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Sample records for epsilon indi ba

  1. The Properties of the local Interstellar Medium and the Interaction of the Stellar Winds of epsilon Indi and lambda Andromedae with the Interstellar Environment

    NASA Technical Reports Server (NTRS)

    Wood, Brian E.; Alexander, William R.; Linsky, Jeffrey L.

    1996-01-01

    We present new observations of the Ly alpha lines of Epsilon Indi (K5 5) and A Andromedae (G8 4-3 + ?) These data were obtained by the Goddard High Resolution Spectrograph (GHRS) on the Hubble Space Telescope. Analysis of the interstellar H 1 and D 1 absorption lines reveals that the velocities and temperatures inferred from the H 1 lines are inconsistent with the parameters inferred from the D 1 lines, unless the H 1 absorption is assumed to be produced by two absorption components. One absorption component is produced by interstellar material. For both lines of sight observed, the velocity of this component is consistent with the velocity predicted by the local flow vector. For the Epsilon Indi data, the large velocity separation between the stellar emission and the interstellar absorption allows us to measure the H 1 column density independent of the shape of the intrinsic stellar Ly alpha profile. This approach permits us to quote an accurate column density and to assess its uncertainty with far more confidence than in previous analyses, for which the errors were dominated by uncertainties in the assumed stellar profiles.

  2. K-H2 quasi-molecular absorption detected in the T-dwarf \\varepsilon Indi Ba

    NASA Astrophysics Data System (ADS)

    Allard, F.; Allard, N. F.; Homeier, D.; Kielkopf, J.; McCaughrean, M. J.; Spiegelman, F.

    2007-11-01

    Context: T-type dwarfs present a broad and shallow absorption feature centred around 6950 Å in the blue wing of the K doublet at 0.77 μm which resembles in depth and shape the satellite absorption predicted by detailed collisional broadening profiles. In our previous work, the position of the predicted line satellite was however somewhat too blue compared to the observed feature. Aims: In this paper, we investigate whether new calculations of the energy surfaces of the potentials in the K-H2 system, including spin-orbit coupling, result in a closer coincidence of the satellite with the observed position. We also investigate the extent to which CaH absorption bands contribute to the feature and at what T_eff these respective opacity sources predominate. Methods: We present model atmospheres and synthetic spectra, including gravitational settling for an improved description of depth-dependent abundances of refractory elements, and based on new K-H2 line profiles using improved interaction potentials. Results: By comparison with a high signal-to-noise optical spectrum of the T1 dwarf \\varepsilon Indi Ba, we find that these new models do reproduce the observed feature, while CaH does not contribute for the atmospheric parameters considered. We also find that CaH is settled out so deep into the atmosphere that even turbulent vertical mixing would appear insufficient to bring significant amounts of CaH to the observable photosphere in dwarfs of later type than L5. Conclusions: We conclude that previous identification of the feature at this location in the spectra of T dwarfs as well as the latest L dwarfs with CaH was erroneous, as expected on physical grounds: calcium has already condensed onto grains in early L dwarfs and thus should have settled out of the photosphere in cooler brown dwarfs. This finding revokes one of the observational verifications for the cloud-clearing theory assumption: a gradual clearing of the cloud cover in early T dwarfs.

  3. Crystal structures and magnetic order of La{sub 0.5+{delta}} A{sub 0.5-{delta}}Mn{sub 0.5+{epsilon}}Ru{sub 0.5-{epsilon}}O{sub 3} (A=Ca,Sr,Ba): Possible orbital glass ferromagnetic state

    SciTech Connect

    Granado, E.; Huang, Q.; Lynn, J. W.; Gopalakrishnan, J.; Ramesha, K.

    2004-12-01

    The crystallographic and magnetic properties of La{sub 0.5+{delta}}A{sub 0.5-{delta}}Mn{sub 0.5+{epsilon}}Ru{sub 0.5-{epsilon}}O{sub 3}= (A=Ca,Sr,Ba) were investigated by means of neutron powder diffraction. All studied samples show the orthorhombic perovskite crystal structure, space group Pnma, with regular (Mn,Ru)O{sub 6} octahedra and no chemical ordering of the Mn{sup 3+} and Ru{sup 4+} ions. Ferromagnetic spin structures were observed below T{sub c}{approx}200-250 K, with an average ordered moment of {approx}1.8-2.0{mu}{sub B}/(Mn,Ru). The observation of long-range ferromagnetism and the absence of orbital ordering are rationalized in terms of a strong Mn-Ru hybridization, which may freeze the orbital degree of freedom and broaden the e{sub g} valence band, leading to an orbital glass state with carrier-mediated ferromagnetism.

  4. Epsilon Aurigae

    NASA Astrophysics Data System (ADS)

    Turner, Rebecca; Price, A.; Henden, A.

    2009-05-01

    The IYA 2009 working group on Research Experiences for Students, Teachers, and Citizen-Scientists is planning a multi-year project involving the bright star Eps Aur. The project will go beyond simple observing and also include a major data analysis component. The goal is to introduce the participant to the full scientific process from background research to paper writing for a peer-reviewed journal. It begins with a 10 Star Training Program of several types of binary and transient variable stars that are easy to observe from suburban locations with the naked eye. Participants will be trained both in observing and also in basic data analysis of photometric datasets (light curve and period analysis). Eventually it will lead to a capstone project: monitoring the rare and mysterious 2009-2011 eclipse of Epsilon Aurigae. In the summer of IYA 2009, third-magnitude Eps Aur will experience its next eclipse, which occurs every 27.1 years and lasts 714 days, nearly two years. The star is bright enough to be seen with the naked eye from most urban areas. If fully funded, the project will also involve two public workshops on observing and data analysis in the summers of 2009 and 2010, respectively.

  5. epsilon-Hexachlorocyclohexane (epsilon-HC)

    Integrated Risk Information System (IRIS)

    epsilon - Hexachlorocyclohexane ( epsilon - HC ) ; CASRN 6108 - 10 - 7 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard

  6. How to measure epsilon'/epsilon with lattice QCD

    SciTech Connect

    Sharpe, S.R.

    1987-04-01

    A pedagogical discussion is given of a lattice calculation of epsilon'. The method is outlined, and preliminary results are presented. They suggest that epsilon'/epsilon may be reduced from previous estimates by 60-70%.

  7. The epsilon dataflow processor

    SciTech Connect

    Grafe, V.G.; Davidson, G.S.; Hoch, J.E.; Holmes, V.P.

    1988-01-01

    The epsilon dataflow architecture is designed for high speed uniprocessor execution as well as for parallel processing. The epsilon architecture directly matches ready operands, thus eliminating the need for associative matching stores. epsilon also supports low cost data fan out and critical sections. A 10 MFLOPS CMOS/TTL processor prototype is running and its performance has been measured with several benchmarks. The prototype processor has demonstrated sustained performance exceeding that of comparable control flow processors running at higher clock rates (three times faster than a 20 MHz transputer and 24 times faster than a Sun on a suite of arithmetic tests, for example). 22 refs., 16 figs.

  8. The EPSILON-2 multiprocessor system

    SciTech Connect

    Grafe, V.G.; Hoch, J.E. )

    1990-12-01

    This paper reports on Epsilon-2 which is a general purpose parallel computer architecture that addresses the twin goals of high performance and programmability. Epsilon-2 implements a hybrid computation model that combines the fine-grain parallelism of dataflow computing with the sequential efficiency characteristic of von Neumann computing. It provides instruction-level synchronization, single-cycle context switches, and RISC-like sequential execution. The general parallel computing model and the architecture of Epsilon-2 are described. A sample code is also presented to illustrate Epsilon-2's operation.

  9. Electronic Health Records Place 1st at Indy 500

    MedlinePlus

    ... Navigation Bar Home Current Issue Past Issues EHR Electronic Health Records Place 1st at Indy 500 Past ... last May's Indy 500 had thousands of personal Electronic Health Records on hand for those attending—and ...

  10. Quark masses, B-parameters, and CP violation parameters {epsilon} and {epsilon}{prime}/{epsilon}

    SciTech Connect

    Gupta, R.

    1998-01-20

    After a brief introduction to lattice QCD, the author summarizes the results for the light quark masses and the bag parameters B{sub K}, B{sub 6}{sup 1/2}, and B{sub 8}{sup 3/2}. The implications of these results for the standard model estimates of CP violation parameters {epsilon} and {epsilon}{prime}/{epsilon} are also discussed.

  11. Eclipse of epsilon Aurigae

    NASA Astrophysics Data System (ADS)

    Templeton, Matthew R.

    2009-07-01

    The bright, long-period, eclipsing binary star epsilon Aurigae is predicted to begin its next eclipse late July or early August of 2009. Epsilon Aurigae is now past solar conjunction and has reappeared as a morning object. All observers -- both visual and instrumental -- are encouraged to contribute observations of the eclipse during the next two years, beginning immediately for morning observers. Observations are urgently requested right now because it is less likely to be observed in the morning, and the eclipse will begin within the next month. The AAVSO is participating in a global campaign to record this eclipse as part of the International Year of Astronomy 2009 celebrations, organized by the Citizen Sky project (http://www.citizensky.org). For experienced visual observers, please observe this star on a weekly basis, using charts available via VSP from the AAVSO website. For novice visual observers, we recommend participating in this observing program by following the Citizen Sky 10-Star tutorial program, which provides a simple training experience in variable star observing. Photoelectric observers belonging to the AAVSO PEP-V program may submit data as usual via the WebObs feature of the AAVSO website Blue&Gold section. Photoelectric observers may also contribute reduced observations in all filters (including infrared J- and H-bands) directly to the AAVSO via WebObs. Observers using wide-field CCD and DSLR systems are also encouraged to participate; avoid saturating the star. For those with narrower-field systems (D < 2 degrees), we recommend taking a large number (10-100) of very short exposures and then stacking the resulting images. Observations should be submitted to the AAVSO International Database. Aaron Price is coordinating Citizen Sky for the AAVSO, and Dr. Robert Stencel and Jeffrey Hopkins are co-leading the precision photometry efforts.

  12. Natural Hazards within the West Indies.

    ERIC Educational Resources Information Center

    Cross, John A.

    1992-01-01

    Outlines the vulnerability of the West Indies to various natural hazards, especially hurricanes, earthquakes, and volcanic eruptions. Reviews the geologic and meteorologic causes and consequences of the hazards. Suggests methods of incorporating hazards information in geography classes. Includes maps and a hurricane tracking chart. (DK)

  13. Middle Passage in the Triangular Slave Trade: The West Indies

    ERIC Educational Resources Information Center

    Sawh, Ruth; Scales, Alice M.

    2006-01-01

    Our narrative focuses on the middle passage of the slave trade in the West Indies. Herein we describe why more men, women, and children were imported in the West Indies than other islands. Specifically, our aim was to address how slaves in the middle passage of the triangular slave trade were treated, how they sustained themselves, and how they…

  14. The role of INDY in metabolism, health and longevity

    PubMed Central

    Rogers, Ryan P.; Rogina, Blanka

    2015-01-01

    Indy (I’m Not Dead Yet) encodes the fly homolog of a mammalian SLC13A5 plasma membrane transporter. INDY is expressed in metabolically active tissues functioning as a transporter of Krebs cycle intermediates with the highest affinity for citrate. Decreased expression of the Indy gene extends longevity in Drosophila and C. elegans. Reduction of INDY or its respective homologs in C. elegans and mice induces metabolic and physiological changes similar to those observed in calorie restriction. It is thought that these physiological changes are due to altered levels of cytoplasmic citrate, which directly impacts Krebs cycle energy production as a result of shifts in substrate availability. Citrate cleavage is a key event during lipid and glucose metabolism; thus, reduction of citrate due to Indy reduction alters these processes. With regards to mammals, mice with reduced Indy (mIndy–/–) also exhibit changes in glucose metabolism, mitochondrial biogenesis and are protected from the negative effects of a high calorie diet. Together, these data support a role for Indy as a metabolic regulator, which suggests INDY as a therapeutic target for treatment of diet and age-related disorders such as Type II Diabetes and obesity. PMID:26106407

  15. The EPSILON-2 hybrid dataflow architecture

    SciTech Connect

    Grafe, V.G.; Hoch, J.E.

    1989-11-08

    EPSILON-2 is a general parallel computer architecture that combines the fine grain parallelism of dataflow computing with the sequential efficiency common to von Neumann computing. Instruction level synchronization, single cycle context switches, and RISC-like sequential efficiency are all supported in EPSILON-2. The general parallel computing model of EPSILON-2 is described, followed by a description of the processing element architecture. A sample code is presented in detail, and the progress of the physical implementation discussed. 11 refs., 14 figs.

  16. Motility in the epsilon-proteobacteria.

    PubMed

    Beeby, Morgan

    2015-12-01

    The epsilon-proteobacteria are a widespread group of flagellated bacteria frequently associated with either animal digestive tracts or hydrothermal vents, with well-studied examples in the human pathogens of Helicobacter and Campylobacter genera. Flagellated motility is important to both pathogens and hydrothermal vent members, and a number of curious differences between the epsilon-proteobacterial and enteric bacterial motility paradigms make them worthy of further study. The epsilon-proteobacteria have evolved to swim at high speed and through viscous media that immobilize enterics, a phenotype that may be accounted for by the molecular architecture of the unusually large epsilon-proteobacterial flagellar motor. This review summarizes what is known about epsilon-proteobacterial motility and focuses on a number of recent discoveries that rationalize the differences with enteric flagellar motility. PMID:26590774

  17. The nucleotide sequence of the mouse immunoglobulin epsilon gene: comparison with the human epsilon gene sequence.

    PubMed Central

    Ishida, N; Ueda, S; Hayashida, H; Miyata, T; Honjo, T

    1982-01-01

    We have determined the nucleotide sequence of the immunoglobulin epsilon gene cloned from newborn mouse DNA. The epsilon gene sequence allows prediction of the amino acid sequence of the constant region of the epsilon chain and comparison of it with sequences of the human epsilon and other mouse immunoglobulin genes. The epsilon gene was shown to be under the weakest selection pressure at the protein level among the immunoglobulin genes although the divergence at the synonymous position is similar. Our results suggest that the epsilon gene may be dispensable, which is in accord with the fact that IgE has only obscure roles in the immune defense system but has an undesirable role as a mediator of hypersensitivity. The sequence data suggest that the human and murine epsilon genes were derived from different ancestors duplicated a long time ago. The amino acid sequence of the epsilon chain is more homologous to those of the gamma chains than the other mouse heavy chains. Two membrane exons, separated by an 80-base intron, were identified 1.7 kb 3' to the CH4 domain of the epsilon gene and shown to conserve a hydrophobic portion similar to those of other heavy chain genes. RNA blot hybridization showed that the epsilon membrane exons are transcribed into two species of mRNA in an IgE hybridoma. Images Fig. 4. PMID:6329728

  18. The search for companions to Epsilon Eridani.

    PubMed

    Lawton, A T; Wright, P

    1990-12-01

    The authors review efforts to examine the star Epsilon Eridani and determine the possibility for the existence of an Earth-like planet. Early data indicated that there must be a habitable ecosphere about 82.5 million Km from the primary. Research into the existence of another planetary system determined that Epsilon Eridani was a binary star with an Oort cloud system, indicating the possibility of planet formation. A review of the evidence suggests that the presence of the small red Dwarf companion star precludes the existence of a planetary system surrounding Epsilon Eridani. It is suggested that observations continue to provide further data about the formation of binary systems. PMID:11540498

  19. Systematic effects of the quenched approximation on the strong penguin contribution to epsilon-prime / epsilon

    SciTech Connect

    Aubin, C.; Christ, N.H.; Dawson, C.; Laiho, J.W.; Noaki, J.; Li, S.; Soni, A.; /Brookhaven

    2006-03-01

    We discuss the implementation and properties of the quenched approximation in the calculation of the left-right, strong penguin contributions (i.e. Q{sub 6}) to {epsilon}{prime}/{epsilon}. The coefficient of the new chiral logarithm, discovered by Golterman and Pallante, which appears at leading order in quenched chiral perturbation theory is evaluated using both the method proposed by those authors and by an improved approach which is free of power divergent corrections. The result implies a large quenching artifact in the contribution of Q{sub 6} to {epsilon}{prime}/{epsilon}. This failure of the quenched approximation affects only the strong penguin operators and so does not affect the Q8 contribution to {epsilon}{prime}/{epsilon} nor ReA{sub 0}, ReAP{sub 2} and thus, the {Delta}I = 1/2 rule at tree level in chiral perturbation theory.

  20. Systematic effects of the quenched approximation on the strong penguin contribution to {epsilon}{sup '}/{epsilon}

    SciTech Connect

    Aubin, C.; Christ, N. H.; Li, S.; Dawson, C.; Noaki, J.; Laiho, J. W.; Soni, A.

    2006-08-01

    We discuss the implementation and properties of the quenched approximation in the calculation of the left-right, strong penguin contributions (i.e. Q{sub 6}) to {epsilon}{sup '}/{epsilon}. The coefficient of the new chiral logarithm, discovered by Golterman and Pallante, which appears at leading order in quenched chiral perturbation theory is evaluated using both the method proposed by those authors and by an improved approach which is free of power divergent corrections. The result implies a large quenching artifact in the contribution of Q{sub 6} to {epsilon}{sup '}/{epsilon}. This failure of the quenched approximation affects only the strong penguin operators and so does not affect the Q{sub 8} contribution to {epsilon}{sup '}/{epsilon} nor ReA{sub 0}, ReA{sub 2} and thus, the {delta}I=1/2 rule at tree level in chiral perturbation theory.

  1. Epsilon Aurigae Eclipse 2009 - Ingress

    NASA Astrophysics Data System (ADS)

    Hopkins, Jeffrey L.; Stencel, Robert E.; Leadbeater, Robin; Beckmann, Paul J.; Buil, Christian; Collins, Donald; Colombo, Tiziano; Garrel, Thierry; Gorodenski, Stanley; Gudmundsson, Snaevarr; Karlsson, Mukund Kurtadikar; Lindberg, Hans-Goran; Loughney, Des; Mauclaire, Benji; McCandless, Brian E.; Melillo, Frank J.; Miles, Richard; Pearson, Robert T.; Samolyk, Gerard; Schanne, Lothar; Strikis, Iakovos Marios; Teyssier, François; Thizy, Olivier

    The mysterious star system epsilon Aurigae undergoes an eclipse every 27.1 years that lasts nearly two years. The most recent eclipse started during the late summer of 2009. An international campaign for observing this eclipse was created in 2006, with a web site for information and, to-date, 17 periodic newsletters for details, as well as a Yahoo forum List for immediate announcements and comments. Photometric data in the UBVRIJH bands have been submitted. Ingress occurred with first contact in the V band estimated at the second week of 2009 August and second contact estimated at 2010 mid-January. Spectroscopic data were also obtained during ingress. Spectroscopic data have been provided in the potassium I region, hydrogen alpha and beta regions and sodium D line region of the star system's spectrum. In this paper we describe details of observations and preliminary analysis during ingress and second contact. We introduce the observers and discuss plans for observing throughout totality and the end of the eclipse in 2011.

  2. Making data sharing work: The FCP/INDI experience

    PubMed Central

    Mennes, Maarten; Biswal, Bharat; Castellanos, F. Xavier; Milham, Michael P.

    2012-01-01

    Over a decade ago, the fMRI Data Center (fMRIDC) pioneered open-access data sharing in the task-based functional neuroimaging community. Well ahead of its time, the fMRIDC effort encountered logistical, sociocultural and funding barriers that impeded the field-wise instantiation of open-access data sharing. In 2009, ambitions for open-access data sharing were revived in the resting state functional MRI community in the form of two grassroots initiatives: the 1000 Functional Connectomes Project (FCP) and its successor, the International Neuroimaging Datasharing Initiative (INDI). Beyond providing open access to thousands of clinical and non-clinical imaging datasets, the FCP and INDI have also demonstrated the feasibility of large-scale data aggregation for hypothesis generation and testing. Yet, the success of the FCP and INDI should not be confused with widespread embracement of open-access data sharing. Reminiscent of the challenges faced by fMRIDC, key controversies persist and include participant privacy, the role of informatics, and the logistical and cultural challenges of establishing an open science ethos. We discuss the FCP and INDI in the context of these challenges, highlighting the promise of current initiatives and suggesting solutions for possible pitfalls. PMID:23123682

  3. University of the West Indies Distance Teaching Experiment (UWIDITE). Report.

    ERIC Educational Resources Information Center

    Lalor, Gerald C.; Marrett, Christine

    Since March 1983, the University of the West Indies has been conducting a distance teaching experiment that links its three campuses and the Extra Mural Centres in Antigua, Dominica, and St. Lucia by telecommunications. The network is used for interactive distance teaching and other types of teleconferences. A variety of modern audio and video…

  4. Increased mitochondrial biogenesis preserves intestinal stem cell homeostasis and contributes to longevity in Indy mutant flies

    PubMed Central

    Rogers, Ryan P.; Rogina, Blanka

    2014-01-01

    The Drosophila Indy (I'm Not Dead Yet) gene encodes a plasma membrane transporter of Krebs cycle intermediates, with robust expression in tissues associated with metabolism. Reduced INDY alters metabolism and extends longevity in a manner similar to caloric restriction (CR); however, little is known about the tissue specific physiological effects of INDY reduction. Here we focused on the effects of INDY reduction in the Drosophila midgut due to the importance of intestinal tissue homeostasis in healthy aging and longevity. The expression of Indy mRNA in the midgut changes in response to aging and nutrition. Genetic reduction of Indy expression increases midgut expression of the mitochondrial regulator spargel/dPGC-1, which is accompanied by increased mitochondrial biogenesis and reduced reactive oxygen species (ROS). These physiological changes in the Indy mutant midgut preserve intestinal stem cell (ISC) homeostasis and are associated with healthy aging. Genetic studies confirm that dPGC-1 mediates the regulatory effects of INDY, as illustrated by lack of longevity extension and ISC homeostasis in flies with mutations in both Indy and dPGC1. Our data suggest INDY may be a physiological regulator that modulates intermediary metabolism in response to changes in nutrient availability and organismal needs by modulating dPGC-1 PMID:24827528

  5. No Influence of Indy on Lifespan in Drosophila after Correction for Genetic and Cytoplasmic Background Effects

    PubMed Central

    Toivonen, Janne M; Walker, Glenda A; Martinez-Diaz, Pedro; Bjedov, Ivana; Driege, Yasmine; Jacobs, Howard T; Gems, David; Partridge, Linda

    2007-01-01

    To investigate whether alterations in mitochondrial metabolism affect longevity in Drosophila melanogaster, we studied lifespan in various single gene mutants, using inbred and outbred genetic backgrounds. As positive controls we included the two most intensively studied mutants of Indy, which encodes a Drosophila Krebs cycle intermediate transporter. It has been reported that flies heterozygous for these Indy mutations, which lie outside the coding region, show almost a doubling of lifespan. We report that only one of the two mutants lowers mRNA levels, implying that the lifespan extension observed is not attributable to the Indy mutations themselves. Moreover, neither Indy mutation extended lifespan in female flies in any genetic background tested. In the original genetic background, only the Indy mutation associated with altered RNA expression extended lifespan in male flies. However, this effect was abolished by backcrossing into standard outbred genetic backgrounds, and was associated with an unidentified locus on the X chromosome. The original Indy line with long-lived males is infected by the cytoplasmic symbiont Wolbachia, and the longevity of Indy males disappeared after tetracycline clearance of this endosymbiont. These findings underscore the critical importance of standardisation of genetic background and of cytoplasm in genetic studies of lifespan, and show that the lifespan extension previously claimed for Indy mutants was entirely attributable to confounding variation from these two sources. In addition, we saw no effects on lifespan of expression knockdown of the Indy orthologues nac-2 and nac-3 in the nematode Caenorhabditis elegans. PMID:17571923

  6. 9 CFR 93.423 - Ruminants from Central America and the West Indies.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Ruminants from Central America and the... PRODUCTS; REQUIREMENTS FOR MEANS OF CONVEYANCE AND SHIPPING CONTAINERS Ruminants Central America and West Indies 9 § 93.423 Ruminants from Central America and the West Indies. (a) Ruminants intended...

  7. 9 CFR 93.423 - Ruminants from Central America and the West Indies.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Ruminants from Central America and the... PRODUCTS; REQUIREMENTS FOR MEANS OF CONVEYANCE AND SHIPPING CONTAINERS Ruminants Central America and West Indies 9 § 93.423 Ruminants from Central America and the West Indies. (a) Ruminants intended...

  8. 9 CFR 93.423 - Ruminants from Central America and the West Indies.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Ruminants from Central America and the... PRODUCTS; REQUIREMENTS FOR MEANS OF CONVEYANCE AND SHIPPING CONTAINERS Ruminants Central America and West Indies 9 § 93.423 Ruminants from Central America and the West Indies. (a) Ruminants intended...

  9. 9 CFR 93.423 - Ruminants from Central America and the West Indies.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Ruminants from Central America and the... PRODUCTS; REQUIREMENTS FOR MEANS OF CONVEYANCE AND SHIPPING CONTAINERS Ruminants Central America and West Indies 9 § 93.423 Ruminants from Central America and the West Indies. (a) Ruminants intended...

  10. 9 CFR 93.423 - Ruminants from Central America and the West Indies.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Ruminants from Central America and the... PRODUCTS; REQUIREMENTS FOR MEANS OF CONVEYANCE AND SHIPPING CONTAINERS Ruminants Central America and West Indies 9 § 93.423 Ruminants from Central America and the West Indies. (a) Ruminants intended...

  11. 9 CFR 93.320 - Horses from Central America and the West Indies.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Horses from Central America and the... PRODUCTS; REQUIREMENTS FOR MEANS OF CONVEYANCE AND SHIPPING CONTAINERS Horses Central America and the West Indies 17 § 93.320 Horses from Central America and the West Indies. Horses from Central America and...

  12. 9 CFR 93.320 - Horses from Central America and the West Indies.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Horses from Central America and the... PRODUCTS; REQUIREMENTS FOR MEANS OF CONVEYANCE AND SHIPPING CONTAINERS Horses Central America and the West Indies 17 § 93.320 Horses from Central America and the West Indies. Horses from Central America and...

  13. 9 CFR 93.320 - Horses from Central America and the West Indies.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Horses from Central America and the... PRODUCTS; REQUIREMENTS FOR MEANS OF CONVEYANCE AND SHIPPING CONTAINERS Horses Central America and the West Indies 17 § 93.320 Horses from Central America and the West Indies. Horses from Central America and...

  14. 9 CFR 93.320 - Horses from Central America and the West Indies.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Horses from Central America and the... PRODUCTS; REQUIREMENTS FOR MEANS OF CONVEYANCE AND SHIPPING CONTAINERS Horses Central America and the West Indies 17 § 93.320 Horses from Central America and the West Indies. Horses from Central America and...

  15. 9 CFR 93.320 - Horses from Central America and the West Indies.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Horses from Central America and the... PRODUCTS; REQUIREMENTS FOR MEANS OF CONVEYANCE AND SHIPPING CONTAINERS Horses Central America and the West Indies 17 § 93.320 Horses from Central America and the West Indies. Horses from Central America and...

  16. The University of the West Indies Distance Teaching Project. Report to the Advisory Council. ACEP 7.

    ERIC Educational Resources Information Center

    Lalor, Gerald C.

    The three papers in this report relate to the development and activities of the University of the West Indies Distance Teaching Project (UWIDITE), through which the University of the West Indies (UWI) is continuing experiments on the use of telecommunications to extend its regional services. A report to the advisory council, the first paper,…

  17. Chlordecone exposure and adverse effects in French West Indies populations.

    PubMed

    Multigner, Luc; Kadhel, Philippe; Rouget, Florence; Blanchet, Pascal; Cordier, Sylvaine

    2016-01-01

    Chlordecone (Kepone) is an organochlorine insecticide that has been used as insecticide and fungicide. In the French West Indies, Guadeloupe and Martinique, it was intensively applied to banana fields from 1973 to 1993 to control root borers. This pesticide undergoes no significant biotic or abiotic degradation in the environment and is still present in soils where it was applied. It was only in 1999 that health and environmental authorities became aware of the extent of the chlordecone pollution of environmental media, including soils, waterways, and the food chain. Earlier observations and toxicological studies have demonstrated that chlordecone is a reproductive and developmental toxicant, neurotoxic and carcinogenic in rodents, and is an endocrine-disrupting chemical because of its estrogenic properties both in vitro and in vivo. Several surveys have confirmed that the French West Indian population continues to be exposed to this chemical though consumption of contaminated foodstuffs. Here, we report the findings of various epidemiological studies conducted in the French West Indies to assess the impact of environmental exposure to chlordecone on the health of the population. PMID:25940496

  18. epsilon3epsilon4 genotype as risk factor of myocardial infarction in middle-aged people in Spain.

    PubMed

    Garcés, Carmen; Maicas, Carolina; Grande, Rosario; Benavente, Mercedes; Viturro, Enrique; Cano, Beatriz; López, Dolores; de Oya, Manuel

    2005-01-01

    Apolipoprotein E (apoE) plays an important role in lipid metabolism. Its epsilon4 allele has been consistently associated with lipoprotein disorders but its connection to myocardial infarction (MI) is controversial. Because epsilon4 frequency decreases with age we thought that the contradictory results in different studies could be due to the wide age range of the subjects included. To test our hypothesis, ApoE genotyping was performed in 474 MI cases and an analysis was performed by percentiles of age. The frequencies of epsilon3epsilon4 genotype and epsilon4 allele in the MI group as a whole (subjects aged 31 to 92) were not significantly different from those in our area general population. However, significant differences were observed when comparing by group of age. The frequencies decreased as age increased. The epsilon3epsilon4 and epsilon4 frequencies were significantly higher in MI subjects aged 31 to 56 than in subjects over 74. The epsilon3epsilon4 genotype prevalence in an age and sex matched control group of subjects aged 31 to 56 was significantly lower than in the 31-56 year-old MI group. In conclusion, our data shows different epsilon3epsilon4 and epsilon4 frequencies depending on the age range of the subjects with MI, being significantly higher in the middle-aged group. This finding may help explain the discrepancies between studies analyzing association between apoE genotype and MI, and emphasizes the idea of considering apoE genotype for prevention at early age. PMID:16276010

  19. Epsilon Aur monitoring during predicted pulsation phase

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.; Templeton, Matthew R.

    2014-09-01

    Dr. Robert Stencel (University of Denver Astronomy Program) has requested that AAVSO observers monitor epsilon Aurigae from now through the end of the observing season. "Studies of the long-term, out-of-eclipse photometry of this enigmatic binary suggest that intervals of coherent pulsation occur at roughly 1/3 of the 27.1-year orbital period. Kloppenborg, et al. noted that stable variation patterns develop at 3,200-day intervals' implying that 'the next span of dates when such events might happen are circa JD ~2457000 (2014 December)'. "These out-of-eclipse light variations often have amplitudes of ~0.1 magnitude in U, and ~0.05 in V, with characteristic timescales of 60-100 days. The AAVSO light curve data to the present may indicate that this coherent phenomenon has begun, but we encourage renewed efforts by observers...to help deduce whether these events are internal to the F star, or externally-driven by tidal interaction with the companion star." Nightly observations or one observation every few days (CCD/PEP/DSLR, VUBR (amplitude too small for visual)) are requested. Finder charts with sequence may be created using the AAVSO Variable Star Plotter (http://www.aavso.org/vsp). Observations should be submitted to the AAVSO International Database. Epsilon Aur was the subject of major international campaigns and the AAVSO's Citizen Sky project as it went through its 27.1-year eclipse in 2009-2011. Over 700 observers worldwide submitted over 20,000 multicolor observations to the AAVSO International Database for this project. Much information on eps Aur is available from the AAVSO, including material on the Citizen Sky website (http://www.aavso.org/epsilon-aurigae and http://www.citizensky.org/content/star-our-project). The Journal of the AAVSO, Volume 40, No. 2 (2012) was devoted to discussion of and research results from this event. See full Alert Notice for more details and observations.

  20. Classical closure theory and Lam's interpretation of epsilon-RNG

    NASA Technical Reports Server (NTRS)

    Zhou, YE

    1995-01-01

    Lam's phenomenological epsilon-renormalization group (RNG) model is quite different from the other members of that group. It does not make use of the correspondence principle and the epsilon-expansion procedure. We demonstrate that Lam's epsilon-RNG model is essentially the physical space version of the classical closure theory in spectral space and consider the corresponding treatment of the eddy viscosity and energy backscatter.

  1. New atmospheric model of Epsilon Eridani

    NASA Astrophysics Data System (ADS)

    Vieytes, Mariela; Fontenla, Juan; Buccino, Andrea; Mauas, Pablo

    2016-05-01

    We present a new semi-empirical model of the atmosphere of the widely studied K-dwarf Epsilon Eridani (HD 22049). The model is build to reproduce the visible spectral observations from 3800 to 6800 Angstrom and the h and k Mg II lines profiles. The computations were carried out using the Solar-Stellar Radiation Physical Modeling (SSRPM) tools, which calculate non-LTE population for the most important species in the stellar atmosphere. We show a comparison between the synthetic and observed spectrum, obtaining a good agreement in all the studied spectral range.

  2. Revealing the Hot Side of Epsilon Aurigae

    NASA Astrophysics Data System (ADS)

    Hoard, Donald; Stencel, Robert; Howell, Steve

    2012-12-01

    We request a small investment of 24 minutes of Spitzer time, to obtain four IRAC observations of epsilon Aurigae. A naked eye object located near Capella, epsilon Aurigae is the eclipsing binary star with the longest known orbital period, showing a single long duration (~2 yr) eclipse every 27.1 yr. For much of the last 200 years, the nature of the eclipsing object defied explanation. We recently demonstrated that epsilon Aurigae consists of a high luminosity F0 post-AGB star in orbit with a B5 V star surrounded by a solar system sized (~8 AU diameter) disk of cool, dust-dominated material. The eclipse of epsilon Aurigae is a rare event; moreover, it is a unique astrophysical opportunity, since the backlighting of the disk by the high luminosity eclipsed star reveals details that cannot be detected in similar dusty disks around single stars. The current eclipse started in August 2009 and ended in July 2011; we are now in the post-eclipse phase, when the irradiation-heated side of the disk will begin rotating into view. The goals for these observations include: (1) extend our ongoing IRAC monitoring campaign covering the current eclipse to post-eclipse visits; (2) provide a consistent, well-calibrated space-based set of IR photometry for comparison with ongoing ground-based work; and (3) use the composite results to constrain the thermal profile of the disk. A key expectation of these particular observations is to reveal the irradiation-heated portion of the disk, which will be visible on its trailing side following eclipse. Observations of this side of the disk will be crucial to test and constrain new models of disk structure. As part of our overall monitoring campaign with Spitzer, Hubble, Herschel, and numerous ground-based facilities, these proposed observations will make an important contribution to the understanding of stellar evolution in binary stars, including mass transfer and evolution studies, along with new insights into astrophysical disks and post

  3. Epsilon Aurigae at the End of Eclipse

    NASA Astrophysics Data System (ADS)

    Hoard, Donald; Stencel, R.; Howell, S.

    2011-05-01

    We request a small investment of 24 minutes of Spitzer time, to obtain four IRAC observations of epsilon Aurigae. A naked eye object located near Capella, epsilon Aurigae is the eclipsing binary star with the longest known orbital period, showing a single long duration (~2 yr) eclipse every 27.1 yr. For much of the last 150 years, the nature of the eclipsing object defied explanation. We recently demonstrated that epsilon Aurigae consists of a high luminosity F0 post-AGB star in orbit with a B5 V star surrounded by a solar system sized (~8 AU diameter) disk of cool, dust-dominated material. The eclipse of epsilon Aurigae is a rare event; moreover, it is a unique astrophysical opportunity, since the backlighting of the disk by the high luminosity eclipsed star reveals details that cannot be detected in similar dusty disks around single stars. The current eclipse started in August 2009 and is expected to reach its photometric conclusion in May 2011 (with the spectroscopic conclusion as late as December 2011). The goals for these observations include: (1) extend our ongoing IRAC monitoring campaign covering the current eclipse to late-phase and post-eclipse visits; (2) provide a consistent, well-calibrated space-based set of IR photometry for comparison with ongoing ground-based work; and (3) use the composite results to constrain the thermal profile of the disk. A key expectation of these particular observations is to reveal the irradiation-heated portion of the disk, which will be visible on its trailing side following eclipse. Observations of this side of the disk will be crucial to test and constrain new models of disk structure. As part of our overall monitoring campaign with Spitzer, Hubble, Herschel, and numerous ground-based facilities, these proposed observations will make an important contribution to the understanding of stellar evolution in binary stars, including mass transfer and evolution studies, along with new insights into astrophysical disks and post

  4. The Final Measurement of Epsilon'/Epsilon from KTeV

    SciTech Connect

    Worcester, E.T.

    2009-10-01

    The authors present precise measurements of CP and CPT symmetry based on the full dataset of K {yields} {pi}{pi} decays collected by the KTeV experiment at Fermi National Accelerator Laboratory during 1996, 1997, and 1999. This dataset contains about 15 million K {yields} {pi}{sup 0}{pi}{sup 0} and 70 million K {yields} {pi}{sup +}{pi}{sup -} decays. They measure the direct CP violation parameter Re({epsilon}'/{epsilon}) = (19.2 {+-} 2.1) x 10{sup -4}. they find the K{sub L}-K{sub S} mass difference {Delta}m = (5265 {+-} 10) x 10{sup 6} {bar h}s{sup -1} and the K{sub S} lifetime {tau}{sub S} = (89.62 {+-} 0.05) x 10{sup -12} s. They test CPT symmetry by finding the phase of the indirect CP violation parameter {epsilon}, {phi}{sub {epsilon}} = (44.09 {+-} 1.00){sup o}, and the difference of the relative phases between the CP violating and CP conserving decay amplitudes for K {yields} {pi}{sup +}{pi}{sup -} ({phi}{sub +-}) and for K {yields} {pi}{sup 0}{pi}{sup 0} ({phi}{sub 00}), {Delta}{phi} = (0.29 {+-} 0.31){sup o}. these results are consistent with other experimental results and with CPT symmetry.

  5. The psychiatrist as administrator: the career of W.F. Theunissen in the Dutch East Indies.

    PubMed

    Pols, Hans

    2012-01-01

    W. F. Theunissen (1882-1961) was a leading psychiatrist in the Dutch East Indies. He was the medical director of several large mental hospitals after which he became director of the Dutch East Indies Public Health Service. Theunissen was not known for his research into the causes of mental illness. Instead, he made his mark as an administrator greatly reducing the expenses of the Lawang mental hospital by expanding occupational therapy in new and innovative ways. His accomplishments earned him the position of director of the Indies Public Health Department, where he oversaw the decentralisation of health services and the development of public health initiatives. PMID:23066606

  6. Epsilon Metal Summary Report FY 2011

    SciTech Connect

    Strachan, Denis M.; Crum, Jarrod V.; Zumhoff, Mac R.; Bovaird, Chase C.; Windisch, Charles F.; Riley, Brian J.

    2011-09-30

    The Epsilon-metal ({var_epsilon}-metal) phase was selected in FY 2009 as a potential waste form to for immobilizing the noble metals found in the undissolved solids + aqueous stream, and the soluble Tc from ion-exchange process, each resulting from proposed aqueous reprocessing. {var_epsilon}-metal phase is observed in used nuclear fuel and the natural reactors of Oklobono in Gabon, where the long-term corrosion behavior was demonstrated. This makes {var_epsilon}-metal a very attractive waste form. Last fiscal year, {var_epsilon}-metal was successfully fabricated by combining the five-metals, Mo, Ru, Rh, Pd and Re (surrogate for Tc), into pellets followed by consolidation with an arc melter. The arc melter produced fully dense samples with the epsilon structure. However, some chemistry differences were observed in the microstructure that resulted in regions rich in Re and Mo, and others rich in Pd, while Ru and Rh remained fairly constant throughout. This year, thermal stability (air), and corrosion testing of the samples fabricated by arc melting were the main focus for experimental work. Thermal stability was measured with a differential scanning calorimeter - thermogravimetric analyzer, by both ramp heating as well as step heating. There is clear evidence during the ramp heating experiment of an exothermic event + a weight loss peak both beginning at {approx}700 C. Step heating showed an oxidation event at {approx}690 C with minimal weight gain that occurs just before the weight loss event at 700 C. The conclusion being that the e-metal begins to oxidize and then become volatile. These findings are useful for considering the effects of voloxidation process. Three different pellets were subjected to electrochemical testing to study the corrosion behavior of the epsilon-metal phase in various conditions, namely acidic, basic, saline, and inert. Test was done according to an interim procedure developed for the alloy metal waste form. First an open circuit potential

  7. In-die mask registration for multi-patterning

    NASA Astrophysics Data System (ADS)

    Laske, F.; Kunitani, S.; Kamibayashi, T.; Yamana, M.; Fuse, A.; Wagner, M.; Roeth, K.-D.; Ferber, M.; Daneshpanah, M.; Czerkas, S.; Sakaguchi, H.

    2013-09-01

    193nm immersion lithography is the mainstream production technology for the 20nm and 14nm logic nodes. Considering multi-patterning as the technology to solve the very low k1 situation in the resolution equation puts extreme pressure on the intra-field overlay, to which mask registration error is a major error contributor. The International Technology Roadmap for Semiconductors (ITRS) requests a registration error below 4 nm for each mask of a multi-patterning set forming one layer on the wafer. For mask metrology at the 20nm and 14nm logic nodes, maintaining a precision-to-tolerance (P/T) ratio below 0.25 will be very challenging. Mask registration error impacts intra-field wafer overlay directly and has a major impact on wafer yield. We will discuss a solution to support full in-die registration metrology on reticles.

  8. Underestimation of Leptospirosis Incidence in the French West Indies

    PubMed Central

    Cassadou, Sylvie; Rosine, Jacques; Flamand, Claude; Escher, Martina; Ledrans, Martine; Bourhy, Pascale; Picardeau, Mathieu; Quénel, Philippe

    2016-01-01

    Background Leptospirosis is a neglected zoonosis affecting mainly tropical and subtropical regions worldwide, particularly South America and the Caribbean. As in many other countries, under-reporting of cases was suspected in the French West Indies because of inadequate access to diagnostic tests for the general population. Methodology/Principal findings In order to estimate the real incidence of leptospirosis in Guadeloupe and Martinique, a study was performed in 2011 using the three prevailing available biological tests for diagnosis: Microscopic Agglutination Test (MAT), IgM ELISA and PCR. The study investigated inpatients and outpatients and used active case ascertainment from data provided by a general practitioners’ sentinel network. The epidemiology of the disease was also described in terms of severity and demographic characteristics. Leptospirosis incidence was estimated at 69.4 (95%CI 47.6–91.1) and 60.6 (95%CI 36.3–85.0) annual cases per 100 000 inhabitants in Guadeloupe and Martinique, respectively, which was 3 and 4 times higher than previous estimations. Conclusion/Significance Inclusion of PCR and IgM ELISA tests for diagnosis of leptospirosis resulted in improved sensitivity in comparison with MAT alone. Our results highlighted the substantial health burden of the disease in these two territories and the importance of access to appropriate laboratory tests. Based on our results, PCR and IgM ELISA tests have now been included in the list of tests reimbursed by the national system of social security insurance in France. Our results also underline the relevance of implementing an integrated strategy for the surveillance, prevention and control of leptospirosis in the French West Indies. PMID:27128631

  9. Clostridium perfringens epsilon toxin inhibits the gastrointestinal transit in mice.

    PubMed

    Losada-Eaton, D M; Fernandez-Miyakawa, M E

    2010-12-01

    Epsilon toxin produced by Clostridium perfringens type B and D is a potent toxin that is responsible for a highly fatal enterotoxemia in sheep and goats. In vitro, epsilon toxin produces contraction of the rat ileum as the result of an indirect action, presumably mediated through the autonomic nervous system. To examine the impact of epsilon toxin in the intestinal transit, gastric emptying (GE) and gastrointestinal transit (GIT) were evaluated after intravenous and oral administration of epsilon toxin in mice. Orally administered epsilon toxin produced a delay on the GIT. Inhibition of the small intestinal transit was observed as early as 1 h after the toxin was administered orally but the effects were not observed after 1 week. Epsilon toxin also produced an inhibition in GE and a delay on the GIT when relatively high toxin concentrations were given intravenously. These results indicate that epsilon toxin administered orally or intravenously to mice transitorily inhibits the GIT. The delay in the GIT induced by epsilon toxin could be relevant in the pathogenesis of C. perfringens type B and D enterotoxemia. PMID:20434186

  10. T*{sub {epsilon}} integral analysis of fracture specimens

    SciTech Connect

    Omori, Y.; Ma, L.; Kobayashi, A.S.

    1996-12-31

    T*{sub {epsilon}} integral values associated with stable crack growth in thin 2024-T3 aluminum compact (CT) specimens and A606 HSLA steel single edge notched (SEN) specimens were determined directly from the crack tip displacement field obtained by moire interferometry. Stable crack growth in the SEN specimen was also simulated by an elastic-plastic finite element (FE) model which was driven by the experimentally determined boundary conditions. T*{sub {epsilon}} obtained experimentally and by FE were in reasonable agreements with each other. Unlike the vanishing J integrals with crack extension, T*{sub {epsilon}} reached steady state values with stable crack growth. Thus, for a given integration contour, {Gamma}{sub {epsilon}}, near the crack tip, T*{sub {epsilon}} can be used as a stable crack growth as well as a ductile fracture criteria.

  11. Modelling Epsilon Aurigae without solid particles

    NASA Technical Reports Server (NTRS)

    Cheng, A. Y. S.; Woolf, N. J.

    1985-01-01

    Three components can be expected to contribute to the emission of epsilon Aurigae. There is a primary F star. There is an opaque disk which occults it, and there is a gas stream which is observed to produce absorption lines. Evidence that the disk is not responsible for the gas stream lines comes both from the radial velocities, which are too small, and from the IR energy distribution out of eclipse, which shows free-free emission that would produce inadequate optical depth in electron scattering. The color temperature of the IR excess can give misleading indications of low temperature material. Free-free emission at 10,000 K between 10 and 20 microns has a color temperature of 350 K. Attempts to mold the system are discussed.

  12. Modeling the Variable Polarization of Epsilon Aurigae

    NASA Astrophysics Data System (ADS)

    Ignace, Richard; Henson, Gary D.; Asbury, William

    2016-06-01

    The nature of the edge-on eclipsing binary Epsilon Aurigae remains perplexing, despite notable progress since the recent 2009-2011 eclipse. The binary involves an early F supergiant with a still unknown companion enshrouded in a disk. Although the eclipse geometry produces a significant broad band polarization signature, semiregular pulsations of the F supergiant are also a source of variable polarization, with an amplitude that is commensurate with the effect of the eclipse. This fact makes use of the polarization for studying the disk of the companion far more challenging. In an effort to better understand the pulsation nature of the supergiant, we explore a simple model for the stellar contribution to the polarization signal. The model does reasonably well in characterizing the gross properties of the time-variable polarization.

  13. Perturbative matching of the staggered four-fermion operators for {epsilon}'/{epsilon}

    SciTech Connect

    Lee, Weonjong

    2001-09-01

    Using staggered fermions, we calculate the perturbative corrections to the bilinear and four-fermion operators that are used in the numerical study of weak matrix elements for {epsilon}'/{epsilon}. We present results for one-loop matching coefficients between continuum operators, calculated in the naive dimensional regularization (NDR) scheme, and gauge invariant staggered fermion operators. In particular, we concentrate on Feynman diagrams of the current-current insertion type. We also present results for the tadpole improved operators. These results, combined with existing results for penguin diagrams, provide a complete one-loop renormalization of the staggered four-fermion operators. Therefore, using our results, it is possible to match a lattice calculation of K{sup 0}-{bar K}{sup 0} mixing and K{yields}{pi}{pi} decays to the continuum NDR results with all corrections of O(g{sup 2}) included.

  14. VARIABILITY IN OPTICAL SPECTRA OF {epsilon} ORIONIS

    SciTech Connect

    Thompson, Gregory B.; Morrison, Nancy D. E-mail: nmorris@utnet.utoledo.edu

    2013-04-15

    We present the results of a time series analysis of 130 echelle spectra of {epsilon} Ori (B0 Ia), acquired over seven observing seasons between 1998 and 2006 at Ritter Observatory. The equivalent widths of H{alpha} (net) and He I {lambda}5876 were measured and radial velocities were obtained from the central absorption of He I {lambda}5876. Temporal variance spectra (TVS) revealed significant wind variability in both H{alpha} and He I {lambda}5876. The He I TVS have a double-peaked profile consistent with radial velocity oscillations. A periodicity search was carried out on the equivalent width and radial velocity data, as well as on wavelength-binned spectra. This analysis has revealed several periods in the variability with timescales of two to seven days. Many of these periods exhibit sinusoidal modulation in the associated phase diagrams. Several of these periods were present in both H{alpha} and He I, indicating a possible connection between the wind and the photosphere. Due to the harmonic nature of these periods, stellar pulsations may be the origin of some of the observed variability. Periods on the order of the rotational period were also detected in the He I line in the 1998-1999 season and in both lines during the 2004-2005 season. These periods may indicate rotational modulation due to structure in the wind.

  15. EPSILON AURIGAE: AN IMPROVED SPECTROSCOPIC ORBITAL SOLUTION

    SciTech Connect

    Stefanik, Robert P.; Torres, Guillermo; Lovegrove, Justin; Latham, David W.; Zajac, Joseph; Pera, Vivian E.; Mazeh, Tsevi

    2010-03-15

    A rare eclipse of the mysterious object {epsilon} Aurigae will occur in 2009-2011. We report an updated single-lined spectroscopic solution for the orbit of the primary star based on 20 years of monitoring at the CfA, combined with historical velocity observations dating back to 1897. There are 518 new CfA observations obtained between 1989 and 2009. Two solutions are presented. One uses the velocities outside the eclipse phases together with mid-times of previous eclipses, from photometry dating back to 1842, which provide the strongest constraint on the ephemeris. This yields a period of 9896.0 {+-} 1.6 days (27.0938 {+-} 0.0044 years) with a velocity semi-amplitude of 13.84 {+-} 0.23 km s{sup -1} and an eccentricity of 0.227 {+-} 0.011. The middle of the current ongoing eclipse predicted by this combined fit is JD 2,455,413.8 {+-} 4.8, corresponding to 2010 August 5. If we use only the radial velocities, we find that the predicted middle of the current eclipse is nine months earlier. This would imply that the gravitating companion is not the same as the eclipsing object. Alternatively, the purely spectroscopic solution may be biased by perturbations in the velocities due to the short-period oscillations of the supergiant.

  16. Interleukin-4 production by Fc epsilon R+ cells.

    PubMed

    Paul, W E

    1991-01-01

    Among non-B, non-T cells in the spleen and among unfractionated bone marrow cells, there is a population of cells that are capable of producing IL-4 in response to cross-linkage of FC epsilon RI or Fc gamma RII. Their IL-4-producing capacity is strikingly enhanced by treatment of the cells or of the animals donating such cells with interleukin-3 (IL-3). Fc epsilon R+ cells constitute 1-2% of splenic non-B, non-T cells and of bone marrow cells from normal donors but they contain all the capacity to produce IL-4 in response to cross-linkage of Fc epsilon RI or Fc gamma RII or to treatment with ionomycin. Fc epsilon R- cells fail to make such responses. Electron-microscopic analysis indicates that virtually all the granulated or vacuolated Fc epsilon R+ cells are of the basophil lineage. However, it has not yet been resolved whether these cells or immature mast cells, presumably in the Fc epsilon R+ granule/vacuole-negative cell population, are the principal producers of IL-4 in response to these stimuli. PMID:1837220

  17. Naturally acquired antibodies against Clostridium perfringens epsilon toxin in goats.

    PubMed

    Veschi, Josir Laine A; Bruzzone, Octavio A; Losada-Eaton, Daniela M; Dutra, Iveraldo S; Fernandez-Miyakawa, Mariano E

    2008-09-15

    Clostridium perfringens type D-producing epsilon toxin is a common cause of death in sheep and goats worldwide. Although anti-epsilon toxin serum antibodies have been detected in healthy non-vaccinated sheep, the information regarding naturally acquired antibodies in ruminants is scanty. The objective of the present report was to characterize the development of naturally acquired antibodies against C. perfringens epsilon toxin in goats. The levels of anti-epsilon toxin antibodies in blood serum of goat kids from two different herds were examined continuously for 14 months. Goats were not vaccinated against any clostridial disease and received heterologous colostrums from cows that were not vaccinated against any clostridial disease. During the survey one of these flocks suffered an unexpectedly severe C. perfringens type D enterotoxemia outbreak. The results showed that natural acquired antibodies against C. perfringens epsilon toxin can appear as early as 6 weeks in young goats and increase with the age without evidence of clinical disease. The enterotoxemia outbreak was coincident with a significant increase in the level of anti-epsilon toxin antibodies. PMID:18538416

  18. INFRARED STUDIES OF EPSILON AURIGAE IN ECLIPSE

    SciTech Connect

    Stencel, Robert E.; Kloppenborg, Brian K.; Wall, Randall E.; Hopkins, Jeffrey L.; Howell, Steve B.; Hoard, D. W.; Rayner, John; Bus, Schelte; Tokunaga, Alan; Sitko, Michael L.; Bradford, Suellen; Russell, Ray W.; Lynch, David K.; Hammel, Heidi; Whitney, Barbara; Orton, Glenn; Yanamandra-Fisher, Padma; Hora, Joseph L.; Hinz, Philip; Hoffmann, William; and others

    2011-11-15

    We report here on a series of medium resolution spectro-photometric observations of the enigmatic long period eclipsing binary epsilon Aurigae, during its eclipse interval of 2009-2011, using near-infrared spectra obtained with SpeX on the Infrared Telescope Facility (IRTF), mid-infrared spectra obtained with BASS on AOES and IRTF, MIRSI on IRTF, and MIRAC4 on the MMT, along with mid-infrared photometry using MIRSI on IRTF and MIRAC4 on the MMT, plus 1995-2000 timeframe published photometry and data obtained with Denver's TNTCAM2 at WIRO. The goals of these observations included: (1) comparing eclipse depths with prior eclipse data, (2) confirming the re-appearance of CO absorption bands at and after mid-eclipse, associated with sublimation in the disk, (3) seeking evidence for any mid-infrared solid state spectral features from particles in the disk, and (4) providing evidence that the externally irradiated disk has azimuthal temperature differences. IR eclipse depths appear similar to those observed during the most recent (1983) eclipse, although evidence for post-mid-eclipse disk temperature increase is present, due to F star heated portions of the disk coming into view. Molecular CO absorption returned 57 days after nominal mid-eclipse, but was not detected at mid-eclipse plus 34 days, narrowing the association with differentially heated sub-regions in the disk. Transient He I 10830A absorption was detected at mid-eclipse, persisting for at least 90 days thereafter, providing a diagnostic for the hot central region. The lack of solid-state features in Spitzer Infrared Spectrograph, BASS, and MIRAC spectra to date suggests the dominance of large particles (micron-sized) in the disk. Based on these observations, mid-infrared studies out of eclipse can directly monitor and map the disk thermal changes, and better constrain disk opacity and thermal conductivity.

  19. Meeting overlay requirements for future technology nodes with in-die overlay metrology

    NASA Astrophysics Data System (ADS)

    Schulz, Bernd; Seltmann, Rolf; Busch, Jens; Hempel, Fritjof; Cotte, Eric; Alles, Benjamin

    2007-03-01

    As a consequence of the shrinking sizes of the integrated circuit structures, the overlay budget shrinks as well. Overlay is traditionally measured with relatively large test structures which are located in the scribe line of the exposure field, in the four corners. Although the performance of the overlay metrology tools has improved significantly over time it is questionable if this traditional method of overlay control will be sufficient for future technology nodes. For advanced lithography techniques like double exposure or double patterning, in-die overlay is critical and it is important to know how much of the total overlay budget is consumed by in-die components. We reported earlier that small overlay targets were included directly inside die areas and good performance was achieved. This new methodology enables a wide range of investigations. This provides insight into processes which were less important in the past or not accessible for metrology. The present work provides actual data from productive designs, instead of estimates, illustrating the differences between the scribe line and in-die registration and overlay. The influence of the pellicle on pattern placement on mask and wafer overlay is studied. Furthermore the registration overlay error of the reticles is correlated to wafer overlay residuals. The influence of scanner-induced distortions (tool to tool differences) on in-die overlay is shown. Finally, the individual contributors to in-die-overlay are discussed in the context of other overlay contributors. It is proposed to use in-die overlay and registration results to derive guidelines for future overlay and registration specifications. It will be shown that new overlay correction schemes which take advantage of the additional in-die overlay information need to be considered for production.

  20. Asteroseismology of the nearby SN II Progenitor Rigel. II. epsilon-mechanism Triggering Gravity-mode Pulsations?

    NASA Astrophysics Data System (ADS)

    Moravveji, Ehsan; Moya, Andres; Guinan, Edward F.

    2012-04-01

    The cores of luminous B- and A-type (BA) supergiant stars are the seeds of later core-collapse supernovae. Thus, constraining the near-core conditions in this class of stars can place tighter constraints on the size, mass, and chemical composition of supernova remnants. Asteroseismology of these massive stars is one possible approach into such investigations. Recently, Moravveji et al. in 2012 (hereafter Paper I) extracted 19 significant frequencies from a 6-year radial velocity monitoring of Rigel (β Ori, B8 Ia). The periods they determined broadly range from 1.22 to 74.74 days. Based on our differentially rotating stellar structure and evolution model, Rigel, at its current evolutionary state, is undergoing core He burning and shell H burning. Linear fully non-adiabatic non-radial stability analyses result in the excitation of a dense spectrum of non-radial gravity-dominated mixed modes. The fundamental radial mode (l = 0) and its overtones are all stable. When the hydrogen-burning shell is located even partially in the radiative zone, a favorable condition for destabilization of g-modes through the so-called epsilon-mechanism becomes viable. Only those g-modes that have high relative amplitudes in the hydrogen-burning (radiative) zone can survive the strong radiative damping. From the entire observed range of variability periods of Rigel (found in Paper I), and based on our model, only those modes with periods ranging between 21 and 127 days can be theoretically explained by the epsilon-mechanism. The origin of the short-period variations (found in Paper I) still remains unexplained. Because Rigel is similar to other massive BA supergiants, we believe that the epsilon-mechanism may be able to explain the long-period variations in α Cygni class of pulsating stars.

  1. [Population born in Indonesia or in the former Dutch East-Indies].

    PubMed

    Prins, C J

    1997-04-01

    "The number of persons born in Indonesia or in the former Dutch East Indies and residing in the Netherlands decreases every year. This is primarily caused by ageing. Moreover, immigration from Indonesia has been at a relatively low level for many years. About 178 thousand persons born in Indonesia or in the former Dutch East Indies were living in the Netherlands on 1 January 1996." Information is included on parents' nationality, length of time in the Netherlands, migration policy, and spatial distribution. (EXCERPT) PMID:12348139

  2. Prediction of two-dimensional momentumless wake by k- epsilon - gamma model

    NASA Astrophysics Data System (ADS)

    Ahn, Jong Woo; Sung, Hyung Jin

    1995-04-01

    The k-epsilon-gamma model performance is extended to resolve the jet/wake anomaly, which is encountered in calculating free shear flows by the standard k-epsilon model. In the k-epsilon-gamma model, the relation between the rate of dissipation epsilon and the level of intermittency gamma is well incorporated. The model is run to predict the two-dimensional momentumless wake where a jet and a wake coexist. The predictions of the k-epsilon-gamma model are compared with those of the k-epsilon model as well as the experiment. It is shown that the model performance is generally satisfactory.

  3. Shhh! No Opinions in the Library: "IndyKids" and Kids' Right to an Independent Press

    ERIC Educational Resources Information Center

    Vender, Amanda

    2011-01-01

    "Nintendo Power," "Sports Illustrated for Kids," and a biography of President Obama were on prominent display as the author entered the branch library in Forest Hills, Queens. The librarian looked skeptical when the author asked the librarian if she could leave copies of "IndyKids" newspapers on the free literature table. The branch manager…

  4. Observations of the 1761 and 1769 transits of Venus from Batavia (Dutch East Indies)

    NASA Astrophysics Data System (ADS)

    van Gent, Robert H.

    2005-04-01

    This paper discusses the observations of the 1761 and 1769 transits of Venus by the Dutch-German clergyman Johan Maurits Mohr (1716-1775) from Batavia (Dutch East Indies). We will investigate how Mohr became interested in observing this phenomenon and how he made the necessary preparations. Finally, the fate of his observatory and his instruments will be discussed.

  5. Art Education in the Former Dutch East Indies in the 1930s: Questions of Different Cultures.

    ERIC Educational Resources Information Center

    Van Rheeden, Herbert

    1990-01-01

    Analyzes drawings by children from a Dutch East Indies exhibition in 1937 organized by educator Johan Toot. Divides the drawings thematically and discusses how the drawings are influenced by various cultures. Describes how Johan Toot worked to replace rote learning with an activity-based education. (KM)

  6. TOXOPLASMA GONDII AND NEOSPORA CANINUM ANTIBODIES IN DOGS FROM GRENADA, WEST INDIES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxoplasma gondii and Neospora caninum are structurally similar parasites with many common hosts. The prevalence of antibodies to T. gondii and N. caninum was determined in sera from dogs in Grenada, West Indies. Using a modified agglutination test, antibodies to T. gondii were found in 52 (48.5%) o...

  7. A Historical Perspective: Curriculum Development and Instrumentalism in the Educational System in the British West Indies.

    ERIC Educational Resources Information Center

    Deonanan, Carlton R.

    That the instrument of education in any civilization or nation, and in particular the British West Indies relfects the totality of that civilization and vice versa is the thesis of this paper. The instrument of education reveals a structure and a profile with the following components: a design and a structure, a philosophy, a psychology, a system…

  8. Distance Learner Ecologies of the University of the West Indies Open Campus Program

    ERIC Educational Resources Information Center

    Beaubrun, Elizabeth

    2012-01-01

    This research project examined the learner ecologies of University of the West Indies (UWI) distance learning program participants in two countries within the regional university's network: Dominica, and Antigua and Barbuda. The descriptive study focused on a period of transition from dual-mode delivery (teleconference and in-person tutorial…

  9. Search for radio emission from the nearby binary brown dwarf system ɛ Indi Bab

    NASA Astrophysics Data System (ADS)

    Blank, D. L.

    2004-11-01

    We have observed the nearest known brown dwarfs, the binary system ɛ Indi Bab (d= 3.626 pc), for 8.6- and 4.8-GHz radio emission with the Australia Telescope Compact Array. If either brown dwarf emits radio flares, then they are respectively at least 5.5 and 1.2 times weaker than LP 944-20, the nearest brown dwarf with detected radio emission. We associate the ROSAT source 1WGA J2203.9 - 5647 with ɛ Indi Bab since the separation was about 30 arcsec at the time of the ROSAT observation. Assuming the association, then ɛ Indi Bab has an L0.4-2.4keV X-ray luminosity of 5.6 × 1025 erg s-1 which makes it roughly a factor of 2 less luminous than LP 944-20. The radio non-detections imply that ɛ Indi Bab does not violate, or at least does not violate as strongly as LP 944-20, the Güdel-Benz relationship of X-ray and radio emission.

  10. Epsilon-near-zero mode for active optoelectronic devices.

    PubMed

    Vassant, S; Archambault, A; Marquier, F; Pardo, F; Gennser, U; Cavanna, A; Pelouard, J L; Greffet, J J

    2012-12-01

    The electromagnetic modes of a GaAs quantum well between two AlGaAs barriers are studied. At the longitudinal optical phonon frequency, the system supports a phonon polariton mode confined in the thickness of the quantum well that we call epsilon-near-zero mode. This epsilon-near-zero mode can be resonantly excited through a grating resulting in a very large absorption localized in the single quantum well. We show that the reflectivity can be modulated by applying a voltage. This paves the way to a new class of active optoelectronic devices working in the midinfrared and far infrared at ambient temperature. PMID:23368264

  11. The Challenge of Observing the Recent Eclipse of Epsilon Aurigae

    NASA Astrophysics Data System (ADS)

    Melillo, Frank J.

    2013-07-01

    This author participated in the 'International Epsilon Aurigae Campaign' in 2009. A total of 100 V-band observations were made in Holtsville, New York for the 2009-2011 eclipse of Epsilon Aurigae. A lightcurve has been plotted using data from these observations, which cover the phase before, during and after the eclipse. The lightcurve shows precise timing during the first, second, third and fourth contacts and possibly mid-eclipse brightening. The magnitude and the duration of the eclipse in photometric V band are discussed. This poster represents the work by Frank J Melillo and the observations were close enough to generate the true shape of the lightcurve.

  12. An improved k-epsilon model for near wall turbulence

    NASA Technical Reports Server (NTRS)

    Shih, T. H.; Hsu, Andrew T.

    1991-01-01

    An improved k-epsilon model for low Reynolds number turbulence near a wall is presented. In the first part of this work, the near-wall asymptotic behavior of the eddy viscosity and the pressure transport term in the turbulent kinetic energy equation are analyzed. Based on these analyses, a modified eddy viscosity model with the correct near-wall behavior is suggested, and a model for the pressure transport term in the k-equation is proposed. In addition, a modeled dissipation rate equation is reformulated, and a boundary condition for the dissipation rate is suggested. In the second part of the work, one of the deficiencies of the existing k-epsilon models, namely, the wall distance dependency of the equations and the damping functions, is examined. An improved model that does not depend on any wall distance is introduced. Fully developed turbulent channel flows and turbulent boundary layers over a flat plate are studied as validations for the proposed new models. Numerical results obtained from the present and other previous k-epsilon models are compared with data from direct numerical simulation. The results show that the present k-epsilon model, with added robustness, performs as well as or better than other existing models in predicting the behavior of near-wall turbulence.

  13. Detection of Clostridium perfringens epsilon toxin by ELISA.

    PubMed

    Naylor, R D; Martin, P K; Sharpe, R T

    1987-03-01

    An enzyme-linked immunosorbent assay (ELISA) has been developed as an alternative to neutralisation tests in mice to detect Clostridium perfringens type D epsilon toxin in the intestinal contents of animals which have died from suspected enterotoxaemia. The test was sensitive and quantitative and gave excellent agreement with the mouse protection test. PMID:2884704

  14. Observations of Epsilon Lyrae by the Video Drift Method

    NASA Astrophysics Data System (ADS)

    Wasson, Rick; Nelson, Nancy; Nelson, Eric; Buehlman, William; Wilson, Earl; Zapata, Deanna

    2015-01-01

    The major components of the famous "double-double" star Epsilon Lyrae, STF2382AB and STF2383CD, were measured by the Video Team at the Apple Valley Double Star Workshop in 2013, using the Video Drift Method. The results are in reasonable agreement with other recent measures and predictions of the latest orbital solutions.

  15. Fate of the Epsilon Phase in the Oklo Natural Reactors

    SciTech Connect

    S. Utsunomiya; R.C. Ewing

    2005-03-31

    In spent nuclear fuel (SNF), the micron- to submicron-sized epsilon phase (Mo-Ru-Pd-Tc-Rh) is an important host of {sup 99}Tc which has a long half life (2.13 x 10{sup 5} years) and can be an important contributor to dose in safety assessments of nuclear waste repositories. In addition, Tc is predominantly present as TcO{sub 4}{sup -} under oxidizing conditions at wide range of pH, weakly adsorbed onto mineral surfaces, and unlikely to be incorporated into alteration uranyl minerals. In the Oklo natural reactor (2.0 Ga), essentially all of the {sup 99}Tc has decayed to {sup 99}Ru. Thus, this study focuses on Ru and the other metals of the epsilon phase in order to investigate the occurrence and the fate of the epsilon phase during the corrosion of this natural SNF. Samples from reactor zone (RZ)-10 (836, 819, 687); from RZ-13 (864, 910); were investigated using TEM (transmission electron microscopy). Within the UO{sub 2} matrix, a Bi-Pd particle (40-60 nm), fioodite, PdBi{sub 2}, was observed with trace amounts of As, Fe, and Te surrounded by an amorphous Pb-rich area. (Pd,Rh){sub 2}As, palladodymite or rhodarsenide, was observed (400-500 nm in size). Ruthenarsinite, (Ru,Ni)As, was identified in most samples: with a representative composition of As, 59.9: Co, 2.5: Ni, 5.2; Ru, 18.6; Rh, 8.4; Pd, 3.1; Sb, 2.4 in atomic percent. The particles diameters are a few hundred nanometers and, in most cases, surrounded by a Pb-rich phase (400-500 nm). Typically, the ruthenarsenite does not occur as single particle but an aggregate of {approx}200 nm-sized particles. Some Ru-particles revealed a complex phase separation within the grain such as a Ru-particle (600-700 nm) with Pb at the core of the particle and enrichment of Ni, Co, and As at the rim. Some ruthenarsenite crystals were embedded in chlorite immediately adjacent to uraninite. A few particles were still coated by Pb. These results suggest a history for the epsilon phases: (1) The original epsilon phase was

  16. Association of apolipoprotein E allele {epsilon}4 with late-onset sporadic Alzheimer`s disease

    SciTech Connect

    Lucotte, G.; David, F.; Berriche, S.

    1994-09-15

    Apolipoprotein E, type {epsilon}4 allele (ApoE {epsilon}4), is associated with late-onset sporadic Alzheimer`s disease (AD) in French patients. The association is highly significant (0.45 AD versus 0.12 controls for {epsilon}4 allele frequencies). These data support the involvement of ApoE {epsilon}4 allele as a very important risk factor for the clinical expression of AD. 22 refs., 1 fig., 3 tabs.

  17. A new extinct species of Snipe (Aves: Scolopacidae: Gallinago) from the West Indies.

    PubMed

    Steadman, David W; Takano, Oona M

    2016-01-01

    We describe an extinct species of snipe (Gallinago kakuki, new species) from late Quaternary fossils in the Bahamian Archipelago (Abaco, New Providence, Little Exuma, Long, and Middle Caicos islands). The new species is known as well from fossils on Cuba, and Cayman Brac in the Cayman Islands. This rather large species of snipe was volant, although because of its relatively short carpometacarpus, the primary flight feathers probably were short. The only other species of Gallinago from the West Indies is the extant, migratory G. delicata, which breeds only in North America. Gallinago kakuki shares more osteological characters with two Eurasian species (G. media, G. hardwickii) than with either of the New World species we examined (G. delicata, G. paraguaiae). A possible inter-hemispherical relationship has been proposed as well for the two extinct, late Quaternary species of woodcocks from the West Indies (Scolopax anthonyi of Puerto Rico, S. brachycarpa of Hispaniola). PMID:27394869

  18. [Mental illness in the former Dutch Indies--four psychiatric syndromes: amok, latah, koro and neurasthenia].

    PubMed

    Bartelsman, M; Eckhardt, P P

    2007-12-22

    --At the beginning of the 20th century Dutch psychiatrists in the former Dutch Indies encountered exotic psychiatric syndromes and variant expressions of psychopathological diseases that were also prevalent in Europe. --The amok and latah syndromes were reported relatively frequently and were considered typical endemic psychopathologies. Amok is an acute condition of insanity in which the affected individual, a man, attempts to kill others. Latah is a shock-like condition in which the affected individual, a woman, mimics the movements and sounds of those nearby against her will. --The koro syndrome is considered a typical but rare psychosis seen primarily among the Chinese population of the former Dutch Indies. Patients have a recurring fear of the penis retracting into the body. --A diagnosis of 'tropical neurasthenia' was frequently made in Europeans for what today would be referred to as dysthymic disorder or minor depressive disorder. PMID:18237055

  19. Effect of epsilon toxin-GFP on MDCK cells and renal tubules in vivo.

    PubMed

    Soler-Jover, Alex; Blasi, Juan; Gómez de Aranda, Inma; Navarro, Piedad; Gibert, Maryse; Popoff, Michel R; Martín-Satué, Mireia

    2004-07-01

    Epsilon toxin (epsilon-toxin), produced by Clostridium perfringens types B and D, causes fatal enterotoxemia, also known as pulpy kidney disease, in livestock. Recombinant epsilon-toxin-green fluorescence protein (epsilon-toxin-GFP) and epsilon-prototoxin-GFP were successfully expressed in Escherichia coli. MTT assays on MDCK cells confirmed that recombinant epsilon-toxin-GFP retained the cytotoxicity of the native toxin. Direct fluorescence analysis of MDCK cells revealed a homogeneous peripheral pattern that was temperature sensitive and susceptible to detergent. epsilon-Toxin-GFP and epsilon-prototoxin-GFP bound to endothelia in various organs of injected mice, especially the brain. However, fluorescence mainly accumulated in kidneys. Mice injected with epsilon-toxin-GFP showed severe kidney alterations, including hemorrhagic medullae and selective degeneration of distal tubules. Moreover, experiments on kidney cryoslices demonstrated specific binding to distal tubule cells of a range of species. We demonstrate with new recombinant fluorescence tools that epsilon-toxin binds in vivo to endothelial cells and renal tubules, where it has a strong cytotoxic effect. Our binding experiments indicate that an epsilon-toxin receptor is expressed on renal distal tubules of mammalian species, including human. PMID:15208360

  20. On the benefit of high resolution and low aberrations for in-die mask registration metrology

    NASA Astrophysics Data System (ADS)

    Beyer, Dirk; Seidel, Dirk; Heisig, Sven; Steinert, Steffen; Töpfer, Susanne; Scherübl, Thomas; Hetzler, Jochen

    2014-10-01

    With the introduction of complex lithography schemes like double and multi - patterning and new design principles like gridded designs with cut masks the requirements for mask to mask overlay have increased dramatically. Still, there are some good news too for the mask industry since more mask are needed and qualified. Although always confronted with throughput demands, latest writing tool developments are able to keep pace with ever increasing pattern placement specs not only for global signatures but for in-die features within the active area. Placement specs less than 3nm (max. 3 Sigma) are expected and needed in all cases in order to keep the mask contribution to the overall overlay budget at an accepted level. The qualification of these masks relies on high precision metrology tools which have to fulfill stringent metrology as well as resolution constrains at the same time. Furthermore, multi-patterning and gridded designs with pinhole type cut masks are drivers for a paradigm shift in registration metrology from classical registration crosses to in-die registration metrology on production features. These requirements result in several challenges for registration metrology tools. The resolution of the system must be sufficiently high to resolve small production features. At the same time tighter repeatability is required. Furthermore, tool induced shift (TIS) limit the accuracy of in-die measurements. This paper discusses and demonstrates the importance of low illumination wavelength together with low aberrations for best contrast imaging for in-die registration metrology. Typical effects like tool induced shift are analyzed and evaluated using the ZEISS PROVE® registration metrology tool. Additionally, we will address performance gains when going to higher resolution. The direct impact on repeatability for small features by registration measurements will be discussed as well.

