economic political and military objectives in the Northern Flank. Flexible naval forces and strong political and economic ties to the governments of the nations bordering the Baltic are essential. Strong NATO naval forces operating in the Baltic Sea must be seen as guarantors of the West's strategic aims and interests. A Nordic NWFZ would prevent this.

  1. Preliminary design of the PANSAT electrical-power subsystem. Master's thesis

    SciTech Connect

    Noble, M.L.

    1990-06-01

    This thesis presents a preliminary design of the electrical power system (EPS) for the Naval Postgraduate School's Petite Amateur Navy Satellite (PANSAT). The EPS is a photovoltaic silicon cell system consisting of solar array, batteries, battery charge regulator (BCR), and dc-dc convertors. The EPS provides power for up to two years of low earth orbit (480 km) operations. The solar array consists of 17 panels with thirty-two 2 {times} 4 cm solar cells in series on each panel. The cells have an efficiency of 14.3% and generate a panel voltage of 14.1 volts at beginning of life, providing an unregulated bus voltage of 13.5 volts. The bus voltage is clamped at a minimum 10.5 volts by two lead acid batteries in parallel with the bus. Each battery consists of five 2.1 volt, 5 ampere-hour lead acid cells and is capable of meeting mission requirements. The BCR monitors individual battery voltage, an indication of reserve capacity, and provides a pulse-modulated charge current alternately to each battery.

  2. Experimental optimization of cooling-tower-fan control based on field data. Master's thesis

    SciTech Connect

    Herman, D.L.

    1991-04-01

    Energy costs continue to play an important role in the decision-making process for building design and operation. Since the chiller, cooling tower fans, and associated pumps consume the largest fraction of energy in a heating, ventilating, and air-conditioning (HVAC) system, the control of these components is of major importance in determining building energy use. A significant control parameter for the chilled water system is the minimum entering condenser water set point temperature at which the cooling tower fans are cycled on and off, several studies have attempted to determine the optimum value for this minimum set point temperature, but direct measurements are not available to validate these studies. The purpose of this study was to experimentally determine the optimum minimum entering condenser water set point temperature from field data based on minimum energy consumption and to validate a chilled water system analytical model previously developed in earlier work. The total chiller system electrical consumption (chiller and cooling tower fan energy) was measured for four entering condensor water set point temperatures (70, 75, 80, and 85 deg F). The field results were compared to results obtained using an analytical model previously developed in a thesis entitled Optimized Design of a Commercial Building Chiller/Cooling Tower System, written by Joyce.

  3. Study of mid-latitude 5577A CI dayglow emissions. Doctoral thesis

    SciTech Connect

    Hume, E.E.

    1992-01-01

    Summary of thesis: The green line (5577angstroms) is a bright, persistent component of the visible airglow. It is produced by an electric quadruple transition from the metastable second excited state (1So) to the first excited state (1D2) of atomic oxygen. These two excited states all lie in the same electron shell of the atom and have the same electron configuration as the ground state of 1s22s22p4, which is the 3P2,1,0. This emission is present in both the daytime and night airglow and in the aurora, and despite a long history of study it is still not fully understood. The emission in the dayglow and the nightglow is relatively homogeneous spatially and global in coverage. In the aurora, the emission is much brighter than the airglow, high structured and very localized being restricted to higher latitudes. The structure of the 5577angstroms emission with altitude and the chemistry responsible for the production of the emission are complex. The vertical structure for the emission has two distinct layers in the airglow each with its own set of production and loss mechanisms. the chemistry for either of these layers is not completely known. The auroral emission is not understood either since it overlaps the upper and lower layer altitudes and it tends to contain some parts of the chemistry of both layers as sources and losses.

  4. Management of Stress and Anxiety Among PhD Students During Thesis Writing: A Qualitative Study.

    PubMed

    Bazrafkan, Leila; Shokrpour, Nasrin; Yousefi, Alireza; Yamani, Nikoo

    2016-01-01

    Today, postgraduate students experience a variety of stresses and anxiety in different situations of academic cycle. Stress and anxiety have been defined as a syndrome shown by emotional exhaustion and reduced personal goal achievement. This article addresses the causes and different strategies of coping with this phenomena by PhD students at Iranian Universities of Medical Sciences. The study was conducted by a qualitative method using conventional content analysis approach. Through purposive sampling, 16 postgraduate medical sciences PhD students were selected on the basis of theoretical sampling. Data were gathered through semistructured interviews and field observations. Six hundred fifty-four initial codes were summarized and classified into 4 main categories and 11 subcategories on the thematic coding stage dependent on conceptual similarities and differences. The obtained codes were categorized under 4 themes including "thesis as a major source of stress," "supervisor relationship," "socioeconomic problem," and "coping with stress and anxiety." It was concluded that PhD students experience stress and anxiety from a variety of sources and apply different methods of coping in effective and ineffective ways. Purposeful supervision and guidance can reduce the cause of stress and anxiety; in addition, coping strategy must be in a thoughtful approach, as recommended in this study. PMID:27455365

  5. Conic Sector Analysis of Hybrid Control Systems. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Thompson, P. M.

    1982-01-01

    A hybrid control system contains an analog plant and a hybrid (or sampled-data) compensator. In this thesis a new conic sector is determined which is constructive and can be used to: (1) determine closed loop stability, (2) analyze robustness with respect to modelling uncertainties, (3) analyze steady state response to commands, and (4) select the sample rate. The use of conic sectors allows the designer to treat hybrid control systems as though they were analog control systems. The center of the conic sector can be used as a rigorous linear time invariant approximation of the hybrid control system, and the radius places a bound on the errors of this approximation. The hybrid feedback system can be multivariable, and the sampler is assumed to be synchronous. Algorithms to compute the conic sector are presented. Several examples demonstrate how the conic sector analysis techniques are applied. Extensions to single loop multirate hybrid feedback systems are presented. Further extensions are proposed for multiloop multirate hybrid feedback system and for single rate systems with asynchronous sampling.

  6. Determination of algorithm parallelism in NP-complete problems for distributed architectures. Master's thesis

    SciTech Connect

    Beard, R.A.

    1990-03-01

    The purpose of this thesis is to explore the methods used to parallelize NP-complete problems and the degree of improvement that can be realized using a distributed parallel processor to solve these combinatoric problems. Common NP-complete problem characteristics such as a priori reductions, use of partial-state information, and inhomogeneous searches are identified and studied. The set covering problem (SCP) is implemented for this research because many applications such as information retrieval, task scheduling, and VLSI expression simplification can be structured as an SCP problem. In addition, its generic NP-complete common characteristics are well documented and a parallel implementation has not been reported. Parallel programming design techniques involve decomposing the problem and developing the parallel algorithms. The major components of a parallel solution are developed in a four phase process. First, a meta-level design is accomplished using an appropriate design language such as UNITY. Then, the UNITY design is transformed into an algorithm and implementation specific to a distributed architecture. Finally, a complexity analysis of the algorithm is performed. the a priori reductions are divided-and-conquer algorithms; whereas, the search for the optimal set cover is accomplished with a branch-and-bound algorithm. The search utilizes a global best cost maintained at a central location for distribution to all processors. Three methods of load balancing are implemented and studied: coarse grain with static allocation of the search space, fine grain with dynamic allocation, and dynamic load balancing.

  7. Peroxone groundwater treatment of explosive contaminants demonstration and evaluation. Master`s thesis

    SciTech Connect

    McCrea, M.V.

    1997-03-01

    The purpose of this thesis is to evaluate the performance and cost effectiveness of a Peroxone Groundwater Treatment Plant (PGTP) designed and operated by Montgomery Watson, in support of the Defense Evaluation Support Agency`s independent analysis for the United States Army Environmental Center (USAEC). Many Department of Defense installations have sites that contain groundwater contaminated with explosive materials. Primary methods for the removal of explosive materials involve the use of Granular Activated Carbon (GAC). This process, however, requires additional waste disposal and treatment of explosive laden GAC, thereby incurring additional costs. An alternate method for the treatment of contaminated groundwater involves the use of hydrogen peroxide (H2O2) in conjunction with ozone (03). This method is referred to as the Peroxone oxidation process. A demonstration of the PGTP was conducted from 19 August to 8 November, 1996, at Cornhusker Army Ammunition Plant (CAAP), Grand Island, Nebraska using a small scale version with a maximum flow rate of 25 gallons per minute. The explosive contaminants analyzed during the demonstration include 2,4,6-Trinitrotoluene (TNT), 1,3,5-Trinitrobenzene (TNB), 1,3,5-Triazine (RDX), and Total Nitrobodies. Peroxone cost effectiveness was evaluated using a 30 year life cycle cost comparison to GAC and Ultraviolet/Ozone processes.

  8. Wireless communications for a multiple robot system. Master`s thesis

    SciTech Connect

    Bekas, A.J.

    1997-03-01

    A multi-disciplinary research project is being undertaken at NPS to develop a semi-autonomous robotic system to detect and clear land mines and Unexploded Ordnance (UXO). The robotic system under development consists of a land vehicle, an aerial vehicle, and a ground-based control station. Reliable communication between these three stations is needed. A traditional wire-based network requires that the vehicles be tethered and severely limits the mobility of the vehicles. A wireless Local Area Network (LAN) is proposed to provide communications between the control station and the vehicles. The objective of this thesis is to develop the physical (hardware) and logical (software) architecture of a wireless LAN that accommodates the needs of the mine/UXO project. Through an analysis of wireless modulation techniques, a market survey of wireless devices, and a field testing of wireless devices, a wireless LAN is designed to meet the technological, performance, regulation, interference, and mobility requirements of the mine/UXO project. Finally, the wireless communication protocols and the development of an error-free application protocol (specified by a FSM model and implemented in ANSI C code using Windows socket network programming) completes the wireless LAN implementation.

  9. Israeli nuclear weapons and war in the Middle East. Master`s thesis

    SciTech Connect

    Harden, J.D.

    1997-12-01

    This thesis examines the influence of the Israeli nuclear weapons capability on conflict in the Middle East. There are two perspectives regarding the impact of nuclear proliferation on strategic stability. Three paths to strategic instability are examined: preventive attacks, preemptive attacks, and the escalation of conventional conflict to nuclear war. The optimistic perspective argues that nuclear weapons make preventive and preemptive attacks less likely, and keep conventional conflict from escalating to nuclear war. The pessimistic perspective argues the opposite that nuclear weapons make preventive and preemptive attacks more likely, and raise the likelihood of escalation to nuclear war. My analysis of the Israeli cases shows that opaque nuclear proliferation decreases the pressure for preventive attacks, increases the chances for miscalculation, and creates sufficient concern about nuclear weapons to reduce the likelihood of preemptive attacks. Two factors help reduce the risk of nuclear proliferation as posed by proliferation pessimists, opaque nuclear weapons programs and nondeclaratory nuclear weapons policies. The implication of this research is that if the United States cannot dissuade a country from going nuclear, it should reinforce its incentives to maintain opacity and a nondeclaratory policy. Particular attention should be given to states which resist these efforts, as they represent the greatest risk of nuclear weapons use.

  10. Error modeling for differential GPS. M.S. Thesis - MIT, 12 May 1995

    NASA Technical Reports Server (NTRS)

    Blerman, Gregory S.

