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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. Indy Mutations and Drosophila Longevity

    PubMed Central

    Rogina, Blanka; Helfand, Stephen L.

    2013-01-01

    Decreased expression of the fly and worm Indy genes extends longevity. The fly Indy gene and its mammalian homolog are transporters of Krebs cycle intermediates, with the highest rate of uptake for citrate. Cytosolic citrate has a role in energy regulation by affecting fatty acid synthesis and glycolysis. Fly, worm, and mice Indy gene homologs are predominantly expressed in places important for intermediary metabolism. Consequently, decreased expression of Indy in fly and worm, and the removal of mIndy in mice exhibit changes associated with calorie restriction, such as decreased levels of lipids, changes in carbohydrate metabolism and increased mitochondrial biogenesis. Here we report that several Indy alleles in a diverse array of genetic backgrounds confer increased longevity. PMID:23580130

  3. 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

  4. Epsilon Eridani Inner Asteroid Belt

    NASA Image and Video Library

    2017-09-14

    SCI2017_0004: Artist's illustration of the Epsilon Eridani system showing Epsilon Eridani b, right foreground, a Jupiter-mass planet orbiting its parent star at the outside edge of an asteroid belt. In the background can be seen another narrow asteroid or comet belt plus an outermost belt similar in size to our solar system's Kuiper Belt. The similarity of the structure of the Epsilon Eridani system to our solar system is remarkable, although Epsilon Eridani is much younger than our sun. SOFIA observations confirmed the existence of the asteroid belt adjacent to the orbit of the Jovian planet. Credit: NASA/SOFIA/Lynette Cook

  5. 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.

  6. 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 ...

  7. Measurement of /var epsilon/'//var epsilon/ at Fermilab

    SciTech Connect

    Hsiung, Yee B.

    1988-10-01

    The current status of the measurement of ''direct'' CP violation parameters /var epsilon/'//var epsilon/ in the Fermilab experiment E731 is reviewed. Preliminary results on upper limit for the decays K/sub L/ ..-->.. ..pi../sup 0/e/sup +/e/sup /minus// and ..pi../sup 0/ ..-->.. e/sup +/e/sup /minus// (from 20% of the data taken in 1987-88) are also reported. 9 refs., 9 figs., 1 tab.

  8. 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)

  9. 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)

  10. 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…

  11. 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…

  12. 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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. {epsilon}{prime}/{epsilon} and rare KL decays from KTeV Experiment

    SciTech Connect

    Yee Bob Hsiung

    2001-01-16

    The authors update the current status for the measurement of the direct-CP violation parameters {epsilon}{prime}/{epsilon} in the KTeV experiment at Fermilab. Substantial statistics have been accumulated during the 1996-7 run and 1999 run for both {epsilon}{prime}/{epsilon} and rare K{sub L} decay searches. The first KTeV result on {epsilon}{prime}/{epsilon} published last year was Re({epsilon}{prime}/{epsilon}) = (28.0 {+-} 4.1) x 10{sup {minus}4} based on the 23% data from 1996-7 run. Combining with the previous E731, NA31 and the recent preliminary NA48 results, the grand average is Re({epsilon}{prime}/{epsilon}) = (19.3 {+-} 3.6) x 10{sup {minus}4} (with S = 1:49), more than 5{sigma} above zero. More data from both KTeV and NA48 after completing the analysis will further improve the precision of this measurement in the near future and hopefully further improve the agreement. New results on the branching ratio and form factor measurements of K{sub L} {r_arrow} {mu}{sup +} {mu}{sup {minus}} {gamma} using 1997 data are also presented. We find that BR(K{sub L} {r_arrow} {mu}{sup +} {mu}{sup {minus}} {gamma}) = (3.66 {+-} 0.04{sub stat} {+-} 0.07{sub syst}) x 10{sup {minus}7}. The form factor parameter {alpha}{sub K}* is measured to be {alpha}{sub K}* = {minus}0.157{sub {minus}0.027}{sup +0.025}. We make the first measurement of the parameter {alpha} from the D'Ambrosio, Isidori, and Portoles form factor, finding {alpha} = {minus}1.53 {+-} 0.09. This measurement of {alpha} limits the CKM parameter {rho} > {minus}0.2.

  18. Contraception and induced abortion in the West Indies: a review.

    PubMed

    Boersma, A A; de Bruijn, J G M

    2011-10-01

    Most islands in the West Indies do not have liberal laws on abortion, nor laws on pregnancy prevention programmes (contraception). We present results of a literature review about the attitude of healthcare providers and women toward (emergency) contraception and induced abortion, prevalence, methods and juridical aspects of induced abortion and prevention policies. Articles were obtained from PubMed, EMBASE, MEDLINE, PsychlNFO and Soclndex (1999 to 2010) using as keywords contraception, induced abortion, termination of pregnancy, medical abortion and West Indies. Thirty-seven articles met the inclusion criteria: 18 on contraception, 17 on induced abortion and two on both subjects. Main results indicated that healthcare providers' knowledge of emergency contraception was low. Studies showed a poor knowledge of contraception, but counselling increased its effective use. Exact numbers about prevalence of abortion were not found. The total annual number of abortions in the West Indies is estimated at 300 000; one in four pregnancies ends in an abortion. The use of misoprostol diminished the complications of unsafe abortions. Legislation of abortion varies widely in the different islands in the West Indies: Cuba, Puerto Rico, Martinique, Guadeloupe and St Martin have legal abortions. Barbados was the first English-speaking island with liberal legislation on abortion. All other islands have restrictive laws. Despite high estimated numbers of abortion, research on prevalence of abortion is missing. Studies showed a poor knowledge of contraception and low use among adolescents. Most West Indian islands have restrictive laws on abortion.

  19. Contaminants in magnificent frigatebird eggs from Barbuda, West Indies.

    PubMed

    Trefry, Sarah A; Diamond, Antony W; Spencer, Nora C; Mallory, Mark L

    2013-10-15

    We examined persistent organic pollutant and trace element concentrations in eggs of magnificent frigatebirds (Fregata magnificens), a species of conservation concern breeding in the West Indies. Despite that frigatebirds feed at high positions in tropical marine food chains, we detected low levels of most contaminants, suggesting limited contamination of their prey. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. 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…

  1. Killing Unwanted West Indies Mahogany Trees by Peeling and Frilling

    Treesearch

    R. W. Nobles; C. B. Briscoe

    1966-01-01

    Peeling and frilling each killed approximately 70 percent of treated West Indies mahogany, but peeling killed a higher percentage of trees between 18 and 33 centimeters (7 and 13 inches) than did frilling. Essentially all mortality occurred within the first 15 months following treatment.

  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. Request for additional epsilon Aurigae observations

    NASA Astrophysics Data System (ADS)

    Templeton, Matthew R.

    2009-10-01

    Dr. Robert Stencel (Denver U.) requests enhanced coverage of the bright, long-period eclipsing binary star epsilon Aurigae through Wednesday. Observations are requested beginning immediately (October 29, 2009; JD 2455134) and continuing through November 5, 2009 (JD 2455141). This request is in conjunction with scheduled observations with the CHARA optical interferometer at Mount Wilson in California. Optical photometry by a number of observers will provide a continuous photometric baseline of epsilon Aurigae during the course of the interferometry, enabling Stencel and collaborators to more easily interpret the interferometric images. These interferometric observations are being made to image the system as it enters eclipse; the optical interferometric observations being made by CHARA are completely analogous to those made with radio interferometers like the Very Large Array, and allow ground based observers to obtain images with far higher resolution than a single optical telescope is capable of. The CHARA observations are scheduled for the nights of November 1, 2, and 3 (through mid-day UT on November 4, 2009). All observations, including visual estimates, DSLR and CCD photometry, and photoelectric photometry, are encouraged. The observations are part of a larger, long-term collaborative effort to study epsilon Aurigae. For more information on epsilon Aurigae, see the Citizen Sky website http://www.citizensky.org/. Epsilon Aurigae is currently in the ingress phase of the eclipse, which likely began in August of 2009. The star is now near V ~ 3.4 and declining. The nature of the eclipsing object is not known, but is likely to be an opaque disk surrounding an unseen, massive secondary star or binary pair. Interferometric images of epsilon Aurigae may yield strong constraints on the shape of the eclipsing! disk and size of the system. Observations should be reported to the AAVSO International Database as EPS AUR.

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

    PubMed

    Rogers, Ryan P; Rogina, Blanka

    2014-04-01

    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.

  5. Apparatus and method to measure dielectric properties (epsilon(') and epsilon(")) of ionic liquids.

    PubMed

    Göllei, Attila; Vass, András; Pallai, Elisabeth; Gerzson, Miklós; Ludányi, Lajos; Mink, János

    2009-04-01

    Conventional techniques for measurement of dielectric properties of ionic liquids or electrolyte solutions fail because the samples are largely short circuited by the high electrical conductance. The object of the author's research activity was to elaborate an apparatus (microwave dielectrometer) and method suitable to measure the dielectric constant (epsilon(')) and loss factor (epsilon(")) of well conducting ionic liquids and other solvents. This process is based on a revised waveguide method completed with an automatic calibration possibility. Contrary to conventional measuring methods this technique uses about 20 W/g power density. The measurements were carried out at 2.45 GHz frequency in the temperature range from 10 up to 100 degrees C. The obtained (epsilon(')) and (epsilon(")) values of different solvents were compared with several published (calculated and measured) data. Statistical analysis was used to determine the error of measurements and distilled water was chosen as a standard for study of data dispersion. To accomplish statistical analysis, namely, the dielectric characteristics have to be determined at the same temperature. The values of variances were less or equal 1 in case of epsilon(') and decrease with increasing temperature. In case of epsilon(") the variance data were much smaller.

  6. The life-extending gene Indy encodes an exchanger for Krebs-cycle intermediates.

    PubMed

    Knauf, Felix; Mohebbi, Nilufar; Teichert, Carsten; Herold, Diana; Rogina, Blanka; Helfand, Stephen; Gollasch, Maik; Luft, Friedrich C; Aronson, Peter S

    2006-07-01

    A longevity gene called Indy (for 'I'm not dead yet'), with similarity to mammalian genes encoding sodium-dicarboxylate cotransporters, was identified in Drosophila melanogaster. Functional studies in Xenopus oocytes showed that INDY mediates the flux of dicarboxylates and citrate across the plasma membrane, but the specific transport mechanism mediated by INDY was not identified. To test whether INDY functions as an anion exchanger, we examined whether substrate efflux is stimulated by transportable substrates added to the external medium. Efflux of [14C]citrate from INDY-expressing oocytes was greatly accelerated by the addition of succinate to the external medium, indicating citrate-succinate exchange. The succinate-stimulated [14C]citrate efflux was sensitive to inhibition by DIDS (4,4'-di-isothiocyano-2,2'-disulphonic stilbene), as demonstrated previously for INDY-mediated succinate uptake. INDY-mediated efflux of [14C]citrate was also stimulated by external citrate and oxaloacetate, indicating citrate-citrate and citrate-oxaloacetate exchange. Similarly, efflux of [14C]succinate from INDY-expressing oocytes was stimulated by external citrate, alpha-oxoglutarate and fumarate, indicating succinate-citrate, succinate-alpha-oxoglutarate and succinate-fumarate exchange respectively. Conversely, when INDY-expressing Xenopus oocytes were loaded with succinate and citrate, [14C]succinate uptake was markedly stimulated, confirming succinate-succinate and succinate-citrate exchange. Exchange of internal anion for external citrate was markedly pH(o)-dependent, consistent with the concept that citrate is co-transported with a proton. Anion exchange was sodium-independent. We conclude that INDY functions as an exchanger of dicarboxylate and tricarboxylate Krebs-cycle intermediates. The effect of decreasing INDY activity, as in the long-lived Indy mutants, may be to alter energy metabolism in a manner that favours lifespan extension.

  7. The West Indies as a laboratory of biogeography and evolution.

    PubMed

    Ricklefs, Robert; Bermingham, Eldredge

    2008-07-27

    Islands have long provided material and inspiration for the study of evolution and ecology. The West Indies are complex historically and geographically, providing a rich backdrop for the analysis of colonization, diversification and extinction of species. They are sufficiently isolated to sustain endemic forms and close enough to sources of colonists to develop a dynamic interaction with surrounding continental regions. The Greater Antilles comprise old fragments of continental crust, some very large; the Lesser Antilles are a more recent volcanic island arc, and the low-lying Bahama Islands are scattered on a shallow oceanic platform. Dating of island lineages using molecular methods indicates over-water dispersal of most inhabitants of the West Indies, although direct connections with what is now southern Mexico in the Early Tertiary, and subsequent land bridges or stepping stone islands linking to Central and South America might also have facilitated colonization. Species-area relationships within the West Indies suggest a strong role for endemic radiations and extinction in shaping patterns of diversity. Diversification is promoted by opportunities for allopatric divergence between islands, or within the large islands of the Greater Antilles, with a classic example provided by the Anolis lizards. The timing of colonization events using molecular clocks permits analysis of colonization-extinction dynamics by means of species accumulation curves. These indicate low rates of colonization and extinction for reptiles and amphibians in the Greater Antilles, with estimated average persistence times of lineages in the West Indies exceeding 30Myr. Even though individual island populations of birds might persist an average of 2Myr on larger islands in the Lesser Antilles, recolonization from within the archipelago appears to maintain avian lineages within the island chain indefinitely. Birds of the Lesser Antilles also provide evidence of a mass extinction event within

  8. Structure refinement and dielectric relaxation of M-type Ba, Sr, Ba-Sr, and Ba-Pb hexaferrites

    SciTech Connect

    Ashima; Sanghi, Sujata; Agarwal, Ashish; Reetu; Ahlawat, Neetu; Monica

    2012-07-01

    M-type hexaferrites with compositions BaFe{sub 12}O{sub 19} (BFO), SrFe{sub 12}O{sub 19} (SFO), Ba{sub 0.5}Sr{sub 0.5}Fe{sub 12}O{sub 19} (BSFO), and Ba{sub 0.5}Pb{sub 0.5}Fe{sub 12}O{sub 19} (BPFO) were synthesized by commercial solid state reaction method. The Rietveld refinement of x-ray powder diffraction revealed a single hexagonal phase with space group P6{sub 3}/mmc for BFO, SFO, and BSFO samples, whereas BPFO sample contains hematite ({alpha}-Fe{sub 2}O{sub 3}) phase with space group R3c along with the M-type main phase. All the samples show dispersion in dielectric constant ({epsilon} Prime ) and dielectric loss (tan {delta}) values with frequency. The values of {epsilon} Prime and tan {delta} increase with increase in temperature due to increase in the number of charge carriers and their mobilities, which are thermally activated. The reciprocal temperature dependence of conductivity ({sigma}{sub ac}) and the most probable relaxation time ({tau}{sub M Double-Prime }) satisfies the Arrhenius relation. A perfect overlapping of the normalized plots of modulus isotherms on a single 'super curve' for all the studied temperatures reveals a temperature independence of dynamic processes involved in conduction and for relaxation. Further, the complex plots of M{sup *} (M Double-Prime vs M Prime ) indicate that dc conductivity dominates in the region below the M Double-Prime {sub max} point. Above M Double-Prime {sub max}, the variations follow Jonscher power law ({sigma} = A{omega}{sup s}) implying that ac conductivity is dominating in this region. Among the prepared samples, SFO hexaferrite has lowest values of {sigma}{sub ac}, {epsilon} Prime , and tan {delta} making it suitable for use in microwave devices.

  9. The American Political Intervention in the Conflict in the Dutch East Indies 1945-1949

    DTIC Science & Technology

    2009-06-12

    East Indies related to the lines of communication to China. If the East Indies were occupied, the Philippines would be almost surrounded. For the...react on any suspicion of Republican hostilities. A local commander seized more territory to secure the lines of communication between Batavia and...

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. 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 the...

  16. 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 the...

  17. 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 the...

  18. 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 the...

  19. 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...

  20. CD3-epsilon overexpressed in prothymocytes acts as an oncogene.

    PubMed Central

    Wang, B.; She, J.; Salio, M.; Allen, D.; Lacy, E.; Lonberg, N.; Terhorst, C.

    1997-01-01

    BACKGROUND: Upon engagement of the T cell receptor for antigen, its associated CD3 proteins recruit signal transduction molecules, which in turn regulate T lymphocyte proliferation, apoptosis, and thymocyte development. Because some signal transducing molecules recruited by CD3-epsilon, i.e., p56lck and p59fyn, are oncogenic and since we previously found that overexpression of CD3-epsilon transgenes causes a block in T lymphocyte and NK cell development, we tested the hypothesis that aberrant CD3-epsilon signaling leads both to abnormal T lymphocyte death and lymphomagenesis. MATERIALS AND METHODS: Ten independently derived transgenic mouse lines were generated with four different genomic CD3-epsilon constructs. Mice either homozygous or hemizygous for each transgene were analyzed for an arrest in T lymphocyte development and for the occurrence of T cell lymphomas. RESULTS: Aggressive clonal T cell lymphomas developed at very high frequencies in seven mouse lines with intermediate levels of copies of CD3-epsilon derived transgenes. However, these lymphomas were not found when high copy numbers of CD3-epsilon transgenes caused a complete block in early thymic development or when a transgene was used in which the exons coding for the CD3-epsilon protein were deleted. Analyses of a series of double mutant mice, tgCD3-epsilon x RAG-2null, indicated that lymphomagenesis was initiated in lineage-committed prothymocytes, i.e., before rearrangement of the T cell receptor genes. In addition, the transgene coding for the CD3-epsilon cytoplasmic domain and its transmembrane region induced a T cell differentiation signal in premalignant tgCD3-epsilon x RAG-2null mice. CONCLUSION: The nonenzymatic CD3-epsilon protein acted as a potent oncogene when overexpressed early in T lymphocyte development. Lymphomagenesis was dependent on signal transduction events initiated by the cytoplasmic domain of CD3-epsilon. Images FIG. 2 FIG. 4 FIG. 5 PMID:9132282

  1. 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.

  2. RS INDI - A photometric analysis using the grid technique

    NASA Astrophysics Data System (ADS)

    Marton, S. F.; Grieco, A.; Lapasset, E.; Sistero, R. F.; Claria, J. J.

    1990-10-01

    Simultaneous solutions from 2484 UBV photelelectric observations of the EB-type system RS Indi has been obtained with the Wilson-Devinney code. Using the grid technique, families of solutions were found for all possible configurations. As different configurations gave similar quality of fit, the more probable configuration was suggested by physical criteria. New times of minimum light obtained in the years 1985 and 1986 confirm the decreasing period of the system. No interpretation was found for the asymmetries observed in the light curves.

  3. Probabilistic Storm Surge Hazard Assessment in the French West Indies

    NASA Astrophysics Data System (ADS)

    Krien, Y.; Dudon, B.; Roger, J.; Zahibo, N.; Arnaud, G.

    2016-12-01

    The French West Indies are prone to hurricanes formed over the warm tropical waters of the Atlantic Ocean and Caribbean Sea. These events can have great consequences in terms of human, property, and economic losses. Storm surge hazard assessment is therefore required to provide guidance to emergency managers and decision-makers. By combining statistical-deterministic approaches and wave-current coupled models, we assessed storm surge hazard in Guadeloupe and Martinique islands. We present here the methodology, the results, as well as the on-going work on the impact of climate change in the framework of the FEDER-funded project C3AF.

  4. 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.

  5. 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

  6. 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

  7. 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.

  8. 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

  9. 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.

  10. Clinical Significance of Epsilon Waves in Arrhythmogenic Cardiomyopathy.

    PubMed

    Protonotarios, Alexandros; Anastasakis, Aris; Tsatsopoulou, Adalena; Antoniades, Loizos; Prappa, Efstathia; Syrris, Petros; Tousoulis, Dimitrios; McKENNA, William J; Protonotarios, Nikos

    2015-07-16

    Epsilon waves are hallmark features of arrhythmogenic cardiomyopathy (ACM) but information about their clinical significance is variable. We evaluated epsilon wave prevalence, characteristics, and their clinical significance in an ACM population. Eighty-six unselected patients fulfilling the 2010 Task Force criteria were enrolled. Seventy-six of them were carriers of desmosomal mutations. All subjects were serially evaluated with standard 12-lead ECG and 2-dimensional echocardiography. Epsilon waves were evaluated in all precordial and inferior leads. Novel parameters assessed included their duration and precordial/inferior lead extension. Twenty-five subjects (29%) had epsilon waves that were present in lead V3 and beyond in 9, and in the inferior leads in 7. Epsilon waves were associated with right ventricular outflow tract (RVOT) (P = 0.001) but not RV posterior wall (P = 0.21), RV apex (P = 0.30), or left ventricular (P = 0.94) wall motion abnormalities. Patients with epsilon waves had increased RVOT diameter (P < 0.0001). Extension of epsilon waves in lead V3 and beyond was associated with increased epsilon wave duration (P = 0.002) and RVOT diameter (P = 0.04). The duration of epsilon waves was positively correlated with RVOT diameter (r = 0.70, P = 0.0001). Epsilon waves were also associated with episodes of sustained ventricular tachycardia (P = 0.004) but not with heart failure (P = 0.41) or sudden cardiac death (P = 0.31). Detection of epsilon waves on 12-lead ECG reflects significant RVOT involvement, which was associated with episodes of sustained ventricular tachycardia but not sudden cardiac death. © 2015 Wiley Periodicals, Inc.

  11. 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.

  12. Long-lived Indy induces reduced mitochondrial reactive oxygen species production and oxidative damage

    PubMed Central

    Neretti, Nicola; Wang, Pei-Yu; Brodsky, Alexander S.; Nyguyen, Hieu H.; White, Kevin P.; Rogina, Blanka; Helfand, Stephen L.

    2009-01-01

    Decreased Indy activity extends lifespan in D. melanogaster without significant reduction in fecundity, metabolic rate, or locomotion. To understand the underlying mechanisms leading to lifespan extension in this mutant strain, we compared the genome-wide gene expression changes in the head and thorax of adult Indy mutant with control flies over the course of their lifespan. A signature enrichment analysis of metabolic and signaling pathways revealed that expression levels of genes in the oxidative phosphorylation pathway are significantly lower in Indy starting at day 20. We confirmed experimentally that complexes I and III of the electron transport chain have lower enzyme activity in Indy long-lived flies by Day 20 and predicted that reactive oxygen species (ROS) production in mitochondria could be reduced. Consistently, we found that both ROS production and protein damage are reduced in Indy with respect to control. However, we did not detect significant differences in total ATP, a phenotype that could be explained by our finding of a higher mitochondrial density in Indy mutants. Thus, one potential mechanism by which Indy mutants extend life span could be through an alteration in mitochondrial physiology leading to an increased efficiency in the ATP/ROS ratio. PMID:19164521

  13. 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.

  14. 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.

  15. Epsilon Aurigae in an evolutionary context

    NASA Technical Reports Server (NTRS)

    Webbink, R. F.

    1985-01-01

    Basic observational data of Epsilon Aurigae are summarized and used as the basis of a discussion of possible evolutionary states of the system. Constraints posed by the presence of a cold disk surrounding the secondary star are also outlined. Possible evolutionary models of the F0 Ia supergiant range from pre-main sequence contraction through shell hydrogen burning, core helium burning, to shell helium burning, depending on the absolute luminosity of the system, for models in which no mass transfer has taken place. Models invoking binary interaction include core and shell helium burning stars, and pre-white dwarfs, again depending on the absolute luminosity of the system. A massive shell helium burning star or a pre-white dwarf mass transfer remnant would appear the most likely of these models at present. Observational tests of these models are briefly outlined.

  16. 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.

  17. Epidemiology of histoplasmosis in the French West Indies (Martinique).

    PubMed

    Garsaud, P; Boisseau-Garsaud, A M; Desbois, N; Verneuil, L; Calès-Quist, D; Hélénon, R; Jouannelle, A; Delord, J M; Sobesky, G; Panelatti, G

    1999-01-01

    The Caribbean islands are presumed to be an endemic zone for Histoplasma capsulatum infection, but no epidemiological studies have been done in this area. Our purpose was to report the epidemiology of histoplasmosis from 1991 to 1997 in the French West Indies (Martinique). Cases identified from the register of the mycology laboratory were analysed retrospectively. Ten cases (9 male and 1 female) were identified; 8 of the patients were infected with HIV (average T4 lymphocyte count in these 8 patients was 32/mm3). Eight patients had cutaneous involvement. The incidence in AIDS patients was 1.7%. The annual incidence in the general population was 0.34/100,000. Our data showed that histoplasmosis is endemic in Martinique, with an incidence in AIDS patients slightly inferior to that in endemic areas of the USA. The high rate of cutaneous forms (80%) is uncommon.

  18. 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

  19. Underestimation of Leptospirosis Incidence in the French West Indies.

    PubMed

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

    2016-04-01

    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. 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. 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.

  20. [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)

  1. Electrical properties of ferroelectric BaTi{sub 2}O{sub 5} and dielectric Ba{sub 6}Ti{sub 17}O{sub 40} ceramics

    SciTech Connect

    Beltran, Hector; Gomez, Beatriz; Maso, Nahum; Cordoncillo, Eloisa; Escribano, Purificacion; West, Anthony R.

    2005-04-15

    Single phase powders of BaTi{sub 2}O{sub 5} and Ba{sub 6}Ti{sub 17}O{sub 40} were made by a sol-gel method with final heating at 1100-1200 deg. C. Ceramic samples were prepared and fired at temperatures in the range 1100-1300 deg. C. Both sets were highly insulating, with conductivities of, e.g., 10{sup -6}-10{sup -7} S cm{sup -1} at 600 deg. C and activation energies for conduction in the range 1.75-1.86 eV. BaTi{sub 2}O{sub 5} compositions are ferroelectric with a permittivity maximum dependent on firing conditions: {epsilon}{sub max}{sup '}=122 at 450 deg. C on firing at 1100 deg. C; and {epsilon}{sub max}{sup '}=130 at 475 deg. C on firing at 1225 deg. C. Ba{sub 6}Ti{sub 17}O{sub 40} is a dielectric with {epsilon}{sup '}{approx}57-55 over the range 40-400 deg. C.

  2. 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.

  3. 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.

  4. Epsilon substituted lysinol derivatives as HIV-1 protease inhibitors.

    PubMed

    Jones, Kristen L G; Holloway, M Katharine; Su, Hua-Poo; Carroll, Steven S; Burlein, Christine; Touch, Sinoeun; DiStefano, Daniel J; Sanchez, Rosa I; Williams, Theresa M; Vacca, Joseph P; Coburn, Craig A

    2010-07-15

    A series of HIV-1 protease inhibitors containing an epsilon substituted lysinol backbone was synthesized. Two novel synthetic routes using N-boc-L-glutamic acid alpha-benzyl ester and 2,6-diaminopimelic acid were developed. Incorporation of this epsilon substituent enabled access to the S2 pocket of the enzyme, affording high potency inhibitors. Modeling studies and synthetic efforts suggest the potency increase is due to both conformational bias and van der Waals interactions with the S2 pocket.

  5. 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.

  6. 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.

  7. 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.

  8. A survey of canine heartworm awareness in Grenada, West Indies.

    PubMed

    Lohmann, Sylke; Sage, Sharon; Stone, Diana; Gibson, Kathryn

    2015-01-01

    Heartworm is a common parasite of dogs in Grenada, West Indies, due to the tropical climate and large number of mosquitoes. Because Grenada is a developing country and a small island, resources and education on heartworm are limited. In an effort to raise awareness of canine heartworm and the preventive measures available, observations and surveys were performed to determine the following: (a) heartworm knowledge among Grenadian dog caregivers seeking veterinary care at the Grenada Society for the Prevention of Cruelty to Animals (GSPCA), (b) dissemination of heartworm information by GSPCA staff to Grenadian dog caregivers, and (c) reasons Grenadians are not administering heartworm prevention to their dogs. Results indicated a marked deficiency in both heartworm knowledge among Grenadian dog caregivers and heartworm knowledge acquisition and dissemination. Lack of knowledge was also cited as a major reason Grenadian dog caregivers were not using heartworm prevention. These results are currently being utilized to modify heartworm education practices at the GSPCA by incorporating Grenada-specific educational tools, with the ultimate goal of reducing illness and death by canine heartworm.

  9. Prostate Cancer Incidence and Mortality in Barbados, West Indies

    PubMed Central

    Hennis, Anselm J. M.; Hambleton, Ian R.; Wu, Suh-Yuh; Skeete, Desiree H.-A.; Nemesure, Barbara; Leske, M. Cristina

    2011-01-01

    We describe prostate cancer incidence and mortality in Barbados, West Indies. We ascertained all histologically confirmed cases of prostate cancer during the period July 2002 to December 2008 and reviewed each death registration citing prostate cancer over a 14-year period commencing January 1995. There were 1101 new cases for an incidence rate of 160.4 (95% Confidence Interval: 151.0–170.2) per 100,000 standardized to the US population. Comparable rates in African-American and White American men were 248.2 (95% CI: 246.0–250.5) and 158.0 (95% CI: 157.5–158.6) per 100,000, respectively. Prostate cancer mortality rates in Barbados ranged from 63.2 to 101.6 per 100,000, compared to 51.1 to 78.8 per 100,000 among African Americans. Prostate cancer risks are lower in Caribbean-origin populations than previously believed, while mortality rates appeared to be higher than reported in African-American men. Studies in Caribbean populations may assist understanding of disparities among African-origin populations with shared heredity. PMID:22110989

  10. Incidence of tongue carcinoma in Trinidad and Tobago, West Indies

    PubMed Central

    RAMDASS, MICHAEL J.; HARRACKSINGH, AVIND; MAHARAJ, KHEMANAND; SING, QUILLAN YOUNG; MOOTEERAM, JUSTIN; BARROW, SHAHEEBA

    2015-01-01

    The incidence of tongue carcinoma in Trinidad and Tobago and the greater West Indies is unknown; therefore, the present study examines the frequency of tongue carcinoma cases, drawing comparisons to worldwide and regional data. A retrospective analysis of all confirmed cases of tongue carcinoma was conducted using eight years of data from the pathology records at the Port of Spain General Hospital (Port of Spain, Trinidad and Tobago). A total of 26 cases were confirmed, of which 21 were male (81%) and five were female (19%). The age range was 29–86 years, with a mean age of 57 years, and the most common group affected was the 61–70 years age group. In addition, the number of newly diagnosed cases per year ranged between one and seven, with an average of 3.25 new cases per year and a peak incidence of seven new cases in the year of 2009. In the 19 cases where the degree of differentiation was recorded, histological analysis revealed the extent of differentiation as follows: Five cases (26%) were poorly-differentiated squamous cell carcinoma (SCC); eight cases (42%) were moderately-differentiated SCC; and six cases (32%) were well-differentiated SCC. In addition, one case of chronic inflammatory process and one case of mucoepidermoid adenocarcinoma of the tongue in a 57-year-old female were identified. Overall, the incidence of tongue carcinoma in Trinidad and Tobago appears to be low, estimated at 0.46/100,000 individuals/year. The male:female ratio is 4:1 and SCC is the dominant cancer type (96% of cases). The peak age of occurrence is at 61–70 years. These findings are in agreement with previously determined global data, however, additional research of the risk factors and outcomes of surgery as a treatment strategy for tongue carcinoma is required. PMID:25663924

  11. Efficient Vortex Generation in Subwavelength Epsilon-Near-Zero Slabs.

    PubMed

    Ciattoni, Alessandro; Marini, Andrea; Rizza, Carlo

    2017-03-10

    We show that a homogeneous and isotropic slab, illuminated by a circularly polarized beam with no topological charge, produces vortices of order 2 in the opposite circularly polarized components of the reflected and transmitted fields, as a consequence of the transverse magnetic and transverse electric asymmetric response of the rotationally invariant system. In addition, in the epsilon-near-zero regime, we find that vortex generation is remarkably efficient in subwavelength thick slabs up to the paraxial regime. This physically stems from the fact that a vacuum paraxial field can excite a nonparaxial field inside an epsilon-near-zero slab since it hosts slowly varying fields over physically large portions of the bulk. Our theoretical predictions indicate that epsilon-near-zero media hold great potential as nanophotonic elements for manipulating the angular momentum of the radiation, since they are available without resorting to complicated micro- or nanofabrication processes and can operate even at very small (ultraviolet) wavelengths.

  12. [Bleeding after extracorporeal circulation and epsilon-aminocaproic acid].

    PubMed

    Saussine, M; Delpech, S; Allien, M; Grolleau, D; Daures, M F; Coulon, P; Chaptal, P A

    1985-01-01

    In order to assess the efficacy of epsilon aminocaproic acid in reducing bleeding after extracorporeal circulation for aorto-coronary bypass grafting, a double blind study was carried out in 57 patients. The efficiency of epsilon aminocaproic acid was assessed by the fibrinolytic activity as measured by a Von Kaulla test one hour after injection of protamine, by the amount of blood transfusions required and by the measurement of blood losses between the end of the injection of protamine and transfer of the patient to the intensive care unit, and then during the first 24 h following operation. No significant difference (p less than 0.05) between the group of treated patients and the group with placebo could be found concerning the postoperative bleeding, the amount of blood transfusions necessary and the occurrence of fibrinolysis. It was therefore concluded that there was no reason to routinely use epsilon aminocaproic acid after aorto-coronary bypass grafting.

  13. Efficient Vortex Generation in Subwavelength Epsilon-Near-Zero Slabs

    NASA Astrophysics Data System (ADS)

    Ciattoni, Alessandro; Marini, Andrea; Rizza, Carlo

    2017-03-01

    We show that a homogeneous and isotropic slab, illuminated by a circularly polarized beam with no topological charge, produces vortices of order 2 in the opposite circularly polarized components of the reflected and transmitted fields, as a consequence of the transverse magnetic and transverse electric asymmetric response of the rotationally invariant system. In addition, in the epsilon-near-zero regime, we find that vortex generation is remarkably efficient in subwavelength thick slabs up to the paraxial regime. This physically stems from the fact that a vacuum paraxial field can excite a nonparaxial field inside an epsilon-near-zero slab since it hosts slowly varying fields over physically large portions of the bulk. Our theoretical predictions indicate that epsilon-near-zero media hold great potential as nanophotonic elements for manipulating the angular momentum of the radiation, since they are available without resorting to complicated micro- or nanofabrication processes and can operate even at very small (ultraviolet) wavelengths.

  14. Framework for improved lattice calculations of epsilion'/epsilon

    NASA Astrophysics Data System (ADS)

    Laiho, Jack

    In this thesis we show that it is possible to construct epsilon '/epsilon to NLO using both full and partially quenched chiral perturbation theory (PQChPT) from amplitudes that are computable using numerical lattice gauge theory. We find that the electro-weak penguin (Delta I = 3/2 and 1/2) contributions to epsilon'/epsilon in PQChPT can be determined to NLO using only degenerate (mK = mpi) K → pi computations without momentum insertion. All one-loop formulas needed to extract the necessary NLO constants from the lattice are presented in this work. Issues pertaining to power divergent contributions, originating from mixing with lower dimensional operators in a lattice regularization, are addressed. In embedding the QCD penguin left-right operator onto PQChPT an ambiguity arises when the number of light sea quarks is not the physical value of three, as first emphasized by Golterman and Pallante. In the quenched theory they have pointed out that there are additional effective operators that appear in the quenched chiral perturbation theory needed to make contact with K → pipi amplitudes at physical kinematics. They have also proposed a method for determining the leading order low-energy constant, aNSq , associated with the new operators. We show that their method has difficulties due to power divergent contributions and propose a new method to obtain this constant from the lattice which does not suffer from this problem. Using this alternative method, we obtain aNSq , and show that our value implies a large ambiguity in the quenched contribution of Q6 to epsilon'/epsilon.

  15. Does Planet Exist in Epsilon Eridani? A Comparison Between Observations and Numerical Simulations

    NASA Technical Reports Server (NTRS)

    Liou, J.-C.; Zook, H. A.; Greaves, J. S.; Holland, W. S.

    2000-01-01

    We report results from our numerical simulations of the Epsilon Eridani dust disk. We also compare our results with actual observations of the disk and address the question of whether or not planet(s) exist in Epsilon Eridani.

  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. 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…

  18. Training in Support of Leadership Development at the University of the West Indies, Mona Campus Library

    ERIC Educational Resources Information Center

    Newman, Dunstan; Newman, Nadine

    2010-01-01

    Purpose: The purpose of this paper is to focus on training in support of leadership development at the University of the West Indies, Mona Campus, main and branch libraries. Design/methodology/approach: The paper is based on an interview with a campus librarian and desk research. Findings: Like any other institution in the world, the Mona Library…

  19. AN ANNOTATED BIBLIOGRAPHY ON THE CLIMATE OF THE FRENCH WEST INDIES,

    DTIC Science & Technology

    The bibliography on the climate of the French West Indies including Martinque, Guadeloupe and Dependencies (Marie Galante, Isles des Saintes...Desirade, St. Barthelemy and French part of St. Martin), consists of sources in the Weather Bureau Library, the Library of Congress, the U.S. Navy Oceanographic Office Library and the Department of Agriculture Library.

  20. Deformation properties of pharmaceutical excipients determined using an in-die and out-die method.

    PubMed

    Ilić, Ilija; Govedarica, Biljana; Šibanc, Rok; Dreu, Rok; Srčič, Stane

    2013-03-25

    This study investigated deformation mechanisms of some commonly used pharmaceutical fillers, such as microcrystalline cellulose, lactose, dicalcium phosphate, isomalt and cornstarch, using a combination of the in-die and out-die method with the Heckel and Walker models. The tableting mixtures contained of 98.5% (w/w) filler, the rest consisted of dry binder and an antiadhesive agent. Our results showed that plasticity and elasticity may be considered independent deformation properties as highly plastic materials (microcrystalline cellulose, cornstarch) also exhibited high elasticity. Particular emphasis was placed on explaining the differences observed between the in-die and out-die method-comparison revealed that the differences are a consequence of the material's elastic properties. Larger error of in-die results can be expected for more elastic materials, and thus in-die Heckel should be used with some considerations. In contrast, the Walker model was found to be more robust and smaller differences were observed between the two methods. We consider the most correct results to have been obtained by the out-die approach, which excludes the elastic properties of the material evaluated. An excellent correlation between elastic determination at the single-particle level and multiple-particle scale was demonstrated, suggesting a great potential of nanoscale determination of a material's mechanical properties for better elucidation of deformation mechanisms. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. 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…

  2. Increasing Public Access to University Qualifications: Evolution of The University of the West Indies Open Campus

    ERIC Educational Resources Information Center

    Thomas, Michael L.; Soares, Judith

    2009-01-01

    This paper traces the evolution of The University of the West Indies' Open Campus (UWIOC), which is expected to expand service and increase access to the underserved communities of the Eastern Caribbean. At present, UWI, which caters to the needs of the 16 far flung countries of the Commonwealth Caribbean, has not been able to fully serve these…

  3. 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…

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

    USDA-ARS?s Scientific Manuscript database

    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...