  1. Seroprevalence of toxoplasma gondii in cats from Sr. Kitts, West Indies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The prevalence of antibodies to Toxoplasma gondii was determined in sera from 106 domestic cats from St. Kitts, West Indies. Using a modified agglutination test, antibodies to this parasite were found in 90 (84.9%) of the cats with titers of 1:20 in 23, 1:40 in 34, 1:80 in 18, 1:160 in 2, 1:32...

  2. The bacterial dicarboxylate transporter VcINDY uses a two-domain elevator-type mechanism.

    PubMed

    Mulligan, Christopher; Fenollar-Ferrer, Cristina; Fitzgerald, Gabriel A; Vergara-Jaque, Ariela; Kaufmann, Desirée; Li, Yan; Forrest, Lucy R; Mindell, Joseph A

    2016-03-01

    Secondary transporters use alternating-access mechanisms to couple uphill substrate movement to downhill ion flux. Most known transporters use a 'rocking bundle' motion, wherein the protein moves around an immobile substrate-binding site. However, the glutamate-transporter homolog GltPh translocates its substrate-binding site vertically across the membrane, through an 'elevator' mechanism. Here, we used the 'repeat swap' approach to computationally predict the outward-facing state of the Na(+)/succinate transporter VcINDY, from Vibrio cholerae. Our model predicts a substantial elevator-like movement of VcINDY's substrate-binding site, with a vertical translation of ~15 Å and a rotation of ~43°. Our observation that multiple disulfide cross-links completely inhibit transport provides experimental confirmation of the model and demonstrates that such movement is essential. In contrast, cross-links across the VcINDY dimer interface preserve transport, thus revealing an absence of large-scale coupling between protomers. PMID:26828963

  3. Quarks with Twisted Boundary Conditions in the Epsilon Regime

    SciTech Connect

    Thomas Mehen; Brian C. Tiburzi

    2005-05-01

    We study the effects of twisted boundary conditions on the quark fields in the epsilon regime of chiral perturbation theory. We consider the SU(2){sub L} x SU(2){sub R} chiral theory with non-degenerate quarks and the SU(3){sub L} x SU(3){sub R} chiral theory with massless up and down quarks and massive strange quarks. The partition function and condensate are derived for each theory. Because flavor-neutral Goldstone bosons are unaffected by twisted boundary conditions chiral symmetry is still restored in finite volumes. The dependence of the condensate on the twisting parameters can be used to extract the pion decay constant from simulations in the epsilon regime. The relative contribution to the partition function from sectors of different topological charge is numerically insensitive to twisted boundary conditions.

  4. A k-epsilon modeling of near wall turbulence

    NASA Technical Reports Server (NTRS)

    Yang, Z.; Shih, T. H.

    1991-01-01

    A k-epsilon model is proposed for turbulent bounded flows. In this model, the turbulent velocity scale and turbulent time scale are used to define the eddy viscosity. The time scale is shown to be bounded from below by the Kolmogorov time scale. The dissipation equation is reformulated using the time scale, removing the need to introduce the pseudo-dissipation. A damping function is chosen such that the shear stress satisfies the near wall asymptotic behavior. The model constants used are the same as the model constants in the commonly used high turbulent Reynolds number k-epsilon model. Fully developed turbulent channel flows and turbulent boundary layer flows over a flat plate at various Reynolds numbers are used to validate the model. The model predictions were found to be in good agreement with the direct numerical simulation data.

  5. EISCAT observations during MAC/SINE and MAC/Epsilon

    NASA Technical Reports Server (NTRS)

    Roettger, J.; Hoppe, U.-P.; Hall, C.

    1989-01-01

    The EISCAT incoherent scatter radar facility in Tromsoe, Norway was operated during the MAC/SINE campaign for 78 hours in the period 10 June to 17 July 1987, and during the MAC/Epsilon campaign for 90 hours in the period 15 October to 5 November 1987. The VHF (224 MHz) radar operations during MAC/SINE yielded most interesting observations of strong coherent echoes from the mesopause region. Characteristic data of these polar mesospheric summer echoes are presented. The UHF (933 MHz) radar operations during MAC/Epsilon were done with 18 deg off zenith beam and allows the deduction of meridonal and horizontal wind components as well as radial velocity spectra in addition to the usual electron density profiles in the D and lower E regions. Some results from the VHF and UHF radars indicating the presence of gravity waves are examined.

  6. Structure of the Martian atmosphere from Epsilon Gem occultation observations

    NASA Technical Reports Server (NTRS)

    Hubbard, W. B.

    1982-01-01

    Information about Martian atmospheric scale heights derived from observations of the occultation of Epsilon Gem by Mars on April 8, 1976 has been collected. The observations give data in the altitude range of about 50 to 80 km. A rough, unweighted average of results so far available yields a temperatue of approximately 165 K. Excursions of about + or - 4 K about this mean may be present as a function of both altitude and areographic coordinates.

  7. Structure of the Martian atmosphere from Epsilon Gem occultation observations

    NASA Technical Reports Server (NTRS)

    Hubbard, W. B.

    1978-01-01

    Information has been collected on Martian atmospheric scale heights derived from observations of the occultation of Epsilon Gem by Mars on Apr. 8, 1976; the observations give data in the altitude range of approximately 50-80 km. A rough, unweighted average of results so far available yields a temperature of approximately 165 K. Excursions of plus or minus 40 K about this mean may be present as a function of both altitude and areographic coordinates.

  8. MAGNETIC ACTIVITY CYCLES IN THE EXOPLANET HOST STAR {epsilon} ERIDANI

    SciTech Connect

    Metcalfe, T. S.; Mathur, S.; Buccino, A. P.; Mauas, P. J. D.; Petrucci, R.; Brown, B. P.; Soderblom, D. R.; Henry, T. J.; Hall, J. C.; Basu, S.

    2013-02-01

    The active K2 dwarf {epsilon} Eri has been extensively characterized both as a young solar analog and more recently as an exoplanet host star. As one of the nearest and brightest stars in the sky, it provides an unparalleled opportunity to constrain stellar dynamo theory beyond the Sun. We confirm and document the 3-year magnetic activity cycle in {epsilon} Eri originally reported by Hatzes and coworkers, and we examine the archival data from previous observations spanning 45 years. The data show coexisting 3-year and 13-year periods leading into a broad activity minimum that resembles a Maunder minimum-like state, followed by the resurgence of a coherent 3-year cycle. The nearly continuous activity record suggests the simultaneous operation of two stellar dynamos with cycle periods of 2.95 {+-} 0.03 years and 12.7 {+-} 0.3 years, which, by analogy with the solar case, suggests a revised identification of the dynamo mechanisms that are responsible for the so-called 'active' and 'inactive' sequences as proposed by Boehm-Vitense. Finally, based on the observed properties of {epsilon} Eri, we argue that the rotational history of the Sun is what makes it an outlier in the context of magnetic cycles observed in other stars (as also suggested by its Li depletion), and that a Jovian-mass companion cannot be the universal explanation for the solar peculiarities.

  9. Advanced k-epsilon modeling of heat transfer

    NASA Technical Reports Server (NTRS)

    Kwon, Okey; Ames, Forrest E.

    1995-01-01

    This report describes two approaches to low Reynolds-number k-epsilon turbulence modeling which formulate the eddy viscosity on the wall-normal component of turbulence and a length scale. The wall-normal component of turbulence is computed via integration of the energy spectrum based on the local dissipation rate and is bounded by the isotropic condition. The models account for the anisotropy of the dissipation and the reduced mixing length due to the high strain rates present in the near-wall region. The turbulent kinetic energy and its dissipation rate were computed from the k and epsilon transport equations of Durbin. The models were tested for a wide range of turbulent flows and proved to be superior to other k-epsilon models, especially for nonequilibrium anisotropic flows. For the prediction of airfoil heat transfer, the models included a set of empirical correlations for predicting laminar-turbulent transition and laminar heat transfer augmentation due to the presence of freestream turbulence. The predictions of surface heat transfer were generally satisfactory.

  10. Alzheimer amyloid-beta peptide forms denaturant-resistant complex with type epsilon 3 but not type epsilon 4 isoform of native apolipoprotein E.

    PubMed Central

    Zhou, Z.; Smith, J. D.; Greengard, P.; Gandy, S.

    1996-01-01

    BACKGROUND: The apolipoprotein E (apoE) type epsilon 4 isoform specifies increased cerebral and cerebrovascular accumulation of amyloid-beta protein (A beta) and contributes to the genetic susceptibility underlying a large proportion (approximately 60%) of typical, sporadic Alzheimer disease. Unfortunately, in vitro biochemical studies of direct apoE isoform-specific interactions with A beta have been inconsistent, perhaps due to the use by different research groups of apoE isoform preparations in different conformational states (purified denatured versus native). MATERIALS AND METHODS: In the current study, we have investigated the possibility that synthetic A beta(1-40) preferentially associates with native apoE of either the type epsilon 3 or the type epsilon 4 isoform. RESULTS: Here, we demonstrate the preferential association of synthetic A beta(1-40) with native apoE epsilon 3. The complex between apoE epsilon 3 and A beta(1-40) could not be disrupted by sodium dodecyl sulfate. In a parallel assay, no denaturant-resistant association of A beta(1-40) with apoE epsilon 4 was detectable. CONCLUSIONS: These results support the notion that the apoE epsilon 4 isoform may foster beta-amyloidogenesis because apoE epsilon 4 is inefficient in forming complexes with A beta. Images FIG. 1 FIG. 2 PMID:8726460

  11. New prediction for the direct CP-violating parameter {var_epsilon}{prime}/{var_epsilon} and the {Delta}I=1/2 rule

    SciTech Connect

    Wu, Yue-Liang

    2001-07-01

    The low-energy dynamics of QCD is investigated with special attention paid to the matching between QCD and chiral perturbation theory (ChPT), and also to some useful algebraic chiral operator relations which survive even when we include chiral loop corrections. It then allows us to evaluate the hadronic matrix elements below the energy scale {Lambda}{sub {chi}}{approx_equal}1GeV. Based on the new analyses, we present a consistent prediction for both the direct CP-violating parameter {var_epsilon}{prime}/{var_epsilon} and the {Delta}I=1/2 rule in kaon decays. In the leading 1/N{sub c} approximation, the isospin amplitudes A{sub 0} and A{sub 2} are found to agree well with the data, and the direct CP-violating parameter {var_epsilon}{prime}/{var_epsilon} is predicted to be large, which also confirms our earlier conclusion. Its numerical value is {var_epsilon}{prime}/{var_epsilon}=23.6{sub {minus}7.8}{sup +12.4}{times}10{sup {minus}4}(Im{lambda}{sub t}/1.2{times}10{sup {minus}4}) which is no longer sensitive to the strange quark mass due to the matching conditions. Taking into account a simultaneous consistent analysis on the isospin amplitudes A{sub 0} and A{sub 2}, the ratio {var_epsilon}{prime}/{var_epsilon} is in favor of the values {var_epsilon}{prime}/{var_epsilon}=(20{+-}9){times}10{sup {minus}4}.

  12. {epsilon} expansion of the conductivity at the superconductor{endash}Mott-insulator transition

    SciTech Connect

    Fazio, R.; Zappala, D.

    1996-04-01

    We study the critical behavior of the conductivity {sigma}({omega}) at the zero-temperature superconductor{endash}Mott-insulator transition in {ital d} spacetime dimensions for a model of bosons with short-range interaction and no disorder. We obtain {sigma}({omega}{sub {ital n}})=(4{ital e}{sup 2}/{h_bar}){sigma}{sub {epsilon}}{omega}{sub {ital n}}{sup 1{minus}{epsilon}}, as predicted by the scaling theory, and the prefactor {sigma}{sub {epsilon}} is calculated in the {epsilon} expansion, to order {epsilon}{sup 2} ({epsilon}=4{minus}{ital d}). In two spatial dimensions ({ital d}=3), we find a value of the universal conductance {sigma}{sup {sq_bullet}}=0.315(4{ital e}{sup 2}/{ital h}), in good agreement with the known Monte Carlo results. {copyright} {ital 1996 The American Physical Society.}

  13. Epsilon Canis Majoris and the ionization of the local cloud

    NASA Technical Reports Server (NTRS)

    Vallerga, J. V.; Welsh, B. Y.

    1995-01-01

    The Lyman continuum radiation from the brightest extreme ultraviolet (EUV) source, the B2 II star epsilon Canis Majoris (Adara), is so intense that it dominates the local stellar EUV radiation field at wavelengths longer than 450 A and therefore sets a lower limit to the ionization of hydrogen in the Local Cloud. Using the EUV (70-730 A) spectrum of epsilon CMa taken with the Extreme Ultraviolet Explorer Satellite (EUVE) and simple models that extrapolate this spectrum to the Lyman edge at 912 A, we have determined the local interstellar hydrogen photionizatin parameter Gamma solely from epsilon CMa to be 1.1 x 10(exp -15)/s. This fiugre is a factor of 7 greater than previous estimates of Gamma calculated for all nearby stars combined (Bruhweiler & Cheng 1988). Using measured values of the density and temperature of neutral interstellar hydrogen gas in the Local Cloud, we derive a particle density of ionized hydrogen n(H(+)) and electrons n(sub e) of 0.015-0.019/cu cm assuming ionization equilibrium and a helium ionization fraction of less than 20%. These values correspond to a hydrogen ionizatin fraction, chi(sub H) from 19% to 15%, respectively. The range of these derived quantities is due to the uncertainties in the local values of the neutral hydrogen and helium interstellar densities derived from both (1) solar backscatter measurements of Ly alpha lines of hydrogen and helium (1216 and 584 A), and (2) the average neutral densities along the line of sight to nearby stars. The local proton density produced by epsilon CMa is enough to allow the ionization mechanism of Ripken & Fahr (1983) to work at the heliopause and explain the discrepancy between the neutral hydrogen density derived from solar backscatter measurements and line-of-sight averages to nearby stars. A large value of electron density in the Local Cloud of n(sub e) is approximately 0.3-0.7/cu cm (T = 7000 K) has recently been reported by Lallement et al. (1994) using observations of Mg II and Mg I

  14. The 1982-1984 Eclipse of Epsilon Aurigae

    NASA Technical Reports Server (NTRS)

    Stencel, R. E. (Editor)

    1985-01-01

    A workshop proceedings concerned with the new data collected during the 1982-1984 eclipse period of the 27-year system Epsilon Aurigae is presented. This binary star has been a classic problem in astrophysics because the opaque eclipsing object is nonstellar, and probably disk shaped. Invited papers concerning the history of the system, optical, infrared and ultraviolet photometry, optical polarimetry and ultraviolet spectroscopy are included. An invited paper concerning comprehensive theoretical interpretation in the context of stellar evolution also is included. The information collected herein is unparalleled in scope and will remain a standard reference until the next eclipse cycle in the year 2009 A.D., in all probability.

  15. Observations on the formation of [var epsilon] martensite in an Fe-23. 2%Mn alloy

    SciTech Connect

    Akguen, I.; Durlu, T.N. . Dept. of Physics)

    1994-11-15

    In Fe-Mn binary alloys the formation behavior of [var epsilon] martensite is quite sensitive to the Mn percentage and although both [var epsilon] and [alpha][prime] type martensites are formed in low Mn alloys, mostly [gamma] [yields] [var epsilon] transformation occur as the Mn concentration is increased. The present study was undertaken to examine the formation of thermally induced and also strain-induced [var epsilon] martensites, and their intersections in a Fe-23.2%Mn alloy by using transmission electron microscopy techniques.

  16. A new species of Woodcock (Aves: Scolopacidae: Scolopax) from Hispaniola, West Indies.

    PubMed

    Takano, Oona M; Steadman, David W

    2015-01-01

    Several hundred late Holocene fossils from Trouing Jean Paul, a cave in Massif de la Selle, Haiti, represent an extinct species of woodcock (Scolopax brachycarpa, new species). Scolopax brachycarpa is known from most major skeletal elements; although volant, its carpometacarpus was very short relative to its humerus. The only other species of Scolopax from the West Indies is the extinct and presumably closely related S. anthonyi of Puerto Rico, which also had a relatively short carpometacarpus compared to continental congeners. Both Scolopax brachycarpa and S. anthonyi share more osteological characters with the Eurasian S. rusticola than with the North American S. minor. PMID:26624342

  17. Upgrade of the time-of-flight diffractometer EPSILON

    NASA Astrophysics Data System (ADS)

    Ulyanov, V.; Walther, K.; Kuznetsov, I.; Frischbutter, A.; Medvedev, E.; Scheffzük, Ch.; Schebetov, A.

    At beam line 7A of the pulsed reactor IBR-2 (JINR Dubna) the strain diffractometer EPSILON has been working for several years. Due to a flight path of 102m a good resolution (Δd/d<3×10-3) was achieved. Nevertheless, further improvements of the instrument were required because of intended studies on geological samples. The modernisation of EPSILON is a renewal of the whole recording system, including collimators and detectors. The two previously used Soller collimators are replaced by nine radial collimators. Each collimator consists of 48 gadolinium oxide coated mylar foils with an angular distance of about 20' of arc to each other and therefore covers a range of nearly 16° for 2Θ. In the other direction a range of about 18° is covered. Three collimators in each case are grouped into a unit covering 66° in the plane perpendicular to the incident beam. Single 3He counter tubes with a diameter of 10mm and an active length of 120mm are used. Each collimator/detector block is mounted on a ring carrier with its surface perpendicular to the incident neutron beam. All blocks have the possibility of adjustment in three directions. The transparency of the collimators is about 90-95%.

  18. An Amateur's Spatial Model of the epsilon Aurigae System

    NASA Astrophysics Data System (ADS)

    Gemma, Marina

    This project has its origins in a summer program I attended in astrophysics (COSMOS) last year at the University of California, Irvine. The Intel Corporation offered a small number of 500 grants to students that submitted proposals for an independent research project that had to span the length of the next academic year. I received an initial exposure to astronomical data analysis in the COSMOS summer program, and was interested in expanding my experience with astronomy because I plan to major in astronomy or astrophysics in college. I had heard about the upcoming epsilon Aurigae eclipse, and decided that the eclipse was the perfect option for a research project. I ended up submitting a proposal, and was awarded the 500 grant. The original question I was attempting to answer was: Is it possible for an amateur astronomer to build a spatial model of the object that periodically eclipses the star epsilon Aurigae? One of the requirements of the grant was that the project be presented in the spring of 2010. This paper describes my efforts thus far.

  19. High Precision Polarimetry of the Epsilon Aurigae Eclipse

    NASA Astrophysics Data System (ADS)

    Wiktorowicz, Sloane

    2013-07-01

    Polarimetry of the epsilon Aurigae eclipse has the potential to discern the stellar latitude occulted by the companion's dusty disk, which may directly test interferometric results. In addition, the limb polarization of the primary star may be measured, which is an effect predicted by S. Chandrasekhar and verified by spatially resolved observations of the Sun. I will present B band, polarimetric observations of epsilon Aurigae taken over six nights in September and October 2009 using the POLISH high precision polarimeter at the Lick 3-m telescope. Polarimetric precision achieved during each night is of order 1 part in 10^5. Extensive post-eclipse observations have been taken with the significantly upgraded POLISH2 polarimeter at Lick Observatory. This instrument simultaneously measures all four Stokes parameters (I, Q, U, and V) and achieves precision within 2.0 times the photon shot noise limit over an entire observing run. This work is supported by a NExScI Sagan Fellowship, UC Lab Fees Research Grant, and UCO/Lick Observatory.

  20. The strong isospin-breaking correction for the gluonic penguin contribution to {epsilon}{prime}/{epsilon} at next-to-leading order in the chiral expansion

    SciTech Connect

    Wolfe, Carl E.; Maltman, Kim

    2001-01-01

    The strong isospin-breaking correction {Omega}{sub st}, which appears in estimates of the standard model value for the direct CP-violating ratio {epsilon}{prime}/{epsilon}, is evaluated to next-to-leading order (NLO) in the chiral expansion using chiral perturbation theory. The relevant linear combinations of the unknown NLO CP-odd weak low-energy constants (LEC's) which, in combination with one-loop and strong LEC contributions, are required for a complete determination at this order, are estimated using two different models. It is found that, to NLO, {Omega}{sub st}=0.08{+-}0.05, significantly reduced from the ''standard'' value, 0.25{+-}0.08, employed in recent analyses. The potentially significant numerical impact of this decrease on standard model predictions for {epsilon}{prime}/{epsilon}, associated with the decreased cancellation between gluonic penguin and electroweak penguin contributions, is also discussed.

  1. Ultraviolet observations of cool stars. IV - Intensities of Lyman-alpha and Mg II in epsilon Pegasi and epsilon Eridani, and line width-luminosity correlations

    NASA Technical Reports Server (NTRS)

    Mcclintock, W.; Linsky, J. L.; Henry, R. C.; Moos, H. W.

    1975-01-01

    A spectrometer on the Copernicus satellite has been used to confirm the existence of a line width-luminosity relation for the Ly-alpha and Mg II 2800-A chromospheric emission lines in K-type stars by observation of a K2 dwarf (epsilon Eri) and a K2 supergiant (epsilon Peg). Combined with previously reported observations of lines in three K giants (alpha Boo, alpha Tau, and beta Gem), the data are consistent with an identical dependence of line width on absolute visual magnitude for the Ca II K, Ly-alpha, and Mg II 2795-A lines. Surface fluxes of Ly-alpha, Mg II 2800-A, and O V 1218-A (upper limit) for epsilon Eri, and of Mg II 2800-A for epsilon Peg are also compared with values reported previously for the three giant stars.

  2. Quantitative comparison of FBP, EM, and Bayesian reconstruction algorithms for the IndyPET scanner.

    PubMed

    Frese, Thomas; Rouze, Ned C; Bouman, Charles A; Sauer, Ken; Hutchins, Gary D

    2003-02-01

    We quantitatively compare filtered backprojection (FBP), expectation-maximization (EM), and Bayesian reconstruction algorithms as applied to the IndyPET scanner--a dedicated research scanner which has been developed for small and intermediate field of view imaging applications. In contrast to previous approaches that rely on Monte Carlo simulations, a key feature of our investigation is the use of an empirical system kernel determined from scans of line source phantoms. This kernel is incorporated into the forward model of the EM and Bayesian algorithms to achieve resolution recovery. Three data sets are used, data collected on the IndyPET scanner using a bar phantom and a Hoffman three-dimensional brain phantom, and simulated data containing a hot lesion added to a uniform background. Reconstruction quality is analyzed quantitatively in terms of bias-variance measures (bar phantom) and mean square error (lesion phantom). We observe that without use of the empirical system kernel, the FBP, EM, and Bayesian algorithms give similar performance. However, with the inclusion of the empirical kernel, the iterative algorithms provide superior reconstructions compared with FBP, both in terms of visual quality and quantitative measures. Furthermore, Bayesian methods outperform EM. We conclude that significant improvements in reconstruction quality can be realized by combining accurate models of the system response with Bayesian reconstruction algorithms. PMID:12716002

  3. Real-time in-die compaction monitoring of dry-coated tablets.

    PubMed

    Liu, Jingfei; Stephens, James D; Kowalczyk, Brian R; Cetinkaya, Cetin

    2011-07-29

    The practicability of a pulse-echo ultrasonic approach developed for the real-time quality monitoring of dry-coated tablets in the tablet press during compaction is evaluated. The punch-tablet interface (i.e., steel-tablet) is the boundary condition that dictates the viability of acoustic in-die compaction monitoring. The current study utilizes compacted tablets with a simulated punch-tablet interface to achieve the required waveform detectability levels needed for in-die compaction monitoring. The geometric and mechanical properties of a dry-coated tablet are crucial to its structural functions and therapeutic effectiveness, therefore they are monitored especially when the control of dissolution rates of their active ingredients are critically important. Acquired pulse-echo ultrasonic waveforms in the tablet could provide the time-of-flight information needed to determine the thickness, elasticity and/or integrity of the relevant layer, and bonding quality between layers depending on the given parameters. Since the amplitudes of the reflected waves are extremely low due to the high acoustic impedance mismatches of tablet materials and die/punch materials, signal processing techniques are required to extract the wave arrival times. In current study, it is demonstrated that the reflection of an ultrasonic pulse generated by a transducer embedded in a die or a punch from the coat-core interface can be acquired by the same transducer. PMID:21605647

  4. epsilon-N-trimethyllysine availability regulates the rate of carnitine biosynthesis in the growing rat

    SciTech Connect

    Rebouche, C.J.; Lehman, L.J.; Olson, L.

    1986-05-01

    Rates of carnitine biosynthesis in mammals depend on the availability of substrates and the activity of enzymes subserving the pathway. This study was undertaken to test the hypothesis that the availability of epsilon-N-trimethyllysine is rate-limiting for synthesis of carnitine in the growing rat and to evaluate diet as a source of this precursor for carnitine biosynthesis. Rats apparently absorbed greater than 90% of a tracer dose of (methyl-/sup 3/H)epsilon-N-trimethyllysine, and approximately 30% of that was incorporated into tissues as (/sup 3/H)carnitine. Rats given oral supplements of epsilon-N-trimethyllysine (0.5-20 mg/d), but no dietary carnitine, excreted more carnitine than control animals receiving no dietary epsilon-N-trimethyllysine or carnitine. Rates of carnitine excretion increased in a dose-dependent manner. Tissue and serum levels of carnitine also increased with dietary epsilon-N-trimethyllysine supplementation. There was no evidence that the capacity for carnitine biosynthesis was saturated even at the highest level of oral epsilon-N-trimethyllysine supplementation. Common dietary proteins (casein, soy protein and wheat gluten) were found to be poor sources of epsilon-N-trimethyllysine for carnitine biosynthesis. The results of this study indicate that the availability of epsilon-N-trimethyllysine limits the rate of carnitine biosynthesis in the growing rat.

  5. Botanical remedies of the former Dutch East Indies (Indonesia). Part I: Eumycetes, Pteridophyta, Gymnospermae, Angiospermae (Monocotyledones only).

    PubMed

    Hirschhorn, H H

    1983-03-01

    The botanical remedies reported in Heyne's De Nuttige Planten van Nederlandsch-Indië (Volumes 1--IV, 1913--1922) have been screened out of economic botanical context, translated into English and summarized as a table of names, therapeutic indications, plant parts, and available details of preparation and use. PMID:6345940

  6. Botanical remedies of the former Dutch East Indies (Indonesia). Part II: Dicotyledones up to and including leguminosae.

    PubMed

    Hirschhorn, H H

    1983-07-01

    The botanical remedies reported in Heyne's De Nuttige Planten van Nederlandsch-Indië (Volumes I-IV, 1913-1922) have been screened out of economic botanical context, translated into English and summarized as a table of names, therapeutic indications, plant parts, and available details of preparation and use. PMID:6632938

  7. A Cross-Cultural Examination of Racial Identity and Racial Preference of Preschool Children in the West Indies.

    ERIC Educational Resources Information Center

    Gopaul-McNicol, Sharon-Ann

    1995-01-01

    Investigated the racial attitudes of 302 preschool children in the West Indies whose racial preference was tested using black and white Cabbage Patch dolls. Standard Clark doll questions, plus four researcher-supplied questions, were individually administered. Findings show that 71.9 percent of the children chose to play with a white doll,…

  8. Quality Management in Course Development and Delivery at the University of the West Indies Distance Education Centre

    ERIC Educational Resources Information Center

    Thurab-Nkhosi, Dianne; Marshall, Stewart

    2009-01-01

    Purpose: In 2004, the University of the West Indies Distance Education Centre (UWIDEC) began incorporating the use of new information and communication technologies (ICTs) in the delivery of its programmes and courses, taking a "blended learning" approach. There is a recognition, however, of the need to ensure the quality of the programme…

  9. Prevention of diet-induced hepatic steatosis and hepatic insulin resistance by second generation antisense oligonucleotides targeted to the longevity gene mIndy (Slc13a5)

    PubMed Central

    Pesta, Dominik H.; Perry, Rachel J.; Guebre-Egziabher, Fitsum; Zhang, Dongyan; Jurczak, Michael; Fischer-Rosinsky, Antje; Daniels, Martin A.; Willmes, Diana M.; Bhanot, Sanjay; Bornstein, Stefan R.; Knauf, Felix; Samuel, Varman T.; Shulman, Gerald I.; Birkenfeld, Andreas L.

    2015-01-01

    Reducing the expression of the Indy (I'm Not Dead Yet) gene in lower organisms extends life span by mechanisms resembling caloric restriction. Similarly, deletion of the mammalian homolog, mIndy (Slc13a5), encoding for a plasma membrane tricarboxylate transporter, protects from aging- and diet-induced adiposity and insulin resistance in mice. The organ specific contribution to this phenotype is unknown. We examined the impact of selective inducible hepatic knockdown of mIndy on whole body lipid and glucose metabolism using 2′-O-methoxyethyl chimeric anti-sense oligonucleotides (ASOs) in high-fat fed rats. 4-week treatment with 2′-O-methoxyethyl chimeric ASO reduced mIndy mRNA expression by 91% (P<0.001) compared to control ASO. Besides similar body weights between both groups, mIndy-ASO treatment lead to a 74% reduction in fasting plasma insulin concentrations as well as a 35% reduction in plasma triglycerides. Moreover, hepatic triglyceride content was significantly reduced by the knockdown of mIndy, likely mediating a trend to decreased basal rates of endogenous glucose production as well as an increased suppression of hepatic glucose production by 25% during a hyperinsulinemic-euglycemic clamp. Together, these data suggest that inducible liver-selective reduction of mIndy in rats is able to ameliorate hepatic steatosis and insulin resistance, conditions occurring with high calorie diets and during aging. PMID:26647160

  10. Prevention of diet-induced hepatic steatosis and hepatic insulin resistance by second generation antisense oligonucleotides targeted to the longevity gene mIndy (Slc13a5).

    PubMed

    Pesta, Dominik H; Perry, Rachel J; Guebre-Egziabher, Fitsum; Zhang, Dongyan; Jurczak, Michael; Fischer-Rosinsky, Antje; Daniels, Martin A; Willmes, Diana M; Bhanot, Sanjay; Bornstein, Stefan R; Knauf, Felix; Samuel, Varman T; Shulman, Gerald I; Birkenfeld, Andreas L

    2015-12-01

    Reducing the expression of the Indy (I'm Not Dead Yet) gene in lower organisms extends life span by mechanisms resembling caloric restriction. Similarly, deletion of the mammalian homolog, mIndy (Slc13a5), encoding for a plasma membrane tricarboxylate transporter, protects from aging- and diet-induced adiposity and insulin resistance in mice. The organ specific contribution to this phenotype is unknown. We examined the impact of selective inducible hepatic knockdown of mIndy on whole body lipid and glucose metabolism using 2'-O-methoxyethyl chimeric anti-sense oligonucleotides (ASOs) in high-fat fed rats. 4-week treatment with 2'-O-methoxyethyl chimeric ASO reduced mIndy mRNA expression by 91% (P=0.001) compared to control ASO. Besides similar body weights between both groups, mIndy-ASO treatment lead to a 74% reduction in fasting plasma insulin concentrations as well as a 35% reduction in plasma triglycerides. Moreover, hepatic triglyceride content was significantly reduced by the knockdown of mIndy, likely mediating a trend to decreased basal rates of endogenous glucose production as well as an increased suppression of hepatic glucose production by 25% during a hyperinsulinemic-euglycemic clamp. Together, these data suggest that inducible liver-selective reduction of mIndy in rats is able to ameliorate hepatic steatosis and insulin resistance, conditions occurring with high calorie diets and during aging. PMID:26647160

  11. Preferential emission into epsilon-near-zero metamaterial [Invited

    SciTech Connect

    Galfsky, Tal; Sun, Zheng; Jacob, Zubin; Menon, Vinod M.

    2015-11-23

    We report the use of epsilon near zero (ENZ) metamaterial to control spontaneous emission from Zinc-Oxide (ZnO) excitons. The ENZ material consists of alternating layers of silver and alumina with subwavelength thicknesses, resulting in an effective medium where one of the components of the dielectric constant approach zero between 370nm-440nm wavelength range. Bulk ZnO with photoluminescence maximum in the ENZ regime was deposited via atomic layer deposition to obtain a smooth film with near field coupling to the ENZ metamaterial. Preferential emission from the ZnO layer into the metamaterial with suppression of forward emission by 90% in comparison to ZnO on silicon is observed. We attribute this observation to the presence of dispersionless plasmonic modes in the ENZ regime as shown by the results of theoretical modeling presented here. Integration of ENZ metamaterials with light emitters is an attractive platform for realizing a low threshold subwavelength laser.

  12. Shock initiation of an {epsilon}-CL-20-estane formulation

    SciTech Connect

    Tarver, C.M.; Simpson, R.L.; Urtiew, P.A.

    1995-07-19

    The shock sensitivity of a pressed solid explosive formulation, LX-19, containing 95.2% by weight epsilon phase 2,4,6,8,10,12-hexanitrohexaazaisowurtzitane (HNIW) and 4.8% Estane binder, was determined using the wedge test and embedded manganin pressure gauge techniques. This formulation was shown to be slightly more sensitive than LX-14, which contains 95.5% HMX and 4.5% Estane binder. The measured pressure histories for LX-19 were very similar to those obtained using several HMX-inert binder formulations. An Ignition and Growth reactive model for LX-19 was developed which differed from those for HMX-inert binder formulations only by a 25% higher hot spot growth rate.

  13. Shock initiation of an {epsilon}-CL-20-estane formulation

    SciTech Connect

    Tarver, C.M.; Simpson, R.L.; Urtiew, P.A.

    1996-05-01

    The shock sensitivity of a pressed solid explosive formulation, LX-19, containing 95.2{percent} by weight epsilon phase 2,4,6,8,10,12-hexanitrohexaazaisowurtzitane (HNIW) and 4.8{percent} Estane binder, was determined using the wedge test and embedded manganin pressure gauge techniques. This formulation was shown to be slightly more sensitive than LX-14, which contains 95.5{percent} HMX and 4.5{percent} Estane binder. The measured pressure histories for LX-19 were very similar to those obtained using several HMX-inert binder formulations. An Ignition and Growth reactive flow model for LX-19 was developed which differed from those for HMX-inert binder formulations only by a 25{percent} higher hot spot growth rate. {copyright} {ital 1996 American Institute of Physics.}

  14. Data Evaluation for 56Co epsilon + beta+ Decay

    SciTech Connect

    Baglin, Coral M.; MacMahon, T. Desmond

    2005-02-28

    Recommended values for nuclear and atomic data pertaining to the {var_epsilon} + {beta}{sup +} decay of {sup 56}Co are provided here, followed by comments on evaluation procedures and a summary of all available experimental data. {sup 56}Co is a radionuclide which is potentially very useful for Ge detector efficiency calibration because it is readily produced via the {sup 56}Fe(p,n) reaction, its half-life of 77.24 days is conveniently long, and it provides a number of relatively strong {gamma} rays with energies up to {approx}3500 keV. The transition intensities recommended here for the strongest lines will be included in the forthcoming International Atomic Energy Agency Coordinated Research Programme document ''Update of X- and Gamma-ray Decay Data Standards for Detector Calibration and Other Applications'', and the analysis for all transitions along with relevant atomic data have been provided to the Decay Data Evaluation Project.

  15. K-epsilon models of the lower overshoot layer

    NASA Astrophysics Data System (ADS)

    Petrovay, K.

    Apart from the solar core, the overshoot layer below the convective zone is the layer where some discrepancies between the standard and seismic solar models continue to exist. Non-local mixing length models are in clear conflict with the seismic evidence. A major difficulty for the development of more sophisticated models is the large degree of arbitrariness in formulating expressions for input parameters like the length scale. We propose that the application of the k-epsilon modelling approach, widely used in physics and engineering, could help in alleviating these difficulties. We present some simple overshoot models calculated with this approach, and we point out that the resulting expression of the length scale naturally reduces to the usual mixing length expression (proportional to the pressure scale height) well inside the convectively unstable region. Implications for the solar Li problem and for dynamo theory will also be discussed.

  16. The 5' flanking region of human epsilon-globin gene.

    PubMed Central

    Baralle, F E; Shoulders, C C; Goodbourn, S; Jeffreys, A; Proudfoot, N J

    1980-01-01

    The structural analysis of the 2.0 kb region upstream from the epsilon-globin gene has been carried out. A genomic DNA map around the gene was worked out in some detail to ensure that the cloned DNA was representative of the actual chromosomal arrangement. Furthermore, a new technique was developed to precisely map a reiterated DNA sequence present 1.5 kb to the 5' side of the gene. The complete nucleotide sequence of the 2.0 kb 5' flanking region was then determined and overlapped with the gene. The sequence included the reiterated DNA sequence which is homologous to the so-called AluI family of repeats. Unusual stretches of sequence 50 nucleotides long, where A + T represent about 90% of the bases, are present at both the 5' and 3' sides of the repeat. Images PMID:6253916

  17. Scattered light in the IUE spectra of Epsilon Aurigae

    NASA Technical Reports Server (NTRS)

    Altner, B.; Chapman, R. D.; Kondo, Y.; Stencel, R. E.

    1986-01-01

    Recent infrared photometry indicates that the alleged disk of particulate matter surrounding the mysterious secondary object in the Epsilon Aur system is cold, around 500 K. IUE spectra, on the other hand, contain significant flux in excess of that expected from an F0 Ia star in the far UV, which if interpreted as a hot secondary star leads to a possible contradiction with the IR data. Other models of the UV excess have been proposed, including the idea that the bulk of the short-wavelength flux is light scattered into the SWP camera from longer wavelengths. With the recent availability of a detailed generalized IUE descattering algorithm it is possible to thoroughly investigate the scattered-light contribution to the short-wavelength continuum. It is found that the IUE spectra are indeed partially contaminated by scattered light, but that even after correction for this instrumental effect a significant time-dependent UV excess is still present.

  18. The mid-ultraviolet spectrum of Epsilon Aurigae

    NASA Technical Reports Server (NTRS)

    Castelli, F.; Hoekstra, R.; Kondo, Y.

    1982-01-01

    An LTE synthetic spectrum with Te = 7800 K and log g = 1 has been computed for the 2455-to-3230 A range of Epsilon Aurigae (F0 1a). This has been compared with the spectra observed with 0.2 A resolution with the IUE experiment and with 0.1 A resolution with the BUSS experiment. As a consequence of this comparison, identifications and abundance values have been obtained. Ions definitely present include Mg I, Mg II, Al I, Al II, Si I, Ca II, Ti II, V II, Cr II, Mn II, Fe I, Fe II, Co II, Ni I, Ni II, Zr II. Ions which are possibly present include Ti III, Mn I, Fe III, Nb II, Mo I. The abundances are nearly 10 times the solar values for the iron group, with the exception of Fe, which has solar abundance. The abundances of the other elements are solar.

  19. Terahertz epsilon-near-zero graded-index lens.

    PubMed

    Torres, Víctor; Pacheco-Peña, Víctor; Rodríguez-Ulibarri, Pablo; Navarro-Cía, Miguel; Beruete, Miguel; Sorolla, Mario; Engheta, Nader

    2013-04-01

    An epsilon-near-zero graded-index converging lens with planar faces is proposed and analyzed. Each perfectly-electric conducting (PEC) waveguide comprising the lens operates slightly above its cut-off frequency and has the same length but different cross-sectional dimensions. This allows controlling individually the propagation constant and the normalized characteristic impedance of each waveguide for the desired phase front at the lens output while Fresnel reflection losses are minimized. A complete theoretical analysis based on the waveguide theory and Fermat's principle is provided. This is complemented with numerical simulation results of two-dimensional and three-dimensional lenses, made of PEC and aluminum, respectively, and working in the terahertz regime, which show good agreement with the analytical work. PMID:23572004

  20. Binding of epsilon-toxin from Clostridium perfringens in the nervous system.

    PubMed

    Dorca-Arévalo, Jonatan; Soler-Jover, Alex; Gibert, Maryse; Popoff, Michel R; Martín-Satué, Mireia; Blasi, Juan

    2008-09-18

    Epsilon-toxin (epsilon-toxin), produced by Clostridium perfringens type D, is the main agent responsible for enterotoxaemia in livestock. Neurological disorders are a characteristic of the onset of toxin poisoning. Epsilon-Toxin accumulates specifically in the central nervous system, where it produces a glutamatergic-mediated excitotoxic effect. However, no detailed study of putative binding structures in the nervous tissue has been carried out to date. Here we attempt to identify specific acceptor moieties and cell targets for epsilon-toxin, not only in the mouse nervous system but also in the brains of sheep and cattle. An epsilon-toxin-GFP fusion protein was produced and used to incubate brain sections, which were then analyzed by confocal microscopy. The results clearly show specific binding of epsilon-toxin to myelin structures. epsilon-Prototoxin-GFP and epsilon-toxin-GFP, the inactive and active forms of the toxin, respectively, showed identical results. By means of pronase E treatment, we found that the binding was mainly associated to a protein component of the myelin. Myelinated peripheral nerve fibres were also stained by epsilon-toxin. Moreover, the binding to myelin was not only restricted to rodents, but was also found in humans, sheep and cattle. Curiously, in the brains of both sheep and cattle, the toxin strongly stained the vascular endothelium, a result that may explain the differences in potency and effect between species. Although the binding of epsilon-toxin to myelin does not directly explain its neurotoxic effect, this feature opens up a new line of enquiry into its mechanism of toxicity and establishes the usefulness of this toxin for the study of the mammalian nervous system. PMID:18406080

  1. Differential regulation of alternative 3{prime} splicing of {epsilon} messenger RNA variants

    SciTech Connect

    Diaz-Sanchez, D.; Zhang, K.; Saxon, A.

    1995-08-15

    Alternative 3{prime} splicing of the one active human {epsilon} heavy chain gene results in variants of {epsilon} mRNA encoding distinct IgE proteins. The same relative amounts of these {epsilon} mRNA variants were produced by non-atopic donor B cells when driven in a variety of T-dependent or T-independent systems. The most abundant variants were those for classic secreted {epsilon} and a novel secreted form (CH4-M2{double_prime}). In contrast, cells from subjects with high levels of serum IgE secondary to parasitic infection or atopy spontaneously produced higher relative levels of the CH4-M2{prime} {epsilon} mRNA variant, lower relative amounts of both the membrane and CH4-M2{double_prime} secreted variants, and very low levels of the CH4{prime}-CH5 variant. The existence of and corresponding changes in levels of the CH4-M2{prime}-enclosed secreted protein were demonstrated. IL-10 induced this same differential expression of {epsilon} splice variants in vitro when used to costimulate IL-4 plus CD40-driven B cells and could differentially enhance the production of CH4-M2{prime} protein by established IgE-secreting cell lines. Inhibition of IgE by cross-linking the low affinity IgE receptor (CD23) decreased the levels of {epsilon} mRNA and resulted in a distinct pattern of {epsilon} mRNA characterized by a dramatic decrease in CH4-M2{prime} splice variant. IL-6, IL-2, or IFN-{gamma} did not change the {epsilon} mRNA pattern. Overall, the absolute and relative amounts of the different {epsilon} mRNA splice variants produced appear to be controlled in a differentiation-related fashion.

  2. Campaign Photometry During The 2010 Eclipse Of Epsilon Aurigae

    NASA Astrophysics Data System (ADS)

    Hopkins, Jeff; Stencel, R. E.

    2011-01-01

    Epsilon Aurigae is a long period (27.1 years) eclipsing binary star system with an eclipse that lasts nearly 2 years, but with severe ambiguities about component masses and shape. The current eclipse began on schedule in August of 2009. During the previous, 1982-1984 eclipse, an International Campaign was formed to coordinate a detailed study of the system. While that Campaign was deemed successful, the evolutionary status of the star system remained unclear. Epsilon Aurigae has been observed nearly continuously since the 1982 eclipse. The current Campaign was officially started in 2006. In addition to a Yahoo forum we have a dedicated web site and more than 18 online newsletters reporting photometry, spectroscopy, interferometry and polarimetry data. High quality UBVRIJH band photometric data since before the start of the current eclipse has been submitted. We explore the color differences among the light curves in terms of eclipse phases and archival data. At least one new model of the star system has been proposed since the current Campaign began: a low mass but very high luminosity F star plus a B star surrounded by a debris disk. The current eclipse and in particular the interferometry and spectroscopic data have caused new thoughts on defining eclipsing variable star contact points and phases of an eclipse. Second contact may not be the same point as start of totality and third contact may not be the same point as the start of egress and end of totality. In addition, the much awaited mid-eclipse brightening may or may not have appeared. This paper identifies the current Campaign contributors and the photometric data. This work was supported in part by the bequest of William Herschel Womble in support of astronomy at the University of Denver, by NSF grant 1016678 to the University of Denver.

  3. CONSTRAINTS FROM ASYMMETRIC HEATING: INVESTIGATING THE EPSILON AURIGAE DISK

    SciTech Connect

    Pearson, Richard L. III; Stencel, Robert E. E-mail: robert.stencel@du.edu

    2015-01-01

    Epsilon Aurigae is a long-period eclipsing binary that likely contains an F0Ia star and a circumstellar disk enshrouding a hidden companion, assumed to be a main-sequence B star. High uncertainty in its parallax has kept the evolutionary status of the system in question and, hence, the true nature of each component. This unknown, as well as the absence of solid state spectral features in the infrared, requires an investigation of a wide parameter space by means of both analytic and Monte Carlo radiative transfer (MCRT) methods. The first MCRT models of epsilon Aurigae that include all three system components are presented here. We seek additional system parameter constraints by melding analytic approximations with MCRT outputs (e.g., dust temperatures) on a first-order level. The MCRT models investigate the effects of various parameters on the disk-edge temperatures; these include two distances, three particle size distributions, three compositions, and two disk masses, resulting in 36 independent models. Specifically, the MCRT temperatures permit analytic calculations of effective heating and cooling curves along the disk edge. These are used to calculate representative observed fluxes and corresponding temperatures. This novel application of thermal properties provides the basis for utilization of other binary systems containing disks. We find degeneracies in the model fits for the various parameter sets. However, the results show a preference for a carbon disk with particle size distributions ≥10 μm. Additionally, a linear correlation between the MCRT noon and basal temperatures serves as a tool for effectively eliminating portions of the parameter space.

  4. Constraints from Asymmetric Heating: Investigating the Epsilon Aurigae Disk

    NASA Astrophysics Data System (ADS)

    Pearson, Richard L., III; Stencel, Robert E.

    2015-01-01

    Epsilon Aurigae is a long-period eclipsing binary that likely contains an F0Ia star and a circumstellar disk enshrouding a hidden companion, assumed to be a main-sequence B star. High uncertainty in its parallax has kept the evolutionary status of the system in question and, hence, the true nature of each component. This unknown, as well as the absence of solid state spectral features in the infrared, requires an investigation of a wide parameter space by means of both analytic and Monte Carlo radiative transfer (MCRT) methods. The first MCRT models of epsilon Aurigae that include all three system components are presented here. We seek additional system parameter constraints by melding analytic approximations with MCRT outputs (e.g., dust temperatures) on a first-order level. The MCRT models investigate the effects of various parameters on the disk-edge temperatures; these include two distances, three particle size distributions, three compositions, and two disk masses, resulting in 36 independent models. Specifically, the MCRT temperatures permit analytic calculations of effective heating and cooling curves along the disk edge. These are used to calculate representative observed fluxes and corresponding temperatures. This novel application of thermal properties provides the basis for utilization of other binary systems containing disks. We find degeneracies in the model fits for the various parameter sets. However, the results show a preference for a carbon disk with particle size distributions >=10 μm. Additionally, a linear correlation between the MCRT noon and basal temperatures serves as a tool for effectively eliminating portions of the parameter space.

  5. Crash protection of stock car racing drivers--application of biomechanical analysis of Indy car crash research.

    PubMed

    Melvin, John W; Begeman, Paul C; Faller, Ronald K; Sicking, Dean L; McClellan, Scott B; Maynard, Edwin; Donegan, Michael W; Mallott, Annette M; Gideon, Thomas W

    2006-11-01

    Biomechanical analysis of Indy car crashes using on-board impact recorders (Melvin et al. 1998, Melvin et al. 2001) indicates that Indy car driver protection in high-energy crashes can be achieved in frontal, side, and rear crashes with severities in the range of 100 to 135 G peak deceleration and velocity changes in the range of 50 to 70 mph. These crashes were predominantly single-car impacts with the rigid concrete walls of oval tracks. This impressive level of protection was found to be due to the unique combination of a very supportive and tight-fitting cockpit-seating package, a six-point belt restraint system, and effective head padding with an extremely strong chassis that defines the seat and cockpit of a modern Indy car. In 2000 and 2001, a series of fatal crashes in stock car racing created great concern for improving the crash protection for drivers in those racecars. Unlike the Indy car, the typical racing stock car features a more spacious driver cockpit due to its resemblance to the shape of a passenger car. The typical racing seat used in stock cars did not have the same configuration or support characteristics of the Indy car seat, and five-point belt restraints were used. The tubular steel space frame chassis of a stock car also differs from an Indy car's composite chassis structure in both form and mechanical behavior. This paper describes the application of results of the biomechanical analysis of the Indy car crash studies to the unique requirements of stock car racing driver crash protection. Sled test and full-scale crash test data using both Hybrid III frontal crash anthropomorphic test devices (ATDs) and BioSID side crash ATDs for the purpose of evaluating countermeasures involving restraint systems, seats and head/neck restraints has been instrumental in guiding these developments. In addition, the development of deformable walls for oval tracks (the SAFER Barrier) is described as an adjunct to improved occupant restraint through control

  6. Arylhydrocarbon receptor-dependent mIndy (Slc13a5) induction as possible contributor to benzo[a]pyrene-induced lipid accumulation in hepatocytes.

    PubMed

    Neuschäfer-Rube, Frank; Schraplau, Anne; Schewe, Bettina; Lieske, Stefanie; Krützfeldt, Julia-Mignon; Ringel, Sebastian; Henkel, Janin; Birkenfeld, Andreas L; Püschel, Gerhard P

    2015-11-01

    Non-alcoholic fatty liver disease is a growing problem in industrialized and developing countries. Hepatic lipid accumulation is the result of an imbalance between fatty acid uptake, fatty acid de novo synthesis, β-oxidation and secretion of triglyceride-rich lipoproteins from the hepatocyte. A central regulator of hepatic lipid metabolism is cytosolic citrate that can either be derived from the mitochondrium or be taken up from the blood via the plasma membrane sodium citrate transporter NaCT, the product of the mammalian INDY gene (SLC13A5). mINDY ablation protects against diet-induced steatosis whereas mINDY expression is increased in patients with hepatic steatosis. Diet-induced hepatic steatosis is also enhanced by activation of the arylhyrocarbon receptor (AhR) both in humans and animal models. Therefore, the hypothesis was tested whether the mINDY gene might be a target of the AhR. In accordance with such a hypothesis, the AhR activator benzo[a]pyrene induced the mINDY expression in primary cultures of rat hepatocytes in an AhR-dependent manner. This induction resulted in an increased citrate uptake and citrate incorporation into lipids which probably was further enhanced by the benzo[a]pyrene-dependent induction of key enzymes of fatty acid synthesis. A potential AhR binding site was identified in the mINDY promoter that appears to be conserved in the human promoter. Elimination or mutation of this site largely abolished the activation of the mINDY promoter by benzo[a]pyrene. This study thus identified the mINDY as an AhR target gene. AhR-dependent induction of the mINDY gene might contribute to the development of hepatic steatosis. PMID:26303333

  7. Antibacterial functionalization of wool via mTGase-catalyzed grafting of epsilon-poly-L-lysine.

    PubMed

    Wang, Qiang; Jin, Guibiao; Fan, Xuerong; Zhao, Xianfei; Cui, Li; Wang, Ping

    2010-04-01

    epsilon-Poly-L-lysine (epsilon-PL), a natural biomacromolecule having a broad spectrum of antibacterial activity, was grafted on the wool fiber via the acyl transfer reaction catalyzed by microbial transglutaminase (mTGase) to develop a new strategy for antibacterial functionalization of proteinous materials. The effects of the concentrations of epsilon-PLs and mTGases on the graft yields were investigated. A coating of epsilon-PL that almost completely covered the scale profile on the wool surface was visualized by scanning electron microscopy (SEM) and further demonstrated in terms of Allwörden's reaction characteristic of wool. Identifiable differences in lysine content and color depth among the stained wool samples reveal the changes in the surface composition and polarity caused by the incorporation of epsilon-PL onto the wool substrate, respectively. The ratio of bacteriostasis to Escherichia coli of the wool fabric grafting epsilon-PL reached 96.6 %, indicating an excellent antibacterial effect. The application of epsilon-PL and corresponding mTGase-catalyzed grafting reaction would provide a worthwhile reference for antibacterial functionalization of proteinous materials in various forms. PMID:19649747

  8. Selection of a Clostridium perfringens type D epsilon toxin producer via dot-blot test.

    PubMed

    Gonçalves, Luciana A; Lobato, Zélia I P; Silva, Rodrigo O S; Salvarani, Felipe M; Pires, Prhiscylla S; Assis, Ronnie A; Lobato, Francisco C F

    2009-11-01

    Clostridium perfringens type D produces enterotoxemia, an enteric disease in ruminants, also known as pulpy kidney disease. Caused by epsilon toxin, enterotoxemia is a major exotoxin produced by this microorganism. Epsilon toxin is also the main component of vaccines against this enteric disorder. In this study, a standardized dot-blot was used to choose strains of C. perfringens type D that are producers of epsilon toxin. Clones producing epsilon toxin were chosen by limiting dilution; after three passages, lethal minimum dose titers were determined by soroneutralization test in mice. These clones produced epsilon toxin 240 times more concentrated than the original strain. The presence of the epsilon toxin gene (etx) was verified by polymerase chain reaction. All clones were positive, including those determined to be negative by dot-blot tests, suggesting that mechanisms in addition to the presence of the etx gene can influence toxin production. The dot-blot test was efficient for the selection of toxigenic colonies of C. perfringens type D and demonstrated that homogeneous populations selected from toxigenic cultures produce higher titers of epsilon toxin. PMID:19779698

  9. Clostridium perfringens type-D enterotoxaemia in cattle: the diagnostic significance of intestinal epsilon toxin.

    PubMed

    Jones, A L; Dagleish, M P; Caldow, G L

    2015-10-17

    The aims of this study were to describe 42 cases of Clostridium perfringens type-D enterotoxaemia in cattle seen between 2003 and 2014 and to determine the diagnostic value of detecting epsilon toxin in bovine intestinal content. All cases in the series had histological brain changes considered pathognomonic for C. perfringens type-D enterotoxaemia in sheep and goats and the epsilon toxin of C. perfringens was concurrently detected in the intestinal contents of 15 (36 per cent) cases. The data from the case series indicate that intestinal epsilon toxin has a sensitivity of 56 per cent compared with histology of the brain for diagnosis of bovine C. perfringens type-D enterotoxaemia. The diagnostic specificity of detecting epsilon toxin in bovine intestinal content was investigated by screening intestinal contents of 60 bovine carcases submitted for postmortem examination. Epsilon toxin was detected in 11 (18 per cent) carcases but no pathognomonic histological brain change was found in any. The specificity of intestinal epsilon toxin was estimated to be 80.4 per cent. These studies demonstrate that for a definitive diagnosis of C. perfringens type-D enterotoxaemia in cattle histological examination of the brain is essential as the presence of epsilon toxin in the intestinal contents alone is neither sensitive nor specific enough. PMID:26428898

  10. epsilon-Poly-L: -lysine producer, Streptomyces albulus, has feedback-inhibition resistant aspartokinase.

    PubMed

    Hamano, Y; Nicchu, I; Shimizu, T; Onji, Y; Hiraki, J; Takagi, H

    2007-09-01

    Streptomyces albulus NBRC14147 produces epsilon-poly-L: -lysine (epsilon-PL), which is an amino acid homopolymer antibiotic. Despite the commercial importance of epsilon-PL, limited information is available regarding its biosynthesis; the L: -lysine molecule is directly utilized for epsilon-PL biosynthesis. In most bacteria, L: -lysine is biosynthesized by an aspartate pathway. Aspartokinase (Ask), which is the first enzyme in this pathway, is subject to complex regulation such as through feedback inhibition by the end-product amino acids such as L: -lysine and/or L: -threonine. S. albulus NBRC14147 can produce a large amount of epsilon-PL (1-3 g/l). We therefore suspected that Ask(s) of S. albulus could be resistant to feedback inhibition to provide sufficient L: -lysine for epsilon-PL biosynthesis. To address this hypothesis, in this study, we cloned the ask gene from S. albulus and investigated the feedback inhibition of its gene product. As predicted, we revealed the feedback resistance of the Ask; more than 20% relative activity of Ask was detected in the assay mixture even with extremely high concentrations of L: -lysine and L: -threonine (100 mM each). We further constructed a mutated ask gene for which the gene product Ask (M68V) is almost fully resistant to feedback inhibition. The homologous expression of Ask (M68V) further demonstrated the increase in epsilon-PL productivity. PMID:17611754

  11. [Military veterinary services in the former Dutch East Indies 1849-1950].

    PubMed

    Steltenpool, Bas

    2008-01-01

    The former Dutch colony is a vast archipelago and Java was the center of the Dutch colonial authority. In the outlying districts this authority had lesser influence. The army had a double task, at the one hand the protection of Java against foreign aggression and on the other hand police actions in the outlying districts. As usual during the 19th century, the army used animals, principally horses, but elephants were also used for provisioning the remote districts. In the beginning the veterinary care was in the hands of empiricists, but in 1830 the first officer horsedoctor was active and little by little a military veterinary service was developed and well trained vets came to the colony They were at the basis of the development of; veternnary medicine in the Dutch East Indies. PMID:20642140

  12. Evolution of in vitro fertilization at the University of the West Indies, Jamaica.

    PubMed

    Pottinger, A M; Everett-Keane, D; McKenzie, C

    2012-07-01

    In vitro fertilization (IVF) provides hope for many couples who believed that they could not have children. This paper tracks the development of IVF treatment at The University of the West Indies (UWI), Mona, from its genesis in 2000. It highlights changes over the years in the population seeking IVF at UWI, Mona, and describes clinical services offered to clients, comparing success rates of services internationally. It also reports on seminal research emerging out of UWI, Mona, in the field of assisted reproductive health. The Hugh Wynter Fertility Management Unit (HWFMU), UWI, Mona, leads the way in shaping how society views those challenged with infertility and in its use of assisted reproductive technologies that improve the quality of life for many locally, within the Caribbean and the Diaspora. PMID:23240486

  13. Transcription in vivo of an Alu family member upstream from the human epsilon-globin gene.

    PubMed Central

    Allan, M; Paul, J

    1984-01-01

    The more distal Alu repeat flanking the epsilon-globin gene is transcribed in K562 cells to generate transcripts 350-400 nucleotides in length. Initiation occurs at the start of the repeat, upstream of a putative PolIII control signal. These transcripts originate from the strand which does not code epsilon-globin and are oriented in the opposite direction from the gene. They are non-polyadenylated, nucleus-confined and are only detectable in association with expression of the epsilon-globin gene. Images PMID:6320117

  14. Simulations of free shear layers using a compressible kappa-epsilon model

    NASA Technical Reports Server (NTRS)

    Yu, S. T.; Chang, C. T.; Marek, C. J.

    1991-01-01

    A two-dimensional, compressible Navier-Stokes equation with a k-epsilon turbulence model is solved numerically to simulate the flow of a compressible free shear layer. The appropriate form of k and epsilon equations for compressible flow is discussed. Sarkar's modeling is adopted to simulate the compressibility effects in the k and epsilon equations. The numerical results show that the spreading rate of the shear layers decreases with increasing convective Mach number. In addition, favorable comparison was found between the calculated results and experimental data.

  15. Citizen Sky, Solving the Mystery of epsilon Aurigae

    NASA Astrophysics Data System (ADS)

    Turner, Rebecca; Price, A.; Kloppenborg, B.; Henden, A.

    2010-01-01

    Citizen Sky is a multi-year, NSF funded citizen science project involving the bright star eps Aur. The project was conceived by the IYA 2009 working group on Research Experiences for Students, Teachers, and Citizen-Scientists. Citizen Sky goes beyond simple observing to include a major data analysis component. The goal is to introduce the participant to the full scientific process from background research to paper writing for a peer-reviewed journal. It begins with a 10 Star Training Program of several types of binary and transient variable stars that are easy to observe from suburban locations with the naked eye. Participants then move on to monitoring the rare and mysterious 2009-2011 eclipse (already underway) of epsilon Aurigae. This object undergoes eclipses only every 27.1 years and each eclipse lasts nearly two years. The star is bright enough to be seen with the naked eye from most urban areas. Training will be provided in observing techniques as well as basic data analysis of photometric and visual datasets (light curve and period analysis). The project also involves two public workshops, one on observing (already held in August of 2009) and one on data analysis and scientific paper writing (to be held in 2010.) This project has been made possible by the National Science Foundation.

  16. Copernicus observations of the Ap star Epsilon Ursae Majoris

    NASA Technical Reports Server (NTRS)

    Mallama, A. D.; Molnar, M. R.

    1977-01-01

    Spectral scans of the Ap star Epsilon UMa made with the Copernicus satellite show strong line blanketing from profuse Cr II and Fe II lines. In the spectral region covering 1900 to 3000 A, about 500 lines are present which suppress the apparent continuum by at least 15-30%. An accurate line-identification list is compiled showing Eu II present in addition to Mn II and Ni II. The identification of Eu II, however, rests on very stringent identification limits for Fe II. If these are relaxed, the existence of Eu II is dubious. There are no broad features in this spectral region which would suggest strong photoionization discontinuities by metals, but one feature near 2137 A might contain the photoionization edge due to Cr I 5S lying 0.94 eV above the ground level. However, a significant correlation between the line-blanketing strength and the amplitude of the OAO-2 ultraviolet light curves was found such that both monotonically increase in the same proportion toward shorter wavelengths. This gives additional strength to the suggestion that variations in the metal line-blanketing cause the observed photometric variations.

  17. The Fourier analysis technique and epsilon-pseudo-eigenvalues

    SciTech Connect

    Donato, J.M.

    1993-07-01

    The spectral radii of iteration matrices and the spectra and condition numbers of preconditioned systems are important in forecasting the convergence rates for iterative methods. Unfortunately, the spectra of iteration matrices or preconditioned systems is rarely easily available. The Fourier analysis technique has been shown to be a useful tool in studying the effectiveness of iterative methods by determining approximate expressions for the eigenvalues or condition numbers of matrix systems. For non-symmetric matrices the eigenvalues may be highly sensitive to perturbations. The spectral radii of nonsymmetric iteration matrices may not give a numerically realistic indication of the convergence of the iterative method. Trefethen and others have presented a theory on the use of {epsilon}-pseudo-eigenvalues in the study of matrix equations. For Toeplitz matrices, we show that the theory of c-pseudo-eigenvalues includes the Fourier analysis technique as a limiting case. For non-Toeplitz matrices, the relationship is not clear. We shall examine this relationship for non-Toeplitz matrices that arise when studying preconditioned systems for methods applied to a two-dimensional discretized elliptic differential equation.

  18. Infrared Studies of Epsilon Aurigae in Eclipse 2010

    NASA Astrophysics Data System (ADS)

    Stencel, Robert E.; Kloppenborg, B.; Wall, R.; Howell, S.; Hoard, D.; Rayner, J.; Bus, S.; Tokunaga, A.; Sitko, M.; Russell, R.; Lynch, D.; Brafford, S.; Hammel, H.; Whitney, B.; Orton, G.; Yanamandra-Fisher, P.; Hora, J.; Hoffman, W.; Skemer, A.

    2011-01-01

    We report a series of observations of the enigmatic long period eclipsing binary epsilon Aurigae during its eclipse interval 2009-2011, using near-infrared spectra & photometry obtained with SpeX/IRTF, Spitzer/IRAC, mid-infrared data with BASS on IRTF & AEOS, MIRSI on IRTF and MIRAC4 on MMT, along with MIRSI on IRTF and MIRAC4 on MMT & Denver's TNTCAM2 at WIRO, and an Optec SSP-4 J&H photometer at Mt.Evans Observatory. The objective of these observations include: (1) confirm the appearance of CO absorption bands at and after mid-eclipse, due to the dark disk, and (2) seek evidence for any mid-infrared solid state spectral features from particles in the disk, seen during different portions of total eclipse. The results to date show that the infrared eclipse is less deep than the optical one, and the implied disk temperature has begun to increase from 550K toward 1100K as eclipse progresses past midpoint and heated portions of the disk come into view. Material properties of the disk are consistent with large particles. This work was supported in part by the bequest of William Herschel Womble in support of astronomy at the University of Denver, by NSF grant 1016678 and JPL RSA 1414715 to the University of Denver, by NASA ADP grant NNX09AC73G to the University of Cincinnati, by The Aerospace Corporation's Independent Research and Development Program.

  19. Epsilon toxin: a fascinating pore-forming toxin.

    PubMed

    Popoff, Michel R

    2011-12-01

    Epsilon toxin (ETX) is produced by strains of Clostridium perfringens classified as type B or type D. ETX belongs to the heptameric β-pore-forming toxins including aerolysin and Clostridium septicum alpha toxin, which are characterized by the formation of a pore through the plasma membrane of eukaryotic cells consisting in a β-barrel of 14 amphipatic β strands. By contrast to aerolysin and C. septicum alpha toxin, ETX is a much more potent toxin and is responsible for enterotoxemia in animals, mainly sheep. ETX induces perivascular edema in various tissues and accumulates in particular in the kidneys and brain, where it causes edema and necrotic lesions. ETX is able to pass through the blood-brain barrier and stimulate the release of glutamate, which accounts for the symptoms of nervous excitation observed in animal enterotoxemia. At the cellular level, ETX causes rapid swelling followed by cell death involving necrosis. The precise mode of action of ETX remains to be determined. ETX is a powerful toxin, however, it also represents a unique tool with which to vehicle drugs into the central nervous system or target glutamatergic neurons. PMID:21535407

  20. Preferential emission into epsilon-near-zero metamaterial [Invited

    DOE PAGESBeta

    Galfsky, Tal; Sun, Zheng; Jacob, Zubin; Menon, Vinod M.

    2015-11-23

    We report the use of epsilon near zero (ENZ) metamaterial to control spontaneous emission from Zinc-Oxide (ZnO) excitons. The ENZ material consists of alternating layers of silver and alumina with subwavelength thicknesses, resulting in an effective medium where one of the components of the dielectric constant approach zero between 370nm-440nm wavelength range. Bulk ZnO with photoluminescence maximum in the ENZ regime was deposited via atomic layer deposition to obtain a smooth film with near field coupling to the ENZ metamaterial. Preferential emission from the ZnO layer into the metamaterial with suppression of forward emission by 90% in comparison to ZnOmore » on silicon is observed. We attribute this observation to the presence of dispersionless plasmonic modes in the ENZ regime as shown by the results of theoretical modeling presented here. Integration of ENZ metamaterials with light emitters is an attractive platform for realizing a low threshold subwavelength laser.« less

  1. The Epsilon Eridani Debris Disk Resolved by Millimeter Interferometry

    NASA Astrophysics Data System (ADS)

    Wilner, David J.; MacGregor, Meredith A.; Andrews, Sean M.; Jean-Francois, Lestrade; Tahli Maddison, Sarah

    2016-01-01

    At a distance of only 3.22 pc, epsilon Eridani hosts the closest debris disk to the Sun. We present the first millimeter interferometric observations of this system, using the Submillimeter Array (SMA) at 1.3 mm and the Australia Telescope Compact Array (ATCA) at 7 mm, reaching 4 arcsec (13 AU) resolution. These observations reveal two distinct emission components: (1) the well-known outer dust belt, which is resolved in the radial direction, and (2) a compact source coincident with the position of the star. Model-fitting the visibilities constrains the basic properties of these components. The outer belt is located at 64 +/- 3 AU with fractional width 0.3, wider than the classical Kuiper Belt. This belt shows no significant azimuthal structure, or stellocentric offset, that might result from the presence of unseen giant planets on wide orbits in the system. The flux density of the unresolved central component exceeds predictions for thestellar photosphere; this excess may arise from a stellar chromosphere.

  2. Polarimetry of Epsilon Aurigae from Mid Eclipse to Third Contact

    NASA Astrophysics Data System (ADS)

    Cole, Gary M.; Stencel, Robert E.

    2011-05-01

    In a previous paper, the author discussed the construction of an automated dual beam imaging polarimeter and of observations made in the November 2009 to February 2010 period. Here, we discuss observations and instrumental improvements that span the period from late August 2010 through third and into fourth contacts in Spring 2011. Approximately 930 linear polarization measurements of the target star in BVR bands were obtained during 99 nights of observation. Additional measurements were made of both known polarization standards and zero polarization stars to verify instrument calibration. The polarization of Epsilon Aurigae was observed to vary by nearly 0.4% peak to valley during this period. These variations occurred in several major cycles of varying duration. Measurement error is estimated to be on the order of +/-0.05%. The observed variations resemble excess polarization seen during the 1984 eclipse egress, but may show some differences in detail. During this project, a new optical rotator was developed in conjunction with Optec, Inc., and used for the last two months of observations. This project was initiated at the suggestion of Dr. Robert Stencel at the May 2009 SAS meeting to extend measurements done during the 1984 eclipse by Dr. Jack Kemp and followed up by his student, Dr. Gary Henson thereafter.

  3. Electrically Tunable Epsilon-Near-Zero (ENZ) Metafilm Absorbers

    PubMed Central

    Park, Junghyun; Kang, Ju-Hyung; Liu, Xiaoge; Brongersma, Mark L.

    2015-01-01

    Enhancing and spectrally controlling light absorption is of great practical and fundamental importance. In optoelectronic devices consisting of layered semiconductors and metals, absorption has traditionally been manipulated with the help of Fabry-Pérot resonances. Even further control over the spectral light absorption properties of thin films has been achieved by patterning them into dense arrays of subwavelength resonant structures to form metafilms. As the next logical step, we demonstrate electrical control over light absorption in metafilms constructed from dense arrays of actively tunable plasmonic cavities. This control is achieved by embedding indium tin oxide (ITO) into these cavities. ITO affords significant tuning of its optical properties by means of electrically-induced carrier depletion and accumulation. We demonstrate that particularly large changes in the reflectance from such metafilms (up to 15% P) can be achieved by operating the ITO in the epsilon-near-zero (ENZ) frequency regime where its electrical permittivity changes sign from negative to positive values. PMID:26549615

  4. Electrically Tunable Epsilon-Near-Zero (ENZ) Metafilm Absorbers.

    PubMed

    Park, Junghyun; Kang, Ju-Hyung; Liu, Xiaoge; Brongersma, Mark L

    2015-01-01

    Enhancing and spectrally controlling light absorption is of great practical and fundamental importance. In optoelectronic devices consisting of layered semiconductors and metals, absorption has traditionally been manipulated with the help of Fabry-Pérot resonances. Even further control over the spectral light absorption properties of thin films has been achieved by patterning them into dense arrays of subwavelength resonant structures to form metafilms. As the next logical step, we demonstrate electrical control over light absorption in metafilms constructed from dense arrays of actively tunable plasmonic cavities. This control is achieved by embedding indium tin oxide (ITO) into these cavities. ITO affords significant tuning of its optical properties by means of electrically-induced carrier depletion and accumulation. We demonstrate that particularly large changes in the reflectance from such metafilms (up to 15% P) can be achieved by operating the ITO in the epsilon-near-zero (ENZ) frequency regime where its electrical permittivity changes sign from negative to positive values. PMID:26549615

  5. Coherent perfect absorption in epsilon-near-zero metamaterials

    NASA Astrophysics Data System (ADS)

    Feng, Simin; Halterman, Klaus

    2012-10-01

    In conventional materials, strong absorption usually requires that the material have either high loss or a large thickness-to-wavelength ratio (d/λ≫1). We find the situation to be vastly different for bilayer structures composed of a metallic substrate and an anisotropic epsilon-near-zero (ENZ) metamaterial, where the permittivity in the direction perpendicular to its surface, ɛz, vanishes. Remarkably, perfect absorption can occur in situations where the metamaterial is arbitrarily thin (d/λ≪1) and arbitrarily low loss. Our numerical and analytical solutions reveal that under the conditions ɛz→0 and ℑ(ɛz)≫ℜ(ɛz), at perfect absorption there is a linear relationship between the thickness and the loss, which means the thickness of the absorber can be pushed to zero by reducing the material loss to zero. This counterintuitive behavior is explained in terms of coherent perfect absorption (or stimulated absorption) via critical coupling to a fast wave propagating along the ENZ layer.