    1995-01-01

    Differential Global Positioning System (DGPS) positioning is used to accurately locate a GPS receiver based upon the well-known position of a reference site. In utilizing this technique, several error sources contribute to position inaccuracy. This thesis investigates the error in DGPS operation and attempts to develop a statistical model for the behavior of this error. The model for DGPS error is developed using GPS data collected by Draper Laboratory. The Marquardt method for nonlinear curve-fitting is used to find the parameters of a first order Markov process that models the average errors from the collected data. The results show that a first order Markov process can be used to model the DGPS error as a function of baseline distance and time delay. The model's time correlation constant is 3847.1 seconds (1.07 hours) for the mean square error. The distance correlation constant is 122.8 kilometers. The total process variance for the DGPS model is 3.73 sq meters.

  11. Implementation of a multi-lingual database system - multi-backend database system interface. Master's thesis

    SciTech Connect

    Holste, S.T.

    1986-06-01

    The limitations of the traditional Database Management System(DBMS) have become increasingly clear in recent years. Some of these limitations are interface inflexibility for user accesses, mono-lingual restriction in data languages, performance degradations over time, and excessive costs in upgrading. Two complementary approaches to the DBMS design and implementation--the multilingual database system(MLDS) and the multi-backend database system(MBDS)--effectively deal with the limitations of the traditional DBMS approach. MLDS offers a multi-lingual capability to the DBMS environment, thus freeing the user from the limitations and inflexibility of the single-data-model-and-language approach. MBDS, by contrast, is designed to deal with the issues of performance degradation and upgrading costs by providing a parallel-processing capability, and utilizing replicated software and identical hardware for expansion. System upgrades with BDS have been shown to provide an essentially proportional performance gain-to-upgrade-cost ratio. This thesis presents the implementation of an interface between MLDS and MBDS. Specifically, the author presents the procedures which create the template and Descriptor files in MLDS that are required by MBDS. Additionally the integration process tying these two systems together are described.

  12. Nuclear proliferation and the stability-instability paradox. Master`s thesis

    SciTech Connect

    Barretta, M.A.

    1995-06-01

    This thesis tests the theory that nuclear proliferation might enhance strategic stability by making the use of military force between possessors of nuclear weapons unlikely. It discusses the existing literature on deterrence and nonproliferation, emphasizing the stability-instability paradox. The stability-instability paradox offers an alternative to the optimism of deterrence logic, which views nuclear weapons as a beneficial and stabilizing force, and the pessimism of nonproliferation, which foresees dire consequences in the spread of nuclear weapons. The paradox is a synthesis of deterrence and nonproliferation logic because it allows for the coexistence of nuclear peace and lower levels of conventional war. Three cases of nuclear rivalry are examined. They are the United States and the Soviet Union, the Soviet Union and the People`s Republic of China, and India and Pakistan. These cases provide evidence that challenges the Waltzian argument that nuclear weapons enhance international stability by forbidding violent response to confrontations between nuclear-armed states. Nuclear powers that have employable conventional forces at their disposal, a territorial interest at stake, and exist in a condition of nuclear stalemate can, and do, engage in conventional warfare.

  13. Automated infrared detection of organophosphorus compounds in multicomponent solutions. Master`s thesis

    SciTech Connect

    Schuchardt, D.A.

    1995-12-01

    In-situ monitoring of the environment in peacetime and wartime is required of today`s technology with particular concern toward organophosphorus pesticides and chemical warfare agents. Of the many tools available for monitoring, infrared spectrometry combined with fiber optic sensors is one method of remote sensing which shows promise. This thesis models the problem of automatically detecting organophosphorus chemicals in water and automatically specifying what chemical is present. Computer generated infrared spectra are modeled as well as sensor characteristics and Computer generated infrared spectra are modeled as well as sensor characteristics and instrument noise over various binary mixture concentrations. A standard pattern recognition data reduction technique known as Principle Components Analysis is employed to compute meaningful features for detection of target chemicals in water. Methods of detection of the target chemical include the k-nearest neighbor classifier and Parzen window/maximum a-posteriori probability decision rule. By systematically varying chemical amounts, the order of magnitude of the limit of detection is determined. To determine the detection error bound beyond a simple point estimate of the error, Bayes error bounding is implemented. Once the lower range of detection is determined, k-nearest neighbor tests are done to determine classification of specific target chemicals.

  14. Systematics of the auroral boundary as indicated by particle precipitation. Master's thesis

    SciTech Connect

    Phillips, C.D.

    1984-12-01

    This thesis examined several ways of grouping data acquired by the DMSP/F7 satellite's electron and ion spectrometers, and used that data to decide the relationship between the latitude of the equatorward boundary of the electron and ion diffuse aurora. The statistical analysis was done with the SPSS computer package and data from the Special Sensor J/4 on board the Defense Meteorological Satellite Program F7 (Block 5D) spacecraft. The analytic technique used was bivariate linear regression, with the General Linear Test for the equality of two regression lines being used to compare different regression lines. The analysis of precipitating electrons and ions above the polar regions at about 840 kilometers found that the precipitation at different measured boundaries according to their magnetic local times of occurrence. Three hour wide bins were attempted, and were found to be less desirable than one hour wide bins. It was found that measured boundaries from the two poles can be combined in a single regression line.

  15. Preliminary development of a nuclear propulsion officer enlistment supply model. Master's thesis

    SciTech Connect

    Serfass, P.T.

    1986-09-01

    This study constructs linear forecasting models, for each of the six Navy Recruiting Areas and the Recruiting Command, that attempt to predict future United States Navy Nuclear Propulsion Officer contracts signed in any one of four fiscal year quarters, given estimates of independent supply variables included in the models. The models are developed using stepwise multiple regression analysis with ordinary least squares and are supported by historical data from fiscal years 1981 through 1985. In developing the models, the thesis examines the relationship between the contracts signed in a given quarter and the following supply variables: number of recruiters, annual goals of number of contracts to be signed, military-to-civilian pay ratio, unemployment rate, size of target population (in the form of market share), advertising and marketing costs and seasonal effects, represented by proxy variables. The assumptions of using multiple regression analysis and linear models are examined through a graphical study of the residuals and do not seem to be refuted. Each of the models are corrected for first order autocorrelation. Validation of the forecasting models was attempted by the comparison of predicted contracts signed in a quarter against new contract data obtained for fiscal year 1986. The results of the forecasting comparisons are much worse than expected. Possible causes for the large error percentages in the comparisons are mentioned in this study but not examined in detail.

  16. Design for dependability: A simulation-based approach. Ph.D. Thesis, 1993

    NASA Technical Reports Server (NTRS)

    Goswami, Kumar K.

    1994-01-01

    This research addresses issues in simulation-based system level dependability analysis of fault-tolerant computer systems. The issues and difficulties of providing a general simulation-based approach for system level analysis are discussed and a methodology that address and tackle these issues is presented. The proposed methodology is designed to permit the study of a wide variety of architectures under various fault conditions. It permits detailed functional modeling of architectural features such as sparing policies, repair schemes, routing algorithms as well as other fault-tolerant mechanisms, and it allows the execution of actual application software. One key benefit of this approach is that the behavior of a system under faults does not have to be pre-defined as it is normally done. Instead, a system can be simulated in detail and injected with faults to determine its failure modes. The thesis describes how object-oriented design is used to incorporate this methodology into a general purpose design and fault injection package called DEPEND. A software model is presented that uses abstractions of application programs to study the behavior and effect of software on hardware faults in the early design stage when actual code is not available. Finally, an acceleration technique that combines hierarchical simulation, time acceleration algorithms and hybrid simulation to reduce simulation time is introduced.

  17. Strategic culture and ballistic missile defense: Russia and the United States. Master's thesis

    SciTech Connect

    Becker, M.D.

    1993-06-01

    This thesis examines U.S. and Russian history and current policy debates to advance understanding of: (1) the strategic cultures of these nations, particularly with respect to BMD policies in the recent past; and (2) whether and how their strategic cultures and approaches to BMD are changing and how that may affect future strategic BMD developments and the status of the ABM Treaty. The development of BMD strategies, including policies concerning the ABM Treaty, within the framework of the established American and Russian strategic cultures is studied, with due attention to the Soviet experience and legacy in the Russian case. U.S. strategic culture does not seem to have changed significantly with the end of the Cold War, but U.S. BMD priorities have been redefined to reflect a higher priority attached to regional and theater-level defenses. It is apparent that the Soviet experience did have a significant impact on Russian strategic culture. Faced with major changes in its international status, domestic political-military arrangements, and scope of national security concerns, Russian strategic culture is nonetheless moving beyond the old Soviet culture. Future Russian policies regarding the transfer of BMD technology, sharing early warning data, and participating in a global protective system are heavily dependent on domestic political developments. United States, Russia, USSR, Strategic culture, Ballistic missile defense, National strategy, Nuclear strategy, Strategic defense, ABM Treaty, Arms control, Strategic stability.

  18. Two nonlinear models of the free-electron laser. Master's thesis

    SciTech Connect

    Kiel, D.H.

    1990-11-01

    The dynamics of the Free Electron Laser are governed by Maxwell's equations which causes many highly nonlinear regimes to exist in Free Electron Laser Physics. This thesis will examine two such areas and develop simple models to describe the highly dynamic and rich behavior two of these regimes. In the strong-field, high current regime, the Free Electron Laser driving current can be modeled by a single macroparticle representing the trapped electrons. When the trapped electrons act collectively as a macroparticle, solutions which include synchrotron oscillations can be found for the self-consistent pendulum and wave equations. In an FEL oscillator with low single-pass gain, the evolution of the optical wave can lead to sideband development. This phenomenon is studied by applying Maxwell's equations to an oscillator with two optical modes and deriving a two-mode wave and pendulum equation. The two-mode wave and pendulum equations are implemented numerically on computers so that the onset of the sideband can be explored.

  19. Random vibration analysis of the Topaz-II nuclear reactor power system. Master`s thesis

    SciTech Connect

    Campbell, S.E.

    1995-06-01

    The TOPAZ-II Ya-21U is one of six Russian made space nuclear power systems which is based on theomionic power conversion. The U.S. is presently analyzing TOPAZ-II to determine the reliability and feasibility of using this system. A structural analysis test was conducted on the TOPAZ unit in May 1993 to provide data from which modal parameters could be identified. This test showed the fundamental frequency to be 10.5 Hz, yet the test results that the Russians conducted identified a fundamental frequency of 5 Hz. Another finite element model was created incorporating new developments in TOPAZ-II and modifications to the finite element model to better simulate the mass properties of the TOPAZ-II2. A second structural analysis test was conducted on the TOPAZ unit 06-09 September 1994. This thesis focuses on the random vibration analysis of the TOPAZ-II Ya-2lU utilizing the most recent test results and the Master Series (updated version) I-DEAS software. The modal respose of the model and simulated random vibration tests were within 8.33%. This model is a feasible tool which can be used to analyze the TOPAZ unit without testing the unit to fatigue.

  20. Investigation of finite element: ABC methods for electromagnetic field simulation. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Chatterjee, A.; Volakis, John L.; Nguyen, J.