  5. 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…

  6. Characterization of the interface between gamma and epsilon subunits of Escherichia coli F1-ATPase.

    PubMed

    Tang, C; Capaldi, R A

    1996-02-09

    The interaction faces of the gamma and epsilon subunits in the Escherichia coli F1-ATPase have been explored by a combination of cross-linking and chemical modification experiments using several mutant epsilon subunits as follows: epsilonS10C, epsilonH38C, epsilonT43C, epsilonS65C, epsilonS108C, and epsilonM138C, along with a mutant of the gamma subunit, gammaT106C. The replacement of Ser-10 by a Cys or Met-138 by a Cys reduced the inhibition of ECF1 by the epsilon subunit, while the mutation S65C increased this inhibitory effect. Modification of the Cys at position 10 with N-ethylmaleimide or fluoroscein maleimide further reduced the binding affinity of, and the maximal inhibition by, the epsilon subunit. Similar chemical modification of the Cys at position 43 of the epsilon subunit (in the mutant epsilonT43C) and a Cys at position 106 of the gamma subunit (gammaT106C) also affected the inhibition of ECF1 by the epsilon subunit. The various epsilon subunit mutants were reacted with TFPAM3, and the site(s) of cross-linking within the ECF1 complex was determined. Previous studies have shown cross-linking from the Cys at positions 10 and 38 with the gamma subunit and from a Cys at position 108 to an alpha subunit (Aggeler, R., Chicas-Cruz, K., Cai, S. X., Keana, J. F. W., and Capaldi, R. A. (1992) Biochemistry 31, 2956-2961; Aggeler, R., Weinreich, F., and Capaldi, R. A. (1995) Biochim. Biophys. Acta 1230, 62-68). Here, cross-linking was found from a Cys at position 43 to the gamma subunit and from the Cys at position 138 to a beta subunit. The site of cross-linking from Cys-10 of epsilon to the gamma subunit was localized by peptide mapping to a region of the gamma subunit between residues 222 and 242. Cross-linking from a Cys at position 38 and at position 43 was with the C-terminal part of the gamma subunit, between residues 202 and 286. ECF1 treated with trypsin at pH 7.0 still binds purified epsilon subunit, while enzyme treated with the protease at pH 8.0 does

  7. Photonic doping of epsilon-near-zero media

    NASA Astrophysics Data System (ADS)

    Liberal, Iñigo; Mahmoud, Ahmed M.; Li, Yue; Edwards, Brian; Engheta, Nader

    2017-03-01

    Doping a semiconductor with foreign atoms enables the control of its electrical and optical properties. We transplant the concept of doping to macroscopic photonics, demonstrating that two-dimensional dielectric particles immersed in a two-dimensional epsilon-near-zero medium act as dopants that modify the medium’s effective permeability while keeping its effective permittivity near zero, independently of their positions within the host. The response of a large body can be tuned with a single impurity, including cases such as engineering perfect magnetic conductor and epsilon-and-mu-near-zero media with nonmagnetic constituents. This effect is experimentally demonstrated at microwave frequencies via the observation of geometry-independent tunneling. This methodology might provide a new pathway for engineering electromagnetic metamaterials and reconfigurable optical systems.

  8. The embedded objects in epsilon Cha I cloud

    NASA Technical Reports Server (NTRS)

    Prusti, Timo; Assendorp, R.; Wesselius, P. R.

    1989-01-01

    A study was made of the embedded objects in the epsilon Cha I cloud. General shapes of the spectra were constructed for the members in the cloud. The near infrared data were compiled from the literature and combined with the IRAS Point Source Catalog information. Pointed observations by the IRAS were used in the regions of high source density where the Point Source Catalog is confused. Member objects near the late B star HD 97300 were measured recently in the 3 to 10 micron bands using the ESO 2.2 m telescope in order to study the effects of disks seen in other young stellar objects. A picture is presented of the complete initial luminosity function in the epsilon Cha I cloud. The observations were compared with the theoretical views on low mass star formation.

  9. 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.

  10. Developing a Polarimeter to Support the Epsilon Aurigae Campaign

    NASA Astrophysics Data System (ADS)

    Cole, Gary M.

    This paper discusses the design, construction, and programming of a simplified, automated, dual-beam imaging polarimeter to support the ongoing epsilon Aurigae campaign. This project was initiated at the suggestion of Dr. Robert Stencil at the 2009 May Society for Astronomical Sciences annual Symposium to extend measurements done in the 1986 eclipse by Dr. Gary Henson. The instrument uses a rotating achromatic waveplate, a Savart calcite analyzer, and CCD camera. Calibration using polarimetric standard stars shows that the system detects at least 97% of the polarized flux with less than 0.1% instrumental contamination. The custom software operates the instrument and reduces the data in real time. Observations began in 2009 November. The first 90 days of operation yielded 200 measurements across 20 stars, including 20 nights of multi-band data on epsilon Aurigae. This will be the first of two papers; the second is planned after the eclipse when the full data series is available.

  11. 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.

  12. 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.

  13. 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.

  14. An Attempt to Derive the epsilon Equation from a Two-Point Closure

    NASA Technical Reports Server (NTRS)

    Canuto, V. M.; Cheng, Y.; Howard, A. M.

    2010-01-01

    The goal of this paper is to derive the equation for the turbulence dissipation rate epsilon for a shear-driven flow. In 1961, Davydov used a one-point closure model to derive the epsilon equation from first principles but the final result contained undetermined terms and thus lacked predictive power. Both in 1987 and in 2001, attempts were made to derive the epsilon equation from first principles using a two-point closure, but their methods relied on a phenomenological assumption. The standard practice has thus been to employ a heuristic form of the equation that contains three empirical ingredients: two constants, c(sub 1 epsilon), and c(sub 2 epsilon), and a diffusion term D(sub epsilon) In this work, a two-point closure is employed, yielding the following results: 1) the empirical constants get replaced by c(sub 1), c(sub 2), which are now functions of Kappa and epsilon; 2) c(sub 1) and c(sub 2) are not independent because a general relation between the two that are valid for any Kappa and epsilon are derived; 3) c(sub 1), c(sub 2) become constant with values close to the empirical values c(sub 1 epsilon), c(sub epsilon 2), (i.e., homogenous flows); and 4) the empirical form of the diffusion term D(sub epsilon) is no longer needed because it gets substituted by the Kappa-epsilon dependence of c(sub 1), c(sub 2), which plays the role of the diffusion, together with the diffusion of the turbulent kinetic energy D(sub Kappa), which now enters the new equation (i.e., inhomogeneous flows). Thus, the three empirical ingredients c(sub 1 epsilon), c(sub epsilon 2), D (sub epsilon)are replaced by a single function c(sub 1)(Kappa, epsilon ) or c(sub 2)(Kappa, epsilon ), plus a D(sub Kappa)term. Three tests of the new equation for epsilon are presented: one concerning channel flow and two concerning the shear-driven planetary boundary layer (PBL).

  15. An Attempt to Derive the epsilon Equation from a Two-Point Closure

    NASA Technical Reports Server (NTRS)

    Canuto, V. M.; Cheng, Y.; Howard, A. M.

    2010-01-01

    The goal of this paper is to derive the equation for the turbulence dissipation rate epsilon for a shear-driven flow. In 1961, Davydov used a one-point closure model to derive the epsilon equation from first principles but the final result contained undetermined terms and thus lacked predictive power. Both in 1987 and in 2001, attempts were made to derive the epsilon equation from first principles using a two-point closure, but their methods relied on a phenomenological assumption. The standard practice has thus been to employ a heuristic form of the equation that contains three empirical ingredients: two constants, c(sub 1 epsilon), and c(sub 2 epsilon), and a diffusion term D(sub epsilon) In this work, a two-point closure is employed, yielding the following results: 1) the empirical constants get replaced by c(sub 1), c(sub 2), which are now functions of Kappa and epsilon; 2) c(sub 1) and c(sub 2) are not independent because a general relation between the two that are valid for any Kappa and epsilon are derived; 3) c(sub 1), c(sub 2) become constant with values close to the empirical values c(sub 1 epsilon), c(sub epsilon 2), (i.e., homogenous flows); and 4) the empirical form of the diffusion term D(sub epsilon) is no longer needed because it gets substituted by the Kappa-epsilon dependence of c(sub 1), c(sub 2), which plays the role of the diffusion, together with the diffusion of the turbulent kinetic energy D(sub Kappa), which now enters the new equation (i.e., inhomogeneous flows). Thus, the three empirical ingredients c(sub 1 epsilon), c(sub epsilon 2), D (sub epsilon)are replaced by a single function c(sub 1)(Kappa, epsilon ) or c(sub 2)(Kappa, epsilon ), plus a D(sub Kappa)term. Three tests of the new equation for epsilon are presented: one concerning channel flow and two concerning the shear-driven planetary boundary layer (PBL).

  16. Multiple sclerosis among the United Kingdom-born children of immigrants from the West Indies.

    PubMed Central

    Elian, M; Dean, G

    1987-01-01

    Multiple sclerosis has been reported to be very uncommon in the West Indies. In previous studies immigrants from the West Indies resident in Greater London had only one-eighth the likelihood of being diagnosed in hospital as having multiple sclerosis compared with those born in the United Kingdom. No studies of the incidence and prevalence of multiple sclerosis were available for London or South East England but there is evidence that it is much the same as occurs in Ireland. In the age groups studied the United Kingdom-born children of West Indian immigrants had an incidence and prevalence of probable multiple sclerosis of the same order as has been reported in Northern Ireland and in the Irish Republic. Although there is evidence that genetic factors play a part, our findings are strong evidence that the cause of the disease is mainly environmental and is therefore potentially preventable. PMID:3559614

  17. [Prostate cancer in Guadeloupe (French West Indies): incidence, mortality and clinicopathological features].

    PubMed

    Brureau, L; Multigner, L; Wallois, A; Verhoest, G; Ndong, J-R; Fofana, M; Blanchet, P

    2009-02-01

    In mainland France, as in most Western countries, prostate cancer is the most frequent cancer in men. However, the incidence of this cancer is highly variable, depending on the region of the world. This variability is largely accounted for by differences in access to care, but also by environmental conditions and the ethnogeographic origins of the populations. The French West Indies--the archipelago of Guadeloupe and the island of Martinique--are unique in terms of their geography, environment and the lifestyle and origins of their populations. We report the incidence and mortality rates for prostate cancer in the French West Indies and also provide the first description of the major clinical and anatomical characteristics of this disease in this region.

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

    PubMed

    Steadman, David W; Takano, Oona M

    2016-05-09

    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).

  19. Adapting the mini mental status to the context of the West-Indies.

    PubMed

    Godaert, Lidvine; Godard-Sebillotte, Claire; Bousquet, Lionel; Devouche, Emmanuel; Hugonot-Diener, Laurence; Nuissier, Joëlle; Triboulet, Frank; Fanon, Jean-Luc

    2017-03-01

    The mini mental state examination (MMSE) has become a benchmark for the screening and follow-up of cognitive impairment. The numerous translations of the MMS into other languages attest to its popularity. Clinical practice suggests that the consensual French version from the Greco (Groupe de réflexion sur les évaluations cognitives - Research working group for cognitive assessment) is not adapted to the West-Indies population because of the low socio-economic level and the widespread use of the Creole language among the elderly population. Modification of certain items by a multidisciplinary committee made it possible to adapt the instrument to the Creole culture. This procedure increases comprehension of the instrument, and should lead to improved detection of cognitive impairment in the West-Indies.

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

    PubMed Central

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

    2016-01-01

    Secondary transporters use alternating access mechanisms to couple uphill substrate movement to downhill ion flux. Most known transporters utilize a “rocking bundle” motion, where the protein moves around an immobile substrate binding site. However, the glutamate transporter homolog, GltPh, translocates its substrate binding site vertically across the membrane, 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°; multiple disulfide crosslinks which completely inhibit transport provide experimental confirmation and demonstrate that such movement is essential. In contrast, crosslinks across the VcINDY dimer interface preserve transport, revealing an absence of large scale coupling between protomers. PMID:26828963

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

    USDA-ARS?s Scientific Manuscript database

    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. Indy gene variation in natural populations confers fitness advantage and life span extension through transposon insertion.

    PubMed

    Zhu, Chen-Tseh; Chang, Chengyi; Reenan, Robert A; Helfand, Stephen L

    2014-01-01

    Natural selection acts to maximize reproductive fitness. However, antagonism between life span and reproductive success frequently poses a dilemma pitting the cost of fecundity against longevity. Here, we show that natural populations of Drosophila melanogaster harbor a Hoppel transposon insertion variant in the longevity gene Indy (I'm not dead yet), which confers both increased reproduction and longevity through metabolic changes. Heterozygosity for this natural long-lived variant has been maintained in isolates despite long-term inbreeding under laboratory conditions and advantageously confers increased fecundity. DNA sequences of variant chromosome isolates show evidence of selective sweep acting on the advantageous allele, suggesting that natural selection acts to maintain this variant. The transposon insertion also regulates Indy expression level, which has experimentally been shown to affect life span and fecundity. Thus, in the wild, evolution reaffirms that the mechanism of heterozygote advantage has acted upon the Indy gene to assure increased reproductive fitness and, coincidentally, longer life span through regulatory transposon mutagenesis.

  3. The 1755 tsunami propagation in Atlantics and its effects on the French West Indies

    NASA Astrophysics Data System (ADS)

    Pelinovsky, E.; Zahibo, N.; Yalciner, A.; Zaitsev, A.; Talipova, T.; Chernov, A.; Insel, I.; Dilmen, D.; Ozer, C.; Nikolkina, I.

    2009-04-01

    The present study examines the propagation of tsunami waves generated by the 1755 Lisbon earthquake in the Atlantic Ocean and its effects on the coasts of the French West Indies in the Caribbean Sea. Historical data of tsunami manifestation in the French West Indies are briefly reproduced. The mathematical model named NAMI DANCE which solves the shallow-water equations has been applied in the computations. Three possible seismic source alternatives of the tsunami source are selected for 1755 event in the simulations. The results obtained from the simulations demonstrate that the directivity of tsunami energy is divided into two strong beams directed to the southern part of North America (Florida, the Bahamas) and to the northern part of South America (Brazil). The tsunami waves reach the Lesser Antilles in 7 hrs. The computed distribution of tsunami wave height along the coasts of Guadeloupe and Martinique are presented. Calculated maximum of wave amplitudes reached 2 m in Guadeloupe and 1.5 m in Martinique. These results are also in agreement with observed data (1.8 - 3 m). The experience and data obtained in this study show that transatlantic events must also be considered in the tsunami hazard assessment and development of mitigation strategies for the French West Indies.

  4. Identification of epsilon martensite in a Fe-based shape memory alloy by means of EBSD.

    PubMed

    Verbeken, K; Van Caenegem, N; Raabe, D

    2009-01-01

    Ferrous shape memory alloys (SMAs) are often thought to become a new, important group of SMAs. The shape memory effect in these alloys is based on the reversible, stress-induced martensitic transformation of austenite to epsilon martensite. The identification and quantification of epsilon martensite is crucial when evaluating the shape memory behaviour of this material. Previous work displayed that promising results were obtained when studying the evolution of the amount of epsilon martensite after different processing steps with Electron BackScatter Diffraction (EBSD). The present work will discuss in detail, on the one hand, the challenges and opportunities arising during the identification of epsilon martensite by means of EBSD and, on the other hand, the possible interpretations that might be given to these findings. It will be illustrated that although the specific nature of the austenite to epsilon martensite transformation can still cause some points of discussion, EBSD has a high potential for identifying epsilon martensite.

  5. Mutation screening in the human epsilon-globin gene using single-strand conformation polymorphism analysis.

    PubMed

    Papachatzopoulou, Adamantia; Menounos, Panagiotis G; Kolonelou, Christina; Patrinos, George P

    2006-02-01

    The human epsilon-globin gene is necessary for primitive human erythropoiesis in the yolk sac. Herein we report a non-radioactive single-strand conformation polymorphism (SSCP) approach to screen the human epsilon-globin gene and its regulatory regions for possible mutations and single-nucleotide polymorphisms in normal adult subjects, in order to determine those genomic regions, which are not necessary for its proper regulation and function. We identified no sequence variations apart from the expected 5'epsilon /HincII polymorphism in the fragments analyzed, suggesting that genomic alterations in the epsilon-globin gene are most likely incompatible with normal erythropoiesis and proper embryonic development.

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

    NASA Astrophysics Data System (ADS)

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

    1995-05-01

    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 10-15/s. This figure 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 ne 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, chiH 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 ne 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 toward Sirius A. We show

  7. Real and Imaginary Properties of Epsilon-Near-Zero Materials

    NASA Astrophysics Data System (ADS)

    Javani, Mohammad H.; Stockman, Mark I.

    2016-09-01

    From the fundamental principle of causality we show that epsilon-near-zero (ENZ) materials with a very low (asymptotically zero) intrinsic dielectric loss do necessarily possess a very low (asymptotically zero) group velocity of electromagnetic wave propagation. This leads to the loss function being singular and causes high nonradiative damping of the optical resonators and emitters (plasmonic nanoparticles, quantum dots, chromophore molecules) embedded into them or placed at their surfaces. Rough ENZ surfaces do not exhibit hot spots of local fields suggesting that surface modes are overdamped. Reflectors and waveguides also show very large losses both for realistic and idealized ENZ materials.

  8. Protein kinase C epsilon in cell division: control of abscission.

    PubMed

    Saurin, Adrian T; Brownlow, Nicola; Parker, Peter J

    2009-02-15

    Cell division requires the separation and partitioning of sister chromatids to opposite ends of the cell before an actomyosin ring contracts the membrane in between during cytokinesis. The final irreversible step occurs during abscission when the ring breaks down and the membrane is sealed in its place. The physical mechanics of contraction depend on RhoA, which is stimulated by a centralspindlin complex around the cell equator. However exactly how these events are reversed to allow actomyosin breakdown and abscission were not well understood. Here we will discuss new findings that implicate Protein Kinase C epsilon (PKCepsilon) as a regulator of RhoA signalling required for abscission.

  9. New epsilon-Bi2O3 metastable polymorph.

    PubMed

    Cornei, Nicoleta; Tancret, Nathalie; Abraham, Francis; Mentré, Olivier

    2006-06-26

    The new metastable epsilon-Bi2O3 polymorph has been prepared by hydrothermal treatment and structurally characterized. It shows strong relationships with the room temperature alpha form and the metastable beta form through rearrangements of [Bi2O3] columns formed by edge-sharing OBi4 tetrahedra. Its fully ordered crystal structure yields an ionic insulating character. It irreversibly transforms at 400 degrees C to the alpha form. The chemical analysis indicates its undoped bismuth oxide nature, then leading to the fifth characterized Bi2O3 polymorph to date.

  10. 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

  11. Electric field measurements during the MAC/EPSILON campaign

    NASA Technical Reports Server (NTRS)

    Croskey, C. L.; Hale, L. C.; Mitchell, J. D.; Schmidlin, F. J.; Hoppe, U.-P.

    1990-01-01

    The MAC/EPSILON observational campaign in northern Norway involved the taking of three-axis electric field measurements of the middle atmosphere by means of five rocketborne payloads during October and November, 1987. Simultaneous horizontal electric field measurements made by two of the rocket flights were in general agreement in their limited overlap region. The more extensive horizontal E-field measurements exhibited a decreasing mapping function with decreasing altitude, thereby indicating the presence of fields from a local auroral patch. Small-scale variations in the horizontal fields of the lights were similar to observed wavelike variations in the neutral wind field.

  12. 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.

  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. Applications of Epsilon Radial Networks in Neuroimage Analyses

    PubMed Central

    Adluru, Nagesh; Chung, Moo K.; Lange, Nicholas T.; Lainhart, Janet E.; Alexander, Andrew L.

    2016-01-01

    “Is the brain ’wiring’ different between groups of populations?” is an increasingly important question with advances in diffusion MRI and abundance of network analytic tools. Recently, automatic, data-driven and computationally efficient framework for extracting brain networks using tractography and epsilon neighborhoods were proposed in the diffusion tensor imaging (DTI) literature [1]. In this paper we propose new extensions to that framework and show potential applications of such epsilon radial networks (ERN) in performing various types of neuroimage analyses. These extensions allow us to use ERNs not only to mine for topo-physical properties of the structural brain networks but also to perform classical region-of-interest (ROI) analyses in a very efficient way. Thus we demonstrate the use of ERNs as a novel image processing lens for statistical and machine learning based analyses. We demonstrate its application in an autism study for identifying topological and quantitative group differences, as well as performing classification. Finally, these views are not restricted to ERNs but can be effective for population studies using any computationally efficient network-extraction procedures. PMID:28251191

  15. Homogenization of epsilon near zero composite metamaterials (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Pinchuk, Anatoliy O.

    2016-09-01

    Epsilon Near Zero (ENZ) metamaterials are interest for a broad range of applications in optoelectronics, communication and photovoltaic. Composite metal-dielectric metamaterials can be designed to exhibit ENZ in a specific frequency range. However, the frequency range if the ENZ is oftentimes limited. Recently, we developed a few different routs to designs metal-dielectric metamaterials with a broadband ENZ in the visible and infrared frequency domain. In this talk, I will present a homogenization theory for 1D and 2D metamaterials based on a few different geometries of metal-dielectric composites. Our approach is conceptually simple, elegant, and technically feasible, while its underlying physics is clear. We use a homogenization technique to estimate the real part of the effective permittivity nulling for a few different geometries of metal-dielectric composites. The design of broadband epsilon-near-zero metamaterials have been demonstrated through the solution of an inverse problem. Furthermore, we consider a few different geometries for realization of a broadband ENZ, such as core-shell spherical nanoparticle and nano-cylinders.

  16. {epsilon}-optimality conditions for weakly convex problems

    SciTech Connect

    Pappalardo, M.

    1994-12-31

    There are several generalizations concerning the concept of convexity both for sets and for functions. Weak convexity, among these, has showed many possibilities of applications and many theoretical properties. It has, in fact, been applied in several fields of mathematics: see for example geometry and optimization. We want to analyze this generalization of the concept of convexity via the image-space approach. This kind of approach has showed its utility in many fields of optimization. In particular, we introduce a new concept of {open_quotes}image{close_quotes} based on a suitable relaxation or reduction (lower and upper) of the image itself. Moreover we analyze the main properties of this concept and we show how to utilize it in the study of weakly convex constrained extremum problems in order to obtain {epsilon}-optimality conditions. The paper is divided in three parts: in the first we introduce the concept of perturbed image and we investigate the main theoretical properties. In the second we state {epsilon}-optimality conditions for weakly convex constrained extremum problems. In the third one we study relationships between this type of image and the augmented lagrangian.

  17. 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.

  18. Robust association of the APOE epsilon4 allele with premature myocardial infarction especially in patients without hypercholesterolaemia: the Aachen study.

    PubMed

    Schmitz, F; Mevissen, V; Krantz, C; Kimmel, M; Erdmann, J; Hoffmann, R; Zerres, K; Ortlepp, J R

    2007-02-01

    Genetic influence on the manifestation of coronary artery disease (CAD) and myocardial infarction (MI) has been shown previously. From many candidate genes the APOE (apolipoprotein E) with the major alleles epsilon2/epsilon3/epsilon4 is in the focus of interest. In 1817 patients admitted for their first left heart catheterization at a premature age (males < 55 and females < 65) the association of APOE alleles with MI was analysed. Genotyping was done by 5' exonuclease assay (TaqMan). RESULTS APOE was significantly associated with hypercholesterolaemia (epsilon4 72% vs. epsilon3 66% vs. epsilon2 51%; P < 0.0001), and premature MI (epsilon4 57% vs. epsilon3 50% vs. epsilon2 41%; P < 0.0001; hazard ratio 1.41, 95%CI 1.14-1.75). In patients without hypercholesterolaemia, the APOE allele epsilon4 was highly predictive for the presence of premature MI (epsilon4 55% vs. epsilon3 45% vs. epsilon2 28%; P < 0.0001; hazard ratio 1.75, 95%CI 1.19-2.57). The APOEepsilon4 allele shows a robust association with premature MI independent of hypercholesterolaemia.

  19. Further studies on T*{sub {epsilon}} integral for curved crack growth

    SciTech Connect

    Lam, P.W.; Kobayashi, A.S.; Atluri, S.N.; Tan, P.W.

    1999-07-01

    T*{sub {epsilon}} integral values associated with stable, curved crack growth in biaxially loaded, fatigued precracked, 2024-T3 single edge notched (SEN) specimens were determined. The SEN specimens were loaded under combined Modes 1 and 2 and mimicked the flapping of a failed lap splice joint of a pressurized airplane fuselage. Most specimens were provided with a tear strap, which was either bonded, bonded and riveted, or integrally machined (machined pad-up) in the specimen. The stably growing crack curved and either penetrated or curved again upon hitting the tear strap. The displacement field, which was determined by Moire interferometry as well as with finite element analysis, was used to directly determine the T*{sub 2{epsilon}} and T*{sub 2{epsilon}} integral values. These T*{sub {epsilon}} values agreed reasonably well with those determined by an elastic-plastic finite element modeling of the experiments. T*{sub 1{epsilon}} was identical to that obtained previously for pure Mode I crack extension while the T*{sub 2{epsilon}} integral oscillated about its null value. The results of this study suggest that T*{sub 1{epsilon}} could represent the resistance for locally self-similar crack growth and that a crack will curve in the direction of vanishing T*{sub 2{epsilon}}.

  20. Pharmacological properties of GABAA receptors in rat hypothalamic neurons expressing the epsilon-subunit.

    PubMed

    Sergeeva, Olga A; Andreeva, Nadja; Garret, Maurice; Scherer, Annette; Haas, Helmut L

    2005-01-05

    The pharmacological properties and functional role of native GABA(A) receptors (GABA(A)Rs) were investigated in rat hypothalamic neurons expressing the epsilon-subunit with the help of whole-cell patch-clamp recording and single-cell reverse transcription-PCR. Two cell groups were identified: histaminergic tuberomamillary and orexinergic/hypocretinergic neurons. Approximately 25% of histaminergic and 70% of orexinergic neurons contained mRNA encoding for the epsilon-subunit. Double-immunofluorescence staining revealed a somatic localization of this protein in these two neuronal groups. Constitutive activity, diazepam modulation, fast desensitization of maximal currents, and activation by propofol (6-98 microm) of GABA(A)Rs did not correlate with epsilon-subunit expression. Propofol at 3-12 microm potentiated GABA-mediated currents similarly in all neurons. However, noise variance analysis of GABA-mediated currents enhanced by propofol revealed a significant difference between epsilon-positive and epsilon-negative neurons. The former displayed no difference between control and potentiated responses, and, in the latter, noise was decreased in the presence of propofol. Spontaneous IPSCs recorded in cultured hypothalamic neurons were prolonged in the presence of propofol in all epsilon-negative neurons, whereas propofol-resistant IPSCs were recorded in epsilon-positive cells. The infrequent expression of the epsilon-subunit may be a key factor in the recently discovered central role of the tuberomamillary nucleus in anesthesia.

  1. 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.

  2. In-die photomask registration and overlay metrology with PROVE using 2D correlation methods

    NASA Astrophysics Data System (ADS)

    Seidel, D.; Arnz, M.; Beyer, D.

    2011-11-01

    According to the ITRS roadmap, semiconductor industry drives the 193nm lithography to its limits, using techniques like double exposure, double patterning, mask-source optimization and inverse lithography. For photomask metrology this translates to full in-die measurement capability for registration and critical dimension together with challenging specifications for repeatability and accuracy. Especially, overlay becomes more and more critical and must be ensured on every die. For this, Carl Zeiss SMS has developed the next generation photomask registration and overlay metrology tool PROVE® which serves the 32nm node and below and which is already well established in the market. PROVE® features highly stable hardware components for the stage and environmental control. To ensure in-die measurement capability, sophisticated image analysis methods based on 2D correlations have been developed. In this paper we demonstrate the in-die capability of PROVE® and present corresponding measurement results for shortterm and long-term measurements as well as the attainable accuracy for feature sizes down to 85nm using different illumination modes and mask types. Standard measurement methods based on threshold criteria are compared with the new 2D correlation methods to demonstrate the performance gain of the latter. In addition, mask-to-mask overlay results of typical box-in-frame structures down to 200nm feature size are presented. It is shown, that from overlay measurements a reproducibility budget can be derived that takes into account stage, image analysis and global effects like mask loading and environmental control. The parts of the budget are quantified from measurement results to identify critical error contributions and to focus on the corresponding improvement strategies.

  3. Development and field performance of indy race car head impact padding.

    PubMed

    Melvin, J W; Bock, H; Anderson, K; Gideon, T

    2001-11-01

    The close-fitting cockpit of the modern Indy car single seat race car has the potential to provide a high level of head and neck impact protection in rear and side impacts. Crash investigation has shown that a wide variety of materials have been used as the padding for these cockpits and, as a result, produced varying outcomes in crashes. Additionally, these pads have not always been positioned for optimal performance. The purpose of this study was to investigate the head impact performance of a variety of energy-absorbing padding materials under impact conditions typical of Indy car rear impacts and to identify superior materials and methods of improving their performance as race car head pads. An extensive series of tests with the helmeted Hybrid III test dummy head and neck on an impact mini-sled was conducted to explore head padding concepts. Following this, a performance specification for a simplified impact test using a rigid headform that simulates the helmeted head was developed and recommendations for performance levels of head padding based on biomechanical data on helmeted head impacts were made. In 1997, during the time that the head pad research was being performed, the Indy Racing League introduced a new chassis specification for their cars. There were a number of rear- and side-impact crashes during that season that resulted in seven severe head injuries. Examples of the head padding in those cars were included in the experimental study. The results of the head pad research were used to specify new padding materials that met the new biomechanical criteria. The placement of the head pads was also changed for better location of the padding. These changes instituted in 1998 have reduced the number of head injuries in crashes similar to or more severe than those of 1997 and have resulted in only occasional moderate head injuries (concussions) in the 1998 and 1999 seasons.

  4. Four new caponiids species (Araneae, Caponiidae) from the West Indies and redescription of Nops blandus (Bryant).

    PubMed

    Sánchez-Ruiz, Alexander; Brescovit, Antonio D; Alayón, Giraldo

    2015-06-10

    We update the knowledge of the unusual Caponiidae spiders from the West Indies with the description of four new species, and the redescription of Nops blandus (Bryant) including the first description of the female. Specimens previously assigned to N. blandus from Hispaniola and Puerto Rico represents two new species: Nops hispaniola n. sp. and Nops agnarssoni n. sp. respectively; while the distribution of the former is limited to British and U. S. Virgin Islands. The others two new species are Nops finisfurvus n. sp. from British Virgin Islands and Cubanops luquillo n. sp. from Puerto Rico. Female internal genitalia of Nops species are described, photographed and illustrated for the first time.

  5. Moral justification of anatomical dissection and conquest in the Spanish Chronicles of the Indies.

    PubMed

    Fernandez, Enrique

    2015-06-01

    Three cases of dissections of dead bodies are included in the Spanish Chronicles of the Indies. By reporting on these advanced medico-scientific practices, the chroniclers appear to be confirming the superiority of the conquistadors over the natives and justifying the conquest. However, they problematize this supposed superiority by framing the events in complex scenarios that resound of some of the controversies surrounding dissection in the period. This contradictory treatment of dissection can be interpreted as a manifestation of the conquistadors' anxiety around being physically identical to the natives except for a fragile, skin-deep veneer of civilized behaviour.

  6. Apolipoprotein E epsilon4 allele and neurobehavioral status after on-pump coronary artery bypass grafting.

    PubMed

    Askar, Fatma Zekiye; Cetin, Hasan Yurday; Kumral, Emre; Cetin, Ozgul; Acarer, Ahmet; Kosova, Buket; Yagdi, Tahir

    2005-01-01

    Abstract Background and Aim: The presence of apolipoprotein E epsilon4 allele is being considered as a risk factor for cognitive decline after cardiac surgery. We sought the effect of apolipoprotein E epsilon4 allele on neurobehavioral status after on-pump coronary artery bypass grafting. Prior to the operation, neurologic examination and neurobehavioral cognitive status test (COGNISTAT) were performed. Both procedures were repeated on the day of discharge and 3 months after surgery. Apolipoprotein E epsilon4 allele positive and apolipoprotein E epsilon4 allele negative patients' performance on COGNISTAT were compared. There was no statistically significant demographic and operative data difference between two groups. No neurological impairment was observed on examinations. There was no statistically significant neurocognitive decline difference between two groups' postoperative performances. It seems that apolipoprotein E epsilon4 allele may not affect neurobehavioral status in the intermediate period after on-pump coronary artery bypass grafting.

  7. Identification of epsilon-crystallin from swan lens as lactate dehydrogenase.

    PubMed

    Chiou, S H; Chang, W P; Lai, T A

    1989-10-01

    Characterization of lens crystallins from black swan, a rare aquatic bird belonging to the family Anatidae, was carried out to search for epsilon-crystallin with lactate dehydrogenase activity. Biochemical comparison of epsilon-crystallins isolated from the swan and duck lenses plus lactate dehydrogenase of chicken heart has also been made in order to establish the structural/functional relatedness of these proteins. Amino acid analyses showed essentially similar overall compositions for these three proteins. Kinetic analysis revealed differences between avian epsilon-crystallins and the authentic heart-type lactate dehydrogenase. The swan lenses similar to duck lenses appeared to contain a thermostable epsilon-crystallin which possesses very high enzymatic activity of lactate dehydrogenase. The characterization of epsilon-crystallins from the available species of aquatic birds may provide some insights into the evolution of this unique crystallin in the Aves and their enzymatic roles inside the lens.

  8. 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.

  9. Neural regulation of muscle acetylcholine receptor epsilon- and alpha- subunit gene promoters in transgenic mice

    PubMed Central

    1993-01-01

    The effects of denervation were investigated in mice with transgenes containing promoter elements from the muscle acetylcholine receptor epsilon- and alpha-subunit genes. The promoter sequences were coupled to a nuclear localization signal-beta-galactosidase fusion gene (nlacZ) as a reporter. While many postsynaptic specializations form in the embryo, expression of the epsilon subunit is induced during the first two postnatal weeks. When muscles were denervated at birth, before the onset of epsilon expression, epsilon nlacZ still appeared at the former synaptic sites on schedule. This result suggests that the nerve leaves a localized "trace" in the muscle that can continue to regulate transcription. An additional finding was that epsilon nlacZ expression was much stronger in denervated than in intact muscles. This suggests that the epsilon promoter is similar to the other subunits in containing elements that are activated on cessation of neural activity. However, even after denervation, epsilon nlacZ expression was always confined to the synaptic region whereas alpha nlacZ expression increased in nuclei along the entire length of the fiber. This suggests that while the epsilon gene is similar in its activity dependence to other subunit genes, it is unique in that local nerve-derived signals are essential for its expression. Consequently, inactivity enhances epsilon expression only in synaptic nuclei where such signals are present, but enhances expression throughout the muscle fiber. Truncations and an internal deletion of the epsilon promoter indicate that cis-elements essential for the response to synaptic signals are contained within 280 bp of the transcription start site. In contrast to these results in young animals, denervation in older animals leads to an unexpected reduction in nlacZ activity. However, mRNA measurements indicated that transgene expression was increased in these animals. This discordance between nlacZ mRNA and enzyme activity, demonstrates a

  10. 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.

  11. Improved solution for system identification equations by Epsilon-Decomposition

    NASA Technical Reports Server (NTRS)

    Ojalvo, Irving U.

    1990-01-01

    Matrix eigenvalue theory is used to examine the source of ill-conditioning in linear algebraic equations. This approach highlights the crucial role played by the zero and near-zero eigenvalues and corresponding eigenvectors of poorly conditioned systems. Insight gained from this approach is used to significantly improve a recently developed solution procedure called Epsilon-Decomposition (E-D). E-D is an efficient alternative to Singular Value Decomposition (SVD) for ill-conditioned systems arising in parameter estimation and system identification studies. The efficiency of the improved E-D over SVD resides in the need to only obtain the zero and near-zero eigenvalues of the coefficient matrix as opposed to all of its eigenvalues and vectors (as required by SVD). Thus, the efficiency of E-D is significant for large matrices with small rank deficiency.

  12. 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

    2013-04-08

    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.

  13. Spectrophotometry of Epsilon Aur, 3295-8880 A

    NASA Technical Reports Server (NTRS)

    Lockwood, G. W.; Thompson, D. T.; Lutz, B. L.; Sowell, J.

    1985-01-01

    Spectrophotometric scans were obtained at 8 A resolution from 3295 to 8880 A on twenty nights before, during, and after the recent eclipse of epsilon Aurigae, beginning with a pre-eclipse observation on 5 March 1982 U.T. The observations were reduced to absolute flux using the standard stars 109 Vir or xi(2) Ceti. The data confirm that the eclipse is essentially gray over the entire visible spectrum, as others have noted from broadband photometry. High resolution echellograms (450 to 6700 A) made through mid-eclipse and the scans show changes in the equivalent widths of H alpha, Na D, and O I as large as a factor of two.

  14. 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.

  15. 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.}

  16. 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.

  17. 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.

  18. Kenneth Harrison Uttley (1901-1972). Historian to the diseases of Antigua, British West Indies.

    PubMed

    Kendig, J W

    2001-09-01

    Dr Kenneth Harrison Uttley (1901-1972) served as the Chief Medical Officer in Antigua, British West Indies, from 1955 until 1966. During this time, Dr. Uttley personally reviewed and tabulated an island-wide governmental demographic database of all births, deaths and causes of death during the preceding 100 years. This database was the result of a Compulsory Birth and Death Registration Ordinance enacted as one of several Colonial Poor Laws in 1856. His efforts resulted in the publication of a total of 30 papers in American and British medical journals. Many of these papers reviewed historical demographic trends in births, fertility rates, neonatal deaths, infant mortality and early childhood mortality rates. Others focussed on the historical epidemiology of specific diseases such as neonatal tetanus, leprosy, tuberculosis and malaria. This is the first complete bibliographical account of Uttley's contributions to the history of diseases in the West Indies in general and Antigua in particular. Dr Uttley also served as an ordained priest in the Anglican Church and, upon retirement from the Colonial Medical Services, returned to England to serve as the Vicar of Purton, Oxfordshire.

  19. Alfred E. Moss: 1924 Indy 500 race driver, British dentist and father of Sir Stirling Moss.

    PubMed

    Christen, Joan A

    2005-03-01

    Alfred Ethelbert Moss (1896-1972), a highly successful London dentist, was also a pioneer in English auto racing. In 1923, 27-year old Alfred (already a dentist), arrived in Indianapolis, Indiana, ostensibly to study "advanced dental practice" at the Indiana Dental College. However, his primary motive for coming to Indianapolis was to participate in the Indy 500 race. On Friday, May 30, 1924, 22 car racers started the 12th running of the Indy 500. Among them was Alfred, who finished respectably, in 16th place. Thus, he became the first dentist to compete in the famed Indianapolis 500 race. In 1925, after months of dirt-track running around the U.S., he returned to England. His initial plan was to continue racing in his own country. However, this goal vanished as his dental career began to flourish. Soon he had developed a large and prosperous dental practice in London. In 1927, Moss married Aileen Craufurd, who eventually became a champion female race car driver in England. In 1929, the couple had a son, Stirling. By the 1950s, Stirling Moss was hailed as Britain's best known sports star, and one of the world's fastest and most versatile race drivers of all time. This article follows the life and times of the Moss family, with an emphasis on Alfred's two life endeavors racing and dentistry, and on Stirling's famed racing career. In 1999, Stirling Moss was knighted by Queen Elizabeth II.

  20. Major West Indies MRSA clones in human beings: do they travel with their hosts?

    PubMed

    Chroboczek, Tomasz; Boisset, Sandrine; Rasigade, Jean-Philippe; Meugnier, Helene; Akpaka, Patrick E; Nicholson, Alison; Nicolas, Muriel; Olive, Claude; Bes, Michele; Vandenesch, François; Laurent, Frederic; Etienne, Jerome; Tristan, Anne

    2013-01-01

    Descriptions of the epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) have seldom been produced in the Caribbean, which is a major tourism destination. Using DNA microarrays and spa typing, we characterized 85 MRSA isolates from human skin and soft-tissue infections from five different islands. In the French West Indies (n = 72), the most frequently isolated clones were the same clones that are specifically isolated from mainland France [Lyon (n = 35) and Geraldine (n = 11) clones], whereas the clones that were most frequently isolated from the other islands (n = 13) corresponded with clones that have a worldwide endemic spread [Vienna/Hungarian/Brazilian (n = 5), Panton Valentine leukocidin-positive USA300 (n = 4), New York/Japan (n = 2), and pediatric (n = 1) clones]. The distribution of the major MRSA clones in the French (Guadeloupe and Martinique) and non-French West Indies (Jamaica, Trinidad, and Tobago) is different, and the clones most closely resemble those found in the home countries of the travelers who visit the islands most frequently. The distribution might be affected by tourist migration, which is specific to each island. © 2013 International Society of Travel Medicine.

  1. 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.

  2. Noise reduction combining time-frequency epsilon-filter and M-transform.

    PubMed

    Abe, Tomomi; Matsumoto, Mitsuharu; Hashimoto, Shuji

    2008-08-01

    This paper introduces noise reduction combining time-frequency epsilon-filter (TF epsilon-filter) and time-frequency M-transform (TF M-transform). Musical noise is an offensive noise generated due to noise reduction in the time-frequency domain such as spectral subtraction and TF epsilon-filter. It has a deleterious effect on speech recognition. To solve the problem, M-transform is introduced. M-transform is a linear transform based on M-sequence. The method combining the time-domain epsilon-filter (TD epsilon-filter) and time-domain M-transform (TD M-transform) can reduce not only white noise but also impulse noise. Musical noise is isolated in the time-frequency domain, which is similar to impulse noise in the time domain. On these prospects, this paper aims to reduce musical noise by improving M-transform for the time-frequency domain. Noise reduction by using TD M-transform and the TD epsilon-filter is first explained to clarify its features. Then, an improved method applying M-transform to the time-frequency domain, namely TF M-transform, is described. Noise reduction combining the TF epsilon-filter and TF M-transform is also proposed. The proposed method can reduce not only high-level nonstationary noise but also musical noise. Experimental results are also given to demonstrate the performance of the proposed method.