  6. Microstructure and microwave dielectric characteristics of (1 - x)Ba(Zn{sub 1/3}Ta{sub 2/3})O{sub 3}-xBaTi{sub 4}O{sub 9} ceramics

    SciTech Connect

    Tzou, W.-C. Yang, Y.-S.; Yang, C-F.; Chung, H.-H.; Huang, C.-J.; Diao, C.-C.

    2007-11-06

    (1 - x)Ba(Zn{sub 1/3}Ta{sub 2/3})O{sub 3}-xBaTi{sub 4}O{sub 9} (0.1 {<=} x {<=} 0.85) composites are prepared by mixing 1150 deg. C-calcined BaTi{sub 4}O{sub 9} with 1150 deg. C-calcined Ba(Zn{sub 1/3}Ta{sub 2/3})O{sub 3} powders. The crystal structure, microwave dielectric properties and sinterabilites of the (1 - x)Ba(Zn{sub 1/3}Ta{sub 2/3})O{sub 3}-xBaTi{sub 4}O{sub 9} ceramics have been investigated. X-ray diffraction patterns reveal that BaTi{sub 4}O{sub 9}, ordered and disordered Ba(Zn{sub 1/3}Ta{sub 2/3})O{sub 3} phases exist independently over the whole compositional range. The sintering temperatures of (1 - x)Ba(Zn{sub 1/3}Ta{sub 2/3})O{sub 3}-xBaTi{sub 4}O{sub 9} ceramics are about 1240 - 1320 deg. C and obviously lower than those of Ba(Zn{sub 1/3}Ta{sub 2/3})O{sub 3} ceramics. The dielectric constants ({epsilon}{sub r}) and the temperature coefficient of resonant frequency ({tau}{sub f}) of (1 - x)Ba(Zn{sub 1/3}Ta{sub 2/3})O{sub 3}-xBaTi{sub 4}O{sub 9} ceramics increase with the increase of BaTi{sub 4}O{sub 9} content. Nevertheless, the bulk densities and the quality values (Q x f) of (1 - x)Ba(Zn{sub 1/3}Ta{sub 2/3})O{sub 3}-xBaTi{sub 4}O{sub 9} ceramics increase with the increase of Ba(Zn{sub 1/3}Ta{sub 2/3})O{sub 3} content. The results are attributed to the higher density and quality value of Ba(Zn{sub 1/3}Ta{sub 2/3})O{sub 3} ceramics, the better grain growth, and the densification of sintered specimens added a small BaTi{sub 4}O{sub 9} content. The (1 - x)Ba(Zn{sub 1/3}Ta{sub 2/3})O{sub 3}-xBaTi{sub 4}O{sub 9} ceramic with x = 0.1 sintered at 1320 deg. C exhibits a {epsilon}{sub r} value of 31.5, a maximum Q x f value of 68500 GHz and a minimum {tau}{sub f} value of 4.1 ppm/deg. C.

  7. Preclinical memory profile in Alzheimer patients with and without allele APOE-epsilon4.

    PubMed

    Estévez-González, Armando; García-Sánchez, Carmen; Boltes, Anunciación; Otermín, Pilar; Baiget, Montserrat; Escartín, Antonio; del Rio, Elisabeth; Gironell, Alex; Kulisevsky, Jaime

    2004-01-01

    To investigate the association between APOE-epsilon4 allele and memory phenotype in the preclinical stage of Alzheimer's disease (AD). We compared an extensive preclinical memory profile at the baseline evaluation of 2 AD genotype groups: APOE-epsilon4 allele carriers and patients with APOE-epsilon3 homozygosity. Baseline memory performance was carried out at least 2 years (interval of 27.7 +/- 4 months) before AD diagnosis was established, and analysis included different modalities of working memory (visuoperceptive, visuospatial, digit span and processing speed), of declarative memory (recent, verbal learning, prospective and semantic) and of nondeclarative memory (procedural, incidental and priming). We found no significant differences: memory performance was similar in both genotype groups. The presence of the APOE-epsilon4 allele does not seem to be sufficient to cause a distinctive preclinical memory phenotype in AD patients. PMID:15159600

  8. Epsilon carbide - A low-temperature component of interplanetary dust particles

    NASA Technical Reports Server (NTRS)

    Christoffersen, R.; Buseck, P. R.

    1983-01-01

    Transmission electron microscope study of a chondritic interplanetary dust particle has revealed the presence of epsilon iron-nickel carbide, a low-temperature carbide previously encountered only in metallurgical studies. In these studies epsilon-carbide was synthesized by carburization of iron or nickel grains in a stream of carbon monoxide or carbon monoxide plus hydrogen. Similar carburization of an iron-nickel metal in situ may have produced epsilon-carbide during particle heating on atmospheric entry or in solar orbit. Alternatively, the epsilon-carbide may be a by-product of Fischer-Tropsch reactions in the solar nebula. Such reactions have been proposed as the mechanism of hydrocarbon formation in the early solar system.

  9. T{sub {epsilon}}{sup *} integral under plane stress crack growth

    SciTech Connect

    Omori, Yoshika; Ma, Leong; Kobayashi, A.S.; Okada, Hiroshi; Atluri, S.N.

    1997-12-01

    The T{sub {epsilon}}{sup *} integral values associated with stable crack growth in A606 HSLA steel single-edge-notched (SEN) specimens were determined experimentally and numerically. The displacement fields obtained through Moire interferometry and elastic-plastic finite element analysis were used to evaluate T{sub {epsilon}}{sup *} associated with the moving crack tip. T{sub {epsilon}}{sup *} decreased with the reduction in the size of the integration contour, {Gamma}{sub {epsilon}}, and continually increased with stable crack growth in this specimen. The measured and computed crack-tip opening angle (CTOA), on the other hand, was a constant 15{degree} during stable crack growth after dropping from the measured and computed initial high values of 35 and 57{degree}, respectively.

  10. Specification of an IF1 to PG translator for the Epsilon-2 dataflow machine

    SciTech Connect

    Boehm, W.; Hoch, J.E.

    1992-11-01

    This report describes a mechanism for compiling the functional language SISAL for Sandia`s Epsilon-2 hybrid dataflow machine. The strategy couples the front-end of the standard SISAL compiler (which generates a data dependence graph intermediate form called IF1) with an optimizing code-generator for Epsilon-2. The Epsilon-2 code-generator is the back-end of a compiler for the functional language Id. It translates a data dependence graph intermediate form called Program Graphs into Epsilon-2 machine code. This report describes a translation path from IF1 graphs to Program Graphs. This report also comments on the relative merits of the IF1 and Program Graph representations.

  11. Specification of an IF1 to PG translator for the Epsilon-2 dataflow machine

    SciTech Connect

    Boehm, W. . Dept. of Computer Science); Hoch, J.E. )

    1992-11-01

    This report describes a mechanism for compiling the functional language SISAL for Sandia's Epsilon-2 hybrid dataflow machine. The strategy couples the front-end of the standard SISAL compiler (which generates a data dependence graph intermediate form called IF1) with an optimizing code-generator for Epsilon-2. The Epsilon-2 code-generator is the back-end of a compiler for the functional language Id. It translates a data dependence graph intermediate form called Program Graphs into Epsilon-2 machine code. This report describes a translation path from IF1 graphs to Program Graphs. This report also comments on the relative merits of the IF1 and Program Graph representations.

  12. Low Reynolds number k-epsilon modelling with the aid of direct simulation data

    NASA Technical Reports Server (NTRS)

    Rodi, W.; Mansour, N. N.

    1993-01-01

    The constant C sub mu and the near-wall damping function f sub mu in the eddy-viscosity relation of the k-epsilon model are evaluated from direct numerical simulation (DNS) data for developed channel and boundary layer flow at two Reynolds numbers each. Various existing f sub mu model functions are compared with the DNS data, and a new function is fitted to the high-Reynolds-number channel flow data. The epsilon-budget is computed for the fully developed channel flow. The relative magnitude of the terms in the epsilon-equation is analyzed with the aid of scaling arguments, and the parameter governing this magnitude is established. Models for the sum of all source and sink terms in the epsilon-equation are tested against the DNS data, and an improved model is proposed.

  13. Low Reynolds number kappa-epsilon modeling with the aid of direct simulation data

    NASA Technical Reports Server (NTRS)

    Rodi, W.; Mansour, N. N.

    1990-01-01

    The constant C(sub mu) and the near-wall damping function f(sub mu) in the eddy-viscosity relation of the kappa-epsilon model are evaluated from direct numerical simulation (DNS) data for developed channel and boundary layer flow at two Reynolds numbers each. Various existing f(sub mu) model functions are compared with the DNS data, and a new function is fitted to the high-Reynolds-number channel flow data. The epsilon-budget is computed for the fully developed channel flow. The relative magnitude of the terms in the epsilon-equation is analyzed with the aid of scaling arguments, and the parameter governing this magnitude is established. Models for the sum of all source and sink terms in the epsilon-equation are tested against the DNS data, and an improved model is proposed.

  14. DNA replication: polymerase epsilon as a non-catalytic converter of the helicase.

    PubMed

    Zegerman, Philip

    2013-04-01

    In eukaryotes DNA polymerase epsilon (ε) synthesises the leading DNA strand during replication. A new study provides insight into how this polymerase also functions independently of its enzyme activity to assemble and activate the replicative helicase. PMID:23578873

  15. Calculations of diffuser flows with an anisotropic K-epsilon model

    NASA Astrophysics Data System (ADS)

    Zhu, J.; Shih, T.-H.

    1995-10-01

    A newly developed anisotropic K-epsilon model is applied to calculate three axisymmetric diffuser flows with or without separation. The new model uses a quadratic stress-strain relation and satisfies the realizability conditions, i.e., it ensures both the positivity of the turbulent normal stresses and the Schwarz' inequality between any fluctuating velocities. Calculations are carried out with a finite-element method. A second-order accurate, bounded convection scheme and sufficiently fine grids are used to ensure numerical credibility of the solutions. The standard K-epsilon model is also used in order to highlight the performance of the new model. Comparison with the experimental data shows that the anisotropic K-epsilon model performs consistently better than does the standard K-epsilon model in all of the three test cases.

  16. Calculations of Diffuser Flows with an Anisotropic K-Epsilon Model

    NASA Technical Reports Server (NTRS)

    Zhu, J.; Shih, T.-H.

    1995-01-01

    A newly developed anisotropic K-epsilon model is applied to calculate three axisymmetric diffuser flows with or without separation. The new model uses a quadratic stress-strain relation and satisfies the realizability conditions, i.e., it ensures both the positivity of the turbulent normal stresses and the Schwarz' inequality between any fluctuating velocities. Calculations are carried out with a finite-element method. A second-order accurate, bounded convection scheme and sufficiently fine grids are used to ensure numerical credibility of the solutions. The standard K-epsilon model is also used in order to highlight the performance of the new model. Comparison with the experimental data shows that the anisotropic K-epsilon model performs consistently better than does the standard K-epsilon model in all of the three test cases.

  17. Navier-Stokes cascade analysis with a stiff Kappa-Epsilon turbulence solver

    NASA Technical Reports Server (NTRS)

    Liu, Jong-Shang; Sockol, Peter M.; Prahl, Joseph M.

    1987-01-01

    The two dimensional, compressible, thin layer Navier-Stokes equations with the Baldwin-Lomax turbulence model and the kinetic energy-energy dissipation (k-epsilon) model are solved numerically to simulate the flow through a cascade. The governing equations are solved for the entire flow domain, without the boundary layer assumptions. The stiffness of the k-epsilon equations is discussed. A semi-implicit, Runge-Kutta, time-marching scheme is developed to solve the k-epsilon equations. The impact of the k-epsilon solver on the explicit Runge-Kutta Navier-Stokes solver is discussed. Numerical solutions are presented for two dimensional turbulent flow over a flat plate and a double circular arc cascade and compared with experimental data.

  18. BA Degree Handbook, 1978.

    ERIC Educational Resources Information Center

    Open Univ., Walton, Bletchley, Bucks (England).

    This 1978 Open University BA degree Handbook begins with information about the university organization, correspondence materials, assignments and examinations, television and radio broadcasts, audio-cassette loan service, books and libraries, study centers, the computing service, handicapped students, tutor-counselors and course tutors, tuition,…

  19. Attenuation of epsilon(sub eff) of coplanar waveguide transmission lines on silicon substrates

    NASA Technical Reports Server (NTRS)

    Taub, Susan R.; Young, Paul G.

    1993-01-01

    Attenuation and epsilon(sub eff) of Coplanar Waveguide (CPW) transmission lines were measured on Silicon substrates with resistivities ranging from 400 to greater than 30,000 ohm-cm, that have a 1000 angstrom coating of SiO2. Both attenuation and epsilon(sub eff) are given over the frequency range 5 to 40 GHz for various strip and slot widths. These measured values are also compared to the theoretical values.

  20. Regulation of the expression of human C[epsilon] germline transcript

    SciTech Connect

    Ichiki, T.; Takahashi, W.; Watanabe, T. )

    1993-06-15

    Transcriptional regulation for Ig H chain germline transcripts induced by cytokines is a topic of recent interest for the understanding of the mechanism of class switch recombination. Among human B cell lines examined, the authors have found that a human IgM-producing B cell line, DND39 (EBV negative) expressed germ-line transcripts of [epsilon] constant gene (C[epsilon]) when stimulated with lL-4. In this study, the regulatory element responsible for the expression of lL-4-induced human C[epsilon] germ-line transcript was determined using DND39 cells. To identify the lL-4 responsive promotor/enhancer element, deletion analysis of the upstream region of the germ-line exon (l[epsilon]) of the C[epsilon] germ-line transcript which is located 5' to the switch region, was performed by using a luciferase gene as a reporter. Deletion analysis showed that a DNA fragment which lies between [minus]215 and [minus]154 bp upstream from the most 3' transcriptional initiation site of human l[epsilon] gene is fully responsible for the induction of germ-line transcripts by IL-4. According to a mutational analysis, the DNA fragment between [minus]163 and [minus]152 bp was identified to be a novel IL-4 responsive element in a human C[epsilon] gene. Electrophoretic gel mobility shift assay showed the presence of IL-4-induced nuclear factor that specifically bound to this IL-4 responsive element. This novel IL-4 responsive element and an IL-4-induced DNA binding protein may play an important role for the induction of C[epsilon] germ-line transcript as well as class switching to IgE. 54 refs., 7 figs.

  1. Expression of bactericidal/permeability-increasing protein requires C/EBP epsilon.

    PubMed

    Tanaka, Miyuki; Gombart, Adrian F; Koeffler, H Phillip; Shiohara, Masaaki

    2007-05-01

    Bactericidal/permeability-increasing protein (BPI) is a 55-kd cationic protein found mainly in neutrophil primary granules. BPI shows cytotoxicity against Gram-negative bacteria. In this study, we studied the role of a myeloid-specific transcription factor, CCAAT/enhancer binding protein epsilon (C/EBP epsilon), in the regulation of BPI gene expression. A patient with neutrophil-specific granule deficiency with a homozygous inactivating mutation in the CEBP epsilon gene showed severely impaired expression of both BPI messenger RNA (mRNA) and BPI protein. Both U937 and NB4 cells treated with 10-7 M all-trans retinoic acid (ATRA) for 6 days displayed increased levels of BPI protein and accompanying up-regulated C/EBP epsilon expression. Chromatin-immunoprecipitation analysis and electrophoretic mobility shift assays revealed binding of the C/EBP epsilon protein to the C/EBP-binding site in the BPI gene promoter. U937 cells stably transfected with a zinc-inducible C/EBP epsilon expression vector showed a 30-fold increase in BPI mRNA levels compared with cells transfected with control empty vector after culturing for 48 hours with 100 microM ZnSO4. BPI mRNA expression was severely reduced in the bone marrow of C/EBP epsilon-deficient mice compared with wild-type mice. Expression of BPI in human cord blood cells was increased by incubation with 10-7 MATRA for 48 hours. These results demonstrate the requirement for C/EBP epsilon in mediating BPI gene expression in myeloid cells in vitro and in vivo. PMID:17483073

  2. The role of the University of the West Indies Mona libraries in HIV/AIDS information access and dissemination.

    PubMed

    Harris, S

    2013-01-01

    The recommendations for controlling HIV/AIDS, whether prescriptive or descriptive, underscore the value of information: its translation into knowledge, and knowledge into behaviour. Thus, accessing, evaluating, disseminating and applying authoritative, credible and scholarly information on HIV/AIDS are critical elements in the control of this pandemic in the Web 2.0 era. The University of the West Indies (UWI) Mona libraries have embraced this information role. This article provides insights into three of the information initiatives implemented by the UWI Mona libraries in this important capacity. In this regard, it also provides ideas for other West Indian information units and enhances communication on access to information products and services, albeit incrementally, in an important area of health services for the West Indies. PMID:24756597

  3. Phase stability of {epsilon} and {gamma} HNIW (CL-20) at high-pressure and temperature

    SciTech Connect

    Gump, Jared C.; Stoltz, Chad A.; Peiris, Suhithi M.

    2007-12-12

    Hexanitrohexaazaisowurtzitane (CL-20) is one of the few ingredients developed since World War II to be considered for transition to military use. Five polymorphs have been identified for CL-20 by FTIR measurements ({alpha}, {beta}, {gamma}, {epsilon}, {zeta}). As CL-20 is transitioned into munitions it will become necessary to predict its response under conditions of detonation, for performance evaluation. Such predictive modeling requires a phase diagram and basic thermodynamic properties of the various phases at high pressure and temperature. Therefore, the epsilon and gamma phases of CL-20 at static high-pressure and temperature were investigated using synchrotron angle-dispersive x-ray diffraction experiments. The samples were compressed and heated using diamond anvil cells (DAC). Pressures and temperatures achieved were around 5 GPa and 240 deg. C, respectively. The epsilon phase was stable to 6.3 GPa at ambient temperature. When heated at ambient pressure the epsilon phase was sustained to a temperature of 120 deg. C then underwent a transition to the gamma phase above 125 deg. C and then thermal decomposition occurred above 150 deg. C. Upon compression, the gamma phase underwent a phase transition at both ambient temperature and 140 deg. C. Pressure--volume data for the epsilon and gamma phase at ambient temperature and the epsilon phase at 75 deg. C were fit to the Birch-Murnaghan formalism to obtain isothermal equations of state.

  4. Carnitine biosynthesis in Neurospora crassa: enzymatic conversion of lysine to epsilon-N-trimethyllysine.

    PubMed Central

    Rebouche, C J; Broquist, H P

    1976-01-01

    The enzymatic conversion of L-lysine, epsilon-N-trimethyl-L-lysine the first series of reactions in the biosynthesis of carnitine in Neurospora crassa, proceeds via sequential methylation of free L-lysine, epsilon-N-methyl-L-lysine, and epsilon -N-dimethyl-L-lysine. The latter two compounds have been shown to be intermediates in the biosynthesis of carnitine by radioisotope dilution and incorporation experiments in growing cultures of N. crassa 33933 (lys-) and 38706 (met-). Methionine but not choline, has been recognized as an effective methyl donor in vivo. Inclusion of choline in the growth medium of strain 33933 does, however, enhance incorporation of the methyl groups of L-[methyl-3H]methionine into carnitine in an apparent "sparing" effect on methionine synthesis. Studies in cell-free extracts of the lysine auxotroph strain 33933 of N. crassa have established that lysine and epsilon-N-methyl and epsilon-N-dimethyllysine are enzymatically methylated, with S-adenosyl-L-methionine as the methyl group donor. The enzyme system appears to have no essential cofactors. Lysine does not induce synthesis of the enzyme system in the wild-type strain 262, whereas both carnitine and epsilon-N-trimethyllysine repress its synthesis in strain 33933. PMID:133101

  5. Notes from Batavia, the Europeans' graveyard: the nineteenth-century debate on acclimatization in the Dutch East Indies.

    PubMed

    Pols, Hans

    2012-01-01

    Since the advent of European colonial expansion, medical theories of acclimatization have been inextricably related to convictions about the possibility and desirability of white settlement in the colonies, and political ideas of colonial governance. Before 1800, acclimatization theories emphasized the inherent flexibility of the human constitution and its ability to adapt to new environments. During the first half of the nineteenth century, European theorists came to highlight the vulnerability of white Europeans in the tropics to disease, degeneration, and death instead. They consequently argued that white settlement in the tropics was impossible and inadvisable. European physicians in the British and French colonies presented similar views. By contrast, their colleagues in the Dutch East Indies remained optimistic. They associated themselves with the colonial European settler community and shared their grievances against autocratic colonial rule. They presented medical theories which related acclimatization to prudent behavior, morality, and proper management of the environment, thereby downplaying the significance of climate and high temperatures. During the following decades, their views on acclimatization were transferred to the Netherlands, where they were deployed as an argument against the cultivation system, the then-current approach of colonial governance, which emphasized the trade of cash crops grown by the indigenous population, severely limited European settlement, and curtailed the rights of Europeans living in the Indies. Throughout the nineteenth century, the influence of climate and the possibility of acclimatization became recurring themes in debates about colonial governance in both the Dutch East Indies and the Netherlands. PMID:21317422

  6. The Chlordecone crisis in the French West Indies : Its fate in soils and water

    NASA Astrophysics Data System (ADS)

    Voltz, Marc; Cattan, Philippe; Saison, Carine; Berns, Anne E.; Colin, François; Crabit, Armand; Crevoisier, David; Fernandez-Bayo, Jesus; Levillain, Joseph; Pak, Lai-Ting; Samouelian, Anatja; Cabidoche, Yves-Marie

    2013-04-01

    In the French West Indies, chlordecone (CLD), an organochlorine pesticide, which is highly persistent in the environment, was applied in banana plantations from 1972 to 1993 against the banana weevil Cosmopolites sordidus. Pollution surveys conducted in 2001 by the French Department of Health revealed the presence of chlordecone in soils, rivers, springs over large areas in Guadeloupe and Martinique islands. Contamination of drinking water, food crops, aquatic species by CLD has been observed as well as its presence in blood of men, pregnant women and newborns. There is therefore a large social concern about the extent and evolution of CLD pollution in the French West Indies and its impact on human health and ecosystems. From 2008 to 2012 a multidisciplinary project CHLORDEXCO took place to study the CLD fate in water, soils and the contamination characteristics of aquatic species and food crops. Here, we summarize results obtained on the processes controlling the spatial and temporal patterns of soil and water contamination at the scale of the banana cropping area in Guadeloupe and of the Perou catchment. The main soils in the contaminated areas are andosols and nitisols and formed from the weathering of volcanic ashes. They have a high organic carbon content and high content of secondary minerals, allophane for andosols and halloysite for nitisols. An analysis of the spatial distribution of CLD in soil over 1045 field plots showed that the soil type had a strong impact. Andosols, with a high sorption capacity (Koc 20 000 L/kg), had the highest CLD concentrations and stocks, unlike Nitisols, which had 10-fold lower sorption capacities. A significant « farm effect », due to between-farm variations of application times and amounts, was also noticed. The observed stocks of CLD clearly correspond to the accumulation in soil of successive treatments and thereby confirm the high persistence of CLD in soil also observed in incubation studies in soil microcosms. Soil

  7. Protein kinase C epsilon is localized to the Golgi via its zinc-finger domain and modulates Golgi function.

    PubMed Central

    Lehel, C; Olah, Z; Jakab, G; Anderson, W B

    1995-01-01

    Protein kinase C (PKC) is a multigene family of serine/threonine kinases that are central to many signal transduction pathways. Among the PKC isozymes, only PKC epsilon has been reported to exhibit full oncogenic potential. PKC epsilon also displays unique substrate specificity and intracellular localization. To examine the interrelationship between the biological effects and domain structure of PKC epsilon, NIH 3T3 cells were stably transfected to overexpress different epitope-tagged fragments of PKC epsilon. The overexpressed proteins each contain the epsilon-tag peptide at the C terminus to allow ready detection with an antibody specific for the tag. The holo-PKC epsilon was found to localize with the Golgi network and other compartments, whereas the zinc-finger domain localized exclusively at the Golgi. Golgi-specific glycosaminoglycan sulfation was strongly inhibited in cells overexpressing either holo-PKC epsilon or its zinc-finger domain, while the secretion of sulfated glycosaminoglycans into the medium was impaired in cells expressing the PKC epsilon zinc-finger domain. Thus, these results suggest that PKC epsilon may be involved in specifically regulating Golgi-related processes. Further, the results indicate that PKC epsilon domains other than the kinase domain may also have biological activity and that the zinc-finger domain may function as a subcellular localization signal. Images Fig. 1 Fig. 2 Fig. 3 PMID:7877991

  8. Lessons Learned During the Recent Epsilon Aurigae Eclipse Observing Campaign

    NASA Astrophysics Data System (ADS)

    Stencel, Robert E.

    2011-05-01

    The 18 month long eclipse of the 3rd magnitude star, epsilon Aurigae, is forecast to end during May 2011, based on six eclipse events, in 2010, 1982, 1955, 1930, 1902 and 1874. In partnership with AAVSO, Hopkins Phoenix Observatory and others, we have organized observing campaigns during the past several years in order to maximize data acquired during this rare event and to promote reporting and analysis of observations of all kinds. Hundreds of registered participants have signed up for alert notices and newsletters, and many dozens of observers have contributed photometry, spectra and ideas to the ongoing effort - see websites: www.CitizenSky.org and www.hposoft.com/Campaign09.html . In this presentation, I will provide an update on the participation leading to extensive photometric results. Similarly, bright star spectroscopy has greatly benefited from small telescope plus spectrometer capabilities, now widely available, that complement traditional but less-frequent large telescope high dispersion work. Polarimetry provided key insights during the last eclipse, and we promoted the need for new data using this method. Finally, interferometry has come of age since the last eclipse, leading to the direct detection of the transiting dark disk causing the eclipse. Along with these traditional measurements, I will outline campaign-related efforts to promote Citizen Science opportunities among the public. Support for these efforts derives in part from AAVSO/NSF-Informal Science Education, NSF AAG grant 10-16678 and a bequest to the University of Denver Astronomy Program by alumnus William Herschel Womble, for which I am grateful.

  9. Pharmacokinetics of Epsilon-Aminocaproic Acid in Neonates

    PubMed Central

    Eaton, Michael P.; Alfieris, George M; Sweeney, Dawn M; Angona, Ronald E; Cholette, Jill M; Venuto, Charles; Anderson, Brian

    2016-01-01

    Background Antifibrinolytic medications such as epsilon-aminocaproic acid (EACA) are used in pediatric heart surgery to decrease surgical bleeding and transfusion. Dosing schemes for neonates are often based on adult regimens, or are simply empiric, in part due to the lack of neonatal pharmacokinetic information. We sought to determine the pharmacokinetics of EACA in neonates undergoing cardiac surgery and to devise a dosing regimen for this population. Methods Ten neonates undergoing cardiac surgery with cardiopulmonary bypass were given EACA according to standard practice, and blood was drawn at 10 time points to determine drug concentrations. Time-concentration profiles were analyzed using nonlinear mixed effects models. Parameter estimates (standardized to a 70 kg person) were used to develop a dosing regimen intended to maintain a target concentration shown to inhibit fibrinolysis in neonatal plasma (50 mg/L). Results Pharmacokinetics were described using a two compartment model plus an additional compartment for the cardiopulmonary bypass pump. First order elimination was described with a clearance of 5.07 L/h*(WT/70) 0.75. Simulation showed a dosing regimen with a loading dose of 40 mg/kg, and an infusion of 30 mg/kg/h, with a pump prime concentration of 100 mg/L maintained plasma concentrations above 50 mg/L in 90% of neonates during cardiopulmonary bypass surgery. Conclusions EACA clearance, expressed using allometry, is reduced in neonates compared to older children and adults. Loading dose and infusion dose are approximately half those required in children and adults. PMID:25723765

  10. Discovery of the February Epsilon Virginids (FEV, IAU#506)

    NASA Astrophysics Data System (ADS)

    Steakley, Kathryn; Jenniskens, P. M.

    2013-01-01

    Halley type comets are relatively few, but at Earth they are sampled over a large part of the inner solar system because dust accumulates in comparatively stable orbits. We have detected a new meteor shower with a Halley-type orbit, the February epsilon Virginids (FEV), from video observations with the Cameras for All-Sky Meteor Surveillance (CAMS) and by examining orbits listed in the SonataCo Japanese database. Twenty-two meteors were detected during the period from February 1st through February 9th of 2008 to 2012 that are part of this shower. The FEVs originate from the geocentric radiant of R.A. = 201.66° and Dec = +10.39° with a mean geocentric velocity of 63.01 km/s. The mean orbital elements of these meteoroids are q = (0.488 ± 0.021) AU, 1/a = ( 0.085 ± 0.095) 1/AU, e = 0.958 ± 0.046, i = 138.05° ± 1.28°, ω = 271.15° ± 3.70°, Ω = 315.26 ± 0.86°, and Π = 228.12°. We investigated whether this meteoroid stream could have originated from comets C/1978 T3 (Bradfield), C/1808 F1 (Pons), or C/1939 H1 (Jurlof-Achmarof-Hassel). If the parent body can be identified, we can determine when the comet was first captured into a low perihelion distance orbit. Future examination of the shower will allow us to examine the physical properties of the parent comet.

  11. [A psychopathologic conflict in the 18th century in the East Indies Squadron].

    PubMed

    Alliez, J; Le Goarant de Tromelin, G

    1989-11-01

    The authors first give a psychological evocation of the Bailli de Suffren, a great captain who vastly contributed to improve the image of the French Navy after the appalling seven years war, but whose character showed, nevertheless, originality, authoritarism, violence, sometimes vindictiveness and often negligence. The quarrels he had with most of his subordinates culminated as he was in command of the East Indies Squadron, applying sometimes exaggerated punishments. Chevalier de Tromelin was hierarchically just under him; this Chevalier had a character as chilly and stiff as the Bailli was the opposite; both were ambitious and deserving officers, the Chevalier being as much conformist as his "adversary" was fiery and bold. The shouts and rancours of the Bailli, when confronted to the rigidity and cold technicity of the Chevalier, marked their relationship. More than objective reasons arising from their duties, the fundamental incompatibility of their characters, explain their conflicts. Suffren played a double-game with his immediate subordinate; not lacking verbal smoothness, he nevertheless abused him in such a way in his reports to the authorities, that when Chevalier de Tromelin, being ill, asked to return to France, he learned that he had been dismissed of the Navy without having ever been heard or able to attempt to defend himself. He then spent his time trying to claim for a hearing without ever obtaining it, writing justificatory reports. He was "rehabilitated" in 1793 and died in half-exile in 1815. The authors were struck by the fact that for 200 years, no historian of the Fast Indies has ever taken into account the Squadron's distinctive features and the personality of Suffren. Thanks to their research in family documents, in the National and especially Navy Archives, they are able to show the importance of this psychological, not to say the psychopathological, aspect. One can only be struck by the silence of the various historians who worked on the

  12. Monoclonal antibody (H107) inhibiting IgE binding to Fc epsilon R(+) human lymphocytes.

    PubMed

    Noro, N; Yoshioka, A; Adachi, M; Yasuda, K; Masuda, T; Yodoi, J

    1986-08-15

    A hybridoma-producing monoclonal antibody blocking the binding of human IgE to lymphocytes Fc receptor (Fc epsilon R) was established by the fusion of murine myeloma cells. P3X63.653.Ag8, with BALB/c spleen cells immunized with Fc epsilon R(+) human B lymphoblastoid cell line cells, RPMI1788. A clone of the hybridoma (H107) produced a monoclonal IgG2b antibody that inhibited the rosette formation of Fc epsilon R(+) human B lymphoblastoid cell line cells (RPMI1788, RPMI8866, CESS, Dakiki, and IM9) with fixed ox red blood cells (ORBC) conjugated with human IgE (IgE-ORBC). In contrast, the rosette formation with IgG-conjugated ORBC (IgG-ORBC) on Fc gamma R(+), Fc epsilon R(-) Daudi cells were not affected by the H107 antibodies. A close association of Fc epsilon R and the antigenic determinant recognized by H107 antibody was suggested by the following results. First, the bindings of 125I-labeled IgE (125I-IgE) or 125I-labeled H107 IgG2b antibody (125I-H107) to RPMI8866 cells were inhibited by cold human IgE and H107 IgG2b but not by other classes of human Ig (IgA and IgG), MPC11 IgG2b, or unrelated monoclonal antibodies. Second, H107 antibody reacted with Fc epsilon R(+) B cell lines but not with Fc epsilon R(-) B cell lines as determined by an indirect immunofluorescence. Third, Fc epsilon R(+) cells were depleted by the incubation in the dish coated with H107 antibody or IgE but not in the dish coated with unrelated antibodies. Finally, there was a correlation between the increase of Fc epsilon R(+) cells and that of H107(+) cells in the peripheral blood lymphocytes of the patients with atopic dermatitis. The surface antigens on Fc epsilon R(+) RPMI8866 cells recognized by H107 antibodies had the molecular size of 45,000 as determined by immunoprecipitation and sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis. PMID:2942602

  13. Functional identification of a novel 14-3-3 epsilon splicing variant suggests dimerization is not necessary for 14-3-3 epsilon to inhibit UV-induced apoptosis

    SciTech Connect

    Han, Dingding; Ye, Guangming; Liu, Tingting; Chen, Cong; Yang, Xianmei; Wan, Bo; Pan, Yuanwang; Yu, Long

    2010-05-28

    14-3-3 proteins function as a dimer and have been identified to involve in diverse signaling pathways. Here we reported the identification of a novel splicing variant of human 14-3-3 epsilon (14-3-3 epsilon sv), which is derived from a novel exon 1' insertion. The insertion contains a stop codon and leads to a truncated splicing variant of 14-3-3 epsilon. The splicing variant is translated from the exon 2 and results in the deletion of an N-terminal {alpha}-helix which is crucial for the dimerization. Therefore, the 14-3-3 epsilon sv could not form a dimer with 14-3-3 zeta. However, after UV irradiation 14-3-3 epsilon sv could also support cell survival, suggesting monomer of 14-3-3 epsilon is sufficient to protect cell from apoptosis.

  14. Life-limiting mechanisms in Ba-oxide, Ba-dispenser and Ba-Scandate cathodes

    NASA Astrophysics Data System (ADS)

    Gaertner, G.; Barratt, D.

    2005-09-01

    Ba-oxide, Ba-dispenser and Ba-Scandate cathodes have been continuously improved in their emission performance in the past decades. Ba-oxide and Ba-dispenser cathodes are also the dominant types of thermionic cathodes used in most vacuum tube applications. When improvements in emissive properties are introduced, their impact on cathode life - where several years in a vacuum tube environment are typically required - also needs to be known. Hence, the investigation of cathode life-limiting effects is the basis of accelerated life predictions and of further cathode improvement. In this contribution, the main effects limiting the operating life of Ba/BaO-based thermionic cathodes are discussed, especially related to intrinsic dispensation and resupply to the emissive surface. Emission poisoning induced by adsorption of poisonous gases will not be addressed here. We will stress common points and point out the differences between the three types.

  15. Resistance of ovine, caprine and bovine endothelial cells to Clostridium perfringens type D epsilon toxin in vitro.

    PubMed

    Uzal, F A; Rolfe, B E; Smith, N J; Thomas, A C; Kelly, W R

    1999-08-01

    Ovine, caprine and bovine endothelial cells were grown in vitro and challenged with Clostridium perfringens type D epsilon toxin to compare their susceptibility to this toxin. Madin Darby canine kidney (MDCK) cells, which are known to be susceptible to epsilon toxin, were used as a positive control. No morphological alterations were observed in any of the endothelial cell cultures tested, even after challenging with doses as high as 1200 MLD50/ml of epsilon toxin. MDCK cells showed contour rounding and nuclear condensation as early as 30 min after exposure to 100 MLD50/ml of epsilon toxin and after 60 min of exposure to 12.5 MLD50/ml of the same toxin. All the MDCK cells were dead after 3 h of exposure to all concentrations of epsilon toxin. The results indicate that ovine, caprine and bovine endothelial cells are not morphologically responsive to the action of epsilon toxin in vitro. PMID:10493114

  16. The debate about acclimatization in the Dutch East Indies (1840-1860).

    PubMed

    de Knecht-van Eekelen, A

    2000-01-01

    Around the middle of the nineteenth century, conflicting views were put forward on the influence of climate on health and disease in the Dutch East Indies. In this part of the world, old Hippocratic ideas influenced views on the cause of disease much longer than in the Netherlands. Moreover, Brunonian theories--which had been discarded in the Netherlands--fitted the discussion about the effect of temperature on the body. Additionally, scientific medicine was introduced. Scientific methods, such as the collection of meteorological and statistical data, were promoted by a small group of military health officers. However, the use of scientific data did not guarantee a clear-cut opinion on the causes of disease. Numbers proved as disputable as other, less objective, medical observations. Mortality statistics and numbers of patients especially were used as arguments in various discussions. The example of Bosch, who changed his views on the dangers of tropical climate, demonstrates that statistics could be used for different purposes. At first, in his position as General Inspector, he used them as an argument to provide better care for the military personnel; later, when retired and a civilian, he used them as justification for colonization in relation to an intended improvement of the living conditions of the natives. The dangers of tropical climate for the health of Europeans were played down as soon as other--primarily economic--motives for living in the tropics became strong enough. PMID:11769938

  17. Anaesthesia for operative deliveries at the University Hospital of the West Indies: a change of practice.

    PubMed

    Crawford-Sykes, A; Scarlett, M; Hambleton, I R; Nelson, M; Rattray, C

    2005-06-01

    There has been an increasing trend worldwide to use regional anaesthesia for operative deliveries. The Confidential Enquiry into Maternal Deaths in the United Kingdom has demonstrated a steady decline in the anaesthesia-related deaths since the introduction of regional anaesthesia. There are lower morbidity profiles in mothers delivering under regional anaesthesia as well as better infant Apgar scores. In 1997, a decision was taken to have at least 60% of all elective Caesarean sections done at the University Hospital of the West Indies (UHWI) performed under spinal anaesthesia. This is a review of the anaesthetic technique for Caesarean sections at the UHWI since 1996. The Deliveries and Anaesthetic Books on the labour ward were reviewed and the type of anaesthesia for elective and emergency Caesarean sections recorded for the period January 1996 to December 2001. At the beginning of the period under study, more than 90% of the Caesarean sections were being done under general anaesthesia. By the middle of 1998, spinal anaesthesia was more commonly employed than general anaesthesia for Caesarean sections and by December 2001, more than eight out of every ten Caesarean sections were being done under spinal anaesthesia. The main reasons for the successful change of practice were that it was consultant-led, there was good communication between relevant departments, the junior staff were properly trained, there was a consistent supply of appropriate drugs and there was a high level of patient satisfaction. PMID:16209224

  18. Reef to basin sediment transport using Halimeda as a sediment tracer, Grand Cayman Island, West Indies

    NASA Astrophysics Data System (ADS)

    Johns, Hilary D.; Moore, Clyde H.

    1988-03-01

    Fragments of the calcareous green alga Halimeda form a large part of the sediment in the fringing reef system and adjacent deep marine environments of Grand Cayman Island, West Indies. Nine species combine to form three depth-related assemblages that are characteristic of the major reef-related environments (lagoonpatch reef, reef terraces, and deep reef). These modern plant assemblages form the basis of the use of Halimeda as a sediment tracer. Halimeda-based tracer studies of Holocene sediments indicate that only sediments containing deep reef species of Halimeda are presently being transported through the reef system by sediment creep and being deposited at the juncture of the upper and lower island slope. Sediments containing shallow reef Halimeda are retained within the reef and lithified by marine carbonate cements. Tracer studies of Pleistocene sediment indicate large amounts of reef-derived carbonate sand containing deep water Halimeda were produced during interglacial high stands of sea level. Much of this material was removed by turbidity currents moving out of the reef system to the island slope down submarine channels perpendicular to the reef trend. These channels may still be identified on bathymetric profiles, but are no longer receiving coarse reef debris and are veneered with a blanket of pelagic carbonate mud.

  19. Serovar Diversity of Pathogenic Leptospira Circulating in the French West Indies

    PubMed Central

    Bourhy, Pascale; Herrmann Storck, Cécile; Theodose, Rafaelle; Olive, Claude; Nicolas, Muriel; Hochedez, Patrick; Lamaury, Isabelle; Zinini, Farida; Brémont, Sylvie; Landier, Annie; Cassadou, Sylvie; Rosine, Jacques; Picardeau, Mathieu

    2013-01-01

    Background Leptospirosis is one of the most important neglected tropical bacterial diseases in Latin America and the Caribbean. However, very little is known about the circulating etiological agents of leptospirosis in this region. In this study, we describe the serological and molecular features of leptospires isolated from 104 leptospirosis patients in Guadeloupe (n = 85) and Martinique (n = 19) and six rats captured in Guadeloupe, between 2004 and 2012. Methods and Findings Strains were studied by serogrouping, PFGE, MLVA, and sequencing 16SrRNA and secY. DNA extracts from blood samples collected from 36 patients in Martinique were also used for molecular typing of leptospires via PCR. Phylogenetic analyses revealed thirteen different genotypes clustered into five main clades that corresponded to the species: L. interrogans, L. kirschneri, L. borgpetersenii, L. noguchi, and L. santarosai. We also identified L. kmetyi in at least two patients with acute leptospirosis. This is the first time, to our knowledge, that this species has been identified in humans. The most prevalent genotypes were associated with L. interrogans serovars Icterohaemorrhagiae and Copenhageni, L. kirschneri serovar Bogvere, and L. borgpetersenii serovar Arborea. We were unable to identify nine strains at the serovar level and comparison of genotyping results to the MLST database revealed new secY alleles. Conclusions The overall serovar distribution in the French West Indies was unique compared to the neighboring islands. Typing of leptospiral isolates also suggested the existence of previously undescribed serovars. PMID:23516654

  20. Allele doses of apolipoprotein E type {epsilon}4 in sporadic late-onset Alzheimer`s disease

    SciTech Connect

    Lucotte, G.; Aouizerate, A.; Gerard, N.

    1995-12-18

    Apoliprotein E, type {epsilon}4 allele (ApoE-{epsilon}4) is associated with late-onset sporadic Alzheimer`s disease (AD). We have found that the cumulative probability of remaining unaffected over time decreases for each dose of ApoE-{epsilon}4 in sporadic, late-onset French AD. The effect of genotypes on age at onset of AD was analyzed using the product limit method, to compare unaffected groups during aging. 26 refs., 2 figs., 1 tab.

  1. The early effects of Clostridium perfringens type D epsilon toxin in ligated intestinal loops of goats and sheep.

    PubMed

    Fernandez Miyakawa, M E; Uzal, F A

    2003-04-01

    Clostridium perfringens type D produces enterotoxaemia in goats, sheep and other animals. The disease is caused by C. perfringens epsilon toxin and, while enterotoxaemia in goats is usually characterized by enterocolitis, the disease in sheep is characterized by systemic lesions (such as lung and brain oedema) with minor and inconsistent changes observed in the intestine. A possible explanation for these differences is that epsilon toxin is more promptly absorbed by the ovine than by the caprine intestine. In an attempt to clarify this, we examined the early effects of epsilon toxin on caprine and ovine intestine. Intestinal loop assays were performed to analyse the physiological and morphological changes induced by epsilon toxin in the intestine of these species. Fluid accumulation was observed in caprine and ovine ileum and colon treated with epsilon toxin. Ileal loops from goats treated with epsilon toxin retained sodium and water earlier than ovine ileal loops treated with the same toxin. Histological analysis showed morphological alterations in the colon of both species as early as 2 h after the commencement of epsilon toxin treatment: these changes were more marked in goats than in sheep. No morphological changes were observed in the ileum of either species after 4 h incubation with epsilon toxin. These results suggest that epsilon toxin modifies ion and water transport in the small and the large intestine of goats and sheep through different mechanisms. PMID:12777097

  2. Stabilization of the HCP [var epsilon] phase in an Fe-21%Mn alloy subjected to cathodic hydrogen charging

    SciTech Connect

    Aikawa, T.; Nishino, Y.; Asano, S. )

    1993-07-01

    Cathodic hydrogen charging induces some phase transformation in the surface layer of FCC iron alloys. Such a hydrogen-induced phase transformation has extensively been studied for austenitic stainless steels, where the FCC [gamma] phase transforms partially into an HCP [var epsilon][sub H] phase. The formation of the [var epsilon][sub H] phase has also been found in FCC Fe-Mn alloys and Fe-Ni-Mn alloys. The [var epsilon][sub H] phase is unstable in the absence of hydrogen and decomposes to an [var epsilon] martensite in the metastable FCC alloys. In order to make clear the nature of the [var epsilon][sub H] phase, it is necessary to reveal the stability of the [var epsilon] phase in FCC iron alloys during cathodic hydrogen charging. In the present study, the authors employed an Fe-21%Mn alloy which consisted of a mixture of the [gamma] and [var epsilon] phases in an as-quenched state. For this two-phase alloy, the [var epsilon] [r arrow] [gamma] transformation has so far been examined by a high-pressure equilibration method in a hydrogen-gas atmosphere. The purpose of this study is to compare the stability of the [gamma] phases in the two-phase alloy subjected to cathodic hydrogen charging in an aqueous solution. The influence of hydrogen on the [var epsilon] phase stability will be discussed, including the transformation in a hydrogen-gas atmosphere.

  3. Development of a hybrid k-epsilon turbulence model for swirling recirculating flows under moderate to strong swirl intensities

    NASA Astrophysics Data System (ADS)

    Chang, Keh-Chin; Chen, Ching-Shun

    1993-03-01

    A hybrid k-epsilon turbulence model, based on the concept that the modification of anisotropic effects should not be made in the flow regions inherent to small streamline curvatures, has been developed and examined with the swirling recirculating flows, with the swirl levels ranging from 0.6 to 1.23 in an abrupt pipe expansion. A fairly satisfactory agreement of model predictions with the experimental data shows that this hybrid k-epsilon model can perform better simulation of swirling recirculating flows as compared to the standard k-epsilon model and the modified k-epsilon model proposed by Abujelala and Lilley (1984).

  4. Clostridium perfringens epsilon toxin increases the small intestinal permeability in mice and rats.

    PubMed

    Goldstein, Jorge; Morris, Winston E; Loidl, César Fabián; Tironi-Farinati, Carla; Tironi-Farinatti, Carla; McClane, Bruce A; Uzal, Francisco A; Fernandez Miyakawa, Mariano E

    2009-01-01

    Epsilon toxin is a potent neurotoxin produced by Clostridium perfringens types B and D, an anaerobic bacterium that causes enterotoxaemia in ruminants. In the affected animal, it causes oedema of the lungs and brain by damaging the endothelial cells, inducing physiological and morphological changes. Although it is believed to compromise the intestinal barrier, thus entering the gut vasculature, little is known about the mechanism underlying this process. This study characterizes the effects of epsilon toxin on fluid transport and bioelectrical parameters in the small intestine of mice and rats. The enteropooling and the intestinal loop tests, together with the single-pass perfusion assay and in vitro and ex vivo analysis in Ussing's chamber, were all used in combination with histological and ultrastructural analysis of mice and rat small intestine, challenged with or without C. perfringens epsilon toxin. Luminal epsilon toxin induced a time and concentration dependent intestinal fluid accumulation and fall of the transepithelial resistance. Although no evident histological changes were observed, opening of the mucosa tight junction in combination with apoptotic changes in the lamina propria were seen with transmission electron microscopy. These results indicate that C. perfringens epsilon toxin alters the intestinal permeability, predominantly by opening the mucosa tight junction, increasing its permeability to macromolecules, and inducing further degenerative changes in the lamina propria of the bowel. PMID:19763257

  5. Potency against enterotoxemia of a recombinant Clostridium perfringens type D epsilon toxoid in ruminants.

    PubMed

    Lobato, Francisco C F; Lima, Catarina G R D; Assis, Ronnie A; Pires, Prhiscylla S; Silva, Rodrigo O S; Salvarani, Felipe M; Carmo, Anderson O; Contigli, Christiane; Kalapothakis, Evanguedes

    2010-08-31

    Enterotoxemia, a disease that affects domestic ruminants, is caused mainly by the epsilon toxin from Clostridium perfringens type D. Its eradication is virtually impossible, control and prophylaxis are based on systematic vaccination of herds with epsilon toxoids that are efficient in inducing protective antibody production. The use of recombinant toxins is one of the most promising of these strategies. This work evaluates the potency of a Cl. perfringens type D epsilon toxoid expressed by Escherichia coli administered to goats, sheep, and cattle. The etx gene was cloned into the pET-11a plasmid of E. coli strain BL21 to produce the recombinant toxin. Rabbits (n=8), goats, sheep, and cattle (n=5 for each species) were immunized with 0.2mg of the insoluble recombinant protein fraction to evaluate vaccine potency of the epsilon toxoid studied. Antibody titers were 40, 14.3, 26, and 13.1 IU/mL in the rabbit, goat, sheep, and cattle serum pools, respectively. The epsilon toxoid produced and tested in this work is adequate for immunization of ruminants against enterotoxemia. PMID:20670910

  6. Clostridium perfringens Epsilon Toxin Increases the Small Intestinal Permeability in Mice and Rats

    PubMed Central

    Goldstein, Jorge; Morris, Winston E.; Loidl, César Fabián; Tironi-Farinatti, Carla; McClane, Bruce A.; Uzal, Francisco A.; Fernandez Miyakawa, Mariano E.

    2009-01-01

    Epsilon toxin is a potent neurotoxin produced by Clostridium perfringens types B and D, an anaerobic bacterium that causes enterotoxaemia in ruminants. In the affected animal, it causes oedema of the lungs and brain by damaging the endothelial cells, inducing physiological and morphological changes. Although it is believed to compromise the intestinal barrier, thus entering the gut vasculature, little is known about the mechanism underlying this process. This study characterizes the effects of epsilon toxin on fluid transport and bioelectrical parameters in the small intestine of mice and rats. The enteropooling and the intestinal loop tests, together with the single-pass perfusion assay and in vitro and ex vivo analysis in Ussing's chamber, were all used in combination with histological and ultrastructural analysis of mice and rat small intestine, challenged with or without C. perfringens epsilon toxin. Luminal epsilon toxin induced a time and concentration dependent intestinal fluid accumulation and fall of the transepithelial resistance. Although no evident histological changes were observed, opening of the mucosa tight junction in combination with apoptotic changes in the lamina propria were seen with transmission electron microscopy. These results indicate that C. perfringens epsilon toxin alters the intestinal permeability, predominantly by opening the mucosa tight junction, increasing its permeability to macromolecules, and inducing further degenerative changes in the lamina propria of the bowel. PMID:19763257

  7. Investigations of the adjustment of nitrogen and carbon in the {epsilon}-phase

    SciTech Connect

    Pietzsch, S.; Bohmer, S.; Spies, H.J.

    1995-12-31

    The phase field of {epsilon}-(carbo)nitride together with its equilibrium solubility of nitrogen and carbon can be calculated by thermodynamic models as a function of the temperature and the nitriding potential K{sub N} = {var_phi}(NH{sub 3})/{var_phi}(H{sub 2}) and carburizing potential K{sub c} = {var_phi}(CO){var_phi}(H{sub 2})/{var_phi}(H{sub 2}O). The results are presented in the form of modified Lehrer diagrams. The calculations show that a non-coupled adjustment of nitrogen and carbon is possible in the {epsilon}-phase by a suitable choice of the nitriding and carburizing potential. However, the experimental adjustment of the interstitials in the {epsilon}-phase is not satisfactory. Therefore, iron foils (thickness: 10 {micro}m) were nitrided in retort-type furnaces (150 liters) with precisely controlled atmospheres. The gas mixtures were controlled by gas chromatographic analysis and oxygen probes. The complete transformation of the iron foils into the {epsilon}-(carbo)nitride was controlled by X-ray analysis. The nitrogen and carbon concentrations in the {epsilon}-phase were determined by chemical analysis. The experimental results are in good agreement with the calculations. The investigations of nitrided specimens allow conclusions for the production of compound layers with various nitrogen and carbon concentrations by the purposeful adjustment of the nitriding and carburizing potential. This is of interest for the corrosion and wear resistance of nitrided components.

  8. Packaging of DNA by bacteriophage epsilon15: structure, forces, and thermodynamics.

    PubMed

    Petrov, Anton S; Lim-Hing, Krista; Harvey, Stephen C

    2007-07-01

    The structure of bacteriophage epsilon15 has recently been determined by 3D reconstruction of single particle cryo-electron microscopy images. Although this study revealed that the viral genome inside the bacteriophage is on average coaxially spooled, individual DNA conformations inside the capsid could not be determined. In the current study, we present the results of 40 independent simulations of DNA packaging into epsilon15 using the previously described low-resolution model for bacteriophages. In addition to coaxially spooled conformations, we also observe a number of folded-toroidal patterns, but the density averaged over all conformations closely resembles the experimental density. Thermodynamic analysis of the simulations predicts that a force of approximately 125 pN would be required to package DNA into epsilon15. We also show that the origin of this force is predominantly due to electrostatic and entropic contributions. However, the DNA conformation is determined primarily by the need to minimize the DNA bending energy. PMID:17637341

  9. The fundamental parameters of the chromospherically active K2 dwarf Epsilon Eridani

    NASA Technical Reports Server (NTRS)

    Drake, Jeremy J.; Smith, Geoffrey

    1993-01-01

    A silicon array detector was used to record regions exhibiting calcium and iron lines in the spectrum of the chromospherically active K2 dwarf Epsilon Eri at a resolution of 120,000 and with an SNR of not less than 200. The effective temperature, surface gravity, logarithmic iron and calcium abundances, and microturbulence are determined. Three high-excitation lines of Fe I were found to yield anomalously low iron abundances; it is postulated that the origin of the anomaly lies in the nonthermal excitation of the upper photosphere caused by chromospheric emission. It is shown that Epsilon Eri is in an evolutionary stage consistent with an M/solar mass of 0.85 theoretical zero-age main-sequence model. It is suggested that Epsilon Eri is almost certainly a young star of slightly less than one solar mass.

  10. Computation of turbulent flows using an extended k-epsilon turbulence closure model

    NASA Technical Reports Server (NTRS)

    Chen, Y.-S.; Kim, S.-W.

    1987-01-01

    An extended kappa-epsilon turbulence model is proposed and tested with successful results. An improved transport equation for the rate of dissipation of the turbulent kinetic energy, epsilon, is proposed. The proposed model gives more effective response to the energy production rate than does the standard kappa-epsilon turbulence model. An extra time scale of the production range is included in the dissipation rate equation. This enables the present model to perform equally well for several turbulent flows with different characteristics, e.g., plane and axisymmetric jets, turbulent boundary layer flow, turbulent flow over a backward-facing step, and a confined turbulent swirling flow. A second-order accurate finite difference boundary layer code and a nearly second-order accurate finite difference elliptic flow solver are used for the present numerical computations.

  11. Lattice study of meson correlators in the {epsilon}-regime of two-flavor QCD

    SciTech Connect

    Fukaya, H.; Aoki, S.; Hashimoto, S.; Kaneko, T.; Yamada, N.; Matsufuru, H.; Noaki, J.; Ogawa, K.; Onogi, T.

    2008-04-01

    We calculate mesonic two-point functions in the {epsilon}-regime of two-flavor QCD on the lattice with exact chiral symmetry. We use gauge configurations of size 16{sup 3}x32 at a{approx}0.11 fm generated with dynamical overlap fermions. The sea quark mass is fixed at around 3 MeV and the valence quark mass is varied in the range 1-4 MeV, both of which are in the {epsilon}-regime. We find a good consistency with the expectations from the next-to-leading order calculation in the {epsilon}-expansion of (partially quenched) chiral perturbation theory. From a fit we obtain the pion decay constant F=87.3(5.6) MeV and the chiral condensate {sigma}{sup MS}=[239.8(4.0) MeV]{sup 3} up to next-to-next-to-leading order contributions.

  12. Node-avoiding Levy flight - A numerical test of the epsilon expansion. [random walk

    NASA Technical Reports Server (NTRS)

    Halley, J. W.; Nakanishi, H.

    1985-01-01

    A study is conducted of an extension of Levy flight to include self-repulsion in the path of the walk. The extension is called node-avoiding Levy flight and its equivalence to the n approaches 0 limit of a statistical mechanical model for a magnetic system with long-range interactions between the spins is shown. By use of this equivalence it is possible to make a detailed comparison beween the results of the epsilon expansion for the magnetic model, a Monte Carlo simulation of the Levy flight model, and the results of a Flory-type argument. This is the first comparison of the epsilon expansion for epsilon much less than 1 with a numerical simulation for any model. Some speculations are made on applications of the model of node-avoiding Levy flight.

  13. Evidence on primate phylogeny from epsilon-globin gene sequences and flanking regions.

    PubMed

    Porter, C A; Sampaio, I; Schneider, H; Schneider, M P; Czelusniak, J; Goodman, M

    1995-01-01

    Phylogenetic relationships among various primate groups were examined based on sequences of epsilon-globin genes. epsilon-globin genes were sequenced from five species of strepsirhine primates. These sequences were aligned and compared with other known primate epsilon-globin sequences, including data from two additional strepsirhine species, one species of tarsier, 19 species of New World monkeys (representing all extant genera), and five species of catarrhines. In addition, a 2-kb segment upstream of the epsilon-globin gene was sequenced in two of the five strepsirhines examined. This upstream sequence was aligned with five other species of primates for which data are available in this segment. Domestic rabbit and goat were used as outgroups. This analysis supports the monophyly of order Primates but does not support the traditional prosimian grouping of tarsiers, lorisoids, and lemuroids; rather it supports the sister grouping of tarsiers and anthropoids into Haplorhini and the sister grouping of lorisoids and lemuroids into Strepsirhini. The mouse lemur (Microcebus murinus) and dwarf lemur (Cheirogaleus medius) appear to be most closely related to each other, forming a clade with the lemuroids, and are probably not closely related to the lorisoids, as suggested by some morphological studies. Analysis of the epsilon-globin data supports the hypothesis that the aye-aye (Daubentonia madagascariensis) shares a sister-group relationship with other Malagasy strepsirhines (all being classified as lemuroids). Relationships among ceboids agree with findings from a previous epsilon-globin study in which fewer outgroup taxa were employed. Rates of molecular evolution were higher in lorisoids than in lemuroids. PMID:7714911

  14. Coherent laser excitation of Ba-137 and Ba-138

    NASA Technical Reports Server (NTRS)

    Lam, Kai-Shue

    1992-01-01

    Computations are carried out for the 1S(6s2)-1P(6s,6p) coherent laser excitation of Ba-137 and Ba-138 in a magnetic field. Results are presented for both the steady-state and time-dependent excited-state populations of the Zeeman-split magnetic sublevels. The quantum-statistical Liouville-equation approach (for the reduced density matrix) is compared to the rate-equations approach. Significant differences are found between these, due to the interference between strongly overlapping lines (especially for Ba-137). The time-evolution profiles indicate that the Ba-137 transient time is much longer than that of Ba-138.

  15. The Phylogeography of Rabies in Grenada, West Indies, and Implications for Control

    PubMed Central

    Zieger, Ulrike; Marston, Denise A.; Sharma, Ravindra; Chikweto, Alfred; Tiwari, Keshaw; Sayyid, Muzzamil; Louison, Bowen; Goharriz, Hooman; Voller, Katja; Breed, Andrew C.; Werling, Dirk; Fooks, Anthony R.; Horton, Daniel L.

    2014-01-01

    In Grenada, West Indies, rabies is endemic, and is thought to be maintained in a wildlife host, the small Indian mongoose (Herpestes auropunctatus) with occasional spillover into other hosts. Therefore, the present study was undertaken to improve understanding of rabies epidemiology in Grenada and to inform rabies control policy. Mongooses were trapped island-wide between April 2011 and March 2013 and examined for the presence of Rabies virus (RABV) antigen using the direct fluorescent antibody test (dFAT) and PCR, and for serum neutralizing antibodies (SNA) using the fluorescent antibody virus neutralization test (FAVN). An additional cohort of brain samples from clinical rabies suspects submitted between April 2011 and March 2014 were also investigated for the presence of virus. Two of the 171 (1.7%) live-trapped mongooses were RABV positive by FAT and PCR, and 20 (11.7%) had SNAs. Rabies was diagnosed in 31 of the submitted animals with suspicious clinical signs: 16 mongooses, 12 dogs, 2 cats and 1 goat. Our investigation has revealed that rabies infection spread from the northeast to the southwest of Grenada within the study period. Phylogenetic analysis revealed that the viruses from Grenada formed a monophyletic clade within the cosmopolitan lineage with a common ancestor predicted to have occurred recently (6–23 years ago), and are distinct from those found in Cuba and Puerto Rico, where mongoose rabies is also endemic. These data suggest that it is likely that this specific strain of RABV was imported from European regions rather than the Americas. These data contribute essential information for any potential rabies control program in Grenada and demonstrate the importance of a sound evidence base for planning interventions. PMID:25330178

  16. Coastal accretion on leeward margins of carbonate platforms, Turks and Caicos Islands, British West Indies

    SciTech Connect

    Wanless, H.R.; Rossinsky, V. Jr.

    1986-05-01

    Chance creation of a small patch of emergent topography can initiate an expansive sequence of coastal accretion on leeward margins of carbonate platforms. Without initiating topography, leeward margins remain a featureless marine environment where offbank transport smothers attempts at reefal growth and depletes sand reservoirs. The Pleistocene-Holocene limestones forming West Caicos Island on the leeward (west) margin of Caicos Bank (British West Indies) are an example. Here, two north-south-trending oolitic sand ridges formed about 3 km in from the platform edge in the early Pleistocene. These ridges blocked cross-platform and offplatform flow for a section of the margin. A leeward-margin coral reef formed and built to sea level along this sector. Ooid production on, and influx to, the windward (east) side of the ridges was swept longshore to the ridge ends and then westward by crossbank currents toward the platform margin. These are preserved as fossil beach ridges. Continued ooid production (supply) generated a northward- and southward-prograding series of arcuate beach ridges. At the leeward platform margin, now protected from cross-bank flow, waves and longshore currents moved oolitic sand spits across the reef buildup, smothering it. As the island elongated north-south, longshore removal of oolitic sand became ineffective, triggering a final stage of bankward (eastward) beach-ridge progradation. Although this sequence was interrupted by several glacial sea level lowerings, the scenario is not dependent on them. This accreting coastal complex has severely modified both the leeward platform and offplatform facies. With time it could completely separate this leeward margin from the platform interior.

  17. The phylogeography of rabies in Grenada, West Indies, and implications for control.

    PubMed

    Zieger, Ulrike; Marston, Denise A; Sharma, Ravindra; Chikweto, Alfred; Tiwari, Keshaw; Sayyid, Muzzamil; Louison, Bowen; Goharriz, Hooman; Voller, Katja; Breed, Andrew C; Werling, Dirk; Fooks, Anthony R; Horton, Daniel L

    2014-10-01

    In Grenada, West Indies, rabies is endemic, and is thought to be maintained in a wildlife host, the small Indian mongoose (Herpestes auropunctatus) with occasional spillover into other hosts. Therefore, the present study was undertaken to improve understanding of rabies epidemiology in Grenada and to inform rabies control policy. Mongooses were trapped island-wide between April 2011 and March 2013 and examined for the presence of Rabies virus (RABV) antigen using the direct fluorescent antibody test (dFAT) and PCR, and for serum neutralizing antibodies (SNA) using the fluorescent antibody virus neutralization test (FAVN). An additional cohort of brain samples from clinical rabies suspects submitted between April 2011 and March 2014 were also investigated for the presence of virus. Two of the 171 (1.7%) live-trapped mongooses were RABV positive by FAT and PCR, and 20 (11.7%) had SNAs. Rabies was diagnosed in 31 of the submitted animals with suspicious clinical signs: 16 mongooses, 12 dogs, 2 cats and 1 goat. Our investigation has revealed that rabies infection spread from the northeast to the southwest of Grenada within the study period. Phylogenetic analysis revealed that the viruses from Grenada formed a monophyletic clade within the cosmopolitan lineage with a common ancestor predicted to have occurred recently (6-23 years ago), and are distinct from those found in Cuba and Puerto Rico, where mongoose rabies is also endemic. These data suggest that it is likely that this specific strain of RABV was imported from European regions rather than the Americas. These data contribute essential information for any potential rabies control program in Grenada and demonstrate the importance of a sound evidence base for planning interventions. PMID:25330178

  18. Ralstonia solanacearum Strains from Martinique (French West Indies) Exhibiting a New Pathogenic Potential▿ †

    PubMed Central

    Wicker, Emmanuel; Grassart, Laurence; Coranson-Beaudu, Régine; Mian, Danièle; Guilbaud, Caroline; Fegan, Mark; Prior, Philippe

    2007-01-01

    We investigated a destructive pathogenic variant of the plant pathogen Ralstonia solanacearum that was consistently isolated in Martinique (French West Indies). Since the 1960s, bacterial wilt of solanaceous crops in Martinique has been caused primarily by strains of R. solanacearum that belong to either phylotype I or phylotype II. Since 1999, anthurium shade houses have been dramatically affected by uncharacterized phylotype II strains that also affected a wide range of species, such as Heliconia caribea, cucurbitaceous crops, and weeds. From 1989 to 2003, a total of 224 R. solanacearum isolates were collected and compared to 6 strains isolated in Martinique in the 1980s. The genetic diversity and phylogenetic position of selected strains from Martinique were assessed (multiplex PCRs, mutS and egl DNA sequence analysis) and compared to the genetic diversity and phylogenetic position of 32 reference strains covering the known diversity within the R. solanacearum species complex. Twenty-four representative isolates were tested for pathogenicity to Musa species (banana) and tomato, eggplant, and sweet pepper. Based upon both PCR and sequence analysis, 119 Martinique isolates from anthurium, members of the family Cucurbitaceae, Heliconia, and tomato, were determined to belong to a group termed phylotype II/sequevar 4 (II/4). While these strains cluster with the Moko disease-causing strains, they were not pathogenic to banana (NPB). The strains belonging to phylotype II/4NPB were highly pathogenic to tomato, eggplant, and pepper, were able to wilt the resistant tomato variety Hawaii7996, and may latently infect cooking banana. Phylotype II/4NPB constitutes a new pathogenic variant of R. solanacearum that has recently appeared in Martinique and may be latently prevalent throughout Caribbean and Central/South America. PMID:17720825

  19. Factors affecting hatch success of hawksbill sea turtles on Long Island, Antigua, West Indies.

    PubMed

    Ditmer, Mark Allan; Stapleton, Seth Patrick

    2012-01-01

    Current understanding of the factors influencing hawksbill sea turtle (Eretmochelys imbricata) hatch success is disparate and based on relatively short-term studies or limited sample sizes. Because global populations of hawksbills are heavily depleted, evaluating the parameters that impact hatch success is important to their conservation and recovery. Here, we use data collected by the Jumby Bay Hawksbill Project (JBHP) to investigate hatch success. The JBHP implements saturation tagging protocols to study a hawksbill rookery in Antigua, West Indies. Habitat data, which reflect the varied nesting beaches, are collected at egg deposition, and nest contents are exhumed and categorized post-emergence. We analyzed hatch success using mixed-model analyses with explanatory and predictive datasets. We incorporated a random effect for turtle identity and evaluated environmental, temporal and individual-based reproductive variables. Hatch success averaged 78.6% (SD: 21.2%) during the study period. Highly supported models included multiple covariates, including distance to vegetation, deposition date, individual intra-seasonal nest number, clutch size, organic content, and sand grain size. Nests located in open sand were predicted to produce 10.4 more viable hatchlings per clutch than nests located >1.5 m into vegetation. For an individual first nesting in early July, the fourth nest of the season yielded 13.2 more viable hatchlings than the initial clutch. Generalized beach section and inter-annual variation were also supported in our explanatory dataset, suggesting that gaps remain in our understanding of hatch success. Our findings illustrate that evaluating hatch success is a complex process, involving multiple environmental and individual variables. Although distance to vegetation and hatch success were inversely related, vegetation is an important component of hawksbill nesting habitat, and a more complete assessment of the impacts of specific vegetation types on hatch

  20. Ralstonia solanacearum strains from Martinique (French West Indies) exhibiting a new pathogenic potential.

    PubMed

    Wicker, Emmanuel; Grassart, Laurence; Coranson-Beaudu, Régine; Mian, Danièle; Guilbaud, Caroline; Fegan, Mark; Prior, Philippe

    2007-11-01

    We investigated a destructive pathogenic variant of the plant pathogen Ralstonia solanacearum that was consistently isolated in Martinique (French West Indies). Since the 1960s, bacterial wilt of solanaceous crops in Martinique has been caused primarily by strains of R. solanacearum that belong to either phylotype I or phylotype II. Since 1999, anthurium shade houses have been dramatically affected by uncharacterized phylotype II strains that also affected a wide range of species, such as Heliconia caribea, cucurbitaceous crops, and weeds. From 1989 to 2003, a total of 224 R. solanacearum isolates were collected and compared to 6 strains isolated in Martinique in the 1980s. The genetic diversity and phylogenetic position of selected strains from Martinique were assessed (multiplex PCRs, mutS and egl DNA sequence analysis) and compared to the genetic diversity and phylogenetic position of 32 reference strains covering the known diversity within the R. solanacearum species complex. Twenty-four representative isolates were tested for pathogenicity to Musa species (banana) and tomato, eggplant, and sweet pepper. Based upon both PCR and sequence analysis, 119 Martinique isolates from anthurium, members of the family Cucurbitaceae, Heliconia, and tomato, were determined to belong to a group termed phylotype II/sequevar 4 (II/4). While these strains cluster with the Moko disease-causing strains, they were not pathogenic to banana (NPB). The strains belonging to phylotype II/4NPB were highly pathogenic to tomato, eggplant, and pepper, were able to wilt the resistant tomato variety Hawaii7996, and may latently infect cooking banana. Phylotype II/4NPB constitutes a new pathogenic variant of R. solanacearum that has recently appeared in Martinique and may be latently prevalent throughout Caribbean and Central/South America. PMID:17720825

  1. Survey of Naegleria fowleri in Geothermal Recreational Waters of Guadeloupe (French West Indies)

    PubMed Central

    Moussa, Mirna; De Jonckheere, Johan F.; Guerlotté, Jérôme; Richard, Vincent; Bastaraud, Alexandra; Romana, Marc; Talarmin, Antoine

    2013-01-01

    In 2008 a fatal case of primary amoebic meningoencephalitis, due to the amoeboflagellate Naegleria fowleri, occurred in Guadeloupe, French West Indies, after a child swam in a bath fed with geothermal water. In order to improve the knowledge on free-living amoebae in this tropical part of France, we investigated on a monthly basis, the presence of Naegleria spp. in the recreational baths, and stream waters which feed them. A total of 73 water samples, 48 sediments and 54 swabs samples were collected from 6 sampling points between June 2011 and July 2012. The water samples were filtered and the filters transferred to non-nutrient agar plates seeded with a heat-killed suspension of Escherichia coli while sediment and swab samples were placed directly on these plates. The plates were incubated at 44°C for the selective isolation of thermophilic Naegleria. To identify the Naegleria isolates the internal transcribed spacers, including the 5.8S rDNA, were amplified by polymerase chain reaction and the sequence of the PCR products was determined. Thermophilic amoebae were present at nearly all collection sites. The pathogenic N. fowleri was the most frequently encountered thermophilic species followed by N. lovaniensis. The concentration of N. fowleri was rather low in most water samples, ranging from 0 to 22 per liter. Sequencing revealed that all N. fowleri isolates belonged to a common Euro-American genotype, the same as detected in the human case in Guadeloupe. These investigations need to be continued in order to counsel the health authorities about prevention measures, because these recreational thermal baths are used daily by local people and tourists. PMID:23349880

  2. Detecting the small island effect and nestedness of herpetofauna of the West Indies.

    PubMed

    Gao, De; Perry, Gad

    2016-08-01

    To detect the small island effect (SIE) and nestedness patterns of herpetofauna of the West Indies, we derived and updated data on the presence/absence of herpetofauna in this region from recently published reviews. We applied regression-based analyses, including linear regression and piecewise regressions with two and three segments, to detect the SIE and then used the Akaike's information criterion (AIC) as a criterion to select the best model. We used the NODF (a nestedness metric based on overlap and decreasing fill) to quantify nestedness and employed two null models to determine significance. Moreover, a random sampling effort was made to infer about the degree of nestedness at portions of the entire community. We found piecewise regression with three segments performed best, suggesting the species-area relationships possess three different patterns that resulted from two area thresholds: a first one, delimiting the SIE, and a second one, delimiting evolutionary processes. We also found that taxa with lower resource requirement, higher dispersal ability, and stronger adaptation to the environment generally displayed lower corresponding threshold values, indicating superior taxonomic groups could earlier end the SIE period and start in situ speciation as the increase of island size. Moreover, the traditional two-segment piecewise regression method may cause poor estimations for both slope and threshold value of the SIE. Therefore, we suggest previous SIE detection works that conducted by two-segment piecewise regression method, ignoring the possibility of three segments, need to be reanalyzed. Antinestedness occurred in the entire system, whereas high degree of nestedness could still occur in portions within the region. Nestedness may still be applicable to conservation planning at portions even if it is antinested at the regional scale. However, nestedness may not be applicable to conservation planning at the regional scale even if nestedness does exist

  3. Anomalous nonlinear absorption in epsilon-near-zero materials: optical limiting and all-optical control.

    PubMed

    Vincenti, M A; de Ceglia, D; Scalora, Michael

    2016-08-01

    We investigate nonlinear absorption in films of epsilon-near-zero materials. The combination of large local electric fields at the fundamental frequency and material losses at the harmonic frequencies induce unusual intensity-dependent phenomena. We predict that the second-order nonlinearity of a low-damping, epsilon-near-zero slab produces an optical limiting effect that mimics a two-photon absorption process. Anomalous absorption profiles that depend on low permittivity values at the pump frequency are also predicted for third-order nonlinearities. These findings suggest new opportunities for all-optical light control and novel ways to design reconfigurable and tunable nonlinear devices. PMID:27472631

  4. Psychological knowledge in a colonial context: theories on the nature of the "native mind" in the former Dutch East Indies.