    1994-01-01

    The mechanics of wave propagation in the presence of obstacles is of great interest in many branches of engineering and applied mathematics like electromagnetics, fluid dynamics, geophysics, seismology, etc. Such problems can be broadly classified into two categories: the bounded domain or the closed problem and the unbounded domain or the open problem. Analytical techniques have been derived for the simpler problems; however, the need to model complicated geometrical features, complex material coatings and fillings, and to adapt the model to changing design parameters have inevitably tilted the balance in favor of numerical techniques. The modeling of closed problems presents difficulties primarily in proper meshing of the interior region. However, problems in unbounded domains pose a unique challenge to computation, since the exterior region is inappropriate for direct implementation of numerical techniques. A large number of solutions have been proposed but only a few have stood the test of time and experiment. The goal of this thesis is to develop an efficient and reliable partial differential equation technique to model large three dimensional scattering problems in electromagnetics.

  1. Coded throughput performance simulations for the time-varying satellite channel. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Han, LI

    1995-01-01

    The design of a reliable satellite communication link involving the data transfer from a small, low-orbit satellite to a ground station, but through a geostationary satellite, was examined. In such a scenario, the received signal power to noise density ratio increases as the transmitting low-orbit satellite comes into view, and then decreases as it then departs, resulting in a short-duration, time-varying communication link. The optimal values of the small satellite antenna beamwidth, signaling rate, modulation scheme and the theoretical link throughput (in bits per day) have been determined. The goal of this thesis is to choose a practical coding scheme which maximizes the daily link throughput while satisfying a prescribed probability of error requirement. We examine the throughput of both fixed rate and variable rate concatenated forward error correction (FEC) coding schemes for the additive white Gaussian noise (AWGN) channel, and then examine the effect of radio frequency interference (RFI) on the best coding scheme among them. Interleaving is used to mitigate degradation due to RFI. It was found that the variable rate concatenated coding scheme could achieve 74 percent of the theoretical throughput, equivalent to 1.11 Gbits/day based on the cutoff rate R(sub 0). For comparison, 87 percent is achievable for AWGN-only case.

  2. Common interface real-time multiprocessor operating system for embedded systems. Master's thesis

    SciTech Connect

    Rottman, M.S.

    1991-03-04

    Large real time applications such as aerospace avionics systems, battle management, and factory automation place many demands and constraints on the computing system not found in other applications. Software development is hindered by software dependence on the computer architecture and the lack of portability between systems. This thesis specifies and designs a real time multiprocessor operating system (RTMOS) that implements a consistent programming model, enabling the development of real time parallel software independent of the target architecture. The RTMOS defines the core functionality required to demonstrate the programming model. The RTMOS functional requirements are specified using Structured Analysis and Design Technique (SADT). A hybrid of the Design Approach for Real-Time Software (DARTS) is used to perform the preliminary and detailed designs. The preliminary design is architecture-independent; the detailed design phase maps the design to a specific parallel system, the Intel iPSC/2 hypercube. The modular RTMOS design partitions operating system operations and data structures from hardware-dependent functions for portability.

  3. Recycling decision support system: Design and development of a Web-based DSS. Master thesis

    SciTech Connect

    Tettelbach, C.G.

    1997-03-01

    The explosive growth of the World Wide Web creates new opportunities for the development and deployment of Decision Support Systems. No longer restricted by machine-specific limitations, Web-based Decision Support Systems (DSS) provide global access to widely diversified and geographically dispersed users through sharing of data, models, algorithms, and modeling environments. This thesis examines the design and development processes involved in the creation of a Web-based DSS. The Recycling Decision Support System utilizes a rapid prototype and refinement process to create a Web-based system focusing on supporting ordinary people and industrial users in making good decisions for recycling and disposal of household and industrial waste. Through abstraction of details from the specific Web-based DSS design, a generalized framework for supporting decision-making via the WWW is built which supports functionality in education, queries, and analysis of complex problems. An important aspect of this research is the development of a new architecture which conforms to the complexities specific to Web-based Decision Support Systems. Prompted by the additional interactions required for WWW connectivity, this architecture incorporates agents for negotiating transactions between the functional components of a standard DSS.

  4. Failure analysis and modeling of a multicomputer system. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Subramani, Sujatha Srinivasan

    1990-01-01

    This thesis describes the results of an extensive measurement-based analysis of real error data collected from a 7-machine DEC VaxCluster multicomputer system. In addition to evaluating basic system error and failure characteristics, we develop reward models to analyze the impact of failures and errors on the system. The results show that, although 98 percent of errors in the shared resources recover, they result in 48 percent of all system failures. The analysis of rewards shows that the expected reward rate for the VaxCluster decreases to 0.5 in 100 days for a 3 out of 7 model, which is well over a 100 times that for a 7-out-of-7 model. A comparison of the reward rates for a range of k-out-of-n models indicates that the maximum increase in reward rate (0.25) occurs in going from the 6-out-of-7 model to the 5-out-of-7 model. The analysis also shows that software errors have the lowest reward (0.2 vs. 0.91 for network errors). The large loss in reward rate for software errors is due to the fact that a large proportion (94 percent) of software errors lead to failure. In comparison, the high reward rate for network errors is due to fast recovery from a majority of these errors (median recovery duration is 0 seconds).

  5. Fluid flow and sound generation at hydrothermal vent fields. Doctoral thesis

    SciTech Connect

    Little, S.A.

    1988-04-01

    Several experiments in this thesis examine methods to measure and monitor fluid flow from hydrothermal vent fields. Simultaneous velocity temperature, and conductivity data were collected in the convective flow emanating from a hydrothermal vent field located on the East Pacific rise. The horizontal profiles obtained indicate that the flow field approaches an ideal plume in the temperature and velocity distribution. Such parameters as total heat flow and maximum plume height can be estimated using either the velocity or the temperature information. The results of these independent calculations are in close agreement, yielding a total heat capacity and volume changes slightly alter the calculations applied to obtain these values. In Guaymas Basin, a twelve day time series of temperature data was collected from a point three centimeters above a diffuse hydrothermal flow area. Using concurrent tidal gauge data from the town of Guaymas it is shown that the effects of tidal currents can be strong enough to dominate the time variability of a temperature signal at a fixed point in hydrothermal flow and are a plausible explanation for the variations seen in the Guaymas Basin temperature data. The increase in power due to convected flow inhomogeneities, however, was lower in the near field than expected. Indirect evidence of hydrothermal sound fields showing anomalous high power and low frequency noise associated with vents is due to processes other than jet noise.

  6. Feasibility of automatic storage reclamation with concurrent program execution in a LISP environment. Master's thesis

    SciTech Connect

    Cassidy, K.G.

    1985-12-01

    Storage reclamation is the process of reclaiming discarded information and returning the memory space occupied by that discarded information to an available area or list in memory that is available to be utilized by programmers. This increased interest in storage reclamation is a result of the increasing use of list-processing environments. A list-processing environment is a system in which the language manipulates data structures called lists. In classical LISP implementations, program execution/computation continues until there is no more memory available (i.e., the free list of available cells has become exhausted). When this happens, user program(s) HALT and then storage reclamation, in the form of garbage collection, takes over. This halting of programs in the midst of their computation is not only frustrating to programmers and researchers but can also be of crucial importance in other applications. This thesis investigates the feasibility of allowing concurrent program execution with garbage collection. LISP has been selected because it has been estimated that typical LISP programs take 10%-30% of their processing time to perform garbage collection.

  7. Forecasting jet fuel prices using artificial neural networks. Master`s thesis

    SciTech Connect

    Kasprzak, M.A.

    1995-03-01

    Artificial neural networks provide a new approach to commodity forecasting that does not require algorithm or rule development. Neural networks have been deemed successful in applications involving optimization, classification, identification, pattern recognition and time series forecasting. With the advent of user friendly, commercially available software packages that work in a spreadsheet environment, such as Neural Works Predict by NeuralWare, more people can take advantage of the power of artificial neural networks. This thesis provides an introduction to neural networks, and reviews two recent studies of forecasting commodities prices. This study also develops a neural network model using Neural Works Predict that forecasts jet fuel prices for the Defense Fuel Supply Center (DFSC). In addition, the results developed are compared to the output of an econometric regression model, specifically, the Department of Energy`s Short-Term Integrated Forecasting System (STWS) model. The Predict artificial neural network model produced more accurate results and reduced the contribution of outliers more effectively than the STIFS model, thus producing a more robust model.

  8. Oil policy in Russia toward selected new independent states. Master thesis

    SciTech Connect

    Stevens, J.J.

    1996-12-01

    Following the breakdown of the Soviet Union, one of the world`s strongest oil producing industries was divided into a few major oil provinces. The process of change to the former Soviet oil industry including: Russian efforts to maintain control of its former resources, NIS resource development, Western capital investment, and environmental issues in the major oil provinces of the former Soviet Union, is the main focus of this thesis. Free market world oil majors and their counterparts, both in Russia and the New Independent States (NIS), have developed a number of significant alliances that have resulted in several potentially lucrative joint ventures. The coercive tactics that the Russian government resorts to in an effort to prevent its former republics from efficiently developing their reserves, and the position the United States must take to ensure these efforts are stifled will be addressed. A sound grasp of these critical energy issues by American policy makers will result in the development of these vast resources in a manner favorable to U. S. national interests.

  9. Space-Bounded Church-Turing Thesis and Computational Tractability of Closed Systems

    NASA Astrophysics Data System (ADS)

    Braverman, Mark; Schneider, Jonathan; Rojas, Cristóbal

    2015-08-01

    We report a new limitation on the ability of physical systems to perform computation—one that is based on generalizing the notion of memory, or storage space, available to the system to perform the computation. Roughly, we define memory as the maximal amount of information that the evolving system can carry from one instant to the next. We show that memory is a limiting factor in computation even in lieu of any time limitations on the evolving system—such as when considering its equilibrium regime. We call this limitation the space-bounded Church-Turing thesis (SBCT). The SBCT is supported by a simulation assertion (SA), which states that predicting the long-term behavior of bounded-memory systems is computationally tractable. In particular, one corollary of SA is an explicit bound on the computational hardness of the long-term behavior of a discrete-time finite-dimensional dynamical system that is affected by noise. We prove such a bound explicitly.

  10. Reminiscing about thesis work with E T Jaynes at Stanford in the 1950s

    NASA Astrophysics Data System (ADS)

    Cummings, Frederick W.

    2013-11-01

    Abstract A short personal and historical account of the field of radiation interacting with (two-level) atoms is given. Subsequent to 1963, developments and extensions have been extensive and fruitful. One of the most fortunate changes in my life came in late 1957. I was looking for a thesis advisor, after two years of graduate course-work at Stanford. I chanced to see a notice of an upcoming lecture by a professor named Edwin T Jaynes. I could not understand from the announcement what he intended to talk about, but I was searching; I went to find out. That decision was a very lucky one. Ed was talking about a subject that inspired him then, and had been for many years, namely his concept of 'Max-Ent'. 'Maximum-Entropy' is a subject now close to my heart also. Ed's very-clear, well-thought-out papers, spread over many subsequent years, are transforming the field of probability (albeit too gradually) to the 'subjective' outlook of Bayes. (A recent book 'Maximum Entropy and Ecology' [1] will probably convert many nay-sayers to 'Max-Ent'.) I went into Ed's office (late 1957) and asked if I could work with him on a thesis. Did he have a problem for me? Yes, he did. Somewhat to my surprise, he asked me to look into the 'maser problem', involving a comparison of the semi-classical theory of radiation to a proper quantum treatment. To make a two-year story short, Ed's guidance was expert. (I imagine that if another of Ed's students (e.g. Joe Eberly) had come into his office fifteen minutes before me, the 'Jaynes-Cummings' (J-C) model would now perhaps be called otherwise, e.g., the 'J-E' model). In the two-year time frame (~1958-60), Ed had a number of other PhD dissertation students whom I knew; these included Joe Eberly, Doug Scalapino, Baldwin Robertson, Larry Davis and Mike Duggan. My thesis work under Ed reminds me of a story about Michelangelo and his famous 'Pieta'. Michelangelo was an old man about then, so he hired a young craftsman to do much of the physical

  11. US foreign policy and the Baltic states. Master`s thesis

    SciTech Connect

    Shuey, K.A.