  3. Ba incorporation in benthic foraminifera

    NASA Astrophysics Data System (ADS)

    de Nooijer, Lennart J.; Brombacher, Anieke; Mewes, Antje; Langer, Gerald; Nehrke, Gernot; Bijma, Jelle; Reichart, Gert-Jan

    2017-07-01

    Barium (Ba) incorporated in the calcite of many foraminiferal species is proportional to the concentration of Ba in seawater. Since the open ocean concentration of Ba closely follows seawater alkalinity, foraminiferal Ba / Ca can be used to reconstruct the latter. Alternatively, Ba / Ca from foraminiferal shells can also be used to reconstruct salinity in coastal settings in which seawater Ba concentration corresponds to salinity as rivers contain much more Ba than seawater. Incorporation of a number of minor and trace elements is known to vary (greatly) between foraminiferal species, and application of element / Ca ratios thus requires the use of species-specific calibrations. Here we show that calcite Ba / Ca correlates positively and linearly with seawater Ba / Ca in cultured specimens of two species of benthic foraminifera: Heterostegina depressa and Amphistegina lessonii. The slopes of the regression, however, vary two- to threefold between these two species (0.33 and 0.78, respectively). This difference in Ba partitioning resembles the difference in partitioning of other elements (Mg, Sr, B, Li and Na) in these foraminiferal taxa. A general trend across element partitioning for different species is described, which may help develop new applications of trace elements in foraminiferal calcite in reconstructing past seawater chemistry.

  4. TNF-alpha regulates GM-CSF-, IL-3- or M-CSF-induced Fc epsilon RII/CD23 gene expression and soluble Fc epsilon RII release by human monocytes.

    PubMed

    Hashimoto, S; Gon, Y; Hayashi, S; Tomita, Y; Yodoi, J; Horie, T

    1997-03-01

    The authors examined the regulatory effects of tumour necrosis factor-alpha (TNF-alpha) on granulocyte macrophage colony stimulating factor (GM-CSF)-, interleukin-3 (IL-3)- or macrophage colony stimulating factor (M-CSF)-induced gene expression of the low affinity receptor for IgE (Fc epsilon RII) on human monocytes and GM-CSF-, IL-3- or M-CSF-induced soluble Fc epsilon RII (sFc epsilon RII) release from monocytes. The expression of GM-CSF-, IL-3- or M-CSF-induced Fc epsilon RII on the surface of monocytes was reduced by TNF-alpha. The present analysis was designed to examine whether or not TNF-alpha could suppress GM-CSF-, IL-3- or M-CSF-induced Fc epsilon RII messenger RNA (mRNA) expression and enhance the release of sFc epsilon RII induced by these cytokines. The addition of TNF-alpha to monocyte cultures with GM-CSF, IL-3 or M-CSF significantly reduced Fc epsilon RII expression on the surface of monocytes and significantly increased sFc epsilon RII release from monocytes. These results suggest that TNF-alpha-dependent reduction of GM-CSF-, IL-3- or M-CSF-induced Fc epsilon RII expression on the surface of monocytes resulted, at least in part, from the suppression of Fc epsilon RII mRNA and the enhancement of sFc epsilon RII release.

  5. 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,…

  6. Thesis Writing and Preservation at the University of the West Indies, St. Augustine, Trinidad: A Librarian's In-Put.

    ERIC Educational Resources Information Center

    Clarke, Reginald

    2000-01-01

    Describes the University of the West Indies, focusing on the St. Augustine (Trinidad) campus and the library's involvement with maintaining, preserving, and disseminating postgraduate student theses. Explains quality control efforts and considers implications for the types of scholarship performed by academic librarians. (LRW)

  7. The Evaluative Impact of Graduate Scholarships: The Case of the University of the West Indies, St. Augustine

    ERIC Educational Resources Information Center

    Kalloo-Bhagwandeen, Sarah; Mustapha, Nasser

    2013-01-01

    The UWI Postgraduate Scholarship has been the most longstanding award offered by the University of the West Indies. However, completion rates of students have been decreasing and the number of students registered has not been increasing significantly. This paper investigates the UWI Postgraduate Scholarships awarded from 2001 to 2007. This…

  8. An Exploratory Study Examining Barbadian Students' Knowledge and Awareness of Costs of University of the West Indies Education

    ERIC Educational Resources Information Center

    Persaud, Nadini; Persaud, Indeira

    2016-01-01

    This study explores Barbadian students' knowledge/awareness on various facets of costs associated with their University of the West Indies (UWI) education and student perceptions of State funded education. The study was conducted subsequent to the announcement of UWI tuition fees which came into effect in September 2014. Ninety-three Faculty of…

  9. 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,…

  10. Providing Contexts for Understanding Musical Narratives of Power in the Classroom: Music, Politics, and Power in Grenada, West Indies

    ERIC Educational Resources Information Center

    Sirek, Danielle

    2016-01-01

    The role of music in Grenada, West Indies has traditionally been to pass on knowledges, values, and ideals; and to provide a means of connecting to one another through expressing commonality of experience, ancestry, and nationhood. This paper explores how Eric Matthew Gairy, during his era of political leadership in Grenada (1951-1979), exploited…

  11. St. Lucia, West Indies Ministry of Education. School Library and Information Services: A Status Report with Recommendations.

    ERIC Educational Resources Information Center

    Brown, Gerald R., Comp.

    This research report addresses the scope of school library and information services programs as demonstrated in secondary schools in St. Lucia, West Indies. Most schools were found seriously lacking in all three areas: Independent Learning Skills; Literacy/Literary and Cultural Appreciation; and Organization and Administration. Library staff…

  12. Providing Contexts for Understanding Musical Narratives of Power in the Classroom: Music, Politics, and Power in Grenada, West Indies

    ERIC Educational Resources Information Center

    Sirek, Danielle

    2016-01-01

    The role of music in Grenada, West Indies has traditionally been to pass on knowledges, values, and ideals; and to provide a means of connecting to one another through expressing commonality of experience, ancestry, and nationhood. This paper explores how Eric Matthew Gairy, during his era of political leadership in Grenada (1951-1979), exploited…

  13. 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

  14. Preparation of magnetic microspheres based on poly(epsilon-caprolactone)-poly(ethylene glycol)-poly(epsilon-caprolactone) copolymers by modified solvent diffusion method.

    PubMed

    Men, Ke; Zeng, Shi; Gou, MaLing; Guo, Gang; Gu, Ying Chun; Luo, Feng; Zhao, Xia; Wei, YuQuan; Qian, ZhiYong

    2010-06-01

    Magnetic microspheres have promising application in biomedical field. In this paper, biodegradable poly(epsilon-caprolactone)-poly(ethylene glycol)-poly(epsilon-caprolactone) (PCEC) triblock copolymers were synthesized by ring-opening polymerization method. Through adjusting the epsilon-CL/PEG weight ratio in feed, PCEC copolymers with different block ratio were obtained. A novel modified solvent diffusion method was described to prepare magnetic PCEC composite microspheres containing magnetite nanoparticles. The particle size of microsphere decreased with increase in the PEG/PCL block ratio. The obtained microspheres could response to external magnetic field. This study described a novel method to prepare magnetic microspheres. The obtained magnetic polymeric microspheres might have potential application in drug delivery system or disease diagnosis field.

  15. High interobserver variability in the assessment of epsilon waves: Implications for diagnosis of arrhythmogenic right ventricular cardiomyopathy/dysplasia.

    PubMed

    Platonov, Pyotr G; Calkins, Hugh; Hauer, Richard N; Corrado, Domenico; Svendsen, Jesper H; Wichter, Thomas; Biernacka, Elżbieta Katarzyna; Saguner, Ardan M; Te Riele, Anneline S J M; Zareba, Wojciech

    2016-01-01

    Revision of the Task Force diagnostic criteria for arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) has increased their sensitivity for the diagnosis of early and familial forms of the disease. The epsilon wave is a major diagnostic criterion in the context of ARVC/D, which, however, remains not quantifiable and therefore may leave room for substantial subjective interpretation. The purpose of this study was to assess interobserver agreement in epsilon wave definition and epsilon wave importance for ARVC/D diagnosis. Electrocardiographic (ECG) tracings depicting leads V1, V2, and V3 collected from individuals evaluated for ARVC/D (n = 30) were given to panel members who were asked to respond to the question whether ECG patterns meet epsilon wave definition outlined by the Task Force diagnostic criteria. The prevalence and importance of epsilon waves for ARVC/D diagnosis were assessed in a pooled data set of patients with definite ARVC/D from European and American registries (n = 815). The number of ECG patterns identified as epsilon waves varied from 5 to 18 per reviewer (median 13 per reviewer). A unanimous agreement was reached for only 10 cases (33%), 2 of which qualified as epsilon waves and 8 as non-epsilon waves by all panel members. From a pooled data set, 106 patients reportedly had epsilon waves (13%). In 105 of 106 patients with epsilon waves (99%), exclusion of epsilon waves from the diagnostic score would not affect the "definite" diagnostic category. Interobserver variability in the assessment of epsilon waves is high; however, the impact of epsilon waves on ARVC/D diagnosis is negligibly low. The results urge to exercise caution in the assessment of epsilon waves, especially in patients who would not otherwise meet diagnostic criteria. Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  16. 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.

  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. Navier-Stokes cascade analysis with a stiff k-epsilon turbulence solver

    NASA Technical Reports Server (NTRS)

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

    1988-01-01

    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.

  19. 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.

  20. 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.

  1. APOE-epsilon4 polymorphism and cognitive deficit among the elderly population of Fernando de Noronha.

    PubMed

    Garcia, Anália Nusya; Silva, Helker Albuquerque da; Silva, Renan Carlos; Leal, Eliane Maria Medeiros; Rodrigues, Lorena; Silva, Vanessa Cavalcante da; Dellalibera, Edileine; Freitas, Elizabete Malaquias; Ataíde, Luiz; Muniz, Maria Tereza Cartaxo

    2008-06-01

    Polymorphism of the gene for apolipoprotein E (APOE) is an important risk factor for the development of Alzheimer's disease. The epsilon4 allele of the APOE gene has been linked with a number of neuropsychiatric illnesses, and also with stress and depression among geriatric populations. To identify APOE-epsilon4 polymorphism and correlate this with cognitive deficit among the elderly population of the island of Fernando de Noronha. Neuropsychiatric tests (mini-mental state examination, verbal fluency test and clock drawing test) were applied to 52 elderly people without Alzheimer's disease. DNA was isolated from peripheral blood and genotyping of APOE was done by the PCR-RFLP method. 87% of the elderly population (mean age 69.6+/-7.0) had cognitive deficit. The observed frequency of the epsilon4 allele was 10%, but the correlation between the presence of epsilon4 and cognitive deficit in this population was not statistically significant.

  2. Automatic parameter optimization in epsilon-filter for acoustical signal processing utilizing correlation coefficient.

    PubMed

    Abe, Tomomi; Hashimoto, Shuji; Matsumoto, Mitsuharu

    2010-02-01

    epsilon-filter can reduce most kinds of noise from a single-channel noisy signal while preserving signals that vary drastically such as speech signals. It can reduce not only stationary noise but also nonstationary noise. However, it has some parameters whose values are set empirically. So far, there have been few studies to evaluate the appropriateness of the parameter settings for epsilon-filter. This paper employs the correlation coefficient of the filter output and the difference between the filter input and output as the evaluation function of the parameter setting. This paper also describes the algorithm to set the optimal parameter value of epsilon-filter automatically. To evaluate the adequateness of the obtained parameter, the mean absolute error is calculated. The experimental results show that the adequate parameter in epsilon-filter can be obtained automatically by using the proposed method.

  3. SYNTHESIZING OPTIMAL STRATEGIES IN PURSUIT-EVASION GAMES BY THE EPSILON TECHNIQUE,

    DTIC Science & Technology

    A constructive method for synthesizing optimal strategies in pursuit-evasion games is described using the epsilon technique as described by Balakrishnan. An illustrative example is worked out. (Author)

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

    PubMed

    Zegerman, Philip

    2013-04-08

    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.

  5. Second-harmonic generation in longitudinal epsilon-near-zero materials

    NASA Astrophysics Data System (ADS)

    Vincenti, M. A.; Kamandi, M.; de Ceglia, D.; Guclu, C.; Scalora, M.; Capolino, F.

    2017-07-01

    We investigate second-harmonic generation from anisotropic or longitudinal epsilon-near-zero materials. We find conversion efficiencies well above their isotropic counterparts owing to additional field intensity enhancement provided by the anisotropy. At the same time, anisotropic epsilon-near-zero materials are also less sensitive to the material's losses compared to the isotropic ones. In turn, these improvements become pivotal for epsilon-near-zero materials that do not possess bulk dipole-allowed quadratic nonlinearities. We predict that second-harmonic generation from a Dy:CdO/Si multilayer with longitudinal epsilon-near-zero properties can exceed the conversion efficiency of a homogeneous Dy:CdO slab of equivalent thickness by at least 20 times for almost any angle of incidence.

  6. Magnetic field concentration assisted by epsilon-near-zero media.

    PubMed

    Liberal, Iñigo; Li, Yue; Engheta, Nader

    2017-03-28

    Strengthening the magnetic response of matter at optical frequencies is of fundamental interest, as it provides additional information in spectroscopy, as well as alternative mechanisms to manipulate light at the nanoscale. Here, we demonstrate theoretically that epsilon-near-zero (ENZ) media can enhance the magnetic field concentration capabilities of dielectric resonators. We demonstrate that the magnetic field enhancement factor is unbounded in theory, and it diverges as the size of the ENZ host increases. In practice, the maximal enhancement factor is limited by dissipation losses in the host, and it is found via numerical simulations that ENZ hosts with moderate losses can enhance the performance of a circular dielectric rod resonator by around one order of magnitude. The physical mechanism behind this process is the strongly inhomogeneous magnetic field distributions induced by ENZ media in neighbouring dielectrics. We show that this is an intrinsic property of ENZ media, and that the occurrence of resonant enhancement is independent of the shape of the host. These results might find applications in spectroscopy, in sensing, in light emission and, in general, in investigating light-matter interactions beyond electric dipole transitions.This article is part of the themed issue 'New horizons for nanophotonics'. © 2017 The Author(s).

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

    DOE PAGES

    Galfsky, Tal; Sun, Zheng; Jacob, Zubin; ...

    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

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. September epsilon Perseid cluster as a result of orbital fragmentation

    NASA Astrophysics Data System (ADS)

    Koten, P.; Čapek, D.; Spurný, P.; Vaubaillon, J.; Popek, M.; Shrbený, L.

    2017-04-01

    Context. A bright fireball was observed above the Czech Republic on September 9, 2016, at 23:06:59 UT. Moreover, the video cameras at two different stations recorded eight fainter meteors flying on parallel atmospheric trajectories within less than 2 s. All the meteors belong to the September epsilon Perseid meteor shower. The measured proximity of all meteors during a very low activity meteor shower suggests that a cluster of meteors was observed. Aims: The goal of the paper is first to determine whether this event was a random occurrence or a real meteor cluster and second, if it was a cluster, to determine the epoch and at what distance from the Earth the separation of the particles occurred. Methods: The atmospheric trajectories of the observed meteors, masses, and relative distances of individual particles were determined using a double-station observation. According to the distances and masses of the particles, the most probable distance and time of fragmentation is determined. Results: The observed group of meteors is interpreted as the result of the orbital fragmentation of a bigger meteoroid. The fragmentation happened no earlier than 2 or 3 days before the encounter with the Earth at a distance smaller than 0.08 AU from the Earth.

  13. 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.

  14. 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.

  15. Evaluation of baits for oral rabies vaccination of mongooses: pilot field trials in Antigua, West Indies.

    PubMed

    Linhart, S B; Creekmore, T E; Corn, J L; Whitney, M D; Snyder, B D; Nettles, V F

    1993-04-01

    A field study was conducted on the island of Antigua, West Indies, to evaluate baits for delivering an oral rabies vaccine to the small Indian mongoose (Herpestes auropunctatus). Tracking tiles were used to determine that mongooses were nonselective and took both egg-flavored polyurethane baits and fish-flavored polymer baits containing several different food materials. A high proportion of baits were taken the day of placement with minimal disturbance by nontarget species. DuPont Oil Blue A dye was an effective short-term biomarker for use in baits; based on its subsequent detection in mongooses, some of the population had consumed and not cached or discarded baits. Central point baiting stations showed promise as an alternative delivery technique.

  16. Marine erosion rates and coastal morphology of reef limestones on Grand Cayman Island, West Indies

    NASA Astrophysics Data System (ADS)

    Spencer, Tom

    1985-09-01

    Direct measurements of surface lowering, using the micro-erosion meter technique, have been obtained from Pleistocene and Tertiary limestones in subtidal and intertidal environments on Grand Cayman Island, West Indies. Overall, erosion rates averaged 0.99 mm yr-1; however this figure conceals the fact that the mean erosion rate on open coasts (X=2.77 mm yr-1) was over six times greater than the rate on reef-protected shores (X=0.45 mm yr-1). On lagoonal rocky coasts abrasion and biological action appear to be the dominant erosional processes, but on coasts exposed to high wave surf, bioconstruction dominates over bio-erosion and surface erosion is slight (X=0.17 mm yr-1). Thus, the magnitude and relative importance of physical, chemical and biological erosion processes differ from one locality to the next with variations in coastal exposure and between reef areas with changes in tidal range and wave regime.

  17. Seroprevalence of canine leishmaniasis and American trypanosomiasis in dogs from Grenada, West Indies.

    PubMed

    Rosypal, Alexa C; Tripp, Shanesha; Kinlaw, Christopher; Sharma, R N; Stone, D; Dubey, J P

    2010-02-01

    Canine leishmaniasis and American trypanosomiasis (AT) are caused by related hemoflagellated parasites, Leishmania spp. and Trypanosoma cruzi, which share several common host species. Dogs are reservoirs for human infections by both pathogens. We determined the prevalence of antibodies to Leishmania spp. and T. cruzi in dogs from Grenada, West Indies. We examined 70 dog sera using the qualitative immunochromatographic dipstick tests (ICTs) based on recombinant antigens specific for visceral leishmaniasis and AT. Antibodies to visceral Leishmania were not detected in Grenadian dogs by ICT. Using the canine dipsticks for AT, antibodies to T. cruzi were determined in 3 (4.3%) of the 70 dogs. Results from this study indicate that dogs in Grenada are exposed in low levels to T. cruzi , but not to visceral Leishmania spp. at all.

  18. Seroprevalence of Toxoplasma gondii in pregnant women and cats in Grenada, West Indies.

    PubMed

    Asthana, Sumita P; Macpherson, Calum N L; Weiss, Stanley H; Stephens, Richard; Denny, Thomas N; Sharma, R N; Dubey, J P

    2006-06-01

    Prevalence of antibodies against Toxoplasma gondii was studied in 534 pregnant women and 40 domestic cats in Grenada, West Indies. Antibodies (IgG) for T. gondii were sought in human sera by an enzyme-linked immunosorbent assay and in cat sera by using the modified agglutination test (MAT). Antibodies were found in 57 % of pregnant women. Seroprevalence increased with age; 51% of 15- to 19-yr-old women (100 total) had antibodies versus 60% of 20- to 24-yr-old women (127 total). Antibodies to T. gondii (MAT, 1:25 serum dilution) were found in 35% of cats; titers were 1:25 in 7 cats, 1:50 in 4 cats, and 1:500 in 3 cats. Epidemiological data suggested that the ingestion of food or water contaminated with oocysts was an important mode of transmission of T. gondii to women.

  19. Cooperativity Between Oncogenic PKC Epsilon and Pten Loss in Prostate Cancer Progression

    DTIC Science & Technology

    2016-10-01

    pathway that correlates with motility and metastasis. Based on our preliminary data, PKCε overexpression and Pten loss individually and synergically confer...AWARD NUMBER: W81XWH-14-1-0535 TITLE: Cooperativity Between Oncogenic PKC Epsilon and Pten Loss in Prostate Cancer Progression PRINCIPAL...Sep 2015 - 29 Sep 2016 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Cooperativity Between Oncogenic PKC Epsilon and Pten Loss in Prostate Cancer

  20. 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.

  1. 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.

  2. 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.

  3. Toxicokinetics of chlordecone in goats: Implications for risk management in French West Indies.

    PubMed

    Fournier, Agnès; Feidt, Cyril; Lastel, Marie-Laure; Archimede, Harry; Thome, Jean-Pierre; Mahieu, Maurice; Rychen, Guido

    2017-03-01

    The former use of chlordecone (CLD) in the French West Indies has resulted in long-term pollution of soils. CLD is known to be potentially transferred towards animal products of animals reared outdoors, mainly through accidental soil ingestion. Several studies indicate that soil bound CLD is bioavailable when administered to farm animals. Currently there is a need to quantify the level of CLD absorption and its toxicokinetic characteristics in the ruminant and particularly in the goat. These are considered as important farm species in the French West Indies. The objective of this study was to evaluate the absorption rate and the half-life of CLD in the non-lactating goat. The goats were administered either intravenously (i.v., n = 6) or orally (p.o., n = 6) one dose (1 mg kg(-1) body weight) of CLD. Blood samples were collected at defined times up to 160 days post-dosing. CLD was analyzed in serum by high-resolution gas chromatography. A comparison of the area under the serum concentration-time curves (AUC) showed that the i.v. route is equivalent to the oral route. Thus, CLD is considered almost completely absorbed after p.o. administration, as shown by the mean absolute bioavailability. The comparison between the pharmacokinetic profiles of CLD following oral and intravenous dose showed a difference during the first 14 days and a similar kinetic after this period. The half-life of CLD in serum was close to 20 days. These results highlight a possible strategy of decontamination due to the short half-life of CLD, obtained in dry goats that did not excrete fat matter.

  4. Invasive plant species in the West Indies: geographical, ecological, and floristic insights.

    PubMed

    Rojas-Sandoval, Julissa; Tremblay, Raymond L; Acevedo-Rodríguez, Pedro; Díaz-Soltero, Hilda

    2017-07-01

    The level of invasion (number or proportion of invasive species) in a given area depends on features of the invaded community, propagule pressure, and climate. In this study, we assess the invasive flora of nine islands in the West Indies to identify invasion patterns and evaluate whether invasive species diversity is related to geographical, ecological, and socioeconomic factors. We compiled a database of invasive plant species including information on their taxonomy, origin, pathways of introduction, habitats, and life history. This database was used to evaluate the similarity of invasive floras between islands and to identify invasion patterns at regional (West Indies) and local (island) scales. We found a total of 516 alien plant species that are invasive on at least one of the nine islands studied, with between 24 to 306 invasive species per island. The invasive flora on these islands includes a wide range of taxonomic groups, life forms, and habitats. We detected low similarity in invasive species diversity between islands, with most invasive species (>60%) occurring on a single island and 6% occurring on at least five islands. To assess the importance of different models in predicting patterns of invasive species diversity among islands, we used generalized linear models. Our analyses revealed that invasive species diversity was well predicted by a combination of island area and economic development (gross domestic product per capita and kilometers of paved roadways). Our results provide strong evidence for the roles of geographical, ecological, and socioeconomic factors in determining the distribution and spread of invasive species on these islands. Anthropogenic disturbance and economic development seem to be the major drivers facilitating the spread and predominance of invasive species over native species.

  5. Prevalence of rheumatoid arthritis in the French West Indies: Results of the EPPPRA study in Martinique.

    PubMed

    Brunier, Lauren; Bleterry, Marie; Merle, Sylvie; Derancourt, Christian; Polomat, Katlyn; Dehlinger, Véronique; Deligny, Christophe; Jean-Baptiste, Georges; Arfi, Serge; Banydeen, Rishika; De Bandt, Michel

    2017-07-01

    Studies suggest that rheumatoid arthritis (RA) is less frequent in African populations. However, no recent precise data exists for Afro-Caribbeans. The EPPPRA project is a prospective epidemiological survey to describe prevalence and clinical aspects of RA in the French West Indies (Martinique, Guadeloupe, French Guiana). EPPPRA involved all rheumatologists from the French West Indies who included all patients with a known clinical diagnosis of RA, during a one-year period. We outline here results for Martinique. EPPPRA estimated an overall world age-standardized prevalence of RA at 0.10% [95% CI 0.09% to 0.11%] in Martinique, with a high female predominance (88.1%) and 93.1% of self-reported Afro-Caribbeans. Mean age at diagnosis was 49.6±16.0 years. A majority of subjects presented at least 4 criteria points from the 1987 American College of Rheumatology (ACR) classification (94.4%) and at least 6 points (78.2%) from the 2010 ACR/European League Against Rheumatism (EULAR) classification. A high immune seropositivity rate was highlighted (84.2%). Despite functional impact observed in 40.5% of patients, 71.4% presented a low disease activity level. Methotrexate was the most common ongoing treatment (73%), followed by biotherapies (24.4%). Numerous patients (68.6%) received a steroid regimen. Cardiovascular risk factors were very frequent, contrasting with a very low tobacco use (8.7%), CONCLUSION: This work outlines low standardized prevalence of RA in a French Afro-Caribbean population with specific characteristics (high female predominance, high immune seropositivity, low tobacco use). Despite easy access to care and biotherapies, approximately half of RA patients still present destructive disease with functional impact. Copyright © 2016 Société française de rhumatologie. Published by Elsevier SAS. All rights reserved.

  6. 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.

  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. FcR epsilon+ lymphocytes and regulation of the IgE antibody system. II. FcR epsilon+ B lymphocytes initiate a cascade of cellular and molecular interactions that control FcR epsilon expression and IgE production.

    PubMed

    Marcelletti, J F; Katz, D H

    1984-12-01

    This study additionally explores the orderly sequence of events concerning the induction of Fc receptors for IgE (FcR epsilon) that are initiated by IgE and mediated by IgE-induced regulants (EIR). Thus, lymphoid cells exposed to monomeric IgE displayed an early phase of exclusive B cell FcR epsilon expression, followed by the progressive appearance of FcR epsilon+ T cells, ultimately resulting in equal proportions of FcR epsilon+ B cells and T cells. Parallel cultures of lymphoid cells stimulated with EIR derived from unfractionated lymphoid cells (EIRT) also manifested rapid induction of FcR epsilon+ cells, but these FcR epsilon+ cells were predominantly T cells from the outset. Data presented here demonstrate that IgE-induced FcR epsilon expression by B cells ultimately results in the production of EIRT, which then induces FcR epsilon expression by T cells. The existence of EIRT that selectively induce T cell FcR epsilon expression prompted us to search for an EIRB that is selectively active in inducing FcR epsilon+ B cells. Indeed, IgE-stimulated, T cell-depleted lymphoid cells produce an EIRB that selectively induces FcR epsilon expression by B cells. This EIRB, but not EIRT, can also be generated by IgE stimulation of Lyt-2+ cell-blocked lymphoid cells, indicating that Lyt-1+ cells are not inhibitory to EIRB production and that production of EIRT is dependent upon functionally competent Lyt-2+ cells. Similar to IgE, EIRB induces rapid FcR epsilon expression, first by B cells and then by T cells, so that by 16 hr post induction equal proportions of FcR epsilon+ B and T cells were observed. Although complete T cell depletion does not affect IgE-induced FcR epsilon expression, selective blocking of Lyt-1+ cells markedly diminishes such responses, suggesting that Lyt-2+ cells are antagonistic to the induction of FcR epsilon+ B cells. Studies involving sequential T cell subset depletion clearly demonstrated that in the absence of functionally competent Lyt-1

  9. Epsilon Aurigae: a Laboratory for Understanding Circumstellar Disk Physics

    NASA Astrophysics Data System (ADS)

    Stencel, Robert; Ake, Thomas; Backman, Dana; Guinan, Edward

    2005-06-01

    Circumstellar disks are now known to be common around young stellar objects. However, their dimensions and compositions are measured only with difficulty. Models suffer from lack of key constraints. The disk around the secondary in the epsilon Aurigae binary, in contrast, has some well-determined properties. A disk is inferred from eclipse circumstances to be a 20 AU diameter, viewed edge-on & partially covers the F0 supergiant primary star for 2 full years during the 27 year binary period. This disk was discovered to be a strong thermal IR source during the 1982-84 eclipse, in part by IRAS. We seek IRS & MIPS SED data to clarify the nature and evolutionary status of this large protoplanetary-like disk & help to better constrain a class of disk models. This is among the most massive stellar systems with a disk. Its dimensions are well-known from the eclipse light curve. Temperature of the disk facing us during eclipse is known from its IR SED; the composition & velocities of gas from the secondary are known from absorption lines detected in the last eclipse. The mass of the system & proximity of the disk to the luminous primary star let us explore extremes of circumstellar disk physics. The secondary now is near quadrature, the time of most rapidly changing geometric aspect, so that measurements now give best resolution of temperature versus azimuth angle around the disk. Our goals include: More precisely defining temperature & projected size of the disk-shaped IR-emitting secondary object via IRS and MIPS measurements; Searching with IRS for emission and absorption features, against the cool secondary; Determining grain composition & properties via the full range of SST spectroscopy coverage [IRS & MIPS SED]; Seeking evidence for mass-loss history in extended material around the system [MIPS]; Establishing baselines of these & other measures for comparison during forthcoming eclipse campaigns (2009). It is only with SST that these science goals can be accomplished.

  10. 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.

  11. Mechanism of the mRNA guanylyltransferase reaction: isolation of N epsilon-phospholysine and GMP (5' leads to N epsilon) lysine from the guanylyl-enzyme intermediate.

    PubMed Central

    Toyama, R; Mizumoto, K; Nakahara, Y; Tatsuno, T; Kaziro, Y

    1983-01-01

    The mRNA capping reaction catalyzed by rat liver mRNA guanylyltransferase proceeds through an enzyme-GMP intermediate in which GMP is linked to the enzyme by a phosphoamide linkage. The studies described here show that GMP is bound to the epsilon-amino group of lysine of rat liver guanylyltransferase. The enzyme-[32P]GMP intermediate was digested with pronase to a [32P]GMP-peptide which was then converted to [32P]phosphoryl-peptide through periodate oxidation followed by beta-elimination. After alkaline hydrolysis of the [32P]phosphoryl-peptide, the major radioactive product co-electrophoresed with the authentic N epsilon-phospholysine on DEAE-cellulose paper. Neither [32P]Nimid-phosphohistidine nor Nguanido-phosphoarginine was detected in the hydrolysates. Furthermore, formation of N epsilon-guanylyl-lysine linkage on the enzyme was more directly shown by isolation of [32P]GMP(5' leads to N epsilon)lysine when the steps of periodate oxidation and beta-elimination were omitted. The results indicate that the nucleophile in the guanylyltransferase to which the guanylyl residue is linked is the epsilon-amino group of a lysine residue. [32P]Phosphoryl-lysine was also isolated from the vaccinia virus capping enzyme-[32P]GMP intermediate. Guanylyltransferase from HeLa cells, wheat germ, Artemia salina and yeast also formed the enzyme-GMP complex and, from the stability of the complex, the linkage between the enzyme and GMP was suggested to be a phosphoamide. Images Fig. 2. Fig. 3. Fig. 4. Fig. 6. Fig. 7. Fig. 8. PMID:6321153

  12. Relationship between fluorescence and conformation of epsilonNAD+ bound to dehydrogenases.

    PubMed

    Luisi, P L; Baici, A; Bonner, F J; Aboderin, A A

    1975-01-28

    This work reports on the interaction of the fluorescent nicotinamide 1,N6-ethenoadenine dinucleotide (epsilonNAD+) with horse liver alcohol dehydrogenase, octopine dehydrogenase, and glyceraldehyde-3-phosphate dehydrogenase from different sources (yeast, lobster muscle, and rabbit muscle). The coenzyme fluorescence is enhanced by a factor of 10-13 in all systems investigated. It is shown that this enhancement cannot be due to changes in the polarity of the environment upon binding, and that it must be rather ascribed to structural properties of the bound coenzyme. Although dynamic factors could also be important for inducing changes in the quantum yield of epsilonNAD+ fluorescence, the close similarity of the fluorescence enhancement factor in all cases investigated indicates that the conformation of bound coenzyme is rather invariant in the different enzyme systems and overwhelmingly shifted toward an open form. Dissociation constants for epsilonNAD+-dehydrogenases complexes can be determined by monitoring the coenzyme fluorescence enhancement or the protein fluorescence quenching. In the case of yeast glyceraldehyde-3-phosphate dehydrogenase at pH 7.0 and t = 20 degrees the binding plots obtained by the two methods are coincident, and show no cooperativity. The affinity of epsilonNAD+ is generally lower than that of NAD+, although epsilonNAD+ maintains most of the binding characteristics of NAD+. For example, it forms a tight complex with horse liver alcohol dehydrogenase and pyrazole, and with octopine dehydrogenase saturated by L-arginine and pyruvate. One major difference in the binding behavior of NAD+ and epsilonNAD+ seems to be present in the muscle glyceraldehyde-3-phosphate dehydrogenase. In fact, no difference was found for epsilon NAD+ between the affinities of the third and fourth binding sites. The results and implications of this work are compared with those obtained recently by other authors.

  13. 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.

  14. 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.

  15. 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.

  16. Patterns of Innovation: A Historical Case Study of Military Innovation in the Netherlands East Indies Navy from 1900-1942

    DTIC Science & Technology

    2013-06-13

    colonial empires in the Pacific.67 After the defeat of the Dutch fleet by the Royal Navy in 1811, the Dutch lost command of the seas surrounding the...archipelago. The conventional adage was: “Indies lost , all lost .”118 The predominant discourse became the idea that if a strong navy was feasible it...over. The League of Nations had lost its power. Italy had annexed Abyssinia (modern day Ethiopia), and Germany was speeding up its re- armament

  17. Phame: a novel phase metrology tool of Carl Zeiss for in-die phase measurements under scanner relevant optical settings

    NASA Astrophysics Data System (ADS)

    Perlitz, Sascha; Buttgereit, Ute; Scherübl, Thomas

    2007-03-01

    Meeting the demands of the lithography mask manufacturing industry moving toward 45nm and 32nm node for in-die phase metrology on phase shifting masks, Zeiss is currently developing an optical phase measurement tool (Phame TM), providing the capability of extending process control from large CD test features to in-die phase shifting features with high spatial resolution. In collaboration with Intel, the necessity of designing this optical metrology tool according to the optical setup of a lithographic exposure tool (scanner) has been researched to be fundamental for the acquisition of phase information generated from features the size of the used wavelength. Main cause is the dependence of the image phase of a scanner on polarization and the angle of incidence of the illumination light due to rigorous effects, and on the imaging NA of the scanner due to the loss of phase information in the imaging pupil. The resulting scanner phase in the image plane only coincides with the etch-depth equivalent phase for large test features, exceeding the size of the in-die feature by an order of magnitude. In this paper we introduce the Phame TM phase metrology tool, using a 193nm light source with the optical capability of phase measurement at scanner NA up to the equivalent of a NA1.6 immersion scanner, under varying, scanner relevant angle of incidence for EAPSMs and CPLs, and with the possibility of polarizing the illuminating light. New options for phase shifting mask process control on in-die features will be outlined with first measurement results.

  18. 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

  19. 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.

  20. 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.

  1. Controlling coherence in epsilon-near-zero metamaterials (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Caglayan, Humeyra; Hajian, Hodjat; Ozbay, Ekmel

    2017-05-01

    Recently, metamaterials with near-zero refractive index have attracted much attention. Light inside these materials experiences no spatial phase change and extremely large phase velocity, makes these peculiar systems applicable for realizing directional emission, tunneling waveguides, large-area single-mode devices and electromagnetic cloaks. In addition, epsilon-near-zero (ENZ) metamaterials can also enhance light transmission through a subwavelength aperture. Impedance-matched all-dielectric zero-index metamaterials which exhibit Dirac cone dispersions at center of the Brillouin zone, have been experimentally demonstrated at microwave regime and optical frequencies for transverse-magnetic (TM) polarization of light. More recently, it has been also proved that these systems can be realized in a miniaturized in-plane geometry useful for integrated photonic applications, i.e. these metamaterials can be integrated with other optical elements, including waveguides, resonators and interferometers. In this work, using a zero-index metamaterial at the inner and outer sides of a subwavelength aperture, we numerically and experimental study light transmission through and its extraction from the aperture. The metamaterial consists of a combination of two double-layer arrays of scatterers with dissimilar subwavelength dimensions. The metamaterial exhibits zero-index optical response in microwave region. Our numerical investigation shows that the presence of the metamaterial at the inner side of the aperture leads to a considerable increase in the transmission of light through the subwavelength aperture. This enhancement is related to the amplification of the amplitude of the electromagnetic field inside the metamaterial which drastically increases the coupling between free space and the slit. By obtaining the electric field profile of the light passing through the considered NZI/aperture/NZI system at this frequency we found out that in addition to the enhanced transmission

  2. 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.

  3. Desired Precision in Multi-Objective Optimization: Epsilon Archiving or Rounding Objectives?

    NASA Astrophysics Data System (ADS)

    Asadzadeh, M.; Sahraei, S.

    2016-12-01

    Multi-objective optimization (MO) aids in supporting the decision making process in water resources engineering and design problems. One of the main goals of solving a MO problem is to archive a set of solutions that is well-distributed across a wide range of all the design objectives. Modern MO algorithms use the epsilon dominance concept to define a mesh with pre-defined grid-cell size (often called epsilon) in the objective space and archive at most one solution at each grid-cell. Epsilon can be set to the desired precision level of each objective function to make sure that the difference between each pair of archived solutions is meaningful. This epsilon archiving process is computationally expensive in problems that have quick-to-evaluate objective functions. This research explores the applicability of a similar but computationally more efficient approach to respect the desired precision level of all objectives in the solution archiving process. In this alternative approach each objective function is rounded to the desired precision level before comparing any new solution to the set of archived solutions that already have rounded objective function values. This alternative solution archiving approach is compared to the epsilon archiving approach in terms of efficiency and quality of archived solutions for solving mathematical test problems and hydrologic model calibration problems.

  4. Enhancing the carotenoid content of Brassica napus seeds by downregulating lycopene epsilon cyclase.

    PubMed

    Yu, Bianyun; Lydiate, Derek J; Young, Lester W; Schäfer, Ulrike A; Hannoufa, Abdelali

    2008-08-01

    The accumulation of carotenoids in higher plants is regulated by the environment, tissue type and developmental stage. In Brassica napus leaves, beta-carotene and lutein were the main carotenoids present while petals primarily accumulated lutein and violaxanthin. Carotenoid accumulation in seeds was developmentally regulated with the highest levels detected at 35-40 days post anthesis. The carotenoid biosynthesis pathway branches after the formation of lycopene. One branch forms carotenoids with two beta rings such as beta-carotene, zeaxanthin and violaxanthin, while the other introduces both beta- and epsilon-rings in lycopene to form alpha-carotene and lutein. By reducing the expression of lycopene epsilon-cyclase (epsilon-CYC) using RNAi, we investigated altering carotenoid accumulation in seeds of B. napus. Transgenic seeds expressing this construct had increased levels of beta-carotene, zeaxanthin, violaxanthin and, unexpectedly, lutein. The higher total carotenoid content resulting from reduction of epsilon-CYC expression in seeds suggests that this gene is a rate-limiting step in the carotenoid biosynthesis pathway. epsilon-CYC activity and carotenoid production may also be related to fatty acid biosynthesis in seeds as transgenic seeds showed an overall decrease in total fatty acid content and minor changes in the proportions of various fatty acids.

  5. Phase Stability of Epsilon and Gamma Hniw (CL-20) at High-Pressure and Temperature

    NASA Astrophysics Data System (ADS)

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

    2007-12-01

    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 (α, β, γ, ɛ, ζ). 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 °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 °C then underwent a transition to the gamma phase above 125 °C and then thermal decomposition occurred above 150 °C. Upon compression, the gamma phase underwent a phase transition at both ambient temperature and 140 °C. Pressure—volume data for the epsilon and gamma phase at ambient temperature and the epsilon phase at 75 °C were fit to the Birch-Murnaghan formalism to obtain isothermal equations of state.