    PubMed

    Pols, Hans

    2007-05-01

    This article analyzes the views of 3 Dutch physicians working in the former Dutch East Indies during the first part of the 20th century. These physicians based ideas about the nature of the normal indigenous psyche on both their analysis of Indonesian individuals suffering from mental illness and on casual observations that represented widely shared cultural stereotypes. On that basis, they advocated a psychological colonial policy, which was to be based on a scientific understanding of the psyche of the Indonesian people. Using these ideas, they advocated political repression, justified inequality and racism, and limited educational opportunities for Indonesians. Representatives of the Indonesian nationalist movement vigorously protested against these ideas. PMID:17645127

  5. Cloning of the novel human myeloid-cell-specific C/EBP-epsilon transcription factor.

    PubMed Central

    Chumakov, A M; Grillier, I; Chumakova, E; Chih, D; Slater, J; Koeffler, H P

    1997-01-01

    Chicken NF-M transcription factor, in cooperation with either c-Myb or v-Myb, is active in the combinatorial activation of myeloid-cell-specific genes in heterologous cell types, such as embryonic fibroblasts. In humans, similar effects were observed with homologous members of the CCAAT/enhancer-binding protein (C/EBP) family of transcriptional regulators, especially the human homolog of chicken NF-M, C/EBP-beta (NF-IL6). However, the NF-IL6 gene is expressed in a variety of nonmyeloid cell types and is strongly inducible in response to inflammatory stimuli, making it an unlikely candidate to have an exclusive role as a combinatorial differentiation switch during myelopoiesis in human cells. By using a reverse transcription-PCR-based approach and a set of primers specific for the DNA-binding domains of highly homologous members of the C/EBP family of transcriptional regulators, we have cloned a novel human gene encoding a member of the C/EBP gene family, identified as the human homolog of CRP1, C/EBP-epsilon. A 1.2-kb cDNA encoding full-length human C/EBP-epsilon was cloned from a promyelocyte-late myeloblast-derived lambda gt11 library. Molecular analysis of the cDNA and genomic clones indicated the presence of two exons encoding a protein with an apparent molecular mass of 32 kDa and a pI of 9.5. Primer extension analysis of C/EBP-epsilon mRNA detected a single major transcription start site approximately 200 bp upstream of the start codon. The putative promoter area is similar to those of several other myeloid-cell-specific genes in that it contains no TATAAA box but has a number of purine-rich stretches with multiple sites for the factors of the Ets family of transcriptional regulators. Northern blot analyses indicated a highly restricted mRNA expression pattern, with the strongest expression occurring in promyelocyte and late-myeloblast-like cell lines. Western blot and immunoprecipitation studies using rabbit anti-C/EBP-epsilon antibodies raised against the N

  6. Modification of the Two-equation Turbulence Model in NPARC to a Chien Low Reynolds Number K-epsilon Formulation

    NASA Technical Reports Server (NTRS)

    Georgiadis, Nicholas J.; Chitsomboon, Tawit; Zhu, Jiang

    1994-01-01

    This report documents the changes that were made to the two-equation k-epsilon turbulence model in the NPARC (National-PARC) code. The previous model based on the low Reynolds number model of Speziale, was replaced with the low Reynolds number k-epsilon model of Chien. The most significant difference was in the turbulent Prandtl numbers appearing in the diffusion terms of the k and epsilon transport equations. A new inflow boundary condition and stability enhancements were also implemented into the turbulence model within NPARC. The report provides the rationale for making the change to the Chien model, code modifications required, and comparisons of the performances of the new model with the previous k-epsilon model and algebraic models used most often in PARC/NPARC. The comparisons show that the Chien k-epsilon model installed here improves the capability of NPARC to calculate turbulent flows.

  7. Numerical solution of turbulent flow past a backward facing step using a nonlinear K-epsilon model

    NASA Technical Reports Server (NTRS)

    Speziale, C. G.; Ngo, Tuan

    1987-01-01

    The problem of turbulent flow past a backward facing step is important in many technological applications and has been used as a standard test case to evaluate the performance of turbulence models in the prediction of separated flows. It is well known that the commonly used kappa-epsilon (and K-l) models of turbulence yield inaccurate predictions for the reattachment points in this problem. By an analysis of the mean vorticity transport equation, it will be argued that the intrinsically inaccurate prediction of normal Reynolds stress differences by the Kappa-epsilon and K-l models is a major contributor to this problem. Computations using a new nonlinear kappa-epsilon model (which alleviates this deficiency) are made with the TEACH program. Comparisons are made between the improved results predicted by this nonlinear kappa-epsilon model and those obtained from the linear kappa-epsilon model as well as from second-order closure models.

  8. N epsilon-acetyl-beta-lysine: an osmolyte synthesized by methanogenic archaebacteria.

    PubMed Central

    Sowers, K R; Robertson, D E; Noll, D; Gunsalus, R P; Roberts, M F

    1990-01-01

    Methanosarcina thermophila, a nonmarine methanogenic archaebacterium, can grow in a range of saline concentrations. At less than 0.4 M NaCl, Ms. thermophila accumulated glutamate in response to increasing osmotic stress. At greater than 0.4 M NaCl, this organism synthesized a modified beta-amino acid that was identified as N epsilon-acetyl-beta-lysine by NMR spectroscopy and ion-exchange HPLC. This beta-amino acid derivative accumulated to high intracellular concentrations (up to 0.6 M) in Ms. thermophila and in another methanogen examined--Methanogenium cariaci, a marine species. The compound has features that are characteristic of a compatible solute: it is neutrally charged at physiological pH and it is highly soluble. When the cells were grown in the presence of exogenous glycine betaine, a physiological compatible solute, N epsilon-acetyl-beta-lysine synthesis was repressed and glycine betaine was accumulated. N epsilon-acetyl-beta-lysine was synthesized by species from three phylogenetic families when grown in high solute concentrations, suggesting that it may be ubiquitous among the methanogens. The ability to control the biosynthesis of N epsilon-acetyl-beta-lysine in response to extracellular solute concentration indicates that the methanogenic archaebacteria have a unique beta-amino acid biosynthetic pathway that is osmotically regulated. PMID:2123548

  9. IKK{epsilon} modulates RSV-induced NF-{kappa}B-dependent gene transcription

    SciTech Connect

    Bao Xiaoyong; Indukuri, Hemalatha; Liu Tianshuang; Liao Suiling; Tian, Bing; Brasier, Allan R.; Garofalo, Roberto P.; Casola, Antonella

    2010-12-20

    Respiratory syncytial virus (RSV), a negative-strand RNA virus, is the most common cause of epidemic respiratory disease in infants and young children. RSV infection of airway epithelial cells induces the expression of immune/inflammatory genes through the activation of a subset of transcription factors, including Nuclear Factor-{kappa}B (NF-{kappa}B). In this study we have investigated the role of the non canonical I{kappa}B kinase (IKK){epsilon} in modulating RSV-induced NF-{kappa}B activation. Our results show that inhibition of IKK{epsilon} activation results in significant impairment of viral-induced NF-{kappa}B-dependent gene expression, through a reduction in NF-{kappa}B transcriptional activity, without changes in nuclear translocation or DNA-binding activity. Absence of IKK{epsilon} results in a significant decrease of RSV-induced NF-{kappa}B phosphorylation on serine 536, a post-translational modification important for RSV-induced NF-{kappa}B-dependent gene expression, known to regulate NF-{kappa}B transcriptional activity without affecting nuclear translocation. This study identifies a novel mechanism by which IKK{epsilon} regulates viral-induced cellular signaling.

  10. N. sup. var epsilon. -acetyl-. beta. -lysine: An osmolyte synthesized by mothanogenic archaebacteria

    SciTech Connect

    Sowers, K.R.; Gunsalus, R.P. ); Robertson, D.E.; Noll, D.; Roberts, M.F. )

    1990-12-01

    Methanosarcina thermophila, a nonmarine methanogenic archaebacterium, can grow in a range of saline concentrations. At less than 0.4 M NaCl, Ms. thermophila accumulated glutamate in response to increasing osmotic stress. At greater than 0.4 M NaCl, this organism synthesized a modified {beta}-amino acid that was identified as N{sup {var epsilon}}-acetyl-{beta}-lysine by NMR spectroscopy and ion-exchange HPLC. This {beta}-amino acid derivative accumulated to high intracellular concentrations (up to 0.6 M) in Ms. thermophila and in another methanogen examined - Methanogenium cariaci, a marine species. The compound has features that are characteristic of a compatible solute: it is neutrally charged at physiological pH and it is highly soluble. When the cells were grown in the presence of exogenous glycine betaine, a physiological pH and it is highly soluble. When the cells were grown in the presence of exogenous glycine betaine, a physiological compatible solute, N{sup {var epsilon}}-acetyl-{beta}-lysine synthesis was repressed and glycine betaine was accumulated. N{sup {var epsilon}}-Acetyl-{beta}-lysine was synthesized by species from three phylogenetic families when grown in high solute concentrations, suggesting that it may be ubiquitous among the methanogens. The ability to control the biosynthesis of N{sup {var epsilon}}-acetyl-{beta}-lysine in response to extracellular solute concentration indicates that the methanogenic archaebacteria have a unique {beta}-amino acid biosynthetic pathway that is osmotically regulated.

  11. Using contour plots in elecgroproduction to examine regions in {epsilon}, Q{sup 2}, W space

    SciTech Connect

    Funsten, H.

    1994-04-01

    In determining incident CEBAF beam energies for CLAS electroproduction experiments that separate the longitudinal and transverse cross section components, contour plots of {epsilon} defined over a 2 dimensional Q{sup 2}, W space can be useful. This note describes an approximate method of constructing such plots.

  12. Epsilon Metal Waste Form for Immobilization of Noble Metals from Used Nuclear Fuel

    SciTech Connect

    Crum, Jarrod V.; Strachan, Denis M.; Rohatgi, Aashish; Zumhoff, Mac R.

    2013-10-01

    Epsilon metal (ε-metal), an alloy of Mo, Pd, Rh, Ru, and Tc, is being developed as a waste form to treat and immobilize the undissolved solids and dissolved noble metals from aqueous reprocessing of commercial used nuclear fuel. Epsilon metal is an attractive waste form for several reasons: increased durability relative to borosilicate glass, it can be fabricated without additives (100% waste loading), and in addition it also benefits borosilicate glass waste loading by eliminating noble metals from the glass and thus the processing problems related there insolubility in glass. This work focused on the processing aspects of the epsilon metal waste form development. Epsilon metal is comprised of refractory metals resulting in high reaction temperatures to form the alloy, expected to be 1500 - 2000°C making it a non-trivial phase to fabricate by traditional methods. Three commercially available advanced technologies were identified: spark-plasma sintering, microwave sintering, and hot isostatic pressing, and investigated as potential methods to fabricate this waste form. Results of these investigations are reported and compared in terms of bulk density, phase assemblage (X-ray diffraction and elemental analysis), and microstructure (scanning electron microscopy).

  13. The Students' Take on the Epsilon-Delta Definition of a Limit

    ERIC Educational Resources Information Center

    Fernandez, Eileen

    2004-01-01

    This paper describes a sequence of lessons from two Calculus I classes for teaching the epsilon-delta definition of a limit. In these lessons, the author elicited students' misconceptions and perceptions of this definition through a reading/writing lesson and then used these student ideas to design a lesson aimed at addressing these misconceptions…

  14. Perfect electromagnetic absorption using graphene and epsilon-near-zero metamaterials

    NASA Astrophysics Data System (ADS)

    Lobet, Michaël; Majerus, Bruno; Henrard, Luc; Lambin, Philippe

    2016-06-01

    The ability of graphene/polymer heterostructures to absorb GHz electromagnetic radiation was recently evidenced both theoretically and experimentally [Batrakov et al., Sci. Rep. 4, 7191 (2014), 10.1038/srep07191 and Lobet et al., Nanotechnology 26, 285702 (2015), 10.1088/0957-4484/26/28/285702]. Maximum absorption was shown to depend solely on refractive indices of incident and emergence media once impedance matching conditions are fulfilled. In this paper, analytical models and numerical simulations are performed for both semi-infinite and finite slab substrate. We evidenced that only three graphene layers separated by a dielectric spacer and an epsilon-near-zero metamaterial as emergence medium allow a perfect absorption for normal incidence. The use of lossless epsilon-near-zero metamaterial prevents radiations to go through the device, because of infinite impedance, and forces them to be totally absorbed in the dissipative medium (graphene). The device is proved to be robust regarding angular incidence up to 45 deg for a semi-infinite epsilon-near-zero metamaterial. The proposed strategy is universal and can be applied to any kind of two-dimensional dissipative materials lying on epsilon-near-zero metamaterial. The proposed absorber does not rely on surface patterning or texturing and hence is more appealing for device applications.

  15. Functional analysis of neutralizing antibodies against Clostridium perfringens epsilon-toxin.

    PubMed

    McClain, Mark S; Cover, Timothy L

    2007-04-01

    The Clostridium perfringens epsilon-toxin causes a severe, often fatal illness (enterotoxemia) characterized by cardiac, pulmonary, kidney, and brain edema. In this study, we examined the activities of two neutralizing monoclonal antibodies against the C. perfringens epsilon-toxin. Both antibodies inhibited epsilon-toxin cytotoxicity towards cultured MDCK cells and inhibited the ability of the toxin to form pores in the plasma membranes of cells, as shown by staining cells with the membrane-impermeant dye 7-aminoactinomycin D. Using an antibody competition enzyme-linked immunosorbent assay (ELISA), a peptide array, and analysis of mutant toxins, we mapped the epitope recognized by one of the neutralizing monoclonal antibodies to amino acids 134 to 145. The antibody competition ELISA and analysis of mutant toxins suggest that the second neutralizing monoclonal antibody also recognizes an epitope in close proximity to this region. The region comprised of amino acids 134 to 145 overlaps an amphipathic loop corresponding to the putative membrane insertion domain of the toxin. Identifying the epitopes recognized by these neutralizing antibodies constitutes an important first step in the development of therapeutic agents that could be used to counter the effects of the epsilon-toxin. PMID:17261609

  16. An Optimality Theoretic Account of Hungarian ESL Learners' Acquisition of /[epsilon]/ and /[ash]/

    ERIC Educational Resources Information Center

    Bunta, Ferenc; Major, Roy C.

    2004-01-01

    This paper provides an Optimality Theoretic account of how Hungarian learners of English acquire /[epsilon]/ and /[ash]/. It is hypothesized that as the learners' pronunciation becomes more nativelike, L1 transfer substitutions will diminish; non-transfer substitutions will be especially prevalent in the intermediate stages, and that all learners…

  17. Experience with k-epsilon turbulence models for heat transfer computations in rotating

    NASA Technical Reports Server (NTRS)

    Tekriwal, Prabbat

    1995-01-01

    This viewgraph presentation discusses geometry and flow configuration, effect of y+ on heat transfer computations, standard and extended k-epsilon turbulence model results with wall function, low-Re model results (the Lam-Bremhorst model without wall function), a criterion for flow reversal in a radially rotating square duct, and a summary.

  18. Experience with k-epsilon turbulence models for heat transfer computations in rotating

    NASA Astrophysics Data System (ADS)

    Tekriwal, Prabbat

    1995-03-01

    This viewgraph presentation discusses geometry and flow configuration, effect of y+ on heat transfer computations, standard and extended k-epsilon turbulence model results with wall function, low-Re model results (the Lam-Bremhorst model without wall function), a criterion for flow reversal in a radially rotating square duct, and a summary.

  19. Two-flavor lattice QCD in the {epsilon} regime and chiral random matrix theory

    SciTech Connect

    Fukaya, H.; Aoki, S.; Chiu, T. W.; Ogawa, K.; Hashimoto, S.; Kaneko, T.; Yamada, N.; Matsufuru, H.; Noaki, J.; Onogi, T.

    2007-09-01

    The low-lying eigenvalue spectrum of the QCD Dirac operator in the {epsilon} regime is expected to match with that of chiral random matrix theory (ChRMT). We study this correspondence for the case including sea quarks by performing two-flavor QCD simulations on the lattice. Using the overlap fermion formulation, which preserves exact chiral symmetry at finite lattice spacings, we push the sea quark mass down to {approx}3 MeV on a 16{sup 3}x32 lattice at a lattice spacing a{approx_equal}0.11 fm. We compare the low-lying eigenvalue distributions and find a good agreement with the analytical predictions of ChRMT. By matching the lowest-lying eigenvalue we extract the chiral condensate, {sigma}{sup MS}(2 GeV)=(251{+-}7{+-}11 MeV){sup 3}, where errors represent statistical and higher order effects in the {epsilon} expansion. We also calculate the eigenvalue distributions on the lattices with heavier sea quarks at two lattice spacings. Although the {epsilon} expansion is not applied for those sea quarks, we find a reasonable agreement of the Dirac operator spectrum with ChRMT. The value of {sigma}, after extrapolating to the chiral limit, is consistent with the estimate in the {epsilon} regime.

  20. [Bacteria that degrade low-molecular linear epsilon-caprolactam olygomers].

    PubMed

    Esikova, T Z; Akatova, E V; Taran, S A

    2014-01-01

    Five bacterial strains with the unique ability to utilize low-molecular linear caprolactam olygomers (nylon olygomers) were isolated from soil samples contaminated with industrial wastes of epsilon-caprolactam. Based on the properties studied and also on the analysis of 16S rRNA gene nucleotide sequences, the strains BS2,BS3, BS9, BS38, and BS57 were classified to the general Arthrobacter, Brevibacterium, Microbacteriun, Gulosibacter, and Achromobacter, respectively. All of the strains also utilized 6-aminohexanoic and adipic acids, which are intermidiates of the epsilon-caprolactam catabolism. This indirectly points to the fact that degradation of olygomers in these bacteria occurs via the monomer degradation pathway. The BS9 and BS57 strains utilized only olygomers of the epsilon-caprolactam, while BS2, BS3, and BS38 also degraded epsilon-caprolactam and its homologs, enantolactam and caprylolactam, which differentiates the latter from the previously known degraders of olygomers and suggests the presence in these strains of enzymes with lactam hydrolase activity, in addition to 6-aminohexanoate-dimer hydrolase. PMID:25707105

  1. The Use of Visual Approach in Teaching and Learning the Epsilon-Delta Definition of Continuity

    ERIC Educational Resources Information Center

    Pešic, Duška; Pešic, Aleksandar

    2015-01-01

    In this paper we introduce a new collaborative technique in teaching and learning the epsilon-delta definition of a continuous function at the point from its domain, which connects mathematical logic, combinatorics and calculus. This collaborative approach provides an opportunity for mathematical high school students to engage in mathematical…

  2. Synthesis and characterization of Zn-B-Si-O nano-composites and their doped BaTiO{sub 3} ceramics

    SciTech Connect

    Niu, Ruiyuan; Cui, Bin; Du, Fengtao; Chang, Zhuguo; Tang, Zongxun

    2010-10-15

    We synthesized Zn-B-Si-O (ZBSO) nano-composites via sol-gel process, and then used them to dope BaTiO{sub 3} ceramics. The ZBSO nano-composites and their ceramics were characterized by means of thermogravimetric, Fourier-transform infrared, and X-ray diffraction methods, and using scanning and transmission electron microscopy. We also characterized the dielectric properties of the ceramics. The results indicated that the ZBSO nano-composites were nanometer-scale powders with an amorphous structure. The particle size of the powders increased with increasing pH value, but initially decreased and then increased with increasing calcining temperature. At pH about 2 and with calcining at 400 {sup o}C, the nano-composites attained minimum particle size (about 30 nm). The sintering temperature of the BaTiO{sub 3} ceramics could be reduced to 1100 {sup o}C by adding 5 wt% of the ZBSO nano-composites. Uniform, fine-grained BaTiO{sub 3} ceramics with a high permittivity ({epsilon}{sub r} = 2946 and {epsilon}{sub max} = 5072) were obtained by adding nano-composites; these properties were superior to the ZBSO glass doped BaTiO{sub 3} ceramics.

  3. THE FATE OF THE EPSILON PHASE IN UO2 OF THE OKLO NATURAL FISSON REACTORS

    SciTech Connect

    S. Utsunomiya; R.C. Ewing

    2005-09-08

    In spent nuclear fuel (SNF), the micron- to nano-sized epsilon phase (Mo-Ru-Pd-Tc-Rh) is an important host of {sup 99}Tc which has a long half life (2.13 x 10{sup 5} years) and can be an important contributor to dose in safety assessments of nuclear waste repositories. In order to examine the occurrence and the fate of the epsilon phase during the corrosion of SNF over long time periods, samples of uraninite from the Oklo natural reactors ({approx}2.0 Ga) have been investigated using transmission electron microscopy (TEM). Because essentially all of the {sup 99}Tc has decayed to {sup 99}Ru, this study focuses on 4d-elements of the epsilon phase. Samples were obtained from the research collection at University of Michigan representing reactor zone (RZ) 10 (836, 819,687) and from RZ 13 (864,910). Several phases with 4d-metals have been identified within UO{sub 2} matrix at the scale of 50-700 nm; fioodite, PdBi{sub 2}, with trace amounts of As, Fe, and Te, and palladodymite or rhodarsenide, (Pd,Rh){sub 2}As. The most abundant 4d-metal phase is ruthenarsinite, (Ru,Ni)As, which has a representative composition: As, 59.9; Coy 2.5; Ni, 5.2; Ru, 18.6; Rh, 8.4; Pd, 3.1; Sb, 2.4 in atomic%. Ruthenarsenite nanoparticles are typically surrounded by Pb-rich domains, galena in most cases; whereas, some particles reveal a complexly zoned composition within the grain, such as a Pb-rich domain at the core and enrichment of Ni, Co, and As at the rim. Some ruthenarsenites and Rh-Bi-particles are embedded in surrounding alteration products, e.g., chlorite, adjacent to uraninite (no further than {approx}5 {micro}m). A few of those particles are still coated by a Pb-rich layer. Based on these results, the history that epsilon phases have experienced can be described as follows: (1) The original epsilon phase was changed to, in most cases, ruthenarsenite, by As-rich fluids with other trace metals. Dissolution and a simultaneous precipitation may be responsible for the phase change. (2

  4. Combined adverse effects of cascading events on systems' functionality: an insular case study, French West Indies

    NASA Astrophysics Data System (ADS)

    Desramaut, Nicolas; Wang, Justin; Gehl, Pierre; Marti, Jose; Baills, Audrey; Reveillere, Arnaud

    2013-04-01

    In our modern societies, lifelines play a vital role, even in normal conditions. Therefore, during crises, the dependency to critical infrastructures is likely to be exacerbated. Indeed, in order to provide quick emergency services to the population, systems have to be functional. However, even if not directly damaged, in order to be functional, elements of the different systems have to receive enough resources but also to be able to supply their own services. In a multi-risk approach, this necessity to take into account systemic vulnerability to assess the real impact of natural hazards on society is even made more obvious. For example, impacts of one hazard, taken separately, might not significantly affect societies, but might reduce redundancy, and therefore could increase functional vulnerability to other hazards. The present study aims at analyzing the effects of cascading events on the behaviour of interdependent systems and on the capacities of the health care system to treat the victims. In order to work on a close system, an insular context (Guadeloupe, French West Indies) has been selected. The hazard cascading scenario consists of a M6.3 earthquake striking Basse-Terre, and triggering landslides in the mountainous areas where antecedent precipitations have made the area prone to slide. Damages due to earthquakes have been estimated for the 5 considered systems (buildings, healthcare system, electrical network, water supply network and transportation). Due to their localization in mountainous areas, landslides would affect only transportation networks, with closure of roads. The inter- and intra-dependencies of systems have been modeled thanks to the I2Sim platform developed at UBC. The functionality of each element is therefore the consequence of the physical (direct damage) but also functional (indirect) damage. Analyses are performed for different strategies of resources allocations, and one of the final results is the impact of the induced landslides

  5. Neodymium and strontium isotopic constraints on soil sources in Barbados, West Indies

    NASA Astrophysics Data System (ADS)

    Borg, Lars E.; Banner, Jay L.

    1996-11-01

    Neodymium and strontium isotopic compositions and Sm/Nd ratios are used to constrain the sources of silicate-rich soils developed on uplifted Pleistocene coral-reef limestones on Barbados, West Indies. The geographic and geologic setting of Barbados facilitates the application of these tracers to the evaluation of the following soil sources: (1) Pleistocene reef limestone regolith, (2) Tertiary carbonate rocks, sandstones, and mudstones that are exposed in northeastern Barbados, (3) volcanic ash erupted from the Lesser Antilles arc, (4) Saharan dust transported by trade winds, and (5) fertilizer. The soils have ɛNd values that range from -6.6 to -1.9, 87Sr /86Sr values of 0.70890 to 0.71067, and Sm/Nd ratios of 0.223-0.260. The Pleistocene limestone component is the most significant source of Sr in the soils and a negligible source of Nd. Comparison of Sm and Nd concentrations and neodymium isotopic compositions of soil samples that are weathered to varying extents indicates that Sm and Nd are relatively unfractionated and retained in the soils during weathering. ɛNd and Sm/Nd variations in the soils, therefore, primarily reflect the compositions and proportions of the silicate sources. Mass balance calculations based on SmNd systematics require that the silicate soil components contain between 30-85% volcanic ash, with the remaining silicate fraction comprised of old, continentally-derived sediment. In contrast to Sm and Nd, Sr is mobilized and removed from the soils during weathering. Strontium from volcanic and carbonate sources is preferentially removed relative to continental silicate sources. The strontium isotopic compositions of the soils, therefore, reflect the combined effects of the degree of weathering and the compositions and proportions of the soil sources. Mass balance calculations indicate that at least 35-60% of the initial Sr in the soils has been removed by weathering. These results illustrate (1) the utility of radiogenic isotopes in

  6. Ecological energetics of the tropical sea urchin Diadema antillarum Philippi in Barbados, West Indies

    NASA Astrophysics Data System (ADS)

    Hawkins, Christopher M.; Lewis, John B.

    1982-12-01

    The common tropical sea urchin Diadema antillarum Philippi is the dominant herbivore on fringing coral reefs in Barbados, West Indies. The biological importance of Diadema as an agent of energy transfer was evaluated from energy budgets constructed for the population and for individuals of 10 size groups. Monthly energy budgets for urchins of various size groups balance within 1 kcal except for urchins of the largest size group examined. Approximately 20% of the monthly net benthic primary production of the fringing coral reef is consumed by Diadema. This percentage is considerably larger than the 7% reported for the consumption of benthic algal production by a population of the temperate water sea urchin, Strongylocentrotus droebachiensis, feeding in kelp beds but is lower than the 47% reported for the consumption of sea grass by the tropical urchin Lytechinus variegatus. Higher rates of secondary production of Diadema compared to that of Strongylocentrotus may be in part due to higher net and gross growth efficiencies exhibited by Diadema. It is apparent that Diadema is more efficient at converting its algal food resources into urchin biomass than is Strongylocentrotus of similar size. In comparison to Strongylocentrotus and Lytechinus, Diadema releases as much energy to the benthos in the form of fecal pellet detritus as do the other two species. The production of fecal pellet detritus is the most important pathway of energy transfer on the fringing coral reef. Fecal pellet detritus contributes approximately 26 kcal m -2 month -1 to the benthic community. This amount is equivalent to 7·4% of the monthly net primary production of the benthic algae or approximately 37% of the caloric intake of the urchin population. In addition fecal pellet detritus produced by Diadema contains about 10 times the caloric content of surface sediments found to the north and south of the fringing reef and approximately 1·7 times the caloric content of sediments within the reef. The

  7. Hydrothermal Venting at Kick'Em Jenny Submarine Volcano (West Indies)

    NASA Astrophysics Data System (ADS)

    Carey, S.; Croff Bell, K. L.; Dondin, F. J. Y.; Roman, C.; Smart, C.; Lilley, M. D.; Lupton, J. E.; Ballard, R. D.

    2014-12-01

    Kick'em Jenny is a frequently-erupting, shallow submarine volcano located ~8 km off the northwest coast of Grenada in the West Indies. The last eruption took place in 2001 but did not breach the sea surface. Focused and diffuse hydrothermal venting is taking place mainly within a small (~100 x 100 m) depression within the 300 m diameter crater of the volcano at depths of about 265 meters. Near the center of the depression clear fluids are being discharged from a focused mound-like vent at a maximum temperature of 180o C with the simultaneous discharge of numerous bubble streams. The gas consists of 93-96% CO2 with trace amounts of methane and hydrogen. A sulfur component likely contributes 1-4% of the gas total. Gas flux measurements on individual bubble streams ranged from 10 to 100 kg of CO2 per day. Diffuse venting with temperatures 5 to 35o C above ambient occurs throughout the depression and over large areas of the main crater. These zones are extensively colonized by reddish-yellow bacterial mats with the production of loose Fe-oxyhydroxides largely as a surface coating and in some cases, as fragile spires up to several meters in height. A high-resolution photo mosaic of the crater depression was constructed using the remotely operated vehicle Hercules on cruise NA039 of the E/V Nautilus. The image revealed prominent fluid flow patterns descending the sides of the depression towards the base. We speculate that the negatively buoyant fluid flow may be the result of second boiling of hydrothermal fluids at Kick'em Jenny generating a dense saline component that does not rise despite its elevated temperature. Increased density may also be the result of high dissolved CO2 content of the fluids, although we were not able to measure this directly. The low amount of sulphide mineralization on the crater floor suggests that deposition may be occurring mostly subsurface, in accord with models of second boiling mineralization from other hydrothermal vent systems.

  8. Apolipoprotein E epsilon4 allele differentiates the clinical response to donepezil in Alzheimer's disease.

    PubMed

    Bizzarro, A; Marra, C; Acciarri, A; Valenza, A; Tiziano, F D; Brahe, C; Masullo, C

    2005-01-01

    The existence of an association between apolipoprotein E (APOE) and Alzheimer's disease (AD) has been reported in several studies. The possession of an ApoE epsilon4 allele is now considered a genetic risk factor for sporadic AD. There has been a growing agreement about the role exerted by the ApoE epsilon4 allele on the neuropsychological profile and the rate of cognitive decline in AD patients. However, a more controversial issue remains about a possible influence of the APOE genotype on acetylcholinesterase inhibitor therapy response in AD patients. In order to address this issue, 81 patients diagnosed as having probable AD were evaluated by a complete neuropsychological test battery at the time of diagnosis (baseline) and after 12-16 months (retest). Patients were divided into two subgroups: (1) treated with donepezil at a dose of 5 mg once a day (n = 41) and (2) untreated (n = 40). Donepezil therapy was started after baseline evaluation. The APOE genotype was determined according to standardized procedures. We evaluated the possible effect of the APOE genotype on the neuropsychological tasks in relation to donepezil therapy. The statistical analysis of the results showed a global worsening of cognitive performances for all AD patients at the retest. Differences in the clinical outcome were analysed in the four subgroups of AD patients for each neuropsychological task. ApoE epsilon4 carriers/treated patients had improved or unchanged scores at retest evaluation for the following tasks: visual and verbal memory, visual attention and inductive reasoning and Mini Mental State Examination. These results indicate an effect of donepezil on specific cognitive domains (attention and memory) in the ApoE epsilon4 carriers with AD. This might suggest an early identification of AD patients carrying at least one epsilon4 allele as responders to donepezil therapy. PMID:16103669

  9. Denitrification with epsilon-caprolactam by acclimated mixed culture and by pure culture of bacteria isolated from polyacrylonitrile fibre manufactured wastewater treatment system.

    PubMed

    Lee, C M; Wang, C C

    2004-01-01

    The aim of this study is to isolate denitrifying bacteria utilizing epsilon-caprolactam as the substrate, from a polyacrylonitrile fibre manufactured wastewater treatment system. The aim is also to compare the performance of PAN (polyacrylonitrile) mixed bacteria cultures acclimated to epsilon-caprolactam and isolated pure strain for treating different initial epsilon-caprolactam concentrations from synthetic wastewater under anoxic conditions. The result showed that the PAN mixed bacteria cultures acclimated to epsilon-caprolactam could utilize 1538.5 mg/l of epsilon-caprolactam as a substrate for denitrification. Sufficient time and about 2200 mg/l of nitrate were necessary for the complete epsilon-caprolactam removal. Paracoccus thiophilus was isolated from the polyacrylonitrile fibre manufactured wastewater treatment system and it could utilize 1722.5 mg/l of epsilon-caprolactam as a substrate for denitrification. About 3500 mg/l of nitrate was necessary for the complete removal of epsilon-caprolactam. When the initial epsilon-caprolactam concentration was below 784.3 mg/l, the removal efficiency of epsilon-caprolactam by Paracoccus thiophilus was better than that for the PAN mixed bacteria cultures. The growth of Paracoccus thiophilus was better. However, when the initial epsilon-caprolactam concentration was as high as 1445.8 mg/l, both the epsilon-caprolactam removal efficiency by Paracoccus thiophilus and Paracoccus thiophilus specific growth rate were similar to the PAN mixed bacteria cultures. PMID:15137443

  10. A novel, myeloid transcription factor, C/EBP epsilon, is upregulated during granulocytic, but not monocytic, differentiation.

    PubMed

    Morosetti, R; Park, D J; Chumakov, A M; Grillier, I; Shiohara, M; Gombart, A F; Nakamaki, T; Weinberg, K; Koeffler, H P

    1997-10-01

    Human C/EBP epsilon is a newly cloned CCAAT/enhancer-binding transcription factor. Initial studies indicated it may be an important regulator of human myelopoiesis. To elucidate the range of expression of C/EBP epsilon, we used reverse transcription-polymerase chain reaction (RT-PCR) analysis and examined its expression in 28 hematopoietic and 14 nonhematopoietic cell lines, 16 fresh myeloid leukemia samples, and normal human hematopoietic stem cells and their mature progeny. Prominent expression of C/EBP epsilon mRNA occurred in the late myeloblastic and promyelocytic cell lines (NB4, HL60, GFD8), the myelomonoblastic cell lines (U937 and THP-1), the early myeloblast cell lines (ML1, KCL22, MDS92), and the T-cell lymphoblastic leukemia cell lines CEM and HSB-2. For the acute promyelocytic leukemia cell line NB4, C/EBP epsilon was the only C/EBP family member that was easily detected by RT-PCR. No C/EBP epsilon mRNA was found in erythroid, megakaryocyte, basophil, B lymphoid, or nonhematopoietic cell lines. Most acute myeloid leukemia samples (11 of 12) from patients expressed C/EBP epsilon. Northern blot and RT-PCR analyses showed that C/EBP epsilon mRNA decreased when the HL60 and KG-1 myeloblast cell lines were induced to differentiate toward macrophages. Similarly, Western blot analysis showed that expression of C/EBP epsilon protein was either unchanged or decreased slightly as the promyelocytic cell line NB4 differentiated down the macrophage-like pathway after treatment with a potent vitamin D3 analog (KH1060). In contrast, C/EBP epsilon protein levels increased dramatically as NB4 cells were induced to differentiate down the granulocytic pathway after exposure to 9-cis retinoic acid. Furthermore, very early, normal hematopoietic stem cells (CD34+/CD38-), purified from humans had very weak expression of C/EBP epsilon mRNA, but levels increased as these cells differentiated towards granulocytes. Likewise, purified granulocytes appeared to express higher

  11. In Quest of an Ideal Library Environment: The Case of the Main Library, the University of the West Indies, St. Augustine, Trinidad.

    ERIC Educational Resources Information Center

    Clarke, Reginald

    2002-01-01

    Explains the need for attention to library environment in terms of conservation, disaster planning, and external environmental factors. Discusses measures adopted at the University of the West Indies Trinidad related to operation and maintenance of buildings and physical plant, describes a workplace evaluation project, and examines factors…

  12. Effects of Corporal Punishment, Perceived Caretaker Warmth, and Cultural Beliefs on the Psychological Adjustment of Children in St. Kitts, West Indies.

    ERIC Educational Resources Information Center

    Rohner, Ronald P.; And Others

    1991-01-01

    Structural equation modeling analysis of 349 youths, aged 9-16, in St. Kitts, West Indies, showed that physical punishment by itself does make a modest, but significant, direct and negative contribution to youths' psychological adjustment. Children tended to experience themselves to be rejected in direct proportion to the frequency and severity of…

  13. A Psycholinguistic Analysis of the Oral and Silent Reading Performance of Selected Standard IV Subjects in Trinidad and Tobago, West Indies. Technical Report No. 468.

    ERIC Educational Resources Information Center

    Amoroso, Henry Carmelo, Jr.

    Students from Trinidad and Tobago, West Indies, participated in a study to determine their overall reading ability as measured by norm- and criterion-referenced reading tests and to discover the extent to which linguistically related reading difficulties were manifested in their oral and silent reading performance. The Gates-MacGinitie Reading…

  14. Problem-based Compared with Traditional Methods at the Faculty of Medical Sciences, University of the West Indies: A Model Study.

    ERIC Educational Resources Information Center

    Alleyne, T.; Shirley, A.; Bennett, C.; Addae, J.; Walrond, E.; West, S.; Pinto Pereira, L.

    2002-01-01

    Analyzes results from the final clinical examinations of two separate campuses of the University of the West Indies that use two different learning approaches. Concludes that, except for a few isolated cases, there were no statistically significant differences between the performance of the traditional group and the problem based learning (PBL)…

  15. Predictors of Student Success in an Online Learning Environment in the English-Speaking Caribbean: Evidence from the University of the West Indies Open Campus

    ERIC Educational Resources Information Center

    Warrican, S. Joel; Leacock, Coreen J.; Thompson, Benita P.; Alleyne, Melissa L.

    2014-01-01

    This paper investigated success rates and possible predictors of success among students at The University of the West Indies Open Campus. Archival data were mined from admissions and academic records of students from the 2008 intake to explore retention and completion rates, and for students enrolled in two online undergraduate courses in Semester…

  16. The red imported fire ant (Solenopsis invicta) in the West Indies: distribution of natural enemies and a possible test bed for release of self-sustaining biocontrol agents

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sample collections of Solenopsis invicta (Hymenoptera: Formicidae) were taken from 20 islands of the West Indies and evaluated for the presence of key pathogens and parasites of this invasive pest ant. We hypothesized that bottleneck events during the introduction of this ant species in the West In...

  17. An Assessment of Support Strategies Used to Facilitate Distance Students' Participation in a Web-Based Learning Environment in the University of the West Indies

    ERIC Educational Resources Information Center

    Kuboni, Olabisi; Martin, Alicia

    2004-01-01

    This paper reports on a study undertaken to analyse learner participation in an online teaching-learning environment in the distance education program of the University of the West Indies. In outlining the context of the study, special emphasis was placed on the role of the course coordinator and the site-based technician in facilitating…

  18. Isolation and characterization of viable Toxoplasma gondii isolates revealed possible high frequency of mixed infection in feral cats (felis domesticus) from St. Kitts, West Indies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cats are essential in the epidemiology of Toxoplasma gondii because they are the only hosts that can excrete the environmentally resistant oocysts in nature. Samples of serum, feces, and tissues from feral cats from St. Kitts, West Indies were examined for T. gondii infection. Antibodies to T. gon...

  19. Innovation in Tertiary Education in the Caribbean: Distance Teaching in the Faculty of Education at the University of the West Indies. Verhandelingen No. 44.

    ERIC Educational Resources Information Center

    Jennings, Zellyne D.

    The University of the West Indies Distance Teaching Experiment (UWIDITE) is an example of a conventional institution with a distance teaching department. The UWI is one of two regional universities serving a region covering 17 countries. Some countries are fairly prosperous; others are suffering severe economic difficulties. All the territories…

  20. Does one need the O({epsilon})- and O({epsilon}{sup 2})-terms of one-loop amplitudes in a next-to-next-to-leading order calculation ?

    SciTech Connect

    Weinzierl, Stefan

    2011-10-01

    This article discusses the occurrence of one-loop amplitudes within a next-to-next-to-leading-order calculation. In a next-to-next-to-leading-order calculation, the one-loop amplitude enters squared and one would therefore naively expect that the O({epsilon})- and O({epsilon}{sup 2})-terms of the one-loop amplitudes are required. I show that the calculation of these terms can be avoided if a method is known, which computes the O({epsilon}{sup 0})-terms of the finite remainder function of the two-loop amplitude.

  1. Band-overlap metallization of BaS, BaSe and BaTe

    NASA Technical Reports Server (NTRS)

    Carlsson, A. E.; Wilkins, J. W.

    1983-01-01

    The insulator-metal transition volumes for BaS, BaSe, and BaTe are calculated for the first time, using the self-consistent augmented spherical wave technique. The metallized transition volumes are smaller than those corresponding to the NaCl yields CsCl structural transitions, but, 10 to 15% larger than those obtained by the Herzfeld dielectric theory. The calculated equilibrium energy gaps in the NaCl structure underestimate the measured ones by 50 to 60%.

  2. Evaluation of different fluids for detection of Clostridium perfringens type D epsilon toxin in sheep with experimental enterotoxemia.

    PubMed

    Layana, Jorge E; Fernandez Miyakawa, Mariano E; Uzal, Francisco A

    2006-08-01

    Enterotoxemia caused by Clostridium perfringens type D is a highly lethal disease of sheep, goats and other ruminants. The diagnosis of this condition is usually confirmed by detection of epsilon toxin, a major exotoxin produced by C. perfringens types B and D, in the intestinal content of affected animals. It has been suggested that other body fluids can also be used for detection of epsilon toxin. This study was performed to evaluate the usefulness of intestinal content versus other body fluids in detecting epsilon toxin in cases of sheep enterotoxemia. Samples of duodenal, ileal and colon contents, pericardial and abdominal fluids, aqueous humor and urine from 15 sheep with experimentally induced enterotoxemia, were analysed for epsilon toxin using a capture ELISA. Epsilon toxin was detected in 92% of the samples of ileal content, 64% of the samples of duodenal content, 57% of the samples of colon content and in 7% of the samples of pericardial fluid and aqueous humor. No epsilon toxin was found in samples of abdominal fluid or urine from the animals with enterotoxemia or in any samples from six clinically healthy sheep used as negative controls. The results of this study indicate that with the diagnostic capture ELISA used, intestinal content (preferably ileum) should be used for C. perfringens type D epsilon toxin detection in suspected cases of sheep enterotoxemia. PMID:16857397

  3. Reverse phase passive haemagglutination and single radial immunodiffusion to detect epsilon antigen of Clostridium perfringens type D.

    PubMed

    Beh, K J; Buttery, S H

    1978-11-01

    Two in vitro immunological assays were developed for detection of the epsilon (epsilon) antigen of Cl. perfringens type D. It was found that the reverse phase passive haemagglutination assay (RPHA) was able to detect concentrations of epsilon-antigen as low as 6 x 10-7 mg/ml whereas the single radial immunodiffusion techniques (SRID) was capable of detecting concentrations of epsilon-antigen above 0.01 mg/ml. When applied to gut contents from freshly dead infected sheep the RPHA test was found to be more sensitive than mouse toxicity assay in detecting the presence of epsilon-antigen. However, very low titres were detected in gut contents from normal sheep which meant that in a diagnostic situation interpretation of RPHA titres would be difficult. No epsilon-antigen was detected by SRID in gut contents from normal sheep or in gut contents from freshly dead infected sheep. The SRID assay could detect epsilon-antigen in gut contents from infected sheep allowed to decompose for 20 h post-mortem. PMID:223537

  4. Influence of CuO addition to BaSm{sub 2}Ti{sub 4}O{sub 12} microwave ceramics on sintering behavior and dielectric properties

    SciTech Connect

    Zuo Mingwen; Li Wei . E-mail: liwei@mail.sic.ac.cn; Shi Jianlin; Zeng Qun

    2006-06-15

    Microwave dielectric ceramics of tungsten-bronze-type BaSm{sub 2}Ti{sub 4}O{sub 12} were prepared by doping CuO (up to 2 wt.%) as the liquid-phase sintering aid. The effects of CuO additive on the densification, micro structure and dielectric properties were investigated. Due to the liquid-phase effect, the sintering temperature of BaSm{sub 2}Ti{sub 4}O{sub 12} ceramics with 1 wt.% CuO addition can be effectively reduced to 1160 deg. C, about 200 deg. C lower than that of pure BaSm{sub 2}Ti{sub 4}O{sub 12} ceramics, while good microwave dielectric properties of {epsilon} {sub r} = 75.8, Q*f = 4914.6 GHz and {tau} {sub f} = -7.65 ppm/deg. C were still achieved.

  5. Heat transfer predictions with extended kappa-epsilon turbulence model in radical cooling ducts rotating in orthogonal mode

    NASA Astrophysics Data System (ADS)

    Tekriwal, P.

    1994-05-01

    Standard and extended kappa-epsilon turbulence closure models have been employed for three-dimensional heat transfer calculations for radially outward flow in rectangular and square cooling passages rotating in orthogonal mode. The objective of this modeling effort is to validate the numerical model in an attempt to fill the gap between model predictions and the experimental data for heat transfer in rotating systems. While the trend of heat transfer predictions by the standard kappa-epsilon turbulence model is satisfactory, the differences between the data and the predictions are approximately 30 percent or so in the case of high rotation number flow. The extended kappa-epsilon turbulence model takes an approach where an extra 'source' term based on a second time scale of the turbulent kinetic energy production rate is added to the equation for the dissipation rate of turbulent kinetic energy. This yields a more effective calculation of turbulent kinetic energy as compared to the standard kappa-epsilon turbulence model in the case of high rotation number and high density ratio flow. As a result, comparison with the experimental data available in the literature shows that an improvement of up to a significant 15 percent (with respect to data) in the heat transfer coefficient predictions is achieved over the standard kappa-epsilon model in the case of high rotation number flow. Comparisons between the results of the standard kappa-epsilon model and the extended formulation are made at different rotation numbers, different Reynolds numbers, and varying temperature ratio. The results of the extended kappa-epsilon turbulence model are either as good or better than those of the standard kappa-epsilon model in all these cases of parametric study. Thus, the extended kappa-epsilon turbulence model proves to be more general and reduces the discrepancy between the model predictions and the experimental data for heat transfer in rotating systems.

  6. Development of an injection molded poly(epsilon-caprolactone) intravaginal insert for the delivery of progesterone to cattle.

    PubMed

    Rathbone, Michael J; Bunt, Craig R; Ogle, Colin R; Burggraaf, Shane; Macmillan, Keith L; Pickering, Kim

    2002-12-13

    This paper reports experiments conducted to research, develop and clinically evaluate an injection molded intravaginal insert manufactured from the biodegradable polyester poly(epsilon-caprolactone). The study demonstrated that it is possible to engineer poly(epsilon-caprolactone) into a shape that is well retained, and can be used as a platform for the controlled delivery of progesterone via the vagina of cows. Field evaluation showed that the poly(epsilon-caprolactone) intravaginal inserts containing 10% (w/w) progesterone were at least as effective clinically as the commercially available CIDR intravaginal insert. PMID:12480312

  7. Association of the apolipoprotein E {epsilon}4 allele with clinical subtypes of autopsy-confirmed Alzheimer`s Disease

    SciTech Connect

    Zubenko, G.S.; Stiffler, S.; Kopp, U.

    1994-09-15

    Consistent with previous reports, we observed a significant association of the APOE {epsilon}4 allele with Alzheimer`s Disease (AD) in a series of 91 autopsy-confirmed cases. The {epsilon}4 allele frequency was higher in cases with a family history of AD-like dementia (0.54 {+-} 0.07), although the {epsilon}4 allele frequency in the AD cases with a negative family history (0.38 {+-} 0.05) remained significantly greater than that for the non-AD control group (0.13 {+-} 0.03). A similar increase in {epsilon}4 allele frequency (0.54 {+-} 0.07) was observed in the AD cases with amyloid angiopathy, compared to those who did not have amyloid angiopathy (0.35 {+-} 0.04). Contrary to previous reports, no effect of the dosage of the {epsilon}4 allele was found on the age of onset of dementia among the AD cases and, contrary to reports suggesting an association of {epsilon}4 and atherosclerosis, the {epsilon}4 allele frequency was similar in cases with or without concurrent brain infarcts. Modest but consistent correlations were observed between the dosage of {epsilon}4 alleles and the cortical density of senile plaques, but not neurofibrillary tangles. The last finding suggests that the pathogenic events mediated by the {epsilon}4 allele may be more directly involved in the formation of senile plaques, the identifying lesions in AD, than neurofibrillary tangles. A robust association of both the presence of an {epsilon}4 allele and a family history of AD-like dementia with concurrent amyloid angiopathy occurred within our sample of AD cases. This association arose from an interaction of the {epsilon}4 allele with a separate familial factor for which a family history of dementia served as a surrogate. These results suggest that amyloid angiopathy may be a common or central feature of a form of familial AD that is associated with the transmission of the APOE {epsilon}4 allele. 22 refs., 2 figs., 5 tabs.

  8. Limitations and empirical extensions of the k-epsilon model as applied to turbulent confined swirling flows

    NASA Technical Reports Server (NTRS)

    Lilley, D. G.; Abujelala, M. T.

    1984-01-01

    Shortcomings and recommended corrections to the standard two-equation k-epsilon turbulence model suggested by previous investigators are presented. They are assessed regarding their applicability to turbulent swirling recirculating flow. Recent experimental data on swirling confined flows, obtained with a five-hole pitot probe and a six-orientation hot-wire probe, are used to obtain optimum values of the turbulence parameters C-mu, C2, and sigma-epsilon for swirling flows. General predictions of moderately and strongly swirling flows with these values are more accurate than predictions with the standard or previous simple extensions of the k-epsilon turbulence model.

  9. Imaging subsurface density distribution beneath Montserrat (West Indies) from Bouguer gravity data

    NASA Astrophysics Data System (ADS)

    Hautmann, S.; Camacho, A. G.; Gottsmann, J.; Odbert, H. M.; Syers, T.

    2012-12-01

    High resolution static gravity data allow to resolve for spatial inhomogeneities in the Earth's gravity field by providing information on the density distribution in the shallow subsurface. Images of the subsurface density distribution and identification of structural discontinuities in the ground are of particular interest in active volcanic regions, as they bear implications for fluid migration, edifice stability and the subsurface transmission of volcanically induced stresses. Although the persistently active Soufrière Hills Volcano (SHV; Montserrat, West Indies) is currently one of the most extensively studied actively erupting stratovolcanos, a local Bouguer anomaly map of the volcano and the island of Montserrat is missing to date. In June/July 2012 we conducted a static gravity survey on Montserrat. Using a Scintrex CG-5 Autograv a total of 160 new gravity data were collected on the entire island. Site positions and elevations were obtained via a TOPCON Hiperpro dual frequency GNSS receiver/antenna. Our Bouguer gravity network provides a dense coverage (distance of 200 m between adjacent sites) of the accessible regions of the older volcanic complexes Silver Hills and Centre Hills, while (due to operator's safety) the network coverage around the active SHV is more sparse with about 1 km distance between adjacent sites. The recorded gravity data were corrected for Solid Earth Tides and ocean loading and reduced for the effect of benchmark elevation (free-air effect) and latitude. The correction for topographic effects was done via an automated algorithm based on a digital elevation model and bathymetric data. In order to model our data we performed a non-linear inversion using the inversion package GROWTH 2.0. The inversion is based on a 3-D aggregation of M parallelepiped cells, which are filled, in a growth process, by means of prescribed positive and/or negative density contrasts. This methodology provides, via an automatic approach, a free 3-D geometry

  10. Investigation of nanocomposites based on semi-interpenetrating network of [L-poly (epsilon-caprolactone)]/[net-poly (epsilon-caprolactone)] and hydroxyapatite nanocrystals.

    PubMed

    Hao, Jianyuan; Liu, Yu; Zhou, Shaobing; Li, Zhen; Deng, Xianmo

    2003-04-01

    In this paper the semi-interpenetrating network (semi-IPN) technique was used for the first time to prepare bone implant composites containing hydroxyapatite (HAP) nanocrystals. The prepared nanocomposites are expected to combine several property advantages including good mechanical strength, modified degradation rate and excellent osteoconductivity. The semi-IPN matrix based on the linear poly (epsilon-caprolactone) (L-PCL) and the network poly (epsilon-caprolactone) (net-PCL) structures are revealed to be phase separation structures. The morphology of net-PCL is featured by intracrosslinked microdomains (1-10 microm) that further interconnect with each other to form the network over the whole sample. The net-PCL component is totally amorphous at room temperature for the nanocomposites containing HAP up to 12.3 wt%. Further, the crystallinity of L-PCL is greatly decreased due to the presence of net-PCL as compared with that for pure L-PCL. The incorporation of L-PCL into the net-PCL network could significantly improve the mechanical properties of pure net-PCL. A great improvement in mechanical properties is observed for the nanocomposites if the HAP content is increased to 15.8 wt%. This transition is in agreement with that the net-PCL component changes from amorphous state to crystalline state at this composition. PMID:12559813

  11. Design and synthesis of protein kinase C epsilon selective diacylglycerol lactones (DAG-lactones).

    PubMed

    Ann, Jihyae; Yoon, Suyoung; Baek, Jisoo; Kim, Da Hye; Lewin, Nancy E; Hill, Colin S; Blumberg, Peter M; Lee, Jeewoo

    2015-01-27

    DAG-lactones afford a synthetically accessible, high affinity platform for probing structure activity relationships at the C1 regulatory domain of protein kinase C (PKC). Given the central role of PKC isoforms in cellular signaling, along with their differential biological activities, a critical objective is the design of isoform selective ligands. Here, we report the synthesis of a series of DAG-lactones varying in their side chains, with a particular focus on linoleic acid derivatives. We evaluated their selectivity for PKC epsilon versus PKC alpha both under standard lipid conditions (100% phosphatidylserine, PS) as well as in the presence of a nuclear membrane mimetic lipid mixture (NML). We find that selectivity for PKC epsilon versus PKC alpha tended to be enhanced in the presence of the nuclear membrane mimetic lipid mixture and, for our lead compound, report a selectivity of 32-fold. PMID:25437619

  12. Coherent production of {epsilon}{sup +} particles in crystal using proton beam from SSC

    SciTech Connect

    Okorokov, V.V.; Dubin, A.Yu.

    1995-05-01

    The unique possibilities of the SSC can be ideally used for a new generation of coherent generation experiments with relativistic protons which require 20 Tev energy of the incident beam. The availability of 20 Tev proton beam at SSC allows new experiments on coherent production of {var_epsilon}{sup +} particle by relativistic proton in crystal. Experiment carried out at low energies can now be extended with protons in very narrow energy region (resonance energy, which easy can be calculated) using the new accelerator facilities at SSC. We propose to study coherent production via the Coulomb field of the cristal atoms to excite the transition p + {gamma}{implies} {var_epsilon} {sup +} (1189).

  13. Implementation of a kappa-epsilon turbulence model to RPLUS3D code

    NASA Technical Reports Server (NTRS)

    Chitsomboon, Tawit

    1992-01-01

    The RPLUS3D code has been developed at the NASA Lewis Research Center to support the National Aerospace Plane (NASP) project. The code has the ability to solve three dimensional flowfields with finite rate combustion of hydrogen and air. The combustion process of the hydrogen-air system are simulated by an 18 reaction path, 8 species chemical kinetic mechanism. The code uses a Lower-Upper (LU) decomposition numerical algorithm as its basis, making it a very efficient and robust code. Except for the Jacobian matrix for the implicit chemistry source terms, there is no inversion of a matrix even though a fully implicit numerical algorithm is used. A k-epsilon turbulence model has recently been incorporated into the code. Initial validations have been conducted for a flow over a flat plate. Results of the validation studies are shown. Some difficulties in implementing the k-epsilon equations to the code are also discussed.

  14. Brain lesions associated with clostridium perfringens type D epsilon toxin in a Holstein heifer calf.

    PubMed

    Mete, A; Garcia, J; Ortega, J; Lane, M; Scholes, S; Uzal, F A

    2013-09-01

    A 6-month-old dairy heifer calf with no premonitory signs was acutely down after the morning feeding and could not rise. On presentation, the heifer was in right lateral recumbency and moribund with opisthotonus and left hind limb paddling. Following euthanasia, gross examination of the brain revealed multifocal loss of gray-white matter distinction and extensive petechiae throughout the brainstem. On histopathological examination, there was striking white matter edema and marked perivascular proteinaceous edema surrounding many arterioles and venules (microangiopathy), mainly in the white matter of the internal capsule, thalamus, midbrain, cerebellum, and cerebellar peduncles. The perivascular neuropil was strongly positive for Alzheimer precursor protein A4. Clostridium perfringens epsilon toxin was detected in the intestinal contents. This is the first report of microangiopathy in postneonatal cattle associated with the detection of epsilon toxin in the intestinal contents. PMID:23381925

  15. Infrared photometry of the 1982-4 eclipse of Epsilon Aurigae

    NASA Technical Reports Server (NTRS)

    Backman, D. E.

    1985-01-01

    The infrared photometry of epsilon Aur performed prior to and during the ingress phase of the recent eclipse allowed the first solid determination of the temperature of the secondary object. The eclipse depth was significantly less at lambda 5 micrometers than in the near-infrared. This is explained by a model of the secondary as an opaque and very cool object with a temperature of approx. 500 K. During eclipse, the secondary blocks approximately 45% of the near infrared radiation from the primary star. At the same time, the radiation from the secondary remains completely unobscured, resulting in a shallower light curve at longer wavelengths. This phenomenon is well known in the study of eclipsing binary stars; if the two stars have different colors, then the net color of the system changes during eclipse. In the case of epsilon Aur, the eclipsing object has a color deep in the infrared, so the effect is only noticeable there.

  16. Clostridium perfringens Epsilon Toxin: A Malevolent Molecule for Animals and Man?

    PubMed Central

    Stiles, Bradley G.; Barth, Gillian; Barth, Holger; Popoff, Michel R.

    2013-01-01

    Clostridium perfringens is a prolific, toxin-producing anaerobe causing multiple diseases in humans and animals. One of these toxins is epsilon, a 33 kDa protein produced by Clostridium perfringens (types B and D) that induces fatal enteric disease of goats, sheep and cattle. Epsilon toxin (Etx) belongs to the aerolysin-like toxin family. It contains three distinct domains, is proteolytically-activated and forms oligomeric pores on cell surfaces via a lipid raft-associated protein(s). Vaccination controls Etx-induced disease in the field. However, therapeutic measures are currently lacking. This review initially introduces C. perfringens toxins, subsequently focusing upon the Etx and its biochemistry, disease characteristics in various animals that include laboratory models (in vitro and in vivo), and finally control mechanisms (vaccines and therapeutics). PMID:24284826

  17. Evidence for historical human-induced extinctions of vertebrate species on La Désirade (French West Indies)

    NASA Astrophysics Data System (ADS)

    Boudadi-Maligne, Myriam; Bailon, Salvador; Bochaton, Corentin; Casagrande, Fabrice; Grouard, Sandrine; Serrand, Nathalie; Lenoble, Arnaud

    2016-01-01

    Pit cave 6 on Pointe Gros Rempart (Baie-Mahault, La Désirade, French West Indies) is a stratified fossil-bearing site. While the archaeological material and faunal remains from the oldest assemblage demonstrate it to have formed during the Amerindian period, the second assemblage dates to the first one-hundred years of the island's colonial period (mid-18th to mid-19th centuries). Faunal analysis revealed the presence of 4 now locally extinct or extinct species, three of which have never before been documented on La Désirade (Ameiva sp., Leiocephalus cf. cuneus and Alsophis sp.). Changing faunal spectrums (invertebrates and vertebrates) due to environmental destabilisation combined with aspects of the island's colonial economy demonstrate habitat degradation and over-grazing to be the principal causes of extinctions and or extirpations.

  18. Viral load kinetics of Zika virus in plasma, urine and saliva in a couple returning from Martinique, French West Indies.

    PubMed

    Fourcade, Camille; Mansuy, Jean-Michel; Dutertre, Marine; Delpech, Marie; Marchou, Bruno; Delobel, Pierre; Izopet, Jacques; Martin-Blondel, Guillaume

    2016-09-01

    While the rapid spread of Zika virus (ZIKV) in South America has been declared a public health emergency few data are available on the kinetics of the virus load and the specific antibodies in individual patients. This report describes the kinetics of ZIKV decay in the body compartments and the kinetics of anti ZIKV IgG and IgM of two people returning from Martinique, French West Indies. ZIKV remained detectable in the plasma for roughly 2 weeks indicating that mosquito control measures should be prolonged accordingly. Remarkably, their urine samples consistently tested positive for even longer. The antibodies responses were different between the two patients but for both the rapid onset of IgM allowed a diagnosis from the end of the first week. PMID:27389909

  19. Fossil vertebrates from Antigua, Lesser Antilles: Evidence for late Holocene human-caused extinctions in the West Indies

    PubMed Central

    Steadman, David W.; Pregill, Gregory K.; Olson, Storrs L.

    1984-01-01

    Vertebrate remains recovered from a limestone fissure filling on Antigua, Lesser Antilles, are associated with radiocarbon dates ranging from 4300 to 2500 yr B.P., contemporaneous with the earliest aboriginal human occupation of the island. Nine taxa of lizards, snakes, birds, bats, and rodents (one-third of the total number of species represented as fossils) are either completely extinct or have never been recorded historically from Antigua. These extinctions came long after any major climatic changes of the Pleistocene and are best attributed to human-caused environmental degradation in the past 3500 yr. Such unnatural influences have probably altered patterns of distribution and species diversity throughout the West Indies, thus rendering unreliable the data traditionally used in ecological and biogeographic studies that consider only the historically known fauna. PMID:16593490

  20. Martian occultation of epsilon Gem as observed from the C. E. Kenneth Mees Observatory

    NASA Technical Reports Server (NTRS)

    French, R. G.; Goguen, J. D.; Duthie, J. G.

    1978-01-01

    Ground-based observations of the occultation of epsilon Gem by Mars on April 8, 1976 have been reduced to yield the scale height and temperature profiles of the Martian atmosphere for number densities between 10 to the 13th and 10 to the 15th per cu cm. The deduced variations in temperature are remarkably similar to the in situ measurements from the Viking landers.

  1. Sequence of the dog immunoglobulin alpha and epsilon constant region genes

    SciTech Connect

    Patel, M.; Selinger, D.; Mark, G.E.; Hollis, G.F.; Hickey, G.J.

    1995-03-01

    The immunoglobulin alpha (IGHAC) and epsilon (IGHEC) germline constant region genes were isolated from a dog liver genomic DNA library. Sequence analysis indicates that the dog IGHEC gene is encoded by four exons spread out over 1.7 kilobases (kb). The IGHAC sequence encompasses 1.5 kb and includes all three constant region coding exons. The complete exon/intron sequence of these genes is described. 28 refs., 2 figs., 2 tabs.

  2. Optical response of dipole antennas on an epsilon-near-zero substrate

    NASA Astrophysics Data System (ADS)

    Schulz, Sebastian A.; Tahir, Asad A.; Alam, M. Zahirul; Upham, Jeremy; De Leon, Israel; Boyd, Robert W.

    2016-06-01

    Materials with vanishing permittivity (epsilon-near-zero or ENZ materials) show unconventional optical behavior. Here we show that plasmonic dipole antennas on an ultrathin ENZ substrate have properties significantly different from antennas on a traditional substrate. Specifically, the presence of a 23-nm-thick ENZ material strongly modifies the linear response of plasmonic antennas and, as a result, the resonant wavelength is independent of the linear dimensions of the dipole antenna.

  3. Clostridium perfringens epsilon-toxin increases permeability of single perfused microvessels of rat mesentery.

    PubMed

    Adamson, R H; Ly, J C; Fernandez-Miyakawa, M; Ochi, S; Sakurai, J; Uzal, F; Curry, F E

    2005-08-01

    Epsilon-toxin, the primary virulence factor of Clostridium perfringens type D, causes mortality in livestock, particularly sheep and goats, in which it induces an often-fatal enterotoxemia. It is believed to compromise the intestinal barrier and then enter the gut vasculature, from which it is carried systemically, causing widespread vascular endothelial damage and edema. Here we used single perfused venular microvessels in rat mesentery, which enabled direct observation of permeability properties of the in situ vascular wall during exposure to toxin. We determined the hydraulic conductivity (L(p)) of microvessels as a measure of the response to epsilon-toxin. We found that microvessels were highly sensitive to toxin. At 10 microg ml(-1) the L(p) increased irreversibly to more than 15 times the control value by 10 min. At 0.3 microg ml(-1) no increase in L(p) was observed for up to 90 min. The toxin-induced increase in L(p) was consistent with changes in ultrastructure of microvessels exposed to the toxin. Those microvessels exhibited gaps either between or through endothelial cells where perfusate had direct access to the basement membrane. Many endothelial cells appeared necrotic, highly attenuated, and with dense cytoplasm. We showed that epsilon-toxin, in a time- and dose-dependent manner, rapidly and irreversibly compromised the barrier function of venular microvessel endothelium. The results conformed to the hypothesis that epsilon-toxin interacts with vascular endothelial cells and increases the vessel wall permeability by direct damage of the endothelium. PMID:16041001

  4. Application of the k-epsilon-v(exp 2) model to multi-component airfoils

    NASA Technical Reports Server (NTRS)

    Iaccarino, G.; Durbin, P. A.

    1996-01-01

    Flow computations around two-element and three-element configurations are presented and compared to detailed experimental measurements. The k-epsilon-v(exp 2)(bar) model has been applied and the ability of the model to capture streamline curvature effects, wake-boundary layer confluence, and laminar/turbulent transition is discussed. The numerical results are compared to experimental datasets that include mean quantities (velocity and pressure coefficient) and turbulent quantities (Reynolds normal and shear stresses).

  5. [Coping with leprosy in the Dutch West Indies in the 19th century; opposing but meaningful views from Suriname].

    PubMed

    Menke, Henk; Snelders, Stephen; Pieters, Toine

    2009-01-01

    Leprosy was highly prevalent among African slaves in the Dutch West Indian colony of Suriname. Largely based on observations in Suriname, Dutch physicians described the aetiology of leprosy in terms of'a substrate' to which all sorts of mixtures of infection, heredity and hygiene contributed ('seed and soil'). This explanatory model with multiple options for prevention and treatment left room for different developmental trajectories to control the spread of the disease in the various tropical colonies of the Dutch empire. In Suriname there was a growing worry in the 19th century regarding the spread of leprosy, threatening the health of slaves, settlers and colonial administrators. And this could be harmful to an already weakening plantation economy. This concern prompted the local administration to develop a rigorous policy of strict isolation of leprosy sufferers. This, in turn, intersected with a changing insight in Europe - including the Netherlands - that leprosy was non-contagious. However,'in splendid isolation' in the economically and politically marginal colony Suriname, Dutch physicians like Charles Landre and his son, Charles Louis Drognat Landré, could afford to ignore the European non-contagious approach and continue to support the strict isolation policies. Moreover, they developed a dissident radical explanation of leprosy as a disease caused only by contagion. In the absence of a receptive Dutch audience Drognat Landré published his contagion theory in French and so succeeded in inspiring the Norwegian Hansen, who subsequently discovered the culpable micro-organism. At the same time colonial administrators and physicians in the economically and politically important Dutch colonies in the East Indies adhered to the prevailing European concept and changed policies: the system of isolation was abolished. Given the rather different trajectories of leprosy health policies in the Dutch East and West Indies we point out the importance of a comparative

  6. Implementation and Validation of the Chien k-epsilon Turbulence Model in the Wind Navier-Stokes Code

    NASA Technical Reports Server (NTRS)

    Yoder, Dennis A.; Georgiadis, Nicholas J.

    1999-01-01

    The two equation k-epsilon turbulence model of Chien has been implemented in the WIND Navier-Stokes flow solver. Details of the numerical solution algorithm, initialization procedure, and stability enhancements are described. Results obtained with this version of the model are compared with those from the Chien k-epsilon model in the NPARC Navier-Stokes code and from the WIND SST model for three validation cases: the incompressible flow over a smooth flat plate, the incompressible flow over a backward facing step, and the shock-induced flow separation inside a transonic diffuser. The k-epsilon model results indicate that the WIND model functions very similarly to that in NPARC, though the WIND code appears to he slightly more accurate in the treatment of the near-wall region. Comparisons of the k-epsilon model results with those from the SST model were less definitive, as each model exhibited strengths and weaknesses for each particular case.

  7. An Improved K-Epsilon Model for Near-Wall Turbulence and Comparison with Direct Numerical Simulation

    NASA Technical Reports Server (NTRS)

    Shih, T. H.

    1990-01-01

    An improved k-epsilon model for low Reynolds number turbulence near a wall is presented. The near-wall asymptotic behavior of the eddy viscosity and the pressure transport term in the turbulent kinetic energy equation is analyzed. Based on this analysis, a modified eddy viscosity model, having correct near-wall behavior, is suggested, and a model for the pressure transport term in the k-equation is proposed. In addition, a modeled dissipation rate equation is reformulated. Fully developed channel flows were used for model testing. The calculations using various k-epsilon models are compared with direct numerical simulations. The results show that the present k-epsilon model performs well in predicting the behavior of near-wall turbulence. Significant improvement over previous k-epsilon models is obtained.

  8. The elastic constants and related properties of the epsilon polymorph of the energetic material CL-20 determined by Brillouin scattering.

    PubMed

    Haycraft, James J

    2009-12-01

    The acoustic phonons of the epsilon polymorph of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazatetracyclo [5.5.0.0(5,9).0(3,11)] dodecane (epsilon-CL-20) have been studied using Brillouin scattering spectroscopy. Analysis of the acoustic phonon velocities allowed determination of the complete stiffness tensor for this energetic material. The results are compared to a theoretical determination of the epsilon-CL-20 elastic constants, bulk moduli, and shear moduli. The observed ordering of elastic constants, C(22)>C(33)>C(11), is noted to be different from other nitramine energetic materials. Finally, the elasticity of epsilon-CL-20 is compared to recently published reports on cyclotrimethylene trinitramine's (RDX) elasticity and the beta polymorph of cyclotetramethylene tetranitramine's (beta-HMX) elasticity. PMID:19968345

  9. Sulfur Metabolisms in Epsilon- and Gamma-Proteobacteria in Deep-Sea Hydrothermal Fields

    PubMed Central

    Yamamoto, Masahiro; Takai, Ken

    2011-01-01

    In deep-sea hydrothermal systems, super hot and reduced vent fluids from the subseafloor blend with cold and oxidized seawater. Very unique and dense ecosystems are formed within these environments. Many molecular ecological studies showed that chemoautotrophic epsilon- and gamma-Proteobacteria are predominant primary producers in both free-living and symbiotic microbial communities in global deep-sea hydrothermal fields. Inorganic sulfur compounds are important substrates for the energy conservative metabolic pathways in these microorganisms. Recent genomic and metagenomic analyses and biochemical studies have contributed to the understanding of potential sulfur metabolic pathways for these chemoautotrophs. Epsilon-Proteobacteria use sulfur compounds for both electron-donors and -acceptors. On the other hand, gamma-Proteobacteria utilize two different sulfur-oxidizing pathways. It is hypothesized that differences between the metabolic pathways used by these two predominant proteobacterial phyla are associated with different ecophysiological strategies; extending the energetically feasible habitats with versatile energy metabolisms in the epsilon-Proteobacteria and optimizing energy production rate and yield for relatively narrow habitable zones in the gamma-Proteobacteria. PMID:21960986

  10. Modeling of lipase catalyzed ring-opening polymerization of epsilon-caprolactone.

    PubMed

    Sivalingam, G; Madras, Giridhar

    2004-01-01

    Enzymatic ring-opening polymerization of epsilon-caprolactone by various lipases was investigated in toluene at various temperatures. The determination of molecular weight and structural identification was carried out with gel permeation chromatography and proton NMR, respectively. Among the various lipases employed, an immobilized lipase from Candida antartica B (Novozym 435) showed the highest catalytic activity. The polymerization of epsilon-caprolactone by Novozym 435 showed an optimal temperature of 65 degrees C and an optimum toluene content of 50/50 v/v of toluene and epsilon-caprolactone. As lipases can degrade polyesters, a maximum in the molecular weight with time was obtained due to the competition of ring opening polymerization and degradation by specific chain end scission. The optimum temperature, toluene content, and the variation of molecular weight with time are consistent with earlier observations. A comprehensive model based on continuous distribution kinetics was developed to model these phenomena. The model accounts for simultaneous polymerization, degradation and enzyme deactivation and provides a technique to determine the rate coefficients for these processes. The dependence of these rate coefficients with temperature and monomer concentration is also discussed. PMID:15003027

  11. Variation in the expression of macrophage Fc epsilon receptors in relation to experimental rat schistosome infection.