    1996-03-01

    This thesis examines U. S. foreign policy toward the Baltic states from 1918 to 1991 to determine if the U.S. has been realistic in its dealings with small nations. An analysis of U.S. policy indicates that the United States acts hypocritically by accepting compromises on the very moral principals to which it claims to be the protectorate of when domestic political costs are high. The sacrifice of national values degrades the credibility of the moral high ground necessary for U.S. policy. This study reviews the events that occurred during the three major periods in U.S.-Baltic relations: The initial period of Baltic independence following World War I; the Soviet annexation of the Baltics during World War II: and finally the beginning of the second period of Baltic independence during the breakup of the Soviet Union. In all three cases U.S. policy was unclear and contradictory. The Baltic case provides a good example of the tendency for U.S. policy to be paradoxical and ineffective. This study concludes that despite the U.S. policy of nonrecognition of the Soviet annexation of the Baltic states during the Cold War, the United States failed to adhere to its principals when given the opportunity. In the process, it also neglected problems within its borders that required attention perhaps more urgently than those outside. The tendency for U.S. policy to ignore the issues that actually threaten its security internally and placing a higher priority on external matters that do not have a real impact on its standing could likely lead to its inadvertent downfall.

  12. Marine microbial production of dimethylsulfide from dissolved dimethylsulfoniopropionate. Ph. D. Thesis

    SciTech Connect

    Ledyard, K.M.

    1993-02-01

    Dimethylsulfide (DMS) plays a central role in the transfer of sulfur from the ocean to the atmosphere and ultimately to land. The most abundant volatile organosulfur compound in seawater, DMS is believed to account for the bulk of the sea-to-air biogenic sulfur flux. DMS has also been implicated as the major precursor of submicron-sized sulfate aerosol over the ocean. This aerosol acts as an effective site for cloud droplet condensation suggesting a possibly important role for DMS in marine cloud formation. In the ocean, the precursor of DMS is presumed to be the zwitterionic sulfonium compound dimethylsulfoniopropionate (DMSP), a common osmoticum in certain classes of marine algae. While some algae can cleave DMSP intracellularly to form DMS, correlation of DMS concentrations with indicators of algal productivity on a local scale is poor. This thesis focuses on an alternative pathway of DMS formation: microbial cleavage of dissolved (extracellular) DMSP. In laboratory studies, bacteria able to cleave DMSP to form DMS were isolated from seawater by a DMSP enrichment technique, and the kinetics of DMSP uptake and DMS production were examined closely in pure cultures of a bacterial isolate from the Sargasso Sea. The isolate could grow with both DMSP and acrylic acid, one of the products of DMSP cleavage, as the sole source of carbon and energy, and the enzyme catalyzing DMSP cleavage appeared to be induced by both of these compounds. Kinetic parameters were estimated for DMSP uptake and cleavage by whole cells. Comparison of the 16S rRNA sequence of this isolate with that of known eubacteria showed that it was most closely related to Erythrobacter longus, an aerobic, bacteriochlorophyll-containing member of the alpha proteobacteria.

  13. On recursive least-squares filtering algorithms and implementations. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Hsieh, Shih-Fu

    1990-01-01

    In many real-time signal processing applications, fast and numerically stable algorithms for solving least-squares problems are necessary and important. In particular, under non-stationary conditions, these algorithms must be able to adapt themselves to reflect the changes in the system and take appropriate adjustments to achieve optimum performances. Among existing algorithms, the QR-decomposition (QRD)-based recursive least-squares (RLS) methods have been shown to be useful and effective for adaptive signal processing. In order to increase the speed of processing and achieve high throughput rate, many algorithms are being vectorized and/or pipelined to facilitate high degrees of parallelism. A time-recursive formulation of RLS filtering employing block QRD will be considered first. Several methods, including a new non-continuous windowing scheme based on selectively rejecting contaminated data, were investigated for adaptive processing. Based on systolic triarrays, many other forms of systolic arrays are shown to be capable of implementing different algorithms. Various updating and downdating systolic algorithms and architectures for RLS filtering are examined and compared in details, which include Householder reflector, Gram-Schmidt procedure, and Givens rotation. A unified approach encompassing existing square-root-free algorithms is also proposed. For the sinusoidal spectrum estimation problem, a judicious method of separating the noise from the signal is of great interest. Various truncated QR methods are proposed for this purpose and compared to the truncated SVD method. Computer simulations provided for detailed comparisons show the effectiveness of these methods. This thesis deals with fundamental issues of numerical stability, computational efficiency, adaptivity, and VLSI implementation for the RLS filtering problems. In all, various new and modified algorithms and architectures are proposed and analyzed; the significance of any of the new method depends

  14. Magnetic levitation and confinement of molten metals. Ph.D Thesis

    SciTech Connect

    Roy, S.S.

    1993-12-31

    Electromagnetic forces generated within the bulk of a liquid metal, due to imposed alternating magnetic field, can alter the shape of the free surface of the liquid metal. Most of the research in this area has been focused on theoretical development of electromagnetic processes and there is a lack of well defined experimental results with which to verify the theoretical models. In this thesis, the interaction of electromagnetic field structure with liquid metals was studies both from theoretical and experimental viewpoints. Levitation and shaping experiments were successfully carried out with liquid sodium in mineral oil in a cone-shaped coil. Small droplets ranging from 1.2 to 2.1 gm of liquid sodium were levitated. The modeling of a levitated droplet in an electromagnetic field was carried out using the Free Movement method. This is a surface coupled model where the skin depth is assumed to be zero. There was a good match between the experimental and predicted results. The shaping experiments were also carried out using liquid sodium in a cylindrical coil. Liquid sodium was repelled from the wall of the container and the meniscus profile was measured. The experimental results were compared with the results predicted by the mathematical model. The comparison was good away from the inductor but the model did not predict the shape near the inductor due to fluid flow during shaping. The mathematical model is used to predict the meniscus shapes of liquid steel under an imposed electromagnetic field. This technique is used to investigate the effect of applied magnetic fields on the static meniscus shapes of a liquid steel column and on the equilibrium meniscus shape of liquid steel in the mold of a continuous caster when there is not relative movement between the model and the strand. The heating rate of liquid steel due to induced eddy currents within the bulk of the metal is also studied.

  15. Polar cap auroral arcs: Observations, theories, and a numerical model. Ph.D. Thesis

    SciTech Connect

    Berg, G.A.

    1993-01-01

    This thesis reports the results of probably the most completely documented study of auroras near the polar cap boundary performed to date. Three fully instrumented rockets flew into the morning sector of the polar cap, complemented on the ground by a digital all-sky camera and incoherent scatter radar. Additionally, DMSP satellite passes over the polar cap bracketed the launches. The authors use these data to address two main issues: (1) the relationship between the state of the magnetosphere and the formation of polar cap arcs, and (2) the character of the current systems associated with polar cap arcs. The data indicate that in a decaying magnetosphere sun-aligned arcs erupt into the polar cap at high velocity from regions of enhanced brightness in the auroral oval. Two bright polar cap arcs formed in this manner in the region sampled by the rockets. The most equatorward of the arcs, sampled by two of the rockets during its lifetime, erupted into a region already characterized by strong sunward convection. The most poleward, however, which formed after the rockets had passed, pushed into a region where anti-sunward convection pertained less than two minutes earlier. It is likely that the boundary between sunward and anti-sunward convection shifted poleward so that sunward convection pertained at this arc as well. The formation of polar cap arcs may be tied closely to the reconfiguration of the magnetosphere into a system characterized by a smaller polar cap. One of the payloads measured, with high resolution, both E and delta B as well as energetic particle flux. This permitted an in-depth study of the current systems flown through. The correlation between delta E and delta B is classic, both fields indicating upward field-aligned currents in virtually every region of enhanced electron precipitation. However, the currents deduced from the electrons do not agree in magnitude with those deduced from the fields.

  16. Efficient modeling of interconnects and capacitive discontinuities in high-speed digital circuits. Thesis

    NASA Technical Reports Server (NTRS)

    Oh, K. S.; Schutt-Aine, J.

    1995-01-01

    Modeling of interconnects and associated discontinuities with the recent advances high-speed digital circuits has gained a considerable interest over the last decade although the theoretical bases for analyzing these structures were well-established as early as the 1960s. Ongoing research at the present time is focused on devising methods which can be applied to more general geometries than the ones considered in earlier days and, at the same time, improving the computational efficiency and accuracy of these methods. In this thesis, numerically efficient methods to compute the transmission line parameters of a multiconductor system and the equivalent capacitances of various strip discontinuities are presented based on the quasi-static approximation. The presented techniques are applicable to conductors embedded in an arbitrary number of dielectric layers with two possible locations of ground planes at the top and bottom of the dielectric layers. The cross-sections of conductors can be arbitrary as long as they can be described with polygons. An integral equation approach in conjunction with the collocation method is used in the presented methods. A closed-form Green's function is derived based on weighted real images thus avoiding nested infinite summations in the exact Green's function; therefore, this closed-form Green's function is numerically more efficient than the exact Green's function. All elements associated with the moment matrix are computed using the closed-form formulas. Various numerical examples are considered to verify the presented methods, and a comparison of the computed results with other published results showed good agreement.

  17. A thesis investigating the impact of energy related environmental factors on domestic window design

    NASA Astrophysics Data System (ADS)

    McEvoy, Michael Edward

    In recent years the extent of glazing in houses has been tightly controlled by the Building Regulations in order to save energy. In addition guidelines derived from passive solar principles prescribe the distribution of domestic windows between elevations according to their orientation. This thesis studies the impact of these energy-related environmental factors on domestic window design. The first of these investigations determined the degree to which limitations on the area and arrangement of windows are significant in terms of daylighting. The experiments measured the effect that passive solar requirements and detailed aspects of window design have on the quality of daylighting in houses. The volume of background ventilation required for domestic accommodation has recently been increased. As a result, in a well-sealed construction, heat loss due to background ventilation becomes a larger part of the total heat loss and larger air movements become a potential cause of draughts. The ventilation experiment sought to establish the impact of these more onerous requirements on comfort within rooms. The third experiment combines these factors and asks the question: Could windows be actively involved in overcoming some of these difficulties by being used to preheat ventilation air in order to diminish the extent of heat loss and to alleviate the problem of cold draughts? Also by designing the window to reclaim heat from the room might it be possible to offset the window's thermal inadequacy? Through analysis of responses to a questionnaire and the use of optimisation techniques, scenarios were suggested for the future modification of windows in relation to energy and health expectations. The conclusions form a commentary on recent and future revisions to the Building Regulations and determine whether or not the Regulations facilitate the environmental engineering of windows as an active component of a building's whole environmental system.