  6. Synthesis, characterization, and dielectric properties of Ba(Ti{sub 1-x}Sn{sub x})O{sub 3} nanopowders and ceramics

    SciTech Connect

    Du Fengtao; Cui Bin; Cheng Hualei; Niu Ruiyuan; Chang Zhuguo

    2009-09-15

    We prepared Ba(Ti{sub 1-x}Sn{sub x})O{sub 3} powders and ceramics by means of the sol-gel process, with dibutyltin dilaurate as the Sn precursor. The samples were characterized by means of Fourier-transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, and scanning electron microscopy, and also determined the dielectric properties of the ceramics. The powders synthesized by means of the sol-gel process had a grain size on the nanometer scale, with the grains mainly composed of a cubic BaTiO{sub 3} phase. Sn can disperse into BaTiO{sub 3} more uniformly in the sol-gel technique using dibutyltin dilaurate as the Sn precursor. With increasing Sn concentration, the grain size of the Ba(Ti{sub 1-x}Sn{sub x})O{sub 3} ceramics increased and the maximum dielectric constant ({epsilon}{sub max}) first increased and then decreased. At a Sn concentration of 5 mol%, {epsilon}{sub max} reached its maximum value (19,235).

  7. 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%.

  8. 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.

  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. Sub-micrometer epsilon-near-zero electroabsorption modulators enabled by high-mobility cadmium oxide

    DOE PAGES

    Campione, Salvatore; Wood, Michael; Serkland, Darwin K.; ...

    2017-07-06

    Here, epsilon-near-zero materials provide a new path for tailoring light-matter interactions at the nanoscale. In this paper, we analyze a compact electroabsorption modulator based on epsilon-near-zero confinement in transparent conducting oxide films. The non-resonant modulator operates through field-effect carrier density tuning. We compare the performance of modulators composed of two different conducting oxides, namely indium oxide (In2O3) and cadmium oxide (CdO), and show that better modulation performance is achieved when using high-mobility (i.e. low-loss) epsilon-near-zero materials such as CdO. In particular, we show that non-resonant electroabsorption modulators with sub-micron lengths and greater than 5 dB extinction ratios may be achievedmore » through the proper selection of high-mobility transparent conducting oxides, opening a path for device miniaturization and increased modulation depth.« less

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

    PubMed Central

    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

  12. High-resolution in-die metrology using beam profile reflectometry and ellipsometry

    NASA Astrophysics Data System (ADS)

    Jun, Chungsam; Park, Jangik; Opsal, Jon; Pois, Heath; Kim, In-Kyo; Kim, Jung-Wook; Nicolaides, Lena

    2007-03-01

    A new application for ultra-fast and repeatable in-die determination of CD structures at the ~1 μm length scale using BPR®/BPE® (Beam Profile Reflectometry/Ellipsometry) technologies on an Opti-Probe OP9000 series system, is presented and summarized. Two structures were measured and analyzed, including a poly-silicon CD standard and an advanced poly-silicon recessed structure relevant to advanced memory devices. A focused beam spot (~1 μm) and "fast BPR" data acquisition capability (~17 ms) were utilized to perform high-resolution scans across wafer and within single die regions. Rotating Compensator Spectroscopic Ellipsometry (RCSE®) signals were also used to independently determine and compare to BPR results from data collected over larger areas (~15 μm). The BPR/BPE and SE results for line CD were found to have high correlation. Further, model regression for SE data coupled with an artificial neural network model and fast BPR were utilized to measure and calculate 10,000 points across a 1 mm2 area in a matter of minutes. Overall, the results were found to be repeatable and correlated well to CD-SEM analysis.

  13. Ciguatera fish poisoning and sea surface temperatures in the Caribbean Sea and the West Indies.

    PubMed

    Tester, Patricia A; Feldman, Rebecca L; Nau, Amy W; Kibler, Steven R; Wayne Litaker, R

    2010-10-01

    Ciguatera fish poisoning (CFP) is a circumtropical disease caused by ingestion of a variety of reef fish that bioaccumulate algal toxins. Distribution and abundance of the organisms that produce these toxins, chiefly dinoflagellates of the genus Gambierdiscus, are reported to correlate positively with water temperature. Consequently, there is growing concern that increasing temperatures associated with climate change could increase the incidence of CFP. This concern prompted experiments on the growth rates of six Gambierdiscus species at temperatures between 18 degrees C and 33 degrees C and the examination of sea surface temperatures in the Caribbean and West Indies for areas that could sustain rapid Gambierdiscus growth rates year-round. The thermal optimum for five of six Gambierdiscus species tested was >/=29 degrees C. Long-term SST data from the southern Gulf of Mexico indicate the number of days with sea surface temperatures >/=29 degrees C has nearly doubled (44 to 86) in the last three decades. To determine how the sea surface temperatures and Gambierdiscus growth data correlate with CFP incidences in the Caribbean, a literature review and a uniform, region-wide survey (1996-2006) of CFP cases were conducted. The highest CFP incidence rates were in the eastern Caribbean where water temperatures are warmest and least variable.

  14. Salmonella enterica prevalence in leatherback sea turtles (Dermochelys coriacea) in St. Kitts, West Indies.

    PubMed

    Dutton, Clayton S; Revan, Floyd; Wang, Chengming; Xu, Chuanling; Norton, Terry M; Stewart, Kimberly M; Kaltenboeck, Bernhard; Soto, Esteban

    2013-09-01

    Salmonella spp. are gram-negative bacteria capable of causing diseases in a wide range of aquatic and terrestrial animals, including humans. Sea and terrestrial turtles have been recognized as carriers of this zoonotic pathogen. In this project, conventional and molecular diagnostic methods were combined to investigate the prevalence of Salmonella enterica in leatherback sea turtles (Dermochelys coriacea) that used the island of St. Kitts, West Indies as a nesting ground during 2011 (n = 21). Isolates obtained from selective media were screened and colonies suspected of being Salmonella spp. were confirmed by fluorescence resonance energy transfer polymerase chain reaction. The prevalence of S. enterica within this sample population during this period was found to be 14.2%. Moreover, due to the increasing risk of antibiotic resistance in enteric bacteria, antimicrobial susceptibility was investigated in all recovered Salmonella spp. isolates utilizing the broth microdilution method. All isolates were susceptible to the lowest concentration of kanamycin, gentamicin, ciprofloxacin, enrofloxacin, nalidixic acid, and trimethoprim/sulfamethoxazole tested. Further research should be pursued to understand the interaction of this bacterial pathogen with the environment, host, and other microbial communities, and to further develop faster, more sensitive, and more specific diagnostic methods.

  15. [Television viewing and cardiovascular risk behaviors in the adult population of the French West Indies].

    PubMed

    Carrère, P; Atallah, A; Kelly-Irving, M; Lang, T; Inamo, J

    2013-06-01

    Recent studies have shown a link between prolonged television viewing and cardiovascular (CV) morbidity and mortality. We aimed to estimate the relationship between television viewing and CV risk behaviors and in the adult population of the French West Indies. We used data from Consant, a cross-sectional study carried out in 2007 on a representative sample of the adult Guadeloupean population (1005 subjects aged 25-74 years selected by stratified random sampling and interviewed at home by trained investigators working in pairs). Among respondents who reported watching television for 2 hours or more per day, 46.5% stated practicing no leisure time physical activity, compared with 35.6% among those who reported watching television for less than 2 hours per day. Adjusting for age, sex, education, income, family status, and perceived CV benefits of physical activity, the odds ratio of physical inactivity was estimated at 1.75 (P<10(-3)) among subjects who reported watching television for 2 hours or more per day, compared with other subjects. A similar relationship was observed when considering dieting to prevent weight gain. In this representative sample of a French Caribbean population, a strong and very significant relationship was observed between prolonged television viewing and CV risk behaviors. Prolonged television viewing seems common to a lifestyle that is characterized by little physical activity and unhealthy eating habits. This may play a role in social inequalities observed in CV diseases. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  16. Fatal poisoning in Jamaica: a coroner's autopsy study from the University Hospital of the West Indies.

    PubMed

    Escoffery, Carlos T; Shirley, Suzanne E

    2004-04-01

    This study reviewed cases of fatal poisoning in a coroner's autopsy series at the University Hospital of the West Indies and represented the first such study reported from Jamaica. The autopsy protocols of all coroner's autopsies performed over the 20-year period January 1980 to December 1999 were reviewed retrospectively; 22 (1.0%) cases were identified and relevant clinical and pathological data analysed. There were 13 males and nine females (M:F ratio 1.4:1) with an age range of 2 - 69 years (mean +/- SD = 27 +/- 16.1 years). The 20 - 29 year group was most commonly affected and five patients (22.7%) were children (< 18 years of age). Pesticides (herbicides/ insecticides) were implicated in nine (41%) cases: paraquat was the most common, found in six (27%) cases. Prescription drugs were the next most prevalent group with six (27%) cases, followed by anti-psychotic drugs in four (18%) cases. Cocaine and ackee were each implicated in two (9%) cases. The manner of death was suicidal in 14 (64%) cases and accidental in eight (36%) cases. Seven patients had documented psychiatric illnesses, six of whom committed suicide. Autopsy findings were largely non-specific. The relatively small number of cases was consistent with the low incidence of fatal poisoning in Jamaica.

  17. Serovar diversity of pathogenic Leptospira circulating in the French West Indies.

    PubMed

    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

    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. 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. 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.

  18. Prevalence of Toxoplasma gondii in rats (Rattus norvegicus) in Grenada, West Indies.

    PubMed

    Dubey, J P; Bhaiyat, M I; Macpherson, C N L; de Allie, C; Chikweto, A; Kwok, O C H; Sharma, R N

    2006-10-01

    Cats are important in the natural epidemiology of Toxoplasma gondii, because they are the only hosts that can excrete environmentally resistant oocysts. Cats are infected with T. gondii via predation on infected birds and rodents. During 2005, 238 rats (Rattus norvegicus) were trapped in Grenada, West Indies, and their sera along with tissue samples from their hearts and brains were examined for T. gondii infection. Antibodies to T. gondii were assayed by the modified agglutination test (MAT, titer 1:40 or higher); only 2 (0.8%) of 238 rats were found to be infected. Brains and hearts of all rats were bioassayed in mice. Toxoplasma gondii was isolated from the brain and the heart of only 1 rat, which had a MAT titer of 1:320. All of 5 mice inoculated with the heart tissue, and the 5 mice inoculated with the brain tissue of the infected rat remained asymptomatic, even though tissue cysts were found in their brains. Genetically, the isolates of T. gondii from the heart and the brain were identical and had genotype III by using the SAG1, SAG2, SAG3, BTUB, and GRA6 gene markers. These data indicate that rats are not important in the natural history of T. gondii in Grenada.

  19. Toxoplasma gondii and Neospora caninum antibodies in dogs from Grenada, West Indies.

    PubMed

    Dubey, J P; Stone, D; Kwok, O C H; Sharma, R N

    2008-06-01

    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%) of the 107 dogs, with titers of 1:25 in 17, 1:50 in 19, 1:100 in 7, 1:1,600 in 5, and 1:3,200 or higher in 4. Seroprevalence increased with age from 2.2% in dogs <6 mo old to 18.9% in dogs older than 2 yr, indicating postnatal transmission of T. gondii in this population of canines. There was no correlation between the health of the dogs and the seroprevalence or magnitude of the T. gondii titer. Antibodies to N. caninum were determined by the indirect immunofluorescent antibody test (IFAT). Two of the 107 dogs had N. caninum antibodies (IFAT titers 1:100 and 1:400); these dogs had T. gondii titers of 1:1,600 and 1:50, respectively. Results indicate that these 2 structurally similar protozoa are antigenically different.

  20. Oviposition behaviour and parity rates of Aedes aegypti collected in sticky traps in Trinidad, West Indies.

    PubMed

    Chadee, Dave D; Ritchie, Scott A

    2010-12-01

    The oviposition behaviour of Aedes aegypti was studied using sticky traps (ST), double sticky traps (DST) and standard ovitrap traps in urban St. Augustine and rural Tamana, Trinidad, West Indies. In St. Augustine three traps were deployed in 10 houses for 10 weeks while in Tamana traps were similarly deployed (10 houses for 10 weeks). At each house one ovitrap, one ST and one DST were placed using the criteria established for ovitrap placement. The results showed large numbers of adults collected, 3602 collected in DSTs and 1,670 adults collected in STs. In addition, >9000 immatures were collected in the DST vs >7000 in the STs. Over the 10 weeks 517 Ae. aegypti eggs were collected from ovitraps from Tamana and 3252 eggs from St. Augustine. Most of the females collected were parous (99%) with many older females collected e.g. 7 pars collected in both Tamana and St. Augustine. A major finding of the study was the observation of the "death stress oviposition" behaviour displayed among Ae. aegypti females captures in the sticky traps. This is the first report of this behaviour in the field and may well explain the collection of large numbers of immatures found in the ST and DSTs. The results of this study are discussed in the context of developing surveillance and control strategies, especially for reducing man-vector contact. Copyright © 2010 Elsevier B.V. All rights reserved.

  1. Costs and Utilization of Operating Rooms in a Public Hospital in Trinidad, West Indies

    PubMed Central

    Hariharan, Seetharaman; Chen, Deryk

    2015-01-01

    Context: A top-down evaluation of the costs of operating rooms (ORs) is not commonly done because it is relevant mostly in a publicly funded system. Objective: This study was conducted to determine the costs and utilization of ORs in a public hospital in Trinidad, West Indies, for two one-year periods using a top-down model. Design: Quantitative observational study. Main Outcome Measures: A “cost-block” model suggested for evaluation of intensive care unit costs was adapted to suit ORs. Data were obtained from personal interviews, records, and surveys from the appropriate hospital departments. Adjusted OR utilization times also were recorded for both years. Results: The total annual costs of 4 ORs for the years 2006 and 2009 were approximately US $2.2 and $3.2 million, respectively. Capital expenditure contributed to 70% of the costs, followed by consumables (15%) and medical staff salary (8%). The daily cost of running the ORs was US $6242 in 2006, which rose to $8873 in 2009. The cost of unutilized OR time was approximately US $298,342 in 2006 and was reduced to $198,315 during 2009. Conclusion: The adapted cost-block model was useful to evaluate the costs of ORs in a public hospital in Trinidad and can be used from the government’s expenditure perspective. Because the cost of running the ORs was high, efficiency must be improved to minimize waste. PMID:26828072

  2. 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

  3. Enhanced gene delivery using biodegradable poly(ester amine)s (PEAs) based on low-molecular-weight polyethylenimine and poly(epsilon-caprolactone)-pluronic-poly(epsilon-caprolactone).

    PubMed

    Liu, Tingting; Yu, Xiujun; Kan, Bing; Guo, Qingfa; Wang, Xiuhong; Shi, Shuai; Guo, Gang; Luo, Feng; Zhao, Xia; Wei, Yuquan; Qian, Zhiyong

    2010-08-01

    In this paper, the poly(ester amine)s (PEAs) were successfully prepared from low-molecular-weight PEI (Mn = 2000) and Poly(epsilon-caprolactone)-poly(ethylene glycol)-poly(propylene glycol)-poly(ethylene glycol)-poly(epsilon-caprolactone) (PCFC) copolymers using isophorone diisocyanate (IPDI) as cross-linker. The obtained PEAs copolymers are biodegradable and water-soluble. The PEAs/DNA complexes showed effective and stable DNA condensation with the particle size < or = 200 nm and zeta potential > or =10 mV, indicating its potential for intracellular delivery. Compared to the unmodified low-molecular-weight PEI, PEAs displayed similarly low cytotoxicity in all two cell lines (293T: Human kidney carcinoma, HUVEC: Human umbilical vein Endothelial cell) and revealed much higher transfection efficiency in 293T cell lines. Therefore these PEAs might be a novel safe and efficient polymeric gene delivery vectors.

  4. Directional and monochromatic thermal emitter from epsilon-near-zero conditions in semiconductor hyperbolic metamaterials

    PubMed Central

    Campione, Salvatore; Marquier, Francois; Hugonin, Jean-Paul; Ellis, A. Robert; Klem, John F.; Sinclair, Michael B.; Luk, Ting S.

    2016-01-01

    The development of novel thermal sources that control the emission spectrum and the angular emission pattern is of fundamental importance. In this paper, we investigate the thermal emission properties of semiconductor hyperbolic metamaterials (SHMs). Our structure does not require the use of any periodic corrugation to provide monochromatic and directional emission properties. We show that these properties arise because of epsilon-near-zero conditions in SHMs. The thermal emission is dominated by the epsilon-near-zero effect in the doped quantum wells composing the SHM. Furthermore, different properties are observed for s and p polarizations, following the characteristics of the strong anisotropy of hyperbolic metamaterials. PMID:27703223

  5. Directional and monochromatic thermal emitter from epsilon-near-zero conditions in semiconductor hyperbolic metamaterials

    SciTech Connect

    Campione, Salvatore; Marquier, Francois; Hugonin, Jean -Paul; Ellis, A. Robert; Klem, John F.; Sinclair, Michael B.; Luk, Ting S.

    2016-10-05

    The development of novel thermal sources that control the emission spectrum and the angular emission pattern is of fundamental importance. In this paper, we investigate the thermal emission properties of semiconductor hyperbolic metamaterials (SHMs). Our structure does not require the use of any periodic corrugation to provide monochromatic and directional emission properties. We show that these properties arise because of epsilon-near-zero conditions in SHMs. The thermal emission is dominated by the epsilon-near-zero effect in the doped quantum wells composing the SHM. In conclusion, different properties are observed for s and p polarizations, following the characteristics of the strong anisotropy of hyperbolic metamaterials.

  6. Loss-compensated broadband epsilon-near-zero metamaterials with gain media

    NASA Astrophysics Data System (ADS)

    Sun, Lei; Yang, Xiaodong; Gao, Jie

    2013-11-01

    The concept of loss-compensated broadband epsilon-near-zero metamaterials consisting of step-like metal-dielectric multilayer structures doped with gain media is proposed based on the combination of the Milton representation of the effective permittivity and the optical nonlocality due to the metal-dielectric multilayer structures. With the loss compensation by gain media, broadband epsilon-near-zero metamaterials possesses significantly low material loss in optical frequency range, leading to superior broadband electromagnetic properties for realizing unique functional optical devices, such as the demonstrated prisms for broadband directional emission and S-shaped lenses for phase front shaping.

  7. Directional and monochromatic thermal emitter from epsilon-near-zero conditions in semiconductor hyperbolic metamaterials.

    PubMed

    Campione, Salvatore; Marquier, Francois; Hugonin, Jean-Paul; Ellis, A Robert; Klem, John F; Sinclair, Michael B; Luk, Ting S

    2016-10-05

    The development of novel thermal sources that control the emission spectrum and the angular emission pattern is of fundamental importance. In this paper, we investigate the thermal emission properties of semiconductor hyperbolic metamaterials (SHMs). Our structure does not require the use of any periodic corrugation to provide monochromatic and directional emission properties. We show that these properties arise because of epsilon-near-zero conditions in SHMs. The thermal emission is dominated by the epsilon-near-zero effect in the doped quantum wells composing the SHM. Furthermore, different properties are observed for s and p polarizations, following the characteristics of the strong anisotropy of hyperbolic metamaterials.

  8. Broadband epsilon-near-zero metamaterials with steplike metal-dielectric multilayer structures

    NASA Astrophysics Data System (ADS)

    Sun, Lei; Gao, Jie; Yang, Xiaodong

    2013-04-01

    The concept of the broadband epsilon-near-zero meta-atom consisting of layered stacks with specified metallic filling ratio and thickness is proposed based on the Bergman spectral representation of the effective permittivity. The steplike metal-dielectric multilayer structures are designed to achieve realistic broadband epsilon-near-zero meta-atoms in optical frequency range. These meta-atoms can be integrated as building blocks for unconventional optical components with exotic electromagnetic properties over a wide frequency range, such as the demonstrated broadband directional emission and phase front shaping.

  9. GABAA receptor epsilon subunit expression in identified peptidergic neurons of the rat hypothalamus.

    PubMed

    Moragues, Nathalie; Ciofi, Philippe; Lafon, Pierrette; Tramu, Gérard; Garret, Maurice

    2003-03-28

    Dual-labeling immunohistochemical or in situ hybridization studies for the recently cloned epsilon-subunit and several neuropeptides were performed in the rat hypothalamus. We revealed an extensive co-expression (>90%) with hypocretin (Hcrt), oxytocin (OT), the gonadotropin-releasing hormone (GnRH), and the melanin-concentrating hormone (MCH) peptides, whereas occasional co-expression (<10%) with cocaine-amphetamine-regulated transcript (CART) was found. Our results suggest that novel GABA(A) receptor subtypes comprising epsilon-subunit are important for metabolic and neuroendocrine functions.

  10. A new formulation for the epsilon method applied to the minimum-time-to-climb problem

    NASA Technical Reports Server (NTRS)

    Taylor, L. W., Jr.; Smith, H. J.

    1978-01-01

    Balakrishnan's epsilon technique is used to compute minimum-time profiles for the F-104 airplane. This technique differs from the classical gradient method in that a quadratic penalty on the error in satisfying the equation of motion is included in the cost function to be minimized as a means of eliminating the requirement of satisfying the equations of motion. Although the number of unknown independent functions is increased to include the state variables, the evaluation of the gradient of the cost function is simplified, resulting in considerable computational savings, thereby making it appear feasible to use the epsilon method for real-time application.

  11. 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.

  12. 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.

  13. 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

    1988-01-01

    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.

  14. 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.

  15. Phosphorescence maxima and triplet state lifetimes of NAD+ and epsilon-NAD+ in ternary complexes with horse liver alcohol dehydrogenase.

    PubMed

    Rousslang, K; Allen, L; Ross, J B

    1989-02-01

    This paper describes the phosphorescence emission and decay times of NAD+ and its fluorescent etheno derivative, epsilon-NAD+, in the pyrazole ternary complex with horse liver alcohol dehydrogenase (ADH). We show that the epsilon-NAD+ triplet state, as well as the tryptophan triplet state, can be utilized to monitor the coenzyme-enzyme interaction. The decays of NAD+ and AMP are single exponential, and the lifetimes are the same within experimental error. The phosphorescence lifetimes, evaluated as single exponentials, are slightly shorter in epsilon-NAD+ than they are in epsilon-AMP. Whereas the decay of epsilon-AMP was adequately fit by a single exponential with a time constant of very close to 0.5 s, it was necessary to fit the decay of epsilon-NAD+ to a double exponential. Ternary complexes with NAD+ excited at 297 nm exhibit decay kinetics nearly identical to those of ADH by itself. On the other hand, when excitation of the epsilon-NAD+ ternary complex is provided at 313 nm, where there is very little absorption by either tryptophan residue, the decay law of the ternary complex is similar to that of epsilon-NAD+ in solution. Our results demonstrate that NAD+ and epsilon-NAD+ quench tryptophan phosphorescence in ADH. Normalizing the phosphorescence intensity to the 0-0 vibronic band assigned to Trp-15 (blue-edge), we calculate a 21% decrease in the phosphorescence associated with Trp-314 at stoichiometric saturation of the coenzyme binding sites with NAD+ in the ternary complex. When the active sites are saturated with epsilon-NAD+, the relative phosphorescence due to Trp-314 decreases by 63%.(ABSTRACT TRUNCATED AT 250 WORDS)

  16. Mapping of the high affinity Fc epsilon receptor binding site to the third constant region domain of IgE.

    PubMed Central

    Nissim, A; Jouvin, M H; Eshhar, Z

    1991-01-01

    Identification of the precise region(s) on the IgE molecule that take part in the binding of IgE to its high affinity receptor (Fc epsilon RI) may lead to the design of IgE analogues able to block the allergic response. To localize the Fc epsilon RI-binding domain of mouse IgE, we attempted to confer on human IgE, which normally does not bind to the rodent receptor, the ability to bind to the rat Fc epsilon RI. Employing exon shuffling, we have expressed chimeric epsilon-heavy chain genes composed of a mouse (4-hydroxy-3-nitrophenyl)acetic acid (NP)-binding VH domain, and human C epsilon in which various domains were replaced by their murine counterparts. This has enabled us to test the Fc epsilon RI-binding of each mouse IgE domain while maintaining the overall conformation of the molecule. All of the chimeric IgE molecules which contain the murine C epsilon 3, bound equally to both the rodent and human receptor, as well as to monoclonal antibodies recognizing a site on IgE which is identical or very close to the Fc epsilon RI binding site. Deletion of the second constant region domain did not impair either the binding capacity of the mutated IgE or its ability to mediate mast cell degradation. These results assign the third epsilon domain of IgE as the principal region involved in the interaction with the Fc epsilon RI. Images PMID:1824934

  17. Epsilon-sarcoglycan compensates for lack of alpha-sarcoglycan in a mouse model of limb-girdle muscular dystrophy.

    PubMed

    Imamura, Michihiro; Mochizuki, Yasushi; Engvall, Eva; Takeda, Shin'ichi

    2005-03-15

    Dystrophin and the dystrophin-associated protein (DAP) complex protect the sarcolemma against contraction-induced injury and serve as a mechanical link between the extracellular matrix and the actin cytoskeleton. Some of the functional properties of the DAP complex are mediated by its sarcoglycan (SG) subcomplex, which is composed of alpha-, beta-, gamma- and delta-SGs. Autosomal recessive limb-girdle muscular dystrophy type-2D (LGMD 2D) results from reduction in SG subcomplex levels caused by specific mutations in the muscle-specific alpha-SG gene. epsilon-SG is a widely expressed homolog of the muscle-specific alpha-SG, and expression of epsilon-SG may compensate for the pathologic changes in alpha-SG function. Thus, the goal of the present study was to investigate whether overexpression of epsilon-SG can compensate for dysfunction of alpha-SG. Several transgenic mouse lines that overexpress epsilon-SG in skeletal muscle were established. Overexpression of epsilon-SG in normal mice resulted in substitution of epsilon-SG for alpha-SG in the SG complex of skeletal muscle without any obvious abnormalities. To determine whether an increase in epsilon-SG expression may prevent muscular dystrophy in the context of alpha-SG-deficiency, these epsilon-SG transgenic mice were crossed with alpha-SG deficient mice. alpha-SG-deficient mice overexpressing epsilon-SG exhibited no skeletal muscle cell membrane damage or abnormal contraction. These data suggest that the overexpression of epsilon-SG may represent a therapeutic strategy for treatment of LGMD 2D.

  18. NMR studies of the exocyclic 1,N sub 6 -ethenodeoxyadenosine adduct (. epsilon. dA) opposite thymidine in a DNA duplex. Nonplanar alignment of. epsilon. dA(anti) and dT(anti) at the lesion site

    SciTech Connect

    Kouchakdjian, M.; Patel, D.J. ); Eisenberg, M. ); Yarema, K.; Basu, A.; Essigmann, J. )

    1991-02-19

    Two-dimensional proton NMR studies are reported on the complementary d(C-A-T-G-T-G-T-A-C){center dot}d(G-T-A-C-{epsilon}A-C-A-T-G) nonanucleotide duplex (designated {epsilon}dA{center dot}dT 9-mer duplex) containing 1,N{sup 6}-ethenodeoxyadenosine ({epsilon}dA), a carcinogen-DNA adduct, positioned opposite thymidine in the center of the helix. The authors NMR studies have focused on the conformation of the {epsilon}dA{center dot}dT 9-mer duplex at neutral pH with emphasis on defining the alignment at the dT5{center dot}{epsilon}dA14 lesion site. The through-space NOE distance connectivities establish that both dT5 and {epsilon}dA14 adopt anti glycosidic torsion angles, are directed into the interior of the helix, and stack with flanking Watson-Crick dG4{center dot}dC15 and dG6{center dot}dC13 pairs. Furthermore, the d(G4-T5-G6){center dot}d(C13-{epsilon}A14-C15) trinucleotide segment centered about the dT5{center dot}{epsilon}dA14 lesion site adopts a right-handed helical conformation in solution. Energy minimization computations were undertaken starting from six different alignments of dT5(anti) and {epsilon}dA14(anti) at the lesion site and were guided by distance constraints defined by lower and upper bounds estimated from NOESY data sets on the {epsilon}dA{center dot}dT 9-mer duplex. The NMR data are consistent with a nonplanar alignment of {epsilon}dA14(anti) and dT5(anti) with dT5 displaced toward the flanking dG4{center dot}dC15 base pair within the d(G4-T5-G6){center dot}d(C13-{epsilon}A14-C15) segment of the {epsilon}dA{center dot}dT 9-mer duplex.

  19. Analysis of Epsilon Aurigae light curve from the Solar Mass Ejection Imager

    NASA Astrophysics Data System (ADS)

    Clover, John; Jackson, B. V.; Buffington, A.; Hick, P. P.; Kloppenborg, B.; Stencel, R.

    2011-01-01

    The Solar Mass Ejection Imager (SMEI) was launched aboard the Coriolis spacecraft in 2003. It is equipped with 3 CCD cameras to measure the brightness of Thomson-scattered electrons in the heliosphere. Each CCD images a strip of the sky that is 3°x60°. The three cameras are mounted on the satellite with their fields of view aligned end-to-end so that SMEI sweeps nearly the entire sky each 102 minute orbit. SMEI has now accumulated stellar time series for about 5700 bright stars, including epsilon Aurigae, for each orbit where data is available. SMEI data provide nearly year-round coverage of epsilon Aurigae. The baffled SMEI optics provide more accurate photometric data than ground-based observations, particularly at mid-eclipse when epsilon Aurigae is close to the Sun. We present an analysis of the brightness variations of the epsilon Aurigae system, before and during the eclipse. The University of Denver participants are grateful for support under NSFgrant 10-16678 and the bequest of William Hershel Womble in support of astronomy at the University of Denver.

  20. 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.

  1. 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…

  2. 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).

  3. 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…

  4. 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…

  5. 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.

  6. Molecular cloning and nucleotide sequencing of human immunoglobulin epsilon chain cDNA.

    PubMed Central

    Seno, M; Kurokawa, T; Ono, Y; Onda, H; Sasada, R; Igarashi, K; Kikuchi, M; Sugino, Y; Nishida, Y; Honjo, T

    1983-01-01

    DNA complementary to mRNA of human immunoglobulin E heavy chain (epsilon chain) isolated and purified from U266 cells has been synthesized and inserted into the PstI site of pBR322 by G-C tailing. This recombinant plasmid was used to transform E. coli chi 1776 to screen 1445 tetracycline resistant colonies. Nine clones (pGETI - 9) containing cDNA coding for the human epsilon chain were recognized by colony hybridization and Southern blotting analysis with a nick-translated human IgE genome fragment. The nucleotide sequence of the longest cDNA contained in pGET2 was determined. The results indicate that the sequence of 1657 nucleotides codes for 494 amino acids covering a part of the variable region and all of the constant region of the human epsilon chain. Most of the amino acid sequence deduced from the nucleotide sequence is in substantial agreement with that reported. Furthermore a termination codon after the -COOH terminal amino acid marks the beginning of a 3' untranslated region of 125 nucleotides with a poly A tail. Taking this into account, the structure of the human epsilon chain mRNA, except a part of the 5' end, is conserved fairly well in the cDNA insert in pGET2. Images PMID:6300763

  7. Epsilon metal waste form for immobilization of noble metals from used nuclear fuel

    NASA Astrophysics Data System (ADS)

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

    2013-10-01

    Epsilon metal (ɛ-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, thus the processing problems related to their 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 alloying temperatures, 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).

  8. 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.

  9. Mapping of the continuous epitopes displayed on the Clostridium perfringens type D epsilon-toxin.

    PubMed

    Alves, Guilherme Guerra; Machado-de-Ávila, Ricardo Andrez; Chávez-Olórtegui, Carlos Delfin; Silva, Rodrigo Otávio Silveira; Lobato, Francisco Carlos Faria

    2017-02-03

    The epsilon toxin, produced by Clostridium perfringens, is responsible for enterotoxemia in ruminants and is a potential bioterrorism agent. In the present study, 15 regions of the toxin were recognized by antibodies present in the serum, with different immunodominance scales, and may be antigen determinants that can be used to formulate subunit vaccines.

  10. 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.

  11. 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.

  12. Progress in understanding the renormalization group skewness and kappa-epsilon models

    NASA Technical Reports Server (NTRS)

    Smith, Leslie M.; Reynolds, W. C.

    1991-01-01

    The immediate goal is to understand and validate the Yakhot-Orszag model of the velocity-derivative skewness and model equation for the rate of energy dissipation epsilon. A summary of a more detailed manuscript in preparation is presented. The purpose is to clarify some limitations of the theory by careful examination of key assumptions and approximations, and thereby to encourage its improvement.

  13. Fault Slip and Paleomagnetic Analysis of the Tectonics of Tobago, West Indies

    NASA Astrophysics Data System (ADS)

    Ringerwole, N. A.; Weber, J. C.; Hippolyte, J.; Johnson, M.

    2011-12-01

    We present in-progress results from a multi-disciplinary study of the tectonic history of Tobago, West Indies. Tobago is an accreted arc-forearc terrane in the currently dextral transform (but formerly obliquely colliding) Caribbean-South American plate boundary zone. Fault slip inversions using data collected from 23 sites with rock ages ranging from Cretaceous (Albian) to Quaternary indicate four principal phases of deformation. In current (unrotated) coordinates they are (from youngest to oldest): 1) Quaternary-Pliocene N-S extension, 2) NNW-SSE compression associated with strike-slip and reverse faults, 3) pervasive NE-SW extension that was tilted by phase 2 faults, and 4) a NE-SW compression associated with tilting and the oldest Tobago metamorphic rocks. Published paleomagnetic results from the Cretaceous Tobago Volcanic Group rocks indicate a 90° bulk clockwise rotation of Tobago. We are beginning work to determine a step-wise (incremental) rotation history using NRM analyses on a suite of rock samples from the Tobago metamorphic rocks (containing complex magnetic signatures), Tobago Intrusive Group (gabbro-diorites and dikes; dike paleo-declination = 360-354°), Pliocene Rockly Bay Formation (magnetic moment = 1.038 x 10-4 to 8.283 x 10-5 emu; results from oriented samples forthcoming), and Quaternary carbonate cap rocks (results forthcoming). We will present our fault slip and preliminary paleomagnetic results and are working toward building and using a robust suite of paleomagnetic results to rotate fault-slip paleostress axes into palinspastic orientations to best interpret the tectonic history and evolution of Tobago.

  14. Factors Affecting Hatch Success of Hawksbill Sea Turtles on Long Island, Antigua, West Indies

    PubMed Central

    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

  15. 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

  16. 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.

  17. 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

  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. 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.

  20. A Review of Clostridium difficile Infection at the University Hospital of the West Indies, Jamaica

    PubMed Central

    Clare-Pascoe, N; Lee, MG; Murphy, T; Nicholson, A; Ferguson, TS

    2015-01-01

    ABSTRACT Objectives: This study examined the frequency of Clostridium difficile infection (CDI) among hospital admission and diarrhoeal stool samples over a six-year period. Methods: A review of all suspected cases of C difficile positive patients from 2007 to 2012 at the University Hospital of the West Indies (UHWI), Jamaica, was performed. Clostridium difficile infection was confirmed by clinical features and a positive enzyme-linked immunosorbent assay (ELISA) stool test for Clostridium Toxins A and B. The demographics, clinical features, risk factors, treatment and outcomes were also collated. Results: There were 56 patients reviewed. The most commonly affected age group was 40–59 years of age. The proportion of CDI cases per total stool samples increased from 0.5% in 2007 to 5.9% in 2010 then fell to 2.2% in 2011 but increased again to 4.3% in 2012. The proportion of cases per total UHWI admissions also increased from 0.12 cases per 1000 admissions in 2007 to 1.16 in 2010 and 1.36 in 2012 (p < 0.001). Most CDI cases were nosocomial (76% males, 48.6% females). Co-morbidities included hypertension and end-stage renal disease. Ceftazidime was the most common antibiotic associated with the development of CDI. Resolution occurred in 62.5% of patients. Duration of hospital stay was longer in males than females (≥ 21 versus < 7 days) and males had more adverse outcomes, with death in 23.8% versus 11.4%. Conclusion: There has been an increase in the frequency of CDI at UHWI with a greater than expected frequency of community acquired CDI. Increased awareness is needed of the increasing risk for CDI and measures must be taken to prevent the disease, especially in hospitalized patients. PMID:26624597

  1. 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

  2. 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

  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. The compliance of healthcare workers with universal precautions in the emergency room at the university hospital of the west indies.

    PubMed

    Watson, K; Williams-Johnson, J; Watson, H; Walters, C; Williams, E W; Eldemire-Shearer, D

    2014-06-01

    The study assessed compliance among health workers in the Emergency Room at the University Hospital of the West Indies with universal precautions. This was done by determining the knowledge, practices and perceptions of staff of universal precautions and by assessing compliance. Reported adherence with universal precautions was compared with observed practice. This was a cross-sectional study conducted over a one-year period. It was approved by the University Hospital of the West Indies/University of the West Indies/Faculty of Medical Sciences Ethics Committee. Data were analysed using Stata version 11.1. During the study period, 67 persons gave consent for the study, data were obtained for 62 of these participants and 52 of the respondents were observed. All of the participants were aware that universal precautions related to blood. Eighty-six per cent erroneously thought that universal precautions apply to urine. Seventy-nine per cent of the participants reported always washing their hands after performing a procedure and 43.5% reported always washing their hands before a procedure. Just over half of the participants reported always wearing gloves while doing procedures (56.5%). Only 9% reported always using a gown with a trauma patient. However, 31% and 43.3% reported wearing a gown when placing a chest tube and when anticipating splashes, respectively. Of those participants who reported washing their hands often after a procedure, over 30% did not perform hand-washing when observed. Fifty per cent of persons that reported never recapping needles were observed to recap needles by hand. The study revealed that compliance among staff in the Emergency Room with universal precautions was unsatisfactory. The need for education in this area was recognized.

  5. Hydrostatic pressure decreases the proton mobility in the hydrated BaZr{sub 0.9}Y{sub 0.1}O{sub 3} proton conductor

    SciTech Connect

    Chen Qianli; Braun, Artur; Ovalle, Alejandro; Savaniu, Cristian-Daniel; Graule, Thomas; Bagdassarov, Nikolai

    2010-07-26

    Impedance spectroscopy on the hydrated proton conductor BaZr{sub 0.9}Y{sub 0.1}O{sub 3} at high temperatures shows that the bulk proton conductivity activation energy E{sub b} scales with the strain parameter epsilon, as achieved by hydrostatic pressures up to 2 GPa, suggesting that large lattices favor proton diffusivity. At high temperature, E{sub b} increases upon pressure by 40%. The grain boundary activation energy Eg is around twice as E{sub b}, indicating higher proton mobility in grain boundaries as a result of pressure induced sintering. An expanded lattice with strain parameter epsilon>1 should have lower E{sub b}, suggesting that thin films expansive tensile strain could have larger proton conductivity.

  6. Thin Film Ba(x) Sr(1-x)TiO3 Coupled Microstrip Ku- and K-band Phase Shifters

    NASA Technical Reports Server (NTRS)

    VanKeuls, F. W.; Romanofsky, R. R.; Mueller, C. H.; Warner, J. W.; Miranda, F. A.

    1999-01-01

    In this report authors found that the: (1) Best room temperature CMPS performance seen on 1% Mn-doped Ba(0.6)Sr(0.4)TiO3 annealed films on MgO: K = 74 C/dB. Phase Shift/coupled length: 1427 C/cm (2) Attempt to improve phase shifters through thicker as-deposited films stymied by declining film quality with film thickness. Annealing may alleviate this problem. (3) CMPS phase shift at Ku-band didn't experience the great rise in tunability seen in 1 MHz epsilon(sub r)(0) data. (4) While CMPS circuits may be well suited for arrays, simpler circuits like CPW would be more useful for characterizing epsilon(sub r) and tan(delta) at Ku-and K-band. (5) New substrates and designs are being tested.

  7. 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.

  8. epsilon-COP is a structural component of coatomer that functions to stabilize alpha-COP.