    PubMed

    Pestel, J; Joseph, M; Dessaint, J P; Capron, A

    1988-01-01

    The relationship between IgE and rat peritoneal macrophages during the course of Schistosoma mansoni infection was examined. Immune macrophages exhibited an IgE-dependent schistosomulicidal activity mainly between the 5th and the 7th weeks. At this period the percentages of anti-IgE rosettes whose variations appeared consecutive to the variations in the serum IgE level were higher. Following incubation in a serum-free medium immune macrophages could release membrane-associated IgE, to a certain extent, and consequently formed rosettes with IgE-coated erythrocytes, indicating the existence of Fc epsilon receptors. Thus, in terms of rosettes, their number varied in the course of the disease. In fact IgE-rich serum (i.e. at day 42) as IgE molecules could induce this macrophage Fc epsilon receptor. Moreover when transferred to syngeneic rats in association with parasite-specific IgE Fc epsilon R2+ macrophages led to some protection against challenge infection. All the data reported here emphasize the determining role of macrophages and IgE in immunity to schistosomiasis. PMID:2962948

  12. Nesprin-2 epsilon: A novel nesprin isoform expressed in human ovary and Ntera-2 cells

    SciTech Connect

    Lam, Le Thanh; Boehm, Sabrina V.; Roberts, Roland G.; Morris, Glenn E.

    2011-08-26

    Highlights: {yields} A novel epsilon isoform of nesprin-2 has been discovered. {yields} This 120 kDa protein was predicted by bioinformatic analysis, but has not previously been observed. {yields} It is the main isoform expressed in a teratocarcinoma cell line and is also found in ovary. {yields} Like other nesprins, it is located at the nuclear envelope. {yields} We suggest it may have a role in very early development or in some ovary-specific function. -- Abstract: The nuclear envelope-associated cytoskeletal protein, nesprin-2, is encoded by a large gene containing several internal promoters that produce shorter isoforms. In a study of Ntera-2 teratocarcinoma cells, a novel isoform, nesprin-2-epsilon, was found to be the major mRNA and protein product of the nesprin-2 gene. Its existence was predicted by bioinformatic analysis, but this is the first direct demonstration of both the mRNA and the 120 kDa protein which is located at the nuclear envelope. In a panel of 21 adult and foetal human tissues, the nesprin-2-epsilon mRNA was strongly expressed in ovary but was a minor isoform elsewhere. The expression pattern suggests a possible link with very early development and a likely physiological role in ovary.

  13. The structure and ordering of {epsilon}-MnO{sub 2}

    SciTech Connect

    Kim, Chang-Hoon; Akase, Zentaro; Zhang Lichun; Heuer, Arthur H. . E-mail: heuer@case.edu; Newman, Aron E.; Hughes, Paula J.

    2006-03-15

    The presence of {epsilon}-MnO{sub 2} as a major component of electrolytic manganese dioxide (EMD) has been demonstrated by a combined X-ray diffraction/transmission electron microscopy (TEM) study. {epsilon}-MnO{sub 2} usually has a partially ordered defect NiAs structure containing 50% cation vacancies; these vacancies can be fully ordered by a low temperature (200 deg. C) heat treatment to form a pseudohexagonal but monoclinic superlattice. Numerous fine-scale anti-phase domain boundaries are present in ordered {epsilon}-MnO{sub 2} and cause extensive peak broadening and a massive shift of a very intense, 0.37 nm superlattice peak. This suggests a radically different explanation of the ubiquitous, very broad {approx}0.42 nm peak ({approx}21-22 deg. 2{theta}, CuK{alpha} radiation) in EMDs, which heretofore has been attributed to Ramsdellite containing numerous planar defects. This work confirms the multi-phase model of equiaxed EMDs proposed by Heuer et al. [ITE Lett. 1(6) (2000) B50; Proc. Seventh Int. Symp. Adv. Phys. Fields 92 (2001)], rather than the defective single-phase model of Chabre and Pannetier [Prog. Solid State Chem. 23 (1995) 1] and Bowden et al. [ITE Lett. 4(1) (2003) B1].

  14. Rat costochondral cell characteristics on poly (L-lactide-co-epsilon-caprolactone) scaffolds.

    PubMed

    Honda, M; Morikawa, N; Hata, K; Yada, T; Morita, S; Ueda, M; Kimata, K

    2003-09-01

    This study was designed to examine the adhesion, proliferation, and morphology of chondrocytes on new scaffolds; and to examine these cells histologically for the ability of the chondrocytes to maintain chondrogenic properties after subcutaneous implantation into nude mice. Both 75:25 poly (L-lactide-co-epsilon-caprolactone) (75PLC) and 50:50 poly (L-lactide-co-epsilon-capro-lactone) scaffold (50PLC) were tested as a scaffold for rat costochondral resting zone chondrocytes in comparison with a type I collagen sponge scaffold (collagen scaffold). Both of the poly (L-lactide-co-epsilon-caprolactone) scaffolds (75PLC and 50PLC) were coated with type I collagen solution and the effects of the collagen coat (hybrid-PLC) were also examined. The hybrid-75PLC bound the same number of cells as the collagen scaffold, whereas the 75PLC and the 50PLC bound 60% and 50% fewer cells than the collagen scaffold, respectively. The cell growth on the scaffolds progressed with culture time in all scaffolds. Cell morphology was assessed by scanning electron microscopy for differences in the structure of cellular interaction. Chondrocytes on every scaffold maintained a spherical shape. The hybrid-PLCs were superior to the PLCs with respect to the number of cells attached. The PLCs had an advantageous degradation characteristic in that they retained their original shape better than the collagen scaffold. Additionally, in the PLCs seeded, the cells retained their integrity 4 weeks after implantation, although the volume of collagen scaffold decreased by 50%. PMID:12809780

  15. Metabolic engineering of potato tuber carotenoids through tuber-specific silencing of lycopene epsilon cyclase

    PubMed Central

    Diretto, Gianfranco; Tavazza, Raffaela; Welsch, Ralf; Pizzichini, Daniele; Mourgues, Fabienne; Papacchioli, Velia; Beyer, Peter; Giuliano, Giovanni

    2006-01-01

    Background Potato is a major staple food, and modification of its provitamin content is a possible means for alleviating nutritional deficiencies. beta-carotene is the main dietary precursor of vitamin A. Potato tubers contain low levels of carotenoids, composed mainly of the xanthophylls lutein, antheraxanthin, violaxanthin, and of xanthophyll esters. None of these carotenoids have provitamin A activity. Results We silenced the first dedicated step in the beta-epsilon- branch of carotenoid biosynthesis, lycopene epsilon cyclase (LCY-e), by introducing, via Agrobacterium-mediated transformation, an antisense fragment of this gene under the control of the patatin promoter. Real Time measurements confirmed the tuber-specific silencing of Lcy-e. Antisense tubers showed significant increases in beta-beta-carotenoid levels, with beta-carotene showing the maximum increase (up to 14-fold). Total carotenoids increased up to 2.5-fold. These changes were not accompanied by a decrease in lutein, suggesting that LCY-e is not rate-limiting for lutein accumulation. Tuber-specific changes in expression of several genes in the pathway were observed. Conclusion The data suggest that epsilon-cyclization of lycopene is a key regulatory step in potato tuber carotenogenesis. Upon tuber-specific silencing of the corresponding gene, beta-beta-carotenoid and total carotenoid levels are increased, and expression of several other genes in the pathway is modified. PMID:16800876

  16. Development and application of a zonal k-epsilon turbulence model for complex 3-D flowfields

    NASA Astrophysics Data System (ADS)

    Ladd, J. A.; Kral, L. D.

    1992-07-01

    A compressible, low Reynolds number two-equation turbulence model is applied to complex engineering problems. An upwind, implicit, factored algorithm with an optional TVD operator is used to solve both the mean-flow equations and the k-epsilon equations for three-dimensional turbulenct flow. A zonal approach is used for solution of both the mean flow variables and the turbulence variables. The zonal method allows complex geometries to be broken down into smaller blocks which are then computed sequentially. Several low Reynolds number k-epsilon models are implemented and validated for a subsonic and supersonic flat plate boundary layer. Calculations using the k-epsilon turbulence model are also presented for an axisymmetric jet plume, a supersonic combusting shear layer, a multislot ejector nozzle, and an F/A-18 forebody at high angle of attack. Comparison of the two-equation turbulence model results is made with results using algebraic turbulence models as well as experimental measurements. The two-equation turbulence model predicts better many of the flowfield characteristics for these complex geometries when compared with the algebraic solutions.

  17. Fatty acid represses insulin receptor gene expression by impairing HMGA1 through protein kinase C{epsilon}

    SciTech Connect

    Dey, Debleena; Bhattacharya, Anirban; Roy, SibSankar; Bhattacharya, Samir . E-mail: smrbhattacharya@gmail.com

    2007-06-01

    It is known that free fatty acid (FFA) contributes to the development of insulin resistance and type2 diabetes. However, the underlying mechanism in FFA-induced insulin resistance is still unclear. In the present investigation we have demonstrated that palmitate significantly (p < 0.001) inhibited insulin-stimulated phosphorylation of PDK1, the key insulin signaling molecule. Consequently, PDK1 phosphorylation of plasma membrane bound PKC{epsilon} was also inhibited. Surprisingly, phosphorylation of cytosolic PKC{epsilon} was greatly stimulated by palmitate; this was then translocated to the nuclear region and associated with the inhibition of insulin receptor (IR) gene transcription. A PKC{epsilon} translocation inhibitor peptide, {epsilon}V1, suppressed this inhibitory effect of palmitate, suggesting requirement of phospho-PKC{epsilon} migration to implement palmitate effect. Experimental evidences indicate that phospho-PKC{epsilon} adversely affected HMGA1. Since HMGA1 regulates IR promoter activity, expression of IR gene was impaired causing reduction of IR on cell surface and that compromises with insulin sensitivity.

  18. Molecular cloning and expression of epsilon toxin from Clostridium perfringens type D and tests of animal immunization.

    PubMed

    Souza, A M; Reis, J K P; Assis, R A; Horta, C C; Siqueira, F F; Facchin, S; Alvarenga, E R; Castro, C S; Salvarani, F M; Silva, R O S; Pires, P S; Contigli, C; Lobato, F C F; Kalapothakis, E

    2010-01-01

    Epsilon toxin produced by Clostridium perfringens types B and D causes enterotoxemia in sheep, goats and calves. Enterotoxemia can cause acute or superacute disease, with sudden death of the affected animal. It provokes huge economic losses when large numbers of livestock are affected. Therapeutic intervention is challenging, because the disease progresses very rapidly. However, it can be prevented by immunization with specific immunogenic vaccines. We cloned the etx gene, encoding epsilon toxin, into vector pET-11a; recombinant epsilon toxin (rec-epsilon) was expressed in inclusion bodies and was used for animal immunization. Serum protection was evaluated and cross-serum neutralization tests were used to characterize the recombinant toxin. To analyze the potency of the toxin (as an antigen), rabbits were immunized with 50, 100 or 200 microg recombinant toxin, using aluminum hydroxide gel as an adjuvant. Titers of 10, 30 and 40 IU/mL were obtained, respectively. These titers were higher than the minimum level required by the European Pharmacopoeia (5 IU/mL) and by the USA Code of Federal Regulation (2 IU/mL). This rec-epsilon is a good candidate for vaccine production against enterotoxemia caused by epsilon toxin of C. perfringens type D. PMID:20198582

  19. Initial Evaluation of Processing Methods for an Epsilon Metal Waste Form

    SciTech Connect

    Crum, Jarrod V.; Strachan, Denis M.; Zumhoff, Mac R.

    2012-06-11

    During irradiation of nuclear fuel in a reactor, the five metals, Mo, Pd, Rh, Ru, and Tc, migrate to the fuel grain boundaries and form small metal particles of an alloy known as epsilon metal ({var_epsilon}-metal). When the fuel is dissolved in a reprocessing plant, these metal particles remain behind with a residue - the undissolved solids (UDS). Some of these same metals that comprise this alloy that have not formed the alloy are dissolved into the aqueous stream. These metals limit the waste loading for a borosilicate glass that is being developed for the reprocessing wastes. Epsilon metal is being developed as a waste form for the noble metals from a number of waste streams in the aqueous reprocessing of used nuclear fuel (UNF) - (1) the {var_epsilon}-metal from the UDS, (2) soluble Tc (ion-exchanged), and (3) soluble noble metals (TRUEX raffinate). Separate immobilization of these metals has benefits other than allowing an increase in the glass waste loading. These materials are quite resistant to dissolution (corrosion) as evidenced by the fact that they survive the chemically aggressive conditions in the fuel dissolver. Remnants of {var_epsilon}-metal particles have survived in the geologically natural reactors found in Gabon, Africa, indicating that they have sufficient durability to survive for {approx} 2.5 billion years in a reducing geologic environment. Additionally, the {var_epsilon}-metal can be made without additives and incorporate sufficient foreign material (oxides) that are also present in the UDS. Although {var_epsilon}-metal is found in fuel and Gabon as small particles ({approx}10 {micro}m in diameter) and has survived intact, an ideal waste form is one in which the surface area is minimized. Therefore, the main effort in developing {var_epsilon}-metal as a waste form is to develop a process to consolidate the particles into a monolith. Individually, these metals have high melting points (2617 C for Mo to 1552 C for Pd) and the alloy is

  20. Protein kinase C epsilon, which sensitizes skin to sun's UV radiation-induced cutaneous damage and development of squamous cell carcinomas, associates with Stat3.

    PubMed

    Aziz, Moammir H; Manoharan, Herbert T; Verma, Ajit K

    2007-02-01

    Chronic exposure to UV radiation (UVR) is the major etiologic factor in the development of human skin cancers including squamous cell carcinoma (SCC). We have shown that protein kinase C(epsilon) (PKC(epsilon)), a Ca(2+)-independent, phospholipid-dependent serine/threonine kinase, is an endogenous photosensitizer. PKC(epsilon) is among the six isoforms (alpha, delta, epsilon, eta, mu, and zeta) expressed in both mouse and human skin. PKC(epsilon) transgenic mice, which overexpress PKC(epsilon) in the basal epidermal cells and cells of the hair follicle, are highly sensitive to UVR-induced cutaneous damage and development of SCC. We now present that PKC(epsilon)-overexpressing, but not PKC(delta)-overexpressing, transgenic mice, when exposed to a single (4 kJ/m(2)) or repeated (four doses, 2 kJ/m(2)/dose, thrice weekly) UVR, emitted by Kodacel-filtered FS-40 sun lamps, elicit constitutive phosphorylation of signal transducers and activators of transcription 3 (Stat3) at both Tyr705 and Ser727 residues. UVR-induced phosphorylation of Stat3 accompanied increased expression of Stat3-regulated genes (c-myc, cyclin D1, cdc25A, and COX-2). In reciprocal immunoprecipitation/blotting experiments, phosphorylated Stat3 co-immunoprecipitated with PKC(epsilon). As observed in vivo using PKC(epsilon) knockout mice and in vitro in an immunocomplex kinase assay, PKC(epsilon) phosphorylated Stat3 at Ser727 residue. These results indicate for the first time that (a) PKC(epsilon) is a Stat3Ser727 kinase; (b) PKC(epsilon)-mediated phosphorylation of StatSer727 may be essential for transcriptional activity of Stat3; and (c) UVR-induced phosphorylation of Ser727 may be a key component of the mechanism by which PKC(epsilon) imparts sensitivity to UVR-induced development of SCC. PMID:17283176

  1. Toward the Validation of Ba.

    ERIC Educational Resources Information Center

    Burton, Craig L.; Schwen, Thomas M.

    2003-01-01

    The theory of "ba" or "space" offers a prescription for fostering the conversion of particular kinds of knowledge (tacit-to-explicit, tacit-to-tacit, etc.). Three corporate groups were observed as they collaborated to develop instructional, Web-based stories intended to capture their tacit organizational understandings. A comparative case study…

  2. Phase formation in the BaB2O4-BaF2 system

    NASA Astrophysics Data System (ADS)

    Bekker, T. B.; Fedorov, P. P.; Kokh, A. E.

    2012-07-01

    It is shown that the BaB2O4-BaF2 system is quasi-binary with the following eutectics coordinates: 760°C, 59 mol % BaF2, 41 mol % BaB2O4. Due to the intense pyrohydrolysis during the growth of β-BaB2O4 crystals from the 55.6 mol % BaB2O4-44.4 mol % BaF2 composition, the Ba5B4O11 compound is formed in the system. This process leads to the cocrystallization of the β-BaB2O4 and Ba5B4O11 phases and impedes the formation of high-quality crystals.

  3. Andrew Halliday, Kt FRCPE (1781-1839): service in the Napoleonic Wars and West Indies, and first physician to the Seamen's Hospital Society.

    PubMed

    Cook, G C

    2004-08-01

    Sir Andrew Halliday (1781-1839) was domestic physician to HRH the Duke of Clarence (1765-1837) (who was later to become King William IV). He also served in the Napoleonic Wars-in Portugal, Spain and Waterloo-as well as in the West Indies, and became the first physician to the Seamen's Hospital Society. Unlike many of his contemporaries, Halliday was also a prolific author, many of his publications being on lunatic asylums in Great Britain and Ireland. PMID:15257347

  4. Distribution of type I Fc epsilon-receptors on the surface of mast cells probed by fluorescence resonance energy transfer.

    PubMed Central

    Kubitscheck, U; Schweitzer-Stenner, R; Arndt-Jovin, D J; Jovin, T M; Pecht, I

    1993-01-01

    The aggregation state of type I Fc epsilon-receptors (Fc epsilon RI) on the surface of single living mast cells was investigated by resonance fluorescence energy transfer. Derivatization of Fc epsilon RI specific ligands, i.e., immunoglobulin E or Fab fragments of a Fc epsilon RI specific monoclonal antibody, with donor and acceptor fluorophores provided a means for measuring receptor clustering through energy transfer between the receptor probes. The efficiency of energy transfer between the ligands carrying distinct fluorophores was determined on single cells in a microscope by analyzing the photobleaching kinetics of the donor fluorophore in the presence and absence of receptor ligands labeled with acceptor fluorophores. To rationalize the energy transfer data, we developed a theoretical model describing the dependence of the energy transfer efficiency on the geometry of the fluorescently labeled macromolecular ligands and their aggregation state on the cell surface. To this end, the transfer process was numerically calculated first for one pair and then for an ensemble of Fc epsilon RI bound ligands on the cell surface. The model stipulates that the aggregation state of the Fc epsilon RI is governed by an attractive lipid-protein mediated interaction potential. The corresponding pair-distribution function characterizes the spatial distribution of the ensemble. Using this approach, the energy transfer efficiency of the ensemble was calculated for different degrees of receptor aggregation. Comparison of the theoretical modeling results with the experimental energy transfer data clearly suggests that the Fc epsilon RI are monovalent, randomly distributed plasma membrane proteins. The method provides a novel approach for determining the aggregation state of cell surface components. PMID:8431535

  5. Fyn kinase controls Fc{epsilon}RI receptor-operated calcium entry necessary for full degranulation in mast cells

    SciTech Connect

    Sanchez-Miranda, Elizabeth; Ibarra-Sanchez, Alfredo; Gonzalez-Espinosa, Claudia

    2010-01-22

    IgE-antigen-dependent crosslinking of the high affinity IgE receptor (Fc{epsilon}RI) on mast cells leads to degranulation, leukotriene synthesis and cytokine production. Calcium (Ca{sup 2+}) mobilization is a sine qua non requisite for degranulation, allowing the rapid secretion of stored pro-inflammatory mediators responsible for allergy symptoms. Fyn is a Src-family kinase that positively controls Fc{epsilon}RI-induced mast cell degranulation. However, our understanding of the mechanism connecting Fyn activation to secretion of pre-synthesized mediators is very limited. We analyzed Fc{epsilon}RI-dependent Ca{sup 2+} mobilization in bone marrow-derived mast cells (BMMCs) differentiated from WT and Fyn -/- knock out mice. Fyn -/- BMMCs showed a marked defect in extracellular Ca{sup 2+} influx after Fc{epsilon}RI crosslinking but not after thapsigargin addition. High concentrations of Gadolinium (Gd{sup 3+}) partially blocked Fc{epsilon}RI-induced Ca{sup 2+} influx in WT cells but, in contrast, completely inhibited Ca{sup 2+} mobilization in Fyn -/- cells. Low concentrations of an inhibitor of the canonical transient receptor potential (TRPC) Ca{sup 2+} channels (2-aminoethoxyphenyl-borane, 2-APB) blocked Fc{epsilon}RI-induced maximal Ca{sup 2+} rise in WT but not in Fyn -/- cells. Ca{sup 2+} entry through Fyn-controlled, 2-APB sensitive channels was found to be important for full degranulation and IL-2 mRNA accumulation in WT cells. Immunoprecipitation assays showed that Fyn kinase interacts with TRPC 3/6/7 channels after IgE-antigen stimulation, but its association is not related to protein tyrosine phosphorylation. Results indicate Fyn kinase mediates the receptor-dependent activation of TRPC channels that contribute to degranulation in Fc{epsilon}RI-stimulated mast cells.

  6. The linoleic acid derivative DCP-LA selectively activates PKC-epsilon, possibly binding to the phosphatidylserine binding site.

    PubMed

    Kanno, Takeshi; Yamamoto, Hideyuki; Yaguchi, Takahiro; Hi, Rika; Mukasa, Takeshi; Fujikawa, Hirokazu; Nagata, Tetsu; Yamamoto, Satoshi; Tanaka, Akito; Nishizaki, Tomoyuki

    2006-06-01

    This study examined the effect of 8-[2-(2-pentyl-cyclopropylmethyl)-cyclopropyl]-octanoic acid (DCP-LA), a newly synthesized linoleic acid derivative with cyclopropane rings instead of cis-double bonds, on protein kinase C (PKC) activity. In the in situ PKC assay with reverse-phase high-performance liquid chromatography, DCP-LA significantly activated PKC in PC-12 cells in a concentration-dependent (10 nM-100 microM) manner, with the maximal effect at 100 nM, and the DCP-LA effect was blocked by GF109203X, a PKC inhibitor, or a selective inhibitor peptide of the novel PKC isozyme PKC-epsilon. Furthermore, DCP-LA activated PKC in HEK-293 cells that was inhibited by the small, interfering RNA against PKC-epsilon. In the cell-free PKC assay, of the nine isozymes examined here, DCP-LA most strongly activated PKC-epsilon, with >7-fold potency over other PKC isozymes, in the absence of dioleoyl-phosphatidylserine and 1,2-dioleoyl-sn-glycerol; instead, the DCP-LA action was inhibited by dioleoyl-phosphatidylserine. DCP-LA also activated PKC-gamma, a conventional PKC, but to a much lesser extent compared with that for PKC-epsilon, by a mechanism distinct from PKC-epsilon activation. Thus, DCP-LA serves as a selective activator of PKC-epsilon, possibly by binding to the phosphatidylserine binding site on PKC-epsilon. These results may provide fresh insight into lipid signaling in PKC activation. PMID:16520488

  7. Zuivere en toegepaste wetenschap in de tropen : biologisch onderzoek aan particuliere proefstations in Nederlands-Indië 1870-1940

    NASA Astrophysics Data System (ADS)

    van der Schoor, W. J.

    2012-04-01

    Most experiment stations originated from the cooperation between entrepreneurs and the government. From the 1890s onwards, the government, together with the well organised colonial entrepreneurs, established research departments for several plantation crops at the Botanical Gardens at Buitenzorg (now Bogor), that eventually became independent experiment stations in the first decades of the twentieth century. By the 1920s, the ‘proefstationswezen’ (experiment station system) numbered some fifteen private experiment stations or sub-stations. After the war, the private experiment stations together with the government experiment stations at Buitenzorg were to provide the backbone of Indonesian agricultural science. Dutch biologists in particular, made a striking plea for pursuing the natural sciences in the tropical colonies. First, they pointed out the scientific importance of the tropics. Secondly, they stressed the role of the natural sciences, in particular biology, as a natural ally of colonial agriculture. Pure science was seen as a leading force for technical and social progress. The third motive was the cultural value of science for the Netherlands and its colonies. The cultivation of science in the colonies gave international prestige and strengthened self-confidence in the imperial struggle around 1900. Science had a civilising effect; scientific research, however, was to remain in the hands of western, colonial scientists. From the 1880s and 1890s onward, the experiment stations in the Indies were characterised by their strategic aims and scientific orientation. Up to 1910, the ‘academic’ views of biologists like Treub and Went concerning science and practice were predominant, and research was considered to be the central aim. From 1910 onwards, advice became more central and special extension services were established at the experiment stations. Due to diverging views of science, tasks and aims became a battlefield for discussions in the next

  8. Binary star systems with asymmetrically heated disks: Thermal phase curves for the disk in epsilon Aurigae

    NASA Astrophysics Data System (ADS)

    Pearson, Richard L., III

    Epsilon Aurigae is a long-period eclipsing binary that contains a warm F-star (~7750 K) and a circumstellar disk enshrouding a hidden companion, likely to be a hot B-star (≥15,000 K). The eclipse itself lasts just over two years---thanks, in part, to the size of the disk---and occurs every 27.1-years. Its evolutionary status is still debated, along with the true nature of each stellar component, due to the high uncertainty in its parallax. The disk is similarly debated from the near absence of solid state infrared spectral features indicating its composition, particle size distribution, and density. An investigation of a wide parameter space by means of analytic, Monte Carlo radiative transfer (MCRT), and thermal inertia-dependent methods are presented here in order to minimize the current parameter space. The first MCRT models including all of the epsilon Aurigae components (F-star, B-star, and disk) are included here. Additional parameter constraints are found by melding MCRT outputs (e.g. dust temperatures) with a thermal inertia-based extrapolation. The so-called MCRT-TI models investigate the effects of various parameters on the disk-edge temperatures; these include two distances, three particle size distributions, three compositions, and two disk masses, resulting in thirty-six independent models. Adding in the MCRT temperatures as possible solutions doubles the number of models to seventy-two. Additionally, infrared observations at 7 epochs, spanning nearly 1/3 of the orbit of epsilon Aurigae, are evaluated in order to extract phase-dependent disk temperatures. The resulting temperatures create a thermal phase curve, or TPC, for the system. The TPC correlates the observed disk temperature with orbital phase or date of observation. Then, the best-case MCRT and MCRT-TI models are compared against two different mid-eclipse temperatures. If one considers the evolutionary constraints on the models---where a smaller distance denotes an older system with a disk

  9. Epsilon Lyrae

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    Though not very bright, this is a favorite test object for powerful binoculars and small telescopes. Situated 1.6° north-east of Vega, it is known as `the Double Double'. The star can just be seen to be double with the unaided eye, under good conditions by observers with acute eyesight. With binoculars it is easily separated, the component stars being 3.5' apart at a position angle of 173°. It is...

  10. EUVE spectroscopy of epsilon Canis Majoris (B2 II) from 70 to 730 A

    NASA Technical Reports Server (NTRS)

    Cassinelli, J. P.; Cohen, D. H.; Macfarlane, J. J.; Drew, J. E.; Lynas-Gray, A. E.; Hoare, M. G.; Vallerga, J. V.; Welsh, B. Y.; Vedder, P. W.; Hubeny, I.

    1995-01-01

    We present spectra of the brightest stellar source of extreme ultraviolet (EUV) radiation longward of 400 A, the B2 II star, epsilon CMa. These data were taken with the three spectrometers aboard the NASA Extreme Ultraviolet Explorer satellite (EUVE) during the first cycle of pointed observations. We report on our initial studies of the continuum and line spectrum of the stellar photosphere in the 320 to 730 A region, and on the wind emission lines observed in the 170-375 A region. This is the first EUV spectrum of an early-type star, and thus makes epsilon CMa the most comprehensively observed B star from the X-ray to infrared regimes. The radiation in both the H Lyman continuum and He I continuum (shortward of 504 A) are found to be significantly greater than predicted by both Local Thermodynamic Equilibrium (LTE) and non-LTE model atmospheres. Since epsilon CMa also exhibits a mid-infrared excess, this points to the outer layers being warmer than the models indicate. The anomalously large Lyman continuum flux, combined with the very low column density measured in the direction toward this star implies that it is the dominant source of hydrogen ionization of the local interstellar medium in the immediate vicinity of the sun. All of the lines predicted to be strong from model atmospheres are present and several wind absorption features are also identified. We have detected emission lines from highly ionized iron that are consistent with the ROSAT Position Sensitive Proportional Counter (PSPC) observations if a multi-temperature emission model is used, and the assumption is made that there is significant absorption beyond that of the neutral phase of the ISM. The spectrum shows strong O III 374 A line emission produced by the Bowen flourescence mechanism, which has not previously been observed in the spectra of hot stars.

  11. DNA replication defect in Salmonella typhimurium mutants lacking the editing (epsilon) subunit of DNA polymerase III.

    PubMed Central

    Lifsics, M R; Lancy, E D; Maurer, R

    1992-01-01

    In Salmonella typhimurium, dnaQ null mutants (encoding the epsilon editing subunit of DNA polymerase III [Pol III]) exhibit a severe growth defect when the genetic background is otherwise wild type. Suppression of the growth defect requires both a mutation affecting the alpha (polymerase) subunit of DNA polymerase III and adequate levels of DNA polymerase I. In the present paper, we report on studies that clarify the nature of the physiological defect imposed by the loss of epsilon and the mechanism of its suppression. Unsuppressed dnaQ mutants exhibited chronic SOS induction, indicating exposure of single-stranded DNA in vivo, most likely as gaps in double-stranded DNA. Suppression of the growth defect was associated with suppression of SOS induction. Thus, Pol I and the mutant Pol III combined to reduce the formation of single-stranded DNA or accelerate its maturation to double-stranded DNA. Studies with mutants in major DNA repair pathways supported the view that the defect in DNA metabolism in dnaQ mutants was at the level of DNA replication rather than of repair. The requirement for Pol I was satisfied by alleles of the gene for Pol I encoding polymerase activity or by rat DNA polymerase beta (which exhibits polymerase activity only). Consequently, normal growth is restored to dnaQ mutants when sufficient polymerase activity is provided and this compensatory polymerase activity can function independently of Pol III. The high level of Pol I polymerase activity may be required to satisfy the increased demand for residual DNA synthesis at regions of single-stranded DNA generated by epsilon-minus pol III. The emphasis on adequate polymerase activity in dnaQ mutants is also observed in the purified alpha subunit containing the suppressor mutation, which exhibits a modestly elevated intrinsic polymerase activity relative to that of wild-type alpha. Images PMID:1400246

  12. Wall functions for the kappa-epsilon turbulence model in generalized nonorthogonal curvilinear coordinates

    NASA Technical Reports Server (NTRS)

    Sondak, D. L.; Pletcher, R. H.; Vandalsem, W. R.

    1992-01-01

    A k-epsilon turbulence model suitable for compressible flow, including the new wall function formulation, has been incorporated into an existing compressible Reynolds-averaged Navier-Stokes code, F3D. The low Reynolds number k-epsilon model of Chien (1982) was added for comparison with the present method. A number of features were added to the F3D code including improved far-field boundary conditions and viscous terms in the streamwise direction. A series of computations of increasing complexity was run to test the effectiveness of the new formulation. Flow over a flat plate was computed by using both orthogonal and nonorthogonal grids, and the friction coefficients and velocity profiles compared with a semi-empirical equation. Flow over a body of revolution at zero angle of attack was then computed to test the method's ability to handle flow over a curved surface. Friction coefficients and velocity profiles were compared to test data. All models gave good results on a relatively fine grid, but only the wall function formulation was effective with coarser grids. Finally, in order to demonstrate the method's ability to handle complex flow fields, separated flow over a prolate spheroid at angle of attack was computed, and results were compared to test data. The results were also compared to a k-epsilon model by Kim and Patel (1991), in which one equation model patched in at the wall was employed. Both models gave reasonable solutions, but improvement is required for accurate prediction of friction coefficients in the separated regions.

  13. The historical archaeology of the 17th- and 18th-century Jewish community of Nevis, British West Indies

    NASA Astrophysics Data System (ADS)

    Terrell, Michelle M.

    2000-11-01

    This is an historical archaeological examination of a 17th- and 18th-century Jewish community on the island of Nevis in the British West Indies. Unlike earlier archaeological studies of the Jewish Caribbean Diaspora that focused on single sites, this investigation used a community-wide approach to elucidate the daily experience of Sephardic Jews within the colonial Caribbean. This project included an archaeological excavation at the purported location of the community's synagogue, an electrical resistivity survey of the surviving cemetery, the construction of a map of property ownership in 18th-century Charlestown, and archival research. This study was carded out within a multiscalar and contextual framework that emphasized the importance of understanding the diaspora that brought the Jews to the West Indies, the development of the colonial Caribbean, and the surrounding environs of the port city of Charlestown, Nevis. The archaeological analysis of the supposed site of the synagogue proved that it was in fact that of a late 18th-century townhouse, but the associated land record research revealed the actual location of the community's former synagogue. Furthermore, the reconstruction of the physical layout of colonial-period Charlestown from the land records indicated the presence of a distinct Jewish quarter in the undesirable southern portion of the town. Evidence from the public records of Nevis and the social history of the members of the Jewish population unveiled external social and political pressures placed upon the Sephardim as well as internal religious and ethnic ties dig bound the community together. It is argued in closing that the archival evidence, in conjunction with the continued presence of a clustered settlement pattern like that of European Jewish communities during the medieval period, indicates that the Jews of the Caribbean were not fully integrated socially or politically into British colonial society. This examination of the Nevis community

  14. Arbitrary Steady-State Solutions with the K-epsilon Model

    NASA Technical Reports Server (NTRS)

    Rumsey, Christopher L.; Pettersson Reif, B. A.; Gatski, Thomas B.

    2006-01-01

    Widely-used forms of the K-epsilon turbulence model are shown to yield arbitrary steady-state converged solutions that are highly dependent on numerical considerations such as initial conditions and solution procedure. These solutions contain pseudo-laminar regions of varying size. By applying a nullcline analysis to the equation set, it is possible to clearly demonstrate the reasons for the anomalous behavior. In summary, the degenerate solution acts as a stable fixed point under certain conditions, causing the numerical method to converge there. The analysis also suggests a methodology for preventing the anomalous behavior in steady-state computations.

  15. Super-resolution with a positive epsilon multi-quantum-well super-lens

    SciTech Connect

    Bak, A. O.; Giannini, V.; Maier, S. A.; Phillips, C. C.

    2013-12-23

    We design an anisotropic and dichroic quantum metamaterial that is able to achieve super-resolution without the need for a negative permittivity. When exploring the parameters of the structure, we take into account the limits of semiconductor fabrication technology based on quantum well stacks. By heavily doping the structure with free electrons, we infer an anisotropic effective medium with a prolate ellipsoid dispersion curve which allows for near-diffractionless propagation of light (similar to an epsilon-near-zero hyperbolic lens). This, coupled with low absorption, allows us to resolve images at the sub-wavelength scale at distances 6 times greater than equivalent natural materials.

  16. Goos-Hänchen shift of partially coherent light fields in epsilon-near-zero metamaterials

    NASA Astrophysics Data System (ADS)

    Ziauddin; Chuang, You-Lin; Qamar, Sajid; Lee, Ray-Kuang

    2016-05-01

    The Goos-Hänchen (GH) shifts in the reflected light are investigated both for p and s polarized partial coherent light beams incident on epsilon-near-zero (ENZ) metamaterials. In contrary to the coherent counterparts, the magnitude of GH shift becomes non-zero for p polarized partial coherent light beam; while GH shift can be relatively large with a small degree of spatial coherence for s polarized partial coherent beam. Dependence on the beam width and the permittivity of ENZ metamaterials is also revealed for partial coherent light fields. Our results on the GH shifts provide a direction on the applications for partial coherent light sources in ENZ metamaterials.

  17. Metasurfaces and epsilon-near-zero modes in semiconductors (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Brener, Igal; Campione, Salvatore; Marquier, Francois

    2015-09-01

    Thin layers of semiconductors where the permittivity crosses zero, support a particular polariton mode called epsilon-near-zero (ENZ) mode. This zero crossing can be obtained near optical phonon resonances in dielectrics or the plasma frequency in doped semiconductors. The coupling of metamaterial resonators to these ENZ modes leads to particularly large Rabi splittings. ENZ layers can be added to metamaterial-based strongly coupled systems to increase this coupling even further. I will discuss several examples of these coupled systems that include metasurfaces, phonons, intersubband transitions and ENZ modes.

  18. CONFIRMING FUNDAMENTAL PROPERTIES OF THE EXOPLANET HOST STAR {epsilon} ERIDANI USING THE NAVY OPTICAL INTERFEROMETER

    SciTech Connect

    Baines, Ellyn K.; Armstrong, J. Thomas E-mail: tarmstr@crater.nrl.navy.mil

    2012-01-10

    We measured the angular diameter of the exoplanet host star {epsilon} Eridani using the Navy Optical Interferometer. We determined its physical radius, effective temperature, and mass by combining our measurement with the star's parallax, photometry from the literature, and the Yonsei-Yale isochrones, respectively. We used the resulting stellar mass of 0.82 {+-} 0.05 M{sub Sun} plus the mass function from Benedict et al. to calculate the planet's mass, which is 1.53 {+-} 0.22 M{sub Jupiter}. Using our new effective temperature, we also estimated the extent of the habitable zone for the system.

  19. All-optical modulation in wavelength-sized epsilon-near-zero media.

    PubMed

    Ciattoni, Alessandro; Marini, Andrea; Rizza, Carlo

    2016-07-01

    We investigate the interaction of two pulses (pump and probe) scattered by a nonlinear epsilon-near-zero (ENZ) slab whose thickness is comparable with the ENZ wavelength. We show that when the probe has a narrow spectrum localized around the ENZ wavelength, its transmission is dramatically affected by the intensity of the pump. Conversely, if the probe is not in the ENZ regime, its propagation is not noticeably affected by the pump. Such all-optical modulation is due to the oversensitive character of the ENZ regime, and it is so efficient that it even occurs in a wavelength thick slab. PMID:27367112

  20. Structural Basis for the Potent and Selective Inhibition of Casein Kinase 1 Epsilon

    SciTech Connect

    Long, Alexander M.; Zhao, Huilin; Huang, Xin

    2012-10-29

    Casein kinase 1 epsilon (CK1ε) and its closest homologue CK1δ are key regulators of diverse cellular processes. We report two crystal structures of PF4800567, a potent and selective inhibitor of CK1ε, bound to the kinase domains of human CK1ε and CK1δ as well as one apo CK1ε crystal structure. These structures provide a molecular basis for the strong and specific inhibitor interactions with CK1ε and suggest clues for further development of CK1δ inhibitors.

  1. Numerical simulation of a combined oxidation ditch flow using 3D k-epsilon turbulence model.

    PubMed

    Luo, Lin; Li, Wei-min; Deng, Yong-sen; Wang, Tao

    2005-01-01

    The standard three dimensional(3D) k-epsilon turbulence model was applied to simulate the flow field of a small scale combined oxidation ditch. The moving mesh approach was used to model the rotor of the ditch. Comparison of the computed and the measured data is acceptable. A vertical reverse flow zone in the ditch was found, and it played a very important role in the ditch flow behavior. The flow pattern in the ditch is discussed in detail, and approaches are suggested to improve the hydrodynamic performance in the ditch. PMID:16313008

  2. Magneto-optical characteristics of layered Epsilon-Near-Zero metamaterials

    NASA Astrophysics Data System (ADS)

    Abdi-Ghaleh, Reza; Suldozi, Reza

    2016-09-01

    The transmittance magneto-optical (MO) characteristics of Epsilon-Near-Zero (ENZ) metamaterials are studied, using 4 by 4 transfer matrix method. The considered structures are a free standing ENZ-MO slab, and a microcavity type multi-layer structure containing an ENZ-MO layer. The transmittance coefficients of the right- and left-handed circular polarizations for the slab are analytically obtained and numerically investigated. Furthermore, these characteristics are numerically studied for the multi-layer structure. In addition, the Faraday rotations of both structures are investigated. The results reveal the circular polarization filtering effects.

  3. Interferometric, astrometric, and photometric studies of Epsilon Aurigae: Seeing the disk around a distant star

    NASA Astrophysics Data System (ADS)

    Kloppenborg, Brian

    2012-05-01

    Epsilon (epsilon) Aurigae is a binary star system that has baffled astronomers for 170 years. In 1821 it was first noticed that the star system had dimmed by nearly 50%. After many decades of photometric monitoring, the 27.1 year period was finally established in 1903. A few years later, in 1912, Henry Norris Russell published the first analytic methods for binary star analysis. Later application of these formulae came to an interesting conclusion; the system was composed of two stars: the visible F-type supergiant, and an equally massive, but yet photometrically and spectroscopically invisible, companion. Several theories were advanced to explain this low-light to high-mass conundrum, eventually settling on the notion that the companion object is obscured from view by a disk of opaque material. With this topic solved, the debate shifted the evolutionary state of the system. Two scenarios became dominant: the system is either relativity young, and composed of a massive, 15 Mo (solar mass), F-type supergiant and a nearly equally massive main sequence companion inside of the disk; or a much older and significantly less massive, 4 Mo, F-type post-asymptotic giant branch object with a more massive, 6 Mo, companion surrounded by a debris disk. In this dissertation I disentangle the two evolutionary states by comparing the photometric behavior of the F-type star to known supergiant and post-asymptotic giant branch objects; and deriving a dynamical mass for the two components using astrometric, radial velocity, and interferometric data. Along with this, I provide the first interferometric images during the eclipse which prove the 50% dimming is indeed caused by an opaque disk. The first chapter presents the reader with the status quo of epsilon Aurigae research and the topics I wish to address in this dissertation. Chapter two presents an analysis of nearly 30 years of photometry on the system, concluding the star periodically exhibits stable pulsation on 1/3 orbital

  4. Enhanced third harmonic generation from the epsilon-near-zero modes of ultrathin films

    SciTech Connect

    Luk, Ting S. Liu, Sheng; Campione, Salvatore; Ceglia, Domenico de; Vincenti, Maria A.; Keeler, Gordon A.; Sinclair, Michael B.; Prasankumar, Rohit P.; Scalora, Michael

    2015-04-13

    We experimentally demonstrate efficient third harmonic generation from an indium tin oxide nanofilm (λ/42 thick) on a glass substrate for a pump wavelength of 1.4 μm. A conversion efficiency of 3.3 × 10{sup −6} is achieved by exploiting the field enhancement properties of the epsilon-near-zero mode with an enhancement factor of 200. This nanoscale frequency conversion method is applicable to other plasmonic materials and reststrahlen materials in proximity of the longitudinal optical phonon frequencies.

  5. Enhanced third harmonic generation from the epsilon-near-zero modes of ultrathin films

    NASA Astrophysics Data System (ADS)

    Luk, Ting S.; de Ceglia, Domenico; Liu, Sheng; Keeler, Gordon A.; Prasankumar, Rohit P.; Vincenti, Maria A.; Scalora, Michael; Sinclair, Michael B.; Campione, Salvatore

    2015-04-01

    We experimentally demonstrate efficient third harmonic generation from an indium tin oxide nanofilm (λ/42 thick) on a glass substrate for a pump wavelength of 1.4 μm. A conversion efficiency of 3.3 × 10-6 is achieved by exploiting the field enhancement properties of the epsilon-near-zero mode with an enhancement factor of 200. This nanoscale frequency conversion method is applicable to other plasmonic materials and reststrahlen materials in proximity of the longitudinal optical phonon frequencies.

  6. Stellar model chromospheres. IV - The formation of the H-epsilon feature in the sun /G2 V/ and Arcturus /K2 III/

    NASA Technical Reports Server (NTRS)

    Ayres, T. R.; Linsky, J. L.

    1975-01-01

    The formation of the Balmer-series member H-epsilon in the near-red wing of the Ca II H line is discussed for two cases: the sun (H-epsilon absorption profile) and Arcturus (H-epsilon emission profile). It is shown that although the H-epsilon source functions in both stars are dominated by the Balmer-continuum radiation field through photoionizations, the line-formation problems in the two stars are quantitatively different, owing to a substantial difference in the relative importance of the stellar chromosphere temperature inversion as compared with the stellar photosphere.

  7. Isolation of the epsilon-caprolactam denitrifying bacteria from a wastewater treatment system manufactured with acrylonitrile-butadiene-styrene resin.

    PubMed

    Wang, Chun-Chin; Lee, Chi-Mei

    2007-06-25

    epsilon-Caprolactam has high COD and toxicity, so its discharge to natural water and soil systems may lead to an adverse environmental effect on water quality, endangering public health and welfare. This investigation attempts to isolate epsilon-caprolactam denitrifying bacteria from a wastewater treatment system manufactured with acrylonitrile-butadiene-styrene (ABS) resin. The goal is to elucidate the effectiveness of isolated pure strain and ABS mixed strains in treating epsilon-caprolactam from synthetic wastewater. The results reveal that Paracoccus versutus MDC-3 was isolated from the wastewater treatment system manufactured with ABS resin. The ABS mixed strains and P. versutus MDC-3 can consume up to 1539mg/l epsilon-caprolactam to denitrify from synthetic wastewater. Complete epsilon-caprolactam removal depended on the supply of sufficient electron acceptors (nitrate). Strain P. versutus MDC-3, Hyphomicrobium sp. HM, Methylosinus pucelana and Magnetospirillum sp. CC-26 are related closely, according to the phylogenetic analyses of 16S rDNA sequences. PMID:17161908

  8. Tissue specific transcription of the human epsilon-globin gene following transfection into the embryonic erythroid cell line K562.

    PubMed Central

    Allan, M; Montague, P; Grindlay, G J; Sibbet, G; Donovan-Peluso, M; Bank, A; Paul, J

    1985-01-01

    We have introduced a plasmid containing the human epsilon-globin gene either stably or transiently into a number of erythroid or non-erythroid cell lines, and analysed the accuracy and efficiency of transcription. In non-erythroid cells (or in mouse erythroleukaemia (MEL) cells in which adult but not embryonic globin genes are expressed) transcription of the epsilon-globin gene occurs mainly from a site 200 bp upstream of the major cap site (the -200 cap site). In the human K562 cell line, in which the endogenous epsilon-globin gene is transcribed at high levels, transcription initiation from the introduced gene occurs mainly from the major cap site. Transcriptional activity of the epsilon-globin gene introduced into K562 cell is quantitatively similar to that of the endogenous gene. This suggests the presence (or absence) in K562 cells of factor(s) which activate (or repress) the epsilon-globin gene in a tissue specific manner. Images PMID:2995916

  9. Microstructure and piezoelectric properties of 0.95(Na{sub 0.5}K{sub 0.5})NbO{sub 3}-0.05BaTiO{sub 3} ceramics

    SciTech Connect

    Park, Hwi-Yeol; Ahn, Cheol-Woo; Song, Hyun-Cheol; Lee, Jong-Heun; Nahm, Sahn; Uchino, Kenji; Lee, Hyeung-Gyu; Lee, Hwack-Joo

    2006-08-07

    For 0.95(Na{sub 0.5}K{sub 0.5})NbO{sub 3}-0.05BaTiO{sub 3} (0.95NKN-0.05BT) ceramics sintered at 1040-1075 deg. C, abnormal grain growth occurred but the grain size decreased when the sintering temperature exceeded 1075 deg. C. The dielectric constant ({epsilon}{sub 3}{sup T}/{epsilon}{sub 3}), electromechanical coupling factor (k{sub p}), and piezoelectric constant (d{sub 33}) were considerably increased with increasing relative density and grain size. Evaporation of Na{sub 2}O deteriorated the piezoelectric properties by decreasing the resistivity. To minimize Na{sub 2}O evaporation, specimens were muffled with 0.95NKN-0.05BT powders during the sintering. Improved piezoelectric properties of d{sub 33}=225 pC/N, k{sub p}=36%, and {epsilon}{sub 3}{sup T}/{epsilon}{sub 3}=1058 were obtained for specimen sintered at 1060 deg. C for 2 h with muffling.

  10. Coherent diffraction reactions p + C {r_arrow} ({Epsilon}(1385){sup O}K{sup +}) + C and p + C {r_arrow} ({Epsilon}{sup O}K{sup +}) + C: The search for exotic baryons

    SciTech Connect

    Vavilov, D.V.; Viktorov, V.A.; Golovkin, S.V.

    1995-08-01

    The coherent diffractive reactions p + C {r_arrow} ({Epsilon}(1385){sup O}K{sup +}) + C and p + C {r_arrow} ({Epsilon}{sup O}K{sup +}) + C are investigated in experiments with the SPHINX detector irradiated by 70-GeV protons. A structure X(2050) with M = 2052 {plus_minus} 6 MeV and {Gamma} = 91 {plus_minus} 17MeV in the {Epsilon}{sup O}K{sup +} mass spectrum are observed in the former and latter processes, respectively. The small decay widths of these states and the anomalously large branching ratios of their decays that involve the emission of strange particles make them serious candidates for cryptoexotic varyons with hidden strangeness. 18 refs., 6 figs., 2 tabs.

  11. Distinct bacterial community structure of 3 tropical volcanic soils from banana plantations contaminated with chlordecone in Guadeloupe (French West Indies).

    PubMed

    Mercier, Anne; Dictor, Marie-Christine; Harris-Hellal, Jennifer; Breeze, Dominique; Mouvet, Christophe

    2013-08-01

    In the French West Indies (FWI), the soil, andosols, ferralsols and nitisols, is highly polluted by chlordecone, although this organochlorine insecticide extensively applied to banana crops has been banned for 20years. This contamination has led to a major human health concern inducing the need for remediation of the contaminated soils. Work was conducted to help to evaluate the impact of remediation processes on the microbial communities from these soils. Microbial biomass was estimated after direct DNA extraction from three chlordecone-contaminated soils (an andosol, a ferralsol and a nitisol) and the bacterial community analyzed using t-RFLP. The FWI volcanic andosol was particularly recalcitrant to usual direct DNA extraction protocols hampering analysis of soil microbial communities until now, in contrast with the 2 other soils. For the first time, DNA was directly extracted from a FWI andosol based on yeast RNA addition at the lysis step. Differences in microbial biomass were thus observed between the 3 FWI soils. Moreover, the bacterial community structure was significantly distinct from each other's and related to soil physico-chemical characteristics. Interestingly, differences in bacterial diversity could not be exclusively attributed to the level of chlordecone contamination. PMID:23706897

  12. Identification of Pre-examination Errors in the Chemical Pathology Laboratory at the University Hospital of the West Indies.

    PubMed

    Dilworth, Lowell L; McGrowder, Donovan A; Thompson, Rory K

    2014-04-01

    This study evaluated the types and frequencies of pre-examination errors recorded in the chemical pathology laboratory at the University Hospital of the West Indies, Jamaica. This was a retrospective analysis of errors recorded over a three year period. Data analysis was done on an average of 519,084 samples collected and tested per year. Samples included blood, urine, stool and other fluids. Pre-examination errors were identified and recorded following visual inspection of the samples and corresponding request forms by laboratory staff, then subsequently by the Senior Medical Technologist. Errors were generally classified as inappropriate sample (58 %), inappropriate form (23.4 %), inappropriate sample volume (9.3 %) and inappropriate sample tube (9.3 %). Over 90 % of recorded pre-examination errors were related to blood samples while urine samples accounted for 6.8 % error. Pre-examination errors were lower at this study location than elsewhere. Measures aimed at reducing instances of these errors are recommended for improved laboratory quality output. PMID:24757307

  13. Batrachedra nuciferae, an inflorescence-feeding moth associated with coconut, Cocos nucifera, and palmiste, Roystonea oleracea, in Trinidad, West Indies.

    PubMed

    Cock, Matthew J W

    2013-01-01

    In 2006, Batrachedra nuciferae Hodges (Lepidoptera: Batrachedridae) was the first phytophagous insect to be reported from inflorescences of coconut, Cocos nucifera L. (Arecales: Arecaceae), in Trinidad, West Indies. At that time, it was suggested to be an introduced species contributing to decreasing coconut yields on the island and potentially a threat to other palms. In this preliminary study, inflorescences of coconut, seven indigenous palms, and six exotic ornamental palms were surveyed in several areas of Trinidad. Caterpillars of more than 10 species of Lepidoptera were found and reared through to the adult stage. Batrachedra nuciferae was positively identified. It was concluded that the caterpillars of B. nuciferae feed on pollen in the male flowers of coconut and palmiste or royal palm, Roystonea oleracea (Jacquin) O.F. Cook. There was no evidence that B. nuciferae bred on any of the other palms surveyed, but it is not conclusive that they do not do so. A parasitoid, Apanteles (sensu lato) sp. (Hymenoptera: Braconidae), of B. nuciferae was reared. On available information, B. nuciferae is more likely to be an indigenous species that has hitherto been overlooked than an introduced species. In view of what is known about damage-yield relationships and biological control agents, B. nuciferae is unlikely to cause yield losses to coconut, so control measures are not justified. PMID:24786569

  14. A fossil Diploglossus (Squamata, Anguidae) lizard from Basse-Terre and Grande-Terre Islands (Guadeloupe, French West Indies).

    PubMed

    Bochaton, Corentin; Boistel, Renaud; Casagrande, Fabrice; Grouard, Sandrine; Bailon, Salvador

    2016-01-01

    Today, Diploglossine lizards (Anguidae) are common on the Greater Antillean Islands (West Indies), where they are represented by many endemic species. However these lizards are very rare on the Lesser Antillean Islands, where they are only represented by a single species, the Montserrat galliwasp (Diploglossus montisserrati). Here, we show that diploglossine lizards were present in the past on other Lesser Antillean islands, by reporting the discovery of Anguidae fossil remains in two Amerindian archaeological deposits and in a modern deposit. These remains are compared to skeletons of extant diploglossine lizards, including D. montisserrati, using X-ray microtomography of the type specimen of this critically endangered lizard. We also conducted a histological study of the osteoderms in order to estimate the putative age of the specimen. Our results show that the fossil specimens correspond to a member of the Diploglossus genus presenting strong similarities, but also minor morphological differences with D. montisserrati, although we postulate that these differences are not sufficient to warrant the description of a new species. These specimens, identified as Diploglossus sp., provide a new comparison point for the study of fossil diploglossine lizards and reflect the historical 17(th) century mentions of anguid lizards, which had not been observed since. PMID:27354326

  15. [First case of phaeohyphomycosis due to Pleurostoma ootheca in a kidney transplant recipient in Martinique (French West Indies)].

    PubMed

    Amazan, E; Desbois, N; Fidelin, G; Baubion, E; Derancourt, C; Thimon, S; Ekindi, N; Quist, D

    2014-01-01

    Phaeohyphomycosis is a group of superficial and deep infections due to dematiaceous fungi. They are most common in tropical environments, especially in immunocompromised hosts. We describe the first case of phaeohyphomycosis due to Pleurostoma ootheca in a kidney transplant recipient in Martinique (French West Indies). A 59-year-old man with a kidney graft, treated with mycophenolate mofetil, tacrolimus, and prednisone, presented suppurative tumefaction of the left ankle. Cutaneous and osseous phaeohyphomycosis caused by P. ootheca was diagnosed, based on mycological, histological, and radiological testing. The patient's condition improved with posaconazole treatment. P. ootheca is a known environmental fungus. Immunocompromised hosts are more vulnerable to many infections, due to opportunistic pathogens. Bacteriological, histological, and mycological testing is required for accurate diagnosis and appropriate treatment. Treatment is not well defined and usually relies on antifungal agents or surgical resection or both. An important point to consider is that azole antifungal agents may cause major drug-drug interactions with immunosuppressive agents such as tracrolimus. PMID:24918350

  16. Batrachedra nuciferae, an Inflorescence-Feeding Moth Associated with Coconut, Cocos nucifera, and Palmiste, Roystonea oleracea, in Trinidad, West Indies

    PubMed Central

    Cock, Matthew J. W.

    2013-01-01

    In 2006, Batrachedra nuciferae Hodges (Lepidoptera: Batrachedridae) was the first phytophagous insect to be reported from inflorescences of coconut, Cocos nucifera L. (Arecales: Arecaceae), in Trinidad, West Indies. At that time, it was suggested to be an introduced species contributing to decreasing coconut yields on the island and potentially a threat to other palms. In this preliminary study, inflorescences of coconut, seven indigenous palms, and six exotic ornamental palms were surveyed in several areas of Trinidad. Caterpillars of more than 10 species of Lepidoptera were found and reared through to the adult stage. Batrachedra nuciferae was positively identified. It was concluded that the caterpillars of B. nuciferae feed on pollen in the male flowers of coconut and palmiste or royal palm, Roystonea oleracea (Jacquin) O.F. Cook. There was no evidence that B. nuciferae bred on any of the other palms surveyed, but it is not conclusive that they do not do so. A parasitoid, Apanteles (sensu lato) sp. (Hymenoptera: Braconidae), of B. nuciferae was reared. On available information, B. nuciferae is more likely to be an indigenous species that has hitherto been overlooked than an introduced species. In view of what is known about damage-yield relationships and biological control agents, B. nuciferae is unlikely to cause yield losses to coconut, so control measures are not justified. PMID:24786569

  17. A fossil Diploglossus (Squamata, Anguidae) lizard from Basse-Terre and Grande-Terre Islands (Guadeloupe, French West Indies)

    PubMed Central

    Bochaton, Corentin; Boistel, Renaud; Casagrande, Fabrice; Grouard, Sandrine; Bailon, Salvador

    2016-01-01

    Today, Diploglossine lizards (Anguidae) are common on the Greater Antillean Islands (West Indies), where they are represented by many endemic species. However these lizards are very rare on the Lesser Antillean Islands, where they are only represented by a single species, the Montserrat galliwasp (Diploglossus montisserrati). Here, we show that diploglossine lizards were present in the past on other Lesser Antillean islands, by reporting the discovery of Anguidae fossil remains in two Amerindian archaeological deposits and in a modern deposit. These remains are compared to skeletons of extant diploglossine lizards, including D. montisserrati, using X-ray microtomography of the type specimen of this critically endangered lizard. We also conducted a histological study of the osteoderms in order to estimate the putative age of the specimen. Our results show that the fossil specimens correspond to a member of the Diploglossus genus presenting strong similarities, but also minor morphological differences with D. montisserrati, although we postulate that these differences are not sufficient to warrant the description of a new species. These specimens, identified as Diploglossus sp., provide a new comparison point for the study of fossil diploglossine lizards and reflect the historical 17th century mentions of anguid lizards, which had not been observed since. PMID:27354326

  18. Interdependence and dynamics of essential services in an extensive risk context: a case study in Montserrat, West Indies

    NASA Astrophysics Data System (ADS)

    Sword-Daniels, V. L.; Rossetto, T.; Wilson, T. M.; Sargeant, S.

    2015-02-01

    The essential services that support urban living are complex and interdependent, and their disruption in disasters directly affects society. Yet there are few empirical studies to inform our understanding of the vulnerabilities and resilience of complex infrastructure systems in disasters. This research takes a systems thinking approach to explore the dynamic behaviour of a network of essential services, in the presence and absence of volcanic ashfall hazards in Montserrat, West Indies. Adopting a case study methodology and qualitative methods to gather empirical data we centre the study on the healthcare system and its interconnected network of essential services. We identify different types of relationship between sectors and develop a new interdependence classification system for analysis. Relationships are further categorised by hazard condition, for use in extensive risk contexts. During heightened volcanic activity, relationships between systems transform in both number and type: connections increase across the network by 41%, and adapt to increase cooperation and information sharing. Interconnections add capacities to the network, increasing the resilience of prioritised sectors. This in-depth and context-specific approach provides a new methodology for studying the dynamics of infrastructure interdependence in an extensive risk context, and can be adapted for use in other hazard contexts.

  19. Interdependence and dynamics of essential services in an extensive risk context: a case study in Montserrat, West Indies

    NASA Astrophysics Data System (ADS)

    Sword-Daniels, V. L.; Rossetto, T.; Wilson, T. M.; Sargeant, S.

    2015-05-01

    The essential services that support urban living are complex and interdependent, and their disruption in disasters directly affects society. Yet there are few empirical studies to inform our understanding of the vulnerabilities and resilience of complex infrastructure systems in disasters. This research takes a systems thinking approach to explore the dynamic behaviour of a network of essential services, in the presence and absence of volcanic ashfall hazards in Montserrat, West Indies. Adopting a case study methodology and qualitative methods to gather empirical data, we centre the study on the healthcare system and its interconnected network of essential services. We identify different types of relationship between sectors and develop a new interdependence classification system for analysis. Relationships are further categorised by hazard conditions, for use in extensive risk contexts. During heightened volcanic activity, relationships between systems transform in both number and type: connections increase across the network by 41%, and adapt to increase cooperation and information sharing. Interconnections add capacities to the network, increasing the resilience of prioritised sectors. This in-depth and context-specific approach provides a new methodology for studying the dynamics of infrastructure interdependence in an extensive risk context, and can be adapted for use in other hazard contexts.

  20. Ultrasonic real-time in-die monitoring of the tablet compaction process-a proof of concept study.

    PubMed

    Stephens, James D; Kowalczyk, Brian R; Hancock, Bruno C; Kaul, Goldi; Cetinkaya, Cetin

    2013-02-14

    The mechanical properties of a drug tablet can affect its performance (e.g., dissolution profile and its physical robustness. An ultrasonic system for real-time in-die tablet mechanical property monitoring during compaction has been demonstrated. The reported set-up is a proof of concept compaction monitoring system which includes an ultrasonic transducer mounted inside the upper punch of the compaction apparatus. This upper punch is utilized to acquire ultrasonic pressure wave phase velocity waveforms and extract the time-of-flight of pressure waves travelling within the compact at a number of compaction force levels during compaction. The reflection coefficients for the waves reflecting from punch tip-powder bed interface are extracted from the acquired waveforms. The reflection coefficient decreases with an increase in compaction force, indicating solidification. The data acquisition methods give an average apparent Young's moduli in the range of 8-20 GPa extracted during the compaction and release/decompression phases in real-time. A monitoring system employing such methods is capable of determining material properties and the integrity of the tablet during compaction. As compared to the millisecond time-scale dwell time of a typical commercial compaction press, the micro-second pulse duration and ToF of an acoustic pulse are sufficiently fast for real-time monitoring. PMID:22989980

  1. Prevalence, serovars and antimicrobial susceptibility of Salmonella spp. from wild and domestic green iguanas (Iguana iguana) in Grenada, West Indies.

    PubMed

    Sylvester, W R B; Amadi, V; Pinckney, R; Macpherson, C N L; McKibben, J S; Bruhl-Day, R; Johnson, R; Hariharan, H

    2014-09-01

    Cloacal swabs from 62 green iguanas (Iguana iguana), including 47 wild and 15 domestic ones from five parishes of Grenada, were sampled during a 4-month period of January to April 2013 and examined by enrichment and selective culture for the presence of Salmonella spp. Fifty-five per cent of the animals were positive, and eight serovars of Salmonella were isolated. The most common serovar was Rubislaw (58.8%), a serovar found recently in many cane toads in Grenada, followed by Oranienburg (14.7%), a serovar that has been causing serious human disease outbreaks in Japan. Serovar IV:48:g,z51 :- (formerly, S. Marina) highly invasive and known for serious infections in children in the United States, constituted 11.8% of the isolates, all of them being from domestic green iguanas. Salmonella Newport, a serovar recently found in a blue land crab in Grenada, comprised 11.8% of the isolates from the green iguanas. The remaining four less frequent serovars included S. Javiana and S. Glostrup. Antimicrobial susceptibility tests conducted by a disc diffusion method against amoxicillin-clavulanic acid, ampicillin, cefotaxime, ceftazidime, ciprofloxacin, enrofloxacin, gentamicin, nalidixic acid, streptomycin, tetracycline and trimethoprim-sulfamethoxazole showed that drug resistance is minimal, with intermediate susceptibility, mainly to streptomycin, tetracycline and cefotaxime. This is the first report of isolation and antimicrobial susceptibilities of various Salmonella serovars from wild and domestic green iguanas in Grenada, West Indies. PMID:24325463

  2. Knowledge and use of electronic information resources by medical sciences faculty at The University of the West Indies

    PubMed Central

    Renwick, Shamin

    2005-01-01

    Objective: The objective was to determine faculty's knowledge of electronic resources, access to a computer, use of electronic resources (both number and frequency) available at the Medical Sciences Library (MSL), and the areas of training needed and to identify areas for further research. Methods: A survey was administered to faculty in medicine, pharmacy, dentistry, and veterinary sciences at The University of the West Indies. The questions covered computer literacy, computer access and location, knowledge and use of electronic resources, and training needs. Results: The response rate was 70%, of whom 97% were computer users. Seventy-three percent used computers daily, and 82% felt that their computer literacy level was average or beyond. Overall, it was found that faculty had high awareness of the electronic resources made available by the MSL but low use of MSL-specific resources supporting the suggested problem of underutilization. Many respondents felt that e-resources were important, and, though many felt that they were competent users, 83% were self-taught and many still expressed a need for training. Over 60% felt that a workshop with a hands-on component was the preferred format for training. It was recommended that there be greater promotion of the library's e-resources. PMID:15685270

  3. Wave-matter interactions in epsilon-and-mu-near-zero structures

    NASA Astrophysics Data System (ADS)

    Mahmoud, Ahmed M.; Engheta, Nader

    2014-12-01

    In recent years, the concept of metamaterials has offered platforms for unconventional tailoring and manipulation of the light-matter interaction. Here we explore the notion of ‘static optics’, in which the electricity and magnetism are decoupled, while the fields are temporally dynamic. This occurs when both the relative effective permittivity and permeability attain near-zero values at a given operating frequency. We theoretically investigate some of the resulting wave features in bounded scenarios, such as unusual radiation characteristics of an emitter embedded in such epsilon-and-mu-near-zero media in bounded environments. Using such media, one might in principle ‘open up’ and ‘stretch’ the space, and have regions behaving electromagnetically as ‘single points’ despite being electrically large. We suggest a possible design for implementation of such structures using a single dielectric rod inserted in a waveguide operating near its cutoff frequency, providing the possibility of having electrically large ‘empty’ volumes to behave as epsilon-and-mu-near-zero media.

  4. Optically induced metal-to-dielectric transition in Epsilon-Near-Zero metamaterials

    PubMed Central

    Kaipurath, R. M.; Pietrzyk, M.; Caspani, L.; Roger, T.; Clerici, M.; Rizza, C.; Ciattoni, A.; Di Falco, A.; Faccio, D.

    2016-01-01

    Epsilon-Near-Zero materials exhibit a transition in the real part of the dielectric permittivity from positive to negative value as a function of wavelength. Here we study metal-dielectric layered metamaterials in the homogenised regime (each layer has strongly subwavelength thickness) with zero real part of the permittivity in the near-infrared region. By optically pumping the metamaterial we experimentally show that close to the Epsilon-Near-Zero (ENZ) wavelength the permittivity exhibits a marked transition from metallic (negative permittivity) to dielectric (positive permittivity) as a function of the optical power. Remarkably, this transition is linear as a function of pump power and occurs on time scales of the order of the 100 fs pump pulse that need not be tuned to a specific wavelength. The linearity of the permittivity increase allows us to express the response of the metamaterial in terms of a standard third order optical nonlinearity: this shows a clear inversion of the roles of the real and imaginary parts in crossing the ENZ wavelength, further supporting an optically induced change in the physical behaviour of the metamaterial. PMID:27292270

  5. Hydrothermal vent gastropods from the same family (Provannidae) harbour epsilon- and gamma-proteobacterial endosymbionts.

    PubMed

    Urakawa, Hidetoshi; Dubilier, Nicole; Fujiwara, Yoshihiro; Cunningham, Dale E; Kojima, Shigeaki; Stahl, David A

    2005-05-01

    The discovery of new hydrothermal vent systems in the back-arc basins of the Western Pacific revealed chemosynthesis-based faunal communities distinct from those of other vents. These vents are dominated by two related gastropods (Alviniconcha spp. and Ifremeria nautilei) that harbour symbiotic bacteria in their gills. We used comparative 16S ribosomal RNA (rRNA) gene sequencing and in situ hybridization with rRNA-targeted probes to characterize the bacterial symbionts of Alviniconcha sp. and I. nautilei from the Manus Basin in the Western Pacific. The analyses revealed that these two gastropod species, although affiliated with the same family, harbour phylogenetically distant chemosymbionts, suggesting independent origins of these endosymbioses. The I. nautilei endosymbiont clusters with sulfur-oxidizing bacteria within the gamma-Proteobacteria, as is the case for all previously characterized endosymbionts from a wide diversity of host taxa harbouring thioautotrophic prokaryotes. In contrast, the Alviniconcha endosymbiont is affiliated with sulfur-oxidizing bacteria within the epsilon-Proteobacteria. These results show that bacteria from the epsilon-Proteobacteria are also capable of forming endosymbiotic associations with marine invertebrates from chemosynthetic environments. More generally, the endosymbiotic lifestyle is now shown to be distributed throughout all recognized classes of the Proteobacteria. PMID:15819856

  6. Optically induced metal-to-dielectric transition in Epsilon-Near-Zero metamaterials

    NASA Astrophysics Data System (ADS)

    Kaipurath, R. M.; Pietrzyk, M.; Caspani, L.; Roger, T.; Clerici, M.; Rizza, C.; Ciattoni, A.; di Falco, A.; Faccio, D.

    2016-06-01

    Epsilon-Near-Zero materials exhibit a transition in the real part of the dielectric permittivity from positive to negative value as a function of wavelength. Here we study metal-dielectric layered metamaterials in the homogenised regime (each layer has strongly subwavelength thickness) with zero real part of the permittivity in the near-infrared region. By optically pumping the metamaterial we experimentally show that close to the Epsilon-Near-Zero (ENZ) wavelength the permittivity exhibits a marked transition from metallic (negative permittivity) to dielectric (positive permittivity) as a function of the optical power. Remarkably, this transition is linear as a function of pump power and occurs on time scales of the order of the 100 fs pump pulse that need not be tuned to a specific wavelength. The linearity of the permittivity increase allows us to express the response of the metamaterial in terms of a standard third order optical nonlinearity: this shows a clear inversion of the roles of the real and imaginary parts in crossing the ENZ wavelength, further supporting an optically induced change in the physical behaviour of the metamaterial.

  7. Optically induced metal-to-dielectric transition in Epsilon-Near-Zero metamaterials.

    PubMed

    Kaipurath, R M; Pietrzyk, M; Caspani, L; Roger, T; Clerici, M; Rizza, C; Ciattoni, A; Di Falco, A; Faccio, D

    2016-01-01

    Epsilon-Near-Zero materials exhibit a transition in the real part of the dielectric permittivity from positive to negative value as a function of wavelength. Here we study metal-dielectric layered metamaterials in the homogenised regime (each layer has strongly subwavelength thickness) with zero real part of the permittivity in the near-infrared region. By optically pumping the metamaterial we experimentally show that close to the Epsilon-Near-Zero (ENZ) wavelength the permittivity exhibits a marked transition from metallic (negative permittivity) to dielectric (positive permittivity) as a function of the optical power. Remarkably, this transition is linear as a function of pump power and occurs on time scales of the order of the 100 fs pump pulse that need not be tuned to a specific wavelength. The linearity of the permittivity increase allows us to express the response of the metamaterial in terms of a standard third order optical nonlinearity: this shows a clear inversion of the roles of the real and imaginary parts in crossing the ENZ wavelength, further supporting an optically induced change in the physical behaviour of the metamaterial. PMID:27292270

  8. Stellar model chromospheres. VIII - 70 Ophiuchi A /K0 V/ and Epsilon Eridani /K2 V/

    NASA Technical Reports Server (NTRS)

    Kelch, W. L.

    1978-01-01

    Model atmospheres for the late-type active-chromosphere dwarf stars 70 Oph A and Epsilon Eri are computed from high-resolution Ca II K line profiles as well as Mg II h and k line fluxes. A method is used which determines a plane-parallel homogeneous hydrostatic-equilibrium model of the upper photosphere and chromosphere which differs from theoretical models by lacking the constraint of radiative equilibrium (RE). The determinations of surface gravities, metallicities, and effective temperatures are discussed, and the computational methods, model atoms, atomic data, and observations are described. Temperature distributions for the two stars are plotted and compared with RE models for the adopted effective temperatures and gravities. The previously investigated T min/T eff vs. T eff relation is extended to Epsilon Eri and 70 Oph A, observed and computed Ca II K and Mg II h and k integrated emission fluxes are compared, and full tabulations are given for the proposed models. It is suggested that if less than half the observed Mg II flux for the two stars is lost in noise, the difference between an active-chromosphere star and a quiet-chromosphere star lies in the lower-chromospheric temperature gradient.