  18. A nonlinear thermoviscoelastic stress and fracture analysis of an adhesive bond. Ph.D. Thesis

    SciTech Connect

    Duong, C.N.

    1994-12-31

    The evolution of residual stresses resulting from cooling an adhesive bond configuration on its lateral surfaces at a constant rate through the glass transition of the polymer are considered. A nonlinear, viscoelastic (free-volume) model serves for the thermoviscoelastic characterization of the polymer. Both an infinite (one-dimensional) and a finite (two dimensional) domain are studied. A `critical` cooling time exists, in the present case on the order of a few seconds, which separates the control of the solidification process according to whether the relaxation or thermal diffusion time scale governs. The short time `quenching process,` i.e., when the time scale is governed by thermal diffusion, leads to essentially constant residual stresses. Slower cooling increasingly invokes the time and rate sensitive properties of the polymer and leads to monotonically decreasing residual stresses with longer cooling times. To reduce residual stresses by a factor of two from their maximal values requires cooling times on the order of one or two days. Apart from singular behavior of the stress components in the two-dimensionally finite domain `quenching` has the effect of producing significantly different stress distributions (including stress `spikes`) than slow or thermoelastic analyses would suggest. Implications of these results for systems possessing geometric and material differences subjected to various thermal cooling ranges are also discussed. In the second part of the thesis the effect of the residual stresses on fracture behavior of an adhesive bond are addressed within the context of linear fracture mechanics for dissimilar materials. The crack faces are found to be in contact at the fractured end during the (residually stress) unloading process. A significantly error results if this contact zone is not taken into account. The combined effect of the mechanical loads and the residual stresses on the energy release rate is also studied.

  19. Finding the right doctoral thesis – an innovative research fair for medical students

    PubMed Central

    Steffen, Julius; Grabbert, Markus; Pander, Tanja; Gradel, Maximilian; Köhler, Lisa-Maria; Fischer, Martin R.; von der Borch, Philip; Dimitriadis, Konstantinos

    2015-01-01

    Introduction: The importance of research, as promoted by the CanMEDS framework, is widely acknowledged. Many medical students in Germany work on a research project as part of their doctoral thesis whilst still going to medical school. However, a significant amount of projects are abandoned unfinished, which leads to substantial wastage of resources. One reason for this is an information deficit concerning undergraduate research projects. Project description: To counteract this, we introduced an annual event at LMU Munich called DoktaMed with more than 600 visitors each year. It combines medical convention and research fair including keynote lectures, workshops and poster sessions as well as an exhibition of research groups and institutes. DoktaMed is a peer-to-peer event organized by a team of 40 students. Results: A needs analysis before its implementation underlined the information deficit as a possible cause for the high rate of abandoned projects. In the annual evaluation, visitors of DoktaMed rate the event with an average grade of 2.1 on a six-level Likert scale (n=558, SD=1.06, with "1=very good", "6=poor"). They stated to now feel better informed about the topic and regarded visiting DoktaMed as a worthwhile investment of time. Discussion: Students are generally satisfied with the event and feel better informed after visiting DoktaMed. However, many students never visit DoktaMed for various reasons. A possible improvement would be to present a greater number of clinical studies in addition to the laboratory work that DoktaMed focuses on now. Conclusion: Evaluation after six years of DoktaMed is very promising. Visitors seem to be better informed. Nevertheless there is space for improvement in order to get more students and more faculty members involved. More studies are needed to assess long-term effects. PMID:26413167

  20. [A doctoral thesis on occupational diseases from 1816: workers' diseases in the post-Ramazzinian era].

    PubMed

    Carnevale, F

    2010-01-01

    No medical "classical" work has been in any way as successful as Ramazzini's De Morbis Artificum Diatriba. The book's success is confirmed by the constantly increasing number of new editions, emulations, translations and quotations and corresponding dissemination. As is proven by web access, our contemporaries continue to contemplate Ramazzini with admiration and wonder, confidence, devotion and curiosity and also as a means of seeking confirmation of the concepts that are variously presented. It is possible to describe a temporal phenomenon of "differential impact" of Ramazzini's work. Throughout the twentieth century, and especially on "celebrated" anniversaries (1900, 1913, 1914, 1933, 1964, 2000), many "tributes" to the author were recorded. During the nineteenth century in major European countries, but less so in Italy, Ramazzini's lesson was recorded as superseded "on an objective basis". The context had completely changed, as did both work and workers after a century-old continuity. Between the 1700's and the early 1800's Ramazzini dominated the field like a mountain in the desert; with editions of De Morbis in Latin and in translations following one on the other, with a positive cultural and popularizing impact on a public consisting of the international scientific and professional avant-garde. The means of dissemination consisted first and foremost of including all or part of the corpus of the Diatriba in "dictionaries" or "encyclopaedias" of medicine. Another means that was widely used, efficacious and typically academic, was through the doctoral theses discussed in all major European universities. Among these contributions was the thesis discussed in 1816 in Paris, by Louis-André Gosse of Geneva (1791-1873), which is presented in the previous pages in the translation from the French. PMID:21110453

  1. Reminiscing about thesis work with E T Jaynes at Stanford in the 1950s

    NASA Astrophysics Data System (ADS)

    Cummings, Frederick W.

    2013-11-01

    Abstract A short personal and historical account of the field of radiation interacting with (two-level) atoms is given. Subsequent to 1963, developments and extensions have been extensive and fruitful. One of the most fortunate changes in my life came in late 1957. I was looking for a thesis advisor, after two years of graduate course-work at Stanford. I chanced to see a notice of an upcoming lecture by a professor named Edwin T Jaynes. I could not understand from the announcement what he intended to talk about, but I was searching; I went to find out. That decision was a very lucky one. Ed was talking about a subject that inspired him then, and had been for many years, namely his concept of 'Max-Ent'. 'Maximum-Entropy' is a subject now close to my heart also. Ed's very-clear, well-thought-out papers, spread over many subsequent years, are transforming the field of probability (albeit too gradually) to the 'subjective' outlook of Bayes. (A recent book 'Maximum Entropy and Ecology' [1] will probably convert many nay-sayers to 'Max-Ent'.) I went into Ed's office (late 1957) and asked if I could work with him on a thesis. Did he have a problem for me? Yes, he did. Somewhat to my surprise, he asked me to look into the 'maser problem', involving a comparison of the semi-classical theory of radiation to a proper quantum treatment. To make a two-year story short, Ed's guidance was expert. (I imagine that if another of Ed's students (e.g. Joe Eberly) had come into his office fifteen minutes before me, the 'Jaynes-Cummings' (J-C) model would now perhaps be called otherwise, e.g., the 'J-E' model). In the two-year time frame (~1958-60), Ed had a number of other PhD dissertation students whom I knew; these included Joe Eberly, Doug Scalapino, Baldwin Robertson, Larry Davis and Mike Duggan. My thesis work under Ed reminds me of a story about Michelangelo and his famous 'Pieta'. Michelangelo was an old man about then, so he hired a young craftsman to do much of the physical

  2. Peer Portal: Quality Enhancement in Thesis Writing Using Self-Managed Peer Review on a Mass Scale

    ERIC Educational Resources Information Center

    Aghaee, Naghmeh; Hansson, Henrik

    2013-01-01

    This paper describes a specially developed online peer-review system, the Peer Portal, and the first results of its use for quality enhancement of bachelor's and master's thesis manuscripts. The peer-review system is completely student driven and therefore saves time for supervisors and creates a direct interaction between students without…

  3. Bernstein and the Explanation of Social Disparities in Education: A Realist Critique of the Socio-Linguistic Thesis

    ERIC Educational Resources Information Center

    Nash, Roy

    2006-01-01

    Can an explanation of the origins of social disparities in educational achievement be assisted by a critical examination of Bernstein's sociology? This central question is approached by a consideration of the status of Bernstein's socio-linguistic thesis. The focus is on the nature of the explanations provided. The paper asks: What is the…

  4. Process improvement to the inspection readiness plan in chemical weapons convention challenge inspections. Master`s thesis

    SciTech Connect

    Triplett, W.M.

    1997-09-01

    This thesis identified current Information Technology initiatives to help improve the Navy`s Inspection Readiness Plan for Chemical Warfare Convention (CWC) Challenge Inspection. The CWC is an intensive inspection. The Challenge Inspection allows for a team of international inspectors to inspect a naval facility suspected of violating the CWC on very short notice. This thesis begins with a review of the CWC Challenge Inspection timeline. It then describes the Navy`s Inspection Readiness Plan for CWC Challenge Inspections as well as the Navy Tiger Team that is sent to naval facilities to assist the Commanding Officer and base personnel during inspections. One of the initiatives evaluated by this analysis is the use of videoconferencing. To ascertain the feasibility of using videoconferencing in the CWC Challenge Inspection process, this thesis reviews the current videoconferencing systems and standards, and the results of a questionnaire that was sent to various naval commands. This thesis concludes with recommendations for inclusion of videoconferencing and various other Information Technology initiatives in the CWC Challenge Inspection process.

  5. Getting used to academic public speaking: global self-esteem predicts habituation in blood pressure response to repeated thesis presentations.

    PubMed

    Elfering, Achim; Grebner, Simone

    2012-06-01

    Global self-esteem was tested to predict quicker cardiovascular adaptation during stressful oral thesis presentation and faster habituation from the first to the second and third thesis presentations. Nineteen graduate students initially rated their global self-esteem and afterwards orally presented their theses proposals in 20-min presentations to their thesis supervisor and peers. A second and third presentation of the revised thesis concepts took place at 4-weeks intervals. Ambulatory blood pressure and heart rate were assessed repeatedly during the presentations. Post-talk self ratings of stressfulness indicated presentations to be a strong public speaking stressor. One hundred and thirty-eight measurements of systolic (SBP), diastolic blood pressure (DBP), and heart rate (HR) showed a significant adaptation (decrease) during presentations. There was an overall mean level decrease from the first to the second, and the second to the third presentations in HR, but not in SBP and DBP. However, habituation in SBP and DBP across three presentations was significantly faster (p < .05) in those participants who initially reported higher levels of global self-esteem. Higher global self-esteem did not foster adaptation within the presentations. Self-esteem is discussed as an important individual resource that allows successful coping with recurring evaluative threats. PMID:22392261

  6. The Relation between Feedback Perceptions and the Supervisor-Student Relationship in Master's Thesis Projects

    ERIC Educational Resources Information Center

    de Kleijn, Renske A. M.; Meijer, Paulien C.; Pilot, Albert; Brekelmans, Mieke

    2014-01-01

    Research supervision can be investigated from social-emotional and cognitive perspectives, but most studies include only one perspective. This study aims to understand the interplay between a social-emotional (supervisor-student relationship) and cognitive (feedback) perspective on the outcomes of master's thesis supervision in specific, by…

  7. The Advanced Interdisciplinary Research Laboratory: A Student Team Approach to the Fourth-Year Research Thesis Project Experience

    ERIC Educational Resources Information Center

    Piunno, Paul A. E.; Boyd, Cleo; Barzda, Virginijus; Gradinaru, Claudiu C.; Krull, Ulrich J.; Stefanovic, Sasa; Stewart, Bryan

    2014-01-01

    The advanced interdisciplinary research laboratory (AIRLab) represents a novel, effective, and motivational course designed from the interdisciplinary research interests of chemistry, physics, biology, and education development faculty members as an alternative to the independent thesis project experience. Student teams are assembled to work…

  8. Getting Personal--What Does It Mean? A Critical Discussion of the Personal Dimension of Thesis Supervision in Higher Education

    ERIC Educational Resources Information Center

    Bengtsen, Soren S. E.