    PubMed Central

    Duden, R; Kajikawa, L; Wuestehube, L; Schekman, R

    1998-01-01

    We isolated a novel yeast alpha-COP mutant, ret1-3, in which alpha-COP is degraded after cells are shifted to a restrictive temperature. ret1-3 cells cease growth at 28 degrees C and accumulate the ER precursor of carboxypeptidase Y (p1 CPY). In a screen for high copy suppressors of these defects, we isolated the previously unidentified yeast epsilon-COP gene. epsilon-COP (Sec28p) overproduction suppresses the defects of ret1-3 cells up to 34 degrees C, through stabilizing levels of alpha-COP. Surprisingly, cells lacking epsilon-COP (sec28 Delta) grow well up to 34 degrees C and display normal trafficking of carboxypeptidase Y and KKXX-tagged proteins at a permissive temperature. epsilon-COP is thus non-essential for yeast cell growth, but sec28 Delta cells are thermosensitive. In sec28 Delta cells shifted to 37 degrees C, wild-type alpha-COP (Ret1p) levels diminish rapidly and cells accumulate p1 CPY; these defects can be suppressed by alpha-COP overproduction. Mutant coatomer from sec28 Delta cells behaves as an unusually large protein complex in gel filtration experiments. The sec28 Delta mutation displays allele-specific synthetic-lethal interactions with alpha-COP mutations: sec28 Delta ret1-3 double mutants are unviable at all temperatures, whereas sec28 Delta ret1-1 double mutants grow well up to 30 degrees C. Our results suggest that a function of epsilon-COP is to stabilize alpha-COP and the coatomer complex. PMID:9463377

  9. Multiple sclerosis among United Kingdom-born children of immigrants from the Indian subcontinent, Africa and the West Indies.

    PubMed Central

    Elian, M; Nightingale, S; Dean, G

    1990-01-01

    Multiple sclerosis (MS) is very uncommon among ethnic Asians in the Indian subcontinent, among Asians and Africans resident in the New Commonwealth countries of Africa and in the West Indies. It is also very uncommon among those who have migrated to England from those countries. In contrast, the children born in the United Kingdom of Asian, African and West Indian immigrants have, in the age groups available for study, a high prevalence of MS of a similar order to that occurring in the general population of England. PMID:2266374

  10. 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.

  11. Safeguarding slaves: smallpox, vaccination, and governmental health policies among the enslaved population in the Danish West Indies, 1803-1848.

    PubMed

    Jensen, Niklas Thode

    2009-01-01

    During the first half of the nineteenth century, a unique system of vaccination against smallpox was developed in the island of St. Croix in the Danish West Indies. The primary intention was to protect the population of enslaved workers, which was of fundamental importance to the economy of the colony. However, because the Danish abolition of the slave trade in 1803 had stopped the imports of new enslaved workers from Africa, the population was also decreasing. The vaccination system's success was due to a high degree of governmental control of the enslaved population that was virtually unseen anywhere else in the Caribbean.

  12. FcR epsilon+ lymphocytes and regulation of the IgE antibody system. IV. Delineation of target cells and mechanisms of action of SFA and EFA in inhibiting in vitro induction of FcR epsilon expression.

    PubMed

    Marcelletti, J F; Katz, D H

    1984-12-01

    SFA and EFA are derived from distinct mouse T cell hybridomas secreting one or the other (but not both) factor, and although both are capable of inhibiting FcR epsilon expression by unfractionated spleen cells induced by monomeric IgE, neither was inhibitory for EIRT-induced FcR epsilon expression by T cells in the same cell population. This suggests that the final target cell for the inhibitory effects of SFA and EFA is the FcR epsilon+ B lymphocyte. T cells are required for both SFA- and EFA-mediated FcR epsilon inhibition, and more precisely, as shown in this study, SFA stimulates Lyt-1+ cells in the presence or absence of IgE to produce a suppressive effector molecule (SEM), and EFA together with IgE stimulates Lyt-2+ cells to produce an enhancing effector molecule (EEM), both of which can directly inhibit FcR epsilon expression by B cells. SFA and SEM can inhibit both IgE- and EIRB-induced FcR epsilon expression by B cells, indicating that SFA may act by blocking the EIRB-mediated expansion of the FcR epsilon+ B cell population. EFA and EEM, in contrast, can inhibit IgE-induced but not EIRB-induced FcR epsilon expression, indicating that EFA may act at some point before the release of EIR, perhaps involving those FcR epsilon+ B cells that respond to IgE and produce EIRB. Finally, although neither SFA and EFA display IgE binding properties, both SEM and EEM, in contrast, are IgE binding factors (IgE-BF) and may be homologous to the suppressive IgE binding factor and potentiating IgE binding factor described by other investigators. The possible interrelationships between these various cells and factors are discussed.

  13. 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.

  14. The biology of the circadian Ck1epsilon tau mutation in mice and Syrian hamsters: a tale of two species.

    PubMed

    Loudon, A S I; Meng, Q J; Maywood, E S; Bechtold, D A; Boot-Handford, R P; Hastings, M H

    2007-01-01

    The tau mutation in the Syrian hamster resides in the enzyme casein kinase 1 epsilon (CK1epsilon), resulting in a dramatic acceleration of wheel-running activity cycles to about 20 hours. tau also impacts growth, energy, metabolism, feeding behavior, and circadian mechanisms underpinning seasonal timing, causing accelerated reproductive and neuroendocrine responses to photoperiodic changes. Modeling and experimental studies suggest that tau acts as a gain of function on specific residues of PER, consistent with hamster studies showing accelerated degradation of PER in the suprachiasmatic nucleus in the early circadian night. We have created null and tau mutants of Ck1epsilon in mice. Circadian period lengthens in CK1epsilon(/), whereas CK1epsilon(tau/tau) shortens circadian period of behavior in vivo in a manner nearly identical to that of the Syrian hamster. CK1epsilon(tau/tau) also accelerates molecular oscillations in peripheral tissues, demonstrating its global circadian role. CK1epsilon(tau) acts by promoting degradation of both nuclear and cytoplasmic PERIOD, but not CRYPTOCHROME, proteins. Our studies reveal that tau acts as a gain-of-function mutation, to accelerate degradation of PERIOD proteins. tau has consistent effects in both hamsters and mice on the circadian organization of behavior and metabolism, highlighting the global impact of this mutation on mammalian clockwork in brain and periphery.

  15. Is ApoE epsilon4 associated with cognitive functioning in African Americans diagnosed with Alzheimer Disease? An exploratory study.

    PubMed

    Mount, David L; Ashley, Angela V; Lah, James J; Levey, Allan I; Goldstein, Felicia C

    2009-09-01

    The effect of the apolipoprotein epsilon4 allele (ApoE epsilon4) on cognitive performance in patients with probable Alzheimer disease (AD) has been studied in primarily Caucasian samples. The aim of this exploratory study was to examine whether the presence of ApoE epsilon4 is associated with cognitive performance in African American AD patients. A cross-sectional, retrospective design was used to address the study objective. Data were extracted from the records of 65 African American patients who participated in the National Institutes of Health-National Institute on Aging (NIH-NIA) Emory University Alzheimer Disease Center Registry. Inclusion criteria were a clinical diagnosis of probable AD, cognitive testing using the Mattis Dementia Rating Scale and the Consortium to Establish a Registry for Alzheimer Disease (CERAD) neuropsychological battery, and ApoE genotyping. Seventy percent of the patients were ApoE epsilon4 positive. Multiple regression analyses indicated that ApoE epsilon4 was significantly associated with poorer design copying (CERAD Constructional Praxis subtest), but other significant relationships were not observed between positive epsilon4 status and cognitive performance. These preliminary findings suggest that the ApoE epsilon4 allele is not strongly associated with a particular pattern of cognitive functioning in African Americans once they are diagnosed with AD. However, these findings require replication in a large prospectively recruited and population-based sample of African American AD patients before firm conclusions can be reached.

  16. Event Structure and the "Ba" Construction.

    ERIC Educational Resources Information Center

    Rhys, Catrin Sian

    1996-01-01

    Much earlier controversy surrounding the Chinese "ba" construction stems from dissention over whether or not "ba" has any independent semantic content. "Ba" was assumed either to be a purely formal particle whose function was to assign case, or to have semantic content translating into thematic content. However, under the hypothesis that abstract…

  17. Protein kinase C epsilon induces systolic cardiac failure marked by exhausted inotropic reserve and intact Frank-Starling mechanism.

    PubMed

    Montgomery, David E; Rundell, Veronica L M; Goldspink, Paul H; Urboniene, Dalia; Geenen, David L; de Tombe, Pieter P; Buttrick, Peter M

    2005-11-01

    Myofilament dysfunction is a common point of convergence for many forms of heart failure. Recently, we showed that cardiac overexpression of PKC epsilon initially depresses myofilament activity and then leads to a progression of changes characteristic of human heart failure. Here, we examined the effects of PKC epsilon on contractile reserve, Starling mechanism, and myofilament activation in this model of end-stage dilated cardiomyopathy. Pressure-volume loop analysis and echocardiography showed that the PKC epsilon mice have markedly compromised systolic function and increased end-diastolic volumes. Dobutamine challenge resulted in a small increase in contractility in PKC epsilon mice but failed to enhance cardiac output. The PKC epsilon mice showed a normal length-dependent tension development in skinned cardiac muscle preparations, although Frank-Starling mechanism appeared to be compromised in the intact animal. Simultaneous measurement of tension and ATPase demonstrated that the maximum tension and ATPase were markedly lower in the PKC epsilon mice at any length or Ca2+ concentration. However, the tension cost was also lower indicating less energy expenditure. We conclude 1) that prolonged overexpression of PKC epsilon ultimately leads to a dilated cardiomyopathy marked by exhausted contractile reserve, 2) that PKC epsilon does not compromise the Frank-Starling mechanism at the myofilament level, and 3) that the Starling curve excursion is limited by the inotropic state of the heart. These results reflect the significance of the primary myofilament contractilopathy induced by phosphorylation and imply a role for PKC epsilon-mediated phosphorylation in myofilament physiology and the pathophysiology of decompensated cardiac failure.

  18. Inhibitory transmission in locus coeruleus neurons expressing GABAA receptor epsilon subunit has a number of unique properties.

    PubMed

    Belujon, P; Baufreton, J; Grandoso, L; Boué-Grabot, E; Batten, T F C; Ugedo, L; Garret, M; Taupignon, A I

    2009-10-01

    Fast inhibitory synaptic transmission in the brain relies on ionotropic GABA(A) receptors (GABA(A)R). Eighteen genes code for GABA(A)R subunits, but little is known about the epsilon subunit. Our aim was to identify the synaptic transmission properties displayed by native receptors incorporating epsilon. Immunogold localization detected epsilon at synaptic sites on locus coeruleus (LC) neurons. In situ hybridization revealed prominent signals from epsilon, and mRNAs, some low beta1 and beta3 signals, and no gamma signal. Using in vivo extracellular and in vitro patch-clamp recordings in LC, we established that neuron firing rates, GABA-activated currents, and mIPSC charge were insensitive to the benzodiazepine flunitrazepam (FLU), in agreement with the characteristics of recombinant receptors including an epsilon subunit. Surprisingly, LC provided binding sites for benzodiazepines, and GABA-induced currents were potentiated by diazepam (DZP) in the micromolar range. A number of GABA(A)R ligands significantly potentiated GABA-induced currents, and zinc ions were only active at concentrations above 1 muM, further indicating that receptors were not composed of only alpha and beta subunits, but included an epsilon subunit. In contrast to recombinant receptors including an epsilon subunit, GABA(A)R in LC showed no agonist-independent opening. Finally, we determined that mIPSCs, as well as ensemble currents induced by ultra-fast GABA application, exhibited surprisingly slow rise times. Our work thus defines the signature of native GABA(A)R with a subunit composition including epsilon: differential sensitivity to FLU and DZP and slow rise time of currents. We further propose that alpha(3,) beta(1/3,) and epsilon subunits compose GABA(A)R in LC.

  19. 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.

  20. 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.

  1. Synthesis of biodegradable poly-epsilon-caprolactone microspheres by dispersion ring-opening polymerization in supercritical carbon dioxide.

    PubMed

    Grignard, Bruno; Stassin, Fabrice; Calberg, Cédric; Jérôme, Robert; Jérôme, Christine

    2008-11-01

    A series of fluorinated diblock and triblock copolymers of poly(epsilon-caprolactone) and poly(heptadecafluorodecylacrylate) were prepared by combining ring-opening polymerization of epsilon-CL and atom transfer radical polymerization of the acrylate. These copolymers with well-controlled molecular weight and composition were characterized by (1)H NMR spectroscopy and used as stabilizers for the dispersion ring-opening polymerization of epsilon-CL in supercritical carbon dioxide. The effect of composition and architecture of the polymeric stabilizers on the stabilization of PCL microspheres was investigated. Finally, purification of PCL was successfully implemented by reactive supercritical fluid extraction of the tin catalyst.

  2. 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.

  3. Molecular signatures (unique proteins and conserved indels) that are specific for the epsilon proteobacteria (Campylobacterales)

    PubMed Central

    Gupta, Radhey S

    2006-01-01

    Background The epsilon proteobacteria, which include many important human pathogens, are presently recognized solely on the basis of their branching in rRNA trees. No unique molecular or biochemical characteristics specific for this group are known. Results Comparative analyses of proteins in the genomes of Wolinella succinogenes DSM 1740 and Campylobacter jejuni RM1221 against all available sequences have identified a large number of proteins that are unique to various epsilon proteobacteria (Campylobacterales), but whose homologs are not detected in other organisms. Of these proteins, 49 are uniquely found in nearly all sequenced epsilon-proteobacteria (viz. Helicobacter pylori (26695 and J99), H. hepaticus, C. jejuni (NCTC 11168, RM1221, HB93-13, 84-25, CF93-6, 260.94, 11168 and 81-176), C. lari, C. coli, C. upsaliensis, C. fetus, W. succinogenes DSM 1740 and Thiomicrospira denitrificans ATCC 33889), 11 are unique for the Wolinella and Helicobacter species (i.e. Helicobacteraceae family) and many others are specific for either some or all of the species within the Campylobacter genus. The primary sequences of many of these proteins are highly conserved and provide novel resources for diagnostics and therapeutics. We also report four conserved indels (i.e. inserts or deletions) in widely distributed proteins (viz. B subunit of exinuclease ABC, phenylalanyl-tRNA synthetase, RNA polymerase β '-subunit and FtsH protein) that are specific for either all epsilon proteobacteria or different subgroups. In addition, a rare genetic event that caused fusion of the genes for the largest subunits of RNA polymerase (rpoB and rpoC) in Wolinella and Helicobacter is also described. The inter-relationships amongst Campylobacterales as deduced from these molecular signatures are in accordance with the phylogenetic trees based on the 16S rRNA and concatenated sequences for nine conserved proteins. Conclusion These molecular signatures provide novel tools for identifying and

  4. 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

  5. Isolation, tissue distribution, and molecular characterization of Toxoplasma gondii from chickens in Grenada, West Indies.

    PubMed

    Dubey, J R; Bhaiyat, M I; de Allie, C; Macpherson, C N L; Sharma, R N; Sreekumar, C; Vianna, M C B; Shen, S K; Kwok, O C H; Miska, K B; Hill, D E; Lehmann, T

    2005-06-01

    The prevalence of Toxoplasma gondii in free-range chickens is a good indicator of the prevalence of T. gondii oocysts in the soil because chickens feed from the ground. The prevalence of T. gondii in 102 free-range chickens (Gallus domesticus) from Grenada was determined. Antibodies to T. gondii were assayed by the modified agglutination test (MAT). Antibodies were found in 53 (52%) chickens with titers of 1:5 in 6, 1:10 in 4, 1:20 in 4, 1:40 in 4, 1:80 in 15, 1:160 in 9, 1: 320 in 5, 1:640 in 4, and 1:1,280 or greater in 2. Hearts, pectoral muscles, and brains of 43 seropositive chickens with MAT titers of 1:20 or greater were bioassayed individually in mice. Tissues of each of 10 chickens with titers of 1:5 and 1:10 were pooled and bioassayed in mice. Tissues from the remaining 49 seronegative chickens were pooled and fed to 4 T. gondii-free cats. Feces of cats were examined for oocysts; they did not shed oocysts. T. gondii was isolated from 35 of 43 chickens with MAT titers of 1:20 or greater; from the hearts, brains, and pectoral muscles of 2, hearts and brains of 20, from the hearts alone of 11, and brains alone of 2. T. gondii was isolated from 1 of 10 chickens with titers of 1:5 or 1:10. All 36 T. gondii isolates were avirulent for mice. Genotyping of these 36 isolates using polymorphisms at the SAG2 locus indicated that 29 were Type III, 5 were Type I, 1 was Type II, and 1 had both Type I and Type III. Genetically, the isolates from Grenada were different from those from the United States; Type II was the predominant type from the United States. Phenotypically, all isolates from Grenada were avirulent for mice, whereas those from Brazil were mouse-virulent. This is the first report of isolation of T. gondii from chickens from Grenada, West Indies.

  6. 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.

  7. 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

  8. Epsilon wave on an electronic loop in a case of arrhythmogenic right ventricular dysplasia with myocarditis: an updated definition of the Epsilon wave.

    PubMed

    Fontaine, Guy Hugues; Duthoit, Guillaume; Li, Guoliang; Andreoletti, L; Gandjbakhch, Estelle; Frank, Robert

    2017-07-01

    A young man presented with a history of myocarditis with palpitations and dizziness. He had implantation of a loop recorder that showed repetitive short episodes of VT. In addition, there were fragmented potentials immediately following the large and sharp electrograms (EGMs) before as well as after episodes of VT suggesting an Epsilon wave. This signal can be observed in multiple cardiac conditions including coronary artery disease. It was originally recorded on the epicardium as well as on the endocardium. However, in ARVD it can be defined as an electric signal observed after the end of the QRS complex in the right as opposed to the left precordial leads (difference ≥ 25 ms). It can also be an aid to the diagnosis of patients with ARVD who have other signs or symptoms suggesting ARVD including episodes of myocarditis. This potential consists of a slurring at the end of the QRS complex or an independent potential after the return to the isoelectric line. It can be better observed by increasing amplification of the ECG tracing as well as double speed using the Fontaine lead system. Epsilon wave too small to be recorded on the standard ECG can be extracted by Signal Averaging ECG SAECG). Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For Permissions, please email: journals.permissions@oup.com.

  9. Poly(epsilon-caprolactone)-poly(ethylene glycol)-poly(epsilon-caprolactone) (PCL-PEG-PCL) nanoparticles for honokiol delivery in vitro.

    PubMed

    Gou, MaLing; Zheng, Lan; Peng, XinYun; Men, Ke; Zheng, XiuLing; Zeng, Shi; Guo, Gang; Luo, Feng; Zhao, Xia; Chen, LiJuan; Wei, YuQuan; Qian, ZhiYong

    2009-06-22

    In this article, poly(epsilon-caprolactone)-poly(ethylene glycol)-poly(epsilon-caprolactone) (PCL-PEG-PCL, PCEC) nanoparticles were successfully prepared for honokiol delivery in vitro. Blank or honokiol loaded PCL-PEG-PCL nanoparticles were prepared in moderate condition by solvent diffusion method without using any surfactants. The prepared blank PCL-PEG-PCL nanoparticles are mono-dispersed and smaller than 200 nm. The particle size increased with increase in polymer concentration and oil-water (O/W) ratio. The prepared PCL-PEG-PCL nanoparticles (40 mg/mL, ca. 106 nm) did not induce hemolysis in vitro. And the 50% inhibiting concentration (IC50) of it (48 h) on HEK293 cells was higher than 5 mg/mL. Honokiol could be efficiently loaded into PCL-PEG-PCL nanoparticles and released from these nanoparticles in an extended period in vitro. After honokiol (HK) was entrapped into PCL-PEG-PCL nanoparticles, the particle size increased with the increase in HK/PCEC mass ratio in feed, and the encapsulated honokiol retained potent anticancer activity in vitro. The PCL-PEG-PCL nanoparticle was suitable for honokiol delivery, and such honokiol loaded PCL-PEG-PCL nanoparticle was a novel honokiol formulation.

  10. Directional and monochromatic thermal emitter from epsilon-near-zero conditions in semiconductor hyperbolic metamaterials

    DOE PAGES

    Campione, Salvatore; Marquier, Francois; Hugonin, Jean -Paul; ...

    2016-10-05

    The development of novel thermal sources that control the emission spectrum and the angular emission pattern is of fundamental importance. In this paper, we investigate the thermal emission properties of semiconductor hyperbolic metamaterials (SHMs). Our structure does not require the use of any periodic corrugation to provide monochromatic and directional emission properties. We show that these properties arise because of epsilon-near-zero conditions in SHMs. The thermal emission is dominated by the epsilon-near-zero effect in the doped quantum wells composing the SHM. In conclusion, different properties are observed for s and p polarizations, following the characteristics of the strong anisotropy ofmore » hyperbolic metamaterials.« less

  11. THE INVISIBLE MONSTER HAS TWO FACES: OBSERVATIONS OF {epsilon} AURIGAE WITH THE HERSCHEL SPACE OBSERVATORY

    SciTech Connect

    Hoard, D. W.; Ladjal, D.; Stencel, R. E.; Howell, S. B.

    2012-04-01

    We present Herschel Space Observatory photometric observations of the unique, long-period eclipsing binary star {epsilon} Aurigae. Its extended spectral energy distribution is consistent with our previously published cool (550 K) dust disk model. We also present an archival infrared spectral energy distribution of the side of the disk facing the bright F-type star in the binary, which is consistent with a warmer (1150 K) disk model. The lack of strong molecular emission features in the Herschel bands suggests that the disk has a low gas-to-dust ratio. The spectral energy distribution and Herschel images imply that the 250 GHz radio detection reported by Altenhoff et al. is likely contaminated by infrared-bright, extended background emission associated with a nearby nebular region and should be considered an upper limit to the true flux density of {epsilon} Aur.

  12. 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

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

    NASA Astrophysics Data System (ADS)

    Chitsomboon, Tawit

    1992-02-01

    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. 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.

  15. First detection of the astrometric orbit of the single-lined spectroscopic binary epsilon Librae

    NASA Technical Reports Server (NTRS)

    Castelaz, Michael W.

    1989-01-01

    The Multichannel Astrometric Photometer of the University of Pittsburgh's Allegheny Observatory was used to successfully measure for the first time the astrometric orbit of the single-lined spectroscopic binary epsilon Lib. Solution of the orbit indicates that the secondary component is a 0.5-solar-mass star, assuming that the F5 IV primary is 1.3 solar mass. If the secondary is on the main sequence, then it is later than a K5 star, but earlier than an M2 star. In addition to detection of the astrometric orbit of epsilon Lib, two references stars used in the observations, AO 754 and AO 755, are found to be a common-proper-motion pair.

  16. The Invisible Monster Has Two Faces: Observations of epsilon Aurigae with the Herschel Space Observatory

    NASA Astrophysics Data System (ADS)

    Hoard, D. W.; Ladjal, D.; Stencel, R. E.; Howell, S. B.

    2012-04-01

    We present Herschel Space Observatory photometric observations of the unique, long-period eclipsing binary star epsilon Aurigae. Its extended spectral energy distribution is consistent with our previously published cool (550 K) dust disk model. We also present an archival infrared spectral energy distribution of the side of the disk facing the bright F-type star in the binary, which is consistent with a warmer (1150 K) disk model. The lack of strong molecular emission features in the Herschel bands suggests that the disk has a low gas-to-dust ratio. The spectral energy distribution and Herschel images imply that the 250 GHz radio detection reported by Altenhoff et al. is likely contaminated by infrared-bright, extended background emission associated with a nearby nebular region and should be considered an upper limit to the true flux density of epsilon Aur.

  17. Hyperbranched poly(epsilon-caprolactone) as a nonmigrating alternative plasticizer for phthalates in flexible PVC.

    PubMed

    Choi, Jeongsoo; Kwak, Seung-Yeop

    2007-05-15

    Hyperbranched (dendritic) poly(epsilon-caprolactone)s (HPCLs) were synthesized to have architectural variations, which are the different lengths of linear segments and different numbers of branches, and were used as plasticizers for flexible poly(vinyl chloride) (PVC). The plasticization efficiency estimated by the lowering of glass transition temperature and the enhancement in ultimate elongation indicated that the HPCLs with the shorter linear segments and the larger number of branches imparted as high flexibility as di(ethylhexyl) phthalate (DEHP) and much higher flexibility than their linear analogue, linear poly(epsilon-caprolactone), which is one of currently used polymer plasticizers. Volatility, extractability, and exudation tests for PVC/HPCL samples showed that there was no plasticizer migration even at very harsh condition, while ca. 7-78% of additives in PVC/DEHP was migrated out of samples, indicating that the HPCL can be used as an alternative plasticizer to remove the potential health risk from migrating phthalates during end use.

  18. First detection of the astrometric orbit of the single-lined spectroscopic binary epsilon Librae

    NASA Technical Reports Server (NTRS)

    Castelaz, Michael W.

    1989-01-01

    The Multichannel Astrometric Photometer of the University of Pittsburgh's Allegheny Observatory was used to successfully measure for the first time the astrometric orbit of the single-lined spectroscopic binary epsilon Lib. Solution of the orbit indicates that the secondary component is a 0.5-solar-mass star, assuming that the F5 IV primary is 1.3 solar mass. If the secondary is on the main sequence, then it is later than a K5 star, but earlier than an M2 star. In addition to detection of the astrometric orbit of epsilon Lib, two references stars used in the observations, AO 754 and AO 755, are found to be a common-proper-motion pair.

  19. Isolation and RFLP genotyping of toxoplasma gondii in free-range chicken(Gallus domesticus) in Grenada, West Indies, revealed widespread and dominance of clonal type III parasites

    USDA-ARS?s Scientific Manuscript database

    The objectives of the present cross sectional study were to estimate the prevalence and to isolate and genotype Toxoplasma gondii in free range chickens from Grenada, West Indies. Using the modified agglutination test, antibodies to T. gondii were found in 39 (26.9%) of 145 free-range chickens with ...

  20. 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

    USDA-ARS?s Scientific Manuscript database

    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...

  1. Quality Assurance and the Imperatives for Improved Student Experiences in Higher Education: The Case of the University of the West Indies

    ERIC Educational Resources Information Center

    Gift, Sandra Ingrid; Bell-Hutchinson, Camille

    2007-01-01

    This paper critically examines the outcomes of quality assurance programme reviews on the three campuses of the University of the West Indies (UWI) with an emphasis on the factors that impact upon the quality of students' learning experiences. In establishing the context of the discussion, the authors describe the quality assurance system of the…

  2. 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…

  3. 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…

  4. The Role of the British and Foreign School Society in Elementary Education in India and the East Indies, 1813-75.

    ERIC Educational Resources Information Center

    Bartle, George F.

    1994-01-01

    Describes the role of the British and Foreign School Society in organizing and administering schools for elementary students during the period of British colonial rule in India, Ceylon, Malaya, and the East Indies. Discusses the importance of religious factors and the influences of missionaries as teachers and administrators. (CFR)

  5. Aspects of the breeding biology of the Cattle Egret (Bubulcus ibis) in Montserrat, West Indies, and its impact on nest vegetation

    Treesearch

    W.J. Arendt; A.I. Arendt

    1988-01-01

    Aspects of the Cattle Egret's reproductive ecology and habitat use in an insular environment were studied on Montserrat, West Indies. Average size of 290 nests (17.9 cm) was smaller than sizes reported in the literature and was attributed to a paucity of available nesting materials. We measured 330 eggs to determine: egg volume (24,117.04 mm3), fresh egg weight (...

  6. 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…

  7. 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…

  8. 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…

  9. 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.

  10. CMG–Pol epsilon dynamics suggests a mechanism for the establishment of leading-strand synthesis in the eukaryotic replisome

    PubMed Central

    Janska, Agnieszka; Goswami, Panchali; Renault, Ludovic; Abid Ali, Ferdos; Kotecha, Abhay; Costa, Alessandro

    2017-01-01

    The replisome unwinds and synthesizes DNA for genome duplication. In eukaryotes, the Cdc45–MCM–GINS (CMG) helicase and the leading-strand polymerase, Pol epsilon, form a stable assembly. The mechanism for coupling DNA unwinding with synthesis is starting to be elucidated, however the architecture and dynamics of the replication fork remain only partially understood, preventing a molecular understanding of chromosome replication. To address this issue, we conducted a systematic single-particle EM study on multiple permutations of the reconstituted CMG–Pol epsilon assembly. Pol epsilon contains two flexibly tethered lobes. The noncatalytic lobe is anchored to the motor of the helicase, whereas the polymerization domain extends toward the side of the helicase. We observe two alternate configurations of the DNA synthesis domain in the CMG-bound Pol epsilon. We propose that this conformational switch might control DNA template engagement and release, modulating replisome progression. PMID:28373564

  11. 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.

  12. 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).

  13. Epsilon-near-zero strong coupling in metamaterial-semiconductor hybrid structures.

    PubMed

    Jun, Young Chul; Reno, John; Ribaudo, Troy; Shaner, Eric; Greffet, Jean-Jacques; Vassant, Simon; Marquier, Francois; Sinclair, Mike; Brener, Igal

    2013-01-01

    We present a new type of electrically tunable strong coupling between planar metamaterials and epsilon-near-zero modes that exist in a doped semiconductor nanolayer. The use of doped semiconductors makes this strong coupling tunable over a wide range of wavelengths through the use of different doping densities. We also modulate this coupling by depleting the doped semiconductor layer electrically. Our hybrid approach incorporates strong optical interactions into a highly tunable, integrated device platform.

  14. EPSILON-CP: using deep learning to combine information from multiple sources for protein contact prediction.

    PubMed

    Stahl, Kolja; Schneider, Michael; Brock, Oliver

    2017-06-17

    Accurately predicted contacts allow to compute the 3D structure of a protein. Since the solution space of native residue-residue contact pairs is very large, it is necessary to leverage information to identify relevant regions of the solution space, i.e. correct contacts. Every additional source of information can contribute to narrowing down candidate regions. Therefore, recent methods combined evolutionary and sequence-based information as well as evolutionary and physicochemical information. We develop a new contact predictor (EPSILON-CP) that goes beyond current methods by combining evolutionary, physicochemical, and sequence-based information. The problems resulting from the increased dimensionality and complexity of the learning problem are combated with a careful feature analysis, which results in a drastically reduced feature set. The different information sources are combined using deep neural networks. On 21 hard CASP11 FM targets, EPSILON-CP achieves a mean precision of 35.7% for top- L/10 predicted long-range contacts, which is 11% better than the CASP11 winning version of MetaPSICOV. The improvement on 1.5L is 17%. Furthermore, in this study we find that the amino acid composition, a commonly used feature, is rendered ineffective in the context of meta approaches. The size of the refined feature set decreased by 75%, enabling a significant increase in training data for machine learning, contributing significantly to the observed improvements. Exploiting as much and diverse information as possible is key to accurate contact prediction. Simply merging the information introduces new challenges. Our study suggests that critical feature analysis can improve the performance of contact prediction methods that combine multiple information sources. EPSILON-CP is available as a webservice: http://compbio.robotics.tu-berlin.de/epsilon/.

  15. Structural pierce into molecular mechanism underlying Clostridium perfringens Epsilon toxin function.

    PubMed

    Khalili, Saeed; Jahangiri, Abolfazl; Hashemi, Zahra Sadat; Khalesi, Bahman; Mard-Soltani, Maysam; Amani, Jafar

    2017-03-01

    Epsilon toxin of the Clostridium perfringens garnered a lot of attention due to its potential for toxicity in humans, extreme potency for cytotoxicity in mice and lack of any approved therapeutics prescribed for human. However, the intricacies of the Epsilon toxin action mechanism are yet to be understood. In this regard, various in silico tools have been exploited to model and refine the 3D structure of the toxin and its two receptors. The receptor proteins were embedded into designed lipid membranes within an aqueous and ionized environment. Thereafter, the modeled structures subjected to series of consecutive molecular dynamics runs to achieve the most natural like coordination for each model. Ultimately, protein-protein interaction analyses were performed to understand the probable action mechanism. The obtained results successfully confirmed the accuracy of employed methods to achieve high quality models for the toxin and its receptors within their lipid bilayers. Molecular dynamics analyses lead the structures to a more native like coordination. Moreover, the results of previous empirical studies were confirmed, while new insights for action mechanisms including the detailed roles of Hepatitis A virus cellular receptor 1 (HAVCR1) and Myelin and lymphocyte protein (MAL) proteins were achieved. In light of previous and our observations, we suggested novel models which elucidated the existing interplay between potential players of Epsilon toxin action mechanism with detailed structural evidences. These models would pave the way to have more robust understanding of the Epsilon toxin biology, more precise vaccine construction and more successful drug (inhibitor) design. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Turbulent small-scale neutral and ion density fluctuations as measured during MAC/Epsilon

    NASA Technical Reports Server (NTRS)

    Luebken, F.-J.; Hillert, W.; Vonzahn, U.; Blix, T. A.; Thrane, E. V.

    1989-01-01

    During the MAC/Epsilon campaign (Fall 1987, from Andoya, Northern Norway, 69 N, 16 E) a total of four altitude profiles of neutral gas number densities and six profiles of ion number densities were measured with high spatial resolution in the height range from 60 to 120 km. First results of these rocket-borne experiments are presented with emphasis on small scale turbulent density variations and related turbulent parameter as structure function constants and energy dissipation rates.

  17. Expression and purification of functional Clostridium perfringens alpha and epsilon toxins in Escherichia coli.

    PubMed

    Zhao, Yao; Kang, Lin; Gao, Shan; Zhou, Yang; Su, Libo; Xin, Wenwen; Su, Yuxin; Wang, Jinglin

    2011-06-01

    The alpha and epsilon toxins are 2 of the 4 major lethal toxins of the pathogen Clostridium perfringens. In this study, the expression of the epsilon toxin (etx) gene of C. perfringens was optimized by replacing rare codons with high-frequency codons, and the optimized gene was synthesized using overlapping PCR. Then, the etx gene or the alpha-toxin gene (cpa) was individually inserted into the pTIG-Trx expression vector with a hexahistidine tag and a thioredoxin (Trx) to facilitate their purification and induce the expression of soluble proteins. The recombinant alpha toxin (rCPA) and epsilon toxin (rETX) were highly expressed as soluble forms in the recipient Escherichia coli BL21 strain, respectively. The rCPA and rETX were purified using Ni(2+)-chelating chromatography and size-exclusion chromatography. And the entire purification process recovered about 40% of each target protein from the starting materials. The purified target toxins formed single band at about 42kDa (rCPA) or 31kDa (rETX) in sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and their functional activity was confirmed by bioactivity assays. We have shown that the production of large amounts of soluble and functional proteins by using the pTIG-Trx vector in E. coli is a good alternative for the production of native alpha and epsilon toxins and could also be useful for the production of other toxic proteins with soluble forms. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. Recombinant Alpha, Beta, and Epsilon Toxins of Clostridium perfringens: Production Strategies and Applications as Veterinary Vaccines

    PubMed Central

    Ferreira, Marcos Roberto A.; Moreira, Gustavo Marçal S. G.; da Cunha, Carlos Eduardo P.; Mendonça, Marcelo; Salvarani, Felipe M.; Moreira, Ângela N.; Conceição, Fabricio R.

    2016-01-01

    Clostridium perfringens is a spore-forming, commensal, ubiquitous bacterium that is present in the gastrointestinal tract of healthy humans and animals. This bacterium produces up to 18 toxins. The species is classified into five toxinotypes (A–E) according to the toxins that the bacterium produces: alpha, beta, epsilon, or iota. Each of these toxinotypes is associated with myriad different, frequently fatal, illnesses that affect a range of farm animals and humans. Alpha, beta, and epsilon toxins are the main causes of disease. Vaccinations that generate neutralizing antibodies are the most common prophylactic measures that are currently in use. These vaccines consist of toxoids that are obtained from C. perfringens cultures. Recombinant vaccines offer several advantages over conventional toxoids, especially in terms of the production process. As such, they are steadily gaining ground as a promising vaccination solution. This review discusses the main strategies that are currently used to produce recombinant vaccines containing alpha, beta, and epsilon toxins of C. perfringens, as well as the potential application of these molecules as vaccines for mammalian livestock animals. PMID:27879630

  19. 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].

  20. Direct measurement of the alpha-epsilon transition stress and kinetics for shocked iron

    SciTech Connect

    Jensen, Brian J; Gray, Ill, George T; Hixson, Robert S

    2009-01-01

    Iron undergoes a polymorphic phase transformation from alpha phase (bcc) to the epsilon phase (hcp) when compressed to stresses exceeding 13 CPa. Bccause the epsilon phase is denser than the alpha phase, a single shock wave is unstable and breaks up into an elastic wave, a plastic wave, and a phase transition wave. Examination of this structured wave coupled with various phase transformation models has been used to indirectly examine the transition kinetics. Recently, multimillion atom simulations (molecular dynamics) have been used to examine the shock-induced transition in single crystal iron illustrating an orientation dependence of the transition stress, mechanisms, and kinetics. The objective of the current work was to perform plate impact experiments to examine the shock-response of polycrystalline and single crystal iron with nanosecond resolution for impact stresses spanning the {alpha} - {epsilon} transition. The current data reveal an orientation dependence of the transition stress coupled with a transition time that is nonlinearly dependent on the impact stress with a duration ranging from picoseconds to hundreds of nanoseconds. The higher transition stress for iron[100] is in agreement with the predictions from MD calculations that describe an orientation dependence of the transition stress. However, MD calculations do not capture the complexity of the continuum states achieved or the transition kinetics. Further results and implications are discussed in this paper.

  1. 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.

  2. SPITZER/INFRARED ARRAY CAMERA LIMITS TO PLANETARY COMPANIONS OF FOMALHAUT AND {epsilon} ERIDANI

    SciTech Connect

    Marengo, Massimo; Hora, Joseph L.; Fazio, Giovanni G.; Schuster, Michael T.; Stapelfeldt, Karl; Werner, Michael W.; Carson, Joseph C.; Megeath, S. Thomas

    2009-08-01

    Fomalhaut and {epsilon} Eridani are two young, nearby stars that possess extended debris disks whose structures suggest the presence of perturbing planetary objects. With its high sensitivity and stable point-spread function, Spitzer/Infrared Array Camera (IRAC) is uniquely capable of detecting cool, Jupiter-like planetary companions whose peak emission is predicted to occur near 4.5 {mu}m. We report on deep IRAC imaging of these two stars, taken at 3.6 and 4.5 {mu}m using subarray mode and in all four channels in wider-field full array mode. Observations acquired at two different telescope roll angles allowed faint surrounding objects to be separated from the stellar diffraction pattern. No companion candidates were detected at the reported position of Fomalhaut b with 3{sigma} model-dependent mass upper limits of 3M {sub J} (for an age of 200 Myr). Around {epsilon} Eridani, we instead set a limit of 4 and {approx}<1M {sub J} (1 Gyr model age) at the inner and outer edge of the submillimeter debris ring, respectively. These results are consistent with non-detections in recent near-infrared imaging searches, and set the strongest limits to date on the presence of planets outside {epsilon} Eridani submillimeter ring.

  3. 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%.

  4. IgE isotype suppression in anti-epsilon-treated mice.

    PubMed Central

    Bozelka, B E; McCants, M L; Salvaggio, J E; Lehrer, S B

    1982-01-01

    Two groups of CBA/J mice received a total of eight intraperitoneal (i.p.) injections of heavy-chain-specific rabbit anti-IgE or rabbit gammaglobulin within 48 hr of birth through day 38. A third group of animals was untreated. All mice were subsequently immunized with four i.p. injections of castor allergen plus aluminum hydroxide. Results indicate that anti-treatments severely suppressed murine serum IgE levels as compared with control mice. In addition anti-epsilon-treated mice were initially unable to produce detectable reaginic antibody upon immunization with castor bean allergens (CA). Upon further CA immunization, these animals did produce an IgE antibody response, but this was still lower than that detected in control immunized mice. Other immunoglobulin levels in the anti-epsilon-treated mice were not suppressed as compared with those in the control mice. These results suggest that neonatally administered anti-epsilon antisera selectively diminished total IgE levels as well as antigen-induced IgE antibodies in mice. PMID:6807838

  5. 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.