  9. Wave-matter interactions in epsilon-and-mu-near-zero structures.

    PubMed

    Mahmoud, Ahmed M; Engheta, Nader

    2014-01-01

    In recent years, the concept of metamaterials has offered platforms for unconventional tailoring and manipulation of the light-matter interaction. Here we explore the notion of 'static optics', in which the electricity and magnetism are decoupled, while the fields are temporally dynamic. This occurs when both the relative effective permittivity and permeability attain near-zero values at a given operating frequency. We theoretically investigate some of the resulting wave features in bounded scenarios, such as unusual radiation characteristics of an emitter embedded in such epsilon-and-mu-near-zero media in bounded environments. Using such media, one might in principle 'open up' and 'stretch' the space, and have regions behaving electromagnetically as 'single points' despite being electrically large. We suggest a possible design for implementation of such structures using a single dielectric rod inserted in a waveguide operating near its cutoff frequency, providing the possibility of having electrically large 'empty' volumes to behave as epsilon-and-mu-near-zero media. PMID:25476550

  10. Singularity-driven second- and third-harmonic generation at {epsilon}-near-zero crossing points

    SciTech Connect

    Vincenti, M. A.; Ceglia, D. de; Ciattoni, A.; Scalora, M.

    2011-12-15

    We show an alternative path to efficient second- and third-harmonic generation in proximity of the zero crossing points of the dielectric permittivity in conjunction with low absorption. Under these circumstances, any material, either natural or artificial, will show similar degrees of field enhancement followed by strong harmonic generation, without resorting to any resonant mechanism. The results presented in this paper provide a general demonstration of the potential that the zero-crossing-point condition holds for nonlinear optical phenomena. We investigate a generic Lorentz medium and demonstrate that a singularity-driven enhancement of the electric field may be achieved even in extremely thin layers of material. We also discuss the role of nonlinear surface sources in a realistic scenario where a 20-nm layer of CaF{sub 2} is excited at 21 {mu}m, where {epsilon}{approx} 0. Finally, we show similar behavior in an artificial composite material that includes absorbing dyes in the visible range, provide a general tool for the improvement of harmonic generation using the {epsilon}{approx} 0 condition, and illustrate that this singularity-driven enhancement of the field lowers the thresholds for a plethora of nonlinear optical phenomena.

  11. Status of the PICTURE Sounding Rocket to Image the Epsilon Eridani Circumstellar Environment

    NASA Astrophysics Data System (ADS)

    Douglas, Ewan S.; Mendillo, Christopher Bernard; Hicks, Brian; Cook, Timothy; Martel, Jason; Finn, Susanna; Polidan, Ronald S.; Chakrabarti, Supriya

    2014-06-01

    The PICTURE (Planetary Imaging Concept Testbed Using a Rocket Experiment) sounding rocket will use a visible nulling interferometer to characterize the exozodiacal dust disk of Epsilon Eridani (K2V, 3.22 pc) in reflected visible light to an inner radius of 1.5 AU (0.5”) from the star. Launch is scheduled for Fall 2014 and the PICTURE payload is currently undergoing re-integration. The first launch of PICTURE suffered a science telemetry failure and the primary mirror was shattered upon landing, the second launch will fly a new SiC primary mirror and onboard data storage. PICTURE visible light observations will constrain scattering properties of the Epsilon Eridani exozodiacal dust disk from 600nm to 750 nm, measuring the background brightness which must be overcome for future exoplanet observations. Additionally, PICTURE will demonstrate operation of a MEMS deformable mirror and a visible nulling coronagraph in space. We will present the latest measurements of integrated telescope and interferometer performance.

  12. A Galilean and tensorial invariant k-epsilon model for near wall turbulence

    NASA Astrophysics Data System (ADS)

    Yang, Z.; Shih, T. H.

    1993-07-01

    A k-epsilon model is proposed for wall bounded turbulent flows. In this model, the eddy viscosity is characterized by a turbulent velocity scale and a turbulent time scale. The time scale is bounded from below by the Kolmogorov time scale. The dissipation rate equation is reformulated using this time scale and no singularity exists at the wall. A new parameter R = k/S(nu) is introduced to characterize the damping function in the eddy viscosity. This parameter is determined by local properties of both the mean and the turbulent flow fields and is free from any geometry parameter. The proposed model is then Galilean and tensorial invariant. The model constants used are the same as in the high Reynolds number Standard k-epsilon Model. Thus, the proposed model will also be suitable for flows far from the wall. Turbulent channel flows and turbulent boundary layer flows with and without pressure gradients are calculated. Comparisons with the data from direct numerical simulations and experiments show that the model predictions are excellent for turbulent channel flows and turbulent boundary layers with favorable pressure gradients, good for turbulent boundary layers with zero pressure gradients, and fair for turbulent boundary layer with adverse pressure gradients.

  13. New time scale based k-epsilon model for near-wall turbulence

    NASA Technical Reports Server (NTRS)

    Yang, Z.; Shih, T. H.

    1993-01-01

    A k-epsilon model is proposed for wall bonded turbulent flows. In this model, the eddy viscosity is characterized by a turbulent velocity scale and a turbulent time scale. The time scale is bounded from below by the Kolmogorov time scale. The dissipation equation is reformulated using this time scale and no singularity exists at the wall. The damping function used in the eddy viscosity is chosen to be a function of R(sub y) = (k(sup 1/2)y)/v instead of y(+). Hence, the model could be used for flows with separation. The model constants used are the same as in the high Reynolds number standard k-epsilon model. Thus, the proposed model will be also suitable for flows far from the wall. Turbulent channel flows at different Reynolds numbers and turbulent boundary layer flows with and without pressure gradient are calculated. Results show that the model predictions are in good agreement with direct numerical simulation and experimental data.

  14. A new time scale based k-epsilon model for near wall turbulence

    NASA Technical Reports Server (NTRS)

    Yang, Z.; Shih, T. H.

    1992-01-01

    A k-epsilon model is proposed for wall bonded turbulent flows. In this model, the eddy viscosity is characterized by a turbulent velocity scale and a turbulent time scale. The time scale is bounded from below by the Kolmogorov time scale. The dissipation equation is reformulated using this time scale and no singularity exists at the wall. The damping function used in the eddy viscosity is chosen to be a function of R(sub y) = (k(sup 1/2)y)/v instead of y(+). Hence, the model could be used for flows with separation. The model constants used are the same as in the high Reynolds number standard k-epsilon model. Thus, the proposed model will be also suitable for flows far from the wall. Turbulent channel flows at different Reynolds numbers and turbulent boundary layer flows with and without pressure gradient are calculated. Results show that the model predictions are in good agreement with direct numerical simulation and experimental data.

  15. A Galilean and tensorial invariant k-epsilon model for near wall turbulence

    NASA Technical Reports Server (NTRS)

    Yang, Z.; Shih, T. H.

    1993-01-01

    A k-epsilon model is proposed for wall bounded turbulent flows. In this model, the eddy viscosity is characterized by a turbulent velocity scale and a turbulent time scale. The time scale is bounded from below by the Kolmogorov time scale. The dissipation rate equation is reformulated using this time scale and no singularity exists at the wall. A new parameter R = k/S(nu) is introduced to characterize the damping function in the eddy viscosity. This parameter is determined by local properties of both the mean and the turbulent flow fields and is free from any geometry parameter. The proposed model is then Galilean and tensorial invariant. The model constants used are the same as in the high Reynolds number Standard k-epsilon Model. Thus, the proposed model will also be suitable for flows far from the wall. Turbulent channel flows and turbulent boundary layer flows with and without pressure gradients are calculated. Comparisons with the data from direct numerical simulations and experiments show that the model predictions are excellent for turbulent channel flows and turbulent boundary layers with favorable pressure gradients, good for turbulent boundary layers with zero pressure gradients, and fair for turbulent boundary layer with adverse pressure gradients.

  16. New time scale based k-epsilon model for near-wall turbulence

    NASA Astrophysics Data System (ADS)

    Yang, Z.; Shih, T. H.

    1993-07-01

    A k-epsilon model is proposed for wall bonded turbulent flows. In this model, the eddy viscosity is characterized by a turbulent velocity scale and a turbulent time scale. The time scale is bounded from below by the Kolmogorov time scale. The dissipation equation is reformulated using this time scale and no singularity exists at the wall. The damping function used in the eddy viscosity is chosen to be a function of R(sub y) = (k(sup 1/2)y)/v instead of y(+). Hence, the model could be used for flows with separation. The model constants used are the same as in the high Reynolds number standard k-epsilon model. Thus, the proposed model will be also suitable for flows far from the wall. Turbulent channel flows at different Reynolds numbers and turbulent boundary layer flows with and without pressure gradient are calculated. Results show that the model predictions are in good agreement with direct numerical simulation and experimental data.

  17. Asymptotic behavior of solutions of the renormalization group K-epsilon turbulence model

    NASA Technical Reports Server (NTRS)

    Yakhot, A.; Staroselsky, I.; Orszag, S. A.

    1994-01-01

    Presently, the only efficient way to calculate turbulent flows in complex geometries of engineering interest is to use Reynolds-average Navier-Stokes (RANS) equations. As compared to the original Navier-Stokes problem, these RANS equations posses much more complicated nonlinear structure and may exhibit far more complex nonlinear behavior. In certain cases, the asymptotic behavior of such models can be studied analytically which, aside from being an interesting fundamental problem, is important for better understanding of the internal structure of the models as well as to improve their performances. The renormalization group (RNG) K-epsilon turbulence model, derived directly from the incompresible Navier-Stokes equations, is analyzed. It has already been used to calculate a variety of turbulent and transitional flows in complex geometries. For large values of the RNG viscosity parameter, the model may exhibit singular behavior. In the form of the RNG K-epsilon model that avoids the use of explicit wall functions, a = 1, so the RNG viscosity parameter must be smaller than 23.62 to avoid singularities.

  18. Evidence for apolipoprotein E {epsilon}4 association in early-onset Alzheimer`s patients with late-onset relatives

    SciTech Connect

    Perez-Tur, J.; Delacourte, A.; Chartier-Harlin, M.C.

    1995-12-18

    Recently several reports have extended the apolipoprotein E (APOE) {epsilon}4 association found in late-onset Alzheimer`s disease (LOAD) patients to early-onset (EO) AD patients. We have studied this question in a large population of 119 EOAD patients (onset {<=}60 years) in which family history was carefully assessed and in 109 controls. We show that the APOE {epsilon}A allele frequency is increased only in the subset of patients who belong to families where LOAD secondary cases are present. Our sampling scheme permits us to demonstrate that, for an individual, bearing at least one {epsilon}4 allele increases both the risk of AD before age 60 and the probability of belonging to a family with late-onset affected subjects. Our results suggest that a subset of EOAD cases shares a common determinism with LOAD cases. 19 refs., 3 tabs.

  19. RAYLEIGH-TAYLOR STRENGTH EXPERIMENTS OF THE PRESSURE-INDUCED alpha->epsilon->alpha' PHASE TRANSITION IN IRON

    SciTech Connect

    Belof, J L; Cavallo, R M; Olson, R T; King, R S; Gray, G T; Holtkamp, D B; Chen, S R; Rudd, R E; Barton, N R; Arsenlis, A; Remington, B A; Park, H; Prisbrey, S T; Vitello, P A; Bazan, G; Mikaelian, K O; Comley, A J; Maddox, B R; May, M J

    2011-08-10

    We present here the first dynamic Rayleigh-Taylor (RT) strength measurement of a material undergoing solid-solid phase transition. Iron is quasi-isentropically driven across the pressure-induced bcc ({alpha}-Fe) {yields} hcp ({var_epsilon}-Fe) phase transition and the dynamic strength of the {alpha}, {var_epsilon} and reverted {alpha}{prime} phases have been determined via proton radiography of the resulting Rayleigh-Taylor unstable interface between the iron target and high-explosive products. Simultaneous velocimetry measurements of the iron free surface yield the phase transition dynamics and, in conjunction with detailed hydrodynamic simulations, allow for determination of the strength of the distinct phases of iron. Forward analysis of the experiment via hydrodynamic simulations reveals significant strength enhancement of the dynamically-generated {var_epsilon}-Fe and reverted {alpha}{prime}-Fe, comparable in magnitude to the strength of austenitic stainless steels.

  20. Dose effect of allele {epsilon}4 of apolipoprotein E on risk and age at onset of Pick disease

    SciTech Connect

    Farrer, L.A.; Abraham, C.; Volicer, L.

    1994-09-01

    Pick disease (PD) is a rare progressive dementing illness characterized by severe atrophy of the frontal and temporal lobes. Brains of PD patients lack neurofibrillary tangles which are characteristic findings of Alzheimer disease (AD), but display neuronal swelling and argyrophilic inclusions (i.e., Pick bodies) which contain phosphorylated neurofilaments, tau and complex lipids. Clinically, PD is often difficult to distinguish from AD. The fact that PD is often familial and the evidence suggesting that the {epsilon}4 allele of apoE is a risk factor for AD and multi-infarct dementia prompted us to study apoE isoforms in PD. ApoE genotypes were evaluated in an autopsy series of cases (19 AD, 15 PD, and 7 {open_quotes}controls{close_quotes} with other or no pathology). All subjects were unrelated except for 2 brothers who both had PD. Age at onset in the PD patients ranged from 41 to 59 years. The frequency of {epsilon}4 is significantly higher among AD subjects (47.4%) than in Pick cases (23.3%; P=0.4) or controls (7.1%; P=.008), but the 16% difference between PD and control subjects was not significant, perhaps due to small sample sizes. Linear regression analysis showed that the number of {epsilon}4 alleles was inversely related to age at onset of PD (P=.04) and accounted for 27% of the variation in age at onset. These results suggest that {epsilon}4 may be a susceptibility factor for dementia and not specifically AD. Preliminary experiments using an antibody against apoE suggest that Pick bodies may be immunoreactive with this antibody and that apoE binds to abnormal filaments. The association of the {epsilon}4 allele with dementias other than AD and the apoE staining results support a model postulating an interaction between the {epsilon}4 isoform and tau.

  1. Evolution of octupole correlations in 123Ba

    NASA Astrophysics Data System (ADS)

    Chen, X. C.; Zhao, J.; Xu, C.; Hua, H.; Shneidman, T. M.; Zhou, S. G.; Wu, X. G.; Li, X. Q.; Zhang, S. Q.; Li, Z. H.; Liang, W. Y.; Meng, J.; Xu, F. R.; Qi, B.; Ye, Y. L.; Jiang, D. X.; Cheng, Y. Y.; He, C.; Sun, J. J.; Han, R.; Niu, C. Y.; Li, C. G.; Li, P. J.; Wang, C. G.; Wu, H. Y.; Li, Z. H.; Zhou, H.; Hu, S. P.; Zhang, H. Q.; Li, G. S.; He, C. Y.; Zheng, Y.; Li, C. B.; Li, H. W.; Wu, Y. H.; Luo, P. W.; Zhong, J.

    2016-08-01

    High-spin states of 123Ba have been studied via the 108Cd(19F,3 n p )123Ba fusion-evaporation reaction at a beam energy of 90 MeV. Several E 1 transitions linking the positive-parity ν (d5 /2+g7 /2) band and negative-parity ν h11 /2 band are observed in 123Ba for the first time. Evidence for the existence of octupole correlations in 123Ba is presented based on the systematic comparisons of the B (E 1 )/B (E 2 ) branching ratios and the energy displacements in odd-A Ba isotopes. The characteristics of octupole correlation in the odd-A Ba,125123 are explained by the state-of-the-art multidimensionally-constrained relativistic mean-field model and cluster model based on the dinuclear system concept.

  2. Ba{sub 2}phenanthrene is the main component in the Ba-doped phenanthrene superconductor

    SciTech Connect

    Yan, Xun-Wang; Huang, Zhongbing; Lin, Hai-Qing

    2014-12-14

    We have systematically investigated the crystal structure of Ba-doped phenanthrene with various Ba doping levels by the first-principles calculations combined with the X-ray diffraction (XRD) spectra simulations. Although the experimental stoichiometry ratio of Ba atom and phenanthrene molecule is 1.5:1, the simulated XRD spectra, space group symmetry and optimized lattice parameters of Ba{sub 1.5}phenanthrene are not consistent with the experimental ones, while the results for Ba{sub 2}phenanthrene are in good agreement with the measurements. The strength difference of a few XRD peaks can be explained by the existence of pristine phenanthrene. Our findings suggest that instead of uniform Ba{sub 1.5}phenanthrene, there coexist Ba{sub 2}phenanthrene and undoped phenanthrene in the superconducting sample. The electronic calculations indicate that Ba{sub 2}phenanthrene is a semiconductor with a small energy gap less than 0.05 eV.

  3. Quantum oscillations in iron-based superconductors: BaFe2As2 vs. KFe2As2

    NASA Astrophysics Data System (ADS)

    Terashima, Taichi; Kurita, Nobuyuki; Kimata, Motoi; Tomita, Megumi; Tsuchiya, Satoshi; Satsukawa, Hidetaka; Harada, Atsushi; Hazama, Kaori; Imai, Motoharu; Sato, Akira; Uji, Shinya; Kihou, Kunihiro; Lee, Chul-Ho; Kito, Hijiri; Tomioka, Yasuhide; Ito, Toshimitsu; Iyo, Akira; Eisaki, Hiroshi; Liang, Tian; Nakajima, Masamichi; Ishida, Shigeyuki; Uchida, Shin-ichi; Saito, Taku; Fukazawa, Hideto; Kohori, Yoh; Harima, Hisatomo

    2013-07-01

    We present results of Shubnikov-de Haas oscillation measurements on detwinned BaFe2As2 and de Haas-van Alphen oscillation measurements on KFe2As2. The Fermi surface of BaFe2As2 in the antiferromagnetic phase is found to consist of one hole and two electron pockets, all of which are three-dimensional and closed, and can reasonably be accounted for by LSD A band calculations. We find only moderate mass enhancements m*/mband of 2-3. In the case of KFe2As2, four quasi-two-dimensional Fermi surface cylinders epsilon, α, ζ, and β are observed in qualitative agreement with previous ARPES data. In sharp contrast to BaFe2As2, agreement between the observed and LDA-calculated Fermi surface is poor: LDA calculations seem to predict wrong crystal-field splitting of Fe 3d states. Large effective masses up to 20 me, me being the free electron mass, are found. The Sommerfeld coefficient estimated from the observed Fermi surface and effective masses is consistent with the measured value of 93 mJ/K2mol [H. Fukazawa et al., J. Phys. Soc. Jpn. 80, SA118 (2011)] and is 8-9 times larger than the band value, indicating strong electronic correlations in KFe2As2.

  4. Effects of climate and lifeform on dry matter yield (epsilon) from simulations using BIOME BGC. [ecosystem process model for vegetation biomass production using daily absorbed photosynthetically active radiation

    NASA Technical Reports Server (NTRS)

    Hunt, E. R., Jr.; Running, Steven W.

    1992-01-01

    An ecosystem process simulation model, BIOME-BGC, is used in a sensitivity analysis to determine the factors that may cause the dry matter yield (epsilon) and annual net primary production to vary for different ecosystems. At continental scales, epsilon is strongly correlated with annual precipitation. At a single location, year-to-year variation in net primary production (NPP) and epsilon is correlated with either annual precipitation or minimum air temperatures. Simulations indicate that forests have lower epsilon than grasslands. The most sensitive parameter affecting forest epsilon is the total amount of living woody biomass, which affects NPP by increasing carbon loss by maintenance respiration. A global map of woody biomass should significantly improve estimates of global NPP using remote sensing.

  5. Rabies in the Dutch East Indies a century ago - a spatio-temporal case study in disease emergence.

    PubMed

    Ward, Michael P

    2014-04-01

    Rabies continues to spread through the Indonesian archipelago. During the past 20 years, several islands - including Flores, Ambon and Bali - that had historically been free of rabies have become infected. However, the Dutch East Indies (a Dutch colony that became modern Indonesia following World War II) had been infected since the 1880s. The spread of rabies is a lesson in the emergence of an infectious disease. Reports of human cases treated for rabies and livestock rabies cases from the 1880s to 1917 were compiled. The spatial and temporal distribution of these cases was analyzed using maps, spatial statistics and time-series techniques. The first confirmed case of rabies was reported in 1889 from the Batavia [Jakarta] district (although disease suspicion was reported as early as 1884). During the 1890s rabies was already commonly reported from Java and the east coast of Sumatra, and by the late 1890s, from Celebes [Sulawesi]. Between 1900 and 1916, cases were reported from other parts of Java, Sumatra and Sulawesi, and from Borneo, the Moluccas and other outlying islands. Between 1897 and 1916, a total of 8826 human cases treated for rabies were reported and between 1908 and 1917, 1033 livestock cases were reported. Most (97.5%) human cases treated were attributed to rabid dogs. Increasing numbers of reports were observed during the period. Between 1908 and 1916 the correlation between human and livestock case reports was 64.2%, and at the district level it was 75.9%. Moderate correlations (>40%) were found between human cases and livestock cases reported up to six months previously. Based on year of first report from each district, human cases were strongly clustered (Moran's autocorrelation 0.47, P=0.005). The most likely spatio-temporal cluster of reported cases of humans treated for rabies originated from the west coast of Sumatra between 1899 and 1905, and other clusters were identified in west Java (1898-1899), the district of Batavia and in east Java

  6. Comparative risk assessments for the city of Pointe-à-Pitre (French West Indies): earthquakes and storm surge

    NASA Astrophysics Data System (ADS)

    Reveillere, A. R.; Bertil, D. B.; Douglas, J. D.; Grisanti, L. G.; Lecacheux, S. L.; Monfort, D. M.; Modaressi, H. M.; Müller, H. M.; Rohmer, J. R.; Sedan, O. S.

    2012-04-01

    In France, risk assessments for natural hazards are usually carried out separately and decision makers lack comprehensive information. Moreover, since the cause of the hazard (e.g. meteorological, geological) and the physical phenomenon that causes damage (e.g. inundation, ground shaking) may be fundamentally different, the quantitative comparison of single risk assessments that were not conducted in a compatible framework is not straightforward. Comprehensive comparative risk assessments exist in a few other countries. For instance, the Risk Map Germany project has developed and applied a methodology for quantitatively comparing the risk of relevant natural hazards at various scales (city, state) in Germany. The present on-going work applies a similar methodology to the Pointe-à-Pitre urban area, which represents more than half of the population of Guadeloupe, an overseas region in the French West Indies. Relevant hazards as well as hazard intensity levels differ from continental Europe, which will lead to different conclusions. French West Indies are prone to a large number of hazards, among which hurricanes, volcanic eruptions and earthquakes dominate. Hurricanes cause damage through three phenomena: wind, heavy rainfall and storm surge, the latter having had a preeminent role during the largest historical event in 1928. Seismic risk is characterized by many induced phenomena, among which earthquake shocks dominate. This study proposes a comparison of earthquake and cyclonic storm surge risks. Losses corresponding to hazard intensities having the same probability of occurrence are calculated. They are quantified in a common loss unit, chosen to be the direct economic losses. Intangible or indirect losses are not considered. The methodology therefore relies on (i) a probabilistic hazard assessment, (ii) a loss ratio estimation for the exposed elements and (iii) an economic estimation of these assets. Storm surge hazard assessment is based on the selection of

  7. Contribution to the risk characterization of ciguatoxins: LOAEL estimated from eight ciguatera fish poisoning events in Guadeloupe (French West Indies).

    PubMed

    Hossen, Virginie; Soliño, Lucia; Leroy, Patricia; David, Eric; Velge, Pierre; Dragacci, Sylviane; Krys, Sophie; Flores Quintana, Harold; Diogène, Jorge

    2015-11-01

    From 2010 to 2012, 35 ciguatera fish poisoning (CFP) events involving 87 individuals who consumed locally-caught fish were reported in Guadeloupe (French West Indies). For 12 of these events, the presence of ciguatoxins (CTXs) was indicated in meal remnants and in uncooked fish by the mouse bioassay (MBA). Caribbean ciguatoxins (C-CTXs) were confirmed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. Using a cell-based assay (CBA), and the only available standard Pacific ciguatoxin-1 (P-CTX-1), the lowest toxins level detected in fish samples causing CFP was 0.022 µg P-CTX-1 equivalent (eq.)·kg(-1) fish. Epidemiological and consumption data were compiled for most of the individuals afflicted, and complete data for establishing the lowest observable adverse effects level (LOAEL) were obtained from 8 CFP events involving 21 individuals. Based on toxin intakes, the LOAEL was estimated at 4.2 ng P-CTX-1 eq./individual corresponding to 48. 4 pg P-CTX-1 eq.kg(-1) body weight (bw). Although based on limited data, these results are consistent with the conclusions of the European Food Safety Authority (EFSA) opinion which indicates that a level of 0.01 µg P-CTX-1 eq.kg(-1) fish, regardless of source, should not exert effects in sensitive individuals when consuming a single meal. The calculated LOAEL is also consistent with the U.S. Food and Drug Administration guidance levels for CTXs (0.1 µg C-CTX-1 eq.kg(-1) and 0.01 µg P-CTX-1 eq.kg(-1) fish). PMID:26409497

  8. Microbiological hazard analysis of ready-to-eat meats processed at a food plant in Trinidad, West Indies

    PubMed Central

    Syne, Stacey-Marie; Ramsubhag, Adash; Adesiyun, Abiodun A.

    2013-01-01

    Background A bacteriological assessment of the environment and food products at different stages of processing was conducted during the manufacture of ready-to-eat (RTE) chicken franks, chicken bologna and bacon at a large meat processing plant in Trinidad, West Indies. Methods Samples of air, surfaces (swabs), raw materials, and in-process and finished food products were collected during two separate visits for each product type and subjected to qualitative or quantitative analysis for bacterial zoonotic pathogens and fecal indicator organisms. Results Staphylococcus aureus was the most common pathogen detected in pre-cooked products (mean counts = 0.66, 1.98, and 1.95 log10CFU/g for franks, bologna, and bacon, respectively). This pathogen was also found in unacceptable levels in 4 (16.7%) of 24 post-cooked samples. Fifty percent (10 of 20) of pre-cooked mixtures of bacon and bologna were contaminated with Listeria spp., including four with L. monocytogenes. Pre-cooked mixtures of franks and bologna also contained E. coli (35 and 0.72 log10 CFU/g, respectively) while 5 (12.5%) of 40 pre-cooked mixtures of chicken franks had Salmonella spp. Aerobic bacteria exceeded acceptable international standards in 46 (82.1%) of 56 pre-cooked and 6 (16.7%) of 36 post-cooked samples. Both pre-and post-cooking air and surfaces had relatively high levels of aerobic bacteria, Staphylococcus aureus and coliforms, including equipment and gloves of employees. A drastic decrease in aerobic counts and Staphylococcus aureus levels following heat treatment and subsequent increase in counts of these bacteria are suggestive of post-cooking contamination. Conclusion A relatively high level of risk exists for microbial contamination of RTE meats at the food plant investigated and there is a need for enhancing the quality assurance programs to ensure the safety of consumers of products manufactured at this plant. PMID:23878681

  9. Knowledge, Beliefs and Practices of Patients with Diabetic Retinopathy at the University Hospital of the West Indies, Jamaica.

    PubMed

    Foster, Tecah; Mowatt, Lizette; Mullings, Jasneth

    2016-06-01

    To determine the knowledge, beliefs and practices of patients with diabetic retinopathy attending the Retina Eye Clinic at the University Hospital of the West Indies. A prospective study was done using a questionnaire with a sample population of 150 patients. The questions included their knowledge about the frequency of their eye examination, the relevance of exercise and a healthy diet, the role of the ophthalmologist and their views on the importance of compliance with medications for diabetes and hypertension. One hundred and fifty patients were recruited. Sixty six percent (99/150) were females and 34 % (51/150) males. The ages ranged from 29 to 83 years (mean ± SD, 56.1 ± 10.3) years. Type II diabetes was more common; 63 and 79 % of females and males respectively. A minority (19.8 %) obtained tertiary education. The mean % knowledge scores were 86 ± 14 for males and 82.8 ± 16.4 for females (p = 0.260). Prior to attending the retina clinic, 50 % were unaware of the need for annual eye examinations. Compliance with medication, exercise and a special diet was seen in 73, 40.3 and 49.7 % respectively. Current knowledge scores were good. However, knowledge about the timing and frequency of eye examinations prior to attending the retina clinic was inadequate. Correct knowledge and beliefs did not correspond to a high level of compliant practices. PMID:26684738

  10. Effect of particle size on in-die and out-of-die compaction behavior of ranitidine hydrochloride polymorphs.

    PubMed

    Khomane, Kailas S; Bansal, Arvind K

    2013-09-01

    The present study investigates the effect of particle size on compaction behavior of forms I and II of ranitidine hydrochloride. Compaction studies were performed using three particle size ranges [450-600 (A), 300-400 (B), and 150-180 (C) μm] of both the forms, using a fully instrumented rotary tableting machine. Compaction data were analyzed for out-of-die compressibility, tabletability, and compactibility profiles and in-die Heckel and Kawakita analysis. Tabletability of the studied size fractions followed the order; IB > IA > > IIC > IIB > IIA at all the compaction pressures. In both the polymorphs, decrease in particle size improved the tabletability. Form I showed greater tabletability over form II at a given compaction pressure and sized fraction. Compressibility plot and Heckel and Kawakita analysis revealed greater compressibility and deformation behavior of form II over form I at a given compaction pressure and sized fraction. Decrease in particle size increased the compressibility and plastic deformation of both the forms. For a given polymorph, improved tabletability of smaller sized particles was attributed to their increased compressibility. However, IA and IB, despite poor compressibility and deformation, showed increased tabletability over IIA, IIB, and IIC by virtue of their greater compactibility. Microtensile testing also revealed higher nominal fracture strength of form I particles over form II, thus, supporting greater compactibility of form I. Taken as a whole, though particle size exhibited a trend on tabletability of individual forms, better compactibility of form I over form II has an overwhelming impact on tabletability. PMID:23897036

  11. Plant-hummingbird interactions in the West Indies: floral specialisation gradients associated with environment and hummingbird size.

    PubMed

    Dalsgaard, Bo; Martín González, Ana M; Olesen, Jens M; Ollerton, Jeff; Timmermann, Allan; Andersen, Laila H; Tossas, Adrianne G

    2009-04-01

    Floral phenotype and pollination system of a plant may be influenced by the abiotic environment and the local pollinator assemblage. This was investigated in seven plant-hummingbird assemblages on the West Indian islands of Grenada, Dominica and Puerto Rico. We report all hummingbird and insect pollinators of 49 hummingbird-pollinated plant species, as well as six quantitative and semi-quantitative floral characters that determine visitor restriction, attraction and reward. Using nonmetric multidimensional scaling analysis, we show that hummingbird-pollinated plants in the West Indies separate in floral phenotypic space into two gradients-one associated with the abiotic environment and another with hummingbird size. Plants pollinated by large, long-billed hummingbirds had flowers with long corolla tube, large amounts of nectar and showy orange-red colouration. These attracted few or no insect species, whereas plants pollinated by small, short-billed hummingbirds were frequently pollinated by insects, particularly lepidopterans. The separation of plants related to environmental factors showed that species in the wet and cold highlands produced large amounts of dilute nectar, possessed no or a weak odour, and were associated with few insects, particularly few hymenopterans, compared to plants in the dry and warm lowlands. The most specialised hummingbird-pollinated plants are found in the West Indian highlands where they are pollinated by mainly large, long-billed hummingbirds. At the other extreme, highly generalised plants growing in the dry and warm lowlands are pollinated by small, short-billed hummingbirds and numerous insect species. This illustrates that, even within the hummingbird-pollinated flora, pollination syndrome and the degree of specialisation may vary tremendously depending on pollinator morphology and environment. PMID:19132403

  12. EFFECTS OF "SWIM WITH THE TURTLES" TOURIST ATTRACTIONS ON GREEN SEA TURTLE (CHELONIA MYDAS) HEALTH IN BARBADOS, WEST INDIES.

    PubMed

    Stewart, Kimberly; Norton, Terry; Mohammed, Hamish; Browne, Darren; Clements, Kathleen; Thomas, Kirsten; Yaw, Taylor; Horrocks, Julia

    2016-04-01

    Along the West Coast of Barbados a unique relationship has developed between endangered green sea turtles (Chelonia mydas) and humans. Fishermen began inadvertently provisioning these foraging turtles with fish offal discarded from their boats. Although initially an indirect supplementation, this activity became a popular attraction for visitors. Subsequently, demand for this activity increased, and direct supplementation or provisioning with food began. Food items offered included raw whole fish (typically a mixture of false herring [Harengula clupeola] and pilchard [Harengula humeralis]), filleted fish, and lesser amounts of processed food such as hot dogs, chicken, bread, or various other leftovers. Alterations in behavior and growth rates as a result of the provisioning have been documented in this population. The purpose of this study was to determine how tourism-based human interactions are affecting the overall health of this foraging population and to determine what potential health risks these interactions may create for sea turtles. Juvenile green sea turtles (n=29) were captured from four sites off the coast of Barbados, West Indies, and categorized into a group that received supplemental feeding as part of a tour (n=11) or an unsupplemented group (n=18) that consisted of individuals that were captured at sites that did not provide supplemental feeding. Following capture, a general health assessment of each animal was conducted. This included weight and morphometric measurements, a systematic physical examination, determination of body condition score and body condition index, epibiota assessment and quantification, and clinical pathology including hematologic and biochemical testing and nutritional assessments. The supplemented group was found to have changes to body condition, vitamin, mineral, hematologic, and biochemical values. Based on these results, recommendations were made to decrease negative behaviors and health impacts for turtles as a result

  13. Microencapsulation of superoxide dismutase into poly(epsilon-caprolactone) microparticles by reverse micelle solvent evaporation.

    PubMed

    Youan, Bi-Botti Célestin

    2003-01-01

    The aim of this work was to encapsulate superoxide dismutase (SOD) in poly(epsilon-caprolactone) (PCL) microparticles by reverse micelle solvent evaporation. The concentration of PCL, the hydrophile-lipophile balance (HLB), and concentration of the sucrose ester used as surfactant in the organic phase were investigated as formulation variables. Relatively higher encapsulation efficiency (approximately 48%) and retained enzymatic activity (>90%) were obtained with microparticle formulation made from the 20% (w/v) PCL and 0.05% (w/v) sucrose ester of HLB = 6. This formulation allowed the in vitro release of SOD for at least 72 hr. These results showed that reverse micelle solvent evaporation can be used to efficiently encapsulate SOD in PCL microparticles. Such formulations may improve the bioavailability of SOD. PMID:14612345

  14. Goos-Hänchen shift of partially coherent light fields in epsilon-near-zero metamaterials.

    PubMed

    Ziauddin; Chuang, You-Lin; Qamar, Sajid; Lee, Ray-Kuang

    2016-01-01

    The Goos-Hänchen (GH) shifts in the reflected light are investigated both for p and s polarized partial coherent light beams incident on epsilon-near-zero (ENZ) metamaterials. In contrary to the coherent counterparts, the magnitude of GH shift becomes non-zero for p polarized partial coherent light beam; while GH shift can be relatively large with a small degree of spatial coherence for s polarized partial coherent beam. Dependence on the beam width and the permittivity of ENZ metamaterials is also revealed for partial coherent light fields. Our results on the GH shifts provide a direction on the applications for partial coherent light sources in ENZ metamaterials. PMID:27211050

  15. Goos-Hänchen shift of partially coherent light fields in epsilon-near-zero metamaterials

    PubMed Central

    Ziauddin; Chuang, You-Lin; Qamar, Sajid; Lee, Ray-Kuang

    2016-01-01

    The Goos-Hänchen (GH) shifts in the reflected light are investigated both for p and s polarized partial coherent light beams incident on epsilon-near-zero (ENZ) metamaterials. In contrary to the coherent counterparts, the magnitude of GH shift becomes non-zero for p polarized partial coherent light beam; while GH shift can be relatively large with a small degree of spatial coherence for s polarized partial coherent beam. Dependence on the beam width and the permittivity of ENZ metamaterials is also revealed for partial coherent light fields. Our results on the GH shifts provide a direction on the applications for partial coherent light sources in ENZ metamaterials. PMID:27211050

  16. Experimental verification of epsilon-near-zero plasmon polariton modes in degenerately doped semiconductor nanolayers

    DOE PAGESBeta

    Campione, Salvatore; Kim, Iltai; de Ceglia, Domenico; Keeler, Gordon A.; Luk, Ting S.

    2016-01-01

    Here, we investigate optical polariton modes supported by subwavelength-thick degenerately doped semiconductor nanolayers (e.g. indium tin oxide) on glass in the epsilon-near-zero (ENZ) regime. The dispersions of the radiative (R, on the left of the light line) and non-radiative (NR, on the right of the light line) ENZ polariton modes are experimentally measured and theoretically analyzed through the transfer matrix method and the complex-frequency/real-wavenumber analysis, which are in remarkable agreement. We observe directional near-perfect absorption using the Kretschmann geometry for incidence conditions close to the NR-ENZ polariton mode dispersion. Along with field enhancement, this provides us with an unexplored pathwaymore » to enhance nonlinear optical processes and to open up directions for ultrafast, tunable thermal emission.« less

  17. Epsilon-Near-Zero Modes for Tailored Light-Matter Interaction

    NASA Astrophysics Data System (ADS)

    Campione, Salvatore; Liu, Sheng; Benz, Alexander; Klem, John F.; Sinclair, Michael B.; Brener, Igal

    2015-10-01

    Epsilon-near-zero (ENZ) modes arising from condensed-matter excitations such as phonons and plasmons are a new path for tailoring light-matter interactions at the nanoscale. Complex spectral shaping can be achieved by creating such modes in nanoscale semiconductor layers and controlling their interaction with multiple, distinct, dipole resonant systems. Examples of this behavior are presented at midinfrared frequencies for ENZ modes that are strongly coupled to metamaterial resonators and simultaneously strongly coupled to semiconductor phonons or quantum-well intersubband transitions (ISTs), resulting in double- and triple-polariton branches in transmission spectra. For the double-polariton branch case, we find that the best strategy to maximize the Rabi splitting is to use a combination of a doped layer supporting an ENZ feature and a layer supporting ISTs, with overlapping ENZ and IST frequencies. This design flexibility renders this platform attractive for low-voltage tunable filters, light-emitting diodes, and efficient nonlinear composite materials.

  18. PRKCE gene encoding protein kinase C-epsilon-Dual roles at sarcomeres and mitochondria in cardiomyocytes.

    PubMed

    Scruggs, Sarah B; Wang, Ding; Ping, Peipei

    2016-09-15

    Protein kinase C-epsilon (PKCε) is an isoform of a large PKC family of enzymes that has a variety of functions in different cell types. Here we discuss two major roles of PKCε in cardiac muscle cells; specifically, its role in regulating cardiac muscle contraction via targeting the sarcomeric proteins, as well as modulating cardiac cell energy production and metabolism by targeting cardiac mitochondria. The importance of PKCε action is described within the context of intracellular localization, as substrate selectivity and specificity is achieved through spatiotemporal targeting of PKCε. Accordingly, the role of PKCε in regulating myocardial function in physiological and pathological states has been documented in both cardioprotection and cardiac hypertrophy. PMID:27312950

  19. One-Dimensional Chirality: Strong Optical Activity in Epsilon-Near-Zero Metamaterials.

    PubMed

    Rizza, Carlo; Di Falco, Andrea; Scalora, Michael; Ciattoni, Alessandro

    2015-07-31

    We suggest that electromagnetic chirality, generally displayed by 3D or 2D complex chiral structures, can occur in 1D patterned composites whose components are achiral. This feature is highly unexpected in a 1D system which is geometrically achiral since its mirror image can always be superposed onto it by a 180 deg rotation. We analytically evaluate from first principles the bianisotropic response of multilayered metamaterials and we show that the chiral tensor is not vanishing if the system is geometrically one-dimensional chiral; i.e., its mirror image cannot be superposed onto it by using translations without resorting to rotations. As a signature of 1D chirality, we show that 1D chiral metamaterials support optical activity and we prove that this phenomenon undergoes a dramatic nonresonant enhancement in the epsilon-near-zero regime where the magnetoelectric coupling can become dominant in the constitutive relations. PMID:26274441

  20. Middle Atmosphere Cooperation/Summer in Northern Europe (MAC/SINE) and MAC/Epsilon

    NASA Technical Reports Server (NTRS)

    Thrane, E. V.

    1989-01-01

    Two major international campaigns dedicated to the study of middle atmosphere dynamics in high latitudes were successfully completed in 1987. MAC/SINE (Middle Atmosphere Cooperation/Summer in Northern Europe) was carried out during the period 7 June to 19 July, whereas MAC/Epsilon took place in the period 12 October to 15 November. In both campaigns a large number of ground based and rocket techniques were used in a concerted effort to map the dynamical structure of the middle atmosphere over Northern Europe. Although the analysis of the observations has only just started, it is clear that a large and unique data set was obtained, which is believed will provide new insight into the dynamical processes in this interesting region of the atmosphere. A brief overview of the campaigns, their scientific aims, organization and structure is presented.

  1. Occultation of Epsilon Geminorum by Mars. III - Temperature structure of the Martian upper atmosphere

    NASA Technical Reports Server (NTRS)

    French, R. G.; Elliot, J. L.

    1979-01-01

    High-quality photoelectric observations of the April 8, 1976, occultation of Epsilon Gem by Mars are analyzed which were obtained at five different observatories. Temperature profiles are derived by numerical inversion of the star's light curves and found to be in mutual agreement. This is taken as evidence for the presence of strong atmospheric waves in the Martial upper atmosphere between number densities of 10 to the 13th and 10 to the 15th per cu cm. It is estimated that the vertical wavelength is about 20 km, the horizontal wavelength is greater than 600 km, and the peak-to-peak wave amplitude is approximately 40 K. The results are shown to be qualitatively consistent with Zurek's (1976) model of thermally driven tidal modes. No compelling evidence for turbulence effects is found in the occultation data.

  2. Metamaterial-based lossy anisotropic epsilon-near-zero medium for energy collimation

    NASA Astrophysics Data System (ADS)

    Shen, Nian-Hai; Zhang, Peng; Koschny, Thomas; Soukoulis, Costas M.

    2016-06-01

    A lossy anisotropic epsilon-near-zero (ENZ) medium may lead to a counterintuitive phenomenon of omnidirectional bending-to-normal refraction [S. Feng, Phys. Rev. Lett. 108, 193904 (2012), 10.1103/PhysRevLett.108.193904], which offers a fabulous strategy for energy collimation and energy harvesting. Here, in the scope of effective medium theory, we systematically investigate two simple metamaterial configurations, i.e., metal-dielectric-layered structures and the wire medium, to explore the possibility of fulfilling the conditions of such an anisotropic lossy ENZ medium by playing with materials' parameters. Both realistic metamaterial structures and their effective medium equivalences have been numerically simulated, and the results are in excellent agreement with each other. Our study provides clear guidance and therefore paves the way towards the search for proper designs of anisotropic metamaterials for a decent effect of energy collimation and wave-front manipulation.

  3. IUE observations of cool stars - Alpha Aurigae, HR1099, Lambda Andromedae, and Epsilon Eridani

    NASA Technical Reports Server (NTRS)

    Linsky, J. L.; Ayres, T. R.; Basri, G. S.; Morrison, N. D.; Boggess, A.; Schiffer, F. H., III; Holm, A.; Cassatella, A.; Heck, A.; Macchetto, F.

    1978-01-01

    Initial IUE observations of four cool stars are reported. Observed fluxes and surface fluxes are given for several UV emission lines in the spectral range 1175-2000 A, obtained at low and high dispersion with the short-wavelength spectrograph and camera. These lines are formed in the outer atmospheres of these stars, in regions presumably analogous to the solar chromosphere and transition region. The surface fluxes in the lines increase along the sequence: quiet sun, Epsilon Eri, Lambda And, Alpha Aur, and HR1099. The 2.8-d RS CVn-type binary HR1099, observed on 1 March 1978 near the end of a major flaring episode, has line surface fluxes roughly 100 times that of the quiet sun, similar to those seen in solar flares. Line profiles and flux ratios in multiplets for Capella are presented, and comments given on the opacity of the lines and on a tendency of line width to increase with temperature of formation.

  4. Goos-Hänchen effect in epsilon-near-zero metamaterials

    PubMed Central

    Xu, Yadong; Chan, C. T.; Chen, Huanyang

    2015-01-01

    Light reflection and refraction at an interface between two homogeneous media is analytically described by Snell's law. For a beam with a finite waist, it turns out that the reflected wave experiences a lateral displacement from its position predicted by geometric optics. Such Goos-Hänchen (G-H) effect has been extensively investigated among all kinds of optical media, such as dielectrics, metals, photonic crystals and metamaterials. As a fundamental physics phenomenon, the G-H effect has been extended to acoustics and quantum mechanics. Here we report the unusual G-H effect in zero index metamaterials. We show that when linearly polarized light is obliquely incident from air to epsilon-near-zero metamaterials, no G-H effect could be observed for p polarized light. While for s polarization, the G-H shift is a constant value for any incident angle. PMID:25731726

  5. Experimental verification of epsilon-near-zero plasmon polariton modes in degenerately doped semiconductor nanolayers.

    PubMed

    Campione, Salvatore; Kim, Iltai; de Ceglia, Domenico; Keeler, Gordon A; Luk, Ting S

    2016-08-01

    We investigate optical polariton modes supported by subwavelength-thick degenerately doped semiconductor nanolayers (e.g. indium tin oxide) on glass in the epsilon-near-zero (ENZ) regime. The dispersions of the radiative (R, on the left of the light line) and non-radiative (NR, on the right of the light line) ENZ polariton modes are experimentally measured and theoretically analyzed through the transfer matrix method and the complex-frequency/real-wavenumber analysis, which are in remarkable agreement. We observe directional near-perfect absorption using the Kretschmann geometry for incidence conditions close to the NR-ENZ polariton mode dispersion. Along with field enhancement, this provides us with an unexplored pathway to enhance nonlinear optical processes and to open up directions for ultrafast, tunable thermal emission. PMID:27505841

  6. Field-effect optical modulation based on epsilon-near-zero conductive oxide

    NASA Astrophysics Data System (ADS)

    Shi, Kaifeng; Lu, Zhaolin

    2016-07-01

    Epsilon-near-zero (ENZ, dielectric constant εr ≈ 0) materials have attracted significant research interest, however, their applications in the near-infrared regime are very limited. Conductive oxide (COx), owing to its moderate carrier concentration, is a candidate for ENZ material at telecom wavelengths based on the Drude model. Herein, we report an indium tin oxide (ITO) thin film as an ENZ material with cross-over wavelength, where real part of permittivity crosses zero, and enhanced light absorption at telecom wavelengths. We also report the investigation of electro-absorption modulation based on a metal-oxide-semiconductor (MOS)-like structure, more specifically a metal-oxide-ITO stack, where ITO works around ENZ. Based on the attenuated total reflectance (ATR) configuration, our test shows great promise for future electro-optical (EO) modulators. The operation speed of the MOS-like structure is limited mainly by RC delay.

  7. Pathogenesis of brain damage produced in sheep by Clostridium perfringens type D epsilon toxin: a review.

    PubMed

    Finnie, J W

    2003-04-01

    Microvascular endothelial damage by the epsilon toxin of Clostridium perfringens type D appears to be the fundamental cause of cerebral parenchymal injury and lesions occur in a seemingly dose- and time-dependent manner. Large doses of circulating toxin produce a severe, generalised, vasogenic cerebral oedema and an acute or peracute clinical course to death. With lower doses of toxin, or in partially immune sheep, focal necrosis, often bilaterally symmetrical, occurs in certain selectively vulnerable brain regions, which appear to become fewer as the toxin dose is reduced. These cases follow a more protracted clinical course, but death is the usual outcome. The precise pathogenesis of the focal brain damage found in subacutely intoxicated sheep is unresolved, but several possible mechanisms are discussed. PMID:15080445

  8. Crystal Level Continuum Modeling of Phase Transformations: The (alpha) <--> (epsilon) Transformation in Iron

    SciTech Connect

    Barton, N R; Benson, D J; Becker, R; Bykov, Y; Caplan, M

    2004-10-18

    We present a crystal level model for thermo-mechanical deformation with phase transformation capabilities. The model is formulated to allow for large pressures (on the order of the elastic moduli) and makes use of a multiplicative decomposition of the deformation gradient. Elastic and thermal lattice distortions are combined into a single lattice stretch to allow the model to be used in conjunction with general equation of state relationships. Phase transformations change the mass fractions of the material constituents. The driving force for phase transformations includes terms arising from mechanical work, from the temperature dependent chemical free energy change on transformation, and from interaction energy among the constituents. Deformation results from both these phase transformations and elasto-viscoplastic deformation of the constituents themselves. Simulation results are given for the {alpha} to {epsilon} phase transformation in iron. Results include simulations of shock induced transformation in single crystals and of compression of polycrystals. Results are compared to available experimental data.

  9. Design of matched zero-index metamaterials using nonmagnetic inclusions in epsilon-near-zero media

    SciTech Connect

    Silveirinha, Mario; Engheta, Nader

    2007-02-15

    In this work, we study the electrodynamics of metamaterials that consist of resonant non-magnetic inclusions embedded in an epsilon-near-zero (ENZ) host medium. It is shown that the inclusions can be designed in such a way that both the effective permittivity and permeability of the composite structure are simultaneously zero. Two different metamaterial configurations are studied and analyzed in detail. For a particular class of problems, it is analytically proven that such matched zero-index metamaterials may help improving the transmission through a waveguide bend, and that the scattering parameters may be completely independent of the specific arrangement of the inclusions and of the granularity of the crystal. The proposed concepts are numerically demonstrated at microwaves with a metamaterial realistic realization based on an artificial plasma.

  10. UV-Blue (CCD) and Historic (Photographic) Spectra of epsilon Aurigae - Summary

    NASA Astrophysics Data System (ADS)

    Griffin, R. E.; Stencel, R. E.

    2012-03-01

    While there are numerous "new spectroscopic studies" of epsilon Aurigae reported in this special edition of JAAVSO, the one summarized here is believed to be unique on two counts: it concentrates on the blue and near-UV spectral regions, and it incorporates historical spectra from the previous eclipses of 1983 and 1956. The more data that can be collated, across all wavelength and time base-lines, the more conclusive the final model of this baffling object is likely to be. A more lengthy paper that includes illustrations of the spectra is being prepared for publication elsewhere. This short contribution summarizes the effort that has so far gone into data acquisition and preparation, and the principal results that are now emerging.

  11. Release behaviors of porous poly(butylene succinate)/poly(epsilon-caprolactone) microcapsules containing indomethacin.

    PubMed

    Park, Soo-Jin; Lee, Yun-Mok; Hong, Sung-Kwon

    2006-02-01

    The biodegradable poly(butylene succinate)/poly(epsilon-caprolactone) (PBS/PCL) microcapsules containing indomethacin were prepared by emulsion solvent evaporation method. The morphologies, thermal properties, and release behaviors of PBS/PCL microcapsules were investigated. As a result, the microcapsules exhibited porous and spherical form in the presence of gelatin as a surfactant. From the DSC result, the PBS/PCL microcapsules showed the two exothermic peaks meaning the melting points of PCL and PBS. The results of FT-IR and DSC proved that the PBS and PCL were mixed so that the PBS/PCL microcapsules were composed of two wall-forming materials. And the release rate of indomethacin from the microcapsules was decreased with increasing the PCL content. It was noted that an addition of PCL on the PBS led to the decrease of pore size in the PBS/PCL microcapsules. PMID:16413177

  12. The epsilon Phase in the UO2 of the Oklo Natural Reactors

    SciTech Connect

    S. Utsunomiya and R. Ewing

    2005-04-15

    In spent nuclear fuel (SNF), the metal epsilon phase consists of an alloy of Mo-Ru-Pd-Tc-Rh, occurring at a micron to sub-micron scale. {sup 99}Tc has a long half life (2.13 x 10{sup 5} years) and can be an important contributor to dose in safety assessments of nuclear waste repositories. Under oxidizing conditions, TcO{sub 4}{sup -} is the predominant species of Tc. In this form, Tc is highly soluble and weakly adsorbed onto mineral surfaces. Because the Oklo reactors are 2.0 billion years old, a majority of the {sup 99}Tc formed by natural fission reactions has decayed to {sup 99}Ru. Thus, this study is focused on Ru and the other constituents of the epsilon phase in order to investigate the occurrence and the fate of epsilon phase elements during the corrosion of this natural SNF. Samples from reactor zone (RZ)-10 (836, 819, 687); from RZ-13 (864, 910); from Okklobondo (943) were studied. High resolution transmission electron microscopy (HRTEM) and high-angle annular dark-field scanning TEM (HAADF-STEM) with energy dispersive X-ray analysis (EDX) were completed on thin foil specimens of uraninite from each reactor zone. Among these samples, no Ru-bearing phase is observed in 910 and 943. A Bi-Pd particle (40-60 nm), froodite, PdBi{sub 2}, occurs with trace amounts of As, Fe, and Te surrounded by an amorphous Pb-rich area (No.864). A Ru-As particle ({approx}300nm) occurs surrounded by Pb-rich inclusion (400-500 nm) in uraninite (No.819). Based on EDX analysis the composition is: As, 59.9 Co, 2.5: Ni, 5.2; Ru, 18.6; Th, 8.4; Pd, 3.1; Sb, 2.4 in atomic%. The Ru-As phase is not a single particle, but an aggregate of 100-200 nm-sized ruthenarsenite, (Ru,Ni)As, particles. Another Ru-particle (600-700 nm) shows that Pb occurs at the core of the particle, and the rim portion consists of Ni, Co, and As without Ru (No.819). Ru-particles, ruthenarsenite, occur with Ni between the core and the rim. A Mo-particle (< 50 nm) is embedded in a polycrystalline galena (No.836). A

  13. 1,2-diketones promoted degradation of poly(epsilon-caprolactone)

    SciTech Connect

    Danko, Martin; Borska, Katarina; Ragab, Sherif Shaban; Janigova, Ivica; Mosnacek, Jaroslav

    2012-07-11

    Photochemical reactions of Benzil and Camphorquinone were used for modification of poly({epsilon}-caprolactone) polymer films. Photochemistry of dopants was followed by infrared spectroscopy, changes on polymer chains of matrix were followed by gel permeation chromatography. Benzoyl peroxide was efficiently photochemically generated from benzyl in solid polymer matrix in the presence of air. Following decomposition of benzoyl peroxide led to degradation of matrix. Photochemical transformation of benzil in vacuum led to hydrogen abstraction from the polymer chains in higher extent, which resulted to chains recombination and formation of gel. Photochemical transformation of camphorquinone to corresponding camphoric peroxide was not observed. Only decrease of molecular weight of polymer matrix doped with camphorquinone was observed during the irradiation.

  14. Hydrolytic degradation study of biodegradable polyesteramide copolymers based on epsilon-caprolactone and 11-aminoundecanoic acid.

    PubMed

    Qian, Zhiyong; Li, Sai; He, Yi; Zhang, Hailian; Liu, Xiaobo

    2004-05-01

    In this paper, a new kind of aliphatic biodegradable polyesteramide copolymers P(CL/AU)x/y based on epsilon-caprolactone and 11-aminoundecanoic acid were synthesized by the melt polycondensation method. Hydrolytic degradation behavior of P(CL/AU) copolymers were studied by using FTIR, 1H-NMR and DSC. Chemical compositions, macromolecular weight, thickness of the test sample, and pH of the degradation medium have great effect on degradation rate. The degradation rate decreased with increase in aminoundecanoic acid content, macromolecular weight, and thickness of the test samples, but increased with incubation temperature and pH of the degradation medium. The degradation mechanism was studied according to the mathematical model developed by professor Göpferich. PMID:14741611

  15. Solid-state NMR study of intercalated species in poly(epsilon-caprolactone)/clay nanocomposites.

    PubMed

    Hrobarikova, J; Robert, J-L; Calberg, C; Jérôme, R; Grandjean, J

    2004-10-26

    The structure and dynamics of surfactant and polymer chains in intercalated poly(epsilon-caprolactone)/clay nanocomposites are characterized by (31)P magic-angle spinning (MAS) and (13)C cross-polarization MAS NMR techniques. To obtain hybrid materials with the low polymer content required for this study, in situ intercalative polymerization was performed by adapting a published procedure. After nanocomposite formation, the chain motion of the surfactant is enhanced in the saponite-based materials but reduced in the Laponite ones. Compared to the starting clay, the trans conformer population of the surfactant hydrocarbon chain in the nanocomposite decreases for the saponite systems. Mobility of the polymer chain is higher in the nanocomposites than in the bulk phase. The charge of the modified saponite does not significantly influence chain mobility in the nanocomposites. PMID:15491221

  16. Experimental verification of epsilon-near-zero plasmon polariton modes in degenerately doped semiconductor nanolayers

    SciTech Connect

    Campione, Salvatore; Kim, Iltai; de Ceglia, Domenico; Keeler, Gordon A.; Luk, Ting S.

    2016-01-01

    Here, we investigate optical polariton modes supported by subwavelength-thick degenerately doped semiconductor nanolayers (e.g. indium tin oxide) on glass in the epsilon-near-zero (ENZ) regime. The dispersions of the radiative (R, on the left of the light line) and non-radiative (NR, on the right of the light line) ENZ polariton modes are experimentally measured and theoretically analyzed through the transfer matrix method and the complex-frequency/real-wavenumber analysis, which are in remarkable agreement. We observe directional near-perfect absorption using the Kretschmann geometry for incidence conditions close to the NR-ENZ polariton mode dispersion. Along with field enhancement, this provides us with an unexplored pathway to enhance nonlinear optical processes and to open up directions for ultrafast, tunable thermal emission.

  17. Determinants of bird species richness, endemism, and island network roles in Wallacea and the West Indies: is geography sufficient or does current and historical climate matter?

    PubMed Central

    Dalsgaard, Bo; Carstensen, Daniel W; Fjeldså, Jon; Maruyama, Pietro K; Rahbek, Carsten; Sandel, Brody; Sonne, Jesper; Svenning, Jens-Christian; Wang, Zhiheng; Sutherland, William J

    2014-01-01

    Island biogeography has greatly contributed to our understanding of the processes determining species' distributions. Previous research has focused on the effects of island geography (i.e., island area, elevation, and isolation) and current climate as drivers of island species richness and endemism. Here, we evaluate the potential additional effects of historical climate on breeding land bird richness and endemism in Wallacea and the West Indies. Furthermore, on the basis of species distributions, we identify island biogeographical network roles and examine their association with geography, current and historical climate, and bird richness/endemism. We found that island geography, especially island area but also isolation and elevation, largely explained the variation in island species richness and endemism. Current and historical climate only added marginally to our understanding of the distribution of species on islands, and this was idiosyncratic to each archipelago. In the West Indies, endemic richness was slightly reduced on islands with historically unstable climates; weak support for the opposite was found in Wallacea. In both archipelagos, large islands with many endemics and situated far from other large islands had high importance for the linkage within modules, indicating that these islands potentially act as speciation pumps and source islands for surrounding smaller islands within the module and, thus, define the biogeographical modules. Large islands situated far from the mainland and/or with a high number of nonendemics acted as links between modules. Additionally, in Wallacea, but not in the West Indies, climatically unstable islands tended to interlink biogeographical modules. The weak and idiosyncratic effect of historical climate on island richness, endemism, and network roles indicates that historical climate had little effects on extinction-immigration dynamics. This is in contrast to the strong effect of historical climate observed on the

  18. Systemic administration of an Fcgamma-Fc(epsilon)-fusion protein in house dust mite sensitive nonhuman primates.

    PubMed

    Van Scott, Michael R; Mertsching, Elisabeth; Negrou, Ella; Miles, Jeremy; Stallings, Howard W; Graff, Candace; Kehry, Marilyn R

    2008-09-01

    Crosslinking Fc(epsilon)RI and FcgammaRIIB receptors inhibits mast cell and basophil activation, decreasing mediator release. In this study, a fusion protein incorporating human Fcgamma and Fc(epsilon) domains, hGE2, was shown to inhibit degranulation of human mast cells and basophils, and to exhibit efficacy in a nonhuman primate model of allergic asthma. hGE2 increased the provocative concentration of dust mite aeroallergen that induced an early phase asthmatic response. The treatment effect lasted up to 4 weeks and was associated with reduction in the number of circulating basophils and decreased expression of Fc(epsilon)RI on repopulating basophils. Repeat hGE2 dosing induced production of serum antibodies against human Fcgamma and Fc(epsilon) domains and acute anaphylaxis-like reactions. Immune serum induced histamine release from human IgE or hGE2-treated cord blood-derived mast cells and basophils in vitro. These results indicate that repeat administration with hGE2 induced an antibody response to the human molecule that resulted in activation rather than inhibition of allergic responses. PMID:18583194

  19. Identification of amino acids important for binding of Clostridium perfringens epsilon toxin to host cells and to HAVCR1

    PubMed Central

    Ivie, Susan E.; McClain, Mark S.

    2012-01-01

    Clostridium perfringens epsilon toxin belongs to the aerolysin-like family of pore-forming toxins and is one of the most potent bacterial toxins known. The epsilon toxin causes fatal enterotoxemia in sheep, goats, and possibly humans. Evidence indicates that the toxin binds to protein receptors including hepatitis A virus cellular receptor 1 (HAVCR1), but the region of the toxin responsible for cell binding has not been identified. In the present study, we identify amino acids within the epsilon toxin important for this cell interaction. Site-specific mutagenesis was used to investigate the role of a surface-accessible cluster of aromatic amino acids, and purified mutant proteins were tested in a series of cell-culture assays to assess cytotoxic activity and cell binding. When added to cells, four mutant proteins (Etx-Y29E, Etx-Y30E, Etx-Y36E and Etx-Y196E) were severely impaired in their ability to not only kill host cells, but also in their ability to permeabilize the plasma membrane. Circular dichroism spectroscopy and thermal stability studies revealed that the wild-type and mutant proteins were similarly folded. Additional experiments revealed that these mutant proteins were defective in binding to host cells and to HAVCR1. These data indicate that an amino acid motif including Y29, Y30, Y36, and Y196 is important for the ability of epsilon toxin to interact with cells and HAVCR1. PMID:22938730

  20. Identification of amino acids important for binding of Clostridium perfringens epsilon toxin to host cells and to HAVCR1.

    PubMed

    Ivie, Susan E; McClain, Mark S

    2012-09-25

    Clostridium perfringens epsilon toxin belongs to the aerolysin-like family of pore-forming toxins and is one of the most potent bacterial toxins known. The epsilon toxin causes fatal enterotoxemia in sheep, goats, and possibly humans. Evidence indicates that the toxin binds to protein receptors including hepatitis A virus cellular receptor 1 (HAVCR1), but the region of the toxin responsible for cell binding has not been identified. In the present study, we identify amino acids within the epsilon toxin important for this cell interaction. Site-specific mutagenesis was used to investigate the role of a surface-accessible cluster of aromatic amino acids, and purified mutant proteins were tested in a series of cell-culture assays to assess cytotoxic activity and cell binding. When added to cells, four mutant proteins (Etx-Y29E, Etx-Y30E, Etx-Y36E and Etx-Y196E) were severely impaired in their ability to not only kill host cells, but also in their ability to permeabilize the plasma membrane. Circular dichroism spectroscopy and thermal stability studies revealed that the wild-type and mutant proteins were similarly folded. Additional experiments revealed that these mutant proteins were defective in binding to host cells and to HAVCR1. These data indicate that an amino acid motif including Y29, Y30, Y36, and Y196 is important for the ability of epsilon toxin to interact with cells and HAVCR1. PMID:22938730

  1. Inhibition of proteolytic processing of adenoviral proteins by epsilon-aminocaproic acid and ambenum in adenovirus-infected cells.

    PubMed

    Nosach, Lidiya; Dyachenko, Nataliya; Zhovnovataya, Valentina; Lozinskiy, Miron; Lozitsky, Victor

    2002-01-01

    Maturation of adenovirus particles is markedly affected by proteolytic processing. The possibility for blocking the conversion of precursor structural core protein (preVII) into mature structure protein VII by officinal drugs epsilon-aminocaproic acid and ambenum has been demonstrated in Hep-2 cells infected with adenovirus. Proteolytic processing may be regarded as one of the targets for inhibiting adenovirus reproduction. PMID:12545207

  2. Infrared images of the transiting disk in the epsilon Aurigae system.

    PubMed

    Kloppenborg, Brian; Stencel, Robert; Monnier, John D; Schaefer, Gail; Zhao, Ming; Baron, Fabien; McAlister, Hal; Ten Brummelaar, Theo; Che, Xiao; Farrington, Chris; Pedretti, Ettore; Sallave-Goldfinger, P J; Sturmann, Judit; Sturmann, Laszlo; Thureau, Nathalie; Turner, Nils; Carroll, Sean M

    2010-04-01

    Epsilon Aurigae (epsilon Aur) is a visually bright, eclipsing binary star system with a period of 27.1 years. The cause of each 18-month-long eclipse has been a subject of controversy for nearly 190 years because the companion has hitherto been undetectable. The orbital elements imply that the opaque object has roughly the same mass as the visible component, which for much of the last century was thought to be an F-type supergiant star with a mass of approximately 15M[symbol:see text] (M[symbol:see text], mass of the Sun). The high mass-to-luminosity ratio of the hidden object was originally explained by supposing it to be a hyperextended infrared star or, later, a black hole with an accretion disk, although the preferred interpretation was as a disk of opaque material at a temperature of approximately 500 K, tilted to the line of sight and with a central opening. Recent work implies that the system consists of a low-mass (2.2M[symbol:see text]-3.3M[symbol:see text]) visible F-type star, with a disk at 550 K that enshrouds a single B5V-type star. Here we report interferometric images that show the eclipsing body moving in front of the F star. The body is an opaque disk and appears tilted as predicted. Adopting a mass of 5.9M[symbol:see text] for the B star, we derive a mass of approximately (3.6 +/- 0.7)M[symbol:see text] for the F star. The disk mass is dynamically negligible; we estimate it to contain approximately 0.07M[symbol:see text] (M[symbol:see text], mass of the Earth) if it consists purely of dust. PMID:20376144

  3. Structural analysis of an epsilon-class glutathione transferase from housefly, Musca domestica.

    PubMed

    Nakamura, Chihiro; Yajima, Shunsuke; Miyamoto, Toru; Sue, Masayuki

    2013-01-25

    Glutathione transferases (GSTs) play an important role in the detoxification of insecticides, and as such, they are a key contributor to enhanced resistance to insecticides. In the housefly (Musca domestica), two epsilon-class GSTs (MdGST6A and MdGST6B) that share high sequence homology have been identified, which are believed to be involved in resistance against insecticides. The structural determinants controlling the substrate specificity and enzyme activity of MdGST6s are unknown. The aim of this study was to crystallize and perform structural analysis of the GST isozyme, MdGST6B. The crystal structure of MdGST6B complexed with reduced glutathione (GSH) was determined at a resolution of 1.8 Å. MdGST6B was found to have a typical GST folding comprised of N-terminal and C-terminal domains. Arg113 and Phe121 on helix 4 were shown to protrude into the substrate binding pocket, and as a result, the entrance of the substrate binding pocket was narrower compared to delta- and epsilon-class GSTs from Africa malaria vector Anopheles gambiae, agGSTd1-6 and agGSTe2, respectively. This substrate pocket narrowing is partly due to the presence of a π-helix in the middle of helix 4. Among the six residues that donate hydrogen bonds to GSH, only Arg113 was located in the C-terminal domain. Ala substitution of Arg113 did not have a significant effect on enzyme activity, suggesting that the Arg113 hydrogen bond does not play a crucial role in catalysis. On the other hand, mutation at Phe108, located just below Arg113 in the binding pocket, reduced the affinity and catalytic activity to both GSH and the electrophilic co-substrate, 1-chloro-2,4-dinitrobenzene. PMID:23268341

  4. Clostridium Perfringens Epsilon Toxin Binds to Membrane Lipids and Its Cytotoxic Action Depends on Sulfatide

    PubMed Central

    Gil, Carles; Dorca-Arévalo, Jonatan; Blasi, Juan

    2015-01-01

    Epsilon toxin (Etx) is one of the major lethal toxins produced by Clostridium perfringens types B and D, being the causal agent of fatal enterotoxemia in animals, mainly sheep and goats. Etx is synthesized as a non-active prototoxin form (proEtx) that becomes active upon proteolytic activation. Etx exhibits a cytotoxic effect through the formation of a pore in the plasma membrane of selected cell targets where Etx specifically binds due to the presence of specific receptors. However, the identity and nature of host receptors of Etx remain a matter of controversy. In the present study, the interactions between Etx and membrane lipids from the synaptosome-enriched fraction from rat brain (P2 fraction) and MDCK cell plasma membrane preparations were analyzed. Our findings show that both Etx and proEtx bind to lipids extracted from lipid rafts from the two different models as assessed by protein-lipid overlay assay. Lipid rafts are membrane microdomains enriched in cholesterol and sphingolipids. Binding of proEtx to sulfatide, phosphatidylserine, phosphatidylinositol (3)-phosphate and phosphatidylinositol (5)-phosphate was detected. Removal of the sulphate groups via sulfatase treatment led to a dramatic decrease in Etx-induced cytotoxicity, but not in proEtx-GFP binding to MDCK cells or a significant shift in oligomer formation, pointing to a role of sulfatide in pore formation in rafts but not in toxin binding to the target cell membrane. These results show for the first time the interaction between Etx and membrane lipids from host tissue and point to a major role for sulfatides in C. perfringens epsilon toxin pathophysiology. PMID:26452234

  5. Clostridium Perfringens Epsilon Toxin Binds to Membrane Lipids and Its Cytotoxic Action Depends on Sulfatide.

    PubMed

    Gil, Carles; Dorca-Arévalo, Jonatan; Blasi, Juan

    2015-01-01

    Epsilon toxin (Etx) is one of the major lethal toxins produced by Clostridium perfringens types B and D, being the causal agent of fatal enterotoxemia in animals, mainly sheep and goats. Etx is synthesized as a non-active prototoxin form (proEtx) that becomes active upon proteolytic activation. Etx exhibits a cytotoxic effect through the formation of a pore in the plasma membrane of selected cell targets where Etx specifically binds due to the presence of specific receptors. However, the identity and nature of host receptors of Etx remain a matter of controversy. In the present study, the interactions between Etx and membrane lipids from the synaptosome-enriched fraction from rat brain (P2 fraction) and MDCK cell plasma membrane preparations were analyzed. Our findings show that both Etx and proEtx bind to lipids extracted from lipid rafts from the two different models as assessed by protein-lipid overlay assay. Lipid rafts are membrane microdomains enriched in cholesterol and sphingolipids. Binding of proEtx to sulfatide, phosphatidylserine, phosphatidylinositol (3)-phosphate and phosphatidylinositol (5)-phosphate was detected. Removal of the sulphate groups via sulfatase treatment led to a dramatic decrease in Etx-induced cytotoxicity, but not in proEtx-GFP binding to MDCK cells or a significant shift in oligomer formation, pointing to a role of sulfatide in pore formation in rafts but not in toxin binding to the target cell membrane. These results show for the first time the interaction between Etx and membrane lipids from host tissue and point to a major role for sulfatides in C. perfringens epsilon toxin pathophysiology. PMID:26452234

  6. A brief history of the development of plastic surgery in The Netherlands East-Indies from World War I until the independence of Indonesia (1914-1950).

    PubMed

    Haeseker, B

    1990-05-01

    This study of surgical operations published in the Medical Journal of the Netherlands East-Indies over the period 1914-1950, supplemented with a series of interviews with retired Dutch East-Indian surgeons and their relatives, shows a vivid interest in plastic surgery from World War I until the independence of Indonesia. One can conclude that plastic surgery was performed more frequently and on a larger scale than in Holland, due to a larger number of patients, specific tropical pathology and often a longer patient delay, requiring extensive reconstructive procedures. The East-Indian publications on plastic surgical topics outnumber the Dutch ones enormously. PMID:2190665

  7. Leishmania (Leishmania) martiniquensis n. sp. (Kinetoplastida: Trypanosomatidae), description of the parasite responsible for cutaneous leishmaniasis in Martinique Island (French West Indies)

    PubMed Central

    2014-01-01

    The parasite responsible for autochthonous cutaneous leishmaniasis in Martinique island (French West Indies) was first isolated in 1995; its taxonomical position was established only in 2002, but it remained unnamed. In the present paper, the authors name this parasite Leishmania (Leishmania) martiniquensis Desbois, Pratlong & Dedet n. sp. and describe the type strain of this taxon, including its biological characteristics, biochemical and molecular identification, and pathogenicity. This parasite, clearly distinct from all other Euleishmania, and placed at the base of the Leishmania phylogenetic tree, is included in the subgenus Leishmania. PMID:24626346

  8. Leishmania (Leishmania) martiniquensis n. sp. (Kinetoplastida: Trypanosomatidae), description of the parasite responsible for cutaneous leishmaniasis in Martinique Island (French West Indies).

    PubMed

    Desbois, Nicole; Pratlong, Francine; Quist, Danièle; Dedet, Jean-Pierre

    2014-01-01

    The parasite responsible for autochthonous cutaneous leishmaniasis in Martinique island (French West Indies) was first isolated in 1995; its taxonomical position was established only in 2002, but it remained unnamed. In the present paper, the authors name this parasite Leishmania (Leishmania) martiniquensis Desbois, Pratlong & Dedet n. sp. and describe the type strain of this taxon, including its biological characteristics, biochemical and molecular identification, and pathogenicity. This parasite, clearly distinct from all other Euleishmania, and placed at the base of the Leishmania phylogenetic tree, is included in the subgenus Leishmania. PMID:24626346

  9. Czochralski growth of the mixed halides BaBrCl and BaBrCl:Eu

    NASA Astrophysics Data System (ADS)

    Yan, Z.; Shalapska, T.; Bourret, E. D.