    2011-01-01

    The argument of the article is that contemporary research into thesis supervision overlooks important didactical features of the supervisory dialogue because of its focus on general pedagogical categories. Entailing this argument I suggest that the personal dimension should be seen not only as a means to enhanced communication between supervisor…

  9. The Heritage of Herding and Southern Homicide: Examining the Ecological Foundations of the Code of Honor Thesis

    ERIC Educational Resources Information Center

    Baller, Robert D.; Zevenbergen, Matthew P.; Messner, Steven F.

    2009-01-01

    The authors examine the ecological foundations of the thesis of a "code of honor" as an explanation for southern homicide. Specifically, they consider the effects of indicators of ethnic groups that migrated from herding economies (the Scotch-Irish), cattle and pig herding, and the relative importance of agricultural production across different…

  10. Brotherhood or Brothers in the "Hood"? Debunking the "Educated Gang" Thesis as Black Fraternity and Sorority Slander

    ERIC Educational Resources Information Center

    Hughey, Matthew W.

    2008-01-01

    In this article the author explores the controversial thesis that African American Collegiate Fraternities and Sororities, also known as Black Greek Letter Organizations (BGLOs), are "educated gangs". First, the author examines this polemic as a "truth claim" and compares BGLOs and gangs through: (1) hazing; (2) rape and substance abuse; (3)…

  11. Method for optimizing resource allocation in a government organization. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Afarin, James

    1994-01-01

    The managers in Federal agencies are challenged to control the extensive activities in government and still provide high-quality products and services to the American taxpayers. Considering today's complex social and economic environment and the $3.8 billion daily cost of operating the Federal Government, it is evident that there is a need to develop decision-making tools for accurate resource allocation and total quality management. The goal of this thesis is to provide a methodical process that will aid managers in Federal Government to make budgetary decisions based on the cost of services, the agency's objectives, and the customers' perception of the agency's product. A general resource allocation procedure was developed in this study that can be applied to any government organization. A government organization, hereafter the 'organization,' is assumed to be a multidivision enterprise. This procedure was applied to a small organization for the proof of the concept. This organization is the Technical Services Directorate (TSD) at the NASA Lewis Research Center in Cleveland, Ohio. As part of the procedure, a nonlinear programming model was developed to account for the resources of the organization, the outputs produced by the organization, the decision-maker's views, and the customers' satisfaction with the organization. The information on the resources of the organization was acquired from current budget levels of the organization and the human resources assigned to the divisions. The outputs of the organization were defined and measured by identifying metrics that assess the outputs, the most challenging task in this study. The decision-maker's views are represented in the model as weights assigned to the various outputs and were quantified by using the analytic hierarchy process. The customer's opinions regarding the outputs of the organization were collected through questionnaires that were designed for each division individually. Following the philosophy of

  12. Deletion of SHATI/NAT8L decreases the N-acetylaspartate content in the brain and induces behavioral deficits, which can be ameliorated by administering N-acetylaspartate.

    PubMed

    Toriumi, Kazuya; Mamiya, Takayoshi; Song, Ziyu; Honjo, Tatsuki; Watanabe, Hiroyuki; Tanaka, Junko; Kondo, Mizuki; Mouri, Akihiro; Kim, Hyoung-Chun; Nitta, Atsumi; Fukushima, Takeshi; Nabeshima, Toshitaka

    2015-11-01

    We previously identified a novel molecule "SHATI/NAT8L" that exerts an inhibitory effect on methamphetamine (METH)-induced behavioral deficits. Recently, it has been reported that SHATI might function as an aspartate N-acetyltransferase, which synthesizes N-acetylaspartate (NAA) in vitro. However, whether SHATI actually synthesizes NAA in vivo in the brain is still unclear. In this study, we found that both Shati-deleted mice showed significantly lower NAA levels in all brain areas than wild-type (Shati(+/+)) mice using HPLC and fluorescence detection, suggesting that SHATI regulates NAA content in the brain. Next, we measured the levels of monoamines and their metabolites in the adult mouse brain and found that the activities of monoaminergic systems were altered in Shati(-/-) mice. In particular, dopaminergic turnover increased in the nucleus accumbens (NAc) in Shati(-/-) mice, suggesting activation of the dopaminergic system. In fact, basal level of extracellular dopamine, and METH-induced dopamine release in the NAc of Shati(-/-) mice was significantly higher than that of Shati(+/+) and Shati(+/-) mice, which is consistent with findings that Shati(-/-) mice showed enhanced hyperlocomotion induced by METH. Moreover, in the forced swimming test, Shati-deleted mice showed a shortened immobility time, which was improved by intracerebroventricular (i.c.v.) administration of NAA prior to the test in Shati(+/-) but not in Shati(-/-) mice. The i.c.v. preinjection of NAA inhibited dopamine release after high K(+) stimulation in the NAc of Shati(+/+) and Shati(+/-) mice, but not Shati(-/-) mice. These results suggested that the behavioral deficits in Shati-deleted mice were caused by dopaminergic abnormality via deprivation of NAA. PMID:26361739

  13. CFH Y402H and ARMS2 A69S Polymorphisms and Oral Supplementation with Docosahexaenoic Acid in Neovascular Age-Related Macular Degeneration Patients: The NAT2 Study

    PubMed Central

    Merle, Bénédicte M. J.; Richard, Florence; Benlian, Pascale; Puche, Nathalie; Delcourt, Cécile; Souied, Eric H.

    2015-01-01

    Purpose Genetic susceptibility could be modified by environmental factors and may also influence differential responses to treatments for age-related macular degeneration (AMD). We investigated whether genotype could influence response to docosahexaenoic acid (DHA)-supplementation in the occurrence of choroidal new vessels (CNV). Methods The Nutritional AMD Treatment 2 (NAT2) study was a randomized, placebo-controlled, double-blind, parallel, comparative study, including 250 patients aged 55 to 85 years with early lesions of age-related maculopathy, visual acuity better than 0.4 Logarithm of Minimum Angle of Resolution units in the study eye and neovascular AMD in the fellow eye. Patients were randomized at baseline to receive either 3 daily fish-oil capsules, each containing 280 mg DHA, 90 mg EPA and 2 mg Vitamin E, or placebo. Results Patients carrying the risk allele (C) for CFH Y402H had no statistically significant increased risk for developing CNV in the study eye (Hazard Ratio (HR)=0.97; 95% Confidence Interval (CI): 0.54-1.76 for heterozygous and HR=1.29; 95%CI: 0.69-2.40 for homozygous). Patients carrying the risk allele (T) for ARMS2 A69S had no statistically significant increased risk for developing CNV in the study eye (HR=1.68; 95%CI: 0.91-3.12) for heterozygous and HR=1.78; 95%CI: 0.90-3.52 for homozygous). A significant interaction was observed between CFH Y402H and DHA-supplementation (p=0.01). We showed a protective effect of DHA-supplementation among homozygous non-risk patients. Among these patients, occurrence of CNV was 38.2% in placebo group versus 16.7% in DHA group (p=0.008). Conclusions These results suggest that a genetic predisposition to AMD conferred by the CFH Y402H variant limits the benefit provided by DHA supplementation. Trial Registration ISRCTN registry 98246501 PMID:26132079

  14. Development of ground support equipment for the NPS ionospheric spectroscopy and atmospheric chemistry (ISAAC) ultraviolet spectrograph. Master`s thesis

    SciTech Connect

    Fragiskos, L.

    1995-06-01

    This thesis details the design of Ground Support Equipment (GSE) for the Naval Postgraduate School`s Ionospheric Spectroscopy and Atmospheric Chemistry (ISAAC) Ultraviolet Spectrograph. ISAAC is one of the several experiments to be flown on the Advanced Research and Global Observation Satellite (ARGOS) in 1996. The GSE consists of several software programs written in LabVIEW. These programs simulate the timing signals that ISAAC will receive from the satellite bus. In addition, the programs acquire serial data from ISAAC, perform a serial to parallel conversion and display the resulting spectra. The GSE will allow testing of the spectrograph prior to the interface with the satellite bus. Although the complete flight instrument is not yet available for testing, this thesis describes how the GSE-to-ISAAC interface will be made and how it should be operated. Finally, some hardware/software incompatibilities are identified.

  15. Structure-activity predictions of properties of organophosphorus pesticides and chemical agents important for optical detection. Master`s thesis

    SciTech Connect

    Porte, R.E.

    1995-12-01

    This thesis presents the results of an investigation for estimating various physicochemical properties of chemical warfare agents and organophosphorus pesticides. The determination of aqueous solubility, - octanol/water partition coefficients, and alkaline hydrolysis rate constants will be used in the development of a chemical sensor using fiber optic spectroscopy. These three parameters will effect the limit of detection for each compound by limiting the concentration in the detector. The parameters were estimated by linear free energy relationships and quantitative structure activity relationships using experimental data for compounds of similar chemical structure. The results of this thesis showed that the hydrophobic medium represented by 1-octanol did concentrate the OP pesticides but did not significantly concentrate CWA, CWA simulants, or CWA hydrolysis products. Correlations were evaluated for six classes of organophosphorus compounds. The limitation of this approach to predicting physicochemical parameters is not in the molecular descriptors used in the regression equations but in the availability of existing experimental data.

  16. [The effect of public defense of a doctoral thesis on the heart rate of the doctoral candidate].

    PubMed

    Kiljander, Toni; Toikka, Jyri; Koskenvuo, Juha; Jaakkola, Ilkka

    2011-01-01

    The effect of public defense of a doctoral thesis on the heart rate of the doctoral candidate Most doctoral candidates find the public defense of a doctoral thesis an exciting and stressful experience. In this study, Holter recording during the defense was made for four doctoral candidates of the Faculty of Medicine. Maximum heart rate among the subjects was on the average 172 beats/min with a median heart rate of 116 beats/min. Sympathicotonia and release of stress hormones associated with the defense raise the heart rate to levels that may be very high for several hours. This is a risk factor for a coronary event and should be considered, if the doctoral candidate has coronary heart disease, carries risk factors for coronary heart disease, or is an elderly person. PMID:21805898

  17. [Medecine and chemistry in the context of the Enlightenment: the thesis of the Lausanne physician Marc-Louis Vullyamoz].