  6. Antibody response to the epsilon toxin of Clostridium perfringens following vaccination of Lama glama crias.

    PubMed

    Bentancor, Adriana B; Halperin, Pablo; Flores, Myriam; Iribarren, Fabián

    2009-09-15

    Enterotoxaemia produced by Clostridium perfringens A, C and D is an important cause of mortality in young llamas. There is no data on antibody responses following vaccination with epsilon toxin. Twenty-six L. glama crias were divided into four groups which were vaccinated with a commercial vaccine (Mancha Gangrena Enterotoxemia, Instituto Rosembusch Sociedad Anónima, Argentina) on days 0, 21 and 42 or left as unvaccinated controls. An indirect ELISA was compared with the mouse neutralization test (MNT) for measuring titers to C. perfringens type D epsilon toxin and used to determine titers in sera taken before vaccination and 16, 28, 49, 59, and 93 days later. The ELISA gave comparable results to the MNT and showed animals vaccinated once failed to develop raised titers. A week following a second vaccination, mean antibody titers rose significantly (P < 0.05) and 7/12 animals developed high titers which were present in only one animal at the end of the study (day 93). A third vaccination resulted in a decrease in mean antibody titers a week later. Llamas develop antibodies to Clostridium perfringens type D epsilon toxin after two vaccinations at a 21-day interval. Further studies are indicated to determine if these inoculations protect against enterotoxemia and the most appropriate vaccination schedule.

  7. Molecular weight distributions of industrially-produced poly-(epsilon-caprolactams) by gel permeation chromatography.

    PubMed

    Mateos, Elena; Cebolla, Vicente L; Membrado, Luis; Piera, Elena; Caballero, Miguel A

    2007-09-01

    Gel permeation chromatography with differential refractometry is used to obtain molecular weight distributions (MWD) of poly-(epsilon-caprolactams). Elution is carried out using an m-cresolchlorobenzene mixture (50:50, v/v) at 50 degrees C. MW values are obtained by a Hamielec-based calibration method, using broad-MWD poly-(epsilon-caprolactam) standards with the same chemical nature and similar MWD to the samples. Relative errors for the number-average MW (Mn) using this calibration method range from 0.4% (in the low polyamide MW range) to 20% (in the high polyamide MW range). These values are much lower than those obtained from narrow-MWD polystyrene calibration, which range from 39% to 78%. Similar values have been obtained for the other usual average MW parameters. The ability to obtain repeatability parameters for a given confidence interval and the utilization of statistical criteria for chromatogram rejection allow this method to be used in quality control for MWD of poly-(epsilon-caprolactams). Thus, production variables are related to polyamide-6 behavior in its ulterior treatment. Typical relative standard deviation percentages (for n=6) of a polyamide sample range from 1.9% (for Mn) to 3.3% (for M(z+1)).

  8. Thermal graphene metamaterials and epsilon-near-zero high temperature plasmonics

    NASA Astrophysics Data System (ADS)

    Pendharker, Sarang; Hu, Huan; Molesky, Sean; Starko-Bowes, Ryan; Poursoti, Zohreh; Pramanik, Sandipan; Nazemifard, Neda; Fedosejevs, Robert; Thundat, Thomas; Jacob, Zubin

    2017-05-01

    The key feature of a thermophotovoltaic (TPV) emitter is the enhancement of thermal emission corresponding to energies just above the bandgap of the absorbing photovoltaic cell and simultaneous suppression of thermal emission below the bandgap. We show here that a single layer plasmonic coating can perform this task with high efficiency. Our key design principle involves tuning the epsilon-near-zero frequency (plasma frequency) of the metal acting as a thermal emitter to the electronic bandgap of the semiconducting cell. This approach utilizes the change in the reflectivity of a metal near its plasma frequency (epsilon-near-zero frequency) to lead to spectrally selective thermal emission, and can be adapted to large area coatings using high temperature plasmonic materials. We provide a detailed analysis of the spectral and angular performance of high temperature plasmonic coatings as TPV emitters. We show the potential of such high temperature plasmonic thermal emitter coatings (p-TECs) for narrowband near-field thermal emission. We also show the enhancement of near-surface energy density in graphene-multilayer thermal metamaterials due to a topological transition at an effective epsilon-near-zero frequency. This opens up spectrally selective thermal emission from graphene multilayers in the infrared frequency regime. Our design paves the way for the development of single layer p-TECs and graphene multilayers for spectrally selective radiative heat transfer applications.

  9. Spitzer/Infrared Array Camera Limits to Planetary Companions of Fomalhaut and epsilon Eridani

    NASA Astrophysics Data System (ADS)

    Marengo, Massimo; Stapelfeldt, Karl; Werner, Michael W.; Hora, Joseph L.; Fazio, Giovanni G.; Schuster, Michael T.; Carson, Joseph C.; Megeath, S. Thomas

    2009-08-01

    Fomalhaut and epsilon Eridani are two young, nearby stars that possess extended debris disks whose structures suggest the presence of perturbing planetary objects. With its high sensitivity and stable point-spread function, Spitzer/Infrared Array Camera (IRAC) is uniquely capable of detecting cool, Jupiter-like planetary companions whose peak emission is predicted to occur near 4.5 μm. We report on deep IRAC imaging of these two stars, taken at 3.6 and 4.5 μm using subarray mode and in all four channels in wider-field full array mode. Observations acquired at two different telescope roll angles allowed faint surrounding objects to be separated from the stellar diffraction pattern. No companion candidates were detected at the reported position of Fomalhaut b with 3σ model-dependent mass upper limits of 3M J (for an age of 200 Myr). Around epsilon Eridani, we instead set a limit of 4 and lsim1M J (1 Gyr model age) at the inner and outer edge of the submillimeter debris ring, respectively. These results are consistent with non-detections in recent near-infrared imaging searches, and set the strongest limits to date on the presence of planets outside epsilon Eridani submillimeter ring.

  10. Determination of N epsilon-(carboxymethyl)lysine in foods and related systems.

    PubMed

    Ames, Jennifer M

    2008-04-01

    The sensitive and specific determination of advanced glycation end products (AGEs) is of considerable interest because these compounds have been associated with pro-oxidative and proinflammatory effects in vivo. AGEs form when carbonyl compounds, such as glucose and its oxidation products, glyoxal and methylglyoxal, react with the epsilon-amino group of lysine and the guanidino group of arginine to give structures including N epsilon-(carboxymethyl)lysine (CML), N epsilon-(carboxyethyl)lysine, and hydroimidazolones. CML is frequently used as a marker for AGEs in general. It exists in both the free or peptide-bound forms. Analysis of CML involves its extraction from the food (including protein hydrolysis to release any peptide-bound adduct) and determination by immunochemical or instrumental means. Various factors must be considered at each step of the analysis. Extraction, hydrolysis, and sample clean-up are all less straight forward for food samples, compared to plasma and tissue. The immunochemical and instrumental methods all have their advantages and disadvantages, and no perfect method exists. Currently, different procedures are being used in different laboratories, and there is an urgent need to compare, improve, and validate methods.

  11. Sulfur metabolisms in epsilon- and gamma-proteobacteria in deep-sea hydrothermal fields.

    PubMed

    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.

  12. 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

  13. Y-Ba Superconducting Ceramics

    NASA Astrophysics Data System (ADS)

    Shunbao, Tian; Xiaofei, Li; Tinglian, Wen; Zuxiang, Lin; Shichun, Li; Huijun, Yu

    Polycrystalline Y-Ba-Cu-O superconducting materials have been studied. It was found that chemical composition and processing condition may play an important role in the final structure and superconducting properties. The density has been determined and compared with the calculated value according to the structure model reported by Bell Labs. The grain size and the morphology of the materials were observed by SEM.

  14. Numerical Evaluation by Harmonic Analysis of the (Epsilon)-Function of the Theodorsen Arbitrary-Airfoil Potential Theory

    NASA Technical Reports Server (NTRS)

    Naiman, Irven

    1945-01-01

    Finite trigonometric series is fitted by harmonic analysis as an approximation function to the psi function of the Theodorsen arbitrary-airfoil potential theory. By harmonic synthesis, the corresponding conjugate trigonometric series is used as an approximation to the epsilon function. A set of coefficients of particularly simple form is obtained algebraically for direct calculation of the epsilon values from the corresponding set of psi values. Complete derivation of this process is presented.

  15. cDNA cloning and expression of a gamma-aminobutyric acid A receptor epsilon-subunit in rat brain.

    PubMed

    Moragues, N; Ciofi, P; Lafon, P; Odessa, M F; Tramu, G; Garret, M

    2000-12-01

    A cDNA encoding a GABA(A) receptor subunit was isolated from rat brain. The predicted protein is 70% identical to the human epsilon-subunit. It was recently reported [Sinkkonen et al. (2000), J. Neurosci., 20, 3588-3595] that the rodent epsilon-subunit mRNA encoded an additional sequence ( approximately 400 residues). We provide evidence that human and rat epsilon-subunit are similar in size. The distribution of cells expressing the GABA(A) epsilon-subunit was examined in the rat brain. In situ hybridization histochemistry revealed that epsilon-subunit mRNA is expressed by neurons located in septal and preoptic areas, as well as in various hypothalamic nuclei, including paraventricular, arcuate, dorsomedial and medial tuberal nuclei. The mRNA was also detected in major neuronal groups with broad-range influence, such as the cholinergic (basal nucleus), dopaminergic (substantia nigra compacta), serotonergic (raphe nuclei), and noradrenergic (locus coeruleus) systems. Immunohistochemistry using an affinity-purified antiserum directed towards the N-terminal sequence unique to the rat epsilon-subunit revealed the presence of epsilon-subunit immunoreactivity over the somatodendritic domain of neurons with a distribution closely matching that of mRNA-expressing cells. Moreover, using in situ hybridization, alpha3, theta and epsilon GABA(A) subunit mRNAs were all detected with an overlapping distribution in neurons of the dorsal raphe and the locus coeruleus. Our results suggest that novel GABA(A) receptors may regulate, neuroendocrine and modulatory systems in the brain.

  16. 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.

  17. 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

    2010-02-18

    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.

  18. Thermoluminescence properties of nanophosphors BaSO₄:Dy and BaSO₄:Tb.

    PubMed

    Rezaee Ebrahim Saraee, Kadijeh; Aghay Kharieky, Amin

    2013-12-01

    Nanocrystalline BaSO4:Dy and BaSO4:Tb were prepared by the coprecipitation method. The materials were characterized with X-ray diffractometry, UV-visible spectroscopy, and scanning electron microscopy. The glow curves of the BaSO4:Dy and BaSO4:Tb nanophosphors feature main peaks at 505 K and 480 K, respectively. The responses to the (60)Co dose are linear in the range 0.1-1 kGy for BaSO4:Dy and in the range 0.1-7 kGy for BaSO4:Tb. The energy dependences of the responses were also studied.

  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. 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.

  1. 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

  2. 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.

  3. Expression of GABA(A) receptor alpha3-, theta-, and epsilon-subunit mRNAs during rat CNS development and immunolocalization of the epsilon subunit in developing postnatal spinal cord.

    PubMed

    Pape, J-R; Bertrand, S S; Lafon, P; Odessa, M-F; Chaigniau, M; Stiles, J K; Garret, M

    2009-04-21

    Ionotropic GABA(A) receptors are heteromeric structures composed of a combination of five from at least 16 different subunits. Subunit genes are expressed in distinct cell types at specific times during development. The most abundant native GABA(A) receptors consist of alpha1-, beta2-, and gamma2-subunits that are co-expressed in numerous brain areas. alpha3-, theta-, And epsilon-subunits are clustered on the X chromosome and show striking overlapping expression patterns throughout the adult rat brain. To establish whether these subunits are temporally and spatially co-expressed, we used in situ hybridization to analyze their expression throughout rat development from embryonic stage E14 to postnatal stage P12. Each transcript exhibited a unique or a shared regional and temporal developmental expression profile. The thalamic expression pattern evolved from a restricted expression of epsilon and theta transcripts before birth, to a theta and alpha3 expression at birth, and finally to a grouped epsilon, theta and alpha3 expression postpartum. However, strong similarities occurred, such as a grouped expression of the three subunits within the hypothalamus, tegmentum and pontine nuclei throughout the developmental process. At early stages of development (E17), epsilon and theta appeared to have a greater spatial distribution before the dominance of the alpha3 subunit transcript around birth. We also revealed expression of alpha3, theta, and epsilon in the developing spinal cord and identified neurons that express epsilon in the postnatal dorsal horn, intermediolateral column and motoneurons. Our findings suggest that various combinations of alpha3-, theta- and epsilon-subunits may be assembled at a regional and developmental level in the brain.

  4. [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

  5. IBFM for Ba isotopes and chaoticity

    NASA Astrophysics Data System (ADS)

    Bucurescu, D.; Cáta-Danil, G.; Ivasçu, M.; Gizon, A.; Gizon, J.; Ur, C. A.

    1992-06-01

    Fluctuation properties have been analysed for the energy levels predicted by IBFM calculations in the Ba isotopes121Ba to131Ba. The results indicate, in general, a situation which is close to the chaotic limit. For the lighter isotopes studied (121 and 123), a phase transition is obtained in the low-spin, positive parity states, from a situation close to regularity at low excitation energies, towards chaoticity at higher excitations.

  6. Ba2phenanthrene is the main component in the Ba-doped phenanthrene superconductor

    NASA Astrophysics Data System (ADS)

    Yan, Xun-Wang; Huang, Zhongbing; Lin, Hai-Qing

    2014-12-01

    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 Ba1.5phenanthrene are not consistent with the experimental ones, while the results for Ba2phenanthrene 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 Ba1.5phenanthrene, there coexist Ba2phenanthrene and undoped phenanthrene in the superconducting sample. The electronic calculations indicate that Ba2phenanthrene is a semiconductor with a small energy gap less than 0.05 eV.

  7. 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.

  8. 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.

  9. 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

  10. Quasi-classical Trajectory Study of Ba+HI→BaI+H Reaction

    NASA Astrophysics Data System (ADS)

    Atasie, V. N.

    2010-10-01

    The quasi-classical trajectory calculations based on extended London-Eyring-Polanyi-Sato potential energy surface have been used to study the reaction of Ba+HI→BaI+H system. The rotational, vibrational, translational, and angular distributions of the product BaI have been calculated. The calculated results are in good agreement with the experimental ones.

  11. 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

  12. 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.

  13. Synthesis, crystal structure, dielectric properties, and potential use of nanocrystalline complex perovskite ceramic oxide Ba{sub 2}ErZrO{sub 5.5}

    SciTech Connect

    Jose, R. John, Asha M.; Thomas, J.K.; James, J.; Koshy, J.; Divakar, R.; Mohandas, E.

    2007-12-04

    A new member belongs to Ba{sub 2}REZrO{sub 5.5} (RE = Rare-Earth) perovskites, viz. Ba{sub 2}ErZrO{sub 5.5}, is synthesized as nanocrystals using a combustion process. Unlike the other Ba{sub 2}REZrO{sub 5.5} perovskites, which are cubic, Ba{sub 2}ErZrO{sub 5.5} crystallizes in tetragonal structure having space group P4/mnc (no. 128). Phase purity and ultrafine morphology of Ba{sub 2}ErZrO{sub 5.5} powders were examined using X-ray diffraction (XRD), differential thermal analysis (DTA), thermogravimetric analysis (TGA), Fourier transform of infrared spectroscopy (FT-IR), Brunauer-Emmett-Teller (BET) specific surface area measurements, and transmission electron microscopy (TEM). Nanocrystals of Ba{sub 2}ErZrO{sub 5.5} was sintered at {approx}1500 deg. C for 4 h; whereas coarse-grained powders synthesized through solid state reaction could not be sintered even at 1700 deg. C for prolonged duration. XRD pattern of Ba{sub 2}ErZrO{sub 5.5} was refined for atomic coordinates, lattice parameters, occupancies, and thermal factors using Rietveld analysis of XRD. Dielectric constant ({epsilon}') of Ba{sub 2}ErZrO{sub 5.5} at 10 MHz is 21.62 {+-} 2 and dielectric loss (tan {delta}) is 5 x 10{sup -3} at room temperature. Similar to the other Ba{sub 2}REZrO{sub 5.5} perovskites, Ba{sub 2}ErZrO{sub 5.5} is also showed chemically stability with YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} (YBCO) and Bi{sub 2}Sr{sub 2}Ca{sub 1}Cu{sub 2}O{sub x} (Bi-2212) superconductors. Ba{sub 2}ErZrO{sub 5.5} can possibly be used as a substrate for high temperature superconductor (HTS) films, or be used as an insulator in the active superconductor-insulator-superconductor (SIS) structures.

  14. 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.

  15. The apolipoprotein epsilon4 allele confers additional risk in children with familial hypercholesterolemia.

    PubMed

    Wiegman, Albert; Sijbrands, Eric J G; Rodenburg, Jessica; Defesche, Joep C; de Jongh, Saskia; Bakker, Henk D; Kastelein, John J P

    2003-06-01

    Children with familial hypercholesterolemia (FH) exhibit substantial variance of LDL cholesterol. In previous studies, family members of children with FH were included, which may have influenced results. To avoid such bias, we studied phenotype in 450 unrelated children with FH and in 154 affected sib-pairs. In known families with classical FH, diagnosis was based on plasma LDL cholesterol above the age- and gender-specific 95th percentile. Girls had 0.47 +/- 0.15 mmol/L higher LDL cholesterol, compared with boys (p = 0.002). Also in girls, HDL cholesterol increased by 0.07 +/- 0.03 mmol/L per 5 y (pfor trend = 0.005); this age effect was not observed in boys. The distribution of apolipoprotein (apo) E genotypes was not significantly different between probands, their paired affected siblings, or a Dutch control population. Carriers with or without one epsilon4 allele had similar LDL and HDL cholesterol levels. Within the affected sib-pairs, the epsilon4 allele explained 72.4% of the variance of HDL cholesterol levels (-0.15 mmol/L, 95% confidence interval -0.24 to -0.05, p = 0.003). The effect of apoE4 on HDL cholesterol differed with an analysis based on probands or on affected sib-pairs. The affected sib-pair model used adjustment for shared environment, type of LDL receptor gene mutation, and a proportion of additional genetic factors and may, therefore, be more accurate in estimating effects of risk factors on complex traits. We conclude that the epsilon4 allele was associated with lower HDL cholesterol levels in an affected sib-pair analysis, which strongly suggests that apoE4 influences HDL cholesterol levels in FH children. Moreover, the strong association suggests that apoE4 carries an additional disadvantage for FH children.

  16. 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.

  17. 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.

  18. Rotational dynamics of type I Fc epsilon receptors on individually-selected rat mast cells studied by polarized fluorescence depletion.

    PubMed Central

    Rahman, N A; Pecht, I; Roess, D A; Barisas, B G

    1992-01-01

    We report the first application of polarized fluorescence depletion (PFD), a technique which combines the sensitivity of fluorescence detection with the long lifetimes of triplet probes, to the measurement of membrane protein rotational diffusion on individually selected, intact mammalian cells. We have examined the rotation of type I Fc epsilon receptors (Fc epsilon RI) on rat mucosal mast cells of the RBL-2H3 line in their resting monomeric and differently oligomerized states using as probes IgE and three monoclonal antibodies (mAbs; H10, J17, and F4) specific for the Fc epsilon RI. PFD experiments using eosin (EITC)-IgE show that individual Fc epsilon RI on cells have a rotational correlation time (RCT) at 4 degrees C of 79 +/- 4 microseconds. Similarly, Fc epsilon RI-bound EITC-Fab fragments of the J17 Fc epsilon RI-specific mAb exhibit an RCT of 76 +/- 6 microseconds. These values agree with previous measurements of Fc epsilon RI-bound IgE rotation by time-resolved phosphorescence anisotropy methods. Receptor-bound EITC-conjugated divalent J17 antibody exhibits an increased RCT of 140 +/- 6 microseconds. This is consistent with the ability of this mAb to form substantial amounts of Fc epsilon RI dimers on these cell surfaces. The ratio of limiting to initial anisotropy in these experiments remains constant at about 0.5 from 5 degrees C through 25 degrees C for IgE, Fab, and intact mAb receptor ligands. Extensive cross-linking by second antibody of cell-bound IgE, of intact Fc epsilon RI-specific mAbs or of their Fab fragments, however, produced large fixed anisotropies demonstrating, under these conditions, receptor immobilization in large aggregates. PFD using the mAbs H10 and F4 as receptor probes yielded values for triplet lifetimes, RCT values, and anisotropy parameters essentially indistinguishable from those obtained with the mAb J17 clone. Possible explanations for these observations are discussed. PMID:1547323

  19. 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

  20. Strategy for designing broadband epsilon-near-zero metamaterial with loss compensation by gain media

    NASA Astrophysics Data System (ADS)

    Sun, L.; Yu, K. W.

    2012-06-01

    A strategy is proposed to design the broadband gain-doped epsilon-near-zero (GENZ) metamaterial. Based on the Milton representation of effective permittivity, the strategy starts in a dimensionless spectral space, where the effective permittivity of GENZ metamaterial is simply determined by a pole-zero structure corresponding to the operating frequency range. The physical structure of GENZ metamaterial is retrieved from the pole-zero structure via a tractable inverse problem. The strategy is of great advantage in practical applications and also theoretically reveals the cancellation mechanism of the broadband near-zero permittivity phenomenon in the spectral space.

  1. 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.

  2. Spoof surface plasmons tunneling through an epsilon-near-zero material channel

    NASA Astrophysics Data System (ADS)

    Li, Zhuo; Sun, Yunhe; Sun, Hengyi; Wang, Kuan; Song, Jiajia; Liu, Liangliang; Chen, Xinlei; Gu, Changqing

    2017-09-01

    In this paper, squeezing and tunneling of spoof surface plasmon polaritons (SSPPs) are realized by introducing an effective epsilon-near-zero (ENZ) material channel between two plasmonic waveguides constructed from dielectric filled rectangular waveguide etched with deep sub-wavelength periodical transverse slots on the upper wall. The tunneling frequency can be flexibly tuned by changing the relative permittivity of the effective ENZ material and the SSPPs can tunnel efficiently through a straight or an arbitrarily bent effective ENZ channel with ultra-low loss. This simple design holds great promise in significantly increasing the propagation length or arbitrarily tuning the propagation direction of the SSPPs in the microwave and terahertz frequencies.

  3. 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.

  4. 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.

  5. 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.

  6. Spent fuel reaction - the behavior of the {epsilon}-phase over 3.1 years

    SciTech Connect

    Finn, P.A.; Hoh, J.C.; Wolf, S.F.

    1996-12-31

    The release fractions of the five elements in the {epsilon}-phase ({sup 99}Tc, {sup 97}Mo, Ru, Rh, and Pd) as well as that of {sup 238}U are reported for the reaction of two oxide fuels (ATM-103 and ATM-106) in unsaturated tests under oxidizing conditions. The {sup 99}Tc release fractions provide a lower limit for the magnitude of the spent fuel reaction. The {sup 99}Tc release fractions indicate that a surface reaction might be the rate controlling mechanism for fuel reaction under unsaturated conditions and the oxidant is possibly H{sub 2}O{sub 2}, a product of alpha radiolysis of water.

  7. Temperature-responsive cross-linked poly(epsilon-caprolactone) membrane that functions near body temperature.

    PubMed

    Uto, Koichiro; Yamamoto, Kazuya; Hirase, Shohei; Aoyagi, Takao

    2006-01-10

    The objective of this study is to develop a sensitive temperature-responsive material that would function near body temperature. To achieve this purpose, we compounded 2-branched and 4-branched poly(epsilon-caprolactone) macromonomers to modulate the transition temperatures of the resulting cross-linked materials. The temperature-responsive properties were studied using differential scanning calorimetry and X-ray diffraction measurements. As a result, the mixing ratios of each macromonomer or the total macromonomer concentrations were very dominant in modulating the transition temperatures. The materials could successfully control the permeation of the model drug, prednisolone, near body temperature.

  8. Poly (epsilon-caprolactone)/propolis extract: microencapsulation and antibacterial activity evaluation.

    PubMed

    Durán, N; Marcato, P D; Buffo, C M S; De Azevedo, M M M; Esposito, E

    2007-04-01

    Spherical and homogenous microparticles of poly(epsilon-caprolactone) (PCL), containing propolis were prepared by the emulsification-solvent evaporation technique. Using this method of preparation, a solid formulation of propolis, free of ethanol and suitable for manipulation and storage, was obtained from an ethanolic extract of propolis. The incorporation efficiency of propolis in the microparticles was almost 30% and around 60% of the substance was released in 48 h. In vitro propolis microparticles exhibited similar halo zones in the Petri plate test against Streptococcus mutans (GS5) with a 10-fold lower concentration than the free propolis extract showing that the encapsulated propolis in microparticles is more efficient as antibiotic.

  9. 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.

  10. 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.

  11. An investigation of the {alpha}-{epsilon} phase transition in shock loaded EN3 mild steel

    SciTech Connect

    Millett, J. C. F.; Bourne, N. K.; Rosenberg, Z.

    1998-07-10

    The {alpha}-{epsilon} phase transition in a mild steel has been investigated using manganin stress gauges mounted in longitudinal orientation. The phase transformation has been located at 13.3{+-}0.3 GPa. Since the gauges have been mounted within the specimen, it has been possible to directly measure parameters of the phase change such as the transformation stress and the Hugoniot stress without the interference of releases that attend back-surface measurements. Strain gauges have been embedded alongside the stress gauges. In this orientation they are sensitive to lateral strain. Evidence has been collected that suggests the possibility of non-uniaxial strain behind the transformation front.

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    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.

  13. 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.

  14. epsilon : A tool to find a canonical basis of master integrals

    NASA Astrophysics Data System (ADS)

    Prausa, Mario

    2017-10-01

    In 2013, Henn proposed a special basis for a certain class of master integrals, which are expressible in terms of iterated integrals. In this basis, the master integrals obey a differential equation, where the right hand side is proportional to ɛ in d = 4 - 2 ɛ space-time dimensions. An algorithmic approach to find such a basis was found by Lee. We present the tool epsilon, an efficient implementation of Lee's algorithm based on the Fermat computer algebra system as computational back end.

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

    PubMed

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

    2016-05-23

    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.

  16. The NH2-terminal php domain of the alpha subunit of the Escherichia coli replicase binds the epsilon proofreading subunit.

    PubMed

    Wieczorek, Anna; McHenry, Charles S

    2006-05-05

    The alpha subunit of the replicase of all bacteria contains a php domain, initially identified by its similarity to histidinol phosphatase but of otherwise unknown function (Aravind, L., and Koonin, E. V. (1998) Nucleic Acids Res. 26, 3746-3752). Deletion of 60 residues from the NH2 terminus of the alpha php domain destroys epsilon binding. The minimal 255-residue php domain, estimated by sequence alignment with homolog YcdX, is insufficient for epsilon binding. However, a 320-residue segment including sequences that immediately precede the polymerase domain binds epsilon with the same affinity as the 1160-residue full-length alpha subunit. A subset of mutations of a conserved acidic residue (Asp43 in Escherichia coli alpha) present in the php domain of all bacterial replicases resulted in defects in epsilon binding. Using sequence alignments, we show that the prototypical gram+ Pol C, which contains the polymerase and proofreading activities within the same polypeptide chain, has an epsilon-like sequence inserted in a surface loop near the center of the homologous YcdX protein. These findings suggest that the php domain serves as a platform to enable coordination of proofreading and polymerase activities during chromosomal replication.

  17. Six-month recovery from mild to moderate Traumatic Brain Injury: the role of APOE-epsilon4 allele.

    PubMed

    Chamelian, Laury; Reis, Marciano; Feinstein, Anthony

    2004-12-01

    The possession of at least one APOE-epsilon4 allele may be linked to poor outcome in patients with predominantly severe traumatic brain injury (TBI). In mild TBI, which accounts for approximately 85% of all cases, the role of the APOE-epsilon4 allele is less clear. Studies completed to date have relied on brief cognitive assessments or coarse measures of global functioning, thereby limiting their conclusions. Our study investigated the influence of the APOE-epsilon4 allele in a prospective sample of 90 adults with mild to moderate TBI in whom neuropsychiatric outcome 6 months after injury was assessed as follows: (i) a detailed neuropsychological battery; (ii) an index of emotional distress (General Health Questionnaire); (iii) a diagnosis of major depression (Structured Clinical Interview for DSM-IV); (iv) a measure of global functioning (Glasgow Outcome Scale); (v) an index of psychosocial outcome (Rivermead Head Injury Follow-up Questionnaire); and (vi) symptoms of persistent post-concussion disorder (Rivermead Post-Concussion Symptoms Questionnaire). No association was found between the presence of the APOE-epsilon4 allele and poor outcome across all measures. Given the homogeneous nature of our sample (mild to moderate injury severity), the uniform follow-up period (6 months) and the comprehensive markers of recovery used, our data suggest that the APOE-epsilon4 allele does not adversely impact outcome in this group of TBI patients.

  18. Synergistic effects of apolipoprotein E gene epsilon polymorphism and some conventional risk factors on premature ischaemic heart disease development.

    PubMed

    Balcerzyk, Anna; Zak, Iwona; Krauze, Jolanta

    2007-09-01

    Ischaemic heart disease (IHD), which is a clinical manifestation of atherosclerotic changes in coronary arteries, results from the action of multiple genetic and environmental factors. Genetic susceptibility to IHD may be determined by specific polymorphic variants of genes encoding isoforms involved in processes important in the pathogenesis of atherosclerosis. Due to the multifactorial nature of IHD, participation of a single polymorphism in the determination of the disease risk is relatively small. However, it seems that its significance may increase in the presence of a specific genetic or environmental background. To evaluate a possible association between the epsilon polymorphism of the apolipoprotein E gene (apo E) and premature IHD in the Polish population as well as to determine whether the genotype may modulate the influence of conventional risk factors on IHD. We studied 247 caucasian subjects: 140 patients with angiographically confirmed IHD and 107 blood donors without a history of IHD. Polymorphism epsilon of the apo E gene was genotyped using the PCR-RFLP method. We observed a tendency to a higher prevalence of the epsilon4 allele and carriers of this allele in the IHD group compared to controls. However, these differences were not statistically significant. We also observed a synergistic effect between epsilon4 allele carrier state and smoking, elevated level of total cholesterol and, to a lower degree - LDL cholesterol, on IHD risk. Presented data show the synergistic effects between epsilon4 allele carrier state and some traditional risk factors on determining the risk of premature coronary artery disease.

  19. Reverse pharmacognosy: application of selnergy, a new tool for lead discovery. The example of epsilon-viniferin.

    PubMed

    Do, Quoc-Tuan; Renimel, Isabelle; Andre, Patrice; Lugnier, Claire; Muller, Christian D; Bernard, Philippe

    2005-09-01

    The aim of reverse pharmacognosy is to find new biological targets for natural compounds by virtual or real screening and identify natural resources that contain the active molecules. To demonstrate the applicability of this concept, we report here a study on epsilon-viniferin, an active ingredient for cosmetic development. Nevertheless, this natural substance is weakly defined in terms of biological properties. SELNERGY, an inverse docking computer software, was used to identify putative binding biological targets for epsilon-viniferin. Among the 400 screened proteins two targets were retained. For cosmetic application, cyclic nucleotide phosphodiesterase 4 (PDE4) was the most interesting candidate. Moreover, other PDE subtypes (1, 2, 3, 5 and 6) were not retained, indicating a selectivity for PDE4. The experimental binding tests on the 6 subtypes of PDE revealed a significant selectivity of epsilon-viniferin for the PDE4 subtype. This selectivity was confirmed by evaluation of epsilon-viniferin on the secretion of TNF-alpha and Interleukin-8. Our data demonstrated that epsilon-viniferin possesses anti-inflammatory properties by inhibiting PDE4 subtype. In conclusion, reverse pharmacognosy and its inverse docking component cannot only be integrated into a program for new lead discovery but is also a useful approach to find new applications for identified compounds.

  20. [Specific diversity of plant populations at rainfed scale and crop protection: the example of banana production in the French West Indies].

    PubMed

    Ganry, Jacky

    2004-07-01

    Banana is a major crop in the French West Indies, where it is subjected to strong parasite pressure, resulting in pesticide pollution. An increase in plant population diversity in the cultivated ecosystem is generated by changing cultural practices. This results in a decrease in parasite pressure and hence a decrease in pollutant pesticide loads. Agricultural sustainability is therefore reinforced for better coexistence of populated, cultivated and protected areas.

  1. Molecular cloning and characterization of a novel human protein phosphatase 2C cDNA (PP2C epsilon*).

    PubMed

    Jin, Feng; Ji, Chaoneng; Liu, Lingfeng; Dai, Jianfeng; Gu, Shaohua; Sun, Xianfei; Xie, Yi; Mao, Yumin

    2004-09-01

    We have isolated a novel cDNA from the human fetal brain cDNA library with homology to the Mg2+ -dependent serine/threonine protein phosphatase 2C (PP2C) family. The cDNA is 3055 bp in length, and the predicted coding region encodes a 360-amino-acid protein, which shows 99% identity to the PP2C epsilon from rat and mouse. Then we term it human PP2C epsilon gene. The gene is mapped to chromosome 3q26.1 and contains 4 exons. RT-PCR analysis shows that the PP2C epsilon is widely expressed in human tissues and the expression levels in heart, placenta, lung, liver, kidney, and pancreas are relatively high.

  2. A tyrosine-containing motif mediates ER retention of CD3-epsilon and adopts a helix-turn structure.

    PubMed Central

    Mallabiabarrena, A; Jiménez, M A; Rico, M; Alarcón, B

    1995-01-01

    The CD3-epsilon endoplasmic reticulum (ER) retention motif has been characterized by mutagenesis and NMR spectroscopy. Tyr177, Leu180 and Arg183 are involved in ER retention. The motif forms an elongated alpha-helix in which the tyrosine and leucine residues are closely apposed, followed by a beta I' turn that places Arg183 in the vicinity of Leu180. The structure formed by Tyr177 and the leucine in position +3 is reminiscent of the beta-turn structure adopted by tyrosine-containing endocytosis signals. Moreover, substitution of the transferrin receptor (TfR) internalization sequence by the CD3-epsilon motif still allowed the rapid internalization of the TfR and, conversely, the chimeric protein resulting from the substitution of the CD3-epsilon motif by the endocytosis signal of the low density lipoprotein receptor was ER located. These data support the idea of a functional homology between the two types of signal. Images PMID:7774584

  3. 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.

  4. 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.

  5. Regulation of T cell receptor activation by dynamic membrane binding of the CD3epsilon cytoplasmic tyrosine-based motif.

    PubMed

    Xu, Chenqi; Gagnon, Etienne; Call, Matthew E; Schnell, Jason R; Schwieters, Charles D; Carman, Christopher V; Chou, James J; Wucherpfennig, Kai W

    2008-11-14

    Many immune system receptors signal through cytoplasmic tyrosine-based motifs (ITAMs), but how receptor ligation results in ITAM phosphorylation remains unknown. Live-cell imaging studies showed a close interaction of the CD3epsilon cytoplasmic domain of the T cell receptor (TCR) with the plasma membrane through fluorescence resonance energy transfer between a C-terminal fluorescent protein and a membrane fluorophore. Electrostatic interactions between basic CD3epsilon residues and acidic phospholipids enriched in the inner leaflet of the plasma membrane were required for binding. The nuclear magnetic resonance structure of the lipid-bound state of this cytoplasmic domain revealed deep insertion of the two key tyrosines into the hydrophobic core of the lipid bilayer. Receptor ligation thus needs to result in unbinding of the CD3epsilon ITAM from the membrane to render these tyrosines accessible to Src kinases. Sequestration of key tyrosines into the lipid bilayer represents a previously unrecognized mechanism for control of receptor activation.

  6. Docosahexaenoic acid prevents cognitive deficits in human apolipoprotein E epsilon 4-targeted replacement mice.

    PubMed

    Chouinard-Watkins, Raphaël; Vandal, Milène; Léveillé, Pauline; Pinçon, Anthony; Calon, Frédéric; Plourde, Mélanie

    2017-09-01

    At a population level, dietary consumption of fish rich in docosahexaenoic acid (DHA) is associated with prevention of cognitive decline but this association is not clear in carriers of the apolipoprotein E epsilon 4 allele (E4). Plasma and liver DHA concentrations show significant alterations in E4 carriers, in part corrected by DHA supplementation. However, whether DHA sufficiency in E4 carriers has consequences on cognition is unknown. Mice expressing human E4 or apolipoprotein E epsilon 3 allele (E3) were fed either a control diet or a diet containing DHA for 8 months and cognitive performance was tested using the object recognition test and the Barnes maze test. In E4 mice fed the control diet, impaired memory was detected and arachidonic acid concentrations were elevated in the hippocampus compared to E3 mice fed the control diet. DHA consumption prevented memory decline and restored arachidonic acid concentrations in the hippocampus of E4 mice. Our results suggest that long-term high-dose DHA intake may prevent cognitive decline in E4 carriers. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Synthesis and characterization of novel antimicrobial emulsifiers from epsilon-polylysine.

    PubMed

    Yu, Hailong; Huang, Yuping; Huang, Qingrong

    2010-01-27

    epsilon-Polylysine (EPL) has been used in the food industry as an antimicrobial additive and also a dietary agent. To generate amphiphilic molecules from EPL, hydrophobically modified epsilon-polylysine graft copolymers, which were denoted as OSA-g-EPLs, were synthesized by reacting EPL with octenyl succinic anhydride (OSA). The success of synthesis was confirmed by (1)H NMR and FT-IR spectroscopy. It was found that OSA-g-EPLs had glass transition temperatures lower than EPL. Furthermore, they were able to form polymer micelles in water and to lower the surface tension of water, confirming their amphiphilic properties. The antimicrobial activities of OSA-g-EPLs were also examined, and the minimum inhibitory concentrations of OSA-g-EPLs against Escherichia coli O157:H7 remained the same as that of EPL. Therefore, OSA-g-EPLs have the potential of becoming bifunctional molecules, which can be used either as surfactants or emulsifiers in the encapsulation of nutraceuticals or drugs or as antimicrobial agents.

  8. Synergistic activation of the germline epsilon promoter mediated by Stat6 and C/EBP beta.

    PubMed

    Mikita, T; Kurama, M; Schindler, U

    1998-08-15

    Transcription of the Ig H chain germline transcripts is a prerequisite for class switching. Expression of the epsilon germline transcript is induced by IL-4 and requires the integrity of a composite IL-4 response element. The element is bound by the IL-4-inducible transcription factor Stat6 and one or more members of the CAAT/enhancer-binding protein (C/EBP) family, a constitutively expressed class of transcription factors. Here, we show that Stat6 and C/EBP beta cooperate to synergistically activate transcription from the epsilon element. The effect was most pronounced in lymphoid cells, and the activation domains of both proteins were required to achieve this synergy. Although other members of the C/EBP family are able to bind the element, very little cooperativity was seen with C/EBP alpha and none with C/EBP gamma. In fact, C/EBP gamma was able to inhibit IL-4-induced reporter activity. Stat6 and C/EBP beta bind the IL-4 response element simultaneously. The fast dissociation rate apparent when Stat6 binds this DNA element alone is slowed when C/EBP beta binds at the neighboring site. These data suggest a mechanism whereby C/EBP beta stabilizes Stat6 binding at this element, thereby increasing the likelihood that both of their activation domains will interact, possibly with other factors, to activate transcription in an IL-4-dependent manner.

  9. Low-Reynolds-number k-epsilon model for unsteady turbulent boundary-layer flows

    NASA Technical Reports Server (NTRS)

    Fan, Sixin; Lakshminarayana, Budugur; Barnett, Mark

    1993-01-01

    An assessment of the near-wall and low-Reynolds-number functions used in low-Reynolds-number k-epsilon models suggests that they are not suitable for the near-wall region of unsteady turbulent boundary layers, where the flow is characterized by rapid changes in phase. An improved low-Reynolds-number k-epsilon model is developed in this paper. The near-wall and low-Reynolds-number functions in this model are formulated as functions of the local turbulent Reynolds numbers instead of the inner variable y(+). The present model also has the correct asymptotic behavior in the near-wall region. The turbulence model has been incorporated in an unsteady boundary-layer code and validated for unsteady turbulent boundary layers with and without adverse pressure gradients. The predictions agree well with the experimental data and the theoretical analysis. For the cases tested, the present model correctly predicts the unsteady near-wall flow and the unsteady shin friction at various frequencies.

  10. High dispersion observations of Epsilon Aur from Sept. 1982 to March 1983

    NASA Technical Reports Server (NTRS)

    Wallterstein, G.