    2016-02-01

    We present results from the growth of BaBrCl and BaBrCl:Eu single crystals, using the Czochralski method. Cubic inch crack-free crystals of both undoped and 5% Eu doped BaBrCl were obtained. The BaBr2-BaCl2 phase diagram was acquired by differential thermal analysis revealing that the system forms a solid solution at all concentrations with no significant separation between the solidus and liquidus curves. Details of the Czochralski process used to prevent cracking are presented. The scintillation performance of the Czochralski grown crystals is presented.

  10. Low-temperature sintering and compatibility with silver electrode of Ba{sub 4}MgTi{sub 11}O{sub 27} microwave dielectric ceramic

    SciTech Connect

    Chen, Xiuli; Zhou, Huanfu; Fang, Liang; Liu, Laijun; Li, Changda; Guo, Ruli; Wang, Hong

    2010-10-15

    Ba{sub 4}MgTi{sub 11}O{sub 27} microwave dielectric ceramic was investigated using X-ray diffraction, scanning electron microscopy and dielectric measurement. The pure Ba{sub 4}MgTi{sub 11}O{sub 27} ceramic shows a high sintering temperature ({approx}1275 {sup o}C) and good microwave dielectric properties as Q x f of 19,630 GHz, {epsilon}{sub r} of 36.1, {tau}{sub f} of 14.6 ppm/{sup o}C. It was found that the addition of BaCu(B{sub 2}O{sub 5}) (BCB) can effectively lower the sintering temperature from 1275 to 925 {sup o}C, and does not induce much degradation of the microwave dielectric properties. The BCB-doped Ba{sub 4}MgTi{sub 11}O{sub 27} ceramics can be compatible with Ag electrode, which makes it a promising ceramic for LTCC technology application.

  11. Soil and river contamination patterns of chlordecone in a tropical volcanic catchment in the French West Indies (Guadeloupe).

    PubMed

    Crabit, A; Cattan, P; Colin, F; Voltz, M

    2016-05-01

    The aim of this study was to identify primary flow paths involved in the chlordecone (CLD) river contamination and quantify the CLD fluxes to assess CLD pollution levels and duration according to a typical catchment of the banana cropping area in the French Indies (Guadeloupe): the Pérou Catchment (12 km(2)) characterized by heavy rainfall (5686 mm year(-1)). Three sub-catchments (SC1, SC2 and SC3) were studied during the hydrological year 2009-2010: a pedological survey combined with a spatialized hydrochemical approach was conducted. The average soil concentration is higher in the Pérou Catchment (3400 μg kg(-1)) than in the entire banana cropping area in Guadeloupe (2100 μg kg(-1)). The results showed that CLD stocks in soils vary largely among soil types and farming systems: the weakest stocks are located upstream in SC1 (5 kg ha(-1)), where a majority of the area is non-cultivated; medium stocks are located in Nitisols downstream in SC3 (9 kg ha(-1)); and the greatest stocks are observed in SC2 on Andosols (12 kg ha(-1)) characterized by large farms. The annual water balance and the hydro-chemical analysis revealed that the three sub-catchments exhibited different behaviors. Pérou River contamination was high during low flows, which highlighted that contamination primarily originated from groundwater contributions. The results showed that only a small part of the catchment (SC2), contributing little to the water flow, comprises a major CLD contribution, which is in agreement with the highly contaminated andosol soils observed there. Another significant result considers that at least 50 years would be required to export the totality of the actual CLD soil stocks retained in the topsoil layer. The actual time for soil remediation will however be much longer considering (i) the necessary time for the chlordecone to percolate and be stored in the shallow aquifers and (ii) its travel time to reach the river. PMID:27039897

  12. Revealing the Chamaeleon: Young, low-mass stars surrounding eta and epsilon Chamaeleontis

    NASA Astrophysics Data System (ADS)

    Murphy, S. J.

    2012-01-01

    The deep southern sky surrounding the Chamaeleon dark clouds is abundant with pre-main sequence stars of various ages. Because of their youth (5-10 Myr) and proximity (d~100 pc), members of the open cluster eta Chamaeleontis and the nearby epsilon Chamaeleontis Association are ideal laboratories to study the formation and evolution of extrasolar planetary systems. To better understand their role as potential planet hosts, this thesis explores the formation, dynamical evolution, accretion and disk properties of both groups' low-mass members. The notable lack of low-mass stars in the young open cluster eta Cha has long been puzzling. Two possible explanations have been suggested; a top-heavy initial mass function or dynamical evolution, which preferentially ejected the low-mass members. Previous efforts to find these stars several degrees from the cluster core have been unsuccessful. By undertaking a wider (95 sq deg) photometric and proper motion survey with extensive follow-up spectroscopy, we have identified eight low-mass stars that were ejected from eta Cha over the past 5-10 Myr. Comparison with recent simulations shows our results are consistent with a dynamical origin for the current configuration of the cluster, without the need to invoke an initial mass function deficient in low-mass objects. Two of the dispersed members exhibited strong, variable H-alpha emission during our observations, including a star which had an event suggestive of accretion from a circumstellar disk. New infrared photometry confirms the presence of the disk. This star demonstrates that infrequent, episodic accretion can continue at low levels long after most disks around `old' pre-main sequence stars have dissipated. Another two confirmed non-members are slightly older than the cluster, but are only 42 arcseconds apart and share similar kinematics and distances. We show that they almost certainly form a wide (4000-6000 AU) ~10 Myr-old binary at 100-150 pc. The system is one of the

  13. Quality assurance of C. perfringens epsilon toxoid vaccines--ELISA versus mouse neutralisation test.

    PubMed

    Rosskopf-Streicher, Ute; Volkers, Peter; Noeske, Kerstin; Werner, Esther

    2004-01-01

    Clostridium (C.) perfringens is a Gram-positive anaerobic spore-forming bacterium. Disease caused by C. perfringens infection is called enterotoxaemia. C. perfringens strains are classified on the basis of the lethal exotoxins formed by the bacteria. Epsilon toxin is one of the major lethal toxins and is formed by C. perfringens types B and D. C. perfringens is an ubiquitous bacterium. Infection occurs via food, water, animal litter or soil. Affected animals include mainly sheep, pigs and cattle. C. perfringens infection manifests as pulpy kidney disease and diarrhoea in suckling lambs. Enterotoxaemia development is peracute in most cases. Animals die suddenly while grazing on the pasture, without any prior signs of disease. Therefore, treatment is possible only in very rare cases. Suitable immunoprophylactic measures are the treatment of choice to combat the disease: Vaccines and immunosera have therefore been used extensively for a long time. The requirements for quality, efficacy and safety testing of the inactivated vaccines are laid down in the Ph. Eur. in the monograph: Clostridium perfringens vaccines for veterinary use. After a marketing authorisation is attained, the product batches must be tested in laboratory animal models for their potency against all vaccine components (Pharmeuropa, 1997). For potency testing (batch control) of C. perfringens types B and D, the induction of specific antibodies against epsilon toxin in rabbits must be verified. For this purpose, 10 rabbits are immunised twice with the product to be tested. Their blood is taken 14 days after the last immunisation and the serum is pooled. The pooled serum is then tested for its protective effect. This is done by means of the toxin neutralisation test in mice (optionally also in guinea pigs) in comparison with an international reference serum. The evaluation criterion is the death rate of the mice in the test and reference groups after administration of lethal doses of epsilon toxin. The

  14. Epsilon glutathione transferases possess a unique class-conserved subunit interface motif that directly interacts with glutathione in the active site.

    PubMed

    Wongsantichon, Jantana; Robinson, Robert C; Ketterman, Albert J

    2015-01-01

    Epsilon class glutathione transferases (GSTs) have been shown to contribute significantly to insecticide resistance. We report a new Epsilon class protein crystal structure from Drosophila melanogaster for the glutathione transferase DmGSTE6. The structure reveals a novel Epsilon clasp motif that is conserved across hundreds of millions of years of evolution of the insect Diptera order. This histidine-serine motif lies in the subunit interface and appears to contribute to quaternary stability as well as directly connecting the two glutathiones in the active sites of this dimeric enzyme. PMID:26487708

  15. Epsilon glutathione transferases possess a unique class-conserved subunit interface motif that directly interacts with glutathione in the active site

    PubMed Central

    Wongsantichon, Jantana; Robinson, Robert C.; Ketterman, Albert J.

    2015-01-01

    Epsilon class glutathione transferases (GSTs) have been shown to contribute significantly to insecticide resistance. We report a new Epsilon class protein crystal structure from Drosophila melanogaster for the glutathione transferase DmGSTE6. The structure reveals a novel Epsilon clasp motif that is conserved across hundreds of millions of years of evolution of the insect Diptera order. This histidine-serine motif lies in the subunit interface and appears to contribute to quaternary stability as well as directly connecting the two glutathiones in the active sites of this dimeric enzyme. PMID:26487708

  16. Inferring planar disorder in close-packed structures via epsilon-machine spectral reconstruction theory: structure and intrinsic computation in zinc sulfide.

    PubMed

    Varn, D P; Canright, G S; Crutchfield, J P

    2007-04-01

    We apply epsilon-machine spectral reconstruction theory to analyze structure and disorder in four previously published zinc sulfide diffraction spectra and contrast the results with the most common alternative theory, the fault model. In each case we find that the reconstructed epsilon-machine provides a more comprehensive and detailed understanding of the stacking structure, often detecting stacking structures not previously found. Using the epsilon-machines reconstructed for each spectrum, we calculate a number of physical parameters - such as configurational energies, configurational entropies and hexagonality - and several quantities - including statistical complexity and excess entropy - that describe the intrinsic computational properties of the stacking structures. PMID:17374926

  17. Ba4GaN3O

    PubMed Central

    Hashimoto, Takayuki; Yamane, Hisanori

    2014-01-01

    Red transparant platelet-shaped single crystals of tetra­barium gallium trinitride oxide, Ba4GaN3O, were synthesized by the Na flux method. The crystal structure is isotypic with Sr4GaN3O, containing isolated triangular [GaN3]6− anionic groups. O2− atoms are inserted between the slabs of [Ba4GaN3]2+, in which the [GaN3]6− groups are surrounded by Ba2+ atoms. PMID:24940188

  18. The Admission and Academic Placement of Students from the Caribbean. A Workshop Report: British Patterned Education, Cuba, the Dominican Republic, Dutch Patterned Education, the French West Indies, Haiti, Puerto Rico, and the U.S. Virgin Islands.

    ERIC Educational Resources Information Center

    Fish, Cynthia, Ed.

    This workshop report examines the admission and academic placement of students from the Caribbean. Workshop materials concerning the educational systems of the British patterned Caribbean, Cuba, Dominican Republic; Dutch patterned Caribbean, French West Indies, Haiti, Puerto Rico; and the U.S. Virgin Islands are presented. Workshop recommendations…

  19. Syntheses, crystal structure, and electronic properties of the five ABaMQ4 compounds RbBaPS4, CsBaPS4, CsBaVS4, RbBaVSe4, and CsBaVSe4

    NASA Astrophysics Data System (ADS)

    Mesbah, Adel; Prakash, Jai; Rocca, Dario; Lebègue, Sébastien; Beard, Jessica C.; Lewis, Benjamin A.; Ibers, James A.

    2016-01-01

    Five new compounds belonging to the ABaMQ4 family were synthesized by solid-state chemistry at 1123 K. The compounds RbBaPS4, CsBaPS4, CsBaVS4, RbBaVSe4, and CsBaVSe4 are isostructural and have the TlEuPS4 structure type. They crystallize in space group D162h - Pnma of the orthorhombic system. Their structure consists isolated MQ4 tetrahedra separated by A and Ba atoms to form a salt-like structure. Density Functional Theory (DFT) calculations of the electronic structures with the use of the HSE functional suggest that the compounds are semiconductors with calculated band gaps of 3.3 eV (RbBaPS4), 3.4 eV (CsBaPS4), 2.3 eV (CsBaVS4), and 1.6 eV (RbBaVSe4).

  20. A critical comparison of several low Reynolds number k-epsilon turbulence models for flow over a backward facing step

    NASA Technical Reports Server (NTRS)

    Steffen, C. J., Jr.

    1993-01-01

    Turbulent backward-facing step flow was examined using four low turbulent Reynolds number k-epsilon models and one standard high Reynolds number technique. A tunnel configuration of 1:9 (step height: exit tunnel height) was used. The models tested include: the original Jones and Launder; Chien; Launder and Sharma; and the recent Shih and Lumley formulation. The experimental reference of Driver and Seegmiller was used to make detailed comparisons between reattachment length, velocity, pressure, turbulent kinetic energy, Reynolds shear stress, and skin friction predictions. The results indicated that the use of a wall function for the standard k-epsilon technique did not reduce the calculation accuracy for this separated flow when compared to the low turbulent Reynolds number techniques.

  1. Copernicus observations of interstellar matter toward the Orion OB1 association. I - Epsilon and Pi-5 Orionis

    NASA Technical Reports Server (NTRS)

    Shull, J. M.

    1979-01-01

    Copernicus UV data on interstellar lines toward Epsilon Ori and Pi-5 Ori are analyzed to study abundances and physical conditions in both low- and intermediate-velocity components. Clouds at -8 and +5 km/s (LSR) toward Epsilon Ori show typical depletions of Fe, Ti, Mg, and Si in dense (H number density about 100 per cu cm) gas. Low-column-density intermediate-velocity clouds toward both stars, with low densities (hydrogen number density less than 1 per cu cm) and near-cosmic Si abundances, are consistent with a widespread pattern of high-velocity gas over a 15-deg area surrounding the Orion region. Such activity may be attributed to the repeated action of supernovae in a patchy low-density region of interstellar gas.

  2. Identification of a Lambda Toxin-Negative Clostridium perfringens Strain that Processes and Activates Epsilon Prototoxin Intracellularly

    PubMed Central

    Harkness, Justine M.; Li, Jihong; McClane, Bruce A.

    2012-01-01

    Clostridium perfringens type B and D strains produce epsilon toxin (ETX), which is one of the most potent clostridial toxins and is involved in enteritis and enterotoxemias of domestic animals. ETX is produced initially as an inactive prototoxin that is typically then secreted and processed by intestinal proteases or possibly, for some strains, lambda toxin. During the current work a unique C. perfringens strain was identified that intracellularly processes epsilon prototoxin to an active form capable of killing MDCK cells. This activated toxin is not secreted but instead is apparently released upon lysis of bacterial cells entering stationary phase. These findings broaden understanding of the pathogenesis of type B and D infections by identifying a new mechanism of ETX activation. PMID:22982043

  3. Solid-phase radioimmunoassays for quantitative antibody determination of bacterial exotoxins. Measurement of Clostridium perfringens type D epsilon antitoxin.

    PubMed

    Bernáth, S

    1976-01-01

    Two reversed solid-phase radioimmunoassays have been developed for quantitative determination of antibodies against Clostridium perfringens type D epsilon toxin. 125I labelled prototoxin was used in the bromoacetyl cellulose-bound antibody method and in the antibody coated tube method. The procedures are based on the competition for 125I labelled prototoxin between the insoluble antibodies and the antibodies present in the unknown sample. The radioactivity bound to solid-phase is in inverse ratio to quantity of measured antibodies. The antibody values which can be detected are in the range of 0.004 IU/ml of investigated serum. The methods allow the rapid and inexpensive screening of large groups of vaccinated sheep, and are very suitable for measuring small amounts of Cl. perfringens D epsilon antibodies with a small experimental error. PMID:187514

  4. Application of the k-epsilon turbulence model to the simulation of a fully pulsed free air jet

    NASA Astrophysics Data System (ADS)

    Graham, L. J. W.; Bremhorst, K.

    1993-03-01

    The work describes application of the k-epsilon turbulence model to a fully pulsed air jet. The standard model failed to predict the change in slope of the velocity decay where the jet changes from pulsed to steady jet behavior. A change in one of the constants of the k-epsilon model based on the behavior of the periodic velocity component relative to the intrinsic component yielded satisfactory results. Features of the pulsed jet which were successfully simulated included the flow reversal near the edge of the jet, increased entrainment when compared to steady jets and large radial outflow near the leading edge of the pulse and large radial inflow near the outer edge of the jet for the remainder of the pulse.

  5. Cloning and developmental expression of pea ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit epsilon N-methyltransferase

    DOEpatents

    Houtz, Robert L.

    1999-01-01

    The gene sequence for ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) large subunit (LS) .sup..epsilon. N-methyltransferase (protein methylase III or Rubisco LSMT) is disclosed. This enzyme catalyzes methylation of the .epsilon.-amine of lysine-14 in the large subunit of Rubisco. In addition, a full-length cDNA clone for Rubisco LSMT is disclosed. Transgenic plants and methods of producing same which (1) have the Rubisco LSMT gene inserted into the DNA, and (2) have the Rubisco LSMT gene product or the action of the gene product deleted from the DNA are also provided. Further, methods of using the gene to selectively deliver desired agents to a plant are also disclosed.

  6. Cloning and developmental expression of pea ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit epsilon N-methyltransferase

    DOEpatents

    Houtz, R.L.

    1999-02-02

    The gene sequence for ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) large subunit (LS){sup {epsilon}}N-methyltransferase (protein methylase III or Rubisco LSMT) is disclosed. This enzyme catalyzes methylation of the {epsilon}-amine of lysine-14 in the large subunit of Rubisco. In addition, a full-length cDNA clone for Rubisco LSMT is disclosed. Transgenic plants and methods of producing same which (1) have the Rubisco LSMT gene inserted into the DNA, and (2) have the Rubisco LSMT gene product or the action of the gene product deleted from the DNA are also provided. Further, methods of using the gene to selectively deliver desired agents to a plant are also disclosed. 8 figs.

  7. Role of novel type I interferon epsilon in viral infection and mucosal immunity.

    PubMed

    Xi, Yang; Day, Stephanie L; Jackson, Ronald J; Ranasinghe, Charani

    2012-11-01

    Intranasal infection with vaccinia virus co-expressing interferon epsilon (VV-HIV-IFN-ε) was used to evaluate the role of IFN-ε in mucosal immunity. VV-HIV- IFN-ε infection induced a rapid VV clearance in lung that correlated with (i) an elevated lung VV-specific CD8(+)CD107a(+)IFN-γ(+) population expressing activation markers CD69/CD103, (ii) enhanced lymphocyte recruitment to lung alveoli with reduced inflammation, and (iii) an heightened functional/cytotoxic CD8(+)CD4(+) T-cell subset (CD3(hi)CCR7(hi)CD62L(lo)) in lung lymph nodes. These responses were different to that observed with intranasal VV-HA-IFN-α(4) or VV-HA-IFN-β infections. When IFN-ε was used in an intranasal/intramuscular heterologous HIV prime-boost immunization, elevated HIV-specific effector, but not memory CD8(+)T cells responses, were observed in spleen, genito-rectal nodes, and Peyer's patch. Homing marker α4β7 and CCR9 analysis indicated that unlike other type I IFNs, IFN-ε could promote migration of antigen-specific CD8(+)T cells to the gut. Our results indicate that IFN-ε has a unique role in the mucosae and most likely can be used to control local lung and/or gut infections (i.e., microbicide) such as tuberculosis, HIV-1, or sexually transmitted diseases. PMID:22617838

  8. A novel evolutionary lineage of carbonic anhydrase (epsilon class) is a component of the carboxysome shell.

    PubMed

    So, Anthony K-C; Espie, George S; Williams, Eric B; Shively, Jessup M; Heinhorst, Sabine; Cannon, Gordon C

    2004-02-01

    A significant portion of the total carbon fixed in the biosphere is attributed to the autotrophic metabolism of prokaryotes. In cyanobacteria and many chemolithoautotrophic bacteria, CO(2) fixation is catalyzed by ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO), most if not all of which is packaged in protein microcompartments called carboxysomes. These structures play an integral role in a cellular CO(2)-concentrating mechanism and are essential components for autotrophic growth. Here we report that the carboxysomal shell protein, CsoS3, from Halothiobacillus neapolitanus is a novel carbonic anhydrase (epsilon-class CA) that has an evolutionary lineage distinct from those previously recognized in animals, plants, and other prokaryotes. Functional CAs encoded by csoS3 homologues were also identified in the cyanobacteria Prochlorococcus sp. and Synechococcus sp., which dominate the oligotrophic oceans and are major contributors to primary productivity. The location of the carboxysomal CA in the shell suggests that it could supply the active sites of RuBisCO in the carboxysome with the high concentrations of CO(2) necessary for optimal RuBisCO activity and efficient carbon fixation in these prokaryotes, which are important contributors to the global carbon cycle. PMID:14729686

  9. Low cytoplasmic casein kinase 1 epsilon expression predicts poor prognosis in patients with hepatocellular carcinoma.

    PubMed

    Lin, Shu-Hui; Yeh, Chung-Min; Hsieh, Ming-Ju; Lin, Yueh-Min; Chen, Mei-Wen; Chen, Chih-Jung; Lin, Cheng-Yu; Hung, Hsiao-Fang; Yeh, Kun-Tu; Yang, Shun-Fa

    2016-03-01

    Casein kinase 1 epsilon (CK1ε) is a member of the casein kinase 1 (CK1) family, which comprises highly conserved and ubiquitous serine/threonine protein kinases. Recent studies have demonstrated that CK1ε plays a role in human cancers; however, the role of CK1ε in hepatocellular carcinoma (HCC) remains unclear. The study used immunohistochemistry to examine CK1ε expression in 230 HCC specimens by tissue microarray (TMA) and assessed the effect of CK1ε knockdown on migration of human hepatoma cells in vitro. The immunohistochemical analyses showed that low CK1ε expression was significantly correlated with tumor differentiation (p = 0.008), T classification (p = 0.016), tumor vascular invasion (p = 0.002), and cancer stage (p = 0.010). The univariate and multivariate analyses showed that patients with low CK1ε expression had a considerably lower OS rate than that of the patients with high CK1ε expression (p = 0.041, hazard ratio = 1.4; p = 0.039, hazard ratio = 1.4). Moreover, CK1ε small interfering RNA (siRNA) treatment exerted an invasion-promoting effect in human hepatoma cells. In conclusion, our data indicated that low CK1ε expression is correlated with a low survival rate and CK1ε may play a role as a tumor suppressor in hepatocarcinogenesis. PMID:26482619

  10. Optical properties of metal-dielectric based epsilon near zero metamaterials

    NASA Astrophysics Data System (ADS)

    Subramania, Ganapathi; Fischer, Arthur; Luk, Ting

    2014-03-01

    Epsilon(ɛ) near zero(ENZ) materials are metamaterials where the effective dielectric constant(ɛ) is close to zero for a range of wavelengths resulting in zero effective displacement field (D = ɛE) and displacement current. ENZ structures are of great interest in many application areas such as optical nanocircuits, supercoupling, cloaking, emission enhancement etc. Effective ENZ behavior has been demonstrated using cut-off frequency region in a metallic waveguide where the modal index vanishes. Here we demonstrate the fabrication of ENZ metamaterials operating at visible wavelengths (λ ~ 640nm) using an effective medium approach based on a metal-dielectric composites(App. Phys. Let.,101,241107(2012)) that can act as ``bulk'' ENZ material. The structure consists of a multilayer stack composite of alternating nanoscale thickness layers of Ag and TiO2. Optical spectroscopy shows transmission and absorption response is consistent with ENZ behavior and matches well with simulations. We will discuss the criteria necessary in the design and practical implementation of the composite that better approximates a homogenous effective medium including techniques to minimize the effect of optical losses to boost transmission. The potential for hosting gain media in the gratings to address losses and emission control will be discussed. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. DOE's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  11. Trimethylene carbonate and epsilon-caprolactone based (co)polymer networks: mechanical properties and enzymatic degradation.

    PubMed

    Bat, Erhan; Plantinga, Josée A; Harmsen, Martin C; van Luyn, Marja J A; Zhang, Zheng; Grijpma, Dirk W; Feijen, Jan

    2008-11-01

    High molecular weight trimethylene carbonate (TMC) and epsilon-caprolactone (CL) (co)polymers were synthesized. Melt pressed (co)polymer films were cross-linked by gamma irradiation (25 kGy or 50 kGy) in vacuum, yielding gel fractions of up to 70%. The effects of copolymer composition and irradiation dose on the cytotoxicity, surface properties, degradation behavior, and mechanical and thermal properties of these (co)polymers and networks were investigated. Upon incubation with cell culture medium containing extracts of (co)polymers and networks, human foreskin fibroblasts remained viable. For all (co)polymers and networks, cell viabilities were determined to be higher than 94%. The formed networks were flexible, with elastic moduli ranging from 2.7 to 5.8 MPa. Moreover, these form-stable networks were creep resistant under dynamic conditions. The permanent deformation after 2 h relaxation was as low as 1% after elongating to 50% strain for 20 times. The in vitro enzymatic erosion behavior of these hydrophobic (co)polymers and networks was investigated using aqueous lipase solutions. The erosion rates in lipase solution could be tuned linearly from 0.8 to 45 mg/(cm (2) x day) by varying the TMC to CL ratio and the irradiation dose. The copolymers and networks degraded essentially by a surface erosion mechanism. PMID:18855440

  12. Controlling thermal emission with refractory epsilon-near-zero metamaterials via topological transitions

    PubMed Central

    Dyachenko, P. N.; Molesky, S.; Petrov, A. Yu; Störmer, M.; Krekeler, T.; Lang, S.; Ritter, M.; Jacob, Z.; Eich, M.

    2016-01-01

    Control of thermal radiation at high temperatures is vital for waste heat recovery and for high-efficiency thermophotovoltaic (TPV) conversion. Previously, structural resonances utilizing gratings, thin film resonances, metasurfaces and photonic crystals were used to spectrally control thermal emission, often requiring lithographic structuring of the surface and causing significant angle dependence. In contrast, here, we demonstrate a refractory W-HfO2 metamaterial, which controls thermal emission through an engineered dielectric response function. The epsilon-near-zero frequency of a metamaterial and the connected optical topological transition (OTT) are adjusted to selectively enhance and suppress the thermal emission in the near-infrared spectrum, crucial for improved TPV efficiency. The near-omnidirectional and spectrally selective emitter is obtained as the emission changes due to material properties and not due to resonances or interference effects, marking a paradigm shift in thermal engineering approaches. We experimentally demonstrate the OTT in a thermally stable metamaterial at high temperatures of 1,000 °C. PMID:27263653

  13. Casein Kinase 1 Epsilon Expression Predicts Poorer Prognosis in Low T-Stage Oral Cancer Patients

    PubMed Central

    Lin, Shu-Hui; Lin, Yueh-Min; Yeh, Chung-Min; Chen, Chih-Jung; Chen, Mei-Wen; Hung, Hsiao-Fang; Yeh, Kun-Tu; Yang, Shun-Fa

    2014-01-01

    Casein kinase 1 is a group of ubiquitous serine/threonine kinases that are involved in normal cellular functions and several pathological conditions, such as DNA repair, cell cycle progression, cytokinesis, differentiation, and apoptosis. Recent studies have indicated that casein kinase 1-epsilon (CK1ɛ) and casein kinase 1-delta (CK1δ) expression has a role in human cancers. We investigated the associations between CK1ɛ and CK1δ expression and the clinical parameters of oral cancer using immunohistochemical study methods on oral squamous cell carcinoma specimens. The results of our immunohistochemical analysis showed that the loss of CK1ɛ expression was greatly associated with a poor four-year survival rate in oral cancer patients (p = 0.002). A Kaplan-Meier analysis showed that patients who had a loss of CK1ɛ expression had a considerably poorer overall survival rate than patients who had positive CK1ɛ expressions (p = 0.022). A univariate analysis revealed that patients who had a loss of CK1ɛ expression had considerably poorer overall survival (OS) than patients who had positive expression (p = 0.024, hazard ratio (HR) = 1.7). In conclusion, our data indicated that the loss of cytoplasmic CK1ɛ expression is greatly associated with poor survival and might be an adverse survival factor. PMID:24557581

  14. [Biosorption of chromium (VI) by waste biomass of epsilon-poly-L-lysine fermentation].

    PubMed

    Cao, Yu-Juan; Zhang, Yang; Xia, Jun; Xu, Hong; Feng, Xiao-Hai

    2012-02-01

    The sorption of hexavalent chromium by waste biomass of epsilon-Poly-L-lysine fermentation strains (Streptomyces albulus) PD-1 was studied. Effects of pretreatment ways, pH, initial concentration of Cr(VI), contact time and temperature on biosorption were determined. It was found that homogenization in HCl was the best way to pretreat mycelia, having an increased rate of Cr(VI) biosorption at 22.7%, the optimum pH was about 2.0, while no significant impact of temperature on the biosorption was observed. The fitness of the experimental data for the Langmuir and Freundlich adsorption models was further examined and good correlations with R2 of 0.979 4 and 0.979 8 were observed, indicating the presence of both monolayer biosorption and heterogeneous surface condition. The maximum adsorption capacity of the Streptomyces albulus PD-1 for Cr(VI) was 23.92 mg x g(-1). FT-IR analysis demonstrates that the major functional groups (amide and hydroxyl) may contribute to the absorption of Cr(VI). PMID:22509588

  15. L-lysine epsilon-aminotransferase involved in cephamycin C synthesis in Streptomyces lactamdurans.

    PubMed Central

    Kern, B A; Hendlin, D; Inamine, E

    1980-01-01

    In Streptomyces lactamdurans, the precursor of the alpha-aminoadipoyl side-chain of cephamycin C is L-lysine. In this regard, streptomycetes differ strikingly from the fungi, which produce alpha-aminoadipic acid during the synthesis, rather than the breakdown, of L-lysine. Studies using a cell-free system showed that an aminoadipic acid. The product of this reaction was trapped and subsequently purified by ion-exchange chromatography. Thin-layer chromatography, spectrophotometry, and amino acid oxidase digestion studies identified the reaction product as L-1-piperideine-6-carboxylate, implying enzymatic removal of the epsilon amino group of L-lysine. This enzymatic activity (E.C. 2.6.1.36; L-lysine: 2-oxoglutarate 6-aminotransferase) is highly unusual and was previously conclusively demonstrated only in the genus Flavobacterium. In S. lactamdurans, the specific activity of this enzyme reaches a peak early in the fermentation (approximately 20 h) and decreases as the antibiotic begins to appear. PMID:6772093

  16. Tunneling of obliquely incident waves through PT-symmetric epsilon-near-zero bilayers

    NASA Astrophysics Data System (ADS)

    Savoia, Silvio; Castaldi, Giuseppe; Galdi, Vincenzo; Alù, Andrea; Engheta, Nader

    2014-02-01

    We show that obliquely incident, transversely magnetic-polarized plane waves can be totally transmitted (with zero reflection) through epsilon-near-zero (ENZ) bilayers characterized by balanced loss and gain with parity-time (PT) symmetry. This tunneling phenomenon is mediated by the excitation of a surface wave localized at the interface separating the loss and gain regions. We determine the parameter configurations for which the phenomenon may occur and, in particular, the relationship between the incidence direction and the electrical thickness. We show that, below a critical threshold of gain and loss, there always exists a tunneling angle which, for moderately thick (wavelength-sized) structures, approaches a critical value dictated by the surface-wave phase-matching condition. We also investigate the unidirectional character of the tunneling phenomenon, as well as the possible onset of spontaneous symmetry breaking, typical of PT-symmetric systems. Our results constitute an interesting example of a PT-symmetry-induced tunneling phenomenon, and may open up intriguing venues in the applications of ENZ materials featuring loss and gain.

  17. Ecotoxicological evaluation of poly(epsilon-caprolactone) nanocapsules containing triazine herbicides.

    PubMed

    Clemente, Z; Grillo, R; Jonsson, M; Santos, N Z P; Feitosa, L O; Lima, R; Fraceto, L F

    2014-07-01

    The triazine class of herbicides includes the compounds ametryn, atrazine, and simazine, which are used to control weeds in plantations of crops such as maize, sorghum, and sugar cane. Despite their acceptance in agriculture, these herbicides can be dangerous to the environment, depending on their toxicity, the degree of contamination, and the duration of exposure. Controlled release systems are increasingly used to mitigate problems of toxicity and minimize environmental impacts, and can also increase herbicide efficiency. The objective of this work was to prepare poly(epsilon-caprolactone) nanocapsules containing ametryn and atrazine, and evaluate their toxicity to aquatic organisms as well as in cytogenetic tests employing human lymphocyte cultures. The PCL nanocapsules were prepared according to the interfacial deposition of pre-formed polymer method. Ecotoxicological assays were performed with the alga Pseudokirchneriella subcapitata and the microcrustacean Daphnia similis. The cytogenetic tests consisted of observing mitotic index alterations after exposing lymphocyte cell cultures to different formulations. Encapsulation of the herbicides in the nanocapsules resulted in lower toxicity to the alga and higher toxicity to the microcrustacean, compared to the herbicides alone. The cytogenetic tests showed that formulations of nanocapsules containing the herbicides were less toxic than the herbicides alone. The findings indicate the potential of the nanocapsule formulations in agricultural applications, where they could help to reduce the quantities of herbicides used as well as impacts on the environment and human health. PMID:24757962

  18. Preliminary measurements of auroral energy deposition and middle atmosphere electrodynamic response during MAC/Epsilon

    NASA Technical Reports Server (NTRS)

    Goldberg, R. A.

    1989-01-01

    On the nights of October 21 and 28, 1987 (UT), two Nike Orion payloads (NASA 31.066 and 31.067) were launched from Andoya, Norway, as part of the MAC/Epsilon campaign, to study auroral energetics and their effect on the middle atmosphere. Each payload carried instrumentation to measure relativistic electrons from 0.1 to 1.0 MeV in 12 differential channels, and Bremsstrahlung X-rays from greater than 5 to greater than 80 KeV in 5 integral channels. In addition, instrumentation to measure ion densities and electric fields were also included on these and, in the case of 31.066, on other near simultaneous payloads. The first flight, 31.066, was launched under pre-magnetic midnight conditions during relatively stable auroral conditions. Flight 31.067 was launched during post-breakup conditions at which time pulsations of approx. 100 seconds duration were evident. The measured radiations including their spectral characteristics are compared for these two events, to appraise their effect on the electrodynamic properties of the middle atmosphere as determined by other rocket-borne measurements.

  19. Biocompatibility of poly(epsilon-caprolactone)/poly(ethylene glycol) diblock copolymers with nanophase separation.

    PubMed

    Hsu, Shan-Hui; Tang, Cheng-Ming; Lin, Chu-Chieh

    2004-11-01

    In this study, we prepared diblock copolymers of poly(epsilon-caprolactone) (PCL) and poly(ethylene glycol) (PEG) by aluminum alkoxide catalysts. The biological responses to the spin cast surface of different PCL/PEG diblock copolymers were investigated in vitro. Our results showed that surface hydrophilicity improved with the increased PEG segments in diblock copolymers and that bacteria adhesion was inhibited by increased PEG contents. PCL-PEG 23:77 showed nanotopography on the surface. The number of adhered endothelial cells, platelets and monocytes on diblock copolymer surfaces was inhibited in PCL-PEG 77:23 and enhanced in PCL-PEG 23:77. Nevertheless, the platelet and monocyte activation on PCL-PEG 23:77 was reduced. PCL-PEG 23:77 had better cellular response as well as lower degree of platelet and monocyte activation. The current study was the first one to demonstrate that surface nanotopography could influence not only cell adhesion and growth but also platelet and monocyte activation. PMID:15159075

  20. Epsilon Aminocaproic Acid Pretreatment Provides Neuroprotection Following Surgically Induced Brain Injury in a Rat Model.

    PubMed

    Komanapalli, Esther S; Sherchan, Prativa; Rolland, William; Khatibi, Nikan; Martin, Robert D; Applegate, Richard L; Tang, Jiping; Zhang, John H

    2016-01-01

    Neurosurgical procedures can damage viable brain tissue unintentionally by a wide range of mechanisms. This surgically induced brain injury (SBI) can be a result of direct incision, electrocauterization, or tissue retraction. Plasmin, a serine protease that dissolves fibrin blood clots, has been shown to enhance cerebral edema and hemorrhage accumulation in the brain through disruption of the blood brain barrier. Epsilon aminocaproic acid (EAA), a recognized antifibrinolytic lysine analogue, can reduce the levels of active plasmin and, in doing so, potentially can preserve the neurovascular unit of the brain. We investigated the role of EAA as a pretreatment neuroprotective modality in a SBI rat model, hypothesizing that EAA therapy would protect brain tissue integrity, translating into preserved neurobehavioral function. Male Sprague-Dawley rats were randomly assigned to one of four groups: sham (n = 7), SBI (n = 7), SBI with low-dose EAA, 150 mg/kg (n = 7), and SBI with high-dose EAA, 450 mg/kg (n = 7). SBI was induced by partial right frontal lobe resection through a frontal craniotomy. Postoperative assessment at 24 h included neurobehavioral testing and measurement of brain water content. Results at 24 h showed both low- and high-dose EAA reduced brain water content and improved neurobehavioral function compared with the SBI groups. This suggests that EAA may be a useful pretherapeutic modality for SBI. Further studies are needed to clarify optimal therapeutic dosing and to identify mechanisms of neuroprotection in rat SBI models. PMID:26463967

  1. Evaluations of bioactivity and mechanical properties of poly (epsilon-caprolactone)/silica nanocomposite following heat treatment.

    PubMed

    Yoo, Jeong Joon; Rhee, Sang-Hoon

    2004-03-01

    A composite material consisting of poly(epsilon-caprolactone) (PCL) and silica was prepared and evaluated as a bioactive bone substitute. The composite was synthesized by the co-condensation of tetraethyl orthosilicate and PCL and end-capped with triethoxysilane (Si-PCL). The as-prepared specimens were subjected to an initial heat treatment of 2 days at 60 degrees C, followed by further heat-treatments at 100 degrees C, 150 degrees C, and 200 degrees C for 24 h. The tensile mechanical properties of the heat-treated specimens were determined, and additional specimens were exposed to a simulated body fluid (SBF) for different periods of time. The SBF exposure led to the deposition of a layer of apatite crystals on the surface of the composites. It was found that increasing the second heat-treatment temperature produced an increase in tensile strength and Young's modulus of the composite but a decrease in the initial rate of apatite formation. These phenomena are explained in terms of the condensation reaction that takes place between the silanol groups in the silica and Si-PCL as the heat-treatment temperature is increased. PMID:14762919

  2. Bioactivity improvement of poly(epsilon-caprolactone) membrane with the addition of nanofibrous bioactive glass.

    PubMed

    Lee, Hae-Hyoung; Yu, Hye-Sun; Jang, Jun-Hyeog; Kim, Hae-Won

    2008-05-01

    Nanofibrous glass with a bioactive composition was added to a degradable polymer poly(epsilon-caprolactone) (PCL) to produce a nanocomposite in thin membrane form ( approximately 260 microm). The bioactivity and osteoblastic responses of the nanocomposite membrane were examined and compared with those of a pure PCL membrane. Glass nanofibers with diameters in the range of hundreds of nanometers were added to a PCL solution at 20 wt.%, and the mixture was stirred vigorously and air dried. The obtained nanocomposite membrane showed that many chopped glass nanofibers formed by the mixing step were embedded uniformly into the PCL matrix. The nanocomposite membrane induced the rapid formation of apatite-like minerals on the surface when immersed in a simulated body fluid. Murine-derived osteoblastic cells (MC3T3-E1) grew actively over the nanocomposite membrane with cell viability significantly improved compared with those on the pure PCL membrane. Moreover, the osteoblastic activity, as assessed by the expression of alkaline phosphatase, was significantly higher on the nanocomposite membrane than on the pure PCL membrane. The currently developed nanocomposite of the bioactive glass-added PCL might find applications in the bone regeneration areas such as the guided bone regeneration (GBR) membrane. PMID:18171636

  3. In vivo biocompatibilty and degradation behavior of elastic poly(L-lactide-co-epsilon-caprolactone) scaffolds.

    PubMed

    Jeong, Sung In; Kim, Byung-Soo; Kang, Sun Woong; Kwon, Jae Hyun; Lee, Young Moo; Kim, Soo Hyun; Kim, Young Ha

    2004-12-01

    Tubular scaffolds were fabricated from very elastic poly(L-lactide-co-epsilon-caprolactone) (PLCL, 50:50). The scaffolds were seeded with smooth muscle cells (SMCs) and implanted in nude mice to investigate the tissue compatibility and in vivo degradation behavior. Histological examination of all the implants with haematoxylin and eosin staining, masson trichrome staining, SM alpha-actin antibody, and CM-DiI labeling confirmed that the regular morphology and biofunction of the SMCs seeded and the expression of the vascular smooth muscle matrices in PLCL scaffolds. The implanted PLCL scaffolds displayed a slow degradation on time, where caprolactone units were faster degraded than lactide did. This could be explained by the fact that amorphous regions composed of mainly CL moieties degraded earlier than hard domains where most of the LA units were located. From these results, the scaffolds applied in this study were found to exhibit excellent tissue compatibility to SMCs and might be very useful for vascular tissue engineering. PMID:15183608

  4. Violacein/poly(epsilon-caprolactone)/chitosan nanoparticles against bovine mastistis: Antibacterial and ecotoxicity evaluation

    NASA Astrophysics Data System (ADS)

    Berni, E.; Marcato, P. D.; Nakazato, G.; Kobayashi, R. K. T.; Vacchi, F. I.; Umbuzeiro, G. A.; Durán, N.

    2013-04-01

    The nanocarrier was synthesized by nanoprecipitation, using poly(epsilon-caprolactone) (PCL) as polymer, Tween 80 as surfactant and the biopolymer chitosan (CS) as a charge modification agent. Charge, size and morphology were analyzed by zeta potential, photo correlation spectroscopy (PCS), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). Bactericidal assays were carried out using a resistant strain of Staphylococcus aureus, and the acute ecotoxicity tests were performed with Daphnia similis. The nanoparticle without CS (PCLnp) exhibited an average size of 200 nm and zeta potential of -4.28 mV, while the nanoparticle with 0.04% (w/v) of CS (CS_PCLnp) had 250 nm and +21.3 mV. Both were stables for at least 30 days. 200 μg mL-1 violacein was encapsulated in CS_PCLnp, which was dissolved in the polymer matrix, a shown by DSC analysis. The minimal inhibitory concentration against S. aureus of CS_PCLnp-vio was 25 μmol L-1, while for free violacein it was > 25 μmol L-1. Nanoparticles exhibited an EC50 between 0.3 - 1.1 μmol L-1 with Daphnia, while free violacein was around 3.3 - 5.0 μmol L-1. Thus, it was possible to control the charge of the nanoparticles, without extreme changes in size and that it is possible also to encapsulate a powerful antibactericidal compound such as violacein in nanoparticle.

  5. Structure of Epsilon15 Phage Reveals Organization of Genome and DNA Packaging/Injection Apparatus

    PubMed Central

    Jiang, Wen; Chang, Juan; Jakana, Joanita; Weigele, Peter; King, Jonathan; Chiu, Wah

    2006-01-01

    Using single particle electron cryomicroscopy that does not impose icosahedral averaging, we determined the structure of the entire infectious Salmonella phage Epsilon151, including both icosahedral and non-icosahedral components. At least three layers of condensed viral DNA were observed to pack in coaxial coils with local 25 Å hexagonal inter-strand spacing. At one of the five-fold vertices, a portal complex with twelve subunits replaces a capsid pentamer. A tail hub with six projecting trimeric tailspikes sits on the external face of the portal. Below the portal is a cylindrical protein core. An extended shaft of density fills the central channel of the protein core and the portal complex and appears to consist of about 90 nucleotides at the terminus of the packaged DNA poised for injection. Using an icosahedral symmetry imposed reconstruction, the fold of the capsid shell protein is seen to resemble the capsid protein fold of other tailed double-stranded DNA phages2–5 and human herpesvirus6. These common structural features suggest a common evolutionary origin among these viruses. PMID:16452981

  6. A Combined Spectroscopic and Photometric Stellar Activity Study of Epsilon Eridani

    NASA Astrophysics Data System (ADS)

    Giguere, Matthew J.; Fischer, Debra A.; Zhang, Cyril X. Y.; Matthews, Jaymie M.; Cameron, Chris; Henry, Gregory W.

    2016-06-01

    We present simultaneous ground-based radial velocity (RV) measurements and space-based photometric measurements of the young and active K dwarf Epsilon Eridani. These measurements provide a data set for exploring methods of identifying and ultimately distinguishing stellar photospheric velocities from Keplerian motion. We compare three methods we have used in exploring this data set: Dalmatian, an MCMC spot modeling code that fits photometric and RV measurements simultaneously; the FF‧ method, which uses photometric measurements to predict the stellar activity signal in simultaneous RV measurements; and Hα analysis. We show that our Hα measurements are strongly correlated with the Microvariability and Oscillations of STars telescope (MOST) photometry, which led to a promising new method based solely on the spectroscopic observations. This new method, which we refer to as the HH‧ method, uses Hα measurements as input into the FF‧ model. While the Dalmatian spot modeling analysis and the FF‧ method with MOST space-based photometry are currently more robust, the HH‧ method only makes use of one of the thousands of stellar lines in the visible spectrum. By leveraging additional spectral activity indicators, we believe the HH‧ method may prove quite useful in disentangling stellar signals.

  7. Controlling thermal emission with refractory epsilon-near-zero metamaterials via topological transitions.

    PubMed

    Dyachenko, P N; Molesky, S; Petrov, A Yu; Störmer, M; Krekeler, T; Lang, S; Ritter, M; Jacob, Z; Eich, M

    2016-01-01

    Control of thermal radiation at high temperatures is vital for waste heat recovery and for high-efficiency thermophotovoltaic (TPV) conversion. Previously, structural resonances utilizing gratings, thin film resonances, metasurfaces and photonic crystals were used to spectrally control thermal emission, often requiring lithographic structuring of the surface and causing significant angle dependence. In contrast, here, we demonstrate a refractory W-HfO2 metamaterial, which controls thermal emission through an engineered dielectric response function. The epsilon-near-zero frequency of a metamaterial and the connected optical topological transition (OTT) are adjusted to selectively enhance and suppress the thermal emission in the near-infrared spectrum, crucial for improved TPV efficiency. The near-omnidirectional and spectrally selective emitter is obtained as the emission changes due to material properties and not due to resonances or interference effects, marking a paradigm shift in thermal engineering approaches. We experimentally demonstrate the OTT in a thermally stable metamaterial at high temperatures of 1,000 °C. PMID:27263653

  8. Controlling thermal emission with refractory epsilon-near-zero metamaterials via topological transitions

    NASA Astrophysics Data System (ADS)

    Dyachenko, P. N.; Molesky, S.; Petrov, A. Yu; Störmer, M.; Krekeler, T.; Lang, S.; Ritter, M.; Jacob, Z.; Eich, M.

    2016-06-01

    Control of thermal radiation at high temperatures is vital for waste heat recovery and for high-efficiency thermophotovoltaic (TPV) conversion. Previously, structural resonances utilizing gratings, thin film resonances, metasurfaces and photonic crystals were used to spectrally control thermal emission, often requiring lithographic structuring of the surface and causing significant angle dependence. In contrast, here, we demonstrate a refractory W-HfO2 metamaterial, which controls thermal emission through an engineered dielectric response function. The epsilon-near-zero frequency of a metamaterial and the connected optical topological transition (OTT) are adjusted to selectively enhance and suppress the thermal emission in the near-infrared spectrum, crucial for improved TPV efficiency. The near-omnidirectional and spectrally selective emitter is obtained as the emission changes due to material properties and not due to resonances or interference effects, marking a paradigm shift in thermal engineering approaches. We experimentally demonstrate the OTT in a thermally stable metamaterial at high temperatures of 1,000 °C.

  9. Broadband Epsilon-Near-Zero Perfect Absorption in the Near-Infrared

    PubMed Central

    Yoon, Junho; Zhou, Ming; Badsha, Md. Alamgir; Kim, Tae Young; Jun, Young Chul; Hwangbo, Chang Kwon

    2015-01-01

    Perfect absorption (PA) of incident light is important for both fundamental light-matter interaction studies and practical device applications. PA studies so far have mainly used resonant nanostructures that require delicate structural patterning. Here, we realize tunable and broadband PA in the near-infrared region using relatively simple thin film coatings. We adjust the growth condition of an ITO film and control its epsilon-near-zero (ENZ) wavelength. We show that this results in highly tunable PA in the telecommunication window. Then, using an ITO multilayer of different ENZ wavelengths, we demonstrate broadband PA that covers a wide range of near-infrared wavelengths. The use of ENZ coatings makes PA adjustable during the film growth and does not require any structural patterning afterward. It also facilitates the chip-scale integration of perfect absorbers with other device components. Broadband PA relaxes the single wavelength condition in previous PA studies, and thus it is suitable for many practical device applications, including sensors, photodetectors, and energy harvesting devices. PMID:26239808

  10. Manipulating polarization of light with ultrathin epsilon-near-zero metamaterials.

    PubMed

    Ginzburg, P; Rodríguez Fortuño, F J; Wurtz, G A; Dickson, W; Murphy, A; Morgan, F; Pollard, R J; Iorsh, I; Atrashchenko, A; Belov, P A; Kivshar, Y S; Nevet, A; Ankonina, G; Orenstein, M; Zayats, A V

    2013-06-17

    One of the basic functionalities of photonic devices is the ability to manipulate the polarization state of light. Polarization components are usually implemented using the retardation effect in natural birefringent crystals and, thus, have a bulky design. Here, we have demonstrated the polarization manipulation of light by employing a thin subwavelength slab of metamaterial with an extremely anisotropic effective permittivity tensor. Polarization properties of light incident on the metamaterial in the regime of hyperbolic, epsilon-near-zero, and conventional elliptic dispersions were compared. We have shown that both reflection from and transmission through λ/20 thick slab of the metamaterial may provide nearly complete linear-to-circular polarization conversion or 90° linear polarization rotation, not achievable with natural materials. Using ellipsometric measurements, we experimentally studied the polarization conversion properties of the metamaterial slab made of the plasmonic nanorod arrays in different dispersion regimes. We have also suggested all-optical ultrafast control of reflected or transmitted light polarization by employing metal nonlinearities. PMID:23787679

  11. Perfect imaging, epsilon-near zero phenomena and waveguiding in the scope of nonlocal effects

    PubMed Central

    David, C.; Mortensen, N. A.; Christensen, J.

    2013-01-01

    Plasmons in metals can oscillate on a sub-wavelength length scale and this large-k response constitutes an inherent prerequisite for fascinating effects such as perfect imaging and intriguing wave phenomena associated with the epsilon-near-zero (ENZ) regime. While there is no upper cut-off within the local-response approximation (LRA) of the plasma polarization, nonlocal dynamics suppress response beyond ω/vF, where vF is the Fermi velocity of the electron gas. Nonlocal response has previously been found to pose limitations to field-enhancement phenomena. Accounting for nonlocal hydrodynamic response, we show that perfect imaging is surprisingly only marginally affected by nonlocal properties of a metal slab, even for a deep subwavelength case and an extremely thin film. Similarly, for the ENZ response we find no indications of nonlocal response jeopardizing the basic behaviors anticipated from the LRA. Finally, our study of waveguiding of gap plasmons even shows a positive nonlocal influence on the propagation length. PMID:23982271

  12. Protein Kinase C Epsilon Promotes Cerebral Ischemic Tolerance Via Modulation of Mitochondrial Sirt5

    PubMed Central

    Morris-Blanco, Kahlilia C.; Dave, Kunjan R.; Saul, Isabel; Koronowski, Kevin B.; Stradecki, Holly M.; Perez-Pinzon, Miguel A.

    2016-01-01

    Sirtuin 5 (SIRT5) is a mitochondrial-localized NAD+-dependent lysine desuccinylase and a major regulator of the mitochondrial succinylome. We wanted to determine whether SIRT5 is activated by protein kinase C epsilon (PKCε)-mediated increases in mitochondrial Nampt and whether SIRT5 regulates mitochondrial bioenergetics and neuroprotection against cerebral ischemia. In isolated mitochondria from rat cortical cultures, PKCε activation increased SIRT5 levels and desuccinylation activity in a Nampt-dependent manner. PKCε activation did not lead to significant modifications in SIRT3 activity, the major mitochondrial lysine deacetylase. Assessments of mitochondrial bioenergetics in the cortex of wild type (WT) and SIRT5−/− mice revealed that SIRT5 regulates oxygen consumption in the presence of complex I, complex II, and complex IV substrates. To explore the potential role of SIRT5 in PKCε-mediated protection, we compared WT and SIRT5−/− mice by employing both in vitro and in vivo ischemia paradigms. PKCε-mediated decreases in cell death following oxygen-glucose deprivation were abolished in cortical cultures harvested from SIRT5−/− mice. Furthermore, PKCε failed to prevent cortical degeneration following MCAO in SIRT5−/− mice. Collectively this demonstrates that SIRT5 is an important mitochondrial enzyme for protection against metabolic and ischemic stress following PKCε activation in the brain. PMID:27435822

  13. Clostridium perfringens epsilon toxin: the third most potent bacterial toxin known.

    PubMed

    Alves, Guilherme Guerra; Machado de Ávila, Ricardo Andrez; Chávez-Olórtegui, Carlos Delfin; Lobato, Francisco Carlos Faria

    2014-12-01

    Epsilon toxin (ETX) is produced by Clostridium perfringens type B and D strains and causes enterotoxemia, a highly lethal disease with major impacts on the farming of domestic ruminants, particularly sheep. ETX belongs to the aerolysin-like pore-forming toxin family. Although ETX has striking similarities to other toxins in this family, ETX is often more potent, with an LD50 of 100 ng/kg in mice. Due to this high potency, ETX is considered as a potential bioterrorism agent and has been classified as a category B biological agent by the Centers for Disease Control and Prevention (CDC) of the United States. The protoxin is converted to an active toxin through proteolytic cleavage performed by specific proteases. ETX is absorbed and acts locally in the intestines then subsequently binds to and causes lesions in other organs, including the kidneys, lungs and brain. The importance of this toxin for veterinary medicine and its possible use as a biological weapon have drawn the attention of researchers and have led to a large number of studies investigating ETX. The aim of the present work is to review the existing knowledge on ETX from C. perfringens type B and D. PMID:25234332

  14. Clostridium perfringens epsilon toxin is cytotoxic for human renal tubular epithelial cells.

    PubMed

    Fernandez Miyakawa, Mariano E; Zabal, Osvaldo; Silberstein, Claudia

    2011-04-01

    Clostridium perfringens epsilon toxin (ETX) is responsible for a fatal enterotoxemia in different animal species, producing extensive renal damage, neurological disturbance and edema of lungs, heart and kidneys. However, there is no information about the susceptibility of humans to ETX. Here, we report that primary cultures of human renal tubular epithelial cells (HRTEC) exposed to ETX showed a marked swelling with subsequent large blebs surrounding most cells. The incubation of HRTEC with ETX produced a reduction of cell viability in a dose- and time-dependent manner. The CD(50) after 1-hour and 24-hour incubation were 3 µg/mL and 0.5 µg/mL, respectively. The pulse with ETX for 3 min was enough to produce a significant cytotoxic effect on HRTEC after 1-hour incubation. ETX binds to HRTEC forming a large complex of about 160 kDa similar to what was found in the Madin-Darby canine kidney (MDCK) cell line. The HRTEC could be a useful cell model to improve the understanding of the mechanisms involved on the cell damage mediated by ETX. PMID:20488848

  15. Epsilon-near-zero modes for tailored light-matter interaction

    DOE PAGESBeta

    Campione, Salvatore; Liu, Sheng; Benz, Alexander; Klem, John F.; Sinclair, Michael B.; Brener, Igal

    2015-10-20

    Epsilon-near-zero (ENZ) modes arising from condensed-matter excitations such as phonons and plasmons are a new path for tailoring light-matter interactions at the nanoscale. Complex spectral shaping can be achieved by creating such modes in nanoscale semiconductor layers and controlling their interaction with multiple, distinct, dipole resonant systems. Examples of this behavior are presented at midinfrared frequencies for ENZ modes that are strongly coupled to metamaterial resonators and simultaneously strongly coupled to semiconductor phonons or quantum-well intersubband transitions (ISTs), resulting in double- and triple-polariton branches in transmission spectra. For the double-polariton branch case, we find that the best strategy to maximizemore » the Rabi splitting is to use a combination of a doped layer supporting an ENZ feature and a layer supporting ISTs, with overlapping ENZ and IST frequencies. As a result, this design flexibility renders this platform attractive for low-voltage tunable filters, light-emitting diodes, and efficient nonlinear composite materials.« less

  16. Epsilon-near-zero modes for tailored light-matter interaction

    SciTech Connect

    Campione, Salvatore; Liu, Sheng; Benz, Alexander; Klem, John F.; Sinclair, Michael B.; Brener, Igal

    2015-10-20

    Epsilon-near-zero (ENZ) modes arising from condensed-matter excitations such as phonons and plasmons are a new path for tailoring light-matter interactions at the nanoscale. Complex spectral shaping can be achieved by creating such modes in nanoscale semiconductor layers and controlling their interaction with multiple, distinct, dipole resonant systems. Examples of this behavior are presented at midinfrared frequencies for ENZ modes that are strongly coupled to metamaterial resonators and simultaneously strongly coupled to semiconductor phonons or quantum-well intersubband transitions (ISTs), resulting in double- and triple-polariton branches in transmission spectra. For the double-polariton branch case, we find that the best strategy to maximize the Rabi splitting is to use a combination of a doped layer supporting an ENZ feature and a layer supporting ISTs, with overlapping ENZ and IST frequencies. As a result, this design flexibility renders this platform attractive for low-voltage tunable filters, light-emitting diodes, and efficient nonlinear composite materials.

  17. Whey protein concentrate doped electrospun poly(epsilon-caprolactone) fibers for antibiotic release improvement.

    PubMed

    Ahmed, Said Mahmoud; Ahmed, Hanaa; Tian, Chang; Tu, Qin; Guo, Yadan; Wang, Jinyi

    2016-07-01

    Design and fabrication of scaffolds using appropriate biomaterials are a key step for the creation of functionally engineered tissues and their clinical applications. Poly(epsilon-caprolactone) (PCL), a biodegradable and biocompatible material with negligible cytotoxicity, is widely used to fabricate nanofiber scaffolds by electrospinning for the applications of pharmaceutical products and wound dressings. However, the use of PCL as such in tissue engineering is limited due to its poor bioregulatory activity, high hydrophobicity, lack of functional groups and neutral charge. With the attempt to found nanofiber scaffolds with antibacterial activity for skin tissue engineering, in this study, whey protein concentrate (WPC) was used to modify the PCL nanofibers by doping it in the PCL electrospun solution. By adding proteins into PCL nanofibers, the degradability of the fibers may be increased, and this further allows an antibiotic incorporated in the fibers to be efficiently released. The morphology, wettability and degradation of the as-prepared PCL/WPC nanofibers were carefully characterized. The results showed that the PCL/WPC nanofibers possessed good morphology and wettability, as well as high degradation ability to compare with the pristine PCL fibers. Afterwords, tetracycline hydrochloride as a model antibiotic drug was doped in the PCL/WPC nanofibers. In vitro drug release assays demonstrated that PCL/WPC nanofibers had higher antibiotic release capability than the PCL nanofibers. Also, antibacterial activity evaluation against various bacteria showed that the drug-doped PCL/WPC fibers possessed more efficient antibacterial activity than the PCL nanofibers. PMID:27022878

  18. Radiative engineering with refractory epsilon-near-zero metamaterials (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Dyachenko, Pavel N.; Molesky, Sean; Petrov, Alexander Y.; Störmer, Michael; Krekeler, Tobias; Lang, Slawa; Ritter, Martin; Jacob, Zubin; Eich, Manfred

    2016-04-01

    Improvement in high-temperature stable spectrally selective absorbers and emitters is integral for the further development of thermophotovoltaic (TPV), lighting and solar thermal applications. However, the high operational temperatures (T>1000oC) required for efficient energy conversion, along with application specific criteria such as the operational range of low bandgap semiconductors, greatly restrict what can be accomplished with natural materials. Motivated by this challenge, we demonstrate the first example of high temperature thermal radiation engineering with metamaterials. By employing the naturally selective thermal excitation of radiative modes that occurs near topological transitions, we show that thermally stable highly selective emissivity features are achieved for temperatures up to 1000°C with low angular dependence in a sub-micron thick refractory tungsten/hafnium dioxide epsilon-near-zero (ENZ) metamaterial. We also investigate the main mechanisms of thermal degradation of the fabricated refractory metamaterial both in terms of optical performance and structural stability using spectral analysis and energy-dispersive X-ray spectroscopy (EDS) techniques. Importantly, we observe chemical stability of the constituent materials for temperatures up to 1000°C and structural stability beyond 1100°C. The scalable fabrication, requiring magnetron sputtering, and thermally robust optical properties of this metamaterial approach are ideally suited to high temperature emitter applications such as lighting or TPV. Our findings provide a first concrete proof of radiative engineering with high temperature topological transition in ENZ metamaterials, and establish a clear path for implementation in TPV energy harvesting applications.

  19. Insulin-loaded poly(epsilon-caprolactone) nanoparticles: efficient, sustained and safe insulin delivery system.

    PubMed

    de Araújo, Thiago M; Teixeira, Zaine; Barbosa-Sampaio, Helena C; Rezende, Luiz F; Boschero, Antonio C; Durán, Nelson; Höehr, Nelci F

    2013-06-01

    The aim of this work was to develop an efficient, biodegradable, biocompatible and safe controlled release system using insulin-loaded poly(epsilon-caprolactone) (PCL) nanoparticles. The insulin-loaded PCL nanoparticles were prepared by double emulsion method (water-in-oil-in-water) using Pluronic F68 as emulsifier. Using the double emulsion method a high insulin encapsulation efficiency (90.6 +/-1.6%) with a zeta potential of -29 +/-2.7 mV and average particle size of 796 +/-10.5 nm was obtained. Insulin-loaded PCL nanoparticles showed no toxicity to MIN6 cells. Insulin nanoparticles administered subcutaneously and intraperitoneally in rats reduced glycaemia of basal levels after 15 minutes, and presented a sustainable hypoglycemic effect on insulin-dependent type 1 diabetic rats, showing to be more efficient than unencapsulated insulin. Furthermore, these nanoparticles were not hepatotoxic, as evaluated by the effect over liver cell-death and oxidative stress scavenger system in rats. These results suggest that insulin-loaded PCL nanoparticles prepared by water-in-oil-in-water emulsion method are biocompatible, efficient and safe insulin-delivering system with controlled insulin release, which indicates that it may be a powerful tool for insulin-dependent patients care. PMID:23858976

  20. Selective chemical genetic inhibition of protein kinase C epsilon reduces ethanol consumption in mice.

    PubMed

    Maiya, Rajani; McMahon, Thomas; Wang, Dan; Kanter, Benjamin; Gandhi, Dev; Chapman, Holly L; Miller, Jacklyn; Messing, Robert O

    2016-08-01

    Reducing expression or inhibiting translocation of protein kinase C epsilon (PKCε) prolongs ethanol intoxication and decreases ethanol consumption in mice. However, we do not know if this phenotype is due to reduced PKCε kinase activity or to impairment of kinase-independent functions. In this study, we used a chemical-genetic strategy to determine whether a potent and highly selective inhibitor of PKCε catalytic activity reduces ethanol consumption. We generated ATP analog-specific PKCε (AS-PKCε) knock-in mice harboring a point mutation in the ATP binding site of PKCε that renders the mutant kinase highly sensitive to inhibition by 1-tert-butyl-3-naphthalen-1-ylpyrazolo[3,4-d]pyrimidin-4-amine (1-NA-PP1). Systemically administered 1-NA-PP1 readily crossed the blood brain barrier and inhibited PKCε-mediated phosphorylation. 1-NA-PP1 reversibly reduced ethanol consumption by AS-PKCε mice but not by wild type mice lacking the AS-PKCε mutation. These results support the development of inhibitors of PKCε catalytic activity as a strategy to reduce ethanol consumption, and they demonstrate that the AS- PKCε mouse is a useful tool to study the role of PKCε in behavior. PMID:26947945

  1. Biodegradable fibrous scaffolds composed of gelatin coated poly(epsilon-caprolactone) prepared by coaxial electrospinning.

    PubMed

    Zhao, Pengcheng; Jiang, Hongliang; Pan, Hui; Zhu, Kangjie; Chen, Weiliam

    2007-11-01

    A facile coaxial electrospinning technique was devised to prepare biodegradable core-shell fibrous scaffolds with poly(epsilon-caprolactone) (PCL) comprising the core structure and gelatin forming the coating of the fibers. The effect of the feed rate of the inner dope on the electrospinning process and fiber morphology was investigated. The results indicated that core-shell fibers with narrow size distribution and smooth surface morphology could be obtained when the feed rate was below 8 mL/h. An increase of the feed rate resulted in analogous increase in the diameters of both the inner PCL fiber core and the entire core-shell fibers. XPS analyses revealed that the surface of the core-shell fibers was tainted with a small amount of PCL. The outer gelatin layer in the core-shell fibers was crosslinked with glutaraldehyde. By optimizing the glutaraldehyde/gelatin feed ratio, crosslinked scaffolds with high porosity were obtained. The mechanic strength of the hydrated, crosslinked core-shell fibrous scaffolds was significantly enhanced because of the presence of hydrophobic PCL in the core region of the fibers. Results of cell culture studies suggested that the crosslinked, core-shell fibrous scaffold were nontoxic and capable of supporting fibroblast adhesion and proliferation. PMID:17450578

  2. Supercritical phase inversion of starch-poly(epsilon-caprolactone) for tissue engineering applications.

    PubMed

    Duarte, Ana Rita C; Mano, João F; Reis, Rui L

    2010-02-01

    In this work, a starch-based polymer, namely a blend of starch-poly(epsilon-caprolactone) was processed by supercritical assisted phase inversion process. This processing technique has been proposed for the development of 3D structures with potential applications in tissue engineering applications, as scaffolds. The use of carbon dioxide as non-solvent in the phase inversion process leads to the formation of a porous and interconnected structure, dry and free of any residual solvent. Different processing conditions such as pressure (from 80 up to 150 bar) and temperature (45 and 55 degrees C) were studied and the effect on the morphological features of the scaffolds was evaluated by scanning electron microscopy and micro-computed tomography. The mechanical properties of the SPCL scaffolds prepared were also studied. Additionally, in this work, the in vitro biological performance of the scaffolds was studied. Cell adhesion and morphology, viability and proliferation was assessed and the results suggest that the materials prepared are allow cell attachment and promote cell proliferation having thus potential to be used in some for biomedical applications. PMID:19842016

  3. The occultation of Epsilon Gem by Mars as observed from Agassiz Station. [for atmosphere temperature profile investigation

    NASA Technical Reports Server (NTRS)

    Liller, W.; Papaliolios, C.; French, R. G.; Elliot, J. L.; Church, C.

    1978-01-01

    Observations of the April 8, 1976, occultation of Epsilon Gem by Mars made at the Agassiz Station of the Harvard College Observatory have been analyzed to yield temperature profiles of the Martian atmosphere for number densities between 10 to the 13th and 10 to the 15th power per cu cm. Pronounced wavelike structure is evident in both immersion and emersion profiles, with a peak-to-peak variation of up to 50 K and a vertical scale of 20 km.

  4. Structure of the Edgeworth-Kuiper Belt (EKB) Dust Disk and Implications for Extrasolar Planet(s) epsilon Eridani

    NASA Technical Reports Server (NTRS)

    Liou, J. -C.; Zook, H. A.; Greaves, J. S.; Holland, W. S.; Boehnhardt, H.; Hahn, J. M.

    2000-01-01

    Numerical simulations of the orbital evolution of dust particles from Edgeworth-Kuiper Belt (EKB) objects show that the three giant planets, Neptune, Jupiter, and Saturn impose distinct and dramatic signatures on the overall distribution of EKB dust particles. The features are very similar to those observed in the dust disk around the nearby star Eridani. Numerical simulations of dust particles in the epsilon Eridani system show that planetary perturbations may be responsible for the observed features

  5. [Effect of epsilon-aminocaproic acid, cyclophosphamide and their combination on the growth of autochthonous sarcomas of mice induced by benzo(a)pyrene].

    PubMed

    Anikin, I V; Tyndyk, M L; Zabezhinskiĭ, M A; Popovich, I G; Anisimov, V N; Pliss, G B

    2014-01-01

    Antifibrinolytic drug epsilon-aminocaproic acid as a therapeutic form (5% solution in saline) was tested for antitumor activity in the autochthonous subcutaneous tumors of mice, induced by benzo (a) pyrene, in monotherapy mode (instead animals received drinking water) and in combination with cyclophosphamide, which was administered once intraperitoneally in the dose of 200 mg/kg. In the control groups, treated with drinking water and saline solution instead of water, there was no stabilization and reduction in tumor volume, while in the groups receiving epsilon-aminocaproic acid, cyclophosphamide and their combination statistically significantly in comparison with the control groups there was increased the proportion of tumors with not changed or reduced volume; epsilon-aminocaproic acid enhanced the antitumor effect of cyclophosphamide. The data obtained are for further study of the antitumor effect of epsilon-aminocaproic acid. PMID:24772624

  6. The BaBar electromagnetic calorimeter

    SciTech Connect

    Stahl, A.

    1997-07-01

    The progress on the design and construction of the BaBar electromagnetic calorimeter including its mechanical structure, the readout system, the mechanical and optical properties of the crystals, and the schedule for the final assembly and testing is summarized.

  7. Dielectric response of BaZrO3/BaTiO3 superlattice

    NASA Astrophysics Data System (ADS)

    Wang, D.; Jiang, Z.

    2016-06-01

    We use the first-principles-based molecular dynamic approach to simulate dipolar dynamics of BaZrO3/BaTiO3 superlattice, and obtain its dielectric response. The dielectric response is decomposed into its compositional, as well as the in-plane and out-of-plane parts, which are then discussed in the context of chemical ordering of Zr/Ti ions. We reveal that, while the in-plane dielectric response of BaZrO3/BaTiO3 superlattice also shows dispersion over probing frequency, it shall not be categorized as relaxor.

  8. A New K-epsilon Eddy Viscosity Model for High Reynolds Number Turbulent Flows: Model Development and Validation

    NASA Technical Reports Server (NTRS)

    Shih, T.-H.; Liou, W. W.; Shabbir, A.; Yang, Z.; Zhu, J.

    1994-01-01

    A new k-epsilon eddy viscosity model, which consists of a new model dissipation rate equation and a new realizable eddy viscosity formulation, is proposed. The new model dissipation rate equation is based on the dynamic equation of the mean-square vorticity fluctuation at large turbulent Reynolds number. The new eddy viscosity formulation is based on the realizability constraints: the positivity of normal Reynolds stresses and Schwarz' inequality for turbulent shear stresses. We find that the present model with a set of unified model coefficients can perform well for a variety of flows. The flows that are examined include: (1) rotating homogeneous shear flows; (2) boundary-free shear flows including a mixing layer, planar and round jets; (3) a channel flow, and flat plate boundary layers with and without a pressure gradient; and (4) backward facing step separated flows. The model predictions are compared with available experimental data. The results from the standard k-epsilon eddy viscosity model are also included for comparison. It is shown that the present model is a significant improvement over the standard k-epsilon eddy viscosity model.

  9. A new k-epsilon eddy viscosity model for high Reynolds number turbulent flows: Model development and validation

    NASA Astrophysics Data System (ADS)

    Shih, T.-H.; Liou, W. W.; Shabbir, A.; Yang, Z.; Zhu, J.

    1994-08-01

    A new k-epsilon eddy viscosity model, which consists of a new model dissipation rate equation and a new realizable eddy viscosity formulation, is proposed. The new model dissipation rate equation is based on the dynamic equation of the mean-square vorticity fluctuation at large turbulent Reynolds number. The new eddy viscosity formulation is based on the realizability constraints: the positivity of normal Reynolds stresses and Schwarz' inequality for turbulent shear stresses. We find that the present model with a set of unified model coefficients can perform well for a variety of flows. The flows that are examined include: (1) rotating homogeneous shear flows; (2) boundary-free shear flows including a mixing layer, planar and round jets; (3) a channel flow, and flat plate boundary layers with and without a pressure gradient; and (4) backward facing step separated flows. The model predictions are compared with available experimental data. The results from the standard k-epsilon eddy viscosity model are also included for comparison. It is shown that the present model is a significant improvement over the standard k-epsilon eddy viscosity model.

  10. High-Spin States in 124Ba

    NASA Astrophysics Data System (ADS)

    Al-Khatib, A.; Singh, A. K.; Huebel, H.; Bringel, P.; Buerger, A.; Neusser, A.; Schoenwasser, G.; Hagemann, G. B.; Hansen, C. R.; Herskind, B.; Sletten, G.; Algora, A.; Dombradi, Zs.; Gal, J.; Kalinka, G.; Molnar, J.; Nyako, B. M.; Sohler, D.; Timar, J.; Zolnai, L.; Kmiecik, M.; Maj, A.; Styczen, J.; Zuber, K.; Hauschild, K.; Korichi, A.; Lopez-Martens, A.; Roccaz, J.; Siem, S.; Hannachi, F.; Scheurer, J. N.; Bednarczyk, P.; Byrski, Th.; Curien, D.; Dorvaux, O.; Duchene, G.; Gall, B.; Khalfallah, F.; Piqueras, I.; Robin, J.; Juhasz, K.; Patel, S. B.; Evans, A. O.; Rainovski, G.; Airoldi, A.; Benzoni, G.; Bracco, A.; Camera, F.; Million, B.; Mason, P.; Paleni, A.; Sacchi, R.; Wieland, O.; Petrache, C. M.; Petrache, D.; La Rana, G.; Moro, R.; de Angelis, G.; Fallon, P.; Lee, I.-Y.; Lisle, J. C.; Cederwall, B.; Lagergren, K.; Lieder, R. M.; Podsvirova, E.; Gast, W.; Jaeger, H.; Redon, N.; Goergen, A.