    PubMed

    Terrier, Georges

    2003-01-01

    The chemico-medical essay "De sale lactis essentiali" is a thesis presented in Leyden in 1756 by a physician from Lausanne, M.-L. Vullyamoz, to obtain the medical degree. It shows that chemistry has become a university science connected with medicine and that combustion was explained at that time by G. E. Stahl's theory of the phlogiston. It reminds us that the hypotheses of this German physician, which were part of the animistic doctrine, were widely adopted in Europe. In chemistry they began to fade in 1789 after the publication of Lavoisier's work on oxydation. Nevertheless, they have contributed to establish a modern science. In medicine Stahl's animism evolved towards vitalism, which survived in several forms. Vullyamoz's thesis, which presents chemical experiences intended to analyse and promote a popular medicine, is a testimony of the spirit of Enlightenment, which rejects dogmatism and tries to understand facts through observation and the use of reason. PMID:15030051

  18. Testing, analysis, and correction of the update operation of a parallel, multi-backend data-base supercomputer. Master's thesis

    SciTech Connect

    Williams, M.A.

    1992-03-01

    The Multi-Backend Database Supercomputer (MBDS) is designed to provide high-performance database management parallely for applications with very large and growing database. This thesis is a testing, analysis of and correction of the primary database operation UPDATE of MBDS. We provide an overview of the entire MBDS system and then focus on the parallel UPDATE operation in an attempt to discover and correct the deficiencies of the original UPDATE algorithm.

  19. "Unexplainable" medical histories and childhood sexual abuse. New doctoral thesis tells you how to investigate the links.

    PubMed

    Getz, L

    1999-06-01

    This is a brief summary and a personal reflection on Anne Luise Kirkengen's PhD thesis "Embodiment of sexual boundary violations in childhood". It is written to encourage other clinicians to familiarise themselves with this original and important study. It has high relevance for every clinician who is ever confronted with patients that present medical histories that are "diffuse" or unexplainable according to traditional medical knowledge. PMID:10439487

  20. Analysis of the morality of intention in nuclear deterrence, with special reference to final retaliation. Doctoral thesis

    SciTech Connect

    Zink, J.A.

    1990-01-01

    Quite apart from its apparent political obsolescence, the policy of nuclear deterrence is vulnerable to attack for its seemingly obvious immorality. Nuclear war is blatantly immoral, and nuclear deterrence requires a genuine intention to resort to the nuclear retaliation which would precipitate such a war. Therefore, since it is wrong to intend that which is wrong to do, deterrence is immoral. This thesis seeks to examine the nature of the deterrent intention as a means of verifying the soundness of the above deontological argument. This examination is carried out by first suggesting an acceptable notion of intention in general and then, after analysing the views of deterrent intention by other writers, proceeding to demonstrate the uniqueness of that intention. Having done this, and having explored the possibility that deterrence need not contain a genuine intention to retaliate, the thesis moves on to suggest and defend a moral principle which states that endeavours requiring the formation of an immoral intention may nevertheless be moral. Called the Principle of Double Intention (and based on the Principle of Double Effect), it offers a method for the moral assessment of agents who form immoral intentions within larger contexts. By applying this principle to nuclear deterrence, it is demonstrated that agents who undertake such a policy may be morally justified in doing so, provided certain conditions are met. The thesis closes with a refutation of the objection that an agent cannot rationally form an intention (such as that required in deterrence) which he has no reason to carry out.

  1. Evolution and Development of Dual Ingestion Systems in Mammals: Notes on a New Thesis and Its Clinical Implications

    PubMed Central

    Alberts, Jeffrey R.; Pickler, Rita H.

    2012-01-01

    Traditionally, the development of oral feeding is viewed as a continuous, unitary process in which reflex-dominated sucking behavior gives rise to a more varied and volitional feeding behavior. In contrast, we consider the thesis that the infant develops two separable ingestive systems, one for suckling and one for feeding. First, we apply an evolutionary perspective, recognizing that suckling-feeding is a universal, mammalian developmental sequence. We find that in mammalian evolution, feeding systems in offspring were established prior to the evolution of lactation, and therefore suckling is a separable feature that was added to feeding. We next review an experimental literature that characterizes suckling and feeding as separable in terms of their topography, sensory controls, physiological controls, neural substrates, and experience-based development. Together, these considerations constitute a view of “dual ingestive systems.” The thesis, then, is that suckling is not a simple precursor of feeding but is a complete behavior that emerges, forms, and then undergoes a dissolution that overlaps with the emergence of independent feeding. This thesis guides us to focus differently on the challenges of properly managing and facilitating oral ingestion in infants, especially those born preterm, prior to the developmental onset of suckling. PMID:23028391

  2. KARL: A Knowledge-Assisted Retrieval Language. M.S. Thesis Final Report, 1 Jul. 1985 - 31 Dec. 1987

    NASA Technical Reports Server (NTRS)

    Dominick, Wayne D. (Editor); Triantafyllopoulos, Spiros

    1985-01-01

    Data classification and storage are tasks typically performed by application specialists. In contrast, information users are primarily non-computer specialists who use information in their decision-making and other activities. Interaction efficiency between such users and the computer is often reduced by machine requirements and resulting user reluctance to use the system. This thesis examines the problems associated with information retrieval for non-computer specialist users, and proposes a method for communicating in restricted English that uses knowledge of the entities involved, relationships between entities, and basic English language syntax and semantics to translate the user requests into formal queries. The proposed method includes an intelligent dictionary, syntax and semantic verifiers, and a formal query generator. In addition, the proposed system has a learning capability that can improve portability and performance. With the increasing demand for efficient human-machine communication, the significance of this thesis becomes apparent. As human resources become more valuable, software systems that will assist in improving the human-machine interface will be needed and research addressing new solutions will be of utmost importance. This thesis presents an initial design and implementation as a foundation for further research and development into the emerging field of natural language database query systems.

  3. Master's Thesis Supervision: Relations between Perceptions of the Supervisor-Student Relationship, Final Grade, Perceived Supervisor Contribution to Learning and Student Satisfaction

    ERIC Educational Resources Information Center

    de Kleijn, Renske A. M.; Mainhard, M. Tim; Meijer, Paulien C.; Pilot, Albert; Brekelmans, Mieke

    2012-01-01

    Master's thesis supervision is a complex task given the two-fold goal of the thesis (learning and assessment). An important aspect of supervision is the supervisor-student relationship. This quantitative study (N = 401) investigates how perceptions of the supervisor-student relationship are related to three dependent variables: final grade,…

  4. An Investigation of Non-Thesis Master's Program Geography Teacher Candidates' Attitudes towards Teaching Profession regarding Several Socio-Cultural Features

    ERIC Educational Resources Information Center

    Sezer, Adem; Kara, Hasan; Pinar, Adnan

    2011-01-01

    The purpose of this study is to examine the attitudes of non-thesis master's degree program: geography teacher candidates towards teaching profession regarding several socio-cultural features. The study was conducted in different universities with 218 geography teacher candidates enrolled in the geography education non-thesis master's degree…

  5. Prize of the best thesis 2015: Study of debris discs through state-of-the-art numerical modelling

    NASA Astrophysics Data System (ADS)

    Kral, Q.; Thébault, P.

    2015-12-01

    This proceeding summarises the thesis entitled ``Study of debris discs with a new generation numerical model'' by Quentin Kral, for which he obtained the prize of the best thesis in 2015. The thesis brought major contributions to the field of debris disc modelling. The main achievement is to have created, almost ex-nihilo, the first truly self-consistent numerical model able to simultaneously follow the coupled collisional and dynamical evolutions of debris discs. Such a code has been thought as being the ``Holy Grail'' of disc modellers for the past decade, and while several codes with partial dynamics/collisions coupling have been presented, the code developed in this thesis, called ``LIDT-DD'' is the first to achieve a full coupling. The LIDT-DD model, which is the first of a new-generation of fully self-consistent debris disc models is able to handle both planetesimals and dust and create new fragments after each collision. The main idea of LIDT-DD development was to merge into one code two approaches that were so far used separately in disc modelling, that is, an N-body algorithm to investigate the dynamics, and a statistical scheme to explore the collisional evolution. This complex scheme is not straightforward to develop as there are major difficulties to overcome: 1) collisions in debris discs are highly destructive and produce clouds of small fragments after each single impact, 2) the smallest (and most numerous) of these fragments have a strongly size-dependent dynamics because of the radiation pressure, and 3) the dust usually observed in discs is precisely these smallest grains. These extreme constraints had so far prevented all previous attempts at developing self-consistent disc models to succeed. The thesis contains many examples of the use of LIDT-DD that are not yet published but the case of the collision between two asteroid-like bodies is studied in detail. In particular, LIDT-DD is able to predict the different stages that should be observed

  6. ERBE S10 MFOV SF NAT

    Atmospheric Science Data Center

    2016-06-09

    ... product contains data which have been averaged to a 2.5 grid scale. The S-10 contains data which have been averaged to 5.0 or 10.0 grid scale. Projection: Gridding is an equal-angle projection of 2.5 X 2.5 ...

  7. ERBE S10 WFOV SF NAT

    Atmospheric Science Data Center

    2016-06-13

    ... scanner instruments on board the NOAA-9 and NOAA-10 satellites provide global coverage, while the ERBE scanner instrument onboard ... have 136 degree FOV on ERBS and 126 degree FOV on the NOAA satellites. The MFOV instruments have footprints of approximately 5 geocentric ...

  8. ERBE S10 WFOV NF NAT

    Atmospheric Science Data Center

    2016-06-09

    ... scanner instruments on board the NOAA-9 and NOAA-10 satellites provide global coverage, while the ERBE scanner instrument onboard ... have 136 degree FOV on ERBS and 126 degree FOV on the NOAA satellites. The MFOV instruments have footprints of approximately 5 geocentric ...

  9. ERBE S10N WFV NF NAT

    Atmospheric Science Data Center

    2016-06-13

    ... scanner instruments on board the NOAA-9 and NOAA-10 satellites provide global coverage, while the ERBE scanner instrument onboard ... have 136 degree FOV on ERBS and 126 degree FOV on the NOAA satellites. The MFOV instruments have footprints of approximately 5 geocentric ...

  10. ERBE S10N WFV SF NAT

    Atmospheric Science Data Center

    2016-06-14

    ... scanner instruments on board the NOAA-9 and NOAA-10 satellites provide global coverage, while the ERBE scanner instrument onboard ... have 136 degree FOV on ERBS and 126 degree FOV on the NOAA satellites. The MFOV instruments have footprints of approximately 5 geocentric ...

  11. 3,2'-Dimethyl-4-aminobiphenyl-DNA adduct formation in tumor target and nontarget organs of rapid and slow acetylator Syrian hamsters cogenic at the NAT2 locus.