    1985-01-01

    Between September 1982 and March 1983 I obtained high dispersion spectra of epsilon Aur in selected regions using the Palomar 200-inch coude spectrograph and the Dominion Astrophysical Observatory 48-coude spectrograph. All spectra were taken with the 90-mm ITT image tube and IIa-D emulsion. Radial velocities are listed for the sodium D lines, KI lines, H alpha, and a few other features. While most of the sodium and potassium features are surely circumstellar there is certainly an interstellar component present. In the direction of epsilon Aur interstellar gas is seen mostly with radial velocities between +5 and +10 km s(-1). The sodium D lines and potassium lines show incipient resolution which may involve the interstellar components. The equivalent widths of the sodium and potassium lines are given. For potassium, blending with atmospheric O2 makes the line at lambda 7664 unmeasurable on the dates of these observations. The increase in equivalent widths already noted by Pathasarathy and Lambert is evident. Blending and partial resolution of the circumstellar and interstellar features may account for much of the velocity structure which is only partially discernable at the available resolution.

  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. Epsilon-Near-Zero Substrate Engineering for Ultrathin-Film Perfect Absorbers

    NASA Astrophysics Data System (ADS)

    Rensberg, Jura; Zhou, You; Richter, Steffen; Wan, Chenghao; Zhang, Shuyan; Schöppe, Philipp; Schmidt-Grund, Rüdiger; Ramanathan, Shriram; Capasso, Federico; Kats, Mikhail A.; Ronning, Carsten

    2017-07-01

    Efficient suppression of reflection is a key requirement for perfect absorption of light. Recently, it has been shown that reflection can be effectively suppressed utilizing a single ultrathin film deposited on metals or polar materials featuring phonon resonances. The wavelength at which reflection can be fully suppressed is primarily determined by the nature of these substrates and is pinned to particular values near plasma or phonon resonances—the former typically in the ultraviolet or visible and the latter in the infrared. Here, we explicitly identify the required optical properties of films and substrates for the design of absorbing antireflection coatings based on ultrathin films. We find that completely suppressed reflection using films with thicknesses much smaller than the wavelength of light occurs within a spectral region where the real part of the refractive index of the substrate is n ≲1 , which is characteristic of materials with permittivity close to zero. We experimentally verify this condition by using an ultrathin vanadium dioxide film with dynamically tunable optical properties on several epsilon-near-zero materials, including aluminum-doped zinc oxide. By tailoring the plasma frequency of the aluminum-doped zinc oxide, we are able to tune the epsilon-near-zero point, thus achieving suppressed reflection and near-perfect absorption at wavelengths that continuously span the near-infrared and long-wave midinfrared ranges.

  13. 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.

  14. Mutations in the gene encoding epsilon-sarcoglycan cause myoclonus-dystonia syndrome.

    PubMed

    Zimprich, A; Grabowski, M; Asmus, F; Naumann, M; Berg, D; Bertram, M; Scheidtmann, K; Kern, P; Winkelmann, J; Müller-Myhsok, B; Riedel, L; Bauer, M; Müller, T; Castro, M; Meitinger, T; Strom, T M; Gasser, T

    2001-09-01

    The dystonias are a common clinically and genetically heterogeneous group of movement disorders. More than ten loci for inherited forms of dystonia have been mapped, but only three mutated genes have been identified so far. These are DYT1, encoding torsin A and mutant in the early-onset generalized form, GCH1 (formerly known as DYT5), encoding GTP-cyclohydrolase I and mutant in dominant dopa-responsive dystonia, and TH, encoding tyrosine hydroxylase and mutant in the recessive form of the disease. Myoclonus-dystonia syndrome (MDS; DYT11) is an autosomal dominant disorder characterized by bilateral, alcohol-sensitive myoclonic jerks involving mainly the arms and axial muscles. Dystonia, usually torticollis and/or writer's cramp, occurs in most but not all affected patients and may occasionally be the only symptom of the disease. In addition, patients often show prominent psychiatric abnormalities, including panic attacks and obsessive-compulsive behavior. In most MDS families, the disease is linked to a locus on chromosome 7q21 (refs. 11-13). Using a positional cloning approach, we have identified five different heterozygous loss-of-function mutations in the gene for epsilon-sarcoglycan (SGCE), which we mapped to a refined critical region of about 3.2 Mb. SGCE is expressed in all brain regions examined. Pedigree analysis shows a marked difference in penetrance depending on the parental origin of the disease allele. This is indicative of a maternal imprinting mechanism, which has been demonstrated in the mouse epsilon-sarcoglycan gene.

  15. Detection of epsilon class switching and IgE synthesis in human B cells.

    PubMed

    Pène, Jérôme; Guilhot, Florence; Cognet, Isabelle; Guglielmi, Paul; Guay-Giroux, Angélique; Bonnefoy, Jean-Yves; Elson, Greg C; Yssel, Hans; Gauchat, Jean-François

    2006-01-01

    We observed that mast cells, as other cells expressing the CD40 ligand CD154, can trigger IgE synthesis in B cells in the presence of interleukin (IL)-4. Numerous complementary techniques can be used to follow the succession of molecular events leading to IgE synthesis. This chapter will illustrate how human B cells (naïve or memory) can be purified, stored, and cultivated in medium that is permissive for IgE synthesis and stimulated with IL-4 or IL-13 and CD40 activation, the latter being induced by soluble CD154, anti-CD40 antibodies, or CD154-expressing cells. All these molecules are expressed by mast cells. The quantification of the epsilon-sterile transcript synthesis by polymerase chain reaction or Northern blot, the epsilon excision circles produced during immunoglobulin heavy chain locus rearrangement by polymerase chain reaction, and the IgE production by enzyme-linked immunosorbent assay will be described.

  16. Formation of N epsilon-(gamma-glutamyl)-lysine isodipeptide in Chinese-hamster ovary cells.

    PubMed Central

    Fesus, L; Tarcsa, E

    1989-01-01

    N epsilon-(gamma-Glutamyl)-lysine isodipeptide was detected in a protein-free fraction of Chinese-hamster ovary cells and their culture fluid by using radioactive lysine as a tracer. The identity of the isodipeptide was established by its separation on ion-exchange chromatography, analysis by h.p.l.c. after derivatization, recovery of lysine after acidic hydrolysis or after cleavage by a specific enzyme, namely gamma-glutamylamine cyclotransferase. The amount of isodipeptide was raised (460 pmol/10(7) cells and 61 pmol/ml of culture fluid were observed as highest values) as the cell density increased. Effects of inhibitors of intracellular protein degradation have shown that the isodipeptide derives from cross-linking N epsilon-(gamma-glutamyl)-lysine bonds formed by tissue transglutaminase. Estimated half-life values of cross-linked proteins were about 3 h. gamma-Glutamylamine cyclotransferase, which may split the isodipeptide formed during the continuous turnover of cross-linked proteins, was also found in Chinese-hamster ovary cells. Isodipeptide may have been accumulated when either its generated amount is beyond the capacity of gamma-glutamylamine cyclotransferase or it is generated in cell compartments where this enzyme is not present. PMID:2574570

  17. 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

  18. Low cytotoxic tissue adhesive based on oxidized dextran and epsilon-poly-L-lysine.

    PubMed

    Hyon, Suong-Hyu; Nakajima, Naoki; Sugai, Hajime; Matsumura, Kazuaki

    2014-08-01

    A novel adhesive hydrogel consisting of dextran and epsilon-poly(L-lysine) (dextran-PL) with multiple biomedical applications was developed. Periodate oxidation in aqueous media almost stoichiometrically introduces aldehyde groups in dextran molecules, and aldehyde dextran can react with the primary amino groups in epsilon-PL (ɛ-PL) at neutral pH to form a hydrogel. The gelation time of the hydrogel can be easily controlled by the extent of oxidation in dextran and of the acylation in ɛ-PL by anhydrides. The shear adhesion strength of dextran-PL was 10 times higher than that of fibrin glue, when wet collagen sheets were selected as test specimens. The cytotoxicity of aldehyde dextran and ɛ-PL were 1000 times lower than that of glutaraldehyde and poly(allylamine). The considerably low cytotoxicity of aldehyde dextran could be ascribed to its low reactivity with amine species when compared with glutaraldehyde. In contrast, a high reactivity of amino groups in ɛ-PL was observed when compared with glycine, L-lysine, and gelatin, which could be explained by their poor dissociation at neutral pH, thus leading to low cytotoxicity.

  19. Baeyer-Villiger oxidation of cyclohexanone to epsilon-caprolactone in airlift sonochemical reactor.

    PubMed

    Zhang, Ping; Yang, Mei; Lu, Xiaoping; Han, Pingfang; Wang, Yanru

    2006-12-22

    Baeyer-Villiger oxidation of cyclohexanone to epsilon-caprolactone was studied in a new type reactor--the airlift loop sonochemical reactor. The reactor plays a synergistic effect of sonochemsity and higher oxygen transfer rate. The influences of ultrasound intensity, reaction temperature, the molar ratio of benzaldehyde to cyclohexanone and oxygen gas flow rate on the conversion and selectivity of cyclohexanone were investigated and discussed. Under ultrasound, the amount of benzaldehyde can be reduced from 75% to 67%. Ultrasound not only intensified the rates of reactions but also increased the yield of product. The optimized operation conditions are listed as follows: the reaction temperature is 30 degrees C, the molar ratio of cyclohexanone to benzaldehyde is 1:2, the oxygen gas flow rate is 1.15 cm s(-1), and ultrasonic irradiations 2h at 40 kHz, 2.25 W cm(-2). Under the optimum operation conditions, the average molar yield of epsilon-caprolactone comes up to 87.7%.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. Contribution of Heliborne Electro-Magnetic survey for landslide prediction: application to La Martinique (West Indies, France)

    NASA Astrophysics Data System (ADS)

    Thiery, Yannick; Reninger, Pierre-Alexandre; Vandromme, Rosalie; Nachbaur, Aude

    2017-04-01

    Landslide hazard and risk assessment (LHA & LRA) in French West Indies is a big challenge, because of several factors contributing to high sensitivity of slopes to landslide (complex weathered volcanic grounds, hurricane seasons, heavy land pressure).The initial step is to assess the spatial probability (and sometimes temporal) of failure (i.e. landslide susceptibility assessment; LSA) for a given area. LSA can be evaluated by several approaches (i.e. knowledge approach, data-driven approach, physically based approach). Physically based approaches are used to calculate a slope stability factor taking into account mechanical, geotechnical, hydrological and hydrogeological parameters. However, the parametrization of these models can be difficult because of a lack of information (i.e. soil depths, precipitations chronicles, lithology sometimes due to a difficult ground access, particularly in French Indies. Thus, HEM (Heliborne Electro-Magnetic Survey) appears as a solution to obtain specific information quickly and over large areas. Since 2000, the HEM method is increasingly used for environmental studies: geomorphological and hydrogeological studies. In 2013, The French Geological Survey conducted an HEM survey over La Martinique (West Indies). Resistivity contrasts were imaged up 250-300 meters depth with a horizontal resolution around 30 m and a vertical resolution between 3 and 8 m. Even if the resistivity has not a straightforward relationship with soil mechanical properties (which are key parameters for LHA) it provides relevant information on both the thickness and the extension of formations. The aim of this study is to evaluate the contribution of HEM survey to recognize landslide prone areas and landslide prone formations in volcanic environment. Once the different formations defined, they are introduced in a physically based model to assess the susceptibility of slope for different landslide types with hydrogeological control. The methodology is split in

  5. Self-association of 1,N6-ethenoadenosine 5'-triphosphate (epsilon-ATP) and promotion by metal ions.

    PubMed

    Scheller, K H; Sigel, H

    1986-05-15

    The concentration dependence of the chemical shifts of the protons H-2, H-8, H-10, H-11, and H-1' of 1,N6-ethenoadenosine 5'-triphosphate (epsilon-ATP4-) has been measured in D2O at 27 degrees C to elucidate the self-association. The results are consistent with the isodesmic model of indefinite noncooperative stacking; the association constant, K = 1.9 +/- 0.2 M-1, is only slightly larger than the value for ATP4-, K = 1.3 +/- 0.2 M-1. The self-stacking tendency of epsilon-ATP4- is promoted by a factor of about 4 by (1:1) coordination of Mg2+ to the phosphate moieties, which probably links these together and also neutralizes part of the negative charge; Zn2+ is only about half as effective as Mg2+ in promoting the self-association. This result contrasts with the self-stacking properties of Mg(ATP)2- and Zn(ATP)2-, Zn2+ being considerably more effective in a 1:1 ATP system. It is assumed that due to the enhanced affinity of the N-6/N-7 site of the epsilon-adenine moiety towards Zn2+ repulsion of the bases occurs resulting thus in a lower stacking tendency; in addition, the simple isodesmic model is no longer applicable to the Zn(epsilon-ATP)2- system: to explain the experimental data, the formation of an intermolecular metal ion bridge in the dimeric stacks is proposed. The experimental conditions required for studies of the properties of monomeric epsilon-ATP systems are described. Care should be exercised in employing epsilon-ATP as a probe for ATP.

  6. 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.

  7. 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

  8. Synthesis of an X-ray opaque biodegradable copolyester by chemical modification of poly (epsilon-caprolactone).

    PubMed

    Nottelet, Benjamin; Coudane, Jean; Vert, Michel

    2006-10-01

    Poly (epsilon-caprolactone-co-alpha-iodo-epsilon-caprolactone) was synthesized by binding iodine to PCL chain bearing carbanionic site on alpha-position of carbonyl groups using lithium diisopropylamide. Copolyesters containing from 10% to 25% of iodo-units were thus obtained. Viscoelastic properties (modulus, loss angle), thermal properties (T(m), T(c), DeltaH(m)), crystallinity and in vitro degradability of this new type of copolymers were measured. Their opacity to X-rays was assessed, and appeared high enough to be of interest for biomedical applications.

  9. The anomalous expansion of lattice parameter as a function of temperature for an Fe-24Mn alloy during {gamma}{yields}{epsilon} martensitic transformation

    SciTech Connect

    Lu, X.; Qin, Z.; Zhang, Y.; Ding, B.; Hu, Z.

    2000-02-14

    In the present letter, the authors will report their experiment on an Fe-24Mn alloy using high temperature XRD and dilation. A relation between the lattice parameter of austenite and temperature during {gamma}{yields}{epsilon} martensitic transformation was determined. It is expected to be helpful in the understanding of {gamma}{yields}{epsilon} martensitic transformation in Fe-Mn based alloys.

  10. An Empirical Study of Students' Understanding of a Logical Structure in the Definition of Limit via the epsilon-Strip Activity

    ERIC Educational Resources Information Center

    Roh, Kyeong Hah

    2010-01-01

    This study explored students' understanding of a logical structure in defining the limit of a sequence, focusing on the relationship between epsilon and N. The subjects of this study were college students who had already encountered the concept of limit but did not have any experience with rigorous proofs using the epsilon-N definition. This study…

  11. BaGe6 and BaGe(6-x): incommensurately ordered vacancies as electron traps.

    PubMed

    Akselrud, Lev; Wosylus, Aron; Castillo, Rodrigo; Aydemir, Umut; Prots, Yurii; Schnelle, Walter; Grin, Yuri; Schwarz, Ulrich

    2014-12-15

    We report the high-pressure high-temperature synthesis of the germanium-based framework compounds BaGe6 (P = 15 GPa, T = 1073 K) and BaGe(6-x) (P = 10 GPa, T = 1073 K) which are metastable at ambient conditions. In BaGe(6-x), partial fragmentation of the BaGe6 network involves incommensurate modulations of both atomic positions and site occupancy. Bonding analysis in direct space reveals that the defect formation in BaGe(6-x) is associated with the establishment of free electron pairs around the defects. In accordance with the electron precise composition of BaGe(6-x) for x = 0.5, physical measurements evidence semiconducting electron transport properties which are combined with low thermal conductivity.

  12. Polarizabilities of Ba and Ba2 : Comparison of molecular beam experiments with relativistic quantum chemistry

    NASA Astrophysics Data System (ADS)

    Schäfer, Sascha; Mehring, Max; Schäfer, Rolf; Schwerdtfeger, Peter

    2007-11-01

    The dielectric response to an inhomogeneous electric field has been investigated for Ba and Ba2 within a molecular beam experiment. The ratio of the polarizabilities per atom of Ba2 and Ba is determined to be 1.30±0.13 . The experimental result is compared to a high level ab initio quantum chemical coupled cluster calculation with an energy-consistent scalar relativistic small-core pseudopotential for Ba. For the barium atom a polarizability of 40.82Å3 is obtained and the isotropic value of the polarizability calculated for Ba2 is 97.88Å3 , which is in good agreement with the experimental results, demonstrating that a quantitative understanding of the interaction between two closed-shell heavy element metal atoms has been achieved.

  13. 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.

  14. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2016-06-01

    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.

  16. 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. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Too much to tell: Narrative styles of the first descriptions of the natural world of the Indies.

    PubMed

    Leitão, Henrique; Sánchez, Antonio

    2017-06-01

    Describing a Mundus Novus was a very singular task in the sixteenth century. It was an effort shaped by a permanent inherent tension between novelty and normality, between the immense variety of new facts (some extraordinary) and the demand of credibility. How did these inner strains affect the narrative style of the first descriptions of the natural world of 'the Indies'? How were the first European observers of the nature of America able to simultaneously transmit the idea of immensity and regularity ( mundus), and that of novelty ( novus)? How did they attempt to describe new worlds knowing that there was a lot - perhaps too much - to tell? This paper focuses not on the much-discussed epistemological issues related to those questions, but on their narrative and stylistic consequences. We argue that the first Europeans meeting the new realities of the Americas or India had to meet new challenges, and these translated into texts with specific characteristics. Thus, their first descriptions are essentially different from the texts about the natural world that were written before or after the 'discovery'. We show that they adopted very specific discursive approaches, and were deeply influenced by the credibility strategies of the medical profession in which they had been trained.

  18. Internalized racism, body fat distribution, and abnormal fasting glucose among African-Caribbean women in Dominica, West Indies.

    PubMed Central

    Butler, Cleve; Tull, Eugene S.; Chambers, Earle C.; Taylor, Jerome

    2002-01-01

    The current study examined the relationship of internalized racism to glucose intolerance in a population of Afro-Caribbean women aged 18 to 55. Also of interest was whether this relationship would be differentially influenced by the type of body fat distribution or confounded by the level of hostility. A total of 244 women were selected from a systematic sample of households on the island of Dominica, West Indies. Demographic data together with information on internalized racism were collected by questionnaire. Anthropometric information and fasting blood glucose were also measured. Women with high levels of internalized racism exhibited an increased risk of elevated fasting glucose compared to those with low levels of internalized racism (odds ratio (OR) = 2.4; 95% confidence interval (CI) = 1.1-5.5). There was no difference in mean body mass index (BMI) by level of internalized racism. However those with high internalized racism had a significantly larger waist circumference after adjusting for age, education, hostility, and elevated fasting glucose status. In multivariate analyses controlling for age, education, hostility, and either weight or BMI, internalized racism remained independently associated with elevated fasting glucose. However, once waist circumference was included in the model, the relationship of internalized racism to elevated fasting glucose was not statistically significant. This study demonstrates a significant relationship between internalized racism and abnormal levels of fasting glucose which may be mediated through abdominal fat. The exact nature of the relationship of internalized racism to glucose intolerance may be an important area of future study. PMID:11918383

  19. A comparison of Caribbean and non-Caribbean clients in a residential addiction treatment facility in Antigua, West Indies.

    PubMed

    Martin, Thomas C; Klinedinst, Michelle; Josiah-Martin, Judith A; Burke-Forde, Ashley

    2003-01-01

    The first 50 Caribbean clients admitted to a private, multicultural, not for profit addiction treatment center in Antigua, West Indies, were compared with the first 100 non-Caribbean clients admitted. There was no significant difference in age, 38 years (18-61 years) versus 40 years (22-63 years), or gender, 74% versus 67% male. Caribbean clients were more likely to be Black, 68% versus 2%, P < .001. Caribbean clients were less likely to have a prior psychiatric diagnosis, 18% versus 43%, P < .01, or to have been in prior treatment program, 22% versus 64%, P < .001. Caribbean and non-Caribbean clients were equally likely to be polydrug users, 48% versus 50%, and to use alcohol as a primary drug, 52% versus 51%. Caribbean clients were more likely to use cocaine, 30% versus 11%, P < .01, and marijuana, 12% versus 0%, P < .001, but less likely to use heroin, 6% versus 30%, P < .001 or pills, 0% versus 8%, P < .05. Caribbean clients were less likely to have elevated MCV, 24% versus 57%, P < .001 or serum transaminases, 23% versus 46%, P < .01. Differences between groups in this multicultural setting warrant further investigation.

  20. Field evaluation of baits and baiting strategies for delivering oral vaccine to mongooses in Antigua, West Indies.

    PubMed

    Creekmore, T E; Linhart, S B; Corn, J L; Whitney, M D; Snyder, B D; Nettles, V F

    1994-10-01

    A field study was conducted on Antigua, West Indies, to determine the feasibility of delivering an oral rabies vaccine or population control agent to free-ranging mongooses (Herpestes javanicus). Two biomarkers (tetracycline hydrochloride [THCL] and DuPont Oil Blue A dye) and two bait types (DuPont polymer fish meal and polyurethane foam) were used to bait three study sites. Four hundred polymer baits containing both biomarkers were distributed at 36 central point bait stations (11 baits/station) on an 80 ha study site (5 baits/ha); 69% of the mongoose population consumed one or more baits. Two thousand baits containing THCL and 400 baits containing DuPont dye were distributed on two additional 100 ha study sites (24 baits/ha). Polymer fish meal baits were used on the first site and polyurethane baits on the second site. Based on the presence of biomarkers in bone or soft tissue, 96 to 97% of the mongooses at both sites consumed at least one bait. We conclude that oral baiting of mongooses is a feasible method for delivery of vaccines for the control of rabies in this species.

  1. 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.

  2. 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.

  3. 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

  4. 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

    2016-06-29

    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.

  5. 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

  6. 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

  7. 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.

  8. 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.

  9. The bacteriological analysis and health risks in the urban estuary of St. George's Bay, Grenada, West Indies.

    PubMed

    Patel, Rakesh H; Pedersen, Karsten; Kotelnikova, Svetlana

    2010-09-01

    The dilution rates of indicators Enterococcus faecalis and E. coli were studied from the St. John's River estuary in Grenada, West Indies. Health risk zones were established based on the levels of bacteriological pollution. In accordance with the World Health Organization (WHO) health risk guidelines, risks were in the range of <1% gastrointestinal (GI); <0.3% acute febrile respiratory illness (AFRI) to a 1%-5% GI; and 0.9%-1.9% AFRI within 100 m from the St. John's River outflow site in St. George's Bay. These values were the result of river water dilution, where the most probable number (MPN) levels for both indicator organisms from the river were equivalent to that of raw sewage with an AFRI health risk of >3.9% and a GI risk of >10%. The distance intervals farther than 100 m showed fluctuating values and corresponding health risks. E. faecalis and E. coli strains isolated were resistant to 35.7% and 42.9% of the antibiotics tested, respectively.

  10. Prevalence of Salmonella spp. in cane toads (Bufo marinus) from Grenada, West Indies, and their antimicrobial susceptibility.

    PubMed

    Drake, M; Amadi, V; Zieger, U; Johnson, R; Hariharan, H

    2013-09-01

    Cloacal swabs and caecal contents sampled from 58 cane toads (Bufo marinus) in St George's parish, Grenada, during a 7-month period in 2011 were examined by an enrichment and selective culture method for presence of Salmonella spp. Twenty-four (41%) toads were positive for Salmonella spp. of which eight were Salmonella enterica serovar Javiana, and eight were S. enterica serovar Rubislaw. The other serovars were as follows: Montevideo, 6; Arechavaleta, 1; and serovar: IV:43:-:-, 1. The high frequency of isolation of serovar Javiana, an emerging human pathogen associated with several outbreaks in the recent years in the eastern United States, suggests a possible role for cane toads in transmission of this serovar. Although S. Rubislaw has been isolated from lizards, bats and cases of some human infections, there is no report of its carriage by cane toads, and in such high frequency. The rate of carriage of S. Montevideo, a cause for human foodborne outbreaks around the world was also over 10% in the 58 toads sampled in this study. The antimicrobial drug susceptibility tests against amoxicillin-clavulanic acid, ampicillin, cefotaxime, ceftazidime, ciprofloxacin, enrofloxacin, gentamicin, imipenem, nalidixic acid, streptomycin, tetracycline and trimethoprim-sulfamethoxazole showed that drug resistance is minimal and is of little concern. Antimicrobial resistance was limited to ampicillin and amoxicillin-clavulanic acid in one isolate of S. Javiana and one isolate of S. Rubislaw. This is the first report of isolation and antimicrobial susceptibilities of various Salmonella serovars not identified previously in cane toads in Grenada, West Indies.

  11. Internalized racism, body fat distribution, and abnormal fasting glucose among African-Caribbean women in Dominica, West Indies.

    PubMed

    Butler, Cleve; Tull, Eugene S; Chambers, Earle C; Taylor, Jerome

    2002-03-01

    The current study examined the relationship of internalized racism to glucose intolerance in a population of Afro-Caribbean women aged 18 to 55. Also of interest was whether this relationship would be differentially influenced by the type of body fat distribution or confounded by the level of hostility. A total of 244 women were selected from a systematic sample of households on the island of Dominica, West Indies. Demographic data together with information on internalized racism were collected by questionnaire. Anthropometric information and fasting blood glucose were also measured. Women with high levels of internalized racism exhibited an increased risk of elevated fasting glucose compared to those with low levels of internalized racism (odds ratio (OR) = 2.4; 95% confidence interval (CI) = 1.1-5.5). There was no difference in mean body mass index (BMI) by level of internalized racism. However those with high internalized racism had a significantly larger waist circumference after adjusting for age, education, hostility, and elevated fasting glucose status. In multivariate analyses controlling for age, education, hostility, and either weight or BMI, internalized racism remained independently associated with elevated fasting glucose. However, once waist circumference was included in the model, the relationship of internalized racism to elevated fasting glucose was not statistically significant. This study demonstrates a significant relationship between internalized racism and abnormal levels of fasting glucose which may be mediated through abdominal fat. The exact nature of the relationship of internalized racism to glucose intolerance may be an important area of future study.

  12. Afro-Caribbean pemphigus: epidemiological data from a 5-year prospective study on the island of Guadeloupe (French West Indies).

    PubMed

    Cordel, Nadège; Maire, Cyril; le Gilbert, Daniè; Courville, Philippe; Tressières, Benoît

    2013-11-01

    There are no reported epidemiological data regarding autoimmune pemphigus in the Afro-Caribbean population. To present the epidemiology of autoimmune pemphigus on the island of Guadeloupe (French West Indies, 400,736 inhabitants, mostly black Caribbean of African European descent). Five-year prospective study. Inclusion of the incident cases when directly referred to the Dermatology Department or secondarily referred by their private practice dermatologist once identified by the computerized databases of the Guadeloupian pathology laboratories. World-population-standardized incidence was 6.96 (95% CI: 3.41-10.52) for pemphigus vulgaris and 3.75 (95% CI: 1.12-6.39) for pemphigus foliaceus. Patients usually live in the rural countryside, whereas 75% of the population of Guadeloupe Island live in an urban environment. We report a high incidence of autoimmune pemphigus in Guadeloupe, especially for the foliaceus type, and the existence of particular epidemiological features such as the rural countryside habitat. © 2013 The International Society of Dermatology.

  13. Secular variation study from non-welded pyroclastic deposits from Montagne Pelée volcano, Martinique (West Indies)

    NASA Astrophysics Data System (ADS)

    Genevey, A.; Gallet, Y.; Boudon, G.

    2002-07-01

    We present palaeomagnetic data obtained from large clasts collected in non-welded pyroclastic deposits from Montagne Pelée volcano (Martinique Island, West Indies). These deposits, dated by the 14C method from 5000 yr BP to the present, comprise block- and ash-flows, ash- and pumice-flows and pumice fallouts. Alternating fields treatment was as a routine chosen to demagnetise large samples for which the magnetisation was measured with a specially designed inductometer. The mean directions obtained from block- and ash-flow deposits of the 1902 and 1929 eruptions are in good agreement with the expected geomagnetic directions at these times in Martinique. The so-called P1 eruption (˜1345 AD), which is characterised by a rarely observed transition from a Peléean to a Plinian eruptive style, allows a direct comparison of the palaeomagnetic directions obtained from the three types of pyroclastic deposits. All deposits provide identical mean directions, which further demonstrates the suitability of the non-welded pyroclastic deposits for geomagnetic secular variation study with a very good accuracy and precision. The possibility of using pyroclastic deposits is promising for obtaining a wider distribution of sampling sites, which may better allow us to constrain our knowledge on the geomagnetic secular variation. We find that large geomagnetic changes occurred in Martinique during the last millennium, while the variations appear more limited prior to this period.

  14. Feline immunodeficiency virus, feline leukemia virus and Bartonella species in stray cats on St Kitts, West Indies.

    PubMed

    Kelly, Patrick J; Moura, Lenita; Miller, Tanya; Thurk, Jaime; Perreault, Nicole; Weil, Adriana; Maggio, Ricardo; Lucas, Helene; Breitschwerdt, Edward

    2010-06-01

    Stray cats trapped in various areas of Basseterre, the capital of St Kitts in the West Indies, were tested for infection with feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) using commercial kits. Of 99 (51 male and 48 female) cats trapped in 2006/7, 15% (12 males and three females) were positive for FIV while none were positive for FeLV. Of 72 (41 males and 31 females) cats trapped in 2009, 14% (nine males and one female) were positive for FIV while none were positive for FeLV. Polymerase chain reaction analysis revealed DNA of Bartonella species in whole blood collected from 60/95 (63%) cats trapped in 2006/7. Sequencing of the 16S-23S rRNA gene intergenic transcribed spacer (ITS) region of a convenience sample of nine amplicons and the 11 isolates made from 43 blood samples which were cultured using Bartonella alpha Proteobacteria (BAPGM) enrichment medium revealed B henselae (14) and B clarridgeiae (six).

  15. Research, health policies and health care in the Caribbean. The role of the University of the West Indies.

    PubMed

    Fraser, H S

    2001-09-01

    The University of the West Indies has had a major impact on the provision of health care and the health of Caribbean nations over the last 50 years, through undergraduate, postgraduate and continuing medical education, research, outreach and public service. These roles are fully accepted, and the Faculties of Medical Sciences and School of Clinical Medicine and Research have provided most of the doctors now serving the English-speaking Caribbean, including academic leaders and chief medical officers. The design of a curriculum to produce doctors "designed" for the region has been a well-articulated goal, and the need to carry out relevant and essential national health research is now accepted. But the broader roles of ensuring translation of research into policy and practice, and developing effective ways of promoting on-going continuing training and behaviour change are far from understood or seriously attempted. Communication of research findings and evidence-based practice is crucial. The West Indian Medical Journal clearly has a valuable role to play here and this requires expansion and support. But a multi-faceted approach to communicating research findings and translating evidence into policy, planning and care is necessary. One possible approach would be a University Unit of Health Policy Research and Development.

  16. 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.

  17. Species sanitation of malaria in the Netherlands East Indies (1913-1942)--an example of applied medical history?

    PubMed

    Imam, Irawan; Labisch, Alfons

    2006-01-01

    To the World Health Organization malaria remains "one of the world's most important public health concerns". During the post-eradication era of the 1980s there was no clear answer to the following question: what kind of intervention could be effective against malaria in the 'roll-back malaria' programme? In this situation there were also calls for an 'applied history of medicine', since the anti-malaria programmes during the pre-eradication era might help overcome the crisis of finding an appropriate way to fight malaria. At this point the concept of species sanitation was considered. Developed in the 1920s in the former Netherlands East Indies the thrust of this concept is that anopheles, as obligatory vectors of malaria, have species-specific breeding sites; when these sites are sanitised, malaria is deprived of its ecological preconditions. This double question - the history of species sanitation and the possibility of an applied history of medicine - is the starting point of this paper. The results of the historical analysis are that in terms of the biological, technical, economical, social and political conditions, species sanitation remains limited to a few locally specified exceptions. The attempt to find answers in history demonstrates that an evaluation of historical anti-malaria measures can be helpful in determining the fundamental elements of a given situation necessary for an effective malaria control programme.

  18. 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.

  19. Thermophysical properties of BaUO4

    NASA Astrophysics Data System (ADS)

    Tanaka, Kosuke; Tokushima, Kazuyuki; Kurosaki, Ken; Ohishi, Yuji; Muta, Hiroaki; Yamanaka, Shinsuke

    2013-11-01

    Polycrystalline specimens of barium uranate, BaUO4, were prepared and several properties such as the thermal expansion coefficient, elastic moduli, thermal conductivity, and Debye temperature were evaluated. The sintered specimens had a single-phase orthorhombic structure and were crack-free. The elastic moduli of BaUO4 were determined from the longitudinal and shear sound velocities and from micro-indentation tests. The Debye temperature was also determined from the sound velocities and lattice parameter measurements. The thermal conductivity of BaUO4 was calculated from the measured density at room temperature, literature values of heat capacity, and thermal diffusivity measured by the laser flash method in vacuum. The thermophysical properties of BaUO4 were examined and compared with literature data for other barium ternary oxides and SrUO4.

  20. Stratification of chromium abundance in CP-stars alpha2 Canum Venaticorum, epsilon Ursae Majoris, Sirius and VEGA

    NASA Astrophysics Data System (ADS)

    Ziznovsky, J.; Zverko, J.

    1995-01-01

    High S/N Reticon spectra of alpha2 CVn, epsilon UMa, Sirius and Vega are investigated to estimate the Cr-abundance and its possible depth distribution. While three of the stars show practically normal (homogeneous) distribution of the element, alpha2 CVn was found to be anomalous: the abundance of chromium decreases outwards of the atmosphere.

  1. Calf thymus RF-C as an essential component for DNA polymerase delta and epsilon holoenzymes function.

    PubMed Central

    Podust, V N; Georgaki, A; Strack, B; Hübscher, U

    1992-01-01

    By using a complementation assay that enabled DNA polymerase delta and DNA polymerase epsilon to replicate a singly-DNA primed M13 DNA in the presence of proliferating cell nuclear antigen (PCNA) and Escherichia coli single-stranded DNA binding protein (SSB), we have purified from calf thymus in a five step procedure a multipolypeptide complex with molecular masses of polypeptides of 155, 70, 60, 58, 39 (doublet), 38 (doublet) and 36 kDa. The protein is very likely replication factor C (Tsurimoto, T. and Stillman, B. (1989) Mol. Cell. Biol. 9, 609-619). This conclusion is based on biochemical and physicochemical data and the finding that it contains a DNA stimulated ATPase which is under certain conditions stimulated by PCNA. Together RF-C, PCNA and ATP convert DNA polymerases delta and epsilon to holoenzyme forms, which were able to replicate efficiently SSB-covered singly-DNA primed M13 DNA. Calf thymus RF-C could form a primer recognition complex on a 3'-OH primer terminus in the presence of calf thymus PCNA and ATP. Holoenzyme complexes of DNA polymerase delta and epsilon could be isolated suggesting that these enzymes directly interact with the auxiliary proteins in a similar way. Under optimal replication conditions on singly-DNA primed M13 DNA the DNA synthesis rate of DNA polymerase delta was higher than of DNA polymerase epsilon. Based on these functional date possible roles of these two DNA polymerases in eukaryotic DNA replication are discussed. Images PMID:1354854

  2. Grafting of cellulose fibers with poly(epsilon-caprolactone) and poly(L-lactic acid) via ring-opening polymerization.

    PubMed

    Lönnberg, Hanna; Zhou, Qi; Brumer, Harry; Teeri, Tuula T; Malmström, Eva; Hult, Anders

    2006-07-01

    In this study, ring-opening polymerization (ROP) of epsilon-caprolactone (epsilon-CL) and L-lactide (L-LA) has been performed from cellulose fibers. The hydroxyl groups on cellulose act as initiators in the polymerization, and the polymers are covalently bonded to the cellulose fiber. As an attempt to introduce more available hydroxyl groups on the surface, and thereby obtain higher grafting efficiency in the ROP of epsilon-CL and L-LA, unmodified paper was modified with xyloglucan-bis(methylol)-2-methylpropanamide (XG-bis-MPA) and 2,2-bis(methylol)propionic acid (bis-MPA), respectively. The grafted substrates were characterized via Fourier transform infrared spectroscopy (FTIR), contact angle measurement, atomic force microscopy, and enzymatic degradation. The results showed a successful grafting of poly(epsilon-caprolactone) (PCL) and poly(L-lactic acid) (PLLA) from the cellulose fiber surfaces. Furthermore, the results showed an improved grafting efficiency after activation of the cellulose surface with bis-MPA, and showed that the amount of grafted polymer could be controlled by the ratio of added free initiator to monomer.

  3. Magnetism-Structure Correlations during the epsilon ->tau Transformation in Rapidly-Solidified MnAl Nanostructured Alloys

    SciTech Connect

    Jimenez-Villacorta, F; Marion, JL; Oldham, JT; Daniil, M; Willard, MA; Lewis, LH

    2014-01-21

    Magnetic and structural aspects of the annealing-induced transformation of rapidly-solidified Mn55Al45 ribbons from the as-quenched metastable antiferromagnetic (AF) epsilon-phase to the target ferromagnetic (FM) L1(0) tau-phase are investigated. The as-solidified material exhibits a majority hexagonal epsilon-MnAl phase revealing a large exchange bias shift below a magnetic blocking temperature T-B similar to 95 K (H-ex similar to 13 kOe at 10 K), ascribed to the presence of compositional fluctuations in this antiferromagnetic phase. Heat treatment at a relatively low annealing temperature T-anneal approximate to 568 K (295 degrees C) promotes the nucleation of the metastable L1(0) tau-MnAl phase at the expense of the parent epsilon-phase, donating an increasingly hard ferromagnetic character. The onset of the epsilon ->tau transformation occurs at a temperature that is similar to 100 K lower than that reported in the literature, highlighting the benefits of applying rapid solidification for synthesis of the rapidly-solidified parent alloy.

  4. 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

  5. Theoretical Study of the Nitric Oxide epsilon and 1100 A Bands

    NASA Technical Reports Server (NTRS)

    Sheehy, Jeffrey A.; Bauschlicher, Charles W., Jr.; Langhoff, Stephen R.; Partridge, Harry; Arnold, James O. (Technical Monitor)

    1994-01-01

    Potential-energy curves, transition-moment functions, Einstein Alpha coefficients and radiative lifetimes associated with the Rydberg state of nitric oxide are calculated in large Gaussian basis sets employing internally contracted MRCI from state-averaged CASSCF wave functions. Computationally, a strong sensitivity of the results to the choice of the CASSCF active space is seen, and careful examination of this behavior gives insight into matters related to the treatment of weakly occupied orbitals, which is a consideration in any study Rydberg excited states. The epsilon system transition-moment function and radiative lifetimes are in disagreement with another calculation in the literature, but reasons for the discrepancies are examined, and the present results are determined to be more accurate.

  6. Experimental verification of epsilon-near-zero plasmon polariton modes in degenerately doped semiconductor nanolayers

    DOE PAGES

    Campione, Salvatore; Kim, Iltai; de Ceglia, Domenico; ...

    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

  7. A New Strategy for Designing Broadband Epsilon-Near-Zero Metamaterials

    NASA Astrophysics Data System (ADS)

    Lee, Hon Ping; Hui, Ka Shing; Sun, Lei; Yu, Kin Wah

    2012-02-01

    We have developed a new strategy for designing metamaterials in multi-layered film with permittivity being closed to zero over a broad frequency range, which is as known as broadband epsilon-near-zero (ENZ) materials. Milton representation, Bergman-Milton representation and electromagnetic representation of the effective permittivity (ɛeff) are used, and the strategy consist of the following 3 parts: choosing the operation frequency range, properly placing the poles and zeros into the range, and solving the inverse problem by equating different representations of ɛeff. Demonstration of the strategy is carried out by zeroth and first order design with several examples. The distribution of electric field inside the designed materials is investigated to reveal the physical principles of the broadband ENZ phenomenon. The study would be further extended to other geometries (e.g. multi-shell cylinder) through conformal transformation. The results obtained are useful for designing ENZ metamaterials.

  8. Experimental verification of epsilon-near-zero plasmon polariton modes in degenerately doped semiconductor nanolayers

    DOE PAGES

    Campione, Salvatore; Kim, Iltai; de Ceglia, Domenico; ...

    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

  9. Determination of poly(epsilon-caprolactone) solubility parameters: application to solvent substitution in a microencapsulation process.

    PubMed

    Bordes, C; Fréville, V; Ruffin, E; Marote, P; Gauvrit, J Y; Briançon, S; Lantéri, P

    2010-01-04

    The evolution of regulation on chemical substances (i.e. REACH regulation) calls for the progressive substitution of toxic chemicals in formulations when suitable alternatives have been identified. In this context, the method of Hansen solubility parameters was applied to identify an alternative solvent less toxic than methylene chloride used in a microencapsulation process. During the process based on a multiple emulsion (W/O/W) with solvent evaporation/extraction method, the solvent has to dissolve a polymer, poly(epsilon-caprolactone) (PCL), which forms a polymeric matrix encapsulating or entrapping a therapeutic protein as the solvent is extracted. Therefore the three partial solubility parameters of PCL have been determined by a group contribution method, swelling experiments and turbidimetric titration. The results obtained allowed us to find a solvent, anisole, able to solubilize PCL and to form a multiple emulsion with aqueous solutions. A feasibility test was conducted under standard operating conditions and allowed the production of PCL microspheres.

  10. Successful treatment of Kasabach-Merritt syndrome with prednisone and epsilon-aminocaproic acid.

    PubMed

    Dresse, M F; David, M; Hume, H; Blanchard, H; Russo, P; Van Doesberg, N; Rivard, G E

    1991-01-01

    The Kasabach-Merritt syndrome is characterized by thrombocytopenia and localized coagulopathy associated with a hemangioma. Most techniques applied to eradicate the tumor or accelerate its involution (surgery, radiation therapy, embolization) are invasive and require transfusion of large amounts of blood products. In some cases, medical treatment is the only alternative. Efficacy of steroids and antifibronolytic agents has already been described, but even this approach is associated with the administration of blood products. We report two cases of infants with Kasabach-Merritt syndrome associated with cardiac and hepatic hemangiomas. At admission, both had signs of cardiac failure. They were successfully treated with prednisone and epsilon-aminocaproic acid (EACA). Blood products were not required once the diagnosis was made. These observations have important implications for the management of patients with Kasabach-Merritt syndrome because they show that even in severe cases blood transfusions can be avoided by the use of prednisone and EACA.

  11. Renormalization Group Theory, the Epsilon Expansion and Ken Wilson as I knew Him

    NASA Astrophysics Data System (ADS)

    Fisher, Michael E.

    The tasks posed for renormalization group theory (RGT) within statistical physics by critical phenomena theory in the 1960's are set out briefly in contradistinction to quantum field theory (QFT), which was the origin for Ken Wilson's concerns. Kadanoff's 1966 block spin scaling picture and its difficulties are presented;Wilson's early vision of flows is described from the author's perspective. How Wilson's subsequent breakthrough ideas, published in 1971, led to the epsilon expansion and the resulting clarity is related. Concluding sections complete the general picture of flows in a space of Hamiltonians, universality and scaling. The article represents a 40% condensation (but with added items) of an earlier account: Rev. Mod. Phys. 70, 653-681 (1998).

  12. Renormalization group theory, the epsilon expansion and Ken Wilson as I knew him

    NASA Astrophysics Data System (ADS)

    Fisher, Michael E.

    2015-03-01

    The tasks posed for renormalization group theory (RGT) within statistical physics by critical phenomena theory in the 1960's are set out briefly in contradistinction to quantum field theory (QFT), which was the origin for Ken Wilson's concerns. Kadanoff's 1966 block spin scaling picture and its difficulties are presented; Wilson's early vision of flows is described from the author's perspective. How Wilson's subsequent breakthrough ideas, published in 1971, led to the epsilon expansion and the resulting clarity is related. Concluding sections complete the general picture of flows in a space of Hamiltonians, universality and scaling. The article represents a 40% condensation (but with added items) of an earlier account: Rev. Mod. Phys.70, 653-681 (1998).

  13. Experimental demonstration of near-infrared epsilon-near-zero multilayer metamaterial slabs.

    PubMed

    Yang, Xiaodong; Hu, Changyu; Deng, Huixu; Rosenmann, Daniel; Czaplewski, David A; Gao, Jie

    2013-10-07

    Near-infrared epsilon-near-zero (ENZ) metamaterial slabs based on silver-germanium (Ag-Ge) multilayers are experimentally demonstrated. Transmission, reflection and absorption spectra are characterized and used to determine the complex refractive indices and the effective permittivities of the ENZ metamaterial slabs, which match the results obtained from both the numerical simulations and the optical nonlocalities analysis. A rapid post-annealing process is used to reduce the collision frequency of silver and therefore decrease the optical absorption loss of multilayer metamaterial slabs. Furthermore, multilayer grating structures are studied to enhance the optical transmission and also tune the location of ENZ wavelength. The demonstrated near-infrared ENZ multilayer metamaterial slabs are important for realizing many exotic applications, such as phase front shaping and engineering of photonic density of states.

  14. Fuchsia : A tool for reducing differential equations for Feynman master integrals to epsilon form

    NASA Astrophysics Data System (ADS)

    Gituliar, Oleksandr; Magerya, Vitaly

    2017-10-01

    We present Fuchsia - an implementation of the Lee algorithm, which for a given system of ordinary differential equations with rational coefficients ∂x J(x , ɛ) = A(x , ɛ) J(x , ɛ) finds a basis transformation T(x , ɛ) , i.e., J(x , ɛ) = T(x , ɛ) J‧(x , ɛ) , such that the system turns into the epsilon form : ∂xJ‧(x , ɛ) = ɛ S(x) J‧(x , ɛ) , where S(x) is a Fuchsian matrix. A system of this form can be trivially solved in terms of polylogarithms as a Laurent series in the dimensional regulator ɛ. That makes the construction of the transformation T(x , ɛ) crucial for obtaining solutions of the initial system. In principle, Fuchsia can deal with any regular systems, however its primary task is to reduce differential equations for Feynman master integrals. It ensures that solutions contain only regular singularities due to the properties of Feynman integrals. Program Files doi:http://dx.doi.org/10.17632/zj6zn9vfkh.1 Licensing provisions: MIT Programming language:Python 2.7 Nature of problem: Feynman master integrals may be calculated from solutions of a linear system of differential equations with rational coefficients. Such a system can be easily solved as an ɛ-series when its epsilon form is known. Hence, a tool which is able to find the epsilon form transformations can be used to evaluate Feynman master integrals. Solution method: The solution method is based on the Lee algorithm (Lee, 2015) which consists of three main steps: fuchsification, normalization, and factorization. During the fuchsification step a given system of differential equations is transformed into the Fuchsian form with the help of the Moser method (Moser, 1959). Next, during the normalization step the system is transformed to the form where eigenvalues of all residues are proportional to the dimensional regulator ɛ. Finally, the system is factorized to the epsilon form by finding an unknown transformation which satisfies a system of linear equations. Additional comments

  15. 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.

  16. Apocenter Glow in Eccentric Debris Disks: Implications for Fomalhaut and Epsilon Eridani

    NASA Technical Reports Server (NTRS)

    Pan, Margaret; Nesvold, Erika R.; Kuchner, Marc J.

    2016-01-01

    Debris disks often take the form of eccentric rings with azimuthal asymmetries in surface brightness. Such disks are often described as showing pericenter glow, an enhancement of the disk brightness in regions nearest the central star. At long wavelengths, however, the disk apocenters should appear brighter than their pericenters: in the long-wavelength limit, we find that the apocenter pericenter flux ratio scales as 1 + e for disk eccentricity e. We produce new models of this apocenter glow to explore its causes and wavelength dependence and study its potential as a probe of dust grain properties. Based on our models, we argue that several far-infrared and (sub)millimeter images of the Fomalhaut and Epsilon Eridani debris rings obtained with Herschel, JCMT, SHARC II, ALMA, and ATCA should be reinterpreted as suggestions or examples of apocenter glow. This reinterpretation yields new constraints on the disks dust grain properties and size distributions.

  17. Intense extreme ultraviolet emission from the B star Epsilon Canis Majoris

    NASA Technical Reports Server (NTRS)

    Vallerga, John V.; Vedder, Peter W.; Welsh, Barry Y.

    1993-01-01

    We report the discovery of the brightest nonsolar source of EUV emission: the B2 II star Epsilon Canis Majoris. This source has been detected by the Extreme Ultraviolet Explorer satellite's all-sky photometric survey. It is approximately 30 times brighter at 600 A than the predicted emission from the hot white dwarf star HZ 43, previously believed to be the brightest EUV source. We have fitted a simple B star photospheric model to the observed broadband EUV fluxes to explain this emission. Assuming a stellar temperature of 25,000 K and a gravity (log g) of 3.3, we derive an interstellar hydrogen column density of 1.05 +/- 0.05 x 10 exp 18/sq cm over the 187 pc to the star. This corresponds to a line-of-sight number density of hydrogen, of 0.002/cu cm, which is comparable to values found in the rarefied Local Bubble region which surrounds the sun.

  18. 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.

  19. 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.

  20. Strategies to control the particle size distribution of poly-epsilon-caprolactone nanoparticles for pharmaceutical applications.

    PubMed

    Lince, Federica; Marchisio, Daniele L; Barresi, Antonello A

    2008-06-15

    In this work turbulent precipitation through solvent displacement for the production of poly-epsilon-caprolactone (PCL) nanoparticles is investigated; two different PCL molecular weights have been employed, using acetone and water as solvent and anti-solvent, respectively. The main important thermodynamic and kinetic parameters, such as solubility and interfacial tension of PCL in water-acetone mixtures, are determined and the effect of the process operating conditions on the final particle size distribution is also investigated. Particles produced under different conditions into a Confined Impinging Jets Reactor (CIJR) were characterized by Dynamic Light Scattering, Zeta potential measurements and Scanning Electronic Microscopy. Results clearly show the strong effect of mixing on the particle size distribution and how mixing must be controlled in order to obtain a product with particular characteristics. Eventually the measured thermodynamic and kinetic parameters are used to interpret the obtained experimental data.

  1. 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

    2016-08-08

    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.

  2. Mutations in phospholipase C epsilon 1 are not sufficient to cause diffuse mesangial sclerosis.

    PubMed

    Gilbert, Rodney D; Turner, Claire L S; Gibson, Jane; Bass, Paul S; Haq, Mushfequr R; Cross, Esta; Bunyan, David J; Collins, Andrew R; Tapper, William J; Needell, Juliet C; Dell, Beverley; Morton, Newton E; Temple, I Karen; Robinson, David O

    2009-02-01

    Diffuse mesangial sclerosis occurs as an isolated abnormality or as a part of a syndrome. Recently, mutations in phospholipase C epsilon 1 (PLCE1) were found to cause a nonsyndromic, autosomal recessive form of this disease. Here we describe three children from one consanguineous kindred of Pakistani origin with diffuse mesangial sclerosis who presented with congenital or infantile nephrotic syndrome. Homozygous mutations in PLCE1 (also known as KIAA1516, PLCE, or NPHS3) were identified following genome-wide mapping of single-nucleotide polymorphisms. All affected children were homozygous for a four-basepair deletion in exon 3, which created a premature translational stop codon. Analysis of the asymptomatic father of two of the children revealed that he was also homozygous for the same mutation. We conclude this nonpenetrance may be due to compensatory mutations at a second locus and that mutation within PLCE1 is not always sufficient to cause diffuse mesangial sclerosis.

  3. 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.

  4. Design of zero index metamaterials with PT symmetry using epsilon-near-zero media with defects

    NASA Astrophysics Data System (ADS)

    Fu, Yangyang; Zhang, Xiaojing; Xu, Yadong; Chen, Huanyang

    2017-03-01

    Inspired by the design of matched zero-index metamaterials (ZIMs) using defects in epsilon-near-zero (ENZ) media, we demonstrate in this letter that ZIMs with parity-time (PT) symmetry in a waveguide system can be achieved by introducing defects with loss/gain inside ENZ media. Such results are well verified from the phenomenon of unidirectional transparency, corresponding to the exceptional points in PT symmetric systems. Moreover, by changing the geometry configuration of ENZ, the effective loss/gain in the structure composed of ENZ and defects can be amplified immensely by virtue of the resonances of defects. Therefore, our work also provides a blueprint for obtaining amplified loss/gain in PT symmetric systems.

  5. 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

  6. Terahertz epsilon-near-zero cut-through metal-slit array antenna

    NASA Astrophysics Data System (ADS)

    Suzuki, Takehito; Kimura, Tatsuya; Togashi, Takahisa; Kitahara, Hideaki; Ishihara, Koki; Sato, Tatsuya

    2017-02-01

    Metamaterials can give rise to unprecedented refractive indices and drive the rapid development of metadevices with on-demand electromagnetic properties. Recent advances in terahertz science demand high-performance optical elements beyond conventional designs of naturally occurring materials in the terahertz wave band. However, how an epsilon-near-zero (ENZ) structure can exploit terahertz metadevices is still not fully demonstrated based on a physical analysis. Here, inspired by the ENZ concept, we demonstrate a design guideline of a terahertz ENZ cut-through metal-slit array antenna. Measurements by a terahertz imager visualize the beam profile of a terahertz wave, and the measured permittivity of 0.26 agrees well with that of 0.27 obtained by simulation and theory. The terahertz ENZ antenna provides a wide range of potential applications such as high-directivity antennas, beam dividers, beam-steering elements, phase-control devices, and novel filters.

  7. Low-damping epsilon-near-zero slabs: Nonlinear and nonlocal optical properties

    NASA Astrophysics Data System (ADS)

    de Ceglia, Domenico; Campione, Salvatore; Vincenti, Maria Antonietta; Capolino, Filippo; Scalora, Michael

    2013-04-01

    We investigate second-harmonic generation, low-threshold multistability, all-optical switching, and inherently nonlocal effects due to the free-electron gas pressure in an epsilon-near-zero (ENZ) metamaterial slab made of cylindrical, plasmonic nanoshells illuminated by TM-polarized light. Damping compensation in the ENZ frequency region, achieved by using gain medium inside the nanoshells’ dielectric cores, enhances the nonlinear properties. Reflection is inhibited, and the electric field component normal to the slab interface is enhanced near the effective pseudo-Brewster angle, where the effective ɛ≈0 condition triggers a nonresonant, impedance-matching phenomenon. We show that the slab displays a strong effective, spatial nonlocality associated with leaky modes that are mediated by the compensation of damping. The presence of these leaky modes then induces further spectral and angular conditions, where the local fields are enhanced, thus opening new windows of opportunity for the enhancement of nonlinear optical processes.

  8. Versatile Production of Poly(Epsilon-Caprolactone) Fibers by Electrospinning Using Benign Solvents.

    PubMed

    Liverani, Liliana; Boccaccini, Aldo R

    2016-04-15

    The electrospinning technique is widely used for the fabrication of micro- and nanofibrous structures. Recent studies have focused on the use of less toxic and harmful solvents (benign solvents) for electrospinning, even if those solvents usually require an accurate and longer process of optimization. The aim of the present work is to demonstrate the versatility of the use of benign solvents, like acetic acid and formic acid, for the fabrication of microfibrous and nanofibrous electrospun poly(epsilon-caprolactone) mats. The solvent systems were also shown to be suitable for the fabrication of electrospun structures with macroporosity, as well as for the fabrication of composite electrospun mats, fabricated by the addition of bioactive glass (45S5 composition) particles in the polymeric solution.

  9. 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.

  10. 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.

  11. Optical polarization observations of epsilon Aurigae during the 2009-2011 eclipse

    NASA Astrophysics Data System (ADS)

    Henson, Gary D.; Burdette, John; Gray, Sharon

    2012-05-01

    Polarization observations of the unique eclipsing binary, Epsilon Aurigae, are being carried out using a new dual beam imaging polarimeter on the 0.36m telescope of the Harry D. Powell Observatory. This bright binary system has a 27.1 year period with an eclipse duration of nearly two years. The primary is known to be a pulsating F0 supergiant with the secondary a large and essentially opaque disk. We report here on the characteristics of the polarimeter and on the status of V-band observations that are being obtained to better understand the system's geometry and the nature of its two components. In particular, the characteristics of the secondary disk remain a puzzle. Results are compared to polarization observations from the 1982-1984 eclipse.

  12. A photopolymerized antimicrobial hydrogel coating derived from epsilon-poly-L-lysine.

    PubMed

    Zhou, Chuncai; Li, Peng; Qi, Xiaobao; Sharif, Abdul Rahim Mohamed; Poon, Yin Fun; Cao, Ye; Chang, Matthew W; Leong, Susanna Su Jan; Chan-Park, Mary B

    2011-04-01

    Hydrogels made from epsilon-poly-l-lysine-graft-methacrylamide (EPL-MA) have been found to have impressive wide spectrum antimicrobial activity against both bacteria (specifically Escherichia coli, Pseudomonas aeruginosa, Serratia marcescens and Staphylococcus aureus) and fungi (specifically Candida albicans and Fusarium solani). The EPL-MA hydrogel also possesses in vitro biocompatibility and EPL-MA solution is relatively non-hemolytic: the concentration needed for onset of human red blood cell (hRBC) hemolysis is 12,500 μg/mL so that the selectivity for the pathogenic microorganisms over hRBCs is 230-1560. Further, EPL-MA hydrogel can be conveniently ultraviolet-immobilized onto plasma-treated plastic surfaces to form thin highly adherent antimicrobial hydrogel coatings for medical devices and implants.

  13. 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.

  14. 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.

  15. Versatile Production of Poly(Epsilon-Caprolactone) Fibers by Electrospinning Using Benign Solvents

    PubMed Central

    Liverani, Liliana; Boccaccini, Aldo R.

    2016-01-01

    The electrospinning technique is widely used for the fabrication of micro- and nanofibrous structures. Recent studies have focused on the use of less toxic and harmful solvents (benign solvents) for electrospinning, even if those solvents usually require an accurate and longer process of optimization. The aim of the present work is to demonstrate the versatility of the use of benign solvents, like acetic acid and formic acid, for the fabrication of microfibrous and nanofibrous electrospun poly(epsilon-caprolactone) mats. The solvent systems were also shown to be suitable for the fabrication of electrospun structures with macroporosity, as well as for the fabrication of composite electrospun mats, fabricated by the addition of bioactive glass (45S5 composition) particles in the polymeric solution. PMID:28335202

  16. Analysis of anisotropic epsilon-near-zero hetero-junction lens for concentration and beam splitting.

    PubMed

    Memarian, Mohammad; Eleftheriades, George V

    2015-03-15

    In this Letter, we analyze a recently reported hetero-junction lens of two anisotropic epsilon-near-zero (ENZ) media for its concentration and beam splitting properties. The equivalent lensmakers' equation of the concentrating mechanism is first derived using geometrical optics and dispersion relations; and aberrations are discussed. It is shown that the light concentrator's focal distance is directly proportional to the thickness of the lens, opposite to conventional dielectric lenses. It is then shown that the same hetero-junction structure can be used as a near-field beam-splitter when illuminated from the back, in addition to its concentration property. Equal and unequal beam splitting, as well as beam shifting can be achieved using a very thin device.

  17. Goos-Hänchen effect in epsilon-near-zero metamaterials

    NASA Astrophysics Data System (ADS)

    Xu, Yadong; Chan, C. T.; Chen, Huanyang

    2015-03-01

    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.

  18. 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

  19. 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

  20. Goos-Hänchen effect in epsilon-near-zero metamaterials.

    PubMed

    Xu, Yadong; Chan, C T; Chen, Huanyang

    2015-03-03

    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.

  1. High-Contrast Imaging of Epsilon Eridani with Ground-Based Instruments

    NASA Technical Reports Server (NTRS)

    Mizuki, T.; Yamada, T.; Carson, J. C.; Kuzuhara, M.; Nakagawa, T.; Nishikawa, J.; Sitko, M. L.; Kudo, T.; Kusakabe, N.; Hashimoto, J.; hide

    2016-01-01

    Epsilon Eridani is one of the nearest solar-type stars. Its proximity and relatively young age allow high-contrast imaging observations to achieve sensitivities to planets at narrow separations down to an inner radius of approximately 5 AU. Previous observational studies of the system report a dust disk with asymmetric morphology as well as a giant planet with large orbital eccentricity, which may require another massive companion to induce the peculiar morphology and to enhance the large orbital eccentricity. In this paper, we report results from deep high-contrast imaging observations to detect the previously reported planet and search for other unseen less massive companions with Subaru/HiCIAO, Gemini-South/NICI, and VLT/NACO. No positive detection was made, but high-contrast measurements with the CH4S narrow-band filter of HiCIAO achieved sensitivities at 14.7 mag differential magnitude level, at an angular separation of 1.0''. In terms of planetary mass, as determined by cooling evolutionary models, the highest sensitivities were achieved by the Lp broad-band filter of NACO, resulting in sensitivities corresponding to 1.8, 2.8, and 4.5 M(sub jup) at the projected separation of 3 AU, if 200, 400, and 800 Myr is assumed for the age of the system, respectively. We also discuss origins of the dust disk from the detection sensitivity in the planetary mass and find that a less massive eccentric planet is preferred for disk stirring, which is consistent with the orbital parameters of epsilon Eri b claimed from the previous long-term radial velocity monitoring.

  2. 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

  3. 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

    2010-04-08

    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.

  4. Giant field enhancement in anisotropic epsilon-near-zero films (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Kamandi, Mohammad; Guclu, Caner; Capolino, Filippo

    2016-09-01

    We investigated anisotropic epsilon-near-zero (AENZ) films under TM-polarized plane wave incidence and found they possess peculiar properties. In particular we studied uniaxially anisotropic films where either the permittivity along the surface normal or along the transverse plane tends to zero while the other one does not. Previously, numerous applications of isotropic epsilon-near-zero (ENZ) films including radiation pattern tailoring, enhanced harmonic generation, optical bistability and energy squeezing have been studied. A notable property of these materials is the capability of enhancing electric field. In this paper the capability of AENZ films in local electric field enhancement has been quantified and several AENZ conditions are reported with superior performance in comparison to (isotropic) ENZ films. Specifically, sensitivity to film thickness and losses, and the range of angles of incidence have been elaborated with the aim of achieving large electric field enhancement in the film. It has been proved that in comparison to the (isotropic) ENZ case the AENZ film's field enhancement is not only much larger but it also occurs for a wider range of angles of incidence. Furthermore the field enhancement in AENZ does not exhibit significant dependence on the film thickness unlike the isotropic case. The effect of loss on the value of the field enhancement is also investigated emphasizing the advantages of AENZ versus ENZ. Realization of AENZ materials can be done by a multilayered media made of a stack of conductive and insulator layers or by stacking semiconductor layers. This giant field enhancement is an important target in nonlinear optics for applications like second harmonic generation and other applications like light generation

  5. Epsilon-Q: An Automated Analyzer Interface for Mass Spectral Library Search and Label-Free Protein Quantification.

    PubMed

    Cho, Jin-Young; Lee, Hyoung-Joo; Jeong, Seul-Ki; Paik, Young-Ki

    2017-04-04

    Mass spectrometry (MS) is a widely used proteome analysis tool for biomedical science. In an MS-based bottom-up proteomic approach to protein identification, sequence database (DB) searching has been routinely used because of its simplicity and convenience. However, searching a sequence DB with multiple variable modification options can increase processing time, false-positive errors in large and complicated MS data sets. Spectral library searching is an alternative solution, avoiding the limitations of sequence DB searching and allowing the detection of more peptides with high sensitivity. Unfortunately, this technique has less proteome coverage, resulting in limitations in the detection of novel and whole peptide sequences in biological samples. To solve these problems, we previously developed the "Combo-Spec Search" method, which uses manually multiple references and simulated spectral library searching to analyze whole proteomes in a biological sample. In this study, we have developed a new analytical interface tool called "Epsilon-Q" to enhance the functions of both the Combo-Spec Search method and label-free protein quantification. Epsilon-Q performs automatically multiple spectral library searching, class-specific false-discovery rate control, and result integration. It has a user-friendly graphical interface and demonstrates good performance in identifying and quantifying proteins by supporting standard MS data formats and spectrum-to-spectrum matching powered by SpectraST. Furthermore, when the Epsilon-Q interface is combined with the Combo-Spec search method, called the Epsilon-Q system, it shows a synergistic function by outperforming other sequence DB search engines for identifying and quantifying low-abundance proteins in biological samples. The Epsilon-Q system can be a versatile tool for comparative proteome analysis based on multiple spectral libraries and label-free quantification.

  6. Broadband Epsilon-near-Zero Reflectors Enhance the Quantum Efficiency of Thin Solar Cells at Visible and Infrared Wavelengths.

    PubMed

    Labelle, A J; Bonifazi, M; Tian, Y; Wong, C; Hoogland, S; Favraud, G; Walters, G; Sutherland, B; Liu, M; Li, Jun; Zhang, Xixiang; Kelley, S O; Sargent, E H; Fratalocchi, A

    2017-02-15

    The engineering of broadband absorbers to harvest white light in thin-film semiconductors is a major challenge in developing renewable materials for energy harvesting. Many solution-processed materials with high manufacturability and low cost, such as semiconductor quantum dots, require the use of film structures with thicknesses on the order of 1 μm to absorb incoming photons completely. The electron transport lengths in these media, however, are 1 order of magnitude smaller than this length, hampering further progress with this platform. Herein, we show that, by engineering suitably disordered nanoplasmonic structures, we have created a new class of dispersionless epsilon-near-zero composite materials that efficiently harness white light. Our nanostructures localize light in the dielectric region outside the epsilon-near-zero material with characteristic lengths of 10-100 nm, resulting in an efficient system for harvesting broadband light when a thin absorptive film is deposited on top of the structure. By using a combination of theory and experiments, we demonstrate that ultrathin layers down to 50 nm of colloidal quantum dots deposited atop the epsilon-near-zero material show an increase in broadband absorption ranging from 200% to 500% compared to a planar structure of the same colloidal quantum-dot-absorber average thickness. When the epsilon-near-zero nanostructures were used in an energy-harvesting module, we observed a spectrally averaged 170% broadband increase in the external quantum efficiency of the device, measured at wavelengths between 400 and 1200 nm. Atomic force microscopy and photoluminescence excitation measurements demonstrate that the properties of these epsilon-near-zero structures apply to general metals and could be used to enhance the near-field absorption of semiconductor structures more widely. We have developed an inexpensive electrochemical deposition process that enables scaled-up production of this nanomaterial for large

  7. A molecular enrichment strategy based on cpn60 for detection of epsilon-proteobacteria in the dog fecal microbiome.

    PubMed

    Chaban, Bonnie; Links, Matthew G; Hill, Janet E

    2012-02-01

    Members of the rare microbiome can be important components of complex microbial communities. For example, pet dog ownership is a known risk factor for human campylobacteriosis, and Campylobacter is commonly detected in dog feces by targeted assays. However, these organisms have not been detected by metagenomic methods. The goal of this study was to characterize fecal microbiota from healthy and diarrheic pet dogs using two different levels of molecular detection. PCR amplification and pyrosequencing of the universal cpn60 gene target was used to obtain microbial profiles from each dog. To investigate the relatively rare epsilon-proteobacteria component of the microbiome, a molecular enrichment was carried out using a PCR that first amplified the cpn10-cpn60 region from epsilon-proteobacteria, followed by universal cpn60 target amplification and pyrosequencing. From the non-enriched survey, the major finding was a significantly higher proportion of Bacteroidetes, notably Bacteroides vulgatus, in healthy dogs compared to diarrheic dogs. Epsilon-proteobacteria from the genera Helicobacter and Campylobacter were also detected at a low level in the non-enriched profiles of some dogs. Molecular enrichment increased the proportion of epsilon-proteobacteria sequences detected from each dog, as well as identified novel, presumably rare sequences not seen in the non-enriched profiles. Enriched profiles contained known species of Arcobacter, Campylobacter, Flexispira, and Helicobacter and identified two possibly novel species. These findings add to our understanding of the canine fecal microbiome in general, the epsilon-proteobacteria component specifically, and present a novel modification to traditional metagenomic approaches for study of the rare microbiome.

  8. 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.

  9. Characterization of thymus-derived lymphocytes expressing Ti alpha-beta CD3 gamma delta epsilon zeta-zeta, Ti alpha-beta CD3 gamma delta epsilon eta-eta or Ti alpha-beta CD3 gamma delta epsilon zeta-zeta/zeta- eta antigen receptor isoforms: analysis by gene transfection

    PubMed Central

    1990-01-01

    To characterize the function of the CD3 eta subunit of the T cell receptor (TCR), we have used cDNAs encoding CD3 zeta, CD3 eta, or both to reconstitute a variant of a cytochrome c-specific, I-Ek-restricted murine T cell hybridoma, termed MA5.8, which lacks CD3 zeta and CD3 eta proteins. We provide direct evidence that assembly and surface expression of TCRs can be mediated by either of these subunits separately or together. However, the level of TCR expression on zeta transfectants is up to one order of magnitude greater than that on eta transfectants, implying that CD3 eta is weakly associated with the pentameric Ti alpha-beta CD3 gamma delta epsilon complex and/or inefficient at salvaging the incomplete TCR from lysosomal degradation. As a component of the TCR, the CD3 eta subunit preferentially forms a heterodimer with CD3 zeta, but is also able to form a CD3 eta-eta homodimer. Crosslinking of Ti alpha-beta CD3 gamma delta epsilon zeta- zeta, Ti alpha-beta CD3 gamma delta epsilon eta-eta, or Ti alpha-beta CD3 gamma delta epsilon zeta-zeta/zeta-eta TCR isotypes with anti-CD3 epsilon monoclonal antibody or a cytochrome c peptide epitope on I-Ek antigen-presenting cells mediates signal transduction resulting in reversible cell-cycle arrest of transfected clones. Given the potential for diversity of signals generated by these functional TCR isotypes and the expression of the CD3 eta gene product in the thymus, CD3 eta is likely to play a role in selection and/or activation of thymocytes during development. PMID:2145389

  10. Phospholipase C-epsilon augments epidermal growth factor-dependent cell growth by inhibiting epidermal growth factor receptor down-regulation.

    PubMed

    Yun, Sanguk; Hong, Won-Pyo; Choi, Jang Hyun; Yi, Kye Sook; Chae, Suhn-Kee; Ryu, Sung Ho; Suh, Pann-Ghill

    2008-01-04

    The down-regulation of the epidermal growth factor (EGF) receptor is critical for the termination of EGF-dependent signaling, and the dysregulation of this process can lead to oncogenesis. In the present study, we suggest a novel mechanism for the regulation of EGF receptor down-regulation by phospholipase C-epsilon. The overexpression of PLC-epsilon led to an increase in receptor recycling and decreased the down-regulation of the EGF receptor in COS-7 cells. Adaptor protein complex 2 (AP2) was identified as a novel binding protein that associates with the PLC-epsilon RA2 domain independently of Ras. The interaction of PLC-epsilon with AP2 was responsible for the suppression of EGF receptor down-regulation, since a perturbation in this interaction abolished this effect. Enhanced EGF receptor stability by PLC-epsilon led to the potentiation of EGF-dependent growth in COS-7 cells. Finally, the knockdown of PLC-epsilon in mouse embryo fibroblast cells elicited a severe defect in EGF-dependent growth. Our results indicated that PLC-epsilon could promote EGF-dependent cell growth by suppressing receptor down-regulation.

  11. Enhanced production of epsilon-caprolactone by overexpression of NADPH-regenerating glucose 6-phosphate dehydrogenase in recombinant Escherichia coli harboring cyclohexanone monooxygenase gene.

    PubMed

    Lee, Won-Heong; Park, Jin-Byung; Park, Kyungmoon; Kim, Myoung-Dong; Seo, Jin-Ho

    2007-08-01

    Whole-cell conversion of cyclohexanone to epsilon-caprolactone was attempted by recombinant Escherichia coli BL21(DE3) expressing cyclohexanone monooxygenase (CHMO) of Acinetobacter calcoaceticus NCIMB 9871. High concentrations of cyclohexanone and epsilon-caprolactone reduced CHMO-mediated bioconversion of cyclohexanone to epsilon-caprolactone in the resting recombinant E. coli cells. Metabolically active cells were employed by adopting a fed-batch culture to improve the production of epsilon-caprolactone from cyclohexanone. A glucose-limited fed-batch Baeyer-Villiger oxidation where a cyclohexanone level was maintained less than 6 g/l resulted in a maximum epsilon-caprolactone concentration of 11.0 g/l. The maximum epsilon-caprolactone concentration was improved further to 15.3 g/l by coexpression of glucose-6-phosphate dehydrogenase, an NADPH-generating enzyme encoded by the zwf gene which corresponded to a 39% enhancement in epsilon-caprolactone concentration compared with the control experiment performed under the same conditions.

  12. Enhanced risk for Alzheimer disease in persons with type 2 diabetes and APOE epsilon4: the Cardiovascular Health Study Cognition Study.

    PubMed

    Irie, Fumiko; Fitzpatrick, Annette L; Lopez, Oscar L; Kuller, Lewis H; Peila, Rita; Newman, Anne B; Launer, Lenore J

    2008-01-01

    Diabetes and the apolipoprotein E epsilon4 allele (APOE epsilon4) increase the risk for Alzheimer disease (AD). We hypothesize that APOE epsilon4 may modify the risk for AD in individuals with diabetes. To examine the joint effect of type 2 diabetes and APOE epsilon4 on the risk of AD, AD with vascular dementia (mixed AD), and vascular dementia without AD. The Cardiovascular Health Study (CHS) Cognition Study (1992-2000) is a prospective study designed to identify all existing and new cases of dementia among study participants. Diagnoses were made according to international criteria for dementia and subtypes. There were 2547 dementia-free participants in the CHS Cognition Study cohort with complete information on APOE epsilon4 and type 2 diabetes status; among these, 411 new cases of dementia developed. Risk of dementia was estimated with a Cox proportional hazard model adjusted for age and other demographic and cardiovascular risk factors. Compared with those who had neither type 2 diabetes nor APOE epsilon4, those with both factors had a significantly higher risk of AD (hazard ratio, 4.58; 95% confidence interval, 2.18-9.65) and mixed AD (hazard ratio, 3.89; 95% confidence interval, 1.46-10.40). These data suggest that having both diabetes and APOE epsilon4 increases the risk of dementia, especially for AD and mixed AD.

  13. 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

  14. 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

  15. FcR epsilon+ lymphocytes and regulation of the IgE antibody system. III. Suppressive factor of allergy (SFA) is produced during the in vitro FcR epsilon expression cascade and displays corollary physiologic activity in vivo.

    PubMed

    Marcelletti, J F; Katz, D H

    1984-12-01

    Exposure of lymphoid cells to IgE induces the expression of Fc receptors for IgE (FcR epsilon) and the production of soluble mediators, termed IgE-induced regulants (EIR). Conventional suppressive factor of allergy (SFA) and enhancing factor of allergy (EFA), derived from mouse ascites fluids, both inhibit IgE-induced FcR epsilon expression in vitro in cultures of unfractionated and T cell-enriched, but not B cell-enriched, lymphoid cells. This indicates that the inhibitory activities of both entities are T cell dependent, and distinguishes them from the inhibitory EIRI, which inhibits FcR epsilon induction in the absence of T cells. Moreover, SFA and EFA can be distinguished from one another by differences in the T cell subsets required for the inhibitory activity of each respective mediator on in vitro IgE-induced FcR epsilon expression. Thus, SFA requires the presence of Lyt-1+ T cells, whereas EFA requires the presence of Lyt-2+ T cells. Supernatant fluids from IgE-stimulated unfractionated lymphoid cell cultures suppress in vivo IgE synthesis in mice, indicating that SFA is produced along with the other species of EIR. To define conditions required for SFA production in vitro, EIR-rich supernatant fluids were tested for the presence of SFA by using Lyt-2+ cell-blocked indicator cells in the in vitro FcR epsilon induction assay system (this eliminates the inhibitory activity of EFA). SFA production in vitro by IgE-stimulated lymphoid cells was shown to result from cooperative interactions between B cells and Lyt-1+ T cells. In addition, as observed with the induction of FcR epsilon in general, induction of SFA requires the initial interaction of B cells with IgE, and the release of the B cell-selective EIRB. Once produced, EIRB can directly stimulate Lyt-1+ cells, but not Lyt-2+ cells, to produce SFA. The physiologic significance of the in vitro induction of SFA by the action of EIRB on Lyt-1+ cells was confirmed by the demonstration that EIRB, devoid of

  16. 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). Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Prevalence of oral HPV infection among healthy individuals and head and neck cancer cases in the French West Indies.

    PubMed

    Auguste, Aviane; Gaëte, Stanie; Herrmann-Storck, Cécile; Michineau, Leah; Joachim, Clarisse; Deloumeaux, Jacqueline; Duflo, Suzy; Luce, Danièle

    2017-09-25

    Human papillomavirus (HPV) is known to play a role in the development of head and neck squamous cell carcinomas (HNSCC) and to date, no study has reported on the association between oral HPV infection and HNSCC in the Caribbean. The objective was to determine the prevalence of oral HPV infection in the French West Indies (FWI), overall and by HPV genotype, among HNSCC cases and healthy population controls. We used data from a population-based case-control study conducted in the FWI. The prevalence of oral HPV was estimated separately among 100 HNSCC cases (mean age 59 years) and 308 population controls (mean age 57 years). Odds ratios (OR) and 95% confidence intervals (CI) were estimated using a logistic regression adjusting for age, sex, tobacco, and alcohol consumption, to assess the association between oral HPV infection and HNSCC. Prevalence of oral HPV infections was 26% in controls (30% in men and 14% in women) and 36% in HNSCC cases (36% in men, 33% in women). HPV52 was the most commonly detected genotype, in cases and in controls. The prevalence of HPV16, HPV33, and HPV51 was significantly higher in cases than in controls (p = 0.0340, p = 0.0472, and 0.0144, respectively). Oral infection with high-risk HPV was associated with an increase in risk of HNSCC (OR 1.99, 95% CI 0.95-4.15). HPV16 was only associated with oropharyngeal cancer (OR 16.01, 95% CI 1.67-153.64). This study revealed a high prevalence of oral HPV infection in this middle-aged Afro-Caribbean population, and a specific distribution of HPV genotypes. These findings may provide insight into HNSCC etiology specific to the FWI.

  18. 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

  19. 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.

  20. HTLV-1-associated inflammatory myopathies: low proviral load and moderate inflammation in 13 patients from West Indies and West Africa.

    PubMed

    Desdouits, Marion; Cassar, Olivier; Maisonobe, Thierry; Desrames, Alexandra; Aouba, Achille; Hermine, Olivier; Mikol, Jacqueline; Polivka, Marc; Penisson-Besnier, Isabelle; Marcorelles, Pascale; Zagnoli, Fabien; Papo, Thomas; Lacour, Arnaud; Amoura, Zahir; Haroche, Julien; Cherin, Patrick; Teixeira, Antonio; Benveniste, Olivier; Herson, Serge; Morin, Anne-Sophie; Mortreux, Franck; Wattel, Eric; Huerre, Michel; Cumont, Marie-Christine; Martin-Latil, Sandra; Butler-Browne, Gillian; Gout, Olivier; Taylor, Graham; Gessain, Antoine; Ozden, Simona; Ceccaldi, Pierre-Emmanuel

    2013-05-01

    The Human T-cell Leukemia Virus type 1 (HTLV-1) is the causative agent of several inflammatory diseases, including HTLV-1-associated inflammatory myopathies (HAIM). Little is known about the virological and immunological characteristics of this viral disease. To characterize the histological and virological features of HAIM patients, in order to better understand the pathogenetic mechanisms and unravel new biological markers of this disease. We conducted a retrospective study on 13 patients with HAIM, based on blood and muscle samples. We included blood samples from HTLV-1-infected individuals without myopathy as controls. Muscle biopsies were used for a broad immunohistological evaluation of tissue damage and inflammation, as well as identification of infected cells through in situ hybridization. DNA extracted from patients' PBMC was used to identify the virus genotype by sequencing and to assess the proviral load by quantitative PCR. Anti-viral antibodies in plasma samples were titrated by indirect immunofluorescence. Patients originate from HTLV-1 endemic areas, the West Indies and West Africa. Histological alterations and inflammation in patients muscles were mostly moderate, with classical features of idiopathic myositis and rare HTLV-1-infected infiltrating cells. In all patients, HTLV-1 belonged to the A subtype, transcontinental subgroup. Anti-HTLV-1 antibodies titers were high, but the proviral load was not elevated compared to asymptomatic HTLV-1 carriers. We show here that muscle inflammation is moderate in HAIM, and accompanied by a low HTLV-1 proviral load, suggesting that the pathogenetic events do not exactly mirror those of other HTLV-1-associated inflammatory diseases. Copyright © 2012 Elsevier B.V. All rights reserved.