    2005-04-01

    High-spin states in 124Ba were populated using the 64Ni(64Ni,4n)124Ba reaction at beam energies of 255 and 261 MeV. Gamma-ray coincidences were measured using the EUROBALL detector array.The charged-particle detector array DIAMANT provided channel selection. The previously known rotational bands are extended to higher spins. Five new bands are observed, one of them extends up to the spin 40 hbar region.

  11. Spectral Id of SN ASASSN-15ba

    NASA Astrophysics Data System (ADS)

    Challis, P.; Kirshner, R.; Falco, E.

    2015-01-01

    Spectra (range 350-760 nm) of ASASSN-15ba was obtained on Jan 15, 2015 UT with the F. L. Whipple Observatory 1.5-m telescope (+ FAST). Cross-correlation with a library of supernova spectra using the "Supernova Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) shows ASASSN-15ba is a Normal Ia at a phase of -5 days before maximum brightness.

  12. AMiBA First SZ Measurements

    NASA Astrophysics Data System (ADS)

    Lin, K.-Y.; Wu, J.-H. P.; Umetsu, K.; Kock, P.; Liu, G.-C.; Nishioka, H.; Huang, C.-W.; Liao, Y.-W.; Wang, F.-C.; Ho, P.

    2008-10-01

    Y.T.Lee Array for Microwave Background Anisotropy (AMiBA) is an array utilizing the 90GHz band to measure the CMB power spectrum and the Sunyaev-Zeldovich effect of galaxy clusters. The first stage with seven antennae has been completed, and the second stage with thirteen antennae is being constructed. Using the seven-element array, AMiBA has performed observations on six massive galaxy clusters at redshifts 0.09 - 0.32 during 2007.

  13. Enhanced PKC beta II translocation and PKC beta II-RACK1 interactions in PKC epsilon-induced heart failure: a role for RACK1.

    PubMed

    Pass, J M; Gao, J; Jones, W K; Wead, W B; Wu, X; Zhang, J; Baines, C P; Bolli, R; Zheng, Y T; Joshua, I G; Ping, P

    2001-12-01

    Recent investigations have established a role for the beta II-isoform of protein kinase C (PKC beta II) in the induction of cardiac hypertrophy and failure. Although receptors for activated C kinase (RACKs) have been shown to direct PKC signal transduction, the mechanism through which RACK1, a selective PKC beta II RACK, participates in PKC beta II-mediated cardiac hypertrophy and failure remains undefined. We have previously reported that PKC epsilon activation modulates the expression of RACKs, and that altered epsilon-isoform of PKC (PKC epsilon)-RACK interactions may facilitate the genesis of cardiac phenotypes in mice. Here, we present evidence that high levels of PKC epsilon activity are commensurate with impaired left ventricular function (dP/dt = 6,074 +/- 248 mmHg/s in control vs. 3,784 +/- 269 mmHg/s in transgenic) and significant myocardial hypertrophy. More importantly, we demonstrate that high levels of PKC epsilon activation induce a significant colocalization of PKC beta II with RACK1 (154 +/- 7% of control) and a marked redistribution of PKC beta II to the particulate fraction (17 +/- 2% of total PKC beta II in control mice vs. 49 +/- 5% of total PKC beta II in hypertrophied mice), without compensatory changes of the other eight PKC isoforms present in the mouse heart. This enhanced PKC beta II activation is coupled with increased RACK1 expression and PKC beta II-RACK1 interactions, demonstrating PKC epsilon-induced PKC beta II signaling via a RACK1-dependent mechanism. Taken together with our previous findings regarding enhanced RACK1 expression and PKC epsilon-RACK1 interactions in the setting of cardiac hypertrophy and failure, these results suggest that RACK1 serves as a nexus for at least two isoforms of PKC, the epsilon-isoform and the beta II-isoform, thus coordinating PKC-mediated hypertrophic signaling. PMID:11709417

  14. Effects of Ba loading and calcination temperature on BaAl2O4 formation for BaO/Al2O3 NOx Storage and Reduction Catalysts

    SciTech Connect

    Szailer, Tamas; Kwak, Ja Hun; Kim, Do Heui; Szanyi, Janos; Wang, Chong M.; Peden, Charles HF

    2006-04-30

    The effect of thermal treatment on the structure and chemical properties of Ba-oxide-based NOx storage/reduction catalysts with different Ba loadings was investigated using BET, TEM, EDS, TPD and FTIR techniques. On the basis of the present and previously reported results, we propose that moderate (< ~873 K) temperature calcinations result in a single monolayer (ML) ‘coating’ of BaO on the alumina surface. At high Ba loading in excess of that required for a full monolayer ‘coating’ (> 8 wt.% BaO), small (~5 nm) particles of ‘bulk’ BaO are present on top of the 1 ML BaO/Al2O3 surface. We did not observe any detectable morphological changes upon higher temperature thermal treatment of 2 and 8 wt% BaO/Al2O3 samples, while dramatic changes occurred for the 20 wt% sample. In this latter case, the transformations included BaAl2O4 formation at the expense of the bulk BaO phase. In particular, we conclude that the surface (ML) BaO phase is quite stable against thermal treatment, while the bulk phase provides the source of Ba for BaAl2O4 formation.

  15. CP Violation at BaBar

    SciTech Connect

    Yeche, Christophe; /DSM, DAPNIA, Saclay

    2011-11-15

    We report recent measurements of the three CKM angles of the Unitarity Triangle using about 383 millions b{bar b} pairs collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. The results of the angles ({beta}, {alpha}, {gamma}) of the unitarity triangle are consistent with Belle results, and with other CKM constraints such as the measurement of {epsilon}{sub K}, the length of the sides of the unitarity triangle determined from the measurements of {Delta}m{sub d}, {Delta}m{sub s}, |V{sub ub}|. This is an impressive confirmation of Standard Model in quark-flavor sector.

  16. Synthesis and characterization of shape memory poly (epsilon-caprolactone) polyurethane-ureas

    NASA Astrophysics Data System (ADS)

    Ren, Hongfeng

    Shape memory polymers (SMPs) have attracted significant interest in recent times because of their potential applications in a number of areas, such as medical devices and textiles. However, there are some major drawbacks of SMPs, such as their relatively low moduli resulting in small recovery stresses, and their long response times compared with shape memory alloys (SMAs). A suitable recovery stress which comes from the elastic recovery stress generated in the deformation process is critical in some medical devices. To address some of these shortcomings, the work in this dissertation mainly focuses on the design and synthesis of linear shape memory polymers with higher recovery stress. A series of segmented poly (epsilon-caprolactone) polyurethane-ureas (PCLUUs) were prepared from poly (epsilon-caprolactone) (PCL) diol, different dissociates and chain extenders. NMR and FT-IR were used to identify the structure of the synthesized shape memory polyurethane-ureas. Parameters such as soft segment content (molecular weight and content), chain extender and the rigidity of the main chain were investigated to understand the structure-property relationships of the shape memory polymer systems through DSC, DMA, physical property test, etc. Cyclic thermal mechanic tests were applied to measure the shape memory properties which showed that the recovery stress can be improved above 200% simply by modifying the chain extender. Meanwhile, the synthesis process was optimized to be similar to that of Spandex /LYCRA®. Continuous fibers form shape memory polyurethane-ureas were made from a wet spinning process, which indicated excellent spinnability of the polymer solution. Small angle neutron scattering (SANS) was used to study the morphology of the hard segment at different temperatures and stretch rates and found that the monodisperse rigid cylinder model fit the SANS data quite well. From the cylinder model, the radius of the cylinder increased with increasing hard segment

  17. Toward epsilon levels of measurement precision on 234U/238U by using MC-ICPMS

    NASA Astrophysics Data System (ADS)

    Andersen, M. B.; Stirling, C. H.; Potter, E.-K.; Halliday, A. N.

    2004-10-01

    Variations in 234U/238U have wide-ranging applications as tracers for ground- and river-water fluxes and is an essential component in U-series dating. Analytical developments for measuring 234U/238U have progressed from direct alpha-counting, with precisions at the percent level, to thermal ionization and multiple-collector inductively coupled plasma mass spectrometry (TIMS and MC-ICPMS, respectively) isotopic measurement techniques. However, 234U/238U is difficult to measure with better than permil precision because of the small atomic ratios for most geological samples (~10-4 range). Using a Nu Instruments Nu Plasma MC-ICPMS, we have developed two analytical techniques for the precise measurement of 234U/238U: (1) a conventional standard-bracketing protocol using multiple Faraday cups and electron multipliers with ion counting capabilities (FM) and (2) a standard-bracketing Faraday cup protocol (FF). Both are capable of measuring 234U/238U with precisions at the epsilon level (1 epsilon = 1 part in 104): (1) The conventional standard-bracketing FM measurements are conducted as static measurements with the minor 234U isotope measured in a conventional discrete dynode electron multiplier (SEM) equipped with ion counter and a retardation filter. The Faraday-multiplier gain is measured using bracketing measurements of the U metal standard CRM-145. The external reproducibility of 234U/238U (reformulated into [delta]-notation as [delta]234U), interspersed with frequent measurements of the gain, is at the +/-0.6[per mille sign] level (2[sigma]) for both uraninite and carbonate standards, takes ~75 min and consumes ~120 ng of U per measurement. (2) The static standard-bracketing FF protocol measures all three natural U isotopes in Faraday collectors. This is not usually possible using a standard multiple-Faraday array due to the large differences in the abundances of naturally occurring U isotopes. In our study, this is achieved by replacing the standard 1011 [Omega

  18. Long-term pollution by chlordecone of tropical volcanic soils in the French West Indies: a simple leaching model accounts for current residue.

    PubMed

    Cabidoche, Y-M; Achard, R; Cattan, P; Clermont-Dauphin, C; Massat, F; Sansoulet, J

    2009-05-01

    Chlordecone was applied between 1972 and 1993 in banana fields of the French West Indies. This resulted in long-term pollution of soils and contamination of waters, aquatic biota, and crops. To assess pollution level and duration according to soil type, WISORCH, a leaching model based on first-order desorption kinetics, was developed and run. Its input parameters are soil organic carbon content (SOC) and SOC/water partitioning coefficient (K(oc)). It accounts for current chlordecone soil contents and drainage water concentrations. The model was valid for andosol, which indicates that neither physico-chemical nor microbial degradation occurred. Dilution by previous deep tillages makes soil scrapping unrealistic. Lixiviation appeared the main way to reduce pollution. Besides the SOC and rainfall increases, K(oc) increased from nitisol to ferralsol and then andosol while lixiviation efficiency decreased. Consequently, pollution is bound to last for several decades for nitisol, centuries for ferralsol, and half a millennium for andosol. PMID:19167793

  19. Clostridium perfringens epsilon toxin H149A mutant as a platform for receptor binding studies

    PubMed Central

    Bokori-Brown, Monika; Kokkinidou, Maria C; Savva, Christos G; Fernandes da Costa, Sérgio; Naylor, Claire E; Cole, Ambrose R; Moss, David S; Basak, Ajit K; Titball, Richard W

    2013-01-01

    Clostridium perfringens epsilon toxin (Etx) is a pore-forming toxin responsible for a severe and rapidly fatal enterotoxemia of ruminants. The toxin is classified as a category B bioterrorism agent by the U.S. Government Centres for Disease Control and Prevention (CDC), making work with recombinant toxin difficult. To reduce the hazard posed by work with recombinant Etx, we have used a variant of Etx that contains a H149A mutation (Etx-H149A), previously reported to have reduced, but not abolished, toxicity. The three-dimensional structure of H149A prototoxin shows that the H149A mutation in domain III does not affect organisation of the putative receptor binding loops in domain I of the toxin. Surface exposed tyrosine residues in domain I of Etx-H149A (Y16, Y20, Y29, Y30, Y36 and Y196) were mutated to alanine and mutants Y30A and Y196A showed significantly reduced binding to MDCK.2 cells relative to Etx-H149A that correlated with their reduced cytotoxic activity. Thus, our study confirms the role of surface exposed tyrosine residues in domain I of Etx in binding to MDCK cells and the suitability of Etx-H149A for further receptor binding studies. In contrast, binding of all of the tyrosine mutants to ACHN cells was similar to that of Etx-H149A, suggesting that Etx can recognise different cell surface receptors. In support of this, the crystal structure of Etx-H149A identified a glycan (β-octyl-glucoside) binding site in domain III of Etx-H149A, which may be a second receptor binding site. These findings have important implications for developing strategies designed to neutralise toxin activity. PMID:23504825

  20. The Antimicrobial Mechanism of Action of Epsilon-Poly-l-Lysine

    PubMed Central

    Hyldgaard, Morten; Mygind, Tina; Vad, Brian S.; Stenvang, Marcel; Otzen, Daniel E.

    2014-01-01

    Epsilon-poly-l-lysine (ε-PL) is a natural antimicrobial cationic peptide which is generally regarded as safe (GRAS) as a food preservative. Although its antimicrobial activity is well documented, its mechanism of action is only vaguely described. The aim of this study was to clarify ε-PL's mechanism of action using Escherichia coli and Listeria innocua as model organisms. We examined ε-PL's effect on cell morphology and membrane integrity and used an array of E. coli deletion mutants to study how specific outer membrane components affected the action of ε-PL. We furthermore studied its interaction with lipid bilayers using membrane models. In vitro cell studies indicated that divalent cations and the heptose I and II phosphate groups in the lipopolysaccharide layer of E. coli are critical for ε-PL's binding efficiency. ε-PL removed the lipopolysaccharide layer and affected cell morphology of E. coli, while L. innocua underwent minor morphological changes. Propidium iodide staining showed that ε-PL permeabilized the cytoplasmic membrane in both species, indicating the membrane as the site of attack. We compared the interaction with neutral or negatively charged membrane systems and showed that the interaction with ε-PL relied on negative charges on the membrane. Suspended membrane vesicles were disrupted by ε-PL, and a detergent-like disruption of E. coli membrane was confirmed by atomic force microscopy imaging of supported lipid bilayers. We hypothesize that ε-PL destabilizes membranes in a carpet-like mechanism by interacting with negatively charged phospholipid head groups, which displace divalent cations and enforce a negative curvature folding on membranes that leads to formation of vesicles/micelles. PMID:25304506

  1. Evaluation of the side effects of poly(epsilon-caprolactone) nanocapsules containing atrazine towards maize plants

    NASA Astrophysics Data System (ADS)

    Oliveira, Halley; Stolf-Moreira, Renata; Martinez, Cláudia; Sousa, Gustavo; Grillo, Renato; de Jesus, Marcelo; Fraceto, Leonardo

    2015-10-01

    Poly(epsilon-caprolactone) (PCL) nanocapsules have been used as a carrier system for the herbicide atrazine, which is commonly applied to maize. We demonstrated previously that these atrazine containing polymeric nanocapsules were ten-fold more effective in the control of mustard plants (a target species), as compared to a commercial atrazine formulation. Since atrazine can have adverse effects on non-target crops, here we analyzed the effect of encapsulated atrazine on growth, physiological and oxidative stress parameters of soil-grown maize plants (Zea mays L.). One day after the post-emergence treatment with PCL nanocapsules containing atrazine (1 mg mL-1), maize plants presented 15 and 21 % decreases in maximum quantum yield of photosystem II and in net CO2 assimilation rate, respectively, as compared to water-sprayed plants. The same treatment led to a 1.8-fold increase in leaf lipid peroxidation in comparison with control plants. However, all of these parameters were unaffected four and eight days after the application of encapsulated atrazine. These results suggested that the negative effects of atrazine were transient, probably due to the ability of maize plants to detoxify the herbicide. When encapsulated atrazine was applied at a ten-fold lower concentration (0.1 mg mL-1), a dosage that is still effective for weed control, no effects were detected even shortly after application. Regardless of the herbicide concentration, neither pre- nor post-emergence treatment with the PCL nanocapsules carrying atrazine resulted in the development of any macroscopic symptoms in maize leaves, and there were no impacts on shoot growth. Additionally, no effects were observed when plants were sprayed with PCL nanocapsules without atrazine. Overall, these results suggested that the use of PCL nanocapsules containing atrazine did not lead to persistent side effects in maize plants, and that the technique could offer a safe tool for weed control without affecting crop growth.

  2. Evaluation of the side effects of poly(epsilon-caprolactone) nanocapsules containing atrazine toward maize plants.

    PubMed

    Oliveira, Halley C; Stolf-Moreira, Renata; Martinez, Cláudia B R; Sousa, Gustavo F M; Grillo, Renato; de Jesus, Marcelo B; Fraceto, Leonardo F

    2015-01-01

    Poly(epsilon-caprolactone) (PCL) nanocapsules have been used as a carrier system for the herbicide atrazine, which is commonly applied to maize. We demonstrated previously that these atrazine containing polymeric nanocapsules were 10-fold more effective in the control of mustard plants (a target species), as compared to a commercial atrazine formulation. Since atrazine can have adverse effects on non-target crops, here we analyzed the effect of encapsulated atrazine on growth, physiological and oxidative stress parameters of soil-grown maize plants (Zea mays L.). One day after the post-emergence treatment with PCL nanocapsules containing atrazine (1 mg mL(-1)), maize plants presented 15 and 21% decreases in maximum quantum yield of photosystem II (PSII) and in net CO2 assimilation rate, respectively, as compared to water-sprayed plants. The same treatment led to a 1.8-fold increase in leaf lipid peroxidation in comparison with control plants. However, all of these parameters were unaffected 4 and 8 days after the application of encapsulated atrazine. These results suggested that the negative effects of atrazine were transient, probably due to the ability of maize plants to detoxify the herbicide. When encapsulated atrazine was applied at a 10-fold lower concentration (0.1 mg mL(-1)), a dosage that is still effective for weed control, no effects were detected even shortly after application. Regardless of the herbicide concentration, neither pre- nor post-emergence treatment with the PCL nanocapsules carrying atrazine resulted in the development of any macroscopic symptoms in maize leaves, and there were no impacts on shoot growth. Additionally, no effects were observed when plants were sprayed with PCL nanocapsules without atrazine. Overall, these results suggested that the use of PCL nanocapsules containing atrazine did not lead to persistent side effects in maize plants, and that the technique could offer a safe tool for weed control without affecting crop growth

  3. Silyl ether-coupled poly(epsilon-caprolactone)s with stepwise hydrolytic degradation profiles.

    PubMed

    Wang, M; Zhang, Q; Wooley, K L

    2001-01-01

    Silyl ether-coupled poly(epsilon-caprolactone)s (PCLs) with stepwise degradation profiles were synthesized via the cross-dehydrocoupling polymerizations between 1,4-bis(dimethylsilyl)benzene (BDSB) and telechelic, diol-terminated PCL macromonomers. With the presence of 10 wt % palladium on activated carbon as the catalyst, the condensations between BDSB and diol-terminated PCL macromonomers having molecular weights of 1200, 2010, and 5500 g/mol were performed in toluene at 100 degrees C under argon. Hydrogen was eliminated as the condensate upon the formation of silyl ether bonds linking the PCL blocks, yielding within 24 h, silyl ether-coupled PCLs of molecular mass 7590, 29,900, and 29,500 g/mol, respectively. The characterization of each polymer included (1)H NMR, (13)C NMR, and (29)Si NMR spectroscopies, size exclusion chromatography (SEC), and differential scanning calorimetry. The hydrolytic degradation properties of the polymers in solution were studied, and the molecular weight reductions over time were monitored by SEC. The silyl ether linkages of the polymers underwent hydrolysis in the presence of mineral acids, whereas the PCL segments released from the cleavage of the labile silyl ether coupling unit did not undergo detectable molecular weight reduction over 15 days. In the presence of acetic acid, the silyl ether functionalities were cleaved with a half-life of 3 days; however, the PCL chain required reaction with trifluoroacetic acid to give a number-average molecular weight loss half-life of 4 days. The silyl ether-coupled PCLs underwent degradation in a gradient fashion, therefore, by a protocol that involved the addition of acetic acid for cleavage of the silyl ether functionalities, followed by further addition of trifluoroacetic acid to bring the hydrolysis of the silyl ether functionalities to completion and to trigger the degradation of PCL segments. PMID:11777394

  4. Activity of daptomycin- and vancomycin-loaded poly-epsilon-caprolactone microparticles against mature staphylococcal biofilms

    PubMed Central

    Ferreira, Inês Santos; Bettencourt, Ana F; Gonçalves, Lídia MD; Kasper, Stefanie; Bétrisey, Bertrand; Kikhney, Judith; Moter, Annette; Trampuz, Andrej; Almeida, António J

    2015-01-01

    The aim of the present study was to develop novel daptomycin-loaded poly-epsilon-caprolactone (PCL) microparticles with enhanced antibiofilm activity against mature biofilms of clinically relevant bacteria, methicillin-resistant Staphylococcus aureus (MRSA) and polysaccharide intercellular adhesin-positive Staphylococcus epidermidis. Daptomycin was encapsulated into PCL microparticles by a double emulsion-solvent evaporation method. For comparison purposes, formulations containing vancomycin were also prepared. Particle morphology, size distribution, encapsulation efficiency, surface charge, thermal behavior, and in vitro release were assessed. All formulations exhibited a spherical morphology, micrometer size, and negative surface charge. From a very early time stage, the released concentrations of daptomycin and vancomycin were higher than the minimal inhibitory concentration and continued so up to 72 hours. Daptomycin presented a sustained release profile with increasing concentrations of the drug being released up to 72 hours, whereas the release of vancomycin stabilized at 24 hours. The antibacterial activity of the microparticles was assessed by isothermal microcalorimetry against planktonic and sessile MRSA and S. epidermidis. Regarding planktonic bacteria, daptomycin-loaded PCL microparticles presented the highest antibacterial activity against both strains. Isothermal microcalorimetry also revealed that lower concentrations of daptomycin-loaded microparticles were required to completely inhibit the recovery of mature MRSA and S. epidermidis biofilms. Further characterization of the effect of daptomycin-loaded PCL microparticles on mature biofilms was performed by fluorescence in situ hybridization. Fluorescence in situ hybridization showed an important reduction in MRSA biofilm, whereas S. epidermidis biofilms, although inhibited, were not eradicated. In addition, an important attachment of the microparticles to MRSA and S. epidermidis biofilms was

  5. Activity of daptomycin- and vancomycin-loaded poly-epsilon-caprolactone microparticles against mature staphylococcal biofilms.

    PubMed

    Ferreira, Inês Santos; Bettencourt, Ana F; Gonçalves, Lídia M D; Kasper, Stefanie; Bétrisey, Bertrand; Kikhney, Judith; Moter, Annette; Trampuz, Andrej; Almeida, António J

    2015-01-01

    The aim of the present study was to develop novel daptomycin-loaded poly-epsilon-caprolactone (PCL) microparticles with enhanced antibiofilm activity against mature biofilms of clinically relevant bacteria, methicillin-resistant Staphylococcus aureus (MRSA) and polysaccharide intercellular adhesin-positive Staphylococcus epidermidis. Daptomycin was encapsulated into PCL microparticles by a double emulsion-solvent evaporation method. For comparison purposes, formulations containing vancomycin were also prepared. Particle morphology, size distribution, encapsulation efficiency, surface charge, thermal behavior, and in vitro release were assessed. All formulations exhibited a spherical morphology, micrometer size, and negative surface charge. From a very early time stage, the released concentrations of daptomycin and vancomycin were higher than the minimal inhibitory concentration and continued so up to 72 hours. Daptomycin presented a sustained release profile with increasing concentrations of the drug being released up to 72 hours, whereas the release of vancomycin stabilized at 24 hours. The antibacterial activity of the microparticles was assessed by isothermal microcalorimetry against planktonic and sessile MRSA and S. epidermidis. Regarding planktonic bacteria, daptomycin-loaded PCL microparticles presented the highest antibacterial activity against both strains. Isothermal microcalorimetry also revealed that lower concentrations of daptomycin-loaded microparticles were required to completely inhibit the recovery of mature MRSA and S. epidermidis biofilms. Further characterization of the effect of daptomycin-loaded PCL microparticles on mature biofilms was performed by fluorescence in situ hybridization. Fluorescence in situ hybridization showed an important reduction in MRSA biofilm, whereas S. epidermidis biofilms, although inhibited, were not eradicated. In addition, an important attachment of the microparticles to MRSA and S. epidermidis biofilms was

  6. Selected results from the epsilon Aurigae eclipse campaign, and what lies ahead

    NASA Astrophysics Data System (ADS)

    Stencel, Robert E.

    2013-07-01

    The torrent of data generated during the 2009-2011 eclipse of the enigmatic binary, epsilon Aurigae, has provided abundant opportunity to test and refine the many ideas associated with this system. The UBVRIJH photometric light curves established times of ingress and egress, and also revealed that the differential color of the disk varied, relative to pre- or post- mid-eclipse phase. Inter-eclipse monitoring indicated secular variations suggestive of a rapidly evolving F supergiant star. Interferometric imaging decisively identified the eclipse-causing agent to be an opaque disk (CHARA+MIRC). Spectroscopy has shown that a hot source occupies the center of this disk (He I 10830A, Far-UV excess), that the disk exhibits substructure (K I 7699A) and may have an extended atmosphere (CHARA+VEGA), and that the disk is isotopically-enhanced in 13C (GNIRS) and in rare-earth elements during a third contact "still-stand" in the light curve, suggestive of a mass transfer stream. Polarimetry and spectro-polarimetry provided additional constraints on the F star atmospheric variation and the nature of the dust scattering in the disk. Numerical models of the disk are exploring its relationship to the wider class of transitional and debris-type disks, and how differential heating of the dust may reveal properties not otherwise detected spectroscopically. As the system moves to quadrature in coming years, continued observing opportunities will continue to exist. I am grateful for support from the estate of William Herschel Womble for astronomy at the University of Denver, which has made possible two decades of research on this star that otherwise has revealed its secrets only very slowly.

  7. Proteolytic Processing and Activation of Clostridium perfringens Epsilon Toxin by Caprine Small Intestinal Contents

    PubMed Central

    Freedman, John C.; Li, Jihong; Uzal, Francisco A.

    2014-01-01

    ABSTRACT Epsilon toxin (ETX), a pore-forming toxin produced by type B and D strains of Clostridium perfringens, mediates severe enterotoxemia in livestock and possibly plays a role in human disease. During enterotoxemia, the nearly inactive ETX prototoxin is produced in the intestines but then must be activated by proteolytic processing. The current study sought to examine ETX prototoxin processing and activation ex vivo using the intestinal contents of a goat, a natural host species for ETX-mediated disease. First, this study showed that the prototoxin has a KEIS N-terminal sequence with a molecular mass of 33,054 Da. When the activation of ETX prototoxin ex vivo by goat small intestinal contents was assessed by SDS-PAGE, the prototoxin was processed in a stepwise fashion into an ~27-kDa band or higher-molecular-mass material that could be toxin oligomers. Purified ETX corresponding to the ~27-kDa band was cytotoxic. When it was biochemically characterized by mass spectrometry, the copresence of three ETX species, each with different C-terminal residues, was identified in the purified ~27-kDa ETX preparation. Cytotoxicity of each of the three ETX species was then demonstrated using recombinant DNA approaches. Serine protease inhibitors blocked the initial proteotoxin processing, while carboxypeptidase inhibitors blocked further processing events. Taken together, this study provides important new insights indicating that, in the intestinal lumen, serine protease (including trypsin and possibly chymotrypsin) initiates the processing of the prototoxin but other proteases, including carboxypeptidases, then process the prototoxin into multiple active and stable species. PMID:25336460

  8. Clostridium perfringens epsilon toxin H149A mutant as a platform for receptor binding studies.

    PubMed

    Bokori-Brown, Monika; Kokkinidou, Maria C; Savva, Christos G; Fernandes da Costa, Sérgio; Naylor, Claire E; Cole, Ambrose R; Moss, David S; Basak, Ajit K; Titball, Richard W

    2013-05-01

    Clostridium perfringens epsilon toxin (Etx) is a pore-forming toxin responsible for a severe and rapidly fatal enterotoxemia of ruminants. The toxin is classified as a category B bioterrorism agent by the U.S. Government Centres for Disease Control and Prevention (CDC), making work with recombinant toxin difficult. To reduce the hazard posed by work with recombinant Etx, we have used a variant of Etx that contains a H149A mutation (Etx-H149A), previously reported to have reduced, but not abolished, toxicity. The three-dimensional structure of H149A prototoxin shows that the H149A mutation in domain III does not affect organisation of the putative receptor binding loops in domain I of the toxin. Surface exposed tyrosine residues in domain I of Etx-H149A (Y16, Y20, Y29, Y30, Y36 and Y196) were mutated to alanine and mutants Y30A and Y196A showed significantly reduced binding to MDCK.2 cells relative to Etx-H149A that correlated with their reduced cytotoxic activity. Thus, our study confirms the role of surface exposed tyrosine residues in domain I of Etx in binding to MDCK cells and the suitability of Etx-H149A for further receptor binding studies. In contrast, binding of all of the tyrosine mutants to ACHN cells was similar to that of Etx-H149A, suggesting that Etx can recognise different cell surface receptors. In support of this, the crystal structure of Etx-H149A identified a glycan (β-octyl-glucoside) binding site in domain III of Etx-H149A, which may be a second receptor binding site. These findings have important implications for developing strategies designed to neutralise toxin activity. PMID:23504825

  9. Biodegradable poly(epsilon-caprolactone) nanowires for bone tissue engineering applications.

    PubMed

    Porter, Joshua R; Henson, Andrew; Popat, Ketul C

    2009-02-01

    Critical-sized defects in bone, whether caused by cancer tumor resection, trauma, or selective surgery have in many cases presented insurmountable challenges to the current gold-standard treatment for bone repair. The primary purpose of a tissue-engineered scaffold is to incite and promote the natural healing process of bone, which does not occur in critical-sized defects. In this work, a solvent-free template synthesis technique was utilized to fabricate uniform arrays of substrate-bound poly(epsilon-caprolactone) (PCL) nanowires. Biodegradation of PCL nanowire surfaces was characterized using scanning electron microscopy (SEM) and matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry. Rat bone marrow-derived mesenchymal stem cells (MSCs) were employed to assess short-term biocompatibility and long-term bioactivity of nanowire surfaces. Short-term cell studies indicated that PCL nanowire surfaces supported enhanced cell adhesion and viability compared with control surfaces. MSCs seeded on nanowire surfaces also displayed increased levels of alkaline phosphatase (ALP) after 1, 2, and 3 weeks in culture. Calcium-phosphate mineralization was substantially accelerated on nanowire surfaces compared to control surfaces as indicated through calcium staining, von Kossa staining, SEM, and electron dispersive spectroscopy (EDS). Increased levels of inter- and extracellular levels of osteocalcin and osteopontin were observed on nanowire surfaces using immunofluorescence techniques after 3 weeks of culture. Considering the simplicity of the presented fabrication technique, capacity for solvent-free encapsulation of bioactive molecules or particles, and enhanced MSC performance on nanowire surfaces, this work presents an excellent foundation for the development of 3-D scaffolds for bone tissue regeneration. PMID:19012962

  10. Porous tantalum and poly-epsilon-caprolactone biocomposites for osteochondral defect repair: preliminary studies in rabbits.

    PubMed

    Mrosek, Eike H; Schagemann, Jan C; Chung, Hsi-Wei; Fitzsimmons, James S; Yaszemski, Michael J; Mardones, Rodrigo M; O'Driscoll, Shawn W; Reinholz, Gregory G

    2010-02-01

    Currently, various techniques are in use for the repair of osteochondral defects, none of them being truly satisfactory and they are often two step procedures. Comorbidity due to cancellous bone harvest from the iliac crest further complicates the procedure. Our previous in vitro studies suggest that porous tantalum (TM) or poly-epsilon-caprolactone scaffolds (PCL) in combination with periosteal grafts could be used for osteochondral defect repair. In this in vivo study, cylindrical osteochondral defects were created on the medial and lateral condyles of 10 rabbits and filled with TM/periosteum or PCL/periosteum biosynthetic composites (n = 8 each). The regenerated osteochondral tissue was then analyzed histologically, and evaluated in an independent and blinded manner by five different observers using a 30-point histological score. The overall histological score for PCL/periosteum was significantly better than for TM/periosteum. However, most of the regenerates were well integrated with the surrounding bone (PCL/periosteum, n = 6.4; TM/periosteum, n = 7) along with partial restoration of the tidemark (PCL/periosteum, n = 4.4; TM/periosteum, n = 5.6). A cover of hyaline-like morphology was found after PCL/periosteum treatment (n = 4.8), yet the cartilage yields were inconsistent. In conclusion, the applied TM and PCL scaffolds promoted excellent subchondral bone regeneration. Neo-cartilage formation from periosteum supported by a scaffold was inconsistent. This is the first study to show in vivo results of both PCL and TM scaffolds for a novel approach to osteochondral defect repair. PMID:19743507

  11. Processing methods of ultrathin poly(epsilon-caprolactone) films for tissue engineering applications.

    PubMed

    Tiaw, Kay Siang; Teoh, Swee Hin; Chen, Ran; Hong, Ming Hui

    2007-03-01

    Ultrathin poly(epsilon-caprolactone) (PCL) films were fabricated through biaxially drawn films made from three different methods, namely, spin casting, 2-roll milling, and solution casting. Biaxial drawn spin cast films yield thickness of 1.2 microm which is 9 and 12 times thinner that 2-roll mill and solvent cast films, respectively. The films fabricated were found to exhibit different drawing ratios. 2-roll mill film exhibits the highest drawing ratio of 4 x 4 while spin cast films can only draw up to a ratio of 2 x 2. The morphology of the films, studied using a polarized microscope and atomic force microscope, showed fine fibrillar networks of different thicknesses. Biaxially drawn 2-roll mill and solvent cast films showed thicker fibrils as compared to those for the spin cast films. Such a difference can be attributed to larger spherulites caused by slower cooling rates during melt pressing for both 2-roll mill and solvent cast films and smaller spherulites because of fast cooling during evaporation for spin cast films. Thermal analysis through differential scanning calorimetry revealed a slight increase in the peak-melting temperature after biaxial drawing. A drop in percentage crystallinity was also noted. The result of the water vapor transmission rate (WVTR) was found to be dependent on fabrication techniques that determine the spherulites formation. It was also found that the WVTR was inversely proportional to the thickness of the films. Tensile strength and modulus of the films showed significant improvements after biaxial stretching. By identifying the unique strengths of each individual PCL film produced via different techniques, it is possible to apply to different areas of membrane tissue engineering such as dermatology, ophthalmology, vascular graft engineering, and soft tissue regeneration. PMID:17274653

  12. Clostridium perfringens Epsilon Toxin Causes Selective Death of Mature Oligodendrocytes and Central Nervous System Demyelination

    PubMed Central

    Linden, Jennifer R.; Ma, Yinghua; Zhao, Baohua; Harris, Jason Michael; Rumah, Kareem Rashid; Schaeren-Wiemers, Nicole

    2015-01-01

    ABSTRACT Clostridium perfringens epsilon toxin (ε-toxin) is responsible for a devastating multifocal central nervous system (CNS) white matter disease in ruminant animals. The mechanism by which ε-toxin causes white matter damage is poorly understood. In this study, we sought to determine the molecular and cellular mechanisms by which ε-toxin causes pathological changes to white matter. In primary CNS cultures, ε-toxin binds to and kills oligodendrocytes but not astrocytes, microglia, or neurons. In cerebellar organotypic culture, ε-toxin induces demyelination, which occurs in a time- and dose-dependent manner, while preserving neurons, astrocytes, and microglia. ε-Toxin specificity for oligodendrocytes was confirmed using enriched glial culture. Sensitivity to ε-toxin is developmentally regulated, as only mature oligodendrocytes are susceptible to ε-toxin; oligodendrocyte progenitor cells are not. ε-Toxin sensitivity is also dependent on oligodendrocyte expression of the proteolipid myelin and lymphocyte protein (MAL), as MAL-deficient oligodendrocytes are insensitive to ε-toxin. In addition, ε-toxin binding to white matter follows the spatial and temporal pattern of MAL expression. A neutralizing antibody against ε-toxin inhibits oligodendrocyte death and demyelination. This study provides several novel insights into the action of ε-toxin in the CNS. (i) ε-Toxin causes selective oligodendrocyte death while preserving all other neural elements. (ii) ε-Toxin-mediated oligodendrocyte death is a cell autonomous effect. (iii) The effects of ε-toxin on the oligodendrocyte lineage are restricted to mature oligodendrocytes. (iv) Expression of the developmentally regulated proteolipid MAL is required for the cytotoxic effects. (v) The cytotoxic effects of ε-toxin can be abrogated by an ε-toxin neutralizing antibody. PMID:26081637

  13. Evaluation of the side effects of poly(epsilon-caprolactone) nanocapsules containing atrazine toward maize plants

    PubMed Central

    Oliveira, Halley C.; Stolf-Moreira, Renata; Martinez, Cláudia B. R.; Sousa, Gustavo F. M.; Grillo, Renato; de Jesus, Marcelo B.; Fraceto, Leonardo F.

    2015-01-01

    Poly(epsilon-caprolactone) (PCL) nanocapsules have been used as a carrier system for the herbicide atrazine, which is commonly applied to maize. We demonstrated previously that these atrazine containing polymeric nanocapsules were 10-fold more effective in the control of mustard plants (a target species), as compared to a commercial atrazine formulation. Since atrazine can have adverse effects on non-target crops, here we analyzed the effect of encapsulated atrazine on growth, physiological and oxidative stress parameters of soil-grown maize plants (Zea mays L.). One day after the post-emergence treatment with PCL nanocapsules containing atrazine (1 mg mL−1), maize plants presented 15 and 21% decreases in maximum quantum yield of photosystem II (PSII) and in net CO2 assimilation rate, respectively, as compared to water-sprayed plants. The same treatment led to a 1.8-fold increase in leaf lipid peroxidation in comparison with control plants. However, all of these parameters were unaffected 4 and 8 days after the application of encapsulated atrazine. These results suggested that the negative effects of atrazine were transient, probably due to the ability of maize plants to detoxify the herbicide. When encapsulated atrazine was applied at a 10-fold lower concentration (0.1 mg mL−1), a dosage that is still effective for weed control, no effects were detected even shortly after application. Regardless of the herbicide concentration, neither pre- nor post-emergence treatment with the PCL nanocapsules carrying atrazine resulted in the development of any macroscopic symptoms in maize leaves, and there were no impacts on shoot growth. Additionally, no effects were observed when plants were sprayed with PCL nanocapsules without atrazine. Overall, these results suggested that the use of PCL nanocapsules containing atrazine did not lead to persistent side effects in maize plants, and that the technique could offer a safe tool for weed control without affecting crop growth

  14. Changes in Ba phases in BaO/Al₂O₃ upon thermal aging and H₂O treatment

    SciTech Connect

    Kim, Do Heui; Chin, Ya-Huei; Kwak, Ja Hun; Szanyi, Janos; Peden, Charles HF

    2005-12-01

    The effects of thermal aging and H₂O treatment on the physicochemical properties of a BaO/Al₂O₃ model catalyst were investigated by means of XRD, BET, TEM/EDX and NO₂ TPD. Thermal aging at 1000 °C for 10 hrs resulted in conversion of dispersed BaCO₃ into low surface area crystalline BaAl₂O₄. It was found that H₂O treatment on a BaO/Al₂O₃ sample at room temperature transformed not only the BaAl₂O₄, but also the dispersed BaCO₃ into highly crystalline BaCO₃ segregated from the Al₂O₃ support, as evidenced in TEM/EDX and XRD analysis. The sample containing dispersed BaCO3 in the initial phase segregated more severely than the BaAl₂O₄ containing one, with the Ba in the BaAl₂O₄ matrix exhibiting higher resistance towards segregation. Contacting the BaO/Al₂O₃ sample with liquid water over a prolong period of time leads to an increase in crystallinity of the segregated BaCO₃. These phenomena imply that special care must be taken during catalyst synthesis and during realistic operation of Pt/BaO/Al₂O₃ NOx trap catalysts since both processes involve potential exposure of the material with liquid H₂O. Based on the results, a model to explain the behavior of Ba containing species upon thermal aging and H₂O treatment is proposed.

  15. Studies on karyotype evolution in higher primates in relation to human chromosome 14 and 9 by comparative mapping of immunoglobulin C epsilon genes with fluorescence in situ hybridization.

    PubMed

    Tanabe, H

    1999-01-01

    Karyotypic homologies in relation to human chromosome 14 and 9 were studied through comparative mapping of the immunoglobulin C epsilon genes in higher primates by fluorescence in situ hybridization (FISH) technique. The C epsilon genes will be suitable probes for the analysis of evolutionary rearrangements due to that the multiple recombinational events such as gene duplications and deletions have occurred repeatedly in the immunoglobulin CH gene family (IGH@) during the course of primate evolution. IGH@ locating on the terminal region of human chromosome 14 (HSA14), at band HSA14q32.33, has generated multiple pseudogenes and among subclasses of IGH@ the C epsilon genes have shown most dynamic changes with generating both truncated type (C epsilon 2) and processed type (C epsilon 3) pseudogenes. In this study, chromosomal homologies and rearrangements on HSA14 (C epsilon 1) and HSA9 (C epsilon 3) in relation to the evolutionary genesis of their primate homologous chromosomes in speciation were investigated by comparative mapping with FISH and chromosome painting (ZOO-FISH) techniques. Comparative mapping of the C epsilon 1 gene at HSA14q32.33 was carried out in seven species of nonhuman primates: common chimpanzee (PTR), pygmy chimpanzee (PPA), gorilla (GGO), orangutan (PPY), white-handed gibbon (HLA), agile gibbon (HAG), and Japanese macaque (MFU). The C epsilon 1 gene was assigned to the telomeric region of HSA14 homologues in each species, namely, PTR15q32, PPA15q32, GGO18q16, PPY15q32, HLA17qter, HAG17qter, and MFU7q29, respectively. These results suggested that HSA14 has high degree of syntenic organization with its primate homologues confirmed by ZOO-FISH. Concerning HSA9, comparative mapping of the C epsilon 3 gene at HSA9p24.2-->p24.1 was performed. The mapped positions indicated the HSA9 homologous regions detected by ZOO-FISH in each species, namely, PTR11q34, PPA11q34, GGO13q22, PPY13q16, HLA8qter, HAG8qter, and MFU14q22, respectively, suggesting that

  16. Studies on Structural and Dielectric Properties of ABi{sub 4}Ti{sub 4}O{sub 15} (A Ba, Sr and Pb) Ceramics

    SciTech Connect

    Reddy, T. Gopal; Kumar, B. Rajesh; Rao, T. Subba

    2010-12-01

    Bismuth Titanate based electroceramics of layered perovskite structures are technologically important materials for high temperature piezoelectric and ferroelectric applications, due to their high Curie temperature (675 deg. C), Stable piezoelectric response and excellent dielectric properties. The compounds ABi{sub 4}Ti{sub 4}O{sub 15} (A = Ba, Sr and Pb) belongs to Aurivillius family (n = 4) in which BaBi{sub 4}Ti{sub 4}O{sub 15} crystallizes in tetragonal I4/mmm space group, Sr Bi{sub 4}Ti{sub 4}O{sub 15} and PbBi{sub 4}Ti{sub 4}O{sub 15} crystallizes in orthorhombic space group A2{sub 1}am. In the present work ABi{sub 4}Ti{sub 4}O{sub 15} (A = Ba, Sr and Pb) ceramic samples are prepared through the solid state reaction by conventional mixed oxides by calcination at high temperature. Dielectric constant ({epsilon}'{sub r}) and Dielectric Loss (D) for all the compositions as a function of temperature measured from frequencies 100 Hz to 100 KHz using a HIOKI 3532-50 LCR meter. The dielectric constant increases gradually with an increase in temperature up to transition temperature (T{sub c,} K) and then decreases.

  17. Comparison of four techniques for the detection of Clostridium perfringens type D epsilon toxin in intestinal contents and other body fluids of sheep and goats.

    PubMed

    Uzal, F A; Kelly, W R; Thomas, R; Hornitzky, M; Galea, F

    2003-03-01

    Polyclonal capture enzyme-linked immunosorbent assay (PC-ELISA), monoclonal capture ELISA (MC-ELISA), mouse neutralization test (MNT), and counterimmunoelectrophoresis (CIEP), were compared for their ability to detect epsilon toxin in intestinal contents and body fluids of sheep and goats. When used to evaluate intestinal contents of sheep artificially spiked with epsilon prototoxin, PC-ELISA detected 0.075 mouse lethal dose (MLD)50/ml, whereas the MNT, MC-ELISA, and CIEP detected 6, 25, and 50 MLD50/ml, respectively. Amounts of epsilon toxin detected by PC-ELISA, MC-ELISA, MNT, and CIEP in sheep pericardial fluid artificially spiked with epsilon prototoxin were 0.075, 0.75, 6, and 200 MLD50/ml, respectively. For assaying epsilon toxin in aqueous humor, PC-ELISA and MC-ELISA detected 0.075 MLD50/ml, whereas CIEP detected 200 MLD50/ml (MNT was not evaluated). When 51 samples of intestinal contents of sheep and goats (32 positive and 19 negative to MNT) were analyzed by the other 3 techniques, the relative sensitivity of PC-ELISA, MC-ELISA, and CIEP was 93.75, 84.37, and 37.50%, respectively. The specificity of PC-ELISA, MC-ELISA, and CIEP was 31.57, 57.89, and 84.21%, respectively. The absolute sensitivity of PC-ELISA, MC-ELISA, CIEP, and MNT was 90.90, 69.69, 15.15, and 54.54%. The absolute specificity of the 4 techniques was 100%. These results show that there is a marked inconsistency among techniques routinely used to detect Clostridium perfringens epsilon toxin. Until more consistent results are achieved, the diagnosis of enterotoxemia should not only be based solely on epsilon toxin detection, but also on clinical and pathological data. PMID:12661718

  18. Isolated spinach ribulose-1,5-bisphosphate carboxylase/oxgenase large subunit .epsilon. n-methyltransferase and method of inactivating ribulose-1,5-bishosphatase .epsilon. n-methyltransferase activity

    DOEpatents

    Houtz, Robert L.

    2001-01-01

    The gene sequence for ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) large subunit (LS) .sup..epsilon. N-methyltansferase (protein methylase III or Rubisco LSMT) from a plant which has a des(methyl) lysyl residue in the LS is disclosed. In addition, the full-length cDNA clones for Rubisco LSMT are disclosed. Transgenic plants and methods of producing same which have the Rubisco LSMT gene inserted into the DNA are also provided. Further, methods of inactivating the enzymatic activity of Rubisco LSMT are also disclosed.

  19. Isolated spinach ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit .sup..epsilon. N-methyltransferase and method of inactivating ribulose-1,5-bisphosphatase carboxylase/oxygenase large subunit .sup..epsilon. N-methyltransferase activity

    DOEpatents

    Houtz, Robert L.

    1999-01-01

    The gene sequence for ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) large subunit (LS) .sup..epsilon. N-methyltransferase (protein methylase III or Rubisco LSMT) from a plant which has a des(methyl) lysyl residue in the LS is disclosed. In addition, the full-length cDNA clones for Rubisco LSMT are disclosed. Transgenic plants and methods of producing same which have the Rubisco LSMT gene inserted into the DNA are also provided. Further, methods of inactivating the enzymatic activity of Rubisco LSMT are also disclosed.

  20. Aromatic Residues {epsilon}Trp-55 and {delta}Trp-57 and the Activation of Acetylcholine Receptor Channels.

    PubMed

    Bafna, Pallavi A; Jha, Archana; Auerbach, Anthony

    2009-03-27

    The two transmitter binding sites of the neuromuscular acetylcholine (ACh) receptor channel contain several aromatic residues, including a tryptophan located on the complementary, negative face of each binding pocket. These two residues, Trp-55 in the epsilon subunit and Trp-57 in the delta subunit, were mutated (AEFHILRVY), and for most constructs the rate constants for acetylcholine binding and channel gating were estimated by using single channel kinetic analyses. The rate constants for unliganded channel opening and closing were also estimated for some mutants. From these measurements we calculated all of the equilibrium constants of the "allosteric" cycle as follows: diliganded gating, unliganded gating, dissociation from the C(losed) conformation, and dissociation from the O(pen) conformation. The results indicate the following. (i) These aromatic side chains play a relatively minor role in ACh receptor channel activation. (ii) The main consequence of mutations is to reduce the affinity of the O conformation of the binding site for ACh, with the effect being greater at the epsilon subunit. (iii) In epsilon (but not delta) the aromatic nature of the side chain is important in determining affinity, to a slightly greater degree in the O conformation. Phi value analyses (of both tryptophan residues) show Phi approximately 1 for both the ACh binding and diliganded gating reactions. (iv) This suggests that the structural boundaries of the dynamic elements of the gating conformational change may not be subunit-delimited, and (v) the mutated tryptophan residues experience energy changes that occur relatively early in both the ligand-binding and channel-gating reactions. PMID:19171937

  1. Immunogenicity of a Trivalent Recombinant Vaccine Against Clostridium perfringens Alpha, Beta, and Epsilon Toxins in Farm Ruminants

    PubMed Central

    Moreira, Gustavo Marçal Schmidt Garcia; Salvarani, Felipe Masiero; da Cunha, Carlos Eduardo Pouey; Mendonça, Marcelo; Moreira, Ângela Nunes; Gonçalves, Luciana Aramuni; Pires, Prhiscylla Sadanã; Lobato, Francisco Carlos Faria; Conceição, Fabricio Rochedo

    2016-01-01

    Clostridium perfringens is an anaerobic bacterium that produces several toxins. Of these, the alpha, beta, and epsilon toxins are responsible for causing the most severe C. perfringens-related diseases in farm animals. The best way to control these diseases is through vaccination. However, commercially available vaccines are based on inactivated toxins and have many production drawbacks, which can be overcome through the use of recombinant antigens. In this study, we produced recombinant alpha, beta, and epsilon toxins in Escherichia coli to formulate a trivalent vaccine. Its effectiveness was evaluated through a potency test in rabbits, in which the vaccine generated 9.6, 24.4, and 25.0 IU/mL of neutralizing antibodies against the respective toxins. Following this, cattle, sheep, and goats received the same formulation, generating, respectively, 5.19 ± 0.48, 4.34 ± 0.43, and 4.70 ± 0.58 IU/mL against alpha toxin, 13.71 ± 1.17 IU/mL (for all three species) against beta toxin, and 12.74 ± 1.70, 7.66 ± 1.69, and 8.91 ± 2.14 IU/mL against epsilon toxin. These levels were above the minimum recommended by international protocols. As such, our vaccine was effective in generating protective antibodies and, thus, may represent an interesting alternative for the prevention of C. perfringens-related intoxications in farm animals. PMID:27004612

  2. Guaranteed epsilon-optimal treatment plans with the minimum number of beams for stereotactic body radiation therapy

    NASA Astrophysics Data System (ADS)

    Yarmand, Hamed; Winey, Brian; Craft, David

    2013-09-01

    Stereotactic body radiation therapy (SBRT) is characterized by delivering a high amount of dose in a short period of time. In SBRT the dose is delivered using open fields (e.g., beam’s-eye-view) known as ‘apertures’. Mathematical methods can be used for optimizing treatment planning for delivery of sufficient dose to the cancerous cells while keeping the dose to surrounding organs at risk (OARs) minimal. Two important elements of a treatment plan are quality and delivery time. Quality of a plan is measured based on the target coverage and dose to OARs. Delivery time heavily depends on the number of beams used in the plan as the setup times for different beam directions constitute a large portion of the delivery time. Therefore the ideal plan, in which all potential beams can be used, will be associated with a long impractical delivery time. We use the dose to OARs in the ideal plan to find the plan with the minimum number of beams which is guaranteed to be epsilon-optimal (i.e., a predetermined maximum deviation from the ideal plan is guaranteed). Since the treatment plan optimization is inherently a multi-criteria-optimization problem, the planner can navigate the ideal dose distribution Pareto surface and select a plan of desired target coverage versus OARs sparing, and then use the proposed technique to reduce the number of beams while guaranteeing epsilon-optimality. We use mixed integer programming (MIP) for optimization. To reduce the computation time for the resultant MIP, we use two heuristics: a beam elimination scheme and a family of heuristic cuts, known as ‘neighbor cuts’, based on the concept of ‘adjacent beams’. We show the effectiveness of the proposed technique on two clinical cases, a liver and a lung case. Based on our technique we propose an algorithm for fast generation of epsilon-optimal plans.

  3. Diacylglycerol kinase epsilon in bovine and rat photoreceptor cells. Light-dependent distribution in photoreceptor cells.

    PubMed

    Natalini, Paola M; Zulian, Sandra E; Ilincheta de Boschero, Mónica G; Giusto, Norma M

    2013-07-01

    The present study shows the selective light-dependent distribution of 1,2-diacylglycerol kinase epsilon (DAGKɛ) in photoreceptor cells from bovine and albino rat retina. Immunofluorescence microscopy in isolated rod outer segments from bleached bovine retinas (BBROS) revealed a higher DAGKɛ signal than that found in rod outer segments from dark-adapted bovine retinas (BDROS). The light-dependent outer segment localization of DAGKɛ was also observed by immunohistochemistry in retinas from albino rats. DAGK activity, measured in terms of phosphatidic acid formation from a) [(3)H]DAG and ATP in the presence of EGTA and R59022, a type I DAGK inhibitor, or b) [γ-(32)P]ATP and 1-stearoyl, 2-arachidonoylglycerol (SAG), was found to be significantly higher in BBROS than in BDROS. Higher light-dependent DAGK activity (condition b) was also found when ROS were isolated from dark-adapted rat retinas exposed to light. Western blot analysis of isolated ROS proteins from bovine and rat retinas confirmed that illumination increases DAGKɛ content in the outer segments of these two species. Light-dependent DAGKɛ localization in the outer segment was not observed when U73122, a phospholipase C inhibitor, was present prior to the exposure of rat eyecups (in situ model) to light. Furthermore, no increased PA synthesis from [(3)H]DAG and ATP was observed in the presence of neomycin prior to the exposure of bovine eyecups to light. Interestingly, when BBROS were pre-phosphorylated with ATP in the presence of 1,2-dioctanoyl sn-glycerol (di-C8) or phorbol dibutyrate (PDBu) as PKC activation conditions, higher DAGK activity was observed than in dephosphorylated controls. Taken together, our findings suggest that the selective distribution of DAGKɛ in photoreceptor cells is a light-dependent mechanism that promotes increased SAG removal and synthesis of 1-stearoyl, 2-arachidonoyl phosphatidic acid in the sensorial portion of this cell, thus demonstrating a novel mechanism of light

  4. Population pharmacokinetics of epsilon-aminocaproic acid in infants undergoing craniofacial reconstruction surgery

    PubMed Central

    Stricker, P. A.; Zuppa, A. F.; Fiadjoe, J. E.; Maxwell, L. G.; Sussman, E. M.; Pruitt, E. Y.; Goebel, T. K.; Gastonguay, M. R.; Taylor, J. A.; Bartlett, S. P.; Schreiner, M. S.

    2013-01-01

    Background Understanding the clinical pharmacology of the antifibrinolytic epsilon-aminocaproic acid (EACA) is necessary for rational drug administration in children. The aim of this study is to determine the pharmacokinetics (PKs) of EACA in infants aged 6–24 months undergoing craniofacial reconstruction surgery. Methods Cohorts of six infants were enrolled sequentially to one of the three escalating loading dose–continuous i.v. infusion (CIVI) regimens: 25 mg kg−1, 10 mg kg−1 h−1; 50 mg kg−1, 20 mg kg−1 h−1; 100 mg kg−1, 40 mg kg−1 h−1. Plasma EACA concentrations were determined using a validated high-performance liquid chromatography-tandem mass spectrometry assay. A population non-linear mixed effects modelling approach was used to characterize EACA PKs. Results Population PK parameters of EACA were estimated using a two-compartment disposition model with weight expressed as an allometric covariate and an age effect. The typical patient in this study had an age of 38.71 weeks and a weight of 8.82 kg. PK parameters for this typical patient were: pre-/postoperative plasma drug clearance of 32 ml min−1 (3.6 ml kg−1 min−1), inter-compartmental clearance of 42.4 ml min−1 (4.8 ml min−1 kg−1), central volume of distribution of 1.27 litre (0.14 litre kg−1), and peripheral volume of distribution of 2.53 litre (0.29 litre kg−1). Intra-operative clearance and central volume of distribution were 89% and 80% of the pre-/postoperative value, respectively. Conclusions EACA clearance increased with weight and age. The dependence of clearance on body weight supports weight-based dosing. Based on this study, a loading dose of 100 mg kg−1 followed by a CIVI of 40 mg kg−1 h−1 is appropriate to maintain target plasma EACA concentrations in children aged 6–24 months undergoing these procedures. PMID:23353035

  5. Scattering properties of dust in Orion and the Epsilon Eridani exoplanetary system

    NASA Astrophysics Data System (ADS)

    Mendillo, Christopher B.

    Dust grain properties were investigated in two very different Galactic environments: the interstellar medium and an exoplanetary system. Two sounding rocket missions were developed to study these regions. Wide-field observations of the Orion OB stellar association were performed in the far-ultraviolet using the Spectrograph for Photometric Imaging with Numeric Reconstruction (SPINR) sounding rocket. These observations reveal the diffuse signature of starlight scattering off interstellar dust grains. The spectral-imaging data were used along with a three-dimensional radiative transfer model to measure the dust scattering parameters: the grain albedo (a) and the scattering asymmetry ( g). The measured parameters are consistent with previous measurements made toward Orion. A sharp increase in albedo was measured at ˜1330 A. This feature is not explained by current grain models. The constructed three-dimensional model of Orion includes a two-component dust distribution. The foreground distribution is responsible for the small amount of visible reddening measured toward the bright stars in the Orion constellation. The background distribution represents the Orion Molecular Cloud, which dominates observations of dust emission in the infrared. This model was used to show that backscattered light from the molecular cloud alone cannot produce the observed scattered light distribution. The foreground dust, though optically thin in the visible, significantly contributes to the scattered light in the far-ultraviolet. This suggests that observations of Orion in the infrared and far-ultraviolet may probe entirely different dust populations. The Planetary Imaging Concept Testbed Using a Rocket Experiment (PICTURE) sounding rocket was developed to characterize dust grains in the nearby Epsilon Eridani exoplanetary system. This is a young, dusty system with a Jupiter-massed planet orbiting at ˜3.4 AU (astronomical units). PICTURE sought to capture a direct, visible-light image of

  6. Proteolytic processing and activation of Clostridium perfringens epsilon toxin by caprine small intestinal contents.

    PubMed

    Freedman, John C; Li, Jihong; Uzal, Francisco A; McClane, Bruce A

    2014-01-01

    Epsilon toxin (ETX), a pore-forming toxin produced by type B and D strains of Clostridium perfringens, mediates severe enterotoxemia in livestock and possibly plays a role in human disease. During enterotoxemia, the nearly inactive ETX prototoxin is produced in the intestines but then must be activated by proteolytic processing. The current study sought to examine ETX prototoxin processing and activation ex vivo using the intestinal contents of a goat, a natural host species for ETX-mediated disease. First, this study showed that the prototoxin has a KEIS N-terminal sequence with a molecular mass of 33,054 Da. When the activation of ETX prototoxin ex vivo by goat small intestinal contents was assessed by SDS-PAGE, the prototoxin was processed in a stepwise fashion into an ~27-kDa band or higher-molecular-mass material that could be toxin oligomers. Purified ETX corresponding to the ~27-kDa band was cytotoxic. When it was biochemically characterized by mass spectrometry, the copresence of three ETX species, each with different C-terminal residues, was identified in the purified ~27-kDa ETX preparation. Cytotoxicity of each of the three ETX species was then demonstrated using recombinant DNA approaches. Serine protease inhibitors blocked the initial proteotoxin processing, while carboxypeptidase inhibitors blocked further processing events. Taken together, this study provides important new insights indicating that, in the intestinal lumen, serine protease (including trypsin and possibly chymotrypsin) initiates the processing of the prototoxin but other proteases, including carboxypeptidases, then process the prototoxin into multiple active and stable species. Importance: Processing and activation by intestinal proteases is a prerequisite for ETX-induced toxicity. Previous studies had characterized the activation of ETX using only arbitrarily chosen amounts of purified trypsin and/or chymotrypsin. Therefore, the current study examined ETX activation ex vivo by natural

  7. Ultraviolet and Optical Line Profile Variations in the Spectrum of {epsilon} Persei

    SciTech Connect

    Gies, D. R.; Kambe, E.; Josephs, T. S.; Bagnuolo, W. G. Jr.; Choi, Y. J.; Gudehus, D.; Guyton, K. M.; Hartkopf, W. I.; Hildebrand, J. L.; Kaye, A. B.

    1999-11-01

    The rapid variable star, {epsilon} Per (B0.5 IV-III), displays the largest amplitude profile fluctuations known among the growing number of massive, spectrum-variable stars. Here we present an analysis of a continuous 5 day run of IUE UV spectroscopy, and we show for the first time that the systematic, blue-to-red moving patterns observed in high-quality optical spectra are also present in the UV photospheric lines. We present cross-correlation functions of the individual spectra with that of a narrow-lined standard that produce a high signal-to-noise ratio representation of the blue-to-red moving bump patterns found in individual lines. We then use time series analysis methods to determine the periodic components of the profile variations (after reregistering the spectra to correct for binary motion). There are at least six periods present (ranging from 8.46 to 2.27 hr), and most of these signals are also found in optical line variations observed in 1986 (although the relative amplitudes have changed significantly). Furthermore, analysis of a shorter time series of IUE spectra from 1984 shows that similar periods were present then. We also present H{alpha} and He i {lambda}6678 profiles obtained with the Georgia State University Multi-Telescope Telescope, which were made simultaneously with IUE, and we show that the profile variations are essentially identical in the UV and optical ranges. We rule out rotational modulation and circumstellar gas obscuration as possible causes, and we suggest instead that the variations are the result of photospheric nonradial pulsations of relatively low degree (l=3-5). There were significant changes ({approx}10%) in the equivalent widths of the UV stellar wind lines during the IUE run, and we suggest that wind strengthening events are related to episodes of large-amplitude, constructive interference between the NRP modes. Thus, intermode beating may play an important role in promoting wind loss from massive stars. (c) (c) 1999

  8. UBV photometry of the 1982-4 eclipse of Epsilon Aurigae: A discussion of the observed light curves

    NASA Technical Reports Server (NTRS)

    Schmidtke, P. C.

    1985-01-01

    At least 29 observers in nine countries have contributed photometric measurements of Epsilon Aurigae during the recent observational campaign. The present discussion is limited to data submitted by J. L. Hopkins of the Hopkins Phoenix Observatory and S. I. Ingvarsson of the Tjornisland Astronomical Observatory. Both sources are on the UBV system, with no significant systematic differences. Combined, these two sources cover the entire eclipse, from pre-ingress up to the present (April 1985). It should be noted that this eclipse is the first to have complete photometric coverage in all three broadband filters U, B, and V.

  9. A Tripartite Cocktail of Chimeric Monoclonal Antibodies Passively Protects Mice against Ricin, Staphylococcal Enterotoxin B and Clostridium perfringens Epsilon Toxin

    PubMed Central

    Sully, Erin K.; Whaley, Kevin; Bohorova, Natasha; Bohorov, Ognian; Goodman, Charles; Kim, Do; Pauly, Michael; Velasco, Jesus; Holtsberg, Frederick W.; Stavale, Eric; Aman, M. Javad; Tangudu, Chandra; Uzal, Francisco A.; Mantis, Nicholas J.; Zeitlin, Larry

    2014-01-01

    Due to the fast-acting nature of ricin, staphylococcal enterotoxin (SEB), and Clostridium perfringens epsilon toxin (ETX), it is necessary that therapeutic interventions following a bioterrorism incident by one of these toxins occur as soon as possible after intoxication. Moreover, because the clinical manifestations of intoxication by these toxins are likely to be indistinguishable from each other, especially following aerosol exposure, we have developed a cocktail of chimeric monoclonal antibodies that is capable of neutralizing all three toxins. The efficacy of this cocktail was demonstrated in mouse models of lethal dose toxin challenge. PMID:25260254

  10. Analysis of supersonic flows using k-epsilon model and the RPLUS code: Progress towards high speed combustor analysis

    NASA Technical Reports Server (NTRS)

    Lee, J.

    1993-01-01

    The problem of interest here is the analysis of chemically reacting flow inside of supersonic ramjet combustors. Two key parameters need to be determined: mixing/combustion efficiency and kinetic energy efficiency. In order to determine these parameters, several potential loss mechanisms must be modeled correctly, including mixing, shear, turbulence, vorticity, shock waves, heat transfer, fuel injector drag, poor wall pressure integral, and chemical dissociation. This document discusses k-epsilon turbulence models for use in the RPLUS code for numerical modeling of combustor flow fields.

  11. As the Disk Turns... Monitoring the Azimuthal Thermal Gradient of the Irradiated Dust Disk in Epsilon Aurigae

    NASA Astrophysics Data System (ADS)

    Hoard, Donald; Howell, Steve; Stencel, Robert

    2013-10-01

    Epsilon Aurigae is the eclipsing binary star with the longest known orbital period, showing a single long (~2 yr) eclipse every 27.1 yr. For the last ~200 years, the nature of the eclipsing object defied explanation. We recently showed that epsilon Aur most likely consists of a high luminosity F0 post-AGB star, and a B5 V star surrounded by a solar system size (~8 AU diameter) disk of dusty material. We propose to continue our IRAC monitoring of epsilon Aur, to characterize the disk's azimuthal thermal variation as its irradiated, warm (1150 K) portion increasingly comes into view. We request 0.2 hr to obtain 2 IRAC observations. If Cycle 10 is extended through Jan 2015, we request another 6 visits (0.6 hr) in Dec 2014, coinciding with the predicted start of coherent pulsations of the F star, which occur every ~3000 days. The most recent eclipse was in Aug 2009-Jul 2011; we are now in the post-eclipse phase, when the heated side of the disk begins rotating into view. During the majority of our past IRAC observations (starting a few months prior to the eclipse ingress), only the cool (550 K) side of the disk was visible. In 2014-2015, as we move toward quadrature, the effect of heating due to the F star will increase the IRAC ch1/ch2 flux ratio. The eclipse of epsilon Aur is a rare event and a unique astrophysical opportunity, since backlighting of the disk by the luminous eclipsed star reveals details that cannot be detected in similar disks around single stars. This is one of the very few astrophysical disks where azimuthal thermal gradients can be mapped and interpreted. Observations of the warm side of the disk are crucial to test and constrain new models of disk structure. As part of our overall monitoring campaign with Spitzer, Hubble, Herschel, and numerous ground-based facilities, the proposed observations will make an important contribution to the understanding of binary stars, including mass transfer and evolution, along with new insights into

  12. Fiscal Year 2010 Summary Report on the Epsilon-Metal Phase as a Waste Form for 99 Tc

    SciTech Connect

    Strachan, Denis M.; Crum, Jarrod V.; Buck, Edgar C.; Riley, Brian J.; Zumhoff, Mac R.

    2010-09-30

    Epsilon metal (ε-metal) is generated in nuclear fuel during irradiation. This metal consists of Pd, Ru, Rh, Mo, and some Te. These accumulate at the UO2 grain boundaries as small (ca 5 µm) particles. These metals have limited solubility in the acid used to dissolve fuel during reprocessing and in typical borosilicate glass. These must be treated separately to improve overall waste loading in glass. This low solubility and their survival in 2 Gy-old natural reactors led us to investigate them as a waste form for the immobilization of 99Tc and 107Pd, two very long-lived isotopes.

  13. Thin Film Ba(x)Sr(1-x)TiO3 Ku- and K-Band Phase Shifters Grown on MgO Substrates

    NASA Technical Reports Server (NTRS)

    VanKeuls, F. W.; Mueller, C. H.; Miranda, F. A.; Romanofsky, R. R.; Horwitz, J. S.; Chang, W.; Kim, W. J.

    1999-01-01

    We report measurements of gold circuits fabricated on four Ba(x)Sr(1-x)TiO3 films doped with 1% Mn grown on MgO substrates by laser ablation. Low frequency measurements of epsilon(sub r) and tan(delta) on interdigital capacitors are compared with high frequency measurements of phase shift and insertion loss on coupled microstrip phase shifters done on the same films. The variation in temperature of both high and low frequency device parameters is compared. Annealed and unannealed films are compared. Room temperature figures of merit of phase shift per insertion loss of up to 58.4 C/dB at 18 GHz and 400 V dc bias were measured.

  14. Recombinant expression of in silico identified Bcell epitope of epsilon toxin of Clostridium perfringens in translational fusion with a carrier protein

    PubMed Central

    Kaushik, Himani; Deshmukh, Sachin; Mathur, Deepika Dayal; Tiwari, Archana; Garg, Lalit C

    2013-01-01

    Epsilon toxin secreted by Clostridium perfringens types B and D has been directly implicated as the causative agent of fatal enterotoxemia in domestic animals. The aim of the present study is to use in silico approach for identification of B-cell epitope(s) of epsilon toxin, and its expression in fusion with a carrier protein to analyze its potential as vaccine candidate(s). Using different computational analyses and bioinformatics tools, a number of antigenic determinant regions of epsilon toxin were identified. One of the B cell epitopes of epsilon toxin comprising the region (amino acids 40-62) was identified as a promising antigenic determinant. This Etx epitope (Etx40-62) was cloned and expressed as a translational fusion with B-subunit of heat labile enterotoxin (LTB) of E. coli in a secretory expression system. Similar to the native LTB, the recombinant fusion protein retained the ability to pentamerize and bind to GM1 ganglioside receptor of LTB. The rLTB.Etx40-62 could be detected both with anti-Etx and anti-LTB antisera. The rLTB.Etx40-62 fusion protein thus can be evaluated as a potential vaccine candidate against C. perfringens. Abbreviations aa - amino acid(s), Etx - epsilon toxin of Clostridium perfringens, LTB - B-subunit of heat labile enterotoxin of E. coli. PMID:23904738

  15. Incorporation of Ba in Al and Fe pollucite

    NASA Astrophysics Data System (ADS)

    Vance, Eric R.; Gregg, Daniel J.; Griffiths, Grant J.; Gaugliardo, Paul R.; Grant, Charmaine

    2016-09-01

    Ba, the transmutation product of radioactive Cs, can be incorporated at levels of up to ∼0.07 formula units in Cs(1-2x)BaxAlSi2O6 aluminium pollucite formed by sol-gel methods and sintering at 1400 °C, with more Ba forming BaAl2Si2O8 phases. The effect of Ba substitution in pollucite-structured CsFeSi2O6 was also studied and no evidence of Ba substitution in the pollucite structure via cation vacancies or Fe2+ formation was obtained. The Ba entered a Fe-silicate glass structure. Charge compensation was also attempted with a Cs+ + Fe3+ ↔ Ba2+ + Ni2+ scheme but again the Ba formed a glass and NiO was evident. PCT leaching data showed CsFeSi2O6 to be very leach resistant.

  16. New genus and species of flea beetles (Coleoptera, Chrysomelidae, Galerucinae, Alticini) from Puerto Rico, with comments on flea beetle diversity in the West Indies and a key to the West Indian Monoplatini genera

    PubMed Central

    Konstantinov, A. S.; Konstantinova, A. A.

    2011-01-01

    Abstract A new genus (Borinken) and five new species (Borinken elyunque, Distigmoptera chamorrae, Kiskeya elyunque, Ulrica eltoro, and Ulrica iviei) from Puerto Rico are described and illustrated. A keyto all West Indian Monoplatini genera is provided, as are keys to all speciesof Kiskeya and to the speciesof Ulrica from Puerto Rico. A list of the flea beetle genera, along with the number of species and some of the faunal features is presented and discussed for the West Indies. PMID:22291512

  17. Benzo[a]pyrene (BaP)

    Integrated Risk Information System (IRIS)

    Benzo [ a ] pyrene ( BaP ) ; CASRN 50 - 32 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarc

  18. Unitarity Triangles at BaBar

    SciTech Connect

    Martinez-Vidal, Fernando; /Valencia U., IFIC

    2011-11-23

    The BaBar experiment has used a variety of methods to determine the angles {alpha}, {beta}, and {gamma} of the Cabibbo-Kobayashi-Maskawa Unitarity Triangle, which give insight into the Standard Model description of CP violation in the quark sector of the electroweak interactions. Here we review the main experimental techniques and analyses, with emphasis in the most recent results.

  19. Semileptonic B decays at BaBar

    SciTech Connect

    Cote, D.; /Montreal U.

    2007-05-23

    This paper summarizes the content of a talk given by the author at the Lake Louise Winter Institute, on February 21st 2007. It presents recent measurements of the rates for semileptonic B decays using data collected by the BaBar detector at the PEP-II asymmetric-energy collider at the Stanford Linear Accelerator Center.

  20. Charm Baryon Results from BaBar

    SciTech Connect

    Ziegler, Veronique; /SLAC

    2012-04-27

    We present experimental results from the BaBar experiment on charm baryon spectroscopy and production studies, including studies of excited cascades produced in charm baryon decays. We review the discovery of new decay modes of known states and searches for predicted states.