    PubMed

    Feng, Y; Jiang, W; Deitz, A C; Hein, D W

    1996-10-01

    DNA adduct formation is an important step in initiation of the carcinogenic process. 3,2'-Dimethyl-4-aminobiphenyl (DMABP) is a well-documented multiorgan carcinogenic aromatic amine in rodents. In the present study, DMABP-DNA adduct levels were measured in rapid (Bio. 82.73/H-Pat(r)) and slow (Bio. 82.73/H-Pat(s)) acetylator Syrian hamsters congenic at the NAT2 locus following a single injection of 33 or 100 mg/kg body wt DMABP. Two DNA adducts, N-(deoxyguanosin-8-yl)-DMABP and 5-(deoxyguanosin-N2-yl)-DMABP, were identified and quantitated by 32P-postlabeling assay. After injection of 33 mg/kg, DMABP-DNA adducts were detected in urinary bladder at 6, 18, 24, and 48 hr with adduct levels increasing up to 48 hr postinjection. DMABP-DNA adducts were not detected in liver, colon, and heart. After injection of 100 mg/kg, DMABP-DNA adducts were detected in urinary bladder, liver, prostate, colon, and heart at 48 hr postinjection. DMABP-DNA adduct levels were significantly higher in urinary bladder (primary tumor target organ) than in the other organs of both rapid and slow acetylator congenic hamsters. N-(deoxyguanosin-8-yl)-DMABP levels were significantly higher in liver and prostate than in colon and heart of rapid and slow acetylator congenic hamsters, whereas 5-(deoxyguanosin-N2-yl)-DMABP levels were significantly higher in prostate than in colon and heart of rapid and slow acetylator congenic hamsters. DMABP-DNA adduct levels in each tissue examined did not differ significantly between rapid and slow acetylator hamsters following either 33 or 100 mg/kg injection. The tissue-dependent differences in DMABP-DNA adduct levels observed in the Syrian hamster differ from those reported in the rat and are consistent with previous studies that show DMABP induces primarily urinary bladder tumors in the Syrian hamster. PMID:8887447

  12. Effect of electron-density gradients on propagation of radio waves in the mid-latitude trough. Master's thesis

    SciTech Connect

    Citrone, P.J.

    1991-01-01

    Partial contents of this thesis include: (1) Radio-wave propagation and the mid-latitude trough; (2) Ionospheric measurements; (3) Modification of time-dependent ionospheric model output with latitudinal electron-density profiles from digisonde trough depictions; (4) Ray-tracing simulations to examine ground range; and (5) Effects of three-dimensional gradients in electron density on radio-wave propagation in the trough region. Data is tabulated for geophysical conditions, solar activity level, geomagnetic activity level, conditions for vertical ray refraction to surface, and ray-tracing fixed-input conditions.

  13. Multivariable control of the Space Shuttle Remote Manipulator System using linearization by state feedback. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Gettman, Chang-Ching LO

    1993-01-01

    This thesis develops and demonstrates an approach to nonlinear control system design using linearization by state feedback. The design provides improved transient response behavior allowing faster maneuvering of payloads by the SRMS. Modeling uncertainty is accounted for by using a second feedback loop designed around the feedback linearized dynamics. A classical feedback loop is developed to provide the easy implementation required for the relatively small on board computers. Feedback linearization also allows the use of higher bandwidth model based compensation in the outer loop, since it helps maintain stability in the presence of the nonlinearities typically neglected in model based designs.

  14. Measurement of isomeric yield ratios of 197m,gPt and 190m2,g+m1Ir from the 198Pt(γ,n) and natPt(γ,xn1p) reactions induced by 55-, 60-, and 65-MeV bremsstrahlung

    NASA Astrophysics Data System (ADS)

    Kye, Yong-Uk; Shin, Sung-Gyun; Cho, Moo-Hyun; Kim, Kyung Sook; Namkung, Won; Kim, Guinyun; Kim, Kwangsoo; Kang, Yeong-Rok; Lee, Man-Woo; Yang, Sung-Chul; Nguyen, Van Do; Pham, Duc Khue; Kim, Tien Thanh; Naik, Haladhara

    2015-05-01

    We have measured the isomeric yield ratios of 197m,gPt from the 198Pt(γ,n) reaction and 190m2,g+m1Ir from the natPt(γ,xn1p) reaction, induced with the bremsstrahlung end-point energies of 55-, 60-, and 65-MeV. The measurements were carried out by the activation method in combination with the direct γ-spectrometry. The experiments were performed at the 100 MeV electron linac of the Pohang Accelerator Laboratory (PAL). The obtained results at 55-, 60- and 65-MeV for the 197m,gPt from the 198Pt(γ,n) reaction are 0.166 ± 0.012, 0.174 ± 0.011, and 0.175 ± 0.011, whereas for the 190m2,g+m1Ir from the natPt(γ,xn1p) reaction are 0.072 ± 0.006, 0.084 ± 0.006 and 0.087 ± 0.006, respectively. The present results are measured for the first time over the investigated energy range. The present data are compared with the similar literature data at lower energy to examine the role of excitation energy.

  15. Physician-assisted suicide and public virtue: a reply to the liberty thesis of "the Philosophers' Brief".

    PubMed

    DuBois, J M

    1999-01-01

    The "Philosophers' Brief," penned by six of today's most influential philosophers, was submitted as an amicus curiae brief to the Supreme Court as it prepared to consider the cases of Washington v. Glucksberg and Vacco v. Quill. It set precedent as the first such brief submitted by a group representing itself solely as moral philosophers. The brief became an overnight gold standard statement of the liberal philosophical understanding of the relationship of the State to so-called 'private morality.' The main thesis of the brief is that physician-assisted suicide regards the deeply personal event of death, and that individuals have a constitutionally guaranteed right to make decisions for themselves about the intimate details of their lives. In this article, James DuBois calls this the 'liberty thesis,' and he argues that the brief's application of this principle is both contradictory and impracticable. The contradiction arises as the brief proposes restrictions on the right to physician-assisted suicide--restrictions that require the State to abandon neutrality on intimate value judgments about life's worth. The impracticability arises insofar as the brief fails to leave room for a compelling State interest in promoting a minimal level of public virtue. Ironically, one of the strongest arguments that can be proffered on behalf of a State interest in preserving a minimal level of public virtue stems from its role in safeguarding human liberty. PMID:10597662

  16. Strategic plan for the Persian Gulf region: Options for deterring and/or defeating an emerging threat. Master's thesis

    SciTech Connect

    Ward, M.W.

    1992-12-17

    The Persian Gulf region is, in all likelihood, going to remain crucial to American interests through the next several decades. The world depends on the petroleum reserves of the Gulf region to fuel its economic engine. The recent history of the region has been rife with conflict, and the U.S. has had to intervene militarily on several occasions to ensure its vital interests were protected. This thesis examines the strategic circumstances in the Gulf region and ways in which American political, diplomatic, and military policy can help shape the environment to conform to its interests. Several scenarios are developed which attempt to forecast the results of different environments on regional stability. The thesis reaches the conclusion that the United States must take a proactive role if its short- and long-term interests are to be protected. The short-term goal of U.S. policy must be to maintain a balance of power and regional correlation of forces which serves to deter any would-be aggressor nations. In the long run, the United States must seek a comprehensive regional peace. Various methods of achieving these goals are examined....Persian Gulf, Arms Proliferation, Strategic Planning, Gulf Cooperation Council, GCC, Regional Deterrence, Middle East, Arms Control, Scenario Development, Iraq, Iran, Saudi Arabia, Regional Security Strategy.

  17. Study of magnetic activity effects on the thermospheric winds in the low ionosphere. Master`s thesis

    SciTech Connect

    Davila, R.C.

    1994-09-01

    The purpose of this thesis is to examine the effects of magnetic activity on the low latitude F-region thermospheric winds. The F-region (120-1600 km) is a partially ionized medium where O+ and O are the major ion and neutral species, respectively. The thermospheric winds at these altitudes are driven primarily by pressure gradient forces resulting from the solar heating during the day and cooling at night. For this study, the author used measured Fabry-Perot Interferometer (FPI) winds at Arequipa (16.5 deg S, 71.5 deg W) and measured FPI and incoherent Scatter Radar (ISR) winds at Arecibo (18.6 deg N, 66.8 deg W).

  18. Comparative of nuclear technology and direct energy conversion methods for space power systems. Master`s thesis

    SciTech Connect

    Reason, J.P.

    1997-06-01

    The objectives of this thesis are to investigate the theory of direct energy conversion, research the development of space nuclear power systems, evaluate the status of current systems, and draw conclusions about the feasibility and merit of using nuclear power for future space missions. Development of the earliest systems began in 1955 with the Systems for Nuclear Auxiliary Power (SNAP) Program and Project Rover. A detailed review of system design and performance is provided for the reactors and radioisotope thermoelectric generators (RTG`s) of past and current programs. Thermoelectric and thermionic energy conversion techniques have been used predominantly in space nuclear power systems. The theory of these direct energy conversion methods is analyzed. Also, the safety review procedures and regulations governing the launch of nuclear sources into space are characterized. Conclusions compare accomplished levels of system performance to theoretically predicted limits and comment on the usefulness of space nuclear power for space applications.

  19. The application of the reduced order model Kalman filter to motion estimation of degraded image sequences. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Simpson, Elizabeth C.

    1989-01-01

    Motion estimation is a field of great interest because of its many applications in areas such as robotics and image coding. The optic flow method is one such scheme which, although fairly accurate, is prone to error in the presence of noise. This thesis describes the use of the reduced order model Kalman filter (ROMKF) in reducing errors in displacement estimation due to degradation of the sequence. The implementation of filtering and motion estimation algorithms on the SUN workstation is also discussed. Results from preliminary testing were used to determine the degrees of freedom available for the ROMKF in the SUN software. The tests indicated that increasing the state to the left leads to slight improvement over the minimum state case. Therefore, the software uses the minimum model, with the option of adding states to the left only. The ROMKF was then used in conjunction with a hierarchical pel recursive motion estimation algorithm. Applying the ROMKF to the degraded displacements themselves generally yielded slight improvements in cases with noise degradation and noise plus blur. Filtering the images of the degraded sequence prior to motion estimation was less effective in these cases. Both methods performed badly in the case of blur alone, resulting in increased displacement errors. This is thought to be due in part to filter artifacts. Some improvements were obtained by varying the filter parameters when filtering the displacements directly. This result suggests that further study in varying filter parameters may lead to better results. The results of this thesis indicate that the ROMKF can play a part in reducing motion estimation errors from degraded sequences. However, more work needs to be done before the use of the ROMKF can be a practical solution.

  20. Survivability of the hardened mobile launcher when attacked by a hypothetical rapidly retargetable ICBM system. Master's thesis

    SciTech Connect

    Gearhart, D.J.; Merrow, S.F.

    1986-03-01

    This thesis evaluates the survivability of the hardened mobile launcher system (HML) against a hypothetical enemy ICBM system. The hypothetical system has two key capabilities: it can obtain near real-time intelligence information regarding the HML's location, and it can be retargeted in flight (as necessary) according to the intelligence information. Thus, the hypothetical ICBM threat systems can attack individual HMLs directly rather than rely on a barrage attack against HML bases. Monte Carlo simulation is used to approach the problem. The model is an MBASIC computer program, written and runs on an Apple Macintosh computer. The model simulates the flight of the attacking ICBMs (there may be as few as one or as many as 14 warheads directed at each HML) and the random dispersal tactics of a single HML. The model determines the locations of the detonations and the location of the HML at time of detonation. Based on these locations, probability of kill due to peak-blast overpressure is calculated. A key parameter in the model is intelligence / retargeting cycle time -- the time required to obtain intelligence and retarget accordingly. This time is varied from 1-30 minutes. The model also allows variations in HML speed and hardness and threat system CEP. A subroutine for examining the effects of neutron fratricide on the attacking warheads is included (although the effects were found to be negligible). The thesis concludes that very small intelligence/retargeting cycle times are required for this to be an effective weapon system against the HML. Thus, with today's (or near future) technology, the HML can be considered a very survivable